A Snapback Suppressed RC-IGBT with N-Si/n-Ge Heterojunction at Low Temperature

This article proposes an RC-IGBT structure with N-Si/n-Ge heterojunction (NNH-IGBT) to suppress snapback effect. Because the proposed N-Si/n-Ge heterojunction acts as a gradually reverse bias diode to suppress the electron flow into the N-short region, so the snapback effect can be suppressed. For the same ON-state voltage drop (VCE), the turn-off loss (EOFF) of the NNH-IGBT is lower than the conventional RC-IGBT (Con-RC-IGBT). In addition, the reverse recovery speed of NNH-IGBT is nearly identical to the Con-RC-IGBT. Because of the use of heterojunction, the NNH-IGBT is suitable for operate to suppress the snapback effect, especially at low temperatures.