An improvement of the breakdown voltage characteristic of trench gate IGBTs by using a shielding layer

A trench gate insulated gate bipolar transistor(IGBT) employing a shielding layer, which improves the breakdown voltage characteristic is proposed and verified by 2D numerical simulation. The shielding layer concept is proposed to alleviate the electric field of concentrated on the trench bottom corner. By simulation results, we verified that a shielding layer reduced the electric fields not only in the gate oxide but in the p-base region. Compared with conventional trench gate IGBT, about 33% increment of forward breakdown voltages are achieved.