Investigation of Short-Circuit Failure Mechanism in 1.2kV SiC MOSFET

The reliability and failure mechanism of SiC MOSFET under short-circuit was investigated using experiment and physical simulation in this paper. A short-circuit test platform was constructed, and a physical simulated model was calibrated. A commercial 1.2kV SiC MOSFET operated under different voltages including 200V, 400V, 600V with series short-circuit time was studied. The results showed that the thermal dissipation played a critical role during short-circuit operation, which is one of the most impacting factor to gate voltage and current tails. Two failed mechanisms including gate oxide degradation and parasitic BJT conduction failure were verified during short-circuit. This study may be helpful to the application engineering of SiC MOSFET.