SPECTRAL ELLIPSOMETRIC AND COMPOSITIONAL CHARACTERIZATION OF HYDROGENATED AMORPHOUS-SILICON CARBIDE THIN-FILMS

A spectroscopic (UV-visible) ellipsometric analysis of hydrogenated am orphous silicon carbide (a-Si1-xCx:H) thin films, grown by plasma-enha nced chemical vapour deposition, is presented. The films were analysed by X-ray photoelectron spectroscopy (XPS) and secondary ion mass spec trometry (SIMS) to determine their composition. In this study, a wide range of x values, from 0.16 to 0.59, was covered. These values depend mainly on the composition of the precursor gas. The spectroscopic ell ipsometric analysis of the samples, by a multilayer model, shows that all the a-Si1-xCx:H films studied consist of a homogeneous layer, on a c-Si substrate, with an overlayer (effective medium mixture of the sa me material and 41% voids). This analysis also provides values of the dielectric function of the layer material.