Simulation of 4H-SiC trench junction barrier Schottky diodes with high-k dielectrics

In this paper, a novel 4H-SiC trench junction barrier Schottky diode (TkJBS) with high-k semi-insulating polycrystalline silicon (SIPOS) is proposed. By adopting the new high-k dielectric-trench structure, the peak electric field at the corner of P+ regions (COP) can be weakened significantly, and the device breakdown voltage (BV) is enhanced. The SiC TkJBS has a 60.7% higher BV and a 88.7% higher Baliga's figure of merit (BFOM) than the conventional SiC JBS, and the surface electric field (Esf) of the SiC TkJBS is 0.73 MV/cm lower at BVs, resulting in a much lower tunneling current (Ir). The reverse recovery characteristics of the SiC TkJBS are also slightly better than those of the SiC JBS. It is indicated that a SiC TkJBS is a promising candidate for next-generation high power diodes.