Investigations of UIS Failure Mechanism in 1.2 kV Trench SiC MOSFETs Using Electro-Thermal-Mechanical Stress Analysis

In this study, the avalanche capabilities of 1.2 kV trench SiC MOSFETs were investigated using unclamped inductive switching tests at various negative gate biases, and electro-thermal-mechanical TCAD simulation. The study confirmed UIS metallization failure in an asymmetric trench MOSFET, and UIS high electric field failure in a double trench MOSFET.