The Quantitative Determination of Surface Oxide Thickness on Deposited Metal Films by Combination Auger Spectroscopy and Inert Gas Ion Bombardment

A technique combining Auger spectroscopy and inert gas ion bombardment has been employed for the determination of “surface oxide” thickness on deposited metal films. The quantitative limitation on the technique depends on knowing accurately the sputtering rate for the material under study. Using x-ray fluorescence and atomic absorption spectroscopy as independent analytical methods, an empirical value for the net sputtering rate for the material may be determined. In addition, the technique allows the elemental composition of the film as a function of depth to be determined. Surface oxide thickness on electron beam-deposited erbium films, followed by air exposure, ranged from 170 to 190 Å, whereas hydrided erbium films that were vacuum annealed at 1 × 10⁻⁸ Torr over a range of temperatures up to 500°C had oxide thicknesses from 110 to 350 Å.