Wafer polisher head adapted for easy removal of wafers

Abstract

Device is described that reduces the forces needed to release a wafer from a wet polishing surface after polishing. Device comprises attachment adapted to be mounted to a polishing apparatus to permit attachment surface, configured to mate with two regions of the wafer, to tilt relative to the polishing surface. Means for defining adhesive force between attachment surface and one of the two wafer regions, and means for defining adhesive force between attachment surface and other of the two wafer regions which is different than that defined between attachment surface and the one wafer region so as to cause a non-parallel relationship between the one wafer face and polishing surface, are provided. Unbalanced force causes a non-parallel relationship between wafer and polishing pad and facilitates separation and lifting of wafer from polishing surface. Embodiments wherein attachment is a wafer carrier, and unbalanced adhesive force is a vacuum communicated to a limited region of the surface of the carrier by a plurality of fluid transport channels. Other embodiments include a mechanical lifting force to actively tilt surface, a pressurized fluid delivered to the attachment surface for separating the wafer and cleaning the attachment surface, and/or rotary union for coupling fluids between rotatable and nonrotatable portions of the device. Independent pressure chambers for controlling polishing pressure and the adhesion or release of the wafer may be provided.