4H-SiC Trench MOSFET With L-Shaped Gate

A novel 4H-SiC trench metal-oxide-semiconductor field-effect transistor (MOSFET) with an L-shaped gate (LSG) is proposed and studied via numerical simulations in this letter. Adoption of an additional LSG region that surrounds the bottom corner of the trench allows the peak electric field in the SiO2 dielectric to be significantly relieved by charge compensation, and the device breakdown voltage can be greatly enhanced without causing significant degradation of the output characteristics. In high-voltage blocking states, the electric field at the bottom corner of the trench is weakened, which leads to improved device performance. The peak electric field value in the SiO2 dielectric decreases by 32.3% when compared with that of a conventional 4H-SiC trench MOSFET, while the breakdown voltage increases by 80.4%.