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题名	雕塑双折射薄膜的制备及光学性能研究
作者	王素梅
学位类别	博士
答辩日期	2007
授予单位	中国科学院上海光学精密机械研究所
导师	邵建达
关键词	雕塑薄膜 斜入射沉积 结构 双折射 有效介质理论
其他题名	Preparation and Optical Properties of Sculptured Birefringence Films
中文摘要	雕塑双折射薄膜是一种新型的、具有各向异性微结构的薄膜。斜入射沉积技术是制备雕塑双折射薄膜的一种方法，它以物理气相沉积为基础，以基片的倾斜和旋转为手段。本文采用斜入射沉积的电子束蒸发技术，制备了ZnS, ZrO2 ,TiO2等常用的雕塑双折射薄膜，观察了薄膜的断面结构和表面结构，研究了薄膜的光学特性与沉积工艺的关系，制备了TiO2薄膜位相延迟片。 对于斜入射沉积的ZnS薄膜，沉积角度较低时为立方相，沉积角度较高时为非晶态。在相同的监控厚度时，随沉积角的增大，薄膜的实际厚度变小，但薄膜的多孔性使其总大于余弦曲线对应的理论厚度。当沉积角度从60º增加到85º时，ZnS薄膜的折射率从2.23减小到1.98，随之对应的薄膜堆积密度从0.95减小到0.76。当沉积角度为80º时，ZnS薄膜的双折射效应最显著，其值为Δn= 0.036。 用斜入射沉积技术制备了具有双折射特性的ZrO2 薄膜。由于斜入射沉积的阴影效应和低的原子扩散速率，200-400℃范围内退火的ZrO2薄膜均表现为非晶态，即斜入射沉积技术推迟了薄膜退火时的结晶温度。当基片没有转动时，得到的是具有倾斜柱状结构的薄膜。随着沉积角度的增加，薄膜的折射率从2.03减小到1.36，堆积密度从0.94降低到0.36。薄膜的双折射在沉积角度为70º时达到最大值Δn=0.037。当基片转速从0逐渐增加到17.3rpm时，可依次得到倾斜柱状结构，螺旋结构和垂直的柱状结构，同时薄膜的折射率和堆积密度也逐渐变大，表明薄膜经历一个逐渐致密化的过程。 采用斜入射技术制备了具有双折射特性的TiO2薄膜。同ZrO2薄膜类似，TiO2薄膜断面为倾斜柱状结构，薄膜气孔率较高。对表面结构的快速傅立叶变换表明斜入射沉积的薄膜具有各向异性的结构特征。随沉积角度的增加，TiO2薄膜的折射率从2.18下降到1.60。在沉积角为65º时薄膜双折射达到最大值Δn= 0.067。当基片转动时，对螺旋结构和垂直柱状结构研究发现，柱体的直径与长度之间存在指数关系： ，其中生长指数p在0.60-0.65范围内。 推导了具有倾斜柱状结构薄膜的有效介质理论模型，计算了薄膜的三个主轴折射率、双折射的大小与薄膜堆积密度的关系。研究发现，不同堆积密度下的三个主折射率的变化规律为： 。薄膜的双折射在沉积角度60-70º之间达到最大值。实验结果与有效介质理论得到的计算结果一致。 制备了TiO2薄膜位相延迟片。当波长从430nm变化到850nm时，65º沉积TiO2薄膜的位相延迟量从81º变化到29º。在这个范围内，通过调节薄膜厚度和波长，可以得到所需的薄膜位相延迟量。
英文摘要	Sculptured birefringence thin film is a novel kind of film with anisotropic structure. Glancing angle deposition technique is one of the fabrication methods for sculptured birefringence thin film. In this technique, oblique angle deposition and substrate rotation are employed to obtain the anisotropy structure of thin films. In this thesis, the nanostructured ZnS, ZrO2, TiO2 films were prepared by electron beam evaporation with the glancing angle deposition. The cross-section and surface morphology of films were observed. The relationship between optical properties and structure of sculptured birefringence film was also investigated. The sculptured ZnS films is cubic phase in low oblique angle, but amorphous in high oblique angle. Surface roughness increases with the increase of oblique angle. At the same monitoring thickness, the thickness of ZnS films decreases with the increase of oblique angle. But it is larger than the theoretical thickness due to the porous structure. As oblique angle increases from 0ºto 85º, the refractive index of ZnS films decrease from 2.23 to 1.98, and the packing density decreases from 0.95 to 0.76. The optical birefringence reaches a maximum of 0.036 at the oblique angle of 80º. The sculptured birefringence ZrO2 films were prepared by electron beam evaporation. ZrO2 films annealed at 200-400 ℃ are amorphous due to the shadowing effect and limited adatom diffusion during film growth. The slanted columnar structure was obtained without the rotation of substrate. With the increase of oblique angle, the refractive index of ZrO2 films decreases from 2.03 to 1.36, and the packing density decreases from 0.94 to 0.36. The maximum birefringence of 0.037 was obtained at the oblique angle of 70º. Microstructure evolves from slanted columnar structure to helical structure and pillar structure, as substrate rotational speed increases from zero to 17.3 rpm. Meanwhile, refractive index and packing density increase, indicting a more compact structure evolution from slanted columnar to pillar structure. Similar to ZrO2, TiO2 films also exhibits structure of slanted column. Fast Fourier transform of the surface morphology indicates the anisotropic structure of sculptured TiO2 films. With the increase of the oblique angle, refractive index decreases from 2.18 to 1.60, lower than that of the bulk materials. The maximum birefringence of 0.067 was obtained at the oblique angle of 65º. The relationship of column diameter and column length was investigated for the helical structure and pillar structure. An exponential function was found, in which p is at the range of 0.60-0.65. The effective refractive indices of sculptured birefringence films, containing dielectric and voids in slanted columnar structure, are modeled by effective medium theory. The relationship among three principal refractive indices, birefringence and oblique angle was investigated. The relationship was found. The simulation results indicate that the maximum birefringence was obtained at the oblique angle of 60-70º, which is in agreement with experiments. Finally, the TiO2 phase retarder was fabricated. For TiO2 film deposited at α=65º, the phase retardance change from 81º at 430nm to 29º at 850nm. In these range, we can obtain the request phase retardance by tailoring the film thickness and applied wavelength.
语种	中文
内容类型	学位论文
源URL	[http://ir.siom.ac.cn/handle/181231/15493]
专题	上海光学精密机械研究所_学位论文
推荐引用方式 GB/T 7714	王素梅. 雕塑双折射薄膜的制备及光学性能研究[D]. 中国科学院上海光学精密机械研究所. 2007.

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