Methods for wet metal seed deposition for bottom up gapfill of features
A method of depositing a metal seed for performing bottom-up gapfill of features of a substrate includes providing a substrate including a plurality of features; flowing a dilute metal precursor solution into the features, wherein the dilute metal precursor solution includes a metal precursor and a dilution liquid; evaporating the dilution liquid to locate the metal precursor at bottoms of the plurality of features; exposing the substrate to a plasma treatment to reduce the metal precursor to at least one of a metal or a metal alloy and to form a seed layer; performing a heat treatment on the substrate; and using a selective gapfill process to fill the features with a transition metal in contact with the seed layer.
1. A method of depositing a metal seed for performing bottom-up gapfill of features of a substrate, comprising:
providing a substrate including a plurality of features;
flowing a dilute metal precursor solution into the features, wherein the dilute metal precursor solution includes a metal precursor and a dilution liquid;
evaporating the dilution liquid to locate the metal precursor at bottoms of the plurality of features,
wherein evaporating the dilution liquid includes exposing the substrate to a gradient dry process;
exposing the substrate to a plasma treatment to reduce the metal precursor to at least one of a metal or a metal alloy and to form a seed layer only at the bottoms of the plurality of features;
performing a heat treatment on the substrate; and
using a selective gapfill process to fill the features with a transition metal in contact with the seed layer and not other exposed portions of the plurality of features.
2. The method of claim 1 , wherein the substrate includes a liner layer and the dilute metal precursor solution is applied to the liner layer.
3. The method of claim 1 , wherein the transition metal is selected from a group consisting of nickel (Ni), cobalt (Co), copper (Cu), molybdenum (Mo), ruthenium (Ru), iridium (Ir), platinum (Pt), palladium (Pd) and tungsten (W).
4. The method of claim 1 , wherein the selective gapfill process includes electroless deposition.
5. The method of claim 1 , wherein the dilution liquid comprises at least one of a carrier liquid and a solvent.
6. The method of claim 1 , wherein the dilution liquid is water-free.
7. The method of claim 1 , wherein the dilution liquid comprises a liquid selected from a group consisting of alcohol, ether, ester, perflouro-ether.
8. The method of claim 1 , wherein the dilution liquid comprises a liquid selected from a group consisting isopropyl alcohol (IPA) and ethyl alcohol (EtOH).
9. The method of claim 1 , wherein the dilute metal precursor solution is at least one of deposited or condensed in the plurality of features using by capillary action.
10. A method of depositing a metal seed for performing bottom-up gapfill of features of a substrate, comprising:
providing a substrate including a plurality of features;
flowing a dilute metal precursor solution into the features, wherein the dilute metal precursor solution includes a metal precursor and a dilution liquid;
evaporating the dilution liquid to locate the metal precursor at bottoms of the plurality of features;
exposing the substrate to a plasma treatment to reduce the metal precursor to at least one of a metal or a metal alloy and to form a seed layer;
performing a heat treatment on the substrate; and
using a selective gapfill process to fill the features with a transition metal in contact with the seed layer,
wherein evaporating the dilution liquid includes exposing the substrate to a gradient dry process.
11. The method of claim 10 , wherein the features have openings having a width that is less than or equal to 10 nm.
12. The method of claim 10 , wherein the features have openings having a width in a range from 7 to 9 nm.
13. The method of claim 10 , wherein the features have openings having a width in a range from 4 to 7 nm.
14. The method of claim 10 , wherein the seed layer has a thickness in a range from 2-4 nm.
15. The method of claim 10 , wherein the heat treatment comprises annealing at a temperature in a range from 200° C. to 400° C.
16. The method of claim 10 , wherein the heat treatment comprises annealing at a temperature in a range from 250° C. to 350° C.
17. The method of claim 10 , wherein the transition metal is selected from a group consisting of nickel (Ni), cobalt (Co), copper (Cu), molybdenum (Mo), ruthenium (Ru), iridium (Ir), platinum (Pt), palladium (Pd) and tungsten (W).
18. The method of claim 10 , wherein the selective gapfill process includes electroless deposition.
19. The method of claim 10 , wherein the dilution liquid comprises at least one of a carrier liquid and a solvent.
20. The method of claim 10 , wherein the dilution liquid is water-free.
21. The method of claim 10 , wherein the dilution liquid comprises a liquid selected from a group consisting of alcohol, ether, ester, perflouro-ether.
22. The method of claim 10 , wherein the dilution liquid comprises a liquid selected from a group consisting isopropyl alcohol (IPA) and ethyl alcohol (EtOH).
23. The method of claim 10 , wherein the dilute metal precursor solution is at least one of deposited or condensed in the plurality of features using by capillary action.
24. The method of claim 10 , wherein the substrate includes a liner layer and the dilute metal precursor solution is applied to the liner layer.
25. The method of claim 24 , wherein the liner layer is made of a material selected from a group consisting of titanium nitride (TiN), tungsten carbonitride (WCN), and tantalum nitride (TaN).
26. The method of claim 24 , wherein the liner layer is made of a material selected from a group consisting of silicon dioxide, a metal, or a dielectric.
27. The method of claim 24 , wherein the at least one of the metal or the metal alloy is selected to catalytically react with the transition metal but not the liner layer.