A carrier head of a chemical mechanical polishing apparatus has a support, an elastic membrane secured to the support and spaced from the bottom surface of the support so that a pressure chamber is defined between the membrane and the bottom surface of the support; and at least one annular barrier of...http://www.google.es/patents/US7303466?utm_source=gb-gplus-sharePatente US7303466 - Carrier head of chemical mechanical polishing apparatus having barriers dividing pressure chamber into a plurality of pressure zones
Carrier head of chemical mechanical polishing apparatus having barriers ...
