Plating method, plating apparatus and a method of forming fine circuit wiring

Abstract

A copper plating film has a lower chlorine ion content. Circuit wiring of high electromigration resistance is formed by electroplating. In a method of copper plating using a leveler containing a nitrogen-containing high molecular compound, the leveler is dechlorinated prior to its use for plating. A plating apparatus has a tank for preparing a plating solution, a device for dechlorinating a leveler, a leveler supply station for supplying the dechlorinated leveler to the tank and a plating station. A method of forming fine circuit wiring includes forming a circuit with a phosphorus-doped copper plating layer on a substrate for an electronic circuit having a fine circuit pattern, a barrier layer and any necessary seed layer formed thereon.

1 . A method of copper plating using a leveler containing a nitrogen-containing high molecular compound, wherein the leveler is dechlorinated prior to its use for plating.  
     
     
         2 . The method of copper plating according to  claim 1 , wherein the dechlorinated leveler has a chlorine ion content of 0.1 g or less per gram of nitrogen-containing high molecular compound.  
     
     
         3 . The method of copper plating according to  claim 1 , wherein the dechlorinated leveler has a chlorine ion content of 1 g/l or less.  
     
     
         4 . The method of copper plating according to  claim 1 , wherein the dechlorination is carried out by sedimentation or electrolysis.  
     
     
         5 . A leveler for copper plating containing a nitrogen-containing high molecular compound, the leveler having a chlorine ion content of 0.1 g or less per gram of nitrogen-containing high molecular compound.  
     
     
         6 . A plating apparatus comprising a tank for preparing a plating solution, a device for dechlorinating a leveler, a leveler supply station for supplying the dechlorinated leveler to the tank and a plating station.  
     
     
         7 . A plating apparatus for forming a metal film on a seed layer on a substrate surface by electroplating, the apparatus comprising a loading and unloading station, a substrate conveying device, a cleansing unit, a plating tank, a tank for preparing a plating solution and supplying it to the plating tank, a station for measuring the concentrations of additives, a device for dechlorinating a leveler and a leveler supply station for supplying the dechlorinated leveler to the plating solution, the concentration measuring station measuring the concentration of the leveler in the plating solution and in accordance with the result of the measurement, the leveler supply station adding the dechlorinated leveler to the plating solution.  
     
     
         8 . A method of forming fine circuit wiring, comprising forming a circuit with a phosphorus-doped copper plating layer on a substrate for an electronic circuit having a fine circuit pattern, a barrier layer and any necessary seed layer formed thereon.  
     
     
         9 . The method of forming fine circuit wiring according to  claim 8 , wherein the plating layer has a phosphorus content of 1×10 −6  to 10 atom %.  
     
     
         10 . The method of forming fine circuit wiring according to  claim 8 , wherein the plating layer has a volume resistivity of 5 μΩ·cm or less.  
     
     
         11 . The method of forming fine circuit wiring according to  claim 8 , wherein the plating layer is formed by electroplating.  
     
     
         12 . A phosphorus-doped copper plating solution containing 1'10 −6  to 50% by weight of elemental phosphorus in the form of a phosphorus compound in a copper sulfate plating solution containing copper sulfate, sulfuric acid and chlorine ions.  
     
     
         13 . The phosphorus-doped copper plating solution according to  claim 12 , wherein the phosphorus compound is selected from the group consisting of phosphoric acid, phosphorus oxide or copper sulfate.  
     
     
         14 . A plating apparatus having an anode plate and a substrate to be plated which are positioned opposite each other in a plating tank containing a phosphorus-doped copper plating solution for electroplating the surface of the substrate by supplying an electric current between the anode plate and the substrate from a power source, the apparatus having at least a device for supplying a solution containing a phosphorus compound as a device for supplying a constituent composing the plating solution.  
     
     
         15 . The plating apparatus according to  claim 14 , further including a device for controlling at least the concentration of phosphorus in the plating solution.  
     
     
         16 . The plating apparatus according to  claim 14 , wherein the anode plate is an insoluble plate.