title: Method for determination of the parameters of transparent ultrathin films deposited on transparent substrates under conditions of low optical contrast.
abstract: In the present work we suggest an original ellipsometric technique for independently determining strongly correlated refractive index and thickness of transparent ultrathin films. We demonstrate significant accuracy improvement for the single-wavelength null-ellipsometry measurements when using multiple incidence angles for the system "transparent film on a transparent substrate" studied in the thickness range of 1.0-20.0 nm and the low-contrast region for the film-substrate surface. A straightforward relationship is obtained between the refractive index n(1) of the transparent film and the incidence angle φ. It follows from invariability ensured for the amplitude ellipsometric parameter Ψ with respect to the film thickness changes.
authors.forename: Andriy
authors.initials: A
authors.lastname: Kostruba
authors.forename: Yuriy
authors.initials: Y
authors.lastname: Stetsyshyn
authors.forename: Rostyslav
authors.initials: R
authors.lastname: Vlokh