CMP polishing slurry dewatering and reconstitution

Abstract

A method for reconstituting a chemical-mechanical polishing slurry which has been dewatered to form a dry particulate solids composition is provided.

1 . A method for reconstituting a chemical-mechanical polishing fluid comprising: 
 a) introducing a measured amount of water into a mixing unit;    b) introducing a measured amount of a dry particulate solids composition into the mixing unit, wherein the dry particulate solids composition was previously formed from a chemical-mechanical polishing slurry comprising submicron abrasive particles which has had substantially all water removed therefrom;    c) mixing the water and the slurry with the mixing unit to form a polishing fluid; and    d) filtering the polishing fluid.    
     
     
         2 . The method according to    claim 1   , wherein in step (b) the submicron abrasive particles are selected from the group comprised of alumina, silica, ceria, titania, and mixtures thereof.  
     
     
         3 . The method according to    claim 1   , wherein in step (b) the submicron abrasive particles include titania.  
     
     
         4 . The method according to    claim 1   , wherein in step (b) the chemical-mechanical polishing slurry was further comprised of an oxidizing agent prior to having substantially all water removed therefrom.  
     
     
         5 . The method according to    claim 1   , wherein in step (b) the chemical-mechanical polishing slurry was further comprised of a chemical etchant prior to having substantially all water removed therefrom.  
     
     
         6 . The method according to    claim 1   , wherein in step (b) the chemical-mechanical polishing slurry was further comprised of a dispersing agent prior to having substantially all water removed therefrom.  
     
     
         7 . The method according to    claim 1   , wherein in step (b) the chemical-mechanical polishing slurry was further comprised of a complexing agent prior to having substantially all water removed therefrom.  
     
     
         8 . The method according to    claim 1   , wherein in step (b) the chemical-mechanical polishing slurry was further comprised of a corrosion inhibitor prior to having substantially all water removed therefrom.  
     
     
         9 . The method according to    claim 1   , wherein the mixing unit includes a high speed rotor stator.  
     
     
         10 . The method according to    claim 1   , wherein in step (d) the polishing fluid is filtered through a one-micron filter.  
     
     
         11 . The method according to    claim 1   , further comprising: 
 e) introducing the polishing fluid between a workpiece and a polishing pad    f) producing relative motion between the polishing pad and the workpiece.    
     
     
         12 . The method according to    claim 11   , wherein the workpiece includes an integrated circuit wafer.  
     
     
         13 . The method according to    claim 11   , wherein the workpiece includes an optical surface.