Comparative study of high voltage IGBTs with enhanced conductivity modulation

A new device structure for enhancing conductivity modulation in the Insulated Gate Bipolar Transistor (IGBT) is numerically studied. An N-type hole barrier layer and a deep P+ plug emitter tie are added to the conventional IGBT structure. It is observed that the addition of the P+ plug alone results in a reduction in switching power losses and no change in V_CE(sat), however the avalanche breakdown voltage (BV) and short circuit ruggedness of the device are improved. A further 0.4 V improvement in V_CE(sat) is observed when the P+ plug is implemented in conjunction with an N hole barrier. This is accomplished without the usual degradation of BV and ruggedness normally associated with other N hole barrier structures. The design space of the new IGBT structure is thoroughly characterized using 2-D TCAD simulation.