Ruggedness analysis of 600V 4H-SiC JBS diodes under repetitive avalanche conditions

The repetitive avalanche reliability of power rectifiers is crucial to the safe operation of the hard switching power converters under extreme conditions as well as transient voltage suppression (TVS) applications. In this paper, the ruggedness of two state-of-art 4H-SiC Junction Barrier Schottky (JBS) diodes under repetitive avalanche stresses has been studied. Two different post-stress behaviors have been observed: V_F degradation and BV drifting for the two different JBS diodes. The V_F degradation could happen to the device that avalanches in the active area. However, for the device that avalanches in the edge termination, the repetitive avalanche stress greatly increases the breakdown voltage for about 100V. These results bring new concerns for SiC devices that are expected to be operated in avalanche conditions.