Patent ID: 8866230

Claim:
Semiconductor devices comprising: a substrate; a first gate structure and a second gate structure positioned on the substrate, the first gate structure and the second gate structure comprising a same conductivity type; and a first source/drain formed in the substrate respectively at two sides of the first gate structure and a second source/drain formed in the substrate respectively at two sides of the second gate structure, the first source/drain and the second source/drain comprises a first epitaxial structure and the second source/drain comprises a second epitaxial structure, the first epitaxial structure comprises a diamond shape and the second epitaxial structure comprise a shape different from the diamond shape, wherein the first epitaxial structure comprises a first epitaxy concentration, the second epitaxial structure comprises a second epitaxy concentration, and the first epitaxy concentration is higher than the second epitaxy concentration; and an updoped epitaxial layer respectively formed on a top of the first epitaxial Structure and on a top of the second epitaxial structure.