Updated on 2022/05/19

写真a

 
YANAGITANI, Takahiko
 
Affiliation
Faculty of Science and Engineering, School of Advanced Science and Engineering
Job title
Professor

Concurrent Post

  • Faculty of Science and Engineering   Graduate School of Advanced Science and Engineering

Research Institute

  • 2020
    -
    2022

    理工学術院総合研究所   兼任研究員

Education

  • 2003.04
    -
    2006.03

    Doshisha University  

  • 2001.04
    -
    2003.03

    Doshisha University  

  • 1997.04
    -
    2001.03

    Doshisha University  

Degree

  • 同志社大学   博士(工学)

Research Experience

  • 2022.04
    -
    Now

    Waseda University   School of Advanced Science and Engineering   Professor

  • 2015.04
    -
    2022.03

    Waseda University   Faculty of Science and Engineering

  • 2016.10
    -
    2020.03

    JSTさきがけ研究員(兼任)

  • 2012.04
    -
    2014.03

    Nagoya Institute of Technology

  • 2008.05
    -
    2012.03

    Nagoya Institute of Technology

  • 2007.04
    -
    2008.04

    Tohoku University

  • 2006.04
    -
    2007.03

    産業技術総合研究所   関西産学官連携センター   特別研究員

  • 2006.04
    -
    2007.03

    産業技術総合研究所   ナノテクノロジー部門   日本学術振興会PD

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Professional Memberships

  •  
     
     

    応用物理学会

 

Research Areas

  • Applied condensed matter physics

  • Measurement engineering

  • Crystal engineering

  • Applied physical properties

  • Thin film/surface and interfacial physical properties

  • Mechanics and mechatronics

  • Robotics and intelligent system

  • Electron device and electronic equipment

▼display all

Research Interests

  • BAW filter

  • FBAR

  • RF-MEMS

  • ScAlN

  • スパッタリング

  • イオンビーム

  • 圧電デバイス

  • 弾性表面波

  • ZnO

  • SAW

  • センサ

  • 薄膜

  • 配向制御

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Papers

  • Measurement of antiresonant frequency during DC bias voltage application for analysis of second harmonic response of ScAlN on SMR

    Takumi Soutome, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS2020)     1 - 4  2020.09  [Refereed]

    DOI

  • GHz BAW Piezoelectric Transformers with High Voltage Gain using the Combination of High and Low Dielectric Constant Thin Films

    Sarina Kinoshita, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS2020)     1 - 4  2020.09  [Refereed]

    DOI

  • Enhancement of GHz electromechanical coupling coefficient kt2 of MgZnO and CaZnO thin film BAW resonators

    Kota Izumi, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS2020)     1 - 3  2020.09  [Refereed]

    DOI

  • Experimental and theoretical investigation of kt2and mechanical quality factor Qm in YbAlN films using DFT

    Naoya Iwata, Sarina Kinoshita, Junjun Jia, Masashi Suzuki, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS2020)     1 - 2  2020.09  [Refereed]

    DOI

  • Zig-zag ScAlN multilayer SMR for high power BAW fileter application such as RF base station

    Yusuke Sato, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS2020)     1 - 3  2020.09  [Refereed]

    DOI

  • Self-Standing FBAR Transformer based on Shear Mode Zig-zag ScAlN Multilayer for Rectenna Application

    Sarina Kinoshita, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS2020)     1 - 4  2020.09  [Refereed]

    DOI

  • Extraction of kt2 of piezoelectric film/substrate structure by conversion loss derived by electromagnetic signal including no acoustic losses

    Ryota Tatsumi, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS2020)     1 - 3  2020.09  [Refereed]

    DOI

  • Deterioration in the piezoelectric property of ScAlN thin films by negative ion bombardment increased in low-pressure sputtering deposition

    Takumi Tominaga, Shinji Takayanagi, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS2020)     1 - 4  2020.09  [Refereed]

    DOI

  • Accurate Extraction of kt2 of Piezoelectric Film/Substrate Structure by Conversion Loss Method Subtracting Experimental Acoustic Losses in the Substrate

    Ryota Tatsumi, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS2020)     1 - 3  2020.09  [Refereed]

    DOI

  • c-Axis oriented ScAlN/SiO2 multilayer BAW transformer for rectifying antenna applications

    Kota Izumi, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS2020)     1 - 4  2020.09  [Refereed]

    DOI

  • ScAlN Nano-Rods Structure Thin Film Grown by a Self-Shadowing Oblique Sputtering for High Electromechanical Coupling Transducer Applications

    Takumi Soutome, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS2020)     1 - 4  2020.09  [Refereed]

    DOI

  • Extracting mechanical Q factor of the pure AlN, ScAlN, and ZnO films without etching substrate

    Naoya Iwata, Sarina Kinoshita, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS2020)     1 - 2  2020.09  [Refereed]

    DOI

  • Giga-Hertz Piezoelectric Epitaxial PZT/La-SrTiO3 Transducer for the Application of Fingerprint Imaging

    Yusuke Sato, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS2020)     1 - 3  2020.09  [Refereed]

    DOI

  • Ion beam induced a-axis in-plane oriented c-axis oriented AlN thin film growth for high-Q BAW resonator application

    Chiaki Masamune, Takahiko Yanagitani

    2019 IEEE International Ultrasonics Symposium (IUS2019)     1127 - 1128  2019.10  [Refereed]

    DOI

  • Effect of negative ions generation from sputtering target on crystalline orientation and kt2 of ScAlN thin films

    Rui Kihara, Shinji Takayanagi, Takahiko Yanagitani

    2019 IEEE International Ultrasonics Symposium (IUS2019)     1120 - 1123  2019.10  [Refereed]

    DOI

  • Improvement of c-Axis Parallel Orientaition of ZnO film on Silica Glass Pipes with Various Diameters for SH-SAW Pipe Sensor

    Takuya Wakabayashi, Shinji Takayanagi, Mami Matukawa, Yuta Takamura, Takahiko Yanagitani

    2019 IEEE International Ultrasonics Symposium (IUS2019)     671 - 674  2019.10  [Refereed]

    DOI

  • A method to estimate kt2 of piezoelectric films from the change of lattice strain by XRD without removing substrate

    Takumi Soutome, Takahiko Yanagitani

    2019 IEEE International Ultrasonics Symposium (IUS2019)     301 - 304  2019.10  [Refereed]

    DOI

  • Shear Mode Polarity Inverted ScAlN Multilayer for Application to BAW Transformer in Rectifying Antenna

    Sarina Kinoshita, Takahiko Yanagitani

    2019 IEEE International Ultrasonics Symposium (IUS2019)     1118 - 1119  2019.10  [Refereed]

    DOI

  • A Method for Extracting Mechanical Q Factor of the Piezoelectric Film without Etching Substrate

    Sarina Kinoshita, Takahiko Yanagitani

    2019 IEEE International Ultrasonics Symposium (IUS)     229 - 300  2019.10  [Refereed]

    DOI

  • Frequency-switchable polarity-inverted BAW resonators based on electric-field-induced piezoelectric PMN-PT/PZT epitaxial film stacks

    Takahiro Shimidzu, Takahiko Yanagitani

    Journal of Applied Physics   126 ( 11 ) 114104 - 114104  2019.09  [Refereed]

    DOI

  • ScAlN圧電薄膜の高品質化に向けたScAl合金スパッタターゲットから発生する負イオンの抑制~電子ビーム溶融、アーク溶融、焼結ScAl合金ターゲットの比較~

    柳谷隆彦

    真空ジャーナル     11 - 15  2019.09

  • Frequency-switchable polarity-inverted BAW resonators based on PZT/PTO epitaxial films using difference in coercive field

    Takahiro Shimidzu, Takeshi Mori, Takahiko Yanagitani

    Applied Physics Letters   114 ( 21 ) 212902 - 212902  2019.05  [Refereed]

    DOI

  • Ultrasonically-induced electrical potentials in demineralized bovine cortical bone

    Shunki Mori, Taiki Makino, Daisuke Koyama, Shinji Takayanagi, Takahiko Yanagitani, Mami Matsukawa

    AIP Advances   8 ( 4 ) 45007  2018.04  [Refereed]

     View Summary

    While the low-intensity pulsed ultrasound technique has proved useful for healing of bone fractures, the ultrasound healing mechanism is not yet understood. To understand the initial physical effects of the ultrasound irradiation process on bone, we have studied the anisotropic piezoelectric properties of bone in the MHz range. Bone is known to be composed of collagen and hydroxyapatite (HAp) and shows strong elastic anisotropy. In this study, the effects of HAp on the piezoelectricity were investigated experimentally. To remove the HAp crystallites from the bovine cortical bone, demineralization was performed using ethylene diamine tetra-acetic acid (EDTA) solutions. To investigate the piezoelectricity, we have fabricated ultrasound transducers using the cortical bone or demineralized cortical bone. The induced electrical potentials due to the piezoelectricity were observed as the output of these transducers under pulsed ultrasound irradiation in the MHz range. The cortical bone transducer (before mineralization) showed anisotropic piezoelectric behavior. When the ultrasound irradiation was applied normal to the transducer surface, the observed induced electrical potentials had minimum values. The potential increased under off-axis ultrasound irradiation with changes in polarization. In the demineralized bone transducer case, however, the anisotropic behavior was not observed in the induced electrical potentials. These results therefore indicate that the HAp crystallites affect the piezoelectric characteristics of bone.

    DOI

  • “Temperature characteristics of ScAlN/SiO2 BAW resonators,”

    H.Igeta, M. Totsuka, M. Suzuki, T. Yanagitani

    Proc. IEEE Ultrason. Symp.    2018  [Refereed]

  • “A new method for extracting Qfactor of the piezoelectric film without removing substrate,”

    S. Kinoshita, M. Totsuka, R. Karasawa, T. Yanagitani

    Proc. IEEE Ultrason. Symp.    2018  [Refereed]

  • “Investigation of morphotropic phase boundary in sputter-grown Pb(Zrx, Ti1-x)O3 epitaxial films,

    R. Noda, T. Shimidzu, K. Wasa, T. Yanagitani

    Proc. IEEE Ultrason. Symp.    2018  [Refereed]

  • “High efficiency ultrasonic transducer using polarity inverted ZnO thin film,”

    T. Majima, T. Shimidzu, T. Yanagitani

    Proc. IEEE Ultrason. Symp.    2018  [Refereed]

  • “ScAlN free-standing 0.1mm plates with 30-50 MHz resonance frequency,”

    C. Masamune, R. Karasawa, T. Yanagitani

    Proc. IEEE Ultrason. Symp.    2018  [Refereed]

  • “PZT epitaxial thick film for ultrasonic transducer at frequencies below 100MHz,”

    Y. Mazuda, T. Shimidzu, T. Yanagitani

    Proc. IEEE Ultrason. Symp.    2018  [Refereed]

  • “The influence of negative ions generation on the arc-melted and hot press sintered ScAlN alloy targets to the crystalline orientation and kt2 of the ScAlN films,”

    Y. Endo, R. Karasawa, S. Takayanagi, M.Imakawa, K. Morisaka, T. Yanagitani

    Proc. IEEE Ultrason. Symp.    2018  [Refereed]

  • “c-axis tilted ScAlN film shear mode resonators for biosensing,”

    H. Yazaki, T. Sotome, S. Takayanagi, K. Yoshida, T. Yanagitani

    Proc. IEEE Ultrason. Symp.    2018  [Refereed]

  • “Evaluation of viscoelactic properties of liquids based on the oblique incidence technology using shear horizontal waves at frequencies above 100 megahertz from c-axis tilted ScAlN thin films,”

    Y. Yamakawa, T. Yanagitani

    Proc. IEEE Ultrason. Symp.    2018  [Refereed]

  • “Extraction of electromechanical coupling coefficient of film / substrate structure by using the ration of a third mode resonant frequency to a fundamental mode resonant frequency,”

    M. Totsuka, T. Yanagitani

    Proc. IEEE Ultrason. Symp.    2018  [Refereed]

  • “DC-induced piezoelectric cubic PMN-PT/piezoelectric tetragonal PZT epitaxial stack polarity inverted resonators for frequency switchable filters,”

    T. Shimidzu, T. Yanagitani

    Proc. IEEE Ultrason. Symp.    2018  [Refereed]

  • “Polarity inverted ScAlN multilayer for application to transformer in rectifying antenna,”

    R. Karasawa, T. Yanagitani

    Proc. IEEE Ultrason. Symp.    2018  [Refereed]

  • “Rapid wave velocity measurement by Brillouin scattering using coherent phonons induced by ScAlN piezoelectric thin-film transducer,”

    M. Kawabe, S. Takayanagi, H, Ichihashi, M. Suzuki, T. Yanagitani, M. Matsukawa

    IEEE Trans. Ultrason., Ferroelectr., Freq.Contr.    2018  [Refereed]

  • "ScAlN thick film ultrasonic transducer in 40 MHz ?80 MHz,”

    K-H. Sano, R. Karasawa, T. Yanagitani

    IEEE Trans. Ultrason., Ferroelectr., Freq.Contr.    2018  [Refereed]

  • Effect of anisotropy on stress-induced electrical potentials in bovine bone using ultrasound irradiation

    S. Matsukawa, T. Makino, S. Mori, D. Koyama, S. Takayanagi, K. Mizuno, T. Yanagitani, M. Matsukawa

    APPLIED PHYSICS LETTERS   110 ( 14 ) 143701  2017.04  [Refereed]

     View Summary

    The bone fracture healing mechanism of the low-intensity pulsed ultrasound technique is not yet clearly understood. In our previous study, the electrical potentials induced in bone were successfully measured by focusing on piezoelectricity in the MHz range. Bone is composed of collagen and hydroxyapatite and has strong anisotropy. The purpose of this study is to investigate the effects of bone anisotropy on the electrical potentials induced by ultrasound irradiation. For this study, ultrasound bone transducers were fabricated using cortical bovine bone plates as piezoelectric devices. An ultrasound of 7.4 kPa(peak-peak) (i.e., the peak-to-peak pressure value) was used to irradiate the side surface of each bone plate. Electrical potentials induced in the bone plate were then measured by varying the wave propagation direction in the plate. The peak-to-peak values of these ultrasonically induced electrical potentials were found to vary with changes in the ultrasound propagation direction in the bone sample. The potential was maximized at an inclination of approximately 45 degrees to the bone axis but was minimized around the three orthogonal directions. These maxima and minima ranged from 28 to 33 mu Vpeak-peak and from 5 to 12 mu Vpeak-peak, respectively. Additionally, our ultrasound results indicated a change in polarity due to bone anisotropy in the MHz range. Published by AIP Publishing.

    DOI

  • “Effects of microstructure and water on the electrical potentials in bone induced by ultrasound irradiation,”

    S. Tomita, T. Yanagitani, S. Takayanagi, H. Ichihashi, Y. Shibagaki, H. Hayashi, M. Matsukawa

    J. Appl. Phys.?   121   235102  2017  [Refereed]

  • “Quantitative thickness measurement of polarity-inverted piezoelectric thin-film layer by scanning nonlinear dielectric microscopy,”

    H. Odagawa, K. Terada, Y. Tanaka, H. Nishikawa, T. Yanagitani, Y. Cho

    Jpn. J. Appl. Phys.   56   10PF18  2017  [Refereed]

  • Acoustic-Wave Velocities and Refractive Indices in an m-Plane GaN Single-Crystal Plate and c-Axis-Oriented ScAlN Films Measured by Brillouin Scattering Techniques

    Hayato Ichihashi, Takahiko Yanagitani, Masashi Suzuki, Shinji Takayanagi, Masahiko Kawabe, Shota Tomita, Mami Matsukawa

    IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL   63 ( 5 ) 717 - 725  2016.05  [Refereed]

     View Summary

    We have experimentally investigated wave velocities and refractive indices in bulk and film samples [a GaN single-crystal plate and c-axis-oriented ScxAl(1-x)N (x = 0.00 - 0.63) films] by Brillouin scattering (BRS). All of the piezoelectrically unstiffened elastic constants and the ordinary refractive index of the GaN single-crystal plate were determined from the reflection-induced Theta A(RI Theta A) scattering geometry and the combination of 90R and 180 degrees scattering geometries. The uncertainties of the measured wave velocities were approximately 0.17% (RI Theta A) and 2.5% (combination technique). In addition, the longitudinal-wave velocities of ScxAl(1-x)N films propagating in the normal direction were obtained by the combination technique. The maximum uncertainty was approximately 3.3%. The shear-wave velocities and refractive indices of ScxAl(1-x)N films were also investigated by the 90R scattering geometry using velocities measured by high-overtone bulk acoustic resonators. The softening trends of the elasticity were obtained from the measured longitudinal-and shear-wave velocities, although there were large uncertainties in the Brillouin measurement system owing to thermal instability.

    DOI

  • 「Al極性ScAlNとO極性ZnO薄膜を用いた多層構造の高効率超音波トランスデューサ」

    森剛志, 柳谷隆彦

    超音波テクノ(日本工業出版)   29   84 - 87  2016

  • Method for measuring polarity-inverted layered structure in dielectric thin films using scanning nonlinear dielectric microscopy

    Hiroyuki Odagawa, Koshiro Terada, Hiroaki Nishikawa, Takahiko Yanagitani, Yasuo Cho

    FERROELECTRICS   498 ( 1 ) 47 - 51  2016  [Refereed]

     View Summary

    A method for obtaining a depth profile of polarity inverted structure in a layered ferroelectric and/or piezoelectric thin film is proposed. It is performed by surface measurement non-destructively using scanning nonlinear dielectric microscopy. We describe estimation principle for the depth profile with some calculation results of measurement signal, which is related to tip radius of the measurement probe and depth of the inverted layer. Also, experimental results in zinc oxide films which have layered polarity-inverted structure fabricated by radio frequency magnetron sputtering and the estimation of the polarity state on the films are shown.

    DOI

  • High-T-c/high-coupling relaxed PZT-based single crystal thin films

    K. Wasa, T. Matsushima, H. Adachi, T. Matsunaga, T. Yanagitani, T. Yamamoto

    JOURNAL OF APPLIED PHYSICS   117 ( 12 ) 124106  2015.03  [Refereed]

     View Summary

    Pb(Zr,Ti)O-3 (PZT)-based ferroelectric ceramics exhibit high piezoelectricity, however, their Curie temperature (T-c) values are not so high, i.e., T-c<400 degrees C. PZT-based piezoelectric thin films with higher T-c would be beneficial for improved micro actuators, sensors, memories, and piezoelectric micro-electro mechanical systems. In-plane biaxial strained PZT thin films in a laminated composite structure are known to exhibit enhanced T-c; however, the thickness of PZT-based thin films is limited to below a critical thickness typically <50 nm. The T-c of relaxed PZT-based thin films with thicknesses greater than the critical thickness is the same as bulk T-c. However, a sort of relaxed PZT-based single-crystal thin films exhibit extraordinary high T-c, T-c = similar to 600 degrees C. In addition, the films show extremely low dielectric constant, epsilon/epsilon(o) similar to 100 with high coupling factor, k(t) similar to 0.7, and large remnant polarization, P-r similar to 100 mu C/cm(2). These exotic properties would result from the single-domain/single-crystal structure. The enhanced T-c is possibly caused by the highly stable interface between the PZT-based thin films and substrates. Their ferroelectric performances are beyond those of conventional PZT. The high-T-c/high-coupling performances are demonstrated, and the possible mechanisms of the high T-c behavior in relaxed PZT-based single-crystal thin films are discussed. (C) 2015 AIP Publishing LLC.

    DOI

  • Effects of microstructure and water on the electrical potentials in bone induced by ultrasound irradiation

    H. Tsuneda, S. Matsukawa, S. Takayanagi, K. Mizuno, T. Yanagitani, M. Matsukawa

    APPLIED PHYSICS LETTERS   106 ( 7 ) 73704  2015.02  [Refereed]

     View Summary

    The healing mechanism of bone fractures by low intensity pulse ultrasound is yet to be fully understood. There have been many discussions regarding how the high frequency dynamic stress can stimulate numerous cell types through various pathways. As one possible initial process of this mechanism, we focus on the piezoelectricity of bone and demonstrate that bone can generate electrical potentials by ultrasound irradiation in the MHz range. We have fabricated ultrasonic bone transducers using bovine cortical bone as the piezoelectric device. The ultrasonically induced electrical potentials in the transducers change as a function of time during immersed ultrasonic pulse measurements and become stable when the bone is fully wet. In addition, the magnitude of the induced electrical potentials changes owing to the microstructure in the cortical bone. The potentials of transducers with haversian structure bone are higher than those of plexiform structure bone, which informs about the effects of bone microstructure on the piezoelectricity. (C) 2015 AIP Publishing LLC.

    DOI

  • High Tc/high coupling perovskite thin films

    K. Wasa, T. Matsushima, H. Adachi, T. Matsunaga, T. Yanagitani, T. Yamamoto

    2014 Joint IEEE International Symposium on the Applications of Ferroelectric, International Workshop on Acoustic Transduction Materials and Devices and Workshop on Piezoresponse Force Microscopy, ISAF/IWATMD/PFM 2014     1 - 4  2014.10  [Refereed]

     View Summary

    Ferroelectric thin films with high Curie temperature Tc and high piezoelectric coupling factor k are fascinated for a better piezoelectric MEMS. Pb(Zr, Ti)O3 (PZT)-based ferroelectric ceramics exhibit high piezoelectricity, but the Tc is not high, i.e. Tc &lt
    400°C. PZT-based piezoelectric thin films with higher Tc will be much useful. Based on a strain engineering, it is commonly understood the in-plane biaxial strain enhances the Tc of PZT thin films in a laminated composite structure. However, thickness of the PZT thin films is limited below a critical thickness typically &lt
    50nm. Recently it has been found in-plane relaxed single crystal PZT-based thin films, i.e. PMnN-PZT(48/52) thin films, thickness above the critical thickness (typically 1μm), exhibited enhanced Tc The Tc is extraordinary high, Tc = 600°C. Their ferroelectric performances are beyond bulk PZT. The high Tc phenomena are demonstrated and the possible mechanisms of the high Tc behavior are discussed.

    DOI

  • Electromechanical coupling and gigahertz elastic properties of ScAlN films near phase boundary

    Takahiko Yanagitani, Masashi Suzuki

    APPLIED PHYSICS LETTERS   105 ( 12 ) 122907  2014.09  [Refereed]

     View Summary

    The electromechanical coupling, elastic properties, and temperature coefficient of elastic constant c(33)(D) of ScxAl(1-x)N films with high Sc concentration (x) of 0-0.70 were experimentally investigated. Near the phase boundary, a Sc0.41Al0.59N film exhibited a maximum thickness extensional mode electromechanical coupling coefficient k(t)(2) of 12% (k(t) = 0.35), which is almost double the value of 6.4% for typical pure AlN films. In the region of 0 < x < 0.2, the electromechanical coupling was confirmed to increase without any detectable deterioration in the temperature stability of c(33)(D) (= -54.5 ppm/ degrees C). This region is favorable in terms of temperature stability and is suitable for wideband resonator filter applications. (C) 2014 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.

    DOI

  • Gigahertz Acoustic Wave Velocity Measurement in GaN Single Crystals Considering Acousto-Electric Effect

    Hayato Ichihashi, Takahiko Yanagitani, Shinji Takayanagi, Masahiko Kawabe, Mami Matsukawa

    IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL   61 ( 8 ) 1307 - 1313  2014.08  [Refereed]

     View Summary

    The resistivity-frequency characteristics of longitudinal wave velocities propagating parallel to the c-axis in a GaN single crystal were theoretically estimated by considering the piezoelectric acousto-electric effect. The temperature and frequency dependences of longitudinal and shear wave velocities in conductive and semiconductive GaN single-crystal samples were experimentally investigated by Brillouin scattering. The temperature dependence of longitudinal and shear wave velocities had a linear tendency in the conductive sample, whereas in the semiconductive sample, those had a similar tendency to the predicted velocity changes resulting from the piezoelectric stiffening effect. However, the temperature dependence of shear wave velocity, which does not possess piezoelectric coupling, had a tendency similar to that of the longitudinal wave in the semiconductive sample, unexpectedly. The frequency dependence of longitudinal wave velocities in the semiconductive sample had a tendency similar to the predicted velocity changes resulting from the piezoelectric stiffening effect.

    DOI

  • Polarity-inverted ScAlN film growth by ion beam irradiation and application to overtone acoustic wave (000-1)/(0001) film resonators

    Masashi Suzuki, Takahiko Yanagitani, Hiroyuki Odagawa

    APPLIED PHYSICS LETTERS   104 ( 17 ) 172905-1 - 172905-4  2014.04  [Refereed]

     View Summary

    Polarity inversion in wurtzite film is generally achieved by the epitaxial growth on a specific under-layer. We demonstrate polarity inversion of c-axis oriented ScAlN films by substrate ion beam irradiation without using buffer layer. Substrate ion beam irradiation was induced by either sputtering a small amount of oxide (as a negative ion source) onto the cathode or by applying a RF bias to the substrate. Polarity of the films was determined by a press test and nonlinear dielectric measurement. Second overtone thickness extensional mode acoustic resonance and suppression of fundamental mode resonance, indicating complete polarity inversion, were clearly observed in bilayer highly oriented (000-1)/(0001) ScAlN film. (C) 2014 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.

    DOI

  • Enhanced piezoelectricity in YbGaN films near phase boundary

    Takahiko Yanagitani, Masashi Suzuki

    APPLIED PHYSICS LETTERS   104 ( 8 ) 082911-1 - 082911-4  2014.02  [Refereed]

     View Summary

    Weak piezoelectricity in GaN is a problem in bulk acoustic wave filters and heterostructure field-effect transistors. In this study, enhancement of piezoelectricity in c-axis direction by substituting Yb for Ga was experimentally demonstrated. Thickness extensional mode electromechanical coupling coefficient k(t) for the YbxGa1-xN films increases with the Yb concentration from x = 0 to 0.3. Yb0.30Ga0.70N film near the phase boundary exhibited a maximum k(t) of 3.1%, which is approximately 2.5 times larger than that for a pure GaN. (C) 2014 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.

    DOI

  • “Second harmonic mode polarization inverted resonator consisting of PbTiO3 thin film,”

    K. Katada, T. Yanagitani, M, Suzuki, K. Wasa

    Proc. IEEE Freq. Contr. Symp.     119 - 120  2014  [Refereed]

  • “High electromechanical coupling in PZT epitaxial thick film resonators at 550 oC,”

    T. Yanagitani, K. Katada, M, Suzuki, K. Wasa

    Proc. IEEE Freq. Contr. Symp.     121 - 123  2014  [Refereed]

  • Effect of Sc concentration on shear wave velocities in ScAlN films measured by micro-Brillouin scattering technique

    Hayato Ichihashi, Takahiko Yanagitani, Masashi Suzuki, Shinji Takayanagi, Mami Matsukawa

    2014 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IUS)     2521 - 2524  2014  [Refereed]

     View Summary

    ScAlN film is attractive for the BAW and SAW resonators because of its large piezoelectric constants compared with AlN and ZnO. However, the shear and longitudinal elastic properties perpendicular to the c-axis, which are required for SAW and BAW analyses, have not been reported. In this study, we measured shear and longitudinal wave velocities propagating perpendicular to the c-axis [nu(S) = (c(GG)/rho)(1/2) and nu(L) = (c(11)/rho)(1/2)] in ScAlN films with various Sc concentrations using microBrillouin scattering technique. The shear and longitudinal wave velocities in the Sc0.41Al0.59N films decreased to 69% and 81% of those in a pure AlN film, respectively. The shear wave velocity in the film with Sc concentration more than 50% increased with increasing of Sc concentration.

    DOI

  • Multiple shear wave roundtrips liquid sensor by c-axis parallel oriented ZnO film/silica glass pipe structure

    Shoko Hiyama, Takahiko Yanagitani, Shinji Takayanagi, Yoshiya Kato, Mami Matsukawa

    2014 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IUS)     765 - 768  2014  [Refereed]

     View Summary

    We demonstrated the multiple roundtrips of shear horizontal (SH) waves using IDT/c-axis parallel-oriented (1120) ZnO film/silica glass pipe structure for a high-sensitive liquid sensor. Forth roundtrip was observed in the time response of acoustic waves. The insertion loss of the first lap consisted of two frequency components at 131 MHz and 160-350 MHz. IDT/c-axis parallel-oriented ZnO film/silica glass cylinder structure was also fabricated, but multiple roundtrips were not occurred. Therefore, we considered the waves propagating in the pipe structure as plate type waves, not surface acoustic waves. In addition, the liquid loading characteristics of the pipe structure sensor were measured by immersing inside or outside of the pipe in liquid. Because the insertion loss increases in the pipe structure with pure water loading were relatively small, we can conclude that the waves were SH-type plate wave. Liquid property detections using both outside and inside of the pipe structure sensor are expected.

    DOI

  • Significant shear mode softening in a c-axis tilt nanostructured hexagonal thin film induced by a self-shadowing effect

    T. Yanagitani, M. Suzuki

    SCRIPTA MATERIALIA   69 ( 10 ) 724 - 727  2013.11  [Refereed]

     View Summary

    The mechanical properties of tilted AlN fiber structure caused by self-shadowing are investigated using gigahertz vibration induced through the piezoelectricity of AlN itself. We observed significant shear elastic softening in a highly tilted fiber nanostructure, but only a slight decrease in compressive elasticity. Abnormal 1/4 wavelength thickness mode resonance, indicating the decrease in the shear acoustic wave velocity, is reproducibly observed. We attribute this phenomenon to the weak fiber-to-fiber connection seen in a cross-sectional scanning electron microscopy image. (C) 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

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  • Electrical potentials in bone induced by ultrasound irradiation in the megahertz range

    M. Okino, S. Coutelou, K. Mizuno, T. Yanagitani, M. Matsukawa

    APPLIED PHYSICS LETTERS   103 ( 10 ) 103701-1 - 103701-4  2013.09  [Refereed]

     View Summary

    Low frequency mechanical studies have reported the contribution of stress-induced electrical potentials to bone metabolism. However, the healing mechanism of bone fractures by low intensity ultrasound is not yet clear. We demonstrate that bone can generate electrical potentials by ultrasound irradiation in the MHz range. Electrical potentials were obtained from the output of bovine cortical bone transducers. In the range of 0.7-2.5 MHz, sensitivities of bone transducers were around 1/1000 of a poly (vinylidene fluoride) ultrasonic transducer and did not depend on magnitude and alignment of hydroxyapatite crystallites in bone. (C) 2013 AIP Publishing LLC.

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  • A method for predicting thickness of the unoriented layer in ZnO film using piezoelectricity distribution in depth direction

    S. Takayanagi, T. Yanagitani, M. Matsukawa

    JOURNAL OF PHYSICS D-APPLIED PHYSICS   46 ( 31 ) 315305-1 - 315305-5  2013.08  [Refereed]

     View Summary

    The crystalline orientation of thin films gradually improves as the growth proceeds. Especially in the non-epitaxial growth, its initial layer is often unoriented. Because the unoriented layer degrades the performance of the device, the degree of crystalline orientation in depth direction is a very important issue. We propose a non-destructive method for predicting the thickness of the unoriented layer, making use of piezoelectricity distribution of films. An electromechanical resonator consisting of the single highly oriented layer excites a fundamental mode, but does not excite a second-overtone mode. The unoriented layer, on the other hand, exhibits little piezoelectric effect. A bilayer resonator consisting of the highly oriented layer on the unoriented layer excites a second-overtone mode because of the deference of piezoelectricity in these layers. In this study, the electromechanical resonance characteristics of Cu/ZnO(0 0 0 1)/Ti(0 0 0 1)/SiO2, Cu/ZnO(0 0 0 1)/AZO(0 0 0 1)/Ti(0 0 0 1)/ SiO2 and Cu/ZnO(1 1 (2) over bar 0)/Al/SiO2 were experimentally observed. These results were compared with the theoretical estimations by a mechanical transmission line model to determine the thicknesses of the piezoelectrically inactive layers in the (0 0 0 1) or (1 1 (2) over bar 0) oriented ZnO films. The inactive layer thickness in the (1 1 (2) over bar 0) oriented ZnO film was in good agreement with the unoriented layer thickness observed by the cross-sectional transmission electron microscopy and electron diffraction.

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  • PZT-based high coupling with low permittivity thin films

    Kiyotaka Wasa, Tomoaki Matsushima, Hideaki Adachi, Toshifumi Matsunaga, Masashi Suzuki, Takahiko Yanagitani, Takashi Yamamoto, Shinya Yoshida, Shuji Tanaka, S. Trolier-Mckinstry

    2013 Joint IEEE International Symposium on Applications of Ferroelectric and Workshop on Piezoresponse Force Microscopy, ISAF/PFM 2013     69 - 72  2013  [Refereed]

     View Summary

    PZT-based piezoelectric thin films will make better piezoelectric devices including piezoelectric energy harvesting (EH) power MEMS, when the piezoelectric thin films show high electromechanical coupling and/or high piezoelectric constants with low permittivity. The piezoelectric thin films are mostly polycrystalline structure with high piezoelectric constants and high dielectric constants, i.e. ε*=300-1300 and e31,f = -8 ∼ - 12C/m2. Recently we have found thin films of single c-domain/single crystal PZT-based ternary perovskite, Pb(Mn,Nb)-PZT, exhibit exotic properties, i.e. high coupling and/or high piezoelectric constants with low dielectric constants opposed to the PZT-based thin films. The relative dielectric constants are as low as 100 with e31,f = -12 C/m 2. The low dielectric constants achieve high values of Figures of Merit for the EH-MEMS. This paper will discuss on the origin of the exotic dielectric and piezoelectric properties of the single c-domain/single crystal thin films in comparison with bulk PZT-based ceramics. © 2013 IEEE.

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  • Effect of metal mode and oxide mode on unusual c-axis parallel oriented ZnO film growth on Al/glass substrate in a reactive magnetron sputtering of Zn target

    Shinji Takayanagi, Takahiko Yanagitani, Mami Matsukawa

    Journal of Crystal Growth   363   22 - 24  2013  [Refereed]

     View Summary

    (112̄0) oriented ZnO films where the c-axis is parallel to a substrate are good candidates for acoustic shear wave devices and sensors. Although ZnO film has tendency to develop c-axis normal (0001) orientation, unusual (112̄0) orientation appears in the situation that energetic oxygen ions generated from a target surface bombard the substrate during film growth in a reactive sputtering. The flux and the energy of these ions depend on the transition between the metal mode and the oxide mode on the Zn metal target surface. Here, the effect of the target surface condition on the development of unusual (112̄0) orientation is investigated. The higher crystalline (112̄0) orientation appeared in the oxide mode, probably because a large amount of energetic oxygen ions generated by the oxidized part of the Zn target. © 2012 Elsevier B.V. All rights reserved.

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  • High-performance brillouin spectroscopy of phonons induced by a piezoelectric thin film with a coaxial microwave resonator

    Hiroyuki Sano, Takahiko Yanagitani, Shinji Takayanagi, Takeshi Sugimoto, Mami Matsukawa

    IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control   60 ( 5 ) 873 - 876  2013  [Refereed]

     View Summary

    To overcome the low accuracy of acoustic velocity measurements based on Brillouin scattering from thermal phonons, we attempted to utilize induced coherent phonons, which cause intense Brillouin scattering. A ZnO piezoelectric film was used to induce gigahertz-range coherent phonons in a silica glass block sample. An evanescent electromagnetic wave leaked from a coaxial resonator was applied into the film to excite phonons. The scattered light obtained using this simple system was much more intense than that obtained from thermal phonons. This technique will improve the accuracy and reduce the measurement time. © 1986-2012 IEEE.

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  • Unusual growth of polycrystalline oxide film induced by negative ion bombardment in the capacitively coupled plasma deposition

    S. Takayanagi, T. Yanagitani, M. Matsukawa

    APPLIED PHYSICS LETTERS   101 ( 23 ) 232902-1 - 232902-3  2012.12  [Refereed]

     View Summary

    A polycrystalline film usually grows in its most densely packed plane parallel to the substrate plane. We demonstrated that the unusual crystalline growth can occur by using energetic negative ions generated in the magnetron capacitively coupled plasma deposition without using separated ion source. Negative ion energy and flux entering the substrate were quantitatively measured and compared with the preferential crystalline growth of unusual (11 (2) over bar0) orientation in ZnO films. Strong (11 (2) over bar0) orientation was found at the cathode erosion area where large amount of high energy negative ion of 170-250 eV was observed in low gas pressure of 0.1 Pa. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4769224]

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  • Wideband Multimode Transducer Consisting of c-Axis Tilted ZnO/c-Axis Normal ZnO Multilayer

    Shinji Takayanagi, Takahiko Yanagitani, Mami Matsukawa

    JAPANESE JOURNAL OF APPLIED PHYSICS   51 ( 7 ) 07GC08  2012.07  [Refereed]

     View Summary

    Wideband ultrasonic transducers are required for acoustic imaging and nondestructive evaluation. In this study, we have fabricated transducer consisting of c-axis tilted ZnO/c-axis normal ZnO multilayer on the Au(111)/Ti/silica glass substrate. We have investigated the crystalline orientations and frequency characteristics of the multilayer transducer. An X-ray diffraction analysis and a scanning electron microscopy analysis of the transducer revealed that the c-axis normal ZnO layer was grown on the Au(111) layer during the initial stage of ZnO layer deposition. As ZnO grain growth proceeded, c-axis normal growth change to the c-axis tilted ZnO layer growth. This multilayer transducer excited second-overtone modes of longitudinal and shear waves as well as the fundamental mode in the UHF range. Therefore, the frequency bandwidth of the multilayer transducer was broader than that of a single layer transducer consisting of a c-axis tilted ZnO layer. (C) 2012 The Japan Society of Applied Physics

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  • Relationships between the anisotropy of longitudinal wave velocity and hydroxyapatite crystallite orientation in bovine cortical bone

    Kazufumi Yamamoto, Tomohiro Nakatsuji, Yuichiro Yaoi, Yu Yamato, Takahiko Yanagitani, Mami Matsukawa, Kaoru Yamazaki, Yukihiro Matsuyama

    ULTRASONICS   52 ( 3 ) 377 - 386  2012.03  [Refereed]

     View Summary

    Quantitative ultrasound (QUS) is now widely used for evaluating bone in vivo, because obtained ultrasonic wave properties directly reflect the visco-elasticity. Bone tissue is composed of minerals like hydroxyapatite (HAp) and a collagen matrix. HAp crystallites orientation is thus one parameter of bone elasticity. In this study, we experimentally investigated the anisotropy of ultrasonic wave velocity and the HAp crystallites orientation in the axial-radial and axial-tangential planes in detail, using cylindrical specimens obtained from the cortical bone of three bovine femurs. Longitudinal bulk wave propagation was investigated by using a conventional ultrasonic pulse system. We used the one cycle of sinusoidal pulse which was emitted from wide band transmitter. The nominal frequency of the pulse was 1 MHz. First, we investigated the anisotropy of longitudinal wave velocity, measuring the anisotropy of velocity in two planes using cylindrical specimens obtained from identical bone areas. The wave velocity changed due to the rotation angle, showing the maximum value in the direction a little off the bone axis. Moreover, X-ray pole figure measurements also indicated that there were small tilts in the HAp crystallites orientation from the bone axis. The tilt angles were similar to those of the highest velocity direction. There were good correlations between velocity and HAp crystallites orientation obtained in different directions. However, a comparatively low correlation was found in posterior bone areas, which shows the stronger effects of bone microstructure. In the radial-tangential plane, where the HAp crystallites hardly ever align, weak anisotropy of velocity was found which seemed to depend on the bone microstructure. (C) 2011 Elsevier B.V. All rights reserved.

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  • Fast hypersonic velocity measurement by Brillouin scattering from induced phonons

    Takeshi Sugimoto, Takahiko Yanagitani, Shinji Takayanagi, Mami Matsukawa

    2012 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IUS)     2187 - 2190  2012  [Refereed]

     View Summary

    Brillouin scattering method is a nondestructive and noncontact technique to measure local longitudinal and shear acoustic velocities in the GHz range. However, the measurements of weak scattering from thermal phonons result in the lower measurement accuracy and longer measurement time. To overcome this problem, a technique with artificially induced acoustic phonons was developed using a polycrystalline ZnO film, with a coaxial resonator to apply electric field. In this study, we observed Brillouin scattering by induced longitudinal phonons from ZnO film deposited on the rear surface of a plate sample. We investigated the relationship between the intensity of induced acoustic phonons and the input microwave power of a coaxial resonator. The effect of incident angle of light was also investigated.

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  • “Polarization inverted (0001) / (000-1) ScAlN film resonators operating in second overtone mode,”

    M. Suzuki, T. Yanagitani, H. Odagawa

    Proc. IEEE Ultrason. Symp.     1922 - 1924  2012  [Refereed]

  • Texture modification of wurtzite piezoelectric films by ion beam irradiation

    Takahiko Yanagitani, Masato Kiuchi

    SURFACE & COATINGS TECHNOLOGY   206 ( 5 ) 816 - 819  2011.11  [Refereed]

     View Summary

    Texture modification of wurtzite films in ion beam assisted deposition was investigated. Unusual (1110) texture formation appeared in the ZnO and AlN films prepared by grazing ion beam sputtering. Such a (1110) texture formation was also observed even in the ZnO film deposited under argon ion beam irradiation. Mechanism of the formation probably relates to physical interaction between energetic particle irradiation and wurtzite structure, for example, sputtering, collision etc. Pole figure analysis and SEM image revealed that crystal grains in the films have strong out-of plane and in-plane orientation (have biaxial texture) and in-plane c-axis direction corresponds to incident ion beam direction. (C) 2011 Elsevier B.V. All rights reserved.

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  • Three-Dimensional Anisotropy of Ultrasonic Wave Velocity in Bovine Cortical Bone: Effects of Hydroxyapatite Crystallites Orientation and Microstructure

    Tomohiro Nakatsuji, Kazufumi Yamamoto, Daisuke Suga, Takahiko Yanagitani, Mami Matsukawa, Kaoru Yamazaki, Yukihiro Matsuyama

    JAPANESE JOURNAL OF APPLIED PHYSICS   50 ( 7 ) 07HF18-1 - 07HF18-6  2011.07  [Refereed]

     View Summary

    The three-dimensional anisotropy of longitudinal wave velocity and the hydroxyapatite (HAp) crystallites orientation in bovine cortical bone were experimentally investigated in detail. Bovine cortical bone has two typical microstructures, plexiform and haversian. Two spherical specimens (diameter: 9 mm) were obtained from the anterior (plexiform) and posterior (haversian) parts of a 30-month-old bovine femur. The three-dimensional anisotropy of longitudinal wave velocity was measured using a conventional ultrasonic pulse system by rotating the spherical specimen in the axial-tangential (A-T), axial-radial (A-R), and radial-tangential (R-T) planes. The velocity clearly changed depending on the propagation direction in all the planes. In the A-T and A-R planes, the direction of the highest velocity was slightly inclined from the bone axis direction. Moreover, the results from the X-ray pole figure analysis indicated that there were small tilts in the HAp crystallites orientation. The tilts were similar to those of the highest velocity direction and there were good correlations between velocity and HAp crystallites orientation. However, a comparatively low correlation was found in the posterior part, which shows the stronger effects of bone microstructure. On the other hand, in the R-T plane, where small HAp crystallites oriented, a weak velocity anisotropy was found owing to the bone microstructure. Ultrasonic wave velocities depended on both HAp crystallites orientation and microstructure. The degrees of contribution of these factors varied owing to the position and propagation direction. (C) 2011 The Japan Society of Applied Physics

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  • Observation of Induced Longitudinal and Shear Acoustic Phonons by Brillouin Scattering

    Taisuke Yoshida, Mami Matsukawa, Takahiko Yanagitani

    IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL   58 ( 6 ) 1255 - 1260  2011.06  [Refereed]

     View Summary

    To improve the accuracy of velocity measurements in the Brillouin scattering technique using weak thermal phonons, we have used induced coherent phonons, which intensify the scattering. To induce phonons in the gigahertz range, we used a c-axis tilted ZnO film transducer that was developed in our laboratory. This allowed us to induce longitudinal and shear acoustic phonons effectively at hypersonic frequencies. As a result, we obtained scattered light in the silica glass sample that was much more intense than that obtained from the thermal phonons. Because the Brillouin scattering from induced phonons was measured, the shift frequency was that of the electric signal applied to the ZnO transducer. Strong peaks lead to a reduction of the measurement time. This is useful for two-dimensional mapping of thin film elasticity using Brillouin scattering. Additionally, Brillouin scattering enables the simultaneous measurement of longitudinal and shear phonon velocities in the sample plane. This opens up a potential new technique for non-destructive elasticity measurements of various materials.

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  • c-Axis Zig-Zag ZnO Film Ultrasonic Transducers for Designing Longitudinal and Shear Wave Resonant Frequencies and Modes

    Takahiko Yanagitani, Naoki Morisato, Shinji Takayanagi, Mami Matsukawa, Yoshiaki Watanabe

    IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL   58 ( 5 ) 1062 - 1068  2011.05  [Refereed]

     View Summary

    A method for designing frequencies and modes in ultrasonic transducers above the very-high-frequency (VHF) range is required for ultrasonic non-destructive evaluation and acoustic mass sensors. To obtain the desired longitudinal and shear wave conversion loss characteristics in the transducer, we propose the use of a c-axis zig-zag structure consisting of multilayered c-axis 23 degrees tilted ZnO piezoelectric films. In this structure, every layer has the same thickness, and the c-axis tilt directions in odd and even layers are symmetric with respect to the film surface normal. c-axis zig-zag crystal growth was achieved by using a SiO(2) low-temperature buffer layer. The frequency characteristics of the multilayered transducer were predicted using a transmission line model based on Mason's equivalent circuit. We experimentally demonstrated two types of transducers: those exciting longitudinal and shear waves simultaneously at the same frequency, and those exciting shear waves with suppressed longitudinal waves.

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  • 「RFバイアススパッタ法による簡便なc軸平行配向ZnO膜の形成--RFバイアスを用いたイオン照射による結晶配向制御」

    高柳 真司, 松川真美, 渡辺好章, 柳谷隆彦

    超音波テクノ(日本工業出版)   22   59 - 62  2011

  • 「c軸平行配向AlN薄膜を用いた極性反転すべり共振子」

    鈴木雅視, 柳谷隆彦

    超音波テクノ(日本工業出版)   23   40 - 44  2011

  • Quantitative analysis of the effect of energetic particle bombardment during deposition on (11(2)over-bar0) texture formation in ZnO films

    Shinji Takayanagi, Takahiko Yanagitani, Mami Matsukawa, Yoshiaki Watanabe

    2011 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IUS)     2317 - 2320  2011  [Refereed]

     View Summary

    C-axis parallel-oriented (11 (2) over bar0) ZnO films are suitable for shear mode devices. In previous studies, we pointed out that (11 (2) over bar0) texture formation was induced by the ion bombardment during a planer RF magnetron sputtering deposition. However, quantitative information of the relationship between ion energy and amount of ion irradiation are not clear. In this study, we investigated the effects of energetic ion bombardment during sputtering deposition on (11 (2) over bar0) texture formation. The distribution of crystalline orientation of the films on the anode plane was compared with the distribution of the amount of ion flux in the anode plane. Highly crystallized (11 (2) over bar0) orientation appeared above the target erosion area where highly energetic O-l ions bombardment was observed under the low gas pressure condition. This information will give us how to obtain much better (11 (2) over bar0) textured ZnO films for share mode devices.

    DOI

  • Brillouin scattering from induced phonons excited by the ZnO piezoelectric thin film with a coaxial resonator

    Takeshi Sugimoto, Hiroyuki Sano, Takahiko Yanagitani, Shinji Takayanagi, Mami Matsukawa

    2011 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IUS)     1099 - 1102  2011  [Refereed]

     View Summary

    Brillouin scattering method is a nondestructive and noncontact technique to measure local longitudinal and shear acoustic velocities in the GHz range. However, the measurements of weak scattering from thermal phonons result in the lower measurement accuracy and longer measurement time than those of other methods, such as ultrasonic pulse techniques. To overcome these problems, a technique with induced phonons was developed using a ZnO piezoelectric thin film and a coaxial resonator. Especially, this technique enables simple measurement system without electrodes making use of evanescent electric field to ZnO film. In this study, ZnO piezoelectric thin film was deposited on curved and rear surfaces.

    DOI

  • C-axis parallel oriented ZnO film SH-SAW sensor for electrical conductivity measurement in liquid

    Yuta Nakahigashi, Takahiko Yanagitani, Mami Matsukawa, Watanabe Yoshiaki

    2011 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IUS)     810 - 813  2011  [Refereed]

     View Summary

    A shear horizontal type surface acoustic wave (SH-SAW) device can be a sensor operating in liquid, because SH-SAW propagates at liquid/solid interface without energy leakage to liquid. This device can detect changes in conductivity and viscosity of liquid. c-axis parallel oriented ZnO film can be one of the best candidates for the SH-SAW liquid sensor on various substrates. Theoretical investigation of K-2 value in IDT / ZnO (0 degrees, 90 degrees, Psi) film / silica glass substrate structure showed that maximum value of K-2 = 3.4 % was found at Psi = 55 degrees with H / lambda = 0.21. In this study, we fabricated these structures and evaluated K-2 values. Finally, the electrical conductivity of liquid was detected as the velocity change.

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  • Polarization-inverted multilayered pure shear mode AlN film resonator

    Masashi Suzuki, Takahiko Yanagitani

    2011 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IUS)     312 - 315  2011  [Refereed]

     View Summary

    c-axis parallel AlN film is suitable for pure shear mode devices. Polarization-inverted multilayered structure can excite high order mode resonance. The film thickness of high order mode resonator is thicker than that of fundamental mode resonator in same operating frequency. Therefore, the multilayered resonator is expected to have high power handling capability. c-axis parallel polarization-inverted multilayered AlN films were fabricated by ion beam assisted deposition (IBAD). c-axis parallel orientation was formed under the 3 kV accelerated ion beam irradiation. Shear mode resonator was prepared to investigate piezoelectric properties of the film. Only pure shear wave without any longitudinal wave was excited in the resonators. k(15) was determined to be 0.05 and this value is 71 % of the single crystalline AlN.
    We considered that in-plane crystal growth direction should to be determined by the ion beam irradiation direction. c-axis parallel multilayer AlN film was fabricated by inverting in-plane beam irradiation direction. High order mode resonance was observed in the resonators, showing that polarization was inverted in the multilayer AlN films.

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  • C-axis parallel oriented AlN film resonator fabricated by ion-beam assisted RF magnetron sputtering

    Masashi Suzuki, Takahiko Yanagitani

    2011 IEEE INTERNATIONAL ULTRASONICS SYMPOSIUM (IUS)     1230 - 1233  2011  [Refereed]

     View Summary

    c-axis parallel oriented AlN films excite only pure shear wave. These films are suitable for thickness shear mode film resonators and SH-SAW devices. However, c-axis in the wurzite film such as ZnO and AlN tends to grow normal to the substrate. We previously found that c-axis parallel orientation is induced by ion-beam irradiation during deposition in ZnO films. In this study, we investigated the orientation control of AlN films by using ion-beam assisted RF magnetron sputtering. c-axis parallel oriented AlN films were obtained in the sample deposited under 3 kV accelerated ion beam irradiation The direction of c-axis corresponded to the ion beam direction. c-axis parallel AlN film SMR with asymmetric Bragg reflector was then prepared. Pure shear mode was excited in the resonator. Effective k(15)' of the resonator was determined to be 0.052, and TCF was found to be - 30.2 ppm/degrees C.

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  • A method for measuring in-plane unidirectional electrical properties in a wide band-gap semiconductor using a Brillouin scattering method

    Takahiko Yanagitani, Hiroyuki Sano, Mami Matsukawa

    JOURNAL OF APPLIED PHYSICS   108 ( 2 ) 024910-1 - 024910-4  2010.07  [Refereed]

     View Summary

    It is difficult to measure the in-plane directional electrical properties of a crystal sample without physical contact. This paper describes the measurement of in-plane unidirectional resistivity through electromechanical coupling. The degree of coupling was determined from acoustic velocity data measured using the Brillouin scattering method. The resistivity distribution in a ZnO crystal with a resistivity of less than 1 Omega m, (common in intrinsic wide band-gap semiconductors) was clearly detected through acoustic velocity at gigahertz frequencies. The resistivity values obtained from the acoustic wave velocities showed a good correlation with standard contact electrode measurements in the resistivity range of 0.03-1 Omega m. This noncontact measurement technique should be useful for measuring the microscopic distribution of id-plane resistivity in wide band-gap semiconductors, and is a powerful tool for experiments under extreme conditions, such as high pressure and/or high temperature. (C) 2010 American Institute of Physics. [doi:10.1063/1.3448203]

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  • 「(11-20)配向AlN薄膜を用いた純横波モード共振子」

    柳谷隆彦, 木内正人, 松川真美

    超音波テクノ(日本工業出版)   22   46 - 49  2010

  • 「c軸傾斜反転配向ZnO多層膜の作製」

    守里直希, 高柳真司, 柳谷隆彦, 松川真美, 渡辺好章

    超音波テクノ(日本工業出版)   22   60 - 65  2010

  • “A simple technique for obtaining (11-20) or (10-10)textured ZnO films by RF bias sputtering”

    S. Takayanagi, T. Yanagitani, M. Matsukawa, Y. Watanabe

    Proc. IEEE Ultrason. Symp.     1060 - 1063  2010  [Refereed]

    DOI

  • Deposition techniques of c-axis-tilted ScAlN films by conventional RF magnetron sputtering

    Kazuki Arakawa, Takahiko Yanagitani, Kazuhiko Kano, Akihiko Teshigahara, Morito Akiyama

    Proceedings - IEEE Ultrasonics Symposium     1050 - 1053  2010  [Refereed]

     View Summary

    It is difficult to synthesize c-axis tilted ScAlN films by using co-sputtering because unidirectional oblique incident of sputtered particles is needed to obtain c-axis tilted structure. To realize the oblique incident single source sputtering technique was proposed for c-axis tilted film deposition. ScAl alloy target was used to achieve ScAlN film synthesis instead of co-sputtering. As a result c-axis highly tilted ScAlN film (tilt angle 33) was obtained by using this deposition technique. From the result of film transducer loss measurement we found that longitudinal and shear elasticity of AlN decreases by adding Sc. c-axis highly tilted ScAlN film showed giant k 15' values of 0.32 in spite of its low degree of orientation. © 2010 IEEE.

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  • Influence of shadowing effect on shear mode acoustic properties in the c-axis tilted AlN films

    Masashi Suzuki, Takahiko Yanagitani

    Proceedings - IEEE Ultrasonics Symposium     1478 - 1481  2010  [Refereed]

     View Summary

    C-axis tilted AlN films have been studied for use in quasi-shear mode devices. Highly tilted columnar structure induces the decrease of film density (void between columnar grains) because of the shadowing effect. This could affect the performance of shear mode resonator. In this study, the relationship between the acoustic properties and the grain structure is investigated in c-axis tilted AlN film. Acoustic properties of the resonators were estimated by the characteristic of conversion loss in composite resonator. In c-axis highly tilted AlN film, 1/4 and 3/4 wavelength resonance due to the decrease of shear wave velocity were observed in a number of samples. This phenomenon was not observed in longitudinal wave mode. Porous film structure was also observed in the highly tilted films by across sectional SEM image. Decrease of shear wave velocity would be caused by this structure because shear wave is more sensitive to the porous structure than longitudinal wave. © 2010 IEEE.

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  • Giant shear mode electromechanical coupling coefficient k15 in c-axis tilted ScAlN films

    Takahiko Yanagitani, Kazuki Arakawa, Kazuhiko Kano, Akihiko Teshigahara, Morito Akiyama

    Proceedings - IEEE Ultrasonics Symposium     2095 - 2098  2010  [Refereed]

     View Summary

    Giant shear mode electromechanical coupling coeficient k15' of 0.32 (k15210 %) were found in the c-axis 33° tilted ScAlN films. High k15 values were observed even in the high temperature of 600 C. TCF values were deteriorated in ScAlN film compared with non-doped AlN crystal. Shear mode ScAlN films should be a good candidate for liquid SH-SAW and FBAR sensors in the high temperature. © 2010 IEEE.

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  • Large-Area Growth of In-Plane Oriented (11(2)over-bar0) ZnO Films by Linear Cathode Magnetron Sputtering

    Takayuki Kawamoto, Takahiko Yanagitani, Mami Matsukawa, Yoshiaki Watanabe, Yoshikazu Mori, Sho Sasaki, Masatoshi Oba

    JAPANESE JOURNAL OF APPLIED PHYSICS   49 ( 7 ) 07HD16-1 - 07HD16-4  2010  [Refereed]

     View Summary

    (11 (2) over bar0) textured ZnO films are good candidates for shear-mode piezoelectric devices. In the previous deposition techniques of these films, there have been two problems related to their practical application. These problems are as follows: (i) highly oriented films can be obtained only in a small area and (ii) the crystallite c-axis of in the films is radially oriented in the substrate plane. To resolve these problems, the sputtering deposition technique using a linear cathode has been proposed. The in-plane and out-of-plane orientations of the films were quantitatively determined by pole figure analysis. As a result, we have demonstrated the formation of in-plane unidirectionally oriented (11 (2) over bar0) ZnO films over the entire area of 4-in. silicon wafers. (C) 2010 The Japan Society of Applied Physics

    DOI

  • Anisotropy of Longitudinal Wave Velocity and Hydroxyapatite Orientation in Bovine Cortical Bone

    Yuichiro Yaoi, Kazufumi Yamamoto, Tomohiro Nakatsuji, Takahiko Yanagitani, Mami Matsukawa, Kaoru Yamazaki, Akira Nagano

    JAPANESE JOURNAL OF APPLIED PHYSICS   48 ( 7 ) 07GK06-1 - 07GK06-4  2009.07  [Refereed]

     View Summary

    The anisotropy of longitudinal wave velocity and the hydroxyapatite (HAp) crystallite orientation in bovine cortical bone were experimentally investigated in detail. A ring-shaped cortical bone sample was obtained from the midshaft of a 32-month-old bovine femur. Four cylindrical specimens (diameter 11 mm) were taken from the ring-shaped cortical bone specimen along the radial direction. Velocity was measured by a conventional ultrasonic pulse system, by rotating the specimen in the axial-tangential plane. The direction of the fastest wave velocity observed was inclined 5-10 degrees, from the axial direction. The HAp crystallite orientation in the specimen was also investigated by X-ray diffraction pole-figure analysis. We observed a strong intensive peak of (0002), indicating HAp crystallite c-axis alignment along the bone axis. However, the pole-figure also revealed a small tilt in the HAp crystallite orientation from the axial direction. Comparing the velocity and X-ray diffraction peak at each angle of the axial-tangential plane, a significant correlation between the velocity and the HAp orientation was observed. (C) 2009 The Japan Society of Applied Physics

    DOI

  • 「Brillouin散乱法による圧電半導体の面内方向抵抗率評価に関する検討」

    柳谷隆彦, 吉田泰祐, 佐野 広幸, 松川真美

    超音波テクノ(日本工業出版)   21   35 - 38  2009

  • Multilayered shear wave resonator consisting of c-axis tilted ZnO films

    Naoki Morisato, Shinji Takayanagi, Takahiko Yanagitani, Mami Matsukawa, Yoshiaki Watanabe

    Proceedings - IEEE Ultrasonics Symposium     2162 - 2165  2009  [Refereed]

     View Summary

    Multilayer resonator consisting of six layered ZnO films was fabricated using RF magnetron sputtering. To prevent degradation of crystalline orientation, SiO2 buffer layers were inserted between each ZnO layer. The influences of the method for SiO2 deposition on the crystalline orientation also have been investigated. Crystalline orientation of the c-axis tilted ZnO films were confirmed by XRD pole figure analysis and SEM images. In the sixth order mode shear mode resonant frequency, high efficient shear mode excitation with relatively suppressed extensional mode excitation was observed. More extensional mode suppression is expected by increasing the number of the layer. ©2009 IEEE.

    DOI

  • Measurement of electric properties in a ZnO single crystal via electromechanical coupling using Brillouin scattering method

    Takahiko Yanagitani, Hiroyuki Sano, Mami Matsukawa

    Proceedings - IEEE Ultrasonics Symposium     1074 - 1077  2009  [Refereed]

     View Summary

    In-plane directional electric property measurement in the semiconductors via electromechanical coupling is proposed. To estimate the properties in the crystal with less than 1 Ω·m (which is general value in intrinsic wide band-gap semiconductors), in-plane directional GHz bulk acoustic wave velocities and attenuations in a ZnO crystal have been theoretically and experimentally investigated, using Brillouin scattering method. Distribution of electric properties in the crystal, also separately measured by the electrode, has been clearly detected by the acoustic velocity distribution measurement. ©2009 IEEE.

    DOI

  • Distribution of longitudinal wave velocity and hydroxyapatite crystallite orientation in bovine cortical bone

    Yuichiro Yaoi, Kazufumi Yamamoto, Yu Yamato, Takahiko Yanagitani, Mami Matsukawa, Kaoru Yamazaki, Akira Nagano

    Acoustical Science and Technology   30 ( 4 ) 306 - 309  2009  [Refereed]

     View Summary

    The relationship between the ultrasonic wave velocity and the preferred orientation of HAp crystallites in bovine cortical bones was investigated. The distribution of velocity in the bone axis direction was measured considering the micro-structure and BMD. Cortical bones of four bovine left femurs were used and ring-shaped cortical bone specimens from the middle shaft were obtained. An ultrasonic pulse-echo method was used for the measurement of the longitudinal wave velocity. A pair of wideband self-made polyvinylidene fluoride (PVDF) transducers were used. The received signal was changed into the electric pulse signal, and amplified by a 40 dB preamplifier. Finally, the waveform of the signal was observed using a digital oscilloscope. A significant correlation between the velocity and the preferred orientation of HAp crystallites was observed in the bone with a plexiform structure.

    DOI

  • Propagation Characteristics of Shear Horizontal Surface Acoustic Waves in (11(2)over-bar0) ZnO Film/Silica Glass Substrate Structures

    Atsushi Tanaka, Takahiko Yanagitani, Marni Matsukawa, Yoshiak Watanabe

    IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL   55 ( 12 ) 2709 - 2713  2008.12  [Refereed]

     View Summary

    This paper presents the propagation characteristics of the shear horizontal surface acoustic wave (SH-SAW) in ZnO (0 degrees, 90 degrees, psi) (11 (2) over bar0) textured ZnO films. ZnO (0 degrees, 90 degrees, 0 degrees) film/interdigital transducer (IDT) electrode/silica glass substrate structures were fabricated by RF magnetron sputtering. Experimental results demonstrate that SH-SAW was clearly excited in these structures. We also theoretically estimated the electromechanical coupling coefficient K-2 in the ZnO (0 degrees, 90 degrees, psi) film/silica glass substrate structure. The theoretical results show that the IDT electrode/ZnO (0 degrees, 90 degrees, 55 degrees) film/silica glass substrate structure had a relatively high K-2 value of 3.4%. Moreover, the shear horizontal displacement component of the SH-SAW in this structure is much larger than the transverse and longitudinal displacement components. This structure could be used in SH-SAW sensors for evaluating the electrical properties of liquids.

    DOI

  • Distribution of hydroxyapatite crystallite orientation and ultrasonic wave velocity in ring-shaped cortical bone of bovine femur

    Yu Yamato, Mami Matsukawa, Hirofumi Mizukawa, Takahiko Yanagitani, Kaoru Yamazaki, Akira Nagano

    IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL   55 ( 6 ) 1298 - 1303  2008.06  [Refereed]

     View Summary

    At the nanoscopic level, bone consists of calcium phosphate, which forms incomplete hydroxyapatite (HAp) crystals. The preferred orientation of the c-axis of HAp crystallites induces anisotropy and inhomogeneity of elastic properties in bone. In this study, the effect of the preferred orientation of HAp crystallites on the spatial distribution of ultrasonic wave velocity was experimentally investigated, considering bone mineral density (BMD) and microstructure. Three ring-shaped cortical bone samples were made from a 36-month-old bovine femur. Longitudinal wave velocity was measured by a conventional ultrasonic pulse system, using self-made polyvinylidene fluoride transducers. The integrated intensity of the (0002) peak obtained using X-ray diffraction was estimated to evaluate the amount of preferred orientation. The velocity distribution pattern was similar to the distribution of integrated intensity of (0002). The effect of the preferred orientation of HAp crystallites on velocity was clearly observed in the plexiform structure, despite the fact that the BMD value was almost independent of the preferred orientation of HAp crystallites. Velocity measurement of cortical bone can reveal information about HAp crystallite orientation.

    DOI

  • Ultrasonic Wave Properties in Bone Axis Direction of Bovine Cortical Bone

    Kazufumi Yamamoto, Yuichiro Yaoi, Yu Yamato, Takahiko Yanagitan, Mami Matsukawa, Kaoru Yamazaki

    JAPANESE JOURNAL OF APPLIED PHYSICS   47 ( 5 ) 4096 - 4100  2008.05  [Refereed]

     View Summary

    Quantitative ultrasonography (QUS) is it good method for measuring elastic properties of bone in vivo. Bovine cortical bone has two typical microstructures, plexiform and Haversian. In this study, the relationship between the speed of sound (SOS) and the hydroxyapatite (HAp) crystallite orientation in the axial direction was investigated in two different aged bovine cortical bones. The dependence of attenuation oil anatomical position was also investigated. Two ring-permanent hyphen shaped cortical bone samples were obtained from 36- and 24-month-old bovine femurs. SOS was Measured with a conventional ultrasonic pulse system. The integrated intensity of the (0002) peak obtained by X-ray diffraction was determine to evaluate the amount of preferred orientation. Regardless of the age of the bovine femurs, a significant correlation between SOS and the preferred orientation of HAp crystallites was observed in parts of the plexiform structure, and the gradient of the relationship showed a similar tendency. Attenuation seemed to depend oil bone microstructure.. [DOI: 10.1143/JJAP.47.4096]

    DOI

  • 「c軸傾斜配向ZnO膜の開発〜高い横波変換効率の実現〜」

    松尾卓也, 柳谷隆彦, 松川真美, 渡辺好章

    超音波テクノ(日本工業出版)   20   75 - 78  2008

  • 「イオン照射によるZnO圧電膜の配向制御に関する検討」

    柳谷隆彦, 木内正人

    超音波テクノ(日本工業出版)   20   67 - 70  2008

  • Pure-shear mode BAW resonators consisting of (11-20) textured ZnO films,”

    T. Yanagitani, M. Kiuch, M. Matsukawa, Y. Watanabe

    Acoustics 08 Paris     4987 - 4992  2008  [Refereed]

  • “Electromechanical coupling coefficient of semiconducting hexagonal crystal measured by Brillouin scattering,”

    T. Yanagitani, Y. Yoshida, M. Matsukawa

    Proc. IEEE Ultrason. Symp.     1487 - 1490  2008  [Refereed]

    DOI

  • Pure-shear mode BAW resonator consisting of (112̄0) textured AlN films

    Takahiko Yanagitani, Masato Kiuch

    Proceedings - IEEE Ultrasonics Symposium     90 - 93  2008  [Refereed]

     View Summary

    In-plane and out-of-plane oriented (11 2̄ 0) textured thin films are attractive for shear mode piezoelectric devices sensors, such as FBAR and SH-SAW devices. It is proposed that highly oriented (11 2̄0) AlN thin films can be fabricated ion beam sputter-deposition system with grazing incidence the substrate surface. Full-width-at-half-maximum (FWHM) values of the ∞-scan rocking curve and φ-scan profile curves of (11 22) X-ray diffraction poles were measured to be 4.6° and 23°, respectively. Shear-mode high-overtone acoustic resonator (HBAR) with (11 ̄0) textured AlN film excited pure-shear wave any longitudinal wave excitation. New device structure is because this film can be deposited on various substrates curved surfaces. ©2008 IEEE.

    DOI

  • “Effect of hydroxyapatite crystallites orientation on ultrasonic wave velocities in bovine cortical bone,”

    Y. Yamato, M. Matsukawa, K. Yamazaki, H. Mizukawa, T. Yanagitani, A. Nagano

    Calcif. Tissue. Int.   82 ( 2 ) 162 - 169  2008  [Refereed]

    DOI

  • Highly oriented ZnO thin films deposited by grazing ion-beam sputtering: Application to acoustic shear wave excitation in the GHz range

    Takahiko Yanagitani, Masato Muchi

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS   46 ( 45-49 ) L1167 - L1169  2007.12  [Refereed]

     View Summary

    In-plane and out-of-plane oriented (11 (2) over bar 0) ZnO thin films are attractive for acoustic shear wave excitation in the GHz range. In this study it is proposed that highly oriented and submicron-thick (11 (2) over bar 0) ZnO thin films can be fabricated using an ion beam sputter-deposition system with grazing incidence to the substrate surface.The formation of the (I 1 0) textu.re cannot only. be attributed to the well-known i on-channeling effect or to the self-shadowing effect since the ion beam incidence direction in the system does not correspond to the ion-channeling direction of the ZnO film (the [10 (1) over bar0] or [11 (2) over bar 0] direction). The full width at half-maximum (FWHM) values of the phi- and Psi-scan profile curves of the (11 (2) over bar2) X-ray diffraction poles were measured to be 5 and 28 degrees, respectively. A shear-wave transducer with a 0.9-ltm-thick film exhibited a one-way conversion loss of less than 20 dB at 1-2 GHz and a 3 dB fractional bandwidth of 100%, without any longitudinal wave excitation.

    DOI

  • Characteristics of pure-shear mode BAW resonators consisting of (11(2)over-bar0) textured ZnO films

    Takahiko Yanagitani, Masato Kiuchi, Mami Matsukawa, Yoshiaki Watanabe

    IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL   54 ( 8 ) 1680 - 1686  2007.08  [Refereed]

     View Summary

    Thickness pure-shear mode film bulk acoustic wave resonators (FBARs) made of (11 (2) over bar0) textured ZnO films have been fabricated. We also have fabricated FBAR structure consisting of two layers of the (11 (2) over bar0) textured ZnO film with opposite polarization directions. This FBAR structure operated in second overtone pure-shear mode and allowed shear-mode FBARs at higher frequency. The effective electromechanical coupling coefficients k(eff)(2) of pure- shear mode FBAR and second overtone pure-shear mode FBAR in this study were found to be 3.3% and 0.8%, respectively. The temperature coefficient of frequency (TCF) of thickness extensional mode FBAR, pure-shear mode FBAR, and second overtone pure-shear mode FBAR were measured in the temperature range of 10-60 degrees C. TCF values of -63.1 ppm/degrees C, -34.7 ppm/degrees C, and -35.6 ppm/degrees C were found for the thickness extensional mode FBAR, the pure-shear mode FBAR, and the second overtone pure-shear mode FBAR, respectively. These results demonstrated that pure-shear mode ZnO FBARs have more stable temperature characteristics than the conventional thickness extensional mode ZnO FBARs.

    DOI

  • Control of in-plane and out-of-plane texture in shear mode piezoelectric ZnO films by ion-beam irradiation

    Takahiko Yanagitani, Masato Kiuchi

    JOURNAL OF APPLIED PHYSICS   102 ( 4 ) 044115-1 - 044115-7  2007.08  [Refereed]

     View Summary

    ZnO polycrystalline films have a strong tendency to grow their c-axis perpendicular to the film surface, even on an amorphous substrate. However, unusual (10 $(1) over bar $0) preferred orientations in which the c-axis lies in the substrate plane are often observed when the film is exposed to ion irradiation during its growth. To investigate the effect of ion irradiation on the (10 $(1) over bar $0) preferred orientation, ZnO films were fabricated using a 0-1 keV oxygen ion-beam-assisted electron-beam evaporation of zinc. The results clearly indicated that the tendency of (10 $(1) over bar $0) preferred orientation was enhanced with increasing ion energy and amount of ion irradiation. This demonstrated that the ion bombardment induced the (0001) preferred orientation to change into a (10 $(1) over bar $0) preferred orientation which corresponds to the ion channeling direction. An in-plane preferred orientation was also obtained, probably because of deviations in the incident ion-beam direction from 5 degrees to the substrate surface normal. These in-plane textured (10 $(1) over bar $0) ZnO films, fabricated under the ion-beam irradiation of 0.5-1 keV, excited a shear acoustic wave without any longitudinal wave. The highest shear mode electromechanical coupling coefficient was found to be k(15)=0.16 in the film with ion-beam irradiation of 1 keV. This k(15) value corresponds to 60% of that in a ZnO single crystal (k(15)=0.26). (c) 2007 American Institute of Physics.

    DOI

  • Observation of induced shear acoustic phonons by brillouin scattering

    Shigeo Murata, Takayuki Kawamoto, Mami Matsukawa, Takahiko Yanagitani, Norikazu Ohtor

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS   46 ( 7B ) 4626 - 4628  2007.07  [Refereed]

     View Summary

    As the first step in realizing the simple and nondestructive measurement of shear waves in the GHz range, a technique involving Brillouin scattering and a ZnO shear wave transducer is proposed. Making use of transmitted shear waves, we have succeeded in observing a strong Stokes Brillouin peak in the quartz sample. This technique can be applied to the measurement of anisotropic layers and small samples.

    DOI

  • Effects of sputtering gas conditions on formation of (11(2)over-bar0) textured ZnO films

    Takayuki Kawamoto, Takahiko Yanagitani, Mami Matsukawa, Yoshiaki Watanabe

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS   46 ( 7B ) 4660 - 4664  2007.07  [Refereed]

     View Summary

    The ZnO films in which the crystallite c-axis is unidirectionally aligned in the substrate plane [(1120) textured ZnO films] enable the realization of shear mode devices in the ultra high frequency (UHF) range. In this study, we have investigated the (1120) textured ZnO film, focusing on the effect of total gas pressure and partial gas pressure of oxygen and argon during sputtering deposition. The crystallographic characteristics of the films were measured by X-ray diffraction (XRD) analysis. In addition, optical emissions from the RF plasma were analyzed to investigate the effect of ionic species on the growth of the ZnO films. Highly crystallized (1120) textured ZnO films were obtained under the conditions of low total gas pressure and high oxygen gas concentration. Under these conditions, strong optical emission spectra from oxygen species were observed. From these results, we conclude that energetic oxygen particle bombardment to the substrate contributes to the (1120) texture formation. The film with an omega-scan rocking curve FWHM of 3.3 degrees showed a k(15) value of 0.16, which was 62% of the value for a single crystal.

    DOI

  • Shear mode electromechanical coupling coefficient k(15) and crystallites alignment of (11(2)over-bar0) textured ZnO films

    Takahiko Yanagitani, Masato Kiuchi, Mami Matsukawa, Yoshiaki Watanabe

    JOURNAL OF APPLIED PHYSICS   102 ( 2 ) 024110-1 - 024110-7  2007.07  [Refereed]

     View Summary

    ZnO film, in which the crystallite c axis lies in the substrate plane [(11 (2) over bar0) textured ZnO], is a good candidate for application in shear mode piezoelectric devices. The relationships between the degree of crystallites alignment and the shear mode electromechanical coupling coefficient k(15) in (11 (2) over bar0) textured ZnO films have been investigated. Forty pure-shear mode high overtone bulk acoustic resonators consisting of the (11 (2) over bar0) textured ZnO film were prepared. The film was varied in crystallites alignment and film thickness. The degrees of crystallites alignment of the films were determined by x-ray pole figure analysis. The k(15) values of the films were estimated from the conversion loss characteristics of the resonators. A significant correlation was observed between dispersion of the x-ray poles and the k(15) values. However, the k(15) values in the thinner films were clearly reduced as compared with those in the thicker films despite their similarities in crystallites alignment. In addition, unexpected second harmonic mode resonance was detected in the thinner films. We concluded that the piezoelectrically inactive layer in the initial film growth deteriorated the k(15) value in thinner films. (c) 2007 American Institute of Physics.

    DOI

  • Electromechanical coupling coefficient k(15) of polycrystalline ZnO films with the c-axes lie in the substrate plane

    Takahiko Yanagitani, Natsuki Mishima, Mami Matsukawa, Yoshiaki Watanabe

    IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL   54 ( 4 ) 701 - 704  2007.04  [Refereed]

     View Summary

    The (1120) textured polycrystalline ZnO films with a high shear mode electromechanical coupling coefficient k(15) are obtained by sputter deposition. An overmoded resonator, a layered structure of metal electrode film/(1120) textured ZnO piezoelectric film/metal electrode film/silica glass substrate was used to characterize k(15) by a resonant spectrum method. The (1120) textured ZnO piezoelectric films with excellent crystallite c-axis alignment showed an electromechanical coupling coefficient k(15) of 0.24. This value was 92% of k15 value in single-crystal (k(15) = 0.26).

    DOI

  • 「面内配向ZnO膜のSH型SAW伝搬特性」

    田中厚志, 柳谷隆彦, 松川真美, 渡辺好章

    超音波テクノ(日本工業出版)   19  2007

  • Propagation characteristics of SH-SAW in (11(2)over-bar0) ZnO layer/silica glass substrate structures

    Atsushi Tanaka, Takahiko Yanagitani, Mami Matsukawa, Watanabe Yoshiaki

    2007 IEEE ULTRASONICS SYMPOSIUM PROCEEDINGS, VOLS 1-6     280 - +  2007  [Refereed]

     View Summary

    A (11 (2) over bar0) textured ZnO film can excite SH-SAW. Therefore, the film on various substrates is an attractive option for fabricating the SH-SAW device on a silicon IC, and the device on a curved surface. In this report, the electromechanical coupling coefficients (K-2) in the ZnO (0 degrees, 90 degrees, psi) film/silica glass substrate structures were theoretically estimated. The theoretical results showed that the IDT electrode/ZnO (0 degrees, 90 degrees, 55 degrees) film/sil.ica glass substrate structure had a relatively large K-2 value of 3.4% at H/lambda=0.21. This structure was then fabricated using RF magnetron sputtering technique. The experimental results clearly demonstrated SH-SAW excitation in the structure.

    DOI

  • Highly oriented c-axis 23° tilted ZnO films with high quasi-shear mode electromechanical coupling coefficients

    Takuya Matsuo, Takahiko Yanagitani, Mami Matsukawa, Yoshiaki Watanabe

    Proceedings - IEEE Ultrasonics Symposium     1229 - 1232  2007  [Refereed]

     View Summary

    A quasi-shear mode piezoelectric film with high electromechanical coupling coefficient k'15 is attractive for shear wave transducers, shear mode FBAR and SH-SAW devices. The single crystalline ideal ZnO film with c-axis-tilt angle of 28° from the surface normal of the film has high k'15 value of 0.38. In this study, we have investigated c-axis-tilted ZnO films to obtain sufficient tilt angle and good crystalline alignment using RF magnetron sputtering technique. We focused on the angle between the substrate surface and target surface during the sputtering deposition. In case that the film was deposited on the substrate set at 90° to the target surface, relatively large c-axis tilted angles of 22.6°-26.2° were obtained. Moreover, small ψ-scan FWHM values from 6.7° to 7.8° of the film indicated good crystalline alignment. Finally, k'15 value of this film was estimated as 0.26, which was the highest value ever reported for c-axis-tilted ZnO or AlN films. © 2007 IEEE.

    DOI

  • Ion beam sputter-deposited ZnO thin film for broadband shear wave excitation in the GHz range

    Takahiko Yanagitani, Masato Much

    2007 IEEE ULTRASONICS SYMPOSIUM PROCEEDINGS, VOLS 1-6     1413 - +  2007  [Refereed]

     View Summary

    In-plane and out-of-plane oriented (11 (2) over bar0) ZnO thin films are attractive for shear wave excitation in the GHz range. It Is proposed here that highly oriented and submicron-thick (11 (2) over bar0) ZnO thin films can be fabricated using ion beam sputter-deposition system with grazing incidence to the substrate surface. This (11 (2) over bar0) texture formation cannot only be attributed to the well-known Ion channeling effect or to the self-shadowing effect since the Ion beam Incidence direction In the system does not correspond to the ion channeling direction of the ZnO film (the [10 (1) over bar0] or [11 (2) over bar0] direction). Full-width-at-half-maximum (FWHM) values of the phi-scan and psi-scan profile curves of the (11 (2) over bar2) X-ray diffraction poles were measured to be 5 degrees and 28 degrees, respectively. A shear-wave transducer with a 0.9-mu m-thick film exhibited an untuned one-way conversion loss of less than 20 dB at 1 - 2 GHz and a 3dB-fractional bandwidth of 100%, without any longitudinal wave excitation.

    DOI

  • Thin film stack transducer for simultaneous generation of longitudinal and shear waves at same frequency

    Takahiko Yanagitani, Takuya Matsuo, Mami Matsukawa, Watanabe Yoshiaki

    2007 IEEE ULTRASONICS SYMPOSIUM PROCEEDINGS, VOLS 1-6     1874 - +  2007  [Refereed]

     View Summary

    It is difficult to generate longitudinal and shear bulk waves simultaneously at same frequency. In this study, we propose new film stack transducer structure consisting of two layers of c-axis 23 degrees-tilted ZnO films. The upper layer and lower layer in the stack have same thicknesses, and the c-axis tilt direction in the both layers are symmetric with respect to the film surface normal. This film stack transducers were fabricated on silica glass substrate by using RF magnetron sputtering technique. Crystallographic properties of the transducer were determined by XRD pole figure analysis. Detailed conversion loss characteristics of the transducer were also discussed. Simultaneous generation of both waves at same frequency was then experimentally demonstrated in the VHF range. We also included thin film fabrication technique for obtaining two layers of c-axis-tilted ZnO films with good crystalline orientation.

    DOI

  • “Film growth of c-axis tilted ScAlN on the sapphire substrate for SAW devices,”

    S. Tokuda, S. Takayanagi, M. Matsukawa, T. Yanagitani

    Proc. IEEE Ultrason. Symp.     1 - 4  2007  [Refereed]

  • “The frequency wwitchable multi-layered BST/BaTiO3 epitaxial film resonator,”

    S. Takayanagi, M. Matsukawa, T. Yanagitani

    Proc. IEEE Ultrason. Symp.     1 - 4  2007  [Refereed]

  • “High electromechanical coefficient kt 2=19% thick ScAlN piezoelectric films for ultrasonic transducer in low frequency of 80 MHz,”

    K-h. Sano, R. Karasawa, T. Yanagitani

    Proc. IEEE Ultrason. Symp.     1 - 4  2007  [Refereed]

  • “A new type wide-frequency-range shear viscosity sensor using caxis tilted ScAlN thin film on temperature Stable AT-cut quartz thick plate,”

    Y. Yamakawa, K-h. Sano, R. Karasawa, T. Yanagitani

    Proc. IEEE Ultrason. Symp.     1 - 4  2007  [Refereed]

  • “C-axis zig-zag polarization inverted ScAlN multilayer for FBAR transformer rectifying antenna,”

    R. Karasawa, T. Yanagitani

    Proc. IEEE Ultrason. Symp.     1 - 4  2007  [Refereed]

  • Temperature characteristics of pure shear mode FBARs consisting of (112̄0) textured ZnO films

    Takahiko Yanagitani, Masato Kiuchi, Mami Matsukawa, Yoshiaki Watanabe

    Proceedings - IEEE Ultrasonics Symposium   1   1459 - 1462  2006  [Refereed]

     View Summary

    Thickness extensional mode FBAR consisting of (0001) textured ZnO films and pure thickness shear mode FBAR consisting of (112̄0) textured ZnO films were fabricated. Temperature coefficients of frequency (TCF) of these FBARs were measured in the temperature range of 10-60 °C. In both of the resonators, the parallel resonant frequencies varied linearly with temperature. The TCF were determined as -63.1 [ppm/°C] for thickness extensional mode resonator and -34.7 [ppm/°C] for pure-shear mode resonator. © 2006 IEEE.

    DOI

  • “Electromechanical coupling coefficient k15 and crystallites alignment of (11-20) textured ZnO film,”

    T. Yanagitani, M. Kiuchi, M. Matsukawa, Y. Watanabe

    Proc. IEEE Ultrason. Symp.     1463 - 1466  2006  [Refereed]

  • “Rapid and simultaneous measurement of longitudinal and shear wave velocities by Brillouin scattering from artificially induced phonons,”

    M. Kawabe, Y. Shibagaki, M. Matsukawa, T. Yanagitani, M. Suzuki, S .Takayanagi

    Proc. IEEE Ultrason. Symp.     1 - 4  2006  [Refereed]

    DOI

  • “Effects of energetic negative ions generated from sputtering targets on ScAlN film growth,”

    S. Takayanagi, M. Matsukawa, T. Yanagitani

    Proc. IEEE Ultrason. Symp.     1 - 4  2006  [Refereed]

    DOI

  • Effect of sputtering geometry on (112̄0) textured ZnO piezofilm

    Yoshinori Miyamoto, Takahiko Yanagitani, Mami Matsukawa, Yoshiaki Watanabe

    Acoustical Science and Technology   27 ( 1 ) 53 - 55  2006  [Refereed]

     View Summary

    The effects of sputtering geometry on (112̄0) textured ZnO piezofilm were analyzed. The ZnO film was fabricated using a conventional RF magnetron sputtering apparatus. The crystallite alignment in the substrate normal direction was estimated using the full width half maximum (FWHM) of the ω-scan rocking curve. The results show that crystallites alignment and film thickness are strongly affected by the substrate position, despite that the other sputtering conditions are identical.

    DOI

  • “Conversion characteristics of the shear wave transducer made of unidirectionally aligned ZnO film in plane,”

    T. Nohara, T. Yanagitani, M. Matsukawa, Y. Watanabe

    Jpn. J. Appl. Phys.   45   4201 - 4203  2006  [Refereed]

    DOI

  • Characteristics of (10(1)over-bar1) and (11(2)over-bar0) textured ZnO piezofilms for a shear mode resonator in the VHF-UHF frequency ranges

    T Yanagitani, T Nohara, M Matsukawa, Y Watanabe, T Otani

    IEEE TRANSACTIONS ON ULTRASONICS FERROELECTRICS AND FREQUENCY CONTROL   52 ( 11 ) 2140 - 2145  2005.11  [Refereed]

     View Summary

    This paper reports the fabrication and characterization of ZnO piezoelectric thin films in which the crystallite c-axis is unidirectionally aligned in the plane. The films were deposited by a conventional radio frequency (RF) magnetron sputtering apparatus without epitaxy. We have measured reflection coefficient S-11 of the ZnO film/glass substrate composite shear mode resonator and confirmed that the resonator excites shear wave only in the very high frequency to ultra high frequency ranges (VHF-UHF). The crystallites c-axis orientation and alignment were determined by x-ray diffraction (XRD) patterns, phi-scan pole figure analysis, w-scan rocking curves, and atomic force microscope (AFM) measurement. The transduction of the shear wave showed good agreement with properties of the crystallite alignment in the film.

    DOI

  • Formation of uniaxially (1120) textured ZnO films on glass substrates

    T Yanagitani, M Matsukawa, Y Watanabe, T Otani

    JOURNAL OF CRYSTAL GROWTH   276 ( 3-4 ) 424 - 430  2005.04  [Refereed]

     View Summary

    Making use of the RF magnetron sputtering technique, we have succeeded in fabricating ZnO films where c-axis of crystallites are unidirectionally aligned in the plane, without the mechanism of epitaxy. The alignment of c-axis in the plane was then carefully investigated by the X-ray pole figure analysis and atomic force microscope measurements. From these results, we have revealed the effect of substrate position during sputtering on the c-axis alignment in the plane. We have also pointed out the important effect of the oxygen ions in the RF plasma on the (1 12 0) texture formation. (c) 2004 Elsevier B.V. All rights reserved.

    DOI

  • Electromechanical coupling coefficient k(15) of (11(2)over-bar0) textured ZnO films

    T Yanagitani, N Mishima, M Matsukawa, Y Watanabe

    2005 IEEE Ultrasonics Symposium, Vols 1-4     1824 - 1827  2005  [Refereed]

     View Summary

    The ZnO film, whose crystallites c-axis align parallel to the substrate plane [(1120) textured ZnO films], has many potential advantages as shear-mode piezoelectric devices. In this study, shear mode electromechanical coupling coefficient k(15) of (1120) textured polycrystalline ZnO films was estimated. An over-moded resonator consists of metal electrode film/(1120) textured ZnO piezoelectric film / metal electrode film/silica glass substrate was used to characterize k(15) by a resonant spectrum method. For example, the (1120) textured ZnO piezoelectric films with good crystallite alignment show an electromechanical coupling coefficient k(15) of 0.24 which is 92% of the value of single-crystalline (k(15) = 0.26).

    DOI

  • “Fast wave velocity measurement by Brillouin scattering using coherent induced phonon from ScAlN piezoelectric thin film,”

    M. Kawabe, H. Ichihashi, S. Takayanagi, M. Matsukawa, T. Yanagitani

    Proc. IEEE Ultrason. Symp.    2005  [Refereed]

  • “Shear mode properties of c-axis parallel oriented ScxAl1-xN films grown by RF bias sputtering,”

    S. Takayanagi, M. Matsukawa, T. Yanagitani

    Proc. IEEE Ultrason. Symp.    2005  [Refereed]

  • Characterization of (1120) textured ZnO films fabricated by RF magnetron sputtering

    T Yanagitani, S Tomohiro, T Nohara, M Matsukawa, Y Watanabe, T Otani

    JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS   43 ( 5B ) 3004 - 3007  2004.05  [Refereed]

     View Summary

    Using a conventional RF magnetron sputtering system, we have obtained two types of ZnO films on various kinds of substrate. One is a film with the c-axes of crystallites unidirectionally aligned in the substrate plane {(11 (2) over bar0) textured film}. The other is a film with c-axes parallel and perpendicular to the plane (mixed texture film). The former is expected to realize a shear wave transducer on the surfaces of various materials. The alignment of c-axes of crystallites in the plane was then carefully investigated by the X-ray pole figure analysis. The elastic anisotropy in the film has been successfully measured by the Brillouin scattering method. The (11 (2) over bar0) textured film did not excite the elastic waves; however, comparatively strong shear waves were actually excited by the mixed texture film.

    DOI

  • “Shear wave transducer using (11-20) textured ZnO film,”

    T. Yanagitani, T. Nohara, M. Matsukawa, Y. Watanabe, T. Otani

    Proc. IEEE Ultrason. Symp.     906 - 909  2004  [Refereed]

▼display all

Books and Other Publications

  • 次世代医療・ヘルスケア機器のデバイス技術と最新開発事例集

    技術情報協会  2014.05

  • 次世代医療・ヘルスケア機器のデバイス技術と最新開発事例集

    技術情報協会  2014.05

  • Acoustic Waves - From Microdevices to Helioseismology Chapter 22 Shear Mode Piezoelectric Thin Film Resonators pp.501-520

    Intech  2011.10 ISBN: 9789533075723

Misc

  • AlNとScAlNにおける非線形性に起因するDCバイアス時の周波数シフトおよび格子ひずみの比較

    五月女巧, 柳谷隆彦

    電子情報通信学会技術研究報告   120 ( 222 ) 34 - 39  2020

  • 低圧スパッタ成膜で増大する負イオン照射がScAlN薄膜の結晶性と圧電性に及ぼす影響

    冨永卓海, 髙柳真司, 柳谷隆彦

    電子情報通信学会技術研究報告   120 ( 222 ) 1 - 6  2020

  • ZnO薄膜を用いた厚みすべりモード共振子の作製と液体負荷時の周波数特性

    宮田昌哉, 高柳真司, 松川真美, 柳谷隆彦

    電子情報通信学会技術研究報告   119   33 - 37  2019

  • 擬似すべりモードc軸傾斜配向ScAlN圧電薄膜を用いた複素反射率法による液体試料の粘弾性評価

    天野凌輔, 山川愉生, 柳谷隆彦

    電子情報通信学会技術研究報告   119   19 - 23  2019

  • 「周波数スイッチナブルフィルタを目指した常誘電相PMN-PT/強誘電相PZT分極反転エピ膜音響共振子」

    清水貴博, 柳谷隆彦

    電子情報通信学会技術研究報告vol. 118, no. 48, pp. 29-34 (2018).   118 ( 48 ) 29 - 34  2018

  • 「レクテナ昇圧素子への応用を目指したc軸ジグザグ配向ScAlN多層圧電薄膜共振子」

    唐澤嶺, 柳谷隆彦

    電子情報通信学会技術研究報告vol. 118, no. 48, pp. 23-27 (2018).   118 ( 48 ) 23 - 27  2018  [Refereed]

  • 「c軸傾斜配向厚みすべりモードScAlN薄膜共振子を用いた液体中生体分子相互作用の検出」

    矢崎花, 五月女巧, 唐澤嶺, 高柳真司, 吉田憲司, 柳谷隆彦

    電子情報通信学会技術研究報告vol. 118, no. 229, US2018-53, pp. 31-35 (2018).   118 ( 229 ) 31 - 35  2018  [Refereed]

  • 「c軸傾斜配向ScAlN薄膜/音響多層膜構造の共振子を用いたUHF帯における液体粘性評価」

    山川愉生, 五月女巧, 唐澤嶺, 柳谷隆彦

    電子情報通信学会技術研究報告vol. 118, no. 229, US2018-53, pp. 25-29 (2018).   118 ( 229 ) 25 - 29  2018  [Refereed]

  • 「基板付き薄膜共振子からの新規kt2評価法と従来法の比較 〜 共振周波数比法、変換損失法、共振スペクトル法、共振反共振法 〜」

    戸塚誠, 柳谷隆彦

    電子情報通信学会技術研究報告vol. 118, no. 48, pp. 19-24 (2018).   118 ( 48 ) 19 - 24  2018  [Refereed]

  • 「分極反転PZT/PTOエピ膜を用いた周波数スイッチナブルなGHz帯共振子」

    清水貴博, 森剛志, 柳谷隆彦

    電子情報通信学会技術研究報告vol. 118, no. 229, US2018-53, pp. 13-18 (2018).   118 ( 229 ) 13 - 18  2018  [Refereed]

  • 「製法の異なるScAl合金スパッタターゲットから発生する負イオンがScAlN薄膜の特性に及ぼす影響 〜 電子ビーム溶融、アーク溶融、焼結ScAl合金ターゲットの比較 〜」

    唐澤嶺, 高柳真司, 遠藤結佳, 今川 誠, 森坂啓介, 鈴木 雄, 柳谷隆彦

    電子情報通信学会技術研究報告vol. 118, no. 229, US2018-53, pp. 37-42 (2018).   118 ( 229 ) 37 - 42  2018  [Refereed]

  • 「電気機械結合係数kt2=19%のScAlN厚膜を用いた低周波帯80MHzトランスデューサ」

    佐野耕平, 唐澤嶺, 柳谷隆彦

    電子情報通信学会技術研究報告vol. 117, no. 14, US2017-12, pp.59-63, (2017).   117 ( 14 ) 59 - 63  2017  [Refereed]

  • 「コヒーレントフォノン励起を用いたBrillouin散乱法による縦波・横波音速測定の高速化」

    川部昌彦, 柳谷隆彦, 柴垣慶明, 高柳真司, 鈴木雅視, 松川真美

    電子情報通信学会技術研究報告vol. 117, no. 155, US2017-44, pp. 71-74, (2017).   117 ( 155 ) 71 - 74  2017  [Refereed]

  • 「ScAlN薄膜/低TCF基板構造のすべりモード共振子を用いたMHz帯-GHz帯同時粘性評価」

    山川愉生, 佐野耕平, 唐澤嶺, 柳谷隆彦

    電子情報通信学会技術研究報告vol. 117, no. 155, US2017-42, pp. 61-66, (2017).   117 ( 155 ) 61 - 66  2017  [Refereed]

  • 「GHz帯で純横波超音波を高効率励振するc軸平行ZnO薄膜トランスデューサ」

    森剛志, 鈴木雅視, 柳谷隆彦

    電子情報通信学会技術研究報告vol. 116, no. 5, US3026-1, pp.7-12, (2016).   116 ( 5 ) 7 - 12  2016  [Refereed]

  • 「ScAlN/ZnO極性反転圧電薄膜を用いた2次モード励振超音波トランデューサ」

    森剛志, 鈴木雅視, 柳谷隆彦

    電子情報通信学会技術研究報告vol. 116, no. 5, US2016-1, pp.1-6, (2016).   116 ( 5 ) 1 - 6  2016  [Refereed]

  • 「Brillouin光散乱を用いたc軸配向薄膜の音速および常屈折率の同時測定」

    富田昇太, 柳谷隆彦, 鈴木雅視, 高柳真司, 松川真美

    電子情報通信学会技術研究報告vol. 115, no. 102, pp.23-28, (2015).   115 ( 102 ) 23 - 28  2015  [Refereed]

  • 「低圧RFマグネトロンスパッタ法によるc軸平行配向ZnO膜の形成とSAW、Lamb波デバイスへの応用」

    高柳真司, 柳谷隆彦, Jean-Claude Gerbedoen, Abdelkrim Talbi, 松川真美, Philippe Pernod

    電子情報通信学会技術研究報告vol. 115, no. 207, pp.25-30, (2015).   115 ( 207 ) 25 - 30  2015  [Refereed]

  • 「c軸平行配向ZnO膜/円管石英構造におけるSH波の多重周回伝搬特性と導電率測定への応用」

    日山彰子, 柳谷隆彦, 高柳真司, 松川真美

    電子情報通信学会技術研究報告vol. 115, no. 207, pp.19-24, (2015).   115 ( 207 ) 19 - 24  2015  [Refereed]

  • 「イオンビームアシストRFマグネトロンスパッタ法を用いて作製したc軸平行配向ScAlN薄膜の電気機械結合係数」

    岡峰生, 高柳真司, 柳谷隆彦, 松川真美

    電子情報通信学会技術研究報告vol. 115, no. 207, pp.31-35, (2015).   115 ( 207 ) 31 - 35  2015  [Refereed]

  • 「共振法およびBrillouin散乱法で測定したScAlN薄膜の弾性定数テンソルのSc濃度依存性」

    柳谷隆彦, 市橋隼人, 鈴木雅視, 高柳真司, 松川真美

    電子情報通信学会技術研究報告vol. 115, no. 207, pp.37-42, (2015).   115 ( 207 ) 37 - 42  2015  [Refereed]

  • 「走査型非線形誘電率顕微法による極性反転層状構造圧電膜の層厚の定量測定」

    趙恩慧, 川部昌彦, 高柳真司, 鈴木雅視, 柳谷隆彦, 松川真美

    電子情報通信学会技術研究報告vol. 115, no. 246, pp.27-30, (2015).   115 ( 246 ) 27 - 30  2015  [Refereed]

  • 「非破壊検査用の高分解能超音波プローブ」

    柳谷隆彦, 鈴木雅視, 高柳 真司

    日本音響学会誌   71 ( 5 ) 230 - 238  2015  [Refereed]

    DOI

  • 「超音波により励起される骨中電位の極性について」

    常田裕子, 松川沙弥果, 眞野功, 水野勝紀, 柳谷隆彦, 高柳真司, 松川真美

    電子情報通信学会技術研究報告vol. 114, no. 229, pp. 19-22, (2014).   114 ( 229 ) 19 - 22  2014  [Refereed]

  • 「PbTiO3エピタキシャル薄膜を用いた二次モード分極反転共振子」

    片田克吉, 柳谷隆彦, 鈴木雅視, 和佐清孝

    電子情報通信学会技術研究報告vol. 114, no. 263, pp. 29-34, (2014).   114 ( 263 ) 29 - 34  2014  [Refereed]

  • 「RFマグネトロンスパッタ法における基板へのイオン照射を用いた極性反転ZnO薄膜の作製」

    生駒遼, 柳谷隆彦, 高柳真司, 鈴木雅視, 小田川裕之, 松川真美

    電子情報通信学会技術研究報告vol. 112, no. 213, pp. 21-25, (2012).   112 ( 213 ) 21 - 25  2012  [Refereed]

  • 「ZnO圧電薄膜によるGHz域の励起フォノンを利用した高速Brillouin散乱測定」

    杉本剛士, 佐野広幸, 柳谷隆彦, 高柳真司

    電子情報通信学会技術研究報告 vol. 111, no. 158, pp. 15-19, (2011).   111 ( 158 ) 15 - 19  2011  [Refereed]

  • 「IBAD法を用いたc軸平行配向AlN薄膜の作製および極性反転すべり共振子への応用」

    鈴木雅視, 菅沼信広, 柳谷隆彦

    電子情報通信学会技術研究報告vol. 111, no. 215, pp. 43-48 (2011)   111 ( 215 ) 43 - 48  2011  [Refereed]

  • 「c軸平行配向ZnO膜/非晶質基板上を伝搬するSH-SAWの電気機械結合係数」

    中東佑太, 柳谷隆彦, 松川真美, 渡辺好章

    電子情報通信学会技術研究報告vol. 111, no. 215, pp. 23-26 (2011).   111 ( 215 ) 23 - 26  2011  [Refereed]

  • 「c軸傾斜配向ScAlN膜の擬似すべりモードにおける巨大圧電性」

    柳谷隆彦, 荒川和樹, 鈴木雅視, 加納一彦, 勅使河原明彦, 秋山守人

    電子情報通信学会技術研究報告 vol. 110, no. 213, pp. 81-86, (2010).   110 ( 213 ) 81 - 86  2010  [Refereed]

  • 「ウシ左右大腿骨皮質骨中の特徴的な3次元音速異方性 〜 最大音速方向の骨軸からのずれについて 〜」

    中辻知宏, 山本和史, 高柳真司, 柳谷隆彦, 松川真美, 山崎薫

    電子情報通信学会技術研究報告vol. 110, no. 213, pp. 63-68, (2010).   110 ( 213 ) 63 - 68  2010  [Refereed]

  • 「Brillouin散乱法による同軸共振器と圧電薄膜を用いた励起フォノンの観測」

    佐野広幸, 柳谷隆彦, 高柳真司, 松川真美

    電子情報通信学会技術研究報告vol. 110, no. 213, pp. 99-103, (2010).   110 ( 213 ) 99 - 103  2010  [Refereed]

  • 「RFバイアススパッタ法によるc軸平行配向ZnO薄膜の形成 〜 バイアス周波数が配向性に及ぼす影響〜」

    高柳真司, 柳谷隆彦, 松川真美, 渡辺好章

    電子情報通信学会技術研究報告vol. 110, no. 213, pp. 75-80, (2010).   110 ( 213 ) 75 - 80  2010  [Refereed]

  • 「牛皮質骨の微細構造とHAp結晶配向が長軸方向縦波音速に与える影響」

    矢追佑一郎, 水川裕文, 松川真美, 柳谷隆彦, 山本和史, 大和雄, 山崎薫, 長野昭

    電子情報通信学会技術研究報告vol. 107, no. 96, pp. 33-36, (2007)   107 ( 96 ) 33 - 36  2009  [Refereed]

  • 「(11-20)ZnO膜/石英基板構造のSH型SAW伝搬特性」

    田中厚志, 柳谷隆彦, 松川真美, 渡辺好章

    電子情報通信学会技術研究報告vol. 107, no. 233, pp. 31-36, (2007)   107 ( 233 ) 31 - 36  2009  [Refereed]

  • 「ウシ大腿骨皮質骨中の超音波縦波音速 〜 ハイドロキシアパタイト結晶配向と微細構造の影響 〜」

    中辻知宏, 矢追佑一郎, 松川真美, 山本和史, 山崎薫, 柳谷隆彦

    電子情報通信学会技術研究報告vol. 109, pp. 25-29, (2009)   109   25 - 29  2009  [Refereed]

  • 「c軸傾斜反転配向ZnO多層膜の作製と横波共振子への応用」

    守里直希, 高柳真司, 柳谷隆彦, 松川真美, 渡辺好章

    電子情報通信学会技術研究報告vol. 109, no. 213, pp. 53-58 (2009)   109 ( 213 ) 53 - 58  2009  [Refereed]

  • 「Brillouin散乱法による圧電半導体の面内方向電気特性評価に関する検討」

    柳谷隆彦, 佐野広幸, 松川真美

    電子情報通信学会技術研究報告vol. 109, no. 213, pp. 59-64, (2009)   109 ( 213 ) 59 - 64  2009  [Refereed]

  • 「直線状エロージョンマグネトロンスパッタリングによる(11-20)配向ZnO圧電膜の大面積成膜」

    川本貴之, 柳谷隆彦, 松川真美, 渡辺好章, 森嘉一, 佐々木昌, 大場正利

    電子情報通信学会技術研究報告vol. 109, no. 213, pp. 65-70, (2009)   109 ( 213 ) 65 - 70  2009  [Refereed]

  • 「c軸傾斜配向ZnO膜の作製および厚みすべりモード電気機械結合係数」

    松尾卓也, 田中厚志, 松川真美, 渡辺好章, 柳谷隆彦

    電子情報通信学会技術研究報告vol. 106, no. 250, pp. 19-24, (2006)   106 ( 250 ) 19 - 24  2006  [Refereed]

  • 「ブリユアン散乱法によるGHz域の増幅横波フォノンの観測」

    村田茂雄, 川本貴之, 松川真美, 柳谷隆彦

    電子情報通信学会技術研究報告vol. 106, no. 295, pp. 27-30, (2006)   106 ( 295 ) 27 - 30  2006  [Refereed]

  • 「面内配向ZnO膜の圧電性評価と共振器への応用」

    三島夏樹, 柳谷隆彦, 松川真美, 渡辺好章

    電子情報通信学会技術研究報告vol. 105, no. 312, pp. 7-12, (2005)   105 ( 312 ) 7 - 12  2005  [Refereed]

  • 「牛皮質骨の構造と縦波伝搬速度の異方性について」

    松川真美, 水川裕文, 柳谷隆彦, 大和雄, 山崎薫, 長野昭

    電子情報通信学会技術研究報告vol. 105, no. 346, pp. 15-18, (2005)   105 ( 346 ) 15 - 18  2005  [Refereed]

  • 「RFマグネトロンスパッタ法により作成した面内配向ZnO圧電薄膜の特性」

    野原拓也, 柳谷隆彦, 松川真美, 渡辺好章, 大谷隆彦

    電子情報通信学会技術研究報告vol. 104, no. 468, pp. 43-48, (2004)   104 ( 468 ) 43 - 48  2004  [Refereed]

  • 「横波励振を目的とした面内配向ZnO薄膜の開発」

    柳谷隆彦, 野原拓也, 松川真美, 渡辺好章, 大谷隆彦

    電子情報通信学会技術研究報告vol. 103, no. 340, pp. 31-36, (2003)   103 ( 340 ) 31 - 36  2003  [Refereed]

▼display all

Industrial Property Rights

  • 圧電素子及び圧電変換装置

    柳谷隆彦

    Patent

  • Ultrasonic probe and ultrasonic inspection apparatus

    S. Oono, K. Sumikawa, T. Takahash, T. Yanagitani

    Patent

  • 超音波探触子および超音波検査装置

    大野茂, 住川健太, 高橋卓也, 柳谷隆彦

    Patent

  • 超音波探触子及び超音波探傷システム

    高羅友輔, 柳谷隆彦

    Patent

  • 超音波探触子及び超音波探傷システム

    高羅友輔, 柳谷隆彦

    Patent

  • Thin film producing method and hexagonal piezoelectric thin film produced thereby

    H. Nishio, Y. Mori, Y. Tsurukame, T. Kawamoto, Y. Watanabe, T. Yanagitani

    Patent

  • Thin film producing method

    United States Patent, No. US 7951272 B2

    Y. Watanabe, T. Yanagitani

    Patent

  • 薄膜共振子

    特許第5747318号

    柳谷隆彦, 鈴木雅視, 渡辺好章

    Patent

  • 薄膜製造方法及び前記薄膜製造方法により製造された六方晶系圧電薄膜

    特許第5217051号

    西尾英俊, 森嘉一, 鶴亀宜崇, 渡辺好章, 柳谷隆彦, 川本貴之

    Patent

  • 高次モード薄膜共振器

    特許第4784815号

    渡辺好章, 柳谷隆彦

    Patent

▼display all

Awards

  • 文部科学大臣表彰

    2018  

  • 早稲田大学リサーチアワード(国際研究発信力)

    2016  

  • 名古屋工業大学 優秀賞(教員評価)

    2013.11  

  • 名古屋工業大学 褒賞

    2013.11  

  • 名古屋工業大学 特別優秀賞(教員評価)

    2013.01  

  • 粟屋潔学術奨励賞

    2010.09  

  • 超音波シンポジウム奨励賞(Symposium on Ultrasonic Electronics : Young Scientist Award)

    2007.11  

  • Symposium on Ultrasonic Electronics : Young Scientist Award

    2007.11  

▼display all

Research Projects

  • 分極反転圧電薄膜を用いた基地局向けの耐電力小型音響共振子フィルタの実現

    日本学術振興会  科学研究費助成事業 挑戦的研究(萌芽)

    Project Year :

    2021.07
    -
    2024.03
     

    柳谷 隆彦

  • GHz帯横波斜入射の複素反射率測定による抗原抗体反応の高感度粘弾性計測

    日本学術振興会  科学研究費助成事業 基盤研究(B)

    Project Year :

    2019.04
    -
    2022.03
     

    柳谷 隆彦, 高柳 真司, 吉田 憲司, 鈴木 雅視

     View Summary

    本研究では、抗原抗体反応時の界面での粘弾性変化を用いて、反応を定量を目指すものである。ここで、UHF帯の高周波横波を用いた複素反射率測定法により、液体試料の粘弾性を評価する。液体試料の複素反射係数を測定することにより、横波に関する弾性定数および年度を決定する.先行研究では、測定周波数が数MHzにとどまっているのに対して、本研究では
    c軸傾斜配向のScAlN薄膜を用いる。基板付きの擬似すべりモード共振子TSM-HBARを用いて,複素反射率測定をUHF帯において行うことを目的としている。
    c軸傾斜反転構造のScAlN薄膜は成長基板をスパッタターゲットに対して、垂直に配置して、スパッタ粒子を斜めに入射させることで、成長させた。さらに反転構造を作るために、途中で基板を180度反転させながら、成膜を行った。ここでは、12層反転層の形成を試みた。断面SEM測定からc軸が45度程度傾斜してかつ反転した柱状構造が確認できた。さらに極点X線回折法により3次元的な結晶配向性を調査したところ、0002面の極が仰角45度付近に明瞭に観測されて、実際の結晶のc軸方向も45度傾いていることもわかった。また、各層の傾斜角度のばらつきもさほど大きくなく、12層を一度に測定しても、45度付近に極が観測された。また動作周波数が数百MHz向けの数μmの多層構造と数GHz向けの数百nmのものと両方を得ることができた。

  • Electromagnetical coupling of AlCeN films grown by RF magnetron sputtering

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Research (Exploratory)

    Project Year :

    2018.06
    -
    2021.03
     

    Yanagitani Takahiko

     View Summary

    Nitride piezoelectric films are attractive for FBAR filters. Enhancement of piezoelectricity was recently found in ScAlN films. Electromagnetical coupling directly contribute to the low insertion loss and large band width. In this study, CeAlN piezoelectric films were grown by RF magnetron sputtering. omega-scan rocking curve FWHM of the c-axis oriented CeAlN films were found to be 3.3 deg., indicating good crystalline orientation. Electromechanical coupling coefficient of the films was determined to be 4.4 % using HBAR conversion loss method.

  • Shear mode resonators for detection of biomolecular interactions in liquid

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

    Project Year :

    2016.04
    -
    2019.03
     

    Yanagitani Takahiko

     View Summary

    In the fluid viscosity evaluation based on the QCM (Quartz Crystal Microbalance), the quartz crystal plate is required to be thinned to improve the measurement sensitivity. The QCM, however, becomes to be fragile due to thinning. Sensitive measurement without cracking of the piezoelectric layer can be expected by using the SMR (Solidly Mounted Resonator). In the previous study, however, the quasi-shear mode electromechanical coupling k’15^2 was only 1.7%. Therefore, we propose the fluid viscosity evaluation with the SMR based on the c-axis tilted ScAlN thin film. k’15^2 of the 48° c-axis tilted ScAlN film is determined as 13.0%. In addition, anti-resonant frequency shifts with changing in glycerin concentration were observed.

  • Measurement method for polarity-inverted layered piezoelectric thin films using scanning nonlinear dielectric microscopy

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C)

    Project Year :

    2015.04
    -
    2018.03
     

    ODAGAWA HIROYUKI, CHO YASUO

     View Summary

    Recently, it is reported that the polarity of ZnO and AlN piezoelectric thin film fabricated by radio frequency (RF) magnetron sputtering method can be switched by changing the growth condition, and polarity-inverted structure has been obtained. In this research, we have developed the quantitative measurement method for the thickness of a polarity inverted layer using canning nonlinear dielectric microscopy (SNDM). We derive an equation that represents the relationship between the output signal and the oscillation frequency of the SNDM probe, and developed the measurement procedure that can determine the thickness of polarity-inverted single layer structure. We applied it to two-dimensional distribution measurements of the layer thickness. Moreover, we investigated the measurement for double layered structure. We showed that it is possible to determine the thickness of two layers by controlling depth profile of electric field inside the measurement materials using a soft probe tip.

  • Ultrasonic probe using polarity inverted piezoelectric layer

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research

    Project Year :

    2015.04
    -
    2017.03
     

    Yanagitani Takahiko

     View Summary

    Polarity inverted multilayered transducers are attractive for high order mode excitation and high power operation. The control of the polarity in ScAlN and ZnO films by ion beam irradiation during film growth were reported. We found that the usual ScAlN and ZnO films grown by a standard planar sputtering possess (0001) Al-polarity and (000-1) O-polarity, respectively. In this study, we considered that the polarity inverted (0001)/(000-1) multilayer can be easily obtained by depositing usual (0001) Al-polar ScAlN film on usual (000-1) O-polar ZnO film. The polarities of the layers were determined by a press test using an oscilloscope. 2nd mode excitations were clearly observed in the longitudinal wave conversion loss in the transducers.

  • Study on the piezoelectricity in bone in the MHz range

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B)

    Project Year :

    2012.04
    -
    2015.03
     

    MATSUKAWA Mami, ATSUSHI Hosokawa, YOSHIKI Nagatani, TAKAHIKO Yanagitani, HIRONOBU Hoshino

     View Summary

    Ultrasonically induced electrical potentials in bone were studied experimentally. The potentials were observed by the irradiation of ultrasonic wave of 10 kPa and showed the existence of piezoelectricity in bone in the MHz range. This result indicates the possible contribution of piezoelectricity on the bone fracture curing process by the ultrasonic irradiation. The induced potentials were observed in the wet bone and did not depend on the alignment of HAp crystallites in bone. The polarity of induced potentials showed site dependence.
    A piezoelectric FDTD simulation was performed to estimate the spatial distribution of electric fields during ultrasound propagation in bone. The results showed the dependence of the field on the bone fracture.

  • Piezoelectric thin film MEMS with giant shear electromechanical coupling

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B)

    Project Year :

    2012.04
    -
    2015.03
     

    YANAGITANI Takahiko

     View Summary

    Shear piezoelectric films are attractive for sensors detecting viscosity and conductivity in liquid. High k15 is required for these sensors. We investigated the k15 of the c-axis tilted Sc doped AlN films. k15 of the films showed 16.8 % which is 3.2 times larger than that of AlN single crystal.

  • Development of non contact piezoelectricity measurement system By Brillouin light scattering

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Challenging Exploratory Research

    Project Year :

    2012
    -
    2013
     

    MATSUKAWA Mami, YANAGITANI Takahiko

     View Summary

    A non contact and non destructive measurement system of longitudinal wave velocity in GaN crystals was successfully developed by using a Brillouin light scattering technique. This technique enables to measure velocities in the GHz range, where the piezoelectricity in the conductive material is expected to appear. Using this technique, we could obtain the temperature dependence of longitudinal wave velocity in the conductive GaN crystal. In addition, a velocity dispersion was found in the semi conductive GaN crystal, which was similar to the weak relaxation behavior accompanied by the piezoelectric stiffening effect.

  • Development of surface acoustic wave piezoelectric films sensors for liquid property measurement

    Japan Society for the Promotion of Science  Grants-in-Aid for Scientific Research Grant-in-Aid for Young Scientists (B)

    Project Year :

    2009
    -
    2010
     

    YANAGITANI Takahiko

     View Summary

    To obtain shear type surface acoustic wave (SAW) thin film sensor, we fabricated the c-axis parallel oriented ZnO film on silica glass substrate. Shear type SAW was excited at first time, by applying VHF electric field to inter digital electrode fabricated on the film. Moreover, shear type SAW was propagated even in the liquid. Finally, the change of the conductiviy in the liquid was detected from the change of the SAW velocity.

  • 面内配向六方晶系薄膜の創製および横波モード共振子型分子間相互作用センサへの応用

    日本学術振興会  科学研究費助成事業 特別研究員奨励費

    Project Year :

    2007
    -
    2008
     

    柳谷 隆彦

     View Summary

    [センサ用材料の合成と圧電性能]ZnOと同じ六方晶系ウルツ型構造を有するAlN膜は耐薬品性に優れているためセンサ用材料に適している。本研究ではイオンビームスパッタ法を用いることで、初めて面内配向AlN膜の合成に成功した。さらに得られた薄膜と比較するために、AlN単結晶のセンサ感度関連物理定数をBrillouin散乱法により測定した。これによりAlN単結晶のバルク横波に関する電気⇔機械変換効率(k_<15>定数)を逆解析なしに決定した。AlN単結晶のk_<15>は0.10でZnOのk_<15>=0.26に比べて小さいことが明らかになった。電気⇔機械結合系センサでは、感度の点においてZnOの方が有利であることがわかった。作製されたAlN膜のk_<15>を測定した結果k_<15>=0.03で、AlN単結晶の約30%程度であった。
    [センサ安定性関連物理定数の測定]横波モード単結晶板共振子を作製し、AlN単結晶の横波に関する温度係数(TCF)を決定した。AlN単結晶のTCFは-20ppm/℃でZnOの-35ppm/℃に比べて小さいことが明らかになった。センサの温度安定性の点ではAlNの方が有利であることがわかった。
    [センサ材料(ZnO膜)の量産化に関する研究]面内配向ZnO膜の量産化に向けて従来使用していたの3インチ円形陰極ではなく、10インチの矩形陰極を搭載した大型成膜装置を設計し、成膜を行った。この結果、4インチ基板の大部分の領域において同一ウエハ上でc軸が面内に一方向に配向させることに成功した。さらに簡便に面内配向ZnO膜を合成する手法について研究を行い、陽極に直流バイアス電圧を-200V印加することで、大幅な装置の変更なしに面内配向ZnO膜の配向性を改善することができた。これにより面内配向ZnO膜形成のメカニズムの一端が明らかになり、今後さらなる量産化技術の進展が期待できる。

▼display all

Presentations

  • Giga-Hertz Piezoelectric Epitaxial PZT/La-SrTiO3 Transducer for the Application of Fingerprint Imaging

    Yusuke Sato, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS)  IEEE

    Presentation date: 2020.09

    Event date:
    2020.09
     
     
  • Extracting mechanical Q factor of the pure AlN, ScAlN, and ZnO films without etching substrate

    Naoya Iwata, Sarina Kinoshita, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS)  IEEE

    Presentation date: 2020.09

    Event date:
    2020.09
     
     
  • ScAlN Nano-Rods Structure Thin Film Grown by a Self-Shadowing Oblique Sputtering for High Electromechanical Coupling Transducer Applications

    Takumi Soutome, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS)  IEEE

    Presentation date: 2020.09

    Event date:
    2020.09
     
     
  • c-Axis oriented ScAlN/SiO2 multilayer BAW transformer for rectifying antenna applications

    Kota Izumi, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS)  IEEE

    Presentation date: 2020.09

    Event date:
    2020.09
     
     
  • Accurate Extraction of kt2 of Piezoelectric Film/Substrate Structure by Conversion Loss Method Subtracting Experimental Acoustic Losses in the Substrate

    Ryota Tatsumi, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS)  IEEE

    Presentation date: 2020.09

    Event date:
    2020.09
     
     
  • Deterioration in the piezoelectric property of ScAlN thin films by negative ion bombardment increased in low-pressure sputtering deposition

    Takumi Tominaga, Shinji Takayanagi, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS)  IEEE

    Presentation date: 2020.09

    Event date:
    2020.09
     
     
  • Extraction of kt2 of piezoelectric film/substrate structure by conversion loss derived by electromagnetic signal including no acoustic losses

    Ryota Tatsumi, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS)  IEEE

    Presentation date: 2020.09

    Event date:
    2020.09
     
     
  • Self-Standing FBAR Transformer based on Shear Mode Zig-zag ScAlN Multilayer for Rectenna Application

    Sarina Kinoshita, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS)  IEEE

    Presentation date: 2020.09

    Event date:
    2020.09
     
     
  • Zig-zag ScAlN multilayer SMR for high power BAW fileter application such as RF base station

    Yusuke Sato, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS)  IEEE

    Presentation date: 2020.09

    Event date:
    2020.09
     
     
  • Experimental and theoretical investigation of kt2and mechanical quality factor Qm in YbAlN films using DFT

    Naoya Iwata, Sarina Kinoshita, Junjun Jia, Masashi Suzuki, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS)  IEEE

    Presentation date: 2020.09

    Event date:
    2020.09
     
     
  • Enhancement of GHz electromechanical coupling coefficient kt2 of MgZnO and CaZnO thin film BAW resonators

    Kota Izumi, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS)  IEEE

    Presentation date: 2020.09

    Event date:
    2020.09
     
     
  • GHz BAW Piezoelectric Transformers with High Voltage Gain using the Combination of High and Low Dielectric Constant Thin Films

    Sarina Kinoshita, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS)  IEEE

    Presentation date: 2020.09

    Event date:
    2020.09
     
     
  • Multilayer Piezoelectric ScAlN Film Transducers for Ultrasonic Microscopy in the VHF Range

    Yusuke Korai, Masashi Suzuki, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS) 

    Presentation date: 2020.09

  • Effect of Negative-Ion-Bombardment Suppression by Applying Voltage to Grids Set Between Substrate and Sputtering Target During Sputtering Deposition on Crystalline Orientation of ZnO Film

    Kohei Tominaga, Shinji Takayanagi, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS) 

    Presentation date: 2020.09

  • Improvement of Crystallization and Shear-Mode Electromechanical Coupling of c-Axis-ParallelOriented ZnO Film by Annealing Treatment

    Shinji Takayanagi, Kanae Kimoto, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS) 

    Presentation date: 2020.09

  • Measurement of Time Response of Electrical Properties in Thickness Shear Mode Resonator with Liquid Loadings

    Mao Watabe, Shinji Takayanagi, Takahiko Yanagitani

    2020 IEEE International Ultrasonics Symposium (IUS) 

    Presentation date: 2020.09

  • A Method for Extracting Mechanical Q Factor of the Piezoelectric Film without Etching Substrate

    Sarina Kinoshita, Takahiko Yanagitani

    2019 IEEE International Ultrasonics Symposium (IUS)  IEEE

    Presentation date: 2019.10

    Event date:
    2019.10
     
     
  • Shear Mode Polarity Inverted ScAlN Multilayer for Application to BAW Transformer in Rectifying Antenna

    Sarina Kinoshita, Takahiko Yanagitani

    2019 IEEE International Ultrasonics Symposium (IUS)  IEEE

    Presentation date: 2019.10

    Event date:
    2019.10
     
     
  • A method to estimate kt2 of piezoelectric films from the change of lattice strain by XRD without removing substrate

    Takumi Soutome, Takahiko Yanagitani

    2019 IEEE International Ultrasonics Symposium (IUS)  IEEE

    Presentation date: 2019.10

    Event date:
    2019.10
     
     
  • Improvement of c-Axis Parallel Orientaition of ZnO film on Silica Glass Pipes with Various Diameters for SH-SAW Pipe Sensor

    Takuya Wakabayashi, Shinji Takayanagi, Mami Matukawa, Yuta Takamura, Takahiko Yanagitani

    2019 IEEE International Ultrasonics Symposium (IUS)  IEEE

    Presentation date: 2019.10

    Event date:
    2019.10
     
     
  • Effect of negative ions generation from sputtering target on crystalline orientation and kt2 of ScAlN thin films

    Rui Kihara, Shinji Takayanagi, Takahiko Yanagitani

    2019 IEEE International Ultrasonics Symposium (IUS)  IEEE

    Presentation date: 2019.10

    Event date:
    2019.10
     
     
  • Ion beam induced a-axis in-plane oriented c-axis oriented AlN thin film growth for high-Q BAW resonator application

    Chiaki Masamune, Takahiko Yanagitani

    2019 IEEE International Ultrasonics Symposium (IUS)  IEEE

    Presentation date: 2019.10

    Event date:
    2019.10
     
     
  • Frequency-switchable polarity-inverted BAW resonators based on electric-field-induced piezoelectric PMN-PT/PZT epitaxial film stacks

    Takahiro Shimidzu, Takahiko Yanagitani

    Journal of Applied Physics  AIP Publishing

    Presentation date: 2019.09

    Event date:
    2019.09
     
     
  • Frequency-switchable polarity-inverted BAW resonators based on PZT/PTO epitaxial films using difference in coercive field

    Takahiro Shimidzu, Takeshi Mori, Takahiko Yanagitani

    Applied Physics Letters  AIP Publishing

    Presentation date: 2019.05

    Event date:
    2019.05
     
     
  • Al金属ターゲットへのSc埋め込みの有無によるScAlN薄膜音響共振子の結晶化度の違いと圧電特性

    木原流唯, 高柳真司, 柳谷隆彦

    電子情報通信学会総合大会 

    Presentation date: 2019.03

  • 共振周波数比法を用いた基板付き薄膜共振子の電極付きkeff2の抽出

    龍見亮汰, 戸塚誠, 柳谷隆彦

    電子情報通信学会総合大会 

    Presentation date: 2019.03

  • SH型SAWパイプセンサの作製に向けた石英ガラス管へのc軸平行配向ZnO膜の形成

    篁 佑太, 高柳 真司, 柳谷隆彦, 松川 真美

    第66回応用物理学会 春季学術講演会 

    Presentation date: 2019.03

  • 溶融および焼結ScAl合金ターゲットを用いた高品質なScAlN薄膜の作製

    白寧蕊, 唐澤嶺, 高柳 真司, 今川 誠, 森坂啓介, 鈴木 雄, 柳谷隆彦

    第66回応用物理学会 春季学術講演会 

    Presentation date: 2019.03

  • ScAlN自立薄板を用いた30-40MHz帯振動子

    正宗千明, 唐澤 嶺, 柳谷隆彦

    第66回応用物理学会 春季学術講演会 

    Presentation date: 2019.03

  • 基板付き圧電薄膜の高次モード間共振周波数比を用いたFBARの電極考慮keff2抽出

    戸塚誠, 柳谷隆彦

    圧電材料・デバイスシンポジウム2019 

    Presentation date: 2019.01

  • 基板付き圧電薄膜の電気機械結合係数抽出時における電極サイズの影響

    山中恵理, 戸塚誠, 木下紗里那, 柳谷隆彦

    圧電材料・デバイスシンポジウム2019 

    Presentation date: 2019.01

  • ScAlN自立薄板を用いた30-40MHz帯振動子

    天野凌輔, 木下紗里那, 廣芝伸哉, 柳谷隆彦

    圧電材料・デバイスシンポジウム2019 

    Presentation date: 2019.01

  • スパッタ成膜中の負イオン照射抑制によるScAlN薄膜の圧電性向上

    高柳真司, 柳谷隆彦

    圧電材料・デバイスシンポジウム2019 

    Presentation date: 2019.01

  • 圧電薄膜デバイスと基板の選択

    和佐清孝, 清水貴博, 足立秀明, 吉田慎哉, 柳谷隆彦, 田中秀治

    圧電材料・デバイスシンポジウム2019 

    Presentation date: 2019.01

  • 「常誘電相PMN-PT/強誘電相PZT分極反転エピ膜音響共振子の周波数スイッチング特性」

    野田隆太, 清水貴博, 柳谷隆彦

    電子回路研究会 

    Presentation date: 2018.12

  • 横波モードのc 軸傾斜配向 ScAlN 薄膜 / 音響多層膜反射器共振子を用いた UHF帯液体粘性評価

    五月女巧, 山川愉生, 唐澤 嶺, 柳谷隆彦

    電子回路研究会 

    Presentation date: 2018.12

  • 極性反転ZnO圧電多層構造を用いた高効率な超音波トランスデューサ

    間島 毅, 清水貴博, 柳谷隆彦

    電子回路研究会 

    Presentation date: 2018.12

  • A new electromechanical coupling coefficient extraction method of as-grown film/wafer structure by using the ratio of overtone mode resonant frequencies

    The 39th Symposium on Ultrasonic Electronics (USE 2018) 

    Presentation date: 2018.10

  • 圧電トランス薄膜音響共振子による電波発電

    柳谷隆彦  [Invited]

    第4回分科会ワークショップ「革新的エナジー・ハーベスティングに向けた材料・デバイス技術」 

    Presentation date: 2018.03

  • c 軸傾斜配向 ScAlN 薄膜 / 音響多層膜構造の共振子を用いた 400MHz 付近における液体粘性評価

    山川 愉生, 五月女 巧, 唐澤 嶺, 柳谷 隆彦

    第 39 回超音波エレクトロニクスの基礎と応用に関するシンポジウム 

    Presentation date: 2018

  • c 軸傾斜配向すべりモード ScAlN 薄膜共振子を用いた生体反応検出

    矢崎 花, 五月女 巧, 唐澤 嶺, 高柳 真司, 吉田 憲司, 柳谷 隆彦

    第 39 回超音波エレクトロニクスの基礎と応用に関するシンポジウム 

    Presentation date: 2018

  • PZT エピタキシャル厚膜を用いた 80 MHz 帯の超音波トランスデューサ

    松田 友佳, 清水 貴博, 柳谷 隆彦

    第 39 回超音波エレクトロニクスの基礎と応用に関するシンポジウム 

    Presentation date: 2018

  • 大きな圧電性を持つ ScAlN 自立薄板を用いた 30?40 MHz 帯振動子

    正宗 千明, 唐澤 嶺, 柳谷 隆彦

    第 39 回超音波エレクトロニクスの基礎と応用に関するシンポジウム 

    Presentation date: 2018

  • 周波数スイッチナブルフィルタを目指した分極反転 PZT/PbTiO3エピタキシャル薄膜共振子

    清水 貴博, 森 剛志, 柳谷 隆彦

    第 39 回超音波エレクトロニクスの基礎と応用に関するシンポジウム 

    Presentation date: 2018

  • 大きな電気機械結合係数 (kt 2 =22%) を持つ ScAlN 薄膜

    白 寧蕊, 正宗 千明, 唐澤 嶺, 柳谷 隆彦

    第 39 回超音波エレクトロニクスの基礎と応用に関するシンポジウム 

    Presentation date: 2018

  • 溶融及び焼結 ScAl 合金ターゲットからの負イオン照射が ScAlN 薄膜成長へ及ぼす影響

    遠藤 結佳, 唐澤 嶺, 高柳 真司, 今川 誠, 森坂 啓介, 鈴木 雄, 柳谷 隆彦

    第 39 回超音波エレクトロニクスの基礎と応用に関するシンポジウム 

    Presentation date: 2018

  • 基板付き薄膜構造における高次モード間共振周波数比を用いた圧電薄膜の kt 2 評価法

    戸塚 誠, 柳谷 隆彦

    第 39 回超音波エレクトロニクスの基礎と応用に関するシンポジウム 

    Presentation date: 2018

  • 「サファイア基板上への高角度c軸傾斜ScAlN膜の作製と弾性表面波伝搬特性」

    徳田翔平, 高柳真司, 松川真美, 柳谷隆彦

    圧電材料・デバイスシンポジウム2018 

    Presentation date: 2018

  • 「スパッタ成膜中にSc金属から発生した負イオンの照射によるScAlN薄膜の結晶配向性および圧電性の劣化」

    高柳真司, 柳谷隆彦

    圧電材料・デバイスシンポジウム2018 

    Presentation date: 2018

  • 「厚みすべりモード薄膜共振子の液体負荷時における周波数変化及び減衰の検討」

    岩永陸弥, 高柳真司, 松川真美, 柳谷隆彦

    圧電材料・デバイスシンポジウム2018 

    Presentation date: 2018

  • 「PZT薄膜とバルク圧電材料」

    和佐清孝, 清水貴博, 足立秀明, 吉田慎哉, 柳谷隆彦, 田中秀治

    圧電材料・デバイスシンポジウム2018 

    Presentation date: 2018

  • 「スパッタ法により作製したGHz帯のPb(ZrxTi1-x)O3エピ膜にMPB特性は現れるか?」

    野田隆太, 清水貴博, 和佐清孝, 柳谷隆彦

    圧電材料・デバイスシンポジウム2018 

    Presentation date: 2018

  • 「極性反転ウルツ鉱系圧電薄膜を用いた高効率トランスデューサ」

    間島毅, 清水貴博, 柳谷隆彦

    圧電材料・デバイスシンポジウム2018 

    Presentation date: 2018

  • 「周波数スイッチナブルな常誘電相PMN-PT/強誘電相PZT分極反転エピタキシャル薄膜共振子」

    清水貴博, 柳谷隆彦

    圧電材料・デバイスシンポジウム2018 

    Presentation date: 2018

  • 「擬似すべりモードc軸傾斜配向ScAlN薄膜を用いた複素反射率測定による液体試料のUHF帯粘弾性評価」

    山川愉生, 唐澤嶺, 柳谷隆彦

    圧電材料・デバイスシンポジウム2018 

    Presentation date: 2018

  • 「c軸ジグザグ配向ScAlN圧電トランス薄膜共振子のレクテナ昇圧回路への応用検討」

    唐澤嶺, 柳谷隆彦

    圧電材料・デバイスシンポジウム2018 

    Presentation date: 2018

  • 「高次モード間共振周波数比を用いた基板付き薄膜共振子からの電気機械結合係数の抽出」

    戸塚誠, 柳谷隆彦

    圧電材料・デバイスシンポジウム2018 

    Presentation date: 2018

  • 「圧電トランス薄膜音響共振子による電波発電」

    柳谷隆彦

    第4回分科会ワークショップ「革新的エナジー・ハーベスティングに向けた材料・デバイス技術」 

    Presentation date: 2018

  • 「電子ビーム真空溶融により合成したScAl合金スパッタターゲットを用いた高品質ScAlN薄膜の成長」

    遠藤 結佳, 佐野 耕平, 唐澤 嶺, 柳谷 隆彦

    第65回応用物理学会 春季学術講演会 

    Presentation date: 2018

  • 「高い圧電性を持つPZT厚膜を用いた80 MHz帯高効率トランスデューサ」

    松田友佳, 清水貴博, 柳谷隆彦

    第65回応用物理学会 春季学術講演会 

    Presentation date: 2018

  • 「90?mScAlN厚膜を用いた40MHz帯トランスデューサ」

    正宗 千明, 佐野 耕平, 柳谷 隆彦

    第65回応用物理学会 春季学術講演会 

    Presentation date: 2018

  • 「基本モードと3次モードの共振周波数比を用いた基板付き薄膜の電気機械結合係数kt2の評価法」

    戸塚誠, 柳谷隆彦

    第65回応用物理学会 春季学術講演会 

    Presentation date: 2018

  • 「極性反転ZnO圧電薄膜を用いた高効率トランスデューサ」

    間島毅, 柳谷 隆彦

    第65回応用物理学会 春季学術講演会 

    Presentation date: 2018

  • 「ScAlN/ZnO極性反転構造を用いた高次モードトランスデューサの水中放射特性」 「基本モード/高次モード切替可能な常誘電相PMN-PT/強誘電相PZT分極反転エピ膜共振子」

    清水 貴博, 柳谷 隆彦

    第65回応用物理学会 春季学術講演会 

    Presentation date: 2018

  • 「c軸傾斜配向ScAlN薄膜を用いた擬似すべりモード基板付き共振子による液体試料のMHz帯-GHz帯にわたる粘性評」

    山川 愉生, 唐澤 嶺, 柳谷 隆彦

    第65回応用物理学会 春季学術講演会 

    Presentation date: 2018

  • 「c軸傾斜配向ScAlN薄膜を用いた横波超音波の斜入射による液体試料のVHF帯粘弾性評価」

    山川 愉生, 柳谷 隆彦

    第65回応用物理学会 春季学術講演会 

    Presentation date: 2018

  • 「低角スパッタ粒子入射を用いたc軸傾斜反転ジグザグScAlN圧電薄膜の成長とレクテナ昇圧素子への応用検討」

    唐澤嶺, 柳谷 隆彦

    第65回応用物理学会 春季学術講演会 

    Presentation date: 2018

  • 「最近のBAWデバイス(FBAR)の薄膜材料と評価手法」

    柳谷隆彦

    第65回応用物理学会 春季学術講演会 

    Presentation date: 2018

  • 「周波数スイッチナブルフィルタを目指した常誘電相PMN-PT/強誘電相PZT分極反転エピ膜音響共振子」

    清水貴博, 柳谷隆彦

    電子情報通信学会超音波研究会 

    Presentation date: 2018

  • 「レクテナ昇圧素子への応用を目指したc軸ジグザグ配向ScAlN多層圧電薄膜共振子」

    唐澤嶺, 柳谷隆彦

    電子情報通信学会超音波研究会 

    Presentation date: 2018

  • 「PZT エピ厚膜および ScAlN 厚膜を用いた 30-90 MHz 帯トランスデューサ」

    正宗千明, 松田友佳, 唐澤嶺, 清水貴博, 柳谷隆彦

    第47回EMシンポジウム 

    Presentation date: 2018

  • 「溶融および焼結 ScAl 合金スパッタターゲットから発生する負イオンが ScAlN 薄膜の成長に及ぼす影響」

    唐澤嶺, 遠藤結佳, 高柳真司, 今川誠, 森坂啓介, 鈴木雄, 柳谷隆彦

    第47回EMシンポジウム 

    Presentation date: 2018

  • 「基板付き圧電薄膜の機械的品質係数 Q 値評価の検討」

    木下紗里那, 戸塚誠, 唐澤嶺, 柳谷隆彦

    第47回EMシンポジウム 

    Presentation date: 2018

  • 「基本モード/3 次モード間共振周波数比を用いた基板付き薄膜構造における圧電薄膜の kt抽出法と従来 法との比較」

    戸塚誠, 柳谷隆彦

    第47回EMシンポジウム 

    Presentation date: 2018

  • 「Pb(Zrx,Ti1-x)O3スパッタエピ膜における MPB 特性発現の検証」

    野田隆太, 清水貴博, 和佐清孝, 柳谷隆彦

    第47回EMシンポジウム 

    Presentation date: 2018

  • 「c 軸傾斜配向厚みすべりモード ScAlN 薄膜共振子を用いた生体高分子反応の検出」

    矢崎花, 唐澤嶺, 吉田憲司, 高柳真司, 柳谷隆彦

    第47回EMシンポジウム 

    Presentation date: 2018

  • 「(0001)ScAlN/(000-1)ZnO 極性反転構造を用いた 2 次モードトランスデューサの水中放射特性」

    間島毅, 清水貴博, 柳谷隆彦

    第47回EMシンポジウム 

    Presentation date: 2018

  • 「ウエハ付きAs-grown圧電薄膜のRFフィルタ向け特性評価法およびScAlN薄膜の成長ノウハウ」

    柳谷隆彦

    アルバックシンポジウム 

    Presentation date: 2018

  • New BAW filter materials for 5G smart phone

    T. Yanagitani

    LG化学 Tech Scouting Japan 

    Presentation date: 2018

  • 「抗電界差により周波数スイッチナブルとなるPZT/PbTiO3分極反転エピタキシャル薄膜音響共振子」

    清水貴博, 柳谷隆彦

    第79回応用物理学会秋季学術講演会 

    Presentation date: 2018

  • 「ScAlN, ZnOおよびPZT系薄膜の極性制御と分極反転デバイスへの応用」

    清水貴博, 柳谷隆彦

    第79回応用物理学会秋季学術講演会 

    Presentation date: 2018

  • 「最新の窒化物BAWフィルタの動向と酸化物圧電薄膜の位置づけ」

    柳谷隆彦

    第79回応用物理学会秋季学術講演会 

    Presentation date: 2018

  • 「FBARフィルタ用の圧電薄膜材料の進展とウエハの評価手法」

    柳谷隆彦

    第168回電子セラミック・プロセス研究会 

    Presentation date: 2018

  • 「c軸傾斜配向厚みすべりモードScAlN薄膜共振子を用いた液体中生体分子相互作用の検出」

    矢崎花, 五月女巧, 唐澤 嶺, 高柳真司, 吉田憲司, 柳谷隆彦

    電子情報通信学会超音波研究会 

    Presentation date: 2018

  • 「c軸傾斜配向ScAlN薄膜/音響多層膜構造の共振子を用いたUHF帯における液体粘性評価」

    山川愉生, 五月女巧, 唐澤嶺, 柳谷隆彦

    電子情報通信学会超音波研究会 

    Presentation date: 2018

  • 「基板付き薄膜共振子からの新規kt2評価法と従来法の比較 〜 共振周波数比法、変換損失法、共振スペクトル法、共振反共振法 〜」

    戸塚誠, 柳谷隆彦

    電子情報通信学会超音波研究会 

    Presentation date: 2018

  • 「分極反転PZT/PTOエピ膜を用いた周波数スイッチナブルなGHz帯共振子」

    清水貴博, 森剛志, 柳谷隆彦

    電子情報通信学会超音波研究会 

    Presentation date: 2018

  • 「製法の異なるScAl合金スパッタターゲットから発生する負イオンがScAlN薄膜の特性に及ぼす影響 〜 電子ビーム溶融、アーク溶融、焼結ScAl合金ターゲットの比較 〜」

    唐澤嶺, 高柳真司, 遠藤結佳, 今川 誠, 森坂啓介, 鈴木 雄, 柳谷隆彦

    電子情報通信学会超音波研究会 

    Presentation date: 2018

  • “Thick PZT epitaxial film growth for ultrasonic transducer application below 100 MHz" 12th Japan-Korea Conference on Ferroelectrics,”

    Y. Mazda, T. Yanagitani

    12th Japan-Korea Conference on Ferroelectrics 

    Presentation date: 2018

  • “Frequency switchable polarity inverted resonators based on cubic PMN-PT/tetragonal PZT epitaxial stack,”

    T. Shimidzu, T. Yanagitani

    12th Japan-Korea Conference on Ferroelectrics 

    Presentation date: 2018

  • “Investigation of MPB in Pb(Zrx,Ti1-x)O3 epitaxial films by RF magnetron sputtering growth,”

    R. Noda, T. Yanagitani

    12th Japan-Korea Conference on Ferroelectrics 

    Presentation date: 2018

  • “A method for extracting GHz electromechanical coupling coefficient from piezoelectric film/substrate structure without removing substrate,”

    T. Yanagitani

    12th Japan-Korea Conference on Ferroelectrics 

    Presentation date: 2018

  • “Influence of negative ions generation on the quality of ScAlN films grown by sputtering targets with different concentration of oxygen and carbon,”

    Y. Endo, R. Karasawa, S. Takayanagi, M. Imakawa, K. orisaka, Y. uzuki, T. anagitani

    International Workshop on Piezoelectric Materials and Applications in Actuators(IWPMA2018) 

    Presentation date: 2018

  • “Comparison of kt2 extraction method from film/substrate structure by using the ratio of resonant frequencies with conventional methods,”

    M. Totsuka, T. Yanagitani

    International Workshop on Piezoelectric Materials and Applications in Actuators(IWPMA2018) 

    Presentation date: 2018

  • “Polarity inverted high efficiency ultrasonic transducer with (0001)ZnO/(000-1)ZnO/SiO2 glass buffer rod,”

    T. Majima, T. Shimidzu, T. Yanagitani

    International Workshop on Piezoelectric Materials and Applications in Actuators(IWPMA2018) 

    Presentation date: 2018

  • “Thick PZT epitaxial film and ScAlN film for ultrasonic transducer below 100 MHz,”

    Y. Mazda, C. Masamune, R. Karasawa, T. Shimidzu, T. Yanagitani

    International Workshop on Piezoelectric Materials and Applications in Actuators(IWPMA2018) 

    Presentation date: 2018

  • “Temperature characteristics of ScAlN/SiO2 BAW resonators,”

    H.Igeta, M. Totsuka, M. Suzuki, T. Yanagitani

    IEEE International Ultrasonics Symposium 

    Presentation date: 2018

  • “A new method for extracting Qfactor of the piezoelectric film without removing substrate,”

    S. Kinoshita, M. Totsuka, R. Karasawa, T. Yanagitani

    IEEE International Ultrasonics Symposium 

    Presentation date: 2018

  • “Investigation of morphotropic phase boundary in sputter-grown Pb(Zrx, Ti1-x)O3 epitaxial films,”

    R. Noda, T. Shimidzu, K. Wasa

    IEEE International Ultrasonics Symposium 

    Presentation date: 2018

  • “High efficiency ultrasonic transducer using polarity inverted ZnO thin film,”

    T. Majima, T. Shimidzu, T. Yanagitani

    IEEE International Ultrasonics Symposium 

    Presentation date: 2018

  • “ScAlN free-standing 0.1mm plates with 30-50 MHz resonance frequency,”

    C. Masamune, R. Karasawa, T. Yanagitani

    IEEE International Ultrasonics Symposium 

    Presentation date: 2018

  • “PZT epitaxial thick film for ultrasonic transducer at frequencies below 100MHz,”

    Y. Mazuda, T. Shimidzu, T. Yanagitani

    IEEE International Ultrasonics Symposium 

    Presentation date: 2018

  • “The influence of negative ions generation on the arc-melted and hot press sintered ScAlN alloy targets to the crystalline orientation and kt2 of the ScAlN films,”

    Y. Endo, R. Karasawa, S. Takayanagi, M.Imakawa, K. Morisaka, T. Yanagitani

    IEEE International Ultrasonics Symposium 

    Presentation date: 2018

  • “c-axis tilted ScAlN film shear mode resonators for biosensing,”

    H. Yazaki, T. Sotome, S. Takayanagi, K. Yoshida, T. Yanagitani

    IEEE International Ultrasonics Symposium 

    Presentation date: 2018

  • “Evaluation of viscoelactic properties of liquids based on the oblique incidence technology using shear horizontal waves at frequencies above 100 megahertz from c-axis tilted ScAlN thin films,”

    Y. Yamakawa, T. Yanagitani

    IEEE International Ultrasonics Symposium 

    Presentation date: 2018

  • “Extraction of electromechanical coupling coefficient of film / substrate structure by using the ration of a third mode resonant frequency to a fundamental mode resonant frequency,”

    M. Totsuka, T. Yanagitani

    IEEE International Ultrasonics Symposium 

    Presentation date: 2018

  • “DC-induced piezoelectric cubic PMN-PT/piezoelectric tetragonal PZT epitaxial stack polarity inverted resonators for frequency switchable filters,”

    T. Shimidzu, T. Yanagitani

    IEEE International Ultrasonics Symposium 

    Presentation date: 2018

  • “Polarity inverted ScAlN multilayer for application to transformer in rectifying antenna,”

    R. Karasawa, T. Yanagitani

    IEEE International Ultrasonics Symposium 

    Presentation date: 2018

  • 「抗電界差による基本モード/高次モード周波数切替可能なPZT/PTエピ膜分極反転共振子」

    清水貴博, 森剛志, 柳谷隆彦, 和佐清孝

    圧電材料・デバイスシンポジウム 

    Presentation date: 2017

  • 「c軸傾斜配向ScAlN膜/ATカット水晶基板構造の低TCF横波共振子を用いた 広帯域周波数粘度測定」

    山川愉生, 佐野耕平, 唐澤嶺, 森剛志, 柳谷隆彦

    圧電材料・デバイスシンポジウム 

    Presentation date: 2017

  • 「c軸傾斜配向ScAlN膜/ブラック反射層構造のGHz帯厚みすべりモード共振子を用いた液体粘性評価」

    唐澤嶺, 山川愉生, 森剛志, 矢?花, 佐野耕平, 柳谷隆彦

    圧電材料・デバイスシンポジウム 

    Presentation date: 2017

  • 「RFマグネトロンスパッタ法を用いて作製したc軸平行配向ZnO膜の 圧電不活性層低減に関する検討」

    盛一馬, 高柳真司, 松川真美, 柳谷隆彦

    圧電材料・デバイスシンポジウム 

    Presentation date: 2017

  • 「電気機械結合係数 kt2=19%のScAlN厚膜を用いた低周波帯80 MHzトランスデューサ」

    佐野耕平, 唐澤嶺, 柳谷隆彦

    圧電材料・デバイスシンポジウム 

    Presentation date: 2017

  • 「縦波・横波の超音波伝搬時における骨中誘発電位の検討」

    松川沙弥果, 牧野大輝, 小山大介, 高柳真司, 水野勝紀, 柳谷隆彦, 松川真美

    圧電材料・デバイスシンポジウム 

    Presentation date: 2017

  • 「ScAlN薄膜トランスデューサを用いた縦波・横波のブリュアン散乱光の同時増幅」

    柴垣慶明, 川部昌彦, 柳谷隆彦, 高柳真司, 鈴木雅視, 松川真美

    日本音響学会2016年秋季研究発表会 

    Presentation date: 2017

  • 「単結晶PZT/PTエピタキシャル薄膜を用いた周波数切り替え可能な共振子」

    森剛志, 高柳真司, 清水貴博, 柳谷隆彦

    2017年電子情報通信学会総合大会 

    Presentation date: 2017

  • 「チューナブルフィルタを目指した PMN 常誘電相エピ膜の電界誘起圧電特性と分極反転特性」

    清水貴博, 柳谷隆彦, 和佐清孝

    第46回EMシンポジウム 

    Presentation date: 2017

  • 「c 軸傾斜配向 ScAlN/AT カット水晶基板構造の低 TCF 横波 HBAR を用いた MHz 帯-GHz 帯粘性評価」

    山川愉生, 佐野耕平, 唐澤嶺, 柳谷隆彦

    第46回EMシンポジウム 

    Presentation date: 2017

  • 「高電気機械結合係数を持つ80MHz 帯 ScAlN 厚膜のハイドロフォン応用への検討」

    佐野耕平, 唐澤嶺, 柳谷隆彦

    第46回EMシンポジウム 

    Presentation date: 2017

  • 「分極反転圧電薄膜の成長と応用〜レクテナ昇回路へ検討〜」

    柳谷隆彦, 唐澤嶺

    第46回EMシンポジウム 

    Presentation date: 2017

  • “PMN paraelectric phase epitaxial film for DC field-induced frequency switchable filter”

    T. Shimidzu, K. Wasa, T. Yanagitani

    The 38th Symposium on Ultrasonic Electronics 

    Presentation date: 2017

  • “Film growth of c-axis parallel oriented ZnO films by RF magnetron sputtering for improvement of electromechanical properties”

    K. Mori, S. Takayanagi, M. Matsukawa, T. Yanagitani

    The 38th Symposium on Ultrasonic Electronics 

    Presentation date: 2017

  • “Simple and rapid measurement of hypersonic wave velocity by Brillouin scattering method”

    Y. Shibagaki, M. Kawabe, S. Takayanagi, T. Yanagitani

    The 38th Symposium on Ultrasonic Electronics 

    Presentation date: 2017

  • “Simultaneous viscosity evaluation in the MHz to GHz range with low TCF resonators consisting of shear mode piezoelectric thin films on AT-cut quartz crystal”

    Y. Yamakawa, R. Karasawa, T. Shimidzu, T. Yanagitani

    The 38th Symposium on Ultrasonic Electronics 

    Presentation date: 2017

  • “c-Axis tilted ScAlN film on sapphire substrate for SAW devices with high electromechanical coupling”

    S. Tokuda, S. Takayanagi, M. Matsukawa, T. Yanagitani

    The 38th Symposium on Ultrasonic Electronics 

    Presentation date: 2017

  • “Polarity inverted ScAlN films for application to transformer in rectenna”

    R. Karasawa, T. Yanagitani

    The 38th Symposium on Ultrasonic Electronics 

    Presentation date: 2017

  • “Induced electrical potentials in cortical bone under shear ultrasound exposure”

    T. Makino, K. Takano, S. Nakanishi, D. Koyama, S. Takayanagi, T. Yanagitani, M. Matsukawa

    The 38th Symposium on Ultrasonic Electronics 

    Presentation date: 2017

  • “Effects of highly energetic negative ions generated from Sc grains during sputtering deposition on electromechanical properties of ScAlN film”

    S. Takayanagi, T. Yanagitani

    The 38th Symposium on Ultrasonic Electronics 

    Presentation date: 2017

  • “High efficiency ScAlN thick film hydrophone operating in the ranges of 40-80 MHz”

    K-h. Sano, R. Karasawa, T. Yanagitani

    The 38th Symposium on Ultrasonic Electronics 

    Presentation date: 2017

  • 「高品質ScAlN薄膜の成長条件と圧電特性および音響特性の評価」

    柳谷隆彦, 唐澤嶺, 佐野耕平

    EMデバイス・システムの新技術調査専門委員会 

    Presentation date: 2017

  • "Electromechanical coupling hysteresis curves of PZT epitaxial ferroelectric films determined by gigahertz ultrasonic method"

    T. Yanagitani, T. Mori, K. Wasa

    12th Pacific Rim Conference on Ceramic and Glass Technology (PACRIM 12) 

    Presentation date: 2017

  • "High electromechanical coupling thick ScAlN piezoelectric films for ultrasonic generation in low frequency of 80MHz"

    K. Sano, R. Karasawa, T. Yanagitani

    12th Pacific Rim Conference on Ceramic and Glass Technology (PACRIM 12) 

    Presentation date: 2017

  • "Liquid gigahertz viscosity sensors using shear mode c-axis tilted ScAlN piezoelectric thin films"

    Y. Yamakawa, R. Karasawa, T. Mori, K. Sano, M. Suzuki, T. Yanag

    12th Pacific Rim Conference on Ceramic and Glass Technology (PACRIM 12) 

    Presentation date: 2017

  • "Polarity inverted PZT/PbTiO3 ferroelectric epitaxial film for frequency switchable resonator filters"

    T. Shimizu, T.Mori, M. Suzuki, T. Yanagitani, K. Wasa

    12th Pacific Rim Conference on Ceramic and Glass Technology (PACRIM 12) 

    Presentation date: 2017

  • "Broadband frequency viscosity measurement using low TCF shear mode resonators consisting of c-axis tilted ScAlN thin film on thick AT-Cut quartz plate"

    Y. Yamakawa, K. Sano, R. Karasawa, T. Yanagitani

    The 19th International Conference on Solid-State Sensors, Actuators and Microsystems 

    Presentation date: 2017

  • "Thick ScAlN film for high efficient ultrasonic transducer in low frequency of 81 MHz"

    K.-H. Sano, R. Karasawa, T. Yanagitani

    The 19th International Conference on Solid-State Sensors, Actuators and Microsystems 

    Presentation date: 2017

  • “Film Growth of C-Axis parallel oriented ZnO on entire surface of silica glass pipe for SH-SAW pipe sensor,”

    Y. Takamura, S. Takayanagi, M. Matsukawa, C. Ishida, T. Yanagitani

    IEEE International Ultrason. Symp. 

    Presentation date: 2017

  • “Effects of negative oxygen ions generated during Sc ingot sputtering on electromechanical coupling of ScAlN film ,”

    S. Takayanagi, T. Yanagitani

    IEEE International Ultrason. Symp. 

    Presentation date: 2017

  • “Film growth of c-axis tilted ScAlN on the sapphire substrate for SAW devices,”

    S. Tokuda, S. Takayanagi, M. Matsukawa, T. Yanagitani

    IEEE International Ultrason. Symp. 

    Presentation date: 2017

  • “The frequency wwitchable multi-layered BST/BaTiO3 epitaxial film resonator,”

    S. Takayanagi, M. Matsukawa, T. Yanagitani

    IEEE International Ultrason. Symp. 

    Presentation date: 2017

  • “High electromechanical coefficient kt 2=19% thick ScAlN piezoelectric films for ultrasonic transducer in low frequency of 80 MHz,”

    K-h. Sano, R. Karasawa, T. Yanagitani

    IEEE International Ultrason. Symp. 

    Presentation date: 2017

  • “A new type wide-frequency-range shear viscosity sensor using caxis tilted ScAlN thin film on temperature stable AT-cut quartz thick plate,”

    Y. Yamakawa, K-h. Sano, R. Karasawa, T. Yanagitani

    IEEE International Ultrason. Symp. 

    Presentation date: 2017

  • “C-axis zig-zag polarization inverted ScAlN multilayer for FBAR transformer rectifying antenna,”

    R. Karasawa, T. Yanagitani

    IEEE International Ultrason. Symp. 

    Presentation date: 2017

  • “DC field-induced piezoelectricity of cubic perovskite 0.95Pb(Mg1/3Nb2/3)O3-0.05PbTiO3 epitaxial film for RF switchable resonator,”

    T. Shimidzu, K. Wasa, T. Yanagitani

    IUMRS-ICA 

    Presentation date: 2017

  • “Frequency switchable multi-layered paraelectric-BST/ferroelectric-BaTiO3 stack epitaxial film resonator,”

    R. Noda, T. Shimidzu, K. Wasa, T. Yanagitani

    IUMRS-ICA 

    Presentation date: 2017

  • 「PZTと PT の抗電界差を利用した周波数スイッチナブル分極反転エピタキシャ薄膜共振子」

    森剛志, 柳谷隆彦, 和佐清孝

    第45回EMシンポジウム 

    Presentation date: 2016

  • 「ScAlN/ZnO極性反転圧電薄膜を用いた2次モード励振超音波トランスデューサ」

    森剛志, 鈴木雅視, 柳谷隆彦

    電子情報通信学会 超音波研究会 

    Presentation date: 2016

  • 「GHz帯で純横波超音波を高効率励振するc軸平行ZnO薄膜トランスデューサ」

    森剛志, 鈴木雅視, 柳谷隆彦

    電子情報通信学会 超音波研究会 

    Presentation date: 2016

  • 「励起フォノンを用いたBrillouin散乱測定の高速化に関する検討」

    柴垣慶明, 川部昌彦, 柳谷隆彦, 高柳真司, 鈴木雅視, 松川真美

    第58回光波センシング技術研究会 

    Presentation date: 2016

  • "Piezoelectric stiffening in the thickness direction of c-plane ZnO single crystal measured by Brillouin scattering"

    S. Tomita, T. Yanagitani, S. Takayanagi, M. Matsukawa

    The 37th Symposium on Ultrasonic Electronics (USE2016). 

    Presentation date: 2016

  • "Evaluation of piezoelectricity in bone by ultrasound irradiation"

    S. Matsukawa, S.Mori, D. Koyama, S. Takayanagi, K. Mizuno, T. Yanagitani, M. Matsukawa

    The 37th Symposium on Ultrasonic Electronics (USE2016). 

    Presentation date: 2016

  • "High electromechanical coupling of Sezawa mode SAW using a polarization-inverted ScAlN film/highvelocity substrate structure"

    S. Takayanagi, T. Yanagitani

    The 37th Symposium on Ultrasonic Electronics (USE2016). 

    Presentation date: 2016

  • "Polarity inverted Pb(Zr,Ti)O3/PbTiO3 epitaxial multilayer frequency switchable resonator in the GHz range"

    T. Mori, T. Yanagitani, K. Wasa

    13th International Workshop on Piezoelectric Materials and Applications in Actuators & Energy Conversion Materials and Devices 

    Presentation date: 2016

  • "Electromechanical coupling hysteresis curves of Pb(Zr,Ti)O3 epitaxial films determined by GHz ultrasonic method using film/substrate structure"

    T. Yanagitani, T. Mori, K. Wasa

    13th International Workshop on Piezoelectric Materials and Applications in Actuators & Energy Conversion Materials and Devices 

    Presentation date: 2016

  • "Temperature stable liquid gigahertz viscosity sensors by combining shear mode piezoelectric ScAlN thin film and AT-cut quartz crystal plate"

    K-h. Sano, T. Mori, R. Karasawa, T. Yanagitani

    5th Joint Meeting of the Acoustical Society of America and Acoustical Society of Japan 

    Presentation date: 2016

  • "c-axis tilted ScAlN shear wave acoustic Bragg reflect resonator for gigahertz viscosity measurement"

    Takeshi Mori, Yui Yamakawa, Rei Karasawa, Ko-hei Sano, Takahiko Yanagitani, Shinji Takanayanagi

    5th Joint Meeting of the Acoustical Society of America and Acoustical Society of Japan 

    Presentation date: 2016

  • P5-C2-4 "Brillouin scatteringstudy on piezoelectricstiffening effect in thethickness direction ofc-plane ZnO single crystal"

    S. Tomita, T. Yanagitani, S. Takayanagi, H. Ichihashi, M. Matsukawa

    IEEE International Ultrason. Symp, 

    Presentation date: 2016

  • 4K-2 "Anisotropic behavior ofinduced electric potentialsin bone by ultrasoundirradiation"

    S. Matsukawa, S. Mori, Isao Mano, T. Yanagitani, K. Mizuno, S.Takayanagi, M. Matsukawa

    IEEE International Ultrason. Symp, 

    Presentation date: 2016

  • 6K-1 "Rapid and simultaneousmeasurement of longitudinaland shear wave velocitiesby Brillouin scattering fromartificially induced phonons"

    M. Kawabe, T. Yanagitani, S. Takayanagi, Y. Shibagaki, M. Suzuki, M. Matsukawa

    IEEE International Ultrason. Symp, 

    Presentation date: 2016

  • 6H-4 Improvement ofelectromechanical propertiesin c-axis parallel orientedZnO film by RF magnetronsputtering with negative ionbombardment"

    K. Mori, S. Takayanagi, M. Matsukawa, T. Yanagitani

    IEEE International Ultrason. Symp, 

    Presentation date: 2016

  • 6H-3 "Effects of energeticnegative ions generatedfrom sputtering targets onScAlN film growth"

    S. Takayanagi, M.Matsukawa, T. Yanagitani

    IEEE International Ultrason. Symp, 

    Presentation date: 2016

  • H-2 "Evaluation of viscousliquid using resonance andanti-resonance of thicknessshearmode resonatorconsisting of c-axis paralleloriented ZnO film"

    R. Iwanaga, S. Takayanagi, Y. Watanabe, M. Matsukawa, T. Tsuchiya, T. Yanagitani

    IEEE International Ultrason. Symp, 

    Presentation date: 2016

  • 6H-1 "The frequencyswitchable resonatorconsisting of polarityinverted Pb(Zr,Ti)O3/PbTiO3epitaxial multilayer"

    T. Mori, M. Suzuki, T. Yanagitani

    IEEE International Ultrason. Symp, 

    Presentation date: 2016

  • P3-B2-7 "Electromechanicalcoupling hysteresis curvesof Pb(Zr,Ti)O3and PbTiO3epitaxial films determinedby ultrasonic measurementusing film/substratestructure"

    T. Mori, M. Suzuki, S. Takayanagi, T. Yanagitani

    IEEE International Ultrason. Symp, 

    Presentation date: 2016

  • P3-B2-1 "High electromechanical coupling of Sezawa mode SAW in c-axis-parallel-oriented ScAlN film/high-velocitysubstrate structures"

    S. Takayanagi, M. Matsukawa, T. Yanagitani

    IEEE International Ultrason. Symp, 

    Presentation date: 2016

  • "Rapid wave velocity measurement by Brillouin scattering using artificially induced phonon"

    Y. Shibagaki, M. Kawabe, S. Takayanagi, K. Mori, T. Yanagitani, M. Matsukawa

    5th Joint Meeting of the Acoustical Society of America and Acoustical Society of Japan 

    Presentation date: 2016

  • "Liquid loading characteristics of multiple SH-wave roundtrip in c-axis parallel oriented ZnO film/silica glass pipe"

    S.Takayanagi, S.Hirayama, M.Matsukawa, T.Yanagitani

    5th Joint Meeting of the Acoustical Society of America and Acoustical Society of Japan 

    Presentation date: 2016

  • 陽極RFバイアス法による2次モード(000-1)/(0001)ScAlN FBAR

    鈴木雅視, 柳谷隆彦

    圧電材料・デバイスシンポジウム2015 

    Presentation date: 2015

  • ScAlN薄膜における弾性定数テンソルのSc濃度依存性

    柳谷隆彦, 市橋隼人, 鈴木雅視, 高柳真司, 松川真美

    圧電材料・デバイスシンポジウム2015 

    Presentation date: 2015

  • 走査型非線形誘電率顕微法による層状構造圧電薄膜の極性評価

    小田川裕之, 寺田浩士朗, 西川宏明, 柳谷隆彦, 長康雄

    圧電材料・デバイスシンポジウム2015 

    Presentation date: 2015

  • 基板付き圧電薄膜のkt評価法の比較

    小林勇太, 鈴木雅視, 柳谷隆彦, 荒川元孝, 大橋雄二

    圧電材料・デバイスシンポジウム2015 

    Presentation date: 2015

  • 超音波照射による骨中誘発電位の極性について

    常田裕子, 松川沙弥果, 真野功, 水野勝紀, 柳谷隆彦, 高柳真司, 松川真美

    圧電材料・デバイスシンポジウム2015 

    Presentation date: 2015

  • RFバイアス三極スパッタ法におけるイオン照射を利用したO面,Zn面,a面およびm面ZnO薄膜の形成

    橋本亮介, 高柳真司, 柳谷隆彦, 松川真美

    第62回応用物理学会春季学術講演会 

    Presentation date: 2015

  • 180°,90R散乱配置を用いたBrillouin散乱計測によるGaNの弾性定数測定

    市橋隼人, 柳谷隆彦, 高柳真司, 川部昌彦, 松川真美

    第62回応用物理学会春季学術講演会 

    Presentation date: 2015

  • (EM44-2-05) 「c 軸傾斜ScAlN 薄膜における擬似すべりモード電気機械結合係数のSc 濃度依存性」

    鈴木雅視, 柳谷隆彦

    第44回EMシンポジウム 

    Presentation date: 2015

  • (EM44-2-03) 「スパッタ成膜の高速負イオン照射を用いたc 軸平行配向ZnO 膜の形成と圧電デバイス応用」

    高柳真司, 柳谷隆彦, Jean-Claude Gerbedoen、Abdelkrim Talbi, 松川真美, Philippe Pernod

    第44回EMシンポジウム 

    Presentation date: 2015

  • 「Brillouin散乱法を用いた圧電性ScAlN薄膜による励起フォノンの測定」

    川部 昌彦, 柳谷 隆彦, 市橋 隼人, 高柳 真司, 鈴木 雅視, 松川 真美

    第76回応用物理学会秋季学術講演会 

    Presentation date: 2015

  • 「イオンビーム照射によるc軸平行極性反転構造ZnO薄膜の形成」

    森 剛志, 鈴木 雅視, 柳谷 隆彦

    第76回応用物理学会秋季学術講演会 

    Presentation date: 2015

  • 「斜めスパッタ蒸着法によるc軸傾斜ScAlN薄膜の形成」

    鈴木 雅視, 柳谷 隆彦

    第76回応用物理学会秋季学術講演会 

    Presentation date: 2015

  • 「Al極性(0001)ScAlN/O極性(000-1)ZnO極性反転構造の薄膜音響共振子」

    森 剛志, 鈴木 雅視, 柳谷 隆彦

    第76回応用物理学会秋季学術講演会 

    Presentation date: 2015

  • 「MHz 域における皮質骨の逆圧電効果」

    松川 沙弥果, 森 駿貴, 眞野 功, 水野 勝紀, 柳谷 隆彦, 高柳 真司, 松川 真美

    日本音響学会2016年春季研究発表会 

    Presentation date: 2015

  • 「c軸平行配向ZnO膜によるSH-SAWを用いた液体の粘度・導電率測定」

    日山彰子, 高柳真司, 松川真美, 柳谷隆彦

    圧電材料・デバイスシンポジウム2016 

    Presentation date: 2015

  • 「Brillouin散乱法を用いたc面ZnO単結晶の音響電気効果による緩和測定」

    富田昇太, 高柳真司, 松川真美, 柳谷隆彦

    圧電材料・デバイスシンポジウム2016 

    Presentation date: 2015

  • 「c軸平行配向ScAlN膜/高音速基板構造を用いたセザワ波の高い電気機械結合係数」

    高柳真司, 岡峰生, 松川真美, 柳谷隆彦

    圧電材料・デバイスシンポジウム2016 

    Presentation date: 2015

  • 「RFマグネトロンスパッタにおけるc軸平行配向ZnO膜の高品質化の検討」

    高田千裕, 高柳真司, 松川真美, 柳谷隆彦

    圧電材料・デバイスシンポジウム2016 

    Presentation date: 2015

  • 「イオンビーム照射を用いたc軸平行極性反転構造ZnO薄膜共振子」

    森剛志, 鈴木雅視, 柳谷隆彦

    圧電材料・デバイスシンポジウム2016 

    Presentation date: 2015

  • 「通常のスパッタ法を用いたAl極性ScAlN/O極性ZnO極性反転構造トランスデューサ」

    森剛志, 鈴木雅視, 柳谷隆彦

    圧電材料・デバイスシンポジウム2016 

    Presentation date: 2015

  • 「スパッタターゲットから発生するイオン種がScAlN薄膜の結晶性に及ぼす影響」

    高柳真司, 松川真美, 柳谷隆彦

    圧電材料・デバイスシンポジウム2016 

    Presentation date: 2015

  • 「IBAD 法による c 軸平行配向 ScAlN 薄膜の形成とすべりモード共振子への応用」

    岡 峰生, 高柳 真司, 柳谷 隆彦, 松川 真美

    第 36 回 超音波エレクトロニクスの基礎と応用に関するシンポジウム 

    Presentation date: 2015

  • 「c 軸傾斜 ScxAl-xN 薄膜(0<0.55)における擬似すべりモード電気機械結合係数」

    鈴木 雅視, 柳谷 隆彦

    第 36 回 超音波エレクトロニクスの基礎と応用に関するシンポジウム 

    Presentation date: 2015

  • 「Al 極性 ScAlN/O 極性 ZnO 極性反転多層構造を用いた GHz 帯高効率トランスデューサ 」

    森 剛志, 鈴木 雅視, 柳谷 隆彦

    第 36 回 超音波エレクトロニクスの基礎と応用に関するシンポジウム 

    Presentation date: 2015

  • 「走査型非線形誘電率顕微法による層状極性反転圧電膜の層厚の定量測定」

    寺田 浩士朗, 西川 宏明, 田中 陽, 小田川 裕之, 柳谷 隆彦, 長 康雄

    第 36 回 超音波エレクトロニクスの基礎と応用に関するシンポジウム 

    Presentation date: 2015

  • 「H2O 導入スパッタ法を用いて作製した c 軸平行配向 ZnO 膜のすべりモード電気機械結合係数」

    高田 千裕, 高柳 真司, 柳谷 隆彦, 松川 真美

    第 36 回 超音波エレクトロニクスの基礎と応用に関するシンポジウム 

    Presentation date: 2015

  • 「皮質骨中における超音波誘発電位に関する検討」

    松川 沙弥果, 森 駿貴, フォタネル エロディー, 眞野 功, 水野 勝紀, 柳谷 隆彦, 高柳 真司, 松川 真美

    第 36 回 超音波エレクトロニクスの基礎と応用に関するシンポジウム 

    Presentation date: 2015

  • 「Brillouin光散乱を用いたc軸配向薄膜の音速および常屈折率の同時測定」

    富田昇太, 柳谷隆彦, 鈴木雅視, 高柳真司, 松川真美

    電子情報通信学会 超音波研究会vol. 115, no02, pp.23-28 

    Presentation date: 2015

  • 「低圧RFマグネトロンスパッタ法によるc軸平行配向ZnO膜の形成とSAW、Lamb波デバイスへの応用」

    高柳真司, 柳谷隆彦, Jean-Claude Gerbedoen, Abdelkrim Talbi, 松川真美, Philippe Pernod

    電子情報通信学会 超音波研究会vol. 115, no07, pp.25-30 

    Presentation date: 2015

  • 「c軸平行配向ZnO膜/円管石英構造におけるSH波の多重周回伝搬特性と導電率測定への応用」

    日山彰子, 柳谷隆彦, 高柳真司, 松川真美

    電子情報通信学会 超音波研究会vol. 115, no07, pp.19-24 

    Presentation date: 2015

  • 「イオンビームアシストRFマグネトロンスパッタ法を用いて作製したc軸平行配向ScAlN薄膜の電気機械結合係数」

    岡峰生, 高柳真司, 柳谷隆彦, 松川真美

    電子情報通信学会 超音波研究会vol. 115, no07, pp.31-35 

    Presentation date: 2015

  • 「共振法およびBrillouin散乱法で測定したScAlN薄膜の弾性定数テンソルのSc濃度依存性」

    柳谷隆彦, 市橋隼人, 鈴木雅視, 高柳真司, 松川真美

    電子情報通信学会 超音波研究会vol. 115, no07, pp.37-42 

    Presentation date: 2015

  • 「ScAlN圧電薄膜から励起されたコヒーレントフォノンのBrillouin散乱」

    趙恩慧, 川部昌彦, 高柳真司, 鈴木雅視, 柳谷隆彦, 松川真美

    電子情報通信学会 超音波研究会vol. 115, no46, pp.27-30, 

    Presentation date: 2015

  • 「走査型非線形誘電率顕微法による極性反転層状構造圧電膜の層厚の定量測定」

    寺田浩士朗, 西川宏明, 田中陽平, 小田川裕之, 柳谷隆彦, 長康雄

    電子情報通信学会 超音波研究会vol. 115, no46, pp.23-26 

    Presentation date: 2015

  • “Multiple SH wave roundtrip type liquid sensor of pipe structure with c-axis parallel oriented ZnO film”

    S. Hiyama, T. Yanagitani, S. Takayanagi, M. Matsukawa

    International Congress of Ultrasonics 

    Presentation date: 2015

  • “High Tc /High Coupling Perovskite Thin Films,”

    K. Wasa, T. Matsushima, H. Adachi, T. Matsunaga, T. Yanagitani, T. Yamamoto

    IEEE ISAF/IWATMD/PFM, pp. 1-4, (2014). 

    Presentation date: 2015

  • “ScAlN thin film transducers for ultrasonic microscopy in the VHF range”

    Y. Korai, M.i Suzuki, T. Yanagitani

    IEEE International Ultrasonics Symposium 

    Presentation date: 2015

  • “Measurement of acoustic wave velocity and refractive index in thickness direction of c-axis oriented ScAlN films by Brillouin scattering”

    S. Tomita, T. Yanagitani, M. Suzuki, H. Ichihashi, S. Takayanagi, M. Matsukawa

    IEEE International Ultrasonics Symposium 

    Presentation date: 2015

  • “Shear mode properties of c-axis parallel oriented ScxAl1-xN films grown by RF bias sputtering“

    S. Takayanagi, T. Yanagitani, M. Matsukawa

    IEEE International Ultrasonics Symposium 

    Presentation date: 2015

  • “c-axis parallel polarity inverted multilayer ZnO film resonators fabricated by grazing ion beam assisted RF magnetron sputtering”

    T. Mori, T. Yanagitani, M. Suzuki

    IEEE International Ultrasonics Symposium 

    Presentation date: 2015

  • “Ultrasound radiation from bone transducer in the MHz range”

    S. Matsukawa, H. Tsuneda, I. Mano, K. Mizuno, T. Yanagitani, S. Takayanagi, M. Matsukawa

    IEEE International Ultrasonics Symposium 

    Presentation date: 2015

  • “Quasi-shear mode electromechanical coupling k'15 and shear wave velocity in c-axis tilted ScxAl1-xN films”

    M. Suzuki, T. Yanagitani

    IEEE International Ultrasonics Symposium 

    Presentation date: 2015

  • “Elastic constant cij E tensors of (0001) ScxAl1-xN films (x=0-0.63)”

    T. Yanagitani, H. Ichihashi, M. Suzuki, S. Takayanagi, M. Matsukawa

    IEEE International Ultrasonics Symposium 

    Presentation date: 2015

  • “c-Axis parallel oriented ScAlN films grown by ion-beam assisted RF magnetron sputtering”

    M. Oka, S. Takayanagi, T. Yanagitani, M. Matsukawa

    IEEE International Ultrasonics Symposium 

    Presentation date: 2015

  • “Conductivity measurement of liquid by SH-SAW sensor consisting of IDT/(11-20) oriented ZnO film/silica glass substrate “

    S. Hiyama, T. Yanagitani, S. Takayanagi, M. Matsukawa

    IEEE International Ultrasonics Symposium 

    Presentation date: 2015

  • “High order mode polarity inverted Al-polar (0001) ScAlN/O-polar (000-1) ZnO film resonator”

    T. Mori, T. Yanagitani, M. Suzuki

    IEEE International Ultrasonics Symposium 

    Presentation date: 2015

  • “Fast wave velocity measurement by Brillouin scattering using induced phonon from ScAlN piezoelectric thin film”

    M. Kawabe, T. Yanagitani, H. Ichihashi, S. Takayanagi, M. Suzuki, M. Matsukawa

    IEEE International Ultrasonics Symposium 

    Presentation date: 2015

  • Elastic constants c11 and c66 in ScxAl1-xN films determined by Brillouin scattering method

    The 35th Symposium on Ultrasonic Electronics 

    Presentation date: 2014

  • Brillouin scattering measurement using induced phonon from ScAlN piezoelectric thin film

    The 35th Symposium on Ultrasonic Electronics 

    Presentation date: 2014

  • Effects of microstructure on bone piezoelectricity in the MHz range

    The 35th Symposium on Ultrasonic Electronics 

    Presentation date: 2014

  • Propagation characteristics of SH-wave in c-axis parallel oriented ZnO film/silica glass pipe

    The 35th Symposium on Ultrasonic Electronics 

    Presentation date: 2014

  • Second overtone mode (0001)/(000-1) ScAlN multilayer FBARs fabricated by anode RF bias

    The 35th Symposium on Ultrasonic Electronics 

    Presentation date: 2014

  • Second overtone mode polarization inverted HBAR consisting of (001)/(00-1) PbTiO3 epitaxial

    The 35th Symposium on Ultrasonic Electronics 

    Presentation date: 2014

  • PbTiO3エピタキシャル薄膜を用いた二次モード分極反転共振子

    Presentation date: 2014

  • 極性反転ScAlN系薄膜の境界を伝搬するセザワ波の高い電気機械結合係数

    高柳真司, 柳谷隆彦, 松川 真美

    EMシンポジウム2014 

    Presentation date: 2014

  • イオン照射による極性反転 ScAlN 薄膜の形成と高次モードFBAR への応用

    柳谷隆彦, 鈴木雅視

    EMシンポジウム2014 

    Presentation date: 2014

  • 超音波照射により皮質骨に発生する誘発電位の検討

    Presentation date: 2014

  • 極性反転ZnOおよびAlN系薄膜の境界を伝搬するセザワ波の高い電気機械結合係数

    Presentation date: 2014

  • RFバイアス三極スパッタ法によるイオン照射を用いたO面,Zn面,a面およびm面ZnO薄膜の配向制御

    Presentation date: 2014

  • c軸平行配向ZnO膜/平面・円管状石英上を伝搬するSH-SAWの液体センサ応用

    Presentation date: 2014

  • Bi(Me)O3-PbTiO3 高キュリー温度セラミックスの単結晶薄膜化

    Presentation date: 2014

  • イオンビーム照射成膜によるc軸垂直配向希土類GaN薄膜の形成

    Presentation date: 2014

  • エピタキシャルPZT 厚膜を用いた高温600℃における高効率超音波励振

    Presentation date: 2014

  • 圧電効果を利用した導電率計測技術

    Presentation date: 2014

  • PZT系エピタキシャル薄膜を用いた二次モード分極反転共振子

    Presentation date: 2014

  • c軸傾斜ScAlN薄膜の擬似すべりモード電気機械結合係数

    Presentation date: 2014

  • 音響電気効果を考慮したGaN単結晶のGHz域音速の温度・周波数分散測

    Presentation date: 2014

  • エピタキシャルPZT系厚膜の高温550℃における高い電気機械結合係数

    Presentation date: 2014

  • Second overtone mode polarization inverted resonator consisting of (001)/(00-1) PbTiO3 thin film

    IEEE International Ultrasonics Symposium 

    Presentation date: 2014

  • RF bias induced polarity inversion of ScAlN film for overtone mode BAW resonator

    IEEE International Ultrasonics Symposium 

    Presentation date: 2014

  • Effect of Sc concentration on shear wave velocities in ScAlN films measured by micro-Brillouin scattering technique

    IEEE International Ultrasonics Symposium 

    Presentation date: 2014

  • Effect of sputtering target temperature on crystalline orientations of ZnO piezoelectric films in RF magnetron sputtering

    IEEE International Ultrasonics Symposium 

    Presentation date: 2014

  • Polarity of piezoelectric properties in bone induced by ultrasound irradiation

    IEEE International Ultrasonics Symposium 

    Presentation date: 2014

  • Sezawa mode SAW with high electromechanical coupling at the boundary of polarization-inverted (000-1)/(0001) ZnO, AlN and ScAlN films

    IEEE International Ultrasonics Symposium 

    Presentation date: 2014

  • Multiple shear wave roundtrips liquid sensor by c-axis parallel oriented ZnO film/silica glass pipe structure

    IEEE International Ultrasonics Symposium 

    Presentation date: 2014

  • Measurement of Polarization Structure in Layered Piezoelectric Thin Films Using Scanning Nonlinear Dielectric Microscopy

    European Conference on Application of Polar Dielectrics 2014 

    Presentation date: 2014

  • High electromechanical coupling in PZT epitaxial thick film resonators at 550 degC

    IEEE International Frequency Control Symposium 

    Presentation date: 2014

  • Second harmonic mode polarization inverted resonator consisting of PbTiO3 thin film

    IEEE International Frequency Control Symposium 

    Presentation date: 2014

  • High Tc / High Coupling Perovskite Thin Films

    2014 Joint IEEE ISAF-IWATMD-PFM 

    Presentation date: 2014

  • Sezawa Mode SAW with High Electromechanical Coupling at The Boundary of Polarization-Inverted ScAlN Film Stuructures

    Presentation date: 2014

  • Polarity-inverted ScAlN film growth by ion beam irradiation and application to high overtone acoustic wave film resonators

    Presentation date: 2014

  • RFバイアススパッタ法により生じる高エネルギー正イオン照射を利用した六方晶系薄膜の配向制御

    Presentation date: 2013

  • c軸配向ZnO薄膜を用いた極性反転高次モード多層共振子

    Presentation date: 2013

  • c軸傾斜配向ZnOまたはScAlN膜のレイリーSAWにおける高い電気機械結合

    Presentation date: 2013

  • Brillouin散乱法によるGaN単結晶の音波物性測定

    Presentation date: 2013

  • c軸配向ZnO膜の極性制御と極性反転高次モード共振子への応用

    Presentation date: 2013

  • IDT/c軸平行配向ZnO膜/円柱状石英ガラス上を多重周回するSH-SAWの液体中伝搬特性

    Presentation date: 2013

  • c軸平行配向ZnO膜を用いた厚みすべりモード共振子によるアポリポタンパク質の濃度評価

    Presentation date: 2013

  • c軸傾斜配向ZnOまたはScAlN膜のレイリーSAWにおける高い電気機械結合係数

    Presentation date: 2013

  • 高温で高い圧電性を持つMnドープZnO薄膜

    Presentation date: 2013

  • 厚み共振を利用した圧電薄膜成長初期における無配向層の厚み評価

    Presentation date: 2013

  • 超音波照射による骨の誘発電位

    Presentation date: 2013

  • MHz域の超音波照射による骨の誘発電位

    Presentation date: 2013

  • 超音波骨トランスデューサの受波感度の検討

    Presentation date: 2013

  • RFバイアススパッタ法による高エネルギー正イオン照射を用いた六方晶系圧電薄膜の配向制御

    Presentation date: 2013

  • c-axis parallel oriented multilayer AlN film grown by ion-beam assisted deposition

    Presentation date: 2013

  • Brillouin 散乱法を用いたGaN 単結晶の音速分散測定

    Presentation date: 2013

  • ScAlN 膜における相境界付近のGHz 帯圧電特性と弾性温度係数

    Presentation date: 2013

  • GHz 帯超音波励振を用いたエピタキシャルPZT 薄膜の分極反転挙動観察

    Presentation date: 2013

  • c 軸傾斜および平行配向ScAlN 薄膜/ 基板構造における弾性表面波の高い電気機械結合係数

    Presentation date: 2013

  • イオンビームアシスト成膜法によるc軸平行螺旋構造AlN薄膜の形成

    Presentation date: 2013

  • イオンビームアシスト成膜によるc軸平行極性反転AlN多層構造の形成

    Presentation date: 2013

  • 希土類を添加したGaN薄膜の相境界付近における巨大圧電性

    Presentation date: 2013

  • PZT系単結晶薄膜のGHz帯圧電特性とバイアス印可時の分極反転挙動

    Presentation date: 2013

  • 希土類を添加したAlNおよびGaN薄膜の圧電特性

    Presentation date: 2013

  • AlN系薄膜におけるイオンビームを用いたc軸平行螺旋構造およびc軸垂直極性反転構造の形成

    Presentation date: 2013

  • 平行配向ZnO圧電薄膜を用いた液中横波励振デバイス

    Presentation date: 2013

  • 「講演奨励賞受賞記念講演」イオンビーム照射成膜によるAlN薄膜の極性・配向制御および極性反転多層構造の形成

    Presentation date: 2013

  • Characterization of GHz electromechanical properties of PZT single crystalline thin Films without removing substrate

    IEEE 2013 Joint UFFC, EFTF and PFM Symposium 

    Presentation date: 2013

  • PZT-based high coupling with low permittivity thin films

    IEEE 2013 Joint UFFC, EFTF and PFM Symposium 

    Presentation date: 2013

  • Enhancement of electromechanical coupling kt in rare earth doped c-axis oriented GaN films

    IEEE 2013 Joint UFFC, EFTF and PFM Symposium 

    Presentation date: 2013

  • Electromechanical coupling kt and GHz longitudinal wave velocity in ScAlN films near phase boundary

    IEEE 2013 Joint UFFC, EFTF and PFM Symposium 

    Presentation date: 2013

  • Polarity control of c-axis oriented ZnO films and application to polarity-inverted ZnO multilayer resonators

    IEEE 2013 Joint UFFC, EFTF and PFM Symposium 

    Presentation date: 2013

  • Shear and longitudinal GHz elastic properties in GaN single crystals determined by Brillouin scattering method

    IEEE 2013 Joint UFFC, EFTF and PFM Symposium 

    Presentation date: 2013

  • Orientation control of ZnO films by highly-energetic positive ion irradiation using RF substrate bias sputtering

    IEEE 2013 Joint UFFC, EFTF and PFM Symposium 

    Presentation date: 2013

  • Multiple roundtrip SH-SAW liquid sensor using c-axis parallel oriented ZnO films on silica glass pipe

    IEEE 2013 Joint UFFC, EFTF and PFM Symposium 

    Presentation date: 2013

  • Detection of antigen-antibody reaction by thickness-shear mode resonators consisting of caxis parallel oriented ZnO films

    IEEE 2013 Joint UFFC, EFTF and PFM Symposium 

    Presentation date: 2013

  • Electrical potentials in wet induced by ultrasound irradiation

    European Symposium on Ultrasonic Characterization of Bone 2013 

    Presentation date: 2013

  • Polarization control of c-axis normal ScAlN film by ion beam irradiation

    International Symposium on Advanced Plasma Science and its Applications 

    Presentation date: 2013

  • c軸配向ZnO薄膜における基板へのイオン照射を用いたZn面またはO面極性制御

    Presentation date: 2012

  • MHz域における骨の電気機械変換特性

    Presentation date: 2012

  • c軸傾斜配向ZnO膜/石英基板構造のレイリーSAWにおける高い電気機械結合係数

    Presentation date: 2012

  • RFバイアススパッタ法によるc軸平行配向AlN及びScAlN薄膜の形成

    Presentation date: 2012

  • RFマグネトロンスパッタ法における基板へのイオン照射を用いた c軸配向ZnO薄膜の極性制御

    Presentation date: 2012

  • 圧電薄膜の配向制御技術と液中横波励振

    Presentation date: 2012

  • マグネトロンスパッタ源から生成される高エネルギー負イオン照射によるZnO膜の配向制御

    Presentation date: 2012

  • c軸平行配向ZnO膜を用いたSH-SAWセンサによる液体の導電率測定

    Presentation date: 2012

  • イオンビームアシストスパッタ法によるc軸平行AlN薄膜/石英基板の形成

    Presentation date: 2012

  • マグネトロンスパッタ源から生成する高速負イオンを利用したZnO膜の配向制御

    Presentation date: 2012

  • (0001)配向AlNおよびScAlN薄膜を用いた極性反転共振子

    Presentation date: 2012

  • Sc粒スパッタによる巨大圧電性(0001)ScAlN薄膜の作製 -効率的なSc代替材料探索を目指した成膜法-

    Presentation date: 2012

  • 希土類-III-IV族系巨大圧電性薄膜やPZT単結晶薄膜の相境界の実験的研究

    Presentation date: 2012

  • Al2O3粒スパッタ法よる(0001)配向ScAlN薄膜の極性制御と極性反転共振子

    Presentation date: 2012

  • 巨大圧電性 (0001) ScAlGaN薄膜

    Presentation date: 2012

  • c 軸垂直極性反転ScAlN 多層膜を用いた高次モード音響共振子

    Presentation date: 2012

  • イオンビーム照射成膜による(0001)配向ScAlN薄膜の極性制御と極性反転構造の実現

    Presentation date: 2012

  • Sc粒スパッタによる巨大圧電性(0001)ScAlN薄膜共振子の作製

    Presentation date: 2012

  • c軸平行配向AlN圧電膜を用いた高次モード極性反転すべりモード共振子

    Presentation date: 2012

  • High electromechanical coupling of PMnN-PZT thin film resonator operating in the GHz range

    IEEE International Ultrason. Symp 

    Presentation date: 2012

  • Fast hypersonic velocity measurement by Brillouin scattering from induced phonons

    IEEE International Ultrason. Symp 

    Presentation date: 2012

  • Metal grain ingot sputtering method for ScAlN film fabrication and for searching alternative element of Sc

    IEEE International Ultrason. Symp 

    Presentation date: 2012

  • Polarization inverted (0001)/(000-1) ScAlN film resonators operating in second overtone mode

    IEEE International Ultrason. Symp 

    Presentation date: 2012

  • Micro liquid viscometer by thickness-shear mode resonator with c-axis parallel oriented ZnO film

    IEEE International Ultrason. Symp 

    Presentation date: 2012

  • Bone ultrasound transducer in the MHz range

    IEEE International Ultrason. Symp 

    Presentation date: 2012

  • Fabrication of c-axis parallel oriented AlN and ScAlN films by RF bias sputtering

    IEEE International Ultrason. Symp 

    Presentation date: 2012

  • Polarization control of the c-axis oriented ZnO films by ion bombardment during an RF magnetron sputtering

    IEEE International Ultrason. Symp 

    Presentation date: 2012

  • Sc 粒のスパッタにより作製したScAlN 薄膜の電気機械結合係数

    Presentation date: 2011

  • IBAD 法によるc 軸平行配向AlN 薄膜を用いた極性反転多層膜すべり共振子

    Presentation date: 2011

  • IBAD法を用いたc軸平行配向AlN薄膜の作製および極性反転すべり共振子への応用

    Presentation date: 2011

  • c軸平行配向ZnO膜/非晶質基板上を伝搬するSH-SAWの電気機械結合係数

    Presentation date: 2011

  • ZnO圧電薄膜によるGHz域の励起フォノンを利用した高速Brillouin散乱測定

    Presentation date: 2011

  • 曲面試料上に成膜したZnO 薄膜からの励起フォノンによるBrillouin 散乱

    Presentation date: 2011

  • c軸平行配向ZnO膜/非圧電性基板構造におけるSH-SAWの電気機械結合係数およびセンサ応用の検討

    Presentation date: 2011

  • c軸平行配向AlN薄膜を用いた極性反転すべり共振子

    Presentation date: 2011

  • Polarizaion-inverted multilayered pure shear mode AlN film resonator

    IEEE International Ultrason. Symp 

    Presentation date: 2011

  • c-axis parallel oriented AlN film resonator fabricated by ion-beam assisted RF magnetron sputtering

    IEEE International Ultrason. Symp 

    Presentation date: 2011

  • Brillouin scattering from induced phonons excited by the ZnO piezoelectric thin film with a coaxial resonator

    IEEE International Ultrason. Symp 

    Presentation date: 2011

  • High temperature piezoelectricity in Mn doped ZnO film

    IEEE International Ultrason. Symp 

    Presentation date: 2011

  • c-axis parallel oriented ZnO film SH-SAW sensor for electrical conductivity measurement in liquid

    IEEE International Ultrason. Symp 

    Presentation date: 2011

  • Quantitative analysis of the effect of energetic particle bombardment during deposition on (11-20) ZnO piezoelectric films

    IEEE International Ultrason. Symp 

    Presentation date: 2011

  • Three dimensional anisotropy of ultrasonic wave velocity in bovine cortical bone - Effects of HAp crystallites orientation and microstructure -

    Presentation date: 2010

  • c-axis parallel oriented ZnO film depositions by variable frequency RF bias sputtering

    The 31th Symposium on Ultrasonic Electronics 

    Presentation date: 2010

  • Giant shear mode electromechanical coupling in c-axis tilted ScAlN films

    Presentation date: 2010

  • In-plane and out-of-plane orientation control of AlN films by ion beam assisted RF magnetron sputtering

    Presentation date: 2010

  • Observation of induced phonons by ZnO transducer with coaxial microwave resonator using Brillouin scattering

    The 31th Symposium on Ultrasonic Electronics 

    Presentation date: 2010

  • ウシ左右大腿骨皮質骨中の特徴的な3次元音速異方性 ~ 最大音速方向の骨軸からのずれについて ~

    Presentation date: 2010

  • Brillouin散乱法による同軸共振器と圧電薄膜を用いた励起フォノンの観測

    Presentation date: 2010

  • RFバイアススパッタ法によるc軸平行配向ZnO薄膜の形成 ~ バイアス周波数が配向性に及ぼす影響 ~

    Presentation date: 2010

  • c 軸傾斜配向ScAlN 膜の擬似すべりモードにおける巨大圧電性

    Presentation date: 2010

  • Brillouin 散乱法による導電性ZnO 単結晶を用いた擬似すべりモード電気機械結合係数k15´の評価

    Presentation date: 2010

  • RFバイアススパッタ法による簡便な(11-20)および(10-10)配向ZnO膜の形成

    Presentation date: 2010

  • 傾斜配向AlN膜の結晶粒界と横波音響特性

    Presentation date: 2010

  • Brillouin散乱法による圧電半導体の面内方向抵抗率評価

    Presentation date: 2010

  • 傾斜配向AlN膜の構造が横波音響特性におよぼす影響

    Presentation date: 2010

  • RFバイアススパッタ法による簡便な面内配向ZnO薄膜の形成

    Presentation date: 2010

  • Highest wave velocity direction in the bovine cortical bone: observation of a small tilt relative to the bone axis

    IEEE International Ultrasonics Symposium 

    Presentation date: 2010

  • Deposition techniques of c-axis-tilted ScAlN films by conventional RF magnetron sputtering

    IEEE International Ultrasonics Symposium 

    Presentation date: 2010

  • Influence of shadowing effect on shear mode acoustic properties in the c-axis tilted AlN films

    IEEE International Ultrasonics Symposium 

    Presentation date: 2010

  • Effects of HAp alignment and microstructure on the anisotropy of longitudinal wave velocity in bovine cortical bone

    IEEE International Ultrasonics Symposium 

    Presentation date: 2010

  • A simple technique for obtaining (11-20) or (10-10) textured ZnO films by RF bias sputtering

    IEEE International Ultrasonics Symposium 

    Presentation date: 2010

  • Giant shear mode electromechanical coupling coefficient k15 in c-axis tilted ScAlN films

    IEEE International Ultrasonics Symposium 

    Presentation date: 2010

  • Anisotropy of longitudinal wave velocity in spherically shaped bovine cortical bone

    The third international conference on the development of Biomedical Engineering 

    Presentation date: 2010

  • Piezoelectric properties of c-axis highly tilted AlN films

    The 30th Symposium on Ultrasonic Electronics 

    Presentation date: 2009

  • Multilayer shear mode resonator consisting of c-axis tilted ZnO films

    The 30th Symposium on Ultrasonic Electronics 

    Presentation date: 2009

  • Crystallographic characteristics of (11-20) textured ZnO piezoelectric films fabricated by magnetron sputtering with linear erosion

    The 30th Symposium on Ultrasonic Electronics 

    Presentation date: 2009

  • Measurement of in-plane electric properties in a wide band-gap semiconductor by Brillouin scattering method

    The 30th Symposium on Ultrasonic Electronics 

    Presentation date: 2009

  • ウシ大腿骨皮質骨の縦波音速異方性とHAp結晶配向

    山本 和史, 大和 雄, 山崎 薫, 長野 昭, 矢追 佑一郎, 中辻 智宏, 松川 真美, 柳谷隆彦

    日本整形外科学会基礎学術集会 

    Presentation date: 2009

  • 直線状エロージョンマグネトロンスパッタリングによる(11-20)配向ZnO圧電膜の大面積成膜

    Presentation date: 2009

  • Brillouin散乱法による圧電半導体の面内方向電気特性評価に関する検討

    Presentation date: 2009

  • c軸傾斜反転配向ZnO多層膜の作製と横波共振子への応用

    Presentation date: 2009

  • ウシ大腿骨皮質骨中の超音波縦波音速 ハイドロキシアパタイト結晶配向と微細構造の影響

    Presentation date: 2009

  • ヒト及びウシ円環状皮質骨における骨軸方向への超音波伝搬特性

    Presentation date: 2009

  • Brillouin散乱法による圧電半導体の面内方向抵抗率分布の評価

    Presentation date: 2009

  • Relationships between anisotropy of longitudinal wave velocity and HAp orientation in bovine cortical bone

    3rd European Symposium on Ultrasonic Characterization of Bone 

    Presentation date: 2009

  • Measurement of electric properties in a ZnO single crystal via electromechanical coupling using Brillouin scattering method

    IEEE International Ultrasonics Symposium 

    Presentation date: 2009

  • Multilayered shear wave resonator consisting of c-axis tilted ZnO films

    IEEE International Ultrasonics Symposium 

    Presentation date: 2009

  • Anisotropy of longitudinal wave velocity and HAp orientation in bovine cortical bone

    International Congress on Ultrasonics (ICU) 2009 

    Presentation date: 2009

  • Ultrasonic wave properties in the bone axis direction of human and bovine cortical bone

    International Congress on Ultrasonics (ICU) 2009 

    Presentation date: 2009

  • Anisotropy of longitudinal ultrasound velocity and HAp orientation in bovine cortical bone

    The 29th Symposium on Ultrasonic Electronics 

    Presentation date: 2008

  • Pure-shear mode BAW resonator consisting of (1120) textured AlN films

    The 29th Symposium on Ultrasonic Electronics 

    Presentation date: 2008

  • Electromechanical coupling coefficient of semiconducting piezoelectric crystal measured by Brillouin scattering

    The 29th Symposium on Ultrasonic Electronics 

    Presentation date: 2008

  • イオン照射による六方晶系薄膜の配向制御と横波モード圧電デバイス

    Presentation date: 2008

  • (11-20)配向AlN圧電薄膜を用いた純横波モード共振子

    Presentation date: 2008

  • Brillouin散乱法を用いた六方晶系圧電薄膜の評価

    Presentation date: 2008

  • Pure-shear mode BAW resonators consisting of (11-20) textured ZnO films

    Acoustics 08 

    Presentation date: 2008

  • Observation of induced shear acoustic phonons by Brillouin scattering

    Acoustic 08 

    Presentation date: 2008

  • Ultrasonic wave properties in the bone axis direction of bovine cortical bone

    Acoustic 08 

    Presentation date: 2008

  • Pure-shear mode BAW resonator consisting of (10-10) and (11-20) textured AlN films

    IEEE International Ultrasonics Symposium 

    Presentation date: 2008

  • Electromechanical coupling coefficient of semiconducting hexagonal crystal measured by Brillouin scattering

    IEEE International Ultrasonics Symposium 

    Presentation date: 2008

  • 超音波による骨質の評価

    Presentation date: 2007

  • Propagation characteristics of SH-SAW in (11-20) ZnO film/silica glass substrate structures

    The 28th Symposium on Ultrasonic Electronics 

    Presentation date: 2007

  • A c-axis tilted ZnO film transducer for simultaneous excitation of longitudinal and shear waves

    The 28th Symposium on Ultrasonic Electronics 

    Presentation date: 2007

  • Texture control of ZnO piezoelectric films by ion beam irradiation

    The 28th Symposium on Ultrasonic Electronics 

    Presentation date: 2007

  • (11-20)ZnO膜/石英基板構造のSH型SAW伝搬特性

    Presentation date: 2007

  • c軸傾斜配向ZnO膜を用いたVHF帯縦波横波同時励振トランスデューサ

    Presentation date: 2007

  • c軸傾斜配向ZnO 膜を用いた縦波横波同時励振トランスデューサ

    Presentation date: 2007

  • (11-20)面配向ZnO膜/石英基板構造のSH型SAW伝搬特性

    Presentation date: 2007

  • Brillouin 散乱法を用いたガラス中の横波励起フォノンの観測

    Presentation date: 2007

  • 面内配向ZnO 多結晶膜/基板構造におけるSH 型SAW 特性

    Presentation date: 2007

  • (11-20)ZnO膜/石英基板構造におけるSH型SAW特性

    Presentation date: 2007

  • イオンチャネリング効果によるZnO圧電膜の配向制御に関する検討

    Presentation date: 2007

  • c軸傾斜配向ZnO膜の電気機械結合係数と縦波横波同時励振トランスデューサへの適用

    Presentation date: 2007

  • Thin film stack transducer for simultaneous generation of longitudinal and shear waves at same frequency

    IEEE Ultrason. Symp 

    Presentation date: 2007

  • Ion beam sputter-deposited ZnO thin film for broadband shear wave excitation in the GHz range

    IEEE Ultrason. Symp 

    Presentation date: 2007

  • Highly oriented c-axis 23° tilted ZnO films with high quasi-shear mode electromechanical coupling coefficients

    IEEE Ultrason. Symp 

    Presentation date: 2007

  • Propagation characteristics of SH-SAW in (11 0) ZnO layer/silica glass substrate structures

    IEEE Ultrason. Symp 

    Presentation date: 2007

  • Effect of the preference of hydroxyapatite crystallites on longitudinal wave velocity at small ROIs in bovine cortical bone

    International congress on Ultrasonics 

    Presentation date: 2007

  • 横波モード圧電デバイスを目的としたイオンビームアシスト蒸着法による面内配向ZnO薄膜の作製

    Presentation date: 2006

  • Observation of induced shear acoustic phonons by Brillouin scattering

    Presentation date: 2006

  • Longitudinal wave velocity and orientation of HAp crystallites in local area of bovine femoral cortical bone

    Presentation date: 2006

  • Characteristics of shear mode FBAR using (11-20) textured ZnO films

    Presentation date: 2006

  • Effects of sputtering gas on the formation of (11-20) textured ZnO films

    Presentation date: 2006

  • c軸傾斜配向ZnO 膜の形成および圧電特性

    Presentation date: 2006

  • 面内配向ZnO 膜を用いたすべりモード薄膜共振子の特性

    Presentation date: 2006

  • ウシ皮質骨の弾性異方性と結晶配向性

    Presentation date: 2006

  • 面内配向ZnO膜のk15の評価およびすべりモード薄膜共振子への応用

    Presentation date: 2006

  • Elastic anisotropy and crystallites orientation of the bovine cortical bone

    17th International Bone Densitometry Workshop 

    Presentation date: 2006

  • The effect of hydroxyapatite crystallite orientation on ultrasonic velocity in bovine cortical bone

    4th Joint Meeting Acoustical Society of America and Acoustical Society of Japan 

    Presentation date: 2006

  • Elastic Anisotropy and Crystallites Orientation in Bovine Cortical Bone

    IEEE Ultrason. Symp 

    Presentation date: 2006

  • Temperature Characteristics of Pure Shear Mode FBARs Consisted of (11 0) Textured

    IEEE Ultrason. Symp 

    Presentation date: 2006

  • Study on Formation Mechanism of (11-20) Textured ZnO Films

    IEEE Ultrason. Symp 

    Presentation date: 2006

  • Effect of the crystallites orientation on the elastic anisotropy in the bovine cortical bone

    The 9th Western Pacific Acoustics Conference 

    Presentation date: 2006

  • The relationship between acoustic anisotropy and crystal orientation in bovine cortical bone

    1st European Symposium on Ultrasonic Characterization of Bone 

    Presentation date: 2006

  • 牛皮質骨の超音波伝搬特性と結晶配向

    Presentation date: 2005

  • 面内配向ZnO薄膜の結晶性向上と膜厚均一化に関する検討

    Presentation date: 2005

  • 面内配向ZnO膜の圧電性評価と共振器への応用

    Presentation date: 2005

  • 面内配向ZnO膜の電気機械結合係数k15の評価

    Presentation date: 2005

  • 面内配向ZnO薄膜の作製条件に関する検討

    Presentation date: 2005

  • 面内配向ZnO膜の圧電性

    Presentation date: 2005

  • 顕微ブリユアン光散乱法を用いたZnO薄膜の非破壊評価

    Presentation date: 2005

  • (11-20)面配向ZnO圧電膜の結晶性向上および膜厚分布の低減

    Presentation date: 2005

  • 面内配向ZnO薄膜を用いた横波トランスデューサの変換特性

    Presentation date: 2005

  • Higher-order shear mode FBAR using polarization-inverted layers of (11 0) textured

    IEEE Ultrason. Symp 

    Presentation date: 2005

  • Electromechanical coupling coefficient k15 of (11 0) textured ZnO films

    IEEE Ultrason. Symp 

    Presentation date: 2005

  • 顕微ブリユアン光散乱法による面内配向ZnOフィルムの評価

    Presentation date: 2004

  • 面内配向ZnO薄膜を用いたトランスデューサの評価

    Presentation date: 2004

  • 横波励振を目的とした面内配向ZnO薄膜の結晶性向上に関する検討

    Presentation date: 2004

  • 面内配向ZnO 薄膜を用いた横波トランスデューサ

    Presentation date: 2004

  • (11-20)面配向ZnO薄膜による横波トランスデューサの作製

    Presentation date: 2004

  • Shear Wave Transducer Using (11-20) Textured ZnO Film

    IEEE Ultrason. Symp 

    Presentation date: 2004

  • Nondestructive evaluation of thin ZnO shear transducer by Brillouin scattering

    IEEE Ultrason. Symp 

    Presentation date: 2004

  • 面内配向ZnO 薄膜による横波励振の検討

    Presentation date: 2003

  • 横波励振を目的とした面内配向ZnO薄膜の開発

    Presentation date: 2003

  • ZnO薄膜を用いた横波トランスデューサの検討

    Presentation date: 2003

  • 金属膜上に作製されたZnO 面内一方向配向膜の特性

    Presentation date: 2003

▼display all

Specific Research

  • 分極反転構造圧電薄膜を用いた耐電力性RFフィルタ

    2021  

     View Summary

    圧電効果を用いて波長の短い音波に用いることで、1 mm 角程度の小型フィルタ(BAWフィルタ)がスマートフォンに実用化している。しかし、この方式では耐電力性は1 W程度で、20 W以上が必要な基地局用途では使えない。そのため、基地局用途では、耐電力性を重視して、電磁波をそのまま使った空洞共振器フィルタが使われている。速度の速い電磁波を使うため波長が長く、10 cm以上のサイズとなる。しかしながら、基地局を手軽に大量に設置するニーズは高まるばかりで、小型化が急務である。本研究では、耐電力性の向上が見込まれる分極反転ScAlN多層薄膜SMRの作製および耐電力性の評価系構築に成功した。

  • 5G向け高耐圧RFフィルタ応用に向けた分極反転多層構造の圧電薄膜の開発

    2020  

     View Summary

    同じ動作周波数の薄膜共振子において、n層の分極反転多層構造の膜厚はn倍となり、耐電圧性を向上できると考えられる。基板をターゲットに対して斜めに配置することで、スパッタされた粒子を基板に対して斜めに入射させて、c軸傾斜したScAlN膜を成長させた。c軸ジグザグ構造は、各層の成膜後に基板を180度回転させることによって得た。4層c軸ジグザグ構造ScAlN薄膜を用いた基板なし(FBAR型)圧電共振子についてネットワークアナライザを用いてSパラメータ測定を行い、4次モードの共振特性を確認した。Masonの等価回路モデルによる計算結果ともよく一致した。

  • 巨大圧電性窒化物の厚膜化による高電圧用圧電アクチュエータの実現

    2019  

     View Summary

    計画通り、電子ビーム加熱真空溶解法によるScAl合金スパッタターゲットの合成を行った。ターゲットから飛来する酸素負イオンによって下することが予想されている。ScとAlを合金化すると酸化しにくくなる傾向があることがわかっている。今回、高真空還元雰囲気化で、Sc金属とAl金属を混合溶解させ、ScAl合金スパッタターゲットを作製することに成功した。さらに、。Matlabを用いて電気―機械結合等価回路モデルの構築と分極反転層の圧電薄膜の特性シミュレーションを行った。積層の設計やインピーダンスを含めた挿入損失や整合の特性をシミュレーションすることができた。また、圧電厚膜の電気機械結合係数の新しい評価法および計測系の構築も行っている。

  • 高速負イオン発生抑制成膜による希土類添加AIN薄膜の巨大圧電性発現

    2018   唐澤嶺, 遠藤結佳, 清水貴博, 正宗千明, 松田有佳

     View Summary

    本研究では,製法及び不純物含有量の異なるScAl合金ターゲットを用意し,スパッタ成膜時に発生する負イオン照射量及びScAlN薄膜の圧電性へ及ぼす影響を比較した.アーク溶融ターゲット,焼結ターゲット,電子ビーム溶融ターゲットの3種類のScAl合金ターゲットについてスパッタ成膜中の酸素負イオンO-及び窒化炭素負イオンCN-の発生量を計測した.ScAlN薄膜共振子を作製し,電気機械結合係数kt2を推定した結果,アーク溶融ターゲットで20.6%,焼結ターゲットで20.1%,電子ビーム溶融ターゲットで20.3%と,いずれのターゲットを用いても共に先行研究(kt2=18.5%)よりも高い圧電性を示したが,3種類のターゲットに大きな差は見られなかった.

  • 巨大圧電性薄膜を用いた高感度プローブによる高分解能超音波像装置

    2017  

     View Summary

    本研究は、超音波映像装置に応用することを目指して、巨大圧電効果を持つ常誘電体薄膜について数十μm以上の厚膜成長させる技術を確立することを目的としている。RFマグネトロンスパッタ法を用いて膜応力を低減することで厚さ43μmのScAlN厚膜トランスデューサの作製に成功した.ScAlN(0002)X線回折ピークのロッキングカーブ半値幅が4.4ºであり良好な配向性を示した。ネットワークアナライザで縦波変換損失を測定した結果、共振周波数が81MHzのときの電気機械結合係数ktは0.43とPZT系に匹敵する値であった.現在、広く実用化されているPVDF高分子膜と比べるとktがはるかに大きいこと示された。

  • 極性反転多層構造の圧電薄膜を用いた高分解能超音波プロープの実現

    2015   鈴木雅視

     View Summary

    超音波顕微鏡装置において画像を高分解能化するには、超音波の高周波化と高出力化が必要である。また、高周波化するには使用する圧電体を薄膜化する。本研究では、圧電薄膜を極性反転多層させることにより、周波数を保ったまま耐電圧性を向上させかつ励振面積を大きくし、超音波出力を向上させるものである。本研究では、圧電薄膜の中では最も圧電性の大きなScAlN薄膜とZnO薄膜についてスパッタリング成膜法による成長実験を行った。その結果、ZnO薄膜では300℃以上でプラズマ柱外では配向性が良いものが得られ、極性はO極性となることがわかった。これに対して、ScAlN薄膜では室温でプラズマ柱内では配向性が良いものが得られ、極性はAl極性となることを発見した。そこで、この技術を用いてAu上部電極薄膜/Al極性ScAlN薄膜/O極性ZnO薄膜/高配向Ti下部電極薄膜/石英ガラス基板構造の極性反転超音波プローブの作製に成功した。励振面積は2層反転することにより予想どおり2倍となった(50Ω整合時の面積が2倍)。この研究成果に基づいてIEEE超音波国際会議おける受賞(2016年)、超音波シンポジウム奨励賞(2016年)、応用物理学会講演奨励賞(2016年)を受賞した。

  • 横波超音波の固有振動数変動による抗原抗体反応の高感度質量計測

    2015   鈴木雅視

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    圧電薄膜の固有振動数変動を用いた高感度質量計測センサについて研究を行った。センサの面積を大きくすれば、それに比例して雑音(共振ピークの雑音)を小さくしていくことができ、測定感度を高くすることができると考えられる。しかし、50Ω計測系と整合させるにはセンサのキャパシタンスが定まり、おのずと電極面積が決定される。(膜厚は共振周波数で決定)。本研究では、イオンビームスパッタ法を用いて、酸素イオンビームの照射法を反転させることにより、極性が互いに反転したZnO圧電薄膜を積層成長する技術を開発した。作製した薄膜は高い横波圧電効果を有していることも確認した。これにより、共振周波数を維持したまま膜厚を反転層数倍させ、50Ω整合したままセンサ面積を反転層数倍させたセンサの作製に成功した。

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Syllabus

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Committee Memberships

  • 2014.12
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    Now

    Scientific Reports (Nature Publishing Group) Editorial Board member

  • 2013.10
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    Now

    IEEE UFFC ( IUS Technical Program Committee) IEEE IUS Technical Program Committee

  • 2012.04
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    Now

    日本音響学会誌査読委員 日本音響学会誌 査読委員(2012年04月-現在)

  • 2010.04
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    Now

    超音波エレクトロニクスシンポジウム運営委員 運営委員(2010年04月-現在)

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    弾性波素子技術コンソーシアム 幹事

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    電気情報通信学会超音波研究会専門員

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    日本学術振興会弾性波素子技術第150委員会委員

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    圧電材料・デバイスシンポジウム運営委員

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    EMデバイス・システムの新技術調査専門委員会 幹事

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