Experimental Investigation of the Single Pulse Avalanche Ruggedness of SiC Power MOSFETs

In this paper, the single pulse avalanche ruggedness of commercially available silicon carbide (SiC) power planar and trench MOSFETs is compared and analyzed. A test bench is constructed for unclamped inductive switching (UIS) tests. The experimental results show that at the same avalanche current, the maximum avalanche energy per area of the planar MOSFET is at least 8 times higher than that of the trench MOSFET. A single pulse avalanche SOA is demonstrated. Junction temperature is estimated by the theoretical relationship between voltage and current of the p-n junction under breakdown condition and the typical Cauer thermal network simulation. The results show that the maximum junction temperature of devices under test can reach 550~730K.