Patent ID: 8106446

Claim:
A power semiconductor device comprising: a semiconductor body having a drift region of one conductivity, and a channel region of another conductivity over said drift region; a gate trench formed in said semiconductor body through at least said channel region, said gate trench including sidewalk and a bottom wall; an oxide body disposed at the bottom of said trench; a gate electrode formed over said oxide body; gate oxide interposed between said sidewalls of said trench and said gate electrode, wherein said oxide body is less dense than said gate oxide; a field relief trench, said field relief trench including a field oxide body having a recess, and a T-shaped electrode received at least partially in said recess; at least one highly conductive region of said another conductivity formed directly on at least a sidewall of said field relief trench; a source region adjacent said gate trench and said field relief trench, said source region situated between said gate trench and said field relief trench; and a source electrode electrically connected to said T-shaped electrode and said source region.