1252528 九、發明說明： 【發明所屬之技術領域】 本發明提供一種半導體晶圓的清洗方法，尤指一種具 有更快速且有效之半導體晶圓的清洗方法。 【先前技術】 由於在半導體製程中，半導體晶圓常須反覆地經過各 種化學氣相沈積（chemical vapor deposition，CVD)、乾银刻 (dry etch)、或化學機械研磨（chemical mechanical polishing， CMP)等製程，使得半導體晶片表面往往會殘留有金屬或有 機物等污染微粒(particle)，而且半導體晶片的矽基底表面 也非常谷易氧化形成自然氧化層（native 0>^如），進而影響 到半導體產品的品質。因此半導體晶片在製造的過程中需 要經過多次清洗(clean)製程，以去除這些外界污染物以及 自然氧化層’維持半導體晶圓的表面潔淨度(surface cleanliness) 〇 一般而言，清洗製程可概分為乾式及濕式清洗，其中 濕式清洗法為較常用的清洗方法。其步驟係先利用一含氡 ✓谷劑（fluorine based solvent)、一胺類溶劑（amine based 1252528 solvent)或是至少一化學品（chemical)來進行一濕式清洗 (wet cleaning)製程，再進行一洗濯（rinse)製程以及一乾燥 (dry)製程。舉例來說，在半導體製程中大量使用的微影與 蝕刻製程，便常使用光阻溶劑，例如Ash-land或EKC廠商 所生產之ACT-935、EKC-270等光阻溶劑。然後於定義晶 圓表面圖案並去除光阻之後，再利用N-甲基洛酮 (N-Methyl-Pyrolidone，NMP)以及水等溶液來沖洗晶圓並去 除殘留之光阻溶劑。而在完成前述之晶圓清洗程序後，必 須快速地將晶圓表面的水份去除，以避免殘留於晶圓表面 的水份中的溶氧與晶圓表面的石夕原子發生氧化反應而造成 晶片的缺陷，並且避免產生水痕。相關半導體晶片的清洗 方法可參考如美國專利US-5,516730號等（題目為：APrior art cleaning method of removing small particles on the surface of the semiconductor wafer ;發明人為：Piro〇z 等 人）〇 如岫所述，在半導體製程中，由於半導體晶圓經常反 覆地經過各種製程，使得半導體晶片表面往往會殘留有金 屬或有機物料染微粒，造成晶片品質下降，因此往择有 一清洗過程將晶圓上之殘留物去除。如第丨圖所示，第i 圖為智知清洗晶圓方法之示意圖。清洗製程中會先使伟化 學樂απ清洗晶圓殘留物，再使用去離子水洗濯晶圓12， 1252528 .去除晶圓12上之清洗液，同時利用—旋轉器14之高速旋 .轉所產生之離心力將洗濯之去離子水1〇去除，但由於旋轉 中心之轉速較弱且去離子水10與晶圓12之表 大，往往在晶圓12之圓心部分會有殘留有水珠16，^因 晶圓12與水珠16之接觸角18小，而使得晶圓12上之水 珠16不易去除’如第2圖所示’第2圖為第t圖晶圓放大 示意圖。這些殘留乾涸於晶圓12上的水珠16便會形成水 春潰(water mark)，進而造成晶圓12發生局部氧化、異常介 面、腐敍專之缺陷，嚴重降低後續製程的潔淨度與良率。 因此過去有人想藉由提高旋轉器丨4之速度來去除水 珠16。但在晶圓12高速旋轉的結果，往往會累積電荷於 晶圓12表面上形成靜電，並吸附空氣中的粒子(particle)， 造成晶圓12的表面潔淨度下降，而且旋轉器會因高速影響 而容易受損降低使用週期。另外，也有人因為晶圓12有較 •大之疏水性，因此藉由四曱基氫氧化銨 (tetra-methyl-ammonium hydroxide，TNAH )來改變晶圓 12表面之性質，但由於使用高濃度之四甲基氫氧化銨又會 造成成本提升，不符合經濟效應。因此為減少成本，另外 有人使用少量之四曱基氫氧化銨來洗濯，再配合通入有溫 度之氮氣來使晶圓12在旋轉時較快乾燥，但此法又產生另 一問題，因為氮氣容易有微顆粒產生，反而造成晶圓12表 面不乾淨問題產生。 1252528 簡單總結上述各種習知洗濯的方法，以去離子水洗濯 方法受限於晶圓與去離子水之表面張力、旋轉器之轉速及 靜電因素影響，對於先進製程而言並不適合，而使用四曱 基氫氧化銨以及通入有溫度之氮氣則造成成本過高以及微 顆粒造成晶圓表面不乾淨問題產生。因此必須發展一套更 有效率且能降低成本之晶圓清洗製程。 _ 【發明内容】 因此本發明之主要目的在於提供一種具有有更快速且 有效之半導體晶圓的清洗方法，以解決上述習知半導體晶 圓清洗的問題。 根據本發明之申請專利範圍，係揭露一種清洗晶圓的 方法，用來去除化學機械研磨後的殘餘物。本發明係先利 用一清洗刷清洗化學機械研磨後之晶圓表面的殘餘物，接 著進行一清洗過程，此過程係利用一旋轉方式，並配合以 一 τ型管喷出一混合清洗液沖洗前述之清洗刷處理後的晶 • 圓表面，最後再進行一烘烤製程。 由於本發明之半導體晶圓的清洗方法，係採用化學水 溶液改變晶圓與去離子水的表面張力，使殘留於晶圓之水 1252528 溶液更容易被移除，不但可以減少傳統清洗晶圓之高成 本，而且降低微粒子或有機溶液殘留，因此能更有效清洗 晶圓，以提高產能。 為了使貴審查委員能更近一步了解本發明之特徵及 技術内容，請參閱以下有關本發明之詳細說明與附圖。然 而所附圖式僅供參考與輔助說明用，並非用來對本發明加 •以限制者。 【實施方式】 請參考第3圖，第3圖為本發明清洗晶圓方法示意圖。 本發明以化學機械研磨製程為例，在晶圓30經過化學研磨 後會有殘留金屬或有機物等污染微粒於晶圓30上，造成晶 圓30品質降低，因此本發明提供以下步驟來進行研磨後之 胃晶圓30的清洗方法。首先提供一清洗刷（圖未示）先將經 過化學研磨後之晶圓30上的殘留物去除，接著進行一清洗 過程，清洗晶圓3 0表面，最後再進行一烘烤製程（圖未 . 示）。 在清洗過程中，本發明係先利用一 T型管32，其中T 型管32之一端銜接一去離子水供給源，用來提供去離子水 1252528 34，另一端則銜接一化學溶液供給源，用來提供化學溶液 36。其中，化學溶液36係為一高揮發化學溶液，例如異丙 醇、丙酮或四氫呋喃等高揮發性之溶液，且T型管32另包 含有一控制閥38，可視需要來調整化學溶液36之流量， 用來控制去離子水34與化學溶液36混合後之混合清洗液 40的濃度。如此，本發明便可以利用T型管32將適當濃 度的混合清洗液40喷出至清洗刷處理後之晶圓30的表面 _上進行清洗，然後在混合清洗液40清洗晶圓30時，再配 合利用旋轉器42之高速旋轉將晶圓30上之混合清洗液40 加以去除。 由於本發明之清洗液40為高揮發化學溶液36與去離 子水34之混合液有較高親水性質，例如異丙醇水溶液、丙 酮水溶液或四氫呋喃水溶液，因此不但改變了混合清洗液 • 40與晶圓30之表面張力，使得喷在晶圓30之中心部分之 混合清洗液44與晶圓30之表面張力小且接觸角46大，所 以混合清洗液44會攤在晶圓30上，使得晶圓30圓心部分 • 之混合清洗液44少，因此容易利用旋轉器42將晶圓30圓 心部分之混合清洗液44去除，而不會因旋轉器42轉速不 足等問題造成混合清洗液44殘留在晶圓30上，如第4圖 所示，第4圖為第3圖之晶圓放大示意圖。最後再進行一 11 1252528 烘烤製程，完成晶圓之清洗。 由上述可知，由於清洗液是化學溶液與去離子水之混 合液，其不但可以控制清洗液之濃度，而且更能有效地去 除清洗液並潔淨晶圓，避免單純使用去離子水清洗所造成 晶圓之圓心部分殘留有去離子水的現象，因此本發明能減 少化學溶液之用量以及避免使用氮氣造成晶圓污染。 綜合上述說明，相較習知的清洗晶圓之方法，本發明 清洗晶圓之方法使用之清洗液為化學溶液與去離子水之混 合液，可以有效降低晶圓與清洗液之表面張力，使得殘留 於晶圓之圓心部分之清洗液溶液更容易去除，以提高晶圓 之潔淨度。因此，本發明不但可減少傳統清洗晶圓之高成 本，而且能降低微粒子或有機溶液殘留，並進一步增加旋 鲁轉器之使用週期。 以上所述僅為本發明之較佳實施例，凡依本發明申請 專利範圍所做之均等變化與修飾，皆應屬本發明之涵蓋範 圍。 12 1252528 【圖式簡單說明】 第1圖為習知清洗晶圓方法之示意圖。 第2圖為習知晶圓放大示意圖。 第3圖為本發明清洗晶圓方法之示意圖。 第4圖為本發明晶圓放大示意圖。 【主要元件符號說明】 10 去離子水 12 晶圓 14 旋轉器 16 水珠 18 接觸角 30 晶圓 32 T型管 34 去離子水 36 化學溶液 38 控制閥 40 混合清洗液 42 旋轉器 44 混合清洗液 46 接觸角 131252528 IX. Description of the Invention: [Technical Field] The present invention provides a cleaning method for a semiconductor wafer, and more particularly to a cleaning method for a semiconductor wafer having a faster and more efficient method. [Prior Art] Since semiconductor wafers often have to undergo various chemical vapor deposition (CVD), dry etch, or chemical mechanical polishing (CMP) in a semiconductor process. The process of the semiconductor wafer tends to leave particles of metal or organic particles on the surface of the semiconductor wafer, and the surface of the substrate of the semiconductor wafer is also very oxidized to form a natural oxide layer (native 0>^), thereby affecting the semiconductor product. Quality. Therefore, the semiconductor wafer needs to be cleaned several times during the manufacturing process to remove these external contaminants and the natural oxide layer 'maintaining the surface cleanliness of the semiconductor wafer. In general, the cleaning process can be It is divided into dry and wet cleaning, of which wet cleaning is the more common cleaning method. The step is to carry out a wet cleaning process by using a fluorine based solvent, an amine based solvent (amine based 1252528 solvent) or at least one chemical (chemical cleaning). A rinse process and a dry process. For example, photoresists, such as ACT-935 and EKC-270, which are produced by Ash-land or EKC manufacturers, are often used in lithography and etching processes that are widely used in semiconductor processes. Then, after defining the pattern of the crystal surface and removing the photoresist, the solution is washed with a solution of N-Methyl-Pyrolidone (NMP) and water to remove the residual photoresist. After the above-mentioned wafer cleaning process is completed, the moisture on the surface of the wafer must be quickly removed to prevent the dissolved oxygen in the moisture remaining on the surface of the wafer from oxidizing with the cerium atoms on the surface of the wafer. Defects in the wafer and avoiding water marks. For a method of cleaning a related semiconductor wafer, for example, U.S. Patent No. 5,516,730 (the title: APrior art cleaning method of removing small particles on the surface of the semiconductor wafer; inventor: Piro〇z et al.) In the semiconductor manufacturing process, since the semiconductor wafer often goes through various processes repeatedly, the surface of the semiconductor wafer tends to have residual metal or organic materials, which causes the quality of the wafer to be degraded. Therefore, a cleaning process is selected on the wafer. The residue is removed. As shown in the figure, the i-th picture is a schematic diagram of a method for cleaning the wafer. In the cleaning process, the chemical residue απ is used to clean the wafer residue, and then the deionized water is used to wash the wafer 12, 1252528. The cleaning liquid on the wafer 12 is removed, and the high-speed rotation of the rotator 14 is used. The centrifugal force removes the deionized water from the washing, but since the rotation speed of the rotating center is weak and the surface of the deionized water 10 and the wafer 12 is large, there is a residual water droplet 16 in the center of the wafer 12, ^ Since the contact angle 18 of the wafer 12 and the water droplets 16 is small, the water droplets 16 on the wafer 12 are not easily removed 'as shown in FIG. 2'. FIG. 2 is an enlarged view of the wafer of FIG. The water droplets 16 which are dried on the wafer 12 will form a water mark, which will cause defects in the local oxidation, abnormal interface and rot of the wafer 12, and seriously reduce the cleanliness and goodness of the subsequent processes. rate. Therefore, in the past, some people wanted to remove the water droplets 16 by increasing the speed of the spinner 丨4. However, as a result of the high-speed rotation of the wafer 12, electric charges are accumulated on the surface of the wafer 12 to form static electricity, and particles in the air are adsorbed, resulting in a decrease in the surface cleanliness of the wafer 12, and the rotator may be affected by high speed. It is easy to damage and reduce the life cycle. In addition, because the wafer 12 has a relatively large hydrophobicity, the nature of the surface of the wafer 12 is changed by tetra-methyl-ammonium hydroxide (TNAH), but due to the use of high concentration Tetramethylammonium hydroxide will in turn increase costs and not meet economic effects. Therefore, in order to reduce the cost, another person uses a small amount of tetradecyl ammonium hydroxide for washing, and then with the introduction of temperature nitrogen to make the wafer 12 dry faster when rotating, but this method has another problem because nitrogen It is easy to have microparticles generated, which in turn causes the surface of the wafer 12 to be clean. 1252528 A brief summary of the various conventional methods of washing, the method of deionized water washing is limited by the surface tension of the wafer and deionized water, the rotational speed of the rotator and the influence of static factors, which is not suitable for advanced processes, and uses four. Sulfhydryl ammonium hydroxide and the introduction of nitrogen at a temperature cause excessive cost and microparticles cause wafer surface cleanliness problems. Therefore, a more efficient and cost-effective wafer cleaning process must be developed. SUMMARY OF THE INVENTION It is therefore a primary object of the present invention to provide a cleaning method having a semiconductor wafer that is faster and more efficient to solve the above-described problems of conventional semiconductor wafer cleaning. In accordance with the scope of the present invention, a method of cleaning a wafer for removing residues after chemical mechanical polishing is disclosed. The invention firstly uses a cleaning brush to clean the residue on the surface of the wafer after chemical mechanical polishing, and then performs a cleaning process by using a rotating method and spraying a mixed cleaning liquid with a τ-shaped tube to rinse the foregoing The crystal surface of the treated brush is cleaned, and finally a baking process is performed. Since the semiconductor wafer cleaning method of the present invention uses a chemical aqueous solution to change the surface tension of the wafer and the deionized water, the solution of the water remaining in the wafer 1252528 is more easily removed, which not only reduces the height of the conventional cleaning wafer. Cost, and reduce the residual of particles or organic solutions, so it can clean the wafer more efficiently to increase productivity. In order to provide a more detailed understanding of the features and technical aspects of the present invention, the following detailed description of the invention and the accompanying drawings. The drawings are for illustrative purposes only and are not intended to limit the invention. [Embodiment] Please refer to FIG. 3, which is a schematic view of a method for cleaning a wafer according to the present invention. In the chemical mechanical polishing process of the present invention, after the wafer 30 is chemically polished, residual particles such as metal or organic substances are left on the wafer 30, and the quality of the wafer 30 is lowered. Therefore, the present invention provides the following steps for polishing. A method of cleaning the stomach wafer 30. First, a cleaning brush (not shown) is first removed from the chemically polished wafer 30, followed by a cleaning process to clean the surface of the wafer 30, and finally a baking process (Fig. Show). In the cleaning process, the present invention first utilizes a T-shaped tube 32, wherein one end of the T-shaped tube 32 is connected to a deionized water supply source for providing deionized water 1252528 34, and the other end is connected to a chemical solution supply source. Used to provide a chemical solution 36. The chemical solution 36 is a highly volatile chemical solution, such as a highly volatile solution such as isopropyl alcohol, acetone or tetrahydrofuran, and the T-tube 32 further includes a control valve 38, which can adjust the flow rate of the chemical solution 36 as needed. It is used to control the concentration of the mixed cleaning liquid 40 after the deionized water 34 is mixed with the chemical solution 36. Thus, the present invention can use the T-tube 32 to eject the appropriate concentration of the mixed cleaning liquid 40 to the surface of the wafer 30 after the cleaning brush treatment, and then clean the wafer 30 when the cleaning liquid 40 is cleaned. The mixed cleaning liquid 40 on the wafer 30 is removed by the high speed rotation of the rotator 42. Since the cleaning liquid 40 of the present invention has a high hydrophilic property of a mixture of the high volatile chemical solution 36 and the deionized water 34, such as an aqueous solution of isopropanol, an aqueous solution of acetone or an aqueous solution of tetrahydrofuran, the mixed cleaning solution is not changed. The surface tension of the circle 30 is such that the surface tension of the mixed cleaning liquid 44 sprayed on the central portion of the wafer 30 and the wafer 30 is small and the contact angle 46 is large, so that the mixed cleaning liquid 44 is spread on the wafer 30, so that the wafer The center portion of the center of the 30 is small, so that the mixed cleaning liquid 44 of the center portion of the wafer 30 is easily removed by the rotator 42 without causing the mixed cleaning liquid 44 to remain on the wafer due to problems such as insufficient rotation speed of the rotator 42. On the 30, as shown in Fig. 4, Fig. 4 is an enlarged view of the wafer of Fig. 3. Finally, a 11 1252528 baking process is performed to complete the wafer cleaning. It can be seen from the above that since the cleaning liquid is a mixture of a chemical solution and deionized water, it can not only control the concentration of the cleaning liquid, but also effectively remove the cleaning liquid and clean the wafer, thereby avoiding the crystal caused by pure deionized water cleaning. The phenomenon of deionized water remains in the center of the circle, so the present invention can reduce the amount of the chemical solution and avoid the contamination of the wafer by using nitrogen. According to the above description, compared with the conventional method for cleaning a wafer, the cleaning liquid used in the method for cleaning a wafer of the present invention is a mixture of a chemical solution and deionized water, which can effectively reduce the surface tension of the wafer and the cleaning liquid, so that The cleaning solution remaining in the center of the wafer is easier to remove to improve the cleanliness of the wafer. Therefore, the present invention not only reduces the high cost of conventional cleaning wafers, but also reduces the residual of fine particles or organic solutions, and further increases the life cycle of the rotary rotator. The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the invention are intended to be included in the scope of the present invention. 12 1252528 [Simple description of the drawings] Figure 1 is a schematic diagram of a conventional method of cleaning wafers. Figure 2 is a schematic view of a conventional wafer. Figure 3 is a schematic view of the method of cleaning wafers of the present invention. Figure 4 is a schematic enlarged view of the wafer of the present invention. [Main component symbol description] 10 Deionized water 12 Wafer 14 Rotator 16 Water bead 18 Contact angle 30 Wafer 32 T-tube 34 Deionized water 36 Chemical solution 38 Control valve 40 Mixed cleaning liquid 42 Rotator 44 Mixed cleaning solution 46 contact angle 13