200810100 九、發明說明： 【發明所屬之技術領域】 本發明係關於一種具有波導管之影像感測裝置及其製 作方法。 【先前技術】 互補式金氧半導體電晶體影像感測器（CMOS image 藝 sensor，CIS)為現今一種常見的影像感測裝置，且由於ciS 可以整合於傳統的半導體製程製作，因此具有製作成本較 低、元件尺寸較小以及積集度（integration)較高的優點。此 外CIS還具有低扭作電壓、低功率消耗、高量子效率 (quantum efficiency)、低雜訊（read-〇ut noise)以及可根據需 要進行隨機存取(random access)等優勢，因此已廣泛應用在 個人電腦相機(PC camera)以及數位相機(digital camera)等 0 電子產品上。 典型的CIS結構可依其功能劃分為一光感測區與一周 邊電路區’其中光感測區通常設有複數個成陣列排列的感 光二極體(photodiode)，並分別搭配重置電晶體(reset transistor)、電流汲取元件（current s〇urce f〇ii〇weT)及列選擇 開關（row selector)等之MOS電晶體，用來接收外部的光線 > 並感測光照的強度，而周邊電路區則用來串接内部的金屬 ' 内連線及外部的連接線路。而CIS之感光原理係將入射光 6 200810100 線區分為各種不同波長光線的組合，再分別由半導體基底 上之複數個感光元件予以接收，並轉換為不同強弱之數位 訊號。例如，將入射光區分為紅、藍、綠三色光線之組合， 再由相對應之感光二極體予以接收，進而轉換為數位訊 號。此外，感光二極體主要係依照該光感測區所產生之光 電流來處理訊號資料，例如光感測區於受光狀態所產生的 光電流(light current)代表訊號(signal)，而光感測區於不受 光狀態所產生的暗電流(dark current)則代表雜訊(n〇ise)，因 此感光二極體可以利用訊號雜訊比的強弱方式來處理訊號 資料，並將比對後的訊號資料轉交該周邊電路區傳輸。 請參考第1圖，第1圖為傳統的CIS結構示意圖，包 含有一半導體基底10，其表面設有複數個感光二極體11、 12、13 以及複數個淺溝隔離（shallow trench isolation，STI)14 分隔感光二極體11、12、13，以定義出一像素陣列，其中 感光二極體11、12、13分別包含一 η型摻質區16與一 p 型摻質區17，作為感測外來光源強度的元件。此外’為建 立完整的CIS結構，半導體基底10表面設有複數層介電層 與多重金屬内連線(multilevel interconnects)，例如一層間介 電層（interlevel dielectric layer) 20與二層金屬間介電層 (intermetal dielectric layer，IMD)22、24，而金屬間介電層 22、24間另設置有複數個金屬導線23、25。 200810100 然而如第1圖所示，當來自一外部光源3〇的一入射光 線32 ’以近乎垂直的角度入射至感光二極體I]，並引發相 關的電子訊號傳遞；但同樣來自外部光源3〇的一散射光線 34，則是先射向金屬導線25並在表面反射後，再轉而入射 至鄰近感光二極體12的另一感光二極體13，因而發生了 所謂的跨越干擾現象(crosstalk effect)，使得原本處於不受 光狀態的感光二極體13受到散射光線34的干擾，導致感 先二極體13比對訊號與雜訊的比值無法提昇，明顯影響 CIS在感光功能上的靈敏度（sensitivity)。 為改善傳統CIS各感.光二極體間所發生的跨越干擾現 象，美國專利案號US 6,861,86.6提出一種改良後的CIS結 構，如第2圖所示。第2圖為美國專利案號US 6,861，866 所k出之改良後的ClS結構不意圖’其可大略區分為左側 的一光感測區40以及右側的一金屬内連線電路區42，此 CIS結構包含一基底44、複數層金屬間介電層（IMD)46與 複數層防止金屬原子擴散的擴散阻障層（diffusion barrier layer)48交互相疊於基底44上方，其中金屬内連線電路區 42係包含複數層銅金屬導線50,負責電連接相對應之閘極 52與源極/没極54以控制CIS訊號的傳遞；而光感測區40 則包含設於基底44表面之一感光二極體5卜、一光學通道 (light passageway)58設於感光二極體％上方、複數層金屬 阻障層（metal barrier)60共同構成光學通道58之一内側壁 8 200810100 面62、一用以阻絕跨越干擾現象之保護層64設於光學通 道58之内侧壁面62表面並覆蓋於金屬間介電層46表面、 一透明填充層（transparent filler)66填入光學通道58、一彩 色濾光片68覆蓋於透明填充層66表面以及一微聚光鏡 (microlens) 70設於光學通道58上方。但由於製程的關係， 光學通道58之内侧壁面62係分別由各介電層46中定義光 學通道58位置的金屬阻障層60上下連接而成，因此光學 通道58之内侧壁面62係為一不連續的表面，這將使得部 分照射至光學通道58之内側壁面62的光線容易發生散 射，而無法完全順利到達光學通道58下方的感光二極體 56,相對地造成感.光二極體46可接收到的有效光線數將大 幅減少。 此外，另一美國專利案號US 6,969,899亦揭露相似的 CIS結構，如第3圖所示，其包含有一基底72、複數個感 光二極體74設於基底74表面、複數個淺溝隔離76交錯於 感光二極體74之間、複數層第一介電層78覆蓋於基底72 上方，以及複數個光學通道80直接至連接感光二極體74。 其中，每一個光學通道80内均充填有一第二介電層82， 且各光學通道80之内侧壁面皆形成有一第三介電層84， 用以阻絕跨越干擾現象。但由於其所揭露之光學通道80係 直接連接至感光二極體74，因此在實際的製程上，這將導 致在蝕刻出光學通道80時，感光二極體74的光感測區表 200810100 面非常容易受到電漿損壞(plasma damage)及不純物殘留的 污染，產生大量的表面缺陷，增加漏電流造成雜訊，使得 感光二極體74的感光效果下降，嚴重時，甚至會造成感光 二極體74元件的損壞而喪失其功能。 【發明内容】 因此本發明的主要目的在於提供一種具有波導管之影 _ 像感測裝置以.及其製作方法，可有效避免跨越干擾現象並 大幅提高影像感測裝置的靈敏度。 依據本發明之申請專利範圍，係揭露一種影像感測裝 置’包含一具有至少一光學元件之基底、至少一介電層設 於該基底上以及至少一波導管（wave-guide tube)設於該介 電層中。該波導鲁之侧壁具有一平直表面，且該波導管係 φ 對應該光學元件並與該光學元件相距一預定距離，而該波 導管包含有一鑲嵌於該介電層内之填充層以及一設於該填 充層之侧壁之光學屏障層，其中該填充層與該光學屏障層 分別具有一反射係數〜與n3，且該填充層之該反射係數叱 大於該光學屏障層之該反射係數n3。 依據本發明之申請專利範圍，另揭露一種影像感測裝 i的製作方法。首先提供—具有至少—光學元件之基底， ^ 隨即在該基底上形成至少一介電層，並覆蓋於該光學元 10 200810100 件，之後於該介電層中形成一具有一凹槽，該凹槽係對應 於該光學元件，且該凹槽與該光學元件相隔一預定距離， 然後於該凹槽之内侧璧表面形成一光學屏障層’最後形成 一填充層填滿該凹槽，以形成一波導管’其中該介電層具 有一反射係數恥、該填充層具有一反射係數〜以及該光學 屏障層具有一反射係數113，且該填充層之該反射係數〜大 於該光學屏障層之該反射係數η3 ° 由於本發明之影像感測裝置之波導管底部為具有聚焦 效果之一凹型底面，並與光學元件間相距一預定距離，以 避免光學元件發生表面缺陷而增加漏電流’而波導管内側 壁更具有一光學屏障層，可有效避免不同光路間的跨越效 應，同時藉由光學屏障層與填充層的折射率差異，使非垂 ·· · · 直入射的光線在波導管内進行全反射，造成波導效應 ⑩ （wave-guide effect)，因此下方的光學元件可以收集到更多 的光線，進而能增加該影像感測裝置的感光效果和靈敏 度。此外，波導管内之填充層更可直接利用分色膜(dichr〇ic film)或彩色濾光片的材質製作而成，以縮短光徑，大幅提 高影像感測裝置的解析度。 【實施方式】 為了使突顯本發明之優點及特徵，下文列舉本發明之 -一較佳實施例，並配合圖示作詳細說明如下： 200810100 第4圖至第10圖為本發明之影像感測裝置的製程示意 圖。首先請參考第4圖，提供一基底1〇〇，其上已形成有 至少一光學元件106、至少一絕緣物1〇5分隔光學元件 1 〇6、至少一層間介電層（interlevel dielectric layer， ILD)112、複數層金屬間介電層（intermetal dielectric layer， IMD)114、116、118以及複數個金屬導線l〇7、l〇8、109。 於本較佳實施例中，基底100為一半導體基底，但不限制 _ 為一矽晶圓（wafer)或一矽覆絕緣(SOI)等之基底；光學元件 106可為一感光二極體(photodiode)，用來接收外部的光線 並感測光照的強度，而且光學元件106係另電連接至重置 電晶體、電流汲取元件或列選擇開關等之CMOS電晶體（未 顯示），絕緣物105可為淺溝隔離（shallow trench isolation， STI)或局部碎氧化絕緣層（i〇cai oxidation of silicon isolation layer，LOCOS)，用以避免光學元件106與其他元 φ 件相接觸而發生短路；層間介電層112可以是一氧化矽層 (silicon oxide)或一硼磷矽玻璃（borophosposilicate glass， BPSG)層等；金屬間介電層114、116、118則可由一氮氧化 石夕層（SiON)或一氟石夕玻璃層（fluoride silicate glass，FSG) 等；至於構成多重金屬内連線(multilevel interconnects)之金 屬導線107、108、109及金屬間介電層114、116、118則 可利用雙鑲嵌製程或習知之金屬内連線製程加以製作，在 * 此不多贅述。 200810100 如第5圖所示，首先於金屬間介電層118表面形成一 圖案化的光阻層（圖未示），接著再利用此圖案化的光阻層 當作遮罩來蝕刻光學元件106上方之金屬間介電層114、 116、118，以於金屬間介電層114、116、118中形成一凹 槽120，並使凹槽120底部產生一凹型（concave)底面122。 其中，凹槽120頂端開口的直徑由於蝕刻的結果會自然形 成略大於凹槽120的底面直徑，例如凹槽122之底面直徑 約為開口直徑的75%〜95%之間，最好是在95%以上盡量使 該侧壁保持接近垂直，此一漏斗型結構將有利於後續沉積 製程的進行，並能有效地導引入射光線至光學元件106。 此外，本發明亦可先利用一乾蝕刻製程來蝕刻金屬間介電 層114、116、118，然後再進行一溼蝕刻製程來蝕刻層間介 電層112以產生凹型底面122 ,或者是如前所述藉由控制 該乾蝕刻製程之參數而直接於金屬間介電層114、116、118 中形成此具有凹型底面122之凹槽120。由於凹槽120係 直接蝕刻複數層介電層所得，因此凹槽120具有一平直的 内側壁，不會造成光線無方向性的散射。此外，凹槽120 的外觀並不囿限於如第5圖所示之漏斗型結構，其亦可以 是一具有垂直壁面的管狀結構或是其他開口直徑與底面直 徑一致的柱狀結構，且凹槽120的底面122亦可取代為一 平面或其他可聚光之底面結構。 值得注意的是，本發明之凹槽120的凹型底面122與 13 200810100 光學元件106間相距一預定距離。於本較佳實施例中，此 預疋距離約為層間介電層112的厚度，亦即本較佳實施例 係钱刻金屬間介電層114、116、118而停止於層間介電層 112表面。而且本發明之該預定距離，亦相對應於凹槽12〇 餘刻的深淺，可端視於各產品的規格需求或凹型底面122 的曲率半徑及感光區域的形狀大小而做適度的調整，因此 不但能用以確保凹型底面122相作用於光學元件1 〇6的焦 距’提高感光的靈敏度（sensitivity)，而且該預定距離更可 用以確保光學元件106表面在餘刻製程或其他後續的製程 當中不受外力的影響與傷害，進而增加本發明所示之影像 感測裝置的可靠性。 接著如第6圖所示，利用一沉積製程，如化學氣相沉 積（chemical vapor deposition，CVD)製程、高溫沉積製程、 電漿輔助化學氣相沉積（plasma enhanced chemical vapor deposition，PECVD)製程或物理氣相沉積（phySical vapor deposition，PVD)製程等，形成一平直的光學屏障層124覆 蓋於凹槽120之内侧壁、凹型底面丨22與金屬間介電層118 表面。值得注意的是，在本較佳實施例中，層間介電層112 與金屬間介電層114、116、118的反射係數大於光學屏障 層124的反射係數。例如，若層間介電層Π2與金屬間介 電層114、116、118均具有一相同之反射係數(refiective index，RI) η〗，而光學屏障層124具有一反射係數n3，則層 200810100 114 ' 116、118之反射係數 I數n3。光學屏障層124之 間介電層112與金屬間介電層ll4 ηι大於光學屏障層120的反射係數 材貝可以疋氧化鈦(tltamum Qxide)、氧化石夕或其他反射係數 值符合前述要件的材料所構成。此外，考量金屬本身具有200810100 IX. Description of the Invention: [Technical Field] The present invention relates to an image sensing device having a waveguide and a method of fabricating the same. [Prior Art] Complementary CMOS image sensor (CIS) is a common image sensing device today, and since ciS can be integrated into traditional semiconductor process manufacturing, it has a higher manufacturing cost. Low, small component size and high integration. In addition, CIS has been widely used because of its low torsion voltage, low power consumption, high quantum efficiency, low noise (read-〇ut noise), and random access as needed. On 0 electronic products such as PC camera and digital camera. A typical CIS structure can be divided into a light sensing area and a peripheral circuit area according to its function. The light sensing area is usually provided with a plurality of photodiodes arranged in an array, and respectively matched with a resetting transistor. (Reset transistor), MOS transistor such as current s〇urce f〇ii〇weT and row selector, for receiving external light > and sensing the intensity of illumination, while surrounding The circuit area is used to connect the internal metal 'interconnects' and external connection lines. The sensitization principle of CIS is to divide the incident light 6 200810100 into a combination of light of different wavelengths, and then receive them by a plurality of photosensitive elements on the semiconductor substrate, and convert them into digital signals of different strengths and weaknesses. For example, the incident light is divided into a combination of red, blue, and green light, which is then received by the corresponding photodiode and converted into a digital signal. In addition, the photodiode mainly processes the signal data according to the photocurrent generated by the photo sensing region. For example, the light current generated by the photo sensing region in the light receiving state represents a signal, and the light sensation The dark current generated by the measurement area in the unexposed state represents noise (n〇ise), so the photodiode can use the strength of the signal noise ratio to process the signal data, and the comparison will be made. The signal data is forwarded to the peripheral circuit area for transmission. Please refer to FIG. 1 , which is a schematic view of a conventional CIS structure, including a semiconductor substrate 10 having a plurality of photodiodes 11 , 12 , 13 and a plurality of shallow trench isolations (STIs) on its surface. 14 separating the photodiodes 11, 12, 13 to define a pixel array, wherein the photodiodes 11, 12, 13 respectively comprise an n-type dopant region 16 and a p-type dopant region 17 as sensing Element of external light source intensity. In addition, in order to establish a complete CIS structure, a plurality of dielectric layers and multilevel interconnects are disposed on the surface of the semiconductor substrate 10, such as an interlevel dielectric layer 20 and a two-layer intermetal dielectric. An intermetal dielectric layer (IMD) 22, 24 is provided, and a plurality of metal wires 23, 25 are disposed between the inter-metal dielectric layers 22, 24. 200810100 However, as shown in Fig. 1, when an incident light 32' from an external light source 3' is incident on the photodiode I] at a nearly vertical angle, and the related electronic signal transmission is triggered; but also from the external light source 3 A scattered light 34 of the crucible is first incident on the metal wire 25 and reflected on the surface, and then incident on the other photodiode 13 adjacent to the photodiode 12, so that a so-called crossover phenomenon occurs ( The crosstalk effect) causes the photodiode 13 which is originally in an unopposed state to be interfered by the scattered light 34, so that the ratio of the sense diode to the noise of the first diode 13 cannot be improved, which obviously affects the sensitivity of the CIS in the photosensitive function. (sensitivity). In order to improve the cross-interference between the various senses of the conventional CIS and the photodiode, U.S. Patent No. 6,861,86.6 proposes an improved CIS structure, as shown in Fig. 2. Figure 2 is a modified ClS structure of U.S. Patent No. 6,861,866 which is not intended to be roughly divided into a photo sensing region 40 on the left side and a metal interconnect circuit region 42 on the right side. The CIS structure includes a substrate 44, a plurality of interlayer inter-metal dielectric layers (IMD) 46 and a plurality of diffusion barrier layers 48 for preventing metal atoms from diffusing over the substrate 44, wherein the metal interconnect circuit The region 42 includes a plurality of layers of copper metal wires 50, which are responsible for electrically connecting the corresponding gate 52 and the source/no electrode 54 to control the transmission of the CIS signal; and the light sensing region 40 includes a photosensitive layer disposed on the surface of the substrate 44. A diode 5, a light passageway 58 is disposed above the photodiode %, and a plurality of metal barriers 60 together form an inner side wall 8 of the optical channel 58 200810100 face 62. A protective layer 64 for blocking the interference phenomenon is disposed on the surface of the inner sidewall surface 62 of the optical channel 58 and covering the surface of the intermetal dielectric layer 46, and a transparent filler 66 is filled in the optical channel 58 and a color filter. 68 covered in A surface of the fill layer 66 and a microlens 70 are disposed over the optical channel 58. However, due to the relationship between the processes, the inner side wall surface 62 of the optical channel 58 is respectively connected by the metal barrier layer 60 defining the position of the optical channel 58 in each dielectric layer 46. Therefore, the inner side wall surface 62 of the optical channel 58 is a With a continuous surface, this will cause some of the light that is incident on the inner side wall surface 62 of the optical channel 58 to be easily scattered, and will not completely reach the photodiode 56 below the optical channel 58 relatively, causing a sense that the photodiode 46 can receive The number of effective rays arriving will be greatly reduced. In addition, a similar CIS structure is disclosed in another U.S. Patent No. 6,969,899, which, as shown in FIG. 3, includes a substrate 72, a plurality of photodiodes 74 disposed on the surface of the substrate 74, and a plurality of shallow trench isolations 76 interleaved. Between the photosensitive diodes 74, a plurality of first dielectric layers 78 are overlaid on the substrate 72, and a plurality of optical channels 80 are directly connected to the photodiode 74. Each of the optical channels 80 is filled with a second dielectric layer 82, and a third dielectric layer 84 is formed on the inner sidewall surfaces of each of the optical channels 80 for blocking the interference phenomenon. However, since the optical channel 80 disclosed therein is directly connected to the photodiode 74, in the actual process, this will result in the photo-sensing area of the photodiode 74 when the optical channel 80 is etched. Very susceptible to plasma damage and contamination of impurities, resulting in a large number of surface defects, increasing leakage currents causing noise, resulting in a decrease in the sensitization effect of the photodiode 74. In severe cases, it may even cause a photodiode. 74 components are damaged and lose their function. SUMMARY OF THE INVENTION Accordingly, it is a primary object of the present invention to provide an image sensing device having a waveguide and a method of fabricating the same, which can effectively avoid crossing interference phenomena and greatly improve the sensitivity of the image sensing device. According to the patent application scope of the present invention, an image sensing device includes a substrate having at least one optical component, at least one dielectric layer disposed on the substrate, and at least one wave-guide tube disposed thereon In the dielectric layer. The sidewall of the waveguide has a flat surface, and the waveguide φ corresponds to the optical component and is spaced apart from the optical component by a predetermined distance, and the waveguide includes a filling layer embedded in the dielectric layer and a An optical barrier layer disposed on a sidewall of the filling layer, wherein the filling layer and the optical barrier layer respectively have a reflection coefficient 〜n3, and the reflection coefficient 叱 of the filling layer is greater than the reflection coefficient n3 of the optical barrier layer . According to the patent application scope of the present invention, a method for fabricating an image sensing device is disclosed. First providing a substrate having at least one optical component, and then forming at least one dielectric layer on the substrate and covering the optical element 10 200810100, and then forming a recess in the dielectric layer, the recess The groove corresponds to the optical element, and the groove is spaced apart from the optical element by a predetermined distance, and then an optical barrier layer is formed on the inner side surface of the groove. Finally, a filling layer is formed to fill the groove to form a groove. The waveguide 'where the dielectric layer has a reflection coefficient shame, the filling layer has a reflection coefficient 〜, and the optical barrier layer has a reflection coefficient 113, and the reflection coefficient 〜 of the filling layer is larger than the reflection of the optical barrier layer Coefficient η3 ° Since the bottom of the waveguide of the image sensing device of the present invention has a concave bottom surface with a focusing effect and a predetermined distance from the optical element to avoid surface defects of the optical element and increase leakage current, and the inner side wall of the waveguide It also has an optical barrier layer, which can effectively avoid the spanning effect between different optical paths, and at the same time, the refractive index of the optical barrier layer and the filling layer The difference is that the direct incident light is totally reflected in the waveguide, resulting in a wave-guide effect, so that the lower optical element can collect more light, thereby increasing the image sense. The sensitization and sensitivity of the device. In addition, the filling layer in the waveguide can be directly made of a material of a dichor film or a color filter to shorten the optical path and greatly improve the resolution of the image sensing device. [Embodiment] In order to highlight the advantages and features of the present invention, the following describes a preferred embodiment of the present invention and is described in detail with reference to the following figures: 200810100 Figures 4 through 10 show image sensing of the present invention. Schematic diagram of the process of the device. Referring first to FIG. 4, a substrate 1 is provided having at least one optical component 106 formed thereon, at least one insulator 1〇5 separating the optical component 1 〇6, and at least one interlayer dielectric layer (interlevel dielectric layer, ILD) 112, a plurality of intermetal dielectric layers (IMDs) 114, 116, 118 and a plurality of metal wires 10, 8, 8, 109. In the preferred embodiment, the substrate 100 is a semiconductor substrate, but is not limited to a substrate such as a wafer or a SOI. The optical component 106 can be a photodiode ( Photodiode) for receiving external light and sensing the intensity of the illumination, and the optical component 106 is further electrically connected to a CMOS transistor (not shown) such as a reset transistor, a current extraction element or a column selection switch, and the insulator 105 It may be a shallow trench isolation (STI) or a partial oxidation of silicon isolation layer (LOCOS) to avoid short-circuiting of the optical element 106 in contact with other elements, and inter-layer dielectric The electrical layer 112 may be a silicon oxide layer or a borophosposilicate glass (BPSG) layer, etc.; the intermetal dielectric layers 114, 116, 118 may be a layer of oxynitride layer (SiON) or Fluoride silicate glass (FSG), etc.; as for the metal wires 107, 108, 109 and the inter-metal dielectric layers 114, 116, 118 constituting the multi-level interconnects, Dual damascene process or the conventional process of metal connection to be made, in this little repeat *. 200810100 As shown in FIG. 5, a patterned photoresist layer (not shown) is first formed on the surface of the intermetal dielectric layer 118, and then the patterned photoresist layer is used as a mask to etch the optical component 106. The upper inter-metal dielectric layers 114, 116, 118 form a recess 120 in the inter-metal dielectric layers 114, 116, 118, and a concave bottom surface 122 is formed in the bottom of the recess 120. The diameter of the opening of the top end of the groove 120 naturally forms a diameter slightly larger than the bottom surface of the groove 120. For example, the diameter of the bottom surface of the groove 122 is between 75% and 95% of the diameter of the opening, preferably 95. The funnel-type structure will facilitate the subsequent deposition process and effectively direct incident light to the optical component 106. In addition, the present invention may also first etch the inter-metal dielectric layers 114, 116, 118 by a dry etching process, and then perform a wet etching process to etch the interlayer dielectric layer 112 to produce the concave bottom surface 122, or as described above. The recess 120 having the concave bottom surface 122 is formed directly in the inter-metal dielectric layers 114, 116, 118 by controlling the parameters of the dry etching process. Since the recess 120 is obtained by directly etching a plurality of dielectric layers, the recess 120 has a flat inner side wall which does not cause non-directional scattering of light. In addition, the appearance of the groove 120 is not limited to the funnel-shaped structure as shown in FIG. 5, and may be a tubular structure having a vertical wall surface or other columnar structures having an opening diameter and a diameter of the bottom surface, and the groove. The bottom surface 122 of the 120 may also be replaced by a flat surface or other condensable bottom surface structure. It is noted that the concave bottom surface 122 of the recess 120 of the present invention is a predetermined distance from the 13 200810100 optical element 106. In the preferred embodiment, the pre-turn distance is about the thickness of the interlayer dielectric layer 112. That is, the preferred embodiment is an inter-metal dielectric layer 114, 116, 118 and stops at the interlayer dielectric layer 112. surface. Moreover, the predetermined distance of the present invention is also corresponding to the depth of the recess 12, and can be appropriately adjusted according to the specification requirements of each product or the radius of curvature of the concave bottom surface 122 and the shape of the photosensitive region. Not only can it be used to ensure that the concave bottom surface 122 acts on the focal length of the optical element 1 〇 6 to increase the sensitivity of the sensation, and the predetermined distance can be used to ensure that the surface of the optical element 106 is not in the process of the engraving process or other subsequent processes. The reliability and damage of the image sensing device shown in the present invention are increased by the influence and damage of the external force. Then, as shown in FIG. 6, a deposition process such as a chemical vapor deposition (CVD) process, a high temperature deposition process, a plasma enhanced chemical vapor deposition (PECVD) process, or a physics is utilized. A CVD vapor deposition (PVD) process or the like forms a flat optical barrier layer 124 covering the inner sidewalls of the recess 120, the concave bottom surface 22 and the intermetal dielectric layer 118. It should be noted that in the preferred embodiment, the reflection coefficient of the interlayer dielectric layer 112 and the inter-metal dielectric layers 114, 116, 118 is greater than the reflection coefficient of the optical barrier layer 124. For example, if the interlayer dielectric layer 与2 and the inter-metal dielectric layers 114, 116, 118 both have the same refrective index (RI) η, and the optical barrier layer 124 has a reflection coefficient n3, the layer 200810100 114 '116, 118 reflection coefficient I number n3. The dielectric layer 112 and the inter-metal dielectric layer 114 ηι between the optical barrier layers 124 are larger than the reflection coefficient of the optical barrier layer 120. The titanium oxide (ttamum Qxide), the oxidized oxide or other materials having the same reflectance value as the above-mentioned requirements may be used. Composition. In addition, consider the metal itself
強化光學屏障層124的阻隔效果。 如第7圖所示，進行一回蝕刻製程，用以移除沉積於 金屬間介電層118表面的光學屏障層124與沉積在凹型底 面122上的光學屏障層124，僅保留沉積在凹槽12〇内侧 壁面的部分光學屏障層124。隨後如第8圖所示，進行一 .沉積製程，如旋轉塗佈（S〇G)、化學氣相沉積（CVD)製程、 南’皿’儿積製程電漿辅助化學氣相沉積（piaSma enhanced chemical vapor deposition，PECVD)製程或物理氣相沉積 (PVD)製程等，於金屬間介電層118及光學屏障層124表面 形成一填充層126並填滿凹槽120。於本較佳實施例中， 填充層126可利用如氧化鈦（titanium 〇xide)或氧化釦 (tantalum oxide)等分色膜(dichroic film)材料製作而成，然 填充層126並不僅限定以分色膜材料製作，其亦可利用彩 色濾光片的原料，例如加入彩色染料的樹脂、彩色光阻戋 其他無機化合物等材料製作成一彩色濾光層，又或者利用 其他可供光線通過的透明物質做為填充層126的材料。 15 200810100 如第9圖所示，進行一化學機械研磨之平坦化製程， 用以移除部分形成於金屬間介電層118表面的部分填充層 126 ’使填充層126表面與金屬間介電層118表面齊平。至 此’凹槽120、光學屏障層124以及填充層126即共同構 成本發明之波導管125。 值得注意的是，在本較佳實施例中，填充層126具有 一反射係數n2，且填充層126的反射係數n2大於光學屏障 層124的反射係數n3。因此當一入射光線射向光學屏障層 124時’由於填充層126的反射係數n2大於光學屏障層124 的反射係數n3，所以非垂直入射的入射光線會在光學屏障 層124表面進行全反射，再到達光學元件1〇6，形成波導 效應(wave guide effect)，而不會有穿越金屬間介電層114、 116、118與層間介電層112，造成跨越現象的問題。 如第10圖所示，可於金屬間介電層118與波導管125 上方形成一平i旦層128與一微聚光鏡（microlens) 130。平 坦層128可保護下方的金屬間介電層114、116、118、層間 介電層112與波導管125並形成平坦表面，利於後續形成 微聚光鏡130的製程進行。而平坦層128可以是透明的薄 膜層’例如氧化矽層、透明樹脂、玻璃或其他具有透光特 性的材質製成，而微聚光鏡130可藉由形成一圖案化的聚 合物於平坦層128上，再經由一回火製程將該聚合物形成 16 200810100 相對於凹槽120的微聚參鏡130,以提供有效的聚光效果。 此外，考量填充層126所選用之物質特性，若填充層ι26 選用一透明物質作為其材料，於平坦層128與微聚光鏡13〇 間另可設置一彩色濾光片（圖未示），以選擇入射光之種類。 本發明所述之影像感測裝置的製作方法，不僅能製作 單一波導管的影像感測裝置，亦可製作包含複數個波導管 φ 的影像感測裝置。請參考第11 .圖，第11圖為本發明所揭 示之一較佳實施例之影像感測裝置200，包含有一基底 202、至少一光學元件204、至少一介電層216覆蓋在基底 202表面以及至少一波導管215設於介電層216中。於本 實施例中，介電層216係包含至少一層間介電層2〇 8以及 複數層金靥間介電層210、212、214，且金屬間介電層210、 212、214間設有由複數個金屬導線217、218、219所連結 之金屬内連線（圖未示）與光學元件204或與外部電路電連 接，同時光學元件204間設有一絕緣物206，用來避免光 學元件204與其他元件相接觸而發生短路。影像感測裝置 200所包含之波導管215係對應於各光學元件204,且各波 導管215分別包含一光學屏障層224以及一填充層226， 其中波導管215具有一凹型底面，且波導管215的開口直 徑由於蝕刻的結果會自然形成略大於其底面直徑，而底面 ~ 直#約為開口直徑的75%〜95%之間，最好是在95%以上盡 - 量使波導管215之侧壁保持接近垂直，同時波導管215之 17 200810100 該凹型底面與光學元件2G4間相距-預定距離，於本實施 例中，此預定距離約為層間介電層2〇8的厚度，以確保光 學元件204的可靠性。 ㈣像錢裝置2GG聽含-平垣層22()以及至少一 微聚光鏡222設於介電層216與波導管215上方，保護下 方的介電層加與波導管川，並提供聚光的效用:、值得 籲注意的是，波導管215之倒壁具有一平直表面，故當有外 來光線入射時，較不易造成無方向性的散射，於本較佳實 例中，層間介電層208與金屬間介電層21 〇、212、214 均具有相同之一反射係數ηι，而光學屏障層224具有一反 射係數1I3 ’其中層間介電層208與金屬間介電層21 〇、212、 214之反射係數〜大於光學屏障層224之反射係數〜，由 於反射係數的差異，自外界通過金屬間介電層214射向光 ❿學屏障層224的光線229，將會在光學屏障層224與金屬 間介電層214的介面反射，又填充層226可具有一反射係 數η2 ’且填充層226的反射係數n2大於光學屏障層224的 反射係數h ;故當一光線228射向光學屏障層224時，由 於填充層226的反射係數n2大於光學屏障層224的反射係 數n3’因此光線228在光學屏障層224表面會進行全反射， 而不會有穿越介電層216並造成跨越現象的問題。此外， ^ 考量金屬本身可造成良好的光反射效果且光線不易穿過， - 因此光學屏障層224亦可由一金屬屏障層所取代，以強化 18 200810100 光學屏障層224的阻隔效果。值得注意的是，影像感測裝 置200包含至少一個光學元件2〇4以及其對應的波導管 215 ’可適用於製作具有光學陣列排列的影像感測元件，例 如具有紅、藍、綠或其他顏色之分光或濾光效果的光學陣 列，以應用在相關的電機電子產品當中。 綜上所述，本發明係提供一種影像感測裝置及其製作 _ 方法，其特點在於波導管底部之凹型底面與光學元件間相 距一預定距離，以提高聚焦效果並避免光學元件發生表面 缺陷而增加漏電流；波導管内侧壁具有一光學屏障詹，可 有效避免不同光路間的跨越效應，相對地使影像感測裝置 的靈敏度大幅提幵，再者，藉由折射率之不同，該，光學屏 障層可使非垂直入射的光線在凹槽内進行全反射，造成完 整的波導政應，使下方的光學元件可以收集到更多的光 線，增加該影像感测裝置的感光效果。此外，波導管内之 填充層更可直接利用分色膜或彩色濾光片的材質製作而 成，縮短光徑，進而提高影像感測裝置的解析度〜 以上所述僅為本發明之較佳實施例，凡依本發明f請專 利範圍所做之均等變化與修飾，皆應屬本發明之涵墓範園。 . 【圖式簡單說明】 • 第1圖為傳統的CIS結構示意圖。 19 200810100 第2圖為美國專利案號US 6,861，866所提出之一改良後的 CIS結構示意圖。 第3圖為美國專利案號US 6.969,899所提出之另一改良後 的CIS結構示意圖。 第4圖至第10圖為本發明之影像感測裝置的製程示意圖。 第11圖為本發明所揭示之一較佳實施例。 _ 【主要元件符號說明】 10 半導體基底 11 、 12 、 13感光二極體 14 淺溝隔離 16 η型摻質區 17 P型摻質區 20 .層間介電層 22、24 金屬内連線層 23 ^ 25 金屬.導線 30 外部光源 32 入射光線 34 散射光線 40 光感測區 42 周邊電路區 44 基底 46 介電層 48 擴散阻障層 50 銅金屬導線 52 閘極 54 源極 56 感光二極體 58 光學通道 60 金屬阻障層 62 内侧壁面 64 保護層 66 透明填充層 68 彩色濾光片 70 聚光鏡 72 基底 74 感光二極體 76 淺溝隔離 9Π 200810100The barrier effect of the optical barrier layer 124 is enhanced. As shown in FIG. 7, an etching process is performed to remove the optical barrier layer 124 deposited on the surface of the intermetal dielectric layer 118 and the optical barrier layer 124 deposited on the concave bottom surface 122, leaving only the grooves deposited in the recess. A portion of the optical barrier layer 124 of the inner sidewall surface of the crucible. Subsequently, as shown in Fig. 8, a deposition process such as spin coating (S〇G), chemical vapor deposition (CVD) process, and south-disc plasma-assisted chemical vapor deposition (piaSma enhanced) is performed. A chemical vapor deposition (PECVD) process or a physical vapor deposition (PVD) process or the like forms a filling layer 126 on the surface of the intermetal dielectric layer 118 and the optical barrier layer 124 and fills the recess 120. In the preferred embodiment, the filling layer 126 can be made of a dichroic film material such as titanium oxide or tantalum oxide, and the filling layer 126 is not limited to The color film material can be made of a color filter material, such as a color dye-containing resin, a color photoresist, other inorganic compounds, or the like to form a color filter layer, or use other transparent materials for light to pass through. As the material of the filling layer 126. 15 200810100 As shown in FIG. 9, a chemical mechanical polishing planarization process is performed to remove a portion of the filling layer 126' formed on the surface of the intermetal dielectric layer 118 to make the surface of the filling layer 126 and the intermetal dielectric layer 118 surface is flush. To this end, the recess 120, the optical barrier layer 124, and the fill layer 126 co-construct the waveguide 125 of the present invention. It should be noted that in the preferred embodiment, the filling layer 126 has a reflection coefficient n2, and the reflection coefficient n2 of the filling layer 126 is greater than the reflection coefficient n3 of the optical barrier layer 124. Therefore, when an incident light is incident on the optical barrier layer 124, since the reflection coefficient n2 of the filling layer 126 is greater than the reflection coefficient n3 of the optical barrier layer 124, the incident light that is not normally incident is totally reflected on the surface of the optical barrier layer 124, and then Reaching the optical element 1〇6 forms a wave guide effect without crossing the inter-metal dielectric layers 114, 116, 118 and the interlayer dielectric layer 112, causing a problem of spanning. As shown in FIG. 10, a flat idan layer 128 and a microlens 130 may be formed over the intermetal dielectric layer 118 and the waveguide 125. The planar layer 128 protects the underlying inter-metal dielectric layers 114, 116, 118, the interlayer dielectric layer 112 and the waveguide 125 and forms a flat surface for facilitating subsequent fabrication of the micro-concentrating mirror 130. The flat layer 128 may be a transparent film layer such as a ruthenium oxide layer, a transparent resin, glass or other material having light transmitting properties, and the micro concentrator 130 may be formed on the flat layer 128 by forming a patterned polymer. The polymer is then formed into a micro-polygraph 130 of the 2008 20080100 relative to the groove 120 via a tempering process to provide an effective concentrating effect. In addition, considering the material properties selected for the filling layer 126, if a transparent material is used as the material for the filling layer ι26, a color filter (not shown) may be disposed between the flat layer 128 and the micro concentrating mirror 13 to select The type of incident light. The image sensing device of the present invention can not only produce an image sensing device of a single waveguide, but also can produce an image sensing device including a plurality of waveguides φ. Please refer to FIG. 11. FIG. 11 is an image sensing device 200 according to a preferred embodiment of the present invention. The image sensing device 200 includes a substrate 202, at least one optical component 204, and at least one dielectric layer 216 covering the surface of the substrate 202. And at least one waveguide 215 is disposed in the dielectric layer 216. In this embodiment, the dielectric layer 216 includes at least one interlayer dielectric layer 2 〇 8 and a plurality of layers of inter-metal dielectric layers 210 , 212 , 214 , and inter-metal dielectric layers 210 , 212 , 214 are disposed between A metal interconnect (not shown) connected by a plurality of metal wires 217, 218, 219 is electrically connected to the optical component 204 or to an external circuit, and an insulator 206 is disposed between the optical components 204 for avoiding the optical component 204. Short circuit occurs in contact with other components. The waveguide 215 included in the image sensing device 200 corresponds to each optical component 204, and each waveguide 215 includes an optical barrier layer 224 and a filling layer 226, wherein the waveguide 215 has a concave bottom surface, and the waveguide 215 The opening diameter naturally forms a diameter slightly larger than the bottom surface due to the etching, and the bottom surface ~ straight # is about 75% to 95% of the opening diameter, preferably 95% or more - the side of the waveguide 215 The wall remains nearly vertical, while the waveguide 215 17 200810100 is spaced apart from the optical element 2G4 by a predetermined distance. In this embodiment, the predetermined distance is approximately the thickness of the interlayer dielectric layer 2〇8 to ensure the optical element. 204 reliability. (4) The money-like device 2GG listening-containing layer 22 () and at least one micro-concentrating mirror 222 are disposed above the dielectric layer 216 and the waveguide 215 to protect the underlying dielectric layer from the waveguide tube and provide the effect of collecting light: It should be noted that the inverted wall of the waveguide 215 has a flat surface, so that when there is external light incident, it is less likely to cause non-directional scattering. In the preferred embodiment, the interlayer dielectric layer 208 and the metal The dielectric layers 21 〇, 212, 214 each have the same reflection coefficient ηι, and the optical barrier layer 224 has a reflection coefficient 1I3 'the reflection of the interlayer dielectric layer 208 and the intermetal dielectric layers 21 〇, 212, 214 The coefficient 〜 is greater than the reflection coefficient 〜 of the optical barrier layer 224. Due to the difference in the reflection coefficient, the light 229 from the outside through the intermetal dielectric layer 214 to the optical barrier layer 224 will be interposed between the optical barrier layer 224 and the metal. The interface layer 226 of the electrical layer 214 may have a reflection coefficient η2 ' and the reflection coefficient n2 of the filling layer 226 is greater than the reflection coefficient h of the optical barrier layer 224; therefore, when a light ray 228 is directed toward the optical barrier layer 224, Fill layer 226 The reflection coefficient n2 is greater than the reflection coefficient n3' of the optical barrier layer 224 so that the light 228 is totally reflected on the surface of the optical barrier layer 224 without the problem of crossing the dielectric layer 216 and causing a spanning phenomenon. In addition, it is considered that the metal itself can cause a good light reflection effect and the light is not easily penetrated - and thus the optical barrier layer 224 can also be replaced by a metal barrier layer to enhance the barrier effect of the 18101010 optical barrier layer 224. It should be noted that the image sensing device 200 includes at least one optical component 2 〇 4 and its corresponding waveguide 215 ′ can be adapted to fabricate an image sensing component having an optical array arrangement, for example, having red, blue, green or other colors. An optical array of split or filtered effects for use in related motor electronics. In summary, the present invention provides an image sensing device and a method for fabricating the same, which is characterized in that a concave bottom surface of a waveguide is spaced apart from the optical element by a predetermined distance to improve focusing effect and prevent surface defects of the optical component. Increase the leakage current; the inner side wall of the waveguide has an optical barrier, which can effectively avoid the spanning effect between different optical paths, and relatively improve the sensitivity of the image sensing device. Furthermore, by the difference in refractive index, the optical The barrier layer allows the non-normally incident light to be totally reflected in the groove, resulting in a complete waveguide responsiveness, allowing the underlying optical components to collect more light, increasing the photographic effect of the image sensing device. In addition, the filling layer in the waveguide can be directly made of the material of the color separation film or the color filter, shortening the optical path, and further improving the resolution of the image sensing device. The above is only a preferred embodiment of the present invention. For example, all the equivalent changes and modifications made in accordance with the scope of the present invention should belong to the cemetery garden of the present invention. [Simple description of the diagram] • Figure 1 is a schematic diagram of the traditional CIS structure. 19 200810100 Figure 2 is a schematic diagram of an improved CIS structure proposed by U.S. Patent No. 6,861,866. Figure 3 is a schematic diagram of another modified CIS structure proposed by U.S. Patent No. 6,969,899. 4 to 10 are schematic views showing the process of the image sensing device of the present invention. Figure 11 is a preferred embodiment of the present invention. _ [Main component symbol description] 10 Semiconductor substrate 11, 12, 13 photodiode 14 shallow trench isolation 16 n-type dopant region 17 P-type dopant region 20. Interlayer dielectric layer 22, 24 metal interconnect layer 23 ^ 25 Metal. Wire 30 External Light Source 32 Incident Light 34 Scattering Light 40 Light Sensing Area 42 Peripheral Circuit Area 44 Substrate 46 Dielectric Layer 48 Diffusion Barrier Layer 50 Copper Metal Wire 52 Gate 54 Source 56 Photodiode 58 Optical channel 60 Metal barrier layer 62 Inner sidewall surface 64 Protective layer 66 Transparent filling layer 68 Color filter 70 Condenser 72 Substrate 74 Photodiode 76 Shallow trench isolation 9Π 200810100
78 第一介電層 80 光學通道 82 第二介電層 84 第三介電層 100 基底 105 絕緣物 106 光學元件 107、108、109金屬導線 112 層間介電層 114、 116、118金屬間介電層 120 凹槽 122 凹型底面 124 光學屏障層 125 波導管 126 填充層 128 平坦層 130 微聚光鏡 200 影像感測裝置 202 基底 204 光學元件 206 絕緣物 208 層間介電層 210、212、214金屬間介電層 215 .波導管 216 介電層 217、218、219金屬導線 220 平坦層 222 ·* ♦· 微聚光鏡 224 光學屏障層 226 填充層 228 、 229 光線78 first dielectric layer 80 optical channel 82 second dielectric layer 84 third dielectric layer 100 substrate 105 insulator 106 optical element 107, 108, 109 metal wire 112 interlayer dielectric layer 114, 116, 118 intermetal dielectric Layer 120 recess 122 concave bottom surface 124 optical barrier layer 125 waveguide 126 fill layer 128 flat layer 130 micro concentrator 200 image sensing device 202 substrate 204 optical element 206 insulator 208 interlayer dielectric layer 210, 212, 214 intermetal dielectric Layer 215. Waveguide 216 Dielectric Layer 217, 218, 219 Metal Wire 220 Flat Layer 222 · * ♦ Micro Condenser 224 Optical Barrier Layer 226 Filler Layer 228, 229 Light