1279923 此外為了減少CMOS成像之雜訊，必須確保感測元 所感測到之光線皆是來自彩色濾光陣列區分出之光線， 亦即，必須有效遮蔽自該彩色濾光陣列之間、以及自該感 測陣列外圍射入之光線。請參照第i圖，第丨圖係為一習 知CMOS裝置上半部之剖面圖。第1圖中由彩色濾、光陣列 圖案26、28、30以及感測元件32、34、36等所構成之區 域係為感光區域〗，而第1圖中感光區域I左側之區域則代 φ 表感光隱域I之外圍的周邊電路區（periphery circuits) II。 如第1圖所示，於彩色濾光陣列之下方有一圖案化之金屬 層丨4，用以反射自相鄰之彩色濾光陣列圖案26、28、30 間散射之光線，且僅於濾光陣列圖案26、28、30間隔之下 方設有金屬14以遮蔽雜光，此外該金屬層上覆有一平垣層 20以利後續製程之進行。如第1圖所示，於傳統CMOS穿 置感光區域I外圍之周邊電路區Η内設有用於避免雜光之 • 遮蔽層22等遮光元件。此外，由於CMOS裝置之感光區 域I之外園周邊電路區II 一般均包含有至少一用於電連接 之金屬墊24，由於金屬具有遮蔽光線之功效，因此於金屬 勢24處無須額外之遮光元件。 請繼續參照第1圖，傳統CMOS之製造，係於其他位 於基底40上之下層元件完成後，再於氮化層12上方進行 1279923 彩色濾光陣列之製造。首先，於感光區域i上形成一第一 單色濾光層，其中該單色濾光層一般係由具有光敏感性的 樹脂(resin)所構成，接著再以曝光暨顯影得到所需之第一 圖案，並利用染料染以第一色，以形成一圖案化之第一色 濾光層26。或者亦可使用染有第一色之光阻在感光區域1 上形成一第一色渡光層後，然後再進行後續之曝光暨顯 影’以形成一圖案化之第一色渡光層26。在第一色渡光層 26形成後，可進一步進行一熱烘烤(curing)製f呈以強化該第 一色濾光層26。接著，重複上述步驟以於感光區域I上分 別形成一圖案化之第二色濾光層28，以及一圖案化之第三 色色濾光層3〇。如此，濾光層26、28、30共同構成一彩 色濾光陣列。 在完成彩色濾光陣列之製作後，以類似之方式於感光 區域I外圍之周邊電路區11内形成一遮光層。亦即，先於 感光區域I外層形成一黑色感光材料層，接著再利用光罩 進行曝光暨顯影之製程，以形成一不透光之遮蔽層22。最 後再於遮蔽層22、彩色濾光陣列26、28、30上形成一平 坦層16，以利聚光透鏡18製作，並移除金屬墊24以及其 他必須暴露之部分上方之平坦層。此外，若因為佈局（lay〇ut) 設計的不同，周邊電路區11與感光區域1間可能不存在_ 1279923 金屬塾24，此時遮蔽層22便必須大刻足以遮蔽整個感光 區域1外圍之周邊電路區II。 儘管傳統之CMOS感測裝置製造方式雖可有效遮蔽感 測區域I外圍之雜光，然而使用黑色遮光層不但成本較高， 且可能會產生黑色素殘留的問題。立由於僅遮光層22係使 用黑色感光材料進行製造，是以必須特別為了製造遮光層 22而多進行一道曝光、顯影及熱烘烤製程，並多耗用一套 光罩。因此，目前急需要一種較為經濟簡便的遮光層，以 降低CMOS感測|置之製造成本，提高產能。 【發明内容】 本發明之主要目的在於提供一種改良之用於光學裝置 之遮光層以及其製造方法，以降低於CMOS感測裝置感光 區域外圍形成遮光層之成本。 根據本發明之申請專利範圍，揭露一種位於光學裝覃 之遮光層以及其製造方法，其中該光學裝置係為一種 CMOS感測裝置，該遮光層係為一種製作於一半導體基底 上之遮光層，而且該遮光層係由一第一單色濾光層與一第 二單色滤光層所疊合而成。 1279923 層之CMOS之元件的製造。在完成CMOS感測裝置之下層 元件製造後，需於預定形成彩色濾光陣列之區域下方形成 一圖案化之金屬層214,並依需要於一感光區域I外侧形成 一金屬墊204。其中圖案化金屬層214係用於遮蔽自彩色 濾光陣列之間隔射入之光線，亦即其圖案配置係取決預定 形成之彩色濾光陣列之圖案，且僅於彩色濾光陣列間隔下 方没有用於反射入射光之金屬。在完成金屬墊204、金屬 層214以及其他之金屬内連線等製程之後，於金屬層214 上覆蓋一平坦層220，以利後續製程之進行。接者，可選 擇性地於平坦層220上形成一氮化矽層212作為保護層。 在上述步驟完成後，即可進行本發明之遮光層之製 作。根據本發明，於感光區域j中形成一第一單色濾光層 206之同時’亦於感光區域I外圍之周邊電路區η内以同 樣材料、製程步驟同時形成另一第一單色濾光層262。接 著，請參照第3圖，於感光區域][中形成一第二單色濾光 層208之同時，再於周邊電路區η内之第一單色濾光層 上方以同樣材料、製程步驟同時形成另一第二單色濾光層 282,並使此第二單色濾光層282完全疊合於第一單色淚光 層262之上，從而完成本發明之遮光層。最後，請參照第 3圖，於感光區域I中形成第三單色濾光層21〇，以完成彩 11 1279923 色濾光陣列之製作。 上述第一單色濾光層262和第二單色濾光層282所疊 合而成之複合層即為本發明之方法所提供之遮光層。現請 參照第5圖，第5圖為一曲線圖，其顯示能通過紅、綠、 藍等之單色濾光片之光線波長。根據第5圖，當光線先通 過紅色渡光片，再通過藍色遽光片時，最終透過的僅剩斜 線區域A所顯示之少量光線，亦即紅色滤光片加上藍色滤 光片可濾掉大部分的可見光。換言之，當上述實施例中之 第一單色濾光層262以及第二單色濾光層282分別為紅色 濾光層和藍色濾、光層時，對於可見光具有較佳的遮蔽效 果，從而可替代傳統之黑色光阻而作遮光之用。 除此之外，亦可以其他顏色組合之雙層單色濾光層作 為遮光層。例如，當第一單色濾光層262以及第二單色濾 光層282分別為紅色濾光層和綠色濾光層時，僅區域B部 分之之可見光可通過，因此亦有一定程度之遮光效果，惟 其效果不若紅色和藍色濾光層的組合來得顯著。同樣地， 亦可以單一單色濾光層作為遮光層，然而單一之單色濾光 層遮光效果較為有限’因此不若雙層單色濾光層之組合理 想。當然，亦可以紅色、藍色、以及綠色三色之單色濾光 12 1279923 層相疊而形成遮光層，此種遮光層將具有更完全的遮光的 效果，惟璺合之單色濾光層越多，遮光層將愈厚，且過厚 之遮光層可能造成後續封裝、打線之困難度，然此可視產 品之需求、結構、佈局設計而有不同之調整，以求最佳之 組合效果。而雙層單色濾光層無論在遮光效果上，或厚度 上皆有適當之表現，因此較為理想。 必須強調的是，本發明所提供之遮光層製造流程亦不 限於上述程序。例如，亦可於完成濾光陣列區域中各濾光 層之製造後’再進行本發明之遮光層之製造。如此亦可達 到不使用黑色光阻以避免黑色色素污染的目的。 此外，除了 CMOS感測裝置之外，部分矽基液晶顯示 器（liquid crystal on silicon display，LCoS display)亦需使用 彩色濾光陣列進行分光。請參照第6圖，第6圖為LCoS 顯示1之結構示意圖。如圖所示，一 LCoS至少包含有一 半導體基底622，以及具有反射功能之像素電極624。於電 極624上方設有由數單色濾光層606、608、610構成之彩 色濾光陣列。該彩色濾光陣列所構成之區域係為LCoS顯 示器之像素區域，於該像素區域外圍亦可設置本發明之遮 光層（亦即第一單色濾光層662和第二單色濾光層682疊合 13 1279923 成之遮光層），以防止自'像素電極624反射出之光線自像素 區域外部射出造成漏光。 以上所述僅為本發明之較佳實施例，凡依本發明申請 專利範圍所做之均等變化與修飾，皆應屬本發明之涵蓋範 圍。 【圖式簡單說明】 第1圖為一習知CMOS感測裝置之剖面圖。 第2圖為一 CMOS感測裝置之剖面圖，其顯示製造一種本 發明之遮光層之方法。 第3圖為一 CMOS感測裝置之剖面圖，其顯示製造一種本 發明之遮光層之方法。 第4圖為一 CMOS感測裝置之剖面圖，其顯示製造一種本 發明之遮光層之方法。 第5圖為一曲線圖，其顯示能通過紅綠藍單色濾光片之光 線波長。 第6圖為一 LCoS之結構示意圖，其顯示本發明之另一具 體實施例。 14 12799231279923 In addition, in order to reduce the noise of CMOS imaging, it is necessary to ensure that the light sensed by the sensing element is the light that is distinguished from the color filter array, that is, it must be effectively shielded from between the color filter arrays, and from Sensing the light incident on the periphery of the array. Please refer to the i-th diagram, which is a cross-sectional view of the upper half of a conventional CMOS device. In Fig. 1, the area formed by the color filter, the light array patterns 26, 28, and 30, and the sensing elements 32, 34, 36, etc. is the photosensitive area, and the area on the left side of the photosensitive area I in Fig. 1 is φ. A peripheral circuit II of the periphery of the photographic photosensitive field I. As shown in FIG. 1, there is a patterned metal layer 丨4 under the color filter array for reflecting light scattered between adjacent color filter array patterns 26, 28, 30, and only filtering A metal 14 is disposed under the interval between the array patterns 26, 28, 30 to shield the stray light, and the metal layer is covered with a flat layer 20 for subsequent processing. As shown in Fig. 1, a light-shielding element such as a shielding layer 22 for preventing stray light is provided in a peripheral circuit region of the periphery of the conventional CMOS-shielded photosensitive region I. In addition, since the peripheral circuit area II of the CMOS device generally includes at least one metal pad 24 for electrical connection, since the metal has the effect of shielding light, no additional light shielding elements are required at the metal potential 24. Referring to Figure 1, the conventional CMOS fabrication is performed after the other underlying components on the substrate 40 are completed, and then the 1279923 color filter array is fabricated over the nitride layer 12. First, a first monochromatic filter layer is formed on the photosensitive region i, wherein the monochromatic filter layer is generally composed of a resin having light sensitivity, and then obtained by exposure and development. A pattern is dyed with a first color to form a patterned first color filter layer 26. Alternatively, a first color light-passing layer may be formed on the photosensitive region 1 by using a photoresist having the first color, and then subjected to subsequent exposure and development to form a patterned first color light-passing layer 26. After the formation of the first color light-transmissive layer 26, a further curing can be performed to strengthen the first color filter layer 26. Then, the above steps are repeated to form a patterned second color filter layer 28 and a patterned third color filter layer 3, respectively, on the photosensitive region I. Thus, the filter layers 26, 28, 30 collectively form a color filter array. After the fabrication of the color filter array is completed, a light shielding layer is formed in the peripheral circuit region 11 on the periphery of the photosensitive region I in a similar manner. That is, a black photosensitive material layer is formed on the outer layer of the photosensitive region I, and then a process of exposure and development is performed by using a photomask to form an opaque shielding layer 22. Finally, a planar layer 16 is formed over the masking layer 22, the color filter arrays 26, 28, 30 to facilitate fabrication of the concentrating lens 18 and to remove the planar layer above the metal pads 24 and other portions that must be exposed. In addition, if there is no _ 1279923 metal 塾 24 between the peripheral circuit area 11 and the photosensitive area 1 due to the difference in the layout design, the shielding layer 22 must be large enough to cover the periphery of the periphery of the entire photosensitive area 1. Circuit area II. Although the conventional CMOS sensing device manufacturing method can effectively shield the stray light around the sensing area I, the use of the black light shielding layer is not only costly, but may cause a problem of melanin remaining. Since only the light shielding layer 22 is manufactured using a black photosensitive material, it is necessary to perform an exposure, development, and thermal baking process particularly for the purpose of manufacturing the light shielding layer 22, and a mask is often consumed. Therefore, there is an urgent need for a relatively economical and simple shading layer to reduce the manufacturing cost of CMOS sensing and increase the production capacity. SUMMARY OF THE INVENTION A primary object of the present invention is to provide an improved light shielding layer for an optical device and a method of fabricating the same to reduce the cost of forming a light shielding layer on the periphery of a photosensitive region of a CMOS sensing device. According to the patent application scope of the present invention, a light shielding layer in an optical device and a manufacturing method thereof are disclosed, wherein the optical device is a CMOS sensing device, and the light shielding layer is a light shielding layer formed on a semiconductor substrate. Moreover, the light shielding layer is formed by laminating a first monochromatic filter layer and a second monochromatic filter layer. Manufacturing of 1279923 layer CMOS components. After the fabrication of the underlying components of the CMOS sensing device is completed, a patterned metal layer 214 is formed under the region where the color filter array is to be formed, and a metal pad 204 is formed outside a photosensitive region I as needed. The patterned metal layer 214 is used to shield the light incident from the color filter array, that is, the pattern configuration depends on the pattern of the color filter array that is to be formed, and is not used only under the color filter array interval. A metal that reflects incident light. After the metal pad 204, the metal layer 214, and other metal interconnects are completed, a flat layer 220 is overlaid on the metal layer 214 for subsequent processing. Alternatively, a tantalum nitride layer 212 is selectively formed on the planar layer 220 as a protective layer. After the above steps are completed, the production of the light-shielding layer of the present invention can be carried out. According to the present invention, a first monochromatic filter layer 206 is formed in the photosensitive region j while simultaneously forming another first monochromatic filter in the peripheral circuit region η at the periphery of the photosensitive region I in the same material and process steps. Layer 262. Next, referring to FIG. 3, while forming a second monochromatic filter layer 208 in the photosensitive region], the same material and process steps are simultaneously applied over the first monochromatic filter layer in the peripheral circuit region η. Another second monochromatic filter layer 282 is formed, and the second monochromatic filter layer 282 is completely superposed on the first monochromatic tear layer 262, thereby completing the light shielding layer of the present invention. Finally, referring to FIG. 3, a third monochromatic filter layer 21〇 is formed in the photosensitive region I to complete the fabrication of the color 11 1279923 color filter array. The composite layer formed by laminating the first monochromatic filter layer 262 and the second monochromatic filter layer 282 is a light shielding layer provided by the method of the present invention. Referring now to Figure 5, Figure 5 is a graph showing the wavelength of light that can pass through a monochromatic filter of red, green, blue, and the like. According to Fig. 5, when the light passes through the red light beam and then passes through the blue light beam, only a small amount of light displayed by the oblique line area A is transmitted, that is, the red color filter plus the blue color filter. Most of the visible light can be filtered out. In other words, when the first monochromatic filter layer 262 and the second monochromatic filter layer 282 in the above embodiment are respectively a red filter layer and a blue filter and a light layer, the visible light has a better shielding effect, thereby Can replace the traditional black photoresist for shading. In addition to this, a double-layer monochromatic filter layer of other color combinations may be used as the light shielding layer. For example, when the first monochromatic filter layer 262 and the second monochromatic filter layer 282 are respectively a red filter layer and a green filter layer, only the visible light of the portion B can pass, and thus there is also a certain degree of shading. The effect, but the effect is not as significant as the combination of the red and blue filter layers. Similarly, a single monochromatic filter layer can be used as the light-shielding layer, but the single monochromatic filter layer has a relatively limited light-shielding effect. Therefore, it is not desirable to combine the two-layer monochromatic filter layers. Of course, the red, blue, and green monochromatic filters 12 1279923 can be stacked to form a light-shielding layer. The light-shielding layer will have a more complete shading effect, but a monochromatic filter layer. The more the light-shielding layer will be thicker, and the thicker the light-shielding layer may cause difficulty in subsequent packaging and wire-bonding. However, the requirements of the product, structure, and layout design may be adjusted differently to achieve the best combination effect. The double-layer monochromatic filter layer is ideal in terms of shading effect or thickness. It must be emphasized that the manufacturing process of the light shielding layer provided by the present invention is not limited to the above procedure. For example, the fabrication of the light-shielding layer of the present invention can be carried out after the completion of the manufacture of the respective filter layers in the filter array region. This also achieves the goal of not using black photoresist to avoid black pigment contamination. In addition, in addition to the CMOS sensing device, a liquid crystal on silicon display (LCoS display) also needs to use a color filter array for splitting. Please refer to Figure 6, which is a schematic diagram of the structure of LCoS display 1. As shown, an LCoS includes at least a semiconductor substrate 622 and a pixel electrode 624 having a reflective function. A color filter array composed of a plurality of monochromatic filter layers 606, 608, and 610 is disposed above the electrode 624. The area formed by the color filter array is a pixel area of the LCoS display, and the light shielding layer of the present invention (ie, the first monochromatic filter layer 662 and the second monochromatic filter layer 682 may also be disposed on the periphery of the pixel area). Laminating 13 1279923 into a light-shielding layer) to prevent light reflected from the 'pixel electrode 624 from being emitted from the outside of the pixel area to cause light leakage. The above are only the preferred embodiments of the present invention, and all changes and modifications made to the scope of the invention are intended to be included in the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a conventional CMOS sensing device. Figure 2 is a cross-sectional view of a CMOS sensing device showing a method of making a light-shielding layer of the present invention. Figure 3 is a cross-sectional view of a CMOS sensing device showing a method of fabricating a light-shielding layer of the present invention. Figure 4 is a cross-sectional view of a CMOS sensing device showing a method of fabricating a light-shielding layer of the present invention. Figure 5 is a graph showing the wavelength of light that can pass through a red, green, and blue monochromatic filter. Fig. 6 is a schematic view showing the structure of an LCoS showing another specific embodiment of the present invention. 14 1279923
【主要元件符號說明】 12 氮化層 210 濾光層 14 金屬層 212 氮化層. 16 平坦層 214 金屬層 18 聚光透鏡 220 平坦層 20 半導體基底 232 感光元件 22 遮蔽層 234 感光元件 24 金屬塾 236 感光元件 26 濾光層 240 半導體基材 28 濾光層 262 第一單色濾光層 30 濾光層 282 第二單色濾光層 32 感光元件 606 濾、光層 34 感光元件 608 濾光層 36 感光元件 610 瀘光層 40 半導體基材 622 半導體基底 204 金屬墊 624 像素電極 206 濾光層 662 第一單色濾光層 208 濾光層 682 第二單色濾光層 15[Main component symbol description] 12 nitride layer 210 filter layer 14 metal layer 212 nitride layer. 16 flat layer 214 metal layer 18 concentrating lens 220 flat layer 20 semiconductor substrate 232 photosensitive element 22 shielding layer 234 photosensitive element 24 metal 塾236 photosensitive element 26 filter layer 240 semiconductor substrate 28 filter layer 262 first monochromatic filter layer 30 filter layer 282 second monochromatic filter layer 32 photosensitive element 606 filter, light layer 34 photosensitive element 608 filter layer 36 photosensitive element 610 enamel layer 40 semiconductor substrate 622 semiconductor substrate 204 metal pad 624 pixel electrode 206 filter layer 662 first monochromatic filter layer 208 filter layer 682 second monochromatic filter layer 15