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US 8,912,568 B2Granted
Semiconductor device and manufacturing method thereof
AssigneeSemiconductor Manufacturing International (Beijing) Corporation
InventorsHuanxin Liu, Huojin Tu
Life of this patent
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Abstract
A semiconductor device and manufacturing method therefor includes a Σ-shaped embedded source or drain regions. A U-shaped recess is formed in a Si substrate using dry etching and a SiGe layer is grown epitaxially on the bottom of the U-shaped recess. Using an orientation selective etchant having a higher etching rate with respect to Si than SiGe, wet etching is performed on the Si substrate sidewalls of the U-shaped recess, to form a Σ-shaped recess.
Claims13
A method of manufacturing semiconductor device, comprising:
- forming a U-shaped recess in a Si substrate;
- forming a SiGe layer on the bottom of the U-shaped recess through epitaxial growth;
- performing wet etching having orientation selectivity on said Si substrate from the sidewall of said U-shaped recess by using an etchant having a higher etching rate with respect to Si as compared to SiGe, so as to form a Σ-shaped recess;
- wherein in the step of forming a SiGe layer on the bottom of said U-shaped recess through epitaxial growth, a SiGe thin film is also formed on the sidewall of said U-shaped recess, the thickness of which is less than the thickness of said SiGe layer on the bottom of said U-shaped recess, the method further comprising:
- etching to remove said SiGe thin film before the wet etching of the Si substrate, while retaining at least a portion of said SiGe layer on the bottom of said U-shaped recess to cover the Si substrate at the bottom of said U-shaped recess;
- wherein in said step of forming the SiGe layer on the bottom of said U-shaped recess through epitaxial growth comprise using one or more process gases chosen from the group consisting of:
- SiH4 or SiH2Cl2;
- GeH4;
- HCl;
- B2H6 or BH3;
- and
- H2;
- wherein the flow rate of H2 is 0.1 slm to 50 slm, and the flow rates of the other process gases are 1 sccm to 1000 sccm.
10 more elements
A semiconductor device, comprising:
- a Si substrate with a recess formed therein;
- and
- SiGe material used to fill said recess to form source or drain regions of a PMOS device, wherein
- said recess has a first portion and a second portion,
- the surface of the substrate and the sidewall of said first portion are substantially ones selected among {100} and {110} crystal plane families and are substantially orthogonal to each other,
- said second portion is located above said first portion, and
- the sidewall of said second portion is divided into an upper part and a lower part, which are (111) and (11 1) crystal planes respectively.
4 more elements
Dependencies are inferred from the claim text.