451345 五、發明說明（l) - 發明領域 、 本發明係有關於一種超大型積體電路（integrated circuits ; ICs)製程技術，特別是去光阻後殘留物質的清 除方法，該方法能夠提高清除效率，並且降低製程成本。 相關技術之描述 以下利用第1A圖〜第1D圖所示的定義金屬圖案（metal pattern)之製程剖面圖，以說明習知技術清除殘留物質的 方法。 首先，請參照第1A圖，提供一形成有若干半導體元件 (圖未顯示）之半導體基底10，然後，形成絕緣層12，用來 Γ 復蓋上述半導體基底10。接下來，再次形成鈦/氮化鈦 (Ti/TiN)複合層以當作擴散阻障層（diffusion bar r ier)14 ’接著利用金屬濺鍍法（sputtering)以在上述 阻障層14的表面形成一銘銅金屬層16，其次，在上述铭銅 金屬層16表面沈積一鈦/氮化鈦複合層以當作防反射層 18(anti-reflection coating ;ARC)。再者，符號 20 代表 利用傳統的微影技術（photolithography)形成之光阻圖案 (photoresist pattern)。 之後’請參照第1B與第1C圖，去除未被光阻圖案2〇遮 蔽的防反射層18、鋁銅金屬層16與阻障層14，直到露出上 〇 述絕緣層12為止’此時得到所需的鋁銅金屬圖案16^，以 及外形輪廓有些許變化的光阻圚案20a。然後，剝除光阻 · 圈案20a ’由於光阻圖案20a的材料與上述蚀刻的環境特 性，通常在金屬圖案16a的侧壁（side walls)會形成一層451345 V. Description of the Invention (l)-Field of the Invention The present invention relates to a process technology for ultra-large integrated circuits (ICs), especially a method for removing residual materials after photoresist removal, which can improve the removal efficiency. And reduce process costs. DESCRIPTION OF RELATED ART The following section cross-sectional views of the process for defining a metal pattern as shown in Figs. 1A to 1D are used to explain the conventional method for removing residual substances. First, referring to FIG. 1A, a semiconductor substrate 10 having a plurality of semiconductor elements (not shown) formed is provided, and then an insulating layer 12 is formed to cover the semiconductor substrate 10 as described above. Next, a titanium / titanium nitride (Ti / TiN) composite layer is formed again as a diffusion barrier layer 14 ′. Then, a metal sputtering method is applied to the surface of the barrier layer 14. A copper metal layer 16 is formed. Next, a titanium / titanium nitride composite layer is deposited on the surface of the copper metal layer 16 as an anti-reflection coating (ARC). Furthermore, the symbol 20 represents a photoresist pattern formed using conventional photolithography. Afterwards, please refer to FIGS. 1B and 1C and remove the anti-reflection layer 18, the aluminum-copper metal layer 16 and the barrier layer 14 which are not shielded by the photoresist pattern 20 until the above-mentioned insulating layer 12 is exposed. The required aluminum-copper metal pattern 16 ^, and the photoresist pattern 20a with a slightly changed outline. Then, stripping the photoresist · circle pattern 20a ′ Because of the material of the photoresist pattern 20a and the above-mentioned etching environment characteristics, a layer is usually formed on the side walls of the metal pattern 16a
第4頁 451 345 五、發明說明（2) 殘留物質（r e s i d u e) 2 2。 接著’請參照第ID圖，將半導體基底i〇(晶圓）移至含 有胺類（amine)之化學試劑槽（例如商品名EKc或ACT)，再 移至有機溶劑槽’如異丙酵（lsopropyl Alcohol ； IPA) ’或直接移至去離子水槽（dei〇nized water tank )’亦即以溼式清洗的方式去除上述殘留物質22。 由於銘銅金屬之蝕刻氣體通常含有氣，加上胺類水解 後之氩氧離子會形成導電溶液而容易導致鋁銅本身產生電 池效應（eiectrogalvanic ceil)，而造成銅鋁金屬局部腐 蝕的現象’例如第1D圖之符號3 0所示的缺角。再者，上述 含有胺類的化學試劑價格相當昂貴。 因此，為了改善此問題，有人提出一種殘留物質的清 除方法，以電漿乾式清洗方式取代溼式清洗，以期避免上 述習知缺點，上述電漿乾式清洗方式例如利用微波電源 (microwave power)以產生電漿，並且利用射頻電源產生 偏壓，在400~700mtorr的壓力下，導入適當的反應氣體， 進行兩階段的清洗，以去除側壁殘留物質。 然而，上述電漿乾式清洗方式仍然難以完全去除殘留 物質，需要輔以後續的清除步驟。再者，此種習知電漿乾 式清洗方式需要添購較特殊的機台（此機台需結合微波與 射頻功能），而大幅增加設備的成本。 有鑑於此，本發明的目的在於提供一種去光阻後殘留 物質的清除方法，此方法可有效地去除蝕刻與去光阻後所 殘留的物質，並且使用積艎電路產業習用之磁場加強反應Page 4 451 345 V. Description of the invention (2) Residual substances (r e s i d u e) 2 2. Then 'please refer to the figure ID, move the semiconductor substrate i0 (wafer) to a chemical reagent tank containing amines (such as the trade name EKc or ACT), and then to an organic solvent tank', such as isopropylase ( lsopropyl Alcohol; IPA) 'or directly moved to a deionized water tank', that is, the above-mentioned residual substance 22 is removed by wet cleaning. Because the etching gas of Ming copper metal usually contains gas, and the argon oxygen ions after amine hydrolysis will form a conductive solution, it will easily cause the aluminum copper itself to have a battery effect (eiectrogalvanic ceil), and cause the local corrosion of copper aluminum. The notch shown by symbol 30 in Fig. 1D. Furthermore, the above-mentioned amine-containing chemical reagents are quite expensive. Therefore, in order to improve this problem, some people have proposed a method for removing residual substances. Plasma dry cleaning is used instead of wet cleaning to avoid the conventional disadvantages. The above plasma dry cleaning method uses, for example, microwave power to generate Plasma, and the use of RF power to generate a bias, under the pressure of 400 ~ 700mtorr, the introduction of an appropriate reaction gas, two-stage cleaning to remove residual material on the side wall. However, the above-mentioned plasma dry cleaning method is still difficult to completely remove the residual substances, and it needs to be supplemented by a subsequent removal step. In addition, this conventional plasma dry cleaning method requires the purchase of a more special machine (this machine needs to combine microwave and RF functions), which significantly increases the cost of the equipment. In view of this, the object of the present invention is to provide a method for removing residual material after photoresist removal. This method can effectively remove the material remaining after etching and photoresist removal, and use the magnetic field conventionally used in the accumulated circuit industry to enhance the reaction.
451345 五、發明說明（3) 性離子钱刻（Magnetic Enhance Reactive Ion Etch, MER IE)機台’即可達到清除殘留物質的效果。 本發明的另一目的在於提供一種去光阻後殘留物質的 清除方法’不需要使用含胺類的化學試劑，而減少金屬腐 餘的可能性。再者’本發明的去先阻後殘留物質的清除方 法’不但適用於金屬圖案的定義亦適用於接觸孔（via)的 定義》 根據上述目的，本發明提供一種去光阻後殘留物質的 清除方法’適用於金屬圈案的定義’該清除方法包括下列 | 步驟：（a)提供一半導體基底，該基底形成有若干半導體 | 元件；在該半導體基底形成一鋁銅金屬層；（c)在該鋁 銅金屬層表面形成一光阻圖案；利用該光阻圖案當作 钱刻罩幕，並且選擇性钱刻該铭銅金屬層，以形成一銘麵 金屬圖案；Ce)剝除該光阻圖案，此時該鋁銅金屬圖案的 側壁具有殘留物質；以及（f)利用磁場加強型反應性離子 蚀刻法（MERIE)清除該殘留物質，其反應條件如下：以含 氣與氧之氣體當作反應氣體、採用iOdOnitorr的壓力、採 用20〜100高斯的磁場。在此種低壓的環境下，同時施以磁 場能夠有效地去除殘留物質》 再者，上述清除方法之中，該光阻圖案可以是有機聚 合物材料構成。並且，步驟（d)選擇性蝕刻係採用例如氣 氣（C12)及/或氣化硼（Bci3)之含氣的氣體當作反應氣艘。 並且’上述清除方法之中’該含氟與氧之氣體例如為 四氟化碳及氧氣β451345 V. Description of the invention (3) Magnetic Enhance Reactive Ion Etch (MER IE) machine 'can achieve the effect of removing residual substances. Another object of the present invention is to provide a method for removing residual material after photoresist removal, which does not require the use of amine-containing chemical reagents and reduces the possibility of metal corrosion. In addition, the "removal method of the residual material after removing the first block of the present invention" is applicable not only to the definition of the metal pattern but also to the definition of the via. "According to the above object, the present invention provides a method for removing the residual material after removing the photoresist Method 'applicable to the definition of metal circles' The cleaning method includes the following | steps: (a) providing a semiconductor substrate having a plurality of semiconductors formed thereon; components; forming an aluminum copper metal layer on the semiconductor substrate; (c) A photoresist pattern is formed on the surface of the aluminum-copper metal layer; the photoresist pattern is used as a engraved mask, and the inscribed copper metal layer is selectively engraved to form an inscribed metal pattern; Ce) stripping the photoresist Pattern, at this time, there is a residual substance on the side wall of the aluminum-copper metal pattern; and (f) using magnetic field enhanced reactive ion etching (MERIE) to remove the residual substance, the reaction conditions are as follows: a gas containing oxygen and oxygen is used as The reaction gas uses a pressure of iOdOnitorr and a magnetic field of 20 to 100 Gauss. In such a low-pressure environment, simultaneous application of a magnetic field can effectively remove residual substances. Furthermore, in the above-mentioned removal method, the photoresist pattern may be composed of an organic polymer material. In addition, the step (d) selective etching uses a gas containing gas such as gas (C12) and / or boron gas (Bci3) as a reaction gas vessel. In the above-mentioned cleaning method, the gas containing fluorine and oxygen is, for example, carbon tetrafluoride and oxygen β
第6頁 451345 五'發明說明（4) 再者’上述清除方法之中，步驟（f)可以採用大約 200W〜500W的射頻電源。而清除時間介於1〇〜6〇秒之間。 根據上述目的’本發明提供另一種去光阻後殘留物質 的清除方法’適用於接觸孔圖案的定義，該清除方法包括 下列步驟：（a)提供一半導體基底，該基底形成有若干半 導體元件；（b)在該半導體基底形成一絕緣層；（c)在該絕 緣層表面形成一光阻圖案；（d)利用該光阻圖案當作蝕刻 草幕’並且選擇性蝕刻該絕緣層，以形成一接觸孔圖案； (e)剝除該光阻圖案，此時該接觸孔圈案的側壁具有殘留 物質：（f)利用磁場加強型反應性離子蝕刻法清除該殘留 物質’其反應條件如下：以含氟與氧之氣體當作反應氣 體、採用10~50mtorr的壓力、採用20〜100高斯的磁場。 為了讓本發明之上述目的、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〜第1D圖係根據習知技術定義鋁銅金屬圖案之製 程剖面圖。 第2A〜第2D圖係根據本發明較佳實施例定義鋁銅金屬 圖案之製程剖面圏。 符號之說明 10、100-半導體基底。 12、120〜絕緣層。 14、140〜擴散阻障層。Page 6 451345 Description of the fifth invention (4) Furthermore, among the above-mentioned removal methods, the step (f) can use an RF power source of about 200W to 500W. The clearance time is between 10 and 60 seconds. According to the foregoing objective, the present invention provides another method for removing residual material after photoresist removal, which is applicable to the definition of a contact hole pattern. The method includes the following steps: (a) providing a semiconductor substrate having a plurality of semiconductor elements formed on the substrate; (B) forming an insulating layer on the semiconductor substrate; (c) forming a photoresist pattern on the surface of the insulating layer; (d) using the photoresist pattern as an etching grass curtain; and selectively etching the insulating layer to form A contact hole pattern; (e) the photoresist pattern is stripped, and at this time, the sidewall of the contact hole case has a residual substance: (f) the residual substance is removed by a magnetic field enhanced reactive ion etching method, and the reaction conditions are as follows: Using a gas containing fluorine and oxygen as a reaction gas, a pressure of 10 to 50 mtorr and a magnetic field of 20 to 100 Gauss are used. In order to make the above-mentioned objects, features, and advantages of the present invention more comprehensible, the following exemplifies a preferred embodiment and the accompanying drawings, which are described in detail as follows: Brief description of drawings 1A to 1D It is a cross-sectional view of the process of defining the aluminum-copper metal pattern according to the conventional technology. Figures 2A to 2D are process cross sections 圏 defining the aluminum-copper metal pattern according to the preferred embodiment of the present invention. Explanation of symbols 10, 100-Semiconductor substrate. 12, 120 ~ insulation layer. 14, 140 ~ Diffusion barrier layer.
第7頁 451345 五、發明說明（5) ' 16、160〜鋁銅金屬層》 16a、160a〜鋁銅金屬圖案。 18、180〜防反射層。 20、20a、200、200a~ 光阻圖案。 22、220〜殘留物質。 實施例 以下利用第2A圖〜第2D圖所示的定義金屬圖案（metai pattern)之製程剖面圖’以更詳細地說明本發明清除殘留 物質的方法。 首先，請參照第2A圖，提供一形成有若干半導艘元件 (圖未顯示）之半導逋基底1〇〇 ’然後，利用例如化學氣相 沈積的方式（chemical vapor deposition ;CVD)形成絕緣 保護層120 ’用來覆蓋上述半導體基底^然後，再次利 用CVD法以形成鈦/氮化欽（Ti/TiN)複合層以當作擴散阻障 層（diffusion barrier)140 ’接著利用金屬濺鍍法 (sputtering)以在上述阻障層140的表面形成一鋁銅金屬 層160，其次’在上述鋁銅金屬層160表面沈積一鈦/氮化 鈦複合層以當作防反射層180(anti-reflection coating ARC)。再者，符號200代表利用傳統的微影技術 (photol ithography)形成之光阻圖案（photoresist pattern) ’並且光阻圓案200係設置於欲形成金屬圖案之 位置。 之後’請參照第2B與第2C圓，利用非等向性乾蝕刻 法’在氣氣（C12)或氣化硼（BC13)等氣體的存在下，以去除Page 7 451345 V. Description of the invention (5) '16, 160 ~ aluminum-copper metal layer> 16a, 160a ~ aluminum-copper metal pattern. 18, 180 ~ anti-reflection layer. 20, 20a, 200, 200a ~ Photoresist pattern. 22, 220 ~ Residual substances. EXAMPLES The following is a detailed cross-sectional view of a process for defining a metal pattern shown in Figs. 2A to 2D to illustrate the method for removing residual substances in the present invention in more detail. First, referring to FIG. 2A, a semiconductor substrate 100 ′ having a plurality of semiconductor components (not shown) formed is provided, and then an insulation is formed by, for example, chemical vapor deposition (CVD). The protective layer 120 'is used to cover the semiconductor substrate. Then, a CVD method is used again to form a titanium / nitride (Ti / TiN) composite layer as a diffusion barrier 140'. Then, a metal sputtering method is used. (sputtering) to form an aluminum-copper metal layer 160 on the surface of the barrier layer 140, and secondly, to deposit a titanium / titanium nitride composite layer on the surface of the aluminum-copper metal layer 160 as an anti-reflection layer 180 (anti-reflection coating ARC). Furthermore, the symbol 200 represents a photoresist pattern ′ formed using a conventional photolithography technique, and the photoresist pattern 200 is disposed at a position where a metal pattern is to be formed. Afterwards, please refer to the 2B and 2C circles and use an anisotropic dry etching method to remove it in the presence of gas (C12) or boron gas (BC13).
第8頁 451345 五、發明說明（6) 未被光阻圖案200遮蔽的防反射層180、鋁銅金屬唐16〇與 阻障層140，直到露出上述絕緣層120為止，此時得到所需 的鋁銅金屬圖案160a，以及外形輪廓有些許變化的光阻圈 案200a。然後，利用臨場（in-situ)剝除法在同一敍刻機 台或同一反應室（chamber)進行光阻圖案200a的去除，此 時改用含有氧氣（02)及氮氣（N2)之反應氣體，以去除有機 材料構成之光阻圖案200a，然而由於光阻圖案材料2〇〇a之 黏柄特性，加上前述含氯氣盤與金屬銘及水氣產生反應而 形成第2C圖所示的殘留物質220，通常形成於金屬圔案 160a 的側壁（side walls)。 接著’請參照第2D圈，為了清除此殘留物質220，將 半導艘基底（晶圓）移至利用磁場加強型反應性離子蚀刻 (magnetic enhanced reactive ion etching ;MERIE)機 台，如Applied Materials公司的MxP或MxP+機型，在低 壓的環境下採用射頻（radio frequency ; RF)電源產生偏 壓（bias)，另外配合磁場（magnetic field)以增加離子解 離、促進離子為擊（ion bombardment)效果，以去除上述 含有聚合物質的殘留物質220 »此時例如採用30 0W的射頻 電源、導入流量40sccm的氧氣與lOsccm的四氟化碳（CF4) 於此機台的反應室、將壓力控制在大約2〇mtorr '並且施 以大約20高斯（Gauss)的磁場，處理大約30秒鐘。經過上 述磁場加強型反應性離子清除後，殘留物質220幾乎完全 地去除。後續僅需要利用去離子水槽再次將晶圓清洗即 可。Page 8 451345 V. Description of the invention (6) The anti-reflection layer 180, the aluminum copper metal layer 160 and the barrier layer 140 are not shielded by the photoresist pattern 200 until the above-mentioned insulating layer 120 is exposed. Aluminum-copper metal pattern 160a, and a photoresist ring 200a with a slight change in outline. Then, the in-situ stripping method is used to remove the photoresist pattern 200a on the same engraving machine or the same chamber. At this time, a reaction gas containing oxygen (02) and nitrogen (N2) is used instead. The photoresist pattern 200a made of organic material is removed. However, due to the sticky handle characteristics of the photoresist pattern material 200a, plus the aforementioned chlorine-containing gas plate reacting with the metal name and water vapor, a residual substance shown in FIG. 2C is formed. 220, usually formed on the side walls of metal case 160a. Next, please refer to the 2D circle. In order to remove this residual material 220, the semiconductor substrate (wafer) is moved to a magnetic enhanced reactive ion etching (MERIE) machine, such as Applied Materials. The MxP or MxP + models use radio frequency (RF) power to generate biases in a low-voltage environment. In addition, they cooperate with magnetic fields to increase ion dissociation and promote ion bombardment effects. In order to remove the polymer-containing residual material 220 »At this time, for example, a 30 W radio frequency power supply is used, and oxygen of 40 sccm and lOsccm of carbon tetrafluoride (CF4) are introduced into the reaction chamber of the machine, and the pressure is controlled to about 2 Omtorr 'and applied a magnetic field of about 20 Gauss for about 30 seconds. After the magnetic field-enhanced reactive ions are removed, the residual substance 220 is almost completely removed. It is only necessary to clean the wafer again in a deionized water tank in the future.
451345 五、發明說明（7) 本實施例以定義鋁銅金屬圖案為例，然而本發明不限 於此’亦即上述清除殘留物質的方法亦可適用於蝕刻絕緣 層以形成接觸孔的場合。 發明特徵與效果 本發明的特徵在於將半導體基底（晶圃）移至利用既有 的磁場加強型反應性離子蝕刻機台，在低壓的環境下採用 射頻電源產生偏壓，另外配合磁場以去除含有聚合物質 殘留物質220 根據本發明的清除方法，不需要特殊的機台亦能夠 |效地去除殘留物質，降低缺陷產生，同時避免使用含胺類 |的化學試劑而減少鋁銅金屬腐蝕的可能性’並且降低製 !_ 成本。 雖然本發明已以較佳實 限定本發明，任何熟習此項 神和範圍内，當可作更動與 當梘後附之申請專利範圍所 施例揭露如上’然其並非用以 技藝者’在不脫離本發明之精 潤錦’因此本發明之保護範圍 界定者為準。451345 V. Description of the invention (7) This embodiment takes the definition of an aluminum-copper metal pattern as an example, but the invention is not limited thereto, that is, the above-mentioned method for removing residual substances can also be applied to the case of etching the insulating layer to form a contact hole. Features and Effects of the Invention The present invention is characterized in that the semiconductor substrate (crystal garden) is moved to an existing magnetic field-enhanced reactive ion etching machine, and a radio frequency power source is used to generate a bias voltage in a low-voltage environment, and a magnetic field is added to remove Polymeric Residual Material 220 According to the cleaning method of the present invention, no special machine is needed to effectively remove the residual material, reduce the occurrence of defects, and avoid the use of amine-containing chemical reagents to reduce the possibility of aluminum and copper metal corrosion. 'And reduce the system! _ Cost. Although the present invention has been better defined by the present invention, any person familiar with this god and scope, when making changes and when applying the scope of the attached patent application, discloses the above example, but it is not intended to be an artist. Departing from the essence of the invention, the scope of protection of the invention shall prevail.