使用內照明蜂巢式反應器進行低濃度揮發性有機物的移除

Abstract

在國内高科技半導體技術不斷發展下，預估不久未來晶片之關鍵尺寸會縮小到14奈米，在這樣精密的製程下，低濃度微污染揮發性有機污染物 (VOCs, volatile organic compounds)的控制與偵測便顯得十分重要。高科技廠房潔淨室揮發性有機污染物所產生污染影響製程良率甚鉅，因此潔淨室對揮發性有機污染物防治將刻不容緩。 本研究發展光纖內照明陶瓷式蜂巢載體反應器 (FIHR, Fiber-illuminated Honeycomb Reactor)，用以去除低濃度揮發性有機污染物。光觸媒照射紫外光後可使揮發性有機化合物反應並造成其化性的改變。使原為疏水性有機污染物轉變為親水性有機污染物，其後就可使用水洗方式去除。本研究發現使用FIHR可以達到很高的VOCs去除效率與CO2選擇率，這將可提升晶圓製造良率及延長化學濾網壽命，我們相信這對下世代廠房的設計有推波助瀾的效果。 本研究探討光纖內照明陶瓷式蜂巢載體反應器之設計與反應成效。我們使用水熱法製作光觸媒TiO2，並使用氣相層析質譜儀 (GC-MS, Gas chromatography–mass spectrometry)測量揮發性有機氣體的濃度偵測揮發性有機物的光反應產物。研究發現使用光纖反應器效能明顯提升，使用內照明蜂巢式反應器進行200 ppb二甲苯的光催化，發現與單照光相比，去除率從22%提升至96.5%。本研究也發使用不同重量百分比的錳-二氧化鈦進行揮發性有機氣體，發現不僅可以提升二甲苯的去除率，也可以提高產物中二氧化碳的選擇率。而錳-二氧化鈦也有極佳的再使用率，即使使用了72小時，還是保有82 %的二甲苯去除率。所以我們認為FIHR系統具有極大的潛力，未來可以應用潔淨室的空氣淨化系統，因為其具有高去除效率且可以在室溫下進行反應。在半導體廠中，無塵室裡ppb等級的揮發性有機氣體去除會是一大挑戰，本研究提供了一個有潛力並且可靠的技術。

The feature sizes of the wafer in the semiconductor factory will shrink from 28 nanometers to 14 nm in recent years. Under such precise manufacturing process, the control and the detection of low concentration volatile organic compounds (VOCs) are very important because VOCs will affect the quality of the production process in the high-tech clean room. Therefore, low concentration VOCs removal has become a crucial issue in clean rooms for the semiconductor factories. In this study, fiber-illuminated honeycomb reactor (FIHR) is developed for the removal of VOCs. Photocatalyst with UV light illumination could oxidize the chemical bonds of VOCs and also changes theirs chemical properties. The hydrophobic VOCs may transform into the hydrophilic compounds and then can be removed by a scrubber. FIHR was proved that it can reach the high VOCs’ removal efficiency and CO2 selectivity; it could improve wafer producing quality and extend the lifetime of chemical filter. Furthermore, this research may improve the design of next generation of semiconductor factories. The design and efficiency of fiber-illuminated honeycomb reactor was investigated in this study. The photocatalyst, TiO2, was prepared by thermal-hydrolysis method. Products of VOCs photoreaction were detected by gas chromatography–mass spectrometry (GC-MS). By using FIHR, we found removal efficiency of m-xylene is significantly enhanced to 96.5 % as compared to 22.0 % for UV irradiation only. Using the FIHR with Mn-TiO2 photocatalyst not only increased the m-xylene removal efficiency, but also increased the CO2 selectivity. Interestingly, Mn-TiO2 in FIHR also showed an extremely reusability, 82 % of removal efficiency was still achieved after 72 hours. Therefore, the FIHR gave very high removal efficiency for VOCs at ppb level under room temperature. The FIHR has great potential for the application in the clean room air purification system in the future.