Simulation Study of 4H-SiC Trench MOSFETs with Various Gate Structures

In this paper, we systematically study the effect of gate structures of a 4H-SiC UMOSFET on its performance, focusing on the fast switching performance. Based on the simulation results, DC and AC characteristics of different gate structures are compared. It is found that a structure of UMOSFET, combining a grounded split-gate (SG), a trench bottom protection P+ shielding layer (PS) and a current spreading layer (CSL), yields the best compromise.