Copper plating solution for embedding fine wiring, and copper plating method using the same

Abstract

The present invention provides a copper plating solution for embedding fine wiring, wherein it contains copper sulfate at 100 to 300 g/L as copper sulfate pentahydrate, sulfuric acid at 5 to 300 g/L, chlorine at 20 to 200 mg/L, a macromolecular surfactant at 0.05 to 20 g/L for controlling the electrodeposition reaction, sulfur-based saturated organic compound at 1 to 100 mg/L for accelerating the electrodeposition reaction, leveling agent composed of a macromolecular amine compound at 0.01 to 10 mg/L and reductant at 0.025 to 25 g/L for stabilizing the copper plating solution. The copper plating solution of the present invention for embedding fine wiring can plate the wafer surface provided with fine wiring patterns with sub-micron order gaps in-between and coated with copper serving as the metallic seed film, to fill the gaps neither leaving any defect therein nor dissolving the metallic seed film.

What is claimed is:  
     
         1 . A copper plating solution for embedding fine wiring, containing 100 to 300 g/L of copper sulfate as copper sulfate pentahydrate, 5 to 300 g/L of sulfuric acid, 20 to 200 mg/L of chlorine, 0.05 to 20 g/L of a macromolecular surfactant for controlling the electrodeposition reaction, 1 to 100 mg/L of a sulfur-based saturated organic compound for accelerating the electrodeposition reaction, 0.01 to 10 mg/L of a leveling agent composed of a macromolecular amine compound and 0.025 to 25 g/L of a reductant for stabilizing the copper plating solution.  
     
     
         2 . The copper plating solution for embedding fine wiring according to  claim 1 , containing 0.01 to 20 mg/L of an organic dye compound for controlling leveling of deposited copper.  
     
     
         3 . The copper plating solution for embedding fine wiring according to  claim 1  or  2 , wherein said leveling agent composed of a macromolecular amine compound is polyethylene imine or polypropylene imine.  
     
     
         4 . The copper plating solution for embedding fine wiring according to  claim 3 , wherein said macromolecular amine compound has an average molecular weight of 5,000 to 100,000.  
     
     
         5 . The copper plating solution for embedding fine wiring according to any one of  claims 1  to  4 , wherein said reductant for stabilizing the copper plating solution contains at least one organic compound containing at least one type of functional group selected from aldehyde, hydroxyl and carboxyl, alcohol, and organocarboxylic acid.  
     
     
         6 . A method of copper plating for embedding fine wiring, with the copper plating solution for embedding fine wiring according to any one of  claims 1  to  5  under the conditions of a cathode current density of 0.05 to 5 A/dm 2  and liquid temperature of 5 to 30° C.