Patent ID: 7242058

Claim:
A semiconductor device, comprising: a first trench region having a plurality of trenches formed on a surface of a semiconductor substrate; a second trench region and a third trench region disposed on the same plane as a bottom surface of a concave portion of the first trench region so that the second trench region and the third trench region contact respective opposite ends of the first trench region in the lengthwise direction thereof; a well region formed in the first trench region, the second trench region, and the third trench region; a gate insulating film disposed in the first trench region; a gate electrode disposed on the gate insulating film, the gate electrode having a length extending in a direction generally parallel to lengthwise directions of the trenches; a source region having a conductivity type different from a conductivity type of the well region, the source region being disposed above the well region and in the second trench region and in a first portion of the first trench region; and a drain region having the same conductivity type as that of the source region, the drain region being disposed above the well region and in the third trench region and in a second portion of the first trench region.