微缺陷对薄膜滤光片环境稳定性的影响

用热蒸发方法沉积了薄膜滤光片.并将样品分别在去离子水中浸泡10天和30天.通过分光光度计、光学暗场显微镜、及扫描电子显微镜等多种测试手段,对诱导透射滤光片在潮湿环境下的稳定性进行了研究.实验发现,在潮湿环境下滤光片产生的膜层分离都是从薄膜中微缺陷点处开始发生和发展的,微缺陷是影响滤光片环境稳定性的重要原因之一,其中杂质和针孔是滤光片中两种最常见的微缺陷.EDS能谱分析进一步表明,薄膜中杂质缺陷成分即为Al2O3膜料本身,所以不能推测,薄膜沉积中的喷溅可能是微缺陷产生的根本原因,抑制喷溅可以有效提高薄膜滤光片的环境稳定性.最后还用扩散理论对微缺陷引起滤光片失效的机理进行了分析.

Influence of the Microdefect on the Environment Stability of Thin Film Filters

Thin film filters were prepared by evaporation method, and the samples were soaked in DI-water for 10 days and 30 days respectively. By using spectral photometer, dark field microscope, and scanning electron microscope, stability of induced transmission filters in moisture environment was studied. The experiment results show that the layers delaminations of filters often initiate and expand from microdefect sites in the films in moisture environment. Microdefect in thin films is one of the most important influence factors on the filters environment stability, and impurity and pinhole are two main sorts of defects in thin film filters. EDS energy spectra analysis indicates that component of the impurity is Al_2O_3 coating material itself. So it is reasonable to deduce that the sputtering in film position process may be the original reasons for the defects generation, and sputtering restraining is a useful method to improve the stability of the optical filters. At last, the diffusion theory was used to analysis the mechanism of the defect-induced failure of the thin film filters.