應用於力量量測系統之微米級影像定位系統之設計與開發

Abstract

原子力顯微鏡(Atomic Force Microscope, AFM)是透過偵測微小探針與樣品間的交互力作用，取得奈米級解析度成像的顯微技術。然而，一般商用原子力顯微鏡之掃描範圍在100 µm以內，無法適用於許多工業量測需求。因此，近年來許多研究團隊致力於開發大尺度掃描面積的原子力顯微鏡系統。本論文致力於改善由國立臺灣大學奈米儀器實驗室所開發的大量測範圍力量量測系統之限制。第一，此系統需要使用者以肉眼觀察的方式將雷射光點聚焦於微懸臂探針前端，除了缺乏操作效率外，不良的雷射聚焦位置可能嚴重降低微懸臂偏折量測靈敏度。第二，樣品缺乏影像座標系統，導致無法確認量測之位置與準確度。本篇論文開發一影像定位系統，結合力量量測系統，透過光學影像協助進行雷射聚焦位置調整。同時設計出簡易的操作介面供使用者進行影像定位量測模式，系統可擷取影像資料，並經由LabVIEW運算控制馬達定位量測樣品。實驗結果顯示，影像定位系統在不影響雷射光路的前提下，最佳影像解析度可達15.6233 µm/pixel，並且測試力量量測系統之馬達移動誤差可控制在±10 µm誤差範圍內。

Atomic force microscope (AFM) is a microscopy technology that can generate images at nanoscale resolution by detecting the tip-sample interaction forces. However, the scan range of common AFMs is usually less than an area of 100 µm × 100 µm, which is not sufficient for many industrial measurements. Therefore, several research teams have developed large scanning-area AFM systems. This thesis is devoted to improving a force measurement system with a large measuring range developed by the Nano Instrumentation Laboratory at National Taiwan University. First, this system requires users to align the focal laser on the front end of the cantilever by visual observation. This procedure is inefficient, and an inappropriate focusing position of the laser spot may reduce the sensitivity of the cantilever detection system. Second, the relative position between the sample feature and the measuring point is not available due to the lack of an image coordinate system. In this thesis, a vision-based positioning system was developed to combine with the force measurement system, which can provide an optical image to assist the user for the laser alignment. Moreover, a vision-based positioning interface was developed using LabVIEW software, which allows the user to determine the measuring position on the optical image by integrating the motorized stages and the image analysis. The result shows that the optical resolution of the positioning system can achieve 15.6233 µm/pixel without influencing the laser path for the cantilever detection, and the deviation of the motor positioning system can be controlled within ±10 µm.