Influencing Factors and Mechanisms of Single-Event Burnout in STP SiC MOSFETs

The excellent performance of SiC MOSFETs makes them highly promising for aerospace applications. However, single-event burnout (SEB) induced by particle radiation in space limits their use in space stations. To provide a theoretical basis for single-event protection, this study investigates the factors influencing SEB in 1200V SiC MOSFETs. The results show that when the linear energy transfer (LET) of the incident particle exceeds 0.1 pC/μm, the SEB threshold voltage is 424 V. The most sensitive region of the device to single-event effects is located 0.9 μm from the center of the cell, near the vertical PN junction formed by the P-body and the drift region. This is because the damage to the depletion region of the PN junction after single-particle incidence is more extensive in this area, and the holes generated by single-particle collisions with the lattice in the drift region are more likely to drift and accumulate in the P-body region. As a result, the potential of the P-body increases, and when it exceeds the turnon voltage of the PN junction, the parasitic bipolar junction transistor (BJT) turns on, leading to a sharp increase in electron concentration in the drift region. This causes avalanche breakdown at the interface between the drift region and the substrate, triggering single-event effects. This study provides important data support and design guidance for optimizing the SEB resistance of shallow trench planar-gate MOSFETs (STPMOS).