五、發明說明（1) 【發明之背景】 (1 )發明之領域 本發明係有關於一種蝕刻一開口到金屬接合墊之 法，並且特別是有關於一種在積體電路製造中^ 合墊的腐蝕及氟污染而蝕刻開口到金屬接合塾之方法。 (2 )習知技藝之說明 在積體電路的製造中，許多半導體元件及 立在一半導體結構上的多層中，最後金屬 ” 塾，係典型地位於積體電路的周圍上，積體‘：晶：：： 接線係接合到這些金屬接合墊，在此外接線:二、 鈍態保護層下的金屬接合墊需暴露一 2之=，在 =層’且隨後的清洗製程係進行; 蝕刻及清洗步驟顯著地降低鋁墊金屬的品 程會造成鋁的氟污毕，孫；斗备几加> e 貝挪4衣 良率變化期Π上：ί 乳 成長且在晶圓探針及 二雨電Β，清洗步驟造成及增加鋁墊金屬 界面上的侵#，為銅突然發生。此侵蝕在金屬表面 η部’這些凹陷部將會成長且傳播穿過銘層，如 2 、行，而成為晶圓儲存的一個顯著的問題，對於線 妾口 ^凸墊而言侵蝕為一個品質及可靠度問題。 ^用技藝者試圖避免或減少氣或氟污染或侵蝕的問 »班^ = ί利第5,376,235號（Langley)教導在以去離子水 *文、/合液餘刻以移除氟殘留之後的清洗金屬接合墊。 508684 五、發明說明（2) 美國專利第5, 930, 664號（Hsu等）教導一種首先蝕刻鈍態保 瘦層、然後#刻穿過ARC(抗反射塗佈層）層、然後形成一 聚合物覆蓋於金屬接合墊上作為保護之方法。美國專利第 6, 0 01，538號（Chen等）揭露一種兩步驟蝕刻製程，以形成 二開口到一接合墊。美國專利第5, 54〇, 812號（Kadmura)顯 示一種銘姓刻製程’係使用許多方法以防止由氯污染所造 成的侵触。 【發明之概要】 本發明之一主要目的，係在於提供一種有效且極有製 造性的蝕刻一開口到一接合墊之方法。 本發明之另一目的，係在於提供一種蝕刻一開口到一 接合墊之方法，其中可清除侵蝕。 本發明之又一目的，係在於提供一種餘刻一開口到一 接合墊之方法，其中可清除侵蝕及減少氟污染。 本發明之又一目的，係在於提供一種餘刻一開口到一 接合墊之方法，其中可清除侵蝕及減少氟污染，在完成所 有其他蝕刻及清洗之後，係藉由加入一硬罩幕保護層覆蓋 於鈍態保護層上，且藉由移除在接合墊上的抗反射塗佈 層。 根據本發明之目的，係達成一種蝕刻一開口到一接合 墊之新穎方法，其中可清除侵蝕及減少氟污染，一金屬接 合墊係提供覆接一在半導體結構上的絕緣層上，一抗反射 塗佈（ARC)層係沈積覆接於金屬接合墊上，一鈍態保護層V. Description of the invention (1) [Background of the invention] (1) Field of the invention The present invention relates to a method for etching an opening to a metal bonding pad, and in particular, to a method for bonding pads in the manufacture of integrated circuits. Etching and fluorine contamination to etch openings to metal joints. (2) Description of the know-how In the manufacture of integrated circuits, many semiconductor elements and multiple layers standing on a semiconductor structure, the final metal "塾" is typically located on the periphery of integrated circuits. Crystal ::: The wiring system is bonded to these metal bonding pads. In addition, the wiring is: 2. The metal bonding pads under the passive protection layer need to be exposed to 2 =, at = layer, and the subsequent cleaning process is performed; etching and cleaning The steps significantly reduce the quality of aluminum pad metal, which will cause the fluorine pollution of aluminum, Sun; Dougai > e Bejo 4 Yield change period Π: milk growth and the wafer probe and two rain Electricity B, the cleaning step causes and increases the invasion on the metal interface of the aluminum pad, which is a sudden occurrence of copper. This erosion in the metal surface η portion. These depressions will grow and propagate through the layer, such as 2, lines, and become A significant problem with wafer storage is erosion and quality issues for wire bumps. ^ Problems for artists trying to avoid or reduce gas or fluorine contamination or erosion »ban ^ = ί 利迪No. 5,376,235 (Langley) teaches to leave子 水 * 文 、 / The mixture is cleaned after removing the residual fluorine. 508684 V. Description of the invention (2) US Patent No. 5,930, 664 (Hsu, etc.) teaches a method of first etching the passivation The thin layer, then #etched through the ARC (Anti-Reflective Coating) layer, and then formed a polymer to cover the metal bonding pad as a method of protection. US Patent No. 6, 0 01,538 (Chen et al.) Discloses a two A step etching process is performed to form two openings to a bonding pad. US Patent No. 5,54〇, 812 (Kadmura) shows that an inscription process uses many methods to prevent intrusion caused by chlorine contamination. [Invention of Summary] One of the main objects of the present invention is to provide an effective and highly manufacturable method for etching an opening to a bonding pad. Another object of the present invention is to provide a method for etching an opening to a bonding pad. Among them, the erosion can be removed. Another object of the present invention is to provide a method for opening an opening to a bonding pad, which can remove the erosion and reduce fluorine pollution. Another object of the present invention is to In providing a method for opening an opening to a bonding pad, which can remove erosion and reduce fluorine pollution, after all other etching and cleaning are completed, a hard mask protective layer is added to cover the passive protective layer. And by removing the anti-reflection coating layer on the bonding pad. According to the purpose of the present invention, a novel method for etching an opening to a bonding pad is achieved, in which erosion can be removed and fluorine pollution can be reduced. A metal bonding pad is provided Overlay an insulating layer on a semiconductor structure, an anti-reflection coating (ARC) layer is deposited over a metal bonding pad, and a passivation protective layer
508684 係沈積覆接於ARC層上，一硬罩幕層係沈積覆接於鈍態保 邊層上’一光阻罩幕係形成覆接於具有開口的硬罩幕層 上，且在接觸窗開口到金屬接合墊係形成處，蝕刻穿^未 被光阻罩幕所覆蓋的硬罩幕層及鈍態保護層，停止於arc 層，之後，移除光阻罩幕及清洗開口，在這些步驟期間， ARC層保護金屬接合墊，在開口内的ARC層係被蝕刻掉，其 中覆接於鈍態保護層上的硬罩幕層防止鈍態保護層的侵 敍因此，防止金屬接合塾的污染，以在積體電路製造中 完成一接觸窗到一金屬接合墊的開口。 【圖號對照說明】 10 半導體結構 14 半導體元件結構 20 金屬層 22 抗反射塗佈層 26 鈍態保護層 30 硬罩幕層 35 光阻罩幕 【較佳實施例之說明】 本實施例圖式將揭露一種形成一接觸窗到一金屬接合 塾之新穎方法，係可清除侵独及減少氟污染，熟習本技藝 之人士應瞭解地是本發明可應用且延伸而不背離本發明之 精神與範疇下為之。 現在參閱第1圖’係說明一部份的局部完成的積體電 路’半導體結構1 0係由單晶石夕所組成者較佳，半導體元件508684 is deposited on the ARC layer, and a hard mask layer is deposited on the passive edge protection layer. A photoresist mask is formed on the hard mask layer with an opening, and is on the contact window. Open to the place where the metal bonding pad system is formed, etch through the hard mask layer and passivation protective layer not covered by the photoresist mask, stop at the arc layer, and then remove the photoresist mask and clean the openings. In these steps During this period, the ARC layer protects the metal bonding pad, and the ARC layer in the opening is etched away. The hard cover layer overlying the passive protection layer prevents the invasion of the passive protection layer. Therefore, the contamination of the metal bonding layer is prevented. To complete the opening of a contact window to a metal bonding pad in the manufacture of integrated circuits. [Comparison of drawing numbers] 10 Semiconductor structure 14 Semiconductor element structure 20 Metal layer 22 Anti-reflection coating layer 26 Passive protective layer 30 Hard cover layer 35 Photoresist cover [Explanation of the preferred embodiment] Schematic diagram of this embodiment A novel method for forming a contact window to a metal junction will be disclosed, which can eliminate invasion and reduce fluorine pollution. Those skilled in the art should understand that the present invention can be applied and extended without departing from the spirit and scope of the invention Here it is. Now referring to FIG. 1 ', which illustrates a part of a partially completed integrated circuit. The semiconductor structure 10 is preferably composed of a monocrystalline stone, a semiconductor element.
第8頁 5080^ 五、發明說明（4) 結構（如閘極電極、 綠r去淑-、、 及組合的源極及汲極區、及多層内導 此麻邱-从’、建立於半導體結構上及半導體結構中’這 些底邵7〇件及JS & ^ ^ ^ 仁 9係匕括於第1圖中標號14的層中，在14中 的一隔離層覆蓋底部層上。 你 人感f Ϊ形成最頂部金屬層’接合塾將形成於此最頂部 金屬層中，太絡日日# & (j 货月係為一種蝕刻一開口到一金屬墊及清洗 開^製私流程’以便清除由侵餘所造成的墊凹陷部，且 明顯^減少由餘刻及清洗所導致的氟污染，此將會明顯地 改進屬塾的品質，減少在墊金屬表面上的氟含量，會造 成曰個具^有改良自然氧化物均勻度的較高品質金屬墊，係 在a曰圓探針上具有很滿意的良率、在銲錫凸塊製程中改進 過的良率、及擴大晶圓儲存。 ^金屬層2〇(典型由鋁或具有銅及/或矽的鋁）係沈積覆 蓋於層14中的最頂部隔離層上，一阻障層（未顯示）可沈積 於金屬層20下，銘層20係藉由濺擊或化學氣相沈積（CVD) 而被沈積，以沈積到一個厚度在5 〇 〇 〇到丨8 〇 〇 〇埃之間，一 抗反射塗佈（ARC)層22(氮化鈦、氮化鎢、或幾個有機或無 機ARC材料之一）係沈積覆接於金屬層2〇上，以達到一個在 1 0 0到5 0 0埃之間的厚度。 現在，一鈍態保護層26係沈積覆蓋於ARC層22上，鈍 態保護層26可包括有氮化矽或一個高密度電漿（HDP)氧化 石夕及氮化石夕或四氧乙基石夕（T E 0 S )氧化物的組合，鈍態保護 層典型地係具有一個在5 0 0 0到2 0 0 0 0埃之間的厚度。 現在，將描述本發明的一種新穎製程步驟，參閱第2Page 8 of 5080 ^ V. Description of the invention (4) Structures (such as gate electrode, green r-sv-,-, and combined source and drain regions, and multi-layered internal conductors this Ma Qiu-from ', built on semiconductor Structurally and in semiconductor structures, these bottom 70 pieces and JS & ^ ^ ^ Ren 9 series are enclosed in the layer labeled 14 in Figure 1, and an isolation layer in 14 covers the bottom layer. Sense f Ϊ form the topmost metal layer 'junctions' will be formed in this topmost metal layer, Tailuo Ri Ri # &; (J cargo month is an etching to an opening to a metal pad and cleaning process In order to remove the pad depression caused by invasion, and significantly reduce the fluorine pollution caused by the etch and cleaning, this will significantly improve the quality of the metal, and reduce the fluorine content on the surface of the pad metal, which will cause A higher-quality metal pad with improved uniformity of natural oxides has a satisfactory yield on a round probe, an improved yield in the solder bump process, and expanded wafer storage ^ Metal layer 20 (typically made of aluminum or aluminum with copper and / or silicon) is deposited overlying layer 14 On the topmost isolation layer, a barrier layer (not shown) may be deposited under the metal layer 20, and the layer 20 is deposited by sputtering or chemical vapor deposition (CVD) to a thickness of 5 Å. Between 0.000 and 8000 angstroms, an anti-reflective coating (ARC) layer 22 (titanium nitride, tungsten nitride, or one of several organic or inorganic ARC materials) is deposited overlying the metal layer 20 to achieve a thickness between 100 and 500 angstroms. Now, a passive protection layer 26 is deposited over the ARC layer 22, and the passive protection layer 26 may include silicon nitride or A combination of high-density plasma (HDP) oxide stone oxide and nitride stone oxide or tetraoxyethyl stone oxide (TE 0 S) oxide. The passivation protective layer typically has a range from 5 0 0 0 to 2 0 0 0 Thickness between 0 angstroms. Now, a novel process step of the present invention will be described.
五、發明說明（5) 】包：係沈積覆蓋於鈍態保護層上，此硬罩幕 機鶴化欽、《幾個通常使用於工業中的有 厚度1罩幕Λ之;ΪΛ具有一個在100到500埃之間的 硬卓幕層會或不會由如ARc層相同材料組成。 上，ίϋϋ圖’ 一層光阻係塗佈覆蓋於硬罩幕層30 形成接衫以形成光阻罩幕35，而具有-開口，係 办成接觸®到金屬墊處。 #離麻係進行一電漿蝕刻，以蝕刻穿過硬罩幕層30及 保遵層26 ’停止於廳層22(如第4圖所示），例如，可 用一低壓電漿蝕刻，通常為35〇毫托壓力及一個包括有 3、CF4、及氬氣（Ar)的蝕刻環境，使成1〇 sccm CH&、 sCcm CL、及9〇〇 sccm Ar的流量比例，此蝕刻安排為 y止於底部ARC層或藉由通常使用於工業中的終點偵測方 法而停止。 ARC層22作為一保護膜覆蓋於金屬表面上，在鈍態蝕 刻期間’防止氟污染及侵飿凹陷部。 、、光阻罩幕係使用例如〇2/CF4電漿去灰（如第5圖所示）而 被清除掉，此步驟接著一清洗步驟以移除光阻殘留及蝕刻 聚合物，此清洗步驟可包括有一濕式化學有機溶劑：例 如，十分鐘的EKC265，藉著400秒的異丙醇（IPA)，接著一 去離子水及C〇2攪拌劑沖洗390秒，或者，一顯影液（如氣 氧化四甲銨（TMAH))可使用於1〇到60秒，在光阻清除及濕 式清洗期間，ARC層亦提供作為金屬層的保護。 在清洗步驟之後’進行一第二電漿蝕刻，以移除在開 第10頁 5〇8684 五、發明說明（6) 口内的ARC層22，當底部ARC層由氮化鈦所組成時，相同化 學蝕刻程式使用如同上述的第一電漿蝕刻步驟，及鋁墊金 屬上的終點彳貞測’鼠化學在此案例中並非必要的。 在該較佳實施例中，係教導氮化鈦作為硬罩幕層，必 須第二電漿蝕刻完全同時移除底部ARC層22及硬罩幕層 3 〇 (如第6圖所示）兩者，然而，此要求無須應用於可作為 硬罩幕層的其他材料，於某些案例中，可在完成底部arc 膘以暴露金屬表面的蝕刻之後留下某些所有的硬罩幕層。 在其中案例中，在蝕刻掉ARC層22期間，硬罩幕層3〇 ，止鈍態保護層的侵蝕，氮化矽鈍態保護層具有約一個較 氮化鈦高的1 0比1的蝕刻率，所以若在蝕刻期間鈍態保護 層沒有被硬罩幕層所保護時，會發生明顯的蝕刻。 ^ 現在，暴露於接觸窗開口的金屬接合墊可如一般及繼 續製造接合墊連接的製程使用，諸如藉由線接合、銲錫凸 塊、或其他相似製程（未顯示）。 — 本發明之製程提供一種展開一接觸窗到一金屬墊之有 致方法’其中可清除墊凹陷部及大大地減少氟污染，只直 成本發明的咼品質金屬接合墊之前，加入一硬罩幕層 覆盍於鈍態保護層上、及保持ARC層覆蓋於金屬接合墊 上0 雖然本發明已被特別地表示，並參考其較佳實施例做 \ 各種形式上及細節的改變可於不背離本發明之精 神與範嘴下為之，係為熟習本技藝之人士所能瞭解的。V. Description of the invention (5)] Package: The system is deposited and covered on a passive protective layer. This hard cover machine He Huaqin, "Several thickness 1 covers Λ commonly used in industry; ΪΛ has an The hard curtain layer between 100 and 500 Angstroms may or may not be composed of the same material as the Arc layer. In the above picture, a layer of photoresist is coated on the hard cover layer 30 to form a jumper to form the photoresist cover 35, and it has an opening, which is made to contact the metal pad. # 离 麻 系 Carry out a plasma etching to etch through the hard cover curtain layer 30 and the compliance layer 26 'stop at the hall layer 22 (as shown in Figure 4). For example, a low-voltage plasma etching can be used, usually A pressure of 35 millitorr and an etching environment including 3, CF4, and argon (Ar), so that the flow ratio of 10sccm CH &, sCcm CL, and 900sccm Ar, the etching arrangement is y stop Stop at the bottom ARC layer or by endpoint detection methods commonly used in industry. The ARC layer 22 covers the metal surface as a protective film, and prevents fluorine contamination and invasion of the recessed portion during the passive etching. The photoresist mask is removed by using, for example, 〇2 / CF4 plasma to remove ash (as shown in Figure 5). This step is followed by a cleaning step to remove the photoresist residue and etch the polymer. This cleaning step It can include a wet chemical organic solvent: for example, EKC265 for ten minutes, isopropyl alcohol (IPA) for 400 seconds, followed by a rinse of deionized water and CO 2 agitator for 390 seconds, or a developing solution (such as Tetramethylammonium oxide (TMAH) can be used for 10 to 60 seconds. During photoresist removal and wet cleaning, the ARC layer also provides protection as a metal layer. After the cleaning step, a second plasma etch is performed to remove the ARC layer 22 in the opening on page 10 of 5087864. 5. Description of the invention (6) When the bottom ARC layer is composed of titanium nitride, the same The chemical etching procedure uses the first plasma etching step as described above, and the end point on the aluminum pad metal is measured. 'Mouse chemistry is not necessary in this case. In this preferred embodiment, titanium nitride is taught as the hard mask layer, and the second plasma etching must remove both the bottom ARC layer 22 and the hard mask layer 3 (shown in Figure 6) at the same time. However, this requirement does not need to be applied to other materials that can be used as a hard cover curtain layer. In some cases, some hard cover curtain layers can be left after etching of the bottom arc to expose the metal surface. In one of these cases, during the etching of the ARC layer 22, the hard mask layer 30 was stopped to prevent the passivation of the passivation layer, and the passivation layer of silicon nitride had about a 10 to 1 etch higher than that of titanium nitride. Rate, so if the passive protective layer is not protected by the hard mask layer during the etching, significant etching will occur. ^ Metal bond pads exposed to contact window openings can now be used as usual and continue with bond pad manufacturing processes such as wire bonding, solder bumps, or other similar processes (not shown). — The manufacturing process of the present invention provides an effective method of unfolding a contact window to a metal pad, in which the recessed part of the pad can be removed and fluorine pollution is greatly reduced, and only a hard cover curtain layer is added before the invention's high-quality metal bonding pad. Cover on the passive protection layer and keep the ARC layer on the metal bonding pad. 0 Although the present invention has been specifically shown, and reference is made to its preferred embodiments, various changes in form and details can be made without departing from the present invention. The spirit of Fan and his mouth are all understood by those who are familiar with this technique.
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