Patent ID: 7479684

Claim:
A MOSFET comprising: a source extension; a drain extension; a channel between said source extension and said drain extension; a dielectric layer located above said channel and having rounded edges on a peripheral portion, wherein said dielectric layer is thinner at said rounded edges than at a non-peripheral portion; a gate spacer structure disposed on said peripheral portion of a top surface of said dielectric layer and having an internal surface that meets said top surface at about a right angle, wherein said gate spacer structure is adjacent to said source and drain contacts; and a gate disposed on said non-peripheral portion of said top surface of said dielectric layer and having at least a lower portion surrounded by and in contact with said internal surface of said gate spacer structure; and said gate is substantially aligned at its bottom with said channel and said gate spacer structure has an internal surface abutting the gate that has a curved upper portion that extends to an upper portion of an external vertical surface, and said gate spacer structure does not extend to an upper surface of the gate.