A Development of super radiation-hardened power electronics using silicon carbide semiconductors; Toward MGy-class radiation resistivity

Hijikata, Yasuto*; Mitomo, Satoshi*; Matsuda, Takuma*; Murata, Koichi*; Yokoseki, Takashi*; Makino, Takahiro; Takeyama, Akinori; Onoda, Shinobu; Okubo, Shuichi*; Tanaka, Yuki*; et al.

Proceedings of 11th International Workshop on Radiation Effects on Semiconductor Devices for Space Applications (RASEDA-11) (Internet), p.130 - 133, 2015/11

Recovery of the electrical characteristics of SiC-MOSFETs irradiated with gamma-rays by thermal treatments

Yokoseki, Takashi; Abe, Hiroshi; Makino, Takahiro; Onoda, Shinobu; Tanaka, Yuki*; Kandori, Mikio*; Yoshie, Toru*; Hijikata, Yasuto*; Oshima, Takeshi

Materials Science Forum, 821-823, p.705 - 708, 2015/07

https://doi.org/10.4028/www.scientific.net/MSF.821-823.705

X-ray photoelectron spectroscopy studies of post-oxidation process effects on oxide/SiC interfaces

Hijikata, Yasuto*; Yaguchi, Hiroyuki*; Yoshikawa, Masahito; Yoshida, Sadafumi*

Materials Science Forum, 389-393, p.1033 - 1036, 2002/05

no abstracts in English

Change in electrical properties SiC-MOS capacitor and PiN diode after ray irradiation

Tanaka, Kazuya*; Yokoseki, Takashi*; Fujita, Natsuko; Iwamoto, Naoya; Makino, Takahiro; Onoda, Shinobu; Oshima, Takeshi; Tanaka, Yuki*; Kandori, Mikio*; Yoshie, Toru*; et al.

no journal, , 

no abstracts in English

ray irradiation dose dependence of electrical characterizations of SiC-MOS capacitors

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

no journal, , 

no abstracts in English

-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*; et al.

no journal, , 

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.

Recovery of the degraded characteristics of SiC MOSFETs irradiated with -rays by thermal treatments

Yokoseki, Takashi; Abe, Hiroshi; Makino, Takahiro; Onoda, Shinobu; Tanaka, Yuki*; Kandori, Mikio*; Yoshie, Toru*; Hijikata, Yasuto*; Oshima, Takeshi

no journal, , 

no abstracts in English

The Electrical characteristics of SiC-MOSFETs irradiated with -rays at elevated temperature

Matsuda, Takuma; Yokoseki, Takashi; Mitomo, Satoshi; Murata, Koichi; Makino, Takahiro; Abe, Hiroshi; Onoda, Shinobu; Okubo, Shuichi*; Tanaka, Yuki*; Kandori, Mikio*; et al.

no journal, , 

no abstracts in English

Electrical properties of SiC MOSFETs irradiated with -rays at elevated temperature

Matsuda, Takuma; Yokoseki, Takashi; Mitomo, Satoshi; Murata, Koichi; Makino, Takahiro; Takeyama, Akinori; Onoda, Shinobu; Okubo, Shuichi*; Tanaka, Yuki*; Kandori, Mikio*; et al.

no journal, , 

Silicon carbide (SiC) is expected to be applied to Metal-Oxide-Semiconductor (MOS) FETs used in harsh radiation environments to decommission TEPCO Fukushima Daiichi nuclear reactors. To develop radiation resistant SiC MOS FETs, clarification of their radiation response under elevated temperature is required. We measured capacitance-voltage (C-V) characteristics of SiC MOSFETs irradiated with -rays at 423 K in nitrogen atmosphere. The samples were vertical power 4H-SiC MOSFETs with the blocking voltage of 1200 V and the rated current of 20 A with the gate oxide thickness of 45 nm. Typical C-V curve of a SiC MOSFET irradiated even up to 5 kGy was shifted to negative voltage side, suggesting that the positive charges generated in gate oxide by irradiation. While, no significant change in the slope of the curve was observed, indicating that interface traps between the gate oxide and SiC were merely generated. The radiation response of SiC MOS FETs under elevated temperature predominantly depends on the amount of positive charges generated in the gate oxide.

Effect of high temperature and humidity on dose dependence of charges generated in SiC MOSFETs due to -ray irradiation

Takeyama, Akinori; Matsuda, Takuma*; Yokoseki, Takashi*; Mitomo, Satoshi*; Murata, Koichi*; Makino, Takahiro; Onoda, Shinobu; Okubo, Shuichi*; Tanaka, Yuki*; Kandori, Mikio*; et al.

no journal, , 

Effect of -ray irradiation under high temperature and humidity circumstances on the electrical characteristics of Silicon Carbide (SiC) Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs) was investigated. In the case of irradiation under high humidity circumstance, trapped oxide and interface charges densities generated due to irradiation were smaller than those for irradiation in dry circumstance. It is concluded that humidity circumstance suppressed the degradation of the electrical properties due to irradiation including threshold voltage shift and leakage current.