System and method for CMP head having multi-pressure annular zone subcarrier material removal control

摘要

An apparatus and method for planarizing a substrate are provided. The apparatus (101) includes a subcarrier (354) having an outer surface (378) with an annular first membrane (376) coupled thereto. The first membrane (376) has a receiving surface (380) adapted to receive the substrate (356) thereon, and a lip (382) adapted to seal with a backside of the substrate to define a first chamber (384) therebetween. A second membrane (386) positioned above the first membrane (376), and coupled to the subcarrier (354) defines a second chamber (388). During a polishing operation pressurized fluid introduced into the second chamber (388) causes it to expand outward to exert a force on a portion of the backside of the substrate (356), thereby pressing a predetermined area (392) of the surface of the substrate against the polishing pad. The predetermined area (392) is directly proportional to the pressure of the fluid introduced into the second chamber (388).