Wrap around contact using sacrificial mandrel
A semiconductor structure and a method for fabricating the same. The semiconductor structure includes a plurality of unmerged fin structures each in contact with their own source/drain. The semiconductor structure further includes a contact layer formed on sidewalls and a top surface of each source/drain. The method includes at least the following operations. At least one mandrel layer is formed adjacent to at least one fin structure. The at least one fin structure and at least one source/drain is epitaxially grown in contact with the at least one fin structure and the at least one mandrel layer. The at least one mandrel layer is removed after the at least one source/drain has been epitaxially grown. At least one contact layer is formed in contact with sidewalls and a top surface of the at least one source/drain.
1. A method for forming a semiconductor structure, the method comprising at least:
forming at least one mandrel layer adjacent to at least one fin structure;
recessing the at least one fin structure;
epitaxially growing at least one source/drain in contact with the at least one fin structure and the at least one mandrel layer;
removing the at least one mandrel layer after the at least one source/drain has been epitaxially grown; and
forming at least one contact layer in contact with sidewalls and a top surface of the at least one source/drain.
2. The method of claim 1 , further comprising:
forming at least one spacer in contact with sidewalls of the at least one fin structure prior to forming the at least one mandrel layer.
3. The method of claim 2 , wherein forming the at least one spacer comprises:
forming a first spacer layer in contact with sidewalls of the at least one fin structure; and
forming a second spacer layer in contact with the first spacer layer.
4. The method of claim 2 , wherein forming the at least one mandrel layer comprises:
forming the at least one mandrel layer in contact with the at least one spacer.
5. The method of claim 2 , further comprising:
removing the at least one spacer after the at least one fin structure has been recessed and prior to epitaxially growing the at least one source/drain.
6. The method of claim 1 , further comprising:
recessing the at least one mandrel layer below a top surface of the at least one fin structure prior to recessing the at least one fin structure.
7. The method of claim 5 , further comprising:
forming at least one protective layer at least in contact with a top surface of the at least one mandrel layer.
8. The method of claim 1 , further comprising:
forming at least one dummy gate on a portion of the at least one fin structure.
9. The method of claim 8 , further comprising:
forming at least one protective layer at least in contact with a top surface of the at least one mandrel layer, and in contact with sidewalls of the at least one dummy gate.
10. The method of claim 9 , further comprising:
forming a contact etch stop layer in contact with a top surface of the at least one source/drain, sidewalls of a portion of the protective layer formed in contact with sidewalls of the at least one dummy gate, and a top surface of a portion of the protective layer formed at least in contact with the top surface of the at least one mandrel layer; and
forming an inter-layer dielectric layer in contact with a top surface and sidewalls of the protective layer.
11. The method of claim 10 , wherein after the inter-layer dielectric layer is formed:
removing the at least one dummy gate, wherein the removing exposes inner sidewalls of the protective layer; and
forming a replacement gate at least in contact with the inner sidewalls of the protective layer.
12. The method of claim 11 , further comprising:
removing the inter-layer dielectric layer; and
removing horizontal portions of the contact etch stop layer.
13. The method of claim 1 , further comprising:
forming the at least one fin structure from a single semiconductor layer material.
14. The method of claim 1 , further comprising:
forming the at least one fin structure from an alternating stack of semiconductor material layers.
15. A semiconductor structure comprising at least:
a plurality of unmerged fin structures;
a separate source/drain in contact with each unmerged fin structure of the plurality of unmerged fin structures, wherein the source/drain comprises a rectangular shape; and
a contact layer formed on sidewalls and a top surface of each source/drain.
16. The semiconductor structure of claim 15 , further comprising:
a plurality of gate structures, wherein each gate structure is formed on a portion of an unmerged fin structure of the plurality of unmerged fin structures.
17. The semiconductor structure of claim 15 , wherein each unmerged fin structure of the plurality of unmerged fin structures is formed from a single semiconductor material layer.
18. The semiconductor structure of claim 15 , wherein each unmerged fin structure of the plurality of unmerged fin structures is formed from an alternating stack of semiconductor material layers.
19. An integrated circuit comprising:
one or more semiconductor devices, wherein at least one of the one or more semiconductor devices comprises at least:
a plurality of unmerged fin structures;
a separate source/drain in contact with each unmerged fin structure of the plurality of unmerged fin structures, wherein the source/drain comprises a rectangular shape; and
a contact layer formed on sidewalls and a top surface of each source/drain.