Method of polishing a tungsten-containing substrate

Abstract

The invention provides a chemical-mechanical polishing composition particularly useful in polishing tungsten-containing substrates. The composition comprises a tungsten etchant, an inhibitor of tungsten etching, and water, wherein the inhibitor of tungsten polishing is a polymer, copolymer, or polymer blend comprising at least one repeating group comprising at least one nitrogen-containing heterocyclic ring or a tertiary or quaternary nitrogen atom.

1 - 20 . (canceled)  
   
   
       21 . A chemical-mechanical polishing composition comprising: 
 (a) ferric ion,    (b) an inhibitor of tungsten etching, wherein the inhibitor of tungsten etching is a polymer, copolymer, or polymer blend comprising at least one repeating group comprising at least one nitrogen-containing heterocyclic ring or a tertiary or quaternary nitrogen atom, wherein the inhibitor of tungsten etching is present in an amount of about 1 ppm to about 1000 ppm,    (c) silica,    (d) malonic acid, and    (e) water.    
   
   
       22 . The chemical-mechanical polishing composition of  claim 21 , wherein the inhibitor of tungsten etching is a polyvinylimidazole.  
   
   
       23 . The chemical-mechanical polishing composition of  claim 22 , wherein the inhibitor of tungsten etching is a poly(1-vinylimidazole).  
   
   
       24 . The chemical-mechanical polishing composition of  claim 21 , wherein the inhibitor of tungsten etching is a dialkylamine-epichlorohydrin copolymer.  
   
   
       25 . The chemical-mechanical polishing composition of  claim 24 , wherein the inhibitor of tungsten etching is a copolymer of 2,2′-dichlorodiethyl ether and a bis[Ω-(N,N-dialkyl)alkyl]urea.  
   
   
       26 . The chemical-mechanical polishing composition of  claim 21 , wherein the polishing composition further comprises a per-compound.  
   
   
       27 . The chemical-mechanical polishing composition of  claim 26 , wherein the per-compound is hydrogen peroxide.