Edge polished wafer, polishing cloth for edge polishing, and apparatus and method for edge polishing

摘要

Provided are a novel edge polished wafer in which a wafer peripheral sag is suppressed, a polishing cloth, a polishing apparatus and a polishing method for processing the wafer. The wafer is provided by controlling an over-polish width in edge polishing to 400 μm or less. Also, the polishing cloth has a multi-layer structure of at least two layers including a polishing fabric layer an Asker C hardness of which is 65 or higher and a sponge layer an Asker C hardness of which is 40 or lower, or a single layer structure of the polishing fabric layer. Further, the polishing apparatus and the polishing method are provided by edge polishing such that the wafer in rotation is put into contact with a rotary drum having the polishing cloth adhered thereon at a prescribed angle thereto while supplying polishing slurry to the contact portion of the polishing cloth.