RELATION BETWEEN LIGHT-SCATTERING AND THE MICROSTRUCTURE OF OPTICAL THIN-FILMS

Special substrate-film designs are used to measure roughness-induced s cattering and scattering from the volume of optical thin films separat ely. So theoretical models of surface roughness and volume scattering become applicable to the experimental data, and quantitative informati on on thin-film microstructure can be derived. Measuring total integra ted and angle-resolved scattering on oxide, fluoride, and chalcogenide films of different film thicknesses yields the evolution law of micro structural growth, which for the majority of investigated films roughl y follows a square-root dependence on film thickness. Packing densitie s of fluoride films calculated from volume-scattering data are found t o agree with results from quartz-crystal monitoring.