Reaction chamber passivation and selective deposition of metallic films
Metallic layers can be selectively deposited on one surface of a substrate relative to a second surface of the substrate. In some embodiments, the metallic layers are selectively deposited on a first metallic surface relative to a second surface comprising silicon. In some embodiments the reaction chamber in which the selective deposition occurs may optionally be passivated prior to carrying out the selective deposition process. In some embodiments selectivity of above about 50% or even about 90% is achieved.
1. A process for depositing a thin film on a substrate, the process comprising:
passivating an interior surface of a reaction chamber by a first vapor deposition process while the reaction chamber does not contain the substrate, wherein the first vapor deposition process comprises one or more deposition cycles in which the interior surface of the reaction chamber is contacted with a first vapor-phase precursor and a second vapor-phase precursor;
subjecting the substrate to a first surface treatment process; and
selectively depositing a thin film on the treated substrate in the passivated reaction chamber by a second vapor deposition process.
2. The process of claim 1 , wherein the substrate comprises a first metallic surface and a second surface comprising silicon.
3. The process of claim 2 , wherein the first surface treatment process reduces the first metallic surface.
4. The process of claim 2 , wherein the first surface treatment process removes organic material present on the first metallic surface.
5. The process of claim 4 , wherein the organic material comprises a hydrocarbon.
6. The process of claim 2 , wherein the first surface treatment process removes a passivation layer present on the first metallic surface.
7. The process of claim 2 , wherein the first surface treatment process provides active sites on the first metallic surface.
8. The process of claim 1 , wherein the first surface treatment process is carried out at a temperature of from 30° C. to 110° C.
9. The process of claim 1 , wherein the first surface treatment process comprises exposing the substrate to a plasma.
10. The process of claim 1 , wherein the first surface treatment process comprises exposing the substrate to a treatment reactant comprising formic acid.
11. The process of claim 1 , wherein the first surface treatment process comprises exposing the substrate to a treatment reactant selected from the group consisting of primary alcohols, secondary alcohols, tertiary alcohols, polyhydroxy alcohols, cyclic alcohols, aromatic alcohols, and other derivatives of alcohols.
12. The process of claim 1 , further comprising exposing the substrate to a second surface treatment reactant prior to subjecting the substrate to the first surface treatment process.
13. The process of claim 1 , wherein the second vapor deposition process comprises one or more selective deposition cycles in which the substrate is contacted with a first vapor-phase reactant and a second vapor-phase reactant.
14. The process of claim 13 , further comprising repeating passivating the interior surface of the reaction chamber after two or more selective deposition cycles have been performed.
15. The process of claim 1 , wherein the first vapor deposition process is an atomic layer deposition (ALD) process, a chemical vapor deposition (CVD) process, a plasma enhanced atomic layer deposition (PEALD) process, or a plasma enhanced chemical vapor deposition (PECVD) process.
16. The process of claim 1 , wherein the first vapor phase precursor is a silicon precursor and the second vapor phase precursor is a nitrogen precursor.
17. The process of claim 16 , wherein the first vapor-phase precursor comprises disilane, and the second vapor-phase precursor comprises atomic nitrogen, nitrogen radicals or nitrogen plasma and atomic hydrogen, hydrogen radicals or hydrogen plasma.
18. A process for selectively depositing a thin film on a first metallic surface of a substrate relative to a second surface comprising silicon, the process comprising:
passivating an interior surface of a reaction chamber by one or more deposition cycles in which the interior surface of the reaction chamber is exposed to first and second vapor-phase passivation precursors;
treating the metallic surface of the substrate by exposing it to a treatment reactant; and
depositing the thin film selectively on the first treated metallic surface of the substrate relative to the second surface comprising silicon within the passivated reaction chamber by a vapor deposition process.
19. The process of claim 18 , wherein the treatment reactant is a vapor-phase organic reactant.
20. The process of claim 18 , wherein the treatment reactant comprises a plasma.