Solutions and processes for removal of sidewall residue after dry etching

Abstract

The present invention relates to a novel process for removing sidewall residue after dry-etching process. Conventionally, after dry-etching, photoresist and sidewall residues are removed by ozone ashing and hot sulfuric acid. Normally, they are hard to be removed completely. It was found in the present invention that the addition of fluorine-containing compound, preferably hydrogen fluoride and ammonium fluoride, in sulfuric acid results in complete removal of photoresist and sidewall residue without the need for stripper. The process is simple and does not affect the original procedures or the other films on the substrate. The present invention also relates to a novel solution for removing sidewall residue after dry-etching, which comprises sulfuric acid and a fluorine-containing compound, preferably hydrogen fluoride and ammonium fluoride, in the range of from 10:1 to 1000:1 by weight.

1 . A solution for removing sidewall residue after dry etching, which comprises sulfuric acid and a fluorine-containing compound, in the range of from 10:1 to 1000:1 by weight.  
     
     
         2 . The solution according to  claim 1 , the range being from 100:1 to 700:1 by weight.  
     
     
         3 . The solution according to  claim 1 , the range being from 300:1 to 500:1 by weight.  
     
     
         4 . The solution according to  claim 1 , the solution containing a fluoride compound, which is composed of fluorine ion and mono-charge cation, the types of this mono-charge cation include alkaline metal cation, ammonium cation and hydrogen ion.  
     
     
         5 . The solution according to  claim 1 , the fluorine-containing compound being hydrogen fluoride.  
     
     
         6 . The solution according to  claim 1 , the fluorine-containing compound being ammonium fluoride.  
     
     
         7 . A process for removing sidewall residue after dry etching in which wafer after dry etching is treated with a solution which comprises sulfuric acid and a fluorine-containing compound, in the range of from 10:1 to 1000:1 by weight.  
     
     
         8 . The process according to  claim 7 , the solution being, in the range of from 100:1 to 700:1 by weight.  
     
     
         9 . The process according to  claim 7 , the solution being in the range of from 300:1 to 500:1 by weight.  
     
     
         10 . The process according to  claim 7 , the fluorine-containing compound is composed of fluorine ion and mono-charge cation, the types of cation include alkaline metal cation, ammonium cation and hydrogen ion.  
     
     
         11 . The process according to  claim 7 , the fluorine-containing compound being hydrogen fluoride.  
     
     
         12 . The process according to  claim 7 , the fluorine-containing compound being ammonium fluoride.