201240072 六、發明說明： 【發明所屬之技術領域】 本發明係相關於一背面照光感測器’尤指一種具有較小面積之背 面照光感測器。 【先前技術】 隨著金氧互補(complementary metal-oxide-metal，CMOS)半導體 影像感測器(CMOS image sensor，CIS)中像素尺寸的減小，一感測器 陣列中降低感測效能的各種因素，如：量子效應(quantumefficiency, QE)、串話干擾(crosstalk)以及暗電流(dark current)等，均會變得更加 顯著。對習知影像感測器而言，例如：一前面照光感測器(丘0扮side illuminated sensor)，每個像素感測器的透鏡均被製造在一基板的一 前面(front side)上。是故，入射光需要穿過金屬層所構成的線路間其 中多層的介電質(dielectric)才能到達一光敏二極體(ph〇t〇 diode)，否 則行進中的光會被金屬或其他反射性的物質所吸收或反射。 為了精簡化一影像感測器的面積，習知技術提出了背面照光影像 感測器的結構。對一背面照光影像感測器來說，入射光是由該影像 感測器之一基板的背面所投射進來的，是故該基板的正面可被應用 在許多功能性的電路之上。請參照第丨圖，其為一習知背面照光影 像感測器t-像素結構的部分剖面圖。該像素結構包含有一光敏二 極體100轉移電晶體(疗咖如廿肪也㈣2〇〇、一重置電晶體（⑽技 3 201240072 transistor) 500 ’以及一隔絕結構400。光敏二極體100包含有一 N 型摻雜層NL以及一 P型摻雜層pL，用以將該入射光轉換為電子訊 號。轉移電晶體200(在此範例中，其為形成於一 p型井上之一 n型 金氧互補半導體電晶體)於是依據由一閘極電極所接收到之一控制 指令，將該些電子訊號從光敏二極體1〇〇經由一 N型摻雜連接通道 300轉移至其他電路之中，以便後續的處理。隔絕結構4〇〇在此則 是用來防止雜訊污染該些電子訊號的完整性。而重置電晶體5〇〇則 用以重置光敏二極體100。 經由應用背面照光技術’愈來愈多的基板正面空間可被用來建立 多種不同功能性的電路。然而，為了進一步地應用發展背面照光技 術的優勢，愈來愈多的研究投入精簡化背面照光感測器以及將其面 積利用效率提高的技術。 【發明内容】 本發明的目的之一在於提供一種具有精簡面積的背面照光影像 感測器來解決上述的問題。 依據本發明之-實齡彳，其触了-齡Φ照光(back-side illumination，BSI)影像感測器，包含有至少一像素區域，該像素區域 包含有一光敏二極體(photo diode)以及一轉移電晶體(transfer transistor) ’該轉移電晶體具有由一閘極多晶石夕(职化丨y)與一閘極氧 化層(gateoxide)所構成且用以接收一控制指令之一控制電極 '耦接 201240072 於該光敏二極體之一第一電極，以及一第二電極。其中該轉移電晶 體具有一感應通道，該感應通道部分圍繞著由該轉移電晶體的該閘 極多晶石夕與該閘極氧化層所填入之一凹陷空間。 依據本發明之另-實關，其提供了-種背賴光影像感測器， 包含有至少-像素區域，該像素區域包含有—光敏三極體以及一轉 移電晶體。該光敏二極體包含有-第一摻雜基板(d〇pedsubstrate)以 及一第二摻雜基板。該轉移電晶體具有由一閘極多晶矽與一閘極氧 化層所構成且肋接收—控制指令之—控制電極、祕於該光敏二 極體之-第-電極’以及—第二電極。其中該第—摻雜基板用以作 為該轉移電晶體之該第一電極。 依據本發明之另—實施例，其提供了—歸面照光影像感測器， 包含有至少-像素區域’雜素區域包含有—光敏二極體以及至少 -電晶體。該電晶體具有由一閘極多晶销_閘極氧化層所構成且 用以接收-控制指令之—控制電極、雛於該級二極體之一第一 電極’以及-第二電極。其中該電晶體具有—感應通道，該感應通 道部分圍繞著由轉移電·氧 入之一凹陷空問。 具 【實施方式】 本發明之-實施例的一概念在於結合第丨_示的光敏二極 100之N型摻雜層见以及N型摻雜連接通道3〇〇。如第1圖所示 201240072 N型摻雜連接通道300亦用來作為轉移電晶體2〇〇的一汲極電極 (drain electrode) ’用以連接光敏二極體1〇〇之n型摻雜層见。當轉 移電晶體2⑻被啟動時，—傳導通道會相賊地水平形成於該閘極 電極之-閘極氧化層(在圖中表示為⑻)之下。由於光敏二極體刚 之N型摻雜層NL以及N型摻雜連接通道3〇〇具有相同之摻雜型 (dopmg type) ’兩者可被結合在一起並持續發揮各自的功能。基於上 述的觀察結果，後續的說明書將提出多個關於背面照光影像感測器 的範例與結構相關之細節。 μ參照第2圖’其為鎌本發明之—實補實現的—背面照光影 像感測器的-像素結構之部分剖面圖。相較於第i圖所示的習知像 素結構’帛2圖巾所示的隔絕結構4⑻在製造過程巾被會挖掘出一 凹陷空間，而 得移電晶體200A閘極電極之閘極多晶矽(在圖中^ 為〇)以及閘極氧化層(在圖中表示為G〇)則會被填入隔絕結構 400上的該凹陷空間。是故當轉移電晶體2〇〇A被啟動時，光敏二名 體_之N型摻雜層见會如同轉移電晶體·Α之—_(例如： ,電極）般運作’而一感應通道形成於轉移電晶體細a之 中，且該感應通道部分醜著轉移電晶體2_的該閘極。由於該 1通道的結構，從光敏二極體励所發出的該些電子訊號於是便 以歲乎—直的方式祕遞，科是水平轉遞。她於第丨圖所 =的傳統背面縣像雜構，本發賴出轉移電晶體獅Α所占 用的面積便可因此而大幅減少。 201240072 在本發明之另-實施例之中，像素結構的基板可挖掘來形成一凹 陷空間。請參照第3圖，其為依據本發明之另一實施例實現的一背 面照光影像感測器的-像素結構之部分剖面圖。相較於第2圖所示 的像素、、’u構，第3圖中的隔絕結構娜以及基板2〇2在製造過程中 均經過挖掘以形成該凹陷空間，其中該凹陷空間接著由一轉移電晶 體2_的—閘極多晶賴—閘極氧城所填人。在此實施例中， 光敏二極體100之N型摻雜層见亦會如同轉移電晶體繼之一 電極-般來運作’而由於該凹陷空間係形成於隔絕結構彻以及基 板202 ^中，轉移電晶體2〇犯中所形成的感應通道會幾乎呈現垂 直的狀fe。因此，轉移電晶體細3所占關面積亦可大幅減少以 達到精簡化的目的。 ,睛注意’在第2、3目中的範例僅用說明本說明之精神，而非用 來限定本發明之細。糊來說，本發明之概念可讀帛在p型基 板上如應用在N型基板上’也就是說，本發明巾的電晶體或是光 敏二極體之傳導型可為P型或是N型。 此外u亥凹知空間亦不限定於成形在一隔絕結構之上，該凹陷空 間亦可單獨成形於—基板上。請參照第4 ®來了解本發明之概念， 第4圖為域本㈣之另—實關實賴_背面照絲像感測器的 像素、^構之部分剖面圖。在此實施例中，一轉移電晶體2c與 一重置電晶體500C的閘極氧化層均放置在基板中的凹陷空間内， 而一 N型連接通道3〇〇(：則將光敏二極體1〇〇與轉移電晶體2〇〇c 7 201240072 連接在一起。當轉移電晶體2〇〇c(或是重置電晶體5〇〇c)被啟動時， 一個U型的感應通道便會形成於其閘極氧化層之下，而在維持相同 感應通道長度的前提之下，制極電極的長度便可雜，是故可進 -步將像素結獅©敎加精簡化。這些設計上的變祕在本發明 之範疇之内。 綜上所述’本發_各個實施例提供了具有更加精簡面積的背面 照光影像細制在製作過程巾所形成的—凹陷空間，一電晶 體的-傳導通道可以歪斜(askew)或是垂直的方式來形成(亦即，該傳 並非以水平的方式所形成），因而得到-個具有精簡面積的像 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 所做之均龍化齡飾，皆顧本發明之涵蓋範圍。 【圖式簡單說明】 第1圖為-習知背面照光影像制^之―像素結構的部分剖面圖。 第2圖為依據本發明之—實施例實現的_背面照光影像感測器的一 像素結構之部分剖面圖。 第圖為依據本發明之另一實施例實現的一背面照光影像感測器的 一像素結構之部分剖面圖。 第4圖為依據本發明之另—實施例實現的—背面照光影像感測器的 一像素結構之部分剖面圖。 201240072 【主要元件符號說明】 100 光敏二極體 200、200A、200B、200C 轉移電晶體 202 基板 300 、 300C N型摻雜連接通道 400 隔絕結構 500 、 500C 重置電晶體 PL P型摻雜層 NL N型摻雜層 GO 閘極氧化層 PO 閘極多晶石夕201240072 VI. Description of the Invention: [Technical Field] The present invention relates to a back-illuminated sensor, particularly a back-illuminated sensor having a small area. [Prior Art] With the reduction of pixel size in a complementary metal-oxide-metal (CMOS) semiconductor image sensor (CIS), various sensor performance reductions in a sensor array Factors such as quantum efficiency (QE), crosstalk, and dark current become more pronounced. For conventional image sensors, such as a front-illuminated sensor, the lens of each pixel sensor is fabricated on a front side of a substrate. Therefore, the incident light needs to pass through a plurality of layers of dielectric between the wires formed by the metal layer to reach a photosensitive diode (ph〇t〇diode), otherwise the traveling light will be reflected by metal or other. Absorbed or reflected by a substance. In order to simplify the area of an image sensor, the prior art proposes a structure of a back-illuminated image sensor. For a backlit image sensor, the incident light is projected from the back side of one of the image sensors, so that the front side of the substrate can be applied to many functional circuits. Please refer to the figure, which is a partial cross-sectional view of a conventional t-pixel structure of a back-illuminated image sensor. The pixel structure comprises a photodiode 100 transfer transistor (a ceramic device such as a semiconductor device), a reset transistor (2012), and an isolation structure 400. The photodiode 100 includes An N-type doped layer NL and a P-type doped layer pL are used to convert the incident light into an electronic signal. The transfer transistor 200 (in this example, one of the n-type gold formed on a p-type well) The oxygen-complementary semiconductor transistor is then transferred to the other circuit from the photodiode 1 through the N-type doped connection channel 300 according to a control command received by a gate electrode. For subsequent processing, the isolation structure 4 is used to prevent noise from contaminating the integrity of the electronic signals, and the reset transistor 5 is used to reset the photodiode 100. Illumination technology 'More and more substrate front space can be used to create a variety of different functional circuits. However, in order to further develop the advantages of backlighting technology, more and more research efforts to simplify the backlight A detector and a technique for improving the area utilization efficiency thereof. One of the objects of the present invention is to provide a back-illuminated image sensor having a reduced area to solve the above problems. According to the present invention, The touch-back illumination (BSI) image sensor includes at least one pixel region including a photo diode and a transfer transistor. The transfer transistor has a gate polysilicon and a gate oxide for receiving a control command to control the electrode 'coupled to 201240072 to the photodiode a first electrode of the body, and a second electrode, wherein the transfer transistor has an inductive channel partially surrounding the gate polysilicon of the transfer transistor and the gate oxide layer In accordance with another aspect of the present invention, there is provided a light-receiving image sensor comprising at least a pixel region including a photosensitive triode and Transferring the transistor. The photodiode comprises a first doped substrate and a second doped substrate. The transfer transistor has a gate polysilicon and a gate oxide layer and a rib Receiving-controlling the control electrode, the -electrode of the photodiode and the second electrode, wherein the first doped substrate is used as the first electrode of the transfer transistor. According to another embodiment of the invention, there is provided a surface-illuminated image sensor comprising at least a pixel region, wherein the impurity region comprises a photodiode and at least a transistor. The transistor has a gate. The polycrystalline pin_the gate oxide layer is formed to receive the control command, the control electrode, the first electrode of the one of the diodes, and the second electrode. Wherein the transistor has a sensing channel, and the sensing channel partially surrounds a recessed space by transferring electricity and oxygen. [Embodiment] A concept of the embodiment of the present invention is to refer to the N-type doped layer of the photodiode 100 shown in the first embodiment and the N-type doped connection channel 3〇〇. As shown in Fig. 1, the 201240072 N-type doped connection channel 300 is also used as a drain electrode of the transfer transistor 2' to connect the n-type doped layer of the photodiode 1〇〇. see. When the transfer transistor 2 (8) is activated, the conduction path is formed horizontally below the gate oxide layer (denoted (8) in the figure) of the gate electrode. Since the N-doped layer NL and the N-type doped connection channel 3 of the photosensitive diode have the same dopmg type, both can be bonded together and continue to function as their respective functions. Based on the above observations, the subsequent specification will present a number of details regarding the example and structure of the back-illuminated image sensor. μ refers to Fig. 2, which is a partial cross-sectional view of a pixel structure of a back-illuminated image sensor implemented by the present invention. Compared with the conventional structure shown in Fig. i, the insulating structure 4(8) shown in Fig. 2 is a recessed space in the manufacturing process, and the gate polysilicon of the gate electrode of the transistor 200A is removed. In the figure, ^ 〇) and the gate oxide layer (shown as G 图 in the figure) are filled into the recessed space on the insulating structure 400. Therefore, when the transfer transistor 2A is activated, the N-type doped layer of the photosensitive dimer is seen to behave like a transfer transistor, such as an electrode, and a sensing channel is formed. The transistor is transferred into the thin a, and the sensing channel is partially ugly to transfer the gate of the transistor 2_. Due to the structure of the 1 channel, the electronic signals emitted from the photodiode excitation are secretly transmitted in a straight-forward manner, and the subject is horizontally transferred. In the traditional back county of the second map, the area occupied by the transfer of the crystal griffon can be greatly reduced. 201240072 In another embodiment of the invention, the substrate of the pixel structure can be excavated to form a recessed space. Please refer to FIG. 3, which is a partial cross-sectional view showing a pixel structure of a back-illuminated image sensor according to another embodiment of the present invention. Compared with the pixel shown in FIG. 2, the 'u structure, the isolation structure Na and the substrate 2〇2 in FIG. 3 are excavated during the manufacturing process to form the recessed space, wherein the recessed space is followed by a transfer. The transistor 2_-gate polycrystalline Lai-gate is filled with oxygen. In this embodiment, the N-type doped layer of the photodiode 100 will also function as a transfer transistor along with one of the electrodes, and since the recessed space is formed in the isolation structure and the substrate 202, The sensing channel formed in the transfer transistor 2 will appear almost vertical. Therefore, the area occupied by the transfer transistor fine 3 can be greatly reduced to achieve the purpose of simplification. The examples in the second and third items are merely illustrative of the spirit of the description and are not intended to limit the scope of the invention. For the paste, the concept of the present invention can be read on a p-type substrate such as an N-type substrate. That is, the conductivity of the transistor or photosensitive diode of the present invention can be P-type or N. type. In addition, the U-shaped recessed space is not limited to being formed on an insulating structure, and the recessed space can be separately formed on the substrate. Please refer to the 4th to understand the concept of the present invention, and Fig. 4 is a partial cross-sectional view of the pixel and structure of the back-illuminated image sensor of the domain (4). In this embodiment, both the transfer transistor 2c and the gate oxide layer of a reset transistor 500C are placed in the recessed space in the substrate, and an N-type connection channel 3〇〇 (: the photosensitive diode) 1〇〇 is connected with the transfer transistor 2〇〇c 7 201240072. When the transfer transistor 2〇〇c (or reset transistor 5〇〇c) is activated, a U-shaped sensing channel is formed. Under the gate oxide layer, and under the premise of maintaining the same length of the sensing channel, the length of the electrode can be mixed, so that the pixel lion can be further simplified. It is within the scope of the present invention. In summary, the present invention provides a more compact area of the back-illuminated image that is formed in the process of forming a recessed space, a transistor-conducting The channel may be formed in an askew manner or in a vertical manner (i.e., the transmission is not formed in a horizontal manner), thereby obtaining a preferred embodiment having a reduced area as described above. Everything made in accordance with the scope of the patent application of the present invention The invention covers the scope of the present invention. [Simplified Schematic Description] Fig. 1 is a partial cross-sectional view showing a pixel structure of a conventional back-illuminated image system. Fig. 2 is an embodiment according to the present invention. A partial cross-sectional view of a pixel structure of a back-illuminated image sensor implemented. The figure is a partial cross-sectional view of a pixel structure of a back-illuminated image sensor implemented in accordance with another embodiment of the present invention. A partial cross-sectional view of a pixel structure of a back-illuminated image sensor implemented in accordance with another embodiment of the present invention. 201240072 [Description of Main Components] 100 Photosensitive Diodes 200, 200A, 200B, 200C Transfer Transistor 202 Substrate 300, 300C N-type doped connection channel 400 isolation structure 500, 500C reset transistor PL P-type doped layer NL N-type doped layer GO gate oxide layer PO gate polycrystal