Patent ID: 6293850
Filing Date: 2001-09-25
Classification: B24B

Abstract:
A chemical mechanical polishing machine, comprising:a polishing table;a polishing pad on the polishing table;a slurry supplier, to supply slurry onto the polishing table for polishing a wafer;a polishing head, to dispose the wafer therein; anda retainer ring, at the bottom edge of the polishing head to retain the wafer, whereinthe wafer is retained by the retainer ring with its surface to be polished facing the polishing pad; andthe retainer has a plurality of slurry passages to direct the slurry supplied by the slurry supplier through the retainer ring over the surface of the wafer, and the slurry passages are radially declined from an inner perimeter to an outer perimeter and each of the slurry passages has an acute angle of attack against the slurry flow outside the polishing head while the polishing head is spinning for polishing.