1379734 - 九、發明說明-: - 【發明所屬之技術領域】 . 本發明係有關用於化學機械平坦化（CMP)的研磨墊， 且詳而言之，㈣熟有窗σ形成於其中㈣於實施 終點偵測的研磨墊。 【先前技術】 在積體電路及其他電子裝置的製造中，多層的導電 性’半導電性及介電性材料層係沉積在半導體晶圓的表面 上或從半導體晶圓表面移除。導電性，半導電性及介電性 材料薄層可能由多種沉積技術來沉積。現今製程中普遍的 沉積技術包括物理氣相沉積法(PVD)，亦即所謂的賤鑛 (sputtering) ’化學氣相沉積法（CVD)，電漿增進化學氣相 沉積（PECVD)，及電化學電鑛（ECp)。 隨著數層的材料依序地沉積及移除，基板的最上層表 面可能會跨越其表面變得不平坦而需要平坦化處理。將表 .面平坦化，或研磨”表面，是一種從晶圓表面移除材料以 形成概括地均勾、平坦的表面的製程。平坦化技術係用來 移除不需要的表面拓樸形態（t〇p〇graphy)及表面缺陷，例如 粗糙的表面，黏聚的材料，晶格破壞，刮痕，以及污染的 層或材料。平坦化技術也可用來經由將用於填充特徵 (feature)的過多沉積材料移除以在基板上形成特徵並提供 平坦的表面供後續金屬塗敷和製程階段所用。 化學機械平坦化，，或化學機械研磨（CMp)，是一種普 遍使用於將基板例如半導體晶圓平坦化之技術9在習用的 5 93551 1379734 .CMP中’係將晶圓載具或研磨頭（head)裝置在載具裝配件 -上且經配置成與在CMP·設備中的研磨墊接觸。該载具裝 ’配件提供可控制的壓力至基板而驅策晶圓壓抵住該研磨 墊。該研磨墊係藉由外加的驅動力而與基板相對移動（例 如，轉動）。與此同時地，使化學組成物（“磨漿，，）或其他流 體介質流動於該基板上及於該晶圓與研磨墊之間。如此， 該晶圓表面被研磨墊表面及磨漿的化學及機械作用以從基 板表面選擇性地移除材料之方式所研磨。 籲 於平坦化晶圓時所遭遇的問題為要知曉何時終止該 製程。為達此目的，已經發展出多種平坦化終點偵測方案。 一種此等方案涉及晶圓表面的光學原位（in_situ)測量。該光 學技術包括在研磨墊上裝設可讓選擇波長的光透射之窗 口。將光束導引通過該窗口到晶圓表面，在該處光束被反 射並往回通過該窗口到達偵測器，例如，干涉計。基於回 傳的訊號’晶圓表面的性質，例如在其上之薄膜（例如，氧 •化層）的厚度，即可被測定。 —雖然有許多用於研磨墊窗口的材料類型可供使用，不 過實際上該窗！2典型地是使用與研磨墊相㈣材料所製 成，例如，聚胺基曱酸醋。例如，美國專利帛6,28〇,29〇 號揭露一種具有聚胺基甲酸酯栓形式的窗口之研磨墊。該 研磨墊具有孔而該窗口是以黏著劑固定在該孔中。 當窗口具有表面粗糖時，此等窗口產生了問題。例 如·，聚胺基甲酸醋窗口典型地藉由從聚胺基甲酸醋塊切出 一片所形成。遺憾地，該切斷製程會在研磨墊1〇中的窗口 93551 6 1379734 .1之任一側上產生表面的不完整或粗糙度R，如圖〗中所 '示。粗糙度的深度範圍為從約1 〇到約100微米（micron)。 •在底部表面的粗糙度會使該用於測量晶圓表面拓樸型態的 光散射，由此減少原位光學測量系統的訊號強度。因為液 •體磨漿的存在以及上表面對於晶圓的接近，上表面的粗糙 度對光的散射不傾向於與底表面粗糙度的散射一樣多。 因為由下窗口表面散射造成訊號強度的損失，故會損 及測量解析度，且測量變異性也是一項問題。因此，所需 要的是具有較大的光透射度和較低的光散射性質之改良窗 口的用於化學機械平坦化的研磨墊。 【發明内容】 與於本發明一方面中，提供一種用於實施半導體基板化 學機械平坦化的研磨墊，該研磨墊包括：研磨墊體，其具 有形成於其中的小孔（aPerture);窗口，其經固定在小孔中 以用於實施該基板的原位光學測量，該窗口具有下表面能 鲁°接收入射於其上的光，且其中該下表面係經雷射燒钱處 理過以移除存在於下表面上的表面粗糙度。 於本發明的另一方面中，提供一種用於化學機械平坦 化的研磨墊’該研磨墊包括：研磨墊體，其具有經固定於 其中的窗口以用於實施基板的原位光學測量，該窗口具有 夠將入射於其上的光透射過之下表面；其中該下表面係 經雷射燒蝕處理過以移除存在於該下表面上的表面粗糙 度，且其中該下表面進一步包括經由雷射燒姓所形成的微 透鏡。 93551 7 1379734 於本發明另一方面中，提供一種可用於化學機械平坦 化的研磨墊，該研磨墊包括：研磨墊體，其具有經固定於 其中的窗口以用於實施基板的原位光學測量，該窗口具有 能夠將入射於其上的光透射過之下表面；且其中該下表面 係經雷射燒姓處理過以形成微透鏡。 於本發明另一方面中，提供一種形成用於半導體基板 的化學機械平坦化之研磨墊的方法，該方法包括：提供研 磨塾體’其具有形成於其中的小孔；固定窗口於該小孔中 以用於實施該基板的原位光學測量，該窗 入射於其上的光之下表面；以及經由雷射燒姓處二 面以移除存在於該下表面上的表面粗糙度。 於本發明另一方面中 '丨王川w牡亿学機械平i 化（CMP)f統内實施基板的綠光學測量时法，包括： 於該CMP系統裝設具有窗口的研磨墊，該窗口且有下表 面，該下表㈣經由#射_處理過以移时在於該下名 ;將第一光束導引通過該經雷_ =的表*和“口至該基板；以及從該基板反射該第一 先束傳回通過該窗口和該 經雷射燒蝕處理過的表面。 【實施方式】 發明詳細說明 在下面本發明具體實_的詳細說明中炎 本發明部份的附圖，且其中係 饰>”、、形成 實施本發明的特定具體實施例 農^式顯示出能夠 寺具體貫施例係充分的 93551 1379734 ，詳細描述以使得諳於此技者能夠實施本發明，且應了解.， -其他具體實施例也可利用且可做出改變而不違離本發明範 *圍。所以，下面的詳細說明部份不可視為限制意義，且本 發明範圍僅由後附之申請專利範圍所界定。 參照圖式，第2圖圖解說明研磨墊1〇〇的特寫截面 圖。研磨墊1〇〇具有包括上表面12和下表面14的體區 研磨墊100可為任何已知的研磨墊，例如滲入胺基甲酸酯 的毛氈’微多孔胺基甲酸酯墊（如由R〇hmandHaas • Electronic Materials CMP Inc. (-RHEM»), of Newark,1379734 - IX. INSTRUCTIONS -: - [Technical field to which the invention pertains] The present invention relates to a polishing pad for chemical mechanical planarization (CMP), and in detail, (4) a cooked window σ is formed therein (d) A polishing pad that performs endpoint detection. [Prior Art] In the fabrication of integrated circuits and other electronic devices, multiple layers of conductive 'semiconducting and dielectric materials are deposited on or removed from the surface of the semiconductor wafer. Thin layers of conductive, semi-conductive, and dielectric materials may be deposited by a variety of deposition techniques. Common deposition techniques in today's processes include physical vapor deposition (PVD), the so-called sputtering 'chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), and electrochemistry. Electric mine (ECp). As several layers of material are sequentially deposited and removed, the uppermost surface of the substrate may become uneven across its surface and require planarization. Flattening the surface of the surface, or grinding the surface, is a process of removing material from the surface of the wafer to form a generally uniform, flat surface. The planarization technique is used to remove unwanted surface topography ( And surface defects such as rough surfaces, cohesive materials, lattice damage, scratches, and contaminated layers or materials. Flattening techniques can also be used to pass through features that will be used to fill features. Excessive deposition material removal to form features on the substrate and provide a flat surface for subsequent metal coating and processing stages. Chemical mechanical planarization, or chemical mechanical polishing (CMp), is a common use for substrates such as semiconductor crystals. The technique of circular planarization 9 is in the conventional 5 93551 1379734 . CMP 'to place a wafer carrier or a head on a carrier assembly - and is configured to contact a polishing pad in a CMP apparatus. The carrier assembly provides a controllable pressure to the substrate to urge the wafer against the polishing pad. The polishing pad is moved relative to the substrate (eg, rotated) by an applied driving force. Simultaneously, so that the chemical composition ( ",, refiner), or other fluid medium flows on the substrate and between the wafer and the polishing pad. Thus, the wafer surface is ground by the chemical and mechanical action of the surface of the polishing pad and the refining to selectively remove material from the surface of the substrate. The problem with calling for flattening wafers is to know when to terminate the process. To this end, a variety of flattening endpoint detection schemes have been developed. One such scheme involves optical in-situ measurements of the wafer surface. The optical technique involves the installation of a window on the polishing pad that allows transmission of light of a selected wavelength. A beam of light is directed through the window to the surface of the wafer where it is reflected and passed back through the window to a detector, such as an interferometer. Based on the nature of the back-to-back signal 'wafer surface, such as the thickness of the film (e.g., oxygen layer) thereon, it can be determined. - Although there are many types of materials available for the polishing pad window, the window is actually! 2 Typically, it is formed using a material of the polishing pad phase (IV), for example, a polyamine phthalic acid vinegar. For example, U.S. Patent No. 6,28,29, discloses a polishing pad having a window in the form of a polyurethane plug. The polishing pad has a hole and the window is secured in the hole with an adhesive. These windows create problems when the window has surface coarse sugar. For example, a polyurethane screen is typically formed by cutting a piece from a polyurethane block. Unfortunately, the cutting process produces surface incompleteness or roughness R on either side of the window 93551 6 1379734 .1 in the polishing pad 1 ,, as shown in the figure. The depth of the roughness ranges from about 1 〇 to about 100 microns (micron). • The roughness on the bottom surface causes the light to be used to measure the topography of the wafer surface, thereby reducing the signal strength of the in-situ optical measurement system. Because of the presence of liquid refining and the proximity of the upper surface to the wafer, the roughness of the upper surface does not tend to scatter light as much as the scattering of the bottom surface roughness. Since the loss of signal strength due to scattering from the lower window surface damages the measurement resolution, and measurement variability is also a problem. Accordingly, what is needed is a polishing pad for chemical mechanical planarization of an improved window having greater light transmission and lower light scattering properties. SUMMARY OF THE INVENTION In one aspect of the invention, a polishing pad for performing chemical mechanical planarization of a semiconductor substrate is provided, the polishing pad comprising: a polishing pad body having an aperture formed therein; a window, It is fixed in an aperture for performing in-situ optical measurement of the substrate, the window having a lower surface capable of receiving light incident thereon, and wherein the lower surface is processed by laser burnt Except for the surface roughness present on the lower surface. In another aspect of the invention, there is provided a polishing pad for chemical mechanical planarization comprising: a polishing pad body having a window secured therein for performing in situ optical measurement of the substrate, The window has a surface sufficient to transmit light incident thereon to the lower surface; wherein the lower surface is laser ablated to remove surface roughness present on the lower surface, and wherein the lower surface further comprises via The microlens formed by the laser burning surname. 93551 7 1379734 In another aspect of the invention, there is provided a polishing pad usable for chemical mechanical planarization, the polishing pad comprising: a polishing pad body having a window secured therein for performing in situ optical measurement of the substrate The window has a surface capable of transmitting light incident thereon over the underlying surface; and wherein the lower surface is processed by a laser to form a microlens. In another aspect of the invention, a method of forming a polishing pad for chemical mechanical planarization of a semiconductor substrate, the method comprising: providing a polishing cartridge having an aperture formed therein; securing a window to the aperture In-situ optical measurement for performing the substrate, the window is incident on the lower surface of the light thereon; and the surface roughness is removed by laser burning to remove the surface roughness present on the lower surface. In another aspect of the present invention, a method for performing a green optical measurement of a substrate in a CMP 川 川 , , , , , , , , , , , CMP CMP CMP CMP CMP CMP CMP 绿 绿And having a lower surface, the following table (four) is processed by #射_ to move the time in the lower name; the first light beam is guided through the Ray_= table* and "mouth to the substrate; and reflected from the substrate The first first beam is transmitted back through the window and the laser ablated surface. [Embodiment] The invention is described in detail below in the detailed description of the invention, and The details of the specific embodiment of the present invention are shown in the form of a specific embodiment of the present invention. 93551 1379734, which is described in detail, so that the skilled person can implement the present invention, and It is to be understood that other specific embodiments may be utilized and changes may be made without departing from the scope of the invention. Therefore, the following detailed description is not to be considered as limiting, and the scope of the invention is defined by the scope of the appended claims. Referring to the drawings, Fig. 2 illustrates a close-up cross-sectional view of the polishing pad 1〇〇. The polishing pad 1A having a body region including the upper surface 12 and the lower surface 14 can be any known polishing pad, such as a felt-microporous urethane pad that is infiltrated with a urethane (eg, R〇hmandHaas • Electronic Materials CMP Inc. (-RHEM»), of Newark,
Delaware在商品名稱P〇UTEX下所出售的類型），或經填 充及/或發泡過的複合胺基甲酸酯例如也是由RHEM所製、 造的1C-系列和MH-系列的墊。 研磨墊100也包括於該體U中的小孔18，其具有固 定在其中的窗口 30。於示範具體實施例中，窗口 3〇係永 久地固定（“整合型窗口，，)在小孔中，而於另一示範具體實 籲施例中，其係以可取出的方式固定於該小孔中。窗口 ％ 具有包括上表面32和下表面34的體區31。窗口 3〇對於 在平坦化過程中用於實施基板（例如，晶圓w)的光學原位 測里所用的光的波長係具有透射性。範例波長範圍為介於 190 至 3500 奈米（nanometer)之間。 窗口 30是由可在其一或更多表面上具有粗糙度以第 1圖中）之任何材料（例如，聚合物如聚胺基甲酸酯，丙烯酸 系聚合物’聚碳酸酯’尼龍（nylon)，聚酯，等）所製成。當 實施原位終點測量時，粗糙度R能夠散射明顯量（例如， 9 93551 丄：> /y/:)4 10°/〇或更多）的入射於其上的光。 二上面所討論的’粗缝度R是從用於形成窗口的儀器 (>又有顯示出)經由自較大塊的窗口材料裁切出窗口時產生 :^過’粗糙度R可從任何數目的其他來源而產生，例 ^有的材料祕度，不研磨該窗口材料’不適當地研磨 固口材料，等。 繼續參照第2圖 I Η "、今、奴％不鞄具體實施例中，窗口 匕括在下表面34上經雷射燒則咖卜咖如⑽)處理過的 束53 I ♦換句話說下表面34是以來自雷射51的雷射光 ^3所處理以移除存在於下表面％上的表面祕度，例 f先賴提的裁切製程之後。因此，存在第丨圖中的 X R的減少德由將表面_度R進行微機削 maChining)下降到成為相對地平坦之下表面34。於 較大數量的光會穿透窗口 ％，促成用於在精細 確j㈣平坦化製程中的更強終點偵測訊號和更大的精 =和正確性。再者，雷射的輸出強度可因窗口 30的較大 2性質而減少，因而延長雷射的壽命。要特別提及，上 ^生質2也可用雷射燒鱗理以進—步增強窗口 3G的光透 要特別提及’雷射51可以在任何方向（亦即X、y或 中"，面）移動以料視需要的乡種設計或組態。在本發明 子，1可支撐構件（沒有顯示出），例如，支撐研磨墊的桌 例如不1要相對於雷射51移動。反而，可移動雷射51以， 1與支稽構件的任何移動不相關地.達到所欲的表面粗 10 93551 1379734 糙度R之移除。此外，可從噴嘴（沒有顯示出）提供惰性氣 體以減少在裁切表面的氧氣，減少裁切表面邊緣上的灼燒 和焦化。再者，可將該雷射光束與高愿水刀結合使用來減 少可能由習用雷射裁切製程產生的熱。 於本發明具體實施例中’用於微機削的雷射5ι可為 具有相當低的工作週期（duty cycle)之脈衝準分子雷射。'視 而要地’雷射51可為有光栅（shuttered)(亦即，脈衝寬度（時 間）與脈衝之間的時間相比係非常小者）的連續雷射。^例 雷射為得自Exit吨Ine.的Mi要特別提及， 即使準分子f射與其他較大的雷射相比具有低的平均功 率，準分子雷射的尖蜂功率也可能為相當大。該雷射 峰強度和積分通量（fluenee)係由下面公式所給予： 強度（瓦/平方公分）=尖每功率（瓦)/焦點面積（平方公 分） 積V通篁（焦耳/平方公分）=雷射脈衝能量 點面積（平方公分） “，、斗）… 同時尖峰功率為 尖峰功率（瓦卜脈衝能量（焦耳）/脈衝持續時間（秒） 在雷射:^姓的過程中’有數項關鍵參數應該要被考 慮施-項重要的參數是具有最小吸收深度之波長的選擇。 =該促成在小體積内的高能量沉積以達到快速且完全的 燒。另一項參數是短脈衝持續時間以最大化 最小化對周圍工作材料的熱傳導。此等組 振幅。另一項參數為脈衝重複率。如果該重複率太Π 93551 11 丄： 2燒㈣能量將㈣開燒純域而促成冷卻。如果經由 稷羊可使剩餘的熱保留，因此限制用於傳導 能量朝_且更===外，會有更多的入射 „ 此里抽失到周圍工作材料和環境中。 遲有另-項重要的參數是光束品質 f.聚焦能力，和均勻性予以量度。光束能量如果=(lb 確而有效地龍至独區域，㈣能量就讀不為有用。 再者’如果光束不具有受控制的大小，職純域可能會 大於所欲者且在侧壁中有過大的坡度。 此外，如果歸係以蒸發進行時，必須㈣注意羽狀 物(plume)。羽狀物係一種漿狀物質，係由分子碎片，中性 粒子，自由電子和離子，及化學反應產物所組成。該羽狀 物會促成入射光束的光吸收和散射且可能凝結於周圍工作 材料及/或光束輸送光學H件之上。通常，齡部位是以加 壓的惰性氣體予以清潔，例如用氮氣或氬氣。 • 要特別提及，下表面34不需完全地平坦。例如，下 表面34可具有緩慢地變異的表面曲率，其不會散射光，而 僅於小角度反射光。這是因為經雷射燒蝕處理過的表面5〇 係經設計來消除光的散射之故，光的散射為在光學原位偵 測系統中的訊號衰減之主要肇因。 現在要參照第3圖，於本發明另一項具體實施例中， 於窗口 301裝設一陣列的微透鏡5。微透鏡5可如上面所 纣論經由使用雷射51以雷射燒餘處理窗口 3〇ι(或其部份) 而形成。較佳地係使用光-雷射燒蝕。不過，也可利用熱_ 93551 12 1379734 ，射燒蝕。此等透鏡5可將來自原位光學測量系統的光束 氱…、並増強，以促成更強的用於較佳終點偵測的訊號。微 透鏡5可按尺十製作以最佳化或增強來自雷射Μ的光束 53較佳地，微透鏡5係介於5微米（#m)至2〇〇微米的寬 度。更佳地，微透鏡5係介於1〇微米至1〇〇微米的寬度。 視需要地，微透鏡5可配合雷射燒蝕製程形成以移除粗糙 度R如針對弟2圖所討論的。此外，如在前面的具體實 施例中，雷射的輸出強度可能由因窗口 3〇的更大透射性質 而減低，因而延長雷射的壽命。 、 現在參照第4圖，於此要說明本發明對具有要測量的 表面62之晶圓W實施原位光學測量之操作。於操作中， 系由光源71產生第一光束7〇且將其導引到晶圓表面。 第光束70具有可由窗口 30和雷射燒蝕處理過的表面5〇 兩者透射過的波長。 光束70經由通過雷射燒钱處理過的表面5〇，彳 口下表面34，窗口體部位3卜窗口上表面％，和介於^ 表面32和晶圓表面62之間的間隙G而到達晶圓表面6: 間隙G是由磨漿68(沒有顯示出）所佔據，其於實際上係 為折射率匹配（index_matching)流體以減低從窗口上表面 上的粗糙度R (第1圖）之光散射。第一光束70,或更· 言之：其—部份會從晶圓表面62反射。曰曰曰圓表面62於【 式中係示意地顯示出。實際上，晶圓表面62由於不同的: 臈(例如’氧化物塗覆)而呈現出在晶圓上的表面拓樸型笔 或一個或多個介面。 93551 13 1379734 第一光束70從晶圓表面的反射形成沿著第一光 方向導㈣的第二光束72。於示範具體實施例中， =，面62包括由存在於其上的一層或多層不同薄膜所 致之夕重介面’使得反射出的第二光束72 所致之干涉資訊。 射 在從晶圓表面62反射之後，第二光束72通過間隙g (办包括存在其中的磨漿)，並通過窗口上表面32,窗口體31， 窗:下表面34,且最後通過經雷射燒蝕處理過的表面5〇。 值得注意的是從每個介面的反射，包括在晶圓上的彼等反 射，因為從晶圓表面62的逆反射，而變成兩倍。換句話說， 光除了實際的晶圓表面本身之外，通過每一介面兩次。 ♦ 在離開該經雷射燒蝕處理過的表面50之後，光束72 係由偵測器80所偵測。於示範具體實施例中，使用分光鏡 (沒有顯示出）來分開第一和第二光束7〇和72。偵測器別 接著轉換所偵測的光為電訊號g〗，其接著由電腦82處理 _來取得晶圓W性質的相關資訊，例如，薄膜厚度，表面平 面性’表面平坦度（flatness)，等。 因為窗口 30包括經雷射燒蝕處理過的表面5〇，由在 窗口下表面上的粗糙度尺之散射所致之光損失可大幅地縮 減。此導致較大於其他可能的訊號強度。較佳地，該雷射 燒蝕處理過的表面50所致之第二光束72可在訊號強度上 提供高達3倍的增進。 此等訊號強度上的增進可導致在晶圓表面參數的原 位光學測量上有顯著的改良。特別者，.可靠度和測量準確 14 93551 1379734 度都可改善H因為較強的訊號使得其他訊號損失來 •源較不·顯著而使墊的壽命得以延長。以不同方式言之，從 .粗縫度R散射的減少促成其他的散射來源，例如研磨過程 中增加的窗口上表面粗縫度，以及增加的來自平坦化製程 的碎片量，都變得較大而不需要更換塾或窗口。 【圖式簡單說明】 第1圖說明習用的研磨墊’其伴隨具有表面粗糖度的 明具有減低的表面喊度的窗口之 第3圖說明本發明具有微透鏡形成於其中之窗口之 另一具體實施例之截面圖；以及 第4圖說明⑽线之截面圖，其十顯示本發明」 有命口之研磨墊，該窗口具有經雷射燒蝕處理：> 接於該研磨墊上表面配置的晶圓、以及原 ^ 的基本元件。 祀予偵測糸彳 【主要元件符號說明】 1 窗口 5 微透鏡 10 研磨墊 11 體區. 12, 32 上表面 14, 34 下表面 18 小孔 93551 15 1379734 30, 301 窗口 31 體區 50 雷射燒蝕處理過的表面 51 雷射 53 雷射束 62 晶圓表面 70 第一光束 71 光源 72 第二光束 80 偵測器 81 電訊號 82 電腦 100 研磨墊 G 間隙 R 粗糙度 W 晶圓 16 93551The type sold under the trade name P〇UTEX by Delaware, or the filled and/or foamed complex urethane is, for example, a 1C-series and a MH-series pad made by RHEM. The polishing pad 100 also includes an aperture 18 in the body U having a window 30 secured therein. In the exemplary embodiment, the window 3 is permanently fixed ("integrated window") in the aperture, and in another exemplary embodiment, it is removably secured to the small In the hole, the window % has a body region 31 including an upper surface 32 and a lower surface 34. The window 3 波长 wavelength of light used for optical in-situ measurement of a substrate (eg, wafer w) during planarization The system is transmissive. The exemplary wavelength range is between 190 and 3500 nanometers. Window 30 is any material that can have roughness on one or more of its surfaces (see Figure 1) (for example, A polymer such as a polyurethane, an acrylic polymer 'polycarbonate' nylon, polyester, etc.). When performing an in situ endpoint measurement, the roughness R can scatter a significant amount (eg , 9 93551 丄:> /y/:)4 10°/〇 or more) of the light incident on it. 2. The 'roughness R' discussed above is from the instrument used to form the window (> It is also shown that when the window is cut out from a larger block of window material: ^ over ' Roughness R can be produced from any number of other sources, such as the materiality of the material, does not grind the window material 'inappropriately grinds the fixed material, etc.. Continue to refer to Figure 2 Η ", now, slave % In the specific embodiment, the window is included in the beam 53 I processed on the lower surface 34 by laser firing (10). ♦ In other words, the lower surface 34 is laser light from the laser 51. The treatment is performed to remove the surface secretity present on the lower surface %, for example, after the cutting process of the first drawing. Therefore, there is a reduction in the XR in the second figure by micro-machining the surface _ degree R. Drops to a relatively flat lower surface 34. A larger amount of light will penetrate the window %, resulting in a stronger endpoint detection signal and greater precision and correctness for use in a fine-grained (four) planarization process Furthermore, the output intensity of the laser can be reduced due to the larger 2 properties of the window 30, thereby extending the life of the laser. It is particularly mentioned that the upper biomass 2 can also be enhanced by laser firing. The light penetration of the window 3G should be specifically mentioned 'Laser 51 can be in any direction (ie X , y or medium ", face) movement to materialize the desired design or configuration. In the present invention, a supportable member (not shown), for example, a table supporting the polishing pad, for example, is not The laser 51 moves. Instead, the movable laser 51 is unrelated to any movement of the bearing member. The desired surface thickness is 10 93551 1379734. The removal of the roughness R. In addition, it can be removed from the nozzle (not shown) Provides an inert gas to reduce oxygen on the cut surface and reduce burning and coking on the edge of the cut surface. Furthermore, the laser beam can be used in conjunction with a high water knife to reduce the possibility of laser cutting by conventional lasers. The heat generated by the cutting process. In a particular embodiment of the invention, the laser 5 for laser cutting may be a pulsed excimer laser having a relatively low duty cycle. The 'destination' laser 51 can be a continuous laser having a shuttered (i.e., a pulse width (time) is very small compared to the time between pulses). ^ Example lasers are specifically mentioned for Mi from Exit Toe. Even if the excimer f-shoot has a lower average power than other larger lasers, the excimer laser tip power may be equivalent. Big. The intensity and fluence of the laser peak are given by the following formula: Strength (Watts per square centimeter) = Tip per power (Watts) / Focus area (Units cm) Product V Wanted (Joules per square centimeter) = laser pulse energy point area (square centimeter) ",, bucket"... At the same time, the peak power is the peak power (wab pulse energy (Joule) / pulse duration (seconds) in the course of laser: ^ surname 'there are several items The key parameters should be considered. The important parameter is the choice of the wavelength with the smallest absorption depth. = This contributes to the high energy deposition in a small volume to achieve a fast and complete burn. Another parameter is the short pulse duration. To maximize the minimization of heat transfer to the surrounding working material. These sets of amplitude. Another parameter is the pulse repetition rate. If the repetition rate is too high 93551 11 丄: 2 burn (4) energy will (4) burn pure domain and contribute to cooling. If the remaining heat is retained by the ram, so the limit is used to conduct energy towards _ and more ===, there will be more incidents „ lost to the surrounding working materials and environment. weight The required parameters are the beam quality f. Focusing ability, and uniformity. If the beam energy = (lb is effective and effective, the dragon is not alone, (4) energy reading is not useful. Again, if the beam does not have a controlled size The pure field may be larger than the desired one and have an excessive slope in the side wall. In addition, if the system is carried out by evaporation, it is necessary to pay attention to the plume. The plume is a pulpy substance. Consisting of molecular fragments, neutral particles, free electrons and ions, and chemical reaction products that contribute to the absorption and scattering of light from the incident beam and may condense on the surrounding working material and/or the optical delivery optical H Typically, the aged portion is cleaned with a pressurized inert gas, such as with nitrogen or argon. • It is specifically mentioned that the lower surface 34 need not be completely flat. For example, the lower surface 34 may have a slowly varying surface curvature. It does not scatter light, but only reflects light at a small angle. This is because the surface treated by laser ablation is designed to eliminate the scattering of light, and the scattering of light is in optical in situ. The main cause of signal attenuation in the measurement system. Referring now to Figure 3, in another embodiment of the invention, an array of microlenses 5 is mounted in window 301. Microlens 5 can be as discussed above It is formed by using a laser to process the window 3 〇 (or a portion thereof) by using a laser. Preferably, light-laser ablation is used. However, heat _ 93551 12 1379734 can also be used for ablation. These lenses 5 can illuminate the beam from the in-situ optical measurement system and reluctantly to promote a stronger signal for better endpoint detection. The microlens 5 can be sized to optimize or enhance The light beam 53 from the laser beam preferably has a width of 5 micrometers (#m) to 2 micrometers. More preferably, the microlens 5 is between 1 micrometer and 1 micrometer. width. Optionally, the microlens 5 can be formed in conjunction with a laser ablation process to remove the roughness R as discussed for Figure 2. Moreover, as in the previous specific embodiment, the output intensity of the laser may be reduced by the greater transmission properties of the window 3, thereby extending the life of the laser. Referring now to Figure 4, the operation of the present invention for in situ optical measurement of a wafer W having a surface 62 to be measured will be described herein. In operation, the first beam 7 is generated by the source 71 and directed to the wafer surface. The first beam 70 has a wavelength that can be transmitted by both the window 30 and the laser ablated surface 5〇. The light beam 70 reaches the crystal via the surface 5〇 processed by the laser burnt, the lower surface 34 of the mouth, the upper surface of the window body portion 3, and the gap G between the surface 32 and the wafer surface 62. Round surface 6: The gap G is occupied by the refining 68 (not shown), which is actually an index-matching fluid to reduce the roughness R (Fig. 1) from the upper surface of the window. scattering. The first beam 70, or moreover, is partially reflected from the wafer surface 62. The rounded surface 62 is schematically shown in the formula. In effect, wafer surface 62 presents a surface topographic pen or one or more interfaces on the wafer due to different: 臈 (e.g., <RTI ID=0.0> 93551 13 1379734 The first beam 70 reflects from the surface of the wafer to form a second beam 72 along the first light direction (four). In the exemplary embodiment, =, face 62 includes interference information caused by the reflected second beam 72 by the one or more layers of different films present thereon. After being reflected from the wafer surface 62, the second beam 72 passes through the gap g (including the refining present therein) and passes through the window upper surface 32, the window body 31, the window: the lower surface 34, and finally passes through the laser The ablated surface was 5 〇. It is worth noting that the reflection from each interface, including their reflection on the wafer, becomes twice as large as the retroreflection from the wafer surface 62. In other words, the light passes through each interface twice, in addition to the actual wafer surface itself. ♦ After exiting the laser ablated surface 50, the beam 72 is detected by the detector 80. In the exemplary embodiment, a beam splitter (not shown) is used to separate the first and second beams 7 and 72. The detector then converts the detected light to an electrical signal g, which is then processed by the computer 82 to obtain information about the properties of the wafer W, such as film thickness, surface planarity, and flatness. Wait. Since the window 30 includes the surface 5〇 which has been subjected to laser ablation, the light loss caused by the scattering of the roughness ruler on the lower surface of the window can be greatly reduced. This results in a larger than other possible signal strengths. Preferably, the second ablation 72 of the laser ablated surface 50 provides up to a three-fold increase in signal strength. This increase in signal strength can result in significant improvements in the in situ optical measurement of wafer surface parameters. In particular, reliability and measurement accuracy 14 93551 1379734 degrees can improve H because stronger signals cause other signals to be lost. • The source is less significant and the life of the pad is prolonged. In a different way, the reduction in R-scatter from the slit degree contributes to other sources of scattering, such as the increased surface seam on the window during the grinding process, and the increased amount of debris from the flattening process, which becomes larger. There is no need to replace the cymbal or window. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view showing a conventional polishing pad which is accompanied by a window having a surface roughness and a surface having a reduced surface scream. FIG. 3 is a view showing another specific embodiment of the present invention having a window in which microlenses are formed. A cross-sectional view of the embodiment; and a fourth section illustrating a cross-sectional view of the line (10), wherein the ten shows the polishing pad of the present invention having a polished ablation process: > attached to the upper surface of the polishing pad Wafer, and the basic components of the original ^.祀 糸彳 糸彳 [Main component symbol description] 1 Window 5 Microlens 10 Abrasive pad 11 Body area. 12, 32 Upper surface 14, 34 Lower surface 18 Small hole 93551 15 1379734 30, 301 Window 31 Body area 50 Laser Ablation treated surface 51 Laser 53 Laser beam 62 Wafer surface 70 First beam 71 Light source 72 Second beam 80 Detector 81 Telecommunications 82 Computer 100 Grinding pad G Gap R Roughness W Wafer 16 93551