Study on single-pulse UIS capability of SiC MOSFET with different P-base morphology

At present, the single-pulse unclamped inductive switching (UIS) characteristics of SiC MOSFET have been fully studied. The current mainstream research suggests that the failure mechanism of MOSFET under a single UIS shock is divided into parasitic BJT conduction and metallization failure. However, there are still some shortcomings in the current research. First, it is difficult to distinguish these two failure mechanisms. Second, it is difficult to propose feasible optimization schemes. Therefore, it is still necessary to further explore the mechanism of single-pulse UIS. In this study, Sentaurus TCAD software was used to simulate different P-base doped MOSFETs, and the effect of doping concentration and morphology of the P-base region on the single-pulse UIS failure mechanism was revealed. By designing the P-base region, the BJT conduction failure and metallization failure can be distinguished. In addition, the study also proved the relationship between breakdown voltage and the maximum temperature (T max) in the UIS process, and on this basis, an optimization scheme for the single UIS characteristics of MOSFET was proposed.