Method and apparatus for simultaneously removing multiple conductive materials from microelectronic substrates

Abstract

A method and apparatus for simultaneously removing conductive materials from a microelectronic substrate. A method in accordance with one embodiment of the invention includes contacting a surface of a microelectronic substrate with an electrolytic liquid, the microelectronic substrate having first and second different conductive materials. The method can further include controlling a difference between a first open circuit potential of the first conducive material and a second open circuit potential of the second conductive material by selecting a pH of the electrolytic liquid. The method can further include simultaneously removing at least portions of the first and second conductive materials by passing a varying electrical signal through the electrolytic liquid and the conductive materials. Accordingly, the effects of galvanic interactions between the two conductive materials can be reduced and/or eliminated.

1 - 54 . (Canceled)  
   
   
       55 . An electrolytic liquid for removing first and second conductive materials from a microelectronic substrate, the first conductive material being different than the second conductive material, the electrolytic liquid comprising: 
 a liquid carrier; and    an electrolyte disposed in the liquid carrier and configured to transmit electrical signals from an electrode to the first and second conductive materials of the microelectronic substrate;    wherein a pH of the electrolytic liquid is from about 2 to about 5.    
   
   
       56 . The electrolytic liquid of  claim 55  wherein the electrolyte includes an acid.  
   
   
       57 . The electrolytic liquid of  claim 55  wherein the electrolyte includes at least one of hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid and acetic acid.  
   
   
       58 . The electrolytic liquid of  claim 55  wherein the liquid carrier includes deionized water.  
   
   
       59 . The electrolytic liquid of  claim 55  wherein the pH of the electrolytic liquid is selected to control an absolute value of a difference between a first open circuit potential of the first conductive material and a second open circuit potential of the second conductive material to be about 0.50 volts or less.  
   
   
       60 . The electrolytic liquid of  claim 55  wherein the pH of the electrolytic liquid is selected to control an absolute value of a difference between a first open circuit potential of the first conductive material and a second open circuit potential of the second conductive material to be about 0.25 volts or less.  
   
   
       61 . The electrolytic liquid of  claim 55 , further comprising an oxidizer.  
   
   
       62 . The electrolytic liquid of  claim 55 , further comprising an oxidizer selected from hydroxylamine, peroxide and ammonium persulfate.  
   
   
       63 . The electrolytic liquid of  claim 55 , further comprising a corrosion inhibitor.  
   
   
       64 . The electrolytic liquid of  claim 55 , further comprising a corrosion inhibitor that includes benzotriazole.  
   
   
       65 . A system for removing first and second conductive materials from a microelectronic substrate, the first conductive material being different than the second conductive material, the system comprising: 
 a substrate support configured to carry a microelectronic substrate;    at least one electrode positioned at least proximate to the substrate support;    a liquid support positioned proximate to the substrate support to carry an electrolytic liquid in contact with the microelectronic substrate; and    an electrolytic liquid carried by the liquid support, the electrolytic liquid including: 
 a liquid carrier;  
 an electrolyte disposed in the liquid carrier and configured to transmit electrical signals from the at least one electrode to the first and second conductive materials of the microelectronic substrate, wherein a pH of the electrolytic liquid is from about 2 to about 5.  
   
   
   
       66 . The system of  claim 65  wherein the liquid support includes a liquid vessel.  
   
   
       67 . The system of  claim 65  wherein the liquid support includes a polishing pad having a polishing surface positioned to contact the microelectronic substrate, wherein the at least one of the polishing pad and the substrate support is movable relative to the other.  
   
   
       68 . The system of  claim 65  wherein the electrode is a first electrode and wherein the system further comprises: 
 a second electrode spaced apart from the first electrode; and    an electrical signal transmitter coupled to the first and second electrodes, wherein the first and second electrodes are positioned to be spaced apart from the microelectronic substrate when the substrate carrier carries the microelectronic substrate.    
   
   
       69 . The system of  claim 65 , further comprising a sensor positioned to detect an amount of conductive material on the microelectronic substrate.  
   
   
       70 . The system of  claim 65  wherein at least one of the at least one electrode and the substrate support is movable relative to the other.  
   
   
       71 . The system of  claim 65  wherein the electrolyte includes at least one of hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid and acetic acid.  
   
   
       72 . The system of  claim 65  wherein the pH of the electrolytic liquid is selected to control an absolute value of a difference between a first open circuit potential of the first conductive material and a second open circuit potential of the second conductive material to be about 0.50 volts or less.  
   
   
       73 . The system of  claim 65  wherein the pH of the electrolytic liquid is selected to control an absolute value of a difference between a first open circuit potential of the first conductive material and a second open circuit potential of the second conductive material to be about 0.25 volts or less.