Compositions for chemical-mechanical planarization of noble-metal-featured substrates, associated methods, and substrates produced by such methods
View Patent ↗A composition for chemical-mechanical planarization comprises periodic acid and an abrasive present in a combined amount sufficient to planarize a substrate surface having a feature thereon comprising a noble metal, noble metal alloy, noble metal oxide, or any combination thereof. In one embodiment, the periodic acid is present in an amount in a range of from about 0.05 to about 0.3 moles/kilogram, and the abrasive is present in an amount in a range of from about 0.2 to about 6 weight percent. In another embodiment, the composition further comprises a pH-adjusting agent present in an amount sufficient to cause the pH of the composition to be in a range of from about pH 5 to about pH 10, or of from about pH 1 to about pH 4. A method for planarizing a substrate surface having a feature thereon comprising at least one noble metal, noble metal alloy, or noble metal oxide, or a combination thereof, comprises providing a composition or slurry comprising periodic acid and an abrasive in a combined amount sufficient to planarize the substrate surface, and polishing the surface with the slurry. A substrate produced by such a method is also provided.
1. A method for polishing a substrate surface having at least one feature thereon comprising a noble metal, said method comprising:
a) providing a substrate comprising submicron integrated circuits and having a surface having at least one feature thereon comprising a noble metal selected from the group consisting of Ru, Rh, Pd, Os, Ir, Pt, Ag, Au, alloys thereof, oxides thereof, and combinations thereof;
b) providing a chemical mechanical polishing composition comprising: periodic acid in an amount from about 0.05 to about 0.3 moles/kilogram and an abrasive; and
c) polishing said substrate surface with said chemical mechanical polishing composition,
wherein said periodic acid and said abrasive are present in a combined amount sufficient to render the substrate surface substantially planar and wherein the polishing is maintained at a polishing rate of between 300 Angstroms per minute to about 2000 Angstroms per minute.
2. The method of claim 1 , wherein the periodic acid is present in an amount from about 0.075 to about 0.3 moles/kilogram.
3. The method of claim 1 , wherein the abrasive is present in an amount from about 0.2 to about 6 weight percent.
4. The method of claim 1 , wherein the abrasive comprises an abrasive selected from the group consisting of alumina, silica, zirconia, spinel, zirconium nitride, and combinations thereof.
5. The method of claim 1 , wherein the noble metal is selected from the group consisting of Ir, IrO 2 , Pt, and combinations thereof.
6. The method of claim 1 , wherein said chemical mechanical polishing composition is sufficient to provide the substrate surface with a wafer-within-wafer-nonuniformity (WWNU) of less than about 12% upon polishing of the substrate surface with the chemical mechanical polishing composition.
7. The method of claim 1 , wherein said chemical mechanical polishing composition is sufficient to provide the substrate surface with a wafer-to-wafer-nonuniformity (WTWNU) of less than about 5%.
8. The method of claim 1 , wherein the noble metal is selected from the group consisting of Ru, a Ru alloy, and a Ru oxide.
9. The method of claim 1 , further comprising a pH-adjusting agent, wherein the pH is from about pH 1 to about pH 10.
10. The method of claim 9 , wherein the composition consists essentially of water, periodic acid, an abrasive, and a pH-adjusting agent is selected from the group consisting of a quaternary amine, an inorganic base, and combinations thereof.
11. The method of claim 9 , wherein the pH-adjusting agent comprises an agent selected from the group consisting of tetramethylammonium hydroxide, ammonium hydroxide, potassium hydroxide, sodium hydroxide, and combinations thereof.
12. The method of claim 1 , further comprising a suspension agent.
13. The method of claim 12 , wherein the suspension agent comprises an agent selected from the group consisting of an organic acid, a surfactant, a second abrasive, ammonium polymethacylate, hydrous sodium lithium magnesium silicate, ethyl carbonate and combinations thereof.
14. A method for polishing a substrate surface having at least one feature thereon comprising a noble metal, said method comprising:
a) providing a substrate having a surface, wherein said surface comprises a dielectric material and containing at least one feature thereon comprising a noble metal selected from the group consisting of Ru, Rh, Pd, Os, Ir, Pt, Ag, Au, alloys thereof, oxides thereof, and combinations thereof;
b) providing a chemical mechanical polishing composition comprising periodic acid in an amount from about 0.05 to about 0.3 moles/kilogram; and an abrasive in an amount from about 0.2 to about 6 weight percent, said polishing composition having a pH from above pH 5 to about pH 10; and
c) polishing said substrate surface with said chemical mechanical polishing composition wherein on polishing the substrate surface with the polishing composition a selectivity of the polishing composition for polishing the noble metal over polishing the dielectric material is at least 1:1.
15. The method of claim 14 , wherein the amount of periodic acid is from about 0.075 to about 0.3 moles/kilogram.
16. The method of claim 14 , wherein the amount of the abrasive is from about 0.2 to about 6 weight percent.
17. The method of claim 14 , wherein the pH is from about pH 6 to about pH 10.
18. The method of claim 14 , wherein the abrasive comprises an abrasive selected from the group consisting of alumina, silica, zirconia, spinel, zirconium nitride, and combinations thereof.
19. The method of claim 14 , wherein said composition provides the substrate surface with a wafer-to-wafer-nonuniformity (WTWNU) of less than about 5% upon chemical-mechanical polishing thereof.
20. The method of claim 14 , wherein the noble metal is selected from the group consisting of Ir, IrO 2 , Pt, and combinations thereof.
21. The method of claim 14 , further comprising a pH-adjusting agent.
22. The method of claim 21 , wherein the pH-adjusting agent is selected from the group consisting of a quaternary amine, an inorganic base, and any composition thereof.
23. The method of claim 21 , wherein the pH-adjusting agent comprises an agent selected from the group consisting of tetramethylammonium hydroxide, ammonium hydroxide, potassium hydroxide, sodium hydroxide, and combinations thereof.
24. The method of claim 14 , further comprising a suspension agent.
25. The method of claim 24 , wherein the suspension agent comprises an agent selected from the group consisting of an organic acid, a surfactant, a second abrasive, ammonium polymethacylate, hydrous sodium lithium magnesium silicate, and ethyl carbonate.
26. A method for polishing a substrate surface having at least one feature thereon comprising a noble metal, said method comprising:
a) providing a substrate having a surface, wherein said surface comprises a dielectric material and has at least one feature thereon comprising a noble metal selected from the group consisting of Ru, Rh, Pd, Os, Ir, Pt, Ag, Au, alloys thereof, oxides thereof, and combinations thereof;
b) providing a chemical mechanical polishing composition consisting essentially of
(i) water;
(ii) periodic acid in an amount from about 0.05 to about 0.3 moles/kilogram;
(iii) an abrasive in an amount from about 0.2 to about 6 weight percent;
(iv) a pH-adjusting agent in an amount sufficient to cause the pH of the composition to be between about 1 to about 10; and
(v) a suspension agent; and
c) polishing said substrate surface with said chemical mechanical polishing composition.
27. The method of claim 26 , wherein the noble metal is selected from the group consisting of Ir, IrO 2 , Pt, and combinations thereof.
28. The method of claim 26 , wherein the noble metal comprises gold.
29. The method of claim 26 , wherein the noble metal comprises silver.
30. The method of claim 26 , wherein the abrasive comprises an abrasive selected from the group consisting of alumina, silica, zirconia, spinel, zirconium nitride, and combinations thereof.
31. The method of claim 26 , wherein the substrate further comprises a dielectric material, and wherein the selectivity of the composition for polishing the noble metal over polishing the dielectric material is at least 1:1.
32. The method of claim 26 , wherein the pH-adjusting agent is selected from the group consisting of a quaternary amine, an inorganic base, and combinations thereof.
33. The method of claim 26 wherein the pH-adjusting agent is added in an amount sufficient to cause the pH of the composition to be between about 1 to about 4.
34. The method of claim 26 wherein the pH-adjusting agent is added in an amount sufficient to cause the pH of the composition to be between about 5 to about 10.
35. The method of claim 26 , wherein the suspension agent is selected from the group consisting of an organic acid, surfactant, ethyl carbonate, aluminum oxide, hydrous sodium lithium magnesium silicate, ammonium polymethacrylate, and a second abrasive.
36. The method of claim 35 , wherein the organic acid is succinic acid.
37. The method of claim 35 , wherein the second abrasive is silica.