Patent ID: 9087901
Filing Date: 2015-07-21
Classification: H01L

Abstract:
1. A semiconductor device, comprising: a plurality of gates formed on a surface of a substrate; a plurality of sidewalls formed on side surfaces of the gates; a Sigma-shaped recess formed in the substrate between adjacent gates; a SiGe seed layer formed on an inner surface of the Sigma-shaped recess; boron-doped bulk SiGe formed on a surface of the SiGe seed layer, with the boron-doped bulk SiGe filling the Sigma-shaped recess; and a boron-doped SiGe regeneration layer formed in a first recess beneath the surface of the substrate, wherein the first recess is formed by etching a portion of the SiGe seed layer and the boron-doped bulk SiGe in the Sigma-shaped recess, and the boron-doped SiGe regeneration layer has a higher concentration of boron than the SiGe seed layer or the boron-doped bulk SiGe.