Snapback-free and low-loss SAG-LIGBT with self-driving auxiliary gate

A novel snapback-free and low-loss shorted-anode lateral insulated bipolar transistor (SA-LIGBT) based on silicon on insulator with self-driving auxiliary gate (SAG) in the anode is proposed, named as SAG-LIGBT. The SAG is characterised by metal oxide semiconductor (MOS) structure in the anode, and the gate of the MOS is shorted with the anode electrode, thus self-driving without extra gate signal is achieved. At anode voltage V-A = 0, the P-base serving as a barrier to hinder electrons flowing into the N + anode. At V-A = V-on of the forward conduction, the P-base is depleted to intrinsic, and the anode resistance R-SA is increased from RP-base to R-intrinsic. At V-A = V-bus of the turn-off state, the P-base is fully depleted and an electron accumulation layer is formed under the SiO2, thus the R-SA is decreased from R-intrinsic to Rn-channel to provide a low-resistance path for electron current. Consequently, the device not only eliminates the snapback effect but also reduces the turn-off energy loss E-off. Therefore, a better trade-off is obtained between V-on and E-off. At the same V-on, the E-off of SAG-LIGBT is decreased by 57 and 66% compared with separated shorted-anode LIGBT (SSA-LIGBT) and SA-LIGBT, respectively. Moreover, the SAG-LIGBT exhibits the shorter T-off of 80 ns than the SSA-LIGBT and vertical P-collector and N-buffer LIGBT at J(A) = 100 A/cm(2).