Conductive polishing article for electrochemical mechanical polishing

Abstract

A conductive polishing article is provided. The conductive polishing article at least has a polishing pad, cathodes and anodes. Cathodes and anodes are disposed below the polishing surface of the polishing pad, and an ion exchange membrane at least partially covers the anodes.

1 . A polishing article comprising:
 a polishing pad having a polishing surface adapted to contact a substrate surface;   a first electrode disposed below the polishing surface at a first distance;   a second electrode disposed below the polishing surface at a second distance, wherein the second distance is substantially shorter than the first distance; and   an ion exchange membrane disposed at least partially covering the second electrode, wherein the membrane is permeable to ions and allows ionic communication between the second electrode and the substrate surface.   
   
   
       2 . The polishing article of  claim 1 , wherein the ion exchange membrane is comprised of an ion exchange material. 
   
   
       3 . The conductive polishing article of  claim 1 , wherein the membrane is configured to retain an electrolyte solution therein. 
   
   
       4 . The conductive polishing article of  claim 1 , wherein the first distance is about 1 to 5 millimeters. 
   
   
       5 . The conductive polishing article of  claim 1 , wherein the second distance is about 0.1 to 1 millimeters. 
   
   
       6 . The conductive polishing article of  claim 1 , wherein a ratio of the total exposed surfaces of the first electrode over the total exposed surfaces of the second electrode is about 0.01 to about 100. 
   
   
       7 . The conductive polishing article of  claim 1 , wherein a ratio of the total exposed surfaces of the first electrode over the total exposed surfaces of the second electrode is about 3. 
   
   
       8 . A conductive polishing article for electrochemical mechanical polishing, comprising:
 a polishing pad having a polishing surface for polishing a substrate and a mounting surface located oppositely, wherein the polishing pad has a plurality of first perforations and second perforations distributed evenly;   a plurality of cathodes located in the plurality of first perforations;   a plurality of anodes located in the second perforations, wherein a first distance between a top surface of the cathodes and the polishing surface is greater than a second distance between the top surface of the anodes and the polishing surface;   a plurality of ion exchange membranes respectively encapsulating the anodes to prevent oxygen gas contacting the substrate, the ion exchange membranes being comprised of an ion exchange material; and   a sub pad located adjacent to the mounting surface of the polishing pad.   
   
   
       9 . The conductive polishing article of  claim 8 , wherein the ion exchange material is based on a fluorinated polymer matrix having at least an anionic functional group. 
   
   
       10 . The conductive polishing article of  claim 8 , wherein the ion exchange membrane is configured to retain an electrolyte solution therein. 
   
   
       11 . The conductive polishing article of  claim 8 , wherein the first distance is about 1 mm to about 5 mm. 
   
   
       12 . The conductive polishing article of  claim 8 , wherein the second distance is about 0.1 mm to about 1 mm. 
   
   
       13 . The conductive polishing article of  claim 8 , wherein a ratio of the total top surfaces of the cathodes over the total top surfaces of the anodes is from about 0.01 to about 100. 
   
   
       14 . The conductive polishing article of  claim 8  wherein a ratio of the total top surfaces of the cathodes over the total top surfaces of the anodes is about 3. 
   
   
       15 . A conductive polishing article for electrochemical mechanical polishing, comprising:
 a polishing pad having a polishing surface adapted to polish a substrate, wherein the polishing pad has plural perforations and plural grooves cut into the polishing pad from the polishing surface;   at least one cathode located in or behind the polishing pad, wherein at least a part of the cathode is exposed to the substrate by the perforations;   a plurality of anodes located in the grooves, wherein a first distance between the exposed surface of the cathodes and the polishing surface is greater than a second distance between the top surface of the anodes and the polishing surface;   a plurality of ion exchange membranes respectively encapsulating the anodes to prevent oxygen gas contacting the substrate, the ion exchange membranes being comprised of an ion exchange material; and   a sub pad located behind the polishing pad to support the polishing pad.   
   
   
       16 . The conductive polishing article of  claim 15  wherein the ion exchange material is based on a fluorinated polymer matrix having at least an anionic functional group. 
   
   
       17 . The conductive polishing article of  claim 15  wherein the ion exchange membrane is configured to retain an electrolyte solution therein. 
   
   
       18 . The conductive polishing article of  claim 15  wherein the first distance is about 1 to 2 millimeters. 
   
   
       19 . The conductive polishing article of  claim 15  wherein the second distance is about 0.1 to 0.5 millimeters. 
   
   
       20 . The conductive polishing article of  claim 15 , wherein a ratio of the total exposed surfaces of the cathode over the total top surfaces of the anodes is about 3.