The SiC thyristor has a substrate, an anode, a drift region, a gate, and a cathode. The substrate, the anode, the drift region, the gate, and the cathode are each preferably formed of silicon carbide. The substrate is formed of silicon carbide having one conductivity type and the anode or the cathode,...http://www.google.com/patents/US5539217?utm_source=gb-gplus-sharePatent US5539217 - Silicon carbide thyristor
