Patent ID: 7629634

Claim:
A trenched MOSFET with trenched source contact, comprising: a semiconductor region having a drain region, a body region and a source region, comprising, a silicon substrate, an epitaxial layer corresponding to said drain region disposed on the top of said silicon substrate, a base layer corresponding to said body region disposed on the top of said epitaxial layer, and a source layer corresponding to said source region disposed on the top of said base layer; a front metal layer formed on the upper surface of said semiconductor region; an interlayer oxide film formed between said source layer and said front metal layer, a bottom metal layer formed on the lower surface of said semiconductor region; a plurality of trenched gates covered by said interlayer oxide film are formed on top of said source layer extending downwardly through said base layer to a portion of said epitaxial layer; and a plurality of source contact trenches formed on the top of said interlayer oxide film extending downwardly through said source layer to a portion of said base layer; wherein the sidewalls of said trenches in said base layer are covered by the lateral contact layer; wherein the bottom base of said trenches in said base layer are covered by the base contact layer.