700-V asymmetrical 4H-SiC gate turn-off thyristors (GTO´s)

Silicon Carbide (4H-SiC), asymmetrical gate turn-off thyristors (GTO´s) were fabricated and tested with respect to forward voltage drop (V/sub F/), forward blocking voltage, and turn-off characteristics. Devices were tested from room temperature to 350/spl deg/C in the dc mode. Forward blocking voltages ranged from 600-800 V at room temperature for the devices tested. V/sub F/ of a typical device at 350/spl deg/C was 4.8 V at a current density of 500 A/cm². Turn-off time was less than 1 μs. Although no beveling or advanced edge termination techniques were used, the blocking voltage represented approximately 50% of the theoretical value when tested in an air ambient. Also, four GTO cells were connected in parallel to demonstrate 600-V, 1.4 A (800 A/cm²) performance.