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

In silicon carbide (SiC) thyristors, the turn-on time decreases with increa sing temperature. Experimental data for 400-800 V and 2.6 kV 4H-SiC thyrist ors are analyzed. A qualitative analysis, analytical calculations, and comp uter simulations have been made to clarify the origin of this effect. It is shown that the temperature ionization of the Al dopand in the p(+)-emitter is mainly responsible for the effect. The hole concentration in the p(+)-e mitter grows sharply with increasing temperature, making larger the injecti on coefficient of the p(+)-n junction. The role played by the temperature d ependence of the carrier lifetime in the p(+)-emitter is demonstrated. (C) 2001 Elsevier Science Ltd. All rights reserved.