Chemical mechanical polishing process

Abstract

A first substrate and second substrate both having thereon a top bulk metal layer and a lower barrier layer are prepared. The first substrate is first loaded onto a first platen of a CMP tool, and then an upper portion of the top bulk metal layer of the first substrate is removed by first platen and first slurry. The first substrate is then transferred to a second platen having second slurry. The second substrate is loaded onto the first platen. Simultaneously, the remaining top bulk metal layer of the first substrate and an upper portion of top bulk metal layer of the second substrate are removed at substantially the same copper removal rate until the lower barrier layer of the first substrate is exposed. The first substrate is transferred to a third platen having third slurry for polishing the exposed barrier layer.

1 . A chemical mechanical polishing (CMP) process comprising: 
 providing a first substrate and second substrate both having thereon a top bulk metal layer and a lower barrier layer,    loading said first substrate onto a first platen of a CMP tool, and polishing an upper portion of said top bulk metal layer of said first substrate on said first platen and first slurry;    transferring said first substrate to a second platen having second slurry and loading said second substrate onto said first platen, wherein said second slurry has a copper to barrier polishing selectivity of greater than 30;    simultaneously polishing remaining top bulk metal layer of said first substrate and polishing an upper portion of top bulk metal layer of said second substrate at substantially the same copper removal rate until said lower barrier layer of said first substrate is exposed; and    transferring said first substrate to a third platen having third slurry for polishing said exposed barrier layer.    
   
   
       2 . (canceled)  
   
   
       3 . The chemical mechanical polishing process according to  claim 1  wherein said second slurry has a copper to barrier polishing selectivity of above 100.  
   
   
       4 . The chemical mechanical polishing process according to  claim 1  wherein said second slurry contains alumina.  
   
   
       5 . The chemical mechanical polishing process according to  claim 1  wherein said third slurry contains alumina.  
   
   
       6 . The chemical mechanical polishing process according to  claim 1  wherein said second slurry contains silica.  
   
   
       7 . The chemical mechanical polishing process according to  claim 1  wherein said third slurry contains silica.  
   
   
       8 . The chemical mechanical polishing process according to  claim 1  wherein said first slurry and said second slurry have substantially the same recipe.  
   
   
       9 . The chemical mechanical polishing process according to  claim 1  wherein said first platen and said second platen are substantially the same.  
   
   
       10 . The chemical mechanical polishing process according to  claim 1  wherein said third slurry is different from said first slurry or second slurry.  
   
   
       11 . A chemical mechanical polishing (CMP) process comprising: 
 providing a first substrate and second substrate both having thereon a top bulk metal layer and a lower barrier layer;    loading said first substrate onto a first platen of a CMP tool, and polishing an upper portion of said top bulk metal layer of said first substrate on said first platen with a first polishing recipe setting a plurality of polishing conditions;    transferring said first substrate to a second platen and loading said second substrate onto said first platen;    simultaneously polishing remaining top bulk metal layer of said first substrate and polishing an upper portion of top bulk metal layer of said second substrate with a second polishing recipe substantially the same as said first polishing recipe until said lower barrier layer of said first substrate is exposed; and    transferring said first substrate to a third platen having third slurry for polishing said exposed barrier layer.    
   
   
       12 . The chemical mechanical polishing process according to  claim 11  wherein said plurality of polishing conditions include a polishing pressure, a flow rate of slurry, a rotation rate of platen, and a rotation rate of wafer.  
   
   
       13 . The chemical mechanical polishing process according to  claim 12  wherein said plurality of polishing conditions of said first polishing recipe are the same as those of said second polishing recipe.