Patent ID: 7554153

Claim:
A power semiconductor device comprising: a semiconductor body having a conduction region of one conductivity, and a base region of another conductivity, said semiconductor body including a first surface; a trench extending from said first surface through said base region and into said conduction region, said trench including at least two opposing sidewalls and a bottom; a first gate insulation adjacent one of said sidewalls; a first gate electrode adjacent said first gate insulation and spanning said base region; a source region adjacent at least one sidewall of said trench; a contact region of said another conductivity adjacent said source region; a source contact electrically connected to said source region and said contact region; and a Qgd implant region of said another conductivity inside and contained within said base region and disposed directly below and aligned with said contact region, wherein said Qgd implant varies the resistivity of said base region, whereby the resistivity of said base region adjacent said first gate insulation is higher than the resistivity of said Qgd implant region and said Qgd implant is positioned to retard the encroachment of a depletion region into said base region without varying the threshold voltage of the device.