Simulation of a lateral trench IGBT with p+ diverter for improving latch-up 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 and cathode electrode. Generally, if the conventional LTIGBT had p+ divert region, the forward blocking voltage of device was decreased greatly because n-drift layer corresponding to punch-through region was decreased. However, the forward blocking voltage of the proposed LTIGBT with p+ diverter was about 140V. That of the conventional LTIGBT of the same size was no more than 105V. The forward blocking voltage of the proposed LTIGBT with p+ diverter increased 1.3 times more than those of the conventional LTIGBT. Because the p+ diverter region of the proposed device was enclosed trench oxide layer, the electric field moved toward trench-oxide layer, and punch through breakdown of LTIGBT with p+ diverter was occurred late. Therefore, the p+ diverter of the proposed LTIGBT didn't relate to breakdown voltage in a different way the conventional LTIGBT. The Latch-up current densities of the conventional LTIGBT and proposed LTIGBT with p+ diverter were 540A/cm², and 1453A/cm², respectively. The enhanced latch-up capability of the proposed 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 n+ cathode layer.