64 A7 B7 經濟部智慧財產局員工消費合作社印製 五、發明說明（f ) 發明領域： 本發明係揭露一種抗反射光罩及其製造方法。 發明背景： 隨著半導體積體電路積集度的快速增加及元件的極小 化’微衫技術所要求之線寬也越來越小。例如：製造64百萬 位元（64 Megabit)動態隨機存取記憶體（dram)之設計準 則其最小線寬約為0.35微米；256百萬位元（256 Megabit) 約為0·25微米；10億位元（1 Gegabit)約為〇. 18微米；4〇 億位元（4 Gegabit)約為0· 15 ~ 0.13微米。是以在半導體 製程邁向深次微米領域的過程中，其對微影製程準確度的要 求也將越來越嚴苛。 由於半導體元件結構係由多重不同之層次重疊而成，每 —層結構重疊時之準確性要求亦隨著關鍵尺寸的縮小而越加 嚴苛，是以在習知之微影製程中，每次利用步進機（stepper) 或掃瞄機（scanner)進行曝光（exposing)製程之前，需 先進行一對準（alignment)步驟，利用對準系統將光罩 (mask)上之對準標記（mark)對準晶片上之標記對準，以 避免後續微影蝕刻製程因位置偏移而產生圖案失真的問題。 習知微影製程之光罩A係如圖一所示，其係於一玻璃或 石英基板20上製作出所需圖罩10，其中該圖罩1〇材質係可為 乳膠（emulsion)、硬面鉻（Cr)膜或抗反射（anti-ref lection) 鉻膜等； 然後 ，再利用透明勝膜 （圖中未示） 覆蓋所述已形成圖案之圖罩10,目的在保護所述圖罩10避免 其受污染。接著，在進行微影曝光製程以便將圖罩10上的圖 ___2------------------ 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) < tr n I t— ---訂： -------線 A7 434464 五、發明說明（义） 案轉移到晶片表面之前，必須先進行一對準步驟，其係依不 同系統選擇單一波長之光源，通常為一雷射（laser)光源 (例如.波長為632. 8nm之氦-氖紅光雷射），將所述雷射光 投射至晶片之對準標記上，並產生一繞射光線（diffracti〇n beam) 30，此繞射光線30在穿過圖罩1〇上之對準標記及石英 基板20，最後進入對準台（alignment bl〇ck)進行訊號分 析。雖然，已將所述繞射光線30盡可能的調整到可垂直入射 5玄光罩A.，但事實上該光線30並無法百分之百垂直入射光罩 A，而所述非垂直入射之繞射光線3〇除了會經由所述基板2〇 折射（入射光線30a)而出之外，還會因為有基板2〇界面反 射現象而產生反射光線（reflection beam) 30b。而因為所 述繞射光線30a與所述反射光線3〇b會產生干涉 (interference)現象，將增加到達對準台時之雜訊 (noise) ’造成嚴重的對準誤差（augment error),較嚴 重的情形將可達lOOrai的大小。隨著進入深次微米領域後， 線寬逐漸縮小的情況下，該誤差影響將更加顯著。 發明之概述： 本發明之主要目的是提供一種抗反射光罩。 本發明之另一目的是提供一種抗反射光罩之其製造方 法。 本發明之又一目的是提供一種對準度極高之微影製程。 為達到上述個項目的，本發明係提供一種抗反射光罩及 其製造方法’所述抗反射光罩係用於半導體元件微影曝光製 程前之對準步驟中，該抗反射光罩係指利用旋塗、沉積或濺 - 丨 __2_ 氏張尺度適用中國國家標準（CMS)A4規格（210 x 297公髮） ---- t請先閱讀背面之注意事項再填寫本頁) 裝 訂---------味< ' 經濟部智慧財產局員工消費合作社印製 ,4 3 Α Λ ό Λ ,4 3 Α Λ ό Λ 經濟部智慧財產局員工消費合作社印製 本紙張尺度適用中國國家標準（CNS)A4規格（210 Α7 _______Β7 _;__ 五、發明說明（> ) 鍍（sputtering)等方式於習知微影製程所使用之光罩上形 成一抗反射層，該抗反射層係可消弭非垂直入射之對準光線 所產生的界面反射光線，用以避免在進行對準步驟時，因為 該反射光線與所述對準光線產生干涉現象而造成嚴重的對準 誤差問題，其中所述抗反射層係分為單一層塗佈與多層塗 佈，而又以多層塗佈之抗反射效果較佳，所述多層塗佈係指 由折射率較石英材質高以及較石英材質低的薄膜交互重疊約 層而成’而所述具較高折射率之薄膜的材質係如：ZnS， 並對波長632· 8nm之雷射光具約1. 5〜3· 5之折射率及接近〇之 消光係數；所述具較低折射率之薄膜的材質係如：Mgf?2，並 對波長632. 8nm之雷射光具約1.1〜1. 5之折射率及約〇〜q 2之 消光係數；而且所述已形成圖案之圖罩上係可覆蓋一透明膠 膜，用以保護該圖罩不受污染。故本發明係提供一種優於習 知微影技藝，提高對準步驟之準確性，降低後續圖案轉移時 圖案失真的程度》 藉由上述之發明概述及皆下來之詳細說明為範例說明本 發明創作，將闡述更多關於本發明的優點及主張，請同時閱 讀本發明之洋細說明及所述圖式以更加暸解本發明之特徵。 圖式簡要說明： 圖一為習知對準步驟之剖面示意圖。 圖二為本發明對準步驟之剖面示意圖β 圖二為本發明使用複層抗反射層時之剖面示意圖。 圖號說明： Α-習知光罩 Β-本發明光罩 ^297 ) ----- (請先閲讀背面之注意事項再填寫本頁) I I -----·*--1τ·ιι —---I - 4 3446 4 經濟部智慧財產局員工消費合作社印製 A7 五、發明說明（士） 圖罩 20-基板 30-^Μ^ό^ 3Ga-入射光線 H射^ 40-抗反射層 41，43，45-較低折射率薄膜仏44-較高折射率薄膜 發明詳細說明： ' 本發明之詳細實施例係詳述於下，請同時參閱所附圖 式。 首先’凊參閱圖二’本發明所提供之抗反射光罩係包含 一圖罩10、一基板20及一抗反射層仙，其中所述圖罩係位 於所述基板20之絲’錢為轉、硬祕膜緣反射鉻膜 等材質’並已形成所需圖案；所述基板2〇係為玻璃（436nmG_ 線、365nm I-線用）或石英（248nm ' i93nm深紫外光用）材 質，所述抗反射層40係位於所述基板2〇其未覆蓋圖罩1〇的另 一面上，其係分為單一層塗佈與多層塗佈（如圖三所示）， 其中又以多層塗佈之抗反射效果較佳，所述多層塗佈係指由 折射率較石英材質高42,44以及較石英材質低的薄膜 41，43’45交互重疊約3〜7層而成，而所述具較高折射率之薄 膜42, 44的材質係如：ZnS，並對波長632. 8nm之雷射光具約 1· 5〜3· 5之折射率及接近〇之消光係數；所述具較低折射率之 薄膜41，43,45的材質係如：1^^'2，並對波長632.811111之雷射 光具約1.1〜1. 5之折射率及約0〜〇, 2之消光係數；而且所述已 形成圖案之圖罩10上係可覆蓋一透明膠膜（圖中未示），用 以保護該圖罩10不受污染。 上述抗反射光罩之製造方法係先提供一基板2〇，所述基 本紙張尺度翻t國國家標準（CNS)A4規格 ------- Γ--' f — _ ----訂 ---------ί (請先閱讀背面之注咅？事項再填寫本頁) /1 五 A7 B7 經濟部智慧財產局員工消費合作社印製 發明說明) 板20係為玻璃（436nmG-線、365nm I-線用）或石英（248nm、 193nm深紫外光用）材質；而且所述基板2Q上係已形成一圖 罩10’所述圖罩10係為乳膠、硬面鉻膜或抗反射鉻膜等材質， 並利用紅勝紙照射、雷射直寫或電子束直寫等方式進行圖案 轉移，用以形成所需圖案；然後，利用旋塗（spinc〇ating) 方式、氣相沉積（vapor d印osition )方式或濺鍍 (sputtermg)方式等，於所述基板2〇其未覆蓋圖罩1〇的另 一面上形成一抗反射層40，所述抗反射層40係位於所述基板 20其未覆蓋圖罩10的另一面上，其係分為單一層塗佈與多層 塗佈（如圖三所示）’其中又以多層塗佈之抗反射效果較佳， 所述多層塗佈係指交互重疊塗佈約3〜7層較石英材質折射率 高42,44以及較石英材質折射率低的薄膜41，43,45，而所述 具較咼折射率之薄膜42,44的材質係如：ZnS，厚度係介於400 埃至8000埃，並對波長632.8nm之雷射光具約ι.5~3. 5之折射 率及接近0之消光係數；所述具較低折射率之薄膜41,43, 45 的材質係如：MgF2，厚度係介於9〇〇埃至8〇〇〇埃，並對波長 632.8nm之雷射光具約ΐ·ι〜ι· 5之折射率及約之消光係 數。此外’所述抗反射層40亦可直接形成於無圖罩之基板 20上。 綜上所述，可同時參閱圖一及圖二，本發明之抗反射光 罩Β係指於習知微影製程所使用之光罩Α上形成一抗反射層 40 ’該抗反射層40係為單層塗佈或多層塗佈（如圖三所示）， 其可消弭非垂直入射之對準繞射光線3〇所產生的界面反射光 線30b ’用以避免在進行對準步驟時，因為該反射光線3此與 (請先閱讀背面之注意事項再填寫本頁) 裝--------訂----- 線； 本紙張尺度適用中國國家標革（CNS)A4規格（210x297公爱） 434464 A7 ^ — B7_. 五、發明說明（ς) 戶斤$對準、繞射光線30a產生干涉現象而造成嚴重的對準誤差 問題。故本發明係提供一種優於習知微影技藝，可消弭習知 之干涉現象’進而提高對準步驟之準確性，降低後續圖案轉 移時圖案失真的程度，亦即提高多層結構堆疊時之重疊準確 性’將更有利於積體電路朝向線寬逐漸縮小的深次微米領域 發展。 以上所述係利用較佳實施例詳細說明本發明，而非限制 本發明的範圍’因此熟知此技藝的人士應能明暸，適當而作 些微的改變與調整’仍將不失本發明之要義所在，亦不脫離 本發明之精神和範圍，故都應視為本發明的進一步實施狀 況。謹請貴審查委員明鑑，並祈惠准，是所至禱。 <請先閱讀背面之;1备？事項再填寫木頁> * I n If n 1 i n n ϋ I V · 經濟部智慧財產局員工消費合作社印製 本紙張尺度適用中國國家標準（CNS)A4規格（210 X 297公釐）64 A7 B7 Printed by the Consumer Cooperative of Intellectual Property Bureau of the Ministry of Economic Affairs 5. Description of the Invention (f) Field of the Invention: The present invention discloses an anti-reflection mask and a manufacturing method thereof. BACKGROUND OF THE INVENTION: With the rapid increase of the semiconductor integrated circuit accumulation degree and the miniaturization of components, the line width required by the micro-shirt technology is also getting smaller and smaller. For example: the design guidelines for manufacturing 64 Megabit dynamic random access memory (Dram) have a minimum line width of about 0.35 microns; 256 Megabits are about 0.25 microns; 10 1 Gegabit is approximately 0.018 microns; 4 Gigabit is approximately 0.15 to 0.13 microns. Therefore, as the semiconductor process moves towards the deep sub-micron field, its requirements for the accuracy of the lithography process will become increasingly strict. Because the semiconductor device structure is made up of multiple different layers, the accuracy requirements of each layer structure are becoming more and more severe as the key size is reduced. Therefore, in the conventional lithography process, each use Before the stepper or scanner performs the exposing process, an alignment step is performed first, and the alignment mark on the mask is aligned by the alignment system. Align the marks on the wafer to avoid the problem of pattern distortion due to position shift in the subsequent lithographic etching process. The photomask A of the conventional lithography process is shown in FIG. 1, which is used to make a desired photomask 10 on a glass or quartz substrate 20, wherein the material of the photomask 10 can be emulsion, hard A surface chromium (Cr) film or an anti-ref lection chromium film, etc .; and then, a transparent win film (not shown) is used to cover the patterned picture cover 10 in order to protect the picture cover 10 Avoid contamination. Next, the lithographic exposure process is performed in order to convert the picture on the picture mask 10 ___ 2 ------------------ This paper size applies the Chinese National Standard (CNS) A4 specification (210 X 297 mm) (Please read the notes on the back before filling out this page) < tr n I t— --- Order: ------- line A7 434464 V. Description of invention (meaning) Before the wafer surface, an alignment step must be performed first, which selects a single-wavelength light source according to different systems, usually a laser light source (for example, a helium-neon red laser with a wavelength of 632.8 nm), Projecting the laser light on the alignment mark of the wafer, and generating a diffracting beam 30, the diffracting light 30 passes through the alignment mark on the cover 10 and the quartz substrate 20, Finally enter the alignment table (alignment bloc) for signal analysis. Although the diffracted ray 30 has been adjusted as far as possible to be able to be incident perpendicularly to the mysterious mask A. However, in fact, the ray 30 cannot be incident to the mask A 100% vertically, and the non-normally incident diffracted rays 3 〇 In addition to being refracted (incident light 30a) through the substrate 20, a reflection beam 30b is also generated due to the reflection phenomenon at the substrate 20 interface. And because the diffracted light 30a and the reflected light 30b will generate an interference phenomenon, it will increase the noise when it reaches the alignment stage and cause serious alignment errors, In severe cases, it can reach the size of lOOrai. As the line width gradually decreases after entering the deep sub-micron field, the effect of this error will become more significant. SUMMARY OF THE INVENTION The main object of the present invention is to provide an anti-reflection mask. Another object of the present invention is to provide a method for manufacturing an anti-reflection mask. Another object of the present invention is to provide a photolithography process with extremely high alignment. In order to achieve the above-mentioned item, the present invention provides an anti-reflection mask and a method for manufacturing the same. The anti-reflection mask is used in the alignment step before the lithographic exposure process of the semiconductor device. Using spin coating, deposition or sputtering-丨 __2_ The Zhang scale is applicable to the Chinese National Standard (CMS) A4 specification (210 x 297 public hair) ---- tPlease read the precautions on the back before filling this page) Binding- ------- Taste &'; Printed by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economy, 4 3 Α Λ ό Λ, 4 3 Α Λ ό Λ Printed by the Intellectual Property Bureau of the Ministry of Economic Affairs' Consumer Cooperatives This paper is applicable to China National Standard (CNS) A4 Specification (210 Α7 _______ Β7 _; __ V. Description of the Invention) Sputtering and other methods form an anti-reflection layer on the photomask used in the conventional lithography process, and the anti-reflection layer It can eliminate the interface reflection light generated by the non-normally incident alignment light to avoid serious alignment error problems caused by the interference phenomenon between the reflected light and the alignment light during the alignment step. The anti-reflective layer Single-layer coating and multi-layer coating, and the multi-layer coating has better anti-reflection effect. The multi-layer coating refers to a thin film having a refractive index higher than that of a quartz material and a film having a lower refractive index than a quartz material. The material of the thin film having a higher refractive index is, for example, ZnS, and has a refractive index of about 1.5 to 3.5 and an extinction coefficient close to 0 for a laser light having a wavelength of 632 · 8nm; The material of the refractive index film is such as: Mgf? 2, and has a refractive index of about 1.1 ~ 1.5 and a coefficient of extinction of about 0 ~ q 2 for a laser with a wavelength of 632.8 nm; and the patterned figure The mask can be covered with a transparent adhesive film to protect the mask from contamination. Therefore, the present invention provides a technique that is superior to the conventional lithography technique, improves the accuracy of the alignment step, and reduces the distortion of the pattern during subsequent pattern transfer. Degree "uses the above-mentioned summary of the invention and the detailed description below as examples to illustrate the invention of the invention. It will explain more about the advantages and claims of the invention. Please read the detailed description of the invention and the drawings for a better understanding. Features of the invention. Description: Figure 1 is a schematic sectional view of a conventional alignment step. Figure 2 is a schematic sectional view of an alignment step of the present invention. Β Figure 2 is a schematic sectional view of a multi-layer antireflection layer according to the present invention. Β-Photomask of the present invention ^ 297) ----- (Please read the precautions on the back before filling out this page) II ----- · *-1τ · ιι --- I-4 3446 4 Economy Printed by A7 of the Ministry of Intellectual Property Bureau Consumer Cooperatives V. Description of Invention (Shi) Figure cover 20-substrate 30- ^ Μ ^ ό ^ 3Ga-incident light H-radiation ^ 40-anti-reflective layer 41, 43, 45-low refraction Rate film 仏 44-Higher refractive index film Detailed description of the invention: 'Detailed embodiments of the present invention are detailed below, please refer to the attached drawings. First, 'see FIG. 2', the anti-reflection mask provided by the present invention includes a pattern mask 10, a substrate 20, and an anti-reflection layer. The pattern mask is located on the silk of the substrate 20. Materials such as chrome film and hard-edged film edge and have formed the required pattern; the substrate 20 is made of glass (436nmG_ line, 365nm I-line) or quartz (248nm 'i93nm deep ultraviolet light) The anti-reflection layer 40 is located on the other side of the substrate 20 which does not cover the cover 10, and is divided into a single-layer coating and a multi-layer coating (as shown in FIG. 3). The anti-reflection effect is better. The multi-layer coating refers to a film with a refractive index 42,44 higher than that of quartz and a film 41, 43'45 lower than that of quartz. The materials of the higher refractive index films 42, 44 are such as: ZnS, and have a refractive index of approximately 1.5 to 3.5 and a coefficient of extinction close to 0 for laser light having a wavelength of 632.8 nm; The refractive index of the thin film 41,43,45 is as follows: 1 ^^ '2, and the laser light having a wavelength of 632.811111 is about 1.1 ~ 1.5 And the extinction coefficient of about 0 ~ 0, 2; and the patterned mask 10 can be covered with a transparent adhesive film (not shown) to protect the mask 10 from pollution. The manufacturing method of the above-mentioned anti-reflection photomask is to first provide a substrate 20, and the basic paper size is translated to the national standard (CNS) A4 specification of --------- Γ-- 'f — _ ---- order --------- ί (Please read the note on the back? Matters before filling out this page) / 1 Five A7 B7 Printed invention description by the Consumer Cooperatives of the Intellectual Property Bureau of the Ministry of Economic Affairs) Plate 20 is glass (436nmG -Line, 365nm I-line) or quartz (248nm, 193nm deep ultraviolet light); and the substrate 2Q has been formed with a pattern cover 10 ', said pattern cover 10 is latex, hard-surface chrome or Materials such as anti-reflection chrome film, and pattern transfer using red win paper, laser direct writing or electron beam direct writing to form the desired pattern; then, spin coating method, gas phase An anti-reflection layer 40 is formed on the other side of the substrate 20 which does not cover the mask 10 by a vapor deposition method or a sputtering method, and the anti-reflection layer 40 is located on the substrate 20 The substrate 20, which does not cover the other side of the cover 10, is divided into a single-layer coating and a multi-layer coating (as shown in FIG. 3). Multi-layer coating has better anti-reflection effect. The multi-layer coating refers to about 3 to 7 layers of alternately overlapping coatings. The refractive index is 42,44 higher than the quartz material and the thin film 41,43,45 is lower than the quartz material. 5 ， The material of the thin film with a high refractive index 42,44 is such as: ZnS, the thickness is between 400 angstroms and 8000 angstroms, and the laser light with a wavelength of 632.8nm has a refractive index of about ι.5 ~ 3.5 Rate and extinction coefficient close to 0; the material of the thin film 41,43,45 with lower refractive index is MgF2, the thickness is between 900 angstroms and 80,000 angstroms, and the wavelength is 632.8nm. The laser light has a refractive index of about ΐ · ι ~ ι · 5 and an approximate extinction coefficient. In addition, the anti-reflection layer 40 may be directly formed on the substrate 20 without a mask. In summary, referring to FIG. 1 and FIG. 2 at the same time, the anti-reflection mask B of the present invention refers to the formation of an anti-reflection layer 40 on the mask A used in the conventional lithography process. It is a single-layer coating or a multi-layer coating (as shown in FIG. 3), which can eliminate the interface reflection light 30b generated by the non-normally incident alignment diffraction light 30, so as to avoid the alignment step because The reflected light 3 is related to this (please read the precautions on the back before filling this page). -------- Order ----- Line; This paper size applies to China National Standard Leather (CNS) A4 specifications ( 210x297 (Public Love) 434464 A7 ^ — B7_. V. Description of the Invention (ς) The household collimator aligns and interferes with the diffracted light 30a, causing serious alignment error problems. Therefore, the present invention provides a technique superior to the conventional lithography technique, which can eliminate the conventional interference phenomenon, thereby improving the accuracy of the alignment step and reducing the degree of pattern distortion during subsequent pattern transfer, that is, improving the accuracy of overlapping when multi-layer structures are stacked. "Sexuality" will be more conducive to the development of integrated circuits toward the deep sub-micron field with decreasing line width. The above is a detailed description of the present invention using the preferred embodiments, rather than limiting the scope of the present invention. 'Those skilled in the art should be able to understand, and make small changes and adjustments appropriately' will still lose the essence of the invention Without departing from the spirit and scope of the present invention, it should be regarded as a further implementation status of the present invention. I would like to ask your reviewers to make a clear reference and pray for your sincere prayer. < Please read the back; Please fill in the wood page for the items > * I n If n 1 i n n ϋ I V · Printed by the Consumers' Cooperative of Intellectual Property Bureau of the Ministry of Economic Affairs