Impact of SiC power MOSFET interface trap charges on UIS reliability under single pulse

In this paper, the unclamped inductive switching experimental results of a 1.2-kV rated N-Channel conventional power metal-oxide-semiconductor field-effect transistors are presented. The experimental results show that the sample devices can avoid a drain leakage current degradation under the bias conditions of V_ds = 1520 V and I_av < 20 A. Notably, a severe avalanche failure current degradation is related to interface fixed trap charges. On this basis, the unclamped inductive switching for the 1.2-KV rated MOSFET with different interface fixed trap charges are given. The simulation results show that interface fixed trap charges determine the avalanche drain current degradation degree, and TCAD simulation shows that the interface fixed trap charges make the channel easier to activate. Thus, improving interface fixed trap charges can significantly reduce the degradation of avalanche drain leakage current in devices and enhance their avalanche robustness.