Novel Snapback-Free Reverse-Conducting SOI-LIGBT With Dual Embedded Diodes

Abstract

A novel 500 V reverse-conducting (RC) silicon-on-insulator lateral insulated gate bipolar transistor (SOI-LIGBT) with dual embedded diodes (DEDs) is proposed to eliminate the snapback, and its mechanism is investigated by simulation. The RC is realized by the internal diode, which consists of two p-i-n diodes (D1 and D2). The two diodes are connected in series. In the RC-state, the current flows through D1 first and then through D2. D2 is embedded in the anode region of the proposed DED-LIGBT and is fully isolated by the deep-oxide trench. In the forward conducting state, D2 is reverse biased and the electrons from the N ⁺ cathode can only flow into the P ⁺ anode. The DEDs reroute the electron current path, and thus, the snapback is avoided. Moreover, by adjusting the width of D2 (W _b ), the internal diode of the DED structure achieves superior reverse recovery time (t _rr ) and reverse recovery peak current (I _rrm ) to the conventional SOI p-i-n diode.