X-RAY PHOTOELECTRON-SPECTROSCOPY STUDY OF THE DIFFERENCE BETWEEN REACTIVELY EVAPORATED AND DIRECT SPUTTER-DEPOSITED TIN FILMS AND THEIR OXIDATION PROPERTIES

X-ray photoelectron spectroscopy (XPS) is used to study carefully prepared oxide-free titanium nitride (TiN) films of nearly identical stoichiometry, grown by direct sputtering and reactive evaporation. The line shapes and peak positions of the Ti 2p and N 1s transitions are dependent upon the deposition method. The XPS results showed that oxynitrides are present following exposure of either type of film to dry oxygen; however, reactively evaporated films have a considerably higher oxidation rate. Differences in valence band and electron energy loss spectroscopy (EELS) spectra are correlated with the changes observed in the core levels. The EELS spectra detected the presence of a low energy loss, which is correlated with the TiN electron density of states closest to the Fermi level. The secondary electron emission yields for reactively evaporated TiN were also measured before and after dry oxygen and air exposure, and after heating. The maximum yields are about 10% lower for reactively evaporated films than for similarly treated previously measured sputter-deposited layers. (C) 1995 American Vacuum Society.