Infrared reflectivity spectra of thin porous aluminum oxide films

Angular dependencies of infrared (50-7500 cm -1) reflectivity spectra of thin porous aluminum oxide films on aluminum had been measured. These spectra show vibrational bands and strong interference bands allowing film thickness and dielectric function calculation. Angular dependencies of interference bands give thicknesses and refractive indices of the films. The refractive indices decrease and hence the film porosities increase with the thickness. The dispersion analysis of the reflectivity spectra below 2000 cm -1 allows us to obtain the film dielectric functions in the fundamental vibrations region.