Novel low loss and snapback-free SOI LIGBT controlled by anode junction self-built potential

Abstract

In this work, we evaluated a novel low loss and snapback-free 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 (V_AC) is less than built-in potential (V_bi), 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 V_AC, 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 (V_F) of 1.64V, extra electron flowing channel makes the turn-off loss (E_off) of proposed JSBP LIGBT 22.1% lower than that of conventional (Conv.) LIGBT. Moreover, considering to the same E_off of 0.3mJ/cm², the depletion region with low V_AC contributes to relatively enhanced conductivity modulation, which makes V_F 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 V_F and E_off.