4 3 25 2 6 五、發明說明（f ) 本發明是有關於一種低介電常數（low K)材料層之淸洗 方法’且特別是有關於一種可用來去除光阻之淸洗方法。 J電材料(dielectric material)在VLSI製程裡，通常被 用來作爲兀件中各導體層之間的內介電層（interlayer)。 爲了降低訊號傳遞時間延遲，目前的趨勢是傾向使用較低 介電常數的材料來作爲內介電層。這些低介電常數材料大 部份都含有機的成份在其中，常見的含有機成份之低介電 常數材料包括無機低介電材料(如含CH之 porous dielectric)4 3 25 2 6 V. Description of the invention (f) The present invention relates to a cleaning method of a low dielectric constant (low K) material layer, and in particular to a cleaning method that can be used to remove photoresist. J electrical material (dielectric material) is usually used as an interlayer between conductor layers in a VLSI process. In order to reduce the signal transmission time delay, the current tendency is to use a material with a lower dielectric constant as the internal dielectric layer. Most of these low dielectric constant materials contain organic components. Common low dielectric constant materials containing organic components include inorganic low dielectric materials (such as porous dielectric containing CH).
以及有機聚合物（organic polymer，例如有Flare和SILK 等）。 然而’目前蝕刻製程中，常使用氧（〇2)電漿來剝除光 阻層。氧電漿對於有機低介電常數材料具有侵蝕性。因此， 在進行光阻去除的過程中，往往會對低介電常數材料層造 成傷害，使得低介電常數材料層的輪廓（profile)變形，甚 致造成介電常數的改變。 第1圖是習知利用氧電漿剝除光阻後，含有機成份之 低介電常數材料層在電子顯微鏡（SEM)下之剖面輪廓。如 圖所示，經過氧電漿剝除後，開口側壁的含有機成份之低 介電常數材料層被氧電漿過度侵蝕而形成弓形(bowing)輪 廓。這將影響對後續金屬層塡入，增加製程的困難。 本發明就是在提供一種低介電常數材料的淸洗方法， 可避免在低介電常數材料中造成輪廓變形。 本發明提供一種低介電常數材料層的淸洗方法，利用 乾洗/濕洗/乾洗之淸洗流程，可有效地避免低介電常數材 3 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） (請先閱讀背面之注音？事項再填寫本頁)And organic polymers (for example, Flare and SILK). However, in the current etching process, an oxygen (02) plasma is often used to strip the photoresist layer. Oxygen plasma is aggressive to organic low dielectric constant materials. Therefore, in the process of removing the photoresist, the low-dielectric-constant material layer is often damaged, so that the profile of the low-dielectric-constant material layer is deformed, and even the dielectric constant is changed. The first figure is the cross-section profile of a low dielectric constant material layer containing organic components under the electron microscope (SEM) after the photoresist has been stripped by conventional oxygen plasma. As shown in the figure, after the oxygen plasma is stripped, the low dielectric constant material layer containing organic components on the side wall of the opening is excessively eroded by the oxygen plasma to form a bowing profile. This will affect the penetration of subsequent metal layers and increase the difficulty of the process. The present invention is to provide a scouring method for a low-dielectric-constant material, which can avoid contour deformation in a low-dielectric-constant material. The invention provides a cleaning method for a low dielectric constant material layer, which can effectively avoid low dielectric constant materials by using a dry cleaning / wet cleaning / dry cleaning cleaning process. 3 The paper size is applicable to Chinese National Standard (CNS) A4 specifications 210 X 297 mm) (Please read the phonetic on the back? Matters before filling out this page)
T 經濟部智慧財產局員工消費合作社印製 經濟部智慧財產局員工消費合作社印製 432526 4774t\vf.doc/008 五、發明說明（> ) 料層的輪廓變形。 本發明所提出之低介電常數材料層淸洗方法係先利用 含氮之電漿將大部份的光阻層去除，並使含有機之低介電 常數材料層曝露之表面形成—層氮氧化矽（si〇N)。之後， 利用溶劑將剩餘的光阻層泡軟（swoUen)。最後再利用氧電 漿把光阻層完全地去除。由於進行氧電漿淸洗時，在有機 低介電常數材料層的表面已形成一層薄的氮氧化矽。此氮 氧化矽可保護有機低介電常數材料層不被氧電漿侵蝕。 本發明所提出一種低介電常數材料之淸洗方法包括： 一第一乾洗步驟，一濕洗步驟以及一第二乾洗步驟。第一 乾洗步驟係使用一氮/氫電漿進行淸洗。第二乾洗步驟係 使用一氧電漿進行淸洗。濕洗步驟係利用溶劑進行浸泡。 其中第一乾洗步驟使用之電漿不包含氧。 依照本發明一較佳實施例，本發明所提出一種低介電 常數材料之淸洗方法，用以淸洗低介電材料層之表面，包 括：以一氮電漿去除形成在低介電材料層表面之部份光阻 層’同時轟擊低介電常數材料層暴露出之表面。接著以一 溶劑浸泡殘留之光阻層，使光阻層軟化。再以一氧電漿完 全去除殘留的光阻層。 依照本發明一較佳實施例，本發明所提出一種剝除光 阻層之方法包括：一第一乾洗步驟，一濕洗步驟以及一第 二乾洗步驟。其中第一乾洗步驟係使用一氮/氫電漿進行 淸洗。第二乾洗步驟係使用一含氧電漿進行淸洗。濕洗步 驟係利用水爲溶劑進行浸泡^ 4 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公楚） (請先閱讀背面之注意事項再填寫本頁) 我--------訂----------線* 經濟部智慧財產局員工消費合作社印製 432526 A7 4774t\vf.doc/008 B7 五、發明說明（） 爲讓本發明之上述和其他目的、特徵、和優點能更明 顯易懂，下文特舉一較佳實施例’並配合所附圖式，作詳 細說明如下： 圖式之簡單說明： 第1圖是習知利用氧電漿剝除光阻後’含有機成份之 低介電常數材料層在電子顯微鏡（SEM)下之剖面輪廓圖； 第2圖依照本發明一較佳實施例，一種低介電常數材 料層之淸洗方法之方塊流程圖； 第3A圖到第3D圖是依照本發明一較佳實施例，一 種低介電常數材料層之淸洗流程剖面示意圖；以及 第4圖是利用本發明低介電常數材料層之淸洗方法剝 除光阻後，含有機成份之低介電常數材料層在電子顯微鏡 (SEM)下之剖面輪廓。 圖式之標記說明： 100 :基底 101 :第一乾洗步驟 102 :低介電常數材料層 103 :濕洗步驟 104 :罩幕層 105 :第二乾洗步驟 106、106a :光阻層 108 :氮電漿 110 :氮氧化矽 112 :溶劑 5 (請先閱讀背面之注意事項再填寫本頁) ~ It t— ft— I---訂---------線— 本紙張尺度適用令國國家標準（CNS)A4規格（210 X 297公釐） A7 B7 d32526 4 774twt'.doc/〇〇8 五、發明說明（★) 114 :氧電漿 實施例 本發明係提供-難介電常__淸洗方法，利用 車乙洗/濕洗/乾洗之職流程，可㈣_免低介電常數材 料層的輪廓變形。以下_去除形成在有機低介電常數材 料上之光阻層爲例詳細說明之。 第2圖依照本_—較佳實施例，—種低介電常數材 料層之淸洗方法之方塊流程圖。第3A圖到第3D圖是依 照本發明-雖實肺[|，—種齡電常數材料層之淸洗流 程剖面7K意圖。 請先參照第3A圖，形成在半導體基底1〇〇上爲一低 介電常數材料層102，其中在半導體基底1〇〇中已形成有 部份元件（未繪出），例如電晶體，位元線或是金屬內連線 等。在低介電常數材料層102上有—罩幕層1〇4和一物質 層106。其中低介電常數材料層1〇2典型爲含有機成份之 低介電常數材料，例如是有機聚合物(813(^以&111〇11(1,4]^8, SILK，Flare等）。罩幕層1〇4的材質例如是二氧化矽；物 質層1〇6的材質例如是光阻。通常罩幕層1〇4是用來將光 阻層1〇6上的圖形轉移。此時光阻層1〇6上的圖案已完全 轉移至低介電常數材料層1〇2和罩幕層1〇4上。接上來， 必須將光阻層1〇6剝除，以利後續製程。 請同時參照第2圖和第3B圖，進行第一乾洗步驟101， 以一氮電漿108蝕刻光阻層106,將大部份的光阻層106 剝除。同時氮電漿108轟擊低介電常數材料層102表面曝 本紙張尺度·巾_家標準（CNSM4 x 297公爱） .^1 I Λ n 1 I ^IJOJ Ef K n I I. (請先閲讀背面之注意事項再填寫本頁) 經濟部智慧財產局員工消費合作社印製 經濟部智慧財產局員工消費合作社印製 43 252 6 A7 4UVi d°C/〇〇S_B7___；_ 五、發明說明（f) 露出之部份。其中氮電漿中不可含氧，否則易對低介電常 數材料造成腐蝕。較佳的操作條件例如爲：提供微波功率 約8〇〇_5〇〇瓦；n2/H2(95 : 5)的混合氣體流速控制在爲 1000-4000 seem ;壓力約爲400mtorr-Uorr ;溫度約爲攝氏 50-70 度。 値得注意的，由於低介電常數材料層102之材質爲含 有機成份之低介電質，其組成例如爲含-CH之矽氧化物。 受到氮電漿108轟擊後，會在表面上形成一層薄氮氧化矽 層 110。 接著，請同時參照第2圖和第3C圖，進行濕洗步驟 103，利用溶劑112浸泡殘留的光阻層106a，使光阻層l〇6a 軟化(swollen)。其中溶劑II2例如是水。較佳的操作條件 例如將溫度控製在約爲攝氏70-90度，浸泡約爲30-50分 鐘。 然後，請同時參照第2圖和第3D圖，進行第二乾洗 步驟1〇5，以一氧電漿1H進行轟擊，以完全去除殘留的 光阻層106a。其中氧電漿的操作條件較佳爲：微波功率約 200-400瓦；CF4氣體流速約爲5-15 seem; 02氣體流速約 爲20-150 seem ;壓力約爲400 mtorr-ltorr ;溫度約爲攝氏 5〇-70度。由於低介電常數材料層102之表面已被薄氮氧 化矽層110所覆蓋保護，故此時使用的氧電漿並不會對低 介電常數材料層造成侵蝕，可保持輪廓不會變形。 第4圖是利用本發明低介電常數材料層之淸洗方法剝 除光阻後，有機低介電常數材料層在電子顯微鏡（SEM)下 7 ------------装|---訂---------線- (請先閲讀背面之注意事項再填寫本頁) 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 經濟部智慧財產局員工消費合作社印製 432526 A7 4774t\vl.doc/008 ____B7____ 五、發明說明（乙） 之剖面輪廓。在比較第4圖與第1圖後可看出，利用本發 明確實可得到較佳的低介電常數材料層輪廓，不會在光阻 層剝除的過程中變形。 由上述本發明較佳實施例可知，應用本發明具有下列 特徵。 1·利用乾洗/濕洗/乾洗之淸洗流程，可有效地避免低 介電常數材料層的輪廓變形。 "" 2.本發明所提出之低介電常數材料層淸洗方法係先利 用含氮之電漿將大部份的光阻層去除，並使含有機成丨分之 低介電常數材料層曝露之表面形成一層氮氧化砍（Si〇N)。 之後，利用溶劑將剩餘的光阻層泡軟（sw〇nen)。最後再利 用氧電漿把光阻層完全地去除。由於進行氧電發淸洗時， 在有機低介電常數材料層的表面已形成一層薄的氮氧化 石夕。此氮氧化砂可保護有機低介電常數材料層不被氧電獎 侵触。 本發明所提出一種低介電常數材料之淸洗方法其第一 乾洗步驟使用之電漿不包含氧。 本發明當有其他優點 '目的及特徵，顯示於上文和後 述之專利申請範圍之中，或是在實施本發明的過程中顯示 出來。 雖然本發明已以一較佳實施例揭露如上，然其並非用 以限定本發明，任何熟習此技藝者，在不脫離本發明之精 神和範圍內’當可作各種之更動與潤飾。因此本發明之保 護範圍當視後附之申請專利範圍所界定者爲準。 8 --------------^--------訂---------線- (請先閱讀背面之注意事項再填寫本頁) 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐）T Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 432526 4774t \ vf.doc / 008 5. Description of the invention (>) The contour of the material layer is deformed. The cleaning method of the low dielectric constant material layer proposed by the present invention is to first remove most of the photoresist layer by using a nitrogen-containing plasma, and form an exposed surface of the organic low dielectric constant material layer—layer nitrogen. Silicon oxide (siON). After that, the remaining photoresist layer was softened with a solvent (swoUen). Finally, the photoresist layer is completely removed by using an oxygen plasma. As a result of oxygen plasma cleaning, a thin layer of silicon oxynitride has been formed on the surface of the organic low dielectric constant material layer. This silicon oxynitride can protect the organic low dielectric constant material layer from being attacked by the oxygen plasma. A cleaning method for a low dielectric constant material provided by the present invention includes: a first dry cleaning step, a wet cleaning step, and a second dry cleaning step. The first dry cleaning step was a rinsing using a nitrogen / hydrogen plasma. The second dry cleaning step was rinsing using an oxygen plasma. The wet washing step is a soaking with a solvent. The plasma used in the first dry cleaning step does not contain oxygen. According to a preferred embodiment of the present invention, a cleaning method for a low dielectric constant material provided by the present invention for cleaning the surface of a low dielectric material layer includes: removing a nitrogen dielectric plasma formed on the low dielectric material; A portion of the photoresist layer on the surface of the layer simultaneously bombards the exposed surface of the low dielectric constant material layer. Then, the remaining photoresist layer is soaked with a solvent to soften the photoresist layer. The remaining photoresist layer was completely removed with an oxygen plasma. According to a preferred embodiment of the present invention, a method for stripping a photoresist layer provided by the present invention includes a first dry cleaning step, a wet cleaning step, and a second dry cleaning step. The first dry cleaning step was rinsing using a nitrogen / hydrogen plasma. The second dry-cleaning step is rinsing using an oxygen-containing plasma. The wet washing step is using water as a solvent for soaking ^ 4 This paper size is applicable to China National Standard (CNS) A4 (210 X 297 cm) (Please read the precautions on the back before filling this page) I ----- --- Order ---------- line * Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 432526 A7 4774t \ vf.doc / 008 B7 V. Description of the invention () In order to make the above and other aspects of the present invention The purpose, characteristics, and advantages can be more clearly understood. The following is a detailed description of a preferred embodiment, and in conjunction with the accompanying drawings, as follows: A brief description of the drawings: Figure 1 shows the conventional use of oxygen plasma peeling. Cross-section profile of an organic microscope-containing low-dielectric-constant material layer after removal of photoresist under an electron microscope (SEM); FIG. 2 is a cleaning method of a low-dielectric-constant material layer according to a preferred embodiment of the present invention Block diagrams; Figures 3A to 3D are schematic cross-sectional views of a scouring process of a low dielectric constant material layer according to a preferred embodiment of the present invention; and Figure 4 is a diagram of using the low dielectric constant material layer of the present invention After the photoresist is peeled off, the low dielectric constant containing organic components Cross-sectional profile of the material layer under an electron microscope (SEM) of. Explanation of the marks of the drawings: 100: substrate 101: first dry cleaning step 102: low dielectric constant material layer 103: wet cleaning step 104: cover layer 105: second dry cleaning step 106, 106a: photoresist layer 108: nitrogen electricity Pulp 110: Silicon oxynitride 112: Solvent 5 (Please read the precautions on the back before filling in this page) ~ It t— ft— I --- order --------- line — order for the size of this paper National Standard (CNS) A4 Specification (210 X 297 mm) A7 B7 d32526 4 774twt'.doc / 〇〇8 V. Description of the Invention (★) 114: Oxygen Plasma Example The present invention provides-difficult dielectric constant __ Washing method, using the process of car washing / wet washing / dry cleaning, can avoid the deformation of the outline of the low dielectric constant material layer. The following will explain the removal of the photoresist layer formed on the organic low dielectric constant material as an example. Fig. 2 is a block flow diagram of a cleaning method for a low dielectric constant material layer according to this preferred embodiment. Figures 3A to 3D are in accordance with the present invention-although the lung [|,-the age of the electric constant material layer of the washing process section 7K intent. Please refer to FIG. 3A first. A low-dielectric-constant material layer 102 is formed on the semiconductor substrate 100. Some components (not shown), such as transistors, have been formed in the semiconductor substrate 100. Meta wires or metal interconnects. On the low dielectric constant material layer 102 are a mask layer 104 and a material layer 106. The low-dielectric-constant material layer 10 is typically a low-dielectric-constant material containing an organic component, such as an organic polymer (813 (^ to & 111〇11 (1, 4) ^ 8, SILK, Flare, etc.) The material of the mask layer 104 is, for example, silicon dioxide; the material of the material layer 106 is, for example, photoresist. The mask layer 104 is usually used to transfer the pattern on the photoresist layer 106. This At that time, the pattern on the photoresist layer 106 has been completely transferred to the low dielectric constant material layer 102 and the mask layer 104. Then, the photoresist layer 106 must be stripped to facilitate subsequent processes. Please refer to FIG. 2 and FIG. 3B at the same time, perform the first dry cleaning step 101, etch the photoresist layer 106 with a nitrogen plasma 108, and strip most of the photoresist layer 106. At the same time, the nitrogen plasma 108 bombards the low dielectric The surface of the electrical constant material layer 102 is exposed to the paper size and towel_Home Standard (CNSM4 x 297). ^ 1 I Λ n 1 I ^ IJOJ Ef K n I I. (Please read the precautions on the back before filling this page ) Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs 43 252 6 A7 4UVi d ° C / 〇〇S_B7 ___; _ 5. Description of the invention (f) The nitrogen plasma must not contain oxygen, otherwise it will easily cause corrosion of low dielectric constant materials. The preferred operating conditions are, for example: providing microwave power of about 800-500 watts; n2 / H2 ( 95: 5) The mixed gas flow rate is controlled at 1000-4000 seem; the pressure is about 400mtorr-Uorr; the temperature is about 50-70 degrees Celsius. It should be noted that because the material of the low dielectric constant material layer 102 is made of organic The composition of the low dielectric material, such as -CH-containing silicon oxide. After being bombarded by the nitrogen plasma 108, a thin silicon oxynitride layer 110 will be formed on the surface. Then, please refer to FIG. 2 and FIG. 3C, wet cleaning step 103 is performed, and the remaining photoresist layer 106a is soaked with the solvent 112 to soften the photoresist layer 106a. The solvent II2 is, for example, water. The preferred operating conditions are, for example, controlling the temperature to about It is 70-90 degrees Celsius and soaked for about 30-50 minutes. Then, please refer to Figure 2 and Figure 3D at the same time, and then perform the second dry cleaning step 105, and bombard with an oxygen plasma 1H to completely remove the residue Photoresist layer 106a. The operating conditions of the oxygen plasma are preferably: microwave Rate is about 200-400 watts; CF4 gas flow rate is about 5-15 seem; 02 gas flow rate is about 20-150 seem; pressure is about 400 mtorr-ltorr; temperature is about 50-70 degrees Celsius. Due to low dielectric constant The surface of the material layer 102 has been covered and protected by a thin silicon oxynitride layer 110, so the oxygen plasma used at this time will not cause erosion to the low-dielectric constant material layer, and can maintain the contour without deformation. Figure 4 shows the organic low dielectric constant material layer under an electron microscope (SEM) after stripping off the photoresist using the cleaning method of the low dielectric constant material layer of the present invention. 7 ------------ Loading | --- Ordering --------- Line- (Please read the precautions on the back before filling this page) This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) Economy Printed by the Consumer Cooperatives of the Ministry of Intellectual Property Bureau 432526 A7 4774t \ vl.doc / 008 ____B7____ V. Sectional outline of the description of the invention (B). After comparing Fig. 4 with Fig. 1, it can be seen that using the present invention can indeed obtain a better profile of the low dielectric constant material layer, which will not deform during the photoresist layer stripping process. As can be seen from the above-mentioned preferred embodiments of the present invention, the application of the present invention has the following characteristics. 1. Using the dry-cleaning / wet-washing / dry-cleaning rinsing process can effectively avoid the outline deformation of the low dielectric constant material layer. " " 2. The cleaning method of the low dielectric constant material layer proposed in the present invention is to first remove most of the photoresist layer by using a nitrogen-containing plasma, and make the organic dielectric low dielectric constant. The exposed surface of the material layer forms a layer of nitrous oxide (SiON). After that, the remaining photoresist layer was swallowed with a solvent. Finally, the photoresist layer was completely removed using an oxygen plasma. As a result of the oxygen electrolysis washing, a thin layer of oxynitride has been formed on the surface of the organic low dielectric constant material layer. This oxynitride sand protects the organic low-dielectric constant material layer from being interfered by the oxygen electricity award. A cleaning method for a low dielectric constant material provided by the present invention does not include oxygen in the plasma used in the first dry cleaning step. The present invention should have other advantages' objects and features, which are shown in the scope of the above and subsequent patent applications, or are shown during the implementation of the present invention. Although the present invention has been disclosed above with a preferred embodiment, it is not intended to limit the present invention. Anyone skilled in the art can make various modifications and decorations without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the scope of the appended patent application. 8 -------------- ^ -------- Order --------- line- (Please read the precautions on the back before filling this page) Paper size applies to China National Standard (CNS) A4 (210 X 297 mm)