Two-Part Plastic Retaining Ring

Abstract

A retaining ring includes a generally annular lower portion and a generally annular upper portion. The lower portion has a bottom surface for contacting a polishing pad during polishing and a top surface. The upper portion has a bottom surface secured to the top surface of the lower portion and a top surface configured to be mechanically affixed to and abut a rigid base of a carrier head. The lower portion is a first plastic, and the upper portion is a different second plastic that is about the same or more rigid than the first plastic.

1 . A retaining ring, comprising:
 a generally annular lower portion having a bottom surface for contacting a polishing pad during polishing and a top surface, wherein the lower portion is a first plastic; and   a generally annular upper portion having a bottom surface secured to the top surface of the lower portion and a top surface configured to be mechanically affixed to and abut a rigid base of a carrier head, wherein the upper portion is a different second plastic that is about the same or more rigid than the first plastic.   
     
     
         2 . The retaining ring of  claim 1 , wherein the lower portion is secured to the upper portion and the top surface is configured such that the retaining ring is removable as a unit from the base so that the upper portion remains secured to the lower portion while the retaining ring is removed. 
     
     
         3 . The retaining ring of  claim 1 , wherein the lower portion lacks any aperture from the top surface to the bottom surface of the lower portion. 
     
     
         4 . The retaining ring of  claim 1 , wherein the lower portion is attached to the upper portion by an adhesive. 
     
     
         5 . The retaining ring of  claim 4 , wherein the adhesive is an epoxy. 
     
     
         6 . The retaining ring of  claim 1 , wherein the lower portion has a durometer measurement between about 80 and 95 on the Shore D scale. 
     
     
         7 . The retaining ring of  claim 6 , wherein the upper portion has a durometer measurement of at least 70 on the Shore D scale. 
     
     
         8 . The retaining ring of  claim 7 , wherein the upper portion has a greater elastic modulus than the lower portion. 
     
     
         9 . The retaining ring of  claim 1 , wherein the lower portion is thicker than the upper portion. 
     
     
         10 . The retaining ring of  claim 1 , wherein the first plastic is selected from the group consisting of polyphenylene sulfide (PPS), polyaryletherketone (PAEK), polyetheretherketone (PEEK) and polyetherketoneketone (PEKK). 
     
     
         11 . The retaining ring of  claim 10 , wherein the first plastic is polyphenylene sulfide. 
     
     
         12 . The retaining ring of  claim 1 , wherein the second plastic is selected from the group consisting of polyvinyl chloride (PVC), polypropylene (PP), polycarbonate (PC), polyaryletherketone (PAEK), polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polybutylene terephthalate (PBT), polyoxymethylene (POM), polyethylene terephthalate (PET), perfluoroalkoxy (PFA), polyamideimide (PAI) or polytetrafluoroethylene (PTFE). 
     
     
         13 . The retaining ring of  claim 12 , wherein the second plastic is polyvinyl chloride. 
     
     
         14 . The retaining ring of  claim 1 , wherein the bottom surface of the lower portion has channels for slurry transport. 
     
     
         15 . The retaining ring of  claim 1 , wherein the retaining ring has an inner side wall and an outer side wall, and the inner side wall and outer side wall are oriented vertically from the top surface of the upper portion to the bottom surface of the lower portion. 
     
     
         16 . The retaining ring of  claim 1 , wherein the inner surface and outer surface of the lower portion and upper portion are flush where the lower portion and upper portion are joined. 
     
     
         17 . The retaining ring of  claim 1 , wherein the top surface of the upper portion includes a hole to receive a fastener to mechanically affix the retaining ring to the base.