Comparative Analysis of the Thermal Stress of Si and SiC MOSFETs during Short Circuits

摘要

In this paper, the performance of silicon (Si) and silicon carbide (SiC) power MOSFETs during short circuits is investigated. The response of both semiconductors is examined under hard switch fault and fault under load conditions using a short circuit tester board. In addition, their failure mechanism is recorded and analyzed. Examination results show that the SiC MOSFET fails in the energy limiting mode, due to gate oxide rupture, while the Si MOSFET is destructed during the power limiting mode, at the beginning of the fault. The electro-thermal characterization of these devices is performed through three-dimensional finite element analysis, utilizing the experimentally extracted power dissipation for each transistor. Simulation results confirm the exceptional ruggedness that SiC power MOSFETs exhibit outside their safe operating area.