Abstract: A reflective optical element, in particular for a DUV or VUV operating wavelength range, includes a substrate, a dielectric layer system and a metallic coating between the substrate and the dielectric layer system. The dielectric layer system (26) includes a layer (L) of material having a lower refractive index n1 at the operating wavelength, a layer (H) of material having a higher refractive index n2 at the operating wavelength and a layer (M) of material having a refractive index n3 at the operating wavelength, where n1<n3<n2. The layer (M) is arranged at at least one transition from a layer (L) to a layer (H) and/or from a layer (H) to a layer (L). The dielectric layer system has a four-layer sequence of (LMHM)m or (HMLM)m, where m is equal to the number of four-layer sequences in the dielectric layer system.

Abstract: A beam propagation camera has at least one beam-splitting optical arrangement (240) configured to split a beam, which is incident on the beam-splitting optical arrangement along an optical axis (OA) of the beam propagation camera, into a multiplicity of sub-beams, and a sensor arrangement (250) configured to detect the sub-beams. The beam-splitting optical arrangement has a diffractive structure (241) configured such that at least two of the sub-beams are spatially separated from one another on the sensor arrangement and have respective foci longitudinally offset from one another along the optical axis.

Abstract: A method and apparatus for characterizing the surface form of an optical element, in particular a mirror or a lens element of a microlithographic projection exposure apparatus, includes: carrying out a plurality of interferometric measurements, in each of which an interferogram is recorded between a test wave emanating from a portion of the optical element in each case and a reference wave, the position of the optical element relative to the test wave being altered between these measurements, and calculating the figure of the optical element on the basis of these measurements. This calculation is carried out iteratively such that, in a plurality of iteration steps, the figure of the optical element is ascertained in each case by carrying out a forward calculation, each of these iteration steps being based in each case on a reference wave that was adapted based on the preceding iteration step.

Abstract: When producing a mirror as an optical component for an optical system of a projection exposure apparatus for projection lithography, first, an average value of a global gravitational acceleration is determined. Next, a gravitational acceleration difference between the gravitational acceleration at the production location and the gravitational acceleration average value is determined. After a determination of a target surface shape of a reflection surface of the mirror, a mirror substrate is machined at the production location taking into consideration the gravitational acceleration difference in a manner such that, under the influence of the gravitational acceleration average value, a current surface shape of the reflection surface of the mirror substrate does not deviate from the target surface shape by more than a prescribed figure tolerance value (Pmax). The result is an optical element with a relatively small figure at a use location of the mirror.

Abstract: A method of operating a particle beam microscope includes repeating a sequence to move a particle beam across a surface of an object. The surface of the object has a region defined by a closed boundary line. The sequence includes moving the particle beam from an entry location of the present sequence to an exit location of the present sequence along a scan path. The entry location of the present sequence and the exit location of the present sequence are located on the boundary line. The scan path is located entirely inside the region of the surface of the object. The sequence also includes moving the particle beam from the exit location of the present sequence to an entry location of the next sequence along a return path. The entry location of the next sequence is located on the boundary line. The return path is located entirely outside the region of the surface of the object.

Abstract: A mirror, in particular for a microlithographic projection exposure apparatus or an inspection system, having a mirror substrate (205), a reflection layer (220), which is configured to have a reflectivity of at least 50% for electromagnetic radiation of a predefined operating wavelength that is incident on the optically effective surface (200a) of the mirror at an angle of incidence of at least 65° relative to the respective surface normal, and a barrier layer system (210), which is arranged between the reflection layer and the mirror substrate and has a sequence of alternating layer plies composed of a first material and at least one second material. The barrier layer system reduces penetration of hydrogen atoms that would otherwise penetrate the mirror substrate by at least a factor of 10.

Abstract: The invention relates to a method and an apparatus for repairing at least one defect of a photolithographic mask for the extreme ultraviolet (EUV) wavelength range, wherein the method includes the steps of: (a) determining the at least one defect; and (b) ascertaining a repair shape for the at least one defect; (c) wherein the repair shape is diffraction-based in order to take account of a phase disturbance by the at least one defect.

Abstract: The present invention relates to a method for ascertaining a repair shape for processing at least one defect of a photolithographic mask including the following steps: (a) determining at least one correction value for the repair shape of the at least one defect, wherein the correction value takes account of a position of at least one pattern element of the photolithographic mask, said at least one pattern element not contacting the at least one defect; and (b) correcting the repair shape by applying the at least one correction value.

Abstract: The invention relates to a device for determining the exposure energy during the exposure of an element in an optical system, in particular for microlithography, comprising an optical element, a diffractive structure which has a locally varying grating period, and an intensity sensor arrangement, wherein electromagnetic radiation diffracted at the diffractive structure during operation of the optical system, in at least one order of diffraction, is directed to the intensity sensor arrangement by way of total internal reflection effected in the optical element.

Abstract: In detecting the structure of a lithography mask, a portion of the lithography mask is firstly illuminated with illumination light of an at least partially coherent light source in the at least one preferred illumination direction. A diffraction image of the illuminated portion is then recorded by spatially resolved detection of a diffraction intensity of the illumination light diffracted from the illuminated portion in a detection plane. The steps of “illuminating” and “recording the diffraction image” are then carried out for further portions of the lithography mask. Between at least two portions of the lithography mask that are thereby detected, there is in each case an overlap region whose surface extent measures at least 5% or more of the smaller of the two portions of the lithography mask. The repetition takes place until the detected portions of the lithography mask completely cover a region of the lithography mask to be detected.

Abstract: The present invention relates to a method for calibrating a measuring microscope which may be used to measure masks, in which a calibration mask is utilized in a self-calibration algorithm in order to ascertain error correction data of the measuring microscope, wherein, in the self-calibration algorithm, the calibration mask is imaged and measured in various positions in the measuring microscope in order to ascertain one or more portions of the error correction data, wherein the surface profile of the calibration mask is ascertained and utilized when determining the error correction. Moreover, the invention relates to a measuring microscope and a method for operating same.

Abstract: A reflective optical element for the extreme ultraviolet (EUV) wavelength range having a multi-layer system extending over an area on a substrate. The system includes layers (54, 55?) made of at least two different materials with different real parts of the refractive index in the EUV arranged alternately. A layer of one of the two materials forms a stack with the layer or layers arranged between this layer and the nearest layer of the same material with increasing distance from the substrate. In at least one stack (53?), the material of the layer (55?) with the lower real part of the refractive index and/or the material of the layer (54) with the larger real part of the refractive index is a combination (551, 552) made of at least two substances.

Abstract: For increasing reflectivity a reflective optical element for the extreme ultraviolet wavelength range consists of at least two upper units, in which each upper unit (B1-B5) has a plurality of lower units, for example reflective optical elements in the form of mirror arrays. A method for producing the reflective optical element includes: determination of incidence angles and incidence angle bandwidths occurring during operation above the surface of each upper unit (B1-B5); and application of a reflective coating to each upper unit (B1-B5), adapted to the incidence angles and incidence angle bandwidths respectively determined above the surface of each upper unit. This is particularly suitable for producing reflective optical elements embodied as field facet mirrors, particularly in the form of microelectromechanical mirror arrays, for an EUV lithography device.

Abstract: In an optical system for a projection exposure apparatus, the angle space of the illumination radiation of the projection optical unit at the reticle is twice as large in a first direction as the angle space of the illuminating radiation of the illuminating optical unit.

Abstract: For determining a structure-independent contribution of a lithography mask to a fluctuation of the linewidth, recorded 2D intensity distributions (15zi) of an unstructured measurement region of a lithography mask are evaluated in a spatially resolved manner.

Abstract: The present invention relates to a scanning probe microscope having: (a) a scan unit embodied to scan a measuring probe over a sample surface in a step-in scan mode; and (b) a self-oscillation circuit arrangement configured to excite the measuring probe to a natural oscillation during the step-in scan mode.

Abstract: The disclosure relates to an optical module with first and second components, a supporting structure and an anticollision device. The first component is supported by the supporting structure and is arranged adjacent to and at a distance from the second component to form a gap. The supporting structure defines a path of relative movement, on which the first and second components move in relation to one another under the influence of a disturbance, a collision between collision regions of the first and second components occurring if the anticollision device is inactive. The anticollision device includes a first anticollision unit on the first component, which produces a first field, and a second anticollision unit on the second component, which is assigned to the first anticollision unit and produces a second field.

Abstract: A method and an apparatus for beam analysis in an optical system are disclosed, wherein a plurality of beam parameters of a beam propagating along an optical axis are ascertained. The method includes: splitting the beam into a plurality of partial beams which have a focus offset in the longitudinal direction in relation to the optical axis; recording a measurement image produced by these partial beams; carrying out a forward simulation of the beam in the optical system on the basis of estimated initial values for the beam parameters in order to obtain a simulated image; and calculating a set of values for the beam parameters on the basis of the comparison between the simulated image and the measurement image.

Abstract: A method for restoring an illumination system installed in an EUV apparatus is provided.

Abstract: The disclosure relates to a method for producing an illumination system for an EUV apparatus in and to an illumination system for an EUV apparatus.