Subnanosecond breakage of current in high-power semiconductor switches

The process of high-density current breakage in an SOS diode structure was studied using a corresponding theoretical model. For a p-n junction depth of ∼200 μm, a forward pumping time shorter than 60 ns, and a reverse pumping time of ∼10–15 ns, the structure studied exhibits a subnanosecond breakage of a current with a density of up to 103–104 A/cm2. The mechanism of current breakage involves the formation of two spatially separated domains featuring strong electric field build-up on the p side of the diode structure, which expand during the current breakage at a velocity close to the carrier velocity saturation level.