Patent attributes
The present invention relates to a substrate holding apparatus for holding and pressing a substrate against a polishing surface. The substrate holding apparatus includes a top ring body for holding the substrate, an elastic pad for contacting the substrate, and a support member for supporting the elastic pad. The substrate holding apparatus further includes a contact member mounted on a lower surface of the support member and disposed in a space formed by the elastic pad and the support member. The contact member has an elastic membrane for contacting the elastic pad. A first pressure chamber is defined in the contact member, and a second pressure chamber is defined outside of the contact member. The substrate holding apparatus also includes a fluid source for independently supplying a fluid into, or creating a vacuum in, the first pressure chamber and the second pressure chamber.
