Reliability of 4H-SiC SBD/JBS diodes under repetitive surge current stress

The reliability of power diode under surge current stress is crucial to the applications like motor drives. In this paper, the single and repetitive surge reliability of the 4H-SiC Schottky Barrier Diodes (SBDs) and Junction Barrier Schottky (JBS) diodes have been tested and the corresponding failure mechanisms studied. The single surge test results of two SBDs and three JBS didoes suggest a 450W/mm ² constant power line of the safe operation area for single surge current with a half sinusoidal pulse width of 8.3ms. The stress tests show no degradation of SBDs up to 10,000 cycles of surge current below 34.9A/mm ² . The JBS diodes show V _F degradation after surge stress at different current levels, which might be dependent on the hole injection levels. The aluminum metallization and bipolar degradation are the main limits for the reliability of SiC diodes under surge conditions.