Growth of TiO2 thin films on Si(100) substrates using single molecular precursors by metal organic chemical vapor deposition

Growth of titanium dioxide (TiO2) thin films on Si(100) substrates was carr ied out using a single molecular precursor at deposition temperature in the range of 300-700 degreesC by the metal organic chemical vapor deposition ( MOCVD) method. Titanium(IV) isopropoxide, (Ti[OCH(CH3)(2)](4)), was used as a precursor without any carrier gas. Crack-free, anatase type TiO2 polycry stalline thin films with a stoichiometric ratio of Ti and O were successful ly deposited on Si(100) at temperature as low as 500 degreesC. XRD and TED data showed the formation of the highly oriented anatase phase with the [21 1] direction for the TiO2 thin films grown on Si(100) at below 500 degreesC , whereas with increasing the deposition temperature to 700 degreesC, the m ain film growth direction was changed to be [200], suggesting a possibility of epitaxial thin film growth. Two distinct growth behaviors were observed from the Arrhenius plots. Below 500 degreesC, the growth rate of TiO2 is a pparently limited the substrate temperature. The activation energy for TiO2 film deposition calculated in this region is approximately 77.9 kJ/mol, wh ile that for a film grown above 500 degreesC shows a negative value, indica ting a predominant diffusion controlled deposition process. Using Al/TiO2/p -Si metal-insulator semiconductor (MIS) diode structure, a dielectric const ant was also obtained from a capacitance-voltage (C-V) curve to be 21. (C) 2000 Elsevier Science B.V. All rights reserved.