Silicon Etching Solution, Method for Manufacturing Silicon Device Using Same, and Substrate Treatment Method

An isotropic silicon etching solution contains a quaternary ammonium hydroxide; water; and the at least one compound selected from the group consisting of compounds represented by the following Formulas (1) and (2), in which the following Conditions 1 and 2 are satisfied.R1O-(CmH2mO)n-R2 (1)In the formula, R1 is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, R2 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, m is an integer of 2 to 6, and n is 1 to 3. With the proviso that, R1 and R2 are not hydrogen atoms at the same time, and when m=2, a total number (n+C1+C2) of n, the number of carbon atoms (C1) of R1, and the number of carbon atoms (C2) of R2 is 5 or more.HO-(C2H4O)p-H (2)In the formula, p is an integer of 15 to 1,000.Condition 1: 0.2≤etching rate ratio (R110/R100)≤1Condition 2: 0.8≤etching rate ratio (R110/R111)≤4R100 indicates an etching rate for a 100 plane of a silicon single crystal, R110 indicates an etching rate for a 110 plane of the silicon single crystal, and R111 indicates an etching rate for a 111 plane of the silicon single crystal.