Researcher basic information

• Ph.D. in Biochemistry and Biotechnology, Tokyo University of Agriculture and Technology, 2008
• Master of Agriculture, Tokyo University of Agriculture and Technology, 2005
• Bachelor of Agriculture, Tokyo University of Agriculture and Technology, 2003

• https://researchmap.jp/zenji.yatabe?lang=en

• https://orcid.org/0000-0003-2069-6677
• https://jglobal.jst.go.jp/detail?JGLOBAL_ID=201001063938165263
• https://researchmap.jp/zenji.yatabe/link

• 00621773

• https://orcid.org/0000-0003-2069-6677

• A-5506-2012

• 201001063938165263

• Compound semiconductors
• Surfaces and interfaces
• Mist-CVD
• Fluctuations

• Nanotechnology/Materials, Thin film/surface and interfacial physical properties
• Manufacturing Technology (Mechanical Engineering, Electrical and Electronic Engineering, Chemical Engineering), Electron device and electronic equipment
• Natural Science, Semiconductors, optical properties of condensed matter and atomic physics
• Natural Science, Biophysics, chemical physics and soft matter physics

Research activity information

• Dec. 2024, 熊本大学 大学院先導機構 URA推進室, 熊本大学Top 10 研究者 2024
  Citation部門、Top%部門
  谷田部 然治, Japan, 13160044
• Sep. 2016, The Japan Society of Applied Physics, 38th JSAP Paper Award
  Characterization of electronic states at insulator/(Al)GaN interfaces for improved insulated gate and surface passivation structures of GaN-based transistors
  Zenji Yatabe;Yujin Hori;Joel T. Asubar;Masamichi Akazawa;Taketomo Sato;Tamotsu Hashizume, Official journal, Japan

• Deposition of ternary hafnium aluminum oxide alloy thin films via single-source mist chemical vapor deposition
  Thin Nu Soe; Yusui Nakamura; Zenji Yatabe
  Journal of the Ceramic Society of Japan, 134, 5, 341, 346, The Ceramic Society of Japan, Feb. 2026, [Peer-reviewed], [Last author, Corresponding author], [Domestic magazines]
  English, Scientific journal, In this study, hafnium aluminum oxide (Hf1-xAlxOy) alloy thin films were successfully deposited using a fine-channel, single-source mist chemical vapor deposition (mist-CVD) system. The precursor solution was prepared by co-dissolving hafnium (Hf) and aluminum (Al) precursors in methanol. Hf1-xAlxOy films with different Al compositions in the range 0 ≤ x ≤ 1 were prepared and then characterized using grazing incidence X-ray diffraction (GIXRD), spectroscopic ellipsometry, and X-ray reflectivity measurements. GIXRD analysis confirmed that the incorporation of Al in HfO2 led to the formation of amorphous alloy films (x > 0.38). Increasing the Al content in the film decreased the refractive index and mass density while widening the bandgap, reflecting the compositional change from HfO2 to Al2O3. Moreover, the properties of the mist-CVD-derived Hf1-xAlxOy films were comparable to those reported in the literature, which were prepared via conventional vacuum-based atomic layer deposition. These findings suggest that mist-CVD is a promising solution-processed and non-vacuum technique for depositing high-quality Hf1-xAlxOy alloy films., 42033928
• Low interface state density in Al₂O₃/n-GaN MOS capacitors with rapid deposition of Al₂O₃ gate insulator fabricated via mist-CVD
  Hadirah A. Radzuan; Masaya Fukumitsu; Ryota Ochi; Yusui Nakamura; Taketomo Sato; Zenji Yatabe
  Japanese Journal of Applied Physics, 64, 7, 070906-1, 5, IOP Publishing, Jul. 2025, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal, This study highlights the potential of mist chemical vapor deposition (mist-CVD) as an eco-friendly, cost-effective gate insulator deposition method for GaN-based metal-oxide-semiconductor (MOS) devices. We deposited an Al2O3 gate insulator on homoepitaxial n-GaN structures via mist-CVD. We found that mist-CVD achieved a deposition rate of 30 nm min−1. From an admittance analysis, quantitative characterizations confirmed low interface state density at the Al2O3/n-GaN interface near the conduction band edge, in the range of 1010 cm−2eV−1. These findings demonstrate that mist-CVD exhibits performance comparable to the conventional deposition method, atomic layer deposition, highlighting the potential of mist-CVD for GaN-based MOS device applications., 42033928
• Interface state density in mist chemical vapor deposited Al₂O₃/AlGaN/GaN structure
  Keigo Bito; Masaki Ishiguro; Hadirah A. Radzuan; Hikaru Hiroshige; Tomohiro Motoyama; Yusui Nakamura; Joel T. Asubar; Zenji Yatabe
  Japanese Journal of Applied Physics, 63, 8, 080905-1, 4, IOP Publishing, Aug. 2024, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal, Uniform thickness Al2O3 thin films have been deposited by eco-friendly mist chemical vapor deposition (CVD). The obtained Al2O3 film have optical band gap value of more than 6.5 eV and refractive index of 1.64 at 633 nm (≈ 2.0 eV). The combination of capacitance–voltage (C–V) fitting method with non-linear least-squares algorithm, frequency dispersion, photo-assisted and proposed reverse bias-assisted C–V methods revealed interface state densities ranging from 1 × 1012 to 3 × 1013 cm−2eV−1 along the mist-Al2O3/AlGaN interface. These values are comparable to those reported for atomic layer deposited Al2O3 thin films., 42033928;42033915
• Evidence of reduced interface states in Al₂O₃/AlGaN MIS structures via insertion of ex-situ regrown AlGaN layer
  Ali Baratov; Shinsaku Kawabata; Shun Urano; Itsuki Nagase; Masaki Ishiguro; Shogo Maeda; Takahiro Igarashi; Toi Nezu; Zenji Yatabe; Maciej Matys; Tetsu Kachi; boguslawa adamowicz; Akio Wakejima; Masaaki Kuzuhara; Akio Yamamoto; Joel T. Asubar
  Applied Physics Express, 15, 10, 104002-1, 5, IOP Publishing, Sep. 2022, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal, We report on the impact of the 3-nm-thick ex-situ AlGaN regrown layer prior to insulator deposition on the interfacial properties of Al2O3/AlGaN/GaN metal-insulator-semiconductor (MIS) structures. MIS-capacitors (MIScaps) with regrown AlGaN layer exhibited anomalously excessive threshold voltage shift compared to reference sample without regrown AlGaN, suggesting highly reduced interface states density (Dit). Moreover, MIScaps with regrown AlGaN layer exhibited “spill-over” in the capacitance-voltage (C-V) profiles, further evidencing the improved Al2O3/AlGaN interfaces. Fabricated three-terminal MIS-HEMTs with regrown AlGaN showed less hysteresis in transfer curves, enhanced maximum drain current, and increased linearity over the reference device., 13160044
• Ornstein–Uhlenbeck process in a human body weight fluctuation
  Zenji Yatabe; Joel T. Asubar
  Physica A: Statistical Mechanics and its Applications, 582, 126286-1, 6, Elsevier BV, Nov. 2021, [Peer-reviewed], [Lead author, Corresponding author], [International Magazine]
  English, Scientific journal
• Controlling surface/interface states in GaN-based transistors: Surface model, insulated gate, and surface passivation
  Joel T. Asubar; Zenji Yatabe; Dagmar Gregusova; Tamotsu Hashizume
  Journal of Applied Physics, 129, 12, 121102-1, 28, AIP Publishing, Mar. 2021, [Peer-reviewed], [Invited], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal, Invited Tutorials Article
  
  Gallium nitride (GaN) is one of the front-runner materials among the so-called wide bandgap semiconductors that can provide devices having high breakdown voltages and are capable of performing efficiently even at high temperatures. The wide bandgap, however, naturally leads to a high density of surface states on bare GaN-based devices or interface states along insulator/semiconductor interfaces distributed over a wide energy range. These electronic states can lead to instabilities and other problems when not appropriately managed. In this Tutorial, we intend to provide a pedagogical presentation of the models of electronic states, their effects on device performance, and the presently accepted approaches to minimize their effects such as surface passivation and insulated gate technologies. We also re-evaluate standard characterization methods and discuss their possible pitfalls and current limitations in probing electronic states located deep within the bandgap. We then introduce our own photo-assisted capacitance–voltage (C–V) technique, which is capable of identifying and examining near mid-gap interface states. Finally, we attempt to propose some directions to which some audience can venture for future development., 13160044
• GaN-based MIS-HEMTs with Al₂O₃ dielectric deposited by low-cost and environmental-friendly mist-CVD technique
  Rui Shan Low; Joel T. Asubar; Ali Baratov; Shunsuke Kamiya; Itsuki Nagase; Shun Urano; Shinsaku Kawabata; Hirokuni Tokuda; Masaaki Kuzuhara; Yusui Nakamura; Kenta Naito; Tomohiro Motoyama; Zenji Yatabe
  Applied Physics Express, 14, 3, 031004-1, 5, IOP Publishing, Feb. 2021, [Peer-reviewed], [Last author, Corresponding author], [International Magazine]
  English, Scientific journal, We report on the fabrication and characterization of AlGaN/GaN metal-insulator-semiconductor (MIS) capacitors and high-electron-mobility transistors (MIS-HEMTs) using a 5 nm thick Al2O3 dielectric deposited by cost-effective and environmental-friendly mist chemical vapor deposition (mist-CVD) technique. Practically hysteresis-free capacitance–voltage profiles were obtained from the fabricated two-terminal MIS-capacitors indicating high quality of the mist-Al2O3/AlGaN interface. Compared with reference Schottky-gate HEMTs, mist MIS-HEMTs exhibited much improved performance including higher drain current on-to-off ratio, much lower gate leakage current in both forward and reverse directions and lower subthreshold swing. These results demonstrate the potential and viability of non-vacuum mist-CVD Al2O3 in the development of high-performance GaN-based MIS-HEMTs., 13160044
• Inverse integral transformation method to derive local viscosity distribution measured by optical tweezers
  Ruri Hidema; Zenji Yatabe; Hikari Takahashi; Ryusei Higashikawa; Hiroshi Suzuki
  Soft Matter, 16, 29, 6826, 6833, Royal Society of Chemistry (RSC), Jul. 2020, [Peer-reviewed], [International Magazine]
  English, Scientific journal, Complex fluids have a non-uniform local inner structure; this is enhanced under deformation, inducing a characteristic flow, such as an abrupt increase in extensional viscosity and drag reduction. However, it is challenging to derive and quantify the non-uniform local structure of a low-concentration solution. In this study, we attempted to characterize the non-uniformity of dilute and semi-dilute polymer and worm-like micellar solutions using the local viscosity at the micro scale. The power spectrum density (PSD) of the particle displacement, measured using optical tweezers, was analyzed to calculate the local viscosity, and two methods were compared. One is based on the PSD roll-off method, which yields a single representative viscosity of the solution. The other is based on our proposed method, called the inverse integral transformation method (IITM), for deriving the local viscosity distribution. The distribution obtained through the IITM reflects the non-uniformity of the solutions at the micro scale, i.e., the distribution widens above the entanglement concentrations of the polymer or viscoelastic worm-like micellar solutions., 13376278
• Structural characterization of mist chemical vapor deposited amorphous aluminum oxide films using water-free solvent
  Zenji Yatabe; Koshi Nishiyama; Takaaki Tsuda; Yusui Nakamura
  Journal of the Ceramic Society of Japan, 127, 8, 590, 593, The Ceramic Society of Japan, Aug. 2019, [Peer-reviewed], [Lead author, Corresponding author], [Domestic magazines]
  English, Scientific journal, Excellent quality amorphous aluminum oxide (AlOx) thin films have been obtained by atmospheric pressure solution-processed mist chemical vapor deposition (mist-CVD) technique at 400°C using water-free solvent. X-ray fluorescence investigations verified the formation of AlOx film by the mist-CVD. X-ray diffraction, X-ray photoelectron spectroscopy, ellipsometry and X-ray reflectivity analyses revealed that the synthesized amorphous AlOx films have bandgap of 6.5 eV, refractive index of 1.64 and mass density of 2.78 g/cm3. These values are comparable to those reported for high-quality amorphous Al2O3 thin films deposited by atomic layer deposition method.
• Synthesis and characterization of mist chemical vapor deposited aluminum titanium oxide films
  Zenji Yatabe; Koshi Nishiyama; Takaaki Tsuda; Kazuki Nishimura; Yusui Nakamura
  Japanese Journal of Applied Physics, 58, 7, 070905-1, 4, Jul. 2019, [Peer-reviewed], [Lead author, Corresponding author], [International Magazine]
  English, Scientific journal, 13160044
• On the presence of Ga₂O sub-oxide in high-pressure water vapor annealed AlGaN surface by combined XPS and first-principles methods
  Mary Clare S. Escaño; Joel T. Asubar; Zenji Yatabe; Melanie Y. David; Mutsunori Uenuma; Hirokuni Tokuda; Yukiharu Uraoka; Masaaki Kuzuhara; Masahiko Tani
  Applied Surface Science, 481, 1120, 1126, Elsevier BV, Jul. 2019, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal, We conducted X-ray photoelectron spectroscopy (XPS) and first-principles calculations based on density functional theory (DFT) to confirm the presence of Ga2O sub-oxide in high-pressure water vapor annealed AlGaN surface. We note that the Ga 3d XPS peak broadens and shifts towards higher binding energies, which suggests surface oxide formation. Deconvoluted Ga 3d XPS profiles between HPWVA-treated and reference samples reveal reasonable inclusion of Ga2O peak, suggesting formation of Ga2O sub-oxide. To theoretically confirm the presence of Ga2O, we calculated the Ga 3d core-level shift using initial state approximation. We obtained a 0.74 eV shift, in reasonable agreement with that of Ga2O. Moreover, based on the calculation of net charge on Ga using DFT, we also obtained a +1 oxidation state for Ga, indicating its existence in Ga2O form. By combining theory and experiment, therefore, we have explored the possibility of the formation of Ga2O sub-oxide, which may provide new avenues for obtaining highly stable operation in GaN-based devices.
• Improved linearity, stability, and thermal performance of multi-mesa-channel AlGaN/GaN HEMTs
  Joel Tacla Asubar; Hirokuni Tokuda; Masaaki Kuzuhara; Zenji Yatabe; Kenya Nishiguchi; Tamotsu Hashizume
  PISIKA - Journal of the Physics Society of the Philippines, 1, 1, 11-1, 6, Physics Society of the Philippines (Samahang Pisika ng Pilipinas), Dec. 2018, [Peer-reviewed], [International Magazine]
  English, Scientific journal, With its wide bandgap of 3.4 eV, gallium nitride (GaN) is considered as a key semiconductor material for realizing ultra-low-loss power devices. However, GaN-based devices is still plagued by current collapse, which is the temporary reduction of current after application of electrical stress. In this work, we present the state-of-art Multi-Mesa-Channel (MMC) AlGaN/GaN HEMT being developed in our laboratory. The MMC HEMT is fabricated in a way to realize parallel mesa-shaped nano-channels separated by trenches. Investigations have revealed that the MMC HEMT is highly resistant to current collapse and other instabilities, making it a leading power electronics prospect.
• Structural characteristics of a non-polar ZnS layer on a ZnO buffer layer formed on a sapphire substrate by mist chemical vapor deposition
  Koshi Okita; Katsuhiko Inaba; Zenji Yatabe; Yusui Nakamura
  Japanese Journal of Applied Physics, 57, 6, 065503-1, 7, IOP Publishing, May 2018, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• State of the art on gate insulation and surface passivation for GaN-based power HEMTs
  Tamotsu Hashizume; Kenya Nishiguchi; Shota Kaneki; Jan Kuzmik; Zenji Yatabe
  Materials Science in Semiconductor Processing, 78, 85, 95, Elsevier BV, May 2018, [Peer-reviewed], [Invited], [Last author], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal
• Analytical derivation of charge relaxation time distribution in transistor from current noise spectrum using inverse integral transformation method
  Zenji Yatabe; Shinya Inoue; Joel T. Asubar; Seiya Kasai
  Applied Physics Express, 11, 3, 031201-1, 4, IOP Publishing, Feb. 2018, [Peer-reviewed], [Lead author], [International Magazine]
  English, Scientific journal
• Influence of oxygen-plasma treatment on AlGaN/GaN metal-oxide-semiconductor heterostructure field-effect transistors with HfO₂ by atomic layer deposition: leakage current and density of states reduction
  R. Stoklas; D. Gregušová; M. Blaho; K. Fröhlich; J. Novák; M. Matys; Z. Yatabe; P. Kordoš; T. Hashizume
  Semiconductor Science and Technology, 32, 4, 045018-1, 8, Apr. 2017, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal
• Improvement of m-plane ZnO films formed on buffer layers on sapphire substrates by mist chemical vapor deposition
  Hironobu Tanoue; Masato Takenouchi; Tatsuya Yamashita; Shohei Wada; Zenji Yatabe; Shoji Nagaoka; Yoshihiro Naka; Yusui Nakamura
  Physica Status Solidi A – Applications and Materials Science, 214, 3, 1600603-1, 5, Wiley, Mar. 2017, [Peer-reviewed], [International Magazine]
  English, Scientific journal, The crystal quality of ZnO films grown by mist chemical vapor deposition (mist-CVD) was improved by introducing ZnO buffer layers on sapphire substrates. The ZnO films were grown by high-speed rotation-type mist-CVD with a ZnCl2 aqueous solution, which provided uniform epitaxial layers over 2-inch wafers. To grow the ZnO buffer layers, it is necessary to form small grains of polycrystal. Therefore, we attempted to grow the ZnO buffer layers using a Zn(CH3COO)2 aqueous solution, which provides a small grain size of about 100 nm. By using the buffer layers, the full width at half-maximum of an X-ray ω-rocking curve for the ZnO film was reduced from 0.69° to 0.38°, showing improvement of the crystal quality.
• Single crystalline SnO₂ thin films grown on m-plane sapphire substrate by mist chemical vapor deposition
  Zenji Yatabe; Takaaki Tsuda; Junya Matsushita; Takehide Sato; Tatsuya Otabe; Koji Sue; Shoji Nagaoka; Yusui Nakamura
  Physica Status Solidi C – Current Topics in Solid State Physics, 14, 1-2, 1600148-1, 4, Wiley, Jan. 2017, [Peer-reviewed], [Lead author, Corresponding author], [International Magazine]
  English, International conference proceedings, 11191314
• On the origin of interface states at oxide/III-nitride heterojunction interfaces
  M. Matys; B. Adamowicz; A. Domanowska; A. Michalewicz; R. Stoklas; M. Akazawa; Z. Yatabe; T. Hashizume
  Journal of Applied Physics, 120, 22, 225305-1, 11, Dec. 2016, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal
• Highly-stable and low-state-density Al₂O₃/GaN interfaces using epitaxial n-GaN layers grown on free-standing GaN substrates
  Shota Kaneki; Joji Ohira; Shota Toiya; Zenji Yatabe; Joel T. Asubar; Tamotsu Hashizume
  Applied Physics Letters, 109, 16, 162104-1, 5, Oct. 2016, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Insulated gate and surface passivation structures for GaN-based power transistors
  Zenji Yatabe; Joel T. Asubar; Tamotsu Hashizume
  Journal of Physics D: Applied Physics, 49, 39, 393001-1, 19, Oct. 2016, [Peer-reviewed], [Invited], [Lead author, Corresponding author], [International Magazine]
  English, Scientific journal
• Characterization of capture cross sections of interface states in dielectric/III-nitride heterojunction structures
  M. Matys; R. Stoklas; J. Kuzmik; B. Adamowicz; Z. Yatabe; T. Hashizume
  Journal of Applied Physics, 119, 20, 205304-1, 7, May 2016, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal
• Formation of GaN porous structures with improved structural controllability by photoassisted electrochemical etching
  Yusuke Kumazaki; Zenji Yatabe; Taketomo Sato
  Japanese Journal of Applied Physics, 55, 4S, 04EJ12-1, 5, Mar. 2016, [Peer-reviewed], [International Magazine]
  English, Scientific journal, 10390615
• Large photocurrents in GaN porous structures with a redshift of the photoabsorption edge
  Taketomo Sato; Yusuke Kumazaki; Hirofumi Kida; Akio Watanabe; Zenji Yatabe; Soichiro Matsuda
  Semiconductor Science and Technology, 31, 1, 014012-1, 6, Jan. 2016, [Peer-reviewed], [International Magazine]
  English, Scientific journal, 10390615
• Impact of oxygen plasma treatment on the dynamic on-resistance of AlGaN/GaN high-electron-mobility transistors
  Joel T. Asubar; Yoshiki Sakaida; Satoshi Yoshida; Zenji Yatabe; Hirokuni Tokuda; Tamotsu Hashizume; Masaaki Kuzuhara
  Applied Physics Express, 8, 11, 111001-1, 4, Nov. 2015, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Bias-dependent Photoabsorption Properties of GaN Porous Structures under Back-side Illumination
  Taketomo Sato; Hirofumi Kida; Yusuke Kumazaki; Zenji Yatabe
  ECS Transactions, 69, 2, 161, 166, The Electrochemical Society, Oct. 2015, [Peer-reviewed], [Last author], [International Magazine]
  English, International conference proceedings, 10390615
• Current Collapse Reduction in AlGaN/GaN HEMTs by High Pressure Water Vapor Annealing
  Joel T. Asubar; Yohei Kobayashi; Koji Yoshitsugu; Zenji Yatabe; Hirokuni Tokuda; Masahiro Horita; Yukiharu Uraoka; Tamotsu Hashizume; Masaaki Kuzuhara
  IEEE Transactions on Electron Devices, 62, 8, 2423, 2428, Aug. 2015, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Interface trap states in Al₂O₃/AlGaN/GaN structure induced by inductively coupled plasma etching of AlGaN surfaces
  Zenji Yatabe; Joel T. Asubar; Taketomo Sato; Tamotsu Hashizume
  Physica Status Solidi (a) - Applications and Materials Science, 212, 5, 1075, 1080, May 2015, [Peer-reviewed], [Lead author, Corresponding author], [International Magazine]
  English, Scientific journal
• Formation of GaN-Porous Structures Using Photo-Assisted Electrochemical Process in Back-Side Illumination Mode
  Akio Watanabe; Yusuke Kumazaki; Zenji Yatabe; Taketomo Sato
  ECS Electrochemistry Letters, 4, 5, H11, H13, Mar. 2015, [Peer-reviewed], [International Magazine]
  English, Scientific journal, 10390615
• Calculating relaxation time distribution function from power spectrum based on inverse integral transformation method
  Zenji Yatabe; Toru Muramatsu; Joel T. Asubar; Seiya Kasai
  Physics Letters A, 379, 7, 738, 742, Mar. 2015, [Peer-reviewed], [Lead author], [International Magazine]
  English, Scientific journal
• Characterization of electronic states at insulator/(Al)GaN interfaces for improved insulated gate and surface passivation structures of GaN-based transistors
  Zenji Yatabe; Yujin Hori; Wan-Cheng Ma; Joel T. Asubar; Masamichi Akazawa; Taketomo Sato; Tamotsu Hashizume
  Japanese Journal of Applied Physics, 53, 10, 100213-1, 10, Sep. 2014, [Peer-reviewed], [Lead author], [International Magazine]
  English, Scientific journal
• Correlation between Structural and Photoelectrochemical Properties of GaN Porous Nanostructures Formed by Photo-Assisted Electrochemical Etching
  Yusuke Kumazaki; Akio Watanabe; Zenji Yatabe; Taketomo Sato
  Journal of The Electrochemical Society, 161, 10, 705, 709, Aug. 2014, [Peer-reviewed], [International Magazine]
  English, Scientific journal, 10390615
• Reduced thermal resistance in AlGaN/GaN multi-mesa-channel high electron mobility transistors
  Joel T. Asubar; Zenji Yatabe; Tamotsu Hashizume
  Applied Physics Letters, 105, 5, 053510-1, 5, Apr. 2014, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Interface Characterization and Control of GaN-based Heterostructures
  Tamotsu HASHIZUME; Zenji YATABE; Taketomo SATO
  Hyomen Kagaku, 35, 2, 96, 101, Surface Science Society Japan, Feb. 2014, [Peer-reviewed], [Domestic magazines]
  Japanese, Scientific journal, Interface properties of GaN-based heterostructures have been characterized. Schottky contacts on dry-etched n-GaN layers showed leaky I-V characteristics. An anneal process at 400°C was effective in recovering the rectifying characteristics. To characterize interface properties of Al2O3 insulated gates on AlGaN/GaN structures with and without the inductively coupled plasma (ICP) etching of AlGaN, we have developed a C-V calculation method taking into account electronic state charges at the Al2O3/AlGaN interface and a photoassisted C-V technique utilizing photons with energies less than the bandgap of AlGaN. It was found that the ICP etching caused the monolayer-level interface roughness, disorder of the chemical bonds and formation of various types of defect complexes at the AlGaN surface, resulting in poor C-V characteristics due to high-density interface states at the Al2O3/AlGaN interface.
• Characterization of interface states in Al₂O₃/AlGaN/GaN structures for improved performance of high-electron-mobility transistors
  Y. Hori; Z. Yatabe; T. Hashizume
  Journal of Applied Physics, 114, 24, 244503-1, 8, AIP Publishing, Dec. 2013, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Investigation on optical absorption properties of electrochemically formed porous InP using photoelectric conversion devices
  Yusuke Kumazaki; Tomohito Kudo; Zenji Yatabe; Taketomo Sato
  Applied Surface Science, 279, 116, 120, Elsevier BV, Jul. 2013, [Peer-reviewed], [International Magazine]
  English, Scientific journal, 10390615
• Formation and Photoelectrical Measurements of Pt Schottky Interfaces on InP Porous Structures
  Ryohei Jinbo; Yusuke Kumazaki; Zenji Yatabe; Taketomo Sato
  ECS Transactions, 50, 37, 247, 252, Mar. 2013, [Peer-reviewed], [International Magazine]
  English, International conference proceedings, 10390615
• Effects of Cl₂-Based Inductively Coupled Plasma Etching of AlGaN on Interface Properties of Al₂O₃/AlGaN/GaN Heterostructures
  Zenji Yatabe; Yujin Hori; Sungsik Kim; Tamotsu Hashizume
  Applied Physics Express, 6, 1, 016502-1, 4, IOP Publishing, Dec. 2012, [Peer-reviewed], [Lead author, Corresponding author], [International Magazine]
  English, Scientific journal
• Characterization of Low-Frequency Noise in Etched GaAs Nanowire Field-Effect Transistors Having SiN_x Gate Insulator
  Toru Muramatsu; Kensuke Miura; Yuta Shiratori; Zenji Yatabe; Seiya Kasai
  Japanese Journal of Applied Physics, 51, 6S, 06FE18-1, 5, Jun. 2012, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Large photocurrent-response observed at Pt/InP Schottky interface formed on anodic porous structure
  Ryohei Jinbo; Tomohito Kudo; Zenji Yatabe; Taketomo Sato
  Thin Solid Films, 520, 17, 5710, 5714, Jun. 2012, [Peer-reviewed], [International Magazine]
  English, Scientific journal
• Contraction behaviors of Vorticella sp. stalk investigated using high-speed video camera. II: Viscosity effect of several types of polymer additives
  Junko Kamiguri; Noriko Tsuchiya; Ruri Hidema; Zenji Yatabe; Masahiko Shoji; Chihiro Hashimoto; Robert Bernard Pansu; Hideharu Ushiki
  BIOPHYSICS, 8, 11, 19, Biophysical Society of Japan, Jan. 2012, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal
• Contraction behaviors of Vorticella sp. stalk investigated using high-speed video camera. I: Nucleation and growth model
  Junko Kamiguri; Noriko Tsuchiya; Ruri Hidema; Masatoshi Tachibana; Zenji Yatabe; Masahiko Shoji; Chihiro Hashimoto; Robert Bernard Pansu; Hideharu Ushiki
  BIOPHYSICS, 8, 1, 9, Biophysical Society of Japan, Jan. 2012, [Peer-reviewed], ［Internationally co-authored］, [Domestic magazines]
  English, Scientific journal
• Image analysis of thickness in flowing soap films. I: effects of polymer
  Ruri Hidema; Zenji Yatabe; Masahiko Shoji; Chihiro Hashimoto; Robert Pansu; Gabriel Sagarzazu; Hideharu Ushiki
  Experiments in Fluids, 49, 3, 725, 732, Sep. 2010, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal
• Size evolution of onion structure under oscillatory shear flow
  Zenji Yatabe; Ruri Hidema; Chihiro Hashimoto; Robert Bernard Pansu; Hideharu Ushiki
  Chemical Physics Letters, 475, 1-3, 101, 104, Jun. 2009, [Peer-reviewed], [Lead author, Corresponding author], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal
• Formation process of shear-induced onion structure made of quaternary system SDS/octanol/water/NaCl
  Zenji Yatabe; Yasufumi Miyake; Masatoshi Tachibana; Chihiro Hashimoto; Robert Pansu; Hideharu Ushiki
  Chemical Physics Letters, 456, 1-3, 31, 35, Apr. 2008, [Peer-reviewed], [Lead author, Corresponding author], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal
• Fluorescence lifetime imaging microscopy for in situ observation of the nanocrystallization of rubrene in a microfluidic set-up
  Serge Desportes; Zenji Yatabe; Sébastien Baumlin; Valérie Génot; Jean-Pierre Lefèvre; Hideharu Ushiki; Jacques Alexis Delaire; Robert Bernard Pansu
  Chemical Physics Letters, 446, 1-3, 212, 216, Sep. 2007, [Peer-reviewed], ［Internationally co-authored］, [International Magazine]
  English, Scientific journal

• Cover
  Thin Nu Soe; Yusui Nakamura; Zenji Yatabe, Journal of the Ceramic Society of Japan, 134, 5, H5, 1, May 2026, [Invited], [Last author, Corresponding author], [International Magazine]
  The Ceramic Society of Japan, English, 42033928
• Analysis of 1/f noise by extracting charge relaxation time distribution using inverse integral transformation
  Zenji Yatabe; Seiya Kasai, The Papers of Technical Meeting on "Electron Devices", IEE Japan, EDD-26-037, 11, 14, Mar. 2026, [Lead author, Corresponding author], [Domestic magazines]
  The Institute of Electrical Engineers of Japan (IEEJ), Japanese, Summary national conference, 42033928
• Mist Thermal Oxidation of GaN Surface
  Zenji Yatabe; Ryosuke Hamasuna; Takumi Hirakura; Thin Nu Soe; Yusui Nakamura, IEICE technical report. Electron devices, 125, 257, 53, 56, Nov. 2025, [Lead author, Corresponding author], [Domestic magazines]
  Mist chemical vapor deposition (CVD) is an eco-friendly and cost-effective technique mainly used for oxide semiconductor growth. Recently, it has also been applied to other processes such as gate insulator deposition. In this study, we investigated the thermal oxidation of Si and GaN surfaces using mist-CVD to clarify its oxidation mechanism. The mist-oxidized SiO₂ films exhibited a refractive index and breakdown field comparable to those of conventional thermal SiO₂. For GaN, Ga₂O₃ films were formed above 800 °C. The analysis results indicate that the mist thermal oxidation mechanism is more similar to wet oxidation than to dry oxidation., The Institute of Electronics, Information and Communication Engineers (IEICE), Japanese, 42033928
• Mist Chemical Vapor Deposited Gate Dielectrics for GaN-Based MOS Device
  Zenji Yatabe; Masaya Fukumitsu; Hiroshi Otake; Takumi Hirakura; Hadirah Radzuan; Ryota Ochi; Yusui Nakamura; Taketomo Sato, IEICE technical report. Electron devices, 124, 278, 69, 72, Nov. 2024, [Lead author, Corresponding author], [Domestic magazines]
  GaN-based metal-oxide-semiconductor (MOS) transistors are promising for next-generation high-frequency and high-power devices. A gate dielectric plays an important role in blocking the leakage current. High-quality gate dielectrics have been reportedly obtained using atomic layer deposition (ALD) technique and related vacuum deposition methods. One alternative approach to obtain high-quality gate dielectrics is the mist chemical vapor deposition (mist-CVD), which can deposit various metal oxide thin films from relative non-toxic and nonpyrophoric aqueous solution under atmospheric pressure. In this work, we report on the deposition of Al2O3-based thin films by mist-CVD method. Finally, we have fabricated and characterized GaN-based MOS devices with gate dielectrics deposited by mist-CVD., The Institute of Electronics, Information and Communication Engineers (IEICE), Japanese, Introduction scientific journal, 42033928;42033915
• Insulated gate structures for GaN-based devices using mist-CVD method
  Zenji Yatabe; Hadirah Radzuan; Keigo Bito; Masaya Fukumitsu; Ryota Ochi; Taketomo Sato, The Papers of Technical Meeting on "Electron Devices", IEE Japan, EDD-24-032, 13, 17, Jun. 2024, [Lead author, Corresponding author], [Domestic magazines]
  GaN-based transistors are promising for high-power and high-frequency devices. A gate insulator plays an important role in blocking the leakage current. In this study, we report on the deposition of Al2O3 thin films by mist-CVD method. Finally, we have characterized GaN-based MIS capacitors using Al2O3 insulator deposited by mist-CVD., The Institute of Electrical Engineers of Japan (IEEJ), Japanese, Summary national conference, 42033928;42033915
• Mist chemical vapor deposited-gate insulators for GaN-based MIS devices applications
  Zenji Yatabe; Yusui Nakamura; Joel T. Asubar, 2022 IEEE International Meeting for Future of Electron Devices, Kansai (IMFEDK), 1, 3, Nov. 2022, [Invited], [Lead author, Corresponding author], [International Magazine]
  Mist chemical vapor deposition (mist-CVD) is a non-vacuum technique for depositing various metal oxide/sulfite films from relative non-toxic and nonpyrophoric aqueous solution, resulting in relatively simple, low-cost and fast deposition rate under atmospheric pressure. Recent reports have demonstrated the capability of mist-CVD as an able replacement for conventional vacuum deposition methods in some applications. In this work, firstly state-of-the-art literature reports on mist-CVD techniques are reviewed. Finally, we highlight the important progress in mist-CVD deposited-gate insulators for GaN-based metal-insulator-semiconductor (MIS) devices applications., Institute of Electrical and Electronics Engineers (IEEE), English, Introduction international proceedings
• Mist chemical vapor deposited-Al₂O₃/AlGaN interfacial characterization for GaN MIS-HEMTs
  Tomohiro Motoyama; Zenji Yatabe; Yusui Nakamura; Ali Baratov; Rui Shan Low; Shun Urano; Joel T. Asubar; Masaaki Kuzuhara, 2021 IEEE International Meeting for Future of Electron Devices, Kansai (IMFEDK), 1, 2, Nov. 2021, [Corresponding author], [International Magazine]
  Amorphous Al2O3 gate insulator on AlGaN/GaN structure have been deposited by cost-effective mist chemical vapor deposition (mist-CVD) technique. The properties of deposited mist-Al2O3 gate insulators are comparable to those reported for high-quality amorphous Al2O3 films deposited by atomic layer deposition (ALD) method. In addition, we have fabricated AlGaN/GaN metal–insulator–semiconductor (MIS) diodes using Al2O3 gate insulator deposited by mist-CVD. We obtained practically hysteresis-free with spill-over behavior in capacitance–voltage (C–V) characteristics from the fabricated mist-Al2O3 MIS diodes suggesting high interfacial quality of the mist-Al2O3/AlGaN interface., Institute of Electrical and Electronics Engineers (IEEE), English, Introduction international proceedings, 13160044
• Recessed gate GaN-based MIS-HEMTs with Al₂O₃ gate dielectric deposited by mist-CVD method
  M. Ishiguro; S. Urano; R. S. Low; M. Faris; I. Nagase; A. Baratov; J. T. Asubar; T. Motoyama; Y. Nakamura; Z. Yatabe; M. Kuzuhara, 2021 IEEE International Meeting for Future of Electron Devices, Kansai (IMFEDK), 1, 2, Nov. 2021, [International Magazine]
  We report on the fabrication of recessed gate AlGaN/GaN metal-insulator-semiconductor (MIS) high-electron-mobility transistors (HEMTs) with Al2O3 gate dielectric deposited by mist-CVD method. The fabricated device exhibited a high positive threshold voltage of 1.5 V in combination of high maximum drain current of 450 mA/mm, demonstrating robust enhancement-mode operation., Institute of Electrical and Electronics Engineers (IEEE), English, Introduction international proceedings, 13160044
• Electrical properties of GaN-based MIS-HEMTs with Al₂O₃ gate insulator deposited by ALD and mist-CVD techniques
  S. Urano; R. S. Low; M. Faris; M. Ishiguro; I. Nagase; A. Baratov; J. T. Asubar; T. Motoyama; Y. Nakamura; Z. Yatabe; M. Kuzuhara, 2021 IEEE International Meeting for Future of Electron Devices, Kansai (IMFEDK), 1, 2, Nov. 2021, [International Magazine]
  In this work, we compare the performance of AlGaN/GaN metal-insulator-semiconductor high-electron mobility transistors (MIS-HEMTs) with gate dielectric Al2O3 prepared by either ALD or mist-CVD. While for MIS-HEMTS with ALD-Al2O3 gate insulator, the threshold voltage becomes more negative with increasing thickness of Al2O3 as expected, we found that for MIS-HEMTS with mist-Al2O3 gate insulator, the threshold voltage is anomalously almost independent of Al2O thickness. We believe that these findings have potential exciting applications for achieving normally-off operation in AlGaN/GaN MIS-HEMTs., Institute of Electrical and Electronics Engineers (IEEE), English, Introduction international proceedings, 13160044
• GaN-based MIS-HEMTs with Mist Chemical Vapor Deposited Al₂O₃
  Rui Shan Low; Itsuki Nagase; Ali Baratov; Joel Tacla Asubar; Hirokuni Tokuda; Masaaki Kuzuhara; Zenji Yatabe; Kenta Naito; Motoyama Tomohiro; Yusui Nakamura, IEICE technical report. Electron devices, 120, 254, 49, 52, Nov. 2020, [Corresponding author], [Domestic magazines]
  We have fabricated AlGaN/GaN metal-insulator-semiconductor high-electron mobility transistors (MIS-HEMTs) using Al2O3 gate dielectric deposited by mist chemical vapor deposition (mist-CVD) technique. The mist-Al2O3 MISHEMTs exhibited highly improved performance compared with the Schottky-gate devices. We obtained practically hysteresis-free transfer curves and capacitance-voltage profiles from the fabricated mist-Al2O3 MIS-HEMTs suggesting high interfacial quality of the mist-Al2O3/AlGaN structure., The Institute of Electronics, Information and Communication Engineers (IEICE), Japanese, 13160044
• Epitaxial Tin Oxide Films on Sapphire Substrate Grown by Mist Chemical Vapor Deposition
  Thant Zin Win; Takumi Furukawa; Yuki Kanetake; Katsuhiko Inaba; Zenji Yatabe; Yusui Nakamura, Proceedings of 10th International Conference on Science and Engineering 2019, ICSE2019, EE-2, Dec. 2019
  English, Introduction international proceedings
• Synthesis and characterization of AlTiO films by mist-CVD
  Zenji Yatabe; Koshi Nishiyama; Takaaki Tsuda; Kazuki Nishimura; Yusui Nakamura, 2019 Compound Semiconductor Week (CSW), TuP-H-3, May 2019, [Lead author, Corresponding author], [International Magazine]
  Institute of Electrical and Electronics Engineers (IEEE), English, Introduction international proceedings, 13160044
• Effect of Buffer Layer on Improvement of SnO₂ Thin Film on Sapphire Substrate Formed by Mist Chemical Vapor Deposition
  Thant Zin Win; Takumi Furukawa; Yudai Tanaka; Koshi Okita; Koji Sue; Zenji Yatabe; Yusui Nakamura, 2019 Compound Semiconductor Week (CSW), TuP-H-5, May 2019, [International Magazine]
  Institute of Electrical and Electronics Engineers (IEEE), English, Introduction international proceedings
• Characterization of amorphous aluminium oxide thin films synthesized by mist-CVD
  Zenji Yatabe; Koshi Nishiyama; Takaaki Tsuda; Kazuki Nishimura; Yusui Nakamura, 2019 Compound Semiconductor Week (CSW), TuP-H-6, May 2019, [Lead author, Corresponding author], [International Magazine]
  Institute of Electrical and Electronics Engineers (IEEE), English, Introduction international proceedings, 13160044
• Effect of Buffer Layer on the Structural Properties of Tin Oxide Thin Film on Sapphire Substrate by Mist Chemical Vapor Deposition
  Thant Zin Win; Takumi Furukawa; Yudai Tanaka; Koshi Okita; Kensuke Minami; Koji Sue; Zenji Yatabe; Yusui Nakamura, Proceedings of the Engineering Workshop 2018, OC- 6, Nov. 2018, [Domestic magazines]
  English, Introduction international proceedings
• Formation of N-doped ZnO thin films formed by annealing in NH₃ gas ambient
  Takumi Furukawa; Masato Takenouchi; Yudai Tanaka; Koji Sue; Shoji Nagaoka; Zenji Yatabe; Yusui Nakamura, Proceedings of the Engineering Workshop 2018, PC- 6, Nov. 2018, [Domestic magazines]
  English, Introduction international proceedings
• Epitaxial growth of non-polar ZnO films on buffer layers on sapphire substrates by mist chemical vapor deposition
  Yudai Tanaka; Yuki Nagao; Takumi Furukawa; Zenji Yatabe; Koji Sue; Shoji Nagaoka; Yusui Nakamura, Proceedings of the Engineering Workshop 2018, PC-9, Nov. 2018, [Domestic magazines]
  English
• Mist-CVD deposition of AlTiO thin films for potential applications in AlGaN/GaN MOS-HEMTs
  K. Nishiyama; K. Nishimura; T. Tsuda; Z. Yatabe; K. Sue; Y. Nakamura, Proceedings of the Engineering Workshop 2018, PC- 3, Nov. 2018, [Corresponding author], [Domestic magazines]
  English, Introduction international proceedings
• Mist-chemical vapor deposition grown-single crystalline oxide semiconductors
  Zenji Yatabe; Hironobu Tanoue; Koshi Okita; Masato Takenouchi; Takahiro Ishida; Takaaki Tsuda; Tomoki Mikuriya; Shoji Nagaoka; Koji Sue; Yusui Nakamura, Proceedings of the 35th Samahang Pisika ng Pilipinas Physics Conference, 35, 1, INV-1B-01-1, 4, Jun. 2017, [Invited], [Lead author, Corresponding author], [International Magazine]
  English, Introduction international proceedings
• Cover Picture: Phys. Status Solidi C 1–2/2017
  Zenji Yatabe; Takaaki Tsuda; Junya Matsushita; Takehide Sato; Tatsuya Otabe; Koji Sue; Shoji Nagaoka; Yusui Nakamura, Physica Status Solidi C – Current Topics in Solid State Physics, 14, 1-2, 1770012-1, 1, Jan. 2017, [Invited], [Lead author], [International Magazine]
  In order to obtain good crystallographic properties of tin dioxide, a candidate for realizing next-generation electrical and optical devices, relatively expensive film formation methods such as MOCVD or MBE are required. One alternative approach is a mist chemical vapour deposition (mist-CVD), which can form various oxide semiconductors under atmospheric pressure with a simple and less expensive technique. Yatabe et al. (article No. 1600148) have grown SnO2 thin films on 2-inch diameter m-plane sapphire substrates by mist-CVD at atmospheric pressure. From XRD and EBSD measure¬ments the authors found that the SnO2 films were epitaxially grown on the substrates under optimised growth condition. Epitaxial growth of the SnO2 thin film at three typical areas on the substrate was confirmed by EBSD measurements. Finally, a second SnO2 layer was overgrown on the single-crystalline SnO2 thin film, which functioned as a buffer layer (see cover image). This method drastically improved the surface rough¬ness of the second SnO2 layer., Wiley, English, Others, 11191314
• Improved linearity, stability, and thermal performance of multi-mesa-channel AlGaN/GaN HEMTs
  Joel T. Asubar; Hirokuni Tokuda; Masaaki Kuzuhara; Zenji Yatabe; Kenya Nishiguchi; Tamotsu Hashizume, Proceedings of the 34th Samahang Pisika ng Pilipinas Physics Congress, 34, INV-1B-01-1, 4, Aug. 2016, [Invited], [International Magazine]
  English, Introduction international proceedings
• Improvement of m-plane ZnO films formed on buffer layers on sapphire substrates by mist chemical vapor deposition
  Hironobu Tanoue; Tatsuya Yamashita; Shohei Wada; Zenji Yatabe; Shoji Nagaoka; Yusui Nakamura, 2016 Compound Semiconductor Week (CSW) [Includes 28th International Conference on Indium Phosphide & Related Materials (IPRM) & 43rd International Symposium on Compound Semiconductors (ISCS), 53, MoP-ISCS-103, 34, Jun. 2016, [International Magazine]
  Institute of Electrical and Electronics Engineers (IEEE), English, Introduction international proceedings
• SnO₂ thin films grown on m-plane sapphire substrate by mist chemical vapor deposition
  Tatsuya Otabe; Takehide Sato; Junya Matsushita; Zenji Yatabe; Koji Sue; Shoji Nagaoka; Yusui Nakamura, 2016 Compound Semiconductor Week (CSW) [Includes 28th International Conference on Indium Phosphide & Related Materials (IPRM) & 43rd International Symposium on Compound Semiconductors (ISCS), MoP-ISCS-101, Jun. 2016, [Corresponding author], [International Magazine]
  English, Introduction international proceedings, 11243091
• Electrochemical formation and UV photoresponse properties of GaN porous structures
  Hirofumi Kida; Yusuke Kumazaki; Zenji Yatabe; Taketomo Sato, IEICE technical report. Electron devices, 115, 170, 51, 54, Jul. 2015, [Domestic magazines]
  Photoresponse and photoabsorption properties of GaN porous structures were investigated by measuring photocurrent and spectroscopic photoabsorption under monochromatic light with various wavelengths. The measured photocurrents on the porous GaN electrode were larger than those on the planar electrodes due to the unique features of the former electrode, such as large surface area and low photoreflectance properties. Moreover, the photocurrents were observed even under illumination with wavelength of 380 nm, corresponding to photon energy of 3.26 eV, which is 130 meV lower than the bandgap energy of bulk GaN. The observed redshift of the photoabsorption edge can be qualitatively explained by the Franz-Keldysh effect., The Institute of Electronics, Information and Communication Engineers (IEICE), Japanese, 10390615
• Interface states characterization of Al₂O₃/AlGaN/GaN structures
  Zenji Yatabe; Tamotsu Hashizume, IEICE technical report. Silicon Device and Materials, 115, 108, 1, 4, Jun. 2015, [Invited], [Lead author, Corresponding author], [Domestic magazines]
  To characterize interface properties of Al2O3-insulated gates on AlGaN/GaN structures with and without (w/o) ICP etching of AlGaN surface, in this work, we compared the measured capacitance-voltage (C-V) characteristics with those calculated, considering interface states density at the Al2O3/AlGaN interface. As a complementary method, photo-assisted C-V method utilizing photons with energies less than the bandgap of GaN was also used to probe the interface states density located near the midgap of the AlGaN. It was found that the ICP etching of the AlGaN surface significantly increased the interface state density at the Al2O3/AlGaN interface., The Institute of Electronics, Information and Communication Engineers (IEICE), Japanese, 10958502
• Effects of surface charging and interface states on current stability of GaN HEMTs
  T. Hashizume; Z. Yatabe; K. Nishiguchi, Proceedings of the 39th Workshop on Compound Semiconductor Devices and Integrated Circuits (WOCSDICE 2015), 51, 54, Jun. 2015, [International Magazine]
  English, Introduction international proceedings
• Spectro-electrochemical characterization of GaN/electrolyte interface and its application to the nanostructure formation
  Yusuke Kumazaki; Akio Watanabe; Zenji Yatabe; Taketomo Sato, IEICE technical report. Electron devices, 115, 63, 63, 66, May 2015, [Domestic magazines]
  The Institute of Electronics, Information and Communication Engineers (IEICE), Japanese, 10390615
• Control of Insulated Gate Interfaces for GaN-based Power Transistors
  Tamotsu Hashizume; Zenji Yatabe; Taketomo Sato, The Papers of Technical Meeting on "Electron Devices", IEE Japan, EDD-14, 39-49, 13, 16, Mar. 2014, [Invited], [Domestic magazines]
  最近は絶縁ゲート構造を持つ電力スイッチング用AlGaN/GaN高電子移動度トランジスタ（HEMT）の報告が急激に増加し、様々な絶縁膜が利用されている。パワートランジスタ応用に重要な、GaN系半導体の絶縁膜界面に関連する問題点を概説し、さらに、AlGaN/GaNヘテロ構造に形成した絶縁ゲート界面の電子準位を評価する手法を紹介し、いくつかの結果を報告する。, The Institute of Electrical Engineers of Japan (IEEJ), Japanese, Introduction scientific journal
• Photoelectrode properties of GaN porous structures formed by photo-assisted electrochemical process
  Yusuke Kumazaki; Akio Watanabe; Zenji Yatabe; Taketomo Sato, IEICE technical report. Electron devices, 113, 329, 113, 116, Nov. 2013, [Domestic magazines]
  Optical properties of GaN porous structures formed by the electrochemical process were investigated. We conducted the photo-assisted electrochemical etching for the formation of porous structures, and revealed that pore size and morphology were strongly influenced by the electrochemical conditions. According to the optical spectroscopic method, photoreflectance was so sensitive to the surface morphology and pore depth. By optimizing these structural properties, the photoelectric conversion efficiency was drastically improved at electrolyte/GaN interface, which indicates GaN porous structures are promising materials for use in photoelectrode., The Institute of Electronics, Information and Communication Engineers (IEICE), Japanese, 10390615
• Photoabsorption and Photoelectric Conversion Properties of InP Porous Structures Formed by the Electrochemical process
  Yusuke Kumazaki; Ryohei Jinbo; Zenji Yatabe; Taketomo Sato, IEICE technical report. Electron devices, 113, 39, 61, 64, May 2013, [Domestic magazines]
  We investigated the optical absorption properties of InP porous structures formed by the electrochemical process using photoelectric conversion (PC) devices formed on p-n junction substrates. We found from the results of the photocurrent measurements by changing the incident light power that the absorption properties of InP were enhanced after the formation of porous structures showing the low photoreflectance properties. Then, we proposed the photoelectric conversion devices based on the porous structures and investigated their basic operation properties. According to current-voltage measurements under illumination, the porous devices showed larger photocurrents and higher responsivity than those of a reference planar sample., The Institute of Electronics, Information and Communication Engineers (IEICE), Japanese, 10390615
• Effects of process conditions on AlGaN/GaN hetero-MOS structures
  Yujin Hori; Zenji Yatabe; Wan-Cheng Ma; Tamotsu Hashizume, IEICE technical report. Electron devices, 112, 327, 37, 40, Nov. 2012, [Domestic magazines]
  We have characterized effects of process conditions on Al2O3/AlGaN/GaN hetero-MOS structures prepared by atomic layer deposition. A SiN surface protection layer suppressed nitrogen-vacancy-related chemical disorder at the AlGaN surface even during high-temperature annealing, resulting in reduction of the Al2O3/AlGaN interface states. Photo-assisted C-V characteristics of the Al2O3/AlGaN/GaN structures indicated that an N2O-radical treatment was also effective in reducing the Al2O3/AlGaN interface states. The N2O-radical treated MOS-HEMT showed the improvement of transfer characteristics in the positive bias range, probably due to reduction of the Al2O3/AlGaN interface states., The Institute of Electronics, Information and Communication Engineers (IEICE), Japanese
• Effects of ICP etching of AlGaN on interface properties of Al₂O₃/AlGaN/GaN structures
  Zenji Yatabe; Yujin Hori; Sungsik Kim; Tamotsu Hashizume, Proceedings of the 36th Workshop on Compound Semiconductor Devices and Integrated Circuits (WOCSDICE 2012), 24, 25, May 2012, [Lead author, Corresponding author], [International Magazine]
  English, Introduction international proceedings
• Interface characterization of GaN-based MOS heterostructures employing ICP-etched AlGaN surfaces
  Zenji Yatabe; Yujin Hori; Sungsik Kim; Tamotsu Hashizume, IEICE technical report. Electron devices, 112, 32, 49, 52, May 2012, [Lead author, Corresponding author], [Domestic magazines]
  Our aim is to investigate the effects of dry etching of AlGaN surface on interface properties of GaN-based MOS structure. ICP-assisted plasma with Cl2/BCl3 gas mixture was used for the dry etching. After the dry etching, we fabricated an Al2O3-insulated gate on AlGaN/GaN surface by atomic layer depositon (ALD). To characterize the interface properties of Al2O3/AlGaN, we performed standard capacitance-voltage (C-V) measurements and photo-assisted method. The lager threshold voltage shift due to the photo-assisted electron emission indicated that the ICP etching leads to an increase the Al2O3/AlGaN interface states density. From the X-ray photoelectron spectroscopy, we observed that the ICP process induced the nitrogen vacancy at the AlGaN surface, causing high-density of electron states at Al2O3/AlGaN interface., The Institute of Electronics, Information and Communication Engineers (IEICE), Japanese
• Characterization and Analysis of Low-Frequency Noise in SiN Insulator-Gate GaAs Etched Nanowire FETs
  Toru Muramatsu; Seiya Kasai; Zenji Yatabe, IEICE technical report. Electron devices, 111, 425, 89, 93, Jan. 2012, [Last author], [Domestic magazines]
  Low-frequency noise in SiN-gate GaAs-based nanowire field-effect transistors (FETs) is characterized and analyzed focusing on its device size dependence. Noise in a nanometer-scale semiconductor is an important issue, since it increases as the feature size is decreased. We observe the increased low-frequency noise in the nanowire current, which is caused by charging and discharging electron traps in the SiN gate insulator. As the nanowire width is decreased, the noise intensity increased and the spectral shape changes from 1/f to 1/f^2. Noise spectrum is analyzed by computing the spectrum for specific trap distribution functions in terms of time constant. We find the relationship between the spectral shape and the distribution function. Change of the observed spectral slope is understood in terms of the broadening of the trap distribution., The Institute of Electronics, Information and Communication Engineers (IEICE), Japanese
• Interface characterization of MOS structures fabricated on dry-etched GaN and AlGaN
  Sungsik Kim; Yujin Hori; Zenji Yatabe; Tamotsu Hashizume, IEICE technical report. Electron devices, 111, 290, 25, 28, Nov. 2011, [Domestic magazines]
  We have investigated impacts of dry etching of GaN and AlGaN surfaces on interface properties of GaN-based MOS structures. For the dry etching, we used ECR-assisted plasma with CH4/H2/N2/Ar gas mixture and ICP-assisted plasma with Cl2/BCl3 gas mixture. Both processes induced the disorder of chemical bonds at the GaN surface, causing high-density of electronic states at Al2O3/GaN interfaces. A post-annealing process at 400 ºC is effective in decreasing interface state densities, e.g., 5x10^11 cm^-2eV^-1 for the ICP-processed MOS sample. On the other hand, the interface state densities with 1x10^12cm^-2eV^-1 or higher remained at the ICP-processed Al2O3/AlGaN interface even after the post-annealing process., The Institute of Electronics, Information and Communication Engineers (IEICE), Japanese
• Onion Formation Process of Oil/Water/Surfactant System under Shear Flow
  Zenji Yatabe; Chihiro Hashimoto; Robert Pansu; Hideharu Ushiki, Proceedings of the 8th Asian Thermophysical Properties Conference (ATPC 2007), Paper No. 081, Aug. 2007, [Lead author, Corresponding author], ［Internationally co-authored］
  English, Introduction international proceedings
• New Approach to Effects of Polymer in Flowing Soap Films - Some Methods of Image Processing -
  Ruri Hidema; Zenji Yatabe; Chihiro Hashimoto; Robert Pansu; Hideharu Ushiki, Proceedings of the 8th Asian Thermophysical Properties Conference (ATPC 2007), Paper No. 079, Aug. 2007, ［Internationally co-authored］
  English, Introduction international proceedings

• 半導体・磁性体・電池の固/固界面制御と接合・積層技術
  喜多 浩之; 谷田部 然治; 佐藤 威友; 藤井 茉美; 水野 潤; 松下 智裕; 中塚 理; 大澤 健男; 田辺 克明; 後藤 和泰; 伊澤 誠一郎; 冨岡 克広; 脇坂 聖憲; 高石 慎也; 山下 正廣; 垣尾 省司; 谷川 兼一; 三谷 誠司; レ デゥックアイン; 浜屋 宏平; 谷山 智康; 村上 修一; 日暮 栄治; 重川 直輝; 梁 剣波; 松前 貴司; 梅沢 仁; 倉島 優一; 高木 秀樹; 庄司 一郎; 高 燕林; 丸山 実那; 岡田 晋; 岩﨑 拓哉; 山本 真人; 坂井 伸行; 佐々木 高義; 西尾 和記; 一杉 太郎; 土屋 敬志; 高柳 真; 樋口 透; 寺部 一弥, 第1章パワー半導体の界面現象と制御技術, 第2節GaN半導体デバイスのMIS界面評価と制御
  S&T出版, 2024, 9784911146040, 241, 11-19, Japanese, Scholarly book, 42033928;42033915, [Contributor]

• Analysis of 1/f noise by extracting charge relaxation time distribution using inverse integral transformation method
  Zenji Yatabe; Seiya Kasai
  電子デバイス研究会 化合物半導体を用いた次世代高機能デバイス技術とアプリケーション, 23 Mar. 2026, The Institute of Electrical Engineers of Japan, Japanese, Oral presentation
  24 Mar. 2026 - 24 Mar. 2026, Hotel Hekiryu, Japan, 42033928, [Domestic Conference]
• AlSiO thin films deposited by mist-CVD toward gate insulator application in GaN-based MOS devices
  Zenji Yatabe; Yu Ishihara; Yusui Nakamura; Tetsuya Sakata; Toshinobu Fujimura
  The 73rd JSAP Spring Meeting, 17 Mar. 2026, The Japan Society of Applied Physics, Japanese, Oral presentation
  15 Mar. 2026 - 18 Mar. 2026, Ookayama Campus, Institute of Science Tokyo & Online, Japan, 42033928, [Domestic Conference]
• Improvement of Controllability of Myoelectric Prosthesis Hand Based on Reservoir Computing Framework (2)
  Yusuke Hoshika; Zenji Yatabe; Seiya Kasai
  The 73rd JSAP Spring Meeting, 15 Mar. 2026, The Japan Society of Applied Physics, Japanese, Oral presentation
  15 Mar. 2026 - 18 Mar. 2026, Ookayama Campus, Institute of Science Tokyo & Online, Japan, [Domestic Conference]
• Bio-inspired Force Sensing For Sensory Feedback in Prosthetic Hand
  Yui Iida; Zenji Yatabe; Seiya Kasai
  The 73rd JSAP Spring Meeting, 15 Mar. 2026, The Japan Society of Applied Physics, Japanese, Oral presentation
  15 Mar. 2026 - 18 Mar. 2026, Ookayama Campus, Institute of Science Tokyo & Online, Japan, [Domestic Conference]
• Study on Variable Representation Method in Analog Electronic Amoeba For Solving Large-Scale Satisfiability Problem
  Shu Nagasawa; Zenji Yatabe; Seiya Kasai
  The 73rd JSAP Spring Meeting, 15 Mar. 2026, The Japan Society of Applied Physics, Japanese, Oral presentation
  15 Mar. 2026 - 18 Mar. 2026, Ookayama Campus, Institute of Science Tokyo & Online, Japan, [Domestic Conference]
• Characterization of Solution Search Time in Analog Electronic Amoeba Solving Satisfiability Problem
  Tokushi Maruoka; Zenji Yatabe; Seiya Kasai
  The 73rd JSAP Spring Meeting, 15 Mar. 2026, The Japan Society of Applied Physics, Japanese, Oral presentation
  15 Mar. 2026 - 18 Mar. 2026, Ookayama Campus, Institute of Science Tokyo & Online, Japan, [Domestic Conference]
• Machine Learning Technique for Non-destructive Characterization of Embeded Nano-structures in Si MOSFET
  Renxiang Lyu; Hyoto Yamaguchi; Zenji Yatabe; Seiya Kasai
  The 73rd JSAP Spring Meeting, 15 Mar. 2026, The Japan Society of Applied Physics, Japanese, Oral presentation
  15 Mar. 2026 - 18 Mar. 2026, Ookayama Campus, Institute of Science Tokyo & Online, Japan, [Domestic Conference]
• Study on Machine Learning Technique for Ground Condition Perception in an Amoeba-inspired Four-legged Walking Robot
  Hyoto Yamaguchi; Zenji Yatabe; Seiya Kasai
  General Conference, 12 Mar. 2026, The Institute of Electronics, Information and Communication Engineers (IEICE), Japanese, Oral presentation
  09 Mar. 2026 - 13 Mar. 2026, Kyushu Sangyo University, Japan, [Domestic Conference]
• C–V characterization for evaluation of interface in Al₂O₃/GaN MOS capacitors with Al₂O₃ thin film fabricated by mist-CVD
  Hadirah Radzuan; Ryota Ochi; Yusui Nakamura; Taketomo Sato; Zenji Yatabe
  The 20th International Student Conference on Advanced Science and Technology 2025 (ICAST 2025), 26 Nov. 2025, English, Oral presentation
  26 Nov. 2025 - 27 Nov. 2025, National Chiayi University, Taiwan, Province of China, 42033928
• Mist Thermal Oxidation of GaN Surface
  Zenji Yatabe; Ryosuke Hamasuna; Takumi Hirakura; Thin Nu Soe; Yusui Nakamura
  IEICE Technical Committee on Electron Device, 21 Nov. 2025, The Institute of Electronics, Information and Communication Engineers, Japanese, Oral presentation
  20 Nov. 2025 - 21 Nov. 2025, TENMONKAN VISION HALL, Japan, 42033928, [Domestic Conference]
• Mist Thermal Oxidation of GaN Surface for Mist Etching
  Takumi Hirakura; Thin Nu Soe; Ryosuke Hamasuna; Yusui Nakamura; Zenji Yatabe
  The 86th JSAP Autumn Meeting, 10 Sep. 2025, The Japan Society of Applied Physics, Japanese, Poster presentation
  07 Sep. 2025 - 10 Sep. 2025, Tempaku Campus, Meijo University & Online, Japan, 42033928, [Domestic Conference]
• Mist Thermal Oxidation Process for GaN Surface Oxidation
  Ryosuke Hamasuna; Thin Nu Soe; Takumi Hirakura; Yusui Nakamura; Zenji Yatabe
  The 86th JSAP Autumn Meeting, 10 Sep. 2025, The Japan Society of Applied Physics, Japanese, Poster presentation
  07 Sep. 2025 - 10 Sep. 2025, Tempaku Campus, Meijo University & Online, Japan, 42033928, [Domestic Conference]
• Deposition Mechanism of Al_1−xTi_xO_y Gate Insulator Films for GaN-based MIS Devices by Mist-CVD
  Hiroshi Otake; Yusui Nakamura; Zenji Yatabe
  The 86th JSAP Autumn Meeting, 10 Sep. 2025, The Japan Society of Applied Physics, Japanese, Poster presentation
  07 Sep. 2025 - 10 Sep. 2025, Tempaku Campus, Meijo University & Online, Japan, 42033928, [Domestic Conference]
• Characterization of Interface Properties in Al₂O₃/n-GaN MOS Structures with Mist-CVD Fabricated Al₂O₃ Thin Film
  Hadirah Radzuan; Ryota Ochi; Yusui Nakamura; Takemoto Sato; Zenji Yatabe
  The 86th JSAP Autumn Meeting, 08 Sep. 2025, The Japan Society of Applied Physics, Japanese, Oral presentation
  07 Sep. 2025 - 10 Sep. 2025, Tempaku Campus, Meijo University & Online, Japan, 42033928, [Domestic Conference]
• Mist chemical vapor deposition of alloy gate insulator for potential applications in GaN-based MOS devices
  Z. Yatabe; H. Otake; H. Radzuan; Y. Nakamura
  The 2025 Spring Meeting of the European Materials Research Society (E-MRS), 28 May 2025, European Materials Research Society (E-MRS), English, Oral presentation
  26 May 2025 - 30 May 2025, Strasbourg Convention Centre, France, 42033928;42033915, [International presentation]
• 次世代/次々世代半導体向けゲート絶縁膜堆積プロセス技術
  谷田部 然治
  次世代/次々世代半導体ネットワーク若手研究者交流会, 04 Mar. 2025, 次世代/次々世代半導体ネットワーク, Japanese, Oral presentation
  04 Mar. 2025 - 05 Mar. 2025, 名古屋大学未来エレクトロニクス集積研究センターC-TECs, Japan
• Mist Chemical Vapor Deposited Gate Dielectrics for GaN-Based MOS Device
  Zenji Yatabe; Masaya Fukumitsu; Hiroshi Otake; Takumi Hirakura; Hadirah Radzuan; Ryota Ochi; Yusui Nakamura; Taketomo Sato
  IEICE Technical Committee on Electron Device, 28 Nov. 2024, The Institute of Electronics, Information and Communication Engineers, Japanese, Oral presentation
  29 Nov. 2024 - 29 Nov. 2024, Nagoya Institute of Technology, Japan, 42033928;42033915, [Domestic Conference]
• GaN-based MIS devices with mist chemical vapor deposited gate insulator
  Zenji Yatabe; Hadirah Radzuan; Masaya Fukumitsu; Keigo Bito; Ryota Ochi; Yusui Nakamura; Taketomo Sato
  The 11th Asia-Pacific Workshop on Widegap Semiconductors (APWS) 2024, 14 Oct. 2024, Korea Society of LEDs and Optoelectronics (KSLOE), English, Invited oral presentation
  13 Oct. 2024 - 17 Oct. 2024, Hanwha Resorts Haeundae, Busan, Korea, Republic of, 42033928;42033915, [Invited], [International presentation]
• Mist etching of AlGaN barrier layer for normally-off operation
  Takumi Hirakura; Yusui Nakamura; Zenji Yatabe
  SMDF 2024, 25 Sep. 2024, 熊本高等専門学校 電子材料・デバイス研究部 半導体材料・デバイスフォーラム実行委員会, Japanese, Poster presentation
  25 Sep. 2024 - 25 Sep. 2024, Fukuoka Convention Center, Japan, 第15回半導体材料・デバイスフォーラム ポスター発表優秀賞, 42033928;42033915, [Domestic Conference]
• Extraction of Charge Relaxation Time Distribution of 1/f Noise Based on Inverse Integral Transformation Method
  Zenji Yatabe; Seiya Kasai
  The 85th JSAP Autumn Meeting, 19 Sep. 2024, The Japan Society of Applied Physics, Japanese, Oral presentation
  16 Sep. 2024 - 20 Sep. 2024, TOKI MESSE and adjoining facilities & Online, Japan, [Domestic Conference]
• Mist Chemical Vapor Deposited Alloy Gate Dielectric for Potential Applications in GaN Based MIS Devices
  Hiroshi Otake; Yusui Nakamura; Zenji Yatabe
  The 85th JSAP Autumn Meeting, 18 Sep. 2024, The Japan Society of Applied Physics, Japanese, Poster presentation
  16 Sep. 2024 - 20 Sep. 2024, TOKI MESSE and adjoining facilities & Online, Japan, 42033928;42033915, [Domestic Conference]
• Low-state-density Al₂O₃/n-GaN interfaces using mist chemical vapor deposited Al₂O₃ gate insulator
  Z. Yatabe; H. A. Radzuan; M. Fukumitsu; K. Bito; R. Ochi; Y. Nakamura; T. Sato
  15th Topical Workshop on Heterostructure Microelectronics (TWHM 2024), 29 Aug. 2024, The Technical Committee on Electron Devices, IEICE, English, Poster presentation
  26 Aug. 2024 - 29 Aug. 2024, SENDAI SUNPLAZA Hotel, Japan, 42033928;42033915, [International presentation]
• Insulated gate structures for GaN-based devices using mist-CVD method
  Zenji Yatabe; Hadirah Radzuan; Keigo Bito; Masaya Fukumitsu; Ryota Ochi; Taketomo Sato
  電子デバイス研究会 化合物半導体を用いた次世代高機能デバイス技術とアプリケーション, 15 Jul. 2024, The Institute of Electrical Engineers of Japan, Japanese, Oral presentation
  15 Jul. 2024 - 15 Jul. 2024, サニー会議室, Japan, 42033928;42033915, [Domestic Conference]
• Charge Relaxation Time Distribution of 1/f Noise
  Zenji Yatabe; Seiya Kasai
  The 71st JSAP Spring Meeting, 23 Mar. 2024, The Japan Society of Applied Physics, Japanese, Oral presentation
  23 Mar. 2024 - 25 Mar. 2024, Setagaya Campus, Tokyo City University & Online, Japan, [Domestic Conference]
• Characterization of mist-Al₂O₃/n-GaN Structures Fabricated on Free-standing GaN Substrates
  Zenji Yatabe; Masaya Fukumitsu; Hadirah Radzuan; Keigo Bito; Ryota Ochi; Yusui Nakamura; Taketomo Sato
  The 71st JSAP Spring Meeting, 22 Mar. 2024, The Japan Society of Applied Physics, Japanese, Poster presentation
  22 Mar. 2024 - 25 Mar. 2024, Setagaya Campus, Tokyo City University & Online, Japan, 42033928;42033915, [Domestic Conference]
• 次世代パワー・高周波デバイスの実現に向けたワイドギャップ半導体界面の評価と制御
  谷田部 然治
  2024年年会, 14 Mar. 2024, 日本セラミックス協会, Japanese, Public discourse
  14 Mar. 2024 - 16 Mar. 2024, 熊本大学 黒髪キャンパス, Japan, 42033928;42033915, [Invited], [Domestic Conference]
• Effect of interface states on capacitance–voltage characteristics of wide-bandgap MOS capacitors
  Takumi Fukushima; Zenji Yatabe
  SMDF 2023, 09 Dec. 2023, 熊本高等専門学校 電子材料・デバイス研究部 半導体材料・デバイスフォーラム実行委員会, Japanese, Oral presentation
  09 Dec. 2023 - 09 Dec. 2023, 九州工業大学情報工学部, Japan, 第14回半導体材料・デバイスフォーラム 口頭発表優秀賞, 42033928;42033915, [Domestic Conference]
• ゲート絶縁膜堆積プロセスとデバイス評価技術の開拓
  谷田部 然治
  電子情報通信学会北海道支部講演会, 28 Nov. 2023, 電子情報通信学会 北海道支部, Japanese, Public discourse
  28 Nov. 2023 - 28 Nov. 2023, 北海道大学, Japan, 42033928;42033915, [Invited], [Domestic Conference]
• GaN-based MOS-HEMTs with Mist Chemical Vapor Deposited Gate Insulator
  Keigo Bito; Hikaru Hiroshige; Ren Hashimoto; Masaki Ishiguro; Joel T. Asubar; Yusui Nakamura; Zenji Yatabe
  14th International Conference on Nitride Semiconductors (ICNS-14), 12 Nov. 2023, English, Poster presentation
  12 Nov. 2023 - 17 Nov. 2023, Hilton Fukuoka Sea Hawk, Japan, 42033928;42033915, [International presentation]
• Characterization of mist-Al₂O₃ gate dielectric and interface characterization of mist-Al₂O₃/AlGaN/GaN structure
  Hikaru Hiroshige; Keigo Bito; Ren Hashimoto; Masaki Ishiguro; Joel T. Asubar; Yusui Nakamura; Zenji Yatabe
  The 84th JSAP Autumn Meeting, 22 Sep. 2023, The Japan Society of Applied Physics, Japanese, Oral presentation
  19 Sep. 2023 - 23 Sep. 2023, KUMAMOTO-JO HALL, Japan, 42033928;42033915, [Domestic Conference]
• Correlation between Threshold Voltage Fluctuation and Interface State in Al₂O₃/AlGaN/GaN MOS-HEMT
  Masaya Fukumitsu; Zenji Yatabe
  The 74th Joint Conference of Electrical, Electronics and Information Engineers in Kyushu, 07 Sep. 2023, Committee of Joint Conference of Electrical, Electronics and Information Engineers in Kyushu, Japanese, Oral presentation
  07 Sep. 2023 - 08 Sep. 2023, Sojo University, Japan, 42033928;42033915, [Domestic Conference]
• Mist chemical vapor deposited-gate insulators for GaN-based MIS devices applications
  Zenji Yatabe; Joel T. Asubar; Yusui Nakamura
  The 2022 International Meeting for Future of Electron Devices, Kansai (IMFEDK 2022), 28 Nov. 2022, IEEE EDS Kansai Chapter, English, Invited oral presentation
  28 Nov. 2022 - 30 Nov. 2022, Avanti Kyoto Hall, Japan, [Invited], [International presentation]
• 半導体デバイス解析技術を応用した体重変動のウルトラスローダイナミクスの解析
  谷田部 然治
  第4回熊本大学ライフサイエンスシーズ探索研究会, 23 Nov. 2022, 熊本大学病院 総合臨床研究部, Japanese, Others
  23 Nov. 2022 - 23 Nov. 2022, 熊本大学, Japan, [Domestic Conference]
• Characterization of interface states in All₂O₃/AlGaN/GaN HEMT at room temperature
  Tomohiro Motoyama; Zenji Yatabe
  SMDF 2022, 10 Oct. 2022, 熊本高等専門学校 電子材料・デバイス研究部 半導体材料・デバイスフォーラム実行委員会, Japanese, Oral presentation
  10 Oct. 2022 - 10 Oct. 2022, Kumamoto University, Japan, 第13回半導体材料・デバイスフォーラム 口頭発表優秀賞, [Domestic Conference]
• Anomalously high threshold voltage shift in Al₂O₃/AlGaN/GaN structures with regrown AlGaN layer
  A. Baratov; S. Kawabata; S. Urano; I. Nagase; M. Ishiguro; S. Maeda; T. Igarashi; T. Nezu; Z. Yatabe; M. Matys; T. Kachi; B. Adamowicz; A. Wakejima; M. Kuzuhara; A. Yamamoto; J. T. Asubar
  14th Topical Workshop on Heterostructure Microelectronics (TWHM 2022), 30 Aug. 2022, The Technical Committee on Electron Devices, IEICE, English, Poster presentation
  30 Aug. 2022 - 01 Sep. 2022, Hiroshima Garden Palace, Japan, [International presentation], ［Internationally co-authored］
• Simple characterization of interface states in ALD-Al₂O₃/AlGaN/GaN structure at room temperature
  Zenji Yatabe; Takumi Fukushima; Hikaru Hiroshige; Tomohiro Motoyama; Joel T. Asubar
  14th Topical Workshop on Heterostructure Microelectronics (TWHM 2022), 30 Aug. 2022, The Technical Committee on Electron Devices, IEICE, English, Poster presentation
  29 Aug. 2022 - 01 Sep. 2022, Hiroshima Garden Palace, Japan, [International presentation]
• AlGaN/GaN MIS-HEMTs with mist- and ALD-Al₂O₃ gate dielectric
  Shun Urano; Joel Asubar; Rui Shan Low; Faris Muhammad; Masaki Ishiguro; Itsuki Nagase; Ali Batarov; Tomohiro Motoyama; Yusui Nakamura; Masaaki Kuzuhara; Zenji Yatabe
  The 69th JSAP Spring Meeting, 24 Mar. 2022, The Japan Society of Applied Physics, Japanese, Oral presentation
  22 Mar. 2022 - 26 Mar. 2022, Sagamihara Campus, Aoyama Gakuin University, Sagamihara, Kanagawa, Japan, 13160044
• Characterization of mist-Al₂O₃ gate insulator and its application in mist-Al₂O₃/AlGaN/GaN MOS-HEMTs
  Tomohiro Motoyama; Shun Urano; Ali Baratov; Yusui Nakamura; Masaaki Kuzuhara; Joel Asubar; Zenji Yatabe
  The 69th JSAP Spring Meeting, 24 Mar. 2022, The Japan Society of Applied Physics, Japanese, Oral presentation
  22 Mar. 2022 - 26 Mar. 2022, Sagamihara Campus, Aoyama Gakuin University, Sagamihara, Kanagawa, Japan, 13160044, [Domestic Conference]
• Recessed gate GaN-based MIS-HEMTs with Al₂O₃ gate dielectric deposited by mist-CVD method
  M. Ishiguro; S. Urano; R. S. Low; M. Faris; I. Nagase; A. Baratov; J. T. Asubar; T. Motoyama; Y. Nakamura; Z. Yatabe; M. Kuzuhara
  The 2021 International Meeting for Future of Electron Devices, Kansai (IMFEDK 2021), 19 Nov. 2021, IEEE EDS Kansai Chapter, English, Oral presentation
  18 Nov. 2021 - 19 Nov. 2021, Virtual Conference, Japan, 13160044, [International presentation]
• Electrical properties of GaN-based MISHEMTs with Al₂O₃ gate insulator deposited by ALD and mist-CVD techniques
  S. Urano; R. S. Low; M. Faris; M. Ishiguro; I. Nagase; A. Baratov; J. T. Asubar; T. Motoyama; Y. Nakamura; Z. Yatabe; M. Kuzuhara
  The 2021 International Meeting for Future of Electron Devices, Kansai (IMFEDK 2021), 18 Nov. 2021, IEEE EDS Kansai Chapter, English, Oral presentation
  18 Nov. 2021 - 19 Nov. 2021, Virtual Conference, Japan, 13160044, [International presentation]
• Mist chemical vapor deposited-Al₂O₃/AlGaN interfacial characterization for GaN MIS-HEMTs
  Tomohiro Motoyama; Zenji Yatabe; Yusui Nakamura; Ali Baratov; Rui Shan Low; Shun Urano; Joel T. Asubar; Masaaki Kuzuhara
  The 2021 International Meeting for Future of Electron Devices, Kansai (IMFEDK 2021), 18 Nov. 2021, IEEE EDS Kansai Chapter, English, Oral presentation
  18 Nov. 2021 - 19 Nov. 2021, Virtual Conference, Japan, 13160044, [International presentation]
• Characterization of mist chemical vapor deposited Al₂O₃ thin films and its applications in GaN-based MIS-HEMTs
  Tomohiro Motoyama; Ali Baratov; Rui Shan Low; Rui Shan Low; Yusui Nakamura; Masaaki Kuzuhara; Joel T. Asubar; Zenji Yatabe
  Annual Meeting of The Japan Society of Vacuum and Surface Science 2021, 04 Nov. 2021, The Japan Society of Vacuum and Surface Science, Japanese, Oral presentation
  03 Nov. 2021 - 05 Nov. 2021, Virtual Conference, Japan, 2021年日本表面真空学会学術講演会 講演奨励賞 スチューデント部門, 13160044, [Domestic Conference]
• ミストCVD法によるAl₂O₃絶縁膜を用いたAlGaN/GaN MIS-HEMTの作製と評価
  本山 智洋; Ali Baratov; Rui Shan Low; 浦野 駿; 中村 有水; 葛原 正明; 谷田部 然治; Joel T. Asubar
  第10回TIAパワーエレクトロニクス・サマースクール, 21 Aug. 2021, つくばパワーエレクトロニクスコンステレーション (TPEC), Japanese, Poster presentation
  21 Aug. 2021 - 22 Aug. 2021, Virtual Conference, Japan, 13160044, [Domestic Conference]
• Characterization of mist-CVD deposited Al₂O₃ films on AlGaN/GaN heterostructures
  Tomohiro Motoyama; Kenta Naito; Yusui Nakamura; Zenji Yatabe; Rui Shan Low; Itsuki Nagase; Ali Baratov; Hirokuni Tokuda; Masaaki Kuzuhara; Joel T. Asubar
  IEEE IMFEDK 2020 Satellite event, 27 Nov. 2020, IEEE EDS Kansai Chapter, English, Poster presentation
  27 Nov. 2020 - 27 Nov. 2020, Virtual Conference, Japan, 13160044, [International presentation]
• GaN-based MIS-HEMTs with Mist Chemical Vapor Deposited Al₂O₃
  Rui Shan Low; Itsuki Nagase; Ali Baratov; Joel Tacla Asubar; Hirokuni Tokuda; Masaaki Kuzuhara; Zenji Yatabe; Kenta Naito; Motoyama Tomohiro; Yusui Nakamura
  IEICE Technical Committee on Electron Device, 26 Nov. 2020, The Institute of Electronics, Information and Communication Engineers, Japanese, Oral presentation
  26 Nov. 2020 - 27 Nov. 2020, Virtual Conference, Japan, 13160044, [Domestic Conference]
• Local viscosity distributions of polymer and surfactant solutions measured by optical tweezers
  R. Hidema; R. Higashikawa; Z. Yatabe; H. Suzuki
  The 68th Rheology Symposium, 22 Oct. 2020, The Society of Rheology, Japan, Japanese, Oral presentation
  21 Oct. 2020 - 22 Oct. 2020, Virtual Conference, Japan, 13376278, [Domestic Conference]
• Effects of polymer entanglement in a solution on local viscosity distribution
  R. Higashikawa; R. Hidema; Z. Yatabe; H. Suzuki
  The 68th Rheology Symposium, 21 Oct. 2020, The Society of Rheology, Japan, Japanese, Poster presentation
  21 Oct. 2020 - 22 Oct. 2020, Virtual Conference, Japan, 13376278, [Domestic Conference]
• AlGaN/GaN MIS-HEMTs using 4-nm-thick Al₂O₃ Dielectric Deposited by Mist Chemical Vapor Deposition
  Rui Shan Low; Shinsaku Kawabata; Joel T. Asubar; Hirokuni Tokuda; Masaaki Kuzuhara; Zenji Yatabe; Kenta Naito; Kazuki Nishimura; Yusui Nakamura
  The 67th JSAP Spring Meeting, 14 Mar. 2020, The Japan Society of Applied Physics, Japanese, Oral presentation
  12 Mar. 2020 - 15 Mar. 2020, Yotsuya Campus, Sophia University, Chiyoda, Tokyo, Japan, 13160044, [Domestic Conference]
• Epitaxial Tin Oxide Films on Sapphire Substrate Grown by Mist Chemical Vapor Deposition
  Thant Zin Win; Takumi Furukawa; Yuki Kanetake; Katsuhiko Inaba; Zenji Yatabe; Yusui Nakamura
  The Tenth International Conference on Science and Engineering 2019 (10th ICSE 2019), 08 Dec. 2019, English, Oral presentation
  07 Dec. 2019 - 08 Dec. 2019, Myanmar, [Domestic Conference]
• Formation of amorphous Al₂O₃ thin films by mist chemical vapor deposition
  Kazuki Nishimura; Kenta Naito; Zenji Yatabe; Yusui Nakamura
  The 14th International Student Conference on Advanced Science and Technology 2019 (ICAST 2019), 29 Nov. 2019, English, Poster presentation
  28 Nov. 2019 - 29 Nov. 2019, Kumamoto University, Kumamoto, Kumamoto Prefecture, Japan, 13160044
• Structural properties of SnO₂ thin films on m-plane sapphire formed by mist chemical vapor deposition
  Takumi Furukawa; Thant Zin Win; Yuki Kanetake; Katsuhiko Inaba; Koji Sue; Zenji Yatabe; Yusui Nakamura
  The 14th International Student Conference on Advanced Science and Technology 2019 (ICAST 2019), 29 Nov. 2019, English, Poster presentation
  28 Nov. 2019 - 29 Nov. 2019, Kumamoto University, Kumamoto, Kumamoto Prefecture, Japan
• Epitaxial growth of non-polar ZnO films on ZnO buffer layers on sapphire substrates by mist chemical vapor deposition
  Yuki Nagao; Yudai Tanaka; Zenji Yatabe; Koji Sue; Shoji Nagaoka; Yusui Nakamura
  The 14th International Student Conference on Advanced Science and Technology 2019 (ICAST 2019), 29 Nov. 2019, English, Poster presentation
  28 Nov. 2019 - 29 Nov. 2019, Kumamoto University, Kumamoto, Kumamoto Prefecture, Japan
• Al₂O₃ thin films deposited by mist-CVD for gate insulator application in GaN-based devices
  Kenta Naito; Kazuki Nishimura; Zenji Yatabe; Joel T. Asubar; Yusui Nakamura
  The 4th Asian Applied Physics Conference (Asian-APC), 23 Nov. 2019, Kyushu Chapter, Japan Society of Applied Physics, English, Oral presentation
  23 Nov. 2019 - 24 Nov. 2019, Kumamoto University, Kumamoto, Kumamoto Prefecture, Japan, 13160044, [International presentation]
• Structural Investigation of SnO₂ thin films formed on m-plane sapphire by mist chemical vapor deposition
  Yuki Kanetake; Thant Zin Win; Takumi Furukawa; Koji Sue; Zenji Yatabe; Yusui Nakamura
  The 4th Asian Applied Physics Conference (Asian-APC), 23 Nov. 2019, Kyushu Chapter, Japan Society of Applied Physics, English, Oral presentation
  23 Nov. 2019 - 24 Nov. 2019, Kumamoto University, Kumamoto, Kumamoto Prefecture, Japan, [International presentation]
• Epitaxial growth of a-plane and m-plane ZnO films on ZnO buffer layers on sapphire substrates by mist chemical vapor deposition
  Yuki Nagao; Yudai Tanaka; Zenji Yatabe; Koji Sue; Shoji Nagaoka; Yusui Nakamura
  The 4th Asian Applied Physics Conference (Asian-APC), 23 Nov. 2019, Kyushu Chapter, Japan Society of Applied Physics, English, Oral presentation
  23 Nov. 2019 - 24 Nov. 2019, Kumamoto University, Kumamoto, Kumamoto Prefecture, Japan, [International presentation]
• Local viscosities of viscoelastic solutions measured by optical tweezers and local viscosity distributions
  R. Hidema; H. Takahashi; Z. Yatabe; H. Suzuki
  The 67th Rheology Symposium (fall meeting), 18 Oct. 2019, The Society of Rheology, Japan and Japanese Society of Biorheology, Japanese, Oral presentation
  16 Oct. 2019 - 18 Oct. 2019, The University of Shiga Prefecture, Hikone, Shiga Prefecture, Japan, 13376278, [Domestic Conference]
• Distribution of local viscosity of viscoelastic solutions measured by using optical tweezers
  Ruri Hidema; Hikari Takahashi; Zenji Yatabe; Hiroshi Suzuki
  18th Asian Pacific Confederation of Chemical Engineering Congress (APCChE 2019), 26 Sep. 2019, The Society of Chemical Engineers, Japan (SCEJ), English, Oral presentation
  23 Sep. 2019 - 27 Sep. 2019, Sapporo Convention Center, Sapporo, Hokkaido, Japan, 13376278, [International presentation]
• Characterization of Al_1-xTi_xO_y thin films deposited by mist-CVD
  Zenji Yatabe; Koshi Nishiyama; Kazuki Nishimura; Yusui Nakamura
  2019 International Conference on Solid State Devices and Materials (SSDM2019), 04 Sep. 2019, The Japan Society of Applied Physics, English, Poster presentation
  02 Sep. 2019 - 05 Sep. 2019, Nagoya University, Nagoya, Aichi, Japan, 13160044, [International presentation]
• Calculating charge relaxation time distribution in a transistor device from noise spectrum
  Zenji Yatabe; Joel T. Asubar; Seiya Kasai
  13th Topical Workshop on Heterostructure Microelectronics (TWHM 2019), 27 Aug. 2019, The Technical Committee on Electron Devices, IEICE, English, Poster presentation
  26 Aug. 2019 - 29 Aug. 2019, Hotel Grand Terrace Toyama, Japan, 13376278, [International presentation]
• Characterization of Al_xTi_1-xO_y thin films synthesized using mist-CVD
  Zenji Yatabe; Koshi Nishiyama; Kazuki Nishimura; Yusui Nakamura
  13th Topical Workshop on Heterostructure Microelectronics (TWHM 2019), 27 Aug. 2019, The Technical Committee on Electron Devices, IEICE, English, Poster presentation
  26 Aug. 2019 - 29 Aug. 2019, Hotel Grand Terrace Toyama, Japan, 13160044, [International presentation]
• Effect of Buffer Layer on Improvement of SnO₂ Thin Film on Sapphire Substrate Formed by Mist Chemical Vapor Deposition
  Thant Zin Win; Takumi Furukawa; Yudai Tanaka; Koshi Okita; Koji Sue; Zenji Yatabe; Yusui Nakamura
  Compound Semiconductor Week 2019 (CSW2019), 21 May 2019, English, Poster presentation
  19 May 2019 - 23 May 2019, Nara Kasugano International Forum Iraka, Japan, [International presentation]
• Synthesis and characterization of AlTiO films by mist-CVD
  Zenji Yatabe; Koshi Nishiyama; Takaaki Tsuda; Kazuki Nishimura; Yusui Nakamura
  Compound Semiconductor Week 2019 (CSW2019), 21 May 2019, English, Poster presentation
  19 May 2019 - 23 May 2019, Nara Kasugano International Forum Iraka, Japan, [International presentation]
• Characterization of amorphous aluminium oxide thin films synthesized by mist-CVD
  Zenji Yatabe; Koshi Nishiyama; Takaaki Tsuda; Kazuki Nishimura; Yusui Nakamura
  Compound Semiconductor Week 2019 (CSW2019), 21 May 2019, English, Poster presentation
  19 May 2019 - 23 May 2019, Nara Kasugano International Forum Iraka, Japan, [International presentation]
• Local viscosity measurement of viscoelastic solutions by using optical tweezers
  H. Takahashi; H. Hidema; Z. Yatabe; H. Suzuki
  The 46th Annual Meeting of SRJ, 08 May 2019, The Society of Rheology, Japan, Japanese, Poster presentation
  08 May 2019 - 09 May 2019, Kyoto Institute of Technology, Japan, [Domestic Conference]
• Characterization of amorphous Al₂O₃ thin films prepared by mist-CVD
  Kazuki Nishimura; Koshi Nishiyama; Yuki Fujimoto; Zenji Yatabe; Yusui Nakamura
  The 66th JSAP Spring Meeting, 12 Mar. 2019, The Japan Society of Applied Physics, Japanese, Poster presentation
  09 Mar. 2019 - 12 Mar. 2019, Tokyo Institute of Technology Ookayama Campus, Japan, [Domestic Conference]
• Improvement of crystallinity of a-ZnO and m-ZnO thin films on sapphire substrate formed by mist-CVD
  Yuki Nagao; Yudai Tanaka; Koji Sue; Shoji Nagaoka; Zenji Yatabe; Yusui Nakamura
  The 66th JSAP Spring Meeting, 10 Mar. 2019, The Japan Society of Applied Physics, Japanese, Oral presentation
  09 Mar. 2019 - 12 Mar. 2019, Tokyo Institute of Technology Ookayama Campus, Japan, [Domestic Conference]
• Growth of Tin Oxide Film with Buffer Layer on Sapphire Substrate by Mist Chemical Vapor Deposition
  Thant Zin Win; Takumi Furukawa; Yudai Tanaka; Koshi Okita; Koji Sue; Zenji Yatabe; Yusui Nakamura
  The 66th JSAP Spring Meeting, 09 Mar. 2019, The Japan Society of Applied Physics, English, Oral presentation
  09 Mar. 2019 - 12 Mar. 2019, Tokyo Institute of Technology Ookayama Campus, Japan, [Domestic Conference]
• Buffer Layer Effect on the Crystallinity of Tin Oxide Film on Sapphire Substrate by Mist Chemical Vapor Deposition
  Thant Zin Win; Takumi Furukawa; Yudai Tanaka; Koshi Okita; Kensuke Minami; Koji Sue; Zenji Yatabe; Yusui Nakamura
  The 3rd Asian Applied Physics Conference (Asian-APC), 08 Dec. 2018, JSAP Kyushu Chapter, English, Oral presentation
  09 Dec. 2018 - 09 Dec. 2018, Fukuoka University Nanakuma Campus, Japan, [International presentation]
• Formation of ZnS thin film on m-plane sapphire substrate by mist-CVD
  J. Kikukawa; Y. Kishigawa; Y. Tanaka; S. Nagaoka; Z. Yatabe; K. Sue; Y. Nakamura
  JSAP Kyushu Chapter Annual Meeting 2018, 08 Dec. 2018, JSAP Kyushu Chapter, Japanese, Oral presentation
  08 Dec. 2018 - 09 Dec. 2018, Fukuoka University Nanakuma Campus, Japan, [Domestic Conference]
• Improvement of crystallinity of a-ZnO and m-ZnO thin films on sapphire substrate formed by mist-CVD
  Y. Nagao; Y. Tanaka; Z. Yatabe; K. Sue; S. Nagaoka; Y. Nakamura
  JSAP Kyushu Chapter Annual Meeting 2018, 08 Dec. 2018, JSAP Kyushu Chapter, Japanese, Oral presentation
  08 Dec. 2018 - 09 Dec. 2018, Fukuoka University Nanakuma Campus, Japan, [Domestic Conference]
• AlTiO thin films grown by mist-CVD toward gate insulator application in GaN-based MOSFETs
  K. Nishimura; K. Nishiyama; T. Tsuda; Z. Yatabe; K. Sue; Y. Nakamura
  JSAP Kyushu Chapter Annual Meeting 2018, 08 Dec. 2018, JSAP Kyushu Chapter, Japanese, Oral presentation
  08 Dec. 2018 - 09 Dec. 2018, Fukuoka University Nanakuma Campus, [Domestic Conference]
• Optimal Temperature of Buffer Layers for Tin Oxide Films by Mist Chemical Vapor Deposition
  Zin Win; Takumi Furukawa; Yudai Tanaka; Koshi Okita; Kensuke Minami; Koji Sue; Zenji Yatabe; Yusui Nakamura
  The 13th International Student Conference on Advanced Science and Technology 2018 (ICAST 2018), 28 Nov. 2018, English, Oral presentation
  28 Nov. 2018 - 29 Nov. 2018, De La Salle University, Manila, Philippine, Philippines, [International presentation]
• Effect of Buffer Layer on the Structural Properties of Tin Oxide Thin Film on Sapphire Substrate by Mist Chemical Vapor Deposition
  Thant Zin Win; Takumi Furukawa; Yudai Tanaka; Koshi Okita; Kensuke Minami; Koji Sue; Zenji Yatabe; Yusui Nakamura
  2018 ENGINEERING WORKSHOP in Kumamoto, 16 Nov. 2018, English, Oral presentation
  15 Nov. 2018 - 17 Nov. 2018, Kumamoto University, Japan, BEST PRESENTATION AWARD
• Formation of N-doped ZnO thin films formed by annealing in NH₃ gas ambient
  Takumi Furukawa; Masato Takenouchi; Yudai Tanaka; Koji Sue; Shoji Nagaoka; Zenji Yatabe; Yusui Nakamura
  2018 ENGINEERING WORKSHOP in Kumamoto, 16 Nov. 2018, English, Poster presentation
  15 Nov. 2018 - 17 Nov. 2018, Kumamoto University, Japan
• Epitaxial growth of non-polar ZnO films on buffer layers on sapphire substrates by mist chemical vapor deposition
  Yudai Tanaka; Yuki Nagao; Takumi Furukawa; Zenji Yatabe; Koji Sue; Nagaoka Shoji; Yusui Nakamura
  2018 ENGINEERING WORKSHOP in Kumamoto, 16 Nov. 2018, English, Poster presentation
  15 Nov. 2018 - 17 Nov. 2018, Kumamoto University, Japan
• Mist-CVD deposition of AlTiO thin films for potential applications in AlGaN/GaN MOS-HEMTs
  K. Nishiyama; K. Nishimura; T. Tsuda; Z. Yatabe; K. Sue; Y. Nakamura
  2018 ENGINEERING WORKSHOP in Kumamoto, 16 Nov. 2018, English, Poster presentation
  15 Nov. 2018 - 17 Nov. 2018, Kumamoto University, Japan
• Improvement of crystallinity of two types of non-polar ZnO thin films on sapphire substrate formed by mist-CVD
  Yudai Tanaka; Hironobu Tanoue; Yuki Nagao; Takumi Furukawa; Shoji Nagaoka; Zenji Yatabe; Yusui Nakamura
  The 79th JSAP Autumn Meeting, 20 Sep. 2018, The Japan Society of Applied Physics, Japanese, Oral presentation
  18 Sep. 2018 - 21 Sep. 2018, Nagoya Congress Center, Japan, [Domestic Conference]
• Low Temperature Formation of ZnO Films by Plasma-Assisted Mist-CVD
  Tomotaka Kido; Tomoki Mikuriya; Rena Sugino; Yasutaka Nishi; Makoto Nakazumi; Koichiro Iwahori; Zenji Yatabe; Takao Namihira; Yusui Nakamura
  The 79th JSAP Autumn Meeting, 20 Sep. 2018, The Japan Society of Applied Physics, Japanese, Oral presentation
  18 Sep. 2018 - 21 Sep. 2018, Nagoya Congress Center, Japan, [Domestic Conference]
• Growth and characterization of AlTiO insulating films by mist CVD method
  Kousi Nishiyama; Kazuki Nishimura; Takaaki Tsuda; Qiang Yin; Zenji Yatabe; Kouji Sue; Yusui Nakamura
  The 79th JSAP Autumn Meeting, 20 Sep. 2018, The Japan Society of Applied Physics, Japanese, Oral presentation
  18 Sep. 2018 - 21 Sep. 2018, Nagoya Congress Center, Japan, [Domestic Conference]
• Improvement of Non-polar ZnO Films Formed on Buffer Layers on Sapphire Substrates by Mist Chemical Vapor Deposition
  Yudai Tanaka; Hironobu Tanoue; Masato Takenouchi; Yuki Nagao; Zenji Yatabe; Shoji Nagaoka; Yusui Nakamura
  The 1st International Workshop on the Research and Development of Unique Reaction/Separation Techniques in Kumamoto, 06 Mar. 2018, English, Poster presentation
  06 Mar. 2018 - 06 Mar. 2018, Kumamoto University, Japan
• Formation and bandgap engineering of ZnO_xS_1-x thin films formed by mist-CVD
  T. Ishida; K. Minami; K. Okita; K. Sue; S. Nagaoka; Z. Yatabe; Y. Nakamura
  JSAP Kyushu Chapter Annual Meeting 2017, 02 Dec. 2017, JSAP Kyushu Chapter, Japanese, Oral presentation
  01 Dec. 2017 - 03 Dec. 2017, MIYAZAKI KANKO HOTEL, Japan, [Domestic Conference]
• Growth of AlTiO thin films by mist chemical vapor deposition method
  T. Tsuda; K. Nishiyama; Z. Yatabe; K. Sue; Y. Nakamura
  JSAP Kyushu Chapter Annual Meeting 2017, 02 Dec. 2017, JSAP Kyushu Chapter, Japanese, Oral presentation
  01 Dec. 2017 - 03 Dec. 2017, MIYAZAKI KANKO HOTEL, Japan, 10958502, [Domestic Conference]
• Epitaxial Growth of Non-polar ZnS on Sapphire Substrate by Mist Chemical Vapor Deposition
  K. Okita; T. Goto; Y. Tanaka; M. Takenouchi; Z. Yatabe; Y. Nakamura
  2017 International Conference on Solid State Devices and Materials (SSDM2017), 21 Sep. 2017, The Japan Society of Applied Physics, English, Poster presentation
  19 Sep. 2017 - 22 Sep. 2017, Sendai International Center, Japan, [International presentation]
• N-doping into ZnO thin films by post-annealing in NH₃ ambient gas
  Masato Takenouchi; Syohei Wada; Hironobu Tanoue; Naoya Honogo; Shoji Nagaoka; Zenji Yatabe; Yusui Nakamura
  The 78th JSAP Autumn Meeting, 07 Sep. 2017, The Japan Society of Applied Physics, Japanese, Oral presentation
  05 Sep. 2017 - 08 Sep. 2017, Fukuoka Convention Center, Japan, [Domestic Conference]
• In-plane anisotropy of ZnO crystal on ZnO buffer layer formed by mist-CVD
  Yudai Tanaka; Hironobu Tanoue; Masato Takenouchi; Shoji Nagaoka; Zenji Yatabe; Yusui Nakamura
  The Japan Society of Applied Physics, 07 Sep. 2017, The Japan Society of Applied Physics, Japanese, Oral presentation
  05 Sep. 2017 - 08 Sep. 2017, Fukuoka Convention Center, Japan, [Domestic Conference]
• Improvement of crystallinity of ZnS epitaxial layer on sapphire substrate by mist-CVD
  Koshi Okita; Hironobu Tanoue; Taiki Goto; Yudai Tanaka; Shoji Nagaoka; Zenji Yatabe; Yusui Nakamura
  The 78th JSAP Autumn Meeting, 05 Sep. 2017, The Japan Society of Applied Physics, Japanese, Oral presentation
  05 Sep. 2017 - 08 Sep. 2017, Fukuoka Convention Center, Japan, [Domestic Conference]
• Epitaxial growth of SnO₂ on m-plane sapphire substrate by mist chemical vapor deposition
  Z. Yatabe; T. Tsuda; J. Matsushita; Y. Nakamura
  12th Topical Workshop on Heterostructure Microelectronics (TWHM 2017), 31 Aug. 2017, The Technical Committee on Electron Devices, IEICE, English, Poster presentation
  28 Aug. 2017 - 31 Aug. 2017, Hotel Kyocera, Kirishima, Japan, [International presentation]
• Correlation between V_TH instability and interface states in Al₂O₃/AlGaN/GaN structures
  Shota Kaneki; Zenji Yatabe; Tamotsu Hashizume
  12th Topical Workshop on Heterostructure Microelectronics (TWHM 2017), 29 Aug. 2017, The Technical Committee on Electron Devices, IEICE, English, Poster presentation
  28 Aug. 2017 - 31 Aug. 2017, Hotel Kyocera, Kirishima, Japan, 10958502, [International presentation]
• Threshold voltage shifts induced by acceptor-like interface states in Al₂O₃/AlGaN/GaN HEMTs
  Shota Kaneki; Zenji Yatabe; Kenya Nishiguchi; Tamotsu Hashizume
  12th International Conference on Nitride Semiconductors (ICNS-12), 25 Jul. 2017, English, Poster presentation
  24 Jul. 2017 - 28 Jul. 2017, Strasbourg Convention + Exhibition Centre, France, 10958502, [International presentation]
• Mist-chemical vapor deposition grown-single crystalline oxide semiconductors
  Zenji Yatabe; Hironobu Tanoue; Koshi Okita; Masato Takenouchi; Takahiro Ishida; Takaaki Tsuda; Tomoki Mikuriya; Shoji Nagaoka; Koji Sue; Yusui Nakamura
  35th Samahang Pisika ng Pilipinas Physics Conference and Annual Meeting (SPP 2017), 07 Jun. 2017, Samahang Pisika ng Pilipinas, English, Invited oral presentation
  07 Jun. 2017 - 10 Jun. 2017, Bayfront Hotel in Cebu City, Philippines, Invited Subplenary Talk, [Invited], [International presentation]
• GaN-based semiconductor devices challenges and prospects
  Zenji Yatabe
  Physics Dept. hosts talk on semiconductors, 06 Jun. 2017, Department of Physics, Mapúa University, English, Public discourse
  06 Jun. 2017 - 06 Jun. 2017, Mapúa University, Philippines, Invited Lecture, 10958502, [Invited]
• Epitaxial growth of nonpolar ZnS on sapphire substrate by mist chemical vapor deposition
  Koshi Okita; Hironobu Tanoue; Taiki Goto; Yudai Tanaka; Shoji Nagaoka; Zenji Yatabe; Yusui Nakamura
  The 64th JSAP Spring Meeting, 17 Mar. 2017, The Japan Society of Applied Physics, Japanese, Oral presentation
  14 Mar. 2017 - 17 Mar. 2017, Pacifico Yokohama, Japan, [Domestic Conference]
• Low Temperature Formation of ZnO Films by Mist-CVD
  Tomoki Mikuriya; Hirotaka Ogawa; Tomotaka Kido; Zenji Yatabe; Yasutaka Nishi; Masaru Nakazumi; Koichiro Iwahori; Kei Nara; Takao Namihira; Yusui Nakamura
  The 64th JSAP Spring Meeting, 14 Mar. 2017, The Japan Society of Applied Physics, Japanese, Oral presentation
  14 Mar. 2017 - 17 Mar. 2017, Pacifico Yokohama, Japan, [Domestic Conference]
• Tin (IV) oxide films on m-plane sapphire substrates formed by mist chemical vapor deposition
  T. Tsuda; T. Sato; J. Matsushita; T. Otabe; Z. Yatabe; K. Sue; S. Nagaoka; Y. Nakamura
  JSAP Kyushu Chapter Annual Meeting 2016, 03 Dec. 2016, JSAP Kyushu Chapter, Japanese, Oral presentation
  03 Dec. 2016 - 04 Dec. 2016, Tsushima Civic Center, Japan, [Domestic Conference]
• Low Temperature Formation of ZnO Films by Mist-CVD with Solution of Water and Methanol
  H. Ogawa; T. Mikuriya; K. Minami; Z. Yatabe; Y. Nishi; M. Nakazumi; K. Iwahori; K. Nara; T. Namihira; Y. Nakamura
  JSAP Kyushu Chapter Annual Meeting 2016, 03 Dec. 2016, JSAP Kyushu Chapter, Japanese, Oral presentation
  03 Dec. 2016 - 04 Dec. 2016, Tsushima Civic Center, Japan, [Domestic Conference]
• 絶縁膜/窒化物半導体界面の評価
  谷田部 然治
  界面科学コロキウム, 25 Nov. 2016, 神⼾⼤学⼯学研究科 界⾯科学研究センター, Japanese, Public discourse
  25 Nov. 2016 - 25 Nov. 2016, 神戸大学, Japan, 依頼公演, 10958502, [Invited]
• パワーデバイス応用に向けた絶縁膜/窒化物半導体界面の評価
  谷田部 然治
  第314回RISTフォーラム:RISTシーズ・活用事例発表会, 17 Nov. 2016, くまもと技術革新・融合研究会 (RIST), 熊本産業技術センター, くまもと産業支援財団, Japanese, Public discourse
  17 Nov. 2016 - 17 Nov. 2016, KKRホテル熊本, Japan, 依頼講演, [Invited], [Domestic Conference]
• Effects of Electronic States at Insulator/AlGaN Interfaces on Threshold Voltage Instability of Al₂O₃/AlGaN/GaN Structures
  Z. Yatabe; J. T. Asubar; Y. Nakamura; T. Hashizume
  2016 International Conference on Solid State Devices and Materials (SSDM2016), 28 Sep. 2016, The Japan Society of Applied Physics, English, Oral presentation
  26 Sep. 2016 - 29 Sep. 2016, Tsukuba International Congress Center, Japan, 10958502, [International presentation]
• Evaluation of Zinc Sulfide Films Formed by Mist Chemical Vapor Deposition
  Koshi Okita; Kensuke Minami; Satomi Teraya; Shoji Nagaoka; Zenji Yatabe; Yusui Nakamura
  The 77th JSAP Autumn Meeting, 16 Sep. 2016, The Japan Society of Applied Physics, Japanese, Oral presentation
  13 Sep. 2016 - 16 Sep. 2016, TOKI MESSE Niigata Convention Center, Japan, [Domestic Conference]
• Characterization of electronic states at insulator/(Al)GaN interfaces for improved insulated gate and surface passivation structures of GaN-based transistors
  Zenji Yatabe; Yujin Hori; Wan-Cheng Ma; Joel T. Asubar; Masamichi Akazawa; Taketomo Sato; Tamotsu Hashizume
  The 77th JSAP Autumn Meeting, 14 Sep. 2016, The Japan Society of Applied Physics, Japanese, Invited oral presentation
  13 Sep. 2016 - 16 Sep. 2016, TOKI MESSE Niigata Convention Center, Japan, Invited Talk (JSAP Paper Award Speech), 10958502, [Invited], [Domestic Conference]
• Improved linearity, stability, and thermal performance of multi-mesa-channel AlGaN/GaN HEMTs
  Joel T. Asubar; Hirokuni Tokuda; Masaaki Kuzuhara; Zenji Yatabe; Kenya Nishiguchi; Tamotsu Hashizume
  34thSPP Physics Conference and Annual Meeting (SPP 2016), 18 Aug. 2016, Samahang Pisika ng Pilipinas, English, Invited oral presentation
  18 Aug. 2016 - 21 Aug. 2016, University of the Philippines Visayas Iloilo and Miag-ao Campuses, Philippines, Sub-plenary Talk, [Invited], [International presentation]
• SnO₂ Thin Films Grown on m-Plane Sapphire Substrate by Mist Chemical Vapor Deposition
  Tatsuya Otabe; Takehide Sato; Junya Matsushita; Zenji Yatabe; Koji Sue; Shoji Nagaoka; Yusui Nakamura
  2016 Compound Semiconductor Week (CSW2016), 27 Jun. 2016, The Japan Society of Applied Physics, IEEE, Japanese, Poster presentation
  26 Jun. 2016 - 30 Jun. 2016, Toyama International Conference Center, Japan, [International presentation]
• Improvement of m-plane ZnO Films Formed on Buffer Layers on Sapphire Substrates by Mist Chemical Vapor Deposition
  Hironobu Tanoue; Tatsuya Yamashita; Shohei Wada; Zenji Yatabe; Shoji Nagaoka; Yusui Nakamura
  2016 Compound Semiconductor Week (CSW2016), 27 Jun. 2016, The Japan Society of Applied Physics, IEEE, English, Poster presentation
  26 Jun. 2016 - 30 Jun. 2016, Toyama International Conference Center, Japan, [International presentation]
• Crystallinity of ZnO films on ZnO buffer layers formed by mist-CVD
  Hironobu Tanoue; Shohei Wada; Tatsuya Yamashita; Shoji Nagaoka; Zenji Yatabe; Yusui Nakamura
  The 63rd JSAP Spring Meeting, 20 Mar. 2016, The Japan Society of Applied Physics, Japanese, Oral presentation
  19 Mar. 2016 - 22 Mar. 2016, Tokyo Inst. of Tech.Ookayama Campus, Japan, [Domestic Conference]
• 絶縁膜/AlGaN/GaN構造のMIS界面電子準位の評価
  谷田部 然治
  奈良先端科学技術大学院大学 物質創成科学研究科 情報機能素子科学研究室 特別講演会, 14 Mar. 2016, 奈良先端科学技術大学院大学 物質創成科学研究科 情報機能素子科学研究室, Japanese, Public discourse
  14 Mar. 2016 - 14 Mar. 2016, 奈良先端科学技術大学院大学, Japan, 招待講演, 10958502, [Invited]
• Size-controlled formation of high-aspect ratio porous nanostructures on GaN substrates utilizing photo-assisted electrochemical etching for photovoltaic applications
  Yusuke Kumazaki; Zenji Yatabe; Taketomo Sato
  2015 MRS Fall Meeting & Exhibit, 03 Dec. 2015, Materials Research Society, English, Poster presentation
  29 Nov. 2015 - 04 Dec. 2015, Boston, Massachusetts, USA, United States, 10390615, [International presentation]
• Nature and origin of interface states at dielectric/III-N heterojunction interfaces
  Maciej Matys; Boguslawa Adamowicz; Roman Stoklas; Masamichi Akazawa; Zenji Yatabe; Tamotsu Hashizume
  2015 MRS Fall Meeting & Exhibit, 03 Dec. 2015, Materials Research Society, English, Poster presentation
  29 Nov. 2015 - 04 Dec. 2015, Boston, Massachusetts, USA, United States, [International presentation], ［Internationally co-authored］
• Characterization and control of GaN MOS interfaces for power transistor application
  Tamotsu Hashizume; Zenji Yatabe
  2015 International Workshop on DIELECTRIC THIN FILMS FOR FUTURE ELECTRON DEVICES - SCIENCE AND TECHNOLOGY - (2015 IWDTF), 03 Nov. 2015, English, Invited oral presentation
  02 Nov. 2015 - 04 Nov. 2015, Miraikan, National Museum of Emerging Science and Innovation, Tokyo, Japan, Japan, Invited Talk, [Invited], [International presentation]
• Effect of High Electric Field on Photoabsorption Properties of GaN Porous Structures
  T. Sato; Y. Kumazaki; Z. Yatabe
  228th ECS Meeting, 13 Oct. 2015, The Electrochemical Society, English, Oral presentation
  11 Oct. 2015 - 15 Oct. 2015, Phoenix Convention Center and the Hyatt Regency, United States, 10390615, [International presentation]
• Formation of Self-aligned Pore Arrays on n-GaN Substrates by Photo-assisted Electrochemical Etching Process
  Y. Kumazaki; T. Sato; Z. Yatabe
  2015 International Conference on Solid State Devices and Materials (SSDM2015), 30 Sep. 2015, The Japan Society of Applied Physics, English, Oral presentation
  27 Sep. 2015 - 30 Sep. 2015, Sapporo Convention Center, Japan, 10390615, [International presentation]
• Dynamics of a droplet on Leidenfrost phenomena
  Akio Nishimura; Zenji Yatabe; Masahiko Shoji; Chihiro Hashimoto; Masao Takayanagi; Hideharu Ushiki
  64th Symposium on Macromolecules, 17 Sep. 2015, The Society of Polymer Science, Japan, Japanese, Poster presentation
  15 Sep. 2015 - 17 Sep. 2015, Kawauchi Campus, Tohoku University, Japan, [Domestic Conference]
• Analyses of photoanodized GaN surface in back-side illumination mode
  Masaaki Edamoto; Yusuke Kumazaki; Zenji Yatabe; Taketomo Sato
  The 76th JSAP Autumn Meeting, 15 Sep. 2015, The Japan Society of Applied Physics, Japanese, Oral presentation
  13 Sep. 2015 - 16 Sep. 2015, Nagoya Congress Center, Japan, 10390615, [Domestic Conference]
• Photoelectrochemical characterization of n-type GaN porous structures for use in photocatalytic water-splitting system
  Hirofumi Kida; Yusuke Kumazaki; Zenji Yatabe; Taketomo Sato
  The 76th JSAP Autumn Meeting, 14 Sep. 2015, The Japan Society of Applied Physics, Japanese, Poster presentation
  13 Sep. 2015 - 16 Sep. 2015, Nagoya Congress Center, Japan, [Domestic Conference]
• Electrochemical formation and optical characterization of Cu₂O/GaN heterostructures
  Yusuke Kumazaki; Sayaka Ohmi; Zenji Yatabe; Taketomo Sato
  The 76th JSAP Autumn Meeting, 14 Sep. 2015, The Japan Society of Applied Physics, Japanese, Poster presentation
  13 Sep. 2015 - 16 Sep. 2015, Nagoya Congress Center, Japan, [Domestic Conference]
• Electro-deposition and characterization of Cu₂O/InP heterostructure
  Sayaka Omi; Yusuke kumazaki; Zenji Yatabe; Taketomo Sato
  The 76th JSAP Autumn Meeting, 13 Sep. 2015, The Japan Society of Applied Physics, Japanese, Oral presentation
  13 Sep. 2015 - 16 Sep. 2015, Nagoya Congress Center, Japan, 10390615, [Domestic Conference]
• Comparative study of oxygen plasma treatment and GaN cap layer effects on the current collapse of AlGaN/GaN HEMTs
  Joel T. Asubar; Yoshiki Sakaida; Satoshi Yoshida; Zenji Yatabe; Hirokuni Tokuda; Tamotsu Hashizume; Masaaki Kuzuhara
  11th Topical Workshop on Heterostructure Microelectronics (TWHM 2015), 26 Aug. 2015, The Technical Committee on Electron Devices, IEICE, English, Poster presentation
  23 Aug. 2015 - 26 Aug. 2015, Hida Hotel Plaza, Takayama, Japan, Japan, [International presentation]
• Electrochemical formation of GaN porous structures for photocatalytic applications
  Taketomo Sato; Yusuke Kumazaki; Zenji Yatabe
  11th Topical Workshop on Heterostructure Microelectronics (TWHM 2015), 26 Aug. 2015, The Technical Committee on Electron Devices, IEICE, English, Invited oral presentation
  23 Aug. 2015 - 26 Aug. 2015, Hida Hotel Plaza, Takayama, Japan, Japan, Invited Talk, [Invited], [International presentation]
• Photoelectrochemical characterization of n-type GaN porous structures for use in photocatalytic water-splitting system
  Hirofumi Kida; Yusuke Kumazaki; Zenji Yatabe; Taketomo Sato
  11th Topical Workshop on Heterostructure Microelectronics (TWHM 2015), 26 Aug. 2015, The Technical Committee on Electron Devices, IEICE, English, Poster presentation
  23 Aug. 2015 - 26 Aug. 2015, Hida Hotel Plaza, Takayama, Japan, Japan, [International presentation]
• Electrochemical Formation of Cu₂O Films on n-type InP and n-type GaN Substrates
  Sayaka Omi; Yusuke Kumazaki; Zenji Yatabe; Taketomo Sato
  11th Topical Workshop on Heterostructure Microelectronics (TWHM 2015), 26 Aug. 2015, The Technical Committee on Electron Devices, IEICE, English, Poster presentation
  23 Aug. 2015 - 26 Aug. 2015, Hida Hotel Plaza, Takayama, Japan, Japan, [International presentation]
• High-selective etching of p-GaN layers on AlGaN/GaN heterostructures by electrochemical process
  Masaaki Edamoto; Yusuke Kumazaki; Zenji Yatabe; Taketomo Sato; Tamotsu Hashizume
  11th Topical Workshop on Heterostructure Microelectronics (TWHM 2015), 26 Aug. 2015, The Technical Committee on Electron Devices, IEICE, English, Poster presentation
  23 Aug. 2015 - 26 Aug. 2015, Hida Hotel Plaza, Takayama, Japan, Japan, 10390615, [International presentation]
• Oxygen annealing process of GaN MOS structures
  Joji Ohira; Yutaka Senzaki; Zenji Yatabe; Tamotsu Hashizume
  11th Topical Workshop on Heterostructure Microelectronics (TWHM 2015), 24 Aug. 2015, The Technical Committee on Electron Devices, IEICE, English, Poster presentation
  23 Aug. 2015 - 26 Aug. 2015, Hida Hotel Plaza, Takayama, Japan, Japan, [International presentation]
• Influence of dry etching on Al₂O₃/AlGaN/GaN MOS interface properties
  Zenji Yatabe; Joji Ohira; Taketomo Sato; Tamotsu Hashizume
  11th Topical Workshop on Heterostructure Microelectronics (TWHM 2015), 24 Aug. 2015, The Technical Committee on Electron Devices, IEICE, English, Poster presentation
  23 Aug. 2015 - 26 Aug. 2015, Hida Hotel Plaza, Takayama, Japan, Japan, 10958502;10390615, [International presentation]
• Electrochemical formation and UV photoresponse properties of GaN porous structures
  Hirofumi Kida; Yusuke Kumazaki; Zenji Yatabe; Taketomo Sato
  IEICE Technical Committee on Electron Device, 04 Aug. 2015, The Institute of Electronics, Information and Communication Engineers/The Institute of Electrical Engineers of Japan, Japanese, Oral presentation
  03 Aug. 2015 - 04 Aug. 2015, Kikai-Shinko-Kaikan Bldg., Japan, 10390615, [Domestic Conference]
• Characterization and Control of Insulated Gate Interfaces for Normally-Off AlGaN/GaN HEMTs
  Zenji Yatabe; Tamotsu Hashizume
  2015 Compound Semiconductor Week (CSW 2015), 02 Jul. 2015, UCSB, MIT, English, Invited oral presentation
  28 Jun. 2015 - 02 Jul. 2015, University of California, Santa Barbara, United States, Invited Talk, 10958502, [Invited], [International presentation]
• Influence of the Oxygen-Plasma Treatment on the AlGaN/GaN MOSHFETs with HfO₂ by ALD to Reduce Leakage Current
  Roman Stoklas; Dagmar Gregušová; Michal Blaho; Karol Fröhlich; Jozef Novák; Peter Kordoš; Maciek Matys; Zenji Yatabe; Tamotsu Hashizume
  2015 Compound Semiconductor Week (CSW 2015), 29 Jun. 2015, UCSB, MIT, English, Poster presentation
  28 Jun. 2015 - 02 Jul. 2015, University of California, Santa Barbara, United States, [International presentation], ［Internationally co-authored］
• Characterization and control of interface states for stable operation of GaN transistors
  T. Hashizume; Z. Yatabe
  2015 Asia-Pacific Workshop on Fundamentals and Applications of Advanced Semiconductor Devices (AWAD2015), 29 Jun. 2015, The Institute of Electronics and Information Engineers, Brain Korea 21, IEICE Electronics Society, English, Invited oral presentation
  29 Jun. 2015 - 01 Jul. 2015, Jeju KAL hotel, Korea, Republic of, Invited Talk, [Invited], [International presentation]
• Interface states characterization of Al₂O₃/AlGaN/GaN structures
  Zenji Yatabe; Tamotsu Hashizume
  IEICE Technical Committee on Silicon Device and Materials, 19 Jun. 2015, The Institute of Electronics, Information and Communication Engineers/Silicon Technology Division, The Japan Society of Applied Physics, Japanese, Invited oral presentation
  19 Jun. 2015 - 19 Jun. 2015, VBL, Nagoya University, Japan, Invited Lecture, 10958502, [Invited], [Domestic Conference]
• Effects of surface charging and interface states on current stability of GaN HEMTs
  T. Hashizume; Z. Yatabe; K. Nishiguchi
  39th Workshop on Compound Semiconductor Devices and Integrated Circuits (WOCSDICE 2015), 09 Jun. 2015, Slovak University of Technology in Bratislava, English, Oral presentation
  08 Jun. 2015 - 10 Jun. 2015, Smolenice, Slovakia, Slovakia, Invited Talk, [International presentation]
• 界面電子準位とGaNパワーデバイスの動作安定性
  橋詰 保; 西口 賢弥; 谷田部 然治
  第95回研究会, 29 May 2015, 日本学術振興会 半導体界面制御技術第154委員会, Japanese, Invited oral presentation
  29 May 2015 - 29 May 2015, キャンパス・イノベーションセンター(CIC)東京, Japan, [Domestic Conference]
• Spectro-electrochemical characterization of GaN/electrolyte interface and its application to the nanostructure formation
  Yusuke Kumazaki; Akio Watanabe; Zenji Yatabe; Taketomo Sato
  IEICE Technical Committee on Electron Device, 29 May 2015, The Institute of Electronics, Information and Communication Engineers, Japanese, Oral presentation
  28 May 2015 - 29 May 2015, Toyohashi University of Technology, Japan, 10390615, [Domestic Conference]
• Droplet impacting on a superheated metal plate
  Akio Nishimura; Zenji Yatabe; Masahiko Shoji; Chihiro Hashimoto; Masao Takayanagi; Hideharu Ushiki
  64th SPSJ Annual Meeting, 28 May 2015, The Society of Polymer Science, Japan, Japanese, Poster presentation
  27 May 2015 - 29 May 2015, Sapporo Convention Center, Japan, [Domestic Conference]
• Characterization of Surface/Interface States for Stability Improvement of GaN-Based HEMTs
  Tamotsu Hashizume; Zenji Yatabe
  2015 MRS Spring Meeting & Exhibit, 08 Apr. 2015, Materials Research Society, English, Invited oral presentation
  06 Apr. 2015 - 10 Apr. 2015, San Francisco, California, USA, Invited Talk, [Invited], [International presentation]
• Effects of dry etching on Al₂O₃/AlGaN/GaN MOS interface properties
  Zenji Yatabe; Joji Ohira; Taketomo Sato; Tamotsu Hashizume
  The 62nd JSAP Spring Meeting, 13 Mar. 2015, The Japan Society of Applied Physics, Japanese, Poster presentation
  11 Mar. 2015 - 14 Mar. 2015, Shonan Campus, Tokai University, Japan, 10390615, [Domestic Conference]
• Suppressed Current Collapse in AlGaN/GaN HEMT by High Pressure Water Vapor Annealing
  Yohei Kobayashi; Joel T. Asubar; Koji Yoshitsugu; Zenji Yatabe; Hirokuni Tokuda; Masahiro Horita; Yukiharu Uraoka; Tamotsu Hashizume; Masaaki Kuzuhara
  The 62nd JSAP Spring Meeting, 12 Mar. 2015, The Japan Society of Applied Physics, Japanese, Oral presentation
  11 Mar. 2015 - 14 Mar. 2015, Shonan Campus, Tokai University, Japan, [Domestic Conference]
• Effects of oxygen annealing process on GaN MOS interface properties
  Joji Ohira; Yutaka Senzaki; Zenji Yatabe; Tamotsu Hashizume
  The 62nd JSAP Spring Meeting, 12 Mar. 2015, The Japan Society of Applied Physics, Japanese, Oral presentation
  11 Mar. 2015 - 14 Mar. 2015, Shonan Campus, Tokai University, Japan, [Domestic Conference]
• Electro-deposition and characterization of Cu₂O/GaN heterostructure
  Yusuke Kumazaki; Sayaka Ohmi; Zenji Yatabe; Taketomo Sato
  The 62nd JSAP Spring Meeting, 11 Mar. 2015, The Japan Society of Applied Physics, Japanese, Oral presentation
  11 Mar. 2015 - 14 Mar. 2015, Shonan Campus, Tokai University, Japan, 10390615, [Domestic Conference]
• Effects of thermal oxidation process on GaN MOS interface properties
  Yutaka Senzaki; Zenji Yatabe; Tamotsu Hashizume
  50th JSAP Hokkaido Chapter Annual Meeting, 10 Jan. 2015, Hokkaido Chapter, The Japan Society of Applied Physics, Japanese, Oral presentation
  09 Jan. 2015 - 10 Jan. 2015, 旭川市ときわ市民ホール, Japan, [Domestic Conference]
• Electrochemical formation of GaN porous structures
  Akio Watanabe; Yusuke Kumazaki; Zenji Yatabe; Taketomo Sato
  50th JSAP Hokkaido Chapter Annual Meeting, 10 Jan. 2015, Hokkaido Chapter, The Japan Society of Applied Physics, Japanese, Oral presentation
  09 Jan. 2015 - 10 Jan. 2015, 旭川市ときわ市民ホール, Japan, 10390615, [Domestic Conference]
• Structural Properties and Control of GaN Porous Nanostructures Formed by Photo-assisted Electrochemical Process
  Akio Watanabe; Yusuke Kumazaki; Zenji Yatebe; Taketomo Sato
  The 7th International Symposium on Surface Science (ISSS-7), 03 Nov. 2014, The Surface Science Society of Japan, English, Poster presentation
  02 Nov. 2014 - 06 Nov. 2014, Shimane Prefectural Convention Center, Japan, 10390615, [International presentation]
• Electrochemical Formation of GaN Porous Structures Under UV-Light Irradiation for Photoelectrochemical Application
  T. Sato; A. Watanabe; Y. Kumazaki; Z. Yatabe
  2014 ECS and SMEQ Joint International Meeting, 08 Oct. 2014, The Electrochemical Society, English, Oral presentation
  05 Oct. 2014 - 09 Oct. 2014, Moon Palace Resort, Carretera Cancun-Chetumal Km. 340, Cancun, Mexico, 10390615, [International presentation]
• Electrochemical Formation of Nitride-Semiconductor porous structures
  Akio Watanabe; Yusuke Kumazaki; Zenji Yatabe; Taketomo Sato
  2014 Fall Meeting, 27 Sep. 2014, The Electrochemical Society of Japan, Japanese, Oral presentation
  27 Sep. 2014 - 28 Sep. 2014, Hokkaido University, Japan, 10390615, [Domestic Conference]
• The formation process of multilamellar vesicles in sine shear flow
  Hirokazu Maruoka; Zenji Yatabe; Masahiko Shoji; Chihiro Hashimoto; Hideharu Ushiki
  63rd Symposium on Macromolecules, 26 Sep. 2014, The Society of Polymer Science, Japan, Japanese, Poster presentation
  24 Sep. 2014 - 26 Sep. 2014, Nagasaki University, Japan, [Domestic Conference]
• Energy dynamics of Leidenfrost droplets with a small amount of polymer additives
  Akio Nishimura; Zenji Yatabe; Masahiko Shoji; Chihiro Hashimoto; Masao Takayanagi; Hideharu Ushiki
  63rd Symposium on Macromolecules, 26 Sep. 2014, The Society of Polymer Science, Japan, Japanese, Poster presentation
  24 Sep. 2014 - 26 Sep. 2014, Nagasaki University, Japan, [Domestic Conference]
• Application of Al₂O₃/InAlN interface formed by 2-step ALD to MOSHEMT
  Yoichiro Odanagi; Masamichi Akazawa; Joel T. Asubar; Zenji Yatabe; Tamotsu Hashizume
  The 75th JSAP Autumn Meeting, 19 Sep. 2014, The Japan Society of Applied Physics, Japanese, Poster presentation
  17 Sep. 2014 - 20 Sep. 2014, Sapporo Campus, Hokkaido University, Japan, [Domestic Conference]
• Electrochemical Formation and Structural Control of GaN Porous structures
  Yusuke Kumazaki; Akio Watanabe; Zenji Yatabe; Taketomo Sato
  The 75th JSAP Autumn Meeting, 18 Sep. 2014, The Japan Society of Applied Physics, Japanese, Oral presentation
  17 Sep. 2014 - 20 Sep. 2014, Sapporo Campus, Hokkaido University, Japan, 10390615, [Domestic Conference]
• Electrochemical etching of III-V compound semiconductors for micro- and nano-fabrications
  Taketomo Sato; Yusuke Kumazaki; Akio Watanabe; Zenji Yatabe
  The 75th JSAP Autumn Meeting, 17 Sep. 2014, The Japan Society of Applied Physics, Japanese, Invited oral presentation
  17 Sep. 2014 - 20 Sep. 2014, Sapporo Campus, Hokkaido University, Japan, Invited Talk, 10390615, [Invited], [Domestic Conference]
• Correlation between Structural and Optical Properties of GaN Porous Structures Formed by Photo-assisted Electrochemical Etching
  Yusuke Kumazaki; Akio Watanabe; Zenji Yatabe; Taketomo Sato
  International Workshop on Nitride Semiconductors (IWN 2014), 27 Aug. 2014, English, Poster presentation
  24 Aug. 2014 - 29 Aug. 2014, Wrocław, Poland, Poland, 10390615, [International presentation]
• Interface Trap States in Al₂O₃/AlGaN/GaN Structure Induced by ICP Etching of AlGaN Surfaces
  Zenji Yatabe; Taketomo Sato; Tamotsu Hashizume
  International Workshop on Nitride Semiconductors (IWN 2014), 27 Aug. 2014, English, Invited oral presentation
  24 Aug. 2014 - 29 Aug. 2014, Wrocław, Poland, Poland, Invited Talk, [Invited], [International presentation]
• Study of the density distribution and capture cross section of interface states and interface fixed charge at Al₂O₃/GaN and Al₂O₃/AlGaN interfaces
  M. Matys; Z. Yatabe; Y. Hori; T. Hashizume; B. Adamowicz
  International Workshop on Nitride Semiconductors (IWN 2014), 27 Aug. 2014, English, Poster presentation
  24 Aug. 2014 - 29 Aug. 2014, Wrocław, Poland, Poland, [International presentation], ［Internationally co-authored］
• Structural control of GaN porous structures for high-sensitive chemical sensors
  Akio Watanabe; Yusuke Kumazaki; Zenji Yatabe; Taketomo Sato
  The 6th IEEE International Nanoelectronics Conference (IEEE INEC 2014), 30 Jul. 2014, IEEE Electron Devices Society, English, Poster presentation
  28 Jul. 2014 - 31 Jul. 2014, Hokkaido University, Japan, 10390615, [International presentation]
• Electrochemical Formation of III-V Semiconductor Porous Nanostructures
  Taketomo Sato; Yusuke Kumazaki; Akio Watanabe; Zenji Yatabe
  The 6th IEEE International Nanoelectronics Conference (IEEE INEC 2014), 30 Jul. 2014, IEEE Electron Devices Society, English, Invited oral presentation
  28 Jul. 2014 - 31 Jul. 2014, Hokkaido University, Japan, Invited Talk, 10390615, [Invited], [International presentation]
• 界面・バルク電子準位がGaNトランジスタの動作特性に与える影響
  橋詰 保; 西口 賢弥; 谷田部 然治; 佐藤 威友
  第1回先進パワー半導体分科会研究会「ワイドギャップ半導体パワーデバイスの信頼性」, 30 Jul. 2014, 応用物理学会 先進パワー半導体分科会, Japanese, Invited oral presentation
  30 Jul. 2014 - 30 Jul. 2014, 東京工業大学 大岡山キャンパス, Japan, [Invited], [Domestic Conference]
• Complex Chemical Physics LXIII : Polymer additive effects on a droplet impacting on a heated surface
  Akio Nishimura; Zenji Yatabe; Masahiko Shoji; Chihiro Hashimoto; Hideharu Ushiki
  63rd SPSJ Annual Meeting, 30 May 2014, The Society of Polymer Science, Japan, Japanese, Poster presentation
  28 May 2014 - 30 May 2014, Nagoya Congress Center, Japan, [Domestic Conference]
• The formation process of multilamellar vesicles in sine shear flow
  Hirokazu Maruoka; Zenji Yatabe; Masahiko Shoji; Chihiro Hashimoto; Hideharu Ushiki
  63rd SPSJ Annual Meeting, 30 May 2014, The Society of Polymer Science, Japan, Japanese, Poster presentation
  28 May 2014 - 30 May 2014, Nagoya Congress Center, Japan, [Domestic Conference]
• Characterization of MOS Interface Properties in Al₂O₃/AlGaN/GaN Structures with Dry-etched AlGaN Surface
  Zenji Yatabe; Yujin Hori; Tamotsu Hashizume
  The 61st JSAP Spring Meeting, 19 Mar. 2014, The Japan Society of Applied Physics, Japanese, Oral presentation
  17 Mar. 2014 - 20 Mar. 2014, Sagamihara Campus, Aoyama Univer, Japan, [Domestic Conference]
• Control of insulator interfaces for GaN power electron devices
  Tamotsu Hashizume; Zenji Yatabe, Taketomo Sato
  電子デバイス研究会 次世代化合物電子デバイスとその応用, 13 Mar. 2014, The Institute of Electrical Engineers of Japan, Japanese, Invited oral presentation
  13 Mar. 2014 - 14 Mar. 2014, Hotel Hekiryu, Japan, Invited Talk, [Invited], [Domestic Conference]
• Characterization of insulated gate interfaces on GaN-related materials
  Yujin Hori; Zenji Yatabe; Tamotsu Hashizume
  SiC and Related Materials Researches 22nd Conference, 10 Dec. 2013, Professional Group of Advanced Power Semiconductors, The Japan Society of Applied Physics, Japanese, Invited oral presentation
  09 Dec. 2013 - 10 Dec. 2013, Saitama Assembly Hall, Japan, Invited Lecture, [Invited], [Domestic Conference]
• Structural control of GaN porous structures for high-sensitive chemical sensors
  Akio Watanabe; Yusuke Kumazaki; Zenji Yatabe; Taketomo Sato
  49th JSAP Hokkaido Chapter Annual Meeting, 09 Dec. 2013, Hokkaido Chapter, The Japan Society of Applied Physics, Japanese, Oral presentation
  09 Dec. 2013 - 10 Dec. 2013, Conference Hall, Hokkaido University, Japan, 10390615, [Domestic Conference]
• Photoelectrode properties of GaN porous structures formed by photo-assisted electrochemical process
  Yusuke Kumazaki; Akio Watanabe; Zenji Yatabe; Taketomo Sato
  IEICE Technical Committee on Electron Device, 29 Nov. 2013, The Institute of Electronics, Information and Communication Engineers, Japanese, Oral presentation
  28 Nov. 2013 - 29 Nov. 2013, Suita Campus, Osaka University, Japan, 電子デバイス研究会 論文発表奨励賞, 10390615, [Domestic Conference]
• Photoabsorption and Photoelectric Conversion Properties of InP Porous Structures Formed By Electrochemical Process
  Taketomo Sato; Yusuke Kumazaki; Ryohei Jinbo; Zenji Yatabe
  224th ECS Meeting, 30 Oct. 2013, The Electrochemical Society, English, Oral presentation
  27 Oct. 2013 - 01 Nov. 2013, The Hilton San Francisco Hotel, United States, 10390615, [International presentation]
• Structural and Optical Characterization of GaN Porous Structures Formed By Photo-Assisted Electrochemical Process
  Yusuke Kumazaki; Akio Watanabe; Zenji Yatabe; Taketomo Sato
  224th ECS Meeting, 29 Oct. 2013, The Electrochemical Society, English, Poster presentation
  27 Oct. 2013 - 01 Nov. 2013, The Hilton San Francisco Hotel, United States, 10390615, [International presentation]
• Characterization of MOS Interface States and their Effects on Electrical Properties in GaN-based MOS-HEMTs
  Yujin Hori; Zenji Yatabe; Tamotsu Hashizume
  The 74th JSAP Autumn Meeting, 20 Sep. 2013, The Japan Society of Applied Physics, Japanese, Oral presentation
  16 Sep. 2013 - 20 Sep. 2013, Kyotanabe Campus, Doshisha University, Japan, [Domestic Conference]
• Electrochemical formation of GaN porous nano structures using backside-light irradiation
  Akio Watanabe; Yusuke Kumazaki; Zenji Yatabe; Taketomo Sato
  The 74th JSAP Autumn Meeting, 19 Sep. 2013, The Japan Society of Applied Physics, Japanese, Oral presentation
  16 Sep. 2013 - 20 Sep. 2013, Kyotanabe Campus, Doshisha University, Japan, 10390615, [Domestic Conference]
• Surface morphology and photoelectrochemical characteristics of GaN Porous Structures
  Yusuke Kumazaki; Akio Watanabe; Zenji Yatabe; Taketomo Sato
  The 74th JSAP Autumn Meeting, 16 Sep. 2013, The Japan Society of Applied Physics, Japanese, Oral presentation
  16 Sep. 2013 - 20 Sep. 2013, Kyotanabe Campus, Doshisha University, Japan, 10390615, [Domestic Conference]
• Complex Chemical Physics LXII : Deformation and sound of a droplet impacting on heated surfaces
  Akio Nishimura; Zenji Yatabe; Masahiko Shoji; Chihiro Hashimoto; Toshiyuki Shikata; Hideharu Ushiki
  62nd Symposium on Macromolecules, 12 Sep. 2013, The Society of Polymer Science, Japanese, Poster presentation
  11 Sep. 2013 - 13 Sep. 2013, Kanazawa University, Japan, [Domestic Conference]
• Impact of dry etching of AlGaN on interface properties of Al₂O₃/AlGaN/GaN structure
  Zenji Yatabe; Tamotsu Hashizume
  10th Topical Workshop on Heterostructure Microelectronics (TWHM 2013), 03 Sep. 2013, The Technical Committee on Electron Devices, IEICE, English, Poster presentation
  02 Sep. 2013 - 05 Sep. 2013, Hakodate Kokusai Hotel, Japan, [International presentation]
• Interface State Characterization of Al₂O₃/AlGaN/GaN Structure with Inductively Coupled Plasma Etched AlGaN Surfaces
  Zenji Yatabe; Yujin Hori; Tamotsu Hashizume
  10th International Conference on Nitride Semiconductors (ICNS-10), 27 Aug. 2013, English, Oral presentation
  25 Aug. 2013 - 30 Aug. 2013, Gaylord National Resort & Convention Center, United States, [International presentation]
• Characterization and Control of MOS Interface States in GaN-based MOS-HEMTs Using Al₂O₃ Gate Insulator
  Yujin Hori; Zenji Yatabe; Tamotsu Hashizume
  10th International Conference on Nitride Semiconductors (ICNS-10), 26 Aug. 2013, English, Poster presentation
  25 Aug. 2013 - 30 Aug. 2013, Gaylord National Resort & Convention Center, United States, Outstanding Poster Presentation Award, [International presentation]
• Electrochemical formation and optical characterization of GaN porous structures
  Yusuke Kumazaki; Akio Watanabe; Ryohei Jinbo; Zenji Yatabe; Taketomo Sato
  32nd Electronic Materials Symposium (EMS-32), 10 Jul. 2013, Japanese, Poster presentation
  10 Jul. 2013 - 12 Jul. 2013, LAFORET Biwako, Japan, [Domestic Conference]
• 電気化学的手法によるGaN多孔質構造の形成と光学特性の評価
  熊崎 祐介; 渡部 晃生; 谷田部 然治; 佐藤 威友
  第29回ライラックセミナー・第19回若手研究者交流会, 15 Jun. 2013, 電気化学会北海道支部, Japanese, Poster presentation
  15 Jun. 2013 - 16 Jun. 2013, おたる自然の村おこばち山荘, Japan, [Domestic Conference]
• Complex Chemical Physics LVII : the Formation Process of Multilamellar Vesicles in Sine Shear
  Hirokazu Maruoka; Zenji Yatabe; Masahiko Shoji; Chihiro Hashimoto; Toshiyuki Shikata; Hideharu Ushiki
  62nd SPSJ Annual Meeting, 30 May 2013, The Society of Polymer Science, Japanese, Poster presentation
  29 May 2013 - 31 May 2013, Kyoto International Conference Center, Japan, [Domestic Conference]
• Complex Chemical Physics LVI : Polymer effect on droplet impacting on heated surfaces
  Akio Nishimura; Zenji Yatabe; Masahiko Shoji; Chihiro Hashimoto; Toshiyuki Shikata; Hideharu Ushiki
  62nd SPSJ Annual Meeting, 30 May 2013, The Society of Polymer Science, Japanese, Poster presentation
  29 May 2013 - 31 May 2013, Kyoto International Conference Center, Japan, [Domestic Conference]
• Electrochemical Formation and Optical Characterization of GaN Porous Structures
  Yusuke Kumazaki; Akio Watanabe; Ryohei Jinbo; Zenji Yatabe; Taketomo Sato
  The 40th International Symposium on Compound Semiconductors (ISCS 2013), 22 May 2013, ISCS 2013 Committees, English, Poster presentation
  19 May 2013 - 23 May 2013, Kobe Convention Center, Japan, 10390615, [International presentation]
• Photoabsorption and Photoelectric Conversion Properties of InP Porous Structures Formed by the Electrochemical process
  Yusuke Kumazaki; Ryohei Jinbo; Zenji Yatabe; Taketomo Sato
  IEICE Technical Committee on Electron Device, 17 May 2013, The Institute of Electronics, Information and Communication Engineers, Japanese, Oral presentation
  16 May 2013 - 17 May 2013, Shizuoka University, Japan, 10390615, [Domestic Conference]
• Electrochemical Formation and Optical Characterization of GaN Porous Structures
  Yusuke Kumazaki; Akio Watanabe; Ryohei Jinbo; Zenji Yatabe; Taketomo Sato
  The 60th JSAP Spring Meeting, 2013, 30 Mar. 2013, The Japan Society of Applied Physics, Japanese, Oral presentation
  27 Mar. 2013 - 30 Mar. 2013, Kanagawa Institute of Technology, Japan, [Domestic Conference]
• Characterization of Electrical Properties and Hetero-MOS Interface States of AlGaN/GaN MOS-HEMTs
  Yujin Hori; Zenji Yatabe; Tamotsu Hashizume
  The 60th JSAP Spring Meeting, 2013, 28 Mar. 2013, The Japan Society of Applied Physics, Japanese, Oral presentation
  27 Mar. 2013 - 30 Mar. 2013, Kanagawa Institute of Technology, Japan, [Domestic Conference]
• Effects of Dry Etching on the Interface Properties of AlGaN/GaN MOS Structures
  Zenji Yatabe; Yujin Hori; Wan-cheng Ma; Tamotsu Hashizume
  The 60th JSAP Spring Meeting, 2013, 28 Mar. 2013, The Japan Society of Applied Physics, Japanese, Oral presentation
  27 Mar. 2013 - 30 Mar. 2013, Kanagawa Institute of Technology, Japan, [Domestic Conference]
• Effects of buffer layers on GaN-based junction properties
  Wan-Cheng Ma; Yujin Hori; Zenji Yatabe; Tamotsu Hashizume
  The 60th JSAP Spring Meeting, 2013, 28 Mar. 2013, The Japan Society of Applied Physics, Japanese, Oral presentation
  27 Mar. 2013 - 30 Mar. 2013, Kanagawa Institute of Technology, Japan, [Domestic Conference]
• Interface characterization of AlGaN/GaN hetero-MOS structure with dry-etched AlGaN
  Zenji Yatabe; Yujin Hori; Wancheng Ma; Tamotsu Hashizume
  48^th JSAP Hokkaido Chapter Annual Meeting, 11 Jan. 2013, Hokkaido Chapter, The Japan Society of Applied Physics, Japanese, Oral presentation
  Kushiro-shi, [Domestic Conference]
• Effects of process conditions on AlGaN/GaN hetero-MOS structures
  Yujin Hori; Zenji Yatabe; Wan-Cheng Ma; Tamotsu Hashizume
  IEICE Technical Committee on Electron Device, 29 Nov. 2012, The Institute of Electronics, Information and Communication Engineers, Japanese, Oral presentation
  Osaka City University, [Domestic Conference]
• Insulated gate technologies for high-performance GaN transistors
  Tamotsu Hashizume; Yujin Hori; Sungsik Kim; Zenji Yatabe; Masamichi Akazawa
  International Workshop on Nitride Semiconductors 2012 (IWN2012), 16 Oct. 2012, The Japan Society of Applied Physics / The Japanese Association for Crystal Growth, English, Invited oral presentation
  14 Oct. 2012 - 19 Oct. 2012, Sapporo Convention Center, Japan, Invited Talk, [Invited], [International presentation]
• Photoelectric-conversion Devices Based on InP Porous Structure
  Taketomo Sato; Ryohei Jinbo; Zenji Yatabe
  Pacific Rim Meeting on Electrochemical and Solid-state Science 2012 (PRiME 2012), 10 Oct. 2012, The Electrochemical Society of Japan, The Electrochemical Society, English, Oral presentation
  07 Oct. 2012 - 12 Oct. 2012, Hawaii Convention Center and the Hilton Hawaiian Village, United States, [International presentation]
• Interface characterization of Al₂O₃/AlGaN/GaN structure with inductively coupled plasma etching of AlGaN surface
  Z. Yatabe; Y. Hori; S. Kim; T. Hashizume
  2012 International Conference on Solid State Devices and Materials (SSDM2012), 27 Sep. 2012, The Japan Society of Applied Physics, English, Oral presentation
  25 Sep. 2012 - 27 Sep. 2012, Kyoto International Conference Center, Japan, [International presentation]
• Optical Absorption Properties of InP Porous Structures Formed by Electrochemical Process
  Y. Kumazaki; T. Kudo; Z. Yatabe; T. Sato
  2012 International Conference on Solid State Devices and Materials (SSDM2012), 26 Sep. 2012, The Japan Society of Applied Physics, English, Poster presentation
  25 Sep. 2012 - 27 Sep. 2012, Kyoto International Conference Center, Japan, [International presentation]
• Complex Chemical Physics LII : the formation process of Multilamellar Vesicles in sine shear
  Hirokazu Maruoka; Zenji Yatabe; Masahiko Shoji; Chihiro Hashimoto; Hideharu Ushiki
  61st Symposium on Macromolecules, 19 Sep. 2012, The Society of Polymer Science, Japan, Japanese, Poster presentation
  19 Sep. 2012 - 21 Sep. 2012, Nagoya Institute of Technology, [Domestic Conference]
• Complex Chemical Physics LI : Audio and image analysis of gas-liquid multiphase flow
  Akio Nishimura; Zenji Yatabe; Masahiko Shoji; Chihiro Hashimoto; Hideharu Ushiki
  61st Symposium on Macromolecules, 19 Sep. 2012, The Society of Polymer Science, Japan, Japanese, Poster presentation
  19 Sep. 2012 - 21 Sep. 2012, Nagoya Institute of Technology, Japan, [Domestic Conference]
• Optical Response Properties of InP Porous Structures Formed on p-n Junction Substrates
  Yusuke Kumazaki; Tomohito Kudo; Zenji Yatabe; Taketomo Sato
  The 73rd JSAP Autumn Meeting 2012, 13 Sep. 2012, The Japan Society of Applied Physics, Japanese, Oral presentation
  11 Sep. 2012 - 14 Sep. 2012, Matsuyama University・Ehime University, Japan, [Domestic Conference]
• Interface characterization of MOS structures fabricated on AlGaN/GaN heterostructures
  Wancheng Ma; Yujin Hori; Zenji Yatabe; Tamotsu Hashizume
  The 73rd JSAP Autumn Meeting 2012, 12 Sep. 2012, The Japan Society of Applied Physics, Japanese, Oral presentation
  11 Sep. 2012 - 14 Sep. 2012, Matsuyama University・Ehime University, Japan, [Domestic Conference]
• Formation of patterned semiconductor substrates utilizing self-assembled polystyrene spheres and lithography techniques
  Ryohei Jinbo; Yudai Imai; Zenji Yatabe; Taketomo Sato
  The 73rd JSAP Autumn Meeting 2012, 11 Sep. 2012, The Japan Society of Applied Physics, Japanese, Oral presentation
  11 Sep. 2012 - 14 Sep. 2012, Matsuyama University・Ehime University, Japan, [Domestic Conference]
• Characterization of MOS Interfaces based on GaN-related Heterostructures
  Yujin Hori; Zenji Yatabe; Tamotsu Hashizume
  17th Workshop on Dielectrics in Microelectronics (WoDiM 2012), 26 Jun. 2012, Fraunhofer Center Nanoelectronic Technologies, English, Oral presentation
  25 Jun. 2012 - 27 Jun. 2012, Dresden, Germany, Germany, [International presentation]
• Complex Chemical Physics XLVII : The formation process of multilamellar vesicles in the sine shear flow
  Hirokazu Maruoka; Zenji Yatabe; Masahiko Shoji; Chihiro Hashimot; Hideharu Ushiki
  61st SPSJ Annual Meeting, 31 May 2012, The Society of Polymer Science, Japan, Japanese, Poster presentation
  29 May 2012 - 31 May 2012, Pacifico Yokohama, Japan, [Domestic Conference]
• Complex Chemical Physics XLVIII : Audio and image analysis of bubbles in a solution
  Akio Nishimura; Zenji Yatabe; Masahiko Shoji; Chihiro Hashimoto; Hideharu Ushiki
  61st SPSJ Annual Meeting, 31 May 2012, The Society of Polymer Science, Japan, Japanese, Poster presentation
  29 May 2012 - 31 May 2012, Pacifico Yokohama, Japan, [Domestic Conference]
• Effects of ICP etching of AlGaN on interface properties of Al₂O₃/AlGaN/GaN structures
  Zenji Yatabe; Yujin Hori; Sungsik Kim; Tamotsu Hashizume
  36th Workshop on Compound Semiconductor Devices and Integrated Circuits (WOCSDICE 2012), 28 May 2012, CRHEA-CNRS, English, Oral presentation
  28 May 2012 - 30 May 2012, Island of Porquerolles, France, [International presentation]
• Interface characterization of GaN-based MOS heterostructures employing ICP-etched AlGaN
  Zenji Yatabe; Yujin Hori; Sung-Sik Kim; Tamotsu Hashizume
  IEICE Technical Committee on Electron Device, 18 May 2012, The Institute of Electronics, Information and Communication Engineers, Japanese, Oral presentation
  17 May 2012 - 18 May 2012, Toyohashi University of Technology, Japan, [Domestic Conference]
• Electrochemical formation and position control of InP porous structures
  Ryohei Jinbo; Zenji Yatabe; Taketomo Sato
  The 59th JSAP Spring Meeting, 2012, 18 Mar. 2012, The Japan Society of Applied Physics, Japanese, Oral presentation
  15 Mar. 2012 - 18 Mar. 2012, Waseda University, Japan, [Domestic Conference]
• Analysis on Low-Frequency Noise in SiN Insulator-Gate Etched GaAs Nanowire FETs
  Toru Muramatsu; Kensuke Miura; Zenji Yatabe; Seiya Kasai
  The 59th JSAP Spring Meeting, 2012, 16 Mar. 2012, The Japan Society of Applied Physics, Japanese, Oral presentation
  15 Mar. 2012 - 18 Mar. 2012, Waseda University, Japan, [Domestic Conference]
• Photo-electrical response of InP porous structures and their application to photo-electric conversion devices
  Ryohei Jinbo; Tomohito Kudo; Yudai Imai; Zenji Yatabe; Taketomo Sato
  2012 RCIQE International Workshop for Green Electronics, 05 Mar. 2012, Research Center for Integrated Quantum Electronics (RCIQE), Hokkaido University, English, Poster presentation
  05 Mar. 2012 - 06 Mar. 2012, Hokkaido University, Japan
• Characterization and control of dry-etched AlGaN surfaces
  Zenji Yatabe; Yujin Hori; Taketomo Sato; Tamotsu Hashizume
  2012 RCIQE International Workshop for Green Electronics, 05 Mar. 2012, Research Center for Integrated Quantum Electronics (RCIQE), Hokkaido University, English, Poster presentation
  05 Mar. 2012 - 06 Mar. 2012, Hokkaido University
• Characterization and Analysis on Low-frequency Noise in SiN Insulated Gate GaAs-based Nanowire FETs
  Toru Muramatsu; Seiya Kasai; Zenji Yatabe
  IEICE Technical Committee on Electron Device, 08 Feb. 2012, The Institute of Electronics, Information and Communication Engineers, Japanese, Oral presentation
  07 Feb. 2012 - 08 Feb. 2012, Hokkaido University, Japan, [Domestic Conference]
• Formation and control of a position of porous structure on semiconductor surfaces utilizing self-aligned polystyrene spheres ans lithography technique
  Yudai Imai; Ryouhei Jinbo; Zenji Yatabe; Taketomo Sato
  47th JSAP Hokkaido Chapter Annual Meeting, 07 Jan. 2012, Hokkaido Chapter, The Japan Society of Applied Physics, Japanese, Oral presentation
  06 Jan. 2012 - 07 Jan. 2012, Hokkaido University, Japan, [Domestic Conference]
• Characterization and control of dry-etched GaN surfaces
  Zenji Yatabe; Sungsik Kim; Naoki Azumaishi; Taketomo Sato; Tamotsu Hashizume
  The 6th International Symposium on Surface Science (ISSS-6), 12 Dec. 2011, The Surface Science Society of Japan, English, Oral presentation
  11 Dec. 2011 - 15 Dec. 2011, Tower Hall Funabori, Japan, [International presentation]
• Interface characterization of MOS structures fabricated on dry-etched GaN and AlGaN
  Sungsik Kim; Yujin Hori; Zenji Yatabe; Tamotsu Hashizume
  IEICE Technical Committee on Electron Device, 17 Nov. 2011, The Institute of Electronics, Information and Communication Engineers, Japanese, Oral presentation
  17 Nov. 2011 - 18 Nov. 2011, Kyoto University, Japan, [Domestic Conference]
• Complex Chemical Physics XLIV : The formation process of multilamellar vesicles in the sine type shear flow
  Hirokazu Maruoka; Zenji Yatabe; Masahiko Shoji; Chihiro Hashimoto; Hideharu Ushiki
  60th Symposium on Macromolecules, 30 Sep. 2011, The Society of Polymer Science, Japan, Japanese, Poster presentation
  28 Sep. 2011 - 30 Sep. 2011, Okayama University, Japan, [Domestic Conference]
• Complex Chemical Physics XLIII : Image and audio analysis of boiling of water on the surface of hot solid
  Akio Nishimura; Zenji Yatabe; Masahiko Shoji; Chihiro Hashimoto; Hideharu Ushiki
  60th Symposium on Macromolecules, 30 Sep. 2011, The Society of Polymer Science, Japan, Japanese, Poster presentation
  28 Sep. 2011 - 30 Sep. 2011, Okayama University, Japan, [Domestic Conference]
• Characterization and control of dry etched surfaces of GaN and AlGaN
  Zenji Yatabe; Naoki Azumaishi; Taketomo Sato; Tamotsu Hashizume
  The 72nd JSAP Autumn Meeting, 2011, 31 Aug. 2011, The Japan Society of Applied Physics, Japanese, Oral presentation
  29 Aug. 2011 - 02 Sep. 2011, Yamagata University, Japan, [Domestic Conference]
• Formation of porous structure on semiconductor surfaces utilizing self-aligned polystyrene spheres and lithography technique
  Yudai Imai; Ryouhei Jinbo; Zenji Yatabe; Taketomo Sato
  The 72nd JSAP Autumn Meeting, 2011, 31 Aug. 2011, The Japan Society of Applied Physics, Japanese, Oral presentation
  29 Aug. 2011 - 02 Sep. 2011, Yamagata University, Japan, [Domestic Conference]
• Complex Chemical Physics XL : The formation process of multilamellar vesicles in sine type shear flow
  Hirokazu Maruoka; Zenji Yatabe; Masahiko Shoji; Chihiro Hashimoto; Hideharu Ushiki
  60th SPSJ Annual Meeting, 26 May 2011, The Society of Polymer Science, Japan, Japanese, Poster presentation
  25 May 2011 - 27 May 2011, Osaka International Convention Center, Japan, [Domestic Conference]
• Complex Chemical Physics XLI : Analyzing effects of the polymer addition in the Leidenfrost phenomenon using thermo image processing
  Akio Nishimura; Zenji Yatabe; Masahiko Shoji; Chihiro Hashimoto; Hideharu Ushiki
  60th SPSJ Annual Meeting, 26 May 2011, The Society of Polymer Science, Japan, Japanese, Poster presentation
  25 May 2011 - 27 May 2011, Osaka International Convention Center, Japan, [Domestic Conference]
• Complex Chemical Physics XLII : Acoustic property of Ringing gel
  Zenji Yatabe; Masatoshi Tachibana; Ruri Hidema; Chihiro Hashimoto; Masahiko Shoji; Hideharu Ushiki
  60th SPSJ Annual Meeting, 26 May 2011, The Society of Polymer Science, Japan, Japanese, Poster presentation
  25 May 2011 - 27 May 2011, Osaka International Convention Center, Japan, [Domestic Conference]
• Complex Chemical Physics XXXVIII : The lamellar - vesicle transition of Multilamellar Vesicle in sine oscillatory shear flow
  Hirokazu Maruoka; Zenji Yatabe; Masahiko Shoji; Chihiro Hashimoto; Hideharu Ushiki
  The 48th Annual Meeting of the Biophysical Society of Japan, 22 Sep. 2010, The Biophysical Society of Japan, Japanese, Poster presentation
  20 Sep. 2010 - 22 Sep. 2010, Tohoku University, Japan, [Domestic Conference]
• Complex Chemical Physics XXXIV : The formation process of MLV in sine type of variable shear induced flow
  Hirokazu Maruoka; Zenji Yatabe; Masahiko Shoji; Chihiro Hashimoto; Hideharu Ushiki
  59th Symposium on Macromolecules, 15 Sep. 2010, The Society of Polymer Science, Japan, Japanese, Poster presentation
  15 Sep. 2010 - 17 Sep. 2010, Hokkaido University, Japan, [Domestic Conference]
• Complex Chemical Physics XXV : Polymer Additive Effects on the Contraction Speed of Vorticella Convallaria
  Chihiro Hashimoto; Junko Kamiguri; Ruri Hidema; Zenji Yatabe; Masahiko Shoji; Hideharu Ushiki
  59th SPSJ Annual Meeting, 27 May 2010, The Society of Polymer Science, Japan, Japanese, Poster presentation
  26 May 2010 - 28 May 2010, Pacifico Yokohama, Japan, [Domestic Conference]
• Complex Chemical Physics XXVI : Image analysis of interference patterns in flowing soap films: effects of polymer
  Ruri Hidema; Zenji Yatabe; Masahiko Shoji; Chihiro Hashimoto; Gabriel Sagarzazu; Robert Pansu; Hideharu Ushiki
  59th SPSJ Annual Meeting, 27 May 2010, The Society of Polymer Science, Japan, Japanese, Poster presentation
  26 May 2010 - 28 May 2010, Pacifico Yokohama, Japan, [Domestic Conference], ［Internationally co-authored］
• Complex Chemical Physics XXX : The discussion for the process of formation of multilamellar vesicles in variable shear-induced fluids
  Hirokazu Maruoka; Zenji Yatabe; Masahiko Shoji; Chihiro Hashimoto; Hideharu Ushiki
  59th SPSJ Annual Meeting, 27 May 2010, The Society of Polymer Science, Japan, Japanese, Poster presentation
  26 May 2010 - 28 May 2010, Pacifico Yokohama, Japan, [Domestic Conference]
• 流動石鹸膜の干渉縞に表れる高分子添加効果の画像解析
  日出間 るり; 谷田部 然治; 庄司 雅彦; 橋本 千尋; Gabriel Sagarzazu; Robert Pansu; 牛木 秀治
  高分子基礎研究会2010, 30 Jan. 2010, Japanese, Oral presentation
  29 Jan. 2010 - 31 Jan. 2010, ウェルサンピア新潟, [Domestic Conference], ［Internationally co-authored］
• Contraction process of Vorticella stalk measured by high-speed camera
  Ruri Hidema; Zenji Yatabe; Chihiro Hashimoto; Noriko Tsuchiya; Masatoshi Tachibana; Robert Bernard Pansu; Hideharu Ushiki
  The 47th Annual Meeting of the Biophysical Society of Japan, 01 Nov. 2009, The Biophysical Society of Japan, Japanese, Poster presentation
  30 Oct. 2009 - 01 Nov. 2009, Tokushima, Japan, [Domestic Conference], ［Internationally co-authored］
• Construction of game's relationship theory using five white-rot fungi
  Tatsuaki Dohmitsu; Zenji Yatabe; Masatoshi Yoshimura; Chihiro Hashimoto; Hideharu Ushiki
  The 47th Annual Meeting of the Biophysical Society of Japan, 01 Nov. 2009, The Biophysical Society of Japan, Japanese, Poster presentation
  30 Oct. 2009 - 01 Nov. 2009, Tokushima, Japan, [Domestic Conference]
• Study on Bio-Probe in Polymer Solutions
  Daisuke Maki; Zenji Yatabe; Masatoshi Yoshimura; Chihiro Hashimoto; Hideharu Ushiki
  The 47th Annual Meeting of the Biophysical Society of Japan, 31 Oct. 2009, The Biophysical Society of Japan, Japanese, Poster presentation
  30 Oct. 2009 - 01 Nov. 2009, Tokushima, Japan, [Domestic Conference]
• Complex Chemical Physics XXI : Image Processing of Contraction Process of Vorticella Convallaria
  Chihiro Hashimoto; Ruri Hidema; Noriko Tsuchiya; Zenji Yatabe; Masatoshi Tachibana; Robert Pansu; Hideharu Ushiki
  58th SPSJ Annual Meeting, 28 May 2009, The Society of Polymer Science, Japan, Japanese, Poster presentation
  27 May 2009 - 29 May 2009, Kobe, Japan, [Domestic Conference], ［Internationally co-authored］
• Complex Chemical Physics XXII : Formation process of shear-induced onion structure made of Oil/Water/Surfactant System
  Zenji Yatabe; Ruri Hidema; Chihiro Hashimoto; Robert Pansu; Hideharu Ushiki
  58th SPSJ Annual Meeting, 28 May 2009, The Society of Polymer Science, Japan, Japanese, Poster presentation
  27 May 2009 - 29 May 2009, Kobe, Japan, [Domestic Conference], ［Internationally co-authored］
• Complex Chemical Physics XXIII. New Approach to Effects of Polymer in Flowing Soap Films - Streamline Analysis of Turbulence Image -
  Ruri Hidema; Zenji Yatabe; Chihiro Hashimoto; Robert Pansu; Hideharu Ushiki
  58th SPSJ Annual Meeting, 28 May 2009, The Society of Polymer Science, Japan, Japanese, Poster presentation
  27 May 2009 - 29 May 2009, Kobe, Japan, [Domestic Conference], ［Internationally co-authored］
• Complex Chemical Physics XIX : Onion Structure Formation Process of Water / Oil / Surfactant System under Shear Flow
  Zenji Yatabe; Chihiro Hashimoto; Robert Pansu; Hideharu Ushiki
  56th Symposium on Macromolecules, 21 Sep. 2007, The Society of Polymer Science, Japan, Japanese, Oral presentation
  19 Sep. 2007 - 21 Sep. 2007, Nagoya Institute of Technology, Japan, [Domestic Conference], ［Internationally co-authored］
• New Approach to Effects of Polymer in Flowing Soap Films - Some Methods of Image Processing
  Ruri Hidema; Zenji Yatabe; Chihiro Hashimoto; Robert Pansu; Hideharu Ushiki
  The 8th Asian Thermophysical Properties Conference (ATPC 2007), 23 Aug. 2007, Japanese Society of Thermophysical Properties, English, Poster presentation
  21 Aug. 2007 - 24 Aug. 2007, Kyushu University, Japan, [International presentation], ［Internationally co-authored］
• Onion Formation Process of Oil/Water/Surfactant System under Shear Flow
  Zenji Yatabe; Chihiro Hashimoto; Robert Pansu; Hideharu Ushiki
  The 8th Asian Thermophysical Properties Conference (ATPC 2007), 23 Aug. 2007, Japanese Society of Thermophysical Properties, English, Poster presentation
  Kyushu University, Japan, [International presentation], ［Internationally co-authored］
• Formation Process of Onion Structure of Water/Oil/Surfactant System under Shear Flow
  Zenji Yatabe; Chihiro Hashimoto; Robert Pansu; Hideharu Ushiki
  9th Workshop of Molecular Dynamics Spectroscopy, 05 Jul. 2007, Research Foundation for Opto-Science and Technology, Japanese, Poster presentation
  05 Jul. 2007 - 06 Jul. 2007, Hotel Crown Palais Hamamatsu, Japan, ［Internationally co-authored］
• Streamline Analysis of Turbulence Image for effects of polymer in Flowing Soap Films
  Ruri Hidema; Zenji Yatabe; Chihiro Hashimoto; Robert Pansu; Hideharu Ushiki
  9th Workshop of Molecular Dynamics Spectroscopy, 05 Jul. 2007, Research Foundation for Opto-Science and Technology, Japanese, Poster presentation
  05 Jul. 2007 - 06 Jul. 2007, Hotel Crown Palais Hamamatsu, Japan, ［Internationally co-authored］
• Complex Chemical Physics XV Formation Process of Onion Structure of Water/Oil/Surfactant System under Shear Flowshear flow
  Zenji Yatabe; Chihiro Hashimoto; Robert Pansu; Hideharu Ushiki
  56th SPSJ Annual Meeting, 29 May 2007, The Society of Polymer Science, Japan, Japanese, Poster presentation
  29 May 2007 - 31 May 2007, Kyoto International Conference Center, Japan, [Domestic Conference], ［Internationally co-authored］
• Complex Chemical Physics XVI 'Streamline Analysis of Turbulence Image' for effects of polymer in Flowing Soap Films
  Ruri Hidema; Zenji Yatabe; Chihiro Hashimoto; Robert Pansu; Hideharu Ushiki
  56th SPSJ Annual Meeting, 29 May 2007, The Society of Polymer Science, Japan, Japanese, Poster presentation
  29 May 2007 - 31 May 2007, Kyoto International Conference Center, Japan, [Domestic Conference], ［Internationally co-authored］
• Benzoquinone detection by fluorescent nanoparticles
  Zenji Yatabe; Jean-Alexis Spitz; Sophie Badré; Gabriel Sagarzazu; Rachel Méallet-Renault; Jacques Alexis Delaire; Hideharu Ushiki; Robert Pansu
  Workshop on Nanoscience and Nanotechnology between Sanken and CNRS, 17 Jul. 2006, English, Oral presentation
  17 Jul. 2006 - 17 Jul. 2006, Université Paris-Sud 11, France, 10615797, ［Internationally co-authored］
• Rubrene nanocrystals: Quenching and Microdevice
  Zenji Yatabe; Jean-Alexis Spitz; Sophie Badré; Rachel Méallet-Renault; Serge Desportes; Sébastien Baumlin; Jacques Alexis Delaire; Hideharu Ushiki; Robert Pansu
  Journées de Printemps du Groupe Français de Photochimie (GFP), 19 May 2006, Groupe français de photochimie, photophysique et photosciences, English, Oral presentation
  18 May 2006 - 19 May 2006, Paris, France, 10615797, ［Internationally co-authored］
• Fluorescence microscopy of nano-objects
  Rachel Méallet-Renault; Sophie Badré; Jean-Alexis Spitz; Zenji Yatabe; Robert Bernard Pansu
  2nd Korea-France Joint Workshop on Nanostructured Photonic and Electronic Materials, 05 May 2006, English
  05 May 2006 - 05 May 2006, Cachan, France, 10615797, ［Internationally co-authored］
• Fluorescent nanoparticles : nanobeads and organic nanocrystals as sensors
  Rachel Méallet-Renault; Sophie Badré; Jean-Alexis Spitz; Zenji Yatabe; Boris A. Trofimov; Robert Bernard Pansu
  XXIst IUPAC Symposium on Photochemistry, 02 Apr. 2006, International Union of Pure and Applied Chemistry (IUPAC), English, Oral presentation
  02 Apr. 2006 - 07 Apr. 2006, Kyoto, Japan, 10615797, [International presentation], ［Internationally co-authored］
• Complex Chemical Physics II Morphological Formation Process of Onion Structure of Water/Oil/Surfactant System under Programmable Shear Flow
  Zenji Yatabe; Chihiro Hashimoto; Robert Pansu; Hideharu Ushiki
  54th Society of Polymer Science Japan Annual Meeting, 27 May 2005, The Society of Polymer Science, Japan, Japanese, Oral presentation
  25 May 2005 - 27 May 2005, Pacifico Yokohama, Japan, [Domestic Conference], ［Internationally co-authored］
• Dynamics of Morphological Formation LXXXIII - Study on Forming Process of Onion Structure with Functional Shear Flow Measurements -
  Zenji Yatabe; Chihiro Hashimoto; Jean Lachaise; Alain Graciaa; Hideharu Ushiki
  53rd Symposium on Macromolecules, 15 Sep. 2004, The Society of Polymer Science, Japan, Japanese, Poster presentation
  15 Sep. 2004 - 17 Sep. 2004, Hokkaido University, Japan, [Domestic Conference], ［Internationally co-authored］
• Dynamics of Morphological Formation LXXVI - Study on Formation of Onion Structure under Functional Shear Flow -
  Zenji Yatabe; Jean Lachaise; Alain Graciaa; Hideharu Ushiki
  53rd SPSJ Annual Meeting, 26 May 2004, The Society of Polymer Science, Japan, Japanese, Poster presentation
  25 May 2004 - 27 May 2004, Kobe International Conference Center, Japan, [Domestic Conference], ［Internationally co-authored］
• 流動下でのラメラ→玉葱転移
  谷田部 然治
  第3回物性・物質化学最若手会, 01 Aug. 2003, 広域物性研究会, Japanese, Oral presentation
  関西学院大学千刈セミナーハウス, Japan, [Domestic Conference]
• Chimie Physique de Cosmétique 流動下における化粧品化合物の2次元光散乱の測定
  谷田部 然治
  第2回物性研究最若手の会, 02 Aug. 2002, 広域物性研究会, Japanese, Oral presentation
  関西学院大学スポーツセンター, Japan, [Domestic Conference]

• The Japan Society of Applied Physics

• Gate insulator deposition process for GaN-based MOS devices using mist-CVD technique
  Grants-in-Aid for Scientific Research
  Apr. 2023 - Mar. 2027
  Zenji Yatabe; Joel Asubar; Yusui Nakamura
  ゲート絶縁膜/半導体界面特性は金属-酸化物-半導体(MOS)トランジスタ特性に大きな影響を与える。
  本研究では次世代高周波・高出力半導体デバイス材料である窒化物半導体MOSデバイス用のゲート絶縁膜堆積プロセスを低コストで酸化物薄膜が堆積可能なミスト化学気相成長(ミストCVD)法を用いて、開発・発展させる。さらにMOS界面特性を独自の詳細な解析手法により明らかにし、ゲート絶縁膜堆積プロセスにフィードバックをし、界面準位密度を極限まで低減した、低コストかつ良質な窒化物半導体MOSデバイス向けゲート絶縁膜堆積プロセス技術の確立を目的とする。
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Kumamoto University, Principal investigator, Competitive research funding, 23K03973
• Study on high-κ dielectric/regrown nitride semiconductor interfaces for high efficiency and highly-safe transistors
  Grants-in-Aid for Scientific Research
  Apr. 2023 - Mar. 2026
  Joel Asubar; Zenji Yatabe; Masaaki Kuzuhara
  GaNの広いバンドギャップに起因する望ましい物性値により、GaN 系デバイスは、これまでにないパワー、効率、周波数レベルを実現することが可能であり、現代社会で重要な役割を担う。ただし、この優れた2DEGにより、AlGaN/GaN HEMTは、負のしきい値電圧VTHを持つノーマリーオンとなってしまう。つまりゲートに電圧が印加されていない場合でも、電流が端子(ソース-ドレイン)間に流れてしまう。このため、フェイルセーフを確保し、複雑なゲート駆動回路を組み込む必要のない、正のしきい値電圧VTHを備えた「ノーマリーオフ」デバイスの実現が必須である。
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), University of Fukui, Coinvestigator, Competitive research funding, 23K03971
• 研究機器・設備整備
  令和6年度 研究機能強化促進費
  Sep. 2024 - Mar. 2025
  谷田部 然治
  熊本大学 半導体・デジタル研究教育機構, 熊本大学, Principal investigator
• Integral transformation method to investigate flow characteristics of polymer solution from the phase transition perspective
  Grants-in-Aid for Scientific Research
  Jun. 2019 - Mar. 2022
  Ruri Hidema; Zenji Yatabe; Hiroshi Suzuki
  To clarify characteristic flow regimes of complex fluids such as polymer solutions and surfactant solutions, interactions of inner structure in the fluids were quantified by using a method of micro-rheology. Optical tweezers were used as a tool of micro-rheology; the motion of a trapped particle was analyzed to obtain distribution of local fluids properties around the bead that reflects the complexity of the fluids. Relaxation time of the fluids measured under the extensional stresses was also used to characterize inner structures. Then, flow regimes of these solutions in flow channels in micro and macro length scales were observed, which was affected by enhancement of inner structure of the fluids.
  Japan Society for the Promotion of Science, Grant-in-Aid for Challenging Research (Exploratory), Kobe University, Coinvestigator, Competitive research funding, 19K22083
• Surface passivation and insulated gate structures for nitride-based semiconductor devices using mist-CVD method
  Grants-in-Aid for Scientific Research
  Apr. 2019 - Mar. 2022
  Zenji Yatabe; Joel Asubar; Tetsuro Sueyoshi; Yusui Nakamura
  We have developed a gate insulator deposition process for AlGaN/GaN metal-insulator-semiconductor (MIS-HEMTs) using cost-effective and environmental-friendly mist chemical vapor deposition (mist-CVD) method. Mist-deposited gate insulators deposited using optimum condition exhibited characteristics that are comparable to those reported from high-quality amorphous films prepared by the more conventional method of atomic layer deposition (ALD). In addition, we obtained good transistor characteristics from the fabricated devices suggesting high interfacial quality of the resulting insulator/AlGaN interface. These results demonstrate the potential and viability of non-vacuum mist-CVD technique in the development of high-performance AlGaN/GaN-based MIS-HEMTs.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (C), Kumamoto University, Principal investigator, Competitive research funding, 19K04473
• Characterization and control of insulator/AlGaN interface for power device application
  Grants-in-Aid for Scientific Research
  Apr. 2015 - Mar. 2018
  Zenji Yatabe
  To control reliability and degradation issue such as threshold voltage (VTH) instability in AlGaN/GaN high-electron-mobility transistors (AlGaN/GaN HEMTs) with metal-insulator-semiconductor (MIS) structures, we have investigated insulator/AlGaN interface properties. The correlation between the interface properties and VTH instability in AlGaN/GaN MIS HEMTs were discussed on the basis of both experimental and theoretical results. From the analysis of the results, we have come to the conclusion that that the interface states at insulator/AlGaN caused VTH instability in AlGaN/GaN MIS HEMTs. In addition, aluminum titanate, a novel and promising gate dielectric was successfully fabricated by ultrasonic spray-assisted mist chemical vapor deposition (mist CVD), which is a low-cost and low-damage alternative for dielectric deposition.
  Japan Society for the Promotion of Science, Grant-in-Aid for Young Scientists (B), Hokkaido University and Kumamoto University, Principal investigator, Competitive research funding, 15K18034
• 低温・大気圧におけるプラスチック基板上透明導電膜の作製
  マッチングプランナープログラム「企業ニーズ解決試験」
  Jun. 2016 - Mar. 2017
  谷田部 然治
  科学技術振興機構 (JST), Principal investigator, Competitive research funding
• パワーデバイス応用に向けた絶縁膜/酸化物半導体界面の評価と制御
  平成28年度研究助成
  Apr. 2016 - Mar. 2017
  谷田部 然治
  材料科学技術振興財団 (MST), Principal investigator, Competitive research funding
• 酸化物を用いた新型パワートランジスタの開発
  研究資金
  Dec. 2015 - Mar. 2016
  谷田部 然治
  熊本大学 エコ・エネ研究会, 熊本大学, Principal investigator
• Nanoscale control of nitride semiconductor surface using low-damaged process for high-sensitive chemical sensors
  Grants-in-Aid for Scientific Research
  Apr. 2013 - Mar. 2016
  Taketomo Sato; Tamotsu Hashizume; Junichi Motohisa; Zenji Yatabe
  Towards the higher sensitivity of ion-sensitive field-effect transistors (ISFETs) on nitride semiconductors, the porous-gate ISFETs has been proposed and its basic technology was established. The porous structures with a high-aspect ratio having a several 10 nm-diameter were successfully formed in a controlled fashion utilizing the electrochemical oxidation and etching process. It was found that the unique features of porous structures such as a large surface area and a modified potential involved with a high-electric field are very effective to detect the photo-electrochemical reactions with high-sensitivity. The correlation between the ion-diffusion in the pores and charging and discharging to the double layer were discussed on the basis of the experimental and theoretical results, leading to the new finding for the high-speed and high-sensitive chemical sensors.
  Japan Society for the Promotion of Science, Grant-in-Aid for Scientific Research (B), Hokkaido University, Coinvestigator, Competitive research funding, 25289079
• Onion Formation Process of Oil/Water/Surfactant System Under Shear Flow
  同窓会学生援助事業
  Aug. 2007 - Aug. 2007
  谷田部 然治
  東京農工大学同窓会, 東京農工大学, Principal investigator, Others
• Morphological Formation Process of Onion Structure of Water/Oil/Surfactant System under Programmable Shear Flow
  Collège doctoral franco-japonais (CDFJ)
  Sep. 2005 - Aug. 2006
  Zenji Yatabe
  Consortium japonais du Collège doctoral franco-japonais, Principal investigator, Competitive research funding

• 積層構造体及び発光ダイオード
  Patent right, 中村 有水; 谷田部 然治, 国立大学法人熊本大学
  特願2017-037493, 28 Feb. 2017
  特開2018-140914, 13 Sep. 2018
  201803020681152080

• Member of Program Committee (Electron Devices)
  2025 - Present
  Planning etc, Peer review
  Academic society etc
  International Workshop on Nitride Semiconductors 2026 (IWN 2026)
  Kumamoto-jo Hall, [Contributing to international academic research]
• Local Arrangement, CSW Steering Committee
  2025 - Present
  Planning etc
  Academic society etc
  Compound Semiconductor Week 2026 (CSW2026)
  Kumamoto-Jo Hall, [Contributing to international academic research]
• Program Committee member (Compound and power devices, process technology and characterization)
  2024 - Present
  Planning etc
  Academic society etc
  学術講演会プログラム編集委員 (13.7 化合物及びパワーデバイス・プロセス技術・評価)
  [Contributing to international academic research]
• 化合物半導体を用いた次世代高機能デバイス技術とアプリケーション調査専門委員会
  01 Dec. 2023 - Present
  Planning etc, Academic research planning
  Academic society etc
  電気学会 電子・情報・システム部門(C部門) 電子デバイス技術委員会
  https://www.iee.jp/wp-content/uploads/honbu/16-pdf/CEDD1161s.pdf
• Chairperson, Compound and power devices, process technology and characterization, The 73rd JSAP Autumn Meeting
  17 Mar. 2026 - 17 Mar. 2026
  Panel chair etc
  Academic society etc
  The Japan Society of Applied Physics
  Ookayama Campus, Institute of Science Tokyo & Online
• Japanese Journal of Applied Physics
  2026
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Japanese Journal of Applied Physics
  2026
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Chairperson, Compound and power devices, process technology and characterization, The 86nd JSAP Autumn Meeting
  08 Sep. 2025 - 08 Sep. 2025
  Panel chair etc
  Academic society etc
  The Japan Society of Applied Physics
  Tempaku Campus, Meijo University & Online
• Chairperson, Compound and power devices, process technology and characterization, The 72nd JSAP Autumn Meeting
  17 Mar. 2025 - 17 Mar. 2025
  Panel chair etc
  Academic society etc
  The Japan Society of Applied Physics
  Noda Campus, Tokyo University of Science & Online
• Japanese Journal of Applied Physics
  2025
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Physica Status Solidi (A)
  2025
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Japanese Journal of Applied Physics
  2025
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Japanese Journal of Applied Physics
  2025
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Physica Status Solidi (A)
  2025
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Surface Science
  2025
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Japanese Journal of Applied Physics
  2025
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Japanese Journal of Applied Physics
  2025
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Japanese Journal of Applied Physics
  2025
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Session Chair, Symposium GE: III-N Materials and Electronic Devices, The 11th Asia-Pacific Workshop on Widegap Semiconductors (APWS 2024)
  15 Oct. 2024 - 15 Oct. 2024
  Panel chair etc
  Academic society etc
  Korea Society of LEDs and Optoelectronics (KSLOE
  Hanwha Resorts Haeundae, Busan, [Contributing to international academic research]
• Japanese Journal of Applied Physics
  2024
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Semiconductor Science and Technology
  2024
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Semiconductor Science and Technology
  2024
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Semiconductor Science and Technology
  2024
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Applied Physics Letters
  2024
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Local Steering Committee, The 84th JSAP Autumn Meeting 2023
  19 Sep. 2023 - 23 Sep. 2023
  Planning etc
  Academic society etc
  The Japan Society of Applied Physics
  Kumamoto-jo Hall and other surrounding facilities & Online, [Contributing to international academic research]
• Chairperson, Compound and power devices, process technology and characterization, The 84th JSAP Autumn Meeting
  22 Sep. 2023 - 22 Sep. 2023
  Panel chair etc
  Academic society etc
  The Japan Society of Applied Physics
  Kumamoto Civic Center & Online, [Does not constitute an international academic contribution]
• 2023年度(第76回)電気・情報関係学会九州支部連合大会 半導体・電子デバイス 座長
  07 Sep. 2023 - 07 Sep. 2023
  Panel chair etc
  Academic society etc
  電気・情報関係学会九州支部連合大会委員会
  崇城大学, [Does not constitute an international academic contribution]
• Applied Physics Express
  2023
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Applied Physics Express
  2023
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Applied Physics Express
  2023
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Applied Physics Express
  2023
  Peer review
  Peer review etc
  [Contributing to international academic research]
• 第13回 半導体材料・デバイスフォーラム
  10 Oct. 2022 - 10 Oct. 2022
  Planning etc
  Academic society etc
  熊本高等専門学校 電子材料・デバイス研究部
  熊本大学 工学部, [Does not constitute an international academic contribution]
• Power Electronic Devices and Components
  2022
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Power Electronic Devices and Components
  2022
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Micromachines
  2022
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Applied Physics Express
  2022
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Applied Physics Express
  2022
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Applied Physics Express
  2022
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Steering Committee, Annual Meeting of The Japan Society of Vacuum and Surface Science 2020
  03 Nov. 2021 - 05 Nov. 2021
  Planning etc
  Academic society etc
  The Japan Society of Vacuum and Surface Science
  Virtual Conference
• Secretary
  2018 - 2021
  Planning etc
  Academic society etc
  Kansai Chapter, The Japan Society of Vacuum and Surface Science (JVSS)
• Japanese Journal of Applied Physics
  2021
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Nanomaterials
  2021
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Japanese Journal of Applied Physics
  2021
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Coatings
  2021
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Coatings
  2021
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Applied Physics Letters
  2021
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Steering Committee, Annual Meeting of The Japan Society of Vacuum and Surface Science 2020
  19 Nov. 2020 - 21 Nov. 2020
  Planning etc
  Academic society etc
  The Japan Society of Vacuum and Surface Science
  Virtual Conference
• ACS Applied Electronic Materials
  2020
  Peer review
  Peer review etc
  [Contributing to international academic research]
• ACS Applied Electronic Materials
  2020
  Peer review
  Peer review etc
  [Contributing to international academic research]
• ACS Applied Electronic Materials
  2020
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Applied Physics Letters
  2020
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Applied Physics Letters
  2020
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Applied Physics Letters
  2020
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Applied Physics Letters
  2020
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Applied Physics Express
  2020
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Applied Physics Express
  2020
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Applied Physics Express
  2020
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Applied Physics Express
  2020
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Applied Physics Express
  2020
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Applied Physics Letters
  2020
  Peer review
  Peer review etc
  [Contributing to international academic research]
• IEEE Electron Device Letters
  2020
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Japanese Journal of Applied Physics
  2020
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Japanese Journal of Applied Physics
  2020
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Japanese Journal of Applied Physics
  2020
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Japanese Journal of Applied Physics
  2020
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Steering Committee, JSAP Kyushu Chapter Annual Meeting 2019/The 4th Asian Applied Physics Conference (Asian-APC)
  23 Nov. 2019 - 24 Nov. 2019
  Planning etc
  Academic society etc
  Kyushu Chapter, The Japan Society of Applied Physics (JSAP)
  Kumamoto University, [Contributing to international academic research]
• 日本表面真空学会 関西支部 合同セミナー2019 GaN系半導体デバイスの最近の話題
  05 Jul. 2019 - 05 Jul. 2019
  Planning etc
  日本表面真空学会 関西支部, 大阪大学大学院工学研究科
  大阪大学 中之島センター 佐治敬三メモリアルホール
• Applied Physics Express
  2019
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Applied Physics Express
  2019
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Applied Physics Express
  2019
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Japanese Journal of Applied Physics
  2019
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Japanese Journal of Applied Physics
  2019
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Japanese Journal of Applied Physics
  2019
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Japanese Journal of Applied Physics
  2019
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Physica Status Solidi (B)
  2014
  Peer review
  Peer review etc
  [Contributing to international academic research]
• Physica Status Solidi (B)
  2014
  Peer review
  Peer review etc
  [Contributing to international academic research]

• オープンキャンパス2025
  02 Aug. 2025 - 02 Aug. 2025
  Organizing member
  熊本大学工学部
  黒髪キャンパス南地区
• 半導体デバイスの原理と応用
  23 Oct. 2024 - 23 Oct. 2024
  Lecturer
  宮崎県立日南高等学校
  分野別教養講座
  宮崎県立日南高等学校
  High school students
• オープンキャンパス2024
  03 Aug. 2024 - 03 Aug. 2024
  Organizing member
  熊本大学工学部
  黒髪キャンパス南地区
• 夢科学探検 2022
  03 Nov. 2022 - 03 Nov. 2022
  Organizing member
  熊本大学
  黒髪キャンパス南地区

• 北海道大学、半導体研究者60人が結集 九州からも人材獲得
  Oct. 2025
  Other than myself
  日本経済新聞
  ラピダスと北の変革 ミライの半導体人材㊦
  [Paper]
• 次世代半導体で「熱くならない（高効率な）パワーデバイス」を
  Apr. 2025
  フロムページ 夢ナビ編集部
  夢ナビ
  [Internet]
• 2024 TSMC Semiconductor Day in Japan
  Feb. 2025
  Other than myself
  YouTube
  TSMC
  Join us for TSMC Semiconductor Day in Japan, a dynamic event hosted by TSMC that brings together top experts from TSMC, TSMC Japan Design Technology, TSMC Japan 3DIC R&D Center, and JASM. Discover cutting-edge advancements in the semiconductor industry, learn about TSMC's groundbreaking work in Japan, and explore diverse career opportunities in this field.
  
  Don't miss the chance to connect with industry leaders and ignite your passion for semiconductors!, [Internet]
• 【キャリア支援室】令和６年度熊本大学工学部編入学説明会を実施しました
  Dec. 2024
  Other than myself
  阿南工業高等専門学校 キャリア支援室
  お知らせ, 2024年12月18日(水)に熊本大学工学部情報電気工学科准教授の谷田部然治先生をお招きしてオンラインで編入学説明会を開催しました。谷田部先生からは、熊本大学工学部に関する全体説明や大学編入学試験の説明などをしていただきました。大学編入学に興味のある本科4年生9名が参加しました。
  参加者は谷田部先生からの説明を熱心に聞き、自分の進路について真剣に考える良い機会となりました。谷田部先生からは、各学科、土木建築学科、機械数理工学科、情報電気工学科、材料・応用化学科について詳細に説明していただき、また、半導体デバイス工学課程についても説明していただきました。谷田部先生には、説明会後にも学生の質問を気さくに応えていただきました。誠にありがとうございました。
• 「世界を変える」次世代半導体デバイスの研究
  Jun. 2024
  Other than myself
  熊本大学 工学部
  熊本大学 工学部案内
  教員特集, [Pr]
• エネルギー効率の未来 次世代半導体デバイスの探求
  Jan. 2024
  Myself
  熊本大学
  熊大通信 Vol. 91
  半導体の可能性を探求する研究者たち—DX時代におけるイノベーションをおこす—, 身の回りの電子機器や電気自動車には「パワーデバイス」と呼ばれる重要な部品が使われており、これらは主にシリコンという半導体材料で作られています。シリコンパワーデバイスは既に高度に進化しており、その性能をこれ以上大幅に向上させるのは難しくなっています。私たちの研究グループは、新しい半導体材料を使用した次世代のデバイス開発のほか、デバイスの表面や界面の制御技術、新しい評価方法の開発などにも取り組んでいます。これらの新しいデバイスは、省エネルギーにも大きく貢献する可能性があり、新たな半導体の研究には、世界初の成果を目指す大きなやりがいがあります。私たちの研究が、広く社会で活用されることを目指しています。, [Pr]
• 大学院先端科学研究部 情報・エネルギー部門 電気電子材料分野 准教授 谷田部 然治
  Aug. 2021
  熊本大学工業会会報
  昇任のご挨拶, [Pr]
• Mist-CVD enhances MIS-HEMTs
  May 2021
  Other than myself
  Compound Semiconductor
  27(3) 53, Thanks to mist CVD, pyrophoric materials and vacuum pumps are no longer needed to deposit insulators on GaN HEMTs., 13160044, [Paper]
• 薄膜・表面界面物性
  Feb. 2018
  Myself
  熊本大学 大学院先導機構 URA推進室
  Tenure Track
  テニュア教員・テニュアトラック教員, [Pr]
• 情報電気電子工学科
  Aug. 2017
  Myself
  熊本大学工業会会報
  教室だより, [Pr]
• 大学院先導機構／情報電気工学科 助教 谷田部 然治
  Aug. 2016
  Myself
  熊本大学工業会会報
  新任の挨拶, [Pr]
• 第38回（2016年度）応用物理学会論文賞受賞者紹介
  Aug. 2016
  応用物理学会
  応用物理
  受賞者紹介, 高性能パワーデバイス実現への要請が急速に高まる中で，AlGaN/GaN ヘテロ構造を利用する電力スイッチング用トランジスタの開発が急速に進展しているが，インバータ応用に必須となる絶縁ゲート構造を用いたデバイスは，しきい値電圧変動や電流変動の抑制が実現できていないため，いまだに実用化には至っていない．その根本原因は，絶縁膜/AlGaN/GaN 構造におけるヘテロ界面構造制御の基盤である電子準位の評価法が確立されていないことに由来する．本論文は，1）任意の準位密度分布と電子放出時定数を考慮した数値計算を行い，絶縁膜/AlGaN/GaN 構造の容量 − 電圧（C-V）特性に与える界面準位の影響と室温評価の限界について初めて統一的な見解を示したこと，2）独自に開発した光支援 C-V 法を併用して，AlGaN の禁制帯内の広いエネルギー範囲で絶縁膜/AlGaN 界面の電子準位密度分布を決定することに初めて成功したことが大きなポイントである．このように，電子物性的側面が必ずしも十分に解明されていなかった絶縁膜/AlGaN/GaN ヘテロ構造に対して界面電子密度分布を求めることができた点は，同構造の実用化に大きく貢献する．GaN MOS-HEMT のインバータ応用に必須であるゲート絶縁膜の不明な領域に新たな重要知見を見いだした功績は大きく，本手法を駆使することにより，高性能 AlGaN/GaN ヘテロ構造の実現が加速されると期待される．以上より，本論文を応用物理学会優秀論文賞にふさわしい論文として推薦する．, [Pr]
• 化合物及び酸化物半導体の表面・界面の評価と制御
  2016
  Myself
  熊本大学 大学院先導機構 マーケティング推進部 研究推進課
  平成28年度版 熊本大学 テニュアトラック事業
  テニュアトラック教員紹介, [Pr]
• ムズターグ・アタ遠征記
  May 2003
  東京農工大学山岳会 ムスターグアタ登山隊
  MUZTAG-ATA 2001 慕士塔格山
  [Pr]

• Aug. 2001 - Aug. 2001
  summited Muztagh Ata (7,509 m)
  Ryoichi Okabayashi, Mikio Miyamoto, Yukuto Katsuragi, Nobuo Mizuno, Junji Oguchi, Zenji Yatabe
  Tokyo University of Agriculture and Technology Alpine Club (TUATAC)