LIGHT-SCATTERING FROM MULTILAYER OPTICS .2. APPLICATION TO EXPERIMENT

The tools of investigation presented in part I of this study [J. Opt, Soc. Am. A 11, 197 (1994)] are applied to the analysis of experimental results. First the Limits of the scatterometer are analyzed in detail. Problems of calibration, parasitic light, linearity, and repeatability of measurements are discussed. The roughness spectrum is shown to be an intrinsic property of surface defects. It is proved that this spectrum is perfectly reproduced in the whole range of measurable spatial frequencies by a metallic layer. Dielectric materials under study are TiO2, Ta2O5, and SiO2 obtained by ion-assisted deposition, ion plating, and electron beam evaporation. The inverse problem is solved with isotropy degree curves, and the scattering parameters that are low-pass filters and residual spectra are extracted for single layers and multilayers. Replication of defects in the measurable bandwidth is shown to be perfect at all interfaces of a multilayer. In addition, the thin-film materials bring low residual roughnesses. Coatings are also produced at oblique deposition, and light scattering is used to detect the oblique growth of the thin-film layers. The role of local defects is investigated.