Phosphorous-containing copper anode for electrolytic copper plating, method for manufacturing same, and electrolytic copper plating method

Abstract

Provided are a phosphorous-containing copper anode for electrolytic copper plating, a method for manufacturing the same, and an electrolytic copper plating method using the phosphorous-containing copper anode. The phosphorous-containing copper anode obtains a crystal grain boundary structure having a special grain boundary ratio Lσ N /L N of 0.4 or more. L N is a unit total special grain boundary length corresponding to a unit area of 1 mm 2 obtained by converting a total grain boundary length L. Lσ N is a unit total special boundary length corresponding to a unit area of 1 mm 2 obtained by converting a total special grain boundary length Lσ. By having the configuration described above, a black film is formed evenly on the copper anode at the early stage of the electrolytic copper plating. Plating defect can be reduced by preventing the black film being fallen.

1 . A phosphorous-containing copper anode for electrolytic copper plating comprising a grain boundary structure satisfying the following relationship:
     Lσ   N   /L   N ≧0.4, wherein
   (a) a total crystal grain boundary length L within a measurement area being measured with a scanning electron microscope by irradiating an electron beam to individual crystal grains on a surface of the anode under a condition that an interface between crystal grains laying side-by-side having a mutual crystal orientation difference of 15° or more is defined as the crystal grain boundary, and a unit total crystal grain boundary length L N  being a converted value corresponding to a unit area of 1 mm 2  from the total crystal grain boundary length L;   (b) locations of special crystal grain boundaries, where a special grain boundary is formed between an interface between crystal grains laying side-by-side, being determined, a total special crystal grain boundary length Lσ of the special crystal grain boundaries being measured with a scanning electron microscope by irradiating an electron beam to individual crystal grains on the surface of the anode, and a unit total special crystal grain boundary length Lσ N  being a converted value corresponding to a unit area of 1 mm 2  from the total special crystal grain boundary length Lσ; and   (c) Lσ N /L N  being a ratio of Lσ N , which is the measured unit total special crystal grain boundary length, to L N , which is the measured unit total crystal grain boundary length.   
     
     
         2 . The phosphorous-containing copper anode for electrolytic copper plating according to  claim 1 , wherein the phosphorous-containing copper anode contains 100 ppm to 800 ppm of phosphorous by mass. 
     
     
         3 . The phosphorous-containing copper anode for electrolytic copper plating according to  claim 1 , wherein the average diameter of crystal grain is 3 μm to 1000 μm. 
     
     
         4 . A method for manufacturing the phosphorous-containing copper anode for electrolytic copper plating according to  claim 1  comprising the steps of:
 imparting machining stress by machining the phosphorous-containing copper anode for electrolytic copper plating; and 
 performing recrystallization heat treatment at 350° C. to 900° C. after the step of imparting machining stress, wherein 
 the special grain boundary length ratio Lσ N /L N  is 0.4 or more. 
 
     
     
         5 . The method for manufacturing the phosphorous-containing copper anode for electrolytic copper plating according to  claim 4 , wherein the machining is carried out by either cold working or hot working at least. 
     
     
         6 . The method for manufacturing the phosphorous-containing copper anode for electrolytic copper plating according to  claim 4 , wherein a process having the cold working and the recrystallization heat treatment, a process having the hot working and the recrystallization heat treatment, or a combination of the two processes is carried out repeatedly until the special grain boundary length ratio Lσ N /L N  becomes 0.4 or more. 
     
     
         7 . The method for manufacturing the phosphorous-containing copper anode for electrolytic copper plating according to  claim 4 , wherein
 the step of imparting machining stress is carried out by hot working at a rolling reduction of 5% to 80% within a temperature range of 400° C. to 900° C., and   the step of performing recrystallization heat treatment is carried out by statically holding the phosphorous-containing copper anode for 3 to 300 seconds free of imparting the machining stress after the step of imparting machining stress.   
     
     
         8 . The method for manufacturing the phosphorous-containing copper anode for electrolytic copper plating according to  claim 4 , wherein
 the step of imparting machining stress is carried out by cold working at a rolling reduction of 5% to 80%, and   the step of performing recrystallization heat treatment is carried out by heating the anode within a temperature range of 350° C. to 900° C. and statically holding the phosphorous-containing copper anode for 5 minutes to 5 hours free of imparting the machining stress after the step of imparting machining stress.   
     
     
         9 . An electrolytic copper plating method wherein the phosphorous-containing copper anode for electrolytic copper plating according to  claim 1  is used. 
     
     
         10 . The phosphorous-containing copper anode for electrolytic copper plating according to  claim 2 , wherein the average diameter of crystal grain is 3 μm to 1000 μm. 
     
     
         11 . The method for manufacturing the phosphorous-containing copper anode for electrolytic copper plating according to  claim 5 , wherein a process having the cold working and the recrystallization heat treatment, a process having the hot working and the recrystallization heat treatment, or a combination of the two processes is carried out repeatedly until the special grain boundary length ratio Lσ N /L N  becomes 0.4 or more.