Polishing technique to minimize abrasive removal of material and composition therefor

Abstract

The present invention provides a composition and a method of polishing a surface that minimizes abrasive removal of material from the surface. To that end, the composition is formulated to maximize dissolution of the material from the surface.

1 . A composition comprising: 
 a carrier solution;    a complexing agent to dissolve a predetermined material; and    a corrosion inhibitor to minimize kinetic removal of said predetermined material,    wherein said carrier solution, said complexing agent and said corrosion inhibitor being present in sufficient quantities to provide said composition with a neutral pH; and    wherein said composition has a particle content no greater than approximately two hundred and fifty parts per million.    
     
     
         2 . The composition as recited in  claim 1 , wherein said neutral pH is in a range of 5 to 8.  
     
     
         3 . The composition as recited in  claim 1 , wherein said carrier solution further includes hydrogen peroxide.  
     
     
         4 . The composition as recited in  claim 1 , wherein said complexing agent comprises ammonium salts of citric, oxalic, tartaric, succinic, or actetic acids.  
     
     
         5 . The composition as recited in  claim 4  wherein said complexing agent comprises dibasic ammonium citrate.  
     
     
         6 . The composition as recited in  claim 1 , wherein said corrosion inhibitor comprises triazole.  
     
     
         7 . The composition as recited in  claim 1 , further comprising an oxidizing agent, wherein said oxidizing agent includes approximately 0.1% to 3% by weight of said composition of hydrogen peroxide.  
     
     
         8 . The composition as recited in  claim 1 , wherein said complexing agent includes approximately 0.1% to 12% by weight of said composition of dibasic ammonium citrate.  
     
     
         9 . The composition as recited in  claim 1 , wherein said corrosion inhibitor includes approximately 1% to 6% by weight of said composition of an inhibitor selected from the group consisting of triazole, imidazole, polyvinylimidazole, theophiline, bipyridyl, mercapto benzothizole,phenyl marcapto tetrazole, and pyrazole.  
     
     
         10 . The composition as recited in  claim 1 , wherein said corrosion inhibitor includes benzotriazole.  
     
     
         11 . The composition as recited in  claim 1 , wherein said corrosion inhibitor includes 0.0001% to 1% by weight of the composition of benzotriazole.  
     
     
         12 . A composition comprising: 
 a carrier solution including hydrogen peroxide;    a complexing agent; and    a corrosion inhibitor,    wherein said carrier solution, said complexing agent and said corrosion inhibitor are present in sufficient quantities to provide said composition with a neutral pH, with a range of particles contained therein in a range of zero to 250 parts per million.    
     
     
         13 . The composition as recited in  claim 12 , wherein said complexing agent comprises dibasic ammonium citrate.  
     
     
         14 . The composition as recited in  claim 13 , wherein said corrosion inhibitor includes benzotriazole.  
     
     
         15 . The composition as recited in  claim 13 , wherein said corrosion inhibitor comprises triazole.  
     
     
         16 . The composition as recited in  claim 12 , wherein said hydrogen peroxide is present in said composition in a quantity of approximately 1% to 3% by weight.  
     
     
         17 . The composition as recited in  claim 16 , wherein said complexing agent includes approximately 0.1% to 12% by weight of said composition of dibasic ammonium citrate.  
     
     
         18 . The composition as recited in  claim 17 , wherein said corrosion inhibitor includes approximately 1% to 6% by weight of said composition of triazole.  
     
     
         19 . The composition as recited in  claim 17 , wherein said corrosion inhibitor includes 1% to 3% by weight of the composition of benzotriazole.  
     
     
         20 . A method for polishing a layer containing conductive material and dielectric material, said method comprising: 
 removing portions of said layer by exposing said layer to a composition at a rate of removal, with said rate of removal being principally controlled by a dissolution of said layer with said composition,    wherein said composition includes a quantity of particles in a range of zero to two hundred fifty parts per million.    
     
     
         21 . The method as recited in  claim 20 , wherein said composition has a neutral pH and kinetics of oxide formation do not control removal rate.  
     
     
         22 . The method as recited in  claim 20 , wherein said composition has a pH in a range of 5-8.  
     
     
         23 . The method as recited in  claim 20 , wherein said composition has a pH of approximately 7.5.  
     
     
         24 . A method for polishing a layer having conductive material and dielectric material, said method comprising: 
 removing portions of said layer using a composition to generate a substantially smooth surface including first and second regions, with said first region including said conductive material and said second region including said dielectric material, wherein kinetics of conductive oxide formation do not principally control the removal of material from one of said first and second regions.    
     
     
         25 . The method as recited in  claim 24 , wherein removing further includes principally controlling removal rate by dissolution with the composition.  
     
     
         26 . The method as recited in  claim 24 , wherein said composition has a pH in a range of 5-8.  
     
     
         27 . The method as recited in  claim 26 , wherein said composition has a pH of approximately 7.5.  
     
     
         28 . A method for making a semiconductor device comprising: 
 providing a slurry composition having a particle content no greater than approximately two hundred and fifty parts per million and comprising: 
 a carrier solution;  
 a complexing agent to dissolve a predetermined material; and  
 a corrosion inhibitor to minimize kinetic removal of said predetermined material,  
 wherein said carrier solution, said complexing agent and said corrosion inhibitor being present in sufficient quantities to provide said composition with a neutral pH;  
   providing a semiconductor substrate having a trench formed within a dielectric layer, the trench having a metal layer therein;    providing a polishing apparatus having a polishing pad;    polishing a surface of the semiconductor substrate using the polishing pad and the slurry composition.    
     
     
         29 . The method as recited in  claim 28  wherein wherein said neutral pH is in a range of 5 to 8.  
     
     
         30 . The method as recited in  claim 28  wherein said carrier solution comprises hydrogen peroxide.  
     
     
         31 . The method as recited in  claim 28  wherein said complexing agent comprises dibasic ammonium citrate.  
     
     
         32 . The method as recited in  claim 28  wherein said corrosion inhibitor comprises triazole.  
     
     
         33 . The method as recited in  claim 28  wherein said corrosion inhibitor comprises benzotriazole.