| 摘要 |
PROBLEM TO BE SOLVED: To easily remove a polymer accumulated at dry etching process without corroding a metal film by using an aqueous solution containing specified quaternary ammonium salt, fluorine-containing compound, water soluble or water-miscible organic solvent, inorganic acid and organic acid. SOLUTION: An aqueous solution, expressed with a formula [(R<1> )3 N-R<2> ]<+> aX<a-> (R<1> is an alkyl group of carbon number 1-4, 3R<1> s may be the same or different from one another, and R<2> is an alkyl group of carbon number 1-4 or hydroxy alkyl group. X<a-> is inorganic or organic anion, and (a) is valence of the anion.), containing quaternary ammonium slat, fluorine-containing compound such as hydrofluoric acid and ammonium fluoride, water soluble or water- miscible organic solvent, inorganic acid and organic acid, is used. Thereby an accumulated polymer generated at dry etching process is easily removed without corroding a metal film. |
