A projection lens of an EUV-lithographic projection exposure system with at least two reflective optical elements each comprising a body and a reflective surface for projecting an object field on a reticle onto an image field on a substrate if the projection lens is exposed with an exposure power of EUV light, wherein the bodies of at least two reflective optical elements comprise a material with a temperature dependent coefficient of thermal expansion which is zero at respective zero cross temperatures, and wherein the absolute value of the difference between the zero cross temperatures is more than 6K.

A semiconductor apparatus includes a light source, a reflection mirror, and a heat exchanger. The reflection mirror has a reflection surface configured to reflect a light of the light source and a channel behind the reflection surface. The heat exchanger is connected to the channel and configured to circulate a working fluid in the channel.

A semiconductor apparatus includes a light source, a reflection mirror, and a heat exchanger. The reflection mirror has a reflection surface configured to reflect a light of the light source and a channel behind the reflection surface. The heat exchanger is connected to the channel and configured to circulate a working fluid in the channel.

An x-ray optical filter includes at least one x-ray optical mirror configured to receive a plurality of x-rays having a first x-ray spectrum with a first intensity as a function of energy in a predetermined solid angle range and to separate at least some of the received x-rays by multilayer reflection or total external reflection into reflected x-rays and non-reflected x-rays and to form an x-ray beam including at least some of the reflected x-rays and/or at least some of the non-reflected x-rays. The x-ray beam has a second x-ray spectrum with a second intensity as a function of energy in the solid angle range, the second intensity greater than or equal to 50% of the first intensity across a first continuous energy range at least 3 keV wide, the second intensity less than or equal to 10% of the first intensity across a second continuous energy range at least 100 eV wide.

An X-ray apparatus includes an X-ray source embodied to generate X-rays; an X-ray detector; and an X-ray-reflection unit. The X-ray-reflection unit is embodied to reflect X-rays generated by the X-ray source such that the reflected X-rays hit the X-ray detector. The X-ray detector is in particular embodied to detect the X-rays. The X-ray apparatus can, on the one hand, enlarge the available space above a patient. Furthermore, focusing via the X-ray-reflection unit enables the power of the X-ray source to be increased while retaining a constant spatial resolution or the spatial resolution to be improved while retaining a constant power of the X-ray source.

A method includes simulating diffraction in a transmission geometry of relativistic electron bunches from a crystallographic structure of a crystal thereby simulating diffraction of the relativistic electron bunches into a plurality of Bragg peaks. The method includes selecting a range of angles between a direction of propagation of the relativistic electron bunches and a normal direction of crystal including an angle at which a diffraction portion is maximized. The method includes sequentially accelerating a plurality of physical electron bunches to relativistic energies toward a physical crystal having the crystallographic structure and diffracting the plurality of physical electron bunches off the physical crystal at different angles and measuring the diffraction portion into the respective Bragg peak at the different angles. The method includes selecting a final angle based on the measured diffraction portion into the respective Bragg peak at the different angles and generating a pulse of light.

A mask blank glass substrate having a maximum value of a circularly averaged power spectral density of 1,000 nm.sup.4 or less at a spatial frequency of 0.1 m.sup.1 or more and 20 m.sup.1 or less, the maximum value being obtained by measuring a surface morphology of a region of 10 m10 m with an atomic force microscope.

A pellicle that includes graphene is constructed and arranged for an EUV reticle. A multilayer mirror includes graphene as an outermost layer.

A projection lens of an EUV-lithographic projection exposure system with at least two reflective optical elements each comprising a body and a reflective surface for projecting an object field on a reticle onto an image field on a substrate if the projection lens is exposed with an exposure power of EUV light, wherein the bodies of at least two reflective optical elements comprise a material with a temperature dependent coefficient of thermal expansion which is zero at respective zero cross temperatures, and wherein the absolute value of the difference between the zero cross temperatures is more than 6K.

A cost-effective method for repairing reflective optical elements for EUV lithography. These optical elements (60) have a substrate (61) and a coating (62) that reflects at a working wavelength in the range between 5 nm and 20 nm and is damaged as a result of formation of hydrogen bubbles. The method includes: localizing a damaged area (63, 64, 65, 66) in the coating (62) and covering the damaged area (63, 64, 65, 66) with one or more materials having low hydrogen permeability by applying a cover element to the damaged area. The cover element is formed of a surface structure, a convex or concave surface, or a coating corresponding to the coating of the reflective optical element, or a combination thereof. The method is particularly suitable for collector mirrors (70) for EUV lithography. After the repair, the optical elements have cover elements (71, 72, 73).