US Patent 9419089 Semiconductor structure and manufacturing method thereof

The present invention provides a semiconductor structure, which includes a substrate, at least two gate structures disposed on the substrate, a first recess, disposed in the substrate between two gate structures, the first recess having a U-shaped cross section profile, and a second recess, disposed on the first recess, the second recess having a polygonal shaped cross section profile, and has at least two tips on two sides of the second recess, the first recess and the second recess forming an epitaxial recess.