Control of Ga-oxide interlayer growth and Ga diffusion in SiO/GaN stacks for high-quality GaN-based metal-oxide-semiconductor devices with improved gate dielectric reliability

Yamada, Takahiro*; Watanabe, Kenta*; Nozaki, Mikito*; Yamada, Hisashi*; Takahashi, Tokio*; Shimizu, Mitsuaki*; Yoshigoe, Akitaka; Hosoi, Takuji*; Shimura, Takayoshi*; Watanabe, Heiji*

Applied Physics Express, 11(1), p.015701_1 - 015701_4, 2018/01

https://doi.org/10.7567/APEX.11.015701

A simple and feasible method for fabricating high-quality and highly reliable GaN-based metal-oxide-semiconductor (MOS) devices was developed on the basis of systematic physical and electrical characterizations. Chemical vapor deposition of SiO films directly onto GaN substrates forming Ga-oxide interlayers was used to fabricate SiO/GaO/GaN stacked structures. Although well-behaved hysteresis-free GaN-MOS capacitors with extremely low interface state density below 10cmeV were obtained by post-deposition annealing, Ga diffusion into overlying SiO layers severely degraded the insulating property and dielectric breakdown characteristics of the MOS devices. However, this problem was found to be solved by employing rapid thermal processing, leading to superior performance of the GaN-MOS devices in terms of interface quality, insulating property and gate dielectric reliability.

Investigation into cause of increasing count rate on PIMS at RRP, 1; Search of potential causes

Mukai, Yasunobu; Nakamura, Hironobu; Nakamichi, Hideo; Kurita, Tsutomu; Noguchi, Yoshihiko*; Tamura, Takayuki*; Ikegame, Ko*; Shimizu, Junji*

Proceedings of INMM 56th Annual Meeting (Internet), 9 Pages, 2015/07

The PIMS used at Rokkasho Reprocessing Plant can quantify plutonium amount in each process vessel located inside glovebox by means of neutron measurement. Since the PIMS is not used for the neutron coincidence counting, it is very important to maintain that those constants meet the actual process condition. PIMS was calibrated in 2006, and then JNFL has been started to measure the Pu amount directly in each glovebox for the purpose of facility NMA. However, it was found that PIMS counting was unexpectedly and continuously increased during long time of inter-campaign. In order to find out the main cause, JAEA and JNFL jointly conducted several investigations. In the investigations, correctness of system parameters and relevant constants, behavior of the neutron generation when MOX powder is stored in actual glovebox for a long time (to see O/M and moisture change) and the behavior focused on the relation between MOX powder and light element using inside glovebox (fluorine is included in the PTFE which is used in many gloveboxes as packing of instruments) were experimentally confirmed using MOX powder in PCDF. As a result, since the same behavior happened in the actual PIMS was confirmed in the testing environment in which MOX powder coexists with fluorine, it is concluded that the main potential cause of PIMS is the increasing of the probability of (, ) reactions by a contact between PTFE and MOX powder.

Tomographic reconstruction of bolometry for JT-60U diverted tokamak characterization

Konoshima, Shigeru; Leonard, A. W.*; Ishijima, Tatsuo*; Shimizu, Katsuhiro; Kamata, Isao*; Meyer, W. H.*; Sakurai, Shinji; Kubo, Hirotaka; Hosogane, Nobuyuki; Tamai, Hiroshi

Plasma Physics and Controlled Fusion, 43(7), p.959 - 983, 2001/07

https://doi.org/10.1088/0741-3335/43/7/309

no abstracts in English

Monte Carlo/molecular dynamics simulation on melting and evaporating processes of material due to laser irradiation

*; Kunugi, Tomoaki; *

ASME Proc. of 31st National Heat Transfer Conf. (HTD-Vol. 323), 1, p.171 - 178, 1996/00

no abstracts in English

Numerical simulation of thermo-fluid flow of non-equilibrium plasma impinging jet

Kunugi, Tomoaki; *; *

Dai-32-Kai Nihon Dennetsu Shimpojiumu Koen Rombunshu, 0, p.565 - 566, 1995/05

no abstracts in English

Numerical simulation of heat transfer and fluid flow of an impinging round jet of plasma into confinded walls

*; Kunugi, Tomoaki; *

Therm. Sci. Eng., 3(4), p.27 - 33, 1995/00

no abstracts in English

Conelptual Design of Krypton Recovery Plant by Prous Membrone Method

; ; Shimizu, Toku; Saito, Keiichiro; ; ; *; Naruse, Yuji

JAERI-M 8494, 291 Pages, 1979/10

JAERI-M-8494.pdf:7.21MB

no abstracts in English

Design study of small-sized high temperature gas-cooled reactor (MHR-50/100is), 1; Outline of development of small-sized high temperature gas-cooled reactor concept

Shimizu, Katsusuke*; Minatsuki, Isao*; Otani, Tomomi*; Mizokami, Yoritaka*; Oyama, Sunao*; Tsukamoto, Hiroki*; Kunitomi, Kazuhiko; Tachibana, Yukio; Terada, Atsuhiko

no journal, , 

no abstracts in English