US Patent 11565367 Retaining ring

A retaining ring used in the polishing of semiconductor substrates is described herein. A retaining ring includes a bottom surface configured to contact a polishing pad and a top surface configured to attach to a carrier head. The top surface includes a plurality of screw holes and a plurality of alignment slots. The top surface also includes a first insert disposed in a first alignment slot of the plurality of alignment slots, the first insert flush with or below the top surface, and where the first insert configured to prevent insertion of an alignment pin into the first alignment slot.