Apparatus of carrier in a chemical mechanical polishing equipment comprises a carrier module for holding a wafer face down. A retaining ring and conditioning module is coupled to the carrier module, which is used for protecting the wafer edge against contact with a polishing pad in a deformed shape and executing a conditioning of the polishing pad. A first support module is coupled to the retaining ring and conditioning module, which is used for rotating, pressing down, and supplying conditioning chemicals for the retaining ring and conditioning module.
New baffles and methods of using these baffles are provided. The baffles comprise a body having an edge wall configured to direct the flow of a composition against a substrate (e.g., silicon wafer) edge. The edge wall comprises a vertical surface, a curved sidewall coupled to the vertical surface, and a lip coupled to the curved sidewall. A preferred baffle is annular in shape and formed from a synthetic resinous composition. Even more preferably, the baffle is not formed of a metal. The inventive methods comprise positioning the baffle adjacent a substrate during a spin coating process so that the edge wall causes the composition to cover the edges of the substrate and preferably a portion of the back side of the substrate.