Retaining ring with conductive portion

Abstract

A retaining ring for use with electrochemical mechanical processing is described. The retaining ring has a generally annular body formed with a conductive portion and a non-conductive portion. The non-conductive portion contacts the substrate during polishing. The conductive portion is electrically biased during polishing to reduce the edge effect that tends to occur with conventional electrochemical mechanical processing systems.

1 . A retaining ring for electrochemical mechanical processing, comprising: 
 a conductive portion; and    an annular non-conductive portion, wherein the non-conductive portion partially encapsulates the conductive portion, yet allows for electrolytic reaction of the conductive portion with a polishing solution during a polishing process.    
     
     
         2 . The retaining ring of  claim 1 , wherein the non-conductive portion forms at least a bottom portion of an inner diameter of the retaining ring.  
     
     
         3 . The retaining ring of  claim 1 , wherein the non-conductive portion forms at least a portion of an outer diameter of the retaining ring.  
     
     
         4 . The retaining ring of  claim 1 , wherein the non-conductive portion contacts an entirety of an outer diameter of the annular conductive portion.  
     
     
         5 . The retaining ring of  claim 1 , wherein the conductive portion is annular.  
     
     
         6 . A retaining ring for electrochemical mechanical processing, comprising: 
 an annular conductive portion; and    a non-conductive portion on a bottom of the conductive portion, on a top of the conductive portion and along an outer diameter of the conductive portion.    
     
     
         7 . The retaining ring of  claim 6 , wherein the non-conductive portion forms a lower portion of an inner diameter of the retaining ring.  
     
     
         8 . The retaining ring of  claim 6 , wherein the non-conductive portion is discontinuous along the bottom of the conductive portion.  
     
     
         9 . A retaining ring for electrochemical mechanical processing, comprising: 
 a conductive portion with an inner surface and a lower surface; and    a non-conductive portion that is less rigid than the conductive portion and that covers the inner surface and less than all of the lower surface of the conductive portion.    
     
     
         10 . The retaining ring of  claim 9 , wherein the non-conductive portion covers a portion of the lower surface.  
     
     
         11 . The retaining ring of  claim 9 , wherein the non-conductive portion has a bottom surface for contacting the polishing pad and the lower surface is recessed relative to the bottom surface.  
     
     
         12 . The retaining ring of  claim 9 , wherein the non-conductive portion has a bottom surface for contacting the polishing pad and the lower surface is flush with the bottom surface.  
     
     
         13 . A retaining ring for electrochemical mechanical processing, comprising: 
 a first annular conductive portion with a first conductivity; and    a second annular conductive portion surrounding the first annular conductive portion, the second annular conductive portion having a second conductivity different than the first conductivity.    
     
     
         14 . The retaining ring of  claim 13 , further comprising a non-conductive portion that is less rigid than the conductive portion and that covers an inner surface of the first annular conductive portion.  
     
     
         15 . The retaining ring of  claim 13 , wherein non-conductive portion covers a portion but less than all of the lower surface of the conductive portion.  
     
     
         16 . A method of electrochemical processing, comprising: 
 retaining a substrate in a retaining ring having a conductive portion and a non-rigid substrate contacting portion along a lower portion of its inner diameter;    contacting the substrate to a polishing pad;    generating relative motion between the polishing pad and the substrate; and    applying a voltage to the retaining ring through the polishing pad.    
     
     
         17 . The method of  claim 16 , further comprising preventing at least part of the conductive portion from contacting the polishing pad.  
     
     
         18 . The method of  claim 16 , wherein: 
 the conductive portion includes two different materials; and    applying a voltage to the retaining ring through the polishing pad includes applying a voltage to a first of the two different materials, which applies a voltage to a second of the two different materials.    
     
     
         19 . A system for electrochemical mechanical processing, comprising: 
 a polishing pad assembly having a conductive element;    a carrier head, configured to contact the polishing pad assembly, the carrier head comprising: 
 a base; and  
 a retaining ring attached to the base, wherein the retaining ring comprises: 
 an annular conductive portion having a lower surface and an outer diameter surface; and  
 a substrate contacting portion forming at least part of an inner diameter surface of the retaining ring and contacting the lower surface and the outer diameter surface of the conductive portion, the substrate contacting portion formed of an insulating material; and  
 
   a voltage source electrically coupled to the retaining ring.    
     
     
         20 . The system of  claim 19 , wherein the voltage source is coupled to the retaining ring through the carrier head.  
     
     
         21 . The system of  claim 19 , wherein the conductive portion includes a lower conductivity portion and a higher conductivity portion.  
     
     
         22 . The system of  claim 19 , wherein the substrate contacting portion allows for electrolytic reaction of the conductive portion with a polishing solution during a polishing process.  
     
     
         23 . A system for electrochemical mechanical processing, comprising: 
 a polishing pad assembly having a conductive element;    a carrier head, configured to contact the polishing pad assembly, the carrier head comprising: 
 a base; and  
 a retaining ring attached to the base, wherein the retaining ring comprises: 
 a conductive portion; and  
 a non-conductive portion, wherein the non-conductive portion is configured to contact a substrate during polishing and the conductive portion is configured to move voltage non-uniformity away from an edge of the substrate in comparison to a conventional retaining ring; and  
 
   a voltage source electrically coupled to the retaining ring.    
     
     
         24 . The system of  claim 23 , wherein the voltage source is coupled to the retaining ring through the carrier head.  
     
     
         25 . The system of  claim 23 , wherein the voltage source is coupled to the retaining ring through the carrier head.  
     
     
         26 . The system of  claim 23 , wherein the conductive portion includes a lower conductivity portion and a higher conductivity portion.  
     
     
         27 . The system of  claim 23 , wherein the non-conductive portion covers a portion but less than all of the lower surface of the conductive portion.