A7 B7 414943* 五、發明説明（（） 本發明是有關於一種形成開口的方法，且特別是有關 於一稹藉由在光阻層中之光阻開口的側壁形成聚合物間隙 壁，縮小光阻開口’藉以形成小開口的製造方法。 對於現今日新月異的半導體技術而言，提高積集度一 直是眾人追求的目標’如今線寬〇· 微米的技術已進入量 產階段，如何開發出臨界尺寸（Critical Dimension，CD)更 低的製程技術’已是諸多尖端技術人員目前努力的課題。 在開發更小線寬（亦指臨界尺寸更小）的製ft技術中， 微影製程（Photolithography)是重要的關鍵步驟之一。由於 曝光光源的選擇’以及聚焦深度（Depth of Focus，DOF)的 限制，因此微影之解析度(Resolution)受到侷限。以KrF雷 射來說，以其所發出波長爲2480A的深紫外光爲光源，解 析度最高爲線寬，但相對其聚焦深度較小，且製 程範圍（process window)亦較窄，無法形成理想的光阻圖 案。也因此使得製程向更小線寬的推進發生困難。 請參照第1A圖至第1C圖，其繪示習知一般使用微影 及蝕刻製程形成開口之製程剖面示意圖。 請參照第1A圖，在半導體基底100上形成絕緣層11〇。 接著在絕緣層110上形成光阻層1Π，然後利用微影製程 技術’圖案化光阻層112，在光阻層112中形成開口 114。 請參照第1B圖，接著以圖案化後之光阻層112爲罩 幕進行蝕刻製程，蝕刻開口 114底下之絕緣層110，暴露 出底下的基底100表面，在絕緣層110中形成開口 U6。 請參照第1C圖’最後去除光阻層112，即形成所需之 3 本紙張尺度適用中國國^^準（CNS ) 釐 —.------I 裝----^---訂-----線 (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 4929twf.doc/008 _____B7____ 五、發明説明（>) 開口 116。 然而，在習知的微影製程中，在線寬控制及對準精確 度（align accuracy)上的限制會造成量產上的瓶頸，使得開 口 116無法再繼續縮小。雖然目前已有許多改進的微影技 術，比如是相移式先罩(phase shift mask)或是光學鄰近校 正法（Optical Proximity Correction，OPC)，但是在穩定縮 小線寬上仍有諸多限制，且縮小線寬的程度仍然有限。 因此本發明利用蝕刻/沉積之技術，在光阻詹中之光阻 開口的側壁形成聚合物間隙壁，縮小光阻開口，以達到縮 小線寬之目的，可突破微影製程之限制，而且可與傳統之 製程相結合，不需使用額外之製程設備。 本發明提供一種形成開口的方法，包括提供一基底， 基底上已形成一層絕緣層。於絕緣層上依序形成一薄的阻 障層及一光阻層。接著圖案化此光阻層，形成光阻圖案， 其中此圖案化之光阻層中至少具有一光阻開口。然後以蝕 刻/沉積之技術，在光阻開口之側壁形成一聚合物間隙壁， 以縮小光阻開口之尺寸。之後以圖案化之光阻層及聚合物 間隙壁爲罩幕，去除光阻開口底部之阻障層及絕緣層，至 暴露出基底表面，以在絕緣層中形成一開口。最後去除圖 案化光阻層、聚合物間隙壁以及阻障層，即在絕緣層中形 成所需之開口。 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： 4 本紙張又度適'用中國國家標準（CNS > A4规格（210X297公釐） I-------1DI^----^----tr------J線 (請先閱讀背面之注意事項再填窝本頁) 414943A7 B7 414943 * V. Description of the invention (() The present invention relates to a method for forming an opening, and in particular to a method of forming a polymer barrier wall by forming a sidewall of a photoresist opening in a photoresist layer to reduce light A manufacturing method by which a small opening is formed. For today's fast-changing semiconductor technology, improving the accumulation has always been the goal pursued by everyone. Now the technology of line width 0 · μm has entered the stage of mass production, how to develop a critical size (Critical Dimension (CD) lower process technology 'has been the subject of many cutting-edge technical staff's current efforts. In the development of ft technology with a smaller line width (also referred to as a smaller critical size), Photolithography is One of the important key steps. Due to the limitation of the choice of exposure light source and the depth of focus (DOF), the resolution of the lithography is limited. In terms of KrF lasers, the wavelengths they emit 2480A deep ultraviolet light is used as the light source, the highest resolution is line width, but the depth of focus is relatively small, and the process window is relatively small. Narrow, unable to form an ideal photoresist pattern. This also makes it difficult to advance the process to a smaller line width. Please refer to Figures 1A to 1C, which shows the conventional process of forming openings using lithography and etching processes. A schematic cross-sectional view. Referring to FIG. 1A, an insulating layer 11 is formed on the semiconductor substrate 100. Then, a photoresist layer 1Π is formed on the insulating layer 110, and then the photoresist layer 112 is patterned using the lithography process technology, and the photoresist layer is formed on the photoresist layer. An opening 114 is formed in 112. Please refer to FIG. 1B, and then perform an etching process using the patterned photoresist layer 112 as a mask. The insulating layer 110 under the opening 114 is etched to expose the surface of the substrate 100 underneath, and the insulating layer 110 U6 is formed in the opening. Please refer to FIG. 1C for the final removal of the photoresist layer 112, that is, the required 3 paper sizes are applicable to China's national standard (CNS). -^ --- Order ----- line (Please read the notes on the back before filling out this page) Printed by the Employees 'Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs Printed by the Employees' Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 4929twf.doc / 008 _____B7____ 5. Description of the invention (>) On 116. However, in the conventional lithography process, limitations in line width control and align accuracy will cause bottlenecks in mass production, making the opening 116 unable to continue to shrink. Although there have been many improvements, Lithography technology, such as phase shift mask or Optical Proximity Correction (OPC), but there are still many restrictions on the stable reduction of line width, and the degree of line width reduction is still limited. Therefore, the present invention uses the etching / deposition technology to form a polymer gap wall on the side wall of the photoresist opening in the photoresist and reduce the photoresist opening to achieve the purpose of reducing the line width. It can break through the limitations of the lithography process, and can be compared with the traditional Combined process, no additional process equipment is required. The invention provides a method for forming an opening, which includes providing a substrate on which an insulating layer has been formed. A thin barrier layer and a photoresist layer are sequentially formed on the insulating layer. Then patterning the photoresist layer to form a photoresist pattern, wherein the patterned photoresist layer has at least one photoresist opening. Then, a polymer spacer is formed on the side wall of the photoresist opening by an etching / deposition technique to reduce the size of the photoresist opening. Then, using the patterned photoresist layer and the polymer spacer as a mask, the barrier layer and the insulating layer at the bottom of the photoresist opening are removed to expose the substrate surface to form an opening in the insulating layer. Finally, the patterned photoresist layer, polymer spacer and barrier layer are removed, that is, the required openings are formed in the insulating layer. In order to make the above and other objects, features, and advantages of the present invention more comprehensible, a preferred embodiment is given below and described in detail with the accompanying drawings as follows: 4 This paper is suitable for use in China National Standard (CNS > A4 specification (210X297 mm) I ------- 1DI ^ ---- ^ ---- tr ------ J line (please read the precautions on the back first) Filler page) 414943
4929twf.doc/00S A7 B7 經濟部智慧財產局員工消費合作社印製 五、發明説明（>?) 圖式之簡單說明： 第1A圖至第1C圖是繪示習知一種形成開口的製程剖 面示意圖：以及 第2A圖至第2D圖是繪示依照本發明一較佳實施例之 .製程剖面示意圖。 圖式之標記說明： 100 :半導體基底 110 :絕緣層 : 112 :光阻層 114 :光阻開口 116 :開口 200 :半導體基底 210 :絕緣層 212 :阻障層 214 :光阻層 216、216a :光阻開口 218 :聚合物間隙壁 220 :開口 較佳實施例 請參照第2A圖，提供一半導體基底200，半導體基底 200泛指一般製程進行中的半導體基底，其上可以是已經 形成半導體元件如電晶體，或是甚至已經形成多重內連線 (未顯示）。接著在半導體基底200上形成絕緣層210，其 形成方法比如是以常壓化學氣相沉積法(APCVD)沉積而成 5 本紙張尺度適.用中國國家標準（CNS ) A4規格（210X29*?公釐） ^~ ^ J— n 訂 n. 11.^- (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 414945 A7 _ 4929twf. doc/008 ⑴ 五、發明説明（4) 的氧化矽層，或是以塗佈方式形成的旋塗式玻璃（SOG)等。 然後在絕緣層210上形成阻障層212，其形成方法比 如以低壓化學氣相沉積法(LPCVD)，沉積厚度約500埃左 右之氮化矽層。 而後在阻障層212上形成光阻層214，其材質比如是 一般所熟知的光活性化合物（PAC)。接著以傳統之微影技 術，經過曝光、顯影等步驟，在圖案化光阻層214中形成 光阻開口 216，亦即是在光阻層214中形成所-之光阻圖 案。光阻開口 216之尺寸略大於所欲形成之開口尺寸，因 此在形成光阻開口 216時，不必擔心因爲開口尺寸太小而 無法形成或品質不佳的問題。 請參照第2B圖，接著以蝕刻/沉積之技術，在乾式蝕 刻反應室中，使用蝕刻反應氣體比如是 C4F8/CO/AR/CH2F2 、 C4Fg/CO/AR/CHF3 、 或 C4Fs/CO/AR/CH3F等進行蝕刻。由於蝕刻氣體在反應室中， 會進行聚合反應，在基底200之表面輪廓上沉積覆蓋一層 高分子聚合物(polymer)。而在此同時，蝕刻反應仍然繼續 進行，因而在垂直方向沉積之高分子聚合物受到蝕刻濺擊 (bombard)而被去除，即是去除在開口 216底部及光阻層214 表面之聚合物，所以僅在側面方向形成聚合物沉積，亦即 是僅在光阻開口 216之側壁形成聚合物間隙壁218，因而 縮小了光阻開口 216，而成光阻開口 216a。而且，藉由製 程參數之控制，可控制聚合物間隙壁218形成之厚度，藉 以控制光阻開口 216a縮小之程度。 6 本紙張尺度適.用中國國家標準（CNS ) Λ4規格（210X297公釐） --------ΓΟ—裝------訂------線 (請先閲讀背面之注意事項再填寫本頁) 414943 4929twf.doc/008 A7 B7 經濟部智慧財產局員工消費合作社印製 五、發明説明（ς/) 在此蝕刻/沉積步驟中，雖然光阻層214表面受到蝕刻 而去除部分，然而所沉積之光阻層214甚厚，且被去除之 光阻有限’所以並不影響光阻層214之功能。另外，在此 步驟中’阻障層212即作爲触刻終止層，故阻障層212所 形成之厚度需足以抵擋蝕刻劑穿透，同時阻障層212可避 免其底下之絕緣層210中氧的向上擴散，與高分子聚合物 反應，而影響聚合物間隙壁218之形成。 本發明使用蝕刻/沉積之技術，可突破傳統微影製程中 之限制，形成更小之光阻開口 216a，使得在後續製程中， 藉由光阻開口 216a而在絕緣層210中形成之開口，能有 更小之臨界尺寸。並且製程簡單，可與傳統的製程相結合。 請參照第2C圖，然後更換反應室中之蝕刻劑，使用 傳統對絕緣層210具有高度非等向性蝕刻能力之蝕刻劑， 以圖案化之光阻層214及聚合物間隙壁218爲罩幕，進行 非等向性蝕刻，去除光阻開口 216a底部之阻障層212及 絕緣層210，直到暴露出基底200表面，藉以在絕緣層210 中形成開口 220，此處所形成之開口 220可以是接觸窗開 口（contact hole)或是介層窗開口（via hole)。其中，由於阻 障層212之厚度甚薄，故不會影響鈾刻之進行。 請參照第2D圖，最後去除光阻層214、聚合物間隙壁 218以及阻障層212。如此即可形成所需之開口 。 由上述本發明較佳實施例可知，應用本發明利用蝕刻/ 沉積之技術，可突破傳統微影製程之限制’在光阻層中之 光阻開口的側壁形成聚合物間隙壁，縮小光阻開口 ’藉以 7 本紙張尺度適用中國國家標準（CMS ) A4規格（2丨0 X 297公釐） (請先閲讀背面之注#^項再填寫本買) 訂 i ¥ A7 B7 4!4943 4929twf.doc/008 1、發明説明（6 ) 形成更小的開口。且製程簡單，可與傳統之製程相結合。 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。 (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 度 i尺 I張 -紙 本 準 標 家 A4 一釐 公4929twf.doc / 00S A7 B7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 5. Description of the invention (>?) A brief description of the drawings: Figures 1A to 1C are cross-sections of a conventional process for forming an opening Schematic diagrams: and FIGS. 2A to 2D are schematic diagrams showing the cross-section of a manufacturing process according to a preferred embodiment of the present invention. Description of the drawing symbols: 100: semiconductor substrate 110: insulating layer: 112: photoresist layer 114: photoresist opening 116: opening 200: semiconductor substrate 210: insulating layer 212: barrier layer 214: photoresist layers 216, 216a: Photoresist openings 218: polymer spacers 220: openings For a preferred embodiment, please refer to FIG. 2A. A semiconductor substrate 200 is provided. The semiconductor substrate 200 generally refers to a semiconductor substrate in the course of a general process. A semiconductor element may be formed thereon, such as Transistors, or even multiple interconnects (not shown). Next, an insulating layer 210 is formed on the semiconductor substrate 200. The method of forming the insulating layer 210 is, for example, 5 paper sheets deposited by atmospheric pressure chemical vapor deposition (APCVD). Applicable to China National Standard (CNS) A4 specification (210X29 *? ^) ^ ~ ^ J—n Order n. 11. ^-(Please read the notes on the back before filling out this page] Printed by the Employees ’Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 414945 A7 _ 4929twf. Doc / 008 ⑴ V. Invention The silicon oxide layer described in (4), or spin-on-glass (SOG), etc. formed by coating. Then, a barrier layer 212 is formed on the insulating layer 210, for example, by a low-pressure chemical vapor deposition method ( LPCVD), depositing a silicon nitride layer with a thickness of about 500 angstroms. Then, a photoresist layer 214 is formed on the barrier layer 212, and the material is, for example, a generally known photoactive compound (PAC). Then, the conventional lithography technology is used. After exposure, development and other steps, a photoresist opening 216 is formed in the patterned photoresist layer 214, that is, a photoresist pattern is formed in the photoresist layer 214. The size of the photoresist opening 216 is slightly larger than the desired formation. Opening size, so the photoresist At 216, you do not need to worry about the problem that the opening size is too small to be formed or the quality is not good. Please refer to Figure 2B, and then use the etching / deposition technique to use an etching reaction gas such as C4F8 / CO in the dry etching reaction chamber. / AR / CH2F2, C4Fg / CO / AR / CHF3, or C4Fs / CO / AR / CH3F etc. for etching. Because the etching gas in the reaction chamber will undergo a polymerization reaction, a layer of polymer is deposited and covered on the surface contour of the substrate 200 Polymer, and at the same time, the etching reaction continues, so the polymer deposited in the vertical direction is removed by etching bombardment, that is, the bottom of the opening 216 and the photoresist layer 214 are removed The polymer on the surface, so that the polymer deposition is formed only in the side direction, that is, the polymer spacer 218 is formed only on the side wall of the photoresist opening 216, so the photoresist opening 216 is reduced, and the photoresist opening 216a is formed. By controlling the process parameters, the thickness of the polymer spacer 218 can be controlled to control the degree of shrinkage of the photoresist opening 216a. 6 This paper is suitable in size. Use Chinese national standards CNS) Λ4 specification (210X297mm) -------- ΓΟ—installation ------ order ------ line (please read the precautions on the back before filling this page) 414943 4929twf. doc / 008 A7 B7 Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 5. Description of the Invention (ς /) In this etching / deposition step, although the surface of the photoresist layer 214 is removed by etching, the photoresist layer deposited 214 is very thick, and the photoresist removed is limited, so it does not affect the function of the photoresist layer 214. In addition, in this step, the 'barrier layer 212 is used as a contact stop layer. Therefore, the thickness of the barrier layer 212 must be sufficient to resist the penetration of the etchant, and the barrier layer 212 can prevent oxygen in the insulating layer 210 underneath it. Diffusion upwards and reacts with the macromolecular polymer, which affects the formation of the polymer spacer 218. The present invention uses an etching / deposition technique to break through the limitation in the traditional lithography process and form a smaller photoresist opening 216a, so that in subsequent processes, the opening formed in the insulating layer 210 through the photoresist opening 216a, Can have smaller critical dimensions. And the process is simple and can be combined with the traditional process. Please refer to FIG. 2C, and then change the etchant in the reaction chamber. Use a conventional etchant that has a high anisotropic etching ability for the insulating layer 210, and use a patterned photoresist layer 214 and a polymer spacer 218 as a mask. Anisotropic etching is performed to remove the barrier layer 212 and the insulating layer 210 at the bottom of the photoresist opening 216a until the surface of the substrate 200 is exposed, thereby forming an opening 220 in the insulating layer 210. The opening 220 formed here may be a contact A contact hole or a via hole. Among them, since the thickness of the barrier layer 212 is very thin, it will not affect the progress of the uranium etching. Referring to FIG. 2D, the photoresist layer 214, the polymer spacer 218, and the barrier layer 212 are finally removed. This will form the required opening. It can be known from the above-mentioned preferred embodiments of the present invention that the application of the present invention by using the etching / deposition technology can break through the limitations of the traditional lithography process. 'The sidewall of the photoresist opening in the photoresist layer forms a polymer barrier wall to reduce the photoresist opening. 'Based on 7 paper sizes applicable to the Chinese National Standard (CMS) A4 specification (2 丨 0 X 297 mm) (Please read the note # ^ on the back before filling in this purchase) Order ¥ A7 B7 4! 4943 4929twf.doc / 008 1. Description of the invention (6) Form a smaller opening. And the process is simple and can be combined with the traditional process. Although the present invention has been disclosed as above with a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can make various modifications and decorations without departing from the spirit and scope of the present invention. The scope of protection of the invention shall be determined by the scope of the attached patent application. (Please read the precautions on the back before filling out this page) Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs i-foot I sheet-hard copy standard A4 one centimeter