Design and Optimization of 6.5 kV SiC MOSFET Device Termination

For high-voltage SiC MOSFET power devices, the breakdown voltage is a key parameter in device design, but the cylindrical junction can affect the withstand voltage capability of the device. Aiming at the problem of uneven electric field distribution and high electric field intensity on the surface of SiC MOSFET devices, a new 6.5 kV SiC terminal structure of field limiting rings is designed in this paper. The termination is optimized by adjusting the field limiting ring spacing and adding field plates, acheveing the goal of 8.9 kV breakdown voltage. The termination reduces the junction surface effect to a certain extent, and greatly improves the electric field distribution on the chip surface.