Low On-state Voltage and Latch-up Immunity Thin SOI LIGBT with Multi-Segmented Trench Gates

Abstract

A novel thin SOI lateral insulated gate bipolar transistor (LIGBT) with low on-state voltage drop ( $\boldsymbol{V}_{\mathbf{on}}$ ) and latch-up immunity is proposed. The device features the multi-segmented trench gates in the z-direction, named MST LIGBT. The multi-segmented gates form multi conduction channels along the sidewalls, which increases the channel density so as to reduce $\boldsymbol{V}_{\mathbf{on}}$ and increase saturation current. Furthermore, the multi-segmented gates hinder the holes from being extracted by the cathode in the x- and z- direction, which attracts a large number of electrons injected from the cathode, and therefore the conduction modulation effect is enhanced. The $\boldsymbol{V}_{\mathbf{on}}$ of MST LIGBT reduces by 34.8% and 27.6% in comparison with those of the conventional (Con). LIGBT and the tridimensional channel (TC) LIGBT. In addition, the short circuit time of MST LIGBT increases to $1.92 \mu\mathbf{s}$ in comparison with $1.73 \mu\mathbf{s}$ of the Con. LIGBT and $1.81 \mu\mathbf{s}$ of the TC LIGBT, owing to the smallest shorted cathode resistance ( $\boldsymbol{R}_{\mathbf{SC}}$ ).