| abstract |
In a method of manufacturing a wafer in which at least a part of the concavo-convex pattern includes a silicon element with a concavo-convex pattern on its surface, a cleaning process that is prone to cause pattern collapse is improved, A water repellent protective film is formed on the surface of the concavo-convex pattern of the wafer, and to provide the chemical liquid. A method for preparing a water repellent protective film-forming chemical liquid having a non-aqueous organic solvent, a silylating agent, and an acid or base for forming a water repellent protective film on at least a concave surface of the concave- Wherein the moisture concentration in the non-aqueous organic solvent is 200 mass ppm or less, A mixing step of mixing a non-aqueous organic solvent after the dewatering step with a silylating agent, an acid or a base, Wherein the water-repellent protective film forming liquid is a water-repellent protective film. |