Control of CMP removal rate uniformity by selective heating of pad area

Abstract

A CMP machine ( 100, 200, 300 ) and/or process that uses selective heating of the polishing pad/belt ( 120, 220, 320 ) to improve uniformity. A heating mechanism ( 110 ) is used to heat a selected area such as the perimeter ( 130, 230, 330 ) of the pad or belt ( 120, 220, 320 ). Heating the selected area improves the removal rate in that area. For example, heating along the perimeter of the pad ( 120, 220, 320 ) improves the removal rate at the perimeter of the semiconductor wafer ( 150 ).

1 . A method of fabricating an integrated circuit, comprising the steps of: 
 placing a wafer against a moving polishing pad while adding a slurry and heating a selected portion of said polishing piece.    
     
     
         2 . The method of  claim 1 , wherein said polishing pad is a polishing belt.  
     
     
         3 . The method of  claim 1 , wherein said heating step is accomplished using a heating mechanism comprising a plurality of heat lamps to radiantly heat said polishing piece.  
     
     
         4 . The method of  claim 1 , wherein said polishing piece is a polishing pad and said heating is accomplished using heating wires placed within the polishing pad.  
     
     
         5 . The method of  claim 1 , wherein said selected portion comprises a peripheral area of said polishing piece.  
     
     
         6 . The method of  claim 1 , wherein said selected portion is heated to a temperature on the order of 35° C.  
     
     
         7 . The method of  claim 1 , wherein said heating step supplies a temperature gradient on the order of 15° C.  
     
     
         8 . A method of fabricating an integrated circuit, comprising the steps of: 
 providing a partially fabricated wafer to a wafer carrier of a chemical-mechanical polish (CMP) machine;    moving a polishing piece of said CMP machine;    adding slurry to a surface of said polishing piece;    placing said wafer against said surface while said polishing piece is moving;    providing a temperature gradient across said surface of said polishing piece by heating a selected portion of said polishing piece using a heating mechanism.    
     
     
         9 . The method of  claim 8 , wherein said temperature gradient is about 15° C.  
     
     
         10 . The method of  claim 8 , wherein said heating mechanism comprises a plurality of heat lamps to radiantly heat said selected portion of said polishing piece.  
     
     
         11 . The method of  claim 8 , wherein said polishing piece is a polishing pad and said heating mechanism comprises heating wires placed within the polishing pad.  
     
     
         12 . The method of  claim 8 , wherein said selected portion comprises a peripheral area of said polishing piece.  
     
     
         13 . A chemical-mechanical polish (CMP) machine comprising: 
 a platen;    a polishing piece located over said platen;    a wafer carrier for holding a wafer against said polishing pad; and    a heating mechanism for establishing a temperature gradient across said polishing piece by heating a selected portion of said polishing piece.    
     
     
         14 . The CMP machine of  claim 13 , wherein said polishing pad comprises a polishing belt.  
     
     
         15 . The CMP machine of  claim 13 , wherein said heating mechanism comprises a plurality of heat lamps to radiantly heat said selected portion of said polishing piece.