線型彩色共焦三維形貌顯微術

Line-Scanning Chromatic Confocal Three-Dimensional Microscopic Surface Profilometry

陳亮嘉(Liang-Chia Chen) ； 林宗毅(Tsung-Yi Lin) ； 張奕威(Yi-Wei Chang) ； 林世聰(Shyh-Tsong Lin)

《科儀新知》 190期 (2012/10) Pp. 55-64

https://doi.org/10.29662/IT.201210.0008

摘要

本文主要目的在於提升共焦顯微三維形貌量測之量測精度與速度，將線型共焦量測原理結合白光軸向色散原理，發展成創新式之線型彩色共焦三維形貌量測技術。利用共焦顯微術特有之光學切片能力及光譜色散之高解析能力，建立線型彩色共焦數學模型，發展具有高速、高精度、高縱向量測範圍與具單點空間解析能力之線型彩色共焦顯微三維輪廓量測技術。線型彩色共焦架構可使白光線光源產生軸向色散，並聚焦在不同深度，獲得聚焦表面之反射光譜，經由線型光譜儀解析，並將光譜與深度進行校正比對，可快速精確還原待測物之剖面形貌，經橫向位移，即可重建待測物之三維形貌；透過反摺積演算法降低光擴散影響，使系統達到單點量測之解析。以實際使用之細微元件驗證系統精度與性能驗證，此量測解析可達到0.1 µm高速精確之共焦三維輪廓量測。

並列摘要

An on-line 3D surface profilometer for micro surface profiles with a long range and high resolution measurement was successfully developed using innovative slit-scan multi-wavelength confocal microscopy. In conventional confocal microscopy, vertical scanning of the object's surface by either mechanical depth movement or objective shifting is extremely time-consuming, thus resulting in unacceptable efficiency for on-line inspection. In this paper, a multi-wavelength confocal microscope employing a broadband light source in combination with a chromatic dispersion objective was developed to generate an accurate wavelength-to-depth conversion for microscopic 3D profile measurement. By using the point spread function (PSF) detected with its corresponding wavelength detected at its matching focal depth, the proposed deconvolution method has been proved effective theoretically and experimentally in greatly minimizing the full width half maximum (FWHM) of the dept h response curve. Using the developed deconvolution algorithms, to the measurement resolution of the line-scanning chromatic confocal system can reach the same level of the single point measurement. Using pre-calibrated standard band width and step height targets, the measurement accuracy of the developed method can reach up to 0.1μm.