Abrasive-free chemical mechanical polishing composition and polishing process containing same

Abstract

The present invention relates generally to a chemical mechanical polishing composition for polishing a metal, a metal oxide, and/or a metal nitride layer of a substrate, which composition is substantially free of abrasive particles and comprises: a hydroxylamine derivative; a corrosion inhibitor; and water, wherein water comprises the majority of the composition. The composition may optionally include, or alternately be substantially free from, one or more of the following: hydroxylamine, acid and/or base to adjust pH, two carbon atom linkage alkanolamine compounds, quaternary ammonium salts, chelating agents, organic solvents, non-hydroxyl-containing amine compounds, surfactants, additional oxidizing agents, and non-abrasive additives. A process for chemically mechanically polishing a substrate using such a polishing composition is also provided herein.

What is claimed is:  
     
         1 . A chemical mechanical polishing composition for polishing a metal, a metal oxide, and/or a metal nitride layer of a substrate, which composition is substantially free of abrasive particles and comprises: 
 a hydroxylamine derivative;    a corrosion inhibitor; and    water,    wherein water comprises the majority of the composition.    
     
     
         2 . The chemical mechanical polishing composition of  claim 1 , wherein the hydroxylamine derivative comprises hydroxylamine nitrate, hydroxylamine sulfate, and/or hydroxylamine.  
     
     
         3 . The chemical mechanical polishing composition of  claim 2 , wherein the hydroxylamine derivative is present in a total amount from about 1% to about 5% by weight of the composition.  
     
     
         4 . The chemical mechanical polishing composition of  claim 1 , wherein the corrosion inhibitor comprises benzotriazole.  
     
     
         5 . The chemical mechanical polishing composition of  claim 4 , wherein the corrosion inhibitor consists essentially of benzotriazole.  
     
     
         6 . The chemical mechanical polishing composition of  claim 5 , wherein the corrosion inhibitor is present in a total amount from about 0.01% to about 0.05% by weight of the composition.  
     
     
         7 . The chemical mechanical polishing composition of  claim 1 , wherein the water is present in a total amount from about 90% to about 99% by weight of the composition.  
     
     
         8 . The chemical mechanical polishing composition of  claim 1 , further comprising a sufficient amount of an acid and/or a base to adjust the pH of the composition to a desired level.  
     
     
         9 . The chemical mechanical polishing composition of  claim 8 , wherein the acid and/or base are present in a total amount from about 0.01% to about 2% by weight of the composition.  
     
     
         10 . The chemical mechanical polishing composition of  claim 1 , further comprising one or more of the following: a two carbon atom linkage alkanolamine compound, a quaternary ammonium salt, a chelating agent, an organic solvent, a non-hydroxyl-containing amine compound, a surfactant, an additional oxidizing agent, and a non-abrasive additive.  
     
     
         11 . The chemical mechanical polishing composition of  claim 1 , which is substantially free of one or more of the following: hydroxylamine, acid and/or base to adjust pH, two carbon atom linkage alkanolamine compounds, quaternary ammonium salts, chelating agents, organic solvents, non-hydroxyl-containing amine compounds, surfactants, additional oxidizing agents, and non-abrasive additives.  
     
     
         12 . A chemical mechanical polishing composition for polishing a metal, a metal oxide, and/or a metal nitride layer of a substrate, which composition is substantially free of abrasive particles and consists essentially of: 
 about 1% to about 5% by weight of a hydroxylamine derivative selected from the group consisting of hydroxylamine, hydroxylamine nitrate, hydroxylamine sulfate, and mixtures thereof;    about 0.01% to about 0.05% by weight of benzotriazole;    about 90% to 99% by weight of water; and    less than about 2% by weight of an acid and/or a base to adjust the pH of the composition to a desired level.    
     
     
         13 . The chemical mechanical polishing composition of  claim 12 , which is substantially free of hydroxylamine.  
     
     
         14 . A process for chemical mechanical polishing of a substrate comprising: 
 providing a substantially abrasive-free chemical mechanical polishing composition that comprises a hydroxylamine derivative, a corrosion inhibitor, water, and optionally a sufficient amount of an acid and/or a base to adjust the pH of the composition to a desired level, wherein the majority of the composition comprises water;    contacting the chemical mechanical polishing composition with a substrate having a metal oxide layer surface, upon which metal oxide surface a barrier layer is disposed, upon which barrier layer a metal layer is disposed; and    chemically mechanically polishing the substrate by contacting the substrate surface with an abrasive polishing pad at an applied pressure of not more than about 2 psi and by moving the pad in relation to the substrate,    wherein the removal rate of the barrier layer greater than about 500 Å/min, and wherein the removal rate of the metal oxide layer is less than about 10 Å/min.    
     
     
         15 . The process of  claim 14 , wherein the removal rate of the metal layer during the chemical mechanical polishing step is less than about 250 Å/min.  
     
     
         16 . The process of  claim 14 , wherein the removal rate of the metal layer during the chemical mechanical polishing step is greater than about 10 Å/min.  
     
     
         17 . The process of  claim 14 , wherein the removal rate of the barrier layer during the chemical mechanical polishing step is less than about 750 Å/min.  
     
     
         18 . The process of  claim 14 , wherein the abrasive-free chemical mechanical polishing composition is substantially free of one or more of the following: 
 hydroxylamine, acid and/or base to adjust pH, two carbon atom linkage alkanolamine compounds, quaternary ammonium salts, chelating agents, organic solvents, non-hydroxyl-containing amine compounds, surfactants, additional oxidizing agents, and non-abrasive additives.    
     
     
         19 . The process of  claim 14 , wherein the abrasive-free chemical mechanical polishing composition consists essentially of: 
 about 1% to about 5% by weight of a hydroxylamine derivative selected from the group consisting of hydroxylamine, hydroxylamine nitrate, hydroxylamine sulfate, and mixtures thereof;    about 0.01% to about 0.05% by weight of benzotriazole;    about 90% to 99% by weight of water; and    less than about 2% by weight of an acid and/or a base to adjust the pH of the composition to a desired level.    
     
     
         20 . The process of  claim 19 , wherein the abrasive-free chemical mechanical polishing composition is substantially free of hydroxylamine.  
     
     
         21 . The process of  claim 14 , wherein the metal layer of the substrate comprises copper.  
     
     
         22 . The process of  claim 21 , wherein the barrier layer of the substrate comprises tantalum nitride.  
     
     
         23 . The process of  claim 14 , wherein the barrier layer of the substrate comprises tantalum nitride.