通过引入Si02氧化物缓冲层,在金属Pt电极上利用射频磁控溅射技术成功制备出高质量的V02薄膜.详细研究了Si02厚度对V02薄膜的晶体结构、微观形貌和绝缘体一金属相变(MⅡ)性能的影响.结果表明厚度0.2μm以上的Si02缓冲层能够有效消除V02薄膜与金属薄膜之间的巨大应力,制备出具有明显相变特性的V02薄膜.当缓冲层达到0.7μm以上,获得的薄膜具有明显的(011)晶面择优取向,表面平整致密,相变前后电阻率变化达到3个数量级以上.基于该技术制备了Pt.Si02/V02-AU三明治结构,通过在垂直膜面方向施加很小的驱动电压,观察到明显的阶梯电流跳跃,证实实现了电致绝缘体一金属相变过程.该薄膜制备工艺简单,性能稳定,器件结构灵活可应用于集成式电控功能器件.
High-quality VO2 thin films are deposited on the metal platinum (Pt) electrode buffered by silicon dioxide (SiO2) using radio frequency magnetron sputtering. The effect of the thickness of SiO2 on the the crystal structure, morphology and metal-insulator transition (MIT) performance of the films are discussed. Results show that SiO2 buffer layer with a thickness of 0.2 ~m can effectively eliminate huge stress between the VO2 film and the metal film; and the VO2 thin film with the distinct MIT are deposited. When the buffer layer reaches more than 0.7 Ixm, the VO2 film has a distinct (011) preferred orientation, the smooth surface and compact nanostructure, and the resistance change reaches more than three orders of magnitude. At the same time, Pt-SiO2/VO2-Au sandwiched structure is achieved to test the current versus voltage curves, in which can be seen several distinct steps of current caused by the voltage perpendicular to the plane of a VO2 film. The result confirms the electrically-driven metal-insulator transition. Due to the high-quality VO2 and the flexible device structure, the VO2/Pt-SiO2 can be widely used for large-scale integrated electronic control devices.