Patent ID: 7361558

Claim:
A method of fabricating a closed cell trench metal-oxide-semiconductor field effect transistor (TMOSFET) comprising: epitaxial depositing a first semiconductor layer upon a substrate, wherein said first semiconductor layer is doped with a first type of impurity; etching a plurality of trenches in said first semiconductor layer, wherein a first set of said plurality of trenches are substantially parallel with respect to each other and a second set of said plurality of trenches are substantially normal-to-parallel with respect to said first set of said plurality of trenches; forming a dielectric proximate said plurality of trenches; implanting said first semiconductor layer proximate the bottoms of said first set of said plurality of trenches and not proximate the bottoms of said second set of said plurality of trenches; depositing a second semiconductor layer in said plurality of trenches; implanting a first portion of said first semiconductor layer with a second type of impurity; and implanting a second portion of said first semiconductor layer proximate said dielectric with said first type of impurity.