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

In this paper results concerning the complete optical analysis of inhomogen eous ZrO2 films are introduced. The optical analysis of these films is carr ied out using the combined optical method based on interpreting experimenta l data corresponding to variable angle of incidence spectroscopic ellipsome try (VASE) and near-normal incidence spectroscopic reflectometry (NNSR). Th e model of the ZrO2 films used for interpretation of the experimental data achieved using the combined method exhibits a continuous refractive index p rofile. It is shown that this model is satisfactory for treating the experi mental data. Further, it is shown that all the parameters characterizing th e model mentioned can be determined with high accuracy. By means of atomic force microscopy (AFM) it is found that the upper boundaries of the inhomog eneous ZrO2 films are slightly rough. The values of the basic statistical q uantities characterizing this boundary roughness are evaluated using the AF M data. The optical inhomogeneity of the ZrO2 films studied is explained by the columnar structure of these films. Copyright (C) 2001 John Wiley & Son s, Ltd.