Comparative Evaluation of Short Circuit Robustness Across Generation of 1.2kV SiC MOSFETs

Abstract Silicon Carbide (SiC) MOSFETs are efficient alternatives for power electronics, yet concerns persist regarding their short-circuit withstand capability compared to traditional Si IGBTs. Despite the market evolution of 1200V SiC MOSFET generations, a comprehensive comparative analysis of different device types is lacking. This study addresses this gap, comparing five planar and one trench device representing 1st (1G), 2nd (2G), and 3rd generation (3G) products. The SCWT, short circuit energy and short circuit peak power values are also compared. Findings show 3G devices exhibit inferior performance, indicating a compromise between on-state losses reduction and short-circuit ruggedness. The cause behind this seems to be that the smaller die area in 3G hinders heat dissipation during faults, thereby reducing short-circuit withstand time. Furthermore, 2G device display higher resilience at 400V, this advantage diminishes at higher voltages (⩾600V). Notably, 800V 3G devices exhibit survival times as low as 2 μs, with failure analysis identifying gate oxide dielectric breakdown at 400V and thermal runaway at voltages ⩾600V across all.