Effects of High Gamma-Ray Radiation on 3C-SiC nMOSFETs

For the decommissioning operations for the Fukushima Daiich plants, many robots have been installed, however the operation time is limited by particularly image sensors, because it is difficult to sheild the sensors from radiation. 3C-Silicon carbide (SiC) have absorbance to visible light and there is a possibility to integrate 3C-SiC photodiodes and 3C-SiC MOSFETs in the same 3C-SiC substrate for the radiation hardened image sensors. In this work, 3C-SiC nMOSFETs were fabricated and its radiation hardness was investigated. Fabricated 3C-SiC MOSFETs show the threshold voltage of 5.8V, electron field-effect mobility of 44.6 cm2/V･s. After the gamma-ray irradiation of 2.01 MGy, the electron field effect mobility was almost the same as that before irradiation. Although the threshold voltage decreased from 5.8 to 2.7 V, irradiated device worked well after irradiation. It demonstarets 3C-SiC MOSFETs have a potential to be a base transistor for radiation-hardened image sensors.European Conference on Silicon Carbide and Related Materials (ECSCRM 2018