Patent ID: 8025808

Claim:
A method for machining a ceramic substrate containing Al, comprising: providing a solution containing a phosphorus compound in direct contact with the ceramic of the ceramic substrate, the ceramic of the ceramic substrate comprising Al, the phosphorus compound being an organophosphorus compound, abrasive particles present in the solution as free abrasives, forming a slurry; and machining the substrate with the abrasive particles, wherein a ratio MRR add /MRR con is not less than 1.2, where MRR add is the material removal rate of polishing the substrate with said slurry comprising the abrasive and the organophosphorus compound, and where MRR con is a material removal rate under identical process conditions with a control slurry free of the organophosphorus compound; wherein the organophosphorus compound is selected from the group consisting of hydroxy phosphono acetic acid, aminotri-(methylenephosphonic acid), hexapotassiumhexamethylenediaminetetra-(methylenephosphonic acid), 2-phosphonobutane-1,2,4-tricarboxylic acid, phosphate acid ester of ethoxylated phenol, and hydroxyethylidinediphosphonic acid.