An Novel Thin Layer SOI Carrier-Stored Trench LIGBT With Enhanced Emitter Injection

Abstract

An novel thin layer SOI carrier-stored (CS) trench lateral insulated gate bipolar transistor (TLIGBT) with diode-clamped P-shield layer is proposed. The potential of the P-shield layer is clamped by two series-connected diodes. Therefore, the reverse voltage is sustained by the P-shield/N-drift junction rather than the P-base/CS junction during the off-state. Thus, the doping concentration of the carrier-stored layer ( ${N} _{\mathrm{ cs}}$ ) can be significantly improved without compromising the breakdown voltage. Hence, an ultra-low on-state voltage drop ( ${V} _{\mathrm{ on}}$ ) can be obtained. Besides, the two series-connected diodes clamp the drain-to-source voltage of the intrinsic n-MOS in the TLIGBT, which leads to an ultra-low saturation current and improves the short-circuit withstand capability. The simulation results indicate that the turn-off loss ( ${E} _{\mathrm{ off}}$ ) at ${V} _{\mathrm{ on}} = 1.37$ V is reduced by 28.8% and 21% compared with those of the conventional carrier-stored LIGBT A and LIGBT B, respectively. Moreover, the saturation current density is reduced by over 53.3% and the short circuit withstand time is improved by more than 2 times than those of the conventional and state-of-the-arts.