Copper polishing cleaning solution

Abstract

A cleaning solution for removing copper complex residues from the surface of polishing pads and wafer substrates includes an amine pH-adjusting agent, which can be a unidentate or bidentate amine compound or a quartnary ammonium hydroxide compound or an amine including an alcohol group. The cleaning solution also includes an amino acid complexing agent and an inhibitor. In a preferred embodiment, the cleaning solution has a basic pH.

1 . A copper polishing cleaning solution for cleaning a copper residue from a metal surface comprising: 
 a complexing agent and an inhibitor,    wherein the complexing agent dissolves the copper residue from the metal surface and forms copper ions in solution, and    wherein the complexing agent maintains the copper ions in solution and substantially prevents the copper ions from redepositing on the metal surface.    
     
     
         2 . The copper polishing cleaning solution of  claim 1 , wherein the complexing agent comprises a compound having a nitrogen-containing alkyl compound.  
     
     
         3 . The copper polishing cleaning solution of  claim 3 , wherein the complexing agent comprises a compound selected from the group consisting of a unidentate amine, a bidentate amine and an amino acid.  
     
     
         4 . The copper polishing cleaning solution of  claim 3 , wherein the complexing agent comprises a bidentate amine having the general formula  
       R x H y N z    
       wherein R is selected from the group consisting of alkyl, alkoxy, and aryl, and wherein x is at least 1, y satisfies the expression 2x+4, and z is 2.  
     
     
         5 . The copper polishing cleaning solution of  claim 3 , wherein the complexing agent comprises glycine.  
     
     
         6 . The copper polishing cleaning solution of  claim 1 , wherein the complexing agent comprises an organic acid.  
     
     
         7 . The copper polishing cleaning solution of  claim 6 , wherein the complexing agent comprises an organic acid selected from the group consisting of citric acid, tartaric acid, and acetic acid.  
     
     
         8 . The copper polishing cleaning solution of  claim 1  further comprising a pH-adjusting agent.  
     
     
         9 . The copper polishing cleaning solution of  claim 8 , wherein the pH-adjusting agent comprises a quartnary ammonium hydroxide compound.  
     
     
         10 . The copper polishing cleaning solution of  claim 9 , wherein the pH-adjusting agent comprises tetramethyl ammonium hydroxide.  
     
     
         11 . The copper polishing cleaning solution of  claim 8 , wherein the pH-adjusting agent comprises a compound selected from the group consisting of a unidentate amine and a bidentate amine.  
     
     
         12 . The copper polishing cleaning solution of  claim 8 , wherein the pH-adjusting agent comprises a hydroxy amine compound.  
     
     
         13 . The copper polishing cleaning solution of  claim 12 , wherein the pH-adjusting agent comprises ethanolamine.  
     
     
         14 . A copper polishing cleaning solution comprising: 
 an amino acid complexing agent;    a pH adjusting compound; and    an azole inhibitor.    
     
     
         15 . The copper polishing cleaning solution of  claim 14 , wherein the amino acid complexing agent comprises glycine having an undiluted concentration of about 12 wt. % to about 18 wt. %.  
     
     
         16 . The copper polishing cleaning solution of  claim 14 , wherein the pH-adjusting compound comprises a compound selected from the group consisting of a unidentate amine and a bidentate amine.  
     
     
         17 . The copper polishing cleaning solution of  claim 16 , wherein the pH-adjusting compound comprises a compound selected from the group consisting of an alkyl amine, an alkoxy amine, and a quartnary ammonium hydroxide.  
     
     
         18 . The copper polishing cleaning solution of  claim 17 , wherein the pH-adjusting compound comprises tetramethylammoniumhydroxide having an undiluted concentration of about 15 wt. % to about 20 wt. %.  
     
     
         19 . The copper polishing cleaning solution of  claim 14 , wherein the azole inhibitor comprises BTA having an undiluted concentration of about 0.5 wt. % to about 1.5 wt. %.  
     
     
         20 . The copper polishing cleaning solution of  claim 14 , wherein the solution has a basic pH.  
     
     
         21 . A copper polishing cleaning solution comprising: 
 a complexing agent and an inhibitor,    wherein the complexing agent has a binding constant with copper of at least about 5 and wherein the complexing agent dissolves the copper residue from the metal surface and forms copper ions in solution, and    wherein the complexing agent maintains the copper ions in solution and substantially prevents the copper ions from redepositing on the metal surface.    
     
     
         22 . The copper polishing cleaning solution of  claim 21 , wherein the complexing agent comprises an amino acid.  
     
     
         23 . The copper polishing cleaning solution of  claim 21 , wherein the complexing agent comprises a compound selected from the group consisting of a unidentate amine, a bidentate amine and a tridentate amine.  
     
     
         24 . The copper polishing cleaning solution of  claim 21 , wherein the complexing agent comprises a compound having a copper binding constant of at least about 15.  
     
     
         25 . The copper polishing cleaning solution of  claim 24 , wherein the complexing agent comprises glycine.  
     
     
         26 . The copper polishing cleaning solution of  claim 21  further comprising a pH adjusting compound.  
     
     
         27 . The copper polishing cleaning solution of  claim 26 , wherein the complexing agent comprises an organic acid.  
     
     
         28 . The copper polishing cleaning solution of  claim 26 , wherein the pH adjusting agent maintains the cleaning solution at a pH of about