Electrolytic Deposition Treatment Apparatus and Method

Abstract

The present invention provides an electrolytic deposition treatment apparatus and method which can reduce metal ion concentration of waste water to be treated by electrolytic deposition to the degree to which treated water can be discharged to the outside, and which can treat waste water, even if the quantity of waste water produced in a semiconductor device fabrication apparatus is large. The electrolytic deposition treatment apparatus comprises a cathode( 3 ) for depositing metal ions in water to be treated as metal, a cation exchange membrane( 4 ) disposed so as to face the cathode( 3 ), and an anode( 6 ) disposed so as to face the cation exchange membrane( 4 ) through a cation exchanger( 5 ). The water to be treated is supplied to a space between the cathode( 3 ) and the cation exchange membrane( 4 ).

1 . An electrolytic deposition treatment apparatus comprising: 
 a cathode for depositing metal ions in water to be treated as metal;    a cation exchange membrane disposed so as to face said cathode; and    an anode disposed so as to face said cation exchange membrane through a cation exchanger;    wherein the water to be treated is supplied to a space between said cathode and said cation exchange membrane.    
   
   
       2 . The electrolytic deposition treatment apparatus as recited in  claim 1 , wherein pure water is supplied to an anode chamber having said anode therein.  
   
   
       3 . The electrolytic deposition treatment apparatus as recited in  claim 1 , wherein said anode chamber having said anode therein and an cathode chamber having said cathode therein are partitioned to prevent oxygen gas generated in said anode chamber from flowing into said cathode chamber.  
   
   
       4 . The electrolytic deposition treatment apparatus as recited in  claim 1 , wherein said anode chamber having said anode therein and an cathode chamber having said cathode therein are partitioned; and 
 wherein an inert gas is introduced into said cathode chamber to make said cathode chamber positive pressure, said inert gas flows through a gap between said anode chamber and said cathode chamber into said anode chamber, and oxygen gas generated in said anode chamber is discharged together with said inert gas from said anode chamber.    
   
   
       5 . The electrolytic deposition treatment apparatus as recited in  claim 1 , wherein said cathode is rotatable.  
   
   
       6 . The electrolytic deposition treatment apparatus as recited in  claim 5 , further comprising a scraper disposed in contact with or adjacent to said rotatable cathode so that said scraper scrapes off the metal deposited on said cathode.  
   
   
       7 . The electrolytic deposition treatment apparatus as recited in  claim 6 , wherein the metal removed from the surface of said cathode by said scraper is delivered to a filter together with treated water, and is filtrated and captured by said filter.  
   
   
       8 . The electrolytic deposition treatment apparatus as recited in  claim 7 , wherein filtrate which has passed through said filter is introduced in the tangential direction of said cathode into said cathode chamber.  
   
   
       9 . The electrolytic deposition treatment apparatus as recited in  claim 1 , wherein said anode comprises a gas-permeable anode.  
   
   
       10 . The electrolytic deposition treatment apparatus as recited in  claim 1 , wherein said cation exchanger is made of ion-exchange fibrous materials.  
   
   
       11 . The electrolytic deposition treatment apparatus as recited in  claim 10 , wherein said ion-exchange fibrous materials comprise materials in which ion exchange group is introduced into organic polymer unwoven fabric substrates by utilizing radiation-induced graft polymerization.  
   
   
       12 . An electrolytic deposition treatment method comprising: 
 supplying water to be treated having a pH of a predetermined range between a cathode and a cation exchange membrane;    depositing metal on said cathode by applying direct voltage between an anode and said cathode, said anode being disposed in an anode chamber to which pure water is supplied; and    removing the deposited metal on said cathode.    
   
   
       13 . The electrolytic deposition treatment method as recited in  claim 12 , wherein said cathode is rotated.  
   
   
       14 . The electrolytic deposition treatment method as recited in  claim 13 , wherein the metal deposited on the surface of said cathode is scraped off by a scraper disposed in contact with or adjacent to said rotatable cathode.  
   
   
       15 . The electrolytic deposition treatment method as recited in  claim 14 , wherein the metal removed from the surface of said cathode is filtrated and captured by a filter.  
   
   
       16 . The electrolytic deposition treatment method as recited in  claim 12 , wherein said pH is in the range of 1 to 3.  
   
   
       17 . The electrolytic deposition treatment method as recited in  claim 12 , wherein said anode comprises a gas-permeable anode.  
   
   
       18 . The electrolytic deposition treatment method as recited in  claim 12 , wherein the water to be treated is waste water produced in a semiconductor device fabrication apparatus or waste water pretreated after being produced in said semiconductor device fabrication apparatus.  
   
   
       19 . The electrolytic deposition treatment method as recited in  claim 12 , wherein metal ions in the water to be treated are copper ions produced in a semiconductor device fabrication apparatus for use in a copper interconnect forming process.