ABSTRACT
The optical constants of gold deposited on 300-nm-thick freestanding polyimide films have been measured in the energy range of 40-1350 eV. The optical constants of the polyimide films were known from a previous investigation. By performing both transmission measurements with Kramers-Kronig analysis and multiangle reflection measurements with analysis by fitting to a Fresnel multilayer model including roughness, one could carry out a detailed error analysis. In the energy range above 500 eV systematic deviations between the results obtained by both methods were found. For gold films the discrepancies can be attributed to deviations from Beckmann-type behavior at small grazing-incidence angles.
ABSTRACT
Measurements were performed with synchrotron radiation on free-standing, ~300-nm-thick polyimide films in the photon energy range of 40-1350 eV. We evaluated optical constants both from transmission measurements with the Kramers-Kronig analysis and from multiangle reflection measurements by fitting Fresnel equations modified by two different roughness factors for both sides of the film. A thorough error analysis was carried out for both methods. The results agree well within the error barsthereby strengthening confidence in the applied theoretical formalism as well as in the experimental method in this difficult spectral region.
