Patent ID: 6943400

Claim:
A semiconductor device, comprising: an insulated gate field effect transistor including a first source/drain area of a second conductivity type formed in a semiconductor area of a first conductivity type; a second source/drain area of the second conductivity type formed in the semiconductor area; and a gate electrode structure formed on a gate insulating film on a channel area disposed between the first source/drain area and the second source/drain area, the gate insulating film includes a first gate insulating film formed on a first channel area portion and a second gate insulating film formed on a second channel area portion, the gate electrode structure including a first gate electrode and a second gate electrode electrically connected through a third gate electrode; wherein a second type impurity concentration distribution in the first source/drain area is different from the second type impurity concentration distribution in the second source/drain area when viewed from the gate structure and a thickness of the first gate insulating film is different from a thickness of the second gate insulating film.