Studies of the hot-pressed TiN material by electron spectroscopies

We analyzed chemical composition and electron transport phenomena in surface and sub-surface region of hot-pressed TiN specimens using a combination of X-ray photoelectron spectroscopy (XPS) and elastic-peak electron spectroscopy (EPES) techniques. Both the surface chemical composition and the elements distribution in the bulk of TiN specimens were determined using XPS and XPS depth profiling analysis. In addition to TiN, a mixture of Ti oxynitride (TiOxNy) and TiO2 compounds as well as carbon contaminants have been detected in the surface region of the TiN specimens. The elemental depth-profiles disclosed uniform chemical bulk composition formed mainly by titanium and nitrogen as well as carbon and oxygen contaminants. Surface enrichment of Ti was evidenced as result of Ar ion-induced preferential sputtering of nitrogen. The inelastic mean free path (IMFP) data evaluated from the relative EPES for electron energies 0.5–2 keV were uncorrected for surface excitations and compared with those calculated from the predictive TPP-2M formula for the measured surface composition. Except to the electron energy of 0.5 keV, a good agreement was found between the measured and predicted IMFPs in the TiN specimen. The higher discrepancies in the measured IMFPs at the lowest energy can be explained by the surface excitation effect. The smallest root-mean-square-deviation and the mean percentage deviation of 2.8 Å and 14.8%, respectively, were found between EPES IMFP data and those predicted for TiN with respect to the Ni standard.

► Hot-pressed TiN sputter target material.
► XPS identifies TiN, TiOxNy, TiO2 and carbon contaminants in the surface region of as-prepared hot-pressed TiN sputter target.
► Elemental XPS depth-profiles disclose uniform in-depth chemical composition of hot-pressed material.
► Surface enrichment in Ti was found on the TiN material after Ar ion etching.
► Good agreement is seen between the measured and predicted IMFPs in TiN for 1–2 keV electrons.