Postdeposition annealing on VO2 films for resistive random-access memory selection devices

Abstract

In this study, VO2 films were deposited by thermal atomic layer deposition with vanadium oxytri-isopropoxide as a vanadium precursor and deionized water as a reactant. Postdeposition annealing was performed in order to enhance the crystallinity of VO2 films X-ray diffraction, scanning electron microscopy, atomic force microscopy, x-ray photoelectron spectroscopy, and transmission electron microscopy were used to characterize the physical and chemical properties of the as-deposited and annealed VO2 films. The results indicated that postdeposition annealing enhanced the crystallinity of the VO2 films and increased the area ratio of V4+. Finally, the electrical properties of the VO2 films were analyzed using a semiconductor parameter analyzer. The I-on/I-off ratio increased from 10(2) to 10(4) during postdeposition annealing at 450 degrees C. There were also significant increases in the hysteresis window.