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US 11,600,728 B2Granted
Method of manufacturing a facet-free source/drain epitaxial structure having an amorphous or polycrystalline layer
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsWen-Hsien Tu, Wei-Fan Lee
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Abstract
The present disclosure is directed to source/drain (S/D) epitaxial structures with enlarged top surfaces. In some embodiments, the S/D epitaxial structures include a first crystalline epitaxial layer comprising facets; a non-crystalline epitaxial layer on the first crystalline layer; and a second crystalline epitaxial layer on the non-crystalline epitaxial layer, where the second crystalline epitaxial layer is substantially facet-free.
Claims20
A method, comprising:
- forming spaced apart fins on a substrate;
- forming a dielectric layer on the substrate to surround a bottom portion of the fins;
- forming a gate stack over the fins;
- forming spacers on sidewall surfaces of the fins not covered by the gate stack;
- etching portions of the fins not covered by the gate stack to recess the fins with respect to the spacers and the dielectric layer;
- growing a first epitaxial layer on top surfaces of the etched fins between the spacers;
- forming an amorphous or polycrystalline layer on the first epitaxial layer;
- growing a second epitaxial layer on the amorphous or polycrystalline layer, wherein the second epitaxial layer is substantially facet-free.
5 more elements
A method, comprising:
- forming spaced apart fins on a substrate;
- forming a dielectric layer on the substrate to surround a bottom portion of the fins;
- forming a gate stack over the fins;
- forming spacers on sidewall surfaces of the fins not covered by the gate stack;
- etching portions of the fins not covered by the gate stack to recess the fins with respect to the spacers and the dielectric layer;
- and
- forming a source/drain epitaxial stack on etched portions of the fins, wherein forming the source/drain epitaxial stack comprises:
- growing a first epitaxial layer on the etched fins;
- forming an amorphous or polycrystalline layer on the first epitaxial layer;
- and
- growing a second epitaxial layer on the amorphous or polycrystalline layer.
8 more elements
A method, comprising:
- forming a fin on a substrate;
- forming a source/drain (S/D) structure on the fin, wherein forming the S/D structure comprises:
- forming a first epitaxial layer with facets and a diamond shape profile on the fin;
- forming an amorphous or polycrystalline layer over the first epitaxial layer;
- forming a second epitaxial layer with a substantially facet-free rounded profile on the amorphous or polycrystalline layer;
- and
- forming a gate stack on the fin and adjacent to the S/D structure.
4 more elements
Dependencies are inferred from the claim text.