Method of controlling carrier head with multiple chambers

Abstract

A carrier head with a flexible member connected to a base to define a first chamber, a second chamber and a third chamber. A lower surface of the flexible member provides a substrate receiving surface with an inner portion associated with the first chamber, a substantially annular middle portion surrounding the inner portion and associated with the second chamber, and a substantially annular outer portion surrounding the middle portion and associated with the third chamber. The width of the outer portion may be significantly less than the width of the middle portion. The carrier head may also include a flange connected to a drive shaft and a gimbal pivotally connecting the flange to the base.

1 . A carrier head for use in a chemical mechanical polishing system, comprising: 
 a base; and    a flexible member connected to the base to define a first chamber, a second chamber and a third chamber, a lower surface of the flexible member providing a substrate receiving surface with an inner portion associated with the first chamber, a substantially annular middle portion surrounding the inner portion and associated with the second chamber, and a substantially annular outer portion surrounding the middle portion and associated with the third chamber, such that the pressure on either the inner, middle or outer portions of the flexible membrane may be independently controlled.    
     
     
         2 . The carrier head of  claim 1  wherein a width of the outer portion is significantly less than a width of the middle portion.  
     
     
         3 . The carrier head of  claim 2  wherein the outer portion has an outer radius approximately equal to or greater than 100 millimeters and the width of the outer portion is between about 4 and 20 millimeters.  
     
     
         4 . The carrier head of  claim 1  wherein the flexible member includes an inner annular flap, a middle annular flap, and an outer annular flap, each flap being secured to a lower surface of the base to define the first, second and third chambers.  
     
     
         5 . A carrier head for use in a chemical mechanical polishing system, comprising: 
 first, second and third independently pressurizable chambers;    a flexible inner member associated with the first chamber to apply a first pressure to a central portion of a substrate;    a substantially annular flexible middle member associated with the second chamber and surrounding the inner member to apply a second pressure to a middle portion of the substrate; and    a substantially annular flexible outer member associated with the third chamber and surrounding the middle member to apply a third pressure to an outer portion of the substrate, wherein the outer member is substantially narrower than the middle member.    
     
     
         6 . The carrier head of  claim 5 , wherein the inner member, the middle member, and the outer member are portions of a flexible membrane.