Analysis of the Switching Behavior of Gate Oxide Degradation for SiC MOSFETs in a Phase-Leg Configuration

SiC MOSFETs exhibit reduced junction capacitance and enhanced switching speed when compared to Si-based MOSFETs, while maintaining the same withstand voltage. Nevertheless, the device's rapid switching operation is highly susceptible to the deterioration of the oxide layer, which accelerates the drift of the threshold voltage and hampers the device's efficient functioning. The analysis focused on the impact of SiC MOSFETs on turn-on loss, crosstalk, and turn-on overvoltage between phase angles, taking into account the aging of the oxidation layer. It is found that the turn-on speed of the device will be reduced after aging, the switching loss will be increased, and the influence of crosstalk and turn-on overvoltage will be weakened. The experimental results confirm the accuracy and efficiency of the inference analysis, which can offer valuable help for the design of active drive and condition monitoring of SiC MOSFETs.