Ag膜的特性及金属基宽角宽带高反膜的研究
文献类型：学位论文
| 作者 | 孙喜莲 |
| 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 | 金属薄膜 高反射膜 倾斜入射 宽光谱 应力 附着力 |
| 其他题名 | Study on the Properties of Ag Coatings and Broadband High-reflection Metal-dielectric Multilayer Coatings at Oblique Angles of Incidence |
| 中文摘要 | 本文系统地研究了Ag薄膜的微结构及光学特性与沉积技术和薄膜厚度的关系，分析了不同过渡层对Ag膜光学性质和力学性质的影响。研究了三种反射膜膜系结构的特点，设计了用于可见光波段的宽带宽角金属基多层介质高反射薄膜和全介质高反射膜，并针对具体的要求设计制备了一定带宽的金属基介质高反射膜。论文的主要工作有： 1、系统研究了磁控溅射和热蒸发两种沉积技术制备的单层Ag膜的微结构及光学性能的厚度效应，并对两种沉积技术制备的Ag膜的物理性能进行了比较，结果发现，磁控溅射淀积的Ag膜的聚集密度相对高些，形成连续膜所需的最小膜厚相对小些；相同厚度的Ag膜，前者的反射率高于后者的；不同沉积方法制备的Ag膜的光学常数也有明显不同，主要表现为薄膜厚度较薄时其折射率n值和消光系数k值有较大差异，磁控溅射沉积Ag膜的折射率n值小于热蒸发的，消光系数k值则相对较大。 2、研究了过渡层材料及其厚度对不同沉积技术制备的Ag膜的微结构、光学性能和力学性能的影响。通过分析发现：采用热蒸发技术时，过渡层材料以Al2O3为最佳，一定厚度的Al2O3过渡层可以提高Ag膜光学性能的稳定性，增强薄膜与基底之间的附着力，在我们的实验条件下，此最佳厚度值为24nm左右，此时薄膜的应力也最小；采用磁控溅射技术时，过渡层材料以Cr为最佳，一定厚度的Cr过渡层可以提高Ag膜的光学性能及其稳定性，增强Ag膜的附着性能，在我们的实验条件下，此最佳厚度值为17nm左右。这为过渡层的合理利用提供有力保障。 3、系统分析了三种反射膜的膜系结构特点，设计了三种用于可见光区的宽角度宽光谱反射膜，同时对其进行了容差分析，发现金属反射膜对误差不敏感，适用于对光性要求不高的器件中；采用多个不同中心波长的反射带叠加的方法设计的膜层数为64层，入射角在0－60o范围内反射率达99%以上的介质型反射膜，由于非规整膜层数较多，有一定的制备难度；金属基介质反射膜是采用金属膜上叠加多层低高折射率材料的介质膜来实现的，膜层数为26层，在420－680nm波段，入射角在0－50o范围内反射率达99%以上，该膜系结构容差大，稳定性强。 4、采用金属基介质膜系设计并制备了一种性能优良的宽带高反射膜，所制备的反射膜在可见区475－640nm波长范围内反射率达到99%以上，满足了凹月面形状基片上的光学性能要求，即在此基片上薄膜厚度分布不均匀的情况下，每一点在中心波长532nm处的反射率都能得到满足。 |
| 英文摘要 | This work focused on studying of the relation between microstructure, properties and deposition methods, film thickness of Ag coatings, and on analyzing the influence of different transitional layer on the optical and mechanical properties of Ag coatings. The bandwidth and angular properties of three coatings were discussed. Metal-dielectric multilayer and all-dielectric multilayer coatings used in the visible spectral region were designed. And according to technique requirements a metal-dielectric multilayer coatings with special bandwidth was designed and fabricated in this paper. Our works and conclusions were organized as follows: Firstly, a series of different thickness of Ag films were deposited on glass substrates by magnetron sputtering and thermal evaporation. The influence of preparation methods and deposition parameters on microstructure and optical properties of the Ag films was investigated. The physical performances of Ag films prepared by these deposition methods were compared. It is found that the films prepared by magnetron sputtering are much more dense and the minimal continuous thickness is thinner relative to that of films by evaporation. In addition, the films’ refractive index n value was lower and the extinct index k value was higher than the evaporated films’. These results provide a basis for the preparation of device. Secondly, the influence of transitional layer and preparation methods on the optical and mechanical properties was investigated. The results showed that Al2O3 interlayer between Ag film and substrate improved the adhesion compared with Cr interlayer when deposited by evaporation in ambient temperature. It was also found that the thickness of transitional layer has an obvious effect on the reflectance of Ag films. With the increase of the Al2O3 thickness, the reflectance of Ag films increase to a maximum value and then decrease. The optimal thickness at the peak was about 24nm at which the residual stress was the smallest in our experiment. On the other hand, the same effect of Cr transitional layer on the optical and mechanical properties was found when Ag films were deposited by magnetron sputtering: the adhesion was strengthened and the reflectance was enhanced and stabilized with a definite thickness of Cr transitional layer. The optimal thickness was approximate 17nm in our experiment. This provides a basis for the proper utilization of transitional layer. Thirdly, three types of broadband high reflectors for a range of angles in visible spectral region were analyzed systematically and designed based on single opaque metal layers or on all-dielectric and metal-dielectric multilayer systems. The relations between reflectance deviation and layer thickness, refractive index were discussed. It was shown that there is no wavelength shift of the spectral features that is so characteristic of all-dielectric multilayer systems. The disadvantage of opaque Ag layers is that their reflectance may be somewhat lower than desired. One can design broad-bandwidth high reflectors by connecting the band edges of quarter-wave dielectric stacks with different center wavelength, while small ripples appear in the reflection band. The way to reduce them is to increase the number of periods of the stack or to refine the design, resulting in a non-quarter-wave multilayer stack. Based on the theory, a wideband high reflector of 64-layer system with reflectance above 99% in the visible spectral region and with angles of incidence ranging between 0－60o was designed. It is shown that the design coating is not easy to fabricate due to many non-quarter wavelength layers. And another wideband metal-dielectric high reflectors with reflectance above 99% in the 420－680nm spectral region and with angles of incidence ranging between 0－50o was designed by overcoating Ag with a suitable dielectric multilayer system. It is found that the stability of the stack is fine. At last, a wideband metal-dielectric high-reflectance coating in the spectral region 475－640nm with reflectance above 99% was designed and prepared by thermal evaporation. These characters can fit the demand of the coatings on an irregular shaped glass substrate while the film thickness is uniform on the substrate. |
| 语种 | 中文 |
| 源URL | [http://ir.siom.ac.cn/handle/181231/15498]  |
| 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 | 孙喜莲. Ag膜的特性及金属基宽角宽带高反膜的研究[D]. 中国科学院上海光学精密机械研究所. 2007. |
入库方式： OAI收割
来源：上海光学精密机械研究所
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。