Design and Simulation of 600V 4H-SiC Superjunction JBS Diode

Abstract

A 600V 4H-SiC Superjunction Junction Barrier Diode (SJ-JBS) was designed. Trench sidewall implant was utilized to serve as both the negative charge depletion region for the SJ effect and the buried junction for JBS effect. According to the Synopsys TCAD simulation results, the sidewall angle introduced by the trench etching process is playing an important role in determining the tradeoff window for SJ and JBS effects. The optimized SJ-JBS has a half mesa-width of 0.75 $\\mu$ m and a sidewall angle of 25°, and can achieve both a breakdown voltage (BV) of 867.9 V and a surface electric field of 8.11×l05 V/cm. When comparing to the theoretical maximum SJ BV (909 V) at the critical electric field of 3.01×l06 V/cm, a 95.5% BV maintenance with 73% surface electric field reduction were achieved.