Electrolytic copper plating solution for filling for forming microwiring of copper for ulsi

Abstract

An object of the present invention is to provide an electrolytic copper plating solution which can suppress, upon electrolytic copper plating on a copper seed layer during fabrication of ULSI copper microwiring (damascene copper wiring) having trends to further miniaturization, dissolution of the copper seed layer and accordingly can suppress occurrence of voids on the inner wall of vias/trenches. The present invention provides an electrolytic copper plating solution for filling for forming microwiring for ULSI, characterized in that it has a pH of 1.8 or higher and 3.0 or lower. The electrolytic copper plating solution preferably comprises a saturated carboxylic acid having 1 or more and 4 or less carbon atoms at 0.01 mol/L or more and 2.0 mol/L or less.

1 . An electrolytic copper plating aqueous solution for filling for forming damascene microwiring for ULSI in which the copper seed layer in trenches/vias has a thickness of 2 nm or less, characterized in that it has a pH of 1.8 or higher and 3.0 or lower wherein,
 the plating solution contains copper sulfate at 0.05 to 1.5 mol/L, and   the plating solution contains chloride ions at a concentration of 0.3 to 3.0 mmol/L, and   the plating solution it comprises a saturated carboxylic acid at 0.01 mol/L or more and 2.0 mol/L or less.   
     
     
         2 . The electrolytic copper plating aqueous solution for filling for forming damascene microwiring for ULSI according to  claim 1 , wherein it has a pH of 2.0 or higher and 2.2 or lower. 
     
     
         3 . The electrolytic copper plating aqueous solution for filling for forming damascene microwiring for ULSI according to  claim 1 , wherein saturated carboxylic acid has 1 or more and 4 or less carbon atoms. 
     
     
         4 . The electrolytic copper plating aqueous solution filling for forming damascene microwiring for ULSI microwiring according to  claim 3 , wherein the carboxylic acid is acetic acid. 
     
     
         5 . A method for electrolytic copper plating for ULSI microwiring, characterized in that it uses the electrolytic copper plating aqueous solution for filling for forming damascene microwiring for ULSI according to  claim 1 . 
     
     
         6 . A ULSI microwiring substrate characterized in that a ULSI microwiring is formed by the method for electrolytic copper plating aqueous solution for filling for forming damascene microwiring for ULSI according to  claim 5 .