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

Thin (<7.5 nm) Ta ₂O ₅ films were grown at atmospheric pressure on n-Si(1 0 0) wafers by chemical vapour deposition using Ta(OC ₂H ₅) 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 N ₂ and O ₂. It appears that the thickness of the interfacial SiO ₂ layer depends on the temperature and not on the time of exposure to O ₂. After crystallization of Ta ₂O ₅, detected at 800 °C by X-ray diffraction, our electrical measurements show a decrease of the leakage current.