Impact of Stripe Trench-Gate Structure for 4H-SiC Trench MOSFET with Bottom Oxide Protection Layer

Abstract

An optimized layout for a trench-gate SiC-MOSFET with a self-aligned Bottom P-Well (BPW) was investigated for reduction of the specific on-resistance and switching loss. The static and dynamic characteristics of trench-gate MOSFETs with lattice and stripe in-plane structures were evaluated by varying the distance between neighboring BPWs (dBPWs). For the stripe structure, more significant improvements on the specific on-resistance (Ron,sp), gate-source threshold voltage (Vth) were achieved compared with the lattice structure, which was found to be due to the difference in the spread of the depletion layer and the channel planes in the device.