Simulation of a new lateral trench IGBT employing effective p+ diverter for improving latch-up characteristics

A new lateral trench insulated gate bipolar transistor (LTIGBT) with p+ div erter was proposed to improve the characteristics of the conventional LTIGB T. The p + divert layer was placed between the anode electrode and the cath ode electrode. Generally, as the conventional LTIGBT had a p + divert regio n, the forward blocking voltage was decreased greatly because the n-drift l ayer corresponding to the punch-through region was reduced. However, the fo rward blocking voltage of the proposed LTIGBT with p + diverter was about 1 40 V. That of the conventional LTIGBT of the same size was 105 V. Because t he p + diverter region of the proposed device was an enclosed trench oxide layer, the electric field moved toward the trench-oxide layer, and punch th rough breakdown of LTIGBT with p + diverter occurred. Therefore, the p + di verter of the proposed LTIGBT did not relate to breakdown voltage in a way different to the conventional LTIGBT. The latch-up current densities of the conventional LTIGBT and LTIGBT with p + diverter were 540, and 1453 A/cm(2 ), respectively. The enhanced latch-up capability of the proposed LTIGBT wi th p + diverter was obtained through holes in the current directly reaching the cathode via the p + divert region and the p + cathode layer beneath th e n + cathode layer. (C) 2001 Elsevier Science Ltd. All rights reserved.