Characterization of growth behavior and structural properties of TiO2 thin films grown on Si(1 0 0) and Si(1 1 1) substrates

To comparative study on the growth behavior and structural properties of thin films, in this work, we have deposited the titanium oxide (TiO2) thin films on both Si(1 0 0) and Si(1 1 1) substrates using a single molecular precursor by metal-organic chemical vapor deposition method at temperature in the range of 600–750 °C and working pressure of 1.0×10−5 Torr. X-ray diffraction and transmission electron diffraction data suggest that the main film growth directions are [1 1 0] on Si(1 0 0) and [2 0 0] on Si(1 1 1), respectively, indicating that the film growth direction is highly affected by Si wafer orientation. Atomic force microscope and transmission electron microscope images showed that a TiO2 film deposited on Si(1 0 0) at 750 °C at 1.0×10−5 has more smooth surface than that grown on Si(1 1 1) under the same deposition condition. The as-grown TiO2 films were also investigated using Rutherford backscattering spectroscopy (RBS) and secondary ion mass spectroscopy (SIMS) for detail analysis of relationship between film composition and impurity. RBS analysis showed that the as-grown TiO2 films on both Si(1 0 0) and Si(1 1 1) have nearly stoichiometric composition. Different contamination level, especially hydrogen and carbon, of the TiO2 films grown on either Si(1 0 0) or Si(1 1 1) substrates have been determined by SIMS analysis.