五、發明説明（ 本發月有關於-種半導體製程。具體而言，本發明有關 於種半導體製程之研磨結束最佳化之系統和方法。 目則，淺溝隔離以及内層介電處理法包括各種達成不同 、的:y驟在貫施化學機械研磨平坦化的製程後，研磨 、、’口束的條件對晶圓表面最後的缺陷數目極為重要。在實施 過淺溝隔離，内層介電處理及化學機械研磨平坦化的程序 里⑽上品要二種條件來使晶圓表面殘留有研磨聚或 形成凹:同及刮痕。首先，晶圓表面需具有膠質的微粒。這 些微粒為晶圓表面之殘留微粒的來源，並且這些微粒會造 成竑結，微刮痕以及二氧化物的凹洞。第二，需要高的物 理外力（下壓力）或速度來克服膠體（研磨微粒）與晶圓表面間 的月b卩早。電斥力以及凡得瓦力共同形成晶圓表面及膠體間 的月b障。第三，在高酸鹼值的系統中.，低的酸鹼值會降低 膠體微粒間的電斥力並使晶圓表面以及膠體微粒間的能障 更易於克服。一旦能障被克服，理論上會發生三種破壞性 的現象。第一，膠體微粒開始產生凝塊。第二，膠體微粒 及/或其凝塊附著於晶圓的表面。第三，大的膠體微粒凝塊 在晶圓表面上形成刮痕及凹洞，但不附著於晶圓表面。 目則’淺溝隔離以及内層介電處理法包括各種達成不同 目的的步驟。在實施化學機械砑磨平坦化的製程後，研磨 結束的條件對晶圓表面最後的缺陷度極為重要。 半V·體領域的專家皆知晶圓最後的缺陷度決定半導體的V. Description of the Invention (This month is about a semiconductor process. Specifically, the present invention relates to a system and method for optimizing the polishing end of a semiconductor process. The shallow trench isolation and inner dielectric treatment methods include Various conditions are achieved: After the chemical mechanical polishing and flattening process is carried out, the conditions of polishing, and beam bundles are extremely important for the final number of defects on the wafer surface. After shallow trench isolation has been implemented, the dielectric treatment of the inner layer In the process of chemical mechanical polishing and flattening, two conditions are required for the top product to make the surface of the wafer remain abrasive or concave: the same and scratches. First, the wafer surface must have colloidal particles. These particles are the wafer surface The source of residual particles, and these particles will cause knots, micro scratches and pits of dioxide. Second, a high physical external force (downforce) or speed is required to overcome the colloid (abrasive particles) and the wafer surface The early month b is too early. The electric repulsion and van der Waals force together form a monthly b barrier between the wafer surface and the colloid. Third, in high pH systems, low pH will decrease The repulsive force between the colloidal particles makes the energy barrier between the wafer surface and the colloidal particles easier to overcome. Once the energy barrier is overcome, three destructive phenomena can theoretically occur. First, the colloidal particles begin to form clots. Second Colloidal particles and / or its clots are attached to the surface of the wafer. Third, large colloidal particle clots form scratches and pits on the wafer surface, but are not attached to the surface of the wafer. Isolation and inner dielectric treatment methods include various steps to achieve different purposes. After the chemical mechanical honing and flattening process is performed, the conditions of the end of the polishing are extremely important for the final defect on the wafer surface. Experts in the semi-V and bulk fields Knowing the final defect of the wafer determines the semiconductor
本纸張尺度適用中國國家標準(CNS) A4規格(210X 297公釐) 569333 A7 B7 五、發明説明（2 ) 製程良率。 因此，需要一種方法以在結束研磨程序中減少缺陷數 目，其從晶圓的環境中移除膠狀粒子，並藉由將研磨結束 程序的酸鹼值以及下壓力最佳化，而降低微粒及晶圓表面 間能障破壞的風險。 以下將揭露本發明人的上述及其他目的。 發明概要 本發明有關一種系統及方法，其中在研磨半導體晶圓 時，使晶圓與高酸鹼值的研磨漿接觸，接著在高壓下以高 酸鹼值溶液噴灑研磨墊，而從研磨墊及晶圓表面清除研磨 漿，最後再以去離子水噴灑研磨墊以進一步洗淨晶圓，藉 ： 此便可減少半導體晶圓的缺陷數。此外，當以高酸鹼值溶 液進行沖洗時，最好施以低的下壓力以使半導體晶圓偏斜 地抵靠研磨墊。 以下的描述可使相關的目的及優點更易於瞭解。 圖式簡單說明 發明以例子及伴隨的圖示來加以說明，且不作範圍上的 限制，其中類似的參考標號表示類似的元件。 圖1顯示化學機械研磨機的方塊圖。 圖2顯示半導體晶圓的部分立體側視圖。 圖3-4顯示在研磨結束週期内，目前之化學機械研磨機的 部分立體側視圖。 一一 圖5-6顯示在研磨結束週期内，依據本發明之化學機械研 磨機的部分立體側視圖。 _^_ 本紙張尺度適用中國國家標準(CNS) A4規格(210 X 297公釐） 569333 A7This paper size applies to China National Standard (CNS) A4 (210X 297 mm) 569333 A7 B7 V. Description of the invention (2) Process yield. Therefore, there is a need for a method to reduce the number of defects in the end-of-grinding process, which removes colloidal particles from the wafer environment, and reduces particles and particles by optimizing the pH value and downforce of the end-of-grinding process. Risk of energy barrier damage between wafer surfaces. The above and other objects of the present inventors will be disclosed below. SUMMARY OF THE INVENTION The present invention relates to a system and method, in which a wafer is brought into contact with a polishing slurry with a high pH value when a semiconductor wafer is ground, and then the polishing pad is sprayed with a high pH solution under high pressure, and the polishing pad and The polishing slurry is removed from the wafer surface, and then the polishing pad is sprayed with deionized water to further clean the wafer, thereby reducing the number of defects on the semiconductor wafer. In addition, when rinsing with a high pH solution, it is preferable to apply a low down force so that the semiconductor wafer leans against the polishing pad. The following description makes the related purpose and advantages easier to understand. Brief Description of the Drawings The invention will be described with examples and accompanying drawings, without limitation in scope, in which similar reference numerals denote similar elements. Figure 1 shows a block diagram of a chemical mechanical grinder. FIG. 2 shows a partial perspective side view of a semiconductor wafer. Figure 3-4 shows a partial perspective side view of a current chemical mechanical grinder during the grinding end cycle. Fig. 5-6 shows a partial perspective side view of a chemical mechanical grinder according to the present invention during a grinding end period. _ ^ _ This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) 569333 A7
一特定化學機械研磨 圖7顯示依據本發明之較佳實施例， 週期的流程圖，此製程用以減少缺陷。 發明詳細說明 以下將參考由圖示及特定語言所闡述的實施例，來增進 對本發明的瞭解。應知，這些實施例並不限制本發明的範 圍，且熟悉相關技藝之人可思及從本發明的原理所衍生的 變化及改良。 參考圖1及圖2，其中顯示一習知化學機械研磨機1〇〇的 方塊圖，以及晶圓105的側邊部分立體圖（圖2)。化學機械 研磨機100的手臂101載入要研磨的晶圓並將晶圓放置在旋 轉的研磨墊102上。研磨墊1〇2由彈性的材料所製成並具有 以多個預定溝槽所形成的紋理，以助於研磨製程的進行。 調整手臂103調整研磨墊。手臂101將晶圓定位在研磨墊 102上的適當位置。 在研磨的過程中，晶圓105的下表面置靠在研磨塾1〇2 上。當研磨墊102旋轉時，手臂ιοί以預定的速率轉動晶圓 105。手臂1〇1以預定的下壓力將晶圊1〇5壓入研磨塾ι〇2 中。化學機械研磨機100亦包括徑向延伸過研磨塾1〇2的一 研磨漿散佈管1 07。研磨漿散佈管1 〇7將研磨漿1 〇6流體從 研磨漿源112散佈到研磨墊1〇2的表面。研磨漿106為去離 子水與研磨料的混合物，其有助於以化學的方式使晶圓滑 順及平坦化。在使用二氧化矽作為研磨漿的系統中，酸鹼 值相¥南’通常酸驗值約為10或1 1。此外，在研磨過程 中’手臂101將4-5 psi的高下壓力施加在晶圓上。 ___ _-6- 本紙張尺度適用中國國家標準(CNs) A4規格(210X297公釐)A Specific Chemical Mechanical Polishing FIG. 7 shows a cycle flow chart according to a preferred embodiment of the present invention. This process is used to reduce defects. Detailed description of the invention In the following, reference will be made to the embodiments illustrated by the drawings and specific language to enhance the understanding of the present invention. It should be understood that these embodiments do not limit the scope of the present invention, and those skilled in the relevant art can conceive changes and improvements derived from the principles of the present invention. Referring to FIG. 1 and FIG. 2, a block diagram of a conventional CMP machine 100 and a perspective view of a side portion of a wafer 105 are shown (FIG. 2). The arm 101 of the chemical mechanical polishing machine 100 loads a wafer to be polished and places the wafer on a rotating polishing pad 102. The polishing pad 102 is made of an elastic material and has a texture formed by a plurality of predetermined grooves to facilitate the polishing process. The adjustment arm 103 adjusts the polishing pad. The arm 101 positions the wafer in place on the polishing pad 102. During the polishing process, the lower surface of the wafer 105 rests on the polishing pad 102. When the polishing pad 102 rotates, the arm 105 rotates the wafer 105 at a predetermined rate. The arm 101 presses the crystals 105 into the grinding stones 2 with a predetermined downward force. The CMP machine 100 also includes an abrasive slurry distribution tube 107 extending radially across the grinding surface 102. The polishing slurry distribution tube 107 spreads the slurry 100 fluid from the polishing slurry source 112 to the surface of the polishing pad 102. The polishing slurry 106 is a mixture of deionized water and abrasives, which helps to smooth and planarize the wafer chemically. In a system using silicon dioxide as a slurry, the pH value is usually around 10 or 11. In addition, the 'arm 101 applies a high downforce of 4-5 psi to the wafer during the grinding process. ___ _-6- This paper size applies to Chinese National Standards (CNs) A4 (210X297 mm)
裝 瓢 569333 A7Scoop 569333 A7
研磨塾102及晶圓1〇5的旋轉操作配合研磨聚的研磨作用 便可以預定的操作率進行晶圓的研磨或平坦化。研磨聚的 研磨作用包括研磨料的摩擦成分以及化學成分。研磨料的 摩擦成分係來自於研磨塾表面，水表面以及研磨漿之微粒 間的摩k作用。化學成分則來自於研磨毅與晶圓電介質咬 金屬層間的化學作用。研磨㈣化學成分可心軟化要研 磨的電’丨層’而摩擦成分則從晶圓表面移除材料。The rotation operation of the polishing wafer 102 and the wafer 105 is combined with the polishing action of the polishing wafer, so that the wafer can be polished or planarized at a predetermined operation rate. The abrasive action of the abrasive polymer includes the friction component and chemical composition of the abrasive. The friction component of the abrasive is derived from the friction between the surface of the abrasive pad, the water surface, and the particles of the abrasive slurry. The chemical composition comes from the chemical interaction between the abrasive surface and the dielectric layer of the wafer. The abrasive / chemical component softens the electrical ' layer ' to be ground while the abrasive component removes material from the wafer surface.
在結束研磨聚分佈程序後，將去離子水從去離子水源ιι〇 經由高壓噴嘴1G8噴研料上。可使用美國專利申請第 〇9/871，507號所揭露的高壓噴嘴1〇8。 t 參考圖3，其使用目前的研磨結束方法，其中一旦結束研 磨漿的喷灑，將高酸鹼值的研磨漿與去離子水混合，而形 成-破壞性機制。此外，研磨漿的研磨微粒以及如微粒1〇6 的膠狀物，會黏附於晶圓1 〇 5的表面，研磨墊1 的溝槽 114或纖維中。在目前的研磨墊清洗法中，係以高壓去離子 水130經由高壓噴嘴來清洗研磨墊。在研磨墊清洗步驟中， 晶圓1 0 5漂浮於去離子水上。 在完成研磨墊清洗步驟後，清洗晶圓1〇5 ,此為研磨結束 程序的一部份。參考圖4 ,配合圖3的研磨墊清洗步驟，來 說明目前的研磨結束程序。在目前的研磨結束程序中，以 承載環將下壓力施加至晶圓使:晶.圓置靠在研磨墊上，並持 續地透過高壓噴嘴108喷灑高壓衲去離子水丨3〇。使用此一 程序，仍會有相當多的研磨微粒106黏附在晶圓或研磨墊 102的溝槽114内。如此，當在低酸鹼偯的環境下，若存在 -7- 569333 A7 B7 五、發明説明（5 ) 這些研磨微粒並對晶圓施有下壓力，則會在研磨結束的程 序中產生晶圓的缺陷。 參考圖5-7，顯示一化學機械研磨系統以及研磨結束程序 最佳化的方法，其可減少在半導體晶圓表面成形缺陷的情 形。 當微粒懸浮於液體溶液内時，所有的微粒形成一帶電的 薄層。此電荷稱為zeta勢能，且可為正電荷或負電荷。 Zeta勢能出現於微粒的外表面，而形成包圍微粒的小電 場。在水溶液中的二氧化矽微粒-具有1〇以上的酸鹼值，而 在一氧化石夕的微粒上形成負的zeta勢能。此外，任一其他 U粒以及表面與溶液接觸之微粒的zeta勢能在此高酸驗的 環境下皆為負的。更重要的，表面上的高酸鹼值溶液會避 免二氧化矽微粒克服表面的靜電排斥，並減少凡得瓦引 力。當存在二氧化矽且晶圓表面的酸鹼值降低時，在晶圓 的表面上便出現膠質以及二氧化矽的凝塊。如此，每當晶 圓表面的酸鹼值降低時，微粒的出現便會造成更高的缺陷 度。此外，施加至晶圓的高下壓力會使研磨微粒克服膠體 與晶圓表面間的能障，而形成晶圓的缺陷。產生的缺陷包 括研磨凝塊在晶圓表面所形成的刮痕以及附著於晶圓表面 的研磨微粒。 據此，欲使缺陷減少，在研磨'结束程序中，需從晶圓環 i兄中70全地移除膠質微粒，維捧高酸鹼值，以及將低的下 壓力施加至晶圓（及膠質）。參考圖5 ,圖6及圖7的流程圖， 顯示依據本發明之化學機械研磨系統及製程的特定實施After finishing the grinding and distribution procedure, the deionized water was sprayed from the deionized water source through the high-pressure nozzle 1G8 on the ground material. The high-pressure nozzle 108 disclosed in U.S. Patent Application No. 09 / 871,507 can be used. t Refer to FIG. 3, which uses the current grinding end method, in which, once spraying of the grinding slurry is ended, a high pH alkali slurry is mixed with deionized water to form a destructive mechanism. In addition, the abrasive particles of the polishing slurry and the colloidal material such as particles 106 can adhere to the surface of the wafer 105, the groove 114 of the polishing pad 1, or the fibers. In the current polishing pad cleaning method, the polishing pad is cleaned with a high-pressure deionized water 130 through a high-pressure nozzle. In the polishing pad cleaning step, the wafer 105 floats on deionized water. After the polishing pad cleaning step is completed, the wafer 105 is cleaned, which is part of the polishing end procedure. Referring to FIG. 4 and the polishing pad cleaning step of FIG. 3, the current polishing end procedure will be described. In the current polishing end procedure, a down force is applied to the wafer with a carrier ring so that the crystals are placed against the polishing pad, and high-pressure deionized water is continuously sprayed through the high-pressure nozzle 108. 30. With this procedure, a considerable number of abrasive particles 106 still adhere to the grooves 114 of the wafer or polishing pad 102. In this way, when in a low-acid and alkaline environment, if there is -7- 569333 A7 B7 V. Description of the invention (5) These abrasive particles exert a downward pressure on the wafer, and a wafer will be generated in the process of polishing Defects. Referring to FIGS. 5-7, a chemical mechanical polishing system and a method for optimizing the polishing end procedure are shown, which can reduce the formation of defects on the surface of a semiconductor wafer. When the particles are suspended in a liquid solution, all the particles form a thin, charged layer. This charge is called zeta potential and can be positive or negative. Zeta potential energy appears on the outer surface of the particles and forms a small electric field surrounding the particles. Silicon dioxide particles in an aqueous solution-having a pH value above 10, and a negative zeta potential energy is formed on the particles of the oxide. In addition, the zeta potential of any other U particles and particles in contact with the solution on the surface is negative in this high acid test environment. More importantly, the high pH solution on the surface will prevent the silica particles from overcoming the electrostatic repulsion on the surface and reduce Van der Waals' gravity. When silicon dioxide is present and the pH value of the wafer surface is reduced, colloids and clots of silicon dioxide appear on the surface of the wafer. In this way, whenever the pH value of the surface of the wafer is lowered, the appearance of particles causes a higher degree of defect. In addition, the high downforce applied to the wafer will cause the abrasive particles to overcome the energy barrier between the colloid and the wafer surface, thereby forming wafer defects. Defects include scratches on the wafer surface caused by abrasive clots and abrasive particles attached to the wafer surface. According to this, in order to reduce defects, the colloidal particles need to be completely removed from the wafer ring 70 during the grinding 'end procedure, maintaining a high pH value, and applying low down pressure to the wafer (and Colloid). Referring to the flowcharts of FIGS. 5, 6 and 7, specific implementations of the chemical mechanical polishing system and process according to the present invention are shown.
569333 A7 ________Β7_ 五、發明説明（6 ) 例’其包括研磨結束程序的最佳化，可用以減少缺陷數。 參考圖5及圖7，使用高酸鹼值的研磨漿以及高下壓力來 在平台上研磨晶圓。接著，在步驟31〇中，喷灑高酸鹼值的 高壓溶液，以從研磨墊及晶圓上洗除研磨漿，且以低的下 壓力使晶圓偏斜地壓抵研磨墊。在步驟320中，進一步參考 圖5，本實施例的系統包括具有溝槽214的研磨墊202。研 磨微粒206同樣會黏附於晶圓表面以及研磨墊202的溝槽 2 14内。晶圓承載臂201使半導體晶圓205的表面抵靠研磨 墊202。承載環2 16將一下壓力施加至晶圓205上。施加至 晶圓205的下壓力最好為1-3 pSi。更佳的，在研磨墊及晶 圓的清洗步驟中，施加至晶圓205的下壓力最好為2 psi。 此外’在本發明的系統及方法中，以來自酸鹼調整溶液 源2 12的高壓酸鹼溶液225沖洗研磨墊及晶圓。藉由以高壓 噴嘴208喷灑高酸鹼值的研磨溶液225，來沖洗研磨墊。高 壓喷嘴208以1〇至20 psi的壓力將高酸鹼值溶液225噴至研 磨墊202上。更特定的，高酸鹼值喷液的壓力介於14至18 psi 〇 高酸鹼值溶液直接由閥220導至喷嘴。高酸鹼值溶液可以 是稀釋氨或NH4〇H，且其酸鹼值最好接近研磨漿的酸鹼 值，且最佳地是介於1 0至1 2之間。如此，在沖洗步驟中， 最好使晶圓205及研磨墊202俤持高的酸鹼值，並使晶圓及 研磨‘粒間維持而的界電斥力=5»因此，藉由高酸驗值化學 物質的介電斥力，可從研磨墊及晶圓上沖洗去大部分的研 磨微粒。 __-9- 本紙張尺度適用中國iA4規格(210 X 297公釐) " 569333 A7 B7 五、發明説明（7 ) 並不限於使用上述的閥220，可使用任一種可將高酸鹼值 溶液提供至高壓噴嘴208的方法。例如，可在槽212中裝載 濃縮的高酸鹼值溶液，且當研磨墊需要高酸鹼值溶液時， 可將來自槽2 10及2 12的溶液混合。 參考圖6及圖7，一旦以高酸鹼值溶液沖洗過研磨墊以及 晶圓之後，僅殘留下少量的研磨漿微粒206，此時，將研磨 墊及晶圓的酸鹼值降低。移除研磨微粒之後，再以去離子 水進行沖洗。若需要的話，可利用高壓喷嘴208來噴灑去離 子水230，但並不限制低壓去離子水的使用。圖7步驟 3 30。若需要的話，利用晶圓臂201的承載薄膜2 16來在晶 圓206上維持低的下壓力。 因此，本發明使造成缺陷的研磨劑以及半導體表面間的 淨能障維持在高準位，直到噴洗足以清淨研磨墊及晶圓， 藉此在研磨結束的程序中，減少半導體晶圓的缺陷數目。 僅在從研磨墊移除研磨料之後，才將晶圓的酸鹼值降低。 雖然以藉由圖示及上述的說明來闡述本發明，但須知這 些說明僅為較佳實施例而不具限制性，所有由本發明精神 所做出的改變及改良皆涵蓋於本發明的保護範圍内。 -10- 本紙張尺度適用中國國家標準(CNS) A4規格(210 X 297公釐）569333 A7 ________ Β7_ V. Description of the Invention (6) Example ‘It includes optimization of the end-of-grinding procedure, which can be used to reduce the number of defects. Referring to FIGS. 5 and 7, a wafer having a high pH value and a high downforce is used to grind the wafer. Next, in step 31, a high-pressure solution with a high pH value is sprayed to wash the polishing slurry from the polishing pad and the wafer, and the wafer is pressed obliquely against the polishing pad with a low down pressure. In step 320, referring further to FIG. 5, the system of this embodiment includes a polishing pad 202 having a groove 214. The abrasive particles 206 also adhere to the wafer surface and the grooves 2 14 of the polishing pad 202. The wafer carrying arm 201 abuts the surface of the semiconductor wafer 205 against the polishing pad 202. The carrier ring 2 16 applies a downward pressure to the wafer 205. The down force applied to the wafer 205 is preferably 1-3 pSi. More preferably, in the polishing pad and wafer cleaning steps, the down pressure applied to the wafer 205 is preferably 2 psi. In addition, in the system and method of the present invention, the polishing pad and wafer are rinsed with a high-pressure acid-base solution 225 from the acid-base adjustment solution source 2 12. The polishing pad is rinsed by spraying a high pH polishing solution 225 with a high-pressure nozzle 208. The high-pressure nozzle 208 sprays a high pH solution 225 onto the polishing pad 202 at a pressure of 10 to 20 psi. More specifically, the pressure of the high pH spray is between 14 and 18 psi. The high pH solution is directed from the valve 220 to the nozzle. The high pH value solution can be diluted ammonia or NH4OH, and its pH value is preferably close to the pH value of the grinding slurry, and is most preferably between 10 and 12. In this way, in the washing step, it is better to hold the wafer 205 and the polishing pad 202 at a high pH value, and to maintain the boundary electric repulsion between the wafer and the polishing grains = 5 ». The dielectric repulsive force of the chemical substance can wash away most of the abrasive particles from the polishing pad and wafer. __- 9- This paper size applies to Chinese iA4 specifications (210 X 297 mm) " 569333 A7 B7 V. Description of the invention (7) is not limited to the use of the valve 220 described above, any one can be used for high pH solution The method provided to the high-pressure nozzle 208. For example, the tank 212 may be loaded with a concentrated high pH solution, and when the polishing pad requires a high pH solution, the solutions from tanks 2 10 and 2 12 may be mixed. Referring to FIG. 6 and FIG. 7, once the polishing pad and the wafer are washed with a high pH solution, only a small amount of polishing slurry particles 206 remain. At this time, the pH of the polishing pad and the wafer is reduced. After removing the abrasive particles, rinse with deionized water. If necessary, high-pressure nozzle 208 may be used to spray deionized water 230, but the use of low-pressure deionized water is not limited. Figure 7 steps 3-30. If necessary, the carrier film 2 16 of the wafer arm 201 is used to maintain a low down force on the wafer 206. Therefore, the present invention maintains the high energy level of the polishing agent and the net energy barrier between the semiconductor surfaces until the spray cleaning is sufficient to clean the polishing pad and the wafer, thereby reducing the defects of the semiconductor wafer during the polishing end process number. Only after the abrasive is removed from the polishing pad, the pH of the wafer is reduced. Although the present invention is illustrated by the illustration and the above description, it should be noted that these descriptions are only preferred embodiments and are not restrictive. All changes and improvements made by the spirit of the present invention are covered by the protection scope of the present invention. . -10- This paper size applies to China National Standard (CNS) A4 (210 X 297 mm)