A CMP structure for CMP processing and a method of making a device using the same are presented. The apparatus comprises a polishing pad on a platen table, a head assembly for holding a wafer against the polishing pad, wherein the head assembly includes a retaining ring, a sensor for sensing the depth of grooves on the retaining ring and a controller for determining an update pressure to apply to the retaining ring based on the depth of the grooves and applying the updated pressure to the retaining ring during processing.