Carrier head with a non-stick membrane

Abstract

A carrier head for chemical mechanical polishing of a substrate includes a base and a flexible membrane extending beneath the base to define a chamber. The flexible membrane has a core of a first material and an outer layer of a second material having a lower adhesion to the substrate than the first material. An exposed surface of the outer layer provides a mounting surface for the substrate.

What is claimed is:  
     
         1 . A carrier head for chemical mechanical polishing of a substrate, comprising: 
 a base; and    a flexible membrane extending beneath the base to define a chamber and provide a mounting surface against which a substrate may be positioned, the mounting surface including a low adhesive material to which the substrate does not readily adhere.    
     
     
         2 . A carrier head for chemical mechanical polishing of a substrate, comprising: 
 a base, and    a flexible membrane extending beneath the base to define a chamber, the flexible membrane including a core of a first material and an outer layer of a second material having a lower adhesion to the substrate than the first material, an exposed surface of the outer layer providing a mounting surface for the substrate.    
     
     
         3 . The carrier head of  claim 2 , wherein the first material is an elastomer and the second material is a polymer.  
     
     
         4 . The carrier head of  claim 2 , wherein a thickness of the outer layer is between about 0.1 and 2.0 microns.  
     
     
         5 . The carrier head of  claim 2  wherein a coefficient of friction of the mounting surface against the substrate is less than about 0.5.  
     
     
         6 . The carrier head of  claim 2 , wherein the second material is polyparaxylylene.  
     
     
         7 . The carrier head of  claim 2 , wherein the second material is deposited on the first material.  
     
     
         8 . The carrier head of  claim 7 , wherein the second material is deposited on the first material by gas phase polymerization coating.  
     
     
         9 . The carrier head of  claim 2 , wherein the second material is deposited on selected portions of the first material to form a pattern.  
     
     
         10 . A carrier head for chemical mechanical polishing of a substrate, comprising: 
 a base; and    a flexible membrane extending beneath the base to define a chamber, the flexible membrane including an inner portion formed of a first material and an outer portion formed of a second material, the outer portion providing a mounting surface against which a substrate may be positioned and the second material having a lower adhesion to the substrate than the first material.    
     
     
         11 . A flexible membrane for a carrier head, comprising: 
 a core of a first material; and    an outer layer of a second material formed over the core, an exposed surface of the outer layer providing a mounting surface for a substrate, the second material having a lower adhesion to the substrate than the first material.    
     
     
         12 . A method of moving a substrate with a carrier head, comprising: 
 positioning a substrate against a mounting surface of a flexible membrane of a carrier head, the flexible membrane defining a pressurizable chamber within the carrier head, the flexible membrane including a low adhesion material to which the substrate does not readily adhere;    evacuating the chamber to form a seal between the mounting surface and the substrate;    placing the substrate on a receiving surface; and    pressurizing the chamber to break the seal between the substrate and the mounting surface.    
     
     
         13 . A method of making a flexible membrane for a carrier head, comprising: 
 providing a core formed of a first material;    depositing a second material onto the core to form a layer, the layer providing a mounting surface for a substrate, the second material having a lower adhesion to the substrate than the first material.    
     
     
         14 . The method of  claim 13 , wherein the providing step includes providing a core formed of an elastomer.  
     
     
         15 . The method of  claim 13 , wherein the depositing step includes depositing polymer.  
     
     
         16 . The method of  claim 13 , wherein the depositing step includes depositing polyparaxylylene.  
     
     
         17 . The method of  claim 13 , wherein the depositing step forms the layer with a thickness between about 0.1 and 2.0 microns.  
     
     
         18 . The method of  claim 13 , wherein the depositing step forms the layer with coefficient of friction against the substrate less than about 0.5.  
     
     
         19 . The method of  claim 13 , wherein the depositing step includes gas phase polymerization coating.  
     
     
         20 . The method of  claim 13 , wherein the depositing step forms the layer on selected portions of the first material to form a pattern.