Effect of -ray irradiation on the characteristics of 6H silicon carbide metal-oxide-seminocductor field effect transistor with hydrogen-annealed gate oxide

Oshima, Takeshi; Ito, Hisayoshi; Yoshikawa, Masahito

The effect of gamma-ray irradiation on the electrical characteristics of 6H-SiC MOSFETs with hydrogen-annealed gate oxide was studied.The concentration of radiation induced interface traps increases with increasing gamma-ray dose, however, the number of interface traps is 1/100 smaller than it in Si MOSFET. The channel mobility for 6H-SiC MOSFET does not change at 30 kGy, and it becomes the half of the initial value (52 cm2/Vs) at 500 kGy.Since the channel mobility for Si MOSFET shows 50 % of the initial value at 10 kGy, this indicates that tha radiation resistance of SiC MOSFET is stronger than that of Si MOSFET. As for the cahnnel mobility vs. the concentration of radiation induced interface traps, the same behavior shows for Si and SiC MOSFETs. This suggest the channel mobility in SiC as well as Si decreases by the generation of interface traps which act as scattring centers.