527445 玖、發明說明 (發明說明應敘明：發明所屬之技術領域、先前技術、內容、實施方式及圖式簡單說 明） 本發明是有關於一種用於積體電路製程中的化學配方， 且特別是有關於一種用以形成銅膜的銅電鍍液配方。 隨著半導體製程進入深次微米(Deep Sub-micron)世代，積 體電路中元件的積集度（Integration)也伴隨著大幅提昇。然而， 在提高積集度的過程中也會因爲元件的特性與元件的材質之 限制而遇到一些問題，其中由於金屬內連線本身材質的電阻 値（Resistivity)以及抗電致遷移能力（Electromigration Resistance)等特性不能滿足深次微米製程的需求，而爲積體電 路製程當今最急需解決的問題。 在積體電路製程中，以鋁作爲金屬導線的技術已經發展 的相當成熟了。但是，在深次微米的半導體製程中，常利用 銅取代鋁製作內連線。這是由於銅具有電子遷移阻抗値爲鋁 之30至100倍、介層窗阻抗値降低10至2〇倍以及銅之電阻 値比鋁低30%之特點。因此，利用銅導線製程配合使用低介 鼠吊數（Low K)材料之金屬間介電層（inter-Metal Dielectrics)， 可有效降低電阻電容延遲(RC Delay)以及抗電致遷移能力之特 性。 由於銅金屬不容易蝕刻，因此在銅製程中的金屬導線大 多都以金屬鑲嵌（Damascene)的技術來製作，也就是先形成介 電層之後，於介電層中形成暴露出欲連接導線的區域，再形 成塡滿開口的銅層以作爲導線及插塞。這樣的技術雖然可以 避免銅層不易蝕刻的問題，但是在形成銅層時是否能夠將開 8034twfl.doc/006 7 527445 口完全塡滿並且使銅層中沒有孔洞（Void)或縫隙（Seam)產生， 就成了製作銅層時最大的挑戰。 —般形成銅層的方法包括了物理氣相沉積法（physical Vapor Deposition，PVD)、化學氣相沉積法（Chemical Vap〇r527445 发明 Description of the invention (The description of the invention should state: the technical field to which the invention belongs, the prior art, the content, the embodiments and the simple description of the drawings) The present invention relates to a chemical formula used in the manufacturing process of integrated circuits, and is particularly The invention relates to a copper plating solution for forming a copper film. As the semiconductor process enters the deep sub-micron generation, the integration of components in integrated circuits has also increased dramatically. However, in the process of increasing the accumulation, some problems are encountered due to the limitations of the characteristics of the component and the material of the component. Among them, the resistance of the material of the metal interconnect itself (Resistivity) and the resistance to electromigration Resistance) and other characteristics can not meet the needs of deep sub-micron processes, and are the most urgent problems for integrated circuit manufacturing processes today. In the integrated circuit manufacturing process, the technology of using aluminum as the metal wire has been quite mature. However, in deep submicron semiconductor processes, copper is often used instead of aluminum to make interconnects. This is due to the fact that copper has an electron migration resistance of 30 to 100 times that of aluminum, a reduction of the interlayer window resistance of 10 to 20 times, and the electrical resistance of copper is 30% lower than aluminum. Therefore, the copper wire process and the use of low-k intermetal dielectric layers (inter-Metal Dielectrics) can effectively reduce the RC delay and resistance to electromigration. Because copper metal is not easy to etch, most of the metal wires in the copper process are made by Damascene technology, that is, after the dielectric layer is formed, the area where the wires to be connected are exposed is formed in the dielectric layer. Then, a copper layer with a full opening is formed as a wire and a plug. Although this technique can avoid the problem that the copper layer is not easy to etch, can it completely fill the opening 8034twfl.doc / 006 7 527445 when the copper layer is formed and make no copper holes (Void) or gaps (Seam) occur in the copper layer? Has become the biggest challenge when making copper layers. -Generally, the method of forming a copper layer includes physical vapor deposition (PVD), chemical vapor deposition (Chemical Vapor Deposition)
Deposition’ CVD)以及電鍍銅（Cu Electroplating)技術等。其中， 以物理與化學氣相沉積法來製作銅層不但成本較高，且其所 形成的銅層也因爲塡洞（Gap-filling)能力不佳而造成導線品質 的低落。因此以電鍍銅技術來製作銅導線可以說是積體電路 製程中形成銅層的較佳選擇。 電鍍銅的溝塡塡洞能力與所形成導線之品質，不但與進 行電鍍的條件有關，其所使用之電鍍液的成分更是一項不可 或缺的因素。習知之銅電鍍液之組成除了銅離子源以及電解 質外，更需要加入各種化學添加劑。其中化學添加劑依功能 可分爲加速劑（Accelerator)、抑制劑（Suppressor)以及平整劑 (Leveler)等。於電鍍液中添加加速劑可防止開口於電鍍初期階 段時就被密封住。於電鍍液中添加抑制劑可以抑制銅在開口 頂端或開口側壁的沉積速率。於電鍍液中添加平整劑不但可 以提升銅之塡洞能力，並且可以得到外型較平滑之銅膜。因 此，利用於銅電鍍液中添加各種化學添加劑可以提升銅之塡 洞能力以及得到品質佳之銅膜。然而，若於銅電鍍液中加入 太多種之添加劑，會增加不純物混入銅膜之機會’而造成銅 膜之阻値提高，導致所謂內連線效能降低之問題產生。 此外，目前市售之銅電鍍液之塡洞能力大約都只能達到 毫米等級，然而隨著元件集積度之增加，金屬內連線之尺寸 持續緊縮至〇.l//m以下，溝渠的深寬比(AsPect rati〇)將高達 10 : 1以上，市售之銅電鍍液將無法適用於設計規則（Design 8034twfl .doc/006 8 527445Deposition ’CVD) and Cu Electroplating technology. Among them, the physical and chemical vapor deposition methods are not only costly to produce the copper layer, but also the copper layer formed by the Gap-filling ability is not good, which leads to the degradation of the wire quality. Therefore, using copper electroplating technology to make copper wires can be said to be a better choice for forming copper layers in integrated circuit manufacturing processes. The trench hole ability of electroplated copper and the quality of the formed wires are not only related to the conditions for plating, but the composition of the plating solution used is an indispensable factor. In addition to the copper ion source and electrolyte, the composition of the conventional copper plating solution requires the addition of various chemical additives. Among them, chemical additives can be classified into accelerators, suppressors and levelers according to their functions. Adding an accelerator to the plating solution prevents the openings from being sealed during the early stages of plating. Adding an inhibitor to the plating solution can suppress the copper deposition rate at the top of the opening or the sidewall of the opening. Adding a leveling agent to the plating solution can not only enhance the copper cavitation ability, but also obtain a smoother copper film. Therefore, adding various chemical additives to the copper electroplating bath can improve the cavitation ability of copper and obtain a high-quality copper film. However, if too many kinds of additives are added to the copper plating solution, the chance of impurities being mixed into the copper film will be increased, and the resistance of the copper film will be increased, leading to the problem of the so-called decrease in interconnection performance. In addition, the currently available copper electroplating baths can only reach the millimeter level. However, with the increase of the component concentration, the size of the metal interconnects has continued to shrink to less than 0.1 // m, and the depth of the trenches The aspect ratio (AsPect rati〇) will be as high as 10: 1 or more, and the commercially available copper plating solution will not be applicable to design rules (Design 8034twfl.doc / 006 8 527445
Rule)已經降到深次微米等級的積體電路製程中。所以提供一 種在深次微米積體電路製程中，具有絕佳塡洞能力且銅膜之 品質佳的銅電鍍液就成了積體電路製程中極需突破的一個課 題。 因此，本發明之一目的爲提供一種銅電鍍液配方，可以 適用於深次微米等級之積體電路製程。 本發明的另一目的爲提供一種銅電鍍液配方，以使得形 成於開口中的銅膜具有較佳的品質且不會產生孔洞或是縫 隙。 本發明的再一目的爲提供一種銅電鏟液配方，在具有銅 離子源、抑制劑之溶液中添加混合型添加劑（Hybrid Mode Additive)可以使銅電鍍液具有絕佳的塡洞能力。 依照本發明之目的而提供一種銅電鍍液配方，此電鍍液 配方中至少具備有銅離子源、複數種電解質、抑制劑、以及 混合型添加劑（Hybrid Mode Additive)。其中抑制劑爲分子量 2000 至 10000 之聚乙烯二醇（Polyethylene Glycol，PEG)。混 合型添加劑爲苯並三哩衍生物（Benzotriazole Derivative)或噻 二口坐衍生物（Thiadiazole Derivative)。 其中，苯並三唑衍生物包括苯並三唑（Benzotriazole)、4-甲基-苯並三口坐（4-methyl-benzotriazole)、5-甲基-苯並三口坐（5-methyl-benzotriazole)、4,7-二甲基-苯並三哩（4,7_dimethyl-benzotriazole)、5,6-二甲基-苯並三卩坐（5,6-dimethyl-benzotriazole)等。 噻二唑衍生物包括2,5-二锍基]，3,4-噻二唑（2,5-dimercapto-l，3,4-thiadiazole)、2-胺基-5-疏基-1，3,4-噻二哗（2-&111111〇-5-11^1：〇3口1:〇_1，3,4-1:111&(^2〇16)或2,5-一胺基-1，3,4，嚷二哩 8034twfl.doc/006 9 527445 (2,5-diamino-1，3，4-thiadiazole)等。 本發明係於電鑛液配方添加苯並三唑衍生物或噻二唑衍 生物等混合型添加劑，而混合型添加劑則兼具備有加速 (Acceleration)以及抑制（Inhibition)之功能。由於混合型添加劑 在低濃度時爲單陰離子形式，可以促進銅金屬層沈積；混合 型添加劑在高濃度時爲雙陰離子形式，可以抑制銅金屬層沈 積。因此，在一鑲嵌開口中，開口表面以及在開口頂端與開 口側壁之混合型添加劑濃度高於開口底部的混合型添加劑濃 度，較強的抑制效應會發生在開口頂端與開口側壁，而較強 之促進效應會發生在開口底部，所以開口底部之銅晶體成長 速率相對於開口頂部以及開口側壁部分之銅晶體成長速率爲 高，可以達到超塡塞（Super Filling)的效果，並且能夠增加金 屬鑲嵌開口中電鍍銅之平整能力。 本發明之銅電鍍液配方，可以適用於開口尺寸Ο.ΐμπι， 溝渠的深寬比(Aspect ratio)10: 1之深次微米積體電路製程中。 可以使得形成於積體電路開口中的銅層具有較佳的品質、不 會產生孔洞或是縫隙，並且具有絕佳的塡洞能力。 爲讓本發明之上述目的、特徵、和優點能更明顯易懂， 下文特舉較佳實施例，並配合所附圖示，作詳細說明如下： 圖示之簡單說明 第1A圖至第1C圖爲繪示金屬鑲嵌結構之製程剖面圖。 弟2A圖爲繪不使用貫驗例之電鑛液於〇. 1 g # m之聞p中 沈積銅金屬層之SEM剖面照相圖。 第2B圖爲繪示使用比較例之電鍍液於〇.18//m之開〇中 沈積銅金屬層之SEM剖面照相圖。 第3圖爲繪示實驗例以及比較例之共形沈積厚度對開口 8034twfl .doc/006 10 527445 尺寸之關係圖。 圖示標號說明： 100 :半導體基底 102 :介電層 104 :開口 106 :阻障層 108 :銅晶種層 110 :銅層 實施例 本發明之銅電鍍液配方至少包括銅離子源、複數種電解 質、抑制劑以及混合型添加劑(Hybrid Mode Additive)。其中， 銅離子源例如是硫酸銅（CuS04 · 5H20)。電解質例如是硫酸以 及氯離子。抑制劑例如是聚乙烯二醇（Polyethylene Glycol， PEG)，且聚乙烯二醇分子量爲2000至10000左右。混合型添 加劑例如是苯並三哩衍生物（Benzotriazole Derivative)(如下列 結構式⑴所示）或者是噻二唑衍生物(Thiadiazole Derivative)(如 下列結搆式（II)所示）。Rule) has been reduced to deep sub-micron level integrated circuit manufacturing processes. Therefore, to provide a copper electroplating solution with excellent cavitation ability and good copper film quality in deep sub-micron integrated circuit manufacturing processes has become a subject that needs to be broken through in integrated circuit manufacturing processes. Therefore, an object of the present invention is to provide a copper electroplating bath formulation which can be applied to the fabrication of integrated circuits of deep sub-micron level. Another object of the present invention is to provide a copper plating solution formulation so that the copper film formed in the opening has better quality and does not generate holes or gaps. Yet another object of the present invention is to provide a copper electric shovel liquid formula. Adding a hybrid mode additive to a solution having a copper ion source and an inhibitor can make the copper plating solution have excellent cavitation capabilities. According to the purpose of the present invention, a copper plating solution formulation is provided. The plating solution formulation includes at least a copper ion source, a plurality of electrolytes, an inhibitor, and a hybrid mode additive. The inhibitor is Polyethylene Glycol (PEG) with a molecular weight of 2000 to 10,000. Mixed additives are Benzotriazole Derivative or Thiadiazole Derivative. Among them, benzotriazole derivatives include Benzotriazole, 4-methyl-benzotriazole, 5-methyl-benzotriazole , 4,7-dimethyl-benzotriazole, 5,6-dimethyl-benzotriazole, and the like. Thiadiazole derivatives include 2,5-difluorenyl], 3,4-thiadiazole (2,5-dimercapto-1, 3,4-thiadiazole), 2-amino-5-meryl-1, 3,4-thiathia (2- & 111111〇-5-11 ^ 1: 〇3 mouth 1: 〇_1, 3,4-1: 111 & (^ 2〇16) or 2,5--1 Amine-1,3,4, hydrazine 8034twfl.doc / 006 9 527445 (2,5-diamino-1,3,4-thiadiazole), etc. The present invention is derived from the addition of benzotriazole in the formula of electric mineral liquid Compounds or thiadiazole derivatives and other mixed additives, and mixed additives have both the acceleration (Acceleration) and inhibition (Inhibition) function. Because the mixed additives at a low concentration in the form of a single anion, can promote the copper metal layer Deposition; mixed additives are dianion form at high concentration, which can inhibit the deposition of copper metal layer. Therefore, in a mosaic opening, the concentration of the mixed additive on the surface of the opening and the top and side walls of the opening is higher than that of the mixed type at the bottom of the opening Additive concentration, strong inhibition effect will occur at the top of the opening and the side wall of the opening, and strong promotion effect will occur at the bottom of the opening, so the copper crystal at the bottom of the opening grows The rate is higher than the growth rate of copper crystals at the top of the opening and the side wall of the opening, which can achieve the effect of Super Filling, and can increase the leveling ability of the electroplated copper in the metal inlaid opening. It can be applied to the fabrication process of deep sub-micron integrated circuits with the opening size of 0.ΐμπι and the aspect ratio of the trench of 10: 1. It can make the copper layer formed in the opening of the integrated circuit have better quality, It can produce holes or gaps, and has excellent cavitation capabilities. In order to make the above-mentioned objects, features, and advantages of the present invention more comprehensible, the following describes the preferred embodiments with the accompanying drawings. The detailed description is as follows: Figure 1A to 1C is a cross-sectional view showing the process of the metal mosaic structure. Figure 2A is a drawing of the electric mineral fluid without using the conventional example at 0.1 g # m 的 闻SEM cross-section photograph of the copper metal layer deposited in p. Fig. 2B is a SEM cross-section photograph of the copper metal layer deposited in the 〇.18 // m of the electroplating solution of the comparative example. Fig. 3 is a drawing. Show experimental examples and The relationship between the conformal deposition thickness of the comparative example and the size of the opening 8034twfl.doc / 006 10 527445. The symbols indicate: 100: semiconductor substrate 102: dielectric layer 104: opening 106: barrier layer 108: copper seed layer 110 Example of copper layer The copper plating solution of the present invention includes at least a copper ion source, a plurality of electrolytes, an inhibitor, and a hybrid mode additive (Hybrid Mode Additive). The copper ion source is, for example, copper sulfate (CuS04 · 5H20). The electrolyte is, for example, sulfuric acid and chloride ions. The inhibitor is, for example, Polyethylene Glycol (PEG), and the molecular weight of the polyethylene glycol is about 2000 to 10,000. The mixed type additive is, for example, a Benzotriazole Derivative (as shown in the following structural formula ⑴) or a Thiadiazole Derivative (as shown in the following structural formula (II)).
其中Ri、R2、R3與R4可爲相同或不同，R,、R2、R3與R4包 括氫或碳數1至4之烷基。 8034twfl.doc/006 (I) 527445 N——N / \Wherein Ri, R2, R3 and R4 may be the same or different, and R ,, R2, R3 and R4 include hydrogen or an alkyl group having 1 to 4 carbon atoms. 8034twfl.doc / 006 (I) 527445 N——N / \
其中X|、X2可爲相同或不同，X,、x2包括疏基（Mercapto Group)、胺基（Amino Group)等。 (Π) 苯並三唑衍生物例如是苯並三唑、4_甲基-苯並三唑（4-methyl-benzotriazole) 、 5-甲基-苯並三口坐（5-methyl- benzotriazole)、4,7-二甲基-苯並三哩（4,7-dimethyl-benzotriazole)、5,6-二甲基-苯並三哇（5,6-dimethyl-benzotriazole)等 〇 噻二唑衍生物例如是2,5-二锍基-1，3,4-噻二唑（2,5- dimercapto-l，3,4-thiadiazole)、2-胺基-5-疏基-1，3,4-噻一哩（2-amino-5-mercapto-l，3,4-thiadiazole)或 2,5-二胺基-1，3,4-噻一嗖 (2,5-diamino-l，3,4-thiadiazole)等。 本發明所揭露之銅電鍍液中各個成份的使用濃度則#$ 如下： 銅離子的濃度爲5克/升至60克/升左右。 硫酸的濃度爲45克/升至325克/升左右。 氯離子的濃度爲〇.〇5克/升至0.1克/升左右。 聚乙烯二醇(PEG 2000〜10000)的濃度爲0·2至2克/升° 混合型添加劑的濃度爲〇.〇1克/升至0.06克/升° 其中，聚乙烯二醇(PEG 2000〜10000 )可降低表面張力’ 並可改善晶粒品質。混合型添加劑則兼具@ % $ (Acceleration)以及抑制（Inhibition)之功能。這是因爲丨比1:1:1 土添 8034twfl .doc/006 12 527445 加劑在銅電鍍液中會形成單陰離子（Monoanicm)或雙陰離子 (Dianion)形式以及數種互變異性（Tautomeric)形式，而經由環 系統（Ring System)上疏基（Mercapto Group)、硫酮基（Thione Groups)、N-S 螯合物（N-S Chelate)或重氮（Diazo Nitrogens)與 銅離子（Cu2+)配位在一起。舉例來說，苯並三哩在高濃度時會 形成雙陰離子形式而具有平整劑之功能（如結構式（ΙΠ)所示）， 雙陰離子形式之苯並三唑與銅層表面之銅原子形成螯狀化合 物。由於雙陰離子形式之苯並三唑與銅晶種層與新成長之銅 核團的強吸附作用，可以抑制銅晶體成長的速率。相反的， 苯並三唑在低濃度時會形成單陰離子形式而具有加速劑之功 能（如結構式（IV)所示），單陰離子形式之苯並三唑會接近於電 流限制區域而顯示出較小之抑制效果而具有促進之效果。X | and X2 may be the same or different. X, and x2 include Mercapto Group and Amino Group. (Π) Benzotriazole derivatives are, for example, benzotriazole, 4-methyl-benzotriazole, 5-methyl-benzotriazole, 4,7-dimethyl-benzotriazole, 5,6-dimethyl-benzotriazole and other thiadiazole derivatives For example, 2,5-difluorenyl-1,3,4-thiadiazole (2,5-dimercapto-1,3,4-thiadiazole), 2-amino-5-sulfo-1,3,4 -2-amino-5-mercapto-l, 3,4-thiadiazole or 2,5-diamino-1,3,4-thiadihydrazone (2,5-diamino-l, 3, 4-thiadiazole) and the like. The concentration of each component in the copper plating solution disclosed in the present invention is as follows: The concentration of copper ions is about 5 g / liter to about 60 g / liter. The concentration of sulfuric acid is about 45 g / l to about 325 g / l. The chloride ion concentration is about 0.05 g / L to about 0.1 g / L. The concentration of polyethylene glycol (PEG 2000 ~ 10000) is 0.2 to 2 g / L ° The concentration of the mixed additive is 0.01 g / L to 0.06 g / L ° Wherein, the polyethylene glycol (PEG 2000 ~ 10000) can reduce surface tension 'and improve grain quality. Mixed additives have both @% $ (Acceleration) and inhibition (Inhibition) functions. This is because the ratio of 1: 1: 1 Tutian 8034twfl .doc / 006 12 527445 in the copper electroplating bath will form a monoanion (Dianion) or a double anion (Dianion) and several types of tautomeric (Tautomeric) And through the ring system (Mercapto Group), Thione Groups (Thione Groups), NS chelate (NS Chelate) or diazo (Diazo Nitrogens) coordination with copper ions (Cu2 +) . For example, benzotriazole will form a dianion form at a high concentration with the function of a leveling agent (as shown in structural formula (II)), and benzotriazole in the dianion form with copper atoms on the surface of the copper layer. Chelate compounds. Due to the strong adsorption of benzotriazole, copper seed layer and newly grown copper nuclei in the form of dianion, the rate of copper crystal growth can be suppressed. In contrast, benzotriazole will form a monoanionic form at a low concentration with the function of an accelerator (as shown in structural formula (IV)), and the benzotriazole in the form of a single anion will approach the current-limiting region and show It has a small inhibitory effect and a promoting effect.
(III) (IV) 因此，使用本發明所揭露之混合型添加劑可以取代習知 的加速劑以及平整劑。由於混合型添加劑之濃度在金屬鑲嵌 開口中呈梯度變化，在開口頂端與開口側壁之濃度高於開□ 底部的濃度，因此混合型添加劑在開口頂端與開口側壁是呈 現雙陰離子形式，較強的抑制效應會發生在開口頂端與開口 側壁。擴散至開口底部之混合型添加劑之濃度較低，使得混 合型添加劑在開口底部是呈現單陰離子形式，而具有較強之 8034twfl.doc/006 13 527445 加速效應。所以開口底部之銅晶體成長速率相對於開口頂部 以及開口側壁部分之銅晶體成長速率爲高’因而可達到超塡 塞的效果，可以在金屬鑲嵌開口中增加電鍍銅之平整能力。 爲更詳細的說明本發明，特舉出於銅電鍍液中添加苯並 三哩（Benzotriazole)混合型添加劑作爲實驗例。並且以於銅電 鑛液中添加習知之2-胺基•苯並噻哩（2-Amino-benzothiazole)平 整劑作爲比較例，其中實施例以及比較例之電鍍液之配方如 下： 實驗例 銅離子：30克/升 硫酸：150克/升 氯離子：〇·1克/升 聚乙烯二醇（PEG 2000) : 1克/升 苯並三唑：〇·〇4克/升 比較例 銅離子：30克/升 硫酸：150克/升 氯離子：0·1克/升 聚乙烯二醇（peg 2〇〇〇): 1克/升 2-胺基-苯並噻唑：〇·〇4克/升。 並根據第1A圖至第1C圖所繪示之金屬鑲嵌結構之製护 剖面圖，以實驗例與比較例之電鍍液進行銅金屬層之電鍍A壬 首先，請參照第1A圖，提供一個半導體基底1〇〇，其 於此半導體基底100上已形成有半導體元件（未繪示於圖中')。 接著，於此半導體基底100上形成一層介電層102，其中此二 電層1〇2的材質例如是氧化矽或者其他具有介電特性之材臂；1 8034twfl .doc/006 14 527445 之後，移除部分的介電層102，以在介電層102中形成尺寸爲 1 // m至0.1 # m左右（深寬比1 : 1至10 ·· 1)之開口 1〇4，此 開口 104暴露出位於半導體基底100內之金屬層（未圖示）的部 分表面。 接著，請參照第1B圖，形成一層阻障層1〇6覆蓋於半導 體基底100與介電層102上，且阻障層106共形於與半導體 基底100以及介電層102表面。阻障層106的材質例如是氮 化鉅(TaN)，形成阻障層106之方法，例如爲離子化金屬電漿 法（IMP)。其中，阻障層106的功能在於避免後續形成之導 電層擴散至介電層102中。 請參照第1C圖，形成一層銅晶種層1〇8覆蓋於阻障層106 上，且銅晶種層108共形於阻障層1〇6之表面，其作用在於 增進電鍍時銅質沉積的效率及品質。形成銅晶種層108之方 法，例如是離子化金屬電漿法。接著，將半導體基底1〇〇置 入裝盛有實驗例之銅電鍍液（或比較例之銅電鍍液）的電鍍槽 中，在室溫下（25°C )、電流密度爲ImA/cm2至30mA/cm2左右、 攪拌速度爲50rpm左右，並於通入氮氣之條件下進行電鍍’ 而形成銅層110覆蓋於半導體基底1〇〇上。 接著，說明實驗例與比較例之差異，請參照第2A圖與第 2B圖，第2A圖爲繪示使用實驗例之電鍍液於〇·18// m之開口 中沈積銅金屬導線之掃瞄式電子顯微鏡（Scanning Electron Microsocope，SEM)剖面照相圖。第2B圖爲繪不使用比較例之 電鍍液於0.18/zm之開口中沈積銅金屬導線之SEM剖面照相 圖。在第2A圖中之銅金屬層只顯示出底部-向上塡充(Boitom-Up Fill)之現象。而在第2B圖中之銅金屬層除了底部-向上塡 充（Bottom-Up Fill)現象還有共形塡充（Conformal Fill)之現象。 8034twfl.doc/006 15 527445 這是由於苯並三唑在開口頂端與開口側壁之濃度較高，苯並 三唑會形成雙陰離子形式，並與銅層表面之銅原子形成螯狀 化合物。由於雙陰離子形式之苯並三唑與銅晶種層與新成長 之銅核團的強吸附作用，會降低銅晶體成長的速率，因此較 強的抑制效應會發生在開口頂端與開口側壁。擴散至開口底 部之苯並三唑之濃度較低，苯並三唑會形成單陰離子形式， 而具有較強之促進效應。所以，開口底部之銅晶體成長速率 相對於開口頂部以及開口側壁部分之銅晶體成長速率爲高， 因而可達到超塡塞的效果。可以增加金屬鑲嵌開口中電鍍銅 之平整能力。而2-胺基-苯並噻哗（2-Amino-benzothiazole)在開 口附近有共形塡充(Conformal Fill)之現象，表不2-胺基-苯並噻 唑在開口頂端與開口側壁之抑制效能較差，使得2-胺基-苯並 噻哗之塡充效能較苯並三嗖(Benzotriazole)差。 此外，使用實驗例之電鍍液所鍍出來之銅膜的表面粗糙 度較比較例之電鍍液所鍍出來之銅膜的表面粗糙度小。因此， 苯並三唑（Benzotriazole)具有較2-胺基-苯並噻唑（2-Amino benzothiazole)爲強之抑制效應，且高濃度之苯並三唑 (Benzotriazole)具有平整之功效。 接著請參照第3圖，第3圖繪示實驗例以及比較例之共形 塡充厚度對開口尺寸(FeatureSize)之關係圖。其中，（D 符號表示實驗例，（-〇_)符號表示比較例，（+)符號表示 實驗例/比較例之比値。 在第3圖中，共形塡充厚度越大，開口頂部之銅晶體成 長速率越高，表示要達到無孔洞(Vdd-Free)更加困難。舉例來 說，在開口尺寸爲0.18//m之情況下，實驗例之電鍍液之共形 塡充厚度較比較例之電鍍液之共形塡充厚度小，表示含有苯 8034twf 1 .doc/006 16 527445 並三唑之電鍍液較含有2-胺基-苯並噻唑之電鐽液具有較佳之 塡洞能力。而且，實驗例/比較例之共形塡充厚度比値隨著開 口尺寸縮小而變小，表示開口尺寸越小，含苯並三唑之電鍍 液與含2-胺基-苯並噻唑之電鍍液之塡洞能力相差越大。此外， 以實驗例之電鍍液於尺寸爲〇.l//m之開口中沈積銅膜，仍可 以得到良好之塡洞效果，而比較例之電鍍液在尺寸爲0.1/im 之開口中沈積銅膜卻無法達到良好之塡洞效果。因此，本發 明可適用於深次微米積體電路製程中。 由上述本發明較佳實施例可知，利用本發明之銅電鍍液 配方來進行電鍍，可以將尺寸爲0.1/zm且深寬比大的開口完 全塡滿，而達到超塡塞效能。此乃因本發明之銅電鍍液配方 中之混合型添加劑同時具有加速劑以及平整劑之功效，混合 型添加劑在低濃度時爲單陰離子形式可以促進銅金屬層沈 積，混合型添加劑在高濃度時爲雙陰離子形式，可以抑制銅 金屬層沈積。因混合型添加劑在開口頂端與開口側壁之濃度 高於開口底部的濃度，因此較強的抑制效應會發生在開口頂 端與開口側壁。擴散至開口底部之混合型添加劑之濃度較低， 而具有較強之促進效應，因此開口底部之銅晶體成長速率相 對於開口頂部以及開口側壁部分之銅晶體成長速率爲高，因 而可達到超塡塞的效果。可以在金屬鑲嵌開口中增加電鍍銅 之平整能力。 而且’使用本發明之電鍍液配方所添加之化學添加劑之 劑量極少’以金屬鑲嵌技術製作銅導線就可以得到與上、下 層元件或導線接觸較佳、雜質較少且沒有孔洞或縫隙的銅插 塞，以達到製程所需的要求。 綜上所述’雖然本發明已以較佳實施例揭露如上，然其 8034twfl.doc/006 17 527445 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，當可作各種之更動與潤飾，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。 8034twfl.doc/006(III) (IV) Therefore, using the hybrid additive disclosed in the present invention can replace the conventional accelerator and leveler. Since the concentration of the mixed additive changes gradient in the opening of the metal inlay, the concentration at the top of the opening and the side wall of the opening is higher than the concentration at the bottom of the opening. Therefore, the mixed additive appears as a double anion at the top of the opening and the side wall of the opening. The suppression effect occurs at the top of the opening and the side wall of the opening. The concentration of the mixed additive that diffuses to the bottom of the opening is low, so that the mixed additive appears as a single anion at the bottom of the opening, and has a strong acceleration effect of 8034twfl.doc / 006 13 527445. Therefore, the growth rate of copper crystals at the bottom of the opening is higher than the growth rates of copper crystals at the top of the opening and the side walls of the opening. Therefore, the effect of super-plugging can be achieved, and the leveling ability of electroplated copper can be increased in the metal inlaid opening. In order to explain the present invention in more detail, a mixed additive of Benzotriazole is added to a copper plating solution as an experimental example. In addition, the conventional 2-Amino-benzothiazole leveling agent was added to the copper power mineral liquid as a comparative example. The plating solutions of the examples and comparative examples are as follows: Experimental Example Copper Ion : 30 g / l sulfuric acid: 150 g / l chloride ion: 0.1 g / l polyethylene glycol (PEG 2000): 1 g / l benzotriazole: 0.04 g / l comparative example copper ion: 30 g / l sulfuric acid: 150 g / l chloride ion: 0.1 g / l polyethylene glycol (peg 2000): 1 g / l 2-amino-benzothiazole: 0.04 g / l Rise. And according to the protective cross-sections of the metal mosaic structure shown in Figures 1A to 1C, the copper plating of the copper metal layer is performed using the plating solutions of the experimental and comparative examples. First, please refer to Figure 1A to provide a semiconductor The substrate 100 has a semiconductor element (not shown in the figure) formed on the semiconductor substrate 100. Next, a dielectric layer 102 is formed on the semiconductor substrate 100. The material of the two dielectric layers 102 is, for example, silicon oxide or other materials with dielectric properties. 1 8034twfl.doc / 006 14 527445, Except a part of the dielectric layer 102, an opening 104 having a size of about 1 // m to 0.1 # m (aspect ratio 1: 1 to 10 ·· 1) is formed in the dielectric layer 102, and this opening 104 is exposed A part of the surface of the metal layer (not shown) located in the semiconductor substrate 100 is exposed. Next, referring to FIG. 1B, a barrier layer 106 is formed to cover the semiconductor substrate 100 and the dielectric layer 102, and the barrier layer 106 is conformally formed on the surface of the semiconductor substrate 100 and the dielectric layer 102. The material of the barrier layer 106 is, for example, TaN, and a method of forming the barrier layer 106 is, for example, an ionized metal plasma method (IMP). The function of the barrier layer 106 is to prevent the conductive layer formed later from diffusing into the dielectric layer 102. Referring to FIG. 1C, a copper seed layer 108 is formed to cover the barrier layer 106, and the copper seed layer 108 is conformally formed on the surface of the barrier layer 106, and its role is to promote copper deposition during electroplating. Efficiency and quality. A method of forming the copper seed layer 108 is, for example, an ionized metal plasma method. Next, the semiconductor substrate 100 was placed in a plating bath containing the copper plating solution of the experimental example (or the copper plating solution of the comparative example) at a room temperature (25 ° C) and a current density of ImA / cm2 to About 30 mA / cm2, stirring speed is about 50 rpm, and electroplating is performed under the condition of introducing nitrogen to form a copper layer 110 to cover the semiconductor substrate 100. Next, the differences between the experimental example and the comparative example will be described. Please refer to FIG. 2A and FIG. 2B. FIG. 2A shows a scan of depositing a copper metal wire in an opening of. Scanning Electron Microsocope (SEM) section photograph. Fig. 2B is a SEM cross-sectional view of a copper metal wire deposited in an opening of 0.18 / zm without using the plating solution of the comparative example. The copper metal layer in Figure 2A only shows the phenomenon of bottom-up fill. In addition, the copper metal layer in Figure 2B has a conformal fill phenomenon in addition to the bottom-up fill phenomenon. 8034twfl.doc / 006 15 527445 This is due to the high concentration of benzotriazole at the top of the opening and the side wall of the opening. The benzotriazole will form a double anion and form a chelate compound with copper atoms on the surface of the copper layer. Due to the strong adsorption of benzotriazole, copper seed layer and newly-grown copper nucleus in the form of double anions, the growth rate of copper crystals will be reduced, so a stronger inhibitory effect will occur at the top of the opening and the side wall of the opening. The concentration of benzotriazole diffused to the bottom of the opening is low, and benzotriazole will form a monoanionic form, which has a strong promotion effect. Therefore, the growth rate of the copper crystals at the bottom of the opening is higher than that of the copper crystals at the top of the opening and the side wall portion of the opening, so that the effect of super congestion can be achieved. It can increase the leveling ability of electroplated copper in the metal inlaid opening. And 2-Amino-benzothiazole has a Conformal Fill near the opening, which shows the inhibition of 2-amino-benzothiazole on the top and side walls of the opening. Poor efficacy, making 2-amino-benzothiazol's charge efficiency worse than that of Benzotriazole. In addition, the surface roughness of the copper film plated using the plating solution of the experimental example is smaller than that of the copper film plated using the plating solution of the comparative example. Therefore, Benzotriazole has a stronger inhibitory effect than 2-Amino benzothiazole, and a high concentration of Benzotriazole has a smoothing effect. Next, please refer to FIG. 3, which shows the relationship between the conformal filling thickness of the experimental example and the comparative example and the feature size of the opening. Among them, the (D symbol indicates an experimental example, the (-〇_) symbol indicates a comparative example, and the (+) symbol indicates the ratio of the experimental example / comparative example. In FIG. 3, the larger the conformal filling thickness, the larger the The higher the copper crystal growth rate, the more difficult it is to achieve Vdd-Free. For example, when the opening size is 0.18 // m, the conformal filling thickness of the plating solution in the experimental example is higher than that in the comparative example. The thickness of the conformal charge of the electroplating solution is small, which means that the electroplating solution containing benzene 8034twf 1 .doc / 006 16 527445 benzotriazole has better cavitation ability than the electrorheological solution containing 2-amino-benzothiazole. The experimental example / comparative example's conformal filling thickness ratio becomes smaller as the opening size decreases, indicating that the smaller the opening size, the plating solution containing benzotriazole and the plating solution containing 2-amino-benzothiazole. The difference in the cavitation ability is greater. In addition, the copper plating film deposited in the opening with a size of 0.1 // m in the experimental example can still obtain a good cavitation effect, while the plating solution in the comparative example has a size of The copper film deposited in the opening of 0.1 / im can not achieve a good cavitation effect. Therefore, The invention can be applied to the process of deep sub-micron integrated circuit. From the above-mentioned preferred embodiments of the invention, it can be known that by using the copper plating solution formula of the invention for electroplating, an opening with a size of 0.1 / zm and a large aspect ratio Completely filled to achieve super-clogging effect. This is because the mixed additives in the copper electroplating bath formula of the present invention have the function of accelerator and leveler at the same time. The mixed additives are in the form of a single anion at low concentration to promote copper. Metal layer deposition. The mixed additive is a double anion form at high concentrations, which can inhibit the deposition of copper metal layers. Because the concentration of the mixed additive at the top of the opening and the side wall of the opening is higher than the concentration at the bottom of the opening, a strong inhibitory effect will occur At the top of the opening and the side wall of the opening, the concentration of the mixed additive diffused to the bottom of the opening is low, and has a strong promotion effect, so the growth rate of copper crystals at the bottom of the opening is relative to the growth rate of copper crystals at the top of the opening and the side walls of the opening. High, so that the effect of super congestion can be achieved. Copper plating can be added in the metal inlaid opening Leveling ability. And 'the dosage of chemical additives added by using the plating solution of the present invention is very small.' Using copper inlay technology to make copper wires, you can get better contact with upper and lower components or wires, less impurities, and no holes or gaps. Copper plug to meet the requirements of the manufacturing process. In summary, 'Although the present invention has been disclosed as above with a preferred embodiment, its 8034twfl.doc / 006 17 527445 is not intended to limit the present invention, anyone familiar with this technique Without departing from the spirit and scope of the present invention, various modifications and retouching can be made, so the protection scope of the present invention shall be determined by the scope of the attached patent application. 8034twfl.doc / 006