Compositions for chemical mechanical planarization of copper
A composition and associated method for chemical mechanical planarization of a copper-containing substrate are described and which afford low defectivity levels on copper during copper CMP processing. The composition comprises a colloidal silica that is substantially free of soluble polymeric silicates.
1 . A composition for chemical mechanical planarization of a surface having at least one feature thereon comprising copper, said composition comprising colloidal silica that is substantially free of soluble polymeric silicates.
2 . A composition for chemical mechanical planarization of a surface having at least one feature thereon comprising copper, said composition comprising:
a) colloidal silica that is substantially free of soluble polymeric silicates; and
b) an oxidizing agent.
3 . The composition of claim 2 further comprising c) a surfactant.
4 . The composition of claim 3 wherein the surfactant is a fluorosurfactant.
5 . The composition of claim 2 wherein the oxidizing agent is hydrogen peroxide.
6 . The composition of claim 1 wherein centrifugation has been employed to produce the colloidal silica that is substantially free of soluble polymeric silicates.
7 . A method for chemical mechanical planarization of a surface having at least one feature thereon comprising copper, said method comprising the steps of:
A) placing a substrate having the surface having the at least one feature thereon comprising copper in contact with a polishing pad;
B) delivering a polishing composition comprising colloidal silica that is substantially free of soluble polymeric silicates; and
C) polishing the substrate with the polishing composition.
8 . A method for chemical mechanical planarization of a surface having at least one feature thereon comprising copper, said method comprising the steps of:
A) placing a substrate having the surface having the at least one feature thereon comprising copper in contact with a polishing pad;
B) delivering a polishing composition comprising:
b) colloidal silica that is substantially free of soluble polymeric silicates; and
b) an oxidizing agent.
and
C) polishing the substrate with the polishing composition.
9 . The method of claim 8 wherein the composition further comprises c) a surfactant.
10 . The method of claim 9 wherein the surfactant of the composition is a fluorosurfactant.
11 . The method of claim 8 wherein the oxidizing agent of the composition is hydrogen peroxide.
12 . The method of claim 7 wherein the colloidal silica that is substantially free of soluble polymeric silicates is produced using centrifugation.