A Snapback-Free Reverse Conducting Insulated-Gate Bipolar Transistor With Discontinuous Field-Stop Layer

Abstract

In this paper, a novel reverse conducting insulator gate bipolar transistor (RC-IGBT) with discontinuous field-stop (DFS) layer is proposed and investigated. The DFS increases the distributed resistance near the collector side in the unipolar mode; and thus, eliminates the snapback phenomenon with a reduced half-cell pitch of $60~\mu \text{m}$ . In the blocking state, the depletion region is pinched off by the DFS and thus punchthrough is avoided, ensuring high breakdown voltage of 1200 V. The DFS RC-IGBT shows higher short-circuit ruggedness and increases the short-circuit duration time by 30% compared with the conventional RC-IGBT due to the decreased base transport factor. The proposed structure also achieves better tradeoff between turn-OFF loss and forward voltage drop. For the same forward voltage drop, the turn-OFF loss is reduced by 30%.