Analysis of On-State and Short-Circuit Capability in 3D Trench SiC MOSFET Designs

Silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors (MOSFETs) are successfully replacing traditional silicon insulated gate bipolar transistors (Si IGBTs) in power applications. Nonetheless, two crucial challenges persist: gate-oxide reliability and a reduced short circuit (SC) withstand time. This paper explores a novel MOSFET structure, which is designed to address these concerns and compares it with existing designs through extensive 3D TCAD simulations. The proposed MOSFET structure features a p-region under the gate, providing a unique configuration for improved performance during SC events. This novel structure is then compared to two commercially realized MOSFET structures. Our structure has a superior on-state performance with a specific resistance of 1.48 mΩ /cm 2 , showing an improvement by 25 % and 15 %, respectively. It also increases the blocking capability by 100 V and SC withstand time in comparison to the double-trench MOSFET.