THIN TIO2 FILMS PREPARED BY LOW-PRESSURE CHEMICAL VAPOR-DEPOSITION

The preparation and the properties of titanium dioxide (TiO2) thin films have been studied with respect to its application as a new capacitor dielectric material in low-power high-density dynamic random access memory ultralarge scale integrated circuits. The TiO2 films were deposited by a low pressure metal organic chemical vapor deposition process with tetra-iso-propyltitanate as the precursor metal organic material. The deposition was performed in a hot wall-type vertical furnace at low temperatures (300-350-degrees-C). Very uniform TiO2 thin films with a dielectric constant up to 70 were prepared showing the polycrystalline structure of anatase after the deposition. The electronic properties of the TiO2-silicon interface were investigated in detail using a metal-insulator-semiconductor structure. Stoichiometry, structure, as well as electrical properties of the TiO2 layers were examined before and after an annealing treatment in oxygen ambient.