Papers by Author: Hisayoshi Itoh

Paper TitlePage

Authors: Gerhard Pensl, Frank Schmid, Sergey A. Reshanov, Heiko B. Weber, M. Bockstedte, Alexander Mattausch, Oleg Pankratov, Takeshi Ohshima, Hisayoshi Itoh
Abstract: Nitrogen (N) donors in SiC are partially deactivated either by Si+-/N+-co-implantation or by irradiation with electrons of 200 keV energy and subsequent annealing at temperatures above 1450°C; simultaneously the compensation is decreased. The free electron concentration and the formation of energetically deep defects in the processed samples are determined by Hall effect and deep level transient spectroscopy. A detailed theoretical treatment based on the density functional theory is conducted; it takes into account the kinetic mechanisms for the formation of N interstitial clusters and (N-vacancy)-complexes. This analysis clearly indicates that the (NC)4-VSi complex, which is thermally stable up to high temperatures and which has no level in the band gap of 4HSiC, is responsible for the N donor deactivation.
Authors: Jamie Steward Laird, Toshio Hirao, S. Onoda, H. Mori, Hisayoshi Itoh
Authors: Takeshi Ohshima, Akira Uedono, Osamu Eryu, Kin Kiong Lee, Koji Abe, Hisayoshi Itoh, Kenshiro Nakashima
Authors: Atsuo Kawasuso, F. Redmann, Reinhard Krause-Rehberg, Peter Sperr, Thomas Frank, Michael Weidner, Gerhard Pensl, Hisayoshi Itoh
Authors: Kazutoshi Kojima, Masahito Yoshikawa, Takeshi Ohshima, Hisayoshi Itoh, Sohei Okada
Authors: Atsuo Kawasuso, Hisayoshi Itoh, Dai Bum Cha, Sohei Okada
Authors: Takeshi Ohshima, Takahiro Satoh, Masakazu Oikawa, Shinobu Onoda, Toshio Hirao, Hisayoshi Itoh
Abstract: The charge generated in 6H-SiC n+p diodes by oxygen (O) ion irradiation at energies between 6 and 15 MeV was evaluated using the Transient Ion Beam Induced Current (TIBIC). The signal peak of the transient current increases, and the fall-time decreases with increasing applied reverse bias. The value of collected charge increases with increasing applied reverse bias, and the saturation of the collected charge was observed in high reverse bias regions (e.g. above 70 V in the case of 12MeV O-irradiation). The charge generated in the deeper region than the depletion layer is collected due to the "funneling effect". Almost all charge generated in n+p SiC diodes by O-irradiation between 6 and 15 MeV is collected when the length of the depletion layer becomes longer than the projection range of ions.
Authors: Kin Kiong Lee, Jamie Steward Laird, Takeshi Ohshima, Shinobu Onoda, Toshio Hirao, Hisayoshi Itoh
Abstract: This paper investigates the transient induced currents by energetic carbon ions in 6H-SiC MOSFETs and the carrier dynamic response due to such a heavy ion collision is simulated by Technology Computer Aided Design (TCAD). It was found that a heavy ion strike induces a bipolar effect on the transistor, whereby the current transients can vary in both polarities. And this has been attributed to the inherent in the MOSFET is a parasitic bipolar junction transistor.
Showing 1 to 10 of 51 Paper Titles