多波長差動共焦顯微三維形貌量測技術之研究

Research on Multi-wavelength Differential Confocal Surface Profilometry

張奕威(Yi-Wei Chang)

指導教授 ： 陳亮嘉 ； 林世聰

國立臺北科技大學/機電學院/機電科技研究所/博士(2013年)

https://doi.org/10.6841/NTUT.2013.00726

摘要

本研究主要為研究多波長差動共焦三維形貌量測技術，系統以線型連續多波長光源進行量測，並結合軸向色散物鏡與兩組彩色線型CCD裝置取像，並建立出多波長差動共焦系統之數學模型，研發出一即時線型掃描共焦量測技術。為了使系統達到即時線型掃描量測，使用軸向色散物鏡將連續多波長光源的各個波長聚焦至不同的深度位置上，產生一大深度的即時量測範圍，避免費時的垂直掃描過程；物體之反射光則由兩組彩色線型CCD裝置進行取像，以消除物體反射率對量測之影響。為了達成即時量測，首先，系統以垂直掃描的方式對平面鏡進行Z軸掃描，並透過差動運算式演算得到一組R、G與B顏色比值與深度的對映曲線，由此曲線與兩組彩色線型CCD取得之資訊即可進行快速三維形貌重建量測而不需要任何的垂直掃描。同時，差動運算還可將物體表面反射率的參數消除，量測重建時可有效抑制物體表面反射率的影響。本研究提出之量測方法，其線量測範圍為89.6µm，深度量測解析可達到0.3 µm，並且最大量測誤差可小於全高量測範圍的0.6%以內。此量測方法可達成快速線型掃描量測無需任何垂直掃描，並可獲到高精度量測結果，驗證此量測系統可有效地達成快速即時多波長差動共焦三維形貌量測。

關鍵字

共焦量測技術 ； 差動共焦量測技術 ； 多波長共焦量測技術 ； 表面輪廓量測 ； 三維形貌量測

並列摘要

This study presents a novel Multi-wavelength Differential Confocal surface profilometer using broadband light source, dispersion chromatic objective and two color line CCD devices. Optical confocal microscopy for surface profilometry has become extremely important due to its high longitudinal measurability range and excellent vertical resolution. In this study, the system was developed to establish a multi-wavelength line chromatic confocal mathematical model and generate accurate wavelength-to-depth conversion for in-situ 3-D profile measurement without the need for time-consuming vertical scanning. In this method, two CCD are configured at two different designated focusing positions, which are controlled by CCD focus position. A depth-focus response curve can be established by two colors CCD with Red, Green and Blue ratio curve. In addition, using the principle of differential confocal, an output function is reestablished as the ratio of subtraction and sum values of the two color detectors’ responses to reduce the surface reflectance influence. To test the performance of the developed system, an accurate step-height target and some industrial micro semiconductor components were measured to verify measurement accuracy and repeatability. The depth measurement resolution can reach up to 0.3 µm and the maximum measurement error was verified to be within 0.6% of the overall measuring range without vertical scan.

並列關鍵字

Automatic optical inspection (AOI) ； confocal measurement ； differential confocal ； chromatic confocal ； surface profilometry

參考文獻

[3]高偉傑，白光共焦顯微三維表面輪廓量測系統之研發，碩士論文，國立臺北科技大學自動化科技研究所，台北，2005。

[1]A. K. Ruprecht, K. Korner, T. F. Wiesendanger, H. J. Tiziani and W. Osten, “Chromatic confocal detection for high speed micro topography measurements,” Proc. of SPIE, vol. 5302, 2004, pp. 53-60.

[2]J. B. Tan and F. S. Wang, “Theoretical analysis and property study of optical focus detection based on differential confocal microscopy,” Meas. Sci. Technol. 13, 2002, pp.1289-1293.

[4]張奕威，即時共焦顯微三維輪廓量測技術之研發，碩士論文，國立臺北科技大學自動化科技研究所，台北，2007。

[5]陳昭男，彩色共焦顯微三維形貌量測術之研發，碩士論文，國立臺北 科技大學自動化科技研究所，台北，2009。