Influence of Temperature and Gate Bias on the Atmospheric Neutron-Induced SEB Effect in Double-Trench SiC MOSFETs

This study systematically investigates the effects of temperature and negative gate bias on the atmospheric neutron-induced single-event burnout (SEB) effect in SiC double-trench metal-oxide-semiconductor field-effect transistors (SiC DTMOSFETs). This research combines accelerated irradiation experiments at the China Spallation Neutron Source (CSNS) with technology computer aided design (TCAD) simulations. Experimental results indicate that the SEB failure rate decreases exponentially with increasing temperature, dropping from 14.4 FIT at -35°C to 1.15 FIT at 105°C. The influence of negative gate bias is relatively weak, with the failure rate decreasing only from 9.37 FIT to 7.06 FIT as V_gs varies from -15V to 0V. TCAD simulations reveal the underlying physical mechanism, whereby temperature reduction intensifies impact ionisation and increases transient current peaks, triggering thermal runaway. Consequently, temperature significantly impacts SEB. The dual-trench structure is the cause of the gate voltage's primary effect on the surface channel potential, with minimal influence on the bulk region electric field distribution that determines SEB sensitivity. This results in a smaller influence of negative gate voltage on SEB effect.