Forming thermally stable salicide for salicide first contacts
A method for forming a salicide includes epitaxially growing source/drain (S/D) regions on a semiconductor fin wherein the S/D regions include (111) facets in a diamond shape and the S/D regions on adjacent fins have separated diamond shapes. A metal is deposited on the (111) facets. A thermally stabilizing anneal process is performed to anneal the metal on the S/D regions to form a silicide on the (111) facets. A dielectric layer is formed over the S/D regions. The dielectric layer is opened up to expose the silicide and to form contact holes. Contacts to the silicide are formed in the contact holes.
1. A method for forming a salicide, comprising:
epitaxially growing source/drain (S/D) regions having a cross-sectional quadrilateral diamond shape on semiconductor fins, wherein the S/D regions include (111) facets, and the S/D regions on adjacent semiconductor fins have separated cross-sectional quadrilateral diamond shapes;
depositing a metal on the (111) facets;
performing a thermally stabilizing anneal process to anneal the metal on the (111) facets of the S/D regions to form a silicide on the (111) facets;
forming a dielectric layer over the S/D regions;
opening up the dielectric layer to expose the silicide and to form contact holes; and
forming contacts to the silicide in the contact holes.
2. The method as recited in claim 1 , wherein the cross-sectional quadrilateral diamond shapes of the S/D regions are separated in a non-merged configuration.
3. The method as recited in claim 1 , wherein depositing the metal on the (111) facets includes depositing the metal on top side facets of the (111) facets of the S/D regions.
4. The method as recited in claim 1 , wherein depositing the metal on the (111) facets includes depositing the metal on all facets of the S/D regions in a wrapped around configuration.
5. The method as recited in claim 1 , wherein performing the thermally stabilizing anneal process includes forming merged silicides between the S/D regions.
6. The method as recited in claim 1 , wherein opening up the dielectric layer to expose the silicide and to form contact holes includes opening up the dielectric layer to expose the silicide over a portion of the S/D regions.
7. The method as recited in claim 6 , wherein forming contacts to the silicide in the contact holes includes forming the contacts to the silicide in the contact holes for the portion of the S/D regions to reduce capacitance so that the contacts are a partially strapped configuration.
8. The method as recited claim 1 , wherein performing the thermally stabilizing anneal process includes annealing with a laser anneal at a temperature of between about 900 to 1100 degrees C. for less than or equal to 1 millisecond.
9. The method as recited in claim 8 , further comprising performing an additional anneal process to continue to form the silicide.
10. A method for forming a salicide, comprising:
forming gate structures with a dummy gate material;
epitaxially growing source/drain (S/D) regions having a cross-sectional quadrilateral diamond shape on semiconductor fins, wherein the S/D regions include (111) facets, and the S/D regions on adjacent semiconductor fins have separated cross-sectional quadrilateral diamond shapes;
depositing a metal on the (111) facets;
annealing the metal on the (111) facets of the S/D regions to form a silicide on the (111) facets;
replacing the dummy gate material with a metal gate conductor after the annealing step;
forming a dielectric layer over the S/D regions;
opening up the dielectric layer to expose the silicide and to form contact holes; and
forming contacts to the silicide in the contact holes.
11. The method as recited in claim 10 , wherein the cross-sectional quadrilateral diamond shapes of the S/D regions are separated in a non-merged configuration.
12. The method as recited in claim 10 , wherein depositing the metal on the (111) facets includes depositing the metal on top side facets of the (111) facets of the S/D regions.
13. The method as recited in claim 10 , wherein depositing the metal on the (111) facets includes depositing the metal on all facets of the S/D regions in a wrapped around configuration.
14. The method as recited in claim 10 , wherein annealing the metal includes forming merged silicides between the S/D regions.
15. The method as recited in claim 10 , wherein opening up the dielectric layer to expose the silicide and to form contact holes includes opening up the dielectric layer to expose the silicide over a portion of the S/D regions.
16. The method as recited in claim 15 , wherein forming contacts to the silicide in the contact holes includes forming the contacts to the silicide in the contact holes for the portion of the S/D regions to reduce capacitance so that the contacts are in a partially strapped configuration.
17. The method as recited in claim 10 , wherein annealing the metal includes annealing with a laser anneal at a temperature of between about 900 to 1100 degrees C. for less than or equal to 1 millisecond to thermally stabilize the silicide.
18. The method as recited in claim 17 , further comprising performing an additional anneal process to continue to form the silicide.