Patent ID: 8455859

Claim:
A semiconductor device, comprising: a semiconductor substrate; a gate structure disposed on a surface of the semiconductor substrate; spacers disposed on sidewalls of the gate structure, each spacer having an inner edge and an opposing an outer edge, the inner edge being closer to the gate structure than the outer edge; and strained structures disposed in the semiconductor substrate at either side of the gate structure and formed of a semiconductor material different from the semiconductor substrate, each strained structure having a cross-sectional profile that includes a first portion that extends from the surface of the semiconductor substrate and a second portion that extends from the first portion at a first angle ranging from about 50° to about 70° and a third portion that extends from the surface of the semiconductor substrate and a fourth portion that extends from the third portion at a second angle ranging from about 50° to about 70°, the second portion directly opposing the fourth portion, wherein the first and second angles are measured with respect to an axis that is parallel to the surface of the substrate, wherein the first portion is aligned with the outer edge of one of the spacers.