Carrier head with a multilayer retaining ring for chemical mechanical polishing

A retaining ring for a carrier head having a mounting surface for a substrate, comprising:

• a generally annular lower portion having a bottom surface for contacting a polishing pad during polishing and made of a first material which is inert in a chemical mechanical polishing process;
• and
• a generally annular upper portion joined to the lower portion and made of a second material which is more rigid than the first material;
• wherein the first material is polyphenylene sulfide with a durometer measurement between about 80 and 95 on the Shore D scale, the second material is metal, and the lower portion is affixed to the upper portion by an epoxy.

A chemical mechanical polishing system, comprising:

• a rotatable polishing pad;
• a slurry supply to dispense a slurry onto the polishing pad;
• and
• a carrier head having a substrate mounting surface and a retaining ring to maintain a substrate beneath the mounting surface during polishing, the retaining ring including a lower portion for contacting a polishing pad during polishing and made of a first material, and an upper portion made of a second material which is more rigid than the first material;
• wherein the first material is polyphenylene sulfide with a durometer measurement between about 80 and 95 on the Shore D scale, the second material is metal, and the lower portion is affixed to the upper portion by an epoxy.