Polishing composition having organic polymer particles

Abstract

An aqueous polishing composition for chemical mechanical polishing to remove copper from a buffer material, the composition comprising, an oxidizing agent, a complexing agent, an inhibitor, a dishing reducing agent, and abrasive particles comprising organic polymer particles for clearing relatively soft copper from the buffer material by chemical mechanical polishing while minimizing dishing and avoiding removal of the buffer material.

What is claimed is:  
     
         1 . An aqueous polishing composition for chemical mechanical polishing to remove copper from a buffer material, the composition comprising, an oxidizing agent, abrasive particles, a complexing agent, an inhibitor, and a dishing reducing agent, comprising: 
 organic polymer particles of the abrasive particles for clearing relatively soft copper from the buffer material by chemical mechanical polishing while minimizing dishing of the copper in toughs and avoiding removal of the buffer material.    
     
     
         2 . The aqueous polishing composition as recited in  claim 1 , further comprising: 
 the organic polymer particles comprising, a water soluble carboxylic acid polymer of polymerized unsaturated carboxylic acid monomer having a number average molecular weight of about 20,000 to 1,500,000.    
     
     
         3 . The aqueous polishing composition as recited in  claim 1 , further comprising: 
 the organic polymer particles comprising 0.1 to 5.0% by weight in the aqueous polishing composition, and the organic polymer particles comprising a polymer having a number average molecular weight of at least 500,000 and a glass transition temperature of at least 25° C.    
     
     
         4 . The aqueous polishing composition as recited in  claim 1 , further comprising: 
 the organic polymer particles comprising polystyrene.    
     
     
         5 . The aqueous polishing composition as recited in  claim 1 , further comprising: 
 the organic polymer particles comprising hollow spheres of polystyrene crosslinked with divinyl benzene.    
     
     
         6 . The aqueous polishing composition as recited in  claim 1 , further comprising: 
 the organic particles comprising polymethyl methacrylate.    
     
     
         7 . The aqueous polishing composition of  claim 1 , further comprising: 
 the organic polymer particles have a diameter of 5 to 5,000 nm and a polymer of the organic polymer particles has a number average molecular weight of 500,000 to 3,000,000 and a glass transition temperature of 25 to 130° C.    
     
     
         8 . The aqueous polishing composition of  claim 1 , further comprising: 
 the dishing reducing agent being a polycarboxylic acid polymer comprising a blend of poly(meth)acrylic acid of a low number average molecular weight polymer having a molecular weight of 20,000 to 100,000 and a high number average molecular weight polymer having a molecular weight of 200,000 to 1,500,000.    
     
     
         9 . The aqueous polishing composition of  claim 8  in which the polycarboxylic acid polymer consist essentially of a blend of polyacrylic acid having number average molecular weight of 30,000 and polyacrylic acid having a number average molecular weight of 250,000 in a 1:1 weight ratio.  
     
     
         10 . A method of chemical mechanical polishing to remove relatively soft copper from a buffer material, comprising the steps of: 
 polishing the copper with a polishing pad and with a polishing composition having an oxidizing agent, a complexing agent, an inhibitor, a dishing reducing agent, and abrasive particles comprising organic polymer particles, and    removing the copper from the buffer material while minimizing dishing of the copper in troughs and avoiding removal of the buffer material.