Influences of underlayers on structure of TiO2 thin films prepared by radio frequency magnetron sputtering

In this study, the effects of several underlayers (Cu, Co, Ag and Fe) on the thin structure of TiO2 by RF magnetron sputtering were studied and compared. The results of X-ray diffraction (XRD) revealed that the Cu and Ag underlayer worsened the crystal quality of the TiO2 films. When the Fe underlayer was used, fabricated TiO2 film showed a mixture of rutile and anatase. The Co underlayer, on the other hand, induced TiO2 anatase polycrystalline structure. This study also compared the surfactant effect of a Ag layer on the TiO2 film structure. The results of XRD, X-ray photoelectron spectroscopy, and atomic force microscopy revealed that the Ag layer works as an effective surfactant for reducing the surface roughness and the rutile growth of TiO2 film on the Fe underlayer.