Reflective photomask, reflective photomask blank, and method for manufacturing reflective photomask

A reflective photomask blank comprising

• a substrate,
• a multilayer reflection film that is formed on the substrate and reflects exposure light being light in extreme ultraviolet range,
• a protection film that is formed on and in contact with the multilayer reflection film to protect the multilayer reflection film,
• a light absorbing film that is formed on and in contact with the protection film, and absorbs the exposure light, and
• a hard mask film that is formed on and in contact with the light absorbing film, wherein
• the protection film is constituted of multiple layers comprising one A layer, one or two or more B layers, and one or two or more C layers,
• the A layer of the protection film comprises rhodium (Rh), and has a thickness of not less than 0.5 nm and not more than 2 nm,
• the B layer of the protection film comprises niobium (Nb), is free of rhodium (Rh), has a niobium (Nb) content of not less than 10 at %, and has a thickness of not less than 0.5 nm and not more than 2 nm,
• the C layer of the protection film comprises molybdenum (Mo), or molybdenum (Mo) and at least one selected from the group consisting of ruthenium (Ru), oxygen (O) and nitrogen (N), is free of rhodium (Rh) and niobium (Nb), has a molybdenum (Mo) content of not less than 30 at %, and has a thickness of not less than 0.5 nm and not more than 2 nm,
• the A layer is in contact with the light absorbing film, and
• one layer of the C layer(s) is in contact with the multilayer reflection film.