Patent ID: 11815803

Abstract:
Extreme ultraviolet (EUV) mask blanks, production systems therefor, and methods of increasing multilayer film reflectance are disclosed. The EUV mask blanks comprise a bilayer film on a substrate. The bilayer film comprises a first film layer including silicon (Si), and a second film layer comprising an element selected from the group consisting of ruthenium (Ru), nickel (Ni), cobalt (Co), tungsten (W), iron (Fe), titanium (Ti) and silicides thereof. Some EUV mask blanks further comprise a multilayer reflective stack comprising alternating layers on the bilayer film and a capping layer on the multilayer reflective stack. Some EUV mask blanks include a smoothing layer selected from the group consisting of molybdenum silicide (MoSi), boron carbide (B4C) and silicon nitride (SiN) on the multilayer reflective stack, a capping layer on the smoothing layer, and an absorber layer on the capping layer.