退火对TiO_2和Ta_2O_5光学薄膜的结构和光学性质的影响

Effect of Annealing on the Structure and Optical Properties of the TiO_2 and Ta_2O_5 Optical Films

将反应磁控溅射制备的二氧化钛和五氧化二钽薄膜在温度400℃的条件下退火处理.利用X射线衍射、原子力显微镜和分光光度计等设备对退火后薄膜的结构、表面形貌和光学性质进行研究.实验表明:退火后的T iO2薄膜为多晶结构,薄膜的表面粗糙度、折射率和消光系数都出现增大现象.然而,对于退火后的T a2O5薄膜,它的结构还是非晶态,薄膜的表面粗糙度比退火前小;同时折射率和消光系数均有减小.这些结果说明薄膜退火后的特性与薄膜材料的内部结构及结晶转变温度等有密切相关.

TiO2 and Ta2O5 optical films, which were prepared by reactive magnetron sputtering technique, have been annealed at 400 ℃ in air. The microstructure, morphology and optical properties of the annealed films were investigated by X-ray diffraction, atomic force microscopy and spectrophotometer. The annealed TiO2 film is polycrystalline, and the surface roughness is larger than that of the as-deposited film. Additionally, the refractive index and extinction coefficient of the TiO2 film increase after the annealing. However, for the annealed Ta2O5 film, the structure is amorphous and the surface is smoother than that of the as-deposited film, and the refractive index and extinction coefficient decrease after the annealing. The results show that the properties of the annealed films are determined not only by the annealing temperature, but also by the structure and crystalline properties of the films.