Patent ID: 8308972
Filing Date: 2012-11-13
Classification: C09G,C09K,H01L

Abstract:
1. A solution comprising an at least once used silicon wafer polishing composition and an additive solution, wherein the additive solution assists in maintaining stable properties of a polishing operation, the additive solution being added to a polishing composition that has been used at least once in the polishing operation to adjust the polishing composition, the additive solution comprising an alcohol and two or more amine compounds, and the amine compounds comprises a quaternary ammonium salt and a same amine compound as that contained in the polishing composition, wherein the additive solution, when added to the at least once used polishing composition during the polishing operation, assists in preventing a variation in a polishing rate of the polishing operation, and further wherein the at least once used polishing composition is provided from a collection tank.