Patent ID: 8814298

Claim:
A semiconductor device comprising: a first conductivity type well region formed by counter doping; a transistor having a source region and a drain region having a second conductivity type which is different from the first conductivity type, at least one of the source region and the drain region being arranged in the well region; a LOCOS region arranged around the at least one of the source region and the drain region in the well region; and a channel stop region having the first conductivity type arranged under the LOCOS region, wherein the at least one of the source region and the drain region is arranged at a distance from a tip of a bird's beak of the LOCOS in a direction parallel to a channel width of the transistor, and the channel stop region is arranged at a distance from the tip of the bird's beak at an opposite side to the at least one of the source region and the drain region.