| abstract |
Mask blanks of the invention include an absorber layer, an anti-reflective layer disposed over the absorber layer, and a hard mask layer disposed over the anti-reflective layer. The absorber layer is absorbent at an exposure wavelength and is reflective at an inspection wavelength. The inspection wavelength is greater than or equal to the exposure wavelength. The anti-reflective layer is not reflective at the inspection wavelength. None of the main constituents of the hard mask layer has an atomic number greater than 41. The mask blank may be a reflective EUVL mask blank or a transparent mask blank. |