Preparation of Rutile and Anatase Phases Titanium Oxide Film by RF Sputtering

Titanium oxide films were prepared by RF magnetron sputtering onto glass substrates. The effects of RF power and deposition temperature on crystalline structure, morphology and energy gap were investigated, which were analyzed by X-ray diffraction, SEM and UV-Vis spectrometer, respectively. Results show that rutile phase is the favored structure during deposition. Applying RF power in the range of 50–250 W, the amorphous, rutile, and both rutile and anatase phases TiO₂ films were obtained in sequence, while the content of anatase is similar in the range of 34–37% although the RF power increases. Increasing the deposition temperature, the anatase phase coexists in the rutile phase in the range of 100–200 °C, and the content of anatase increases from 20 to 41% with the deposition temperature. In addition, according to the morphology observation, the granulous surface is found in rutile phase while facetted surface in anatase phase when titanium oxide films deposited at various RF powers and substrate temperatures. The band gap energy of titanium oxide evaluated from (αhν)^1/2 versus energy plots show that the energy gap decreases with RF power increasing.