Patent ID: 7462908

Claim:
A semiconductor switching device comprising a semiconductor die of only one conductivity type formed over a substrate of said one conductivity type and having a plurality of equally spaced trenches, each pair of said trenches including a depletable region of only one conductivity type therebetween; a gate insulation lining at least a portion of the walls of said trenches; a conductive polysilicon mass disposed within each said trench for a height from the bottom of said trench; a source region of said one conductivity type but lower resistivity than said semiconductor die atop each depletable region; a source contact disposed in contact with said source regions and insulated from said conductive polysilicon masses; said polysilicon masses being connectable to a source of gate to source bias to receive pulse voltages; wherein said width and conductivity of said depletable regions are configured such that said depletion regions are generated around each trench and overlap one another inside each depletable region to deplete said depletable regions when said pulse voltages are applied to said polysilicon masses.