Method to increase barrier film removal rate in bulk tungsten slurry
AssigneeCMC Materials, Inc.
InventorsWilliam J. Ward, Matthew E. Carnes, Ji Cui, Helin Huang
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Abstract
The invention relates to a chemical-mechanical polishing composition comprising (a) a first abrasive comprising cationically modified colloidal silica particles, (b) a second abrasive having a Mohs hardness of about 5.5 or more, (c) a cationic polymer, (d) an iron containing activator, (e) an oxidizing agent, and (f) water. The invention also relates to a method of chemically mechanically polishing a substrate, especially a substrate comprising tungsten and barrier layers (e.g., nitrides), with the polishing composition.
Claims28
A chemical-mechanical polishing composition comprising:
- (a) a first abrasive comprising cationically modified colloidal silica particles,
- (b) a second abrasive having a Mohs hardness of about 5.5 or more, wherein the second abrasive is selected from α-alumina particles, zirconia particles, diamond particles, and combinations thereof,
- (c) a cationic polymer,
- (d) an iron containing activator,
- (e) an oxidizing agent, and
- (f) water.
A method of chemically mechanically polishing a substrate comprising:
- (i) providing a substrate,
- (ii) providing a polishing pad,
- (iii) providing a chemical-mechanical polishing composition comprising:
- (a) a first abrasive comprising cationically modified colloidal silica particles,
- (b) a second abrasive having a Mohs hardness of about 5.5 or more,
- (c) a cationic polymer,
- (d) an iron containing activator,
- (e) an oxidizing agent, and
- (f) water,
- (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, wherein the substrate comprises both a tungsten layer and a titanium nitride layer on a surface of the substrate, and wherein both the tungsten layer and the titanium nitride layer are abraded to polish the substrate.
Dependencies are inferred from the claim text.