Lithography mask having high extinction coefficient absorber and related systems and methods

A method, comprising:

• forming a reflective multilayer on a substrate, the reflective multilayer being operable to reflect extreme ultraviolet (EUV) light;
• forming an absorber layer over the reflective multilayer, the absorber layer including ruthenium and having a grain size that does not exceed about 5 nanometers;
• forming a hard mask structure over the absorber layer;
• forming an opening in the hard mask structure;
• and
• forming an absorber by removing a portion of the absorber layer exposed by the opening in the hard mask structure.

An extreme ultraviolet (EUV) mask, comprising:

• a substrate;
• a reflective multilayer over the substrate;
• and
• an absorber over the reflective multilayer, the absorber:
• including a ruthenium-based material;
• or
• having extinction coefficient at an EUV wavelength that exceeds extinction coefficients of TaBN and TaN at the EUV wavelength.