A Snapback-Free and Reverse Conducting SOI-LIGBT With Self-Adaptive Electron Barriers

In this work, a snapback-free and fast-switching silicon-on-insulator lateral insulated-gate bipolar transistor (SOI-LIGBT) with reverse conducting (RC) capability is proposed and investigated by TCAD simulations. The proposed device features an anode p-type polysilicon trench (PT) and a p-type doping region between n+ anode and n-buffer (PR) named PTR-LIGBT. The PT is directly connected to the anode and driven by the anode voltage without any additional control circuits. At the forward conducting state, PT and PR will create electron barriers along the electron path. Those dual barriers will block the flow of electrons to the n+ anode. As a result, by introducing these two structures, the snapback phenomenon is eliminated in this novel PTR-LIGBT. Moreover, at the RC state, the barriers will decrease gradually with the increase of voltage, so that the RC capability is ensured. The simulation results show that, compared with SSA-LIGBT, the reverse recovery time (
${t}_{\text {rr}}$
) and reverse recovery charge (
${Q}_{\text {rr}}$
) of the monolithic diode of PTR-LIGBT are reduced by 65.34% and 18.59%, respectively.
${V}_{F}$
of PTR-LIGBT is reduced by 16.52% under the same
${E}_{\text {off}}$
, and
${V}_{F}$
of PTR-LIGBT is reduced by 20.63% under the same
${T}_{\text {off}}$
.