A novel insulated gate bipolar transistor (IGBT) entitled NPN aided fast switching IGBT (NFS-IGBT) with a P-buffer layer is presented, which enhances the switching speed greatly. Compared with the conventional IGBT, double sided NPN structure is incorporated into the anode to facilitate the turn-off process. The proposed structure is verified by two-dimensional mixed device-circuit simulation, which indicates that the turn-off time is drastically reduced to one third of the conventional value at the expense of acceptable increase of on-state voltage drop. The tradeoff performance also shows great improvement for the new structure.

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In this work, we evaluated a novel low loss and snapbackfree silicon-on-insulator lateral insulated gate bipolar transistor (SOI LIGBT) by numerical simulation, which utilizes the inherent junction self-built potential (JSBP) to form depletion region at the anode. When the anode voltage (VAC) is less than built-in potential (Vbi), the introduced electron flowing channel between P-anode pillars is occupied by the depletion region, which hinders electron current from flowing into N-anode and limits the device to working in MOS mode. Furthermore, due to the offset effect for the JSBP by higher VAC, the depletion region disappears and the anode PN junction turns on, which makes the device work in IGBT mode forming normal electron and hole current. At the same forward voltage drop (VF) of 1.64V, extra electron flowing channel makes the turn-off loss (Eoff) of proposed JSBP LIGBT 22.1% lower than that of conventional (Conv.) LIGBT. Moreover, considering to the same Eoff of 0.3mJ/cm 2 , the depletion region with low VAC contributes to relatively enhanced conductivity modulation, which makes VF of proposed JSBP LIGBT reduce by 19.6% compared to separated shorted-anode (SSA) LIGBT, while also completely eliminates snapback effect. Therefore, the proposed JSBP LIGBT gains the best trade-off performance between VF and Eoff.