SiO2 Sol-gel Films Research Articles

Improved structural properties of SiO2 sol-gel films

Silicon oxide films with a small amount of alpha alumina particles embedded in the glass matrix were prepared using the sol-gel method. It is found that the structural properties of these samples are superior to those observed in similarly prepared films, but without the alumina particles. This conclusion was deduced from analysis of the oxygen diffusion measurements through the SiO2 layer, using a novel method, and from the measured dielectric breakdown field. It is found that the oxygen diffusion coefficient is much lower and the dielectric breakdown field is larger in samples with the alumina particles.

Sol–gel SiO2 films containing colloidal copper particles for surface‐enhanced raman scattering of graphite

Sol–gel SiO2 films containing colloidal copper particles for surface‐enhanced raman scattering of graphite

Sol-gel SiO2 films containing colloidal copper particles for surface-enhanced raman scattering of graphite

Sol-gel SiO2 films containing colloidal copper particles for surface-enhanced raman scattering of graphite

Effects of H2O on structure of acid-catalysed SiO2 sol-gel films

Abstract Thin silica films were deposited on silicon wafers by the sol-gel technique, using spin coating. The sols were prepared by HCl catalysis of tetraethylorthosilicate (TEOS) diluted in ethanol, using different molar ratios, R, of H2O:TEOS. The films were then baked at various temperatures, and characterised using ellipsometry, profilometry, optical scattering and infrared spectroscopy. It was found that the thickness, shrinkage, porosity and pore sizes all decrease with increasing R. It was also found that high water levels yield films of higher homogeneity and finer texture, and less tensile stress.

Dependence of thickness on the withdrawal speed for SiO2 and TiO2 coatings obtained by the dipping method

SiO2 and TiO2 sol-gel thin films were prepared from solutions of different concentration. To fit the experimental coating thickness values, the modification of two theoretical equations, available from the literature, was used. The best-fit results were given by the approach which relates the thickness to the square root of the velocity. It was shown that, provided the same heat treatment is used for the films, the thickness of coatings obtained from solutions of different concentration and at any withdrawal speed may be predicted from just one thickness value obtained at one withdrawal speed, if the solutions' viscosity and density, are known.

Ion‐Beam Analysis of Silica Sol‐Gel Films: Structural and Compositional Evolution

Rutherford backscattering and forward recoil spectrometry have been used to determine the chemical composition and density of SiO2sol‐gel films. The as‐deposited films are relatively dense, because of considerable interpenetration of weakly branched silicate precursors, while they contain significant amounts of hydroxyl groups in their structure. Annealing in flowing Ar increases the density of the films with values approaching that of amorphous silica at temperatures as low as 450°C but it fails to completely remove all the hydroxyl groups from the structure.

Ion-Implantation Effects on Spin-on-Glass (Sol-Gel) SiO2 Films

ABSTRACTSilicon and phosphorus ions were implanted into Spin-On-Glass (Sol-Gel) SiO2 films and were found to modify the material properties. Two SOG types, polysiloxane andsilicate, were ion-implanted with doses in the 5 × 1014 − 1.65 × 1016cm−2range and energies of 40keV - 190keV. The implanted SOG on silicon samples were characterized by ellipsometry, infra-red spectroscopy, etching and capacitance measurement of aluminum/SOG/silicon devices. The results indicate that the polysiloxane type SOG shrinks due to the implant and its effective refractive index increases. The ion-implant of the polysiloxane SOG also changed its structure and composition as seen by the variations of the infra-red transmission spectrum, etching characteristics, and dielectric constant. Silicate SOG exhibits less shrinkage due to the implant but its other characteristics show dependence on the dose similar to that of the polysiloxane SOG.