Abstract:
For work related to the study of the structure and composition of thin films on substrates, the technique of restoring optical constants based on reflectometry data is used. This technique is used with the involvement of synchrotron radiation sources. This is not always convenient and often does not allow for rapid analysis. In this paper, the possibility of using laboratory methods of reflectometry to measure the optical constants of materials in the EUF range is studied. The analysis is carried out using the example of materials used in the structure of lithographic masks for reflection. Namely, on the basis of tantalum compounds, which is an absorber in blanks for masks. In this work, an experiment was numerically modeled to measure the reflection coefficient depending on the wavelength and angle of incidence for the layers of the lithographic mask absorber. The model took into account the actual characteristics of laboratory devices, as well as measurement errors. The numerical experiment shows the prospects of using laboratory reflectometry to determine the parameters of thin films on substrates. Structure parameters such as density, roughness and thickness are restored with a high degree of accuracy. The deviations of the values obtained in all implementations from the model values are significantly less than 1%.
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