Carrier head for workpiece planarization/polishing

An edge control system for deployment on a CMP carrier head comprising a bladder and a carrier head housing having a passage extending therethrough, the bladder includes a flexible diaphragm and is coupled to the carrier head housing, the edge control system comprising:

• first and second annular ribs each comprising:
• a first end portion sealingly coupled to the carrier head housing;
• a second end portion coupled to the diaphragm;
• and
• a strain relief member substantially intermediate said first end portion and said second end portion;
• and
• a plenum substantially defined by said first and second annular ribs and said carrier head housing, the passage fluidly coupled to said plenum to permit pressurization thereof, said strain relief member promoting the extension of said first and second annular ribs away from the carrier head housing when said plenum is pressurized;
• wherein said first and second annular ribs are substantially adjacent and an inner surface of said first annular rib is coupled to an outer surface of said second annular rib.

A carrier head for supporting a workpiece, the carrier head comprising:

• a carrier head housing, comprising:
• a mount plate;
• a first clamp ring coupled to said carrier head housing such that said second end portion of said first annular rib is sealingly secured between said first clamp ring and said carrier head housing;
• and
• a second clamp ring coupled to said first clamp ring such that said second end portion of said second annular rib is sealingly secured between said first clamp ring and said second clamp ring;
• a bladder, comprising:
• a flexible diaphragm having a first surface, a second surface substantially opposite said first surface, and an outer peripheral edge;
• a first annular rib having a first end portion and a second end portion, said first end portion coupled to said first surface proximate said outer peripheral edge, and said second end portion sealingly coupled to said carrier head housing;
• and
• a second annular rib having a first end portion and a second end portion, said first end portion coupled to said first surface and to said first annular rib, and said second end portion sealingly coupled to said carrier head housing;
• and
• a first plenum defined by said carrier head housing, said first annular rib, and said second annular rib, said first annular rib and said second annular rib moving towards said flexible diaphragm when said first plenum is pressurized to produce an annular protrusion along said second surface of said diaphragm.