Novel Ultrafast Low-Loss LIGBT With Reverse-Conduction Capability

An ultrafast switching lateral insulated gate bipolar transistor (LIGBT) with reverse-conduction (RC) capability is proposed and investigated by simulations. The LIGBT features a self-adaptive pMOS with a floating ohmic contact (FOC) as drain electrode and an integrated freewheeling diode (iFWD) (named self-adaptive pMOS and diode (SPD) LIGBT). The gate of pMOS is self-adaptively controlled by the potential extracting contact above the n-drift region of the iFWD. In the turning-off period and blocking state with increasing${V}_{\text {AK}}$, the pMOS is self-adaptively turned on. Then, it not only provides a low-resistance hole current path to accelerate recombining with electrons from the drift region within the FOC but also clamps the voltage drop of$\text{p}^{+}$anode/n-buffer junction to suppress the anode hole injection. Therefore, the SPD LIGBT achieves an ultrafast switching speed to decrease the turnoff loss (${E}_{\text {off}}{)}$and obtains an MOS-like breakdown mode. In the ON-state with a low anode voltage${V}_{\text {AK}}$, the pMOS is turned off and the SPD LIGBT gets into bipolar conduction without snapback effect. The iFWD can realize RC and lower reverse recovery charge (${Q}_{\text {rr}}{)}$. Compared with the separated shorted-anode (SSA) and separated trench anode (STA) LIGBT, the proposed LIGBT decreases${E}_{\text {off}}$by 79% and 68% at the same ON-state voltage drop (${V}_{\text {on}}{)}$. The proposed device achieves 48.1% lower${Q}_{\text {rr}}$than SSA LIGBT.