Highly resolved edge detection and localization of micro structures using optical 3D measurements and simulations

在光学三维测量中，蝙蝠翼等干扰效应限制了微结构边缘定位的精度。这对于基于白光干涉测量法或焦点检测的那些测量系统尤其如此。由于其出色的高度分辨率的能力，这些仪器在实践中得到了广泛的应用。然而，在微米和纳米技术的生产需要详细的边缘位置的知识。这是确定尺寸精度的先决条件，并最终保证测量对象的所需功能。在此背景下，所请求的研究项目涉及使用白光干涉测量或焦点检测技术提高测量精度的前景。该项目旨在研究在三维测量边缘结构的背景下发生的干扰效应。根据这些研究，应获得准确确定边缘位置的方法，并针对不同的测量原理进行验证。研究工作包括白光干涉测量和焦点检测的实验研究，使用基尔霍夫衍射理论和严格耦合波分析（RCWA）模拟光传播，以及基于参考测量系统（原子力显微镜和共焦显微镜）的校准样品的比较测量。由于两位申请人的初步研究工作，E。Manske（TU Ilmenau）和P. Lehmann博士教授（卡塞尔大学）在相关测量原理、模拟模型的理论基础以及可用于参考测量的仪器方面以理想的方式相互补充，他们申请了一个合作研究项目。预期的合作实现了协同效应，因为模拟可以通过合理的修改适应两种测量原理，并且可以相对于精确边缘定位的精度和优化能力来比较评估所获得的结果。伊尔梅瑙工业大学之前开发的纳米测量机通过使用不同的传感器构建了高精度测量平台。

Disturbing effects such as batwings restrict the accuracy of edge localization of microstructures in optical 3D measurement. This is true especially for those measurement systems which are based on either white-light interferometry or focus detection. Because of their outstanding height resolution capabilities such instruments are widely used in practise. However, production in micro- and nanotechnology needs detailed knowledge of edge locations. This is a prerequisite for the determination of dimensional accuracy and finally guarantees the required function of a measuring object.In this context the requested research project addresses prospects of improvement of measurement accuracy using white-light interferometry or focus detection techniques. The project aims at studying disturbing effects occurring in context with three-dimensional measurement of edge structures. Based on these studies approaches of an accurate determination of edge locations shall be obtained and verified for the different measurement principles. The research work consists of experimental investigations of white-light interferometry and focus detection, simulations of light propagation using Kirchhoff diffraction theory and rigorous coupled wave analysis (RCWA) as well as comparative measurements of calibration specimens based on reference measuring systems (atomic force microscopy and confocal microscopy). Since the initial research work of both applicants Prof. Dr. E. Manske (TU Ilmenau) and Prof. Dr. P. Lehmann (University of Kassel) complement each other in an ideal way with respect to the relevant measurement principles, the theoretical basics of the simulation models, and the instruments available for reference measurement, they apply for a cooperative research project. The intended cooperation accomplishes synergy effects, since the simulation can be adapted to both measurement principles with reasonable modification and the results achieved can be evaluated comparatively with respect to accuracy and optimization capabilities for precise edge localization. The nano-measuring machine previously developed at TU Ilmenau builds the platform for high precision measurements by use of different sensors.