Patent ID: 7368777

Claim:
An accumulation-mode field effect transistor comprising: a drain terminal and a source terminal; a semiconductor region comprising: a plurality of gate trenches extending into the semiconductor region from a top surface of the semiconductor region; a channel region of a first conductivity type between each adjacent pair of the plurality of gate trenches; a plurality of columns of conduction region of the first conductivity type extending directly below the plurality of gate trenches; and a plurality of columns of silicon material of a second conductivity type opposite the first conductivity type extending directly below the channel regions, wherein the plurality of columns of conduction region and the plurality of columns of silicon material abut each other to form alternating columns of opposite conductivity type regions extending between the source and drain terminals such that when the accumulation-mode field effect transistor is in the on state a current flows from the drain terminal to the source terminal through the plurality of columns of conduction region and the channel regions.