The Influence of Ta underlayers on the structure of TiO ₂ thin films deposited on an unheated glass substrate

The influence of Ta underlayers on the structures of TiO ₂ thin films grown onto unheated glass substrates by radio frequency magnetron sputtering has been studied and compared. The crystal, electronic, and surface structures of fabricated TiO ₂ films were investigated by X-ray diffraction, X-ray photoelectron spectroscopy, and atomic force microscopy, respectively. The X-ray diffraction results and valence band spectra by X-ray photoelectron spectroscopy revealed that the fabricated TiO ₂ films on the unheated glass substrate with a highly crystallized β-Ta underlayer showed an anatase structure, whereas the TiO ₂ film grown directly onto glass or onto a poorly crystallized Ta film showed an amorphous one. The results showed that the crystallized anatase TiO ₂ films were successfully obtained on glass substrates using the Ta underlayers without substrate heating and additional annealing.