Electroplating cell with copper acid correction module for substrate interconnect formation

Abstract

The present invention generally provides an apparatus and method for neutralizing an acid in a plating solution. The apparatus generally includes a plating cell having an anolyte compartment containing an anolyte and a catolyte compartment containing a catolyte, wherein the anolyte compartment has an anolyte inlet and an anolyte drain and the catolyte compartment has a catolyte inlet and a catolyte drain, and a cell membrane disposed in the cell between the anolyte compartment and the catolyte compartment, wherein the membrane is selective to hydrogen ions and copper ions. The apparatus further includes a catolyte storage unit in fluid communication with the catolyte inlet and an electrochemical device in fluid communication with the catolyte chamber, the electrochemical device being configured to receive a portion of aged catolyte solution and correct a catolyte concentration. The method generally includes supplying an electrolyte solution to a copper plating cell, plating copper onto a substrate in the plating cell with the electrolyte solution, removing aged electrolyte solution from the plating cell, and neutralizing a portion of the used electrolyte solution with an electrochemical device.

1 . A copper plating system, comprising: 
 an anolyte compartment, wherein the anolyte compartment has an anolyte inlet;    an anolyte storage unit in fluid communication with the anolyte inlet;    a catolyte compartment;    a catolyte storage unit in fluid communication with the catolyte inlet;    a membrane disposed between the anolyte compartment and the catolyte compartment, wherein the membrane is selective to hydrogen ions and copper ions; and    a catolyte electrochemical device in fluid communication with the catolyte compartment, the catolyte electrochemical device being configured to correct a catolyte concentration.    
     
     
         2 . The copper plating system of  claim 1 , further comprising an anolyte electrochemical device in fluid communication with the anolyte compartment, the anolyte electrochemical device being configured to correct an anolyte concentration.  
     
     
         3 . The copper plating system of  claim 1 , wherein the catolyte compartment comprises copper sulfate, sulfuric acid, copper chloride, and organic additives.  
     
     
         4 . The copper plating system of  claim 1 , wherein the anolyte compartment comprises copper sulfate and sulfuric acid in an amount sufficient to provide a pH of from about 2 to about 6.  
     
     
         5 . The copper plating system of  claim 1 , wherein the catolyte electrochemical device comprises: 
 a housing having a cathode electrode and an anode electrode;    an anode chamber positioned proximate the anode electrode and between the cathode electrode and the anode electrode, wherein the anode chamber is configured to receive aged catolyte solution;    a cathode chamber positioned proximate the cathode electrode and between the cathode electrode and the anode chamber, wherein the anode chamber is configured to neutralize acid in the aged catolyte solution; and    a bipolar membrane positioned between the anode chamber and the cathode chamber configured to remove hydrogen ions from the aged catolyte solution and provide hydroxide ions to the aged catolyte solution.    
     
     
         6 . The copper plating system of  claim 5 , wherein the anode electrode is insoluble and is configured to provide copper ions to the aged catolyte.  
     
     
         7 . The copper plating system of  claim 5 , wherein the cathode chamber comprises a cathode chamber fluid inlet and a cathode chamber fluid outlet configured to circulate sulfuric acid in the cathode chamber.  
     
     
         8 . The copper plating system of  claim 1 , wherein the catolyte electrochemical device comprises: 
 a housing having a cathode electrode positioned in a first end and an anode electrode positioned in a second end, the second end being oppositely positioned from the first end;    an anode chamber positioned proximate the anode electrode and between the cathode electrode and the anode electrode configured to provide copper ions to an aged catolyte solution;    a cathode chamber positioned proximate the cathode electrode and between the cathode electrode and the anode chamber configured to neutralize acid in the aged catolyte solution; and    an input chamber positioned between the anode and cathode chambers and configured to receive the aged catolyte solution.    
     
     
         9 . The copper plating system of  claim 8 , wherein the input chamber comprises: 
 a cathodic membrane positioned on a cathode side of the input chamber configured to receive hydrogen ions from the input chamber;    a cathodic membrane positioned on an anode side of the input chamber configured to provide copper ions to the input chamber; and    an input chamber fluid outlet configured to dispense restored electrolyte therefrom.    
     
     
         10 . The copper electrochemical plating system of  claim 9 , wherein the cathode chamber comprises a cathode chamber fluid inlet and a cathode chamber fluid outlet configured to circulate sulfuric acid in the cathode chamber.  
     
     
         11 . The copper plating system of  claim 9 , wherein the anode chamber comprises an anode chamber fluid inlet and an anode chamber fluid outlet configured to circulate a copper sulfate solution in the anode chamber.  
     
     
         12 . The copper plating system of  claim 9 , wherein the cationic membrane positioned on the cathode side of the input chamber is selective to hydrogen ions.  
     
     
         13 . The copper plating system of  claim 8 , wherein the input chamber comprises: 
 a bipolar membrane positioned on a cathode side of the input chamber configured to receive hydrogen ions from the input chamber and provide hydroxide ions to the input chamber;    a cathodic membrane positioned on an anode side of the input chamber configured to provide copper ions to the input chamber; and    an input chamber fluid outlet configured to dispense restored electrolyte therefrom.    
     
     
         14 . The copper plating system of  claim 8 , wherein the input chamber comprises: 
 a bipolar membrane positioned on a cathode side of the input chamber configured to receive hydrogen ions from the input chamber and provide hydroxide ions to the input chamber;    an anodic membrane positioned on an anode side of the input chamber configured to receive sulfate ions from the input chamber;    an input chamber fluid outlet configured to dispense restored electrolyte therefrom; and    a control device configured to correct the copper concentration in the restored electrolyte.    
     
     
         15 . The copper plating system of  claim 14 , wherein copper sulfate is added to the restored electrolyte in an amount determined by the control device.  
     
     
         16 . The copper plating system of  claim 1 , wherein the catolyte electrochemical device comprises: 
 a housing having a cathode electrode positioned in a first end and an anode electrode positioned in a second end, the second end being oppositely positioned from the first end;    an anode chamber positioned proximate the anode and between the cathode electrode and the anode electrode configured to neutralize acid in the aged catolyte solution;    a cathode chamber positioned proximate the cathode electrode and between the cathode electrode and the anode chamber configured to neutralize acid in the aged catolyte solution;    at least one input chamber positioned between the cathode electrode and the anode chamber configured to receive aged catolyte;    at least one copper feed chamber positioned between the input chamber and the anode chamber configured to provide copper ions to the aged catolyte; and    at least one isolation chamber positioned between the input chamber and the copper feed chamber to neutralize acid in the aged catolyte solution.    
     
     
         17 . The copper plating system of  claim 16 , wherein the copper feed chamber comprises a feed chamber fluid inlet and a feed chamber fluid outlet configured to circulate copper sulfate in the copper feed chamber.  
     
     
         18 . The copper plating system of  claim 16 , wherein sulfuric acid is circulated between the isolation chamber, the anode chamber, and the cathode chamber.  
     
     
         19 . The copper plating system of  claim 16 , wherein a copper sulfate solution is added to the restored catolyte.  
     
     
         20 . The copper plating system of  claim 16 , wherein the anode electrode is insoluble.  
     
     
         21 . The copper plating system of  claim 16 , wherein the input chamber comprises: 
 an anionic membrane positioned on a cathode side of the anode chamber configured to receive sulfate ions from the copper feed chamber;    a cationic membrane positioned between the copper feed chamber and the input chamber configured to provide copper ions to the input chamber;    a bipolar membrane positioned between the input chamber and the isolation chamber configured to proved hydroxide ions to the input chamber and to receive hydroxide ions from the input chamber;    an anionic membrane positioned between the isolation chamber and the feed chamber configured to receive sulfate ions from the feed chamber; and    a bipolar membrane positioned between the cathode chamber and the feed chamber configured to provide hydroxide ions to the input chamber and receive hydrogen ions from the input chamber.    
     
     
         22 . The copper plating system of  claim 1 , wherein the catolyte electrochemical device comprises: 
 a housing having a cathode electrode positioned in a first end and an anode electrode positioned in a second end, the second end being oppositely positioned from the first end;    an anode chamber positioned proximate the anode and between the cathode electrode and the anode electrode configured to neutralize acid in the aged catolyte solution;    a cathode chamber positioned proximate the cathode electrode and between the cathode electrode and the anode chamber configured to neutralize acid in the aged catolyte solution;    at least one input chamber positioned between the cathode electrode and the anode chamber configured to receive aged catolyte; and    at least one purification chamber positioned between the input chambers to neutralize acid in the aged catolyte solution.    
     
     
         23 . The copper plating system of  claim 22 , wherein sulfuric acid is circulated between the anode chamber, the purification chamber, and the cathode chamber.  
     
     
         24 . The copper plating system of  claim 22 , wherein a copper sulfate solution is added to the restored catolyte.  
     
     
         25 . The copper plating system of  claim 22 , wherein the anode electrode is insoluble.  
     
     
         26 . The copper plating system of  claim 22 , wherein the input chamber comprises: 
 an anionic membrane positioned on a cathode side of the anode chamber configured to receive sulfate ions from the input chamber;    a bipolar membrane positioned between the input chamber and the purification chamber configured to provide hydroxide ions to the input chamber and to receive hydroxide ions from the input chamber;    an anionic membrane positioned between the purification chamber and the input chamber configured to receive sulfate ions from the input chamber; and    an anionic membrane positioned between the cathode chamber and the purification chamber configured to provide hydroxide ions to the purification chamber.    
     
     
         27 . The copper plating system of  claim 22 , further comprising an electrodialysis chamber configured to remove contaminants from the restored catolyte.  
     
     
         28 . The copper plating system of  claim 22 , further comprising a catolyte storage tank in fluid communication with a catolyte electrochemical device configured to receive a portion of catolyte solution and correct a catolyte concentration.  
     
     
         29 . The copper plating system of  claim 22 , further comprising a column comprising copper oxide in fluid communication with the anode chamber configured to correct an anolyte concentration.  
     
     
         30 . A method for plating copper, comprising: 
 supplying an electrolyte solution to a copper plating cell;    plating copper onto a substrate in the plating cell with the electrolyte solution;    removing aged electrolyte solution from the plating cell; and    neutralizing a portion of the aged electrolyte solution with an electrochemical device.    
     
     
         31 . The method of  claim 30 , wherein neutralizing a portion of the aged electrolyte with an electrochemical device comprises: 
 receiving the aged electrolyte solution in a first end of a anode chamber;    urging positive copper ions to diffuse from a soluble anode into the aged electrolyte solution;    urging positive hydrogen ions to diffuse through a bipolar membrane towards a cathode into a cathode chamber;    urging negative hydroxide ions to diffuse through the bipolar membrane towards an anode into the anode chamber; and    removing a copper sulfate solution from the concentration chamber.    
     
     
         32 . The method of  claim 31 , wherein the urging steps comprise applying an electrical bias across the electrodialysis cell.  
     
     
         33 . The method of  claim 31 , further comprising circulating a sulfuric acid solution through the cathode chamber.  
     
     
         34 . The method of  claim 30 , wherein neutralizing a portion of the aged electrolyte with an electrochemical device comprises: 
 receiving the aged electrolyte solution in a first end of an input chamber;    urging positive copper ions to diffuse from a soluble anode in an anode chamber through a cationic membrane into the aged electrolyte solution;    urging positive hydrogen ions to diffuse through a cationic membrane towards a cathode into a cathode chamber; and    removing a copper sulfate solution from the concentration chamber.    
     
     
         35 . The method of  claim 34 , wherein the urging steps comprise applying an electrical bias across the electrochemical device.  
     
     
         36 . The method of  claim 34 , further comprising circulating a sulfuric acid solution through the cathode chamber.  
     
     
         37 . The method of  claim 31 , wherein neutralizing a portion of the aged electrolyte with an electrochemical device comprises: 
 receiving the aged electrolyte solution in a first end of an input chamber;    urging negative sulfate ions to diffuse through an anionic membrane towards an anode into an anode chamber;    urging positive hydrogen ions to diffuse through a bipolar membrane towards a cathode into a cathode chamber; and    urging negative hydrogen ions to diffuse through the bipolar membrane away from the cathode into the input chamber; and    removing a copper sulfate solution from the concentration chamber.    
     
     
         38 . The method of  claim 37 , wherein the urging steps comprise applying an electrical bias across the electrochemical device.  
     
     
         39 . The method of  claim 37 , further comprising circulating a sulfuric acid solution through the cathode chamber.  
     
     
         40 . The method of  claim 37 , further comprising adding a copper sulfate solution to the restored electrolyte.  
     
     
         41 . The method of  claim 31 , wherein neutralizing a portion of the aged electrolyte with an electrochemical device comprises: 
 receiving the aged electrolyte solution in an input chamber;    urging negative sulfate ions to diffuse through an anionic membrane towards an anode into an anode chamber;    urging positive copper ions to diffuse through a cationic membrane from a copper feed chamber into the aged electrolyte solution;    urging positive hydrogen ions to diffuse through a bipolar membrane towards a cathode from the aged electrolyte solution into an isolation chamber;    urging negative hydroxide ions to diffuse through the bipolar membrane towards an anode from the isolation chamber into the aged electrolyte; and    removing a copper sulfate solution from the concentration chamber.    
     
     
         42 . The method of  claim 31 , wherein the urging steps comprise applying an electrical bias across the electrochemical device.  
     
     
         43 . The method of  claim 31 , further comprising circulating a sulfuric acid solution through the cathode chamber, the isolation chamber, and the anode chamber.  
     
     
         44 . The method of  claim 31 , further comprising circulating a copper sulfate solution through the copper feed chamber.  
     
     
         45 . The method of  claim 31 , wherein neutralizing a portion of the aged electrolyte with an electrochemical device comprises: 
 receiving the aged electrolyte solution in an input chamber;    urging negative sulfate ions to diffuse through an anionic membrane towards an anode in the anode chamber;    urging positive hydrogen ions to diffuse through a bipolar membrane towards a cathode from the aged electrolyte into a purification chamber;    urging negative hydroxide ions to diffuse through a bipolar membrane from the purification chamber into the aged electrolyte; and    removing a copper sulfate solution from the concentration chamber.    
     
     
         46 . The method of  claim 45 , wherein the urging steps comprise applying an electrical bias across the electrochemical device.  
     
     
         47 . The method of  claim 45 , further comprising circulating a sulfuric acid solution through the cathode chamber, the purification chamber, and the anode chamber.  
     
     
         48 . The method of  claim 45 , further comprising passing the copper sulfate solution through an electrodialysis cell to further remove contaminants and add copper ions to the solution.