A reflective optical element (17), in particular for an illumination optical unit of a projection exposure apparatus includes: a structured surface (25a) that preferably forms a grating structure (29), and a reflective coating (36) that is applied to the structured surface (25a). The reflective coating (36) covers the structured surface (25a) discontinuously, and the reflective optical element (17) has at least one protective layer (37) that covers the structured surface (25a) continuously. Also disclosed are an illumination optical unit (4) for a projection exposure apparatus (1) including at least one reflective optical element (17) of this type, to a projection exposure apparatus (1) including an illumination optical unit (4) of this type, and to a method for producing a protective layer (37) on a reflective optical element (17) of this type.

A method for producing an optical element includes: providing a substrate (102), applying a layer system (103), wherein an optically effective surface (101) is formed and wherein the layer system has a layer (104) that is thermally deformable for manipulating the geometric shape of the optically effective surface, and applying a temperature field to the optical element while at least regionally heating the thermally deformable layer to above a specified operating temperature of the optical system. The thermally deformable layer is configured such that a deformation that is induced when the temperature field is applied is at least partially maintained after the optical element has cooled. Also disclosed is an optical element (400) that has an optically effective surface (401), a substrate (402), and a layer system (403) that has a reflection layer system (406), which includes a shape-memory alloy.

A substrate with a multilayer reflective film capable of facilitating the discovery of contaminants, scratches and other critical defects by inhibiting the detection of pseudo defects attributable to surface roughness of a substrate or film in a defect inspection using a highly sensitive defect inspection apparatus. The substrate with a multilayer reflective film has a multilayer reflective film obtained by alternately laminating a high refractive index layer and a low refractive index layer on a main surface of a mask blank substrate used in lithography, wherein an integrated value I of the power spectrum density (PSD) at a spatial frequency of 1 μm.sup.−1 to 10 μm.sup.−1 of the surface of the substrate with a multilayer reflective film, obtained by measuring a region measuring 3 μm×3 μm with an atomic force microscope, is not more than 180×10.sup.−3 nm.sup.3, and the maximum value of the power spectrum density (PSD) at a spatial frequency of 1 μm.sup.−1 to 10 μm.sup.−1 is not more than 50 nm.sup.4.

The substrate with a multilayer reflective film includes a substrate and the multilayer reflective film configured to reflect exposure light, the multilayer reflective film comprising a stack of alternating layers on a substrate, the alternating layers including a low refractive index layer and a high refractive index layer, in which the multilayer reflective film contains molybdenum (Mo) and at least one additive element selected from nitrogen (N), boron (B), carbon (C), zirconium (Zr), oxygen (O), hydrogen (H) and deuterium (D), and the crystallite size of the multilayer reflective film calculated from a diffraction peak of Mo (110) by X-ray diffraction is 2.5 nm or less.

A laser irradiation device may include: a laser device configured to emit a pulse laser beam; beam scan optics configured to allocate the pulse laser beam emitted from the laser device to optical paths; beam homogenizers provided in the respective optical paths, each of the beam homogenizers being configured to homogenize distribution of light intensity of the pulse laser beam allocated to a corresponding optical path of the optical paths; and a controller configured to control the beam scan optics to allocate, for each pulse, the pulse laser beam emitted from the laser device to the corresponding optical path of the optical paths.

An x-ray phase contrast imaging apparatus and method of operating the same. The apparatus passes x-rays generated by an x-ray source through, in succession, a source grating, an object of interest, a phase grating, and an analyzer grating. The x-ray source, the source grating, the phase grating, and the analyzer grating move as a single entity relative to an object of interest. The phase grating and the analyzer grating remain in fixed relative location and fixed relative orientation with respect to one another. The detected x-rays are converted to a time sequence of electrical signals. In some cases, the apparatus is controlled, and the electrical signals are analyzed by, by a general purpose programmable computer provided with instructions recorded on a machine readable medium. One or more x-ray phase contrast images of the object of interest are generated, and can be recorded or displayed.

An optical element (1) for reflecting EUV radiation (4) includes: a substrate (2); a coating (3) applied to the substrate (2), which coating reflects the EUV radiation (4); a top layer (5) protecting the reflective coating (3), which top layer is applied to the reflective coating (3); and an intermediate layer (6) having at least one reactive material (7) which, together with an activating gas (O2) penetrating through a gap (5a) in the top layer 95), forms at least one reaction product (8) sealing the gap (5a). A related EUV lithography system has at least one such reflective optical element (1), and a related method for sealing a gap (5a) in the top layer (5) of such an optical element (1) are also disclosed.

A method of manufacturing a multi-layer mirror comprising a multi-layer stack of pairs of alternating layers of a first material and silicon, the method comprising depositing a stack of pairs of alternating layers of the first material and layers of silicon, the stack being supported by a substrate and doping at least a first layer of the first material with a dopant material.

A mirror, in particular for a microlithographic projection exposure apparatus, has an optically effective surface (10a), a mirror substrate (11) and a reflection layer stack (12) configured to reflect electromagnetic radiation that is incident on the optically effective surface. A metallic diffusion barrier layer (13) is arranged on that side of the reflection layer stack which faces toward the optically effective surface, and a stabilization layer (14) is arranged on the side of the diffusion barrier layer that faces toward the optically effective surface (10a). The stabilization layer reduces deformation of the diffusion barrier layer compared to an analogous structure without such a stabilization layer upon irradiation of the optically effective surface with electromagnetic radiation. The stabilization layer has a porosity, a relative density of which is no more than 80%, where the relative density is defined as the ratio between geometric density and true density.

An X-ray system for providing a converging X-rays comprises: (a) an X-ray source having an optical axis thereof; and an X-ray lens comprising at least one ring having a Bragg reflecting surface formed by a plurality of single-crystal tiles. Each tile individually comprises an adjusting arrangement enabling a tridimensional individual displacement thereof in angular and translational manner.