Liquid Chemical for Forming Protective Film, and Cleaning Method for Wafer Surface

摘要

Disclosed is a liquid chemical for forming a water repellent protective film at least on surfaces of recessed portions of a metal-based wafer, the liquid chemical for forming a water repellent protective film being characterized by comprising a surfactant which has an HLB value of 0.001-10 according to Griffin's method and includes a hydrophobic moiety having a C6-C18 hydrocarbon group and water, and characterized in that the concentration of the surfactant in the liquid chemical is not smaller than 0.00001 mass % and not larger than the saturated concentration relative to 100 mass % of the total amount of the liquid chemical. This liquid chemical can improve a cleaning step which tends to induce a metal-based wafer to cause a pattern collapse.