Investigation of Repetitive Short Circuit Stress as a Degradation Metric in Symmetrical and Asymmetrical Double-Trench SiC Power MOSFETs

In this paper, the reliability of planar, symmetrical, and asymmetrical SiC MOSFET is compared under repetitive short circuit shocks. Both static and dynamic parameters are tested after certain cycles to investigate the degradation pattern of the devices. It has been found out that the planar device has the highest reliability and is barely degraded for almost all parameters after 5000 cycles. The symmetrical device has the lowest reliability, which shows degradation after 50 cycles and ultimately fails after 141 cycles. The asymmetrical device shows significant degradation after 100 cycles and fails to turn-on/off after 1000 cycles. For both symmetrical and asymmetrical devices, the degradation is directly linked to the damage of the gate oxide.