Analysis of inhomogeneous thin films of ZrO2 by the combined optical method and atomic force microscopy

Abstract

AbstractIn this paper results concerning the complete optical analysis of inhomogeneous ZrO2 films are introduced. The optical analysis of these films is carried out using the combined optical method based on interpreting experimental data corresponding to variable angle of incidence spectroscopic ellipsometry (VASE) and near‐normal incidence spectroscopic reflectometry (NNSR). The model of the ZrO2 films used for interpretation of the experimental data achieved using the combined method exhibits a continuous refractive index profile. It is shown that this model is satisfactory for treating the experimental data. Further, it is shown that all the parameters characterizing the model mentioned can be determined with high accuracy. By means of atomic force microscopy (AFM) it is found that the upper boundaries of the inhomogeneous ZrO2 films are slightly rough. The values of the basic statistical quantities characterizing this boundary roughness are evaluated using the AFM data. The optical inhomogeneity of the ZrO2 films studied is explained by the columnar structure of these films. Copyright © 2001 John Wiley & Sons, Ltd.