Multilayer reflective film-equipped substrate, reflective mask blank, reflective mask, and method for producing semiconductor device

A reflective mask blank comprising:

• a substrate;
• a multilayer reflective film disposed above the substrate;
• a protective film disposed above the multilayer reflective film;
• and an absorber film disposed above the protective film, wherein
• the protective film 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, and
• the second metal has an extinction coefficient of 0.03 or less at a wavelength of approximately 13.5 nm.

A reflective mask comprising:

• a substrate;
• a multilayer reflective film disposed above the substrate;
• a protective film disposed above the multilayer reflective film;
• and an absorber film disposed above the protective film and having an absorber pattern, wherein
• the protective film 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, and
• the second metal has an extinction coefficient of 0.03 or less at a wavelength of approximately 13.5 nm.