高精度的無光罩微影技術已經廣泛應用於黃光微影製程，其技術重點除了最小線寬/線距的曝光能力外，控制曝光位置的對位能力同樣是極其重要；只有在擁有精準的對位曝光能力後，才能夠將高精度無光罩微影技術應用於多層曝光，避免短路、斷路、電性不良等問題。因此，本研究針對實驗室自行開發之高精度無光罩式曝光機設計一套對位系統，在不影響原機台架構的情況下，利用兩個陣列式數位光學影像感測器搭配影像處理技術，成功擁有控制機台曝光位置的對位曝光能力。本研究開發之對位系統，透過擷取對位靶標的影像，利用銳利度函數與二分搜尋法進行自動對焦，而後透過特徵提取的方式得到對位靶標的座標，以此資訊換算曝光的起始位置，並由兩個對位靶標的座標計算試片的偏移、旋轉、漲縮等資訊進行補償，達到精準曝光的目的，使曝光圖形可以精準匹配試片上的對位標靶。本研究利用測試圖進行對位系統的實測，其結果在X方向平均誤差為 0.5 μm，Y方向平均誤差 1.0 μm，最大誤差值小於 2.0 μm，足以應付中高階電路板的曝光應用。最後將對位系統實際應用於電子封裝產業的產品，其成果除了在最小線寬/線距上滿足產業要求的 10/10 μm，線路圖也與基板的靶標正確對準，成功控制曝光之線路位置。

Photolithography process plays an important role in contemporary semiconductor industry. The maskless lithography system developed earlier in our laboratory can perform photolithography without using a physical mask. In addition to UV patterning of small feature sizes, the alignment of multi-layered UV patterns is also extremely important. Therefore, in this study, an alignment system was designed for a maskless lithography system. Two image sensors with fine pixel resolution were used along with image processing technologies. Sharpness function and binary search method are used for auto-focusing of images. The coordinates of the alignment marks are obtained by means of feature extraction and then used for coordinating the UV exposure processes. The alignment system has been experimentally tested and the average error of alignment is 0.5 μm and 1.0 μm along the scanning (X) direction and its perpendicular (Y) direction. The maximum alignment error value is less than 2.0 μm. Finally, the alignment system and the maskless UV exposure system are applied to real printed circuit board (PCB) products used in IC-packaging industry with a minimum line/space of 10/10 μm. The UV exposed and developed patterns on a photo-resist layer show excellent pattern accuracy and alignment accuracy.

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