Optical characterization of thin Au films by standard and polaritonic ellipsometry

Abstract

This work is aimed at optical characterization of thin Au films by multiple-angle-of-incidence reflectance ellipsometry at the fixed wavelength (632.8 nm) in standard and attenuated total reflection (ATR) modes in contact with different dielectric media (water, alcohol and air). The comparative experimental evaluation of the precision of determined optical parameters (refractive index n and absorption coefficient k) and thickness for both ellipsometric modes has been studied by calculation of their sensitivity correlation coefficients. Medium- and mode-related optical constants of Au films were revealed. In the ATR mode the effective optical parameters were higher then in the standard mode, n decreased and k increased with increasing the refractive index of adjoining medium. This effect must be taken into consideration in polaritonic optoelectronic and optochemical sensor technique.