ANALYSIS OF OPTICAL-SURFACES BY MEANS OF SURFACE-PLASMON SPECTROSCOPY

The sensitivity to material parameters of surface plasmon oscillations is explored for the design of a prototype system operating at a wavel ength of 670 nm, for the simultaneous determination of thickness, comp lex permittivity and surface roughness of metal films, The apparatus w as employed for characterization of gold and silver films with thickne sses within the 10-100 nm range, Thickness data measured with the prot otype system were well correlated with those measured on a conventiona l surface profilometer. The Fourier spectrum of surface irregularities extracted from scattered light, enhanced by surface plasmon oscillati ons, was used to determine surface roughness parameters for the distin ct samples, Those parameters were shown to be representative of typica l surface structures observed with the atomic force microscope.