INVESTIGATIONS OF TITANIUM-OXIDE FILMS DEPOSITED BY DC REACTIVE MAGNETRON SPUTTERING IN DIFFERENT SPUTTERING PRESSURES

Titanium oxide thin films were deposited on glass substrates by the d.c. reactive magnetron sputtering method. The dependence or structural and optical properties of films, and film composition, on the sputtering pressure was studied. The results of the X-ray diffraction show that all films only have the anatase TiO2 phase. At lower sputtering pressure, the film has a preferred orientation along (101) direction. As the sputtering pressure increases, the intensity of the (101) diffraction line decreases gradually. When the sputtering pressure is higher than 2 x 10(-2) mbar. the film exhibits an almost amorphous structure. The results of scanning electron microscopy show that the film structure changes from more dense to more porous as the sputtering pressure increases from 2 x 10(-3) mbar to 2 x 10(-2) mbar. These structure variations result in the variations in the optical properties. As the sputtering pressure increases from 2 x 10(-3) mbar to 2 x 10(-2) mbar, the refractive index n and extinction coefficient k (at 500 nm) vary from 2.48 to 2.14 and from 4.06 x 10(-3) to 0.59 x 10(-3) respectively.