Effect of vanadium layer thickness on the phase transition of fabricated vanadium dioxide thin films

Oxidizing a thin Vanadium layer is one way to develop VO₂; however, the different thicknesses of deposited Vanadium thin layers respond differently to the same annealing parameters during the transformation of vanadium into vanadium dioxide and influence the final VO₂ layer. In this work, we investigated how pure Vanadium layers with thicknesses of 25 nm, 40 nm, 55 nm, 70 nm, and 90 nm will respond to the same annealing parameters by characterizing the final oxidized layer. E-beam was used to deposit the Vanadium layers, then annealed under N₂ and O₂ to form VO₂. X-ray diffraction (XRD) and Raman spectroscopy were used to analyze phase composition and phase fractions. Fourier transform infrared (FTIR) was used to investigate the phase change temperature along with the sample hysteresis curves during heating and cooling. Focused Ion Beam (FIB) equipped with Energy Dispersive Spectroscopy (EDS) was used to investigate the thickness and O₂ diffusivity.