Ruthenium silicide wet etch

Abstract

A method of removing ruthenium silicide from a substrate surface which comprises exposing the ruthenium silicide surface to a solution containing chlorine and fluorine containing chemicals. In particular, said solution is designed to react with said ruthenium silicide film such that water-soluble reaction products are formed.

1 . An etchant for removing ruthenium silicide from a surface, comprising: 
 a solution comprising a chlorine-containing chemical and an acid, wherein the solution has an oxidation potential of about 1150 mV or greater.    
   
   
       2 . The etchant of  claim 1 , wherein the solution has an oxidation potential of between about 1180-1230 mV.  
   
   
       3 . The etchant of  claim 1 , wherein the chlorine-containing chemical comprises a hypochlorite salt.  
   
   
       4 . The etchant of  claim 3 , wherein the hypochlorite salt comprises potassium hypochlorite.  
   
   
       5 . The etchant of  claim 1 , wherein the acid comprises hydrofluoric acid.  
   
   
       6 . An integrated circuit etching system comprising: 
 a first surface comprising ruthenium silicide; and    an etchant comprising an aqueous solution having a chlorine-containing chemical, wherein the solution has an oxidation potential of about 1150 mV or greater.    
   
   
       7 . The system of  claim 6 , wherein the oxidation potential of the solution is between about 1180 to 1230 mV.  
   
   
       8 . The system of  claim 6 , wherein the first surface is a wafer surface.  
   
   
       9 . The system of  claim 6 , wherein the first surface is a tool surface.  
   
   
       10 . The system of  claim 6 , wherein the chlorine-containing chemical is a hypochlorite salt.