Angular-selective optical transmittance of anisotropic inhomogeneous Cr-based films made by sputtering

Abstract

Thin Cr-based films were made by sputtering with oblique incidence of the deposition flux onto a substrate. The films had an inclined columnar microstructure, as verified by atomic force microscopy and scanning electron microscopy. The optical transmittance showed pronounced angular selectivity as well as spectral selectivity. Scaling relations were found for the thickness-dependent transmittance. The optical data could be reconciled with a model based on the Bruggeman effective medium theory.