Corrosion inhibitors and related compositions and methods
The invention provides methods of inhibiting corrosion of a substrate containing metal. The substrate can be in any suitable form. In some embodiments, the metal is cobalt. The methods can be used with semiconductor wafers in some embodiments. The invention also provides chemical-mechanical polishing compositions and methods of polishing a substrate. A corrosion inhibitor can be used in the methods and compositions disclosed herein. The inhibitor comprises an amphoteric surfactant, a sulfonate, a phosphonate, a carboxylate, an amino acid derivative, a phosphate ester, an isethionate, a sulfate, a sulfosuccinate, a sulfocinnimate, or any combination thereof.
1. A chemical-mechanical polishing composition comprising:
(a) an abrasive comprising colloidal silica particles,
(b) a rate accelerator comprising a phosphonic acid, an N-heterocyclic compound, or a combination thereof,
(c) a corrosion inhibitor comprising an amino acid derivative, wherein the amino acid derivative is N-cocoyl sarcosinate, N-lauroyl sarcosinate, N-stearoyl sarcosinate, N-oleoyl sarcosinate, N-myristoyl sarcosinate, or any combination thereof; wherein the inhibitor is present in an amount of from about 0.004 wt. % to about 0.010 wt. %,
(d) an oxidizing agent, and
(e) an aqueous carrier, wherein the polishing composition is substantially free of an aromatic azole, and
the pH of the polishing composition is about 3 to about 8.5.
2. The chemical-mechanical polishing composition of claim 1 , wherein the oxidizing agent is a compound that oxidizes cobalt.
3. The chemical-mechanical polishing composition of claim 1 , wherein the colloidal silica particles are anionic colloidal silica particles.
4. A method of polishing a substrate comprising:
(i) providing a substrate, wherein the substrate comprises a cobalt 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 cobalt layer to polish the substrate.