經濟部智慧財產局員工消費合作社印製 469526 6794twf.d〇c/006 pj _B7__ 五、發明說明（f ) 本發日i是有關於一種半導體製程的淸潔方法，且特別 是有關於一種應用於雙重金屬鑲嵌(Dual Damascene)製程的 淸潔方法。 在多重金屬內連線製程中採用雙重金屬鑲嵌結構(Duel Damascene Structure)，可使元件的可靠度增加，並使製程 能力提昇，因此，在元件高度積集化之後，雙重金屬鑲嵌 已逐漸成爲半導體工業所採用的主要技術。 超大型積體電路製程要得到高良率，晶片在各階段製 程中的洗淨工作爲重要因素之一。晶片上的污染槪分爲微 粒（Particulate)與薄膜污染（Film Contamination)兩類。任何 顆粒出現在晶片表面上都叫微粒，它可能來自於操作人 員，或是從操作設備掉出，如高溫爐之石英管、蝕刻殘留 之薄膜或光阻微粒等，甚至去離子純水內的微粒、細菌都 是微粒的來源。另一方面，晶片表面有任何一層外來物都 叫薄膜污染，如溶劑殘留、顯影液殘留等。 第1A圖是習知雙重金屬鑲嵌製程中，經過雙重金屬 鑲嵌開口之蝕刻與淸潔後的基底剖面圖。 請參照第1A圖，在含有金屬銅層102之基底100上 有一介電層104,且介電層104上已經由乾式鈾刻形成雙 重金屬鑲嵌開口 120。通常在形成雙重金屬鑲嵌開口 120 之後會以稀氟化氫溶液進行淸潔，然而，淸潔過後仍無法 完全去除介層窗開口 106內之聚合物殘留物108。另外， 作爲淸潔用之氟化氫溶液會過度侵蝕金屬銅層】02的表 面，而造成凹陷的現象。 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） -----------ί -裝--------τ訂-------故 (請先閱讀背面之注意事項再填寫本頁) 經濟部智慧財產局員工消費合作杜印製 46 95 2 6 67 94twf. doc/006 A7 _B7 ____ 五、發明說明（z) 第1B圖所繪示爲習知雙重金屬鑲嵌製程中，經化學 機械硏磨與淸潔後的基底剖面圖。 請參照第1B圖，接著於基底100上形成一金屬銅層 以塡滿雙重金屬鑲嵌開口 120,然後以化學機械硏磨法 (Chemical Mechanica丨 Polishing，CMP)去除雙重金屬鑲嵌開 口 120以外的金屬銅層，以得雙重金屬鑲嵌結構122。然 後，以 ESC780 溶液（Amine-containing Solution)作爲淸潔用 的溶液。但是，經過淸潔之後的雙重金屬鑲嵌結構122表 面如第1B圖所示，仍然殘留有碳氫化合物微粒109 (Hydrocarbon Particulate)與硏漿殘留物 110 (Slurry Residue) ° 因此，習知方法的缺點在於以乾蝕刻形成雙重金屬鑲 嵌開口之後，只以稀氟化氫溶液作淸潔並無法完全去除聚 合物殘留物；而習知方法的另一個缺點在於以CMP將介 電層上沉積的金屬層去除之後，所進行的淸潔並無法完全 去除由CMP硏槳與介電層104反應所形成之碳氫化合物 微粒與硏漿殘留物，所以會導致晶片表面局部粗糙、凹凸 不平，進而造成其後微影製程的失敗。 因此，本發明提供一種應用於雙重金屬鑲嵌製程的淸 潔方法，用以在蝕刻形成介層窗開口之後，增進淸潔效率 以達到無殘留的目的：並於化學機械硏磨製程之後，完全 去除碳氫化合物微粒與硏漿殘留物。此方法是在含有導電 層之一基底上形成一介電層，然後進行微影蝕刻製程，以 在介電層中形成一雙重金屬鑲嵌開口，並以導電層作爲蝕 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） (請先閱讀背面之注意事項再填寫本頁) 裝--------；訂-------I--旅 經濟部智慧財產局員工消費合作社印製 ^69526 679 4twf. doc/006 A7 五、發明說明（）） 刻終點。接著，以過氧化氫氧化雙重金屬鑲嵌開口中的聚 合物殘留物，並以控制溫度的方式控制過氧化氫對導電層 的氧化速率，再利用稀氟化氫溶液或稀氟化氫/氯化氫溶液 去除氧化之聚合物殘留物。之後，於基底上形成一層導電 層以塡滿此雙重金屬鑲嵌開口。然後，利用化學機械硏磨 法將雙重金屬鑲嵌開口以外的導電層去除。隨後，利用變 氧化氫去除化學機械硏磨之後所形成的碳氫化合物微粒， 並利用稀氟化氫/氯化氫溶液或稀氟化氫溶液去除化學機械 硏磨用硏漿中的氧化矽，以完成淸潔的製程。 爲讓本發明之上述和其他目的、特徵和優點能更明顯 易懂，下文特舉一較佳實施例，並配合所附圖式，作詳細 說明如下： 圖式之簡單說明： 第1A圖是習知雙重金屬鑲嵌製程中，經過雙重金屬 鑲嵌開口之蝕刻與淸潔後的基底剖靣圖； 第1B圖所繪示爲習知雙重金屬鑲嵌製程中，經化學 機械硏磨與淸潔後的基底剖面圖；以及 第2A圖至第2F圖是依照本發明較佳實施例所得之雙 重金屬鑲嵌的製作流程剖面圖。 標記之簡單說明： 10(Γ，200 :基底 102 :金屬銅層 104，204 :介電層 106，206 :介層窗開口 本紙張尺度適用中囤國家標準（CNS)A4規格（210 X 297公釐） ------------^ t裝--------r 訂---------線 (請先閱讀背面之注意事項再填寫本頁) 9 5 2 6 679 4twf. doc/006 pj _ __B7 _ 五、發明說明（# ) 108，208 :聚合物殘留物 109 ’ 209 :碳氫化合物微粒 110，210 :硏漿殘留物 <請先閱讀背面之注意事項再填寫本頁) 120，220 :雙重金屬鑲嵌開口 122、222a :雙重金屬鑲嵌結構 202，222 :導電層 實施例 第2A圖至第2F圖是依照本發明較佳實施例所得之雙 重金屬鑲嵌的製作流程剖面圖。 請參照第2A圖，首先在基底200上形成導電層202， 此導電層202的材質例如是金屬銅。 然後，請參照第2B圖，在基底200上形成介電層204， 再以乾式蝕刻於導電層202上方之介電層204中形成雙重 金屬鑲嵌開口 220。此時在介層窗開口 206內會殘留有因 蝕刻所產生之聚合物殘留物208。 本實施例以形成雙重金屬鑲嵌開口 220爲例，然而， 本發明並不僅限於形成雙重金屬鑲嵌開口 220,任何形成 內連線之開口也可形成在本發明中。 經濟部智慧財產局員工消費合作社印製 隨後，請參照第2C圖，利用過氧化氫溶液(H202 based aqueous solution)來淸潔雙重金屬鑲嵌開口 220，其淸潔效 率係由溫度來控制，但此溫度之上限需以不會過度侵蝕導 電層2〇2爲準，以將導電層202的凹陷降至最小。過氧化 氫溶液是用來氧化介層窗開口 206內的聚合物殘留物208， 其溫度例如控制在3(TC~45°C左右。另外，當導電層2〇2 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公ΐ ) 經濟部智慧財產局員工消費合作社印製 “09526 6794twf.doc/006 A7 B7 五、發明說明（f) 爲金屬銅時，過氧化氫溶液也可以將金屬銅之表面氧化爲 氧化銅(CuOJ。因此，當利用稀氟化氫溶液或稀氟化氫/氯 化氫溶液（dilute HF/HC1 solution)進行淸潔時’可以將金屬 銅層上所形成之氧化銅層（未繪示於圖中）除去’並使氧化 銅表面之聚合物殘留物上揚。因此’導電層202可具有平 坦的表面。 接著，請參照第2D圖’於介電層204上形成一層導 電層222以塡滿此雙重金屬鑲嵌開口 220,此導電層222 的材質例如是金屬銅。 然後，請參照第2E圖，利用化學機械硏磨法（ChemicalPrinted by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 469526 6794twf.d0c / 006 pj _B7__ V. Description of the Invention (f) The date of issue i relates to a cleaning method for a semiconductor process, and in particular to an application for Cleaning method for dual metal damascene process. The use of a dual metal damascene structure in the multi-metal interconnect process can increase the reliability of the device and improve the process capability. Therefore, after the component is highly integrated, the dual metal damascene has gradually become a semiconductor The main technology used by the industry. To obtain a high yield in the process of ultra-large integrated circuits, the cleaning of the wafer in each stage of the process is one of the important factors. There are two types of contamination on wafers: Particulate and Film Contamination. Any particles appearing on the surface of the wafer are called particles, which may come from the operator or fall out of the operating equipment, such as the quartz tube of a high-temperature furnace, the etched residual film or photoresist particles, and even the deionized pure water. Particles and bacteria are sources of particles. On the other hand, any layer of foreign matter on the surface of the wafer is called film contamination, such as solvent residues and developer residues. Figure 1A is a cross-sectional view of the substrate after the etching and cleaning of the double metal inlaid opening in the conventional double metal damascene process. Referring to FIG. 1A, a dielectric layer 104 is formed on a substrate 100 containing a metallic copper layer 102, and a double heavy metal damascene opening 120 has been formed on the dielectric layer 104 by dry uranium etching. Cleaning is usually performed with a dilute hydrogen fluoride solution after the double metal damascene opening 120 is formed. However, the polymer residue 108 in the interlayer window opening 106 cannot be completely removed after cleaning. In addition, the hydrogen fluoride solution used for cleaning will erode the surface of the metal copper layer excessively, resulting in the phenomenon of depression. This paper size is applicable to China National Standard (CNS) A4 (210 X 297 mm) ----------- ί-installed -------- τ order --------- Therefore (please read the precautions on the back before filling this page) Printed by the consumer cooperation of the Intellectual Property Bureau of the Ministry of Economy 46 95 2 6 67 94twf. Doc / 006 A7 _B7 ____ V. Description of the invention (z) Drawing in Figure 1B Shown is a cross-sectional view of the substrate after chemical mechanical honing and honing in the conventional double metal damascene process. Referring to FIG. 1B, a metal copper layer is formed on the substrate 100 to fill the double metal damascene opening 120, and then the metal copper other than the double metal damascene opening 120 is removed by chemical mechanical honing (CMP). Layer to obtain a dual metal damascene structure 122. Then, use ESC780 solution (Amine-containing Solution) as the cleaning solution. However, as shown in FIG. 1B, the surface of the double metal mosaic structure 122 after cleaning has remained hydrocarbon particles 109 (Hydrocarbon Particulate) and slurry residue 110 (Slurry Residue). Therefore, the disadvantages of the conventional method After the double metal damascene opening is formed by dry etching, the polymer residue cannot be completely removed only by diluting with a dilute hydrogen fluoride solution; another disadvantage of the conventional method is that the metal layer deposited on the dielectric layer is removed by CMP. The cleaning process performed cannot completely remove the hydrocarbon particles and slurry residues formed by the reaction between the CMP paddle and the dielectric layer 104, so it will cause local roughness and unevenness on the wafer surface, which will cause subsequent lithography. Process failure. Therefore, the present invention provides a cleaning method applied to a dual metal damascene process, which is used to improve the cleaning efficiency after the formation of an interstitial window opening to achieve the goal of no residue: and is completely removed after the chemical mechanical honing process Hydrocarbon particles and pulp residues. In this method, a dielectric layer is formed on a substrate containing a conductive layer, and then a lithographic etching process is performed to form a double metal damascene opening in the dielectric layer, and the conductive layer is used as the etching. CNS) A4 size (210 X 297 mm) (Please read the precautions on the back before filling out this page) Packing --------; Ordering -------- I-- Intellectual Property of the Ministry of Travel and Economy Printed by the Bureau's Consumer Cooperatives ^ 69526 679 4twf. Doc / 006 A7 V. Description of Invention () Next, the polymer residue in the opening of the double metal hydroxide inlay is embedded, and the oxidation rate of the conductive layer by hydrogen peroxide is controlled in a temperature-controlled manner, and then the dilute hydrogen fluoride solution or dilute hydrogen fluoride / hydrogen chloride solution is used to remove the oxidized polymerization. Residues. Then, a conductive layer is formed on the substrate to fill the double metal damascene opening. Then, a chemical mechanical honing method is used to remove the conductive layer other than the double metal damascene opening. Subsequently, the hydrocarbon particles formed after the chemical mechanical honing are removed by using variable hydrogen oxide, and the silicon oxide in the slurry for chemical mechanical honing is removed by using a dilute hydrogen fluoride / hydrogen chloride solution or a dilute hydrogen fluoride solution to complete the cleaning process. . In order to make the above and other objects, features, and advantages of the present invention more comprehensible, a preferred embodiment is given below in conjunction with the accompanying drawings for detailed description as follows: Brief description of the drawings: FIG. 1A is In the conventional double metal damascene process, a cross-sectional view of the substrate after etching and cleaning of the double metal damascene opening; Figure 1B shows the chemical mechanical honing and honing in the conventional double metal damascene process. A cross-sectional view of the substrate; and FIGS. 2A to 2F are cross-sectional views of a manufacturing process of a dual metal inlay obtained according to a preferred embodiment of the present invention. Brief description of the mark: 10 (Γ, 200: substrate 102: metal copper layer 104, 204: dielectric layer 106, 206: opening of the dielectric window This paper is applicable to the national standard (CNS) A4 specification (210 X 297 male) Li) ------------ ^ t equipment -------- r order --------- line (please read the precautions on the back before filling this page) 9 5 2 6 679 4twf. Doc / 006 pj _ __B7 _ V. Description of the invention (#) 108, 208: polymer residue 109 '209: hydrocarbon fine particles 110, 210: pulp residue < read first Note on the back, please fill in this page again) 120, 220: Double metal inlay openings 122, 222a: Double metal inlay structure 202, 222: Conductive layer embodiment Figures 2A to 2F are obtained according to the preferred embodiment of the present invention A cross-sectional view of the manufacturing process of double metal inlay. Referring to FIG. 2A, a conductive layer 202 is first formed on a substrate 200. The material of the conductive layer 202 is, for example, metallic copper. Then, referring to FIG. 2B, a dielectric layer 204 is formed on the substrate 200, and then a double metal damascene opening 220 is formed in the dielectric layer 204 above the conductive layer 202 by dry etching. At this time, a polymer residue 208 remaining in the interlayer window opening 206 due to etching remains. In this embodiment, the formation of the double metal inlaid opening 220 is taken as an example. However, the present invention is not limited to the formation of the double metal inlaid opening 220, and any opening forming the interconnection can also be formed in the present invention. Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. Please refer to Figure 2C. Use hydrogen peroxide solution (H202 based aqueous solution) to clean the double metal inlaid opening 220. Its cleaning efficiency is controlled by temperature. The upper limit of the temperature should be based on the fact that the conductive layer 202 will not be excessively eroded to minimize the depression of the conductive layer 202. The hydrogen peroxide solution is used to oxidize the polymer residue 208 in the opening 206 of the interlayer window, and its temperature is controlled at, for example, about 3 ° C to 45 ° C. In addition, when the conductive layer is 002, the Chinese standard is applicable to this paper size (CNS) A4 specification (210 X 297 gong) Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs “09526 6794twf.doc / 006 A7 B7 V. Description of the invention (f) For metallic copper, hydrogen peroxide solution can also be used The surface of metal copper is oxidized to copper oxide (CuOJ. Therefore, when using a dilute hydrogen fluoride solution or a dilute HF / HC1 solution for cleaning, the copper oxide layer (not (Shown in the figure) removes' and raises the polymer residue on the surface of the copper oxide. Therefore, the 'conductive layer 202 may have a flat surface. Next, please refer to FIG. 2D' to form a conductive layer 222 on the dielectric layer 204 The double metal inlaid opening 220 is filled, and the material of the conductive layer 222 is, for example, metal copper. Then, referring to FIG. 2E, a chemical mechanical honing method is used.
Mechanical Polishing, CMP)將雙重金屬鑲嵌開口 220外的 導電層222去除，並以介電層204爲硏磨終點’以形成雙 重金屬鑲嵌222a。在化學機械硏磨製程中例如可添加苯並 三哩(benzotriazol，BTA)以降低導電層222的腐蝕速率’並 防止其表面粗糙；且可添加界面活性劑以防止被去除的微 粒再沉積於晶片表面。經過化學機械硏磨之後的雙重金屬 鑲嵌結構222a表面仍然殘留有碳氫化合物微粒209與硏漿 殘留物210。 最後，請參照第2F圖。利用過氧化氫溶液淸潔雙重 金屬鑲嵌結構222a，以去除由CMP硏漿與介電層204反 應形成的碳氫化合物微粒209。此時，也必須控制過氧化 氫溶液溫度，以確保雙重金屬鑲嵌222a不華過度侵蝕， 其溫度例如控制例如在50°C〜60°C之間。然後’利用稀氟 化氫溶液或稀氟化氫/氯化氫溶液去除大部分的CMP硏漿 7 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） —--------^ .裝i丨丨—Jtri.-------線 (請先閱讀背面之ii意事項再填寫本頁) 46 95 2 6 ^794twf.doc/006 A7 B7___ 五、發明說明（& ) 殘留物210。在淸潔過程中例如可以使用百萬赫茲音波 (Megasonic power)來幫助去除微粒’以獲得表面乾淨、平 坦的雙重金屬鑲嵌結構222a。 本發明之特徵包括下列各點： 1. 在形成雙重金屬鑲嵌開口之後’以及利用CMP將 雙重金屬鑲嵌開口外的導電層去除之後的淸潔製程中’均 利用過氧化氫溶液作爲淸潔溶液，其淸潔效率係由溫度來 控制，但此溫度必須是不致過度侵蝕導電層的溫度。在形 成介層窗開口之後的淸潔製程中，過氧化氫溶液是用來氧 化介層窗開口內的聚合物殘留物，使其易於去除；而在利 用CMP去除雙重金屬鑲嵌開口外的導電層之後的淸潔製 程中，過氧化氫溶液是用來去除由CMP硏漿與介電層反 應所形成之碳氫化合物微粒。 2. 當塡入雙重金屬鑲嵌開口中的導電層爲金屬銅時， 過氧化氫溶液可以氧化雙重金屬鑲嵌側壁的碳氫聚合蝕刻 殘留物，也可將銅氧化爲氧化銅，以減緩隨後用氟化氫作 爲淸潔溶液所造成導電層的破壞。 3. 在形成雙重金屬鑲嵌開口之後的淸潔製程中，稀氟 化氫溶液或稀氟化氫/氯化氫溶液可用來升起氧化銅表面之 聚合物殘留物，以避免殘留物再沉積；而在利用CMP去 除雙重金屬鑲嵌開口外的導電層之後的淸潔製程中，稀氟 化氫溶液或稀氟化氫/氯化氫溶液可用來去除大部分的 CMP硏漿殘留物 4. 淸潔過程中的Magasonic Power有助於去除微粒。 8 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） (請先閱讀背面之注意事項再填寫本頁) 裝 ill--,'11.—·----!據 經濟部智慧財產局員工消費合作社印製 4 b 9 5 2 6 6794twf.d〇c/〇〇6 fij B7 五、發明說明（、） 5, 在CMP過程中加入BTA ( benzotriazol )可以降低 導電層的腐鈾速率，並防止其表面變粗糙。 6. 在CMP過程中使用界面活性劑，可以防止硏磨掉 的顆粒再沉積於基底上。 雖然本發明已以一較佳實施例揭露如上’然其並非用 以限定本發明，任何熟習此技藝者，在不脫離本發明之精 神和範圍內，當可作些許之更動與潤飾，因此本發明之保 護範圍當視後附之申請專利範圍所界定者爲準。 (請先閱讀背面之注意事項再填寫本頁) 裝 -- ------訂 ---Mechanical Polishing (CMP) removes the conductive layer 222 outside the double metal damascene opening 220 and uses the dielectric layer 204 as a honing end point 'to form a double heavy metal damascene 222a. In the chemical mechanical honing process, for example, benzotriazol (BTA) may be added to reduce the corrosion rate of the conductive layer 222 and prevent the surface from being roughened; and a surfactant may be added to prevent the removed particles from being redeposited on the wafer. surface. After the chemical-mechanical honing, the surface of the double metal mosaic structure 222a still has hydrocarbon fine particles 209 and mortar residue 210. Finally, please refer to Figure 2F. The double metal damascene structure 222a is cleaned with a hydrogen peroxide solution to remove hydrocarbon particles 209 formed by the reaction of the CMP slurry and the dielectric layer 204. At this time, the temperature of the hydrogen peroxide solution must also be controlled to ensure that the double metal inlay 222a is not excessively corroded, and its temperature is controlled, for example, between 50 ° C and 60 ° C. Then 'remove most of the CMP slurry using a dilute hydrogen fluoride solution or a dilute hydrogen fluoride / hydrogen chloride solution. 7 The paper size is applicable to the Chinese National Standard (CNS) A4 specification (210 X 297 mm) ---------- ^. Install i 丨 丨 —Jtri .------- line (please read the ii meaning on the back before filling this page) 46 95 2 6 ^ 794twf.doc / 006 A7 B7___ V. & Description of the Residue物 210。 210. During the cleaning process, for example, Megasonic power can be used to help remove particles ' to obtain a clean, flat double metal damascene structure 222a. The features of the present invention include the following points: 1. After the double metal damascene opening is formed, and in the cleaning process after removing the conductive layer outside the double metal damascene opening by CMP, a hydrogen peroxide solution is used as the cleaning solution. Its cleaning efficiency is controlled by temperature, but this temperature must be a temperature that does not excessively etch the conductive layer. In the cleaning process after the formation of the via window, the hydrogen peroxide solution is used to oxidize the polymer residues in the via window opening, making it easy to remove; and the CMP is used to remove the conductive layer outside the double metal damascene opening. In the subsequent cleaning process, the hydrogen peroxide solution is used to remove the hydrocarbon particles formed by the reaction between the CMP slurry and the dielectric layer. 2. When the conductive layer inserted into the double metal damascene opening is metallic copper, the hydrogen peroxide solution can oxidize the hydrocarbon polymerization etching residues of the double metal damascene sidewall, or oxidize copper to copper oxide to slow down the subsequent use of hydrogen fluoride Destruction of conductive layer caused by cleaning solution. 3. In the cleaning process after the double metal mosaic opening is formed, a dilute hydrogen fluoride solution or a dilute hydrogen fluoride / hydrogen chloride solution can be used to raise the polymer residue on the surface of the copper oxide to avoid redeposition of the residue; In the cleaning process after the heavy metal is embedded in the conductive layer outside the opening, a dilute hydrogen fluoride solution or a dilute hydrogen fluoride / hydrogen chloride solution can be used to remove most of the CMP slurry residue. 4. Magasonic Power during the cleaning process helps to remove particles. 8 This paper size is applicable to China National Standard (CNS) A4 (210 X 297 mm) (Please read the precautions on the back before filling this page). Ill-, '11 .------! Printed by the Consumer Cooperative of the Ministry of Intellectual Property Bureau 4 b 9 5 2 6 6794twf.d〇c / 〇〇6 fij B7 V. Description of the invention (,) 5, Adding BTA (benzotriazol) in the CMP process can reduce the corrosion of the conductive layer Uranium rate and prevent its surface from becoming rough. 6. The use of a surfactant during the CMP process can prevent honing particles from re-depositing on the substrate. Although the present invention has been disclosed above in a preferred embodiment, it is not intended to limit the present invention. Anyone skilled in the art can make some modifications and retouching without departing from the spirit and scope of the present invention. The scope of protection of the invention shall be determined by the scope of the attached patent application. (Please read the notes on the back before filling out this page) Loading------- Order ---
A 經濟部智慧財產局員工消費合作杜印製 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐）A Consumption cooperation by employees of the Intellectual Property Bureau of the Ministry of Economic Affairs, printed on paper This paper applies the Chinese National Standard (CNS) A4 specification (210 X 297 mm)