-ray irradiation response of silicon carbide semiconductor devices; Extremely high radiation resistance

Sato, Shinichiro; Onoda, Shinobu; Makino, Takahiro; Fujita, Natsuko   ; Oshima, Takeshi; Yokoseki, Takashi*; Tanaka, Kazuya*; Hijikata, Yasuto*; Tanaka, Yuki*; Kandori, Mikio*; Yoshie, Toru*

We investigate the threshold voltage shift of Si-MOSFETs, SiC-MOSFETs, SiC-MESFETs, and SiC SITs (Static Induction Transistors) due to irradiation. As a result, no significant threshold voltage shift was observed up to the absorbed dose of 10 Gy in all the SiC transistors, whereas the serious degradation was observed in the Si-MOSFETs. This strongly indicates that radiation resistance of SiC-MOSFETs and the other SiC-transistors is far superior to that of Si-MOSFETs. The radiation resistance of SiC-MOSFETs fabricated by pyrogenic oxidation is higher than that of the SiC-MOSFETs fabricated by dry oxidation. This result reflects that radiation resistance of SiC-MOSFETs strongly depends on the gate oxidation process since the formed oxide layers have different properties. Also, radiation resistance of SiC-SITs and SiC MESFETs is higher than that of SiC-MOSFETs, since SITs and MESFETs do not have gate oxide layer.