A7 B7 3 〇0f@N5F*Jb〇C/Frailk/〇〇2 五、發明説明（1 ) 本發明是有關於一種氮化鈦防擴散層的生成方法，且 特別是有關於一種以多層次成長法生成的氮化鈦防擴散 層。 在現今積體電路之金屬化製程中，鋁和鎢可說是最常 使用的金屬材料。其中，鋁因爲電阻率較低，所以主要作 爲元件間的導線之用，且大多是以濺鍍法沈積形成；而鎢 的電阻率雖較高，但由於可利用化學氣相沈積法(CVD)形 成，其階梯覆蓋能力（Step Coverage)較佳，加上本身極易形 成具較高揮發性的氟化物，沒有蝕刻上去除的困難，因此 也廣爲應用於作爲不同金屬層間的接觸栓(Plug)，以便將各 金屬層加以連接。然而，鋁與矽的接觸介面會因爲後續加 熱程序而彼此互相擴散，形成尖峰(Spike)現象，亦造成短 路而影響元件性質，加上鎢與其他材質（例如矽）的附著力 (Adhesion)也不十分理想，所以在使用鋁及鎢這兩種金屬 時，通常會在其與他種材質之間再增加一層稱爲「防擴散 層」（Diffusion Barrier Layer)的導電材料，以避免鋁矽界面 產生尖峰現象，及提昇鎢對其他材質的附著能力。 氮化鈦薄膜是在VLSI製程中，使用最頻繁的一種防擴 散層材料，通常係使用物理氣相沈積法，例如是濺鍍方法 形成。一般製造方法係利用金屬鈦靶，利用氬氣與氮氣所 混合的反應氣體，經離子轟擊而濺出的鈦，將與電漿內因 解離反應所形成的氮原子，形成氮化鈦沈積在晶片表面。 而習知的氮化鈦防擴散層，當沈積的厚度增加時’由 於在膜的厚度較厚時，應變能（Strain Energy)爲主要控制氮 3 nt' In I - i f i I : n (請先閱讀背面之注意事項再填寫本頁) 訂 經濟部中央標準局員工消費合作社印製 本紙浪尺度適用中國國家標準（CNS ) A4規格（210X297公釐） OC/Frank/002 A7 B7 經濟部中央標準局貝工消費合作枉印製 五、發明説明（L) 化鈦成長的因素，此時爲使應變能最小，其優選成長 (Preferred Growth)方向會以（11 l)TiN爲主要方向，造成氮化 鈦膜沿著晶粒邊界（Grain Boundary)產生裂痕（Crack)。如此 一來，提供了金屬層與矽基底間原子互相擴散的途徑，結 果於熱處理後造成接面漏電（Junction Leakage)甚至短路。 因此，爲了使氮化鈦防擴散層能沈積較厚的厚度，又可避 免裂痕的產生，必須利用另一種防擴散層的製造方法來達 成。 有鑑於此，本發明的主要目的就是在提供一種氮化鈦 防擴散層的製造方法，利用以物理氣相蒸鍍法生成氮化鈦 的過程中，断續停止供應氮氣一段時間，以生成多層次的 氮化鈦薄膜，使氮化鈦薄膜優選成長方向以(001)爲主要生 長方向，以避免氮化鈦膜產生裂痕。 爲了達成上述目的，本發明利用表面分析技術來探討 氮化鈦薄膜的成長特性，並由實驗的結果得知：氮化鈦薄 膜會因厚度的不同，造成不同之成長應變能而影響其優選 成長方向。當厚度未超過50nm時，控制氮化鈦生長的因 素爲表面能（Surface Energy)，其優選成長方向爲(001)的氮 化鈦。當厚度超過50nm時，應變能成爲主要控制氮化鈦 成長的因素，此時爲使應變能最小，其優選成長方向爲（111) 的氮化鈦，造成氮化鈦膜沿著晶粒邊界產生裂痕，提供原 子擴散的途徑，之後縱使在增加氮化鈦薄膜厚度也無法達 到防止擴散的效果。本發明提供一種氮化鈦防擴散層的製 造方法，利用以物理氣相蒸鍍法生成氮化鈦的過程中，間 4 (請先閲讀背面之注意事項再填寫本頁) •裝. 訂 」 本紙張尺度逋用中國國家橾準（CNS ) A4規格（210X297公釐） 經濟部中央標隼局員工消費合作社印1i $ Q3gl01RjP〇C/Frank/OO2 A7 五、發明説明（多） 斷停止供應氮氣，改變生成環境，使應變能的累積中斷， 因此控制氮化鈦生長仍爲表面能，其優選生長方向爲(001) 的氮化鈦，並可使防擴散層的厚度提昇至60nm。 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圖爲一次形成之TiN(50nm)/(001)Si試片之X-Ray 繞射圖； 第 1B 圖爲多層次[Ti(10nm)/TiN(20nm)]x2/(001)Si 試片 之X-Ray繞射圖， 第2圖爲依照本發明一較佳實施例，一種多層次氮化 鈦防擴散層的製造剖面圖。 實驗結果與討論 本發明係選用（001)方向切割的矽晶圓當作基底，使用 物理氣相沈積法，例如是濺鍍方法形成氮化鈦防擴散層。 使用金屬鈦靶，利用氬氣與氮氣所混合的反應氣體，經離 子轟擊而漸出的鈦，將與電漿內因解離反應所形成的氮原 子，形成氮化鈦沈積在晶片表面，在氮化鈦生成過程中， 對氮氣的供應做週期性的開（ON)和關（OFF)，使得製程過程 中產生 TiN 與 Ti 交互生成形成[Ti( 10nm)/TiN(20nm)]x2/(001) Si之多層次TiN試片。另外，也形成利用一次成長的 TiN(50nm)/(001)SHS片作爲對照。 本發明之多層次TiN層與一次生成之TiN層不同處 (請先閲讀背面之注意事項再填寫本頁) -裝. 訂 」 本紙張尺度適用中國國家標準（CNS ) A4規格（2丨0 X 297公釐） I39iTWF.D〇C/Frank/002 A7 B7 五、發明説明（f ) 爲，此法生成之厚膜TiN優選成長方向爲(OOl)TiN，且沿 晶粒邊界破裂的情形得到改善。其特性在於，在生成TiN 中停止供應氮氣，改變生成環境，使應變能的累積中斷， 因此控制TiN生長仍爲表面能，其優選成長方向爲 (OOl)TiN。如此一來，可改善TiN層破裂之情形，但卻不 會增加製程困難度，不需在蒸鍍過程中多次開關電源，且 不需對蒸鍍機器作任何調整，只需針對氮氣的供應作週期 性的開關動作即可。而在停止供應氮氣期間，理應形成Ti 薄膜，但由於停止供應氮氣之時間很短，使金屬鈦靶上仍 有些許氮氣可與Ti生成TiN，因此不會對TiN層的成分造 成太大影響。 經濟部中央標準局員工消費合作社印聚 (請先閱讀背面之注意事項再填寫本頁) 而在兩層TiN中所鍍上的Ti層有效的阻止了 TiN層應 變能的累積，使TiN生長一直維持在以表面能爲主的狀態 下，因此TiN優選成長方向爲(OOl)TiN，異於一次成長TiN 的（lll)TiN優選成長方向。此結果可由[Ti(10nm)/TiN(20nm)] x2/(001 )Si 與 TiN(50nm)/(001 )Si 試片之 X-Ray 繞射實驗得知 其優選成長方向之不同。第1A圖爲TiN(50nm)/(001)Si試片 之X-Ray繞射圖，由於應變能累積而出現（m)TiN之繞射 峰；第 1B 圖爲多層次[Ti(10nm)/TiN(20nm)]x2/(001)Si 試片 之 X-Ray 繞射圖，在多層次[Ti(10nm)/TiN(20nm)]x2/(001)Si 試片中則只有(002) TiN之繞射峰，沒有出現（11 l)TiN之繞 射峰’且其沈積的總厚度可超過50nm，而達到60nm。 實施例 基於上述實驗的結果，可將其應用於一半導體積體電 A7 B7 39lT\VF.DOC/Frank/002 五、發明説明（Γ) 路之製程，以多層次TiN膜當作防擴散層，使其發揮防止 原子擴散之效果。首先請參照第2A圖，再依矽基底20上 形成有一半導體元件’例如是MOS電晶體或雙載子電晶 體’爲了簡化圖式，此處僅繪出該半導體元件的接觸區 22 ’其可是一 MOS電晶體的源極/汲極區，或是多層結構 之金屬連線。在矽基底20上沈積一絕緣層24，例如是一 二氧化矽層，在經微影和蝕刻製程在絕緣層24中形成一接 觸開D 26，以露出半導體元件的接觸區22。 然後，進行物理氣相沈積反應，例如使用蒸鍍，使用 一金壩鈦靶，並將氮氣與氬氣通入反應室中，並調節其·流 量’使該反應室內達到一穩定壓力與溫度，然後進行沈積 程序。再接觸開口 26底部和側壁上、以及絕緣層.24表面 上形成一鈦金屬層28，其厚度約爲l〇nm，與一氮化鈦層 3〇 ’其厚度約爲20nm。之後停止供應氮氣，但繼續進行 蒸鍍，而在氮化鈦層30表面形成一鈦金屬層32，其厚度 約爲10nm。此時再度通入氮氣進行蒸鏟，在鈦金屬層32 表面形成一氮化鈦層34，其厚度約爲20nm，完成多層次 氮化鈦防擴散層的製程。 綜上所述，本發明根據實驗分析結果，由於氮化鈦層 生成時的應變能累積中斷，因此控制氮化鈦生長仍爲表面 能，其優選成長方向爲(001)的氮化矽，不致產生沿晶粒邊 界之裂痕，確保防止擴散之最佳效果，從而提昇元件性質。 同時多層次氮化鈦防擴散層的成長方向與基底性質無 關，可是用於矽、氧化矽等任何材質上。 7 (請先閲讀背面之注意事項再填寫本頁) -裝· 訂 經濟部中央標準局員工消費合作社印裝 本紙張尺度適用中國國家標率（CNS)A4現格（21〇Χ 297公釐） OC/Frank/002 A7 B7 五、發明説明（6 ) 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· 、va 經濟部中央標準局員工消費合作社印裝 本紙張尺度適用中國國家標準（CNS ) A4規格（210X 297公釐）A7 B7 3 〇0f @ N5F * Jb〇C / Frailk / 〇〇2 V. Description of the invention (1) The present invention relates to a method for forming a titanium nitride anti-diffusion layer, and in particular to a method of multi-layer growth The titanium nitride anti-diffusion layer produced by the method. In the current metallization process of integrated circuits, aluminum and tungsten are arguably the most commonly used metal materials. Among them, aluminum is mainly used as a wire between elements because of its low resistivity, and it is mostly formed by sputtering deposition; while tungsten has a high resistivity, but it can be used by chemical vapor deposition (CVD) Formation, its step coverage is better, plus itself is very easy to form fluoride with high volatility, there is no difficulty in removing on etching, so it is also widely used as a contact plug between different metal layers (Plug) ) To connect the metal layers. However, the contact interface of aluminum and silicon will diffuse with each other due to the subsequent heating process, forming a spike phenomenon, which also causes a short circuit and affects the properties of the device, plus the adhesion of tungsten to other materials (such as silicon) Not very ideal, so when using two metals, aluminum and tungsten, a layer of conductive material called "Diffusion Barrier Layer" is usually added between them and other materials to avoid the aluminum-silicon interface It produces spikes and enhances the adhesion of tungsten to other materials. Titanium nitride film is one of the most frequently used anti-diffusion layer materials in the VLSI manufacturing process. It is usually formed by physical vapor deposition, such as sputtering. The general manufacturing method is to use a metal titanium target, a reaction gas mixed with argon and nitrogen, and titanium sputtered by ion bombardment, and the nitrogen atoms formed by the dissociation reaction in the plasma to form titanium nitride deposited on the wafer surface . In the conventional titanium nitride anti-diffusion layer, when the thickness of the deposit increases, the strain energy is mainly controlled by nitrogen when the thickness of the film is thicker 3 nt 'In I-ifi I: n (please first Read the precautions on the back and then fill out this page) The standard printed by the Ministry of Economy, Central Bureau of Standards, Employee and Consumer Cooperative of China will be printed in accordance with Chinese National Standard (CNS) A4 (210X297mm) OC / Frank / 002 A7 B7 Central Bureau of Standards Printed by Beigong Consumer Cooperation V. Description of the invention (L) The growth factor of titanium, at this time, in order to minimize the strain energy, the preferred growth direction (Preferred Growth) will take (11 l) TiN as the main direction, causing nitriding The titanium film has cracks along the grain boundary (Grain Boundary). In this way, it provides a way for atoms to diffuse between the metal layer and the silicon substrate, resulting in junction leakage and even short circuit after heat treatment. Therefore, in order to enable the titanium nitride anti-diffusion layer to be deposited with a thicker thickness and to avoid the occurrence of cracks, another method of manufacturing the anti-diffusion layer must be used. In view of this, the main purpose of the present invention is to provide a method for manufacturing a titanium nitride anti-diffusion layer, using the physical vapor deposition method to generate titanium nitride, intermittently stopping the supply of nitrogen for a period of time For the layered titanium nitride film, the growth direction of the titanium nitride film is preferably (001) as the main growth direction to avoid cracks in the titanium nitride film. In order to achieve the above objectives, the present invention uses surface analysis techniques to explore the growth characteristics of titanium nitride films, and from the experimental results, it is known that titanium nitride films will have different growth strain energies due to different thicknesses and affect their optimal growth direction. When the thickness does not exceed 50 nm, the factor controlling the growth of titanium nitride is Surface Energy, which is preferably titanium nitride with a growth direction of (001). When the thickness exceeds 50nm, the strain energy becomes the main factor controlling the growth of titanium nitride. At this time, in order to minimize the strain energy, it is preferred that the growth direction is (111) titanium nitride, which causes the titanium nitride film to occur along the grain boundary Cracks provide a way for atoms to diffuse, and even after increasing the thickness of the titanium nitride film, the effect of preventing diffusion cannot be achieved. The present invention provides a method for manufacturing a titanium nitride anti-diffusion layer, which utilizes the process of generating titanium nitride by physical vapor deposition, time 4 (please read the precautions on the back before filling in this page) • Install. Order " This paper uses the Chinese National Standard (CNS) A4 specification (210X297mm). The Ministry of Economic Affairs Central Standard Falcon Bureau Employee Consumer Cooperative Printed 1i $ Q3gl01RjP〇C / Frank / OO2 A7 5. Description of the invention (many) Stop supplying nitrogen To change the generation environment, the accumulation of strain energy is interrupted. Therefore, the growth of titanium nitride is still controlled by surface energy. The preferred growth direction is (001) titanium nitride, and the thickness of the anti-diffusion layer can be increased to 60 nm. In order to make the above and other objects, features, and advantages of the present invention more obvious and understandable, a preferred embodiment is described below in conjunction with the attached drawings, which are described in detail as follows: Brief description of the drawings: Figure 1A It is the X-Ray diffraction diagram of the TiN (50nm) / (001) Si test piece formed at one time; Figure 1B is the X of the multi-level [Ti (10nm) / TiN (20nm)] x2 / (001) Si test piece -Ray diffraction diagram, FIG. 2 is a cross-sectional view of a multi-layer titanium nitride diffusion prevention layer according to a preferred embodiment of the present invention. Experimental Results and Discussion In the present invention, a silicon wafer cut in the (001) direction is used as a substrate, and a physical vapor deposition method is used, for example, a sputtering method to form a titanium nitride anti-diffusion layer. Using a metal titanium target, using the reaction gas mixed with argon and nitrogen, the titanium that gradually evolved by ion bombardment will form the nitrogen atoms formed by the dissociation reaction with the plasma to form titanium nitride and deposit it on the surface of the wafer. During the generation of titanium, the supply of nitrogen is periodically turned ON and OFF, so that TiN and Ti are generated alternately during the process to form [Ti (10nm) / TiN (20nm)] x2 / (001) Multi-layer TiN test piece of Si. In addition, a TiN (50nm) / (001) SHS sheet using primary growth was also formed as a control. The difference between the multi-layer TiN layer of the present invention and the one-time TiN layer (please read the precautions on the back before filling in this page)-Pack. Order "This paper size is applicable to the Chinese National Standard (CNS) A4 specification (2 丨 0 X 297 mm) I39iTWF.D〇C / Frank / 002 A7 B7 5. Description of the invention (f) The thick film TiN produced by this method preferably grows in the direction of (001) TiN, and the situation of cracking along the grain boundary is improved . The characteristic is that the supply of nitrogen gas is stopped during the generation of TiN, the generation environment is changed, and the accumulation of strain energy is interrupted. Therefore, the growth of TiN is still controlled by the surface energy, and the preferred growth direction is (001) TiN. In this way, the rupture of the TiN layer can be improved, but it will not increase the difficulty of the process. There is no need to switch the power supply multiple times during the evaporation process, and no adjustment is required for the evaporation machine. Only the supply of nitrogen is required. Just make periodic switching actions. During the stop of nitrogen supply, a Ti film should be formed. However, due to the short time to stop the supply of nitrogen, there is still some nitrogen on the metal titanium target that can form TiN with Ti, so it will not have too much influence on the composition of the TiN layer. Printed by the Consumer Cooperative of the Central Bureau of Standards of the Ministry of Economic Affairs (please read the precautions on the back before filling out this page). The Ti layer plated in the two layers of TiN effectively prevents the accumulation of strain energy of the TiN layer and keeps the growth of TiN Maintaining the state where the surface energy is dominant, the preferred growth direction of TiN is (001) TiN, and the preferred growth direction of (111) TiN which is different from primary growth TiN. This result can be seen from the X-Ray diffraction experiment of the [Ti (10nm) / TiN (20nm)] x2 / (001) Si and TiN (50nm) / (001) Si test pieces. Figure 1A is the X-Ray diffraction pattern of the TiN (50nm) / (001) Si test piece. The diffraction peak of (m) TiN appears due to the accumulation of strain energy; Figure 1B is the multi-level [Ti (10nm) / TiN (20nm)] X2 / Ray diffraction pattern of x2 / (001) Si test piece, in multi-level [Ti (10nm) / TiN (20nm)] x2 / (001) Si test piece, only (002) TiN For the diffraction peak, there is no (11 l) TiN diffraction peak 'and the total thickness of its deposition can exceed 50nm and reach 60nm. Embodiments Based on the results of the above experiments, it can be applied to a semiconductor integrated circuit A7 B7 39lT \ VF.DOC / Frank / 002 V. Description of the invention (Γ) Road process, using a multi-layer TiN film as an anti-diffusion layer So that it exerts the effect of preventing atomic diffusion. First, please refer to FIG. 2A, and then a semiconductor element 'such as a MOS transistor or a double carrier transistor' is formed on the silicon substrate 20. In order to simplify the diagram, only the contact area 22 of the semiconductor element is drawn here. The source / drain region of a MOS transistor, or a metal connection of a multilayer structure. An insulating layer 24, such as a silicon dioxide layer, is deposited on the silicon substrate 20, and a contact opening D 26 is formed in the insulating layer 24 through lithography and etching processes to expose the contact region 22 of the semiconductor device. Then, a physical vapor deposition reaction is performed, for example, using vapor deposition, using a Jinba titanium target, and passing nitrogen and argon into the reaction chamber, and adjusting the flow rate to achieve a stable pressure and temperature in the reaction chamber, Then proceed with the deposition procedure. On the bottom and side walls of the contact opening 26, and on the insulating layer. 24, a titanium metal layer 28 having a thickness of about 10 nm and a titanium nitride layer 30 'having a thickness of about 20 nm are formed. After that, the supply of nitrogen gas was stopped, but vapor deposition was continued, and a titanium metal layer 32 was formed on the surface of the titanium nitride layer 30 with a thickness of about 10 nm. At this time, nitrogen gas was blown in again for shoveling, and a titanium nitride layer 34 was formed on the surface of the titanium metal layer 32 with a thickness of about 20 nm to complete the process of the multi-layer titanium nitride anti-diffusion layer. In summary, according to the experimental analysis results of the present invention, since the strain energy accumulation during the generation of the titanium nitride layer is interrupted, the growth of the titanium nitride is still controlled by the surface energy, and the preferred growth direction is (001) silicon nitride, which does not cause Cracks along the grain boundaries are produced to ensure the best effect of preventing diffusion, thereby improving the properties of the device. At the same time, the growth direction of the multi-layer titanium nitride anti-diffusion layer has nothing to do with the nature of the substrate, but it can be used on any material such as silicon or silicon oxide. 7 (Please read the precautions on the back before filling out this page)-Packing and ordering The paper standard printed by the Employee Consumer Cooperative of the Central Bureau of Standards of the Ministry of Economic Affairs is applicable to the Chinese national standard rate (CNS) A4 (21〇Χ 297 mm) OC / Frank / 002 A7 B7 V. Description of the invention (6) Although the present invention has been disclosed as above with a preferred embodiment, it is not intended to limit the present invention. Anyone who is familiar with this skill will not deviate from the spirit and spirit of the present invention. Within the scope, some changes and modifications can be made, so the protection scope of the present invention shall be subject to the scope defined in the attached patent application. (Please read the precautions on the back and then fill out this page). ···· va Printed by the Employee Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs. The paper size is applicable to the Chinese National Standard (CNS) A4 (210X 297mm)