Plating apparatus and method of managing plating liquid composition

Abstract

A plating apparatus comprises a plating unit having a plating bath for holding a plating liquid therein, and a plating liquid monitoring unit having a liquid chromatography device and an arithmetical unit. The liquid chromatography device serves to separate and quantify an additive in a sample of the plating liquid. The arithmetical unit serves to compare a quantified value of the additive with a given concentration predetermined for the additive and to produce an output signal representing the compared result. The plating apparatus further comprises an additive replenishing unit for adding a solution including the additive from an additive tank to the plating liquid in the plating bath based on the output signal from the arithmetical unit in the plating liquid monitoring unit.

What is claimed is:  
     
         1 . A plating apparatus comprising: 
 a plating unit having a plating bath for holding a plating liquid therein;    a plating liquid monitoring unit having a liquid chromatography device for separating and quantifying an additive in a sample of the plating liquid, and an arithmetical unit for comparing a quantified value of said additive with a given concentration predetermined for said additive and producing an output signal representing the compared result; and    an additive replenishing unit for adding a solution including said additive from an additive tank to the plating liquid in said plating bath based on said output signal from said arithmetical unit in said plating liquid monitoring unit.    
     
     
         2 . A plating apparatus according to  claim 1 , wherein said liquid chromatography device comprises an evaporative light-scattering detector for quantifying said additive.  
     
     
         3 . A plating apparatus according to  claim 1 , wherein said plating liquid comprises a sulfuric acid copper plating liquid for embedding copper in a fine recess defined in a substrate to form an interconnection; and 
 ionic components are removed from said plating liquid in advance before said additive is quantified.    
     
     
         4 . A plating apparatus according to  claim 1 , wherein said additive comprises at least one of an oxygen-containing water-soluble polymeric compound, a sulfur-containing organic compound, and a nitrogen-containing organic compound.