Phase and structural characterization of vanadium oxide films grown on amorphous SiO[sub 2]/Si substrates (original) (raw)

The VO 2 multiphases such as V 2 O 5 , VO 2 , and V 2 O 3 are confirmed and the correlations between structural characteristics and growth conditions was investigated using the scanning electron microscopy ͑SEM͒, transmission electron microscopy ͑TEM͒, x-ray diffraction ͑XRD͒, and x-ray photoelectron spectroscopy ͑XPS͒. Also, the electrical characteristics of VO 2-based three terminal devices, attributed to structural and phase changes, are discussed. The spectra of VO 2 have three peaks composed of VO 2 at binding energy (BE)ϭ516.2 eV, V 2 O 3 at BEϭ515.6 eV, and V 2 O 5 at BEϭ517.0 eV. With increase in the growth temperature, crystal quality of VO 2 films improves and approaches single phase of VO 2 , then the peak position shifts to the spectra of oxygen-poor phase (V 2 O 3). With increase in the O 2 flow, the peak position shifts to the spectra of oxygen-rich phase (V 2 O 5). VO 2 films grown at optimal growth conditions have a change in resistivity of the order of 10 2 near a critical temperature, T c ϭ340 K.