Patent attributes
A carrier head includes a housing, a support assembly having a support plate flexibly connected to the housing so as to be vertically movable, a plurality of fluid-impermeable barriers projecting from a bottom of the support plate to define a plurality of recesses that are open at bottom sides thereof, and pneumatic control lines. A volume between the support plate and the housing includes one or more independently pressurizable first chambers to apply pressure on a top surface of the support plate in one or more first zones. The barriers are positioned and configured such that when a planar substrate is loaded into the carrier head the barriers contact the substrate and divide a volume between the support plate and the substrate into a plurality of second chambers. The pneumatic control lines are coupled to the plurality of recesses to provide a plurality of independently pressurizable second zones.