3.3 kV-Class 4H-SiC UMOSFET by Double-Trench with Tilt Angle Ion Implantation

A 3.3 kV trench MOSFET with double-trench structure was demonstrated. The deep buried p-base regions were fabricated using tilt angle ion implantation into the sidewalls of the trench contacts. The distance between the trench gate and trench contact was determined through simulation, in order to optimize the trade-off between on-resistance (RonA) and the electrical field in the oxide (Eox). A tapered trench was located in the connective area between the edge termination and the active area, in order to maintain breakdown voltage. We achieved a RonA of 10.3 mWcm2 and a breakdown voltage of 3843 V and the maximum Eox at breakdown voltage was estimated to be 3.2 MV/cm.