Polishing composition for edge roll-off improvement
The invention provides a chemical-mechanical polishing composition including (a) an abrasive comprising wet-process silica particles, (b) a water-soluble polymer, (c) an oxidizing agent, (d) a chelating agent, (e) a pH-adjusting agent, and (f) an aqueous carrier, wherein the pH of the polishing composition is about 1 to about 7. The invention also provides a method of polishing a substrate, especially a nickel-phosphorus substrate, with the polishing composition.
1. A chemical-mechanical polishing composition comprising:
(a) an abrasive comprising wet-process silica particles,
(b) a water-soluble polymer selected from the group consisting of a polyethylene glycol homopolymer and a polyethylene glycol (PEG) and polypropylene glycol (PPG) block copolymer.
(c) an oxidizing agent,
(d) a cheating agent,
(e) a pH-adjusting agent, and
(f) an aqueous carrier,
wherein the pH of the polishing composition is about 1 to about 7;
wherein the abrasive further comprises alpha particles having an average particle size of about 100 nm to about 1000 nm;
wherein the water-soluble polymer is present in the polishing composition at a concentration of about 0.0001 wt % to about 1 wt %.
2. The chemical-mechanical polishing composition of claim 1 , wherein the wet-process silica particles have an average particle size of about 1 nm to about 1000nm.
3. The chemical-mechanical polishing composition of claim 1 , wherein the wet-process silica particles have an average particle size of about 4 nm to about 300nm.
4. The chemical-mechanical polishing composition of claim 1 , wherein the wet-process silica particles have an average particle size of about 20 nm to about 100nm.
5. The chemical-mechanical polishing composition of claim 1 , wherein the wet-process silica particles are present in the polishing composition at a concentration of about 1 wt. % to about 10 wt. %.
6. The chemical-mechanical polishing composition of claim 5 , wherein the wet-process silica particles are present in the polishing composition at a concentration of about 2 wt. % to about 5 wt. %.
7. The chemical-mechanical polishing composition of claim 1 , wherein the alpha alumina particles have an average particle size of about 100 nm to about 500 nm.
8. The chemical-mechanical polishing composition of claim 1 , wherein the alpha alumina particles have an average particle size of about 200 nm to about 400 nm.
9. The chemical-mechanical polishing composition of claim 1 , wherein the alpha alumina particles are present in the polishing composition at a concentration of about 0.3 wt. % to about 2 wt. %.
10. The chemical-mechanical polishing composition of claim 9 , wherein the alpha alumina particles are present in the polishing composition at a concentration of about 0.5wt. % to about 1 wt. %.
11. The chemical-mechanical polishing composition of claim 1 , wherein the abrasive further comprises fumed alumina particles.
12. The chemical-mechanical polishing composition of claim 11 , wherein the fumed alumina particles are present in the polishing composition at a concentration of about 0.005wt. % to about 1 wt. %.
13. The chemical-mechanical polishing composition of claim 11 , wherein the fumed alumina particles are present in the polishing composition at a concentration of about 0.05 wt. % to about 0.25 wt. %.
14. The chemical-mechanical polishing composition of claim 1 , wherein the water-soluble polymer is a polyethylene glycol (PEG) and polypropylene glycol (PPG) block copolymer.
15. The chemical-mechanical polishing composition of claim 1 , wherein the water-soluble polymer is a polyethylene glycol homopolymer.
16. The chemical-mechanical polishing composition of claim 15 , wherein the polyethylene glycol homopolymer has a molecular weight of about 300 g/mol to about 50,000 g/mol.
17. The chemical-mechanical polishing composition of claim 15 , wherein the polyethylene glycol homopolymer has a molecular weight of about 300 g/mol to about 3500 g/mol.
18. The chemical-mechanical polishing composition of claim 15 , wherein the polyethylene glycol homopolymer has a molecular weight of about 1000 g/mol.
19. The chemical-mechanical polishing composition of claim 15 , wherein the polyethylene glycol homopolymer has a molecular weight of about 2000 g/mol.
20. The chemical-mechanical polishing composition of claim 1 , wherein the water-soluble polymer is present in the polishing composition at a concentration of about 0.01 wt. % to about 0.5 wt. %.
21. The chemical-mechanical polishing composition of claim 1 , wherein the water-soluble polymer is present in the polishing composition at a concentration of about 0.1 wt. % to about 0.2 wt. %.
22. The chemical-mechanical polishing composition of claim 1 , wherein the water-soluble polymer has a hydrophilic-lipophilic balance (HLB) of about 4 or more.
23. The chemical-mechanical polishing composition of claim 22 , wherein the water-soluble polymer has an HLB of about 10 or more.
24. The chemical-mechanical polishing composition of claim 1 , wherein the oxidizing agent comprises hydrogen peroxide.
25. The chemical-mechanical polishing composition of claim 1 , wherein the oxidizing agent is present in the polishing composition at a concentration of about 0.1 wt. % to about 5wt. %.
26. The chemical-mechanical polishing composition of any 1 , wherein the chelating agent comprises an amino acid or an organic carboxylic acid.
27. The chemical-mechanical polishing composition of claims 1 , wherein the chelating agent is tartaric acid, glycine, or malonic acid.
28. The chemical-mechanical polishing composition of claim 1 , wherein the chelating agent is present in the polishing composition at a concentration of about 0.005 wt. % to about 1 wt. %.
29. The chemical-mechanical polishing composition of claim 28 , wherein the chelating agent is present in the polishing composition at a concentration of about 0.5 wt. % to about 1wt. %.
30. The chemical-mechanical polishing composition of claim 1 , wherein the pH of the polishing composition is about 1.5 to about 3.
31. A method of polishing a substrate comprising:
(i) providing a substrate;
(ii) providing a polishing pad;
(iii) providing the chemical-mechanical polishing composition of claim 1 ;
(iv) contacting the substrate with the polishing pad and the chemical-mechanical polishing composition; and
(v) moving the polishing pad and the chemical-mechanical polishing composition relative to the substrate to abrade at least a portion of the substrate to polish the substrate.
32. A method of polishing a substrate comprising:
(i) providing a substrate, wherein the substrate comprises a nickel phosphorus layer;
(ii) providing a polishing pad;
(iii) providing the chemical-mechanical polishing composition of claim 1 ;
(iv) contacting the substrate with the polishing pad and the chemical-mechanical polishing composition; and
(v) moving the polishing pad and the chemical-mechanical polishing composition relative to the substrate to abrade at least a portion of the nickel phosphorus layer on a surface of the substrate to polish the substrate.
33. The method of claim 32 , wherein the substrate is a nickel-phosphorus coated aluminum memory disk.