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 selectively depositing a film on a first metallic surface of a substrate relative to a second dielectric surface of the same substrate, the process comprising:
performing a first metallic surface treatment process comprising removing a surface layer from the first metallic surface of the substrate such that a significant amount of new surface groups or ligands are not provided on the second dielectric surface by the first metallic surface treatment process, wherein the first metallic surface treatment process comprises exposing at least the first metallic surface of the substrate to a plasma generated from a gas comprising HCOOH; and
selectively depositing a film on the treated first metallic surface of the substrate relative to the second dielectric surface of the substrate with a selectivity of greater than about 50%.
2. The process of claim 1 , wherein the first metallic surface treatment process comprises exposing the first metallic surface of the substrate and the second dielectric surface of the substrate to the plasma generated from the gas.
3. The process of claim 1 , wherein the first metallic surface treatment process further comprises reducing and/or removing a metal oxide layer present on the first metallic surface of the substrate.
4. The process of claim 1 , wherein the removed surface layer comprises an organic material.
5. The process of claim 4 , wherein the removed surface layer comprises a passivation layer.
6. The process of claim 5 , wherein the removed surface layer comprises benzotriazole (BTA).
7. The process of claim 1 , wherein the gas comprises formic acid (HCOOH) and H 2 .
8. The process of claim 1 , wherein the gas comprises HCOOH, NH 3 , and H 2 .
9. The process of claim 8 , wherein the gas is provided by a carrier gas comprising a noble gas.
10. The process of claim 1 , wherein a temperature of the substrate during the first metallic surface treatment process is about 300° C.
11. The process of claim 1 , wherein the first metallic surface treatment process comprises exposing at least the first metallic surface of the substrate to the plasma for from about 1 second to about 10 minutes.
12. The process of claim 1 , wherein the plasma is generated by supplying RF power of from about 10 W to about 3000 W to the gas.
13. The process of claim 12 , wherein the frequency of the RF power is from about 1 MHz to about 10 GHz.
14. The process of claim 1 , wherein the pressure of the gas from which the plasma is generated is from about 1 Pa to about 5000 Pa.
15. The process of claim 1 , wherein the selectively deposited film comprises tungsten.
16. The process of claim 1 , wherein the first metallic surface comprises copper or cobalt.
17. The process of claim 1 , wherein the second dielectric surface comprises silicon.
18. A process for selectively depositing a film on a first metallic surface of a substrate relative to a second dielectric surface of the same substrate, the process comprising:
performing a first metallic surface treatment process comprising removing a surface layer from the first metallic surface of the substrate by exposing at least the first metallic surface of the substrate to a plasma generated from a gas comprising HCOOH; and
selectively depositing a film on the first metallic surface of the substrate relative to the second dielectric surface of the substrate with a selectivity of greater than about 50%.