Biocides for polishing slurries

Abstract

Compounds containing both a sulfur and a nitrogen in a five-membered ring structure are used as biocides in polishing solutions and slurries.

What is claimed is:  
     
         1 . An aqueous solution, for use in CMP of semiconductor wafers wherein a fixed abrasive polishing pad is used, which contains essentially no abrasive particles and which is protected from bacterial and fungal activity by means of a biocide comprising an organic compound with a five membered ring containing both a sulfur and a nitrogen group in said ring.  
     
     
         2 . An aqueous slurry, for use in CMP of semiconductor wafers, which contains abrasive particles and which is protected from bacterial and fungal activity by means of a biocide comprising an organic compound with a five membered ring containing both a sulfur and a nitrogen group in said ring.  
     
     
         3 . The solution of  claim 1  wherein said biocide is from the group comprising 2-methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one.  
     
     
         4 . The slurry of  claim 2  wherein said biocide is from the group comprising 2-methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one.  
     
     
         5 . The solution of  claim 1  wherein said biocide is present in the range of 0.01% to 1% by weight of said solution.  
     
     
         6 . The slurry of  claim 2  wherein said biocide is present in the range of 0.01% to 1% by weight of said slurry.  
     
     
         7 . A method of polishing a semiconductor wafer comprising: applying a solution at a polishing interface between a fixed abrasive polishing pad and said wafer, said solution comprising essentially no abrasive particles and which is protected from bacterial and fungal activity by means of a biocide comprising an organic compound with a five membered ring containing both a sulfur and a nitrogen group in said ring.  
     
     
         8 . A method of polishing a semiconductor wafer comprising: applying a slurry at a polishing interface between a polishing pad and said wafer, said solution comprising abrasive particles and which is protected from bacterial and fungal activity by means of a biocide comprising an organic compound with a five membered ring containing both a sulfur and a nitrogen group in said ring.  
     
     
         9 . A method according to  claim 5  wherein said biocide is from the group comprising 2-methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one.  
     
     
         10 . A method according to  claim 6  wherein said biocide is from the group comprising 2-methyl-4-isothiazolin-3-one and 5-chloro-2-methyl-4-isothiazolin-3-one.  
     
     
         11 . A method according to  claim 5  wherein said biocide is present in the range of 0.01% to 1% by weight of said solution.  
     
     
         12 . A method according to  claim 6  wherein said biocide is present in the range of 0.01% to 1% by weight of said slurry.