Lateral trench IGBT with effective p+ diverter having superior electrical characteristics for smart power IC

摘要

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 electrod region and cathode electrode. Generally, if the LTIGBT had p+ divert region, forward blocking voltage was decreased, greatly because n-drift layer corresponding to punch-through was decreased. However, the forward blocking voltage of the proposed LTIGBT with p+ diverter was 140V. That of the conventional LTIGBT of the same size was 105V. The forward blocking voltage of 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, lately. Therefore, the p+ diverter of the proposed LTIGBT didn't related to breakdown voltage in a different way conventional LTIGBT. The Latch-up current densities of the conventional LTIGBT and LTIGBT with p+ diverter were 540A/cm{sup}2, and 1453A/cm{sup}2, respectively. The enhanced latch-up capability of the LTEIGBT was obtained through holes in the current directly reaching the cathode via the p+ divert region and p+ cathode layer beneath n+ cathode layer.