  The broadening and optical parameters of TiO2/SiO2 transition layers
depending on the ion energy have been investigated using the Rutherford
Backscattering Spectrometry (RBS) and Ellipstrometry Spectroscopy (ES) methods.
The TiO2/SiO2 samples were irradiated by Xe+ ions with energies of 100, 150,
200 and 250 keV. The depth profiles of the elements determined by the RBS
spectra show the structure and thickness of the TiO2/SiO2 transition layers
before and after implantation. We have found that the thickness of the
transition region between the TiO2 and SiO2 layers increases with the
increasing incident ion energy. This phenomenon indicates an increasing amount
of atomic mixing at the TiO2/SiO2 interface. In addition, the variation of
transition layers could be explained by defect depth profiles and ions energy
transferred in the mixed layers by means of SRIM calculations. The thickness
obtained from the RBS is in good agreement with that measured using the ES
method. Based on these obtained results, we have also investigated the optical
constants of implanted and non-implanted TiO2/SiO2 structures. The wave forms
measured with varying incident angles suggest that the measurements were made
close to near the main principle point. The yields of \psi and \delta bands
vary at different incident angles, is associated with interference processes of
the light reflected from the structures examined. The refractive index and the
extinction coefficient were found to increase after implantation taking place
up to 200-keV Xe and then decrease at 250 keV.
