Slurry for chemical mechanical polishing of cobalt

Patent metadata

Field	Value
Publication number	US-9944828-B2
Application number	US-201514919526-A
Country	US
Kind code	B2
Filing date	Oct 21, 2015
Priority date	Oct 21, 2014
Publication date	Apr 17, 2018
Grant date	Apr 17, 2018

Abstract

The invention provides a chemical-mechanical polishing composition including (a) an abrasive comprising alumina particles, silica particles, or a combination thereof, (b) a rate accelerator comprising a phosphonic acid, an N-heterocyclic compound, or a combination thereof, (c) a corrosion inhibitor comprising an amphoteric surfactant, a sulfonate, a phosphonate, a carboxylate, a fatty acid amino acid, an amine, an amide, or a combination thereof, (d) an oxidizing agent, and (e) an aqueous carrier. The invention also provides a method of polishing a substrate, especially a substrate comprising a cobalt layer, with the polishing composition.

First claim

The invention claimed is:

1. A chemical-mechanical polishing composition comprising:
(a) about 0.1 wt. % to about 13 wt. % of an abrasive comprising alumina particles, silica particles, or a combination thereof,
(b) about 0.05 wt. % to about 5 wt. % of a rate accelerator comprising a phosphonic acid, an N-heterocyclic compound, or a combination thereof,
(c) a corrosion inhibitor comprising an amphoteric surfactant, a sulfonate, a fatty acid amino acid, an amide, or a combination thereof,
(d) about 0.1 wt. % to about 5 wt. % of an oxidizing agent, and
(e) an aqueous carrier, wherein the polishing composition further comprises a secondary rate accelerator comprising a phosphate salt, a borate salt, or a combination thereof, at a concentration of about 0.1 wt. % to about 1 wt. %.

2. The chemical-mechanical polishing composition of claim 1 , wherein the abrasive comprises alumina particles, wherein the alumina particles are alpha alumina particles, and wherein at least a portion of the surface of the alpha alumina particles is coated with a negatively-charged polymer or copolymer.

3. The chemical-mechanical polishing composition of claim 1 , wherein the abrasive comprises silica particles, and wherein the silica particles are colloidal silica particles.

4. The chemical-mechanical polishing composition of claim 1 , wherein the abrasive is present in the polishing composition at a concentration of about 0.3 wt. % to about 4 wt. %.

5. The chemical-mechanical polishing composition of claim 1 , wherein the rate accelerator is present in the polishing composition at a concentration of about 0.2 wt. % to about 1 wt. %.

6. The chemical-mechanical polishing composition of claim 1 , wherein the rate accelerator comprises a phosphonic acid.

7. The chemical-mechanical polishing composition of claim 6 , wherein the phosphonic acid is an amino tri(methylene phosphonic acid).

8. The chemical-mechanical polishing composition of claim 1 , wherein the rate accelerator comprises an N-heterocyclic compound.

9. The chemical-mechanical polishing composition of claim 8 , wherein the N-heterocyclic compound is picolinic acid, L-histidine, 2-mercapto-1-methylimidazole, or imidazole.

10. The chemical-mechanical polishing composition of claim 1 , wherein the corrosion inhibitor is present in the polishing composition at a concentration of about 0.001 wt. % to about 0.25 wt. %.

11. The chemical-mechanical polishing composition of claim 1 , wherein the corrosion inhibitor is a fatty acid amino acid.

12. The chemical-mechanical polishing composition of claim 11 , wherein the fatty acid amino acid is sodium lauroyl sarcosinate, sodium cocoyl alaninate, cocoyl glutamate, cocoyl sarcosinate, or myristoyl sarcosinate.

13. The chemical-mechanical polishing composition of claim 1 , wherein the corrosion inhibitor is a sodium C 14-17 sec-alkyl sulfonate.

14. The chemical-mechanical polishing composition of claim 1 , wherein the corrosion inhibitor is a cocoyl diethanolamide.

15. The chemical-mechanical polishing composition of claim 1 , wherein the polishing composition further comprises an ethylene oxide/propylene oxide block copolymer.

16. The chemical-mechanical polishing composition of claim 15 , wherein the ethylene oxide/propylene oxide block copolymer is present in the polishing composition at a concentration of about 0.005 wt. % to about 0.1 wt. %.

17. The chemical-mechanical polishing composition of claim 1 , wherein the polishing composition further comprises polyacrylic acid.

18. The chemical-mechanical polishing composition of claim 1 , wherein the pH of the polishing composition is about 4 to about 7.

19. The chemical-mechanical polishing composition of claim 1 , wherein the pH of the polishing composition is about 8 to about 11.

Assignees

• Cabot Microelectronics Corp

Inventors

• Sikma Elise
• Paw Witold
• Petro Benjamin
• Cross Jeffrey
• Whitener Glenn

Classifications

• H10P52/403

  of conductive or resistive materials · CPC title

• C23F3/06

  with acidic solutions · CPC title

• C23F3/04

  Heavy metals · CPC title

• B24B37/044

  characterised by the composition of the lapping agent · CPC title

• C09G1/02 Primary

  containing abrasives or grinding agents {(abrasives as such C09K3/14; polishing of semi-conductors H10P52/40)} · CPC title