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

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 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 140 V. That of the conventional LTIGBT of the same size was 105 V. 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 an enclosed trench oxide layer, the electric field moved toward trench-oxide layer, and punch through breakdown of LTIGBT with p⁺ diverter occurred. Therefore, the p⁺ diverter of the proposed LTIGBT didn´t relate to breakdown voltage in a different way to conventional LTIGBT. The latch-up current densities of the conventional LTIGBT and LTIGBT with p⁺ diverter were 540A/cm², and 1453A/cm², 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