Method of polishing a semiconductor wafer surface

Abstract

The invention provides a chemical mechanical abrasive composition for use in semiconductor processing, which comprises phosphorous acid and/or a salt thereof as an abrasive enhancer. The chemical mechanical abrasive composition of the invention can be in the form of a slurry which comprises 70-99.5% by weight of an aqueous medium, 0.1-25% by weight of an abrasive, and 0.01-2% by weight of said abrasion enhancer. The chemical mechanical abrasive composition of the invention may further comprise an abrasion co-enhancer selected from an amino acid, a salt thereof, a carboxylic acid, a salt thereof, or a mixture of the acids and/or salts.

We claim:  
     
         1 . A chemical mechanical abrasive composition for use in semiconductor processing, which comprises phosphorous acid and/or a salt thereof as an abrasive enhancer.  
     
     
         2 . The composition according to  claim 1  which is in the form of a slurry and comprises: 
 70-99.5% by weight of an aqueous medium;  
 0.1-25% by weight of an abrasive; and  
 0.01-2% by weight of the said abrasion enhancer.  
 
     
     
         3 . The composition according to  claim 2  wherein the abrasive is selected from SiO 2 , Al 2 O 3 , ZrO 2 , CeO 2 , SiC, Fe 2 O 3 , TiO 2 , Si 3 N 4 , or a mixture thereof.  
     
     
         4 . The composition according to  claim 1  or  2  further comprising an abrasion co-enhancer selected from an amino acid, a salt thereof, a carboxylic acid, a salt thereof, or a mixture of the acids and/or salts.  
     
     
         5 . The composition according to  claim 4  wherein the amino acid is selected from glycine, creatine, or alanine.  
     
     
         6 . The composition according to  claim 4  wherein the carboxylic acid is selected from formic acid, acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, malonic acid, glutaric acid, adipic acid, citric acid, malic acid, tartaric acid, or oxalic acid.  
     
     
         7 . The composition according to  claim 2  further comprising a triazole compound and/or a derivative thereof.  
     
     
         8 . The composition according to  claim 2  further comprising an oxidant.  
     
     
         9 . A method for polishing the surface of a semiconductor wafer comprising applying a chemical mechanical abrasive slurry on the surface of the semiconductor wafer, said slurry comprising: 
 70-99.5% by weight of an aqueous medium;    0.1-25% by weight of an abrasive; and    0.01-2% by weight of an abrasion enhancer comprising phosphorous acid and/or a salt thereof.    
     
     
         10 . The method according to  claim 9  wherein the abrasive is selected from SiO 2 , Al 2 O 3 , ZrO 2 , CeO 2 , SiC, Fe 2 O 3 , TiO 2 , Si 3 N 4 , or a mixture thereof.  
     
     
         11 . The method according to  claim 9  wherein said abrasive slurry further comprises an abrasion co-enhancer selected from an amino acid, a salt thereof, a carboxylic acid, a salt thereof, or a mixture of the acids and/or salts.  
     
     
         12 . The method according to  claim 11  wherein the amino acid is selected from glycine, creatine, or alanine.  
     
     
         13 . The method according to  claim 11  wherein the carboxylic acid is selected from formic acid, acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, malonic acid, glutaric acid, adipic acid, citric acid, malic acid, tartaric acid, or oxalic acid.  
     
     
         14 . The method according to  claim 9  wherein said abrasive slurry further comprises a triazole compound and/or a derivative thereof.  
     
     
         15 . The method according to  claim 9  wherein said abrasive slurry further comprises an oxidant.