XPS and ARXPS investigations of ultra thin TaN films deposited on SiO2 and Si

TaN films were deposited by reactive DC magnetron sputtering onto Si and SiO2 with thicknesses of less than one monolayer up to 10 nm. After this, the samples were transferred into the analysis chamber without breaking the vacuum and analysed by means of X-ray photoelectron spectroscopy (XPS) and angular resolved XPS (ARXPS). XPS measurements as a sensitive method to characterise chemical states showed a silicon nitride formation at the interface at deposition on Si. On the SiO2 no reaction was found at the interface. Based on these observations layer models for quantification of ARXPS measurements by means of model calculations were derived, so it was possible to obtain information on the in-depth element distribution in a non-destructive manner. For comparison to the ARXPS investigations analyses of the inelastic background of the Ta4d peak are shown and discussed.