創新式具線上抗振能力共焦顯微三維形貌量測系統之研發

DEVELOPMENT OF NEW IN-SITU CONFOCAL MICROSCOPIC SURFACE PROFILOMETRY WITH VIBRATION RESISTANCE CAPABILITY

李智凱(Chih-Kai Li)

指導教授 ： 陳亮嘉

國立臺北科技大學/機電學院/自動化科技研究所/碩士(2010年)

摘要

本研究發展出一套創新式具線上抗振能力共焦顯微三維形貌量測系統，其結合條紋投射技術、共軛焦顯微術、表面聚焦形貌法與防振技術來完成線上橫向掃描。現今，在光學量測法中，對於線上量測微結構且具有低反射率或高斜率表面等待測物，在重建其三維表面形貌是具有極大之困難。為了克服這個問題，我們使用高數值孔徑(Numerical Aperture, NA)顯微物鏡進行量測，並在同一時間使用壓電位移控制器(Piezo Translator, PZT)進行垂直掃描，以及X軸位移平台進行橫向掃描，來執行線上橫向掃描掃描之流程，其掃描軌跡則類似於V-型之方式，並且結合單點光纖干涉位移偵測器，檢測出環境中之振動，以減少橫向掃描造成之振動，所帶來的誤差影響。在演算法方面，利用高速電荷耦合元件(Charge-Coupled Device, CCD)擷取影像並利用高通濾波器進行計算，並且在連續影像裡，尋找不同影像中之相對應像素點來建構出聚焦反應曲線。經過尋找聚焦反應曲線之峰值位置，並將單點光纖干涉位移偵測儀所偵測出之位移振動誤差進行補償，便可準確得知物體之三維表面輪廓形貌。此系統中深度解析可達0.1μm，而其最大量測誤差低於整體高度之3%以下。

關鍵字

自動化光學檢測(AOI) ； 共焦顯微鏡 ； 線上量測 ； 橫向共焦掃描術 ； 表面輪廓量測

並列摘要

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.

並列關鍵字

Automatic optical inspection (AOI) ； confocal microscopy ； in-situ measurement ； lateral confocal scanning ； surface profilometry

參考文獻

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