1000 V 4H-SiC gate turn off (GTO) thyristor

4H-SiC GTO devices were designed, fabricated and evaluated on the basis of blocking voltage, current density and forward drop. Interdigitated designs with device pitches ranging from 26 to 48 μm and circular devices with diameters from 0.5 to 1.5 mm were fabricated. We measure 600 V forward blocking voltage, and 4 A (1500 A/cm²) forward current on 680 μm diameter involute 4H-SiC GTOs fabricated with a 14 μm base layer. Interdigitated devices of smaller areas (~6.5×10^-4 cm² active area) measure 1000 V forward blocking for a 14 μm epitaxial base layer. By combining 8 interdigitated devices in parallel, a maximum current of 20 A was achieved which corresponds to a current density of 3500 A/cm² (compared to 200 A/cm² maximum for a Si GTO). Current density as a function of forward drop was evaluated over the temperature range of 25°C to 390°C