Power transistor device having ultra deep increased concentration region

摘要

A cellular insulated gate bipolar transistor ("IGBT") device employs increased concentration in the active region between spaced bases to a depth greater than the depth of the base regions. The implant dose which is the source of the increased concentration is about 3.5x1012 atoms per centimeter squared and is driven for about 10 hours at 1175 DEG C. Lifetime is reduced by an increased radiation dose to reduce switching loss without reducing breakdown voltage or increasing forward voltage, drop above previous levels. The increased concentration region permits a reduction in the spacing between bases and provides a region of low localized bipolar gain, increasing the device latch current. The avalanche energy which the device can successfully absorb while turning off an inductive load is significantly increased. The very deep increased conduction region is formed before the body and source regions in a novel process for making the new junction pattern.