200412631 Π) 坎、發明說明 相關申請案 此申請案主張 2002年1月7日提出申請的 U.S.Pr〇vlsl〇nai Application 第 60/34 6,507 號之權利。將前 述申請案所述者全數列入參考。 【發明所屬之技術領域及先前技術】 對於污染物敏感的物件之製造通常須使用一或多種溶 液以自物件移除雜質。傳統上，那些溶劑以液相使用。最 近’使用越來越常以超臨界二氧化碳代替液態溶劑。使用 超臨界二氧化碳通常會減少水的消耗量，減少廢液，減少 散逸和/或增進溶解性。半導體製造中，超臨界二氧化碳 用於許多應用，如：光阻物顯影、光阻物剝除、晶圓淸潔 和晶圓乾燥。 通常，超臨界流體是高於其臨界壓力和溫度的流體， 其並且具有類似氣體和液體的性質。超臨界流體（如：超 臨界二氧化碳）的溶劑性質視流體密度而定，後者又視流 體的壓力/溫度條件而定。用於許多有機雜質時，二氧化 碳的溶劑化性質隨著流體壓力自超臨界降至較低壓力 (如：大氣壓）而降低，此發生於淸潔操作所用腔的減壓期 間內。用於高純度淸潔操作，如：晶圓製造或製造或加工 處理其他工件或底質期間內所見者，隨著壓力的下降，雜 質沉澱於二氧化碳溶劑中，其會損及欲淸理的表面，污染 此表面並降低淸潔程序的效能。 (2) (2)200412631 因此，對於減少或儘量減少前述問題地潔淨物件 (如：晶圓或其他工件）的方法有需求存在。 【發明內容】 本發明一般係關於淸潔物件的方法，使物件與包括二 氧化碳的溶劑流體接觸，藉此自物件移除雜質，及以置換 用的流體置換溶劑流體。此置換用的流體不是二氧化碳。 一個實施例中，物件是晶圓，置換係於足以防止在溶劑流 體中形成第二相的溫度和壓力下進行。另一實施例中，置 換係於足以防止在欲置換的溶劑流體中形成的第二相的溫 度和壓力下進行，且二氧化碳再循環至流體中。 另一實施例中，本發明針對減少非揮發性渣質於工件 淸潔操作期間內沉澱的方法。此方法的步驟包括：工件與 溶劑流體於第一個壓力接觸，溶劑流體包括二氧化碳，藉 此，工件上的污染物被溶劑流體所移除；降低溶劑流體壓 力’使得非揮發性渣質不溶解於溶劑流體中；及於低壓以 二氧化碳以外的置換用氣體置換溶劑流體，藉此減少工件 暴於不溶性非揮發性渣質中的時間，藉此減少不溶性非揮 發性渣質澱積於工件上的情況。 另一實施例中，本發明針對將淸潔用流體施用於容器 中的方法。此方法的步驟包括：於第一個壓力’將溶劑流 體流供應至放置物件的容器，其中，溶劑流體包括二氧化 碳’能夠溶解容器中物件上的污染物；將置換用流體流供 應至容器，其中，置換用流體流的壓力足以置換容器中的 -6 - (3) (3)200412631 '溶劑流體，置換用流體不是二氧化碳；及將溶劑流體排至 容器外。 本發明有數個優點。例如，實施本發明之方法得到超 乾淨表面，如半導體製造和其他工業所須者。本發明之方 法經濟且容易與已有的製造設備成一體。例如，一個特點 中’本發明之方法使用氮置換用氣體，設備通常有氮管 線。一個實施例中，可以使用可資利用的低壓（如：80-10OpsIg)氮。另一實施例中，使用過的二氧化碳係經循 環’以減少二氧化碳消耗及相關成本。另一實施例中，再 循環可以在不須壓縮使用過的流體的條件下進行。此外， 本發明將可能存在於更高純度等級二氧化碳中的非揮發性 殘留雜質以及它們於容器減壓時的沉澱作用造成的問題列 入考慮。 【實施方式】 由下列關於本發明之較佳實施例的更特別描述和附 圖，會更瞭解本發明前述和其他目的、特徵和優點，附圖 中，類似編號是與相同組件。附圖未依標準規格，以強調 方式說明本發明之原理。 本發明一般係關於製造潔淨表面，此如半導體製造或 加工期間內所須者。本發明係關於移除、防止或儘量減少 污染物沉積於晶圓（如：包括一或多種電機械裝置的晶 圓）、一或多種積體電路或其組合上，此爲此技術中已知 者。可以使用本發明加工的其他工件包括半導體製造中所 (4) (4)200412631 用的零件（如·噴濺耙和其他者）、光學零件（如：光學鏡 片、頻率倍增裝置、發出雷射光的晶體、分光組件、光 月空、纖維鏡）和其他者。物件（如：電視、攝影機和照相機 零件、科學和樂學儀器、衛星傳輸、航空工業中所用零件 及其他）及其他工件亦可以此處所述者處理。 物件可製自任何材料，包括無機物（如：矽、二氧化 ’ 砂、石墨或金屬）、有機物（如：聚合物）或製自無機和有機 材料之組合的物質。淸潔法可用於單一物件，或者可用以 同時淸潔二或多個物件。 本發明係關於自物件或環繞物件的環境（如：物件製 造或加工期間內’放置物件的容器）移除污染物或雜質的 方法。此方法本身可以是較大的製造操作，如：沉積或生 長膜的方法，光蝕刻法、蝕刻法、離子植入法、化學機械 平面化法、擴散法、光阻顯影法、使光敏材料顯影的方 法、淸潔光學組件的方法、淸潔可用於航空應用之組件的 方法、光阻物剝除法、晶圓淸潔法、晶圓乾燥法、去脂法 或萃取法。 0 污染物包括最終產物不欲含有的有機和/或無機材 料。它們可能是固體、液體或氣體形式。例子包括聚合 物、和其他有機材料、矽、碳、和/或金屬及其他雜 質。它們可存在於物件表面上或擴散於包含此物件之材料 的至少一部分。 雜負可由物件本身產生，並可包括在晶圓加工期間內 移除的晶圓部分或蝕刻程序期間內製得的碎物。雜質亦可 (5) (5)200412631 能隨處理流體送至物件。操作完成之後，化學品（如：_ 造或處理物件所用者）也可能留在物件表面上，或g @ # 在於加工容器中。 本發明特別適用以移除非揮發性殘渣（NVR)。操作期 間內，使用高壓二氧化碳，特別是於或接近臨界或超臨界 條件，許多NVR溶解於二氧化碳中。隨著壓力的降低， 二氧化碳的密度和溶劑性質改變，NV R沉澱形成第二相， 通常爲氣溶膠液滴和/或固體細粒形式。在第二相中， NVR會衝擊物件表面，因此造成污染。 非揮發性殘渣的例子包括，如：烴（如：C1() + )、重質 烴和其他者，但不在此限。 NVR來源包括壓縮機油、漆、可溶於溶劑中並常見於 襯墊中的彈性材料和閥密封材料、溶劑進料管中所用密封 劑及其他。可能於加工操作期間內（如··晶圓淸潔期間內） 於工件上形成N V R。 亦可使用物件製造、加工或淸潔期間內所用的流體， 使NVR與物件表面接觸。 半導體工業中’例如’光阻物顯影、光阻物剝除、晶 圓淸潔和晶圓乾燥期間內’使用二氧化碳。咸丨言整個二氧 化碳流體含有的NVR濃度不超過i0ppm(以重量計）。—些 較商純度等級（鋼瓶中者）含有約0 . 1 5 p p m N V R (以重量計）。 用於敏感程序中時’其要求最終物件僅能含有低於特 定數目的選定尺寸顆粒’即使更高等級也帶有無法接受量 的NVR。例如，一些製法中，要求每標準立方米氣體所含 (6) (6)200412631 高於某些規定尺寸（基本上約1 00奈米）的顆粒數目低於 100個。估計一升較高純度等級液態二氧化碳（約lOppb)的 汽化反應會得到百萬個NVR顆粒。爲達到這樣的淸潔程 度，必須至少將目前供應的最高純度二氧化碳的純度提高 1 000 倍。 使用高壓二氧化碳的淸潔期間內，第二相NVR之形 成示於附圖1 A、1 B和1 C。附圖1 A所示者是放置晶圓12 的腔10。腔1 0是容器或器皿，如：在半導體製造設備中 的工具或加工區。腔1 0設計用以接收和留置高壓流體， 如：超臨界二氧化碳（高於其臨界溫度和壓力的二氧化 碳，特定言之，高於31t和1 070磅/平方英吋（P si a))。 腔10備有通道（用以引入加工流體和其他化學品）及抽氣 通道，此如此技術已知者。引入和抽空腔1 0的方式爲此 技術所習知。例子包括壓縮機、幫浦、抽氣閥和其他。 如附圖1 A所示者，腔1 〇充滿二氧化碳至壓力爲 2 0 00磅/平方英吋（p si g)。於此壓力，晶圓上的污染物溶 解於二氧化碳溶劑中，第二相（不溶的）N V R濃度極低。隨 著腔10減壓至較低壓力（如：200psig)(如附圖2B所示 者），之後至常壓（如附圖1 C所示者），二氧化碳的溶劑化 性質朝向NVR消失及第二相形成。腔丨〇中的第二相NVR 會衝擊晶圓而造成污染。 一個實施例中，本發明之方法包括使物件（如：晶圓） 與包括二氧化碳的溶劑流體接觸，使得物件上的污染物溶 解於溶劑流體中。以純度較高的二氧化碳爲佳。其他實施 -10- (7) (7)200412631 例中，本發明之方法可以使用整體二氧化碳。 通常，溶劑流體包括至少5 0重量％二氧化碳。溶劑 流體中的二氧化碳含量以至少75重量％爲佳，至少90重 量％較佳，至少9 8重量％最佳。 此溶劑流體可以是1 〇〇 %二氧化碳。其他實施例中， 溶劑流體包括至少一種額外組份，如：輔助溶劑、界面活 性劑或鉗合劑。除了二氧化碳以外’可用組份的（單獨或 倂用）例子包括氨水、鹵化烴、氫氟酸、二氧化硫和其他 者。輔助溶劑、界面活性劑和/或鉗合劑的其他例子包括 石夕院；烴，如：甲院、乙院、丙院、丁院、己院、乙燒和 丙烯；鹵化烴，如：四氟甲烷、氯二氟甲烷、六氟化硫和 全氟丙烷；無機物，如：氨、氨、氪、氬和氧化亞氮； 醇，如：乙醇、甲醇或異丙醇；碳酸丙二酯；大氣氣體， 如：氮、氫、臭氧或氧；水；胺，如：羥基胺和烷醇胺； 丙酮；吡咯啉酮，如：N -甲基吡咯啉酮、n -乙基吡咯啉 酮、N -羥基乙基吡咯啉酮和N -環己基吡咯啉酮；醯胺， 包括二甲基乙醯胺或二甲基甲醯胺；酚和其衍生物；乙二 醇醚；2 -吡咯啉酮；二烷基颯；有機和無機酸及它們衍生 物，如··氫氟酸、氫氯酸、乙酸、硫酸、五倍子酸或五倍 子酸酯；四烷基氫氧化銨；二氟化銨；銨-四甲基二氟化 銨；鹼金屬氫氧化物；酒石酸鹽；磷酸鹽；乙二胺四醋酸 鹽（EDTA);銨與硫化鈉和硫酸鐵；及它們的混合物。 通常，包括二氧化碳的溶劑流體處於污染物（如： N V R)可溶解於溶劑流體中的條件下。例如，包括二氧化 -11- (8) (8)200412631 碳的溶劑流體壓力至少8 0 0 p s l g。較佳情況中，包括二氧 化碳的溶劑流體處於或接近其臨界狀態或處於超臨界條 件。 二氧化碳溶劑可以蒸汽、液體或超臨界相引至容器 中。一旦進入容器內，二氧化碳溶劑與物件接觸，以移除 雜質。雜質之移除可藉物理或化學機構完成，例如，二氧 化碳溶劑可溶解雜質；雜質可自製造物件的材料擴散進入 二氧化碳溶劑；或者，溶劑與二氧化碳溶劑反應，使得它 們自物件移出。此移除亦可爲機械機構，例如，可調整二 氧化碳溶劑的壓力和/或溫度，以提高和/或降低其比體 積，構成壓力使得雜質自物件中被逼出。亦可藉化學和機 械機構之組合移除雜質。 視情況地，可以攪動此二氧化碳溶劑，以增進化學和 機械機構。例如，攪動能夠因爲提高物件表面濃度梯度， 而提高化學移除機構（如：溶解、擴散反應）的速率，藉此 使化學機構趨於完全。類似地，攪動也會提高機械移除機 構的移除速率，這是因爲攪動在流體中形成剪力，此有助 於自物件表面拉出雜質之故。 可以調整二氧化碳的溫度和/或壓力以有助於移除雜 質。這些處理條件之調整會使的二氧化碳溶劑驅動蒸汽、 液體和/或超臨界相之間的一或多相轉變，此視對於二氧 化碳溶劑選用的調整與臨界溫度和/或壓力及其冷凝壓力 和/溫度而定。這些調整以有助於雜質移除爲佳。若物件 上或物件中有數種不同類型的雜質，二氧化碳溶劑可以循 (9) (9)200412631 環於各種處理條件之間’以增進各種類型的雜質之移除。 二氧化碳溶劑施以這些調整時，N V R或移除的雜質可能溶 入和/或沉澱於溶劑流體中。 視情況地’至少一部分包括污染物的溶劑流體可於居 間淸潔步驟以新進流體或純二氧化碳代替，藉此，使用過 的溶劑流體被推移流動，可自欲淸潔的表面移除額外污染 物。 此方法包括以置換用流體（非二氧化碳）於足以避免在 欲加以置換的溶劑流體中形成第二相的溫度和壓力條件下 置換溶劑流體，藉此，自晶圓分離污染物，藉此淸潔晶 圓。 例如，溶劑流體於容器中的壓力條件下被置換，未經 部分或總容器降壓處理。如果容器經降壓，可以降至NVR 於溶劑流體中的溶解度得以維持的壓力。 置換用的流體可以是氣體、液體或超臨界流體。適胃 之置換用的流體是氮、氨、氬或氪、其他氣體（如：氧）和 它們的任何組合。以氮爲佳。本發明的一個實施例中’置 換用的流體是高純度氣體。另一實施例中，置換用的流體 是超高純度氣體，如：純度程度使得所有污染物量爲次 ppb者或工業已知者。高純度和超高純度氣體（如：氮和其 他者）可購自市面上。 本發明之方法可以連續或批次方式進行。 本發明的此實施例階段之說明示於附圖2A-2D。 附圖2 A所示者是放置晶圓1 2的腔1 4。腔1 4可以是 -13- (10) (10)200412631 如前述的容器。其他實施例中，腔14可經設計，使得新 進流體進入容器中，與已存在的二氧化碳溶劑混合（例 如，以連續攪拌容器反應器模式）或者使得流動路徑有助 於使用過的溶劑、雜質和NVR之置換（如：以塞流模式）。 較佳情況中，容器形狀儘可能在二氧化碳溶劑、雜質和 NVR的置換期間內，減少物件中的雜質和NVR。如此技 術已知者，可配備用以將引入流體和抽空腔1 4中之流體 的通道和裝置。 如附圖2A所示者，腔14塡滿二氧化碳至約 2 0 0 0 p s i g，其中包括溶解的污染物。 如附圖2B所不者’壓力局於容器中之二氧化碳的惰 性氣體（如：高於2000psig)引至腔14中。如附圖2C所示 者，二氧化碳和溶解的污染物自腔1 4中被置換出來。如 附圖2D所示者，包括置換用氣體的腔14之後減壓至大氣 壓。 使用較高純度的置換用流體和/或二氧化碳溶劑，或 者提高所用置換用流體的體積，以更徹底置換二氧化碳溶 劑、雜質和NVR，抽真空之後，留在物件上的最終雜質數 目獲改善。 一旦溶劑流體、NVR和其他雜質自容器置換出來，可 以中止置換用流體流，可以將容器抽空。 自容器置換出的二氧化碳可視爲廢流或可引至設備中 的其他操作或工具。 一個較佳實施例中’自腔1 4置換出的流體經純化， -14- (11) (11)200412631 例如，將容器排出的流體引至一或多個純化單元。因腔 14排出流體壓力高（如，2000psig)，所以，使用過的流體 通常引至純化單元中，不須進一步壓縮。可利用的純化技 巧例包括蒸餾、吸附、吸收.、化學反應、相分離和其他方 法。 經置換的溶劑流體可針對NVR、輔助溶劑、界面活性 劑和鉗合劑純化。其他實施例中，所得流體可經進一步純 化以自置換用流體（如：氮）分離二氧化碳。適用以自氮分 離二氧化碳的方法包括蒸餾。 一個較佳實施例中，二氧化碳經再循環，此如2002 年8月17日提出申請的美國專利申請案第1 0/274,302 號，Recycle for Supercritical Carbon Dioxide (超臨界二氧 化碳之再循環）中所述之再循環，茲將其中所述者全數列 入參考。 置換用流體亦可再循環。如果使用氦作爲置換用流 體’因其成本和其顯著的質輕特性使得移除較易，所以再 循環特別有吸引力。 另一實施例中，本發明係關於降低非揮發性渣質於工 件淸潔操作期間內澱積的方法。此方法包括使工件與溶劑 流體（基本上是前述者）接觸。此方法包括降低溶劑流體壓 力，藉此，污染物（如：NVR)可溶於溶劑流體中。此方法 另包括於減低壓力下，以置換用流體（如前述者）置換溶劑 流體，藉此，工件暴於不溶性污染物（如：NVR)的期間降 低’藉此減少不溶性污染物（如：N V R)於工件上之沉積。 (12) (12)200412631 一個實施例中’溶劑流體的壓力降至低於約 lOOOpsig。另一實施例中’壓力降至低於20〇Paig。另一實 施例中，溶劑流體壓力降至比氮氣來源或設備管線壓力低 的値，如：降至低於約80- 1 00psig。 較佳情況中，晶圓暴於不溶性NVR的時間低於30秒 鐘。晶圓暴於不溶性NVR的時間低於3秒鐘更佳。 視情況地，至少一部分溶劑流體和溶解的污染物可於 居間的淸洗步驟以使用新進溶劑流體或純二氧化碳置換。 此淸洗步驟可於容器減壓之前或之後進行。二氧化碳和選 用的置換氣體可再循環，此如前述者。再循環可包括將欲 循環的流體引至純化器之前的壓縮步驟。 如前述者，此方法可以連續或批次方式進行。 本發明的此實施例階段的一個例子示於附圖3 A - 3 E。 附圖3 A中所示者是放置晶圓1 2的腔14，此基本上如前 述者。壓力約2000psig的二氧化碳存在於腔14中。腔14 降壓至200psig，此如附圖3B所示者。壓力下降之後， NVR自溶液沉澱出來，形成第二相。惰性氣體（如：氮）的 壓力足以推動200psiag溶劑流體進入腔14，此如附圖3C 所示者，藉此置換腔14中的二氧化碳和第二相雜質，此 如附圖3D所示者。置換容器中的二氧化碳和第二相雜質 可縮短晶圓暴於不溶性NVR中的時間，藉此減少不溶性 NVR於晶圓上之沉積。如附圖3E所示者，腔14之後降壓 至常壓。 一個實施例中，本發明係關於製造超乾淨物件的方 -16- (13) (13)200412631 法。此處所謂的"超乾淨"是指底質的污染程度低於約 2,000個顆粒/平方米表面積，此雜質的有效直徑大於約 0.1微米，此藉光散射技巧測得。此技術已經知道測定固 體表面上之有效直徑大於約0.1微米顆粒的光散射法。例 如，適當方法述於 R.P. Donovan 編輯的 Contamination-Free Manufacturing for Semiconductors and other Precision Products(半導體和其他精準產物之無污染產製）（Marcell Dekker，200 1 年）中第 79 頁的 Diaz，R.E.,等人，"〇η· Wafer Measurement of Particles in Contamination- Free Manufacturing for Semiconductors and other Precision Products (半導體和其他精準產物之無污染產製中的晶圓 上顆粒測定）"。 此方法包括使物件於容器中與二氧化碳溶劑接觸，藉 此，物件上的雜質溶解於二氧化碳溶劑中，及將置換用氣 體引至容器中，以縮短物件暴於存在於二氧化碳中之非揮 發性雜質的時間，藉此將物件上的雜質數目降至低於約 2000個顆粒/平方米表面積，其中，由光散射技術測得 雜質的有效直徑大於0. 1微米。 另一實施例中，本發明提出一種將淸潔用流體供應至 容器的方法。此方法的步驟包括將於第一個壓力的溶劑流 體流供應至放置物件的容器，其中，溶劑流體包括二氧化 碳且能夠將物件上的污染物溶解於容器中；將置換用流體 流供應至容器，其中，置換用流體流的壓力足以置換容器 中的溶劑流，且置換用流體不是二氧化碳；及將溶劑流體 (14) 200412631 排出容器外。 自容器排出的流體可經純化（如前述者），二氧化碳可 循環至容器中。經純化的二氧化碳回到容器之前，可經此 技術已知方式壓縮。 一個實施例中，置換用流體流壓力至少與第一個壓力 等壓。一個實例中，置換用流體壓力比其置換的溶劑流體 壓力高不超過約lOOpsi。另一實施例中，第一個壓力是至 少lOOOpsig。自容器排出的流體壓力可以比純化單元的操 作壓力來得高。 另一實施例中，溶劑流體自容器排出的壓力比第一個 壓力來得低，置換用流體的壓力足以推動溶劑流體。 已經參考較佳實施例地特別提出和描述本發明，纟閑於^ 此技術者瞭解如何由所描述的細節在不違背所附申請專利j 範圍涵蓋之本發明範圍的情況下作出各式各樣改變。 【圖式簡單說明】 附圖1 A -1 C所不者是放置與一氧化碳接觸的物件的容 器中壓力下降時，第二相的形成階段。 附圖2A-2D是本發明的一個實施例的方法步驟。 附圖3A-3E是本發明另一實施例的方法步驟。 主要元件對照表 10 12 腔 晶圓 -18- (15)200412631200412631 Π) Description of invention and related applications This application claims the right of U.S. Pr0vlslnai Application No. 60/34 6,507, filed on January 7, 2002. All those mentioned in the aforementioned applications are incorporated by reference. [Technical Field and Prior Art to Which the Invention belongs] The manufacture of objects sensitive to contaminants typically requires the use of one or more solutions to remove impurities from the object. Traditionally, those solvents are used in the liquid phase. More recently, supercritical carbon dioxide has been used in place of liquid solvents. The use of supercritical carbon dioxide generally reduces water consumption, reduces waste fluids, reduces fugitiveness and / or improves solubility. In semiconductor manufacturing, supercritical carbon dioxide is used in many applications such as photoresist development, photoresist stripping, wafer cleaning, and wafer drying. Generally, supercritical fluids are fluids above their critical pressure and temperature, and they also have properties similar to those of gases and liquids. The solvent properties of supercritical fluids (eg, supercritical carbon dioxide) depend on the density of the fluid, which in turn depends on the pressure / temperature conditions of the fluid. For many organic impurities, the solvating properties of carbon dioxide decrease as the fluid pressure decreases from supercritical to lower pressures (such as atmospheric pressure), which occurs during the decompression period of the chamber used for cleaning operations. Used for high-purity cleaning operations, such as those seen during wafer manufacturing or manufacturing or processing other workpieces or substrates. As the pressure decreases, impurities precipitate in the carbon dioxide solvent, which will damage the surface to be treated. , Contaminate the surface and reduce the effectiveness of the cleaning process. (2) (2) 200412631 Therefore, there is a need for a method to reduce or minimize the aforementioned problems to clean objects (such as wafers or other workpieces). [Summary of the Invention] The present invention generally relates to a method for cleaning an object by contacting the object with a solvent fluid including carbon dioxide, thereby removing impurities from the object, and replacing the solvent fluid with a replacement fluid. This replacement fluid is not carbon dioxide. In one embodiment, the article is a wafer and the replacement is performed at a temperature and pressure sufficient to prevent the formation of a second phase in the solvent fluid. In another embodiment, the replacement is performed at a temperature and pressure sufficient to prevent the formation of a second phase in the solvent fluid to be replaced, and carbon dioxide is recycled to the fluid. In another embodiment, the present invention is directed to a method for reducing the precipitation of non-volatile slag during the cleaning operation of a workpiece. The steps of the method include: the workpiece is in contact with the solvent fluid at a first pressure, and the solvent fluid includes carbon dioxide, whereby the contaminants on the workpiece are removed by the solvent fluid; reducing the pressure of the solvent fluid 'makes the nonvolatile slag insoluble In the solvent fluid; and replacing the solvent fluid with a replacement gas other than carbon dioxide at a low pressure, thereby reducing the time during which the workpiece is exposed to the insoluble non-volatile slag, thereby reducing the deposition of insoluble non-volatile slag on the workpiece Happening. In another embodiment, the invention is directed to a method of applying a cleaning fluid to a container. The steps of this method include: supplying a solvent fluid stream to a container holding an object at a first pressure, wherein the solvent fluid includes carbon dioxide, capable of dissolving pollutants on the object in the container; and supplying a replacement fluid stream to the container, wherein The pressure of the fluid flow for replacement is sufficient to replace -6 in the container. (3) (3) 200412631 'The solvent fluid, the replacement fluid is not carbon dioxide; and the solvent fluid is discharged to the outside of the container. The invention has several advantages. For example, implementing the method of the present invention results in ultra-clean surfaces, such as those required by semiconductor manufacturing and other industries. The method of the present invention is economical and easily integrated with existing manufacturing equipment. For example, in one feature, the method of the present invention uses a nitrogen replacement gas, and the apparatus usually has a nitrogen line. In one embodiment, available low-pressure (eg, 80-10OpsIg) nitrogen can be used. In another embodiment, the used carbon dioxide is recycled 'to reduce carbon dioxide consumption and related costs. In another embodiment, the recirculation can be performed without compressing the used fluid. In addition, the present invention takes into account non-volatile residual impurities that may be present in higher purity grades of carbon dioxide and problems caused by their precipitation when the vessel is decompressed. [Embodiments] The foregoing and other objects, features, and advantages of the present invention will be better understood from the following more specific description and accompanying drawings of the preferred embodiments of the present invention. In the drawings, similar numbers refer to the same components. The drawings are not according to the standard specifications, and the principle of the present invention is emphasized. The present invention relates generally to the manufacture of clean surfaces, such as those required during semiconductor manufacturing or processing. The present invention is related to removing, preventing or minimizing the deposition of contaminants on a wafer (eg, a wafer including one or more electromechanical devices), one or more integrated circuits, or a combination thereof, which is known in the art By. Other workpieces that can be processed using the present invention include parts used in semiconductor manufacturing (4) (4) 200412631 (such as · splash rakes and others), optical parts (such as optical lenses, frequency multipliers, laser emitting Crystals, beam splitters, light moons, fiberscopes) and others. Objects (such as television, camera and camera parts, scientific and musical instruments, satellite transmission, parts used in the aviation industry, and others) and other artifacts can also be handled as described here. Objects can be made from any material, including inorganic materials (such as silicon, dioxide 'sand, graphite, or metal), organic materials (such as polymers), or materials made from a combination of inorganic and organic materials. Cleaning can be applied to a single object, or it can be used to clean two or more objects simultaneously. The present invention relates to a method for removing contaminants or impurities from an object or the environment surrounding the object (e.g., a container in which the object is placed during the manufacture or processing of the object). This method itself can be a large manufacturing operation, such as: a method of depositing or growing a film, a photoetching method, an etching method, an ion implantation method, a chemical mechanical planarization method, a diffusion method, a photoresist development method, and developing a photosensitive material Method, method of cleaning optical components, method of cleaning components that can be used in aviation applications, photoresist stripping method, wafer cleaning method, wafer drying method, degreasing method or extraction method. 0 Contaminants include organic and / or inorganic materials that are not intended to be contained in the final product. They may be in solid, liquid or gas form. Examples include polymers, and other organic materials, silicon, carbon, and / or metals and other impurities. They may be present on the surface of an object or diffuse through at least a portion of the material containing the object. Miscellaneous charges can be generated by the object itself and can include parts of the wafer that are removed during wafer processing or debris made during the etching process. Impurities are also (5) (5) 200412631 Can be sent to the object with the treatment fluid. After the operation is completed, chemicals (such as: _ used to make or handle the object) may also remain on the surface of the object, or g @ # in the processing container. The invention is particularly suitable for removing non-volatile residue (NVR). During operation, high pressure carbon dioxide is used, especially at or near critical or supercritical conditions. Many NVRs are dissolved in carbon dioxide. As the pressure decreases, the density of carbon dioxide and solvent properties change, and NV R precipitates to form a second phase, usually in the form of aerosol droplets and / or solid fine particles. In the second phase, the NVR will impact the surface of the object, thus causing pollution. Examples of non-volatile residues include, but are not limited to, hydrocarbons (such as C1 () +), heavy hydrocarbons, and others. NVR sources include compressor oils, lacquers, solvent-soluble elastomers and valve seals commonly found in gaskets, sealants used in solvent feed pipes, and others. NV R may form on the workpiece during processing operations (eg, during wafer cleaning). The fluid used during the manufacture, processing or cleaning of the object can also be used to bring the NVR into contact with the surface of the object. In the semiconductor industry, "e.g.," photoresist development, photoresist stripping, wafer cleaning and wafer drying "is used for carbon dioxide. It is stated that the concentration of NVR in the entire carbon dioxide fluid does not exceed i0 ppm (by weight). Some commercial purity grades (in cylinders) contain about 0.15 p p m N V R (by weight). When used in sensitive procedures, 'it requires the final article to contain less than a specified number of particles of a selected size', even with higher grades with an unacceptable amount of NVR. For example, in some manufacturing methods, the number of particles per standard cubic meter of gas (6) (6) 200412631 higher than some specified sizes (basically about 100 nanometers) is required to be less than 100. It is estimated that the vaporization of one liter of higher purity grade liquid carbon dioxide (about 10 ppb) will result in millions of NVR particles. To achieve this level of cleanliness, the purity of the highest purity carbon dioxide currently supplied must be increased by at least 1,000 times. During the cleaning period using high-pressure carbon dioxide, the formation of the second-phase NVR is shown in Figs. 1A, 1B, and 1C. Shown in FIG. 1A is a cavity 10 in which a wafer 12 is placed. The cavity 10 is a container or vessel, such as a tool or processing area in a semiconductor manufacturing facility. Chamber 10 is designed to receive and retain high-pressure fluids, such as: supercritical carbon dioxide (carbon dioxide above its critical temperature and pressure, in particular, higher than 31t and 1 070 psi). The cavity 10 is provided with channels (for introducing process fluids and other chemicals) and suction channels, as known in the art. The manner of introducing and evacuating the cavity 10 is well known in the art. Examples include compressors, pumps, suction valves and others. As shown in Figure 1A, the cavity 10 is filled with carbon dioxide to a pressure of 2,000 pounds per square inch (p si g). At this pressure, the contaminants on the wafer are dissolved in the carbon dioxide solvent, and the second phase (insoluble) NVR concentration is extremely low. As the cavity 10 is decompressed to a lower pressure (such as 200 psig) (as shown in FIG. 2B), and then to normal pressure (such as shown in FIG. 1C), the solvating properties of carbon dioxide disappear toward the NVR and the first Two phases formed. The second-phase NVR in the cavity will impact the wafer and cause contamination. In one embodiment, the method of the present invention includes contacting an object (such as a wafer) with a solvent fluid including carbon dioxide, so that contaminants on the object are dissolved in the solvent fluid. High purity carbon dioxide is preferred. Other implementations -10- (7) (7) 200412631 In the example, the method of the present invention can use whole carbon dioxide. Generally, the solvent fluid includes at least 50% by weight carbon dioxide. The carbon dioxide content in the solvent fluid is preferably at least 75% by weight, more preferably at least 90% by weight, and most preferably at least 98% by weight. This solvent fluid may be 100% carbon dioxide. In other embodiments, the solvent fluid includes at least one additional component, such as a co-solvent, a surfactant, or a chelating agent. Examples of components that can be used other than carbon dioxide (alone or separately) include ammonia, halogenated hydrocarbons, hydrofluoric acid, sulfur dioxide, and others. Other examples of co-solvents, surfactants, and / or clampers include Shi Xiyuan; hydrocarbons, such as: A, B, C, D, D, Y, D, and propylene; halogenated hydrocarbons, such as: tetrafluoro Methane, chlorodifluoromethane, sulfur hexafluoride, and perfluoropropane; inorganic substances such as ammonia, ammonia, krypton, argon, and nitrous oxide; alcohols such as ethanol, methanol, or isopropanol; propylene carbonate; atmospheric Gases, such as: nitrogen, hydrogen, ozone or oxygen; water; amines, such as: hydroxylamine and alkanolamine; acetone; pyrrolidone, such as: N-methylpyrrolidone, n-ethylpyrrolidone, N -Hydroxyethylpyrrolidone and N-cyclohexylpyrrolidone; Amines, including dimethylacetamide or dimethylformamide; phenols and their derivatives; glycol ethers; 2-pyrrolidone Dialkylphosphonium; Organic and inorganic acids and their derivatives, such as · Hydrofluoric acid, hydrochloric acid, acetic acid, sulfuric acid, gallic acid or gallic acid esters; tetraalkylammonium hydroxide; ammonium difluoride; ammonium -Tetramethylammonium difluoride; alkali metal hydroxide; tartrate; phosphate; ethylenediamine tetraacetate (EDTA); ammonium and sodium sulfide And iron sulfate; and mixtures thereof. Generally, a solvent fluid including carbon dioxide is under conditions where contaminants (eg, NVR) are soluble in the solvent fluid. For example, the solvent fluid pressure including carbon dioxide -11- (8) (8) 200412631 carbon is at least 8 0 p ps l g. Preferably, the solvent fluid including carbon dioxide is at or near its critical state or in a supercritical condition. Carbon dioxide solvents can be introduced into the vessel in vapor, liquid or supercritical phases. Once inside the container, the carbon dioxide solvent comes into contact with the object to remove impurities. Removal of impurities can be accomplished by physical or chemical means, for example, carbon dioxide solvents can dissolve impurities; impurities can diffuse from the materials from which the objects are made into carbon dioxide solvents; or, the solvents react with carbon dioxide solvents to remove them from the objects. This removal can also be a mechanical mechanism, for example, the pressure and / or temperature of the carbon dioxide solvent can be adjusted to increase and / or decrease its specific volume, forming pressure so that impurities are forced out of the object. Impurities can also be removed by a combination of chemical and mechanical mechanisms. Optionally, this carbon dioxide solvent can be stirred to enhance chemical and mechanical mechanisms. For example, agitation can improve the rate of chemical removal mechanisms (eg, dissolution, diffusion reactions) by increasing the surface concentration gradient of the object, thereby making the chemical mechanism complete. Similarly, agitation also increases the removal rate of the mechanical removal mechanism because agitation creates shear forces in the fluid, which helps pull impurities from the surface of the object. The temperature and / or pressure of carbon dioxide can be adjusted to help remove impurities. The adjustment of these processing conditions will cause the carbon dioxide solvent to drive one or more phase transitions between the vapor, liquid and / or supercritical phases, depending on the adjustment and critical temperature and / or pressure of the carbon dioxide solvent and its condensation pressure and / Depending on the temperature. These adjustments are better to facilitate impurity removal. If there are several different types of impurities on or in the object, the carbon dioxide solvent can be cycled between various processing conditions (9) (9) 200412631 'to promote the removal of various types of impurities. When carbon dioxide solvents are subjected to these adjustments, NVR or removed impurities may be dissolved and / or precipitated in the solvent fluid. Optionally, 'at least a portion of the solvent fluid including the contaminants can be replaced with fresh fluid or pure carbon dioxide during the intervening cleaning step, whereby the used solvent fluid is moved and additional contaminants can be removed from the surface to be cleaned . This method includes replacing the solvent fluid with a replacement fluid (non-carbon dioxide) at a temperature and pressure sufficient to prevent the formation of a second phase in the solvent fluid to be replaced, thereby separating contaminants from the wafer, thereby cleaning Wafer. For example, the solvent fluid is replaced under pressure in the container without partial or total container pressure reduction. If the container is depressurized, it can be reduced to a pressure at which the solubility of the NVR in the solvent fluid is maintained. The replacement fluid can be a gas, liquid or supercritical fluid. Gastric replacement fluids are nitrogen, ammonia, argon or krypton, other gases (eg, oxygen), and any combination thereof. Nitrogen is preferred. In one embodiment of the present invention, the fluid used for the exchange is a high-purity gas. In another embodiment, the replacement fluid is an ultra-high purity gas, for example, the purity is such that the amount of all pollutants is sub-ppb or known by the industry. High-purity and ultra-high-purity gases (such as nitrogen and others) are commercially available. The method of the invention can be carried out continuously or batchwise. A description of this embodiment of the invention is shown in Figures 2A-2D. The one shown in FIG. 2A is the cavity 14 in which the wafer 12 is placed. The cavity 14 may be a container of -13- (10) (10) 200412631 as previously described. In other embodiments, the cavity 14 may be designed so that the incoming fluid enters the vessel, mixes it with an existing carbon dioxide solvent (for example, in a continuous stirred vessel reactor mode), or makes the flow path useful for used solvents, impurities, and Replacement of NVR (for example: in plug flow mode). In the best case, the shape of the container should be as small as possible during the replacement period of the carbon dioxide solvent, impurities, and NVR to reduce impurities and NVR in the object. Those skilled in the art may be provided with channels and means for introducing fluid into the fluid and evacuating the fluid in the cavity 14. As shown in FIG. 2A, the cavity 14 is filled with carbon dioxide to about 2000 p s i g, which includes dissolved contaminants. As shown in FIG. 2B, an inert gas (e.g., higher than 2000 psig) of carbon dioxide pressure in the container is introduced into the cavity 14. As shown in FIG. 2C, carbon dioxide and dissolved pollutants are replaced from the cavity 14. As shown in Fig. 2D, the cavity 14 including the replacement gas is then decompressed to atmospheric pressure. Use higher-purity replacement fluids and / or carbon dioxide solvents, or increase the volume of the replacement fluids used to more completely replace carbon dioxide solvents, impurities, and NVR. After vacuuming, the number of final impurities remaining on the object is improved. Once the solvent fluid, NVR, and other impurities are replaced from the container, the flow of replacement fluid can be stopped and the container can be evacuated. The carbon dioxide displaced from the container can be considered a waste stream or other operation or tool that can be directed into the equipment. In a preferred embodiment, the fluid displaced from the cavity 14 is purified. For example, -14- (11) (11) 200412631 directs the fluid discharged from the container to one or more purification units. Because the pressure of the fluid discharged from the chamber 14 is high (e.g., 2000 psig), the used fluid is usually introduced into the purification unit without further compression. Examples of purification techniques available include distillation, adsorption, absorption, chemical reactions, phase separation, and other methods. Displaced solvent fluids can be purified for NVRs, co-solvents, surfactants, and clamps. In other embodiments, the resulting fluid may be further purified to separate carbon dioxide from a replacement fluid (e.g., nitrogen). Suitable methods for separating carbon dioxide from nitrogen include distillation. In a preferred embodiment, carbon dioxide is recycled as described in US Patent Application No. 10 / 274,302, filed August 17, 2002, Recycle for Supercritical Carbon Dioxide. The recirculation is hereby incorporated by reference in its entirety. The replacement fluid can also be recycled. Recycling is particularly attractive if helium is used as the replacement fluid ' because of its cost and its significant lightweight characteristics that make it easier to remove. In another embodiment, the present invention relates to a method for reducing the deposition of non-volatile slag during the cleaning operation of a workpiece. This method involves contacting the workpiece with a solvent fluid, essentially the former. This method includes reducing the pressure of the solvent fluid, whereby contaminants such as NVR are soluble in the solvent fluid. This method further includes replacing the solvent fluid with a replacement fluid (such as the above) under a reduced pressure, thereby reducing the period during which the workpiece is exposed to insoluble pollutants (eg, NVR), thereby reducing insoluble pollutants (eg, NVR ) Deposition on the workpiece. (12) (12) 200412631 In one embodiment, the pressure of the ' solvent fluid drops below about 1,000 psig. In another embodiment, the ' pressure drops below 200 Paig. In another embodiment, the pressure of the solvent fluid is reduced to a level below that of the nitrogen source or equipment line pressure, e.g., to less than about 80-100 psig. Preferably, the wafer is exposed to insoluble NVR for less than 30 seconds. It is better that the wafer is exposed to insoluble NVR for less than 3 seconds. Optionally, at least a portion of the solvent fluid and dissolved contaminants can be replaced with fresh solvent fluid or pure carbon dioxide in an intervening washing step. This rinsing step can be performed before or after the container is decompressed. Carbon dioxide and optional replacement gas are recyclable, as described previously. Recycling may include a compression step before the fluid to be recycled is introduced to the purifier. As mentioned previously, this method can be carried out in a continuous or batch manner. An example of this embodiment phase of the invention is shown in Figures 3A-3E. The one shown in Fig. 3A is the cavity 14 in which the wafer 12 is placed, which is basically as described above. Carbon dioxide at a pressure of about 2000 psig is present in the cavity 14. The chamber 14 is depressurized to 200 psig, as shown in FIG. 3B. After the pressure dropped, the NVR precipitated out of solution and formed a second phase. The pressure of the inert gas (such as nitrogen) is sufficient to push the 200 psiag solvent fluid into the cavity 14, as shown in FIG. 3C, thereby replacing the carbon dioxide and second-phase impurities in the cavity 14, as shown in FIG. 3D. Replacing the carbon dioxide and second-phase impurities in the container can reduce the time that the wafer is exposed to the insoluble NVR, thereby reducing the deposition of the insoluble NVR on the wafer. As shown in Figure 3E, the cavity 14 is then depressurized to normal pressure. In one embodiment, the present invention relates to a method of manufacturing an ultra-clean article. (16) (13) (13) 200412631. The so-called "ultra-clean" here means that the degree of contamination of the substrate is less than about 2,000 particles per square meter of surface area, and the effective diameter of this impurity is greater than about 0.1 microns, which is measured by light scattering techniques. This technique is known for measuring light scattering of particles having an effective diameter on the surface of a solid of greater than about 0.1 microns. For example, the appropriate method is described in Diaz, RE, etc. on page 79 in Contamination-Free Manufacturing for Semiconductors and other Precision Products (Marcell Dekker, 2001), edited by RP Donovan. People, " 〇η · Wafer Measurement of Particles in Contamination- Free Manufacturing for Semiconductors and other Precision Products ". The method includes contacting an object with a carbon dioxide solvent in a container, whereby impurities on the object are dissolved in the carbon dioxide solvent, and a replacement gas is introduced into the container to reduce the exposure of the object to the non-volatile impurities present in the carbon dioxide. 1 微米。 Time, thereby reducing the number of impurities on the object to less than about 2000 particles / square meter surface area, wherein the effective diameter of the impurities measured by light scattering technology is greater than 0.1 microns. In another embodiment, the present invention provides a method for supplying a cleaning fluid to a container. The steps of this method include supplying a first pressure solvent fluid stream to a container in which an object is placed, wherein the solvent fluid includes carbon dioxide and is capable of dissolving contaminants on the object in the container; supplying a replacement fluid stream to the container, The pressure of the replacement fluid flow is sufficient to replace the solvent flow in the container, and the replacement fluid is not carbon dioxide; and the solvent fluid (14) 200412631 is discharged out of the container. The fluid discharged from the container can be purified (as described above), and carbon dioxide can be recycled to the container. Before the purified carbon dioxide is returned to the container, it can be compressed in a manner known in the art. In one embodiment, the displacement fluid flow pressure is at least equal to the first pressure. In one example, the replacement fluid pressure is no more than about 100 psi higher than the solvent fluid pressure it is replacing. In another embodiment, the first pressure is at least 1,000 psig. The pressure of the fluid discharged from the container may be higher than the operating pressure of the purification unit. In another embodiment, the pressure at which the solvent fluid is discharged from the container is lower than the first pressure, and the pressure of the replacement fluid is sufficient to push the solvent fluid. The present invention has been particularly proposed and described with reference to preferred embodiments, and those skilled in the art will understand how to make a wide variety of details from the described details without departing from the scope of the invention covered by the scope of the attached application patent change. [Brief description of the drawings] What is attached to Figures 1 A to 1 C is the formation phase of the second phase when the pressure in the container in which the object in contact with carbon monoxide is placed drops. 2A-2D are method steps of an embodiment of the present invention. 3A-3E are method steps of another embodiment of the present invention. Main component comparison table 10 12 cavity wafer -18- (15) 200412631
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