U-shaped channel SOI-LIGBT with dual trenches to improve the trade-off between saturation voltage and turn-off loss

Abstract

This paper proposes a 500V U-shaped channel silicon-on-insulator lateral insulated gate bipolar transistor (SOI-LIGBT) with dual trenches to improve the trade-off between the saturation voltage (VCEsat) and the turn-off loss (Eoff). The proposed dual trenches U-shaped channel (DTU) SOI-LIGBT features a U-shaped gate trench (Gl) and a U-shaped hole barrier trench (G2). By employing the dual trenches, enhanced carrier stored effect at the emitter side and more uniform carriers distribution in the drift region can be obtained, resulting in decreases of VCEsat and Eoff. By optimizing the dimensions of the U-shaped channel, it is found that the proposed DTU SOI-LIGBT can achieve a 52.3% lower Eoff compared with the planar gate U-shaped channel (PGU) SOI-LIGBT at the same VCEsat of 1.22 V.