Review of Avalanche Tolerance of Silicon Carbide Power MOSFETs

Silicon carbide (SiC) MOSFET power devices have received increasing attention, due to its wide band gap, high thermal conductivity, high critical breakdown field strength, and high carrier saturation velocity, etc. Major semiconductor device manufacturers have introduced series of commercial SiC MOSFET products, focusing on high-power applications with high reliability. In practical circuits, the main failure root of SiC MOSFET power devices is avalanche breakdown. The avalanche characteristics and the underlying mechanisms of SiC devices are different from those of Si devices. However, the avalanche tolerance and other parameters of SiC MOSFET are barely included in the current manufacturer's data sheet and related research so far. Therefore, it is of great importance to study the avalanche tolerance of SiC MOSFETs. In this review, we summarized the setups for avalanche tolerance test, mainly focused on unclamped inductive switching tests. Then, the avalanche test results of 650V, 900V, 1200V and 10kV SiC MOSFETs were described according to the voltage level. Next, different theories on the failure mechanism of SiC MOSFET were introduced. Finally, the deficiencies of current research and possible future research directions were proposed. In summary, this paper provides a comprehensive review of avalanche test setup, test results and avalanche failure analysis, and future development trends of SiC MOSFET power devices.