461028461028
【發明領域】 本發明係有關於一種雙鑲嵌（dual damascene )結構 的製造方法，特別是有關於一種可以避免低介電常數之介 電層的介層窗開口毒化（p〇is〇n )的雙鑲嵌結構之製造方 法。 【習知技術】 在積體電路的技術上，為了提高元件的積集度以及資 料，輸速度，製程技術已由次微米（sub_micr〇n )進入了 四分之一微米（quarteriicr〇n )甚或更細微尺寸的範 圍。、然而，當線寬愈來愈小，鋁導線已無法滿足對速度的〔 要求’因此’以具有高導電性之金屬銅做為導線，以降低 RC延遲（RC delay )，係為目前的趨勢。 _但疋’銅金屬無法以乾蝕刻的方式來定義圖案，因為 銅金屬與氯氣電漿氣體反應生成的氯化銅（CuC12)的沸 點極咼（約15〇 〇 〇c ),因此銅導線的製作需以鑲嵌製程 來進行。而雙鑲嵌製程係指同時形成銅導線的溝槽和其下 方的介層窗開口。 第1圖係繪示傳統之雙鑲嵌製程的一中間步驟之結構 剖面圖’其係用以說明傳統之雙鑲嵌製程的製造流程。 首先提供半導體基底1〇 ’其中已形成半導體元件（未（ =示出）’之後於半導體基底1 0上利周化學氣相沈積法覆 蓋一層具低介電常數的碳屋（black diamond)介電層12 和抗反射層14。接著於抗反射層14和碳黑介電材質層12中 形成介層窗開口 1 6 ’然後繼續定義出導線溝槽的圖案，此[Field of the Invention] The present invention relates to a method for manufacturing a dual damascene structure, and in particular, to a dielectric window opening (poison) that can avoid a dielectric layer with a low dielectric constant. Manufacturing method of double mosaic structure. [Known technology] In terms of integrated circuit technology, in order to improve the integration degree of components and data, and the speed of transmission, the process technology has entered from submicron (sub_micr〇n) to a quarter micron (quarteriicr0n) or even Finer size range. However, when the line width is getting smaller and smaller, the aluminum wire can no longer meet the speed requirements [therefore ', therefore, using metal copper with high conductivity as the wire to reduce the RC delay, which is the current trend. . _But copper metal cannot be used to define the pattern by dry etching, because the boiling point of copper chloride (CuC12) produced by the reaction of copper metal with chlorine plasma gas is extremely high (about 150,000c). Production needs to be carried out by a mosaic process. The dual damascene process refers to the formation of a trench of copper conductors and the opening of a via below it. FIG. 1 is a cross-sectional view illustrating a structure of an intermediate step of the conventional dual-damascene process, which is used to explain the manufacturing process of the conventional dual-damascene process. First, a semiconductor substrate 10 'is provided, in which a semiconductor element has been formed (not shown), and then a chemical vapor deposition method is applied on the semiconductor substrate 10 to cover a layer of a low-k dielectric black carbon dielectric. Layer 12 and anti-reflection layer 14. Next, a dielectric window opening 16 'is formed in the anti-reflection layer 14 and the carbon black dielectric material layer 12, and then the pattern of the wire groove is further defined.
第4頁 461028 五、發明說明（2) 時，需先於介層窗開口 1 6中填入光阻層1 8，經回蝕刻步 驟，用以保護介層窗開口 1 6底部所暴露出的元件。再繼續 於抗反射層14上方覆篸一層深紫外光光阻層20，此深紫外 光光阻層2 0係闬以定義出導線溝槽的區域。然而，深紫外 光光阻層20中的光酸虞生成分（photoacid generator.; PAG)會解離出H+而與碳黑介電層12中的鹼基（base)發 生酸鹼中和反應，而造成介層窗開口 16的毒化22，而影響 到顯影製程的品質。 【發明之目的及概要】 有經於此，本發明提供一種可以避免低介電常數之介 電層的介層窗開口毒化的雙鑲嵌結構的製造方法。 、此外，本發明提供一種雙鑲嵌結構的製造方法，可以 避免低介電常數之介電層與光阻材質發生酸鹼中和反應。 因此，本發明之目的係針對於上述習知技術而提出改 良，本發明提供一種雙鑲嵌結構的製造方法，其包括：於 =上形成低介電常數的介電層，並於介電層上形成抗反 射層，之後於介電層和抗反射層中形成第一開口，並於 件開：ΐ二ί ί Γ 一光阻層’用以保護第一開口底部的元 接者於抗反射層、介電層和第一光阻層上覆蓋一 二= 層’再於保護層上覆蓋第二光阻層，並將第 以於介電I的上部份和抗反射層中形成第二開t刻罩幕 鐵ιϊ據較佳實施例丄其中保護層的材質包括似 鐵齓龍W聚乙烯、似聚丙烯或似聚氟乙烯等，介電層的Page 4 461028 5. In the description of the invention (2), the photoresist layer 18 needs to be filled in the opening 16 of the interlayer window, and the etch back step is used to protect the exposed bottom of the opening 16 of the interlayer window. element. Then, a layer of deep ultraviolet photoresist layer 20 is coated on top of the anti-reflection layer 14, and the deep ultraviolet photoresist layer 20 is formed to define a region of the groove of the wire. However, the photoacid generator (PAG) in the deep ultraviolet photoresist layer 20 will dissociate H + and cause acid-base neutralization reaction with the base in the carbon black dielectric layer 12, and The poisoning 22 of the via window 16 is caused, and the quality of the developing process is affected. [Objective and Summary of the Invention] With this in mind, the present invention provides a method for manufacturing a dual damascene structure capable of avoiding poisoning of a dielectric window opening of a dielectric layer having a low dielectric constant. In addition, the present invention provides a method for manufacturing a dual damascene structure, which can avoid acid-base neutralization reaction between a dielectric layer with a low dielectric constant and a photoresist material. Therefore, the object of the present invention is to improve the conventional technology. The present invention provides a method for manufacturing a dual damascene structure, which includes: forming a dielectric layer with a low dielectric constant on the dielectric layer; and An anti-reflection layer is formed, and then a first opening is formed in the dielectric layer and the anti-reflection layer, and the parts are opened: ΐ ί Γ Γ a photoresist layer is used to protect the element at the bottom of the first opening to the anti-reflection layer. , The dielectric layer and the first photoresist layer are covered with one or two = layers, and then the protective layer is covered with a second photoresist layer, and a second opening is formed in the upper part of the dielectric I and the antireflection layer. According to a preferred embodiment, the material of the protective layer includes Tielonglong W polyethylene, polypropylene, or polyvinyl fluoride, and the like of the dielectric layer.
〇28 --- 五、發明說明（3) _ 材質包括碳黑介電層，而第 口為導線溝槽。另外，在上^為介層窗開口，第二開 2開口的蝕刻製程係由蝕玄“C開口的步驟中，第 玫置-層蝕刻終止層，肖以控：：控制’或者在介電層中 為讓本發明之上述目的、二開口的蝕刻終點。 下文特舉-較佳實施例，並配^及優點能更明顯易懂， 下： —D所附圖式5作詳細說明如 【圖式簡單說明】 圖。第1圖係繪示傳統之雙鎮嵌結構的-中間製程之剖面 種雙Ϊ2嵌3 =緣示根據本發明-較佳實施例之-敢、培構的製造流程剖面圖。 第3圖係繪示根據本發明 耿結構的剖面圖。 較佳貫施例之一種雙鑲 【符號說明】 介層窗開口 ： 16、1〇6、106b 導線溝槽：l〇6a 光阻層：1 8、1 〇8 保護層：11 0、11 〇 a Π2、112a 基底：10、 【實施例】 為了避免低介電常數之介電声应井阳# 和反應，因此，太恭+ s，、先阻材質發生駿鹼中 後，再於介發明在介層窗開口的底部為光阻層保護 …丨層“1 口的侧壁形成一層保護層，以避免 介電層：12、1〇2 抗反射層·· 14、1()4 介層窗開口毒化：22 深紫外光光阻層：2〇 461028 五、發明說明（4) 1— —~- 覆蓋之深紫外光光阻層直接與介層窗開口中的介雷芦 觸。第2 A圖至第2 C圖係繪示根據本發明一較佳實施 種雙鑲嵌結構的製造流程剖面圖。 M 之— 請參照第2 A圖，提供一基底丨〇 〇，例如是半導體矽 底’其已形成有半導體元件如電晶體等（未繪示出） 著开>成$介電常數的介電層102，做為内金屬介電層 (inter-metal dielectrics) ’ 其中介電層 1〇2 的材質可 為碳黑介電材質等。之後於介電層102上形成一層抗反''射 層104，以提高曝光製程的可靠度。 接著於抗反射層104和介電層1〇2中形成介層窗開口 106 ’其暴露出下方欲電性連接的區域。之後塗佈—層光 阻，經回蝕刻後’使其僅填入介層窗開口丨〇 6覆蓋其底部 的元件，而形成如圖所示之光阻層108。之後於抗反射層 104、介電層102和光阻層108表面覆蓋一層薄薄的化學隋 性（inert )保護層110，此保護層11〇的材質為耐酸鹼， 較佳的是似鐵氟龍（teflon-like)高分子，即 -(CF2)n- ’其形成方法例如是以CH2F2和Ar為反應氣體 源，進行化學氣相沈積製程，其中CH2F2的流量約為 10~300 seem，Ar的流s約為5〜200 seem °另外，保護層 110亦可為類似聚乙婦（polyethylene ;PE) '聚丙烯 (polyproplyene ;PP)、聚四氟^ 乙烯（PTFE)等材質。 接著請參照第2B圖，於保護層11 〇上方覆蓋一層深紫 外光光阻/層11 2。由於在本發明中，此深紫外光光阻層11 2 未直接與低介電常數的介電層102接觸，故可避免發生中〇28 --- 5. Description of the invention (3) _ The material includes a carbon black dielectric layer, and the port is a wire groove. In addition, in the above process, the etching process of the second opening and the second opening is performed by the step of "C opening," and the second layer is an etching stop layer. In the layer, the above-mentioned purpose of the present invention is provided, and the etching end point of the two openings is described below. The preferred embodiment is described below, and its configuration and advantages can be more clearly understood. Brief Description of the Drawings] Figure. Figure 1 shows the traditional double-embedded structure-the cross-section of the middle process-double Ϊ 2 embedded 3 = edge shows the manufacturing process according to the present invention-preferred embodiment-dare, structure Sectional view. Figure 3 is a cross-sectional view showing the structure of the present invention. A double inlay of a preferred embodiment. [Symbol] Opening of the interlayer window: 16, 106, 106b. Wire groove: 106a Photoresist layer: 18, 108 Protective layer: 11 0, 11 〇a Π2, 112a Substrate: 10, [Example] In order to avoid low dielectric constant dielectric sound response, it is necessary to react with it. Therefore, too Christine + s, after the material is blocked in the base, the invention then protects the photoresist layer at the bottom of the opening of the interlayer window ... 丨"A protective layer is formed on the side wall of port 1 to avoid the dielectric layer: 12, 102 anti-reflection layer ... 14, 1 () 4 Poisoning of the dielectric window opening: 22 Deep ultraviolet photoresist layer: 2046128 V. Description of the invention (4) 1— ~~-The covered deep ultraviolet photoresist layer is in direct contact with the thunderbolt in the opening of the interlayer window. Figures 2A to 2C are cross-sectional views showing the manufacturing process of a dual-mosaic structure according to a preferred embodiment of the present invention. M — Please refer to FIG. 2A to provide a substrate, such as a semiconductor silicon substrate, which has formed semiconductor elements such as transistors and the like (not shown). The electrical layer 102 is used as inter-metal dielectrics. The material of the dielectric layer 102 may be a carbon black dielectric material. An anti-reflection layer 104 is formed on the dielectric layer 102 to improve the reliability of the exposure process. Next, a dielectric window opening 106 'is formed in the anti-reflection layer 104 and the dielectric layer 102, which exposes a region to be electrically connected below. After that, a layer of photoresist is applied, and after etch back, it is filled into the opening of the via window to cover the components on the bottom thereof, and a photoresist layer 108 is formed as shown in the figure. Then, a thin chemical inert protective layer 110 is covered on the surfaces of the anti-reflection layer 104, the dielectric layer 102, and the photoresist layer 108. The material of the protective layer 110 is acid and alkali resistant, preferably iron-fluorine-like. Teflon-like polymer, namely-(CF2) n- ', is formed by, for example, CH2F2 and Ar as the reaction gas source for the chemical vapor deposition process, where the flow of CH2F2 is about 10 ~ 300 seem, Ar The flow s is about 5 ~ 200 seem. In addition, the protective layer 110 may also be made of materials such as polyethylene (PE), polypropylene (PP), and polytetrafluoroethylene (PTFE). Next, referring to FIG. 2B, a layer of deep ultraviolet photoresist / layer 112 is covered on top of the protective layer 110. In the present invention, the deep ultraviolet photoresist layer 11 2 is not directly in contact with the dielectric layer 102 with a low dielectric constant, so it can be avoided.
第7頁 4 6 彳 02 8 五、發明說明（5) 和反應的問題，因而可提高後續之顯影製程的可靠度β且 保護層11 0為耐酸鹼的材質，亦不會與深紫外光光阻廣丨j 2 或低介電常數的介電層102發生反應。 | 接著請參照第2C圖，進行曝光顯影製程，以將深紫外 光光阻層11 2圖案化成深紫外光光阻層11 2a，暴露出欲形 成導線溝槽的區域。之後以深紫外光光阻層丨丨2a及光阻層 1 08為韻刻罩幕，進行蝕刻步騾，藉由控制蝕刻的時間， 以將圖案往下轉移至保護層11 〇、抗反射層丨〇4、介電層 I 102的上部份，而於其中形成導線溝槽1〇6a，而介電層1〇2 的下部份則維持原有圖案，成為如圖所示之介層窗開口 106b。其中保護層no和抗反射層丨〇4轉為如圖所示之保護 層1 l〇a和抗反射層i〇4a。 ★另外，亦可於介電層102中形成一層蝕刻終止層12()， 如第3圖所示，用以控制上述之導線溝槽1〇6a的蝕刻製 【發明之特徵與效果】 综上所述，本發明至少具有下列優點： h由於本發明在低介電常數之介電層和深紫外光光阻 間係夾一層耐酸鹼的保護層，故可避免發生酸鹼中和 2.本發明係在含鹼基的 層之間放置一層保護層，以 阻在介層窗開口處發生毒化 雖然本發明已以較佳實 介電層和含酸基的紫外光光阻 避免低介電常數之介電層與光 ，藉以提高顯影製程的品質。 施例揭露如上，然其並非用以Page 7 4 6 彳 02 8 V. Explanation of the problem (5) and reaction, which can improve the reliability of the subsequent development process β and the protective layer 110 is an acid and alkali resistant material, and it will not be exposed to deep ultraviolet light. A wide photoresistance j 2 or low dielectric constant 102 reacts. Next, referring to FIG. 2C, an exposure and development process is performed to pattern the deep ultraviolet photoresist layer 11 2 into the deep ultraviolet photoresist layer 11 2a, exposing the area where the wire trench is to be formed. After that, the deep ultraviolet photoresist layer 丨 2a and the photoresist layer 1 08 are used as the engraving mask, and an etching step is performed. By controlling the etching time, the pattern is transferred down to the protective layer 11 〇, the anti-reflection layer 丨〇4. The upper part of the dielectric layer I 102, in which a wire trench 106a is formed, and the lower part of the dielectric layer 102 maintains the original pattern and becomes a dielectric window as shown in the figure. Opening 106b. Among them, the protective layer no and the anti-reflection layer 04 are turned into the protective layer 110a and the anti-reflection layer 104 as shown in the figure. ★ In addition, an etch stop layer 12 () can also be formed in the dielectric layer 102, as shown in FIG. 3, to control the etching of the above-mentioned wire trench 106a [Features and Effects of the Invention] Said, the present invention has at least the following advantages: h Since the present invention sandwiches a layer of acid and alkali resistant protective layer between the dielectric layer of low dielectric constant and the deep ultraviolet photoresist, acid and alkali neutralization can be avoided 2. In the present invention, a protective layer is placed between the base-containing layers to prevent poisoning at the opening of the dielectric window. Although the present invention has a better dielectric layer and ultraviolet photoresist containing acid groups to avoid low dielectric A constant dielectric layer and light to improve the quality of the development process. The example is disclosed above, but it is not used to
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