Patent attributes
A polishing head capable of preventing contact between both side walls of an elastic membrane when a negative pressure is formed in a pressure chamber formed by the elastic membrane. The polishing head includes: a first elastic membrane configured to press the workpiece against the polishing pad; a retainer ring surrounding the first elastic membrane; a second elastic membrane configured to press the retainer ring against the polishing pad; a carrier to which the first elastic membrane is secured; and an attachment member arranged in a pressure chamber formed by the second elastic membrane and fixing the second elastic membrane to the carrier. The attachment member has a support portion extending toward the retainer ring along a side wall of the second elastic membrane.
