半導體業化學品供應系統抽取操作優化之研究

Abstract

半導體產業發展數十年為兩兆雙星產業之一，對台灣的經濟成長有相當大的貢獻。晶圓半導體製造屬於高耗能產業，生產過程中需耗費大量的水、電、空調、化學品及氣體等能源及原物料，在面對金融海嘯衝擊及原物料高漲能源短缺的時代，為降低生產成本提升競爭力，企業不僅積極推動能源節約，同時也努力提升設備效能減少原物料浪費。 本研究的目的為藉由減少半導體廠化學品供應系統中空藥桶的化學品殘餘量來降低生產成本。經量測原先一桶空藥桶平均會殘留約 1.7 L(0.85%,200 L/桶)化學品，在此實驗中，我們以田口法(Taguchi Method)重新檢視系統參數設定及硬體設計，以取得最佳化的操作控制因子組合。此外並以一八吋晶圓廠為案例進行驗證。由實驗結果顯示，最佳參數組合為︰墊高高度7 cm；吸管直徑1.1 cm；吸口高度0.5 cm；泵氣源壓力5 kg/cm2，約可將殘餘減量至0.22 L左右。但在實廠運轉上墊高高度及泵氣源壓力可由供應系統直接進行調整，而吸管直徑及吸口高度需與原物料供應商協調，由供應商修改藥桶吸管直徑及吸口高度，此部分涉及層面較廣需耗費較長時間，故本研究將先對墊高高度及泵氣源壓力進行改善。為使藥桶達到墊高傾斜的效果，我們參考工業設計流程進行藥桶自動提升傾斜裝置研發設計。同時在藥桶殘餘量分析期間發現EKC270及NMP藥桶桶面會有變凹或變凸的現象，若桶面凸起會造成吸口位移向中間移動並升高，結果將導致藥桶殘餘量增加，針對此問題點也同時進行桶面下壓裝置研發設計。 依研發設計結果在各供應系統增設自動提升傾斜裝置，EKC270及NMP供應系統再加裝桶面下壓裝置，並將泵氣源壓力調至5 kg/cm2進行實廠運轉測試，殘餘量由平均1.7 L/桶降至平均0.5 L/桶，以案例廠為例，一年可減量6270 L，約31桶化學品，化學品平均單價為144元/L，節省金額一年約90萬元，若在所屬公司集團全面展開將有上千萬元以上的效益。

In Taiwan, the semiconductor industry plays important role and create great revenue in the past decades. However, it is concerned that the high-energy-consuming issue which includes a large amount of water, electricity, air conditioning, chemical stuff and other materials during the process of manufacturing silicon wafers in semiconductor fabrication plant. While facing the impact of global environment and financial, technologists much more concern about the high price of raw materials, the shortages of energy and reducing the production cost to be more competitive. The company promotes energy conservation more actively and works hard for improving equipments to decrease the waste of raw materials. The aim of study is to optimize the operation of the chemical supply system, how to reduce the production cost by decreasing the amount of surplus chemicals in empty drums. In the study, we review the settings of parameters and hardware design of chemical supply system by using the Taguchi method so that we could get an optimum combination of different controlling factors. Besides that, we actually conducted the experiment in an 8 inch Fab. The amount of surplus chemicals in each empty drum was about 1.7 L (0.85%, 200 L/Drum). However, after we installed the drum lift-and-tilt equipment and increased the air pressure, the amount of surplus chemicals decreased to an average of 0.5L. According to the results of experiment, the best set of optimum parameters would be drum-lift-height: 7cm, diameter of tube: 1.1cm, height of the tipped tube: 0.5cm, pump air pressure: 5kg/cm2, all could reduce the surplus of chemicals. In these factors, the durm-lift-height and the pump air pressure could be adjusted by vendors. However, the diameter and height of tipped tube have to be also concerned with vendors and it probably cost more than expected. Therefore, we only adjusted the drum-lift-height and pimp air pressure in this experiment. We have developed the drum lift-and tilt equipment by referring to the industrial design process. After analyzing the amounts of surplus chemicals, we have found that the top cover of EKC270 and NMP drums have become convex and concave. If the top cover becomes convex, the tube would be lift higher and increased the amount of surplus chemicals. To solve the issue, we have also created the cover pressing equipment at the same moment. Once again, according to the results of experiment, we have added drum lift-and-tilt equipments in all supply systems and added top cover pressing equipments in EKC270 & NMP drums. We have also adjusted the pump air pressure to 5 kg/cm2, then found the amount of surplus chemicals to reduce from 1.7 to 0.5 L/Drum. In this case, we would save about 6,270 L and approximately 31 Drums of chemicals a year, the average unit price of chemicals 144 NTD / L, about a year to save 900,000 NTD, If in full swing in their group of companies will benefit more than tens of millions of NTD.