既有的精密定位系統，大多是利用雷射干涉儀量測定位機台的移動量，而非對平台上的物件進行直接量測，因此會受到機台熱漲冷縮、夾具的鬆緊等因素的干擾，使奈米級定位具有很高的難度。本研究以次像素影像定位的技術，針對物件進行直接量測的方法，大幅簡化量測的機構以及對定位平台重現度的要求，而使奈米等級的定位精度更容易被實現。
本研究利用特徵法進行影像定位，可以分為特徵萃取、特徵比對以及參數估測等三個步驟。其中特徵萃取是影像定位精度的關鍵所在，既有的次像素邊跡偵測方法，通常沒有考慮取像系統模糊效應的影響，因此使用錯誤的步階模型進行分析，無法得到正確的估測結果。本研究考慮模糊效應的影響，並有效利用模糊步階模型的特性，對既有的次像素邊跡偵測方法進行改良，由實驗結果可以確實的看出本研究的方法能夠得到更精確的定位結果以及更佳的強健性。
本研究提出的影像定位技術除了可以用在精密定位外，本文還提出該技術在缺陷檢測的應用。配合模糊步階的分析檢驗誤差，能解除過去對樣板檢測法會產生過大灰階值誤差假缺陷的疑慮。

參考文獻

[1] C. Picciotto, J. Gao, E. Hoarau, and W. Wu, “Image displacement sensing (NDSE) for achieving overlay alignment,” Applied Physics A: Materials Science and Processing, vol. 80, no. 6, pp. 1287-1299, 2005.
[2] P. Leroux, D. Ziger, and N. Juig, “Focus characterization using end of line metrology,” IEEE Transactions on Semiconductor Manufacturing, vol. 13, no. 3, pp. 322-330, 2000.
[3] W. Zhang and S. Y. Chou, “Multilevel nanoimprint lithography with submicron alignment over 4 in. Si wafers,” Applied Physics Letters, vol. 79, no. 6, pp. 845, 2001.
[4] X. Li, L. Han, and W. Gu, “Study of overlay metrology in atomic force microscope lithography (overlaying lithography with atomic force microscope),” Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures, vol. 24, no. 6, pp. 3101-3104, 2006.
[5] 袁琪葦，“奈米壓印對位系統之研製：影像檢測技術與雷射干涉儀於多層壓印機台之應用”，台灣大學碩士論文，2004.
[6] 趙育漢，“以類神經網路分析微影覆蓋幾何誤差”，中原大學碩士論文，2002.
[7] Y. Liu and I. Black, “GaAs wafer overlay performance effected by annealing heat treatment - Part II,” Proceedings of SPIE - The International Society for Optical Engineering, vol. 4689II, pp. 1122-1132, 2002.
[8] W. W. Flack, G. E. Flores, and T. Tran, “Application of pattern recognition in mix-and-match lithography,” Proceedings of SPIE - The International Society for Optical Engineering, vol. 2440, pp. 913-927, 1995.
[9] B. Zitovà and J.Flusser, “Image registration methods: a survey,” Image and Vision Computing, vol. 21, pp.977-1000, 2003.
[10] R. C. Gonzalez and R. E. Woods, “Digital Image Processing,” Perntice Hall, 1999.
[11] S. Kaneko, I. Murase, and S. Igarashi, “Robust image registration by increment sign correlation,” Pattern Recognition, vol. 35, no. 10, pp. 2223-2234, 2002.
[12] R. Berthilsson, “Affine correlation,” Proceedings of the International Conference on Pattern Recognition ICPR’98, Brisbane, Australia, pp. 1458-1461, 1998.
[13] B. S. Reddy and B.N. Chatterji, “FFT-based technique for translation, rotation, and scale-invariant image registration,” IEEE Transactions on Image Processing, vol. 5, no. 8, pp. 1266-1271, 1996.
[14] Y. Keller, A. Averbuch, and M. Israeli, “Pseudopolar-based estimation of large translations, rotations, and scalings in images,” IEEE Transactions on Image Processing, vol. 14, no. 1, pp. 12-22, 2005.
[15] B. K. P. Horn and B. G. Schunck, “Determining optical flow,” Artificial Intelligence, vol. 17, no. 1-3, pp. 185-203, 1981.
[16] L. Barron, D. J. Fleet, and S. S. Beauchemin, “Performance of optical flow techniques,” International Journal of Computer Vision, vol. 12, no.1, pp. 43-77, 1994.
[17] J. Flusser and T. Suk, “Degraded image analysis: An invariant approach,” IEEE Transactions on Pattern Analysis and Machine Intelligence, vol. 20, no. 6, pp. 590-603, 1998.
[18] W. Fo¨rstner and E. Gu¨lch, “A fast operator for detection and precise location of distinct points, corners and centers of circular features,” Proceedings of the ISPRS Workshop on Fast Processing of Photogrammetric Data, Interlaken, Switzerland, pp. 281-305, 1986.
[19] S. M. Smith and J. M. Brady, “SUSAN - a new approach to low level image processing,” International Journal of Computer Vision, Vol. 23, no. 1, pp. 45-78, 1997.
[20] S. Banerjee, D. P. Mukherjee, and D. D. Majumdar, “Point landmarks for registration of CT and MR images,” Pattern Recognition Letters, vol. 16, no. 10, pp. 1033-1042, 1995.
[21] J. Ton and A. K. Jain, “Registering Landsat images by point matching,” IEEE Transactions on Geoscience and Remote Sensing, vol. 27, no. 5, pp. 642-651, 1989.
[22] 胡振煇，“高反差直線圖形之次像素定位”，清華大學碩士論文，2005.
[23] J. Canny, “Computational approach to edge detection,” IEEE Transactions on Pattern Analysis and Machine Intelligence, vol. PAMI-8, no. 6, pp. 679-698, 1986.
[24] R. Deriche, “Fast Algorithms for low-level vision,” IEEE Transactions on Pattern Analysis and Machine Intelligence, vol. 12, no. 1, pp. 78-87, 1990.
[25] R. Mehrotra and S. Zhan, “Computational approach to zero-crossing-based two-dimensional edge detection,” Graphical Models and Image Processing, vol. 58, no. 1, pp. 1-17, 1996.
[26] F. Truchetet, F.Nicolier, and O. Laligant, “Subpixel edge detection for dimensional control by artificial vision,” Journal of Electronic Imaging, vol. 10, no. 1, pp. 234-239, 2001.
[27] F. Pedersini, A. Sarti, and S. Tubaro, “Estimation and compensation of subpixel edge localization error,” IEEE Transactions on Pattern Analysis and Machine Intelligence, vol. 19, no. 11, pp. 1278-1284, 1997.
[28] F. Pedersini, A. Sarti, and S. Tubaro, “Improving the performance of edge localization techniques through error compensation,” Signal Processing: Image Communication, vol. 12, no. 1, pp. 33-47, 1998.
[29] E. P. Lyvers and O. R. Mitchell, “Precision edge contrast and orientation estimation,” IEEE Transactions on Pattern Analysis and Machine Intelligence, vol. 10, no. 6, pp. 927-937, 1988.
[30] S. Ghosal and R. Mehrotra, “Orthogonal moment operators for subpixel edge detection,” Pattern Recognition, vol. 26, no. 2, pp. 295-306, 1993.
[31] Y. Shan and G. W. Boon, “Sub-pixel location of edges with non-uniform blurring: A finite closed-form approach,” Image and Vision Computing, vol. 18, no. 13, pp. 1015-1023, 2000.
[32] J. Ye, G. K. Fu, and U. P. Poudel, “High-accuracy edge detection with Blurred Edge Model,” Image and Vision Computing, vol. 23, no. 5, pp. 453-467, 2005.
[33] S. G. Chamberlain, D. H. Harper, “MTF simulation including transmittance effects and experiment results of charge-coupled- imagers.” IEEE Journal of Solid-State Circuits ,vol. SC-13, no. 1, pp. 71-80, 1978.
[34] J. J. Shea, “Lunar limb knife-edge optical transfer function measurements,” Journal of electronic imaging, Vol. 8, No. 2, pp.196-208, 1999.