Analysis of the Novel Snapback-Free LIGBT With Fast-Switching and Improved Latch-Up Immunity by TCAD Simulation

In this letter, a novel snapback-free LIGBT with fast-switching and improved latch-up immunity is proposed and investigated by TCAD simulation. The structure features a shorted-anode NPN (SA NPN) beside the insulated oxide trench in the N-buffer and a lowly doped P-region (PD) alongside the deep-oxide trench (DOT) in the N-drift. The SA NPN provides an effective path of electron extraction and completely suppresses the snapback voltage. The PD changes the transmission path of hole current, makes the distribution of hole current more uniform, and contributes to the depletion of the drift region. As simulation results show, at the same forward voltage drop of 1.40 V, the turn-off time for the proposed SAPD LIGBT is reduced by 36.6% and 57.4%, respectively, compared with SA LIGBT and DOT LIGBT. In addition, compared with DOT LIGBT, breakdown voltage is increased by 7.6% and latch-up voltage is increased by nearly 20% for the proposed SAPD LIGBT.