STRUCTURAL-PROPERTIES OF TIO2 FILMS GROWN BY PULSED-LASER DEPOSITION

Pure titanium dioxide (TiO2) films were prepared by pulsed laser depos ition on a single crystal Si(100) substrate. We have investigated the growth of crystalline titanium dioxide films with respect to substrate temperature and ambient oxygen pressure. The structural properties of the films were analyzed by X-ray diffraction. We found that the anata se as well as the rutile phases could be formed from the original ruti le phase of the target TiO2. At 0.75 torr of ambient oxygen pressure, the structure of TiO2 film was amorphous at room temperature, anatase between 300 and 600 degrees C, a mixture of anatase and rutile between 700 and 800 degrees C, and only rutile at 900 degrees C and above. Ho wever, at a low ambient oxygen pressure, the rutile phase became domin ant; the only rutile phase was obtained at the ambient oxygen pressure of 0.01 torr and the substrate temperature of 800 degrees C. Therefor e, the film structures were largely influenced by substrate temperatur e and ambient oxygen pressure.