氧化法结合快速热处理制备VOx薄膜及其性质研究

采用磁控溅射法在单晶Si〈100〉基底上沉积金属钒(V)薄膜,在高纯氧环境下快速热处理制备具有相变特性的氧化钒(VOx)薄膜.利用X射线衍射仪、X射线光电子能谱和扫描电子显微镜对薄膜结晶结构、薄膜中V的价态与组分及表面微观形貌进行分析,应用四探针测试方法和太赫兹时域频谱技术对样品的电学和光学特性进行测试.结果表明:在一定范围的快速热处理保温温度和保温时间下,都可以制备出具有热致相变特性的氧化钒薄膜,相变前后薄膜的方块电阻变化超过两个数量级,薄膜成分主要由V2O5和VO2混合组成,薄膜中V整体价态不因热处理条件改变而不同.在快速热处理条件范围内,500℃ 25 s左右条件下(中温区)制备出的氧化钒薄膜相变特性最佳,并且对THz波有一定的调制作用.

Preparation of vanadium oxide thin films by oxidation with rapid thermal processing

Vanadium thin films are deposited by magnetron sputter. Then VO_x thin films are fabricated by a series of rapid thermal processes (RTPs) in pure oxygen environment. X-ray diffraction, X-ray photoelectron spectroscopy and scanning electron microscope are employed to analyze crystalline structure of the thin film, phase composition and surface morphology. Electrical and optical properties of VO_x thin film are measured by the four-point probe method and THz time-domain spectroscopy technology, respectively. The results reveale that the VO_x thin film which is composed mainly of V₂O₅ and VO₂ has the properties of phase transition to a certain extent within the RTP condition of heat preservation temperature and time, and the overall valence of vanadium remains unchanged, no matter whether the RTP condition is the same. The best performance VO_x thin film can be obtained under the moderate RTP condition, such as 500 ℃ 25 s, and this film can also modulate the THz wave.