RBSOA study of high voltage SiC bipolar devices

Rapid improvement of 4H-SiC material quality and maturation of SiC device processing have enabled the development of high voltage SiC bipolar devices for high voltage switching applications. As one of the major concern of bipolar devices, the onset of dynamic avalanche breakdown and reverse biased safe operating area (RBSOA) of SiC pnp and npn transistors have been systematically analyzed in this paper. The theoretical analysis predicts the onset power density of dynamic avalanche breakdown of SiC bipolar devices is more than twenty times larger than that of Si bipolar devices, and SiC bipolar devices have a near square RBSOA. The predicted rugged turn-off behavior of SiC bipolar devices is verified by numerical simulations of 10-kV SiC emitter turn-off thyristors (ETOs). The excellent ruggedness of SiC bipolar devices make them attractive for high voltage (≥10-kV) switching applications.