A small-sized lateral trench electrode insulated gate bipolar transistor for improving latch-up and breakdown characteristics

A new small-sized lateral trench electrode insulated gate bipolar transistor (LTEIGBT) was proposed to improve the characteristics of the conventional lateral IGBT (LIGBT) and the lateral trench gate IGBT (LTIGBT). The entire electrode of the LTEIGBT was replaced with a trench-type electrode. The LTEIGBT was designed so that the width of the device was no more than 19 μm. The latch-up current densities of LIGBT, LTIGBT and LTEIGBT were 120 A/cm², 540 A/cm², and 1230 A/cm², respectively. The enhanced latch-up capability of the LTEIGBT was obtained due to the holes in the current directly reaching the cathode via the p+ cathode layer underneath the n+ cathode layer. The forward blocking voltage of the LTEIGBT was 130 V. Those for conventional LIGBT and LTIGBT of the same size were no more than 60 V and 100 V, respectively. Because the proposed device was constructed of trench-type electrodes, the electric field moved toward the trench-oxide layer, and punch-through breakdown of LTEIGBT occurred late.