Polishing slurry used for copper chemical mechanical polishing (CMP) process

Abstract

A polishing slurry for the chemical-mechanical polishing (CMP) process used in the integrated circuit manufacture process is disclosed. The slurry of the present invention may comprise colloid silica (SiO2) as abrasive particles, and a corrosion inhibitor (e.g., benzotriazole (BTA)). The slurry does not require any oxidizing agent. The slurry may be used as a barrier slurry in copper CMP processes; and it has a similar polishing rate for copper, barrier, and dielectric materials on patterned wafers. The slurry of the present invention also reduces CMP defectivity on polished wafers.

What is claimed is:  
     
         1 . A polishing slurry comprising: 
 a dispersing medium;    a colloidal silicon suspended in the dispersing medium; and    a corrosion inhibitor in the dispersing medium.    
     
     
         2 . The polishing slurry of  claim 1  wherein the slurry does not contain an oxidizing agent.  
     
     
         3 . The polishing slurry of  claim 1  wherein the ratio of colloidal silica to corrosion inhibitor is adjustable to a desired selectivity.  
     
     
         4 . The polishing slurry of  claim 1  wherein slurry is a pre-blended or on-platen point-of-use mix.  
     
     
         5 . The polishing slurry of  claim 1  wherein surfactant is added to the slurry.  
     
     
         6 . The polishing slurry of  claim 1  wherein the slurry may be aged before polish.  
     
     
         7 . The polishing slurry of  claim 1  wherein the corrosion inhibitor comprises benzotriazole.  
     
     
         8 . The polishing slurry of  claim 1 , comprising about 0.005 to 0.2% by weight of BTA and about 1 to 30% by weight of SiO2.  
     
     
         9 . A method of polishing a damascene structure using a chemical-mechanical polishing apparatus, comprising the steps of: 
 providing a damascene structure;    providing a polishing pad;    applying a polishing slurry to the interface between the damascene structure and the polishing pad; and    performing polishing using polishing parameters of the CMP apparatus, wherein at least a portion of the metal layer is removed.    
     
     
         10 . The method of  claim 9 , wherein the slurry comprises colloidal silicon and corrosion inhibitors.  
     
     
         11 . The method of  claim 9  wherein the slurry does not contain an oxidizing agent.  
     
     
         12 . The method of  claim 9  wherein the ratio of colloidal silica to corrosion inhibitor in the slurry is adjustable to a desired selectivity.  
     
     
         13 . The method of  claim 9  wherein the slurry can be pre-blended or on-platen point-of-use mixed.  
     
     
         14 . The method of  claim 9  wherein surfactant is added to the slurry.  
     
     
         15 . The method of  claim 9  wherein the slurry may be aged before polish.  
     
     
         16 . The method of  claim 9  wherein the corrosion inhibitor comprises benzotriazole.  
     
     
         17 . The method of  claim 9 , wherein the slurry contains about 0.005 to 0.2% by weight of BTA and about 1 to 30% by weight of SiO2.