1291705 A7 B7 經濟部智慧財產局員工消費合作社印製 五、發明説明（） 發明領域： / 一種含鋁矽系列合金層及其導線的製造方法，適用 於半導體製程中形成多重金屬內連線。 發明背景： 當半導體元件比如積體電路的積集度增加，使得晶片 的表面無法提供足夠的面積來製作所需的內連線時，爲了 配合金氧半導體（metal oxide semiconductor，MOS)電晶 體縮小後所增加的內連線需求，兩層以上的金屬層設計， 便逐漸的成爲許多積體電路所必需採用的方式。多重金屬 內連線(Multilevel Interconnects)的製作，是在金氧半(metal oxide semiconductor;MOS)電晶體的主體已完成之後才開始 的，它的目的是在獨立導通的金屬層之間，建立一些連接 系統，使得這些金屬內連線，可以傳輸訊息，達成彼此相 連串的目的，以成爲一個積體電路的完整迴路(Circuits)。 金屬鋁是積體電路發展至今，非常重要的一種導電性 材料，因其可降低RC時間延遲(Time Delay)，並提升元件 的開關(Switching)頻率；但是也有些缺點，例如因爲矽對鋁 有一定的固態溶解度(Solid Solubility)，使得矽與鋁的接觸 接面(Junction)，易產生所謂的尖峰現象(Spiking)，而且鋁 的抗電移能力（Electromigration Resistance)並不好；所謂的 21291705 A7 B7 Ministry of Economic Affairs Intellectual Property Bureau employee consumption cooperative printing 5, invention description () Field of the invention: / A method for manufacturing aluminum alloy series alloy layers and wires thereof, suitable for forming multiple metal interconnects in a semiconductor process. BACKGROUND OF THE INVENTION: When the degree of integration of a semiconductor component such as an integrated circuit is increased such that the surface of the wafer does not provide sufficient area to fabricate the desired interconnect, the metal oxide semiconductor (MOS) transistor is shrunk. After the increased interconnection requirements, the design of two or more metal layers has gradually become the necessary method for many integrated circuits. The fabrication of Multilevel Interconnects began after the bulk of the metal oxide semiconductor (MOS) transistor was completed. Its purpose was to establish some between the independently conducting metal layers. The connection system allows these metal interconnects to transmit messages and achieve the purpose of connecting strings to each other to become a complete circuit of integrated circuits. Metal aluminum is a very important conductive material developed by integrated circuits, because it can reduce the RC time delay and increase the switching frequency of components; however, it also has some disadvantages, for example, because A certain solid solubility (Solid Solubility) makes the contact surface of tantalum and aluminum easy to produce so-called spikes, and the resistance of aluminum is not good; the so-called 2
本紙張尺度適用中國國家標準(CNS)A4規格(210X297公爱) A7 B7 1291705 i、發明説明（） 尖峰現象，是因爲矽在約400°C左右對鋁有一定的固態溶解 度，因此沉積在矽表面上的鋁，當製程達到約400°C以上的 溫度時，矽將藉著擴散效應而進入鋁，且鋁也會回塡矽因 擴散所遺留下來的空隙，而在鋁與矽接觸(Contact)的部分， 形成一些”尖峰”，如果有些尖峰的長度太長，則容易造成 短路而使元件失敗。 另外所謂的電移能力，習知以濺鍍法所沉積的鋁，經 適當的退火(Anneal)之後，通常都是以多晶(Poly-Crystalline) 的形式存在，當鋁線處於傳導電流的狀態時，因爲電場的 影響，鋁原子將會延著晶粒界面(Grain Boundary)而移動， 這種現象稱之爲電移，假如電移太過劇烈，將導致該金屬 鋁線的斷路，影響元件的可靠性，因此在使用時，我們通 常都在裡面加入適當的矽與銅，形成所謂的鋁矽系列 (Al-Cu-Si)合金，以防止這兩種問題的發生。一般在鋁矽系 列合金中，矽的含量控制在約1%左右，而銅的含量在〇·5% 至4%之間。 經濟部智慧財產局員工消費合作社印製 請參照第1圖’第1圖係繪示習知常用的鋁矽系列合 金金屬導線的製程。在已完成元件製程的晶圓i〇〇上’沉 積一層鈦（Ti)、矽化鈦（Tisix)或矽化鎢(WSix)層102，主 要的目的是降低金屬與金氧半導體接面間的片電阻（Sheet Re si stance)和導線的電阻。接者再丨几積一^氣化欽（TiN)或駄 鎢(TiW)合金之金屬層104作爲阻障層（Barrier Layer)或 3 中 i iiii(CNS)A4 規格(靡297公愛) 12917〇5 A7 B7 五、發明説明（) 黏著層（Adhesion Layer)以防止鋁金屬與矽產生介面矽 化物及增進鋁金屬的附著力。沉積一層鋁矽系列合金層 作爲形成導線的主要材料。沉積一層氮化鈦作爲抗反射 層108(Anti-reflection Layer)。最後，以一微影蝕刻製程定 義出金屬導線(未繪示於圖上）。 經濟部智慧財產局員工消費合作社印製 沉積鋁矽系列合金的方法是採用濺鍍法，接著一個攝 氏450至500度的再熱流(Reflow)熱處理來增加鋁金屬的階 梯覆蓋能力（Step Coverage)。請參照第2圖，第2圖係繪示 矽材質於鋁矽系列合金中析出的情形。矽在鋁金屬中的溶 解度會隨溫度的變化而改變，溫度越高，融解度越好。高 溫沉積或熱處理之後的退火過程中，鋁金屬對矽的溶解度 會隨溫度的下降而下降，請參照第6圖，第6圖摘自 M.Hansen and A. Anderko, Constitution of Binary Alloys 5 McGmw-Hill，New York，1958 ”半導體元件物理與製作技 術”施敏原著，張俊彥譯著”第451頁圖25，係繪示矽材質 對鋁材質在不同溫度下的固溶曲線圖。在第6圖左上角的 放大圖中，可以看出矽材質對鋁金屬材質的固相溶解度在 攝氏577度時爲百分之1·5 ’當溫度降到攝氏500度時，則 降到百分之1左右，而溫度降到攝氏44〇度以下，溶解度 則大幅下滑。所以，若緩慢降溫時’矽在鋁中的固相溶解 度降會依此固溶曲線而行，當冷卻到室溫時，鋁金屬中所 含過飽和的矽會從含鋁矽系列合金之固溶體中成核 (Nucleation)成長(Growth)而成爲砂晶200析出。由於銘金 (請先閲讀背面之注意事項再填寫本頁)This paper scale applies to China National Standard (CNS) A4 specification (210X297 public) A7 B7 1291705 i, invention description () The peak phenomenon is because 矽 has a certain solid solubility to aluminum at about 400 ° C, so it is deposited in 矽On the surface of the aluminum, when the process reaches a temperature above about 400 ° C, the bismuth will enter the aluminum by the diffusion effect, and the aluminum will also return to the void left by the diffusion, and the aluminum will contact with the bismuth (Contact The part that forms some "spikes", if some of the peaks are too long, it is easy to cause a short circuit and the component fails. In addition to the so-called electromigration capability, it is known that the aluminum deposited by sputtering is usually in the form of poly-Crystalline after proper annealing (Anneal), when the aluminum wire is in a conducting current state. At the time, because of the influence of the electric field, the aluminum atoms will move along the grain boundary (Grain Boundary). This phenomenon is called electric shift. If the electric shift is too intense, the metal aluminum wire will be broken and the components will be affected. Reliability, so when used, we usually add appropriate niobium and copper to form a so-called aluminum-bismuth series (Al-Cu-Si) alloy to prevent these two problems. Generally, in the aluminum bismuth series alloy, the content of cerium is controlled to be about 1%, and the content of copper is between 5% and 5%. Printed by the Intellectual Property Office of the Ministry of Economic Affairs and the Consumers' Cooperatives. Please refer to Figure 1 for the first figure. The first series of drawings shows the process of the commonly used aluminum-iridium alloy metal wires. Depositing a layer of titanium (Ti), titanium (Tisix) or tungsten germanium (WSix) layer 102 on the wafer that has completed the component process, the main purpose is to reduce the sheet resistance between the metal and the MOS junction (Sheet Re si stance) and the resistance of the wire. The receiver then uses a metal layer 104 of a TiN or TiW alloy as a barrier layer or a i iiii (CNS) A4 specification (靡297 公公) 12917 〇5 A7 B7 V. INSTRUCTIONS () Adhesion Layer to prevent the formation of interfacial bismuth from aluminum metal and niobium and to enhance the adhesion of aluminum metal. A layer of aluminum bismuth alloy layer is deposited as the main material for forming the wire. A layer of titanium nitride is deposited as an anti-reflection layer 108. Finally, a metal wire (not shown) is defined by a lithography process. Printed by the Ministry of Economic Affairs, the Intellectual Property Office and the Consumer Cooperatives. The method of depositing aluminum alloys is by sputtering, followed by a Reflow heat treatment of 450 to 500 degrees Celsius to increase the step coverage of the aluminum metal. Please refer to Fig. 2, and Fig. 2 shows the deposition of bismuth material in an aluminum-bismuth alloy. The solubility of ruthenium in aluminum metal changes with temperature. The higher the temperature, the better the degree of melting. During the annealing process after high temperature deposition or heat treatment, the solubility of aluminum metal to ruthenium decreases with the decrease of temperature. Please refer to Figure 6, Figure 6 is taken from M. Hansen and A. Anderko, Constitution of Binary Alloys 5 McGmw-Hill , New York, 1958 "Semiconductor Component Physics and Fabrication Technology" by Shi Min, Zhang Junyan, translated on page 451, Figure 25, shows the solid solution curve of yttrium material for aluminum at different temperatures. In the enlarged view of the angle, it can be seen that the solid phase solubility of the yttrium material to the aluminum metal material is 1. 5 percent at 577 degrees Celsius, and when the temperature drops to 500 degrees Celsius, it drops to about 1 percent. When the temperature drops below 44 degrees Celsius, the solubility drops sharply. Therefore, if the temperature is slowly lowered, the solid solution solubility of aluminum in aluminum will depend on the solid solution curve. When cooled to room temperature, aluminum metal The supersaturated cerium will grow from the nucleation (Nucleation) of the solid solution containing the aluminum-bismuth alloy and become the crystal of the crystal 200. Since Mingjin (please read the back of the note first, please fill out this page)
訂· 本紙張尺度顧中S S家標準(CNS)A4規格(21GX 297公爱） 1291705 A7Book · This paper scale Gu S S Family Standard (CNS) A4 specifications (21GX 297 public) 1291705 A7
五、發明説明（） 時間供其成核成長，因而無法析出。 、另外，本發明亦提供另一含鋁矽系列合金導線的製造 方法，先如習知沉積一層鈦、矽化鈦或矽化鎢來降低片電 阻’接者再沉積一層氮化鈦或鈦鎢合金作爲阻障層和黏著 層。以一約攝氏300度至攝氏500度的高溫濺鍍沉積一銘 矽系列合金作爲形成導線的主要材料。降溫進行氮化鈦的 沉積，但下降的溫度不超過攝氏50度，亦即在攝氏25〇度 至攝氏450度的條件下進行氮化鈦的沉積。最後，迅速將 晶圓的溫度降到攝氏20度左右或是更低的溫度，降溫所需 的時間在1秒到10秒之間。同樣的，快速的降溫使過飽和 的矽無適當的溫度和時間供其成核成長，因而無法析出。 式簡單說明： (請先閲讀背面之注意事項再填、寫本頁) 訂 經濟部智慧財產局員工消費合作社印製 第1圖係繪=習知常用的鋁矽系列合金金屬導線的製程； 第2圖係繪示係材質於鋁矽系列合金中析出的情形；， 第3圖係繪示蝕刻具有矽晶析出的鋁矽系列合金； 第4圖及第5圖係繪示根據本發明所揭露的製程所形成的 金屬導線；以及 第6圖係繪示矽材質對鋁材質在不同溫度下的固溶曲線圖。 圖號對照說明： 本紙張尺度適用中國國家標準(CNS)A4規格(210X 297公釐) 經濟部智慧財產局員工消費合作社印製 1291705 Λ7 B7 五、發明説明（） 100、400 :晶圓 102、104 :金屬層 106、406 :鋁矽系列合金層 108、408 :抗反射層 200 :矽晶 202 :鋁金屬晶界 204、410 :金屬導線 402、404 :導體層 發明詳細說明： 鑑於上述發明背景所述關於鋁矽系列合金導線製程 所造成之問題，本發明的目的在提供一含鋁矽系列合金導 線的製造方法，主要是改善高溫沉積或熱處理之後的退火 過程，使矽不再析出。 爲了讓本發明所提供之鋁矽系列合金導線的製造方 法更加清楚起見，茲提供一較佳實施例說明如下。 實施例1 請參照第4圖及第5圖’第4圖及第5圖係繪示根據 本發明所揭露的製程所形成的金屬導線。在—已完成％件 製程的晶圓4〇〇上先沉積-鈦、砂化金太或砂化錫材質^導 8V. Description of the invention () Time for its nucleation and growth, and therefore cannot be precipitated. In addition, the present invention also provides another method for manufacturing an aluminum-containing bismuth series alloy wire. First, a layer of titanium, titanium telluride or thorium telluride is deposited to reduce the sheet resistance, and a layer of titanium nitride or titanium tungsten alloy is deposited as a contact. Barrier layer and adhesive layer. A series of alloys are deposited as a main material for forming wires at a high temperature of about 300 degrees Celsius to 500 degrees Celsius. The deposition of titanium nitride is carried out by lowering the temperature, but the temperature is lowered by no more than 50 degrees Celsius, that is, deposition of titanium nitride is carried out at 25 degrees Celsius to 450 degrees Celsius. Finally, the temperature of the wafer is quickly reduced to about 20 degrees Celsius or lower, and the time required to cool down is between 1 second and 10 seconds. Similarly, rapid cooling causes supersaturated cesium to have no proper temperature and time for its nucleation to grow and therefore cannot be precipitated. Brief description: (Please read the notes on the back and fill in and write this page) The Ministry of Economic Affairs, Intellectual Property Bureau, Staff and Consumer Cooperatives, Printed, 1st, Figure 1 = The common aluminum-bismuth alloy metal wire process; 2 is a diagram showing the precipitation of the material in the aluminum-bismuth alloy; FIG. 3 is a diagram showing the etching of the aluminum-bismuth alloy with twin precipitation; FIGS. 4 and 5 are diagrams according to the present invention. The metal wire formed by the process; and the sixth figure shows the solid solution curve of the bismuth material at different temperatures. Figure number comparison description: This paper scale applies to China National Standard (CNS) A4 specification (210X 297 mm) Ministry of Economic Affairs Intellectual Property Bureau Staff Consumer Cooperative Printed 1291705 Λ7 B7 V. Invention Description () 100, 400: Wafer 102, 104: metal layer 106, 406: aluminum bismuth series alloy layer 108, 408: anti-reflection layer 200: twin crystal 202: aluminum metal grain boundary 204, 410: metal wire 402, 404: conductor layer Detailed description of the invention: In view of the above invention background The object of the invention is to provide a method for manufacturing an aluminum-containing bismuth series alloy wire, which is mainly for improving the annealing process after high-temperature deposition or heat treatment, so that the ruthenium is no longer precipitated. In order to make the manufacturing method of the aluminum-bismuth series alloy wire provided by the present invention more clear, a preferred embodiment is provided as follows. Embodiment 1 Referring to Figures 4 and 5, Figures 4 and 5 illustrate metal wires formed in accordance with the process disclosed in the present invention. Deposited on the wafer 4 of the %-processed process - Titanium, gold-plated gold or tin-soled material.
• I I I I 本紙張尺度適用中國國家標準(CNS)A4規格(210χ 297公釐) A7 B7 缓濟部智慧財產局員工消費合作社印製 1291705 五、發明説明（） 體層402。導體層402的目的係用來降低導線與源/汲/閘 極或是金屬插塞(均未繪示於圖上）間的片電阻。^妾著在^ 體層402之上再沉積一層氮化鈦或鈦鎢合金的導體層 4〇4，導體層404可作爲阻障層或黏著層。再以—約^氏 3〇〇度至攝氏500度的高溫濺鍍沉積一鋁矽系列合金層 4〇6於導體層4〇4之上作爲形成導線的主要材料，^成銘 矽系列合金層406的材質可以爲鋁矽銅合金。 / " 迅速將晶圓400的溫度降到攝氏〇度至攝氏度左 右’較佳的溫度範圍爲攝氏15度至攝氏25度，降溫所需 的時間在1秒到10秒之間，較佳的時間範圍爲5秒至^ 秒。在銘砂系列合金層406之上沉積一層氮化欽作爲抗反 射層408，氮化鈦的沉積約在攝氏15度至攝氏25度間進 行。請參照第5圖，最後，以一微影蝕刻製程定義出金屬 導線410，完成鋁矽系列合金金屬導線的製程。據此，降 溫速率從每秒攝氏27.5度至每秒攝氏500度。較佳的降溫 速率從每秒攝氏27.5度至每秒攝氏485度。更佳的降溫速 率從每秒攝氏27·5度至每秒攝氏97度。 實施例2 請繼I買參照弟4圖，弟4圖係繪不根據本發明所揭露 的製程所形成的金屬導線。在一已完成元件製程的晶圓 400上先沉積一鈦、矽化鈦或矽化鎢材質的導體層4〇2。 9 (請先閱讀背面之注意事項再填寫本頁)• I I I I This paper scale applies to China National Standard (CNS) A4 specification (210χ 297 mm) A7 B7 Jiuji Ministry Intellectual Property Bureau employee consumption cooperative printing 1291705 V. Invention description () Body layer 402. The purpose of conductor layer 402 is to reduce the sheet resistance between the wire and the source/deuterium/gate or metal plug (both not shown). A conductor layer 4?4 of titanium nitride or titanium-tungsten alloy is deposited on top of the body layer 402, and the conductor layer 404 can serve as a barrier layer or an adhesive layer. Then, an aluminum-bismuth alloy layer 4〇6 is deposited on the conductor layer 4〇4 as a main material for forming a wire by a high-temperature sputtering of about 3 degrees Celsius to 500 degrees Celsius, and the alloy layer of the Mingcheng series is formed. The material of 406 can be aluminum beryllium copper alloy. / " Quickly reduce the temperature of wafer 400 to degrees Celsius to degrees Celsius. The preferred temperature range is 15 degrees Celsius to 25 degrees Celsius. The time required to cool down is between 1 second and 10 seconds. The time range is from 5 seconds to ^ seconds. A layer of nitride is deposited as an anti-reflective layer 408 over the Mingsha series alloy layer 406, and the deposition of titanium nitride is performed between about 15 degrees Celsius and 25 degrees Celsius. Referring to FIG. 5, finally, a metal wire 410 is defined by a lithography etching process to complete the process of the aluminum-bismuth alloy metal wire. Accordingly, the rate of cooling is from 27.5 degrees Celsius per second to 500 degrees Celsius per second. The preferred rate of cooling is from 27.5 degrees Celsius per second to 485 degrees Celsius per second. A better cooling rate is from 27.5 degrees Celsius per second to 97 degrees Celsius per second. Embodiment 2 Please refer to Figure 4 for a reference to Figure 4, which depicts a metal wire formed by a process not disclosed in accordance with the present invention. A conductive layer 4〇2 of titanium, titanium telluride or tungsten telluride is deposited on the wafer 400 of the completed component process. 9 (Please read the notes on the back and fill out this page)
本紙張尺度適用中國國家標準(CNS)A4規格(2Κ)>< 297公釐) 1291705 A7 B7 五、發明説明（ 導體層402的目的係用來降低導線與源/汲/閘極或是金屬 插塞(均未繪示於圖上）間的片電阻。接著在導體層402之 上再沉積一層氮化鈦或鈦鎢合金的導體層404，導體層 404可作爲阻障層或黏著層。再以一約攝氏3〇〇度至攝氏 500度的高溫濺鍍沉積一鋁矽系列合金層406於導體層 404之上作爲形成導線的主要材料，形成鋁矽系列合金層 406的材質可以爲鋁矽銅合金。降溫但下降的溫度不超過攝 氏50度，亦即反應室的溫度維持在攝氏250度至攝氏45〇 度。 在溫度爲攝氏250度至攝氏450度的條件下進行氮化 鈦材質的抗反射層408的沉積，在鋁矽系列合金層406形 成抗反射層408。最後，迅速將晶圓的溫度降到攝氏〇度至 攝氏25度，較佳的溫度範圍爲攝氏15度至攝氏25度，降 溫所需的時間在1秒到10秒之間，較佳的時間範圍爲5秒 至10秒。請參照第5圖，最後，以—微影蝕刻製程定義出 金屬導線410,完成鋁矽系列合金金屬導線的製程。其中， 降溫速率與實施例1中揭露者相同。 Μ 經濟部智慧財產局員工消費合作社印製 由兩個較佳實施例中可以了解本發明的特徵。本發明 的特徵在於形成鋁矽系列合金層之後，採用一快速降溫的 步驟。利用一快速降溫的程序使室溫下的銘金屬仍能對石夕 保持局溫時的溶解度’此介穩態的銘合金將不會發生砂析 出的情形。此降溫的步驟可在銘砂系列合金層形成之後立 10 本紙張尺度適用中國國家標準(CNS)A4規格(210><297公釐) 1291705 A7 B7 五、發明説明（） 刻進行’也可以在形成抗反射層之後進行。若要在形成抗 反射層之後進行快速降溫，則形成抗反射層時的溫度不能 低於形成鋁矽系列合金層的溫度太多，此一溫度的差距最 好不要超過攝氏50度。 如熟悉此技術之人員所瞭解的，以上所述僅爲本發明 之較佳實施例而已，並非用以限定本發明之申請專利範 圍；凡其它未脫離本發明所揭示之精神下所完成之等效改 變或修飾，均應包含在下述之申請專利範圍內。 (請先閲讀背面之注意事項再場寫本頁) 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(210x297公釐）This paper scale applies to China National Standard (CNS) A4 specification (2Κ)><297 mm) 1291705 A7 B7 V. Inventive Note (The purpose of conductor layer 402 is to reduce the wire and source/汲/gate or The sheet resistance between the metal plugs (none of which are shown in the figure). Then, a conductor layer 404 of titanium nitride or titanium tungsten alloy is deposited on the conductor layer 402, and the conductor layer 404 can be used as a barrier layer or an adhesive layer. Then, an aluminum-bismuth alloy layer 406 is deposited on the conductor layer 404 as a main material for forming a wire by a high-temperature sputtering of about 3 degrees Celsius to 500 degrees Celsius. The material of the aluminum-bismuth alloy layer 406 may be Aluminum beryllium copper alloy. The temperature is lowered but the temperature does not exceed 50 degrees Celsius, that is, the temperature of the reaction chamber is maintained at 250 degrees Celsius to 45 degrees Celsius. Titanium nitride is carried out at a temperature of 250 degrees Celsius to 450 degrees Celsius. The deposition of the anti-reflective layer 408 of the material forms an anti-reflective layer 408 in the aluminum-bismuth alloy layer 406. Finally, the temperature of the wafer is rapidly lowered to a temperature of 25 degrees Celsius, preferably 15 degrees Celsius. 25 degrees Celsius, the time required to cool down is 1 Between 10 seconds, the preferred time range is 5 seconds to 10 seconds. Please refer to Figure 5, and finally, the metal wire 410 is defined by the lithography process to complete the process of the aluminum-bismuth alloy metal wire. The cooling rate is the same as that disclosed in Embodiment 1. Μ Ministry of Economic Affairs Intellectual Property Office Employee Consumption Cooperative Printing The features of the present invention can be understood from two preferred embodiments. The present invention is characterized in that after forming an aluminum bismuth alloy layer, Use a rapid cooling step. Using a rapid cooling program, the temperature of the metal at room temperature can still maintain the solubility of the stone at the local temperature. This will not cause sand deposition. The steps can be made after the formation of the alloy layer of the Mingsha series. The paper size is applicable to the Chinese National Standard (CNS) A4 specification (210><297 mm). 1291705 A7 B7 V. Invention description () Engraving can also be formed After the anti-reflection layer is performed. If the temperature is to be rapidly cooled after forming the anti-reflection layer, the temperature at which the anti-reflection layer is formed cannot be lower than the temperature at which the aluminum-bismuth alloy layer is formed. The difference in temperature is preferably not more than 50 degrees Celsius. As will be understood by those skilled in the art, the above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the patent application of the present invention; Equivalent changes or modifications made in the spirit of the present invention should be included in the scope of the following patent application. (Please read the notes on the back and write this page again) The printed paper size applies to the Chinese National Standard (CNS) A4 specification (210x297 mm)