經濟部智慧財產局員工消費合作社印製 480583 A7 B7 1 一 五、發明說明（）Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 480583 A7 B7
Hi 並 本發明一般偽關於元件，如積體電路之製造。尤其是 ，本發明像關於在圔案製作時，改善臨界尺寸的控制。 發明背暑 在製造元件時，如積體電路（ICs),特徽是形成在基 板上。例如，該特徽偽相對應於組件，如電晶體，電容 器和電阻器。然後這些組件會相互連接，以完成希望的 電性功能。 為了要形成元件，各層重複地沈積在基板上且選擇性 製作圖案。製作元件各層之圖案僳使用微影製程技術。 此種技術通常傺使用一曝光光源，使其從光罩將光影像 投影在形成在基板表面上之光阻層上。此種光線照射光 阻層，將其曝光成具有希望的圖案。將光阻層曝光或未 曝光的部分移除，像取決於是否使用正光阻或負光阻。 例如，然後將沒有被光阻保護到的部分蝕刻，以在基板 中形成特徽。 光阻的成像機制像為一光酸産生者，當光阻曝露在光 線中時，其會産生酸，以催化光阻中的化學反應。此化 學反應會改變光阻溶解度，使得曝光或未曝光的部分可 用顯影液移除。 特激的尺寸取決於微影製程条統的解析度能力〇藉由 給定檝影製程条統的産生而完成之最小恃徴尺寸（F), 稱為撤影製程基本律（GR)。臨界尺寸（CD)像被定義為必 須控制的最小特徴尺寸。例如，其包含線寬，間隔和接 觸寬度。 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） (請先閱讀背面之注意事項再填寫本頁)Hi and the present invention is generally related to the manufacture of components such as integrated circuits. In particular, the present invention is like improving the control of the critical dimension when making a case. Back to the Invention When manufacturing components such as integrated circuits (ICs), special emblems are formed on the substrate. For example, this special emblem corresponds to components such as transistors, capacitors, and resistors. These components are then interconnected to perform the desired electrical function. To form an element, each layer is repeatedly deposited on a substrate and patterned selectively. The patterning of each layer of the element is made using lithography process technology. This technique usually uses an exposure light source to project a light image from a photomask onto a photoresist layer formed on a substrate surface. This light irradiates the photoresist layer and exposes it to a desired pattern. The exposed or unexposed part of the photoresist layer is removed, depending on whether a positive or negative photoresist is used. For example, a portion that is not protected by photoresist is then etched to form a logo in the substrate. The photoresist's imaging mechanism is like a photoacid generator. When the photoresist is exposed to light, it will generate an acid to catalyze the chemical reaction in the photoresist. This chemical reaction changes the photoresist solubility so that exposed or unexposed parts can be removed with a developer. The size of the special laser depends on the resolution capability of the lithography process system. The minimum size (F) that is completed by the generation of a given photolithography process system is called the basic law of the shadow removal process (GR). The critical dimension (CD) image is defined as the minimum feature size that must be controlled. For example, it includes line width, spacing, and contact width. This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) (Please read the precautions on the back before filling this page)
經濟部智慧財產局員工消費合作社印製 480583 A7 B7 __ 2 五、發明說明（） 由於進入光阻層的光線或反射光會變化，所以CD也會 發生變化。控制CD變化（CD控制）變成一重要的關鍵，尤 其是深紫外光微影製程（DUV>。CD控制傺藉由在光阻之 下，使用抗反射塗層（ARC)的幫助，以減少進入由下層 所造成之光阻的反射光變化。 對於DUV微影製程，無機的ARCS,如介電質ARCs(DARCs) ，僳用以改善微影製程窗口很趿引人之候選者。此是因 為無機的ARCS擁有許多令人滿意的特性，如可調變的性 質，低缺陷準位，良好的共形性，對光阻有很高的蝕刻 選擇比，和很小的搖攞振幅比率。 但是，由於"光阻中毒"的闢偽，已使無機ARCS的使用 受到限制。例如，光阻中毒傜歸因於光阻受到來自無機 ARC之胺基的污染，使得酸産生者失效，形成不能被顯 影液溶解之光阻的污染部分。結果，在顯影之後，會在 光阻縱深中形成腳。 傳統防止光阻中毒的技術，僳在ARC和光阻層之間提 供一氯化層。此氧化層可以沈積在ARC之上，或利用電 漿處理ARC的表面而形成。但是，該氧化層對一些光阻 化學品是無法防止光阻中毒的，如JSR Microelectronics 公司的光阻JSR TM 3 9 9。事實上，氧化層會使光阻中毒 的問題更加嚴重。 如上所述，明顯的，有效地減少光阻中毒，以改善撤 影製程窗口，才能令人滿意。 顬忒夕謎钿銳职 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） (請先閱讀背面之注意事項再填寫本頁) 裝 I I I I ·11111111 · 480583 A7 B7 五、發明說明（ 第1 第2 之光阻 發明總 圖為本發明 圖和第3圖 層縱深。 沭 之說明實施例；及為根據本發明，有作和沒有作矽處理 本發 光阻之 層。該 於光阻 少光阻 □ 〇 發明說 明像關於如 下提供一帽 帽層宜包含 層之下的元 中毒。藉由 明 何減少光阻中毒〇在一實施例中，在 層〇在一實施例中，該帽層包含多矽 一非晶矽層。二擇其一地，可以在位 件層上，産生多出的懸垂鍵結，以減 減少光阻中毒，可以改善撤影製程窗 件之製造，如積體電路（ICs)。尤其 減少光阻中毒，以改善微影製程窗口 由在光阻之下提供一含有矽之帽層， 請 先 閱 讀 背 面 之 注 本發明像關於元 是，本發明僳關於 。根據本發明，藉 可以減少光阻中毒。第1圖為本發明為了減少光阻中毒之一實施例。如圖 以 ο 可 ii 1 也 板但 基 〇 一 圓 供晶 提矽 先如 明 〇 發板 本基 , 體 示導 所半 含 包 板 基 此 如 例 板 基 的 類 I 種 他 其 用 使 訂 經濟部智慧財產局員工消費合作社印製 導製 半在 的可 他板 其基 或該 , ο 矽板 上基 體 變 -45*: ms 緣導 絶半 ，非 鍺用 ， 使 鎵以 化可 #也 含然 包當 些 〇 這料 如材 , 體 段徴 階特 種含 各包 的在 程或 流 ， 程段 如 例 示 圖 未 路 電 體 積 成 形 以 用 僳 徽 之 式 形 他 其 或 階特 始， 起如 的例 程 〇 流段 程階 製程 在製 可殊 板特 基之 體 億 記 取 存 機 隨 態 動 如 用 可 也 徽 特 此 的 磁 B 成 形 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 480583 A7 B7______ 4 五、發明說明（） 或機械的元件。為了方便討論，此處所用之"基板”像鵰 於可在製程流程任何階段之基板。 — I-----r-----1^·裝 (請先閱讀背面之注意事項再填寫本頁) 元件層130像形成在基板之上。在一實施例中，元件 層包含ARC層。在一實施例中，ARC層包含無機ABC層。 例如，無機的ARC層包含DARC,如氮化矽（SixNy)，氮氧 化矽（SiNxOy),氳化的氮氣化矽，或其他種類的介電質 抗反射材料。在優選實施例中，DARC包含氮氣化矽^也 可以使用金屬的ARCS或其他的無機抗反射材料。例如， 無機的ARC層可使用傳統的技術沈積，如化學氣相沈積 (CVD) 〇 經濟部智慧財產局員工消費合作社印製 在另一的實施例中，可提供一使用吸收和破壞干涉性 質之多重層ARC堆疊層多重層ARC堆疊層已被說明在一 篇此處基於參考目的而納入之專利中其正刊在美國國家 標準局之美國專利公報上（美國安任未審案件第98P 7 98 2 號），其名稱為"Improved CD Control”。當然也可以使 用包含漸變折射率之ARC層。漸變折射率ARC層已被說明 在一篇也是此處基於參考目的而納入之專利中，其正刊 在美國國家檫準局之美國專利公報09/276, 026上（美國 安任未審案件第98P 7982 US01號），其名稱為"ARC for improving CD control% 二擇其一地，元件層110包含介電質層。介電質材料 ，如氣化矽，氮化矽，或摻雑的矽酸玻璃，如硼磷矽酸 玻璃，可被用以當作元件層。也可以使用其他種類的介 電質材料。介電質層可以使用傳統的技術形成。 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 480583 A7 B7 5 五、發明說明（） (請先閱讀背面之注意事項再填寫本頁) 在元件層之上，有形成一薄的帽層140,以減少在ARC 和後續形成的光阻之間之光阻中毒。根據本發明之實施 例，帽層包含矽。帽層宜包含薄的非晶矽層。包含之矽 層要夠薄，才能避免在光阻中造成駐波和干涉。在一實 施例中，帽層的厚度要小於3 0 A ,宜小於1 0 A ,但最好小 於3 A。帽層的厚度可以被最佳化，以産生希望的光阻縱 深。 二擇其一地，帽層包含交變元件層表面形態之簞原子 層。在一實施例中，單原子層包含在元件層表面上之多 出的矽懸垂鏈結。在此種情形下，帽層包含多矽層。帽 層的組成取決於在其下之元件層。例如，若在其下之元 件層包含氧化矽或氮氧化物層，則帽層會包含多矽氣化 物或多矽氮氣化物。 例如，光阻層170包含任何用在微影製程中之傳統光 阻。此種光阻可以為正光阻或負光阻〇在一實施例中， 光阻包含JSR ΤΜ 399。光阻僳利用傳統技術形成。例如 ，光阻的厚度要夠厚，才能當作ARC開口製程之蝕刻遮 罩。一般而言，光阻層的厚度約為0.2-10#班〇 經濟部智慧財產局員工消費合作社印製 如上所述，本發明提供一包含帽層之矽，其中帽層僳 位在光阻之下，以防止光阻中毒。矽和光阻的折射率有 很大的差配，所以會形成駐波或干涉。但是，因為帽層 很薄（在某些情形下，厚度並不可量測，如同單原子層 之案例一樣），所以會減少或縮小駐波或干涉的衝擊。 在一實施例中，矽帽層僳利用化學氣相沈積（CVD)而 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 480583 A7 B7__ 6 五、發明說明（） (請先閱讀背面之注意事項再填寫本頁) 形成的，如低壓CVD(LPCVD)，電漿輔助CVD(PECVD)，高 密度電漿CVD(HDPCVD),電子迺旋共振（ECli)CVD。當然 也可以使用其他種類的電漿製程，如PVD。矽先質氣體 和稀釋氣髏或混合氣體被引入内含具有元件層之基板的 腔體中。在一實施例中，採用包含SiH 4之矽先質氣髏。 也可以使用其他種類的矽先質，如TE0S和Si2H6。例 如，稀釋氣體包含氦氣（He),氬氣（Ar),或氖氣（Ne)。 這些氣體在腔體中起反應，然後沈積在元件層上之矽帽 層之上。 形成帽層的製程參數如下： 經濟部智慧財產局員工消費合作社印製 RF電漿功率：約lfl-5000Watts 腔體壓力：約O.lfflTorr到20Torr 氣浴頭和晶圓之間的間隔：約1 〇 - 5 0 0 0 m i 1 s 流率（SilU ):約fl-lOflscem 此沈積製程會在元件層的表面上形成一包含矽的薄帽層 。此帽層宜包含一薄的非晶質矽層。此沈積製程也可藉 由在其上産生多出的矽懸垂鍵結，而被用以改變元件層 的表面形態。在一實施例中，包含帽層之矽，其厚度約 小於30A，以約小於10A為較佳，但最好約小於3A。一般 而言，製程時間約在0 . 1到1 2 0秒之間。 形成帽層之製程可以和元件層的形成，在相同的製程 中執行（卽同時）。為了同時處理，要關掉流入腔體之氣 體，此氣體為形成帽層時為非需要之氣體。反應腔功率 保持在開的狀態。而且需要之氣體，如矽先質和稀釋的 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） 480583 A7 B7 7 五、發明說明（） 氣體（如He)，保持在開的狀態或是將其打開。例如在藉 由PECVD形成氮氧化矽元件層之後，關掉氧氣源，如N 2 0 或02，但RF電漿電源，矽先質氣體和稀釋的氣體仍保 持在開的狀態，以形成帽層。製程時間一般都約為〇·1 到1 2 0秒之間。 在結束形成元件層之後，可以漸漸調整氣體流率，功 率設定，壓力和其他參數到想要形成帽層的準位。在開 始形成帽層之前，先要執行穩定氣體流率之穩定步驟。 尤其是對於不同的製程，當氣體流動架構不同時，此特 別有用。 餹俐 如上所述，第2圖為形成在氮氧化矽ARC 230之上， 沒有包含帽層之矽的光阻層270之SEM圖。此光阻己被製 成圖案，而形成開口 210。如SEM圖，光阻縱深在開口的 底端很窄。此種現象稱為立定，立定僳由氮氣化物ARC ，而使光阻中毒的結果所造成的。當立定扭歪要形成2 特徵的尺寸時，立定就不歡迎〇 參考第3圖，根據本發明之實施例，包含帽層320之 矽僳被提供在光阻層3 7 0和氮氧化矽ARC 3 3 0之間。開口 310傺形成在光阻層之中。圖示之光阻縱深，其在開口 頂端和底端的尺寸大致相同，此表示使用矽帽層，可以 避免光阻中毒。 本發明已特別圖示且參考各實施例說明，利用這些技 術的技巧，所作的修正例和變化例，將不會離開本發明 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐） -I-----1---- 裝 (請先閱讀背面之注意事項再填寫本頁) I I I I ^ — — — — — — — . 經濟部智慧財產局員工消費合作社印製 480583 A7 B7 經濟部智慧財產局員工消費合作社印製Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs 480583 A7 B7 __ 2 V. Description of the invention () Because the light or reflected light entering the photoresist layer will change, the CD will also change. Controlling CD change (CD control) becomes an important key, especially in the deep UV lithography process (DUV). CD control is achieved by using anti-reflective coating (ARC) under the photoresist to reduce entry The change in the reflected light caused by the photoresist caused by the lower layer. For DUV lithography, inorganic ARCS, such as dielectric ARCs (DARCs), are attractive candidates for improving the lithography process window. This is because Inorganic ARCS has many satisfactory characteristics, such as tunable properties, low defect level, good conformality, high etching selection ratio for photoresistance, and small shake amplitude ratio. But The use of inorganic ARCS has been restricted due to the piracy of " photoresist poisoning ". For example, photoresist poisoning is due to the photoresist being contaminated with amine groups from inorganic ARC, making the acid generator ineffective and forming The contaminated part of the photoresist that cannot be dissolved by the developing solution. As a result, feet are formed in the depth of the photoresist after development. Traditional techniques for preventing photoresist poisoning provide a chloride layer between the ARC and the photoresist layer. This Oxide layer can be deposited It is formed on ARC, or the surface of ARC is treated by plasma. However, this oxide layer cannot prevent photoresist poisoning for some photoresist chemicals, such as JSR Microelectronics' photoresist JSR TM 3 9 9. In fact, The oxide layer will make the photoresist poisoning problem more serious. As mentioned above, it is obvious that the photoresist poisoning can be effectively reduced to improve the window of the shadow removal process. Only then can the paper be used in China. National Standard (CNS) A4 specification (210 X 297 mm) (Please read the precautions on the back before filling this page) Installation IIII · 11111111 · 480583 A7 B7 V. Description of the invention (1st 2nd photoresistor invention general drawing This is a drawing of the present invention and the depth of the third layer. 沭 An illustrative embodiment; and a layer of the present photoresistor with and without silicon treatment according to the present invention. The photoresistance is less than the photoresistance. □ The description of the invention is provided as follows: A cap layer should include elemental poisoning under the layer. By reducing the photoresist poisoning, in one embodiment, in layer 0, in one embodiment, the cap layer includes a polysilicon-amorphous silicon layer. Choose In one place, extra dangling bonds can be generated on the bit layer to reduce photoresistance poisoning, which can improve the manufacturing of window removal processes, such as integrated circuits (ICs). Especially to reduce photoresistance poisoning, To improve the lithography process window, a cap layer containing silicon is provided under the photoresist. Please read the note on the back. The present invention is related to the element, the present invention is not related. According to the present invention, the photoresist poisoning can be reduced. Part 1 The picture shows an embodiment of the present invention in order to reduce photoresist poisoning. As shown in the figure, ο may ii 1 is also used, but the substrate is used for crystal extraction. For example, the class I of the board is used for other purposes. The Intellectual Property Bureau ’s Intellectual Property Bureau employee ’s consumer cooperative prints and guides the semi-existing Katapankiji or ο, ο the silicon substrate changes -45 *: ms For the most part, it is used for non-germanium, so that gallium can be used as a material. This material contains materials such as materials, and the segments are in the process or flow. The segments are not shown in the figure. Form him It may start from the beginning, such as a routine. The flow stage process is in the process of making a special plate, and the recorder is changed according to the state. The magnetic B is formed by this special paper. The paper dimensions are applicable to Chinese national standards. (CNS) A4 specification (210 X 297 mm) 480583 A7 B7______ 4 5. Description of the invention () or mechanical components. For the convenience of discussion, the "substrate" used here is carved on a substrate that can be used at any stage of the manufacturing process. — I ----- r ----- 1 ^ · installation (please read the precautions on the back first) (Fill in this page) The element layer 130 is formed on the substrate. In one embodiment, the element layer includes an ARC layer. In one embodiment, the ARC layer includes an inorganic ABC layer. For example, the inorganic ARC layer includes DARC, such as nitrogen SixNy, SiNxOy, halogenated silicon nitride, or other types of dielectric anti-reflective materials. In a preferred embodiment, DARC contains silicon nitride. It is also possible to use metal ARCS or Other inorganic anti-reflective materials. For example, the inorganic ARC layer can be deposited using conventional techniques, such as chemical vapor deposition (CVD). Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. In another embodiment, an Multi-layer ARC stacks using absorbing and destructive interference properties Multi-layer ARC stacks have been described in a patent incorporated herein for reference purposes and are being published in the U.S. National Bureau of Standards (USA) Untrial case 98P 7 9 8 No. 2) and its name is " Improved CD Control. Of course, it is also possible to use an ARC layer containing a graded refractive index. The graded refractive index ARC layer has been described in a patent which is also incorporated here for reference purposes and is being published in US Patent Bulletin 09/276, 026 of the National Bureau of Standards (U.S. Unopened Case 98P 7982 US01), whose name is "ARC for improving CD control%" Alternatively, the element layer 110 includes a dielectric layer. Dielectric materials, such as vaporized silicon, silicon nitride, or erbium-doped silicate glass, such as borophosphosilicate glass, can be used as component layers. Other types of dielectric materials can also be used. The dielectric layer can be formed using conventional techniques. This paper size applies to China National Standard (CNS) A4 (210 X 297 mm) 480583 A7 B7 5 V. Description of the invention () (Please read the precautions on the back before filling this page) On the component layer, there is a form A thin cap layer 140 to reduce photoresist poisoning between the ARC and the subsequent photoresist. According to an embodiment of the invention, the capping layer comprises silicon. The cap layer should preferably include a thin amorphous silicon layer. The silicon layer included must be thin enough to avoid standing waves and interference in the photoresist. In one embodiment, the thickness of the cap layer is less than 30 A, preferably less than 10 A, but preferably less than 3 A. The thickness of the cap layer can be optimized to produce the desired photoresist depth. Alternatively, the cap layer includes a rhenium atomic layer having a surface morphology of the alternating element layer. In one embodiment, the monoatomic layer includes extra silicon dangling links on the surface of the element layer. In this case, the cap layer includes a polysilicon layer. The composition of the cap layer depends on the element layer below it. For example, if the component layer underneath contains a silicon oxide or oxynitride layer, the capping layer may contain polysilicon vapors or polysilicon nitrides. For example, the photoresist layer 170 includes any conventional photoresist used in a lithography process. Such a photoresist may be a positive photoresistor or a negative photoresistor. In one embodiment, the photoresist includes JSR TM 399. Photoresistance is formed using traditional techniques. For example, the photoresist must be thick enough to be used as an etch mask for the ARC opening process. Generally speaking, the thickness of the photoresist layer is about 0.2-10 #. It is printed by the consumer cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs. As described above, the present invention provides a silicon layer including a cap layer, wherein the cap layer is located in the photoresist layer. To prevent photoresist poisoning. The refractive index of silicon and photoresist are very different, so standing waves or interference will be formed. However, because the cap layer is thin (in some cases, the thickness is not measurable, as in the case of a monoatomic layer), the impact of standing waves or interference will be reduced or reduced. In one embodiment, the silicon cap layer is made of chemical vapor deposition (CVD) and the paper size is in accordance with the Chinese National Standard (CNS) A4 (210 X 297 mm) 480583 A7 B7__ 6 V. Description of the invention () (please Read the precautions on the back before filling in this page), such as low-pressure CVD (LPCVD), plasma-assisted CVD (PECVD), high-density plasma CVD (HDPCVD), and electron spin resonance (ECli) CVD. Of course, other types of plasma processes can also be used, such as PVD. A silicon precursor gas and a diluent gas or a mixed gas are introduced into a cavity containing a substrate having an element layer. In one embodiment, a silicon precursor gas skeleton containing SiH 4 is used. Other silicon precursors can also be used, such as TE0S and Si2H6. For example, the diluent gas includes helium (He), argon (Ar), or neon (Ne). These gases react in the cavity and are then deposited on top of the silicon cap layer on the element layer. The process parameters for forming the cap layer are as follows: The RF plasma printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Power: about lfl-5000Watts Cavity pressure: about O.lfflTorr to 20Torr The interval between the air bath head and the wafer: about 1 〇- 5 0 0 0 mi 1 s Flow rate (SilU): about fl-lOflscem This deposition process will form a thin cap layer containing silicon on the surface of the element layer. The capping layer should preferably include a thin amorphous silicon layer. This deposition process can also be used to change the surface morphology of the device layer by generating extra silicon overhang bonds thereon. In one embodiment, the thickness of the silicon containing the cap layer is less than about 30A, and preferably less than about 10A, but most preferably less than about 3A. Generally speaking, the process time is between 0.1 and 120 seconds. The process of forming the cap layer can be performed in the same process as the formation of the element layer (at the same time). For simultaneous processing, the gas flowing into the cavity should be turned off. This gas is an unnecessary gas when forming the cap layer. The reaction chamber power is kept on. In addition, the required gases, such as silicon precursor and diluted paper, are in accordance with Chinese National Standard (CNS) A4 (210 X 297 mm) 480583 A7 B7 7 V. Description of the invention () Gas (such as He), keep it on. Or open it. For example, after the silicon oxynitride element layer is formed by PECVD, the oxygen source, such as N 2 0 or 02, is turned off, but the RF plasma power, silicon precursor gas and diluted gas are still kept on to form a cap layer. . The process time is generally between about 0.1 to 120 seconds. After forming the element layer, you can gradually adjust the gas flow rate, power setting, pressure, and other parameters to the level where you want to form the cap layer. Before forming the cap layer, a stabilization step to stabilize the gas flow rate is performed. This is especially useful for different processes when the gas flow architecture is different. As described above, the second figure is an SEM image of a photoresist layer 270 formed on silicon oxynitride ARC 230 without a cap layer. This photoresist is patterned to form an opening 210. As seen in the SEM image, the depth of the photoresist is narrow at the bottom of the opening. This kind of phenomenon is called Li Ding, Li Ding is caused by the result of photoresist poisoning caused by the nitrogen compound ARC. When the standing distortion is to form a 2 feature size, standing is not welcome. Referring to FIG. 3, according to an embodiment of the present invention, a silicon wafer including a cap layer 320 is provided on the photoresist layer 3 7 0 and silicon oxynitride ARC. Between 3 3 0. The opening 310 'is formed in the photoresist layer. The photoresistor depth shown in the figure is roughly the same at the top and bottom of the opening. This means that the use of a silicon cap layer can avoid photoresist poisoning. The present invention has been particularly illustrated and explained with reference to the embodiments. Using the techniques of these technologies, corrections and changes will not depart from the present invention. The paper size applies the Chinese National Standard (CNS) A4 specification (210 X 297 mm) Li) -I ----- 1 ---- (Please read the precautions on the back before filling out this page) IIII ^ — — — — — — — Printed by the Intellectual Property Bureau of the Ministry of Economic Affairs Consumer Cooperatives 480583 A7 B7 Printed by the Consumer Cooperative of the Intellectual Property Bureau of the Ministry of Economic Affairs