Annealing behaviour of the vanadium oxide films prepared by modified ion beam enhanced deposition

摘要

Different annealing conditions were adopted to anneal the vanadium oxide films prepared by modified Ion Beam Enhanced Deposition (IBED) method. An X-Ray Diffraction (XRD) was used to analyze the orientation of the IBED films and the resistance was tested with temperature change to measure the Temperature Coefficient of Resistance (TCR). Experiments indicated that there existed a critical temperature for crystallization of VO_2, which changed with the different deposition conditions of the IBED method. It is very difficult to obtain VO_2 structure if the annealing temperature was lower than the critical temperature. If the temperature is much higher than the critical temperature or annealing tune is too long, the valence of vanadium in VO_2 film will easily reduce from 4 to low value. The TCR of the IBED VO_2 polycrystalline films annealed in appropriate condition could reach higher than 4%/K.