Light scattering from the volume of optical thin films: theory and experiment

Abstract

A theoretical model is presented that describes the volume scattering in thin optical films, particularly in typical columnar structures. It is based on a first-order perturbation theory that concerns the fluctuation of the dielectric permittivity in the film. For evaporated PbF(2) films that show a pronounced columnar morphology, angular as well as total integrated scattering measurements at lambda = 633 nm have been performed on a special layer design to suppress roughness-induced scattering. A comparison of the predicted theoretical and the measured experimental values leads to such structural parameters as packing density and the evolutionary exponent of the columns.

Interface roughness statistics of thin films from angle-resolved light scattering at three wavelengths

“…35,36 This scattering source was neglected in this paper. Recently, considerable efforts have been made to investigate scattering originating from inhomogeneities in the bulk of a thin film, i.e., volume inhomogeneities.…”

Angle-resolved ellipsometry of light scattering: discrimination of surface and bulk effects in substrates and optical coatings

“…Several theories have been developed at the Fresnel Institute 9 -16 and elsewhere 17,18 that allow us to calculate angular scattering from roughness and inhomogeneity at surfaces and bulk of optical materials. For high scattering levels that cannot be neglected with regard to incident power, the roughness-towavelength ratio at surfaces as well as inhomogeneity in the bulk is of the order of unity.…”

Characterization of optical coatings using a multisource table-top scatterometer

“…Topographic measurements were only used exceptionally, to verify the wavelength scaling analysis [38]. Crosspolarization techniques using a single illumination wavelength approach were shown to also be applicable for analyzing correlation properties, volume scattering, subsurface damage, or contaminations [39][40][41].…”