A method of forming a semiconductor device is disclosed wherein sigma-shaped cavities are formed in alignment with a gate structure such that a cavity tip of the sigma-shaped cavities has a small lateral distance to the channel region, while a lateral distance from the silicon-germanium material filled into the cavity and extending along the sidewall of the gate structure above the active region is at least maintained, if not increased. A semiconductor device is formed wherein the semiconductor device comprises a gate structure disposed over an active region of a semiconductor substrate. The gate structure has a gate electrode and a sidewall spacer structure with a first spacer of L-shape and a second spacer disposed on the first spacer. In alignment with the gate structure, sigma-shaped cavities are formed in the active region and embedded SiGe material is epitaxially grown in the sigma-shaped cavities.