Evaluation of Neutron Radiation Impact for 1200-V Class 4H-SiC MOSFET at Gate Switching Mode With TCAD Simulation

We evaluated and analyzed power silicon carbide (SiC) metal-oxide-semiconductor field-effect-transistors (MOSFETs) with gate switching mode during neutron irradiation with our commercial single event effect (SEE) analyzer. Based on evaluation and analysis, we found 1) difference of radiation robustness characteristics; 2) switching mode to be worse condition than non-switching (dc bias condition) mode for 1200-V-rated SiC MOSFETs; and 3) temperature dependence with three manufacturers' SiC MOSFETs. In order to clarify the difference between the switching mode and non-switching mode effect, and between the electrical characteristics of the devices, we extracted device-related parameters through physical structure analysis and systematically investigated the cause of the difference by performing simulations with technology computer-aided design (TCAD). As a result, we found that the distribution of electric field according to the gate structure and oxide thickness of SiC MOSFET affects SiC MOSFET radiation robustness. It was also observed that one of the acceleration factors for increased cross section was a higher temperature during the irradiation test.