Electrochemically polishing conductive films on semiconductor wafers

Abstract

An electropolish process may remove a conductive film from a semiconductor wafer. An electropolish apparatus having a pad over a platen may make surface-to-surface electrical contact with the conductive film of the wafer across the entire surface of the pad and the conductive film on the wafer. An electric field may be applied through openings in the pad and electrodes which receive potential by feedthroughs that extend through the platen to those electrodes. The electrodes in the feedthroughs may be electrically isolated from the pad and the platen. As a result, more uniform application of electrical potential across the surface to be polished may be achieved in some embodiments.

1 . A polishing pad for an electrochemical polishing process comprising: 
 a conductive body and a plurality of regularly spaced openings through said body; and    an electrode in said openings connectable to a potential, said electrode insulated from said body.    
   
   
       2 . The pad of  claim 1  wherein said openings have a circular shape.  
   
   
       3 . The pad of  claim 1  including an insulator between said electrode and said body.  
   
   
       4 . An electrochemical polishing apparatus comprising: 
 a platen;    a pad positioned over said platen, said pad being conductive; and    a plurality of electrodes formed within openings in said pad, said electrodes being electrically isolated from said pad.    
   
   
       5 . The apparatus of  claim 4  wherein said platen is electrically conductive.  
   
   
       6 . The apparatus of  claim 4  including insulators to insulate said electrode electrically from said pad.  
   
   
       7 . The apparatus of  claim 4  wherein said electrodes extend through said pad and said platen.