1249647 九、發明說明： 【發明所屬之技術領域】 本發明是關於一種光罩修正方法，特別是關於一種 可減少光罩報廢率之光罩修正方法。 【先前技術】BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a reticle correction method, and more particularly to a reticle correction method which can reduce the reticle rejection rate. [Prior Art]
於半導體製程中，微影製程居於相當重要的地位， 藉由微影製程才可將所需之圖案定義於光阻層，再利用 蝕刻步驟使光阻層圖案轉移至半導體基板以形成電路構 造。微影製程主要包含光阻塗佈、曝光與顯影等步驟。 其中，曝光程序係決定最後成型之電路精細程度的關鍵 因素，而曝光解析度的良窳則取決所使用的光罩品質。 一般而言，光罩的基材大多由平坦透光的玻璃絕緣 材質所形成，而光罩的製造係於平坦透光基材上沉積數 f埃之不透光薄膜，如鉻金屬薄膜，接著塗佈光阻層覆 ，不透光薄膜；再以高解析度之電子束或能量束進行曝 光，顯影光阻層以形成所需的圖案，最後 ^圖案轉移至不透光薄膜。而使光罩包=In the semiconductor process, the lithography process is in a very important position. The lithography process can be used to define the desired pattern on the photoresist layer, and the etch step is used to transfer the photoresist layer pattern to the semiconductor substrate to form a circuit structure. The lithography process mainly includes steps of photoresist coating, exposure and development. Among them, the exposure program determines the key factors of the final level of circuit formation, and the brightness of the exposure depends on the quality of the mask used. In general, the substrate of the reticle is mostly formed of a flat transparent light-insulating glass insulating material, and the reticle is manufactured by depositing an opaque film of a few angstroms on a flat transparent substrate, such as a chrome metal film, and then The photoresist layer is coated with an opaque film; the electron beam or the energy beam is exposed to a high resolution, the photoresist layer is developed to form a desired pattern, and finally the pattern is transferred to the opaque film. And make the mask package =
/、不透光區域所組成的光罩圖案。 一 θ牵然iff罩製財絲難㈣成完美無缺之光罩 多次使用之後，造成鮮®案的受損， —。ΐ3 2陷之光軍進行半導體製程，將造成不必要 =貝失。因此’於騎半導體製程之前，需進行光罩的 檢測：罩缺陷時需進行修補。光罩的缺陷 區原本應為不透光區的部分形成透光 (_一縣，_么鮮又二 6 1249647 因素。 〜為解決光罩缺陷的問題，一般所使用的光罩修正技 術’主要為手動曝光、雷射光束以及聚焦離子束等修正 方式。習知的手動曝光方式是結合光微影與蝕刻步驟， 先以手動曝光方式於光罩上形成所需的光阻圖案露出光 罩之遮光缺陷，再進一步顯影蝕刻掉遮光缺陷以避免損 傷基材，但是由於此方法進行曝光所使用的光束的聚焦 尺寸較大，故解析度有限，而容易造成光罩圖案的誤差。 因此發展出解析度較高之應用雷射光束與聚焦離子束的 修正方法，利用高能量之能量束去除遮光缺陷。 。以雷射光束進行光罩修正之方法，如美國第5965301 號專利所述，係以雷射光束燒钕遮光缺陷，然而雷射光 束之大i熱旎，可能會溶解與蒸發與缺陷區域相鄰之不 透，薄膜，而傷害到光阻圖案。再加上雷射光束所傳遞 之高能量不僅會移除遮光缺陷，亦會使缺陷附近之基材 受到傷害而變粗糙，進而降低基材的透光率以及改變透 射光的相位，故僅以雷射光束來進行光罩修正，會產生 相當多的副作用。 使用聚焦離子束亦為常見之修正方法，如美國第 6322955號專利，其修正方法係先檢測出遮光缺陷之後， 再以聚焦離子束去除遮光缺陷，由於聚焦離子束之聚焦 尺寸遠小於雷射光束，因此就修補準確度上，佔有較^ 優勢，但是聚焦離子束之能量也可能會傷害到基材。也 由於聚焦離子束之聚焦尺寸較小，因而需將檢測出的遮 光缺卩曰刀成複數個微小區域，再以聚焦離子束一一將微 小區域的缺陷移除，故相當耗費時間。因此當同一光罩 出現過多缺陷時，通常會將光罩直接報廢，否則將耗費 過多修補時間。 1249647 會傷ίίΐΐ光ίίϋ種更有效率、更精準並且不 f發明内容】 *置技術的缺點’本發明的目的在於提供-種 ί ίίίίθΖ去除殘留於光罩透光區域的遮光缺 避免先罩圖案的射度糾影響，並且避免光 材於修正過程中受到損害。 土 修正光罩圖案，光微影製程所需使用 於、3透光基材與光罩圖案，鮮圖案係形成 ^ΐϋϊί面以遮斷光線，並且使透光基材表面未被 光罩圖案遮蔽的區域形成透光區。由於在光罩製程中，/, a mask pattern composed of opaque areas. A θ is difficult to cover the treasury (4) into a perfect mask. After repeated use, it caused damage to the Fresh® case. ΐ 3 2 The light of the military to carry out the semiconductor process will cause unnecessary = lost. Therefore, before the semiconductor manufacturing process, the reticle inspection is required: the hood is repaired when it is defective. The defect area of the mask should originally be transparent to the part of the opaque area (_1 county, _ ○ fresh and 2 6 1249647 factors. ~ In order to solve the problem of reticle defect, the reticle correction technology generally used 'mainly For manual exposure, laser beam and focused ion beam correction, the conventional manual exposure method is a combination of photolithography and etching step, first forming a desired photoresist pattern on the reticle by manual exposure to expose the reticle. The shading defect is further developed to etch away the shading defect to avoid damage to the substrate. However, since the focusing size of the beam used for exposure by this method is large, the resolution is limited, and the mask pattern error is easily caused. A higher degree of application of a modified method of laser beam and focused ion beam, using a high energy energy beam to remove shading defects. The method of mask correction with a laser beam, as described in US Pat. No. 5,965,301 The beam is burnt and the shading defect, but the laser beam is hot, which may dissolve and evaporate with the imperfect area adjacent to the defect area, and damage the light. The resistance pattern, coupled with the high energy transmitted by the laser beam, not only removes the shading defects, but also causes the substrate near the defect to be damaged and roughened, thereby reducing the transmittance of the substrate and changing the phase of the transmitted light. Therefore, only the laser beam is used to correct the mask, which will cause quite a lot of side effects. The use of the focused ion beam is also a common correction method, such as the US Patent No. 6,322,955, the correction method is to detect the shading defect first, and then The focused ion beam removes the shading defect. Since the focused beam size is much smaller than the laser beam, it has a superiority in repair accuracy, but the energy of the focused ion beam may also damage the substrate. The focus size of the beam is small, so it is necessary to remove the detected light-shielding knives into a plurality of micro-areas, and then remove the defects of the micro-regions by the focused ion beam one by one, which is quite time consuming. Therefore, when the same mask appears When there are too many defects, the mask will usually be scrapped directly, otherwise it will cost too much time to repair. 1249647 Will hurt ίίΐΐίίϋ More precise and not invented] * Disadvantages of the technology. The purpose of the present invention is to provide a radiance correction that avoids the opaque pattern of the hood pattern remaining in the light-transmitting region of the reticle, and avoids the light material. Damaged during the correction process. Soil correction mask pattern, photolithography process required to use, 3 transparent substrate and reticle pattern, fresh pattern to form ^ ΐϋϊ 面 surface to block light, and to make light-transmitting substrate The area of the surface not covered by the mask pattern forms a light transmitting area. Because in the mask process,
需於透光基材上沉積不透光細，再圖案化不透光薄膜 以在基板表面形成光罩圖案及露出透光區。因此，容易 有殘留的不透光薄膜或雜質存在於透光區，而本發明之 光罩修正方法，係用以去除透光區之遮光缺陷。X 根據上述目的，本發明所揭露之光罩修正方法，苴 步驟包含有··首先，提供—光罩，其包含透光基材、& 罩圖案與透光區，光罩圖案與透光區形成於透光基材表 面，且透光區内具有遮光缺陷；接著，於透光基材表面 塗佈保護層以覆蓋光罩圖案與透光區；利用能量束移除 對應遮光缺陷處的保護層，以露出遮光缺陷表面；以及， 進行姓刻程序，以去除未被保護層覆蓋之遮光缺陷。 其中，上述步驟中所採用之能量束可為雷射光束或 電子束，而透光基材一般採用石英玻璃基材，保護層需 為透光材質，以利於檢測遮光缺陷的位置。此外，亦可 利用微探針（tip)取代雷射光束來移除對應遮光缺陷處 的保瘦層，以露出遮光缺陷表面，再同樣的進行姓刻等 後續步驟。 為使對本發明的目的、構造特徵及其功能有進一步 8 1249647 的了解，茲配合圖示詳細說明如下： 【實施方式】 由^在光罩製程或後續使用流程中，容易有 不透光薄膜或雜質存在於光罩理應透光的區域， 遮光缺陷，故本發明揭露一種光罩修正 光罩之透統的遮級陷。 ㈣去除 的流發明實施例之光罩修正方法 首先，請參考第1A圖，提供一光罩1〇〇，包含 光ί圖案12G，光罩圖案12G係形成於透光基 =12G遮蔽的區域形成透光區13()，且透光^ 此定義後續所提之透光基材110表； 先罩圖案⑽之面。光罩圖案⑽可由塗佈不 透光的巧料卿成，如鉻、氧化鉻或其組合。 hi Hf考第1β圖’於透祕材iig表面塗佈透 妹i牛驟料層200於塗佈完成之後’需經過硬烤愈軟 且ϊίΐ後續步驟的進行，使用保護層200、ΐ 為保if 2有透光、祕取得與製程料等優點。 r πΐ二ίf 1C圖，利用雷射光束300移除對應遮光缺 乂以露出遮光缺陷131表面。由於 光祕131處之保制細，故所 使用，射，束3GG能量不用太高。 ^ 列篡ί參·1D圖’進行_程序，以保護層為蝕 保護層細覆蓋之遮光缺陷131。餘刻 2 it 懷佳’如濕蝕刻，以電聚直接對透2 面進行㈣。此步驟的目的在於⑽刻方式 矛、遮先缺陷131，將遮光缺陷131之外的區域以保護^ 1249647 ΠίΛΓ/1時精準的去除光罩100上的多處缺 衫⑽騎修正，又不會對㈣絲材110造 成才貝傷。 枚當溶液去除倾層_ ,此外，根據相同原理，本發明亦可提供另一實施例， it述修正流程中，_微探針取代雷射光束來移除 對應遮光缺陷處的保護層。 口本發明之光罩修正方法，可去除殘留於光罩之透光 區的遮光缺陷，避免藉由於光微影製程中，光罩所形成 光阻圖案精確度受到影響。而用以去除對應遮光缺陷處 的保護層之能量束除使用雷射光束之外，亦可採用電子 束。利用電子束作為光源的微影技術，其精準度可以達 到100奈米線寬以下。同時電子束不受限於繞射現象， 且具有相當的焦點深度（focal depth)。 本發明係提供簡化之光罩修正程序，可精準的同時 去除光罩上的多處缺陷，縮短修正時間，並可避免習知 技術f用雷射光束或聚焦離子束直接去除缺陷所造成的 基材損害，提升光罩的良率與降低光罩的報廢率。另外， 本發明利用現有之製程與設備即可完成快速與精密的光 罩修正流程，無須增加額外的成本。 雖然本發明之較佳實施例揭露如上所述，然其並非 用以限定本發明，任何熟習相關技藝者，在不脫i本發 明之精神和範圍内，當可作些許之更動與潤飾，因此本 發明之專利保護範圍須視本說明書所附之申請專利範圍 所界定者為準。 【圖式簡單說明】 第1A圖至第1E圖為本發明實施例之光罩修正方法的流 程截面示意圖。 1249647 【主要元件符號說明】 100 光罩 110 透光基材 120 光罩圖案 130 透光區 131 遮光缺陷 200 保護層 300 雷射光束A opaque thin film is deposited on the light-transmissive substrate, and the opaque film is patterned to form a reticle pattern on the surface of the substrate and expose the light-transmitting region. Therefore, it is easy to have residual opaque film or impurities present in the light-transmitting region, and the reticle correction method of the present invention is for removing the light-shielding defect of the light-transmitting region. According to the above object, the reticle correction method disclosed in the present invention comprises the following steps: First, a photomask is provided, which comprises a light-transmitting substrate, a mask pattern and a light-transmitting region, a mask pattern and a light-transmitting layer. The region is formed on the surface of the light-transmitting substrate, and has a light-shielding defect in the light-transmitting region; then, a protective layer is coated on the surface of the light-transmitting substrate to cover the reticle pattern and the light-transmitting region; and the corresponding light-shielding defect is removed by using the energy beam Protecting the layer to expose the shading defect surface; and, performing a surname procedure to remove the shading defect not covered by the protective layer. Wherein, the energy beam used in the above steps may be a laser beam or an electron beam, and the transparent substrate is generally a quartz glass substrate, and the protective layer needs to be a light-transmitting material to facilitate detecting the position of the shading defect. In addition, a micro-tip can be used instead of the laser beam to remove the thin layer corresponding to the shading defect to expose the shading defect surface, and the subsequent steps such as surname and the like are performed in the same manner. In order to make the object, structural features and functions of the present invention have a further understanding of the following description, the following is a detailed description of the following: [Embodiment] It is easy to have an opaque film or a process in the reticle process or subsequent use. The impurity is present in the area where the reticle is supposed to transmit light, and the light-shielding defect is present. Therefore, the invention discloses a shimming correction reticle of the reticle. (4) Removal of the reticle correction method of the embodiment of the invention First, referring to FIG. 1A, a mask 1 is provided, including a light pattern 12G, and the mask pattern 12G is formed in a region where the light-transmitting base = 12G is shielded. The light-transmissive region 13(), and the light-transmissive surface, defines the surface of the light-transmitting substrate 110 which is subsequently mentioned; the surface of the mask pattern (10). The reticle pattern (10) may be formed by coating a opaque material such as chromium, chromium oxide or a combination thereof. Hi Hf test 1β map 'through the secret material iig surface coating through the sister i cattle extract layer 200 after coating is completed 'to be hard-baked soft and ϊίΐ subsequent steps, using the protective layer 200, ΐ to protect If 2 has the advantages of light transmission, secret acquisition and process materials. The r π ΐ ί ί ί ί ί 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Since the light secret 131 is fine, it is used, shot, and the beam 3GG energy is not too high. ^ 篡 篡 · 1 1D ’ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ The engraving 2 it Huaijia's as wet etching, with electro-convergence directly on the surface of the two sides (four). The purpose of this step is to (10) engrave the spear, cover the defect 131, and correct the area outside the shading defect 131 to protect the multiple missing shirts (10) on the mask 100 when protecting ^ 1249647 ΠίΛΓ/1, without The (four) wire material 110 causes the shellfish injury. In addition, according to the same principle, the present invention can also provide another embodiment in which the micro-probe replaces the laser beam to remove the protective layer corresponding to the light-shielding defect. The reticle correction method of the present invention can remove the light-shielding defect remaining in the light-transmitting region of the reticle, thereby avoiding the influence of the precision of the photoresist pattern formed by the reticle during the photolithography process. The energy beam for removing the protective layer corresponding to the light-shielding defect may be an electron beam in addition to the laser beam. The lithography technology using an electron beam as a light source can have an accuracy of less than 100 nm line width. At the same time, the electron beam is not limited to the diffraction phenomenon and has a considerable focal depth. The invention provides a simplified reticle correction program, which can accurately remove multiple defects on the reticle at the same time, shorten the correction time, and avoid the base caused by the conventional technology to directly remove the defects by using the laser beam or the focused ion beam. Material damage, increase the yield of the mask and reduce the scrap rate of the mask. In addition, the present invention utilizes existing processes and equipment to perform a fast and precise reticle correction process without additional cost. While the preferred embodiments of the present invention are disclosed as described above, it is not intended to limit the invention, and those skilled in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The patent protection scope of the present invention is defined by the scope of the patent application attached to the specification. BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A to 1E are schematic cross-sectional views showing a process of a reticle correction method according to an embodiment of the present invention. 1249647 [Description of main component symbols] 100 Photomask 110 Translucent substrate 120 Photomask pattern 130 Transmissive area 131 Blackout defect 200 Protective layer 300 Laser beam
1111