Abstract: A method for acquiring a 3D image of a sample structure includes acquiring a first raw 2D set of 2D images of a sample structure at a limited number of raw sample planes; calculating a 3D image of the sample structure represented by a 3D volumetric image data set; and extracting a measurement parameter from the 3D volumetric image data set. A further number of interleaving 2D image acquisitions are recorded at a further number of interleaved sample planes which do not coincide with previous acquisition sample planes. The steps “calculating,” “extracting” and “assigning” are repeated for the further interleaving 2D set until convergence or a maximum number of 2D image acquisitions is recorded. A projection system used for such method comprises a projection light source, a rotatable sample structure holder and a spatially resolving detector. Such method can also be used to acquire virtual tomographic images of a sample.

Abstract: Methods for characterizing the surface shapes of optical elements include the following steps: carrying out, in an interferometric test arrangement, at least a first interferogram measurement on the optical element by superimposing a test wave, which has been generated by diffraction of electromagnetic radiation on a diffractive element and has been reflected at the optical element, carrying out at least one additional interferogram measurement on in each case one calibrating mirror for determining calibration corrections, and determining the deviation from the target shape of the optical element based on the first interferogram measurement carried out on the optical element and the determined calibration corrections. At least two interferogram measurements are carried out for the at least one calibrating mirror, which differ from one another with regard to the polarization state of the electromagnetic radiation.

Abstract: The invention relates to an apparatus and a method for characterizing a microlithographic mask. According to one aspect, an apparatus according to the invention comprises at least one light source which emits coherent light, an illumination optical unit which produces a diffraction-limited light spot on the mask from the coherent light of the at least one light source, a scanning device, by use of which it is possible to implement a scanning movement of the diffraction-limited light spot relative to the mask, a sensor unit, and an evaluation unit for evaluating the light that is incident on the sensor unit and has come from the mask, an output coupling element for coupling out a portion of the coherent light emitted by the at least one light source, and an intensity sensor for capturing the intensity of this output coupled portion.

Abstract: A detection system serves for X-ray inspection of an object. An imaging optical arrangement serves to image the object in an object plane illuminated by X-rays generated by an X-ray source. The imaging optical arrangement comprises an imaging optics to image a transfer field in a field plane into a detection field in a detection plane. A detection array is arranged at the detection field. An object mount holds the object to be imaged and is movable relative to the X-ray source via an object displacement drive along at least one lateral object displacement direction in the object plane. A shield stop with a transmissive shield stop aperture is arranged in an arrangement plane in a light path and is movable via a shield stop displacement drive in the arrangement plane.

Abstract: The invention relates to an optical system and, in particular for characterizing a microlithography mask, comprising a light source for generating light of a wavelength of less than 30 nm, an illumination beam path leading from the light source to an object plane, an imaging beam path leading from the object plane to an image plane and a beam splitter, via which both the illumination beam path and the imaging beam path run.

Abstract: In a method to acquire a 3D image of a sample structure initially a first raw 2D set of 2D images of a sample structure is acquired at a limited number of raw sample planes. From this first raw 2D set a 3D image of the sample structure being represented by a 3D volumetric image data set is calculated and a measurement parameter is extracted from the 3D volumetric image data set. Such measurement parameter is assigned to the number of 2D image acquisitions recorded during the acquisition step. Then, a further interleaving 2D set of 2D images of the sample structure is required by recording a further number of interleaving 2D image acquisitions at a further number of interleaved sample planes which do not coincide with the previous acquisition sample planes. The steps “calculating,” “extracting” and “assigning” are repeated for the further interleaving 2D set. The actual and the last extracted measurement parameters are compared to check whether a convergence criterion is met.

Abstract: An imaging optical arrangement serves to image an object illuminated by X-rays. An imaging optics serves to image a transfer field in a field plane into a detection field in a detection plane. A layer of scintillator material is arranged at the transfer field. A stop is arranged in a pupil plane of the imaging optics. The imaging optics has an optical axis. A center of a stop opening of the stop is arranged at a decentering distance with respect to the optical axis. Such imaging optical arrangement ensures a high quality imaging of the object irrespective of a tilt of X-rays entering the transfer field. The imaging optical arrangement is part of a detection assembly further comprising a detection array and an object mount. Such detection assembly is part of a detection system further comprising a X-ray source.

Abstract: A detection system serves for X-ray inspection of an object. An imaging optical arrangement serves to image the object in an object plane illuminated by X-rays generated by an X-ray source. The imaging optical arrangement comprises an imaging optics to image a transfer field in a field plane into a detection field in a detection plane. A detection array is arranged at the detection field. An object mount holds the object to be imaged and is movable relative to the light source via an object displacement drive along at least one lateral object displacement direction in the object plane. A shield stop with a transmissive shield stop aperture is arranged in an arrangement plane in a light path and is movable via a shield stop displacement drive in the arrangement plane.

Abstract: An imaging optical unit for EUV microlithography is configured so that, when used in an optical system for EUV microlithography, relatively high EUV throughput and high imaging quality can achieved.

Abstract: Methods for characterizing the surface shapes of optical elements include the following steps: carrying out, in an interferometric test arrangement, at least a first interferogram measurement on the optical element by superimposing a test wave, which has been generated by diffraction of electromagnetic radiation on a diffractive element and has been reflected at the optical element, carrying out at least one additional interferogram measurement on in each case one calibrating mirror for determining calibration corrections, and determining the deviation from the target shape of the optical element based on the first interferogram measurement carried out on the optical element and the determined calibration corrections. At least two interferogram measurements are carried out for the at least one calibrating mirror, which differ from one another with regard to the polarization state of the electromagnetic radiation.

Abstract: The invention relates to an apparatus and a method for characterizing a microlithographic mask. According to one aspect, an apparatus according to the invention comprises at least one light source which emits coherent light, an illumination optical unit which produces a diffraction-limited light spot on the mask from the coherent light of the at least one light source, a scanning device, by use of which it is possible to implement a scanning movement of the diffraction-limited light spot relative to the mask, a sensor unit, and an evaluation unit for evaluating the light that is incident on the sensor unit and has come from the mask, an output coupling element for coupling out a portion of the coherent light emitted by the at least one light source, and an intensity sensor for capturing the intensity of this output coupled portion.

Abstract: An optical system transfers original structure portions (13) of a lithography mask (10), which have an x/y-aspect ratio of greater than 4:1, and are aligned on the lithography mask, separated respectively by separating portions (14) that carry no structures to be imaged. The optical system transfers the original structure portions onto image portions (31) of a substrate (26). Each of the original structure portions is transferred to a separate image portion. The image portions onto which the original structure portions are transferred are arranged in a line next to one another. An associated projection optical unit may have an anamorphic embodiment with different imaging scales for two mutually perpendicular field coordinates specifically, one that is reducing for one of the field coordinates and the other is magnifying for the other field coordinates.

Abstract: An imaging optical unit includes a plurality of mirrors to guide imaging light along an imaging beam path. The plurality of mirrors includes a number of mirrors for grazing incidence (GI mirrors), which deflect a chief ray of a central object field point with an angle of incidence of more than 45°. At least two of the GI mirrors are in the imaging beam path as basic GI mirrors so that the deflection effect thereof adds up for the chief ray. At least one further GI mirror is arranged in the imaging beam path as a counter GI mirror so that the deflection effect thereof acts in subtractive fashion for the chief ray in relation to the deflection effect of the basic GI mirrors. This can yield an imaging optical unit having enhanced flexibility in relation to an installation space used for mirror bodies of the mirrors of the imaging optical unit.

Abstract: An optical system transfers original structure portions (13) of a lithography mask (10), which have an x/y-aspect ratio of greater than 4:1, and are aligned on the lithography mask, separated respectively by separating portions (14) that carry no structures to be imaged. The optical system transfers the original structure portions onto image portions (31) of a substrate (26). Each of the original structure portions is transferred to a separate image portion. The image portions onto which the original structure portions are transferred are arranged in a line next to one another. An associated projection optical unit may have an anamorphic embodiment with different imaging scales for two mutually perpendicular field coordinates specifically, one that is reducing for one of the field coordinates and the other is magnifying for the other field coordinates.

Abstract: An imaging optical unit for EUV microlithography is configured so that, when used in an optical system for EUV microlithography, relatively high EUV throughput and high imaging quality can achieved.

Abstract: An imaging optical unit includes a plurality of mirrors to guide imaging light along an imaging beam path. The plurality of mirrors includes a number of mirrors for grazing incidence (GI mirrors), which deflect a chief ray of a central object field point with an angle of incidence of more than 45°. At least two of the GI mirrors are in the imaging beam path as basic GI mirrors so that the deflection effect thereof adds up for the chief ray. At least one further GI mirror is arranged in the imaging beam path as a counter GI mirror so that the deflection effect thereof acts in subtractive fashion for the chief ray in relation to the deflection effect of the basic GI mirrors. This can yield an imaging optical unit having enhanced flexibility in relation to an installation space used for mirror bodies of the mirrors of the imaging optical unit.

Abstract: In a method for three-dimensionally measuring a 3D aerial image in the region around an image plane during the imaging of a lithography mask, which is arranged in an object plane, a selectable imaging scale ratio in mutually perpendicular directions (x, y) is taken into account. For this purpose, an electromagnetic wavefront of imaging light is reconstructed after interaction thereof with the lithography mask. An influencing variable that corresponds to the imaging scale ratio is included. Finally, the 3D aerial image measured with the inclusion of the influencing variable is output. This results in a measuring method with which lithography masks that are optimized for being used with an anamorphic projection optical unit during projection exposure can also be measured.

Abstract: An imaging optical unit serves within a metrology system for examining a lithography mask. The lithography mask can be arranged in an object field of the imaging optical unit. The object field is defined by two mutually perpendicular object field coordinates. The imaging optical unit has an aperture stop of which the aspect ratio in the direction of the two object field coordinates differs from 1. This results in an imaging optical unit which can be used for the examination of lithography masks that are designed for projection exposure with an anamorphic projection optical unit.

Abstract: A projection lens is disclosed for imaging a pattern arranged in an object plane of the projection lens into an image plane of the projection lens via electromagnetic radiation having an operating wavelength ? from the extreme ultraviolet range. The projection lens includes a multiplicity of mirrors having mirror surfaces arranged in a projection beam path between the object plane and the image plane so that a pattern of a mask in the object plane is imagable into the image plane via the mirrors. A first imaging scale in a first direction running parallel to a scan direction is smaller in terms of absolute value than a second imaging scale in a second direction perpendicular to the first direction. The projection lens also includes a dynamic wavefront manipulation system for correcting astigmatic wavefront aberration portions caused by reticle displacement.

Abstract: The present application relates to a method for examining at least one element of a photolithographic mask for an extreme ultraviolet (EUV) wavelength range, wherein the method includes the steps of: (a) examining the at least one element with light in the EUV wavelength range; and (b) determining the behavior of the at least one element in the EUV wavelength range.