Abstract
In this paper, we propose and simulate a novel lateral silicon carbide (SiC) high voltage PN diode structure. These devices employ the superjunction principle to reduce the specific on-resistance and to enhance the blocking voltage (BV). Through the excellent material characteristics of SiC the devices are expected to have good IV characteristics. The simulation results show that the lateral SiC high voltage diodes behave similar to majority carrier devices which the specific on-resistance rises with increasing temperature and the reverse recovery is better than convention PiN diodes due to the devices fabricated on semi-insulating substrate. The specific on-resistance of a 3500V lateral 4H-SiC diode is 32.5mΩ-cm2. The Baliga Figure of Merit (BFOM) is 390 MW/cm2, comparable to the 4H-SiC Schottky diodes and superior to the 4H-SiC lateral MOSFETs in the literature. The lateral high voltage PN diodes are combined with lateral MOSFETs to form the lateral high voltage MOSFETs which have the same blocking ability with lateral PN diodes when these two devices have close BV designs. The simulation results show that the lateral MOSFETs have a specific on-resistance 0.16Ω-cm2, and an offset near drain to source voltage is near to zero. This offset problem can be solved through controlling drift region etching depth.