Structural and electrical properties of Ta2O5 thin films deposited on Si(1 0 0) from Ta(OC2H5)5 precursor

Thin (<7.5 nm) Ta2O5 films were grown at atmospheric pressure on n-Si(1 0 0) wafers by chemical vapour deposition using Ta(OC2H5)5 as precursor. X-ray photoemission spectroscopy and X-ray reflectivity were used to study the composition of the films, as-deposited and annealed at 600 and 800 °C in a furnace in N2 and O2. It appears that the thickness of the interfacial SiO2 layer depends on the temperature and not on the time of exposure to O2. After crystallization of Ta2O5, detected at 800 °C by X-ray diffraction, our electrical measurements show a decrease of the leakage current.