Patent ID: 7824244

Claim:
An apparatus, comprising: a base on which a substrate may be releasably coupled; a moving abrasive member located with respect to the base such that a contact surface thereof is operable to remove material from a top surface of the substrate; and a plurality of actuators, at least two of which are independently controllable, and at least one of the plurality of actuators is a fluid controlled actuator, located with respect to the base and the moving abrasive member such that a corresponding plurality of pressure zones are defined to provide pressure between the moving abrasive member and the top surface of the substrate, wherein the at least one fluid controlled actuator includes a self compensating hydrostatic pad defined by a volume of relatively higher pressure fluid in communication with one of the moving abrasive member and a bottom surface of the substrate such that the hydrostatic pad is operable to vary the pressure between the moving abrasive member and the top surface of the substrate in the associated pressure zone.