Comparison of short-circuit characteristics of trench gate and planar gate U-shaped channel SOI-LIGBTs

Comparison of short-circuit (SC) characteristics of 500 V rated trench gate U-shaped channel (TGU) SOI-LIGBT and planar gate U-shaped channel (PGU) SOI-LIGBT is made for the first time in this paper. The on-state carrier profile of the TGU structure is reshaped by the dual trenches (a gate trench G1 and a hole barrier trench G2), which leads to a different conduction behavior from that of the PGU structure. The TGU structure exhibits a higher latchup immunity but a severer self-heating effect. At current density (JC) < 640 A/cm2, the SC destruction is suspected to be latchup-dependent and short-circuit withstand time (tSC) of the TGU structure is much longer than that of the PGU structure. Due to the high lattice temperature rise caused by the high current density at the emitter side in the TGU structure, the PGU exhibits a better JC-tSC trade-off at JC > 640 A/cm2. Comparison of layouts and fabrication processes are also made between the two types of devices.