Patent attributes
A substrate holding device according to the present invention includes an elastic membrane to be brought into contact with a rear surface of a substrate, an attachment member for securing at least a portion of the elastic membrane, and a retainer ring for holding a peripheral portion of the substrate while in contact with the elastic membrane. The elastic membrane comprises at least one projecting portion, and the attachment member comprises at least one engagement portion engaging side surfaces of the at least one projecting portion of the elastic membrane. The elastic membrane further comprises bellows portions expandable in a pressing direction so as to allow the elastic membrane to press the substrate, and contractible along the pressing direction.
