Total Ionizing Dose Effects of 60Co γ-Ray Radiation on Split-Gate SiC MOSFETs
Haonan Feng, Xiaowen Liang, Xiaojuan Pu, Yutang Xiang, Teng Zhang, Ying Wei, Jie Feng, Jing Sun, Dan Zhang, Yudong Li, Xue‐Feng Yu, Qi Guo
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.