Novel double MOS-resistors SOI-LIGBT with low forward voltage and high short-circuit capability

In this paper, a novel SOI-LIGBT with double MOS-Resistors (MR SOI-LIGBT) is proposed. It integrates MOS resistors of MR1 and MR2 in a conventional LIGBT. Their resistance values determine the voltage of P+(V
P
) and N+(V
N
) at cathode, and thus affect states of the parasitic diode D1 in the conventional LIGBT and parasitic diode D2 in the MR1. In the on-state, D1 adaptively turns on due to the small value of MR1, and thus the conduction modulation is enhanced. When the anode voltage increases, the D2 is triggered to clamp the potential across D1 and the device turns into saturation. Due to the enhanced conductivity modulation, V
on
of the MR LIGBT is reduced by 54% and 43% compared with Con. LIGBT and SCMT LIGBT, respectively. During short-circuit operation, the rising lattice temperature leads to degeneration of both the mobility and drift-region resistance, then V
P
falls and D1 turns off, reducing the current density. Consequently, the rise of lattice temperature slows down and the short-circuit time of the MR device increases from 7.12μs and 19.8μs to 24.7μs, compared with Con. and SCMT device, respectively.