Control of CMP removal rate uniformity by selective control of slurry temperature

Abstract

A CMP machine ( 100, 200, 300 ) and/or process that uses selective heating of the slurry ( 160 ) to improve uniformity. A temperature control mechanism ( 110 ) is used to heat and/or cool slurry ( 160 ) applied to a selected area of the pad or belt ( 120, 220, 320 ). Heating in the selected area improves the removal rate in that area, whereas cooling decreases the removal rate in that area. For example, heating along the perimeter of the pad ( 120, 220 ) improves the removal rate at the perimeter of the semiconductor wafer ( 150 ).

In the claims:  
     
         1 . A method of fabricating an integrated circuit, comprising the steps of: 
 placing a wafer against a moving polishing pad while adding a first slurry to a first location and a second slurry to a second location wherein a temperature of said first slurry is higher than a temperature of said second slurry.    
     
     
         2 . The method of    claim 1   , wherein said polishing pad is a polishing belt.  
     
     
         3 . The method of    claim 1   , wherein said temperature of said first slurry is between room temperature and 40° C.  
     
     
         4 . The method of    claim 1   , wherein said temperature of said second slurry is between 5° C. and room temperature.  
     
     
         5 . The method of    claim 1   , wherein said second slurry spends a higher percentage of time near a center said wafer than said first slurry.  
     
     
         6 . The method of    claim 1   , wherein said second slurry penetrates further under said wafer than said first slurry.  
     
     
         7 . 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 pad of said CMP machine;    adding slurry to a surface of said polishing pad from at least two dispense points, wherein there is a slurry temperature gradient between said at least two dispense points; and    placing said wafer against said surface while said polishing pad is moving.    
     
     
         8 . The method of    claim 7   , wherein said polishing pad is a polishing belt.  
     
     
         9 . The method of    claim 7   , wherein a first of said at least two dispense points is located near a center of said polishing piece and a second of said at least two dispense points is located near an edge of said polishing piece.  
     
     
         10 . The method of    claim 9   , wherein a temperature of said slurry from said first dispense point is less than a temperature of said slurry from said second dispense point.  
     
     
         11 . The method of    claim 7   , wherein slurry from a first of said at least two dispense points penetrates further under the wafer than slurry from a second of said at least two dispense points.  
     
     
         12 . The method of    claim 7   , wherein slurry from a first of said at least two dispense points has a lower temperature than slurry from a second of said at least two dispense points.  
     
     
         13 . A chemical-mechanical polish (CMP) machine comprising: 
 a platen;    a polishing pad located over said platen;    a wafer carrier for holding a wafer against said polishing pad; and    at least two slurry dispense outlets, wherein at least one of said slurry dispense outlets contains a temperature control mechanism for establishing a slurry temperature gradient between said at least two slurry dispense outlets.    
     
     
         14 . The CMP machine of    claim 13   , wherein said a first of said at least two slurry dispense outlets is located nearer a center of said polishing piece and a second of said at least two slurry dispense outlet is located nearer an edge of said polishing piece.