1272158 (1) 玖、發明說明 【發明所屬技術領域】 本發明有關一種包含無泡沬樹脂材料之拋光墊，以及 藉著使用此一墊子之拋光方法。 【先前技術】 由具有不同物理特性之不同材料製成之拋光墊業已用 於諸如半導體基板及磁片基板等電子裝置表面之所謂平坦 化拋光。泡沬氨基甲酸乙酯墊一般業已用於半導體裝置之 化學機械拋光（CMP )，因爲內側具有氣泡之泡沬墊具有 某些優點，諸如其收進由該拋光表面內側所刮除微粒、諸 如內部形成之水泡之能力。然而，由諸如泡沬氨基甲酸乙 酯之泡沬材料製成之墊子具有某些缺點，諸如難以控制該 厚度及提供一均勻之硏磨表面及未能執行一極細之拋光工 作。 【發明內容】 因此本發明之一般目的係提供一種無此由泡沬材料製 成墊子所共有缺點之拋光墊，且因此更佳適用於該細緻拋 光。 本發明之另一目的是提供一種使用此一拋光墊以施行 改良之拋光工作之方法。 本發明係基於本發明家之發現’即由無泡沫材料所製 成及具有某些物理特性之拋光墊能達成上面及其他目的。 -6 - (2) 1272158 特別地是，一具體化本發明之拋光墊特徵可爲實質上包含 一無泡沬樹脂材料，諸如無泡沬丙烯酸樹脂、氨基甲酸乙 酯及聚酯，及具有於0.1·10微米、或最好0.5-1·5微米範 圍中之表面粗糙度Ra，且厚度中之變動少於30微米、或 最好少於1 〇微米。藉著由泡沬材料所製成之墊子 '諸如 先前技藝之泡沫氨基甲酸乙酯墊通常未能滿足此條件。當 藉著指定方法測量時，根據本發明之一較佳具體實施例之 拋光墊之進一步特徵可爲具有大於60度之蕭氏（shore) D級硬度、少於百分之3之壓縮性及大於百分之30之彈 性。 該墊子之拋光表面可設有溝槽，此溝槽係形成超過該 拋光表面之總面積之百分之30至百分之70，或最好百分 之40至百分之60。 如此，本發明拋光墊之特徵爲能以一習知方式使用， 即壓抵住一欲拋光之目標表面及造成相對該目標表面移動 ，舉例來說，藉著一習知種類之拋光機。可進行一習知種 類之所謂修整製程，以恢復該拋光表面之最初狀態。在一 具體化本發明之方法中所進行修整製程之特徵爲該拋光表 面在該修整製程之後之表面粗糙度Ra係再次於0.1-10微 米、或最好0.5-1.5微米之範圍中。 【實施方式】 根據本發明可用於諸如半導體基板等半導體裝置及磁 片基板之細緻拋光之拋光墊特徵爲首先其係由諸如無泡沬 -7- (3) 1272158 丙烯酸樹脂、氨基甲酸乙酯及聚酯之無泡沫樹脂材料所製 成，且其次具有於0.1-10微米、或最好0.5-1.5微米範圍 中之表面粗糙度Ra，及厚度中之變動少於30微米、或最 好少於1 0微米之一拋光表面。 可藉著使用一拋光製程用之旋轉式皮帶、藉著一端面 加工製程或藉著使用一鑽石砂輪機製備具有此範圍中之表 面粗糙度之拋光墊。可藉著一硏磨製程產生具有此厚度一 致性之拋光墊。此墊子係有利的，因爲最初不須使它們遭 受一所謂之修整製程即能開始使用，該修整製程是一種用 於調整拋光墊之拋光表面之製程，舉例來說，藉著移去阻 塞該拋光表面之微粒。此製程通常係費時的。 對於一由泡沬材料所製成之拋光墊，氣泡之尺寸及位 置係不一致，且某些氣泡係在該拋光表面，通至外部。如 此，該表面粗糙度通常係遠較大，且其遠較難以控制其一 致性。換言之’依據本發明之無泡沬材料所製成之拋光墊 係更佳適用於需要一較高精確程度之裝置表面之細緻拋光 〇 使用無泡沬材料之另一優點係該無泡沬材料比泡沬材 料大致上具有一更佳之導熱性，因爲泡沬材料內側具有氣 泡’且空氣係一不佳之導熱體。當拋光墊係用於拋光一目 標表面時將產生熱，且雖然可藉著提升溫度改善化學機械 拋光之速率’需要一嚴格之溫度控制以減少拋光速率中之 變動。表1顯示一項實驗結果，用於比較相同材料及相同 1 · 0公分厚度之泡沬及無泡沬墊子之導熱性。於此實驗中 -8 - (4) 1272158 ’這些拋光墊係放在〜維持於攝氏5 5度之平板上，並以 5为—之間隔測里在其頂部表面之溫度變化。表1淸楚地 顯示一由無泡沬材料所製成之墊子具有一遠較高之導熱性 ’且因此係更佳適用於化學物理拋光中之溫度控制。 表1 加熱時間（分鐘） 無泡样墊之表面溫度（攝氏度） 泡沬墊之表面溫度（攝氏度） 0 23.8 23.8 5 28.9 27.5 10 31.5 29.2 15 31.7 29.5 20 33.7 30.2 25 34.7 30.4 30 37.9 29.2 35 42.5 36.5 40 43.2 37.0 45 43.9 37.3 由一、泡、沫材料所製成之拋光墊在該拋光表上具有氣泡 開孔’且因此硏磨微粒可儲存於它們中。用由無泡沬材料 所製成之拋光墊即無此狀況。如此，假如欲拋光之目標表 面係不平、即具有突出部份及凹口，用無泡沬墊子之拋光 處S能迅速地進行，但該處理在該目標表面變平之後慢下 $ °於形成在一電路佈線上之氧化物層之化學機械拋光中 • 9 - (5) 1272158 ，當該氧化物層係已平坦化時停止該製程，但其通常繼續 該拋光操作，直至該整個表面已平坦化。既然具有無泡沬 墊子之拋光操作在已平坦化部份變得較慢，該氧化物層之 厚度係減少，以便減少該化學機械拋光上之負荷。假如該 墊子係太軟，該處理變成太依靠該佈路圖案。爲了克服此 問題，其較佳的是該墊子之蕭氏D級硬度係大於60度， 且最好大於百分之68。 以壓縮性及彈性方面而言，本發明之無泡沬墊子之特 徵可爲具有少於百分之3、或最好少於百分之1之壓縮性 ，及大於百分之30、或最好大於百分之50之彈性。該壓 縮性及彈性係由一合適尺寸之樣品所獲得之値，這是藉著 當以80公克之最初負載壓縮該樣品時測量其厚度T〇，再 者加上一額外之負載達5分鐘之久及隨後測量其厚度h ，移去該全部負載880公克及此後使其遭受骸最初負載 80公克達30秒之久以再次測量其厚度TV。該壓縮性係 計算爲100 ( To-Ti ) /TG及該壓縮彈性係計算爲 100 ( τη ) / ( Τ0-Τι )。 該拋光表面可設有不只用於收集拋光離開微粒、同時 也用於均勻地穩定該泥漿流動及分佈壓力之溝槽。然而， 假如該拋光表面形成溝槽部份之比率太大，與欲拋光目標 表面之接觸面積可變成不足’且不利地影響拋光效率。此 比率較好係百分之30至百分之70，及更好係百分之40-60 〇 如上述之拋光墊可結合一習知種類之拋光機一起使用 •10· (6) 1272158 ’使得其拋光表面係壓抵住欲拋光之目標表面及造成相對 該目標表面移動。壓縮抵住該目標表面欲拋光之及係造成 移動關於該目標表面。在一拋光墊之拋光表面之狀態已因 使用而充分惡化之後，其已熟悉譬如藉著移去阻塞該拋光 表面之微粒更新該墊子。使該拋光表面之回復其最初狀態 之製程，舉例來說，藉著使用一拋光用之鑽石整修器係以 各種名稱稱爲一*修整製程、一整修製程或一變質製程。此 一製程亦可包含當作根據本發明方法之一部份。具體彳匕本 發明之方法中之修整製程特徵爲一由無泡沬材料所製成之 拋光墊表面在遭受此一修整製程之後具有於〇·Κι〇微米 、或最好0·5-1.5微米範圍中之表面粗糙度Ra。1272158 (1) Description of the Invention [Technical Field] The present invention relates to a polishing pad comprising a non-foaming resin material, and a polishing method by using the same. [Prior Art] Polishing pads made of different materials having different physical properties have been used for so-called flat polishing of electronic device surfaces such as semiconductor substrates and magnetic sheet substrates. Buffered urethane mats have generally been used for chemical mechanical polishing (CMP) of semiconductor devices because the bubble pad having bubbles inside has certain advantages, such as its ingestion of particles scraped from the inside of the polishing surface, such as the interior. The ability to form blisters. However, mats made of a foam material such as styrene urethane have certain disadvantages such as difficulty in controlling the thickness and providing a uniform honing surface and failing to perform a very fine polishing operation. SUMMARY OF THE INVENTION It is therefore a general object of the present invention to provide a polishing pad that does not have the disadvantages inherent in making a mat from a foam material, and is therefore better suited for such fine polishing. Another object of the present invention is to provide a method of using such a polishing pad to perform an improved polishing operation. The present invention achieves the above and other objects based on the findings of the present invention, i.e., a polishing pad made of a non-foaming material and having certain physical properties. -6 - (2) 1272158 In particular, a polishing pad characterized by the present invention may comprise substantially a non-foamed resin material such as a non-foamed acrylic resin, urethane, and polyester, and The surface roughness Ra in the range of 0.1·10 μm, or preferably 0.5-1·5 μm, and variations in thickness are less than 30 μm, or preferably less than 1 μm. A mat made of a foam material, such as a foamed urethane mat of the prior art, generally fails to satisfy this condition. A polishing pad according to a preferred embodiment of the present invention may further have a Shore D hardness of greater than 60 degrees and a compressibility of less than 3 percent when measured by a specified method. More than 30 percent flexibility. The polishing surface of the mat may be provided with grooves that form from 30 to 70 percent, or preferably from 40 to 60 percent, of the total area of the polishing surface. Thus, the polishing pad of the present invention is characterized in that it can be used in a conventional manner, i.e., against a target surface to be polished and caused to move relative to the target surface, for example, by a conventional polishing machine. A conventional sorting process can be performed to restore the original state of the polished surface. The finishing process performed in a method of the present invention is characterized in that the surface roughness Ra of the polishing surface after the finishing process is again in the range of 0.1 to 10 μm, or preferably 0.5 to 1.5 μm. [Embodiment] A polishing pad which can be used for fine polishing of a semiconductor device such as a semiconductor substrate and a magnetic sheet substrate according to the present invention is characterized in that it is firstly made of, for example, a non-foaming -7-(3) 1272158 acrylic resin, urethane, and a non-foamed resin material of polyester, and secondly having a surface roughness Ra in the range of 0.1 to 10 μm, or preferably 0.5 to 1.5 μm, and a variation in thickness of less than 30 μm, or preferably less than One of 10 micron polished surfaces. A polishing pad having a surface roughness in this range can be prepared by using a rotary belt for a polishing process, by a one-end machining process, or by using a diamond grinder. A polishing pad having such a thickness can be produced by a honing process. This mat is advantageous because it can be used initially without having to undergo a so-called trimming process, which is a process for adjusting the polishing surface of the polishing pad, for example, by removing the blockage. Particles on the surface. This process is usually time consuming. For a polishing pad made of a foam material, the size and position of the bubbles are inconsistent, and some bubbles are attached to the polishing surface to the outside. As such, the surface roughness is generally much larger and it is much more difficult to control its consistency. In other words, the polishing pad made of the foam-free material according to the present invention is more suitable for fine polishing of the surface of the device requiring a higher degree of precision. Another advantage of using the bubble-free material is the ratio of the material without foam. The foam material generally has a better thermal conductivity because the inner side of the foam material has a bubble and the air is a poor thermal conductor. Heat is generated when the polishing pad is used to polish a target surface, and although the rate of chemical mechanical polishing can be improved by raising the temperature, a strict temperature control is required to reduce variations in polishing rate. Table 1 shows the results of an experiment for comparing the thermal conductivity of the same material and the same 1 / 0 cm thickness of the foam and non-bubble mat. In this experiment -8 - (4) 1272158 'These polishing pads were placed on a plate maintained at 55 degrees Celsius and measured at a temperature of 5 Å on the top surface thereof. Table 1 shows that a mat made of a non-foaming material has a much higher thermal conductivity' and is therefore better suited for temperature control in chemical and physical polishing. Table 1 Heating time (minutes) Surface temperature of the bubble-free pad (degrees Celsius) Surface temperature of the bubble pad (degrees Celsius) 0 23.8 23.8 5 28.9 27.5 10 31.5 29.2 15 31.7 29.5 20 33.7 30.2 25 34.7 30.4 30 37.9 29.2 35 42.5 36.5 40 43.2 37.0 45 43.9 37.3 A polishing pad made of a foaming or foaming material has a bubble opening on the polishing table and thus the honing particles can be stored in them. This is not the case with polishing pads made of a non-foaming material. Thus, if the target surface to be polished is uneven, that is, has a protruding portion and a notch, the polishing portion S with the bubble-free mat can be quickly performed, but the treatment is slowed down by a distance of $ ° after the target surface is flattened. In chemical mechanical polishing of an oxide layer on a circuit trace • 9 - (5) 1272158, the process is stopped when the oxide layer has been flattened, but it typically continues the polishing operation until the entire surface is flat Chemical. Since the polishing operation with the bubble-free mat becomes slower in the flattened portion, the thickness of the oxide layer is reduced to reduce the load on the chemical mechanical polishing. If the mat is too soft, the treatment becomes too dependent on the layout pattern. To overcome this problem, it is preferred that the mat has a Class D hardness of greater than 60 degrees, and preferably greater than 68 percent. The foam-free mattress of the present invention may be characterized by a compressibility and elasticity of less than 3 percent, or preferably less than 1 percent, and greater than 30 percent, or most Better than 50% flexibility. The compressibility and elasticity are obtained from a sample of a suitable size by measuring the thickness T〇 when the sample is compressed at an initial load of 80 grams, plus an additional load of 5 minutes. The thickness h was measured for a long time and then, the entire load was removed by 880 g and thereafter subjected to an initial load of 80 g for 30 seconds to measure the thickness TV again. The compressibility is calculated as 100 ( To-Ti ) /TG and the compressive elasticity is calculated as 100 ( τη ) / ( Τ0-Τι ). The polishing surface can be provided with grooves that are not only used to collect polishing away particles, but also to uniformly stabilize the mud flow and distribute pressure. However, if the ratio of the groove portion formed by the polishing surface is too large, the contact area with the target surface to be polished may become insufficient & adversely affect the polishing efficiency. The ratio is preferably from 30 to 70 percent, and more preferably from 40 to 60 percent. The polishing pad as described above can be used in conjunction with a conventional polishing machine. • 10· (6) 1272158 ' The polishing surface is pressed against the target surface to be polished and caused to move relative to the target surface. Compression against the surface of the target to be polished causes the movement to be related to the target surface. After the state of the polishing surface of a polishing pad has deteriorated sufficiently due to use, it has been familiar with, for example, renewing the mat by removing particles that block the polishing surface. The process of returning the polished surface to its original state, for example, by using a polishing diamond finisher, is referred to by various names as a *finishing process, a finishing process, or a metamorphic process. This process may also be included as part of the method according to the invention. Specifically, the finishing process in the method of the present invention is characterized in that the surface of the polishing pad made of the non-foaming material has a thickness of 〇·Κι〇 micron, or preferably 0·5-1.5 micron, after being subjected to the finishing process. Surface roughness Ra in the range.