Patent ID: 7928530

Claim:
A semiconductor device comprising: a semiconductor substrate; a first isolation region formed on the semiconductor substrate; a first element region isolated via the first isolation region; a first gate insulating film formed on the first element region; a first gate electrode formed on the first gate insulating film; a second isolation region formed on the semiconductor substrate; a second element region isolated via the second isolation region; a second gate insulating film formed on the second element region; and a second gate electrode formed on the second gate insulating film, wherein the first isolation region has a width smaller than a width of the second isolation region, in a direction perpendicular to a main surface of the semiconductor substrate, a portion of the first gate insulating film that contacts a center of the first gate electrode is thinner than a portion of the first gate insulating film that contacts an end of the first gate electrode, and in the direction perpendicular to the main surface of the semiconductor substrate, the portion of the first gate insulating film that contacts the end of the first gate electrode is thinner than a portion of the second gate insulating film that contacts an end of the second gate electrode.