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US 6,641,631 B2Granted
Polishing of semiconductor substrates
AssigneeRodel Holdings, Inc.
InventorsTerence M. Thomas, Craig D. Lack, Steven P. Goehringer
Life of this patent
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Abstract
An aqueous polishing composition having abrasive particles of a metal oxide has a pH that undergoes pH drift, because ions are provided by dissolution of the metal oxide, and the pH drift is minimized by providing the aqueous polishing composition with an equilibrium concentration of the ions at said pH.
Claims5
In a method of controlling pH of an aqueous polishing composition having abrasive particles of a metal oxide that provides ions upon dissolution, the improvement comprising the step of:
- providing the aqueous polishing composition with an equilibrium concentration of said ions at said pH, which avoids drift of said pH caused by dissolution of the particles.
Dependencies are inferred from the claim text.