| Summary: | 碩士 === 國立臺北科技大學 === 自動化科技研究所 === 98 === In the article, an in-situ three-dimensional microscopic surface profilometer employing novel lateral confocal scanning principle was developed to achieve on-line measurement with effective vibration resistance capability. The developed methodology combines digital structured fringe projection, lateral confocal scanning, shape from focus and anti-vibration technique to perform lateral scanning for in-situ 3-D surface measurement. For microstructures having low reflectivity and high-slope surfaces to be measured within in-field process environment, it has been recognized as a technical difficulty to achieve accurate 3-D surface inspection by using various existing optical metrological methods available nowadays. To overcome this, the presented method proposes a new lateral confocal scanning strategy in combining a Z-axis vertical scanning with a horizontal X-axis scanning simultaneously, in which the scan pattern is similar to a V-shape. Meanwhile, to detect potential environmental vibration, a laser fiber interferometric positioning sensor based on heterodyne interferometry was developed to detect the vibratory displacement between the optical probe and a tested surface for minimizing potential measurement errors. A standard step-height target and several industrial V-groove microstructures have been measured to attest the measurement accuracy and feasibility of the developed approach. From the experimental results, it is confirmed that the depth resolution can reach 0.1μm and the maximum measurement error can be controlled within 3% of the overall measuring height.
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