Evolution mechanism of damage locations in drift region of SiC MOSFETs under heavy ion irradiation

This paper investigates the evolution mechanism of severe thermal damage locations in the drift region of the SiC MOSFETs under different applied drain voltages (VDS(irra)) during heavy ion irradiation using 587 MeV 36Kr ions. It is interesting to find from the post-irradiation blocking I–V curves that the drain–source leakage current increases significantly at about 500 V for the case under relatively low VDS(irra) (175–300 V) and increases rapidly at low voltage for the case under relatively high VDS(irra) (350 V). To explain this phenomenon, a local damage-related lifetime-model along the ion track is proposed and validated by technology computer-aided design simulations. The model indicates that thermal damage will develop near the p-base/n-drift junction once the damage near the n-drift/n-sub junction along the ion track becomes sufficiently serious with increasing VDS(irra). The proposed evolution mechanism of severe thermal damage locations can help analyze mechanisms of single-event leakage current and single-event burnout in SiC devices and guide radiation-hardening designs for SiC devices.