Experimental and simulation studies of radiation-induced single event burnout in SiC-based power MOSFETs

The single event burnout (SEB) effects of SiC power MOSFET are investigated by irradiations. An SEB is observed when drain biased above 400 V for Ta-181 ion irradiation. The failure analysis shows a melting "hole" near the gate region due to the thermal runaway. Based on TCAD simulations, the impact ionization and parasitic bipolar are the key factors to trigger SEB in SiC MOSFET. Unlike the impact ionization, the turning on of the parasitic bipolar is not necessary for an SEB. But it will significantly reduce the threshold of SEB. Except for SEB, another permanent damage mode is also observed, which is manifested as the increase of leakage current and the abnormal of the output characteristics. This damage may be related to the latent track produced by heavy ion according to the failure analysis. The SEBs are observed for proton irradiations. The maximum LET value of the proton-induced secondary ions can reach 13.9 MeV cm(2)/mg for 100 MeV proton. The simulations imply that most of the secondary ions can contribute to SEB. The biggest discrepancy from heavy ion irradiation is that no leakage current increases and output characteristics degradations are observed for the device without SEB after proton irradiation.