SiC MOSFETs are classified as wide bandgap semiconductors

enabling high-speed and high-temperature performance in practical applications. Nonetheless

threshold voltage drift induced by SiC/SiO2 surface traps constitutes a significant reliability concern that hinders the effective utilization of SiC MOSFETs. The mechanism of threshold voltage drift resulting from the switching-on process has been documented; however

the physical rationale for threshold voltage drift under high-speed switching stress

particularly during the switching off process

remains inadequately explored. Initially

a deterioration method featuring an adjustable drive current is introduced to satisfy the requirements of high-speed switching and a straightforward design. This study examines the threshold voltage drift rule of SiC MOSFETs under high-speed switching stress

with particular emphasis on the impact of the turn-off procedure. The switching-off process

at varying speeds

can either facilitate or impede the forward drift of threshold voltage and is significantly influenced by temperature. Based on the tunnelling theory

a physical interpretation model is subsequently developed and confirmed by experimental methods. This study serves not only to elucidate the aforementioned drift principles but also to offer methodological guidelines for mitigating threshold voltage drift in SiC MOSFETs within high-speed switching applications.