VO2 Films Prepared by Atomic Layer Deposition and RF Magnetron Sputtering

Among the many vanadium suboxides and different stoichiometries, VO2 has received considerable attention due to its remarkable metal-insulator transition (MIT) behavior, which causes a significant reversible change in its electrical and optical properties occurring across the phase transition at 67 oC. The initially amorphous VO2 thin films were fabricated by the emerging, Atomic Layer Deposition (ALD) technique with (tetrakis[ethylmethylamino]vanadium) {V(NEtMe)4} as precursor and H2O vapor as oxidation agent. For benchmarking we have also used the RF Magnetron Sputtering technique to deposit metallic vanadium thin films, which were later oxidized during furnace annealing. Post annealing of the as-deposited ALD films was performed in order to obtain the technologically important form of crystallized VO2 thin films using furnace annealing. All film depositions were carried out on native oxide covered (100) Si substrates. The conditions for successful furnace annealing are reported in terms of temperature and annealing gas composition and the physical characterization results are presented.