An optical system (OS) for focusing a beam of radiation (B) on a region of interest in a metrology apparatus is described. The beam of radiation (B) comprises radiation in a soft X-ray or Extreme Ultraviolet spectral range. The optical system (OS) comprises a first stage (S1) for focusing the beam of radiation at an intermediate focus region. The optical system (OS) comprises a second stage (S2) for focusing the beam of radiation from the intermediate focus region onto the region of interest. The first and second stages each comprise a Kirkpatrick-Baez reflector combination. At least one reflector comprises an aberration-correcting reflector.

The present teaching relates to methods, systems, and apparatus for X-ray imaging with a detector capable of resolving photon energy. In one example, an X-ray microscope is disclosed. The X-ray microscope comprises an X-ray source and a detector. The X-ray source is configured for irradiating X-ray to a sample. The detector is configured for: detecting X-ray photons from the irradiated X-ray, determining energy of each of the detected X-ray photons, and generating an image of the sample based on detected X-ray photons that have energies in a predetermined range.

A device for the collection of X-rays includes at least one multi-reflection reflector cone. The multi-reflection reflector cone has a focal axis. A first portion of the multi-reflection reflector cone is oriented at a first angle to the focal axis, and a second portion of the multi-reflection reflector cone is oriented at a second angle to the focal axis.

A method of analyzing a specimen using X-rays, comprising the steps of: Irradiating the specimen with input X-rays; Using a detector to detect a flux of output X-rays emanating from the specimen in response to said irradiation,
which method further comprises the following steps: Using the detector to intercept at least a portion of said flux so as to produce a set {I.sub.j} of pixeled images I.sub.j of at least part of the specimen, whereby the cardinality of the set {I.sub.j} is M>1. For each pixel p.sub.i in each image I.sub.j, determining the accumulated signal strength S.sub.ij, thus producing an associated set of signal strengths {S.sub.ij}. Using the set {S.sub.ij} to calculate the following values: A mean signal strength S per pixel position i; A variance .sup.2.sub.S in S per pixel position i. Using these values S and .sup.2.sub.S to produce a map of mean X-ray photon energy E per pixel.

A method of analyzing a specimen using X-rays, comprising the steps of: Irradiating the specimen with input X-rays; Using a detector to detect a flux of output X-rays emanating from the specimen in response to said irradiation,
which method further comprises the following steps: Using the detector to intercept at least a portion of said flux so as to produce a set {I.sub.j} of pixeled images I.sub.j of at least part of the specimen, whereby the cardinality of the set {I.sub.j} is M>1. For each pixel p.sub.i in each image I.sub.j, determining the accumulated signal strength S.sub.ij, thus producing an associated set of signal strengths {S.sub.ij}. Using the set {S.sub.ij} to calculate the following values: A mean signal strength S per pixel position i; A variance .sup.2.sub.S in S per pixel position i. Using these values S and .sup.2.sub.S to produce a map of mean X-ray photon energy E per pixel.

Systems and process are provided to make X-ray radiographs sufficiently quantitative and standardized for bone and other biological material or non-biologic material density evaluations. The X-ray radiograph methodology and system provide a cost effective diagnostic tool that may be used with existing X-ray radiography sources already present in many clinics and hospitals to ultimately produce large volumes of scientifically valid data and useful diagnostic and prognostic information. A calibration bar is added to a conventional X-ray film cartridge and images thereof subsequently incorporated into radiographs for interpretation or a cartridge is designed to integrate a calibration function. The calibration standard affords a standard against which material density is measured. A software program is provided to interpret tissue densities (including bone) to ultimately identify values compared to preselected thresholds.

Systems and process are provided to make X-ray radiographs sufficiently quantitative and standardized for bone and other biological material or non-biologic material density evaluations. The X-ray radiograph methodology and system provide a cost effective diagnostic tool that may be used with existing X-ray radiography sources already present in many clinics and hospitals to ultimately produce large volumes of scientifically valid data and useful diagnostic and prognostic information. A calibration bar is added to a conventional X-ray film cartridge and images thereof subsequently incorporated into radiographs for interpretation or a cartridge is designed to integrate a calibration function. The calibration standard affords a standard against which material density is measured. A software program is provided to interpret tissue densities (including bone) to ultimately identify values compared to preselected thresholds.

A method of controlling a needle actuator to interact with a cell is provided, the method comprising: providing an actuator comprising a tower, a stage and a needle, wherein the needle is mounted on the stage; applying an electrostatic potential between the tower and the stage to retract the needle; moving the actuator towards the cell; reducing the potential so as to allow the stage and needle to move towards the cell; applying calibration data to detect when the needle has pierced the cell; and reducing the potential further once it has been detected that the needle has pierced the cell. The cell can be a biological cell. The needle can be a micro-needle and the stage can be a micro-stage.

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.

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.