POLISHING HEAD OF CMP APPARATUS

摘要

PURPOSE: A polishing head of a CMP(Chemical Mechanical Polishing) apparatus is provided to polish uniformly a wafer by improving a structure of the polishing head. CONSTITUTION: A surface of a wafer(W) is contacted with a polishing pad. A back face of the wafer(W) is contacted with a polishing head(32). A main body(34) is formed with a housing(36), a base(38), and a retainer ring(40). The base(38) is used for supporting the housing(36). The retainer ring(40) is installed at an edge of a lower portion of the base(38) in order to prevent an escape of the wafer. The housing(36) is connected with a drive portion. The housing(36) has a circular upper face and a circular lower face. The housing(36) includes the first tube(42a). The second and the third tubes(42b,42c) are formed at a predetermined position apart from the first tube(42a). A base(38) is used for supporting the housing(36). The first chamber(44) is formed between the housing(36) and the base(38). A perforate plate(46) is installed at a lower portion of the main body(34). A plurality of through-holes(46a) are formed on the perforate plate(46). A separation plate(48) is formed between the base(38) and the perforate plate(46). An air cushion(50) is installed on an edge portion of the perforate plate(46). A membrane(52) is formed on a lower face of the perforate plate(46).