Selective deposition on non-metallic surfaces
Methods for selectively depositing on non-metallic surfaces are disclosed. Some embodiments of the disclosure utilize an unsaturated hydrocarbon to form a blocking layer on metallic surfaces. Deposition is performed to selectively deposit on the unblocked non-metallic surfaces. Some embodiments of the disclosure relate to methods of forming metallic vias with decreased resistance.
1. A method of forming a blocking layer, the method comprising exposing a substrate comprising a metallic material having a first surface and a non-metallic material having a second surface to an unsaturated hydrocarbon to selectively form a blocking layer on the first surface over the second surface, the unsaturated hydrocarbon comprising at least one linear or branched compound with a general formula R′≡R″ where R′ and R″ are independent C2-C6 groups.
2. The method of claim 1 , wherein R′ and R″ are identical.
3. The method of claim 1 , wherein the at least one compound comprises 4-12 carbon atoms.
4. The method of claim 1 , wherein the at least one compound contains only one unsaturated bond.
5. The method of claim 1 , wherein the unsaturated hydrocarbon comprises 3-hexyne.
6. The method of claim 1 , wherein the metallic material comprises one or more of copper, cobalt, tungsten, molybdenum or ruthenium.
7. The method of claim 1 , wherein the non-metallic material comprises silicon oxide.
8. The method of claim 1 , further comprising selectively depositing a film on the second surface over the blocking layer on the first surface.
9. The method of claim 8 , wherein the film is deposited by sequentially exposing the substrate to a metal precursor and a reactant.
10. The method of claim 9 , wherein the metal precursor comprises pentakis(dimethylamino)tantalum, the reactant comprises ammonia and the film comprises tantalum nitride.
11. The method of claim 1 , further comprising exposing the substrate to a plasma to remove the blocking layer.
12. The method of claim 11 , wherein the plasma consists essentially of argon.
13. A method of selective deposition, the method comprising:
exposing a substrate comprising a metallic material having a first surface and a non-metallic material having a second surface to an unsaturated hydrocarbon to selectively form a blocking layer on the first surface over the second surface, the unsaturated hydrocarbon comprising at least one linear or branched compound with a general formula R′≡R″ where R′ and R″ are independent C2-C6 groups;
sequentially exposing the substrate to a metal precursor and a reactant to form a film on the second surface over the blocking layer on the first surface; and
removing the blocking layer from the first surface.
14. The method of claim 13 , wherein the unsaturated hydrocarbon comprises 3-hexyne.
15. A method of forming low-resistance metal vias, the method comprising:
exposing a substrate having a substrate surface with at least one feature formed therein to an unsaturated hydrocarbon to selectively form a blocking layer on a metallic material surface over a non-metallic material surface, the at least one feature having a sidewall and a bottom, the sidewall comprising a non-metallic material surface, the bottom comprising a metallic material surface, and the unsaturated hydrocarbon comprising at least one linear or branched compound with a general formula R′≡R″ where R′ and R″ are independent C2-C6 groups;
sequentially exposing the substrate to a metal precursor and a reactant to form a film on the non-metallic material surface over the blocking layer on the metallic material surface;
optionally removing the blocking layer from the metallic material surface; and
depositing a conductive fill material within the at least one feature to form a low-resistance metal via.
16. The method of claim 15 , wherein the unsaturated hydrocarbon comprises 3-hexyne.
17. The method of claim 15 , wherein the film comprises tantalum nitride.
18. The method of claim 15 , wherein the low-resistance metal via has a resistance less than or equal to about 80% of a metal via formed without a blocking layer.