THE EFFECT OF SUBSTRATE-TEMPERATURE ON THE PROPERTIES OF SPUTTERED TITANIUM-OXIDE FILMS

TiO2 films have been deposited on glass substrates (75 X 25 mm2) by DC reactive magnetron sputtering from a pure 99.6% titanium plate of 100 X 100 mm2. During the sputtering process, the oxygen partial and total pressure were 6 X 10(-4) and 8 x 10(-3) mbar, respectively. The substrate temperature varied from ambient to 500-degrees-C. The results of X-ray diffraction show that all films have a anatase crystal structure. The film deposited at ambient has a (101) preferred orientation. With an increase in the substrate temperature, the films tend towards a random orientation. When the substrate temperature is higher than 450-degrees-C, the film again has a preferred orientation. However, the preferred orientation is not (101) but (004). As the substrate temperature is varied, the optical properties (refractive index, optical band gap and extinction coefficient) of TiO2 films also change significantly.