Hirohisa Hirai - Papers

Dipole scattering at the interface: The origin of low mobility observed in SiC MOSFETs

Tetsuo Hatakeyama, Hirohisa Hirai, Mitsuru Sometani, Dai Okamoto, Mitsuo Okamoto, Shinsuke Harada

Journal of Applied Physics, 131(14) 145701-145701, Apr 14, 2022

Crystal-orientation-dependent flatband voltage of non-polar GaN MOS interfaces investigated using trench sidewall capacitors

Hirohisa Hirai, Yoshinao Miura, Akira Nakajima, Shinsuke Harada, Hiroshi Yamaguchi

APPLIED PHYSICS LETTERS, 119(7), Aug, 2021

Accurate determination of threshold voltage shift during negative gate bias stress in 4H-SiC MOSFETs by fast on-the-fly method

Hiroki Sakata, Dai Okamoto, Mitsuru Sometani, Mitsuo Okamoto, Hirohisa Hirai, Shinsuke Harada, Tetsuo Hatakeyama, Hiroshi Yano, Noriyuki Iwamuro

Japanese Journal of Applied Physics, 60(6) 060901-060901, Jun 1, 2021

Free carrier density enhancement of 4H-SiC Si-face MOSFET by Ba diffusion process and NO passivation

Shogo Sekine, Masakazu Okada, Teruaki Kumazawa, Mitsuru Sometani, Hirohisa Hirai, Naoya Serizawa, Ryu Hasunuma, Mitsuo Okamoto, Shinsuke Harada

Japanese Journal of Applied Physics, 60({SB}), May 1, 2021 Peer-reviewed

Difference in electron mobility at 4H–SiC/SiO2 interfaces with various crystal faces originating from effective-field-dependent scattering

Hirohisa Hirai, Tetsuo Hatakeyama, Mitsuru Sometani, Mitsuo Okamoto, Shinsuke Harada, Hajime Okumura, Hiroshi Yamaguchi

Applied Physics Letters, 117(4), Jul 27, 2020 Peer-reviewed

Electrically detected magnetic resonance study on interface defects at nitrided Si-face, a-face, and m-face 4H-SiC/SiO2 interfaces

E. Higa, M. Sometani, H. Hirai, H. Yano, S. Harada, T. Umeda

Applied Physics Letters, Apr 27, 2020 Peer-reviewed

Ideal phonon-scattering-limited mobility in inversion channels of 4H-SiC(0001) MOSFETs with ultralow net doping concentrations

Mitsuru Sometani, Takuji Hosoi, Hirohisa Hirai, Tetsuo Hatakeyama, Shinsuke Harada, Hiroshi Yano, Takayoshi Shimura, Heiji Watanabe, Yoshiyuki Yonezawa, Hajime Okumura

Applied Physics Letters, 115(13) 132102-132102, Sep 23, 2019 Peer-reviewed

Mobility-limiting Coulomb scattering in nitrided 4H-SiC inversion channel on 1 1 ¯ 00 m-face and 11 2 ¯ 0 a-face characterized by Hall effect measurements

Hirohisa Hirai, Tetsuo Hatakeyama, Mitsuru Sometani, Mitsuo Okamoto, Shinsuke Harada, Hajime Okumura

Applied Physics Letters, 115(13) 132106-132106, Sep 23, 2019 Peer-reviewed

Low temperature wet-O2 annealing process for enhancement of inversion channel mobility and suppression of Vfb instability on 4H-SiC (0001) Si-face

Hirohisa Hirai, Koji Kita

Applied Physics Letters, 113(17) 172103-172103, Oct 22, 2018 Peer-reviewed

Retraction: “Effects of high-temperature diluted-H

Hirai Hirohisa, Kita Koji

Jpn. J. Appl. Phys., 56(7) 79201-79201, Jun 19, 2017

Investigation of origins of the critically different MOS interface characteristics between dry-oxidized and wet-oxidized silicon carbide

Kita, Koji, Hirai, Hirohisa, Kajifusa, Hiroyuki, Kuroyama, Kohei, Ishinoda, Kei

Microelectronic Engineering, 178 186-189, 2017 Peer-reviewed

Effects of high-temperature diluted-H-2 annealing on effective mobility of SiC MOSFETs estimated by split capacitance-voltage technique

Hirai, Hirohisa, Kita, Koji

Japanese Journal of Applied Physics, 56(11), 2017 Peer-reviewed

Difference of near-interface strain in SiO2 between thermal oxides grown on 4H-SiC by dry-O-2 oxidation and H2O oxidation characterized by infrared spectroscopy

Hirai, Hirohisa, Kita, Koji

Applied Physics Letters, 110(15), 2017 Peer-reviewed

Difference of Near-Interface SiO2 Structures between O-2-Oxidation and H2O-Oxidation of 4H-SiC (0001) and Its Impact on MOS Interface Characteristics

Kita, K., Hirai, H., Ishinoda, K.

Gallium Nitride and Silicon Carbide Power Technologies 7, 80, 2017 Peer-reviewed

Effects of high-temperature diluted-H

Hirai Hirohisa, Kita Koji

Jpn. J. Appl. Phys., 55(4) 04ER16, Mar 10, 2016

Suppression of byproduct generation at 4H-SiC/SiO2 interface by the control of oxidation conditions characterized by infrared spectroscopy

Hirai, Hirohisa, Kita, Koji

Applied Physics Express, 8(2), 2015 Peer-reviewed

Control of 4H-SiC (0001) Thermal Oxidation Process for Reduction of Interface State Density

Koji Kita, Richard Heihachiro Kikuchi, Hirohisa Hirai, Yuki Fujino

SEMICONDUCTORS, DIELECTRICS, AND METALS FOR NANOELECTRONICS 12, 64(8) 23-28, 2014 Peer-reviewed

Understanding of Growth Kinetics of Thermal Oxides on 4H-SiC (0001) for Control of MOS Characteristics

Kita, K., Kikuchi, R. H., Hirai, H.

Dielectrics For Nanosystems 6: Materials Science, Processing, Reliability, and Manufacturing, 61(2), 2014 Peer-reviewed

Structural difference between near interface oxides grown on Si and C faces of 4H-SiC characterized by infrared spectroscopy

Hirohisa Hirai, Koji Kita

APPLIED PHYSICS LETTERS, 103(13), Sep, 2013 Peer-reviewed

FTIR-ATR Study on Near-interface Structure of Thermal Oxides on 4H-SiC Substrates

Hirai, Hirohisa, Kita, Koji

Semiconductors, Dielectrics, and Metals For Nanoelectronics 11, 58(7) 317-323, 2013 Peer-reviewed