Determining when to replace a retaining ring used in substrate polishing operations

摘要

Apparatus and methods of polishing substrates are disclosed. A retaining ring (22) for a polishing apparatus includes an inner surface exposed to contact a peripheral edge of a substrate to be polished against a polishing surface, a bottom surface (32) exposed to contact the polishing surface while the substrate is being polished, and a wear marker (33) indicative of a preselected amount of wear of the bottom surface (32). The inner surface, bottom surface (32) and wear marker (38) may form part of a retaining ring (22) used in chemical mechanical polishing operations. In one method, one or more substrates may be polished against a polishing surface using the retaining ring (22), and at least a portion of the retainer may be replaced when the bottom surface (32) has been worn away by the preselected amount indicated by the wear marker (38). In another method, one or more substrate may be polished against a polishing surface with a substrate carrier that includes a substrate retaining ring with a wear marker indicative of a preselected amount of wear of the retaining ring, and a warning signal may be generated upon detection of the wear marker.