Chemical-mechanical polishing slurry with improved defectivity

Abstract

The copper CMP in a damascene structure composes of copper removal step, which removes majority or all of the redundant copper, and subsequent barrier removal step. The embodiment of the present invention includes the removal of the barrier layer with a slurry blended from abrasive silica particles, chemical materials, and de-ionized water. The blended slurry is aged for at least 4 days before use to achieve an improved defect performance.

What I claim is:  
     
         1 . A method of providing a slurry used for CMP process comprising the steps of: 
 mixing abrasive part and chemical part of said slurry and    aging said mixture at least five days or the equivalent before polishing a wafer using the aged slurry.    
     
     
         2 . The method of  claim 1 , wherein said CMP process is copper CMP barrier removal.  
     
     
         3 . The method of  claim 1 , wherein said abrasive part is silica (SiO2).  
     
     
         4 . The method of  claim 1 , wherein said abrasive part is a colloid silica.  
     
     
         5 . The method of  claim 1 , wherein said chemical part contains a corrosion inhibitor.  
     
     
         6 . The method of  claim 1 , wherein said chemical part contains a corrosion inhibitor know as BTA (Benzotriazole).  
     
     
         7 . The method of  claim 1 , wherein said slurry is Rodel electrapolish, blended from Rodel CUS1201A, Rodel CUS1201B, and DI water.  
     
     
         8 . The method of  claim 1 , wherein said aged slurry composition includes Electrapolish. aged for at least six days.  
     
     
         9 . The method of  claim 1 , wherein said equivalent aging process is by one or more accelerated steps of elevated temperature, mechanical stirring or re-circulation in a slurry supply loop.  
     
     
         10 . A method of CMP processing a wafer using a slurry comprising the steps of: 
 mixing abrasive part and chemical part of said slurry;    aging said mixture at least five days or the equivalent thereof by an accelerating step; and    polishing the wafer using the aged slurry.    
     
     
         11 . The method of  claim 10 , wherein said CMP process is copper CMP barrier removal.  
     
     
         12 . The method of  claim 10 , wherein said abrasive part is silica (SiO2).  
     
     
         13 . The method of  claim 10 , wherein said abrasive part is a colloid silica.  
     
     
         14 . The method of  claim 10 , wherein said chemical part contains a corrosion inhibitor.  
     
     
         15 . The method of  claim 10 , wherein said chemical part contains a corrosion inhibitor know as BTA (Benzotriazole).  
     
     
         16 . The method of  claim 10 , wherein said slurry is Rodel electrapolish, blended from Rodel CUS1201A, Rodel CUS1201B, and DI water.  
     
     
         17 . The method of  claim 10 , wherein said aged slurry composition includes Electrapolish. aged for at least six days.  
     
     
         18 . The method of  claim 10 , wherein said equivalent aging process is by one or more accelerated steps of elevated temperature, mechanical stirring or re-circulation.