A Novel Full Tun-on Reverse-Conducting IGBT with Enhanced Carrier Concentration Modulation in Collector Side

This paper proposes a novel full turn-on reverse-conducting IGBT (RC-IGBT) with enhanced carrier concentration modulation in collector side. The proposed RC-IGBT features P-type drift region and oxide trench inserted between the N + -shorted region and the P + -collector region, which can enhance carrier concentration modulation in the collector side mainly in two aspect. First, during the forward conducting state, the P-drift region combined with the oxide trench can suppress the carrier extraction of the N + -shorted region, and thus the carriers can be stored near the P + -collector/FS-layer junction until the junction turns on, suppressing the snapback effect and leading to the full turn-on of the P + -collector/FS-layer junction. Second, during the turn-off transient, the P-drift region increases the electric filed in the collector side to deplete the most area in this region, leaving little carriers that need removed by recombination, and hence reducing the turn-off time. The simulation results show that, when compared with the other RC-IGBT, the proposed RC-IGBT can reduce the forward voltage drop by at least 23% without degrading other device characteristics.