Ivan Ohlídal, Daniel Franta, Petr Klapetek
Proc: Ellipsometry in characterization of thin films
Proceedings of Solar Renewable Energy News (2005) pp.81-111
Published by Comenius University, Bratislava, Slovakia
In this paper the principles of ellipsometry together with a description of important ellipsometric techniques are briefly presented. A general classification of the ellipsometric methods significant from the practical point of view is performed as well. Furthermore, the general principles of the optical characterization of thin film systems are introduced. Thus, the main steps for creating the structural models of the thin film systems are described together with classification of the mathematical formalism usable for deriving the formulae usable for the optical characterization of the system mentioned. The three significant dispersion models enabling us to express the spectral dependences of the optical constants of the amorphous dielectric and semiconductor thin films within the wide spectral region are also described, i.e. the Tauc–Lorentz model, Ferlauto et al. model and model based on parameterization of the density of electronic states are discussed. Three examples of the optical characterization of thin films are illustrated, i.e. the results of the optical characterization of polymorphous silicon films, As–S chalcogenide films and TiO2 films achieved using the ellipsometric methods combined with spectrophotometric ones are presented and discussed. A possibility of using the methods presented here for characterizing the films employed for creating solar cells is introduced too.
You may also contact one of the authors: ohlidal@physics.muni.cz, franta@physics.muni.cz