Patent ID: 9559165
Date: 2017-01-31
CPC Classifications: H01L

Claim:
1. A semiconductor structure, comprising: a substrate; a first gate structure and a second gate structure formed over the substrate; first recesses formed in the substrate adjacent to the first gate structure; first strained source and drain structures formed in the first recesses; second recesses formed in the substrate adjacent to the second gate structure; and second strained source and drain structures formed in the second recesses, wherein each of the first strained source and drain structures within the first recesses has a shape of a trapezoid, and each of the second strained source and drain structures within the second recesses has a shape of an inverted trapezoid, two angles between two sidewalls and a bottom surface of the trapezoid of the first strained source and drain structures within the first recesses are smaller than 90°, and a top surface of the first strained source and drain structures is raised above a top surface of the substrate.