MEMBRANE ASSEMBLY AND CARRIER HEAD HAVING THE MEMBRANE ASSEMBLY

摘要

Provided is a membrane assembly of a carrier head in a chemical-mechanical polishing apparatus. The membrane assembly includes a main membrane and a circular ring. The main membrane has a wafer contacting surface in contact with a wafer while a chemical-mechanical polishing process is being performed. The circular ring is disposed at an edge portion of the main membrane and receives an air pressure to downwardly apply the air pressure to the main membrane at the edge portion.