Textured titanium oxide thin films produced by vacuum arc deposition

Results of vacuum arc deposition of titanium oxide at room temperature on silicon (100) and (111), with and without applying high voltage pulses of up to 10 kV to the substrate, are presented in this report. A titanium cathode in oxygen atmosphere was used to produce the titanium and oxygen ions. Rutile, the high temperature modification of the TiO2 phase, was found with some minor additions of substoichiometric oxides like Ti4O7 using X-ray diffraction (XRD). Columnar growth of strongly textured rutile was observed at all pulse bias voltages. The epitaxial relation is [110]TiO2‖[111]Si and [110]TiO2‖[311]Si. The rutile orientation is facilitated by a rather small lattice misfit of 3.4% for the Si[111] direction and 0.86% for the Si[311] direction. While applying a negative d.c. bias or high voltage pulses to the substrate, only a gradual loss of texture was observed, so that at 10-kV pulses, oriented rutile was still observed.