Optical constants of TiN, amorphous SiO₂, and SiN in the extreme ultraviolet range

Using reflectometry, we studied the optical constants of TiN and amorphous SiO 2 thin films in the spectral range 5–24 nm (ca. 250 eV–ca. 52 eV), and for SiN in the spectral range 5–33 nm (ca. 250 eV–ca. 37 eV). The films’ elemental concentration depth profiles were measured using elastic recoil detection analysis (ERDA). The reflectance was measured using monochromatized synchrotron radiation. For the analysis of reflectivity data, Markov chain Monte-Carlo (MCMC)-based Bayesian inferences Bayesian inferences were used to obtain the optical constants and their model uncertainties. For SiO 2 and SiN, dispersion profiles were sampled with sub-Ångström resolution in certain intervals around the Si-L 1 and Si-L 2,3 transitions. The obtained optical constants are compared with literature values and with estimations based on the independent atom approximation (IAA).