Novel SOI LIGBT with fast‐switching by the electric field modulation

Abstract

A novel silicon-on-insulator lateral insulated gate bipolar transistor (SOI LIGBT) is proposed and investigated in this work. The device features a single-step buried oxide (SSBO) structure formed on the silicon-on-insulator (SOI) layer. The SSBO structure introduces a high electric field peak by the electric field modulation to modulate electric field distributions. Therefore, the proposed SOI LIGBT can maintain the high breakdown voltage (BV) while shortening the length of drift region, which achieves the decreased total number of stored carriers during the turn-on and fast depletion of drift region during the turn-off. As the simulation results show, under the same BV of 98 V, the drift region length of the proposed SOI LIGBT is 4.4 μm, which is much shorter than that of the conventional SOI LIGBT of 12.0 μm. So the turn-off time of SSBO SOI LIGBT is 76.6% lower than that of the conventional SOI LIGBT at the same forward voltage drop of 1.72 V. It shows that the tradeoff between forward voltage drop and turn-off time can be significantly improved.