Ruthenium or cobalt as an underlayer for tungsten film deposition
Embodiments of the invention provide a method for depositing materials on substrates. In one embodiment, the method includes depositing a barrier layer containing tantalum or titanium on a substrate, depositing a ruthenium layer or a cobalt layer on the barrier layer, and depositing a tungsten bulk layer thereover. In some examples, the barrier layer may contain tantalum nitride deposited by an atomic layer deposition (ALD) process, the tungsten bulk layer may be deposited by a chemical vapor deposition (CVD) process, and the ruthenium or cobalt layer may be deposited by an ALD process. The ruthenium or cobalt layer may be exposed to a soak compound, such as hydrogen, diborane, silane, or disilane, during a soak process prior to depositing the tungsten bulk layer. In some examples, a tungsten nucleation layer may be deposited on the ruthenium or cobalt layer, such as by ALD, prior to depositing the tungsten bulk layer.
1. A method for depositing materials on a substrate surface, comprising:
depositing a barrier layer comprising tantalum or titanium on a substrate;
depositing a ruthenium layer on the barrier layer; and
depositing a tungsten bulk layer over the ruthenium layer.
2. The method of claim 1 , wherein the barrier layer comprises tantalum nitride deposited by an atomic layer deposition process and the tungsten bulk layer is deposited by a chemical vapor deposition process.
3. The method of claim 1 , wherein the ruthenium layer is deposited by exposing the substrate having the barrier layer to a ruthenium precursor during an atomic layer deposition process.
4. The method of claim 3 , wherein the ruthenium precursor is selected from the group consisting of bis(cyclopentadienyl) ruthenium compounds, bis(alkylcyclopentadienyl) ruthenium compounds, bis(dialkylcyclopentadienyl) ruthenium compounds, bis(pentadienyl) ruthenium compounds, bis(alkylpentadienyl) ruthenium compounds, and bis(dialkylpentadienyl) ruthenium compounds.
5. The method of claim 4 , further comprising exposing the substrate having the barrier layer to a reagent during the atomic layer deposition process, wherein the reagent is selected from the group consisting of hydrogen, silane, disilane, diborane, derivatives thereof, and combinations thereof.
6. The method of claim 3 , wherein the ruthenium precursor is selected from the group consisting of bis(cyclopentadienyl) ruthenium, bis(methylcyclopentadienyl) ruthenium, bis(ethylcyclopentadienyl) ruthenium, bis(pentamethylcyclopentadienyl) ruthenium, bis(2,4-dimethylpentadienyl) ruthenium, bis(2,4-diethylpentadienyl) ruthenium, derivatives thereof, and combinations thereof.
7. The method of claim 3 , further comprising exposing the ruthenium layer to a soak compound during a soak process prior to depositing the tungsten bulk layer.
8. The method of claim 7 , wherein the ruthenium layer is exposed to the soak compound for a time period within a range from about 5 seconds to about 90 seconds during the soak process.
9. The method of claim 8 , wherein the soak compound is selected from the group consisting of hydrogen, borane, diborane, silane, disilane, trisilane, derivatives thereof, and combinations thereof.
10. The method of claim 1 , further comprising depositing a tungsten nucleation layer on the ruthenium layer prior to depositing the tungsten bulk layer thereto.
11. The method of claim 10 , wherein the tungsten nucleation layer is deposited by sequentially exposing the substrate having the ruthenium layer to a tungsten precursor and a reducing gas during an atomic layer deposition process.
12. The method of claim 11 , wherein the reducing gas comprises a reagent selected from the group consisting of hydrogen, silane, disilane, trisilane, borane, diborane, triethylborane, derivatives thereof, and combinations thereof.
13. The method of claim 12 , wherein the tungsten precursor comprises tungsten hexafluoride and the reducing gas comprises silane or diborane.
14. The method of claim 10 , further comprising exposing the tungsten nucleation layer to a soak compound during a soak process prior to depositing the tungsten bulk layer, wherein the soak compound is selected from the group consisting of hydrogen, borane, diborane, silane, disilane, trisilane, derivatives thereof, and combinations thereof.
15. A method for depositing materials on a substrate surface, comprising:
depositing a barrier layer comprising tantalum or titanium on a substrate;
depositing a cobalt layer on the barrier layer; and
depositing a tungsten bulk layer over the cobalt layer.
16. The method of claim 15 , wherein the barrier layer comprises tantalum nitride deposited by an atomic layer deposition process.
17. The method of claim 16 , wherein the tungsten bulk layer is deposited by a chemical vapor deposition process.
18. The method of claim 15 , wherein the cobalt layer is deposited by exposing the substrate having the barrier layer to a cobalt precursor during an atomic layer deposition process.
19. The method of claim 18 , wherein the cobalt precursor is selected from the group consisting of bis(cyclopentadienyl) cobalt, (cyclopentadienyl) (cyclohexadienyl) cobalt, cyclopentadienyl (1,3-hexadienyl) cobalt, (cyclobutadienyl) (cyclopentadienyl) cobalt, bis(methylcyclopentadienyl) cobalt (cyclopentadienyl) (5-methylcyclopentadienyl) cobalt, bis(ethylene) (pentamethylcyclopentadienyl) cobalt, derivatives thereof.
20. The method of claim 18 , further comprising exposing the cobalt layer to a soak compound during a soak process prior to depositing the tungsten bulk layer.
21. The method of claim 20 , wherein the cobalt layer is exposed to the soak compound for a time period within a range from about 5 seconds to about 90 seconds during the soak process, and the soak compound is selected from the group consisting of hydrogen, borane, diborane, silane, disilane, trisilane, derivatives thereof, and combinations thereof.
22. The method of claim 15 , further comprising depositing a tungsten nucleation layer on the cobalt layer prior to depositing the tungsten bulk layer thereto.
23. The method of claim 22 , wherein the tungsten nucleation layer is deposited by an atomic layer deposition process.
24. The method of claim 22 , further comprising exposing the tungsten nucleation layer to a soak compound during a soak process prior to depositing the tungsten bulk layer, wherein the soak compound is selected from the group consisting of hydrogen, borane, diborane, silane, disilane, trisilane, derivatives thereof, and combinations thereof.
25. A method for depositing materials on a substrate surface, comprising:
depositing a tantalum-containing barrier layer on a substrate;
depositing a noble metal layer comprising ruthenium or cobalt on the tantalum-containing barrier layer during an atomic layer deposition process;
exposing the noble metal layer to a soak compound during a soak process, the soak compound is selected from the group consisting of hydrogen, borane, diborane, silane, disilane, trisilane, derivatives thereof, and combinations thereof; and
depositing a tungsten bulk layer over the noble metal layer.