Etching composition and etching process

Abstract

An etching composition which comprises at least one organic carboxylic acid compound selected from acetic acid, propionic acid, butyric acid, succinic acid, citric acid, lactic acid, malic acid, tartaric acid, malonic acid, maleic acid, glutaric acid, aconitic acid, 1,2,3-propanetricarboxylic acid and ammonium salts of these acids, a polysulfonic acid compound and water, and an etching process which comprises etching a conductive film comprising zinc oxide as the main component using the etching composition described above.

1 . An etching composition which comprises at least one organic carboxylic acid compound selected from acetic acid, propionic acid, butyric acid, succinic acid, citric acid, lactic acid, malic acid, tartaric acid, malonic acid, maleic acid, glutaric acid, aconitic acid, 1,2,3-propanetricarboxylic acid and ammonium salts of these acids, a polysulfonic acid compound, and water.  
   
   
       2 . An etching composition according to  claim 1 , wherein the organic carboxylic acid compound is acetic acid or ammonium acetate.  
   
   
       3 . An etching composition according to  claim 1 , wherein the organic carboxylic acid compound is acetic acid and ammonium acetate.  
   
   
       4 . An etching composition according to  claim 1 , wherein the polysulfonic acid compound is a compound selected from condensation products of naphthalenesulfonic acid with formaline, ligninsulfonic acid, polystyrenesulfonic acid and salts of these compounds.  
   
   
       5 . An etching composition according to  claim 4 , wherein the condensation product of naphthalenesulfonic acid with formaline is a compound obtained by sulfonation using naphthalene and sulfuric acid, followed by condensation by addition of formaline or by condensation by addition of formaline and neutralization with an alkali.  
   
   
       6 . An etching composition according to  claim 1 , wherein a concentration of the polysulfonic acid compound is 0.0001 to 10% by weight.  
   
   
       7 . An etching process which comprises etching a conductive film comprising zinc oxide as a main component using an etching composition described in  claim 1 .  
   
   
       8 . An etching process according to  claim 7 , wherein the conductive film comprises at least one of aluminum and gallium.