Patent ID: 6802983
Filing Date: 2004-10-12
Classification: B24B

Abstract:
A method for separating and removing potentially damaging particles in a polishing slurry prior to a chemical mechanical polishing process, the method comprising:filtering an abrasive polishing slurry through a filter having a pore size not greater than 25 microns; introducing the filtered polishing slurry into a solid bowl, sedimentation-type centrifuge comprising a vertical stack of thin discs; separating abrasive polishing particulates having a particle size greater than about 0.5 micron from the filtered polishing slurry and ejecting the particulates through a plurality of nozzles on solid bowl sedimentation-type centrifuge to yield a product slurry; and continuously removing the product slurry from the solid bowl sedimentation-type centrifuge, the product slurry having abrasive particles of about 0.5 microns and less, to provide a polishing slurry for chemical mechanical polishing.