I 8 7 51 w f. d o c / Ο Ο 8I 8 7 51 w f. D o c / Ο Ο 8
40636E A7 B740636E A7 B7
AA
I 消 iV 合 fi U 印 五、發明説明（I ) 本發明是有關於一種半導體之製程，且特別是有關於 一種接觸窗插塞之製造方法。 茌半導體製程中，對已完成的金氧半導體（MOS)元件 所進行的金屬化步驟，就是要對金氧半導體元件上的三個 電極，例如源極（Source)、汲極（Drain)和閘極（Gate)， 以金屬導線加以連接。鋁是現在常用來做爲導接的金屬材 料，但是因爲鋁與矽的接觸面極易形成尖峰現象 (Spiking)，且附著力（Adhesion)也不十分的理想，接觸 面電阻値也會升高。因此在金屬與矽之間，加入一層稱爲 阻絕層（Barrier Layer)的導電材料，以避免金屬砂界面 間的尖峰現象，並降低金屬與金氧半導體元件各電極進行 接觸時的接觸電阻（Con t ac t Res i s t ance)，以提昇金屬對 矽進行歐姆式接觸（Ohmic Contact)的能力以及金屬與其 他材質的附著力。 常用來當作阻絕層的材料例如有氮化鈦（ΊΊ tarn uni Nitride ; ΤιΝ)、矽化鈦（TiSn)、矽化鎢（WSh)或鎢鈦合 金（UW)等，在習知技藝中阻絕層的形成均在接觸窗 (Contact Hole)打開之後將氮化欽以潑鍍（Sput ter )方式 或鈦沈積後以快速加熱製程（Rapid Thermal Processing ; RTP)進行氮化反應（Nitridation)而形成。 第1A〜ID圖係繪示習知接觸窗插褰之製造流程剖面 圖。請參照第1A圖，提供一半導體基底10，該半導體基 底10上已形成有源/汲極區（未顯示）與氧化層11，以及定 義此氧化層11以形成接觸窗口 12暴露出源/汲極區。 (請先閱讀背面之注意事項再填寫本頁) . 訂 本紙乐尺度进用中國國家標肀（CNS ) Λ4規格（210X297公f ) A7 IS75twf.d〇c/00S 406365 B7 五、發明説明（7) 請參照第1B圖，依序沈積鈦層13與氮化鈦14層覆蓋 氧化層11、接觸窗口 12側壁以及覆蓋暴露出之源/汲極 區，其中沈積鈦層13之方法係爲磁控直流電濺鍍法，沈 積氮化鈦層14之方法係爲反應性濺鍍法。 請參照第1C圖，進行熱處理製程，例如係使用氧化 爐，藉以使得覆蓋源/汲極區的鈦層13與矽基底10產生 反應而形成矽化鈦層15。 S照第1D圖，沈積金屬層16於接觸窗口 12中，並 覆鈦層14，以形成接觸窗插塞，金屬層16之 材質例®鋁等金屬。 然而此觸窗插塞之製造方法，因爲是在鈦層Π 與氮化鈦層14沈積後直接做熱處理，而在氮化鈦層14與 矽基底10之界面形成矽化鈦層15以減低接觸電阻，但是 因爲氮化鈦層中之丨氮化欽受熱後之應力過大，因此極易發 生氧化層11與氮化鈦層Μ產生裂縫（Crack)現象，或者 是發生氮化鈦層14與氧化層11之附著力降低產生剝除 (Peel ing)現象。 因此，本發明的主要目的就是在提供一種接觸窗插塞 之製造方法以改善上述習知之裂縫與剝除現象。 根據本發明的主要目的，提出一種接觸窗插塞之製造 方法，包括下列步驟：首先，提供一矽基底，此矽基底上 已形成有源/汲極區與氧化層，然後定義氧化層以形成接 觸窗口暴露出源/汲極區。接著形成鈦層於接觸窗口中， 覆蓋接觸窗口之側壁、源/汲極區與氧化層。然後，形成 4 · (誚先閱讀背面之注意事項再填寫本頁) '-aI. iV and fi U. V. V. INTRODUCTION (I) The present invention relates to a semiconductor manufacturing process, and in particular to a method for manufacturing a contact window plug.茌 In the semiconductor manufacturing process, the metallization step performed on the completed metal-oxide-semiconductor (MOS) device involves the three electrodes on the metal-oxide-semiconductor device, such as the source, drain, and gate. The gate is connected by a metal wire. Aluminum is now commonly used as a conductive metal material, but because the contact surface between aluminum and silicon is very easy to form a spike, and the adhesion is not very satisfactory, the contact surface resistance will also increase. . Therefore, a layer of conductive material called a barrier layer is added between the metal and the silicon to avoid spikes at the metal sand interface and reduce the contact resistance when the metal is in contact with the electrodes of the metal-oxide semiconductor device (Con t ac t Resistance) to improve the ability of metal to make ohmic contact with silicon and the adhesion of metal to other materials. Materials commonly used as barrier layers are, for example, titanium nitride (ΊΊarn uni Nitride; TiN), titanium silicide (TiSn), tungsten silicide (WSh), or tungsten-titanium alloy (UW). The formation is formed after the contact hole is opened, and the nitride is sputtered or the titanium is deposited by a rapid thermal process (RTP) to perform a nitriding reaction (Nitridation). Figures 1A to ID are sectional views showing the manufacturing process of a conventional contact window insert. Referring to FIG. 1A, a semiconductor substrate 10 is provided. An active / drain region (not shown) and an oxide layer 11 have been formed on the semiconductor substrate 10, and the oxide layer 11 is defined to form a contact window 12 to expose the source / drain. Polar region. (Please read the notes on the back before filling in this page). The paper scale is used in the Chinese National Standard (CNS) Λ4 specification (210X297 male f) A7 IS75twf.d〇c / 00S 406365 B7 V. Description of the invention (7 ) Please refer to FIG. 1B, sequentially deposit titanium layer 13 and titanium nitride 14 layers to cover oxide layer 11, contact window 12 sidewalls, and cover exposed source / drain regions. The method for depositing titanium layer 13 is magnetron. In the DC sputtering method, the method for depositing the titanium nitride layer 14 is a reactive sputtering method. Referring to FIG. 1C, a heat treatment process is performed. For example, an oxidation furnace is used to make the titanium layer 13 covering the source / drain region react with the silicon substrate 10 to form a titanium silicide layer 15. According to FIG. 1D, a metal layer 16 is deposited in the contact window 12 and a titanium layer 14 is deposited to form a contact window plug. The material of the metal layer 16 is a metal such as aluminum. However, the manufacturing method of the contact plug is because the titanium layer Π and the titanium nitride layer 14 are directly heat-treated after the deposition, and a titanium silicide layer 15 is formed at the interface between the titanium nitride layer 14 and the silicon substrate 10 to reduce contact resistance. However, because the stress in the titanium nitride layer after heating is too large, it is very easy for cracks to occur in the oxide layer 11 and the titanium nitride layer M, or the titanium nitride layer 14 and the oxide layer may occur. The decrease in the adhesion of 11 results in peeling. Therefore, the main object of the present invention is to provide a method for manufacturing a contact window plug to improve the conventional cracking and peeling phenomenon. According to the main purpose of the present invention, a method for manufacturing a contact plug is provided, which includes the following steps: First, a silicon substrate is provided, and an active / drain region and an oxide layer have been formed on the silicon substrate, and then an oxide layer is defined to form The contact window exposes the source / drain region. Next, a titanium layer is formed in the contact window to cover the sidewall of the contact window, the source / drain region and the oxide layer. Then, form 4 · (诮 Read the notes on the back before filling in this page) '-a
T 本紙张尺度適川中國國家標率（CNS ) 規格（2】OX2W公釐) I 875t\vr.d〇c/〇〇8 406365 A7 B7 " 1 -----------— ---------------------- 五、發明説明（今） 氮化鈦層於接觸窗口中’覆蓋接觸窗口中之鈦層、與氧化 層上之鈦層。接著沈積金屬層於接觸窗口中，覆蓋氮化鈦 層。然後去除部份之金屬層，使金屬層大約與氧化層位於 同一平面以形成接觸窗插塞，以及最後形成矽化鈦層於接 觸窗口中氮化鈦層與源/汲極區之界面。 其中，去除部份之金屬層的方法，係爲使用回蝕法或 者是使用化學機械硏磨法。 本發明之特徵之一是進行金屬層回蝕或化學機械硏磨 法使金屬層大約與氧化層大約位於同一平面之後，因爲此 步驟包括將鈦層與氮化鈦層全部或部份去除，接著再進行 熱處理，因此無氮化鈦層之氮化鈦應力過大之問題。 本發明之特徵之二是可沈積厚度較厚之鈦層與氮化鈦 層以降低接觸面阻値並增加阻絕層之阻絕能力’而無應力 所產生之裂縫與剝除問題。 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： :^··ΛΛ'部屮"枒"而u T,消於合的^印1 I I ^1 —^1- 1 -i I ‘一欠 ^^1» 1^1 m m 0¾ 、1' - --(邡先閱讀背面之注意事項再填寫本頁) 第1A~1D圖係繪示習知接觸窗插塞之製造流程剖面 圖；以及 第2A〜2E圖係繪示依照本發明之一、較佳實施例的一種 接觸窗插塞之製造流程剖面圖。 實施例 請參照第2A圖，第2A-2E圖係繪示依照本發明之一較 5 本紙ίΑ尺廋適州中國國家標窣（CNS ) Λ4規格（210X29?公釐） U75u、f , A7 ^^Oc/004〇6365__B7__ 五、發明説明（y M寶施例的一種接觸窗插塞之製造流程剖面圖。 請參照第2Α圖，提供一半導體基底20 ’該半導體基 底2〇比已形成有源/汲極區（未顯示）與氧化層21，以及定 義此氧化層21以形成接觸窗口 22暴露出源/汲極區。 請參照第2Β圖，依序沈積鈦層23與氮化鈦層24覆蓋 氧化層21 '接觸窗口 22側壁以及覆蓋暴露出之源/汲極區 以作爲阻絕層之用，其中沈積鈦層23之方法係爲磁控直 流電濺鍍法，沈積氮化鈦層24之方法係爲反應性濺鍍法。 請參照第2C圖，沈積金屬層25a於接觸窗口 22中’ 並覆蓋氧化層21上之氮化鈦層24，其中金屬層25a之材 質例如爲鎢或鋁等金屬。 請參照第2D圖，進行回蝕（Etch Back)製程’或者是 利用化學機械硏磨法（Chemical Mechanical Polishing; CM?)，去除氧化層21上之金屬層25a以及去除氧化層21 上之部份或全部之鈦層23與氮化鈦層24以形成金屬層 25b，使金屬層25b大約與氧化層21位於同一平面以形成 接觸窗插塞。 請參照第2E圖，進行熱處理製程，例如係使用氧化 爐，藉以使得覆蓋源/汲極區的鈦層23與矽基底20產生 反應而形成矽化鈦層26以降低電阻値。 本發明之特徵之一是進行金屬回學機械硏磨法 使金屬層25b大約與氧化層21大約位於同一平面之後’ 因爲此步驟包括將鈦凰與氮化鈦層或部份去 除，接著再進行熱處理，园此不會產生氮俗膝屬24之氮 6 (邡先閱讀背面之注意事項再填寫本頁) -裝 本纸張尺度进用中國國家標率（（、NS ) Λ4規格（210X297公釐） A7 B7 ^06365 五、發明説明（<) 化鈦應力過大之問題。 本發明之特徵之二是可沈積厚度較厚之鈦層23與氮 化鈦層24以降低接觸面阻値並增加阻絕層之阻絕能力， 而無應力所產生之裂縫與剝除問題。 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。 7 本紙汰尺度適则，職m ( Γ—NS ) Λ4規格（21GX 297公楚） i I n I n I I·"' - - . ("先閱讀背面之注意事項再填寫本頁)T This paper is suitable for China National Standards (CNS) specifications (2) OX2W mm) I 875t \ vr.d〇c / 〇〇8 406365 A7 B7 " 1 ----------- — ---------------------- 5. Description of the invention (today) The titanium nitride layer in the contact window 'covers the titanium layer and the oxide layer in the contact window On the titanium layer. A metal layer is then deposited in the contact window to cover the titanium nitride layer. Then remove a part of the metal layer, so that the metal layer is about the same plane as the oxide layer to form a contact window plug, and finally a titanium silicide layer is formed at the interface between the titanium nitride layer and the source / drain region in the contact window. Among them, the method of removing a part of the metal layer is to use an etch-back method or a chemical mechanical honing method. One of the features of the present invention is that the metal layer is etched back or the chemical mechanical honing method is performed so that the metal layer is approximately on the same plane as the oxide layer, because this step includes removing the titanium layer and the titanium nitride layer in whole or in part, and then Further heat treatment is performed, so there is no problem that the titanium nitride stress of the titanium nitride layer is excessive. The second feature of the present invention is that a thicker titanium layer and a titanium nitride layer can be deposited to reduce the contact barrier and increase the barrier capacity of the barrier layer 'without the problems of cracks and peeling caused by stress. In order to make the above and other objects, features, and advantages of the present invention more comprehensible, a preferred embodiment is given below and described in detail with the accompanying drawings as follows: Brief description of the drawings: ^ · ΛΛ '部 屮 " 桠 " and u T, the disappearing ^ 印 1 II ^ 1 — ^ 1- 1 -i I' 一 ow ^^ 1 »1 ^ 1 mm 0¾, 1 '-- (邡 Please read the precautions on the back before filling this page) Figures 1A ~ 1D are cross-sectional views showing the manufacturing process of a conventional contact window plug; and Figures 2A ~ 2E are one according to the present invention. A cross-sectional view of a manufacturing process of a contact plug according to an embodiment. For examples, please refer to FIG. 2A, and FIGS. 2A-2E show 5 papers according to one of the present invention, 廋 ΑΑΑShizhou China National Standard (CNS) Λ4 specification (210X29? Mm) U75u, f, A7 ^ ^ Oc / 004〇6365__B7__ 5. Description of the invention (y M Bao example of a contact window plug manufacturing process cross-sectional view. Please refer to Figure 2A, provide a semiconductor substrate 20 'This semiconductor substrate has a ratio of 20% active / Drain region (not shown) and the oxide layer 21, and define the oxide layer 21 to form a contact window 22 to expose the source / drain region. Referring to FIG. 2B, a titanium layer 23 and a titanium nitride layer 24 are sequentially deposited. Covering the oxide layer 21 ′ contacting the side wall of the window 22 and covering the exposed source / drain region as a barrier layer, wherein the method for depositing the titanium layer 23 is a magnetron DC sputtering method and the method for depositing the titanium nitride layer 24 It is a reactive sputtering method. Referring to FIG. 2C, a metal layer 25a is deposited in the contact window 22 and covers the titanium nitride layer 24 on the oxide layer 21. The material of the metal layer 25a is, for example, tungsten or aluminum. Please refer to Figure 2D for Etch Back process' or By using Chemical Mechanical Polishing (CM?) Method, the metal layer 25a on the oxide layer 21 and a part or all of the titanium layer 23 and the titanium nitride layer 24 on the oxide layer 21 are removed to form a metal layer 25b. So that the metal layer 25b is located at about the same plane as the oxide layer 21 to form a contact window plug. Please refer to FIG. 2E to perform a heat treatment process, such as using an oxidation furnace, so that the titanium layer 23 and silicon covering the source / drain region are covered. The substrate 20 reacts to form a titanium silicide layer 26 to reduce electrical resistance. One of the features of the present invention is to perform a metal honing mechanical honing method so that the metal layer 25b is located approximately after the same plane as the oxide layer 21 'because this step includes The titanium phoenix and titanium nitride layer or part of it is removed, and then heat treatment is performed. This will not produce nitrogen of the genus 24. (邡 Please read the precautions on the back before filling this page) Using the Chinese national standard ((, NS) Λ4 specification (210X297 mm) A7 B7 ^ 06365 V. Description of the invention (<) The problem of excessive titanium stress. The second feature of the present invention is the deposition of thicker titanium Layer 23 The titanium nitride layer 24 reduces the contact surface barrier and increases the barrier capacity of the barrier layer, without the problems of cracks and peeling caused by stress. Although the present invention has been disclosed above in a preferred embodiment, it is not intended to limit Anyone skilled in the art of this invention can make various modifications and retouching without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope of the attached patent application. 7 The paper is of appropriate size, and the size is Γ4 (21GX 297). I I n I n II · " '--. (&Quot; Read the precautions on the back before filling this page)