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The maximum controllable current of an EST, which employs the segmented p-base (SB-EST), is investigated with the various design parameters, such as p-base surface doping concentration, segmented gate length and carrier lifetime, by performing 2-dimensional numerical simulation. The simulation results show that the maximum controllable current of the SB-EST with the p-base surface doping concentration of 5 × 1017 cm-3 is 900 A/cm2, while that of the conventional EST is 540 A/cm2. The SB-EST shows 52% higher maximum controllable current that the conventional EST independent of the carrier lifetime (0.1 µs to 0.5 µs).

A new dual gate shorted anode silicon on insulator (SOI) lateral insulated gate bipolar transistor (LIGBT), which suppresses effectively the snap back without sacrificing the forward voltage drop, the switching speed and the breakdown voltage, is proposed and verified by numerical simulation. The numerical simulation results show that the snap-back is reduced less than the anode voltage of 2.5 V while the snap-back occurs at anode voltage of about 4 V for the conventional structure with the drift length of 35 µ m. We have verified that the snap-back is suppressed due to the enhancement of the hole injection and investigated the snap-back as a function of the device parameters such as the n- drift region doping concentration and drift region length.

A trench-gate silicon-on-insulator (SOI) lateral insulated gate bipolar transistor (LIGBT) with the p+ cathode well is proposed to improve the latch-up characteristics, and the improved characteristics are verified numerically by MEDICI simulation. It is found that the trench-gate SOI LIGBT exhibits at least 6 times larger latch-up capability than the conventional devices. The enhanced latch-up capability of the trench-gate SOI LIGBT is obtained due to the fact that the hole current in the device bypasses the resistance of the p body region which is the source of the latch-up and reaches the cathode via the p+ cathode well.