Simulation of a lateral trench IGBT with p+ diverter having superior electrical characteristics

A new lateral trench insulated gate bipolar transistor (LTIGBT) with p+ diverter was proposed to improve the characteristics of the conventional LTIGBT. The p+ divert layer was placed between anode electrode region and cathode electrode. Generally, if the LTIGBT had a p+ divert region, forward blocking voltage was decreased greatly because the n-drift layer corresponding to punchthrough was decreased. However, the forward blocking voltage of the proposed LTIGBT with p+ diverter was about 140 V, while that of the conventional LTIGBT of the same size was 105 V. The forward blocking voltage of LTIGBT with p+ diverter is 1.3 times greater than those of the conventional LTIGBT. Since the p+ diverter region of the proposed device was enclosed by a trench oxide layer, the electric field moved toward the trench oxide layer, and punchthrough breakdown of LTIGBT with p+ diverter occurred subsequently. Therefore, the p+ diverter of the proposed LTIGBT did not relate to breakdown voltage in the same way as a conventional LTIGBT. The latch-up current densities of the conventional LTIGBT and LTIGBT with p+ diverter were 540 A/cm², and 1453 A/cm², respectively. The enhanced latch-up capability of the LTIGBT with p+ diverter was obtained through holes in the current directly reaching the cathode via the p+ divert region and p+ cathode layer beneath the n+ cathode layer