以酸鹼型化學濾網吸附氣態分子污染物之效能探討

Abstract

隨著國內高科技半導體技術不斷發展下，製程元件與線寬已逐漸進入32奈米世代，如此高階製程技術下，各製程環境中之氣態分子污染物質(airborne molecular contaminant, AMC)，已成為影響製程良率之關鍵因子，而氣態分子污染物其污染途徑，可藉由化學反應(酸鹼反應、氧化還原反應)與產品元件產生反應或以物理性吸附沈積方式於晶圓表面或曝光鏡頭表面形成薄膜，將造成晶圓產品元件之缺陷或製程可靠度降低。目前國內各半導體廠已開始重視AMC議題，特別是12吋高階晶圓廠，已經開始陸續於外氣空調箱中、FFU系統、循環系統與微環境系統內使用氣態污染控制技術「化學濾網」來解決AMC之問題，雖然化學濾網不是高科技廠房之主要核心生產設備，但其對製程良率的提升卻扮演極重要關鍵的角色。本研究選擇一本土自製組合式化學濾網，針對三種AMC污染物SO2/H2S及NH3，分別在實驗室及實廠，研究探討其處理效率、壓損及壽命特性分析。 研究探討結果顯示針對化學濾網處理SO2/H2S及NH3之特性，在半導體或光電業界化學濾網一般採用的面風速2.5m/sec下，本研究結果得到該新型組合式化學濾網壓損低於13mmAq、初始去除效率NH3型大於95%、SO2/H2S型大於90%、飽和吸附量大於100,000 ppbv*hr以上，符合實廠測試之性能需求。

With the continuous development of domestic high-tech semiconductor technology, the process components and line width have gradually entered the 32-nanometer generation. For this high-end process technology, the airborne molecular contaminant has been the one of the key factors that affect the process yield. The airborne molecular contaminants would induce chemical reaction (acid-base reactions, redox reactions) and the product components would be adsorbed or deposited on the wafer surface and result in wafer defects or process component of the lower reliability. Therefore semiconductor AMC issues have reached attentions, particularly by the high-end 12-inch wafer fab. Makeup Air Unit, Fan Filter Unit System, circulatory system, micro-environment system, and gaseous pollution control technologies using chemical filters have been used to solve the problem. In this study, chemical filters are evaluated for removing AMC pollutants of SO2, H2S and NH3. The processing efficiency, pressure loss and their life time are characterized. The research for using chemical filter to remove SO2, H2S and NH3 in the semiconductor or optical filters was done at a common surface wind speed of 2.5m/sec. The results of this study indicated that the low-pressure drop chemical filter of under 13mmAq was achieved, the initial removal efficiency was greater than 95% for NH3-type, and for SO2/H2S type it was greater than 90%.The total adsorption capacity was greater than 100,000 ppbv*hr. As a result, the chemical filter is in line with actual plant performance testing requirements.