4H-SiC p-n diodes and gate turnoff thyristors for high-power, high-temperature applications

Abstract

This paper presents an overview of SiC power devices. The progress in pn junction diode development is described. The data on 10 A, 1000 V, packaged 4H-SiC ion-implanted p+ nn+ diode are presented. It is found that in order to develop high voltage, high current diodes, it is critical to reduce dislocation density below 103 cm-2, and increase substrate doping of n+ 4H-SiC above 1019 cm-3. It is simply not enough to reduce the micropipe density to below 1 cm-2. The paper introduces a new power switching device configuration, namely, JFET controlled thyristor (JCT). It is the most promising near term SiC switching device given its high power potential, ease of turn-off, potential for 500°C operation and resulting reduction in cooling requirements. Experimental demonstration of the hybrid JCT is presented with a turn-off measurement of 1 A in less than 100 ns. It is further concluded that in order to take advantage of SiC power devices, high temperature packages and components with double sided attachment need to be developed along with the SiC power devices.