Design and optimization of cell and field limiting ring termination for 1200 V 4H-SiC Junction Barrier Schottky (JBS) Diodes

Compared with Si, SiC has advantages of wide band gap, high critical electric field, high electron saturation velocity and high thermal conductivity, making SiC power devices develop rapidly in recent years. In the field of power diode, junction barrier Schottky (JBS) diode not only inherits the advantages of Schottky diode with high switching speed and low reverse recovery current, but also greatly improves the reverse breakdown voltage without increasing the leakage current of the device. In this paper, a 4H-SiC JBS with a breakdown voltage of 1200V was designed and simulated. The termination of the device adopts the field limiting ring (FLR) structure, and the parameters of the cell and FLR termination protection structure are optimized. With the optimized structure parameters, the TCAD simulation results show the reverse breakdown voltage of the designed 4H-SiC JBS can reach 1676.2 V without considering the terminal protection efficiency. And the breakdown voltage can reach 1542.7 V when considering the FLR termination structure. The termination protection efficiency is up to 92%.