Trade-off analysis of the p-base doping on ruggedness of SiC MOSFETs

Reliability represents a very important factor for the design of Silicon Carbide (SiC) power metal oxide semiconductor field effect transistors (MOSFETs). Ruggedness of the device during abnormal operating conditions like the short circuit (SC) and avalanche conduction (during unclamped inductive switching - UIS) is an important aspect of reliability. Often, variation in design parameters to improve ruggedness during SC and UIS shows negative impact on the nominal operating performance. This paper presents a comprehensive analysis of the impact of modification of p-base doping on the performance of a 1.2 kV SiC MOSFET during SC and UIS by means of TCAD simulations. The improvement in MOSFET ruggedness by optimizing the p-base doping and its influence on the nominal operating performance is evaluated.