Patent ID: 8834230
Filing Date: 2014-09-16
Classification: B24B,B24D,H01L

Abstract:
1. A wafer polishing method including simultaneously polishing both surfaces of a wafer by providing an upper turn table having a flat polishing-lower-surface so as to face toward a lower turn table having a flat polishing-upper-surface; providing polishing pads attached to the respective upper and lower turn tables; holding the wafer with the upper turn table, the lower turn table, and a carrier having a wafer-holding hole for holding the wafer; and pressing and rubbing the wafer while the upper turn table and the lower turn table are rotationally driven, wherein: the polishing is performed while supplying a polishing slurry from above the held wafer and measuring a thickness of the wafer through a plurality of openings provided between a rotation center and an edge of the upper turn table or the lower turn table, switching the polishing slurry with a polishing slurry having a different polishing rate during the polishing of the wafer, and a timing of the switching of the polishing slurry is determined on the basis of a lifetime of the polishing pads.