| abstract |
The present invention relates to a method for preparing a chemical solution for forming a water repellent protective film, which is used for forming a water repellent protective film on a surface of at least a concave portion of the concave-convex pattern of a wafer having a concave-convex pattern on the surface thereof, and having a solvent and a water repellent protective film forming agent And including the following steps: a first purification step of removing Na, Mg, K, Ca, Mn, Fe, Cu, Li in the above solvent by distilling the solvent or by removing the particle film and the ion exchange resin film , each element of Al, Cr, Ni, Zn, and Ag (metal impurities); a mixing step of mixing the solvent after the first purification step with a water repellent protective film forming agent; and a second purification step of removing particles The membrane removes particles in the liquid after the mixing step. |