Patent ID: 11890717
Assignee: APPLIED MATERIALS, INC.
Field: Machine tools (Mechanical engineering)
Classification: CPC B | IPC B

Claim 19:
20. A polishing system, comprising:
an annular platen having a top surface to support a main polishing pad, the annular platen having an aperture in a top surface of the annular platen that overlaps a center of the annular platen, the annular platen rotatable about an axis of rotation that passes through approximately the center of the annular platen;
an annular flange projecting radially inward from the annular platen into the aperture to support an inner polishing pad, the annular flange being a unitary body having an outer edge secured to and rotatable with the annular platen and vertically fixed relative to the top surface of the annular platen, the annular flange being vertically deflectable such that an inner edge of the annular flange being deformable and vertically movable relative to the outer edge of the annular flange;
an actuator configured to apply pressure to an underside of the annular flange in an angularly limited region such that the angularly limited region of the annular flange and an angularly limited portion of the inner polishing pad are lifted relative to the annular platen, an undeformed portion of the annular flange, and main polishing pad; and
a carrier head to hold a substrate in contact with the main polishing pad and movable to selectively position a portion of the substrate over the angularly limited portion of the inner polishing pad.