Patent ID: 7137874
Filing Date: 2006-11-21
Classification: B24B

Abstract:
1. Wafer polishing apparatus comprising: a base for supporting elements of the polishing apparatus; a turntable having a polishing pad thereon and mounted on the base for rotation of the turntable and polishing pad relative to the base about an axis perpendicular to the turntable and polishing pad, the polishing pad including a work surface engageable with a front surface of a wafer for polishing the front surface of the wafer; a drive mechanism mounted on the base for imparting rotational motion about an axis substantially parallel to the axis of the turntable; a polishing head connected to the drive mechanism for driven rotation of the polishing head, the polishing head being adapted to hold at least one wafer for engaging a front surface of the wafer with the work surface of the polishing pad; and a spherical bearing assembly mounting the polishing head on the drive mechanism for pivoting of the polishing head about a gimbal point lying below the interface of the front surface of the wafer and the work surface on a side of the interface containing the turntable when the polishing head holds the wafer in engagement with the polishing pad, thereby allowing the plane of the front surface of the wafer to continuously align itself to apply slightly more polishing pressure to a trailing edge of the wafer, while rotation of the polishing head is driven by the driving mechanism for maintaining the front surface and work surface in flatwise engagement for more uniform polishing of a semiconductor wafer.