manufacturing method | in the washing process after wet etching or dry etching, A treatment liquid for suppressing pattern collapse of a fine structure is used and water containing at least one of an imidazolium halide selected from an alkyl group having 12 carbon atoms, 14 carbon atoms or 16 carbon atoms, a pyridinium halide having an alkyl group having 14 carbon atoms or 16 carbon atoms, and an ammonium halide having an alkyl group having 16 carbon atoms or 18 carbon atoms. The fine structure formed by silicon oxide is a semiconductor device or a micromachine. |