The aim of this study was to examine the stoichiometries of certain electron beam evaporated optical coatings. A series of SiO2, TiO2, and Al2O3 films were electron beam evaporated from compound source materials onto silicon substrates at various substrate temperatures and 18O vacuum ambient partial pressures. Rutherford backscattering spectrometry (RBS) was used to determine the oxygen to metal ratio of the deposited films, while hydrogen forward scattering (HFS) was used to measure the hydrogen concentrations in the respective materials. Secondary ion mass spectrometry (SIMS) was used to measure the 18O/16O isotope ratio in the films, and thus determine the relative contribution of the ambient gas to the final film stoichiometry. © 1990.
