COMPOSITIONAL CHARACTERIZATION OF VERY THIN SIO2 SI3N4/SIO2 STACKED FILMS BY X-RAY PHOTOEMISSION SPECTROSCOPY AND TIME-OF-FLIGHT SECONDARY-ION MASS-SPECTROSCOPY TECHNIQUES/

The chemical composition of ultrathin oxide-nitride-oxide multilayer f ilms grown onto p-type silicon substrates and subjected to different a nnealing processes and to various oxidation times of the nitride layer has been studied by means of x-ray photoelectron spectroscopy and tim e-of-flight-secondary-ion-mass spectroscopy. Our results show that the annealing process strongly influences the bottom SiO2/Si interface al lowing the saturation of the dangling bonds present at this interface and decreasing the concentration of free hydrogen. By increasing the o xidation time, a better silicon dioxide layer is formed in the topmost layer of this structure. (C) 1997 American Vacuum Society.