Patent ID: 8636561

Claim:
A polishing head configured to operate by a rubber-chuck method, the polishing head including at least: an annular rigid ring; a rubber film bonded to the rigid ring with a uniform tension; a mid plate joined to the rigid ring, the mid plate forming a space together with the rubber film and the rigid ring; an annular template provided concentrically with the rigid ring in a peripheral portion on a lowermost face portion of the rubber film; and a pressure adjustment mechanism configured to change pressure of the space, the polishing head holding a back surface of a workpiece on the lowermost face portion of the rubber film, holding an edge portion of the workpiece with the template, pressing the workpiece toward a polishing pad by inflating the rubber film with the pressure of the space, and polishing the workpiece by bringing a surface of the workpiece into sliding contact with the polishing pad attached onto a turn table, wherein the space is divided by at least one annular wall concentric with the rigid ring to form a plurality of sealed spaces; an outer diameter of at least one inside sealed space of the plurality of sealed spaces divided by the at least one annular wall is formed so as to be equal to or more than a diameter of a flatness-guaranteed region of the workpiece and to be equal to or less than 102% of an inner diameter of the template; and the pressure adjustment mechanism separately controls pressure of each of the plurality of sealed spaces.