Abstract: Methods and a platen control parameters of a removal rate characteristic in chemical mechanical planarization, while allowing a low-cost polishing pad to be used especially in fast edge operations, and while reducing the amount of fluid used to support the polishing pad. Platen configuration provides fluid pressure control to reduce leakage of fluid from beneath the polishing pad, and contributes to control of a location of an inflection point of the removal rate characteristic. Another configuration controls a shape of a section of the removal rate characteristic between the inflection point and a leading wafer edge.

Abstract: An invention is provided for a CMP apparatus that enhances removal rate uniformity. The CMP apparatus includes a polishing belt disposed below a carrier head that is capable of applying a wafer to the polishing belt. Also included is a platen disposed below the polishing belt. The platen includes a circular shim section disposed on the top surface of the platen. The circular shim section is higher than the top surface of the platen. When using this configuration, increasing pressure to the backside of the polishing belt decreases the edge removal rate of the wafer. Conversely, decreasing pressure to the backside of the polishing belt increases the edge removal rate of the wafer.