The influence of the substrate on the optical constants of Al films

Attenuated total reflection (ATR) spectroscopy employing a prism and a dielectric spacer layer is used to determine the optical constants of vacuum deposited aluminium films. In the energy range of the 1.5 eV interband transition, a strong dependence of the optical constants on the material of the underlying layer is found. This dependence is attributed to structural effects in the Al film.