Patent ID: 7847346

Claim:
A trench MOSFET comprising a plurality of semiconductor power cells with each cell comprising a plurality of trench gates surrounded by a plurality of source regions of a first type conductivity above a plurality of body regions of second type conductivity above a drain region disposed on a bottom surface of a substrate, said trench MOSFET further comprising: a substrate of said first type conductivity; an epitaxial layer of said first type conductivity over said substrate, having a lower doping concentration than said substrate; a plurality of trenches extending into said epitaxial layer, surrounded by a plurality of said source regions of said first type conductivity above said body regions of said second type conductivity; a first insulating layer lining said trenches as gate oxide; a doped polysilicon of said first type conductivity as said trench gates overlying said first insulating layer; a second insulating layer disposed over said epitaxial layer to isolate a source metal which contacts said both source and body regions, from said doped polysilicon as said trench gates; a plurality of source contact trenches penetrating through said second insulating layer and said source regions with vertical sidewalls substantially perpendicular to a top epitaxial surface within said source regions, and further extending into said body regions with tapered sidewalls with respect to said top surface of said epitaxial layer; a front metal disposed on the front surface of said trench MOSFET as said source metal; a backside metal disposed on the backside of said substrate as a drain metal; at least one copper wire electrically bonded to said source metal.