Simulation of 4H-SiC Trench Junction Barrier Schottky Diodes with High-k Dielectrics

Abstract

In this paper, a novel 4H-SiC trench JBS (TkJBS) with high-k semi-insulating polycrystalline silicon (SIPOS) is proposed. By adopting a new high-k dielectrics-trench structure, the peak electric field at the corner of P+ region (COP) in Silicon Carbide (SiC) can be weakened significantly, and the device breakdown voltage can be enhanced significantly. SiC TkJBS has a 60.7% higher breakdown voltage (BV) and a 110.6% higher Baliga’s figure of merit (BFOM) than the conventional SiC JBSs, and the surface electric field (Esf) of the SiC TkJBS is 0.73 MV/cm lower than it at breakdown voltages, resulting in a much lower tunneling current (Ir). The reverse recovery characteristics of SiC TkJBS are also slightly better than those of the SiC JBS. It is indicated that SiC TkJBS is a promising candidate for next-generation high power diodes.