Patent ID: 7390596

Claim:
A reflective mask blank comprising a substrate on which a reflective layer for reflecting exposure light in a short-wavelength region including an extreme ultraviolet region and an absorber layer for absorbing the exposure light are successively formed, the absorber layer having an at least two-layer structure including as a lower layer an exposure light absorbing layer comprising an absorber for the exposure light and as an upper layer a low-reflectivity layer comprising an absorber for inspection light used in inspection of a mask pattern, the upper layer being farther from the substrate than the lower layer, wherein: the upper layer is made of a material containing tantalum (Ta), boron (B), and nitrogen (N), the content of B being 5 at % to 30 at %, the ratio of Ta and N (Ta:N) falling within a range of 8:1 to 2:7.