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7.14 EUV-Nanometrology


The EUV-Nanometrology group is working on the development of new measurement techniques in the field of synchrotron radiation for the characterization of nanostructured surfaces. One focus is the dimensional reconstruction of optical components for semiconductor lithography. For this purpose, different experimental techniques in the wavelength range from 0.2 nm to 20 nm are combined at PTB's own beamlines at BESSY II and MLS. Besides light scattering and reflection (GISAXS, EUV-SAS, Scatterometry, XRR), secondary effects such as fluorescence radiation are more and more included (GIXRF, XRF) in order to be able to investigate the constantly more complex nanostructures in an element sensitive way.

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    • Characterization of nanostructured surfaces by light scattering and fluorescence excitation
    • Dimensional reconstruction of 2D and 3D nanostructures
    • Statistical validation of uncertainties by Bayesian statistical methods
    • Investigation of process-related roughness and its influence on the reconstruction
    • Determination of optical constants in the soft X-ray range
    • Further development of theoretical models for scattering and optimization methods

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    The OCDB is a database for optical constants in the soft X-ray range and is continuously being expanded.



    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..


    GISAXS is a modern non-destructive measurement technique for the investigation of nanostructured surfaces. In a GISAXS experiment a nanostructured sample is illuminated with X-rays under grazing incidence and the angular distribution of the reflected and scattered X-ray photons is determined...



    In X-ray fluorescence analysis, electrons from inner atomic shells are excited by incident X-ray photons. The subsequent decay of these excited states leads to the emission of element-specific X-ray fluorescence radiation...



    Numerical simulations

    For the simulation of electromagnetic waves and the interaction with nanostructured surfaces...



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