Total Ionizing Dose Effects of 60Co γ-Ray Radiation on Split-Gate SiC MOSFETs

Abstract

SiC power devices require resistance to both single-event effects (SEEs) and total ionizing dose effects (TIDs) in a space radiation environment. The split-gate-enhanced VDMOSFET (SGE-VDMOSFET) process can effectively enhance the radiation resistance of SiC VDMOS, but it has a certain impact on the gate oxide reliability of SiC VDMOS. This paper investigates the impact mechanism and regularity of using the SGE process to determine the radiation resistance and long-term reliability of SiC VDMOS under other identical processes and radiation conditions. Our experimental results show that after 60Co γ-ray irradiation, the degradation degrees of the static parameters of SGE-VDMOSFET and planar gate VDMOSFET (PG-VDMOSFET) are similar. The use of the new process leads to more defects in the oxide layer, reducing the long-term reliability of the device, but its stability can recover after high-temperature (HT) accelerated annealing. This research indicates that enhancing the resistance of SEEs using an SGE-VDMOSFET structure requires simultaneously considering the demand for TIDs and long-term reliability.