1 research outputs found
Effect of Vanadium Thickness and Deposition Temperature on VO2 Synthesis using Atmospheric Pressure Thermal Oxidation
Vanadium dioxide (VO2) is a phase transition material that undergoes a
reversible insulator-metal phase transition at ~ 68 C. Atmospheric pressure
thermal oxidation (APTO) of vanadium (V) is a simple VO2 synthesis method in
which V thin film is oxidized in open air. For an optimum oxidation duration,
VO2 films are obtained with good phase transition properties. We recently
reported a modified APTO process using a step temperature profile for oxidation
(Thin Solid Films 706, 138003 (2020)). We demonstrated an ultra-low thermal
budget synthesis of VO2 thin films with good electrical and optical phase
transition properties. For a 130 nm room-temperature RF sputtered V thin film,
an optimum oxidation duration of ~ 30 s was obtained. In this work, we study
how the starting V film thickness and deposition temperature affects the
optimum oxidation duration. V thin films of varying thickness (15-212 nm) and
120 nm thick V films with varying deposition temperature (~27-450 C) are
prepared using RF magnetron sputtering. These films are oxidized for different
oxidation durations and characterized using Raman and four-probe measurements
to find the optimum oxidation duration for each deposition condition. We find
that the optimum oxidation duration increases with the increase in V film
thickness and V deposition temperature. We model the effect of V film thickness
and deposition temperature on the optimal oxidation time using a parabolic law
which can be used to obtain the optimal oxidation times for intermediate V
thicknesses/deposition temperatures.Comment: 17 pages, 6 figure