Patent ID: 8735999

Claim:
A semiconductor device comprising: a substrate; a gate electrode provided on the substrate via a gate insulator; a source region of a first conductivity type and a drain region of a second conductivity type provided in the substrate to sandwich the gate electrode, the second conductivity type being a reverse conductivity type of the first conductivity type; and a channel region provided between the source region and the drain region in the substrate, wherein the gate insulator comprises: a first insulator portion having a first edge which is positioned on the source region and is parallel to a channel-width direction, and a second edge which is positioned on the channel region or the source region and is parallel to the channel-width direction, and having a first thickness; and a second insulator portion positioned on a drain region side with respect to the first insulator portion, and having a second thickness greater than the first thickness; and the gate electrode comprises: a first electrode portion provided on the second insulator portion, and formed of a first gate electrode material; and a second electrode portion provided on the first insulator portion, formed of a second gate electrode material different from the first gate electrode material, and that is a sidewall film of the first electrode portion.