A comprehensive study of the TiN/Si interface by X-ray photoelectron spectroscopy

Highlights: • A comprehensive XPS study of the TiN/Si interface bonds formation is presented. • An experimental procedure is shown to minimize oxygen contamination of the interface. • The role of H₂ promoting Ti–Si bonds are discussed. • The influence of the substrate preparation on the interface-local bond is proposed. In this paper, a comprehensive X-ray photoelectron spectroscopy (XPS) study of the first atomic layers of TiN nanofilms grown by ion beam assisted deposition on crystalline silicon is reported. This deposition technique allows a fine control of the ion species and energy arriving at the substrate. The substrates are prepared by ion beam cleaning involving Xe⁺ ion bombardment in different partial pressures of molecular H₂. The expected hydrogen passivation effect by the Si–H formation bond limiting the Si–O bonds was quantitatively evaluated and correlated with some retention of H and O at the substrate surface. The effects of molecular H₂ and residual H₂O atmosphere present during the process on the chemical bonding on both the naked Si substrate and afterward on the interface are reported. A detailed XPS analysis performed in an attached UHV chamber to the preparation chamber of the TiN/Si interface shows that the bombarding cleaning procedure plays an important role in the bond formation at the interface since minute amounts the oxygen jeopardize the bulk properties.