Nanostructured V2O5 thin films deposited at low sputtering power

Vanadium pentoxide (V2O5) films were deposited on cleaned silicon (Si) and glass substrates by reactive dc magnetron sputtering at different sputtering powers (50-70 W) at room temperature (RT). Microstructural, morphological, topological, optical and electrical properties of the films were studied by X-ray diffraction (XRD), field emission-scanning electron microscope (FE-SEM), atomic force microscopy (AFM), UV-vis spectroscopy and four point probe method (FPP) respectively to analyze the impact of the sputtering power on the properties of V2O5 films. The average grain size of the films increased from 77 to 90 nm on increasing the sputtering power and also all the deposited films showed characteristic peaks in the range 920-970 cm−1 in Fourier transform infrared spectroscopy (FT-IR) spectrum corresponding to the V2O5. The optical bandgap and electrical resistivity of the films were found to be decreased while increasing the sputtering power. Four probe electrical resistivity measurements show the typical semiconductor behavior of the deposited film. The film deposited at 70 W sputtering power at RT exhibited a temperature coefficient of resistance (TCR) of −1.22%/°C and resistivity (Rs) of 22 Ω m. The low sputtering power used and room temperature deposition of the V2O5 films in the present investigation is suitable for complementary metal oxide semiconductor (CMOS) fabrication.