Experimental demonstration and mechanism study of single-event gate leakage current in 4H-SiC power MOSFET with top oxide and double P-well structures

This work proposes and fabricates the 4H-SiC power MOSFET with top oxide and double P-well (TODP-MOSFET) to enhance the single-event radiation tolerance of the gate oxide. Simulation results suggest that the proposed TODP structure reduces the peak electric field within the oxide and minimizes the sensitive region by more than 70% compared to C-MOSFETs. Experimental results show that the gate degradation voltage of the TODP-MOSFET is higher than that of the C-MOSFET, and the gate leakage current is reduced by 95% compared to the C-MOSFET under heavy-ion irradiation with a linear energy transfer (LET) value exceeding 75 MeV⋅cm²/mg.