Copper electrolytic plating bath and copper electrolytic plating method

Abstract

Disclosed herein is a copper electrolytic plating bath including copper sulfate used in an amount of 50 to 250 g/liter calculated as copper sulfate pentahydrate, 20 to 200 g/liter of sulfuric acid, and 20 to 150 mg/liter of a chloride ion, and a sulfur atom-containing organic compound and a nitrogen atom-containing organic compound serving as organic additives. The nitrogen atom-containing organic compound includes a nitrogen atom-containing polymer compound obtained by a two-stage reaction including reacting one mole of morpholine with two moles of epichlorohydrin in an acidic aqueous solution to obtain a reaction product and further reacting one to two moles, relative to one mole of the morpholine, of imidazole with the reaction product.

1 . A copper electrolytic plating bath comprising copper sulfate in an amount of 50 to 250 g/liter calculated as copper sulfate pentahydrate, 20 to 200 g/liter of sulfuric acid, and 20 to 150 mg/liter of chloride ions, and a sulfur atom-containing organic compound and a nitrogen atom-containing organic compound serving as organic additives, said nitrogen atom-containing organic compound being a nitrogen atom-containing polymer compound obtained by a two-stage reaction comprising reacting one mole of morpholine with two moles of epichlorohydrin in an acidic aqueous solution to obtain a reaction product and further reacting one to two moles, relative to one mole of the morpholine, of imidazole with the reaction product. 
     
     
         2 . The copper electrolytic plating bath as defined in  claim 1 , wherein said nitrogen atom-containing polymer compound is present in an amount of 1 to 1,000 mg/liter. 
     
     
         3 . The copper electrolytic plating bath as defined in  claim 1 , wherein said sulfur atom-containing organic compound is a compound selected from sulfur atom-containing organic compounds represented by the following formulas (1) to (4) and is present in an amount of 0.001 to 100 mg/liter 
       
         
           
           
               
               
           
         
       
       wherein R 1 , R 2  and R 3  independently represent an alkyl group having 1 to 5 carbon atoms, M represents a hydrogen atom or an alkali metal, a is an integer of 1 to 8, and b, c and d are, respectively, 0 or 1. 
     
     
         4 . A copper electrolytic plating method comprising plating an article to be plated with the copper electrolytic plating bath defined in any one of  claims 1  to  3  at a temperature of 30 to 50° C. 
     
     
         5 . The copper electrolytic plating method as defined in  claim 4 , wherein the article to be plated is a substrate having through-holes, blind via holes or posts. 
     
     
         6 . The copper electrolytic plating method as defined in  claim 5 , wherein the through-hole has a diameter of 0.05 to 2.0 mm, a height of 0.01 to 2.0 mm and an aspect ratio of 0.1 to 10, the blind via hole has a diameter of 20 to 300 μm and a height of 20 to 150 μm, and the post has a diameter of 30 to 300 μm, a height of 25 to 200 μm and an aspect ratio of 0.2 to 3.