Abstract: An EUV collector has a reflection surface with a basic mirror shape of a spherical section. A diffraction grating for EUV used light is applied to the reflection surface. The diffraction grating is designed so that the EUV used light, which emanates from a sphere center of the spherical section, is diffracted by the diffraction grating toward a collection region. The collection region is spatially spaced apart from the sphere center. This creates an EUV collector in which an effective separation between EUV used light, which is to be collected with the aid of the collector, and extraneous light having a wavelength that differs from a used light wavelength is made possible.

Abstract: An EUV collector is used to collect EUV used light eminating from a source area. On a reflective surface of the collector, there is mounted a diffraction grating for the EUV used light. The EUV used light which emanates from the source area is diffracted by the diffraction grating toward a collection area. The reflective surface is designed at least partly as a planar reflective surface, as a parabolic reflective surface, as a rotationally symmetrically frustoconical reflective surface, or as a hollow-cylindrical reflective surface. A design of the reflective surface with ellipsoid reflective surface portions with first focal points, which lie in the source area, and second focal points, which are at a distance from one another and from the collection area, is also possible.

Abstract: 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.

Abstract: An optical component has a diffraction structure for diffractively influencing a direction of emergence of light of at least one wavelength incident on the optical component. The diffraction structure includes at least two diffraction substructures superimposed in at least one portion of the optical component and having first positive diffraction structures and first negative diffraction structures. A first diffraction substructure has first positive diffraction structures and first negative diffraction structures arranged to have a symmetry following a first symmetry condition. A second diffraction substructure has second positive diffraction structures and second negative diffraction structures arranged to have a second symmetry condition differing from the first symmetry condition.

Abstract: A mirror for a projection exposure apparatus has a spectral filter, embodied as a grating structure, for light reflected by the mirror. The grating structure has at least two grating levels and hence specifies at least two optical path lengths for the reflected light. An overall flank portion of the grating structure is arranged in each case between grating level structure portions of the grating structure, which each specify adjacent grating levels. A lower limit spatial wavelength over a defect-free partial flank portion of the overall flank portion making up at least an extent of 90% of the overall flank portion is in the range from 0.01 ?m to 1 ?m exclusive.

Abstract: An optical component has a diffraction structure for diffractively influencing a direction of emergence of light of at least one wavelength incident on the optical component. The diffraction structure includes at least two diffraction substructures superimposed in at least one portion of the optical component and having first positive diffraction structures and first negative diffraction structures. A first diffraction substructure has first positive diffraction structures and first negative diffraction structures arranged to have a symmetry following a first symmetry condition. A second diffraction substructure has second positive diffraction structures and second negative diffraction structures arranged to have a second symmetry condition differing from the first symmetry condition.

Abstract: 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.

Abstract: An EUV collector has a reflection surface with a basic mirror shape of a spherical section. A diffraction grating for EUV used light is applied to the reflection surface. The diffraction grating is designed so that the EUV used light, which emanates from a sphere center of the spherical section, is diffracted by the diffraction grating toward a collection region. The collection region is spatially spaced apart from the sphere center. This creates an EUV collector in which an effective separation between EUV used light, which is to be collected with the aid of the collector, and extraneous light having a wavelength that differs from a used light wavelength is made possible.