Patent ID: 8154136

Claim:
A semiconductor device comprising: a semiconductor substrate including at least a source region and a drain region; a gate electrode over the semiconductor substrate with a gate insulating film interposed therebetween; a first insulating film formed over the semiconductor substrate and the gate electrode; a second insulating film formed on the first insulating film; a contact hole formed in the first and second insulating films to reach at least one of the source region and the drain region; and an electrode electrically connected to at least one of the source region and the drain region through said contact hole, wherein an edge of said contact hole is rounded off at a top of said contact hole, wherein an inner side surface of the first insulating film in the contact hole at a bottom of the first insulating film has a first taper angle and an inner side surface of the second insulating film in the contact hole has a second taper angle, and the first taper angle is smaller than the second taper angle, wherein the electrode is in contact with the first insulating film and the second insulating film in the contact hole, and wherein the electrode fills the contact hole, and wherein the electrode does not cover the top of the contact hole, which is rounded off.