Variation of TiO2/SiO2 mixed layers induced by different Xe+ ion energies

TL;DR

This study investigates how different Xe+ ion energies affect the structure and optical properties of TiO2/SiO2 transition layers, revealing increased atomic mixing and changes in optical constants with ion energy.

Contribution

It provides detailed analysis of the structural and optical modifications in TiO2/SiO2 layers induced by varying Xe+ ion energies, combining RBS, ES, and SRIM calculations.

Findings

Transition layer thickness increases with ion energy.

Optical constants change notably after implantation.

Refractive index and extinction coefficient vary with ion energy.

Abstract

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.