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Similar to X-ray reflectometry, the reflectivities of layer stacks are investigated angle- and energy-dependent in the EUV spectral range. Reflectometry is the main method for "At-Wavelength-investigation" of components for EUV lithography at PTB. Besides the development of powerful EUV radiation sources, the production of suitable optical components is a great challenge. There are no materials transparent for EUV radiation. Therefore only mirrors can be used as optical components. By using periodic multilayers as Bragg reflectors, a sufficient degree of reflection can be achieved.
By reconstructing the interference patterns of the reflected radiation, the layer systems can be characterized for layer thickness, roughness and homogeneity.
When investigating periodic nanostructures, the softer radiation in the EUV range can significantly increase the required angles of incidence in the scattering experiment (EUV-SAS). The larger angles make it possible to significantly reduce the measuring spot on the samples.

(further information Opens internal link in current windowEUV-Radiometrie 7.12)



Soft X-ray Beamline
Energy range:50 eV - 1800 eV
Photon flux:10^10 / s (max at 100 eV and 1 keV)
beam waist:0.3 mm x 1 mm (can be slightly restricted)
Divergence: < 2 mrad (horizontal) < 0.2 mrad (vertical)
Energy resolution:10^-4



  • Different photodiodes mounted on a movable detector arm
  • Lubricant free instrument
  • Options for CCD mounting on fixed flange positions (horizontal & vertical)
Scattering angles in plane:0° - 180°
Scattering angles out of plane:-10° - 180°
Sample-Detector distance300 mm


EUV-SAS (small angle-scattering chamber)

Commissioning planned around 2/20

Scattering angles in plane:0° - 30°
Sample-Detector distance20 mm
DetectorAndor CCD (13.5 µm pixel size)
Spot size at exp0.1 mm

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