Temperature dependence of turn-on processes in 4H–SiC thyristors

Abstract

In silicon carbide (SiC) thyristors, the turn-on time decreases with increasing temperature. Experimental data for 400–800 V and 2.6 kV 4H–SiC thyristors are analyzed. A qualitative analysis, analytical calculations, and computer simulations have been made to clarify the origin of this effect. It is shown that the temperature ionization of the Al dopant in the p +-emitter is mainly responsible for the effect. The hole concentration in the p +-emitter grows sharply with increasing temperature, making larger the injection coefficient of the p +–n junction. The role played by the temperature dependence of the carrier lifetime in the p +-emitter is demonstrated.