Patent ID: 7589384

Claim:
A semiconductor device comprising: a semiconductor substrate including first and second element regions of first conductivity-type isolated from each other; a MOS transistor including a first gate insulating film provided on the first element region, a first gate electrode provided on the first gate insulating film, and first impurity regions of second conductivity-type different from the first conductivity-type provided in the first element region on both sides of the first gate electrode; and an ESD protection element including a second gate insulating film provided on the second element region and having substantially the same thickness as the first gate insulating film, a second gate electrode provided on the second gate insulating film and connected to the first gate electrode, and second impurity regions of second conductivity-type provided in the second element region on both sides of the second gate electrode, wherein a position of a junction interface between the second impurity region of the second conductivity-type of the ESD protection element and the second element region of the first conductivity-type in the surface of the semiconductor substrate is away from the side face of the second gate electrode on the outer side of the second gate electrode.