Improvement of radiation response of SiC MOSFETs under high temperature and humidity conditions

Abstract

The response of hexagonal (4H) silicon carbide (SiC) power metal–oxide–semiconductor field effect transistors (MOSFETs) to gamma-ray irradiation was investigated under elevated temperature and humid conditions. The shift in drain current–gate voltage (ID–VG) curves towards negative voltages and the leakage of ID with a current hump due to elevated temperature irradiation were suppressed under high humidity conditions relative to dry conditions. This result can be explained in terms of the reduction in trapped oxide charge and oxide–SiC interface traps generated by irradiation due to the humid conditions. In addition, during irradiation at elevated temperature in humid conditions, electron traps at the oxide–SiC interface obviously decrease at doses above 100 kGy.