Metal polishing composition

Abstract

An object of the present invention is to provide a metal polishing composition which can polish a metal such as Cu and Ta at a high speed, has a higher efficiency of washing for a hydrophobic low dielectric constant film, and is excellent stability without precipitation of a polishing particle during storage (excellent in stability for storing). The object is achieved by a metal polishing composition comprising an anionic surfactant having 2 or more anionic functional groups in a molecule, a polishing abrasive, an inorganic salt, and water.

1 . A metal polishing composition comprising an anionic surfactant having 2 or more anionic functional groups in a molecule, a polishing abrasive, an inorganic salt and water.  
     
     
         2 . The metal polishing composition according to  claim 1 , wherein the anionic surfactant is an anionic surfactant having further an ether linkage in a molecule.  
     
     
         3 . The metal polishing composition according to  claim 1 , wherein the anionic functional group is a functional group selected from the group consisting of a sulfonic acid group, a phosphonic acid group, a phosphoric acid group and a carboxylic acid group.  
     
     
         4 . The metal polishing composition according to  claim 1 , wherein the composition further contains a nonionic surfactant represented by the formula (I): 
       Y—O—(C a H 2a O) b —(C x H 2x O) y Z  (I) 
       (wherein a, b, x and y are independently a positive integer, and Y and Z are independently a hydrogen atom or a hydrocarbon group having a carbon number of 9 to 19).  
     
     
         5 . The metal polishing composition according to  claim 4 , wherein a is equal to x in the formula (I).  
     
     
         6 . The metal polishing composition according to  claim 4 , wherein the composition contains at least two nonionic surfactants represented by the formula (I).  
     
     
         7 . The metal polishing composition according to  claim 6 , wherein a is equal to x in at least one nonionic surfactant represented by the formula (I).  
     
     
         8 . The metal polishing composition according to  claim 1 , wherein the polishing abrasive is an inorganic particle.  
     
     
         9 . The metal polishing composition according to  claim 8 , wherein the inorganic particle is metal oxide.  
     
     
         10 . The metal polishing composition according to  claim 9 , wherein the metal oxide is silicon dioxide.  
     
     
         11 . The metal polishing composition according to  claim 1 , wherein the inorganic salt is a salt of an inorganic acid, and one selected from the group consisting of alkylammonium hydroxide, ammonia, alkylamine, alkanolamine and hydroxylamines.  
     
     
         12 . The metal polishing composition according to  claim 11 , wherein the inorganic acid is one selected from the group consisting of nitric acid, phosphoric acid, hydrochloric acid and sulfuric acid.  
     
     
         13 . The metal polishing composition according to claim 1, wherein the composition further contains an organic acid or a salt thereof.  
     
     
         14 . The metal polishing composition according to  claim 9 , wherein the organic acid or a salt thereof is at least one selected from the group consisting of acetic acid, citric acid, lactic acid, malonic acid, tartaric acid, succinic acid, oxalic acid, amino acid, and a salt thereof.