Patent ID: 7700452

Claim:
A method of forming a semiconductor device, the method comprising: providing a substrate; forming a gate dielectric on the substrate; forming a gate electrode on the gate dielectric; forming a first set of spacers alongside the gate electrode; recessing the substrate on opposing sides of the gate electrode and under the gate electrode, thereby forming a recess that extends completely under the gate electrode from a first side of the gate electrode to a second side of the gate electrode, the recessing being performed after the forming the first set of spacers; epitaxially growing an epitaxial layer in the recess, the epitaxial layer being a single type of epitaxial material extending completely under the gate electrode and filling the recess on opposing sides of the gate electrode, a bottom surface of the recess being completely covered with the epitaxial layer; and removing the first set of spacers; forming lightly-doped drain regions; forming a second set of spacers alongside the gate electrode; and forming heavily-doped drain regions.