五、發明說明（1) 〈發明背景〉 本發明之發明領域係有關於使用在由微影技術製造微 細圖樣之程序中，製造光電投射掩模的方法。 〈相關技術說明〉 光電投射掩模為在由微影技術製造微細圖樣程序中使 用的上圖樣罩。如第1圖中所示者，光電投射掩模包含薄 膜1，其中由曝露作用的應力均勻地傳送到整個光電投射 掩模中，在薄膜1的前侧形成吸收劑2，因此可吸收或反射 該投射的曝露，且在薄膜1的後側形成架子3，因此可支樓 整個結構。 已使用一絕緣體上的矽"SOI"晶圓製造光電投射掩模。 SOI晶圓包含矽層，用於在矽層上形成絕緣以支撐整個s〇i 晶圓結構的埋入氮化層，及在埋入氮化層上形成之；g夕層， 此矽層上可形成一裝置。 第2A圖到第2E圖之截面圖，用於顯示製造傳統光電投 射掩模的方法。 首先’具有如第2A圖所示，提供用於薄膜具有埋入氮 化膜12之SOI晶圓，及堆疊在矽基體1〇的矽層14 β在此矽 基艘10 ’埋入氮化膜12及矽層14的厚度分別為725 //m，1 Um 及2〇 βΐη。 如第2Β圖所示，此後，在矽層14上形成一第一光阻層 圖樣1 6以曝露矽層1 4中的某些部位。如第2C圖所示，由蚀 刻延伸去除曝露的矽層14 ’其中使用第一光阻層圖樣16作 為触刻罩’因此形成一吸收劑15 β 。其次，去除第一光阻V. Description of the invention (1) <Background of the invention> The field of invention of the present invention relates to a method for manufacturing a photo-projection mask used in a process for manufacturing a fine pattern by a lithography technique. <Description of Related Technology> A photo-projection mask is an upper pattern mask used in a micro-pattern manufacturing process by lithography technology. As shown in FIG. 1, the photo-projection mask includes a thin film 1 in which the stress caused by the exposure is uniformly transmitted to the entire photo-projection mask, and an absorbent 2 is formed on the front side of the film 1 so that it can absorb or reflect This projected exposure, and the shelf 3 is formed on the rear side of the film 1, so the entire structure of the building can be supported. Photoelectric projection masks have been fabricated using silicon " SOI " wafers on an insulator. The SOI wafer includes a silicon layer, which is used to form insulation on the silicon layer to support the buried nitride layer of the entire SOI wafer structure, and is formed on the buried nitride layer; the layer is on the silicon layer A device can be formed. 2A to 2E are sectional views showing a method of manufacturing a conventional photovoltaic projection mask. Firstly, as shown in FIG. 2A, a SOI wafer for providing a thin film with an embedded nitride film 12 and a silicon layer 14 β stacked on a silicon substrate 10 are provided. Here, the silicon substrate 10 is embedded with a nitride film. The thicknesses of 12 and silicon layer 14 are 725 // m, 1 Um, and 20βΐη, respectively. As shown in FIG. 2B, thereafter, a first photoresist layer pattern 16 is formed on the silicon layer 14 to expose some parts of the silicon layer 14. As shown in FIG. 2C, the exposed silicon layer 14 ' is removed by etching extension, wherein the first photoresist layer pattern 16 is used as a touch engraving mask ', thereby forming an absorber 15 [beta]. Second, remove the first photoresist
第6頁 五、發明說明（2) 層圖樣16。 如第2D圖所示’在矽基體丨〇的後側形成第二光阻層圖 樣1 8 °該第二光阻層圖樣丨8為用於蝕刻矽基體丨〇之後側的 姓刻罩。如第2 E圖中所示者，經由光阻層圖樣1 8作為蝕刻 罩’且由後側姓刻程序’傾斜蝕刻矽基體丨〇的後側，稱為 曝露，埋入氧化膜12為止’因此形成架子11。此後，去除 第一光阻層圖樣18，因此製造包含架子u，薄膜12及吸收 劑15的光電投射掩模。 同時’當具有技術結構的光電投射掩模用於微影程 序’其中電子束的加速電壓約50KeV時，電子穿過吸收劑 15以吸收或反射電子束。即在使用光電投射掩模2〇之微影 程序中由經吸收劑發射的光，在半導體基體上形成一不需 要的圓樣。因此，為了解決上述問題，可形成厚度超過2〇 仁m而使用在吸收劑上的矽層。 但是，當用於吸收劑之矽層14的厚度超過2〇#m時， 很難製造SO I晶圓。必需要有一額外的製造程序，以製造 SOI晶圓，但是此勢必更進一步增加生產成本。而且在 蝕刻厚度超過20ym的矽層時，需要較長的蝕刻時間且 蝕刻程序不穩定。 〈發明之總論〉 產生穩定及簡單製造程序之光電投射掩模製造方法 含下列步驟：在基體上形成一薄膜；在薄膜上形成一且 電子穿透防止能力的金屬層；在金屬層上形成第一光^ 圖樣，以曝露出金屬層中的某些部位；經由使用第一光阻Page 6 5. Description of the invention (2) Layer pattern 16. As shown in FIG. 2D, a second photoresist layer pattern 18 is formed on the rear side of the silicon substrate. The second photoresist layer pattern 8 is a mask for etching the rear side of the silicon substrate. As shown in FIG. 2E, the photoresist layer pattern 18 is used as an etching mask 'and the rear side is engraved with the program' tilt etching the rear side of the silicon substrate. It is called exposure until the oxide film 12 is buried ' Thus, the shelf 11 is formed. Thereafter, the first photoresist layer pattern 18 is removed, and thus a photo-projection mask including a frame u, a thin film 12, and an absorbent 15 is manufactured. At the same time, when a photo-projection mask having a technical structure is used in a lithography program, where the acceleration voltage of the electron beam is about 50 KeV, the electrons pass through the absorbent 15 to absorb or reflect the electron beam. That is, in the lithography process using the photo-projection mask 20, the light emitted by the absorber forms an unnecessary circular pattern on the semiconductor substrate. Therefore, in order to solve the above problems, a silicon layer having a thickness of more than 20 μm can be formed on the absorbent. However, when the thickness of the silicon layer 14 used for the absorbent exceeds 20 μm, it is difficult to manufacture an SO I wafer. There must be an additional manufacturing process to manufacture SOI wafers, but this is bound to increase production costs even further. In addition, when etching a silicon layer having a thickness of more than 20 μm, a longer etching time is required and the etching process is unstable. <Summary of Invention> A method for manufacturing a photoelectric projection mask that produces a stable and simple manufacturing process includes the following steps: forming a thin film on a substrate; forming a metal layer on the thin film with electron penetration prevention capability; forming on the metal layer First light ^ pattern to expose some parts of the metal layer; by using a first photoresist
五、發明說明（3) 層作為蝕刻罩而對金屬層上圖樣，因此形成吸收劑；去除、 第一光阻層圖樣；形成第二光阻層圖樣’而在支撐基體的 後側，曝露出支撐基體的後側之一部份；以第二光阻層圖 樣作為蝕刻罩，蝕刻基體後側的曝露部位，直到曝露出薄 膜為止，因此形成一架子；以及去除第二光阻層圖樣。 〈圖式之簡單說明〉 第1圖之載面圖顯示傳統的光電投射掩模。 第2A圖到第2E圓之截面圖，用於\顯示製造傳 射掩模的方法。 、光電投 第3A圖到第3D圖之截面圖，用於顯示依據本 光電投射掩模的方法。 8 月製造 〈圖式中元件名稱與符號對照> I :薄膜 10 :矽基體 II :架子 12 :氮化膜 14 :矽層 15 :吸收劑 1 6 :第一光阻層圓樣 18 :光阻層圓樣 2 :吸收劑 2 0 :光電投射掩模 3 :架子 3 0 :支撐矽基體V. Description of the invention (3) The layer is used as an etching mask to pattern the metal layer, thereby forming an absorbent; removing the first photoresist layer pattern; forming the second photoresist layer pattern ', and exposing it on the back side of the support substrate Supporting a part of the rear side of the substrate; using the second photoresist layer pattern as an etching cover, etching the exposed portion on the rear side of the substrate until the film is exposed, so forming a shelf; and removing the second photoresist layer pattern. <Simplified Explanation of Drawings> The front view of FIG. 1 shows a conventional photoelectric projection mask. Sections 2A to 2E are used to show the method of manufacturing a transmission mask. 3. Photoelectricity The sectional views of Figs. 3A to 3D are used to show the method of the photoelectric projection mask according to the present invention. August Manufacturing <Comparison of component names and symbols in the drawings> I: Thin film 10: Silicon substrate II: Shelf 12: Nitrided film 14: Silicon layer 15: Absorbent 16: First photoresist layer round sample 18: Light Barrier circle sample 2: Absorbent 2 0: Photoelectric projection mask 3: Shelf 3 0: Supporting silicon substrate
第8頁 五、發明說明 ⑷ 31 架 子 32 薄 膜 34 金 屬 層 35 吸 收 劑 36 第 光 阻層 圖 樣 38 第 二 光 阻層 圖 樣 〈較佳具體實施例之詳細描述> 第3D圖中所示的光電投射掩模包含一支撐矽基體3〇， 一在支撐矽基體30上形成的薄膜32，及一在薄膜32上形成 的吸收劑35。 傳統上使用裸矽晶圓於支撐矽基體30上。由二氧化石夕 層Si〇2或I化；6夕層SixNy製造薄膜32。由如鹤層或氣化鈇 層的金屬層製造吸收劑35，其可有效地防止使用電子束作 為光源時’微影程序中的電子束穿透。吸收劑35的厚度介 於1. 5至2. 5 # m之間。 " 第3A圖至第3D圖之截面圖顯示本發明實施例中製造光 電投射掩模的方法。現在請參考第3A圖，提供由裸矽晶圓 製造的支撐基體30。厚度2到5#m之間的薄膜32於基體上 形成’且薄膜32包含二氧化矽層或氮化矽層，其厚度介於 2到5 # m之間》由低壓化學蒸汽沉積（LPCVD)方法形成薄膜 32。因此可加強吸收劑的介面黏著性，可在一連串的步驟 中形成吸收劑。在此，具有蝕刻選擇比率γ : i到丨〇 .工且 含基體30的薄膜32包含二氧化矽或氮化矽層之一。結果， 薄膜32動作如在餘刻基體30之一連串動作中的蝕刻止動Page 8 V. Description of the invention ⑷ 31 shelf 32 film 34 metal layer 35 absorber 36 pattern of photoresist layer 38 pattern of second photoresist layer <detailed description of preferred embodiment> Photoelectricity shown in FIG. 3D The projection mask includes a supporting silicon substrate 30, a thin film 32 formed on the supporting silicon substrate 30, and an absorbent 35 formed on the thin film 32. Traditionally, a bare silicon wafer is used on the supporting silicon substrate 30. The thin film 32 is made of a layer of SiO2 or SiO2; a layer of SixNy. The absorber 35 is made of a metal layer such as a crane layer or a vaporized hafnium layer, which can effectively prevent the electron beam from penetrating in the 'lithography process when an electron beam is used as a light source. The thickness of the absorbent 35 is between 1.5 and 2.5 # m. " The sectional views of Figs. 3A to 3D show a method for manufacturing a photo-projection mask in an embodiment of the present invention. Referring now to FIG. 3A, a support substrate 30 made from a bare silicon wafer is provided. A thin film 32 having a thickness of 2 to 5 # m is formed on the substrate ', and the thin film 32 includes a silicon dioxide layer or a silicon nitride layer, and the thickness is between 2 and 5 # m by a low pressure chemical vapor deposition (LPCVD) The method forms a thin film 32. Therefore, the interface adhesion of the absorbent can be enhanced, and the absorbent can be formed in a series of steps. Here, the thin film 32 having an etching selection ratio γ: i to SiO 2 and containing the substrate 30 includes one of a silicon dioxide or a silicon nitride layer. As a result, the film 32 operates as an etch stop in a series of operations of the remaining substrate 30
第9頁 五 '發明說明（5) 劑。 現在請參考第3B囷，在薄膜3 2上形成用於吸收劑的金 屬層34。如鎢層W或氮化鈦層τ :1^的金屬層可有效在經由 曝露作為光源的微影程序中可有效地防止曝露穿透。金屬 層34厚度範圍介於丨· 5 到2. 5 之間。然後，在金屬層 34上形成第一光阻層圖樣3 6以曝露出金屬層34中的某些部 位。 現在請參考第3C圈，由蝕刻程序蝕刻金屬層34，其中 使用第一光阻層圖樣34作為蝕刻罩，因此形成吸收劑35。 在此吸故劑的厚度範圍介於1.5〜2.5#m之間。因為吸收 劑$的厚度比傳統厚度2〇 β m的矽層還要薄，因此可得到 穩定及快速的處理。其次，去除動作如蝕刻罩的第一光阻 廣圖樣36 ’且在基體後側形成曝露基體3〇之中心區域的第 二光阻層圖樣38。 現在請參考第3D圖’蝕刻基體3〇的曝露後側，直到經 由作為蝕刻罩的第二光阻層圖樣曝露薄膜32 =姓刻程序，因此形成-架子3卜然後，去除第二^ 層圓樣38及具有架子31的光電投射掩模4〇 , 膜32及吸收劑35 β 乂 了侍到4 於思依據本實施例，傳統上用於蝕刻厚度20 βΜΟΖ晶圓之 層的方法比較之下，執行用於吸收劑的穩 係因為吸收劑34從具有高電子穿透防止能的材料中擇 之故，該材料如鎢或氮化鈦，且吸收劑34 於u到2.5财間。而且，對基細上圖樣厚m介 第10頁 五、發明說明（6) ^------ 行用於基體的穩定蝕刻程序時，薄膜32之叙& 劑。 助作如蝕刻停止 因此’與傳統上的SOI晶圓比較下’可得到由穩定及 簡單方法產生之光阻層圖樣。 ~ 雖然文中已應較佳實施例說明本發明，但嫻熟本技術 者需了解可對上述實施例加以更改及變更，而不偏離本發 明的精神及觀點，其中本發明的精神及觀點係由申請專利 範圍所定義。Page 9 Five 'Explanation of invention (5) agent. Referring now to Section 3B 囷, a metal layer 34 for an absorbent is formed on the film 32. A metal layer such as a tungsten layer W or a titanium nitride layer τ: 1 ^ can effectively prevent the exposure from penetrating in the lithography process through exposure as a light source. The thickness of the metal layer 34 ranges from 丨 · 5 to 2.5. Then, a first photoresist layer pattern 36 is formed on the metal layer 34 to expose portions of the metal layer 34. Referring now to circle 3C, the metal layer 34 is etched by an etching process, wherein the first photoresist layer pattern 34 is used as an etching mask, and thus an absorber 35 is formed. The thickness of the absorbent is between 1.5 ~ 2.5 # m. Because the thickness of the absorbent $ is thinner than the conventional silicon layer with a thickness of 20 β m, stable and rapid processing can be obtained. Next, the removal operation is like the first photoresist pattern 36 'of the etching mask, and a second photoresist layer pattern 38 is formed on the rear side of the substrate to expose the central area of the substrate 30. Now please refer to the 3D picture of the exposed rear side of the etching substrate 30 until the thin film is exposed through the second photoresist layer pattern as the etching mask. Sample 38 and the photoelectric projection mask 40 with the frame 31, the film 32 and the absorber 35 β are compared to the above. According to this embodiment, the traditional method for etching a layer with a thickness of 20 βM0Z is compared. The stabilization for the absorbent is performed because the absorbent 34 is selected from a material having a high electron penetration preventing ability, such as tungsten or titanium nitride, and the absorbent 34 is between u and 2.5. Moreover, the thickness of the pattern on the substrate is described in page 10 5. Explanation of the invention (6) ^ ------ When performing a stable etching process for the substrate, the thin film 32 is used as an & It can be used as an etch stop. Therefore, compared with the conventional SOI wafer, a photoresist layer pattern produced by a stable and simple method can be obtained. ~ Although the present invention should be explained with preferred embodiments, those skilled in the art need to understand that the above embodiments can be modified and changed without departing from the spirit and viewpoints of the present invention. The spirit and viewpoints of the present invention are provided by the application. Defined by patent scope.
第11頁Page 11