Investigation and Improvement of Switching Characteristics of SiC Optically Controlled Transistor

Abstract

Aiming to the switching characteristics of SiC optically controlled transistor, SiC NPN optically controlled transistor was investigated through Silvaco TCAD. The results show that under 4500V bias voltage, the turn-on and turn-off dV/dt of the SiC transistor are 428.5V/ns and 23.9V/ns, respectively. And the tailing problem in the turn-off process is obvious. In order to improve the switching characteristics of SiC optically controlled transistor, the minority carrier lifetime in base layer is regional controlled. The simulation results indicate that, by using minority carrier lifetime control technology, the turn-off time and turn-off dV/dt are improved by about 28.2% and 39.3%, respectively. Meanwhile, turn-on time and turn-on dV/dt are only degenerated by about 3.6% and 3.4%, respectively. The overall level of switching characteristics of SiC optically controlled transistor are improved.