SPECTROSCOPIC ELLIPSOMETRY OF THIN COPPER-FILMS ON GLASS SUBSTRATES

The complex reflectance ratio, rho=R(p)/R(s), for p- and s-polarized lights of copper island films with the mean mass thickness d(w) of 4 to 16 nm on glass substrates was measured in the visible region by means of in-situ ellipsometry. The observed wavelength dependence of rho was interpreted with the effective anisotropic continuous film model. The clear resonance peak of plasma oscillation in epsilon(x)'' was observed at E congruent-to 1.8 eV, which corresponded to the mean distance between the particles of 7.5 nm in the film of d(w)=4 nm. The estimated particle radius r was smaller by a factor of 10(-1) or 10(-2) than the island size directly observed by means of a scanning electron microscope.