Current Transport Mechanism for Heavy-Ion Degraded SiC MOSFETs

High sensitivity of silicon-carbide (SiC) power MOSFETs has been observed under heavy-ion irradiation, leading to permanent increase of drain and gate leakage currents. The electrical postirradiation analysis confirmed the degradation of the gate oxide and the blocking capability of the devices. At low drain bias, the leakage path is formed between drain and gate, while at higher bias the heavy-ion-induced leakage path is mostly from drain to source. An electrical model is proposed to explain the current transport mechanism for heavy-ion degraded SiC power MOSFETs.