Improvement of the Short Circuit Immunity for the Trench IGBT Employing the Curved P-body Junction and the Wide Cell Pitch

A trench punch-through (PT) insulated gate bipolar transistor (IGBT) employing a curved p-body junction and a wide cell pitch, which improves the short circuit immunity without an increase of the saturation voltage, is proposed and verified by 2D numerical simulation. The curved p-body junction and the carrier stored layer (CSL) increase the spreading angle of the electron current injected from the channel and also enable the highly resistive area under the p-body junction to shift toward the surface below the shallow p(++) well so that the saturation voltage of the proposed IGBT does not increase while the channel density is reduced by using the wide cell pitch. The proposed IGBT exhibits 1.6 times higher short circuit withstanding time than the conventional one.