Comprehensive Short Circuit Behavior and Failure Analysis of 1.2kV SiC MOSFETs Across Multiple Vendors and Generations

Silicon Carbide (SiC) MOSFETs have gained significant attention in power electronics for their superior characteristics. Despite advances in 1.2kV SiC MOSFET generations, a comprehensive comparative analysis of different device types remains limited. This study examines the short-circuit (SC) behavior of 1.2kV SiC MOSFETs across multiple vendors and generations, including planar and trench structures. Key metrics such as Short Circuit Withstand Time (SCWT), SC energy, SC peak power, SC energy density, and SC current density were evaluated at DC bus voltages of 400V, 600V, and 800V. Our findings reveal that third-generation (3G) devices exhibit inferior SC performance due to smaller die areas that impede heat dissipation, with 800V survival times as low as 2.25 mu s for GeneSiC-3G. In contrast, trench-based designs showed improved resilience. Infineon-1G, with an active area 44.3% smaller than Littelfuse-1G and 45% smaller than CREE-2G, achieved comparable SCWT ( 4.5 mu s vs. 4.5 mu s for Littelfuse and 4 mu s for CREE-2G) while demonstrating superior thermal management, with a SC energy density of 0.096 J/mm(2) and current density of 41.74 A/mm(2) at 800V. Similarly, another trench device, Rohm-3G, outperformed planar 3G devices, with a SCWT of 3.5 mu s and peak power of 110 kW at 800V. Post-SC failure mechanisms were systematically analyzed using optical microscopy, Lock-In Thermal Emission Microscopy (LITEM), and Focused Ion Beam (FIB), revealing gate leakage paths and damage in the active regions and two-finger area. These findings offer significant insights into the trade-offs between on-state performance and SC robustness, providing manufacturers and designers with crucial guidance for developing optimized SiC MOSFET designs for high-power applications.