A snapback-free shorted-anode SOI LIGHT with multi-segment anode

摘要

A new 600V SOI shorted-anode LIGBT with multi-segment anode (MSA) is proposed and investigated in this paper. The device features a multi-segmented P+ anode and p-buried layers (PBL) formed in both anode and cathode regions. The combination of MSA and the PBL below the anode increase the anode distributed resistance (R) and effectively suppress snapback effect with small dimensions in both x- and z-directions. The PBL below cathode n+ serves as a low-resistance bypass for on-state hole current and is conducive to latch-up immunity. A compact analytical model is further presented to evaluate the impact of key parameters of the MSA on the snapback voltage (V). Simulation shows that the MSA LIGBT achieves the V <;1V with 80% reduction in the z-direction dimension compared with the segment-anode (SEG) LIGBT. At the same tumoff energy loss (E), the MSA LIGBT reduces the on-state voltage (F) by 50% compared to the separated shorted anode (SSA) LIGBT. The MSA LIGBT exhibits no latch-up issue at the high voltage and high current up to 1600A/cm. The short circuit withstand time of the proposed structure achieves 6X improvement compared to that of the conventional LIGBT.