Circuit modeling of vertical geometry SiC photoconductive semiconductor switches

Compact vertical geometry photoconductive semiconductor switches (PCSS) made from SiC are promising candidates for high power switching. Silvaco TCAD is used to simulate the time-resolved electric field current distribution and volt-ampere characteristics of different light power in vertical geometry V-doped semi-insulated 6H-SiC photoconductive switches excited by 532 nm laser. The simulation shows that the carriers drift velocity with increasing field saturates at a constant velocity, and the time-resolved electric field current is uniformly distributed along the major electric field current direction that is perpendicular to laser incidence direction. With the simplification of semiconductor equations based on the Silvaco TCAD simulations, a SiC-PCSS circuit model has been developed in consideration of carrier field dependent mobility. With the help of the validation in reported experiment, the influence of exterior electric parameters is discussed by using the SiC-PCSS circuit model.