Stability of dielectric multilayer coatings for the Vacuum ultraviolet

Laser Damage Pub Date : 2019-11-20 DOI:10.1117/12.2536346

Weili Zhang, Zhenkun Yu, Ruijuan Zhu, Xiaofeng Liu, Kui Yi, Meiping Zhu, J. Shao

{"title":"Stability of dielectric multilayer coatings for the Vacuum ultraviolet","authors":"Weili Zhang, Zhenkun Yu, Ruijuan Zhu, Xiaofeng Liu, Kui Yi, Meiping Zhu, J. Shao","doi":"10.1117/12.2536346","DOIUrl":null,"url":null,"abstract":"Vacuum ultraviolet (VUV) reflective coatings play an important role in many high-tech fields including cosmic physics, space research, life science and synchrotron radiation. In this research, the emphasis are focused on the aging effect of 135.6nm high reflective coatings. The coatings were deposited by resistive heating method based on Lanthanum fluoride (LaF3) and Aluminum fluoride (AlF3). Optical property, surface morphology and roughness, and composition were characterized in different period after deposited. Due to the porous structure and the worse stability of lanthanum fluoride, the content of C and O element increased in LaF3 thin films during aging process. On one hand, the content of C and O are the hydrocarbon contamination from environment and packing boxes. On the other hand, due to the oxidation of film materials, the fluorides will turn into oxyfluoride, which will increase O content. As a result, there will be an increase of absorption and a decrease of reflectance of the 135.6nm high reflective coating. The surface roughness decreased which led to the reduction of scattering and the rise of reflectivity. There will be LaF3-AlF3 mixed layers between interfaces because of interface diffusion, which will further reduce the film performance.","PeriodicalId":202227,"journal":{"name":"Laser Damage","volume":"32 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2019-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Laser Damage","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1117/12.2536346","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}

引用次数: 0

Abstract

Vacuum ultraviolet (VUV) reflective coatings play an important role in many high-tech fields including cosmic physics, space research, life science and synchrotron radiation. In this research, the emphasis are focused on the aging effect of 135.6nm high reflective coatings. The coatings were deposited by resistive heating method based on Lanthanum fluoride (LaF3) and Aluminum fluoride (AlF3). Optical property, surface morphology and roughness, and composition were characterized in different period after deposited. Due to the porous structure and the worse stability of lanthanum fluoride, the content of C and O element increased in LaF3 thin films during aging process. On one hand, the content of C and O are the hydrocarbon contamination from environment and packing boxes. On the other hand, due to the oxidation of film materials, the fluorides will turn into oxyfluoride, which will increase O content. As a result, there will be an increase of absorption and a decrease of reflectance of the 135.6nm high reflective coating. The surface roughness decreased which led to the reduction of scattering and the rise of reflectivity. There will be LaF3-AlF3 mixed layers between interfaces because of interface diffusion, which will further reduce the film performance.

查看原文本刊更多论文

真空紫外介质多层涂层的稳定性

真空紫外(VUV)反射涂层在宇宙物理、空间研究、生命科学和同步辐射等高科技领域发挥着重要作用。本研究重点研究了135.6nm高反射涂层的老化效应。以氟化镧(LaF3)和氟化铝(AlF3)为基材，采用电阻加热法制备涂层。表征了沉积后不同时期的光学性能、表面形貌和粗糙度以及成分。由于氟化镧的多孔结构和较差的稳定性，在老化过程中，LaF3薄膜中C和O元素的含量增加。C和O的含量一方面是环境和包装箱的烃污染。另一方面，由于薄膜材料的氧化，氟化物会变成氟氧化物，这将增加O含量。因此，135.6nm高反射涂层的吸收会增加，反射率会降低。表面粗糙度降低导致散射减少，反射率上升。由于界面扩散，界面之间会形成LaF3-AlF3混合层，进一步降低膜的性能。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Laser Damage

自引率

0.00%

发文量