Measuring thermal expansion variations in ULE glass with interferometry
Measuring thermal expansion variations in ULE glass with interferometry
复制标题
使用干涉测量法测量 ULE 玻璃的热膨胀变化
DOI：
10.1117/12.535133
复制
发表时间：
2004
期刊：
影响因子：
--
通讯作者：
Andrew W. Fanning
中科院分区：
文献类型：
--
作者：
Brian L. Harper;K. Hrdina;W. D. Navan;J. Ellison;Andrew W. Fanning
康宁最近的工作重点是热膨胀系数（CTE）测量的改进。由于EUVL技术所需的独特环境，EUVL光学器件（和光掩模）需要非常均匀的CTE特性，目标变化小于1 ppb/K。到目前为止，由于缺乏精度，还没有实用的计量技术可以准确地验证材料是否符合这些要求。康宁之前已经通过发现ULE（注册商标）玻璃中折射率与CTE之间的相关性，引入了使用相位测量干涉法（PMI）测量ULE（注册商标）玻璃中CTE的想法。然而，有必要对相关性进行细化。本文重点介绍了朝着这一目标取得的进展，这导致了非破坏性测量峰谷CTE变化的能力，在57万亿分之一每开氏度（ppt/K）在可能的空间分辨率在微米范围内厚或薄的样品。
Corning has focused its recent efforts on coefficient of thermal expansion (CTE) metrology improvements. Due to the unique environment required for EUVL technology, EUVL optics (and photomasks) require extremely uniform CTE properties, with targeted variations of less than 1ppb/K. Until now, no practical metrology technique existed that could accurately verify if a material met such requirements due to the lack of precision. Corning has previously introduced the idea of measuring CTE in ULE (registered trademark) Glass using Phase Measuring Interferometry (PMI) by discovering the correlation between refractive index and CTE in ULE (registered trademark) Glass. However, refinement of the correlation was necessary. This paper focuses on the progress made towards that end, which has resulted in the ability to non-destructively measure peak to valley CTE variations to within 57 parts per trillion per degree Kelvin (ppt/K) at possible spatial resolutions in the micron range on thick or thin samples.