射频磁控溅射纳米二氧化钒薄膜的电致相变特性

Electric Field-Induced Phase Transition of Nanoparticle Vanadium Dioxide Thin Films Prepared by Radio Frequency Magnetron Sputtering

采用射频磁控溅射方法和热处理工艺制备了二氧化钒(VO2)薄膜,并制作了金属钨/VO2/金属钨三明治结构,通过改变金属钨/VO2/金属钨三明治结构中VO2薄膜与金属钨电极的接触面积,研究了VO2薄膜的电致相变特性.采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、四探针和半导体参数测试仪对VO2薄膜的结晶取向、表面形貌、方块电阻和I-V特性进行了测试.实验结果表明,所制备的VO2薄膜为具有热致相变特性的单一组分VO2纳米薄膜,在热激励下,薄膜的方块电阻相变幅度达到2个数量级;在电压的激励下,VO2薄膜与金属钨的接触面积为12μm×12μm时,电流发生跳变的阈值电压为9.4 V,随着接触面积的减小,阈值电压也逐渐降低.

Vanadium dioxide （VO2 ） thin films and a tungsten/VO2/ tungsten sandwich structure were prepared by radio frequency magnetron sputtering method and thermal annealing. The effects of contact area on electric field-induced phase transition of VO2 were investigated by varying the contact area between tungsten and VO2 in tungsten/VO2/tungsten sandwich structure. X-ray diffraction （XRD） , scanning electron microscope （SEM） , four probes and semiconductor device analyzer were used to analyze the crystal structure, moIphology, squared resistance and I-V properties of VO2. The results show that the film is only composed of VO2 and has thermal-induced phase transition property, and its squared resistance reaches 2 orders of magnitude when heated ; that the current sharply changes when a static voltage is applied onto the electrodes, and the threshold voltage is 9.4 V when the contact area is 12μm×12um, and the threshold voltage decreases as the contact area decreases.