Recovery of the Electrical Characteristics of SiC MOSFETs Irradiated with Gamma-Rays by Thermal Treatments

Effects of gamma-ray irradiation and subsequent thermal annealing on the characteristics of vertical structure power Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs) fabricated on 4H-SiC were studied. After irradiation at 1.2 MGy, the drain current – gate voltage curves of the MOSFETs shifted to the negative voltage side and the leakage drain current at inverse voltage increased. No significant change in the degraded electrical characteristics of SiC MOSFETs was observed by room temperature annealing. The degraded characteristics of SiC MOSFETs began to recover by annealing above 120 °C, and their characteristics reached almost the initial ones by annealing at 360 °C.