Impact Of Repetitive UIS And SC Stress On Degradation Of Power SIC TrenchMosfets

This paper investigates the reliability of commercial 1.2-kV 4H-SiC MOFSETs under repetitive unclamped inductive switching (UIS) and short circuit (SC) stresses. The degradation of device characteristics, including the transfer characteristics, drain leakage current I
dss
, and output characteristics, is observed. Significant increase of leakage current was observed after 20Meg of avalanche cycles (UIS stress) and device destruction occurred after 30Meg of cycles. Repetitive SC stress was performed for different buss voltages. Increased buss voltages during stress have higher impact on electrical performance of tested devices. The hot carriers injection and trapping into the gate oxide in the channel region may occur during the aging experiments and are believed to be responsible for the variation of electrical parameters.