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US 7,442,645 B2Granted
Method of polishing a silicon-containing dielectric
AssigneeCabot Microelectronics Corporation
InventorsPhillip W. Carter, Timothy P. Johns
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Abstract
The inventive method of polishing a silicon-containing dielectric layer involves the use of a chemical-mechanical polishing system comprising (a) an inorganic abrasive, (b) a polishing additive, and (c) a liquid carrier, wherein the polishing composition has a pH of about 4 to about 6. The inventive chemical-mechanical polishing system comprises (a) ceria, (b) a polishing additive, and (c) a liquid carrier, wherein the polishing system has a pH of about 4 to about 6.
Claims15
A method of polishing a substrate comprising:
- (i) contacting a substrate comprising a silicon dioxide layer and a silicon nitride layer with a chemical-mechanical polishing system comprising:
- (a) an inorganic abrasive,
- (b) a polishing additive bearing a functional group with a pKa of about 3 to about 9, wherein the polishing additive is selected from the group consisting of aniline and arylamines having one or more substituents selected from the group consisting of carboxylic acids, sulfonic acids, phosphonic acids, thiol groups, sulfonamides, salts thereof, and combinations thereof, and
- (c) a liquid carrier,
- wherein the polishing system has a pH of about 7 or less and does not contain a significant amount of cross-linked polymer abrasive particles that are electrostatically associated with the inorganic abrasive, and
- (ii) abrading at least a portion of the silicon dioxide layer to polish the substrate.
3 more elements
Dependencies are inferred from the claim text.