Today, the combination of new generation X-ray sources with modern optical elements gives a strong impetus to the development of new research methods, and to improve the classical methods. One such method is X-ray reflectometry (XRR). Despite the widespread use for thin-film structures study, XRR has a strong limitation related with the size and surface quality of the samples.
Refractive optics is the most dynamically developing kinds of X-ray optical elements [1-2]. CRLs quickly gained popularity among synchrotron sources users due to their ease of operation and the possibility of application in a wide range of energies [3-4].
In this work, a new X-ray reflecto-interferometer (XRI), based on CRL, was demonstrated to study thin-film structures using the synchrotron X-ray source . Due to the CRL focusing properties, X-rays incident on the sample surface contain the necessary range of angles for the formation of an interference pattern in one shot.
The capabilities of the new XRI were demonstrated at the ESRF ID10 beamline (Grenoble, France). The Si3N4 and diamond membranes with thicknesses 100 and 200 nm were studied using X-rays of energy 22 keV. Experimentally obtained reflecto-interferograms are in good agreement with calculated ones, and the distance between fringes in the interference patterns corresponds to the thickness of the tested membranes.
The new XRI opens wide horizons both for rapid thin-film and multilayer analysis and for studying the dynamics of processes on the surface and in the depth of the sample, as well as for studying complex structured and biological samples.
This research was supported by the Russian Science Foundation (Project No. 19-72- 30009).
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