Fabricating a photomask includes forming a protection layer over a substrate. A plurality of multilayers of reflecting films are formed over the protection layer. A capping layer is formed over the plurality of multilayers. An absorption layer is formed over capping layer. A first photoresist layer is formed over portions of absorption layer. Portions of the first photoresist layer and absorption layer are patterned, forming first openings in absorption layer. The first openings expose portions of the capping layer. Remaining portions of first photoresist layer are removed and a second photoresist layer is formed over portions of absorption layer. The second photoresist layer covers at least the first openings. Portions of the absorption layer and capping layer and plurality of multilayer of reflecting films not covered by the second photoresist layer are patterned, forming second openings. The second openings expose portions of protection layer and second photoresist layer is removed.

A reflective film coated substrate includes a substrate having two main surfaces opposite to each other and end faces connected to outer edges of the two main surfaces; and a reflective film formed on one of the main surfaces and extending onto at least part of the end faces. The reflective film on the main surface has a multilayer structure including low refractive index layers and high refractive index layers alternately formed. The reflective film which extends onto the end faces has a single-layer structure containing a first element higher in content than any other element in the low refractive index layers and a second element higher in content than any other element in the high refractive index layers.

A mirror for extreme ultraviolet light includes: a substrate (41); a multilayer film (42) provided on the substrate and configured to reflect extreme ultraviolet light; and a capping layer (53) provided on the multilayer film, and the capping layer includes a first layer (61) containing an oxide of a metal, and a second layer (62) arranged between the first layer and the multilayer film and containing at least one of a boride of the metal and a nitride of the metal.

A mirror for extreme ultraviolet light includes: a substrate (41); a multilayer film (42) provided on the substrate and configured to reflect extreme ultraviolet light; and a capping layer (53) provided on the multilayer film, and the capping layer includes a first layer (61) containing an oxide of a metal, and a second layer (62) arranged between the first layer and the multilayer film and containing at least one of a boride of the metal and a nitride of the metal.

A reflective mask includes a substrate, a lower reflective multilayer disposed over the substrate, an intermediate layer disposed over the lower reflective multilayer, an upper reflective multilayer disposed over the intermediate layer, a capping layer disposed over the upper reflective multilayer, and an absorber layer disposed in a trench formed in the upper reflective layers and over the intermediate layer. The intermediate layer includes a metal other than Cr, Ru, Si, Si compound and carbon.

A reflective mask blank has a substrate 10; a multilayer reflective film 20 that is provided on the substrate 10 and reflects exposure light; a protective film 50 including a metal oxide film 51 provided on the multilayer reflective film 20; and an absorber film 70 that is provided on the protective film 50 and absorbs exposure light. The multilayer reflective film 20 is configured such that a Mo layer and a Si layer are alternately stacked and a layer on a side farthest from the substrate 10 is the Si layer. The metal oxide film 51 is configured such that an oxygen content in a layer on a side far from the substrate 10 is higher than the oxygen content in a layer on a substrate side.

A reflective mask blank has a substrate 10; a multilayer reflective film 20 that is provided on the substrate 10 and reflects exposure light; a protective film 50 including a metal oxide film 51 provided on the multilayer reflective film 20; and an absorber film 70 that is provided on the protective film 50 and absorbs exposure light. The multilayer reflective film 20 is configured such that a Mo layer and a Si layer are alternately stacked and a layer on a side farthest from the substrate 10 is the Si layer. The metal oxide film 51 is configured such that an oxygen content in a layer on a side far from the substrate 10 is higher than the oxygen content in a layer on a substrate side.

An extreme ultraviolet mask including a substrate, a reflective multilayer stack on the substrate and a capping layer on the reflective multilayer stack is provided. The reflective multilayer stack is treated prior to formation of the capping layer on the reflective multilayer stack. The capping layer is formed by an ion-assisted ion beam deposition or an ion-assisted sputtering process.

A photomask includes a substrate, a multilayer stack disposed over the substrate and configured to reflect a radiation, a capping layer over the multilayer stack, and an anti-reflective layer over the capping layer. The anti-reflective layer comprises a first pattern, wherein the first pattern exposes the capping layer and is configured as a printable feature. The photomask also includes an absorber spaced apart from the printable feature from a top-view perspective.

Provided is a reflective mask blank.

The reflective mask blank has a multilayer reflective film and a thin film for pattern formation in this order on a main surface of a substrate; the thin film consists of a single layer structure consisting of a ruthenium-containing layer at least containing ruthenium, nitrogen, and oxygen or a multilayer structure including the ruthenium-containing layer; and when the ruthenium-containing layer is subjected to an analysis by an In-Plane measurement of an X-ray diffraction method to obtain an X-ray diffraction profile where, provided I_P1 is the maximum value of diffraction intensity within a diffraction angle 2θ ranging from 65 degrees to 75 degrees and I_avg is the average value of diffraction intensity within a diffraction angle 2θ ranging from 55 degrees to 65 degrees, I_P1/I_avg is greater than 1.0 and less than 3.0.