Patent ID: 8164162

Claim:
A vertical semiconductor power IGBT device comprising a plurality of trenched gates in a silicon layer surrounded by emitter regions with a first type conductivity in active area encompassed in base regions with a second type conductivity, further comprising: a first insulating layer serving as a gate oxide lining an inner surface of openings for said trenched gates; a second insulating layer functioning as a thick oxide interlayer; a plurality of trench emitter-base contacts filled with a barrier layer and tungsten plugs; an emitter metal layer connected to the emitter regions and the base regions via said trench emitter-base contacts; a gate-emitter clamp diode connected between a first gate metal and said emitter metal layer, composed of multiple back-to-back Zener diodes disposed inside of an edge termination area; a gate-collector clamp diode connected between a second gate metal and a first collector metal, composed of multiple back-to-back polysilicon Zener diodes disposed outside of said edge termination area without having said polysilicon zener diodes or said second gate metal cross over said edge termination area; said first collector metal connected to a front side of said silicon layer via a trench collector contact filled with said barrier layer and another tungsten plug; a second collector metal layer formed on a back side of said silicon layer, and said first and second gate metals connected together through multiple metal stripes with metal gap between two adjacent metal stripes.