STUDY OF THE OPTICAL-CONSTANTS DETERMINATION OF THIN-FILMS - DEPENDENCE ON THEORETICAL ASSUMPTIONS

We present a critical study of the known reflectance (R) and transmitt ance (T) method to extract the optical constants of thin film-substrat e systems. In order to study the effect of the usual assumptions (homo geneous layers, semi-infinite substrate, normal incidence angle for re flectance measurement, etc.) in the loss of solution during the numeri cal inversion process, we have developed a theoretical model that over comes these approximations. Simulated film-substrate systems as well a s RT measurements from a ZnSe film onto a CaF2 substrate have been use d to show how accurate Rim thickness and optical constants can be obta ined using a more complete optical model. (C) 1995 American Vacuum Soc iety.