Low Loss Lateral Insulated Gate Bipolar Transistor with an Anode PNP Structure and Integrated Freewheeling Diode

A low loss lateral insulated gate bipolar transistor (LIGBT) features an anode PNP structure and an integrated freewheeling diode (iFWD), named as PD LIGBT, is proposed and investigated by simulation. For the anode PNP structure, its P+ Collector shorts to the potential extracting contact above the P-top layer of iFWD, and its emitter is the anode of the LIGBT. During turning off period with the increasing $V_{\text{AK}}$ , the PNP is activated and hole current is allowed to flow through the PNP to iFWD. It suppresses the hole injection of the anode into the N-drift region, and thus the current density decreases quickly. Therefore, the PD LIGBT achieves a fast turning-off speed and reduces the $E_{\text{off}}$ significantly. In the on-state with low anode voltage $V_{\text{AK}}$ , the PNP is not activated, hence the PD LIGBT gets into bipolar conduction without snapback effect. Moreover, the iFWD can realize reverse conduction and obtain a low reverse recovery charge ( $Q_{\text{rr}}$ ). Compared with the SSA and STA LIGBTs, the proposed LIGBT reduces the $E_{\text{off}}$ by 81% and 70% at the same on-state voltage drop ( $V_{\text{on}}$ ), respectively. The reverse recovery charge of the proposed device is reduced by 49.5% compared with that of SSA LIGBT.