Removing fluorine-based plasma etch residues

Abstract

Supercritical carbon dioxide may be utilized to remove fluorine-based etch residues such as those residues left when etching dielectrics in fluorine-based plasma gases. The supercritical carbon dioxide may have dissolved in it various reagents and fluorocarbon materials that, together, cause the residue to swell and to be exposed for reactions with the reagents, the supercritical carbon dioxide, and the fluorocarbons. As a result, relatively hard to penetrate fluorine-based residues may be entered and removed using aggressive chemistries.

What is claimed is:  
     
         1 . A method comprising: 
 forming a fluorine-based etch residue on a dielectric or having a fluorine-based photoresist to begin with as in 157 nm process; and    exposing said dielectric to supercritical carbon dioxide.    
     
     
         2 . The method of  claim 1  including removing said etch residue using said supercritical carbon dioxide.  
     
     
         3 . The method of  claim 2  including providing a fluorocarbon material with said supercritical carbon dioxide.  
     
     
         4 . The method of  claim 1  including providing a reagent that is soluble in supercritical carbon dioxide to dissolve said residue.  
     
     
         5 . The method of  claim 1  including causing the fluorine-based etch residue to swell.  
     
     
         6 . A cleaner for cleaning fluorine-based etch residue comprising: 
 supercritical carbon dioxide;    a fluorocarbon material; and    at least one chemical reagent that is soluble in supercritical carbon dioxide.    
     
     
         7 . The cleaner of  claim 6  wherein said fluorocarbon is selected from the group consisting of perfluoroalkanes, perfluoroaromatics, and perfluoro-cyclohydrocarbons.  
     
     
         8 . The cleaner of  claim 6  wherein the chemically reactive agent is selected from the group composed of dimethyl acetamide, sulfolane, organic peroxides, ethers, glycols, organic bases, and organic and mineral acids.  
     
     
         9 . A method comprising: 
 exposing a fluorine-based etch residue to supercritical carbon dioxide and a fluorocarbon;    causing said fluorine-based etch residue to swell; and    cleaning said fluorine-based etch residue.    
     
     
         10 . The method of  claim 9  including providing a reagent that is soluble in supercritical carbon dioxide to dissolve said residue.  
     
     
         11 . The method of  claim 9  including breaking through the hard crust of the residue using the fluorocarbon.  
     
     
         12 . The method of  claim 11  including introducing a reactive agent into said residue after breaking through said hard crust using the fluorocarbon.  
     
     
         13 . The method of  claim 9  including flowing said supercritical carbon dioxide over said residue.  
     
     
         14 . The method of  claim 9  including exposing said residue to a fluorocarbon selected from the group including perfluoroalkanes, perfluoroaromatics, and perfluoro-cyclohydrocarbons.  
     
     
         15 . The method of  claim 9  including removing dissolved residues in a flow of supercritical carbon dioxide.