To remove polymer deposits so as to protect a metal material against corrosion by a method wherein composition which contains a specific amount of specific quaternary ammonium hydroxide and water-soluble organic solvent and water as the rest is used as cleaning agent.
In a formula, R1 to R4 may be identical or different and denote an alkyl group possessed of carbon atoms 1 to 4 in number, a hydroxy- substituted alkyl group whose number of carbon atoms is 1 to 4, or an aryl group. In the formula, 0.01 to 15 wt.% of quaternary ammonium hydroxide is contained in all solution, a mixture of one or more kinds of solvent is used as water-soluble organic solvent, and 20 to 95 wt.% of the above mixture is contained in the solution. This cleaning agent is used to remove resist, modified resist, or polymer deposits left on the processed layer after an inorganic base is subjected to dry etching or subjected to an oxygen plasma ashing treatment after dry etching. Photoresist and the like deposited on a side wall are easily separated off, and a metal material is completely protected against corrosion caused by etching.
HASEMI TAKASHI
IKEDA HIDETOSHI
HANEDA MAYUMI
