Dual reduced agents for barrier removal in chemical mechanical polishing

Abstract

Compositions and methods for removal of barrier layer materials by a chemical mechanical polishing technique are provided. In one aspect, the invention provides a composition adapted for removing a barrier layer material in a chemical mechanical polishing technique including at least one reducing agent selected from the group of bicarboxylic acids, tricarboxylic acids, and combinations thereof, at least one reducing agent selected from the group of glucose, hydroxylamine, and combinations thereof, and deionized water, wherein the composition has a pH of about 7 or less. The composition may be used in a method for removing the barrier layer material including applying the composition to a polishing pad and polishing the substrate in the presence of the composition to remove the barrier layer.

1 . A method for removing barrier layer materials from a substrate in chemical mechanical polishing technique, comprising: 
 applying a composition to a polishing pad, the composition comprising: 
 at least one reducing agent selected from the group of bicarboxylic acids, tricarboxylic acids, and combinations thereof;  
 at least one reducing agent selected from the group of glucose, hydroxylamine, and combinations thereof; and  
 deionized water, wherein the composition has a pH of about 7 or less; and  
   contacting the substrate with the polishing pad in the presence of the composition to remove the barrier layer materials.    
   
   
       2 . The method of  claim 1 , wherein the at least one reducing agent selected from the group of bicarboxylic acids, tricarboxylic acids, and combinations thereof comprises oxalic acid.  
   
   
       3 . The method of  claim 1 , wherein the at least one reducing agent selected from the group of bicarboxylic acids, tricarboxylic acids, and combinations thereof comprises up to about 1 wt. % of the composition.  
   
   
       4 . The method of  claim 1 , wherein the at least one reducing agent selected from the group of glucose, hydroxylamine, and combinations thereof comprises up to about 1 wt. % of the composition.  
   
   
       5 . The method of  claim 1 , wherein the composition further comprises abrasive particles, a surfactant, a corrosion inhibitor, at least one pH adjusting agent, a buffer agent, and combinations thereof.  
   
   
       6 . The method of  claim 1 , further comprising up to about 2 wt. % of abrasive particles, up to about 1 wt. % of corrosion inhibitor, and combinations thereof.  
   
   
       7 . The method of  claim 6 , wherein the composition comprises: 
 between about 0.01 wt. % and about 0.5 wt. % of a bicarboxylic acid;    between about 0.01 wt. % and about 0.5 wt. % of reducing agent selected from the group of glucose, hydroxylamine, and combinations thereof;    between about 0.02 wt. % and about 0.4 wt. % of a corrosion inhibitor;    between about 0.5 wt. % and about 2 wt. % of abrasive particles;    deionized water; and    a pH between about 5.8 and about 6.    
   
   
       8 . The method of  claim 7 , wherein the composition comprises: 
 about 0.2 wt. % oxalic acid;    about 0.25 wt. % hydroxylamine;    about 0.2 wt. % benzotriazole;    about 1 wt. % abrasive particles;    deionized water; and    a pH of about 5.8.    
   
   
       9 . The method of  claim 1 , wherein the barrier layer material comprises a material selected from the group of tantalum, tantalum nitride, and combinations thereof.  
   
   
       10 . The method of  claim 1 , wherein a pressure of about 6 psi or less is applied between the substrate and the polishing pad and the polishing pad is rotated at a rotational speed of about 1000 cps or less.  
   
   
       11 . The method of  claim 1 , wherein the substrate further comprises a low k material, and a pressure of about 2 psi or less is applied between the substrate and the polishing pad and the polishing is rotated at a rotational speed of about 200 cps or greater.