1221315 ⑴ 玖、發明說明 【發明所屬之技術領域】 本發明係關於銅電鍍方法，特別是關於半導體銅製程 中’用以形成銅導線之銅電鍍的方法。 【先前技術】1221315 ⑴ 玖, Description of the invention [Technical field to which the invention belongs] The present invention relates to a copper plating method, and more particularly to a method of copper plating used to form copper wires in a semiconductor copper process. [Prior art]
近年來，隨著積體電路微小化的顯著提升，在積體電 路製程中屬於後段製程之金屬化製程中的鋁導線，已逐漸 由導電係數較小的銅導線所取代，亦即由所謂的銅製程形 成銅導線。舉例而言，在銅製程中，會形成所謂的嵌刻結 構（damascene structure )，在嵌刻結構中形成障壁層及 /或種子層之後，以電鍍銅之方式，形成銅導線。在積體 電路製程中，由於製造及檢測過程中，會有例如有機物等 污染物殘留於，雖然，這些殘留物會被控制在適當範圍之 內，但是，隨著積體電路進一步地微小化，特徵尺寸持續 縮減，這些污染物所造成的負面影響愈加顯著，以致於愈 來愈難以取得無缺陷之銅塡充。 【發明內容】 慮及上述問題，本發明之目的在於提供銅電鍍方法， 其能夠在進行銅電鍍時，先除去障壁層及/或種子層上的 污染物，而曝露新銅層以致於電鍍時能夠從新銅層上沈積 銅，而能無縫地生長銅。 根據本發明的一態樣，用於銅製程之銅電鍍方法；包 -4- (2) 1221315 括下述步驟：淸洗步驟，以去離子水稀釋低濃度的H2〇2 所形成的淸洗液，淸洗形成有銅種子層的基底，以致於在 该銅種子層的表面上形成銅氧化物；銅氧化物移除步驟， 將該基底置於包含硫酸銅（CuS04 )及硫酸（H2S04 )的 電解液中，以移除該銅種子層上的銅氧化物；及電鍍步驟 ’執行銅電鍍以在曝露的新銅種子層上生長銅。In recent years, with the significant improvement in the miniaturization of integrated circuits, the aluminum wires in the metallization process, which is a later stage of the integrated circuit process, have gradually been replaced by copper wires with a smaller conductivity, which is called the so-called The copper process forms copper wires. For example, in a copper manufacturing process, a so-called damascene structure is formed. After forming a barrier layer and / or a seed layer in the engraved structure, copper wires are formed by electroplating copper. In the manufacturing process of integrated circuits, pollutants such as organics will remain during the manufacturing and testing process. Although these residues will be controlled within an appropriate range, as the integrated circuits are further miniaturized, The size of features has continued to shrink, and the negative effects of these pollutants have become increasingly significant, making it increasingly difficult to obtain defect-free copper charge. [Summary of the Invention] In view of the above problems, an object of the present invention is to provide a copper electroplating method, which can remove contaminants on the barrier layer and / or seed layer when performing copper electroplating, and expose a new copper layer so as to electroplat Copper can be deposited from a new copper layer and copper can be grown seamlessly. According to one aspect of the present invention, a copper electroplating method for a copper process; the package -4- (2) 1221315 includes the following steps: a rinsing step, diluting a low concentration of H2O2 with deionized water The substrate with the copper seed layer formed thereon, so that a copper oxide is formed on the surface of the copper seed layer; the copper oxide removing step places the substrate containing copper sulfate (CuS04) and sulfuric acid (H2S04) An electrolytic solution to remove copper oxide on the copper seed layer; and a plating step 'perform copper plating to grow copper on the exposed new copper seed layer.
在根據本發明之銅電鍍方法中，淸洗液之H2o2的濃 度爲幾十PPM至百分之幾，而淸洗之時間約1_10秒，然 後’再以諸如旋轉等方式乾燥化。 此外’在根據本發明之銅電鍍方法，在一秒內完成該 銅氧化物移除步驟，然後立即執行該電鍍步驟。 根據本發明之銅電鍍方法，能夠增加電解液對狹窄特 徵的潤濕性並能夠將表面銅氧化物與不需要的污染物一起 移除’以在銅開始電鍍之前曝露出新銅層，藉以取得具有 良好品質的電鑛銅。In the copper electroplating method according to the present invention, the concentration of H2o2 in the washing solution is several tens of PPM to several percent, and the washing time is about 1 to 10 seconds, and then 'dried by means such as spinning. In addition, in the copper plating method according to the present invention, the copper oxide removing step is completed in one second, and then the plating step is performed immediately. According to the copper electroplating method of the present invention, the wettability of the electrolyte to narrow features can be increased and the surface copper oxide can be removed together with unwanted contaminants to expose a new copper layer before the copper begins to electroplate, thereby obtaining Electric ore copper with good quality.
根據本發明，現有的電鍍機僅需稍微修改硬體以塡加 淸洗液’即可執行本發明，因此，可以減少設備投資，但 又可取得具有優良性能之銅導線，因而能以高產能製造半 導體裝置，顯著地減少生產成本。 再者，根據本發明，可以簡單及容易地取得無縫生長 的銅，並可在室溫下執行銅電鍍，不會劣化任何重要的界 面，而能以低成本可靠地形成銅導線。 -5 - (3) (3)1221315 【實施方式】 將於下參考附圖’說明根據本發明之製造積體電路中 的銅導線的銅電鍍實施例。應瞭解下述說明僅作爲舉例說 明之用’並非用以限定本發明。此外，爲了提供更淸楚的 說明，圖示並未依比例繪製。 在下述說明中，根據本發明的實施例的製程步驟及對 應結構，並未涵蓋製造完整的I c電路的完整製程，但是 可以配合半導體技術領域中不同的I c電路中的其它製程 而製造所需的完整IC電路。 圖1係擬形成銅導線及/或銅栓塞的嵌刻結構實施例 ，其係使用根據本發明的銅電鍍方法的實施例，進行銅電 鍍之前的嵌刻結構。如圖1所示，1 0 1係S i 0 2層，作爲層 間金屬介電質，在Si〇2層101中形成有溝槽，且在Si02 層101上以物理汽相沈積法（PVD)形成障壁層/種子層 1 〇2。爲了簡潔起見，在圖1中僅顯示一個溝槽，但是， 溝漕數目可以爲多於一之數目。此外，在圖1中多個黑色 顆粒係代表製造過程或檢測過程中附著於種子層表面上的 有機物或及不必要的污染物。 接著，在下述中，以圖1所示的嵌刻結構爲例以說明 根據本發明的銅電鍍方法的實施例。 根據本實施例，銅電鍍方法主要包括三個程序’分別 爲淸洗程序、銅氧化物層移除程序、及電鍍程序。 首先，說明淸洗程序。如圖2所示，在淸洗程序中’ 係以去離子水稀釋H202而形成的稀釋H2〇2溶液淸洗如圖 -6 - (4)1221315 1所不的嵌刻結構。根據本實施例，稀釋的Η 2 Ο 2溶液是 以去離子水稀釋含有3 %的Η 2 0 2之非常低濃度的奧克多（ Gxydol )而形成的。嵌刻結構在浸入如此取得的稀釋溶液 後’會在銅種子層上形成厚度約5 〇 A的薄銅氧化物層1 〇3 ’並能增進電解液對狹窄特徵之可濕性，而有利於銅。上 述銅氧化物形成之化學反應如下所示：According to the present invention, the existing electroplating machine can perform the present invention only by slightly modifying the hardware to add a washing liquid, so that the equipment investment can be reduced, but copper wires with excellent performance can be obtained, and thus high productivity can be achieved. Manufacturing semiconductor devices significantly reduces production costs. Furthermore, according to the present invention, seamlessly grown copper can be obtained simply and easily, and copper plating can be performed at room temperature without deteriorating any important interface, and copper wires can be reliably formed at low cost. -5-(3) (3) 1221315 [Embodiment] An example of copper plating of a copper wire in manufacturing a integrated circuit according to the present invention will be described below with reference to the accompanying drawings'. It should be understood that the following description is for illustrative purposes only 'and is not intended to limit the invention. In addition, for better explanation, the illustrations are not drawn to scale. In the following description, the process steps and corresponding structures according to the embodiments of the present invention do not cover the complete process of manufacturing a complete IC circuit, but can be manufactured in cooperation with other processes in different IC circuits in the field of semiconductor technology. Required complete IC circuit. FIG. 1 is an embodiment of an embedded structure intended to form copper wires and / or copper plugs, which is an embodiment of the embedded structure before copper electroplating using the embodiment of the copper plating method according to the present invention. As shown in FIG. 1, a 101-series Si 0 layer, as an interlayer metal dielectric, has a trench formed in the Si02 layer 101, and a physical vapor deposition method (PVD) is used on the Si02 layer 101. A barrier layer / seed layer 102 was formed. For brevity, only one groove is shown in FIG. 1, but the number of grooves may be more than one. In addition, the multiple black particles in Fig. 1 represent organic matter and unnecessary pollutants attached to the surface of the seed layer during the manufacturing process or inspection process. Next, in the following, an embodiment of the copper plating method according to the present invention will be described by taking the engraved structure shown in FIG. 1 as an example. According to this embodiment, the copper electroplating method mainly includes three processes', namely a scouring process, a copper oxide layer removal process, and a plating process. First, the washing procedure will be described. As shown in FIG. 2, in the cleaning process, the dilute H202 solution formed by diluting H202 with deionized water is shown in Figure -6-(4) 1221315 1. According to the present embodiment, the dilute gadolinium 2 02 solution is formed by diluting a very low concentration of Gxydol containing 3% gadolinium 2 2 with deionized water. The etched structure, after being immersed in the diluted solution thus obtained, 'will form a thin copper oxide layer 1 0 3' on the copper seed layer with a thickness of about 50 Å, and can improve the wettability of the electrolyte to narrow features, which is beneficial. copper. The chemical reaction of the above copper oxide formation is as follows:
Η 2 Ο 2 + C u C υ Ο + Η 2 〇 Η2〇2 + 2Cu -> Cu20 + Η2〇 此預淸洗步驟可以在NovelUs公司製造的Sabre電鍍 機或Applied Materials公司製造的Iecp電鍍機中的淸洗 及乾燥室中執行，僅需在硬體上稍微修改以塡加稀釋的 H202溶液即可。 接著，參考圖3說明根據本實施例之新銅層曝露程序 。在完成上述淸洗程序並於銅種子層上形成所需的薄氧化 物膜之後，將嵌刻結構置於電解液中一極短時間’小於一 秒，則淸洗程序中所形成的銅氧化物層1 0 3會由主要由硫 酸銅（CuS02)及硫酸（H2S04)所組成的電解液快速地 溶，原先附著於種子層表面上的有機物或不必要的污染物 會隨著銅氧化物溶解於電解液中而被移除’並且曝露出未 受污染的新銅種子層以在後續的電鍍程序中作爲銅電鍍之 初始層。關於銅氧化物與電解液的化學反應如下所示： -7- (5) (5)1221315Η 2 Ο 2 + C u C υ Ο + Η 2 〇Η2〇2 + 2Cu-> Cu20 + Η2〇 This pre-rinsing step can be performed in a Sabre plating machine manufactured by NovelUs or an Iecp plating machine manufactured by Applied Materials. The washing and drying chamber is performed, and only a slight modification on the hardware is needed to add the diluted H202 solution. Next, a new copper layer exposure procedure according to this embodiment will be described with reference to FIG. 3. After completing the cleaning process and forming the required thin oxide film on the copper seed layer, the embedded structure is placed in the electrolyte for a very short time 'less than one second, and the copper formed in the cleaning process is oxidized. The material layer 1 0 3 will be quickly dissolved by the electrolyte mainly composed of copper sulfate (CuS02) and sulfuric acid (H2S04). Organic matter or unnecessary pollutants originally attached to the surface of the seed layer will dissolve with the copper oxide. It is removed in the electrolyte 'and exposed to a new, uncontaminated copper seed layer to serve as an initial layer for copper plating in subsequent plating processes. The chemical reaction between copper oxide and electrolyte is as follows: -7- (5) (5) 1221315
CuO + H2S〇4 + CuS〇4 + H2〇 (3) C u 2 0 + 2H2 S 〇4 ^ 2 C u S O 4 + 2H2 〇 ( 4 ) 最後，在嵌刻結構置於電解液中一段時間後’立即執 行電鍍程序以無縫地沈積生長如圖4所示之銅導線及/或 銅栓塞1 04。電鍍程序可使用一般之電鍍程序，亦即，將 適當的電極置入電解液中再通以適當電流以執行電鍍。 根據本發明，現有的電鍍機僅需稍微修改硬體，即可 執行本發明，因此，可以減少設備投資，但又可取得具有 優良性能之銅導線及/或銅栓塞，因而能以高產能製造半 導體裝置，顯著地減少生產成本。此外，本發明可以簡單 及容易地實施銅電鍍，並可在室溫下執行銅電鍍而不會劣 化任何重要的界面，可靠地取得無縫生長的銅，可顯著地 增進生產效率及降低生產成本。 在上述中，以較佳實施例說明本發明，但本發明並不 侷限於上述較佳實施例，在不悖離本發明的精神及範圍之 下’習於此技藝者可以實施不同的修改及改變，本發明的 範圍僅受限於後述之申請專利範圍所界定的範圍及其等效 範圍。 【圖式簡單說明】 在爹考附圖之實施例說明中，將可更加淸楚本發明的 上述及其它目的和優點，其中： 圖1係擬形成銅導線及/或銅栓塞的嵌刻結構實施例 -8- (6) (6)1221315 圖2係用以說明根據本發明的銅電鍍方法之實施例的 淸洗程序； 圖3係用以說明根據本發明的銅電鍍方法之實施例的 銅氧化物層移除程序；及 圖4係顯示根據本發明的銅電鍍方法之實施例所形成 的最後銅導線及/或銅栓塞。CuO + H2S〇4 + CuS〇4 + H2〇 (3) C u 2 0 + 2H2 S 〇 4 ^ 2 C u SO 4 + 2H2 〇 (4) Finally, after the embedded structure is placed in the electrolyte for a period of time 'Immediately perform the plating process to seamlessly deposit and grow the copper wires and / or copper plugs 104 as shown in FIG. 4. The plating process may use a general plating process, that is, an appropriate electrode is placed in an electrolytic solution and then an appropriate current is passed to perform the plating. According to the present invention, the existing electroplating machine can perform the present invention with only a slight modification of the hardware. Therefore, the equipment investment can be reduced, but copper wires and / or copper plugs with excellent performance can be obtained, so that it can be manufactured with high productivity. Semiconductor devices, significantly reducing production costs. In addition, the present invention can perform copper plating simply and easily, and can perform copper plating at room temperature without degrading any important interface, reliably obtain seamless copper growth, and can significantly improve production efficiency and reduce production costs. . In the above, the present invention has been described using preferred embodiments, but the present invention is not limited to the above preferred embodiments, and those skilled in the art can implement different modifications and changes without departing from the spirit and scope of the present invention. Varying, the scope of the present invention is limited only by the scope defined by the scope of patent application mentioned below and its equivalent scope. [Brief description of the drawings] The above and other objects and advantages of the present invention will be better understood in the description of the embodiments of the drawings. Among them: Figure 1 is an embedded structure intended to form copper wires and / or copper plugs. Example-8- (6) (6) 1221315 FIG. 2 is a cleaning process for explaining an embodiment of a copper plating method according to the present invention; FIG. 3 is a view for explaining an embodiment of a copper plating method according to the present invention The copper oxide layer removal process; and FIG. 4 shows the final copper wires and / or copper plugs formed by the embodiment of the copper plating method according to the present invention.
【主要元件對照表】 10 1 Si〇2 層 1 02 種子層 1 03 銅氧化物層 104 銅導線 -9-[Comparison table of main components] 10 1 Si〇2 layer 1 02 Seed layer 1 03 Copper oxide layer 104 Copper wire -9-