Vanadium oxide thin films produced by magnetron sputtering from a V2O5 target at room temperature

Vanadium oxide thin films were grown by RF magnetron sputtering from a V2O5 target at room temperature, an alternative route of production of vanadium oxide thin films for infrared detector applications. The films were deposited on glass substrates, in an argon–oxygen atmosphere with an oxygen partial pressure from nominal 0% to 20% of the total pressure. X-ray diffraction (XRD) and X-ray photon spectroscopy (XPS) analyses showed that the films were a mixture of several vanadium oxides (V2O5, VO2, V5O9 and V2O3), which resulted in different colors, from yellow to black, depending on composition. The electrical resistivity varied from 1 mΩ cm to more than 500 Ω cm and the thermal coefficient of resistance (TCR), varied from −0.02 to −2.51% K−1. Computational thermodynamics was used to simulate the phase diagram of the vanadium–oxygen system. Even if plasma processes are far from equilibrium, this diagram provides the range of oxygen pressures that lead to the growth of different vanadium oxide phases. These conditions were used in the present work.