200915009 九、發明說明： 【發明所屬之技術領域】 本發明係關於一種操作微影工具之方法。 【先前技術】 在半導體裝置的製造中，料与总 τ微衫係—重要的程序步驟。總 _ 的看來’在微影中’一電路設外 冲係經由一被成像至一沈積 於基板表面上之光阻層上的圖宰 系來轉移至一基板。之後該 基板在一新設計被轉移至兑矣；^ i 移至其表面之前經歷各種#刻及沈積 广， 程序。此循環程序繼續進扞，奸&冰 《 胃進仃從而建造了該半導體裝置之 多個層。 在用於半導體裝置之製造中夕彡 心表化〒之镟影程序中，為改良光學 解析度而仙極短波長之輻射使㈣裝置巾之極小特徵可 被精確複製係有利的。在先前技術中，已使用各種波長的 單色可見光’ |近來已使用在深紫外線（Duv)範圍内之輻 射’包含248咖及193 nm之輻射。為進一步改良光學解析 度，亦已提議使用在超紫外線（EUV)範圍内的韓射，包含 13.5 nm的輻射。 EUV輻射源可基於錫、鐘或氤之激勵，且通常被容納於 -位於鄰近該微影工具之腔室内。為將該輕射源與該微影 工具隔離，-通常由錐、鎳或矽形成之薄羯經常被用作為 -窗，Eimi射透過該窗而透射至該卫具腔室内。除將該 工具與該輻射源隔離外，該箔可藉由限制電磁輻射之頻率 帶寬進入該工具而作用為一光譜純度過濾器（spF)。 該微影工具腔室通常包括一基板台以托住待處理基板， 131273.doc 200915009 及-遮罩台以托住一印有待成像至該基板上之該電路設計 之圖案之遮罩。從该來源腔室進入該工具腔室之EM輻射 ’、、、儿忒遮罩。一通常由一系列鏡面或—透鏡提供的投影系 、先位於》亥遮罩台與一基板台之間以聚焦該所照亮的圖案至 該基板上。 在大氣壓力下，EUV韓射具有穿過所有物質及氣體之較 ，的透射性’ 因此必須在—高純度的真空環境下操作該 微影工具腔室。此真线常藉由—包括—或多㈣輪分子 泵之真空抽吸配置實現。 已觀察到EUV輻射可促進在透鏡或鏡面表面之碳沈積的 沈積該等透鏡或鏡面表面用於引導並聚焦該EUV轄射朝 向該基板表面。此輻射刺激來自此等表面的次級電子發 射’違等電子與存在於該工具腔室内之碳污染物（通常為 丈二類）交互作用以形成此等碳沈積。這可導致透鏡之暗晦 或鏡面反射率之損失，從而導致照度降低及X具生產率隨 後之損失。由於此等光學組件之成本高，所以總是不願替 換此等組件，且在許多情形下係完全不切實際的。 此等fe類之共同來源係在該微影工具内被處理的該基 板，（例如）來自光致抗蝕劑或光致抗蝕劑副產品。鑒於 此，已知供應一淨化氣體至該工具腔室以在該基板台與該 才又衫系統之間產生一抑制從該光致抗蝕劑發射至該投影系 統之碎片遷移的氣體簾幕。 用以形成淨化氣體之氣體的選擇取決於數個因素。除了 具有一對於污染物之足夠低的擴散係數外，該氣體應具有 131273.doc 200915009 一對於EUV輻射之低的吸收值。為避免與位於該工具腔室 内之高壓裝置相關之電衆放電問題，該氣體亦應具有—高 的崩潰電壓。此等裝置包含用於調動該工具腔室内之該遮 罩台與該基板台之線性馬達，及用於旋轉該投影系統之該 等鏡面之洛倫茲馬達（L〇rentz motor)。此外，需要該淨化 氣體提供一減少的大氣以防止該等鏡面之氧化。 一具有一對EUV輻射之相對較低吸收值及一相對較高崩 潰電壓兩者之氣體係氫氣（HO。然而，氫氣不係特別有效 (' 於抑制該投影系統之污染物，且由於其相對較低之分子質 量，所以當利用渦輪分子泵時，較困難從該等裝置上去除 之。諸如氫氣之類的輕氣體既難壓縮又易於從該泵之高壓 排氣台朝該低壓進氣台向後遷移，有效地減小從該腔室抽 取氣體的速度。 為增加從該工具腔室去除該氫氣的比率，已知增加渦輪 分子泵之大小或數目兩者皆可顯著增加真空抽取系統之成 本。 本發明試圖解決此等問題及其它問題。 【發明内容】 在一第一態樣中，本發明提供一種操作微影工具之方 法，該方法包括以下步驟：供應氫氣至一容納該工具之腔 至中，及添加一定量氬氣至該腔室或至從該腔室所排出的 氣體’其中選擇該氬氣之量而使得該腔室内的氣體之崩潰電 壓不小於無氬氣添加之腔室内的氣體之崩潰電壓的〇75倍。 【實施方式】 I31273.doc 200915009 如上所述’諸如氫氣之類的輕氣體既難於壓縮又易於向 後遷移，有效地減小抽取速度。#由添加一定量氨氣至爷 腔室或至從該腔室所排出的氣體，該更大、更重的氣氣^ 高該氣體之平均分子大小’其趨向於抑制氫氣之向後遷移 並提高該抽取速度。此可使—簡單且具成本效㈣真空抽 :系統能夠用於抽空該微影工具；若該抽取系統僅抽取氫 氣’則與所需要的一等效抽取系統相較之下，期望藉由本 發明可使該真^抽取线之成本減小至少。 重要事項為’被添加至該腔室或至從該腔室所排出的氣 體之該氬氣量對於該腔室内所進行的程序不具有負面影 響。舉例而言’需要該腔室内之該氬氣量（藉由直接添加 乳體至該腔室中或經由氩氣向後遷移添加至該腔室中）係 致使錢室㈣氣體之崩潰f M為足夠高以避免與該微影 :、相關聯並可存在於該腔室内之高電壓裝置之電漿放電 0鑒於此選擇氬氣量以使得該腔室内的氣體之崩潰 電壓不小於叙_ ΛΤ 、…、虱巩添加之該腔室内之氣體之崩潰電壓的 Λ /較佳為不小於0.8倍。此可防止該崩潰電壓下降至 二X微I工具内的裝置（諸如線性馬達及洛侖茲馬達）通 常所使用之該等電壓之下。 、、擇^氣里以使得穿過該腔室内之氣體之EUV輻射透射 、〇氩氣添加之該腔室内之氣體之EUV輻射透射之至少 95°/。為較佳，至 乂 98/。為更佳’且至少99%為最佳，而使 知該腔室内之备# ϋτΤΛ,± 風氣的存在不顯著影響該腔室内之氣體之 EUV輻射吸收特性。 131273.doc 200915009 在一第二態樣中，本發明提供一種操作微影工具之方 法，該方法包括以下步驟：供應氫氣至一容納該工具之腔 室中，及添加一定量氬氣至該腔室或至從該腔室所排出的 氣體，其中選擇該氬氣之量以使得穿過該腔室内之氣體之 該EUV輻射透射為無氬氣添加之該腔室内之氣體之至少 95%。 藉由選擇該量而使得該腔室内之氣體包含不多於5%的 氬氣而可符合上述準貝,！：⑴㈣室内《氣體的崩潰電壓不 小於無氬氣添加之該腔室内之氣體之崩潰電壓的〇·75倍； 及（Π)穿過該氣㈣礙之辦輕射透料無氬氣添加之該 腔室内之氣體之EUV輻射透射之至少95%。較佳地選擇該 氬氣量而使得該腔室内的氣體包含在2%至4%範圍内之氬 氣。 可直接供應氫氣與氬氣之—混合物至該腔室。該腔室可 容納一投影系統及-與該投影系統間隔之基板台，且一用200915009 IX. INSTRUCTIONS: TECHNICAL FIELD OF THE INVENTION The present invention relates to a method of operating a lithography tool. [Prior Art] In the manufacture of a semiconductor device, it is important to process the τ micro-coating system. It appears that the 'in the lithography' circuit is transferred to a substrate via a pattern imaged onto a photoresist layer deposited on the surface of the substrate. The substrate is then transferred to a new design in a new design; ^ i is subjected to various etching and deposition procedures before moving to its surface. This cycle procedure continues, and the sputum & ice enters the stomach to build multiple layers of the semiconductor device. In the photographic process for the manufacture of semiconductor devices, in order to improve the optical resolution, the extremely short-wavelength radiation makes it possible to accurately replicate the extremely small features of the device. In the prior art, monochromatic visible light of various wavelengths has been used, and radiation which has recently been used in the deep ultraviolet (Duv) range contains 248 coffee and 193 nm radiation. To further improve the optical resolution, it has also been proposed to use a Korean shot in the ultra-ultraviolet (EUV) range, containing 13.5 nm of radiation. The EUV radiation source can be based on the excitation of tin, clock or cymbal and is typically housed in a chamber adjacent to the lithography tool. To isolate the light source from the lithography tool, a thin web, typically formed of a cone, nickel or tantalum, is often used as a window through which the Eimi beam is transmitted through the window. In addition to isolating the tool from the source of radiation, the foil can act as a spectral purity filter (spF) by limiting the frequency bandwidth of the electromagnetic radiation into the tool. The lithography tool chamber typically includes a substrate stage for holding the substrate to be processed, 131273.doc 200915009 and a masking station for holding a mask printed with a pattern of the circuit design to be imaged onto the substrate. From the source chamber, the EM radiation ', , , and the child's mask are accessed into the tool chamber. A projection system, typically provided by a series of mirrors or lenses, is placed between the black mask stage and a substrate stage to focus the illuminated pattern onto the substrate. At atmospheric pressure, EUV Han shots have a higher transmission through all materials and gases. Therefore, the lithography tool chamber must be operated in a high purity vacuum environment. This true line is often achieved by a vacuum suction configuration of a -including or multiple (four) wheel molecular pump. It has been observed that EUV radiation can promote deposition of carbon deposits on the lens or specular surface that are used to direct and focus the EUV radiation toward the surface of the substrate. This radiation stimulates secondary electron emission from such surfaces. The unequal electrons interact with carbon contaminants (usually the second type) present in the tool chamber to form such carbon deposits. This can result in loss of darkness or specular reflectance of the lens, resulting in reduced illumination and subsequent loss of X-product productivity. Because of the high cost of such optical components, they are always reluctant to replace such components and, in many cases, are completely impractical. A common source of such fe classes is the substrate being processed within the lithography tool, for example from a photoresist or photoresist by-product. In view of this, it is known to supply a purge gas to the tool chamber to create a gas curtain between the substrate table and the shirt system that inhibits migration of debris from the photoresist to the projection system. The choice of gas used to form the purge gas depends on several factors. In addition to having a sufficiently low diffusion coefficient for contaminants, the gas should have a low absorption value for EUV radiation of 131273.doc 200915009. To avoid the problem of battery discharge associated with high voltage devices located within the tool chamber, the gas should also have a high breakdown voltage. These devices include a linear motor for mobilizing the mask table and the substrate table within the tool chamber, and a Lorentz motor for rotating the mirrors of the projection system. In addition, the purge gas is required to provide a reduced atmosphere to prevent oxidation of the mirrors. a gas system having a relatively low absorption value of EUV radiation and a relatively high breakdown voltage (HO. However, hydrogen is not particularly effective ('shibiting the pollutants of the projection system, and due to its relative Lower molecular mass, so when using a turbomolecular pump, it is more difficult to remove from such devices. Light gases such as hydrogen are both difficult to compress and easy to move from the pump's high pressure exhaust station to the low pressure inlet station. Migration backwards, effectively reducing the rate of gas extraction from the chamber. To increase the rate of removal of the hydrogen from the tool chamber, it is known that increasing the size or number of turbomolecular pumps can significantly increase the cost of the vacuum extraction system. The present invention seeks to solve such problems and other problems. SUMMARY OF THE INVENTION In a first aspect, the present invention provides a method of operating a lithography tool, the method comprising the steps of: supplying hydrogen to a chamber containing the tool To the middle, and adding a certain amount of argon gas to the chamber or to the gas discharged from the chamber, wherein the amount of the argon gas is selected to cause the gas in the chamber to collapse The pressure is not less than 〇75 times the collapse voltage of the gas in the chamber without argon gas addition. [Embodiment] I31273.doc 200915009 As described above, a light gas such as hydrogen is difficult to compress and easy to migrate backward, effectively reducing Small extraction speed. # by adding a certain amount of ammonia gas to the chamber or to the gas discharged from the chamber, the larger, heavier gas ^ high the average molecular size of the gas 'it tends to suppress hydrogen Move backwards and increase the speed of the extraction. This can be simple and cost effective (4) vacuum pumping: the system can be used to evacuate the lithography tool; if the extraction system only extracts hydrogen, then it is equivalent to an equivalent extraction system required In contrast, it is desirable to reduce the cost of the imaginary extraction line by at least the present invention. The important thing is that the amount of argon gas added to the chamber or to the gas discharged from the chamber is for the chamber. The procedure performed does not have a negative impact. For example, 'the amount of argon required in the chamber (by adding the milk directly into the chamber or moving back into the chamber via argon) causes the money The chamber (d) gas collapse f M is high enough to avoid plasma discharge associated with the lithography:, and may exist in the high voltage device within the chamber. In view of this, the amount of argon gas is selected to cause gas collapse in the chamber. The voltage 不 / is preferably not less than 0.8 times the voltage of the gas in the chamber to which the voltage is not less than 。 、, ..., which is to prevent the collapse voltage from dropping to a device within the two X micro I tool (such as The linear motor and the Lorentz motor are generally used under the voltages, and the EUV of the gas in the chamber in which the gas passing through the chamber is transmitted through EUV radiation. Radiation transmission of at least 95 ° /. is preferred, to 乂 98 /. is better ' and at least 99% is optimal, so that the presence of the chamber # ϋ ΤΛ ΤΛ, ± the presence of wind does not significantly affect the chamber The EUV radiation absorption characteristics of the gas. In a second aspect, the present invention provides a method of operating a lithography tool, the method comprising the steps of: supplying hydrogen to a chamber containing the tool, and adding a quantity of argon to the chamber The chamber or to the gas exhausted from the chamber, wherein the amount of argon is selected such that the EUV radiation passing through the gas within the chamber is transmitted to at least 95% of the gas within the chamber without argon added. By selecting this amount, the gas in the chamber contains not more than 5% of argon gas to meet the above-mentioned quasi-before! (1) (4) Indoor "The gas breakdown voltage is not less than 75 times the collapse voltage of the gas in the chamber without argon gas addition; and (Π) passes through the gas. (4) It is difficult to handle the light-transmitting material without argon gas. At least 95% of the EUV radiation transmission of the gas within the chamber. The amount of argon is preferably selected such that the gas in the chamber contains argon in the range of 2% to 4%. A mixture of hydrogen and argon can be supplied directly to the chamber. The chamber can accommodate a projection system and a substrate table spaced from the projection system, and
於抑制污染物向該投影系統遷移之氣體障礙可由氫氣與氬 :之混合物建立在該腔室内。與—僅由氫氣所形成之氣體 障礙作比較，纟氫氣與氬氣兩者所形成的—氣體障礙的形 成可“該氣體障礙抑制該投影系統之污染物的能力。 T氫氣與氬氣可被包含在各自的氣體小罐中，從中氫氣 與虱軋被供應至一氣體流量控制 窃該軋體流量控制器混 合適ΐ的氧氣與氩氣，並供應該 .^ ^ ^ ιν ^ β侍的虱軋與氬氣混合物 至該腔至以建立該氣體障礙。或 量可所控制的氫氣與氬氣 刀至該腔室’使得-包含該所選氣氣量之氣 131273.doc 200915009 體障礙被建立在該腔室内。可提供一或多個氣體淨化器以 淨化來自該腔室上游之氫氣與氬氣。 該氣體障礙可被建立在一位於該基板台與該投影系統之 間的空心管内，且該空心管被持續沖入氣體以形成該氣體 障礙。該管子之形式及大小較佳為：使得由該投影系統所 聚焦朝向該基板台之EUV輻射不攔截該空心管之壁。該氣 體可透過該管子之壁之一開口或越過該管子之一頂邊而被 引進至該空心管子内。或者，藉由氣體流動越過該Euv輻 射之光學路徑，可在該基板台與該投影系統之間的間隔内 建立該氣體障礙。可朝該基板台引導該氣體流量，且較佳 為以至該基板台之一角度引導。 另一直接添加氬氣至該腔室之方法為，該氬氣可被添加 至從該腔室所排出的氣體。該氬氣可被添加至在一延伸於 忒腔室與一真空泵之間的前級管道内的氣體，或該氬氣可 被添加至該真空泵本身内的氣體。由於在該氬氣被添加至 該氣體處的區域接近該真空泉，所以可能回流至該腔室内 之氬氣量將減小。因此，藉由將氬氣注射至在一鄰近於該 真空豕之進口之區域處或在該泵本身内之氣體中，一增加 的氬氣量可被添加至該氣體而不對該腔室内之氣體成分有 負面影響。此穿過該抽取系統之氬氣量的增加可進一步減 J渦輪刀子泵之大小或數目，因此進一步減小真空抽取系 統之成本。 131273.docA gas barrier that inhibits migration of contaminants to the projection system can be established in the chamber by a mixture of hydrogen and argon. Compared with the gas barrier formed by hydrogen alone, the formation of a gas barrier formed by both hydrogen and argon can "the ability of the gas barrier to suppress contaminants of the projection system. T hydrogen and argon can be Included in the respective gas small tanks, from which hydrogen and rolling are supplied to a gas flow control to steal the appropriate flow of oxygen and argon from the rolling body flow controller, and supply the ^ ^ ^ ^ ιν ^ 侍Rolling a mixture with argon to the chamber to establish the gas barrier. Or the amount of hydrogen and argon gas that can be controlled to the chamber 'to make - the gas containing the selected gas volume 131273.doc 200915009 One or more gas purifiers may be provided in the chamber to purify hydrogen and argon from upstream of the chamber. The gas barrier may be established in a hollow tube between the substrate table and the projection system, and The hollow tube is continuously flushed into the gas to form the gas barrier. The tube is preferably in the form and size such that EUV radiation directed by the projection system toward the substrate table does not intercept the wall of the hollow tube. Introduced into the hollow tube through one of the walls of the tube or over the top edge of the tube. Alternatively, by the gas flowing over the optical path of the Euv radiation, between the substrate table and the projection system The gas barrier is established in the interval. The gas flow can be directed toward the substrate stage, and preferably at an angle to the substrate stage. Another method of directly adding argon gas to the chamber is that the argon gas can be Adding to the gas discharged from the chamber. The argon gas may be added to a gas in a front stage pipe extending between the helium chamber and a vacuum pump, or the argon gas may be added to the vacuum pump itself Gas. Since the area where the argon gas is added to the gas approaches the vacuum spring, the amount of argon that may flow back into the chamber will decrease. Therefore, by injecting argon gas adjacent to the vacuum At the region of the inlet of the crucible or in the gas within the pump itself, an increased amount of argon gas may be added to the gas without adversely affecting the gas composition within the chamber. The amount of argon gas passing through the extraction system is increased. The addition can further reduce the size or number of J-turbine knives, thus further reducing the cost of the vacuum extraction system.