Abstract: Provided are a substrate with a multilayer reflective film comprising a protective film having high resistance to a fluorine-based etching gas used in an absorber pattern repair step without reducing a reflectance of the multilayer reflective film, a reflective mask blank, and a reflective mask. A substrate with a multilayer reflective film 100 comprises a substrate 10, a multilayer reflective film 12 disposed on the substrate 10, and a protective film 14 disposed on the multilayer reflective film 12. The protective film 14 comprises a first metal and a second metal. Standard free energy of formation of a fluoride of the first metal is higher than standard free energy of formation of RuF5. The second metal has an extinction coefficient of 0.03 or less at a wavelength of 13.5 nm.

Abstract: Provided is a reflective mask blank. The reflective mask blank has a multilayer reflective film and a thin film for pattern formation in this order on a main surface of a substrate; the thin film consists of a single layer structure consisting of a ruthenium-containing layer at least containing ruthenium, nitrogen, and oxygen or a multilayer structure including the ruthenium-containing layer; and when the ruthenium-containing layer is subjected to an analysis by an In-Plane measurement of an X-ray diffraction method to obtain an X-ray diffraction profile where, provided I_P1 is the maximum value of diffraction intensity within a diffraction angle 2? ranging from 65 degrees to 75 degrees and I_avg is the average value of diffraction intensity within a diffraction angle 2? ranging from 55 degrees to 65 degrees, I_P1/I_avg is greater than 1.0 and less than 3.0.