Analysis of slightly rough thin films by optical methods and AFM

In this paper the analysis of a family of rough silicon single crystal surfaces covered with native oxide layers is performed using a combined optical method based on a multisample treatment of the experimental data obtained using variable angle of spectroscopic ellipsometry and near normal spectroscopic reflectometry. Within this analysis the values of the thicknesses of the native oxide layers are determined together with the values of statistical parameters of roughness, i.e, with the rms values of the heights and the values of the autocorrelation lengths, fur all the samples studied. For interpreting experimental data the perturbation Rayleigh - Rice theory and scalar diffraction theory are employed. By means of the results of the analysis achieved using both the theories limitations of the validity of these theories is discussed. The correctness of the values Of the statistical parameters determined using the optical method is verified using AFM measurements.