- 學位論文
透過潔淨乾燥空氣去除極紫外線光罩傳送盒內的氣態分子污染物
Removal of Airborne Molecular Contamination in Extreme Ultraviolet Lithography pod by Clean Dry Air
摘要
隨著集成電路飛速的發展，傳統光學的193nm浸潤式搭配雙重曝光技術，讓產業得以延伸到32nm~22nm製程，但發展到22nm製程以下採用多重曝光技術，製程難度會大幅增加，間接使生產成本大增。極短紫外光 (EUV) 波長可達到13.5nm，被視為延續moore‘s law(摩爾定理)最有效的方法。 極短紫外光與傳統曝光的差異是，所有的設計都是採用反射式鏡片，但目前的問題是微影機台曝光功率和無缺陷光罩。無缺陷光罩的可用性是一個問題，微影機台曝光功率則會影響到晶圓量產的速度。機台的曝光功率會影響到成本效益，EUV微影機台本體的消耗功率約在350千瓦[26]，由於二氧化碳雷射產生極短紫外光，會耗去非常多的能量，真正利用到的能量很少，ASML的EUV微影機台可用功率已經達到60W，必須要將功率提高到250W，每小時生產100片晶圓才能符合效益。由於所有物直接會吸收極紫外光輻射(包括空氣)，無法採用傳統的防塵薄膜來防護微粒和化學汙染物，勢必需要一個特殊的容器來存放、運輸，防止光罩受到外界汙染。 新的EUV Pod (EUV光罩盒)是採用雙層盒設計，保護方式主要是利用進氣和出氣口的濾片和內外盒的間隔來做汙染物的隔離，但已經進入到EUV Pod的汙染物仍需要透過外力來清除。 本實驗是藉由在光罩盒中放甲苯、氨比較充填潔淨乾燥空氣和抽真空的移除效果。充填條件分為，兩進兩出、兩進一出與一進一出，SEMI E152-0709在2009年有規範兩個進氣口，增加了兩個通氣口做為預留用，但沒有明確規定用途。因為實驗架構是經由出氣口量測盒內汙染物之濃度，故選用兩進兩出、兩進一出來比較，一進一出是驗證文獻中CFD模擬進氣條件不同去除汙染物的優劣，經由實驗比較後，發現光罩盒有洩漏情形下，兩進兩出、兩進一出去除汙染物至原濃度5%的時間並無差別，一進一出移除效果比兩進兩出來的差。在氣態分子汙染物去除部分，甲苯容易排除；氨則是易殘留在光罩盒中。抽真空與充填CDA比較後發現，CDA是充填流量越高，去除效果越佳。真空腔體和光罩盒內容積比在51：1下，抽至15.9 torr所花的時間為兩分三十秒，模擬一個長、寬、高比光罩盒多五公分的真空腔體進行推算，抽真空能在短時間內去除大量的氣態分子汙染物。
並列摘要
When the rapid development of integrated circuits, the traditional optical 193nm immersion with double exposure technique, the industry can be extended to 32nm ~ 22nm process.But the development of 22nm process uses the following multiple exposure techniques, process significantly increases the difficulty of indirect production costs substantially.Extremely short ultraviolet (EUV) wavelengths can be achieved 13.5nm,moore's law is regarded as a continuation of the most effective methods. EUV exposure is very short and the traditional difference is that all designs are based on the reflective lens, but the current problem is the exposure lithography machine power and defect-free mask.Availability of defect-free mask is a problem, the exposure lithography machine power will affect the speed of the wafer production.Power of exposure machine will affect the cost-effectiveness, Power consumption EUV lithography machine body of about 350 kilowatts, Since carbon dioxide laser to produce deep ultraviolet light, Will burn off a lot of energy, Little real use of energy , ASML's EUV lithography machines available power has reached 60W, It must power up to 250W, thenthe production of 100 wafers per hour in order to meet efficiency.Since all objects directly absorb EUV radiation (including air), not using traditional film to protect against dust particles and chemical contaminants bound to need a special container to store, transport and prevent pollution by outsiders mask. The new EUV Pod is designed with dual pod. Her protection is mainly isolated by the filters of gas gate and thegap between inner pod and outter pod, to keep away from pollutants. It has entered the EUV Pod by external contaminants still need to be cleared. The experiment was put through in the EUV POD in toluene, ammonia, comparing removal effect by cleandry air purgingand the vacuum system.purging conditions divided, 2 in 2 out, 2 in 1 out and 1 in 1 out. SEMI E152-0709 specification has two intake ports in 2009. Added two vent as a placeholder to use, but there is no clearly defined purpose.Experimental architecture is measured by the concentration of the outlet box pollutants, so the selection of 2 in 2 out, 2 in 1 out to compare, 1 in 1 out literature CFD simulation is to verify the intake removal efficiency of the pros and cons of different conditions,After the experiment by comparing the situation found a leak under the mask box, 2 in 2 out, 2 in 1 out removal efficiency and No difference, 1 in 1 out remove effects than 2 in 2 out of the poor.Remove part of the gaseous molecules of pollutants, toluene easily excluded;Ammonia is easy to remain in the EUV POD. Compare purging CDA and the vacuum, it find out that the removal effect of CDA purging is depending on flow rate, the larger flow rate gain the better removal efficiency,In the vacuum chamber and mask box volume ratio at 51:1, via projections, vacuuming can remove large amounts of gaseous molecules of pollutants in a short time.