Patent ID: 7436021

Claim:
A power semiconductor device with trench gates comprising: a) a semiconductor substrate; b) a source layer on one surface of said substrate and comprising a high concentration of a dopant of a first polarity; c) a single drain region on the other surface of said substrate; d) a well layer beneath said source layer doped with a dopant of a second polarity opposite to said first polarity; e) a region lightly doped with said one polarity positioned above said drain region and below said well layer; f) plurality of trenches penetrating said source layer and terminating in said region lightly doped with said one polarity, said trenches substantially filled with conductive material; g) a highly conductive layer on the surface of said source layer comprising a material reacted from a metal and said substrate which forms a highly conductive path extending from a first of said plurality of trenches to a of said plurality of trenches; h) an insulating layer on said highly conductive layer and on said conductive material in said trenches; i) vias formed in said insulating layer and extending to said highly conductive layer; and j) conductive material filling said vias for contacting said highly conductive layer.