Ghim Young-Sik, Rhee Hyug-Gyo, Davies Angela
Center for Space Optics, Korea Research Institute of Standards and Science (KRISS), Science Town, Daejeon, 34113, South Korea.
Department of Science of Measurement, University of Science and Technology(UST), Science Town, Daejeon, 34113, South Korea.
Sci Rep. 2017 Sep 19;7(1):11843. doi: 10.1038/s41598-017-11825-6.
With the growth of 3D packaging technology and the development of flexible, transparent electrodes, the use of multilayer thin-films is steadily increasing throughout high-tech industries including semiconductor, flat panel display, and solar photovoltaic industries. Also, this in turn leads to an increase in industrial demands for inspection of internal analysis. However, there still remain many technical limitations to overcome for measurement of the internal structure of the specimen without damage. In this paper, we propose an innovative optical inspection technique for simultaneous measurements of the surface and film thickness corresponding to each layer of multilayer film structures by computing the phase and reflectance over a wide range of wavelengths. For verification of our proposed method, the sample specimen of multilayer films was fabricated via photolithography process, and the surface profile and film thickness of each layer were measured by two different techniques of a stylus profilometer and an ellipsometer, respectively. Comparison results shows that our proposed technique enables simultaneous measurements of the top surface and its underlying film surfaces with high precision, which could not be measured by conventional non-destructive methods.
随着3D封装技术的发展以及柔性透明电极的开发，多层薄膜在包括半导体、平板显示器和太阳能光伏产业在内的整个高科技产业中的应用正在稳步增加。此外，这反过来又导致了对内部分析检测的工业需求增加。然而，在无损检测样品内部结构方面，仍有许多技术限制需要克服。在本文中，我们提出了一种创新的光学检测技术，通过计算宽波长范围内的相位和反射率，同时测量多层膜结构各层对应的表面和膜厚。为了验证我们提出的方法，通过光刻工艺制作了多层膜的样品，并分别用触针轮廓仪和椭偏仪这两种不同技术测量了各层的表面轮廓和膜厚。比较结果表明，我们提出的技术能够高精度地同时测量顶层表面及其下面的膜表面，而这是传统无损方法无法测量的。
