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

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
_sa
) 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
_sb
). Simulation shows that the MSA LIGBT achieves the V
_sb
<;1V with 80% reduction in the z-direction dimension compared with the segment-anode (SEG) LIGBT. At the same tumoff energy loss (E
_off
), the MSA LIGBT reduces the on-state voltage (F
_on
) 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
²
. The short circuit withstand time of the proposed structure achieves 6X improvement compared to that of the conventional LIGBT.