An apparatus for holding a substrate to be polished comprises: a rotating rotary shaft; a substrate holding head in the form of a disc; a sealing member provided to the back face of the substrate holding head; a guiding member which is provided to the back face of the substrate holding head to be located...http://www.google.se/patents/US6074289?utm_source=gb-gplus-sharePatent US6074289 - Apparatus for holding substrate to be polished
