1227216 玖、發明說明 【發明所屬之技術領域】 本發明係一種銅-化學機械研磨廢液之光化學處理方 法，特別是一種添加光催化劑至銅-化學機械研磨廢液中， 以光化學作用使銅沉積，同時使銅-化學機械研磨製程中之 有機污染物分解之有效廢液處理方法者。 【先前技術】 化學機械研磨（Chemical Mechanical Polishing，CMP) 為超大型積體電路（ultra large-scale integration, ULSI) 中，含有次-〇· 25 微米金屬（sub-quarter micron metal)及 電質線（dielectric lines)的石夕晶圓（silicon device)的 主要平坦化技術。 習用之矽晶圓製造過程中，主要係使用鋁作為間介材 料（interconnect material)，在導入銅作為間介材料之前， 化學機械研磨的廢棄物處理不是一項重要的課題，因為含 矽及氟化物的污染物被其它製程中使用的水所稀釋，並以 安排送至一酸性廢棄物中和系統中處理即告完成，而當製 程中以銅來取代作為間介材料之後，許多針對後程序廢液 處理的挑戰即產生了，因為此種銅-化學機械研磨製程會大 量消耗資源（研磨漿，水），且大多數會產生固體廢棄物（晶 圓研磨墊）與含有廢棄物的流出物（用剩之研磨漿）。 一般銅-化學機械研磨製程中包含有源自於研磨漿、設 備清洗、及後續CMP晶圓清除程序上所使用的多種有機及 無機污染物，而破壞與移除些污染物則須要數個控制因素， 1227216 包含有系統的酸鹼控制及氧化還原化學反應。 在有機污染物方面，CMP製程中廢液的有機成份包含有 金屬錯合劑、界面活性劑、穩定劑及抗腐蝕劑，這些有機 成份的穩定性與研磨漿的pH值有高度相關性，以芳香胺類 的苯並二唑（benz〇triaz〇le，BTA)為例，其同時作為腐蝕 抑制劑及銅的移除控制劑，在酸性的情形下可與銅形成一 酸性鹽類的水溶性錯合物，但當酸鹼值增加接近鹼性狀態 時，該錯合物變成不可溶，因此增加後續處理的困難。另 外，分散劑如聚丙烯酸（polyacrylic acid)，其因可在大 範圍的pH值之間保持水溶性，因此調整pH值並不一定能 作為有效移除有機污染物的方法，系統中固體的凝結或許 疋有效移除金屬的機制，然而添加有機添加劑至研磨漿料 中會導致研磨漿料凝結，而造成後續處理的困難。 來自於研磨漿料組成中的粉體（如：二氧化鈽、二氧化 鋁、二氧化矽）等無機成份在後續處理中，往往會呈現不溶 解的狀態，其濃度約在50—500ppm之間，研磨漿中之研磨 粒會以氧化的形態分散懸浮在水溶液，而氧化劑的選擇（如 過氧化氫及氫氧化胺）可造成不溶性無機成份轉變成可溶 性。 主要無機污染物係從晶圓表面移除而來，如金屬、氧 化金屬、低介電常數材料等，當銅—化學機械研磨製程中接 近1微米的銅金屬自晶圓的表面被移除時，每2〇〇顏晶圓 直徑的金制約有〇為義料，伴料㈣耗掉的金 屬的另有同樣須要處理的無機及有機材料，一般程序上會 1227216 以一多重步驟處理系統分別處理每一種成份，此種處理程 序之不僅繁複，同時因控制因素多（酸鹼性及化學性等等） 而效果不佳。 【發明內容】 本發明者有鑑於現今銅-化學機械研磨廢棄物處理的困 難與成效不彰，特別提供一種光化學的銅-化學機械研磨廢 液處理方法，以達到快速而有效地處理、移除及回收銅-化 學機械研磨廢液中金屬銅或其它有用物質之發明目的。 本發明之主要目的係為提供一種銅-化學機械研磨製程 中之廢水處理程序，其可藉由添加光催化劑，並接受紫外 線放射線（UV radiation)的照射，使銅離子轉移成銅元素沉 積於光催化劑粒子表面，並產生光化學分解以同時消除主 要有機污染物，並最後產生出乾淨的廢水流以符合環保標 準。 本發明之另一目的在於後處理的廢水流出物在經過復 原及進一步處理程序後，會產生可應用於微電子的銅覆蓋 導電性粒子，以增加廢棄物利用性來降低整體程序上之成 本0 為了可達到前述的發明目的，本發明所運用的技術手 段係在於提供一種銅-化學機械研磨廢液之光化學處理方 法，其中廢液中含銅離子及有機化合物，其製程步驟如下： 在廢液中加入光催化劑；與 將廢液接受光照射，使銅離子沉積於光催化劑的表面 產生銅覆蓋粒子，並讓有機化合物產生光分解。 1227216 本發明可以利用添加光催化劑，並接受光照射之能量， 使鋼離子轉移成銅元素沉積於光催化劑粒子表面，並產生 光化學分解以同時消除有機污染物，以達到去除廢液中金 屬離子及有機污染物之目的者。 【實施方式】 本發明係一種銅—化學機械研磨廢液光化學處理方法， 其包括有：在含銅及有機化合物的廢液中加人光催化劑； 將廢液曝曬於uv光或陽光下使銅離子完全沉積於光催化 劑的表面產生銅覆蓋粒子’並讓有機化合物完全光分解； 藉由上述步驟，可去除廢液中之銅離子及破壞有害的有機 化合物，並回收乾淨的水迴流至設備中再利用，另外，銅 覆蓋粒子可再用於各種微電子方面的應用，以沖銷操作上 之成本。 進一步配合第一圖，以詳細說明本發明之銅-化學機械 研磨廢液光化學處理方法完整的操作流程。 當廢液自設備中回收後被送入一處理室，在此時加 入一些光催化劑，接著將固態的粒子從可溶性的污染物及 水中被分離，其中光催化劑可為氧化鋅（Zn〇）、硫化鋅 (ZnS)、三氧化鋇鈦（BaTi〇3)、三氧化鋅鈦（ZnTi〇3)、三氧 化鐵鈦（FeTi〇3)、三氧化二鐵（Fe2〇3)、二氧化鈦（丁丨·〇2)， 與其匕具有與同樣二氧化鈦相近性質之價電子帶差（bancj gap)與價電子帶位置（band position)之金屬氧化物。以二氧 化鈦為例，二氧化鈦在太陽能源的轉換下，可被使用於各 種有機化合物的光還原和光氧化反應，以及金屬（銀、金、 1227216 銅、银、把、始）的光還原反應，二氧化鈦的廣泛應用在 於其可產生多功能的氧化及還原定點因此能產生高效能的 反應及降解程序(degradation processes) 〇 其原理在於：由於半導體粒子的特性一般都表現在電子 定位價帶（electrically populated valance band)和空白傳導 帶（largely vacant conduction band)之間的能量差異 (energy gap)，該能量差異決定激發該半導體粒子所需的吸 收光波長，如第二圖所示，該圖表示一個二氧化鈦之半導 體粒子之價帶結構，當波長在400nm以下之紫外光放射線 照射超微粒之二氧化鈦時，在電子定位價帶上的電子被 紫外線之能量激發，跳升到傳導帶，此時會在半導體粒子 表面形成成對的電子-電洞對（electron-electron hole 「ecombination pairs)，因而產生兩個反應位置（電子與電 洞），利用電洞因缺乏電子所帶正電產生的氧化能力，以及 電子單獨存在時的還原能力，因此可以同時對接觸物質進 行氧化及還原的反應。 作為光催化劑之半導體粒子材料一般可以依其分解水 的粒子能力來區分為三種，一種為氧化的或氧化型（〇_type) 半導體粒子，例如氧化鎢或三氧化二鐵，其氧化的微粒粉 末足以氧化水但並不能還原水。另一種為還原的或還原型 (R-type)半導體粒子，例如碳化矽及硒化鎘，其能還原水但 並不能氧化水。最後一種為氧化還原型（〇R-type)半導體粒 子，其能同時提供氧化及還原能力，例如二氧化鈦（Ti〇2)、 氧化辞（Zn〇）、硫化鋅（ZnS)、三氧化鋇鈦（BaTi〇3)、三氧 1227216 化鋅鈦（ZnTi〇3)、三氧化鐵鈦（FeT丨·〇3)、三氧化二鐵（ρ:~〇3) 與其它具有與同樣二氧化鈦相近性質之價電子帶差（band gap)與價電子帶位置（band position)之金屬氧化物。同樣以 二氧化鈦為例，當其在控制好電子與電子洞再結合的情形 下，能同時氧化及還原接觸物質，藉此達成本發明中所需 產生之氧化及還原功能。接著將略含有水份及光催化劑的 固悲粒子送入反應室（B)，在此曝曬紫外光放射線約1〇-1 〇〇 分鐘以促進過氧化氫（在CMp製程中原本所使用的氧化劑） 或自粒子表面微附的有機物分解，處理過後的粒子再被送 至一乾燥室（D)，以進一步移除水份及其它微量的有機物， 並且二氧化鈦能被回收再利用。 其中光照之時間主要依據金屬離子與有機添加劑的化 學組成或是光能量強度而定，若照射光為陽光，照射時間 約為30-300分鐘。。 廢液的水溶液中含有溶解的污染物及金屬離子，該廢 液被送入氧化室（C)以進行氧化反應，在此時加入適當的矯 正化學劑（remediation chemistry)，適當的橋正化學劑係指 可同時使有機物氧化並使金屬還原的矯正化學劑，其包含 但不受限於僅使用半導體粒子之光催化劑，或與其它傳統 或新賴的方法結合使用臭氧、過氧化氫與直接性光催化劑。 此含有端正化學劑的水溶液接受陽光或紫外光的照射，使 得有機化合物氧化成惰性物質及過氧化氫分解，此時溶液 中含有惰性的有機金屬化合物質，被送往還原室（E)，在此 還原室（E)中再一次進行紫外光或陽光的曝曬以進行還原作 11 1227216 用’以有利於金屬離子，也就是銅離子沈澱至光催化劑的 表面。為使反應完全，含有惰性水溶液及覆蓋金屬的粒子 的研磨漿送入一分離室（F)。 在分離室（F)中，覆蓋金屬的光催化劑粒子（10)會自水 溶液中被分離並作為其它利用，而剩餘的水（2〇)則被送回 設備中再利用。 原理說明： 使用二氧化鈦作為光催化劑的方法可以單獨使用，或 與其匕添加臭氧、過氧化氫或生物程序的高階氧化程序 (advanced oxidization processes)結合使用，或者與傳統 的廢棄物處理程序結合使用。在氧化過程中，少量的光催 化劑可選擇性加入拋光前研磨漿中或拋光後廢液令，其目 的在於光催化性地破壞有機污染物，包括有界面活性劑、 螯合劑、低介電常數K值的殘留物和氧化劑，其中半導體 粒子可在添加其它氧化劑或螯合劑於研磨漿前，被單獨混 入研磨漿中❹，其存在並不會影響晶圓研磨的移除率與 靜態敍刻率。此步驟之優點在於利用已存在的氧化劑（如過 氧化氫及過硫化物），並同時摧毀所有有機污染物。 在分離程序中，有研磨作用的粒子（如二氧化石夕、二氧 化飾、鑽石、氧仙）會自水溶液中被分離出，使水溶液中 不3有金屬及有機染物，因此可以被垃圾填埋。昂貴的 研磨粒子如鑽石和二氧化鈽可被回收。 在還原程序中，金屬離子會轉變成金屬型態，其化學 條件會被控制使得组與銅分離或同時沉積在光催化劑的表 12 1227216 面’與其它金屬成份分離，該金屬覆蓋的粒子可被回收並 使用在各種微電子的應用上，此為_種減少操作成本的可 行性方法。 還原程序中的化學條件為使用一組如前面所述但不受 限與此之特殊性整合劑，而姐的分離程序的可行步驟有很 多種，下列僅列舉兩種，其中之一為利用组與銅兩者的氧 化還原反應潛能差異’當使用一適當的螯合劑如氨基乙酸 或者檸檬酸時，銅離子可在組之前被還原而沉積於二氧化 鈦之表面上，而组溶解於溶液中以離子交換樹脂吸收，在 2進入離子交換樹脂後再加入酸溶液以釋放出姐離子，取 溶液表層物濃縮純化而可回收鈕。 另一種方法為將鈕與銅沉積在二氧化鈦之表面，之後 使用一含有特殊螯合劑的溶液以自二氧化鈦之表面提取 (extract)出銅或鈕，對銅離子的提取而言，螯合劑可以為 風基乙酸或者相近的氨基酸；對组離子的提取而言，整合 劑必須為可靠的種類例如：1,2-二醇（12_d丨〇|s)，間苯二^ (「贿c_s)，w·二醇（1,3__s)^ 3_二胺（1 3_加加叫 聯I定（bipyridyls)及任何可與组有效形成亞胺（imid〇)鍵的 化合物；當一種金屬已被提取後，第二種或剩下的其它金 屬可以用魏處理，其中川濃度_酸被將清洗吸收粒 子。 第種方法的優點在於單純回收銅以作為二氧化鈦表 面的傳導物質，而缺點在於使用離子交換樹脂會增加額外 的處理步驟’第二種方法的優點在於單純回收銅離子溶液， 13 1227216 但針對回收鈕所須的特定螯合劑較貴，會增加操作成本。 在經過上述三步驟後，二價銅離子被還原成金屬並沉積在 光催化粒子表面，同時有機物會被氧化並降解（degrac|ec|)， 顯示處理後的廢水流為銅離子5〇ppb，因此符合排放標準， 此程序可處理高金屬含量研磨漿並產生可排放的水，而有機 物的總量於處理後可降至2〇ppm以下，單獨有機物甚至可 達〇 4ppm以下。 本發明的一項重點在於金屬的回收及再利用，其主要係因 為鋼沉積在二氧化鈦上以形成可導電的粒子，此導電性粒 子可被用於高效電容器上的前導區（丨ead area)中，一般來 說，該前導區的材質多為銀/鈀合金卻有容易造成不協調的 熱膨脹效應的缺點，使用銅金屬覆蓋的二氧化鈦粒子可以 解決此項問題。另一項優點為鈕的再利用，以解決未來鈕 短缺的問題，此項優點的關鍵點在於鈕與銅在沉積時的分 離’藉由選擇性的螯合劑即能完成组與銅的分離，為了要 能在利用鈕，金屬必須被粒子吸收、濃縮及純化，而添加 之螯合劑在廢液排放前須透過另一氧化程序來破壞。 藉由本發明之製法只須在銅-化學機械研磨廢液中添加 光催化劑並接受光照產生光化學反應，即可同時達到去除 鋼離子及有機成份之目的，使得處理製程具有簡單及容易 控制的特點，並能產生有用之導電性粒子沖銷製程方面之 成本，而此法亦未見於同業中使用，因此兼具有新穎性、 實用性及產業利用性之發明專利申請標的，因此具文提出 專利申請。 14 1227216 【圖式簡單說明】 (一） 圖式部份： 第一圖：係本發明之操作設備流程圖。（本圖為代表圖） 第二圖：二氧化鈦之半導體粒子之價帶說明結構圖。 (二） 元件代表符號： (A)處理室 （B)反應室 (C)氧化室 （D)乾燥室 (E)還原室 （F)分離室 (10)覆蓋金屬的粒子 (20)水 151227216 发明 Description of the invention [Technical field to which the invention belongs] The present invention is a photochemical treatment method of copper-chemical mechanical polishing waste liquid, in particular, a photocatalyst is added to the copper-chemical mechanical polishing waste liquid, and the photochemical action is used to make An effective waste liquid treatment method for copper deposition and decomposition of organic pollutants in the copper-chemical mechanical polishing process. [Previous Technology] Chemical Mechanical Polishing (CMP) is an ultra large-scale integration (ULSI) circuit that contains sub-quarter micron metal and electric mass lines. (Dielectric lines) The main planarization technology of silicon devices. In the manufacturing process of conventional silicon wafers, aluminum is mainly used as an interconnect material. Prior to the introduction of copper as an intermediary material, chemical mechanical polishing waste treatment is not an important issue because it contains silicon and fluorine. Contaminants of the compounds are diluted by the water used in other processes and arranged to be sent to an acidic waste neutralization system for treatment. When copper is used as an intermediary material in the process, many post-procedures are targeted. The challenge of waste liquid treatment arises because this copper-chemical mechanical polishing process consumes a lot of resources (polishing slurry, water), and most of them generate solid waste (wafer polishing pads) and waste-containing effluents (Use the remaining slurry). The general copper-chemical mechanical polishing process includes a variety of organic and inorganic pollutants derived from the polishing slurry, equipment cleaning, and subsequent CMP wafer cleaning procedures. Destruction and removal of these pollutants require several controls Factor, 1227216 contains systematic acid-base control and redox chemical reactions. In terms of organic pollutants, the organic components of the waste liquid in the CMP process include metal complexing agents, surfactants, stabilizers and anticorrosives. The stability of these organic components is highly related to the pH of the slurry. As an example, benzotriazol (BTA), which acts as a corrosion inhibitor and a copper removal control agent, can form an acidic water-soluble complex with copper under acidic conditions. However, when the acid-base value increases near the basic state, the complex becomes insoluble, thereby increasing the difficulty of subsequent processing. In addition, dispersants, such as polyacrylic acid, can maintain water solubility between a wide range of pH values. Therefore, adjusting the pH value may not be a method to effectively remove organic pollutants. The solidification of solids in the system Perhaps the mechanism of effective metal removal, however, the addition of organic additives to the polishing slurry will cause the polishing slurry to condense, resulting in difficulties in subsequent processing. Inorganic components such as powders (such as hafnium dioxide, alumina, and silica) in the composition of the grinding slurry often appear insoluble in subsequent processing, and the concentration is about 50-500 ppm. The abrasive particles in the grinding slurry will be dispersed and suspended in the aqueous solution in an oxidized form, and the choice of oxidant (such as hydrogen peroxide and amine hydroxide) can cause the insoluble inorganic components to become soluble. The main inorganic pollutants are removed from the wafer surface, such as metals, oxidized metals, and low-dielectric constant materials. When copper-chemical-mechanical polishing processes are used, copper metal close to 1 micron is removed from the wafer surface. For every 200-mm wafer diameter, there are 0 restrictions on gold. The materials consumed by the material are also inorganic and organic materials that also need to be processed. The general procedure will be 1227216 and processed by a multi-step processing system. For each ingredient, this processing procedure is not only complicated, but also ineffective due to many control factors (acidity, alkalinity, chemical nature, etc.). [Summary of the Invention] In view of the difficulties and inefficiency of current copper-chemical-mechanical grinding waste treatment, the present inventors particularly provide a photochemical copper-chemical-mechanical grinding waste liquid treatment method to achieve rapid and effective treatment, removal The purpose of the invention is to remove and recover metallic copper or other useful substances in copper-chemical mechanical grinding waste liquid. The main purpose of the present invention is to provide a wastewater treatment program in a copper-chemical mechanical polishing process, which can add copper catalysts and receive ultraviolet radiation to convert copper ions into copper elements and deposit them in light. On the surface of the catalyst particles, photochemical decomposition is performed to eliminate major organic pollutants at the same time, and finally a clean wastewater stream is produced to meet environmental standards. Another object of the present invention is that after the post-treatment wastewater effluent undergoes recovery and further processing procedures, copper-coated conductive particles that can be applied to microelectronics are generated to increase waste availability and reduce overall program costs. In order to achieve the foregoing object of the present invention, the technical means used in the present invention is to provide a photochemical treatment method of copper-chemical mechanical polishing waste liquid, wherein the waste liquid contains copper ions and organic compounds, and the process steps are as follows: A photocatalyst is added to the liquid; and the waste liquid is irradiated with light, so that copper ions are deposited on the surface of the photocatalyst to generate copper-coated particles, and the organic compounds are photoly decomposed. 1227216 In the present invention, by adding a photocatalyst and receiving the energy of light irradiation, steel ions are transferred into copper elements and deposited on the surface of the photocatalyst particles, and photochemical decomposition is generated to eliminate organic pollutants at the same time, so as to remove metal ions in the waste liquid And organic pollutants. [Embodiment] The present invention is a copper-chemical mechanical polishing waste liquid photochemical treatment method, which comprises: adding a photocatalyst to a copper and organic compound-containing waste liquid; exposing the waste liquid to UV light or sunlight to make Copper ions are completely deposited on the surface of the photocatalyst to produce copper-covered particles and completely decompose the organic compounds. Through the above steps, copper ions in the waste liquid can be removed and harmful organic compounds can be destroyed, and clean water can be recycled back to the equipment. In addition, copper-coated particles can be reused in various microelectronic applications to offset the cost of operations. Further to the first figure, the complete operation flow of the photochemical treatment method of the copper-chemical mechanical polishing waste liquid of the present invention is explained in detail. When the waste liquid is recovered from the equipment and sent to a processing chamber, some photocatalysts are added at this time, and then the solid particles are separated from soluble pollutants and water. The photocatalyst can be zinc oxide (Zn〇), Zinc sulfide (ZnS), barium titanium oxide (BaTi〇3), titanium zinc oxide (ZnTi03), titanium iron oxide (FeTi03), iron oxide (Fe2O3), titanium dioxide (but 〇2), a metal oxide with a bancj gap and a band position similar to that of titanium dioxide. Taking titanium dioxide as an example, under the conversion of solar energy, titanium dioxide can be used in the photoreduction and photooxidation reactions of various organic compounds, and the photoreduction reaction of metals (silver, gold, 1227216 copper, silver, handle, etc.). It is widely used because it can generate multi-functional oxidation and reduction fixed-point and thus can generate high-efficiency reaction and degradation processes. The principle is that because of the characteristics of semiconductor particles, they are generally expressed in the electrically populated valance band. ) And a large vacant conduction band, the energy gap determines the wavelength of the absorbed light required to excite the semiconductor particle, as shown in the second figure, which shows a titanium dioxide semiconductor The valence band structure of particles. When ultraviolet radiation with a wavelength below 400 nm is irradiated to ultrafine titanium dioxide, the electrons on the electron positioning valence band are excited by the energy of ultraviolet rays and jump to the conduction band. At this time, they will form on the surface of semiconductor particles. 1. electron-electron pair hole "ecombination pairs), so there are two reaction sites (electrons and holes), the use of holes due to the lack of positivity of the electrons and the ability to reduce the electrons alone, so it can simultaneously perform contact with the material Oxidation and reduction reactions. Semiconductor particle materials used as photocatalysts can generally be divided into three types according to their ability to decompose water. One is oxidized or oxidized (0_type) semiconductor particles, such as tungsten oxide or ferric oxide. Its oxidized particulate powder is sufficient to oxidize water but cannot reduce water. The other is reduced or reduced (R-type) semiconductor particles, such as silicon carbide and cadmium selenide, which can reduce water but cannot oxidize water. Finally One is redox-type semiconductor particles, which can provide both oxidation and reduction capabilities, such as titanium dioxide (Ti〇2), oxide (Zn〇), zinc sulfide (ZnS), barium titanium oxide (BaTi 〇3), trioxide 1227216 titanium zinc oxide (ZnTi〇3), titanium iron oxide (FeT 丨 · 〇3), iron oxide (ρ: ~ 〇3) and others have the same dioxygen Titanium has similar properties to the metal oxides of the band gap and band position of valence electrons. The same is the case of titanium dioxide, which can simultaneously oxidize when it controls the recombination of electrons and electron holes. And reduce the contact with the material, so as to achieve the oxidation and reduction functions required in the invention. Then, the solid particles containing slightly water and photocatalyst are sent to the reaction chamber (B), where the ultraviolet radiation is exposed for about 10%. -1 00 minutes to promote the decomposition of hydrogen peroxide (the oxidant originally used in the CMP process) or organic matter slightly attached to the surface of the particles, and the treated particles are sent to a drying chamber (D) for further removal Water and other trace organic substances, and titanium dioxide can be recycled. The time of light irradiation is mainly determined by the chemical composition of metal ions and organic additives or the intensity of light energy. If the light is sunlight, the exposure time is about 30-300 minutes. . The aqueous solution of the waste liquid contains dissolved pollutants and metal ions. The waste liquid is sent to the oxidation chamber (C) for the oxidation reaction. At this time, an appropriate remediation chemistry and an appropriate bridge chemical are added. Refers to corrective chemical agents that can simultaneously oxidize organics and reduce metals, including but not limited to photocatalysts using only semiconductor particles, or combining ozone, hydrogen peroxide, and directness with other traditional or new methods catalyst of light. The aqueous solution containing the orthodox chemical agent is irradiated by sunlight or ultraviolet light, so that the organic compounds are oxidized to inert substances and decomposed by hydrogen peroxide. At this time, the solution contains inert organometallic compounds and is sent to the reduction chamber (E). This reduction chamber (E) is exposed to ultraviolet light or sunlight again for reduction. 11 1227216 is used to facilitate the precipitation of metal ions, that is, copper ions to the surface of the photocatalyst. To complete the reaction, a slurry containing an inert aqueous solution and metal-coated particles is sent to a separation chamber (F). In the separation chamber (F), the metal-coated photocatalyst particles (10) are separated from the aqueous solution and used for other purposes, and the remaining water (20) is returned to the equipment for reuse. Principle description: The method using titanium dioxide as a photocatalyst can be used alone or in combination with its advanced oxidization processes, such as adding ozone, hydrogen peroxide, or biological processes, or in combination with traditional waste treatment processes. During the oxidation process, a small amount of photocatalyst can be selectively added to the polishing slurry before polishing or the waste liquid after polishing. The purpose is to photocatalytically destroy organic pollutants, including surfactants, chelating agents, and low dielectric constant. Residues and oxidants of K value, in which semiconductor particles can be separately mixed into the polishing slurry before adding other oxidants or chelating agents to the polishing slurry. Its presence will not affect the removal rate and static etch rate of wafer polishing. . This step has the advantage of using existing oxidants (such as hydrogen peroxide and persulfides) and destroying all organic pollutants simultaneously. In the separation process, particles with abrasive effects (such as stone dioxide, dioxide decoration, diamonds, and oxen) will be separated from the aqueous solution, so that there are no metal and organic dyes in the aqueous solution, so it can be filled with garbage. Buried. Expensive abrasive particles such as diamonds and hafnium dioxide can be recycled. During the reduction process, the metal ions will be converted into a metal form, and their chemical conditions will be controlled so that the group is separated from copper or deposited on the photocatalyst's surface 12 1227216 'separately from other metal components. The metal-covered particles can be Recycling and use in various microelectronics applications is a feasible method to reduce operating costs. The chemical conditions in the reduction procedure are the use of a set of specific integrators as described above, but not limited to this. There are many possible steps in the separation procedure of the sister, only two are listed below, one of which is the utilization group Potential difference between redox reaction with copper 'When using a suitable chelating agent such as aminoacetic acid or citric acid, copper ions can be reduced and deposited on the surface of titanium dioxide before the group, and the group is dissolved in solution to ionize The exchange resin absorbs. After entering the ion exchange resin, the acid solution is added to release the sister ions. The surface layer of the solution is concentrated and purified to recover the button. Another method is to deposit buttons and copper on the surface of titanium dioxide, and then use a solution containing a special chelating agent to extract copper or buttons from the surface of titanium dioxide. For the extraction of copper ions, the chelating agent can be a wind Glycolic acid or similar amino acids; for the extraction of group ions, the integrator must be a reliable type such as: 1,2-diol (12_d 丨 〇 | s), m-phenylene ^ ("brief c_s), w · Diols (1,3__s) ^ 3_ diamines (1 3_ plus is called bipyridyls) and any compound that can effectively form an imid bond with the group; when a metal has been extracted, The second or remaining other metals can be treated with Wei, where the Chuan concentration_acid will be washed to absorb the particles. The advantage of the first method is that copper is simply recovered as a conductive material on the surface of titanium dioxide, and the disadvantage is that the use of ion exchange resin will Adding additional processing steps' The second method has the advantage of simply recovering the copper ion solution, 13 1227216, but the specific chelating agent required for the recovery button is more expensive and will increase the operating cost. After the above three steps, the divalent copper The ions are reduced to metal and deposited on the surface of the photocatalytic particles. At the same time, the organic matter will be oxidized and degraded (degrac | ec |). It shows that the treated wastewater stream is copper ion 50ppb, so it meets the discharge standard. This program can handle high The metal content grinds the slurry and produces dischargeable water, and the total amount of organic matter can be reduced to less than 20 ppm after treatment, and the organic matter alone can even be less than 0. 4 ppm. An important point of the present invention is the recovery and reuse of metals. It is mainly because steel is deposited on titanium dioxide to form conductive particles. This conductive particle can be used in the lead area of high-efficiency capacitors. Generally, the material of the lead area is mostly silver / However, palladium alloys have the disadvantage of easily causing inconsistent thermal expansion effects. The use of copper metal-coated titanium dioxide particles can solve this problem. Another advantage is the reuse of buttons to solve the problem of future button shortages. The key to this advantage The point is that the button and copper are separated at the time of deposition. The selective chelating agent can complete the separation of the group and copper. In order to use the button, the metal Must be absorbed, concentrated and purified by particles, and the added chelating agent must be destroyed by another oxidation process before the waste liquid is discharged. By the method of the present invention, it is only necessary to add a photocatalyst to the copper-chemical mechanical grinding waste liquid and generate light. The photochemical reaction can simultaneously achieve the purpose of removing steel ions and organic components, making the processing process simple and easy to control, and can generate useful conductive particles to offset the cost of the process, and this method has not been seen in the industry The use of the invention patent application subject that has both novelty, practicability and industrial applicability, so the patent application has been filed. 14 1227216 [Simplified description of the drawings] (a) Schematic part: The first picture: the book Flow chart of the operating device of the invention. (This picture is a representative picture) Second picture: Structure diagram of valence band of semiconductor particles of titanium dioxide. (2) Symbols of components: (A) processing chamber (B) reaction chamber (C) oxidation chamber (D) drying chamber (E) reduction chamber (F) separation chamber (10) metal-covered particles (20) water 15