In this study, a range of dielectric coatings have been deposited onto soda-lime glass substrates by reactive sputtering from metallic targets. The magnetron was driven in mid-frequency pulsed DC mode. Process variables investigated include operating pressure, oxygen flow rate and magnetron configuration. The as-deposited coatings were analyzed by micro Raman spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). Selected coatings were annealed at temperatures in the range 200-600^oC and re-analysed. The oxide samples were then over-coated with silver and annealed for a second time. These coatings were analysed by secondary ion mass spectroscopy (SIMS) and X-ray photoelectron spectroscopy (XPS) to determine the diffusion rates of silver and sodium (from the substrate) through the oxide coatings.

The results to date, presented here, indicate that the structure of the coating, particularly the degree of crystallinity, has a greater impact on the diffusion of sodium through the coating than the diffusion of silver. Preliminary attempts have been made to estimate diffusion coefficients for these coating systems and to relate these values to processing conditions and the structural variations observed.

The interest on mixed metal-silicon oxides includes their application, among others, as optical coatings with an adjustable refractive index. Chemical vapour deposition of these coatings is commonly used, although it frequently causes the undesirable incorporation of chlorine, hydrogen or carboxyl groups to the films. In this paper we report the formation of chromium and silicon mixed oxides using a novel alternative method. We induce the formation of mixed oxides from a sputter-deposited chromium film on a silicon substrate by reactive ion beam mixing bombarding the Cr/Si interface with oxygen. We have varied both the ion dose (from 1x10¹⁷ up to 1x10¹⁸ ions cm-²) and the implantation energy (40-100 keV) in order to modify the final composition of the coating. The composition profiles have been obtained by means of Rutherford backscattering spectrometry (RBS) with He ions at 3.035 MeV to make use of the resonance of alpha particles with oxygen at this specific energy. A more detailed analysis of the composition depth profiles was obtained by changing the He energy from 3.035 up to 3.105 MeV. Results have been compared with depth profiles obtained by secondary ion mass spectrometry (SIMS) and elastic recoil detection analysis using a time of flight station (ERDA-TOF) and by Monte Carlo TRIDYN simulations. X-ray photoelectron spectroscopy (XPS) depth profiles were carried out using a simultaneous Ar⁺ bombardment at low energy. Additional chemical state in-depth distributions were obtained by hard X-ray photoelectron spectroscopy (HAXPES) using synchrotron radiation and angle-resolved (ARXPS). Data obtained by ARXPS show that the Cr-O-Si system does not display preferential sputtering phenomena during Ar⁺ bombardment in depth profiling. X-ray diffraction (XRD) and scanning and transmission electron microscopy (SEM, TEM) assessed structural changes of the sample from polycrystalline to amorphous state upon increasing the implantation dose. We have determined how structural changes brought about by varying the ion beam implantation parameters are related to the optical properties of the coatings (mainly refractive index, extinction coefficient and reflectivity) as measured by spectroscopic ellipsometry and UV-VIS spectroscopy.