Plating method

Abstract

An object of the present invention is to provide a plating method which can form defect-free, completely-embedded interconnects of a conductive material in recesses in the surface of a substrate even when the recesses are of a high aspect ratio, and which can improve the flatness of a plated film on the substrate even when narrow trenches and broad trenches are co-present in the surface of the substrate. A plating method according to the present invention includes: providing a high resistance structure between a surface of a substrate, said surface being connected to a cathode electrode, and an anode electrode; filling the space between the substrate and the anode electrode with a plating solution while applying a voltage between the cathode electrode and the anode electrode; and growing a plated film on the surface of the substrate while controlling an electric current flowing between the cathode electrode and the anode electrode at a constant value.

What is claimed is:  
     
         1 . A plating method, comprising: 
 providing a high resistance structure between a surface of a substrate, said surface being connected to a cathode electrode, and an anode electrode;    filling the space between the substrate and the anode electrode with a plating solution while applying a voltage between the cathode electrode and the anode electrode; and    growing a plated film on the surface of the substrate while controlling an electric current flowing between the cathode electrode and the anode electrode at a constant value.    
     
     
         2 . The plating method according to  claim 1 , wherein the voltage is applied for 100 to 2000 msec after the electric current begins to flow between the cathode electrode and the anode electrode.  
     
     
         3 . The plating method according to  claim 1 , wherein the voltage applied is such as to allow an electric current with an average cathodic current density, with respect to the surface of the substrate, of 1 to 30 mA/cm 2  to flow.  
     
     
         4 . The plating method according to  claim 3 , wherein the voltage is applied for 100 to 2000 msec after the electric current begins to flow between the cathode electrode and the anode electrode.  
     
     
         5 . A plating method, comprising: 
 providing a high resistance structure between a surface of a substrate, said surface being connected to a cathode electrode, and an anode electrode;    filling the space between the substrate and the anode electrode with a plating solution; and    growing a plated film on the surface of the substrate while controlling an electric current flowing between the cathode electrode and the anode electrode at stepwise changing constant values.    
     
     
         6 . The plating method according to  claim 5 , wherein the plating solution is changed for a different plating solution in the process of film formation.  
     
     
         7 . The plating method according to  claim 6 , wherein the surface of the substrate is cleaned in the process of film formation.  
     
     
         8 . The plating method according to  claim 5 , wherein the value of the electric current flowing between the cathode electrode and the anode electrode is increased stepwise.  
     
     
         9 . The plating method according to  claim 8 , wherein the plating solution is changed for a different plating solution in the process of film formation.  
     
     
         10 . The plating method according to  claim 9 , wherein the surface of the substrate is cleaned in the process of film formation.  
     
     
         11 . A plating method, comprising: 
 providing a high resistance structure between a surface of a substrate, said surface being connected to a cathode electrode, and a anode electrode;    filling the space between the substrate and the anode electrode with a plating solution;    growing a plated film on the surface of the substrate while controlling an electric current flowing between the cathode electrode and the anode electrode at a constant value;    reversing the direction of the electric current flowing between the cathode electrode and the anode electrode to etch away the surface of the plated film; and    further growing the plated film on the surface of the substrate while controlling an electric current flowing between the cathode electrode and the anode electrode at a constant value.    
     
     
         12 . The plating method according to  claim 11 , wherein the step of etching the surface of the plated film and the subsequent step of growing the plated film are carried out repeatedly.  
     
     
         13 . A plating method, comprising: 
 filling the space between a surface of a substrate, said surface being connected to a cathode electrode, and an anode electrode with a plating solution while applying a voltage between the cathode electrode and the anode electrode; and    growing a plated film on the surface of the substrate while controlling an electric current flowing between the cathode electrode and the anode electrode at a constant value.    
     
     
         14 . The plating method according to  claim 13 , wherein the voltage is applied for 100 to 200 msec after the electric current begins to flow between the cathode electrode and the anode electrode.  
     
     
         15 . The plating method according to  claim 13 , wherein the voltage applied is such as to allow an electric current with an average cathodic current density, with respect to the surface of the substrate, of 1 to 30 mA/cm 2  to flow.  
     
     
         16 . The plating method according to  claim 15 , wherein the voltage is applied for 100 to 2000 msec after the electric current begins to flow between the cathode electrode and the anode electrode.