磁控溅射法制备二氧化钒薄膜及其性能表征

Preparation and Characterization of Vanadium Dioxide Films by Magnetron Sputtering

摘要:

采用射频反应磁控溅射法在镀有SiO2膜的钠钙硅玻璃基片上沉积了二氧化钒（VO2）薄膜。研究了在300 ℃沉积温度下，不同溅射时间(5~35 min)对VO2薄膜结构和性能的影响。用X射线衍射、扫描电镜、自制电阻测量装置、紫外-可见光谱仪、双光束红外分光光度计对薄膜结构、形貌、电学及光学性能进行了表征。结果表明：薄膜在低温半导体相主要以四方相畸变金红石结构存在，在（011）方向出现明显择优取向生长，随着溅射时间的延长，晶粒生长趋于完整，晶粒尺寸增大；对溅射时间为35 min的薄膜热处理，发现从室温到90 ℃范围内，薄膜方块电阻的变化接近3个数量级；由于本征吸收，薄膜在可见光范围透过率较低，且随膜厚的增加而逐渐降低；在1500~4000 cm-1波数范围内，原位测量薄膜样品加热前后（20和80 ℃）的红外反射率，发现反射率的变化幅度随着膜厚增加而提高，最高可达59%。

Abstract:

Vanadium dioxide (VO2) films were deposited on 300 ℃ SiO2 coated soda-lime glass substrates by rf-reactive magnetron sputtering. The influences of sputtering time (from 5 to 35 min) on the microstructure, the morphology and electrical and optical performances of the films were investigated and characterized by X-ray diffraction, scanning electron microscopy, resistance testing, ultraviolet-visible spectrometry and doubled beam infrared spectrometry. The obtained results show that the films present a distortion rutile structure and preferred orientation of (011), the crystalline growth trends to completion, and the grains size increase with the increase of sputtering time. Heat-treating the films from room temperature to 90 ℃ for 35 min, the change of the film sheet resistance is nearly 103 magnitudes. The films have low visible transmittance due to the intrinsic absorption, and the visible transmittance decreases with the increase of film thickness. In the range from 1500 to 4000 cm-1, the infrared reflectance of the films heat-treated at 20 ℃ and 80 ℃ shows that the variation of reflectance increases with the increase of film thickness, and the maximum of which is as high as 59%.