STUDY OF POROSITY OF TITANIUM-OXIDE FILMS BY X-RAY PHOTOELECTRON-SPECTROSCOPY AND IR TRANSMITTANCE

Titanium oxide films were deposited on glass substrates by d.c. reacti ve magnetron sputtering at different oxygen partial pressures (3.4 x 1 0(-4) mbar to 3 x 10(-3) mbar) and total pressures (2 x 10(-3) mbar to 2 x 10(-2),mbar). Two resolved peaks in the Ols spectra of XPS were o bserved. These two peaks were attributed to the O-Ti bonding and the O -H bonding. The O-H bonding component increased as the oxygen partial pressure and total pressure were increased. The near IR transmittance measurements showed that all films had an absorption near 2:8 mu m, an d the absorption increased as the total pressure and oxygen partial pr essure were increased. These phenomena were related to the porosity of the film. The films prepared by d.c. reactive magnetron sputtering ge nerally have a columnar structure with many pores. In air some of thes e pores are filled with water, and this results in the appearence of t he O-H bonding component and the absorption around 2.8 mu m. The incre ase of the O-H bonding component and the absorption around 2.8 mu m in dicates the increase of the film porosity.