Area-Efficient and Snapback-Free SOI LIGBT With L-Shaped Extraction Path

A novel area-efficient snapback-free silicon-on-insulator lateral insulated gate bipolar transistor (SOI-LIGBT) is proposed and investigated for the first time in this paper. The device features an N+ anode, three separated P+ anodes, and a P-buried layer (PBL) in the N-buffer of the anode region. The N-buffer between all these components above forms a 3-D L-shaped extraction path. The L-shaped extraction path not only makes the device area-efficient but also increases the anode distributed resistance (RSA). Therefore, the snapback effect could be suppressed, and the tradeoff between the on-state voltage (Von) and turn-off energy (Eoff) is improved effectively. Simulation results show that the proposed device eliminates the snapback effect with 63% and 77% reduction of the anode region area compared with the segmented trenches in the anode region (STA) LIGBT and the separated shorted anode (SSA) LIGBT, respectively. At the same Von, the LEP LIGBT reduces the turn-off time (toff) and Eoff by 40% and 28%, respectively, compared with the STA LIGBT. Moreover, at the same Eoff, the LEP LIGBT reduces Vonby 17%, compared with the SSA LIGBT.