SILICON ETCHING LIQUID, AND METHOD FOR PRODUCING SILICON DEVICES AND METHOD FOR PROCESSING SUBSTRATES, EACH USING SAID ETCHING LIQUID

A silicon etching solution contains: a quaternary ammonium hydroxide represented by the following Formula (1): R11R12R13R14N+·OH− (1) (in the formula, R11, R12, R13, and R14 are each independently an aryl group, a benzyl group, or an alkyl group having 1 to 4 carbon atoms, and the alkyl group, the aryl group, or the benzyl group may have a hydroxy group); a quaternary ammonium salt represented by the following Formula (2) and having 11 to 20 carbon atoms in total: R21R22R23R24N+·X− (2) (in the formula, one of R21, R22, R23, and R24 is an alkyl group having 16 or less carbon atoms, which may have a substituent, each of the remaining three is an alkyl group having 1 or 2 carbon atoms, the alkyl group having 16 or less carbon atoms and the alkyl group having 1 or 2 carbon atoms may have a hydroxy group, and X is at least one selected from the group consisting of BF4, a fluorine atom, a chlorine atom, and a bromine atom); a polyhydroxy compound having 2 to 12 carbon atoms and having two or more hydroxy groups in a molecule; and water.