Bi-Directional Operation and Active Err Reduction of 2nd Generation Back-Gate-Controlled IGBTs (BC-IGBTs)

We demonstrated bi-directional operation and active reduction of reverse recovery loss (Err) in reverse conduction mode to realize freewheel diode (FWD) less switching of Back-gate-Controlled IGBT (BC-IGBT). Compared to conventional RC-IGBT, bi-directional BC-IGBT has advantages in terms of active Eoff, Err reduction, snapback free, and area efficiency. 2nd generation BC-IGBT was designed with the additional Deep P-layer (DP), which is able to reduce parasitic bipolar gain above the n-source region. DP can improve the Eoff-Vcesat tradeoff in the forward mode and also prevent latch-up failure in the reverse mode. Reverse recovery current can be dynamically suppressed by applying a front-side gate pulse just before the end of reverse conducting period. These results demonstrate that the BC-IGBT can achieve a freewheel diode (FWD)-less inverter and realize truly ideal bi-directional IGBTs.