Source/drain structure for semiconductor device
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsShahaji B. More, Cheng-Han Lee
Life of this patent
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Abstract
The present disclosure describes a semiconductor structure and a method for forming the same. The semiconductor structure can include a substrate, a gate structure over the substrate, and a source/drain (S/D) region adjacent to the gate structure. The S/D region can include first and second side surfaces separated from each other. The S/D region can further include top and bottom surfaces between the first and second side surfaces. A first separation between the top and bottom surfaces can be greater than a second separation between the first and second side surfaces.
Claims20
A semiconductor structure, comprising:
- a substrate;
- a gate structure over the substrate;
- and
- a source/drain (S/D) region, adjacent to the gate structure, that comprises:
- first and second side surfaces separated from each other;
- and
- top and bottom surfaces between the first and second side surfaces, wherein a first separation between the top and bottom surfaces is greater than a second separation between the first and second side surfaces.
A semiconductor structure, comprising:
- a substrate;
- a fin structure over the substrate;
- a gate structure over the fin structure;
- and
- a source/drain (S/D) region formed in the fin structure and adjacent to the gate structure, wherein the S/D region comprises:
- a first epitaxial layer extending from a first top surface of the fin structure towards the fin structure, wherein the first epitaxial layer is doped with a first doping concentration;
- and
- a second epitaxial layer over the first epitaxial layer, wherein the second epitaxial layer is doped with a second doping concentration greater than the first doping concentration, and wherein a first separation between a second top surface of the second epitaxial layer and a bottom surface of the first epitaxial layer is greater than a second separation between first and second side surfaces of the second epitaxial layer.
A method, comprising:
- forming a fin structure over a substrate;
- forming a gate structure over the fin structure;
- forming a recess structure in the fin structure and adjacent to the gate structure;
- forming a first epitaxial layer in the recess structure, wherein forming the first epitaxial layer comprises doping the first epitaxial layer with a first doping concentration;
- and
- forming a second epitaxial layer with a height and a width over the first epitaxial layer, wherein forming the second epitaxial layer comprises doping the second epitaxial layer with a second doping concentration greater than the first concentration, and wherein the height is greater than the width.
Dependencies are inferred from the claim text.