Operation of 4H-SiC Schottky diodes at dV/dt values over 700 kV/μs

This work describes the operation of commercial 4H-SiC Junction-Barrier Schottky (JBS) Diodes at extreme voltage slew rates (dV/dt) in an attempt to force failures. Slew rates in excess of 700 kVμs were required to damage parts, in combination with high values of the reverse bus voltage. Cryogenic temperatures reduced the maximum bus voltage required to induce failure. Large quantities of parts were subjected to repetitive dV/dt stress with a slew rate of 400 kVμs, then tested for avalanche ruggedness in unclamped inductive switching (UIS) conditions. No differences were detected between the stressed diode population and a control population, indicating that dV/dt stress induces neither immediate failures nor latent weakness.