Thermoplastic chemical mechanical polishing pad and method of manufacture

Abstract

The present invention is directed, in general, to a chemical mechanical polishing pad comprising a closed-cell thermoplastic foam polishing body. The polishing body comprises an ethylene vinyl acetate block copolymer. The ethylene vinyl acetate block copolymer comprises a vinyl acetate content ranging from about 1 to about 18 wt %. The closed-cell thermoplastic foam polishing body also comprises filler particles comprising an average size ranging from about 1 to about 20 microns. Other aspects of the invention comprise a method for manufacturing the above-described chemical mechanical polishing pad and chemical mechanical polishing apparatus comprising the chemical mechanical polishing pad.

1 . A chemical mechanical polishing pad comprising: 
 a closed-cell thermoplastic foam polishing body comprising: 
 an ethylene vinyl acetate block copolymer comprising a vinyl acetate content ranging from about 1 to about 18 wt %; and  
 filler particles comprising an average size ranging from about 1 to about 20 microns, and 
 wherein an interior of said closed-cell thermoplastic foam polishing body comprise cells having an average size ranging from about 50 to about 300 microns.  
 
   
     
     
         2 . The chemical mechanical polishing pad as recited in  claim 1 , wherein a polishing surface of said closed-cell thermoplastic foam polishing body comprise projections raised above said polishing surface by no more than said average size.  
     
     
         3 . The chemical mechanical polishing pad as recited in  claim 1 , wherein a polishing surface of said closed-cell thermoplastic comprises concave cells having said average diameter.  
     
     
         4 . The chemical mechanical polishing pad as recited in  claim 1 , wherein said ethylene vinyl acetate block copolymer has a vinyl acetate content ranging from about 6 to about 12 wt %.  
     
     
         5 . The chemical mechanical polishing pad as recited in  claim 1 , wherein said ethylene vinyl acetate block copolymer has a melt index ranging from 0.2 to about 25 dg/min (ASTM D1238).  
     
     
         6 . The chemical mechanical polishing pad as recited in  claim 1 , wherein said closed-cell thermoplastic foam polishing body has a hardness ranging from about 20 to about 75 Shore A.  
     
     
         7 . The chemical mechanical polishing pad as recited in  claim 1 , wherein said closed-cell thermoplastic foam polishing body has a gel fraction ranging from about 60 to about 90 percent.  
     
     
         8 . The chemical mechanical polishing pad as recited in  claim 1 , wherein said thermoplastic foam polishing body has a density ranging from about 0.1 to about 0.4 g/cm 3 .  
     
     
         9 . The chemical mechanical polishing pad as recited in  claim 1 , wherein said closed-cell thermoplastic foam polishing body comprise said filler particle ranging from about 3 to about 20 wt %.  
     
     
         10 . The chemical mechanical polishing pad as recited in  claim 1 , wherein said closed-cell thermoplastic foam polishing body comprise said filler particles ranging from about 10 to about 20 wt %.  
     
     
         11 . The chemical mechanical polishing pad as recited in  claim 1 , wherein said filler particles have a hardness ranging from about 6 to about 8 mohs.  
     
     
         12 . The chemical mechanical polishing pad as recited in  claim 1 , wherein said closed-cell thermoplastic foam polishing body has a tungsten removal rate of least about 200 nm/min, a non-uniformity (WIWNU) of about 8% or less and longevity of at least about 1000 polishing minutes per pad.  
     
     
         13 . The chemical mechanical polishing pad as recited in  claim 1 , wherein said closed-cell thermoplastic foam polishing body has a dishing parameter of less than 100 nm on a 100 micron line and an erosion parameter of less than 300 nm on an array of 1 micron lines and spaces at 50% pattern density.  
     
     
         14 . The chemical mechanical polishing pad as recited in  claim 1 , wherein said closed-cell thermoplastic foam polishing body has a defect count of less than about 50 counts per 200 mm substrate.  
     
     
         15 - 20 . (canceled)  
     
     
         21 . A chemical mechanical polishing apparatus comprising: 
 a mechanically driven carrier head; a polishing platen, said carrier head being positionable against said polishing platen to impart a polishing force against said polishing platen; and    a polishing pad attached to said polishing platen, said polishing pad comprising: 
 a closed-cell thermoplastic foam polishing body comprising:—
 an ethylene vinyl acetate block copolymer comprising a vinyl acetate content ranging from about 1 to about 18 wt %; and  
 
 filler particles comprising an average size ranging from about 1 to about 20 microns, and  
 wherein an interior of said closed-cell thermoplastic foam polishing body comprise cells having an average size ranging from about 50 to about 300 microns.  
   
     
     
         22 . The chemical mechanical polishing pad as recited in  claim 1 , wherein said average size ranges from about 100 to about 200 microns.