在半導體製程中，晶圓清洗為重要的一環，透過酸槽大批清洗的技術，現今仍被廣泛地使用。酸槽系統透過內部濾心過濾不斷循環的化學液來促進晶圓洗淨的效率。而在循環系統中的濾心更扮演著重要的角色，其內部的精密濾心設計專門用來防止從晶圓上洗下來的碎屑再次流入酸槽中。濾心於使用一定時間後，阻塞使流阻上升，因此必須定期更換才能維持酸槽的潔淨。本研究希望發展一套能簡易預測濾心壽命的工具，幫助監控並隨時掌握濾心狀況，甚至能利用反向循環清洗來延長其使用期限，相信在工業應用上將可有效降低酸槽清洗晶圓的成本。本研究將從了解阻塞理論開始，並了解半導體業界所使用之濾心內部構造等相關資訊，再透過掃描式電子顯微鏡(scanning electron microscope；SEM) 檢視濾材，選用最佳實驗雜質粒徑尺寸以符合業界現況。透過流阻的概念，我們可以快速了解濾心當前阻塞情況，並將此概念作為實驗的設計與衡量標準。同時，透過實驗累積大量數據，了解濾心阻塞的關鍵因素，再將實驗數據套入阻塞理論中，建立分析模型。最後希望在此研究下能發展一套簡易工具來判斷濾心剩餘使用壽命，最終目標則為延長濾心使用期限，期望開發出反洗系統於機台保養的過程中啟動，使得機台重新開始生產時，濾心又回復到最佳的效率。

In semiconductor manufacturing processes, acid tanks for wafer cleaning employ a circulation system to enhance cleaning effectiveness. Meanwhile, a filtration film is deployed in the circulation system to intercept debris. The filtration film eventually becomes clogged and thus fails. Clearly, it is desirable to have a good estimate of the remaining lifetime of the filter in use, and to have effective strategies for cleaning the filter during periodic maintenance to prolong its lifetime. In this work, a scaled-down liquid filtration apparatus is constructed for monitoring the filter’s flow-resistance increase with time, and for testing the effectiveness of various filtration-film cleaning strategies. It is found that filtration film clogging generally is caused by “complete blocking” first, and then by “cake filtration”. Also, reverse-flow cleaning appears to be effective for reducing cake filtration, but much less so for complete blocking. Moreover, when the flow rate of the cleaning fluid is periodically varied (by use of an electromagnetically actuated valve), the efficiency of filtration film cleaning can be significantly enhanced, and the enhancement becomes profound as the frequency of flow rate oscillation increases.

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