Reflective mask blank, reflective mask and manufacturing method thereof, and semiconductor device manufacturing method

A reflective mask comprising:

• a substrate;
• a multilayer reflective film on the substrate;
• and
• a phase shift film with a pattern on the multilayer reflective film, wherein
• the phase shift film comprises ruthenium (Ru) and at least one selected from chromium (Cr), nickel (Ni), cobalt (Co), aluminum (Al), silicon (Si), titanium (Ti), vanadium (V), germanium (Ge), niobium (Nb), molybdenum (Mo), tin (Sn), tellurium (Te), hafnium (Hf), tungsten (W) and rhenium (Re),
• the phase difference of the phase shift film is 130 degrees to 160 degrees or 200 degrees to 230 degrees,
• the refractive index n to EUV light is 0.860 to 0.950 and the extinction coefficient k to EUV light is 0.009 to 0.095 when the phase difference of the phase shift film is 130 degrees to 160 degrees, and
• the refractive index n to EUV light is 0.860 to 0.940 and the extinction coefficient k to EUV light is 0.008 to 0.057 when the phase difference of the phase shift film is 200 degrees to 230 degrees.