Patent attributes
A membrane for a CMP carrier head includes a circular lower portion that provides a substrate mounting surface for a central region of a substrate, a first plurality of flaps that extend upward from the circular lower portion to form a plurality of inner chambers, an annular upper portion that provides a lower surface for applying pressure to an annular outer region of the substrate, and a second plurality of flaps that extend upward from the annular upper portion to form a plurality of independently pressurizable outer chambers. The annular upper portion surrounds the circular lower portion and is vertically offset from the circular lower portion such that the lower surface is positioned above a plane defined by the circular lower portion, and the annular upper portion is coupled to an outermost flap of the first plurality of flaps.