Reliability of SiC SBD Edge Terminations under HV-H3TRB and Thermal Cycling Tests

This study examined the reliability of molded SiC Schottky barrier diodes (SBDs) under high-voltage, high-humidity, and high-temperature reverse bias (HV-H3TRB) and temperature cycling. The combined HV-H3TRB and temperature-cycling tests promoted delamination, accelerated anodic oxidation, and eroded shallow p+ guard rings, resulting in pronounced degradation of the breakdown voltage. In contrast, the HV-H3TRB tests induced only minor anodic oxidation without degradation of the breakdown voltage. Reproduced practical failure modes indicated that the conventional HV-H3TRB tests are insufficient and that complementary temperature-cycling tests are therefore essential for a comprehensive evaluation of edge termination reliability.