Surge current failure mechanisms in 4H-SiC JBS rectifiers

4H-SÍC Junction Barrier Schottky (JBS) rectifiers can operate in both a purely unipolar mode during normal operation, and a bipolar mode during surge conditions. The transition between operation modes is not only a function of the static device physics, but also the dynamic heating that occurs during a surge transient. For long surge transients on the order of 1ms, heat diffusion into the package allows for 4H-SiC JBS diodes to absorb up to an order of magnitude more energy than surge transients that occur in the 10 μβ time scale. Data from surge operation of 4H-SiC diodes at varying time scales was used to map surge currents to an allowed operation space.