Atomic Layer Deposition Barrier Layers on Large Silver-coated Mirrors

大型镀银反射镜上的原子层沉积阻挡层

• 批准号: 1407353
• 负责人: Andrew Phillips
• 金额: $ 59.01万
• 依托单位: University of California-Santa Cruz
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-08-15 至 2020-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1407353&HistoricalAwards=false
• 关键词: Atomic; Layer; Deposition; Barrier; Layers

Even with all the dazzling technology that has been brought to bear on astronomical observations, and the furthering of that technology in turn that has been inspired by astronomical applications, it is still difficult to make a metal mirror coating that is highly reflective at all optical wavelengths yet durable enough to last in field use. Traditional aluminum coatings are durable, but not highly reflective at all wavelengths. Silver has better all-wavelength reflectance, but will develop pin-holes and flake away in a short time unless clever methods are used to deposit it on a glass mirror blank. The development of such methods is the goal of this investigation, and a goal with far-reaching applications to many different kinds of future instruments.The essence of the technical approach to improved durability, high-reflectance silver coatings, is Atomic Layer Deposition (ALD). ALD is a relatively new, sequential chemical vapor process taking advantage of self-limiting surface reactions. ALD coatings have several desirable properties, notably excellent film structure, conformal coverage, and excellent thickness uniformity and control. ALD is now a mature process used widely in the silicon wafer industry. To date, however, ALD has been limited to relatively small substrate sizes and is rarely used for optics, owing to its relatively slow speed. This project will place ALD barrier layers on top of silver deposited by conventional physical vapor deposition (PVD) to get films more durable than PVD alone. The process proposed is a thus hybrid process, with most of the coating done with PVD processes and the barrier layers added with the ALD system. Improvements in ALD deposition speed are also planned to allow coating of larger substrates in reasonable times.This project has immense broader impacts in that it enables dramatically improved practical performance of a vast range of astronomical instrumentation. In addition, students will be involved, and there is a strong commitment to plain-language explication of the research and its results.Funding for this project is being provided by NSF's Division of Astronomical Sciences through its Advanced Technologies and Instrumentation program.

即使拥有所有令人眼花ant乱的技术，这些技术已在天文观测上得到了影响，而该技术反过来又受到了天文学应用的启发，仍然很难制作一种金属镜涂层，在所有光学波长上都具有很高的反射性，但足以在现场使用中持久耐用。传统的铝制涂层耐用，但在所有波长上都不是反射性的。 银具有更好的全波长反射率，但是除非使用巧妙的方法将其存放在玻璃镜上，否则会在短时间内产生针孔和剥落。 这种方法的开发是该调查的目标，并且在许多不同类型的未来工具上采用深远的应用程序。提高耐用性，高再耐力银涂层的技术本质是原子层沉积（ALD）。 ALD是一种利用自限制的表面反应的相对较新的，顺序的化学蒸气过程。 ALD涂层具有几种理想的特性，尤其是出色的膜结构，保形覆盖范围以及出色的厚度均匀性和对照。 ALD现在是硅晶圆行业中广泛使用的成熟过程。但是，迄今为止，ALD仅限于相对较小的底物尺寸，由于其相对较慢的速度，因此很少用于光学元件。 该项目将将ALD屏障层放在传统物理蒸气沉积（PVD）沉积的银顶部，以使膜比单独的PVD更耐用。 提出的过程是这样的混合过程，大多数涂层都使用PVD过程进行，并且与ALD系统添加了屏障层。 还计划在合理时期内提高ALD沉积速度，以允许更大的基材涂层。该项目具有巨大的广泛影响，因为它可以极大地改善各种天文学仪器的实践表现。 此外，学生还将参与其中，并且对研究及其结果的简单语言阐释有着坚定的承诺。该项目的资金由NSF的天文科学部通过其先进的技术和仪器计划提供。