Secondary ion mass spectroscopy studies of glass thin films prepared with sol/gel techniques

Secondary ion mass spectroscopy (SIMS) was used to analyze thin multicomponent glass films. The films were deposited by a sol/gel process onto bare glass and silver-coated glass substrates. SIMS spectra and SIMS depth profiles were recorded for the microporous gel films as well as films densified by heat treatment. The SIMS spectra showed a dependence of the relative secondary ion yields of elemental and molecular species upon the densification heat treatment. It is suggested that this dependence reflected the effect of heat treatment upon polymerization of the film structure. This suggestion was further supported by the decrease in sputter rate which accompanied the densification heat treatments. Although the depth profiles changed significantly with heat-treatment, presumably due to interdiffusion between the film and substrate as well as oxidation of the Ag-films, the observations were difficult to interpret. It was found that quantitative analysis of microporous glass films with SIMS is a difficult task, particularly when the redistribution of atomic species between the film and a reactive substrate is of interest. This is due to simultaneous changes in the sputtering rate, film composition and ionization probabilities with heat treatment, all of which influence the measured secondary ion signals.