Novel Snapback-Free SOI LIGBT With Shorted Anode and Trench Barriers

Abstract

A novel fast-switching silicon-on-insulator lateral insulated gate bipolar transistor (SOI LIGBT) is proposed and investigated in this article. The proposed device introduces trench barriers (TBs) at the collector end based on shorted anode (SA) structure to eliminate the snapback effect. The introduced TB structure can make the flow path of electron current be compressed and extended when the SA LIGBT is turned on so that the opening of collector p+/n-junction is prior to that of collector n+/n-junction. At the same time, it retains the ability to extract unbalanced electrons when the SA LIGBT is turned off. Through the TCAD simulation, the obtained results show that snapback-free can be realized by changing trench depth and pitch between TB structures. Compared with the separated SA (SSA) LIGBT, the forward voltage drop of the proposed LIGBT is reduced by 13.9% with snapback-free and much shorter collector region, which also retains the ability to extract unbalanced electrons. Thus, under the same forward voltage drop of 1.49 V, the turn-off time, and loss of the proposed LIGBT is 20.3% and 21.1% lower than those of the conventional (Conv.) LIGBT, respectively. In general, the tradeoff between turn-off time and forward voltage drop of the proposed LIGBT has much better performance.