Degradation of 4H-SiC Trench MOSFET under single and repetitive short-circuit stress

Abstract

It is well known that despite the superior performance of SiC MOSFETs, reliability issues persist and limit their development. In this work, short-circuit (SC) stresses have been applied to commercial SiC trench MOSFETs to verify their reliability under extreme conditions. First, a single-pulse SC stress was applied to the device. Two different short-circuit failure mechanisms were identified. One type of failure was thermal runaway and the other was gate failure. Subsequently, multiple non-destructive short-circuit pulses have been applied to the device. After the stress, the shift in the device static characteristics has been measured and recorded to determine the effects of the stress on the degradation of the device's electrical parameters. Finally, TCAD device simulations have been used to help understand the intrinsic degradation mechanism.