Single shot avalanche energy characterization of 10kV, 10A 4H-SiC MOSFETs

Abstract

Higher switching frequency capability and lower switching loss associated with 10kV 4H-SiC MOSFETs make them attractive for medium voltage applications, mostly in inductive circuits e.g. solid state transformers, grid connectors and high speed machine drives. Due to exposure to inductive circuits, avalanche ruggedness of these MOSFETs needs to be established to improve their reliability in case of unintended unclamped inductive switching. In this paper, the avalanche ruggedness of 10kV, 10A 4H-SiC MOSFETs is established experimentally using single shot unclamped inductive switching. The minimum and the maximum energy is found out for the MOSFET to remain in avalanche without being failed permanently. The junction temperature at the permanent failure is estimated using semiconductor device physics.