Patent Publication Number: US-2022238586-A1

Title: Sensing device and electronic device

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of China Application No. 202110112148.4, filed Jan. 27, 2021, the entirety of which is incorporated by reference herein. 
     BACKGROUND 
     Technical Field 
     The present disclosure is related to a sensing device and an electronic device, and in particular it is related to an electronic device that can increase the sensitivity of the sensing device. 
     Description of the Related Art 
     Optical sensing devices are widely used in consumer electronics such as smartphones and wearable devices etc., and have become indispensable necessities in modern society. With the flourishing development of such consumer electronics, consumers have high expectations regarding the quality, functionality, or price of these products. 
     The sensing element in the optical sensing device can convert the received light into an electrical signal, and the generated electrical signal can be transmitted to the driving element and logic circuit in the optical sensing device for processing and analysis. Generally, the sensitivity of the sensing element is affected by quantum efficiency and photoelectric conversion efficiency, and the photoelectric conversion efficiency is mainly affected by the equivalent capacitance of the sensing element. 
     In order to increase the sensitivity of the sensing element and thereby improve the performance of the sensing device, the development of a structural design that can further reduce the equivalent capacitance of the sensing element is still currently an important research topic in the industry. 
     SUMMARY 
     In accordance with some embodiments of the present disclosure, a sensing device is provided. The sensing device includes a sensing circuit, a plurality of sensing elements, and a plurality of light-collecting elements. The light-collecting elements are for collecting lights to the plurality of sensing elements. The plurality of sensing elements are configured to generate a plurality of sensing signals according to the lights that are collected, and output the plurality of sensing signals as a whole to the sensing circuit. 
     In accordance with some embodiments of the present disclosure, an electronic device is also provided. The electronic device includes a display device and a sensing device, and the sensing device is disposed opposite the display device. In addition, the sensing device includes a sensing circuit, a plurality of sensing elements, and a plurality of light-collecting elements. The light-collecting elements are for collecting lights to the plurality of sensing elements. The plurality of sensing elements are configured to generate a plurality of sensing signals according to the lights that are collected, and output the plurality of sensing signals as a whole to the sensing circuit. 
     A detailed description is given in the following embodiments with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The disclosure may be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein: 
         FIG. 1  is a cross-sectional diagram of a sensing device in accordance with some embodiments of the present disclosure; 
         FIG. 2  is a top-view diagram of some elements of a sensing device in accordance with some embodiments of the present disclosure; 
         FIG. 3  is an equivalent circuit diagram of a sensing circuit in accordance with some embodiments of the present disclosure; 
         FIGS. 4A-4C  are top-view diagrams of some elements of a sensing device in accordance with some embodiments of the present disclosure; 
         FIGS. 5A-5C  are top-view diagrams of some elements of a sensing device in accordance with some embodiments of the present disclosure; 
         FIGS. 6A-6C  are top-view diagrams of some elements of a sensing device in accordance with some embodiments of the present disclosure; 
         FIGS. 7A-7C  are top-view diagrams of some elements of a sensing device in accordance with some embodiments of the present disclosure; 
         FIG. 8A  and  FIG. 8B  are schematic diagrams of an electronic device in accordance with some embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The sensing device and the electronic device according to the present disclosure are described in detail in the following description. It should be understood that in the following detailed description, for purposes of explanation, numerous specific details and embodiments are set forth in order to provide a thorough understanding of the present disclosure. The elements and configurations described in the following detailed description are set forth in order to clearly describe the present disclosure. These embodiments are used merely for the purpose of illustration, and the present disclosure is not limited thereto. In addition, different embodiments may use like and/or corresponding numerals to denote like and/or corresponding elements in order to clearly describe the present disclosure. However, the use of like and/or corresponding numerals of different embodiments does not suggest any correlation between different embodiments. 
     It should be understood that relative expressions may be used in the embodiments. For example, “lower”, “bottom”, “higher” or “top” are used to describe the position of one element relative to another. It should be appreciated that if a device is flipped upside down, an element that is “lower” will become an element that is “higher”. The present disclosure can be understood by referring to the following detailed description in connection with the accompanying drawings. The drawings are also regarded as part of the description of the present disclosure. It should be understood that the drawings of the present disclosure may be not drawn to scale. In fact, the size of the elements may be arbitrarily enlarged or reduced to clearly represent the features of the present disclosure. 
     Furthermore, the expression “a first material layer is disposed on/over a second material layer”, may indicate that the first material layer is in direct contact with the second material layer, or it may indicate that the first material layer is in indirect contact with the second material layer. In the situation where the first material layer is in indirect contact with the second material layer, there may be one or more intermediate layers between the first material layer and the second material layer. However, the expression “the first material layer is directly disposed on/over the second material layer” means that the first material layer is in direct contact with the second material layer. 
     Moreover, it should be understood that the ordinal numbers used in the specification and claims, such as the terms “first”, “second”, etc., are used to modify an element, which itself does not mean and represent that the element (or elements) has any previous ordinal number, and does not mean the order of a certain element and another element, or the order in the manufacturing method. The use of these ordinal numbers is to make an element with a certain name can be clearly distinguished from another element with the same name. Claims and the specification may not use the same terms. Accordingly, the first element in the specification may refer to the second element in the claims. 
     In accordance with the embodiments of the present disclosure, regarding the terms such as “connected”, “interconnected”, etc. referring to bonding and connection, unless specifically defined, these terms mean that two structures are in direct contact or two structures are not in direct contact, and other structures are provided to be disposed between the two structures. The terms for bonding and connecting may also include the case where both structures are movable or both structures are fixed. In addition, the term “electrically connected” or “electrically coupled” may include any direct or indirect electrical connection means. 
     In the following descriptions, terms “about” and “substantially” typically mean+/−10% of the stated value, or typically +/−5% of the stated value, or typically +/−3% of the stated value, or typically +/−2% of the stated value, or typically +/−1% of the stated value or typically +/−0.5% of the stated value. The stated value of the present disclosure is an approximate value. When there is no specific description, the stated value includes the meaning of “about” or “substantially”. The expression “in a range from the first value to the second value” or “between the first value and the second value” means that the range includes the first value, the second value, and other values in between. 
     It should be understood that in the following embodiments, without departing from the spirit of the present disclosure, the features in several different embodiments can be replaced, recombined, and mixed to complete another embodiment. The features between the various embodiments can be mixed and matched arbitrarily as long as they do not violate or conflict the spirit of the present disclosure. 
     Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It should be appreciated that, in each case, the term, which is defined in a commonly used dictionary, should be interpreted as having a meaning that conforms to the relative skills of the present disclosure and the background or the context of the present disclosure, and should not be interpreted in an idealized or overly formal manner unless so defined. 
     In accordance with some embodiments of the present disclosure, a sensing device including a plurality of light-collecting elements is provided. The light-collecting elements of the sensing device can collect lights to a plurality of sensing elements, and the sensing elements can convert the collected lights into a plurality of sensing signals, and the sensing signals generated by these sensing elements are output as a whole to a terminal of the sensing circuit. Furthermore, in accordance with some embodiments of the present disclosure, the areas that are not irradiated by the lights collected from the light-collecting elements may not be provided with the sensing element. In accordance with the embodiments of the present disclosure, through the configuration design of the sensing circuit and the sensing element, the equivalent capacitance of the sensing element can be reduced, the sensitivity of the sensing element can be improved, or the overall performance of the sensing device can be improved. 
     Refer to  FIG. 1 , which is a cross-sectional diagram of a sensing device  10  in accordance with some embodiments of the present disclosure. It should be understood that, for clear description, some elements of the sensing device  10  may be omitted in the drawing, and only some elements are schematically shown. In accordance with some embodiments, additional features may be added to the sensing device  10  described below. In accordance with some other embodiments, some of the features of the sensing device  10  described below may be replaced or omitted. 
     As shown in  FIG. 1 , in some embodiments, the sensing device  10  includes a substrate  102 , an active layer  200 , sensing elements  100 U, and light-collecting elements  400 . The active layer  200  is disposed on the substrate  102 , and the sensing elements  100 U are disposed on the active layer  200 , and the light-collecting elements  400  are disposed on the sensing elements  100 U. In addition, a sensing circuit SC of the sensing device  10  is disposed in the active layer  200 . 
     In some embodiments, the substrate  102  includes a flexible substrate, a rigid substrate, or a combination thereof, but it is not limited thereto. In some embodiments, the material of the substrate  102  may include, but is not limited to, glass, quartz, sapphire, ceramic, polyimide (PI), polycarbonate (PC), polyethylene terephthalate (PET), polypropylene (PP), another suitable material, or a combination thereof. Furthermore, in some embodiments, the substrate  102  may include a metal-glass fiber composite plate, or a metal-ceramic composite plate, but it is not limited thereto. In addition, the light transmittance of the substrate  102  may not be limited. That is, the substrate  102  may be a light-transmitting substrate, a semi-transmitting substrate, or a non-transmitting substrate. 
     In some embodiments, the sensing device  10  further includes a buffer layer (not illustrated), and the buffer layer is disposed between the substrate  102  and the active layer  200 . Furthermore, in some embodiments, the active layer  200  includes thin-film transistors, such as a thin-film transistor TR 1 , a thin-film transistor TR 2 , and a thin-film transistor TR 3  shown in the figure, and the active layer  200  may include conductive elements and signal lines that are electrically connected to the thin-film transistors, insulating layers formed between conductive elements, and planarization layers, and so on. In some embodiments, the signal lines include, for example, current signal lines, voltage signal lines, high-frequency signal lines, and low-frequency signal lines, and the signal lines that can transmit device operating voltage (VDD), common ground voltage (VSS), or the voltage driving device terminal, but the present disclosure is not limited thereto. 
     In some embodiments, thin-film transistors may include switching transistors, driving transistors, reset transistors, transistor amplifiers, or another suitable thin-film transistor. Specifically, in some embodiments, the thin-film transistor TR 1  may be a reset transistor, the thin-film transistor TR 2  may be a transistor amplifier or a source follower, and the thin-film transistor TR 3  may be a switching transistor, but it is not limited thereto. 
     It should be understood that the number of thin-film transistors is not limited to that shown in the figure. According to different embodiments, the sensing device  10  may have another suitable number or type of thin-film transistor. Furthermore, the types of thin-film transistors may include top gate thin-film transistors, bottom gate thin-film transistors, dual gate or double gate thin-film transistors, or a combination thereof. In some embodiments, the thin-film transistor may be further electrically connected to the capacitor elements, but it is not limited thereto. Furthermore, the thin-film transistor may include at least one semiconductor layer, a gate dielectric layer, and a gate electrode layer. The thin-film transistor can exist in various forms well known to those skilled in the art, and the detailed structure of the thin-film transistor will not be repeated herein. 
     Furthermore, in some embodiments, the sensing device  10  includes a planarization layer PN 1 , and the planarization layer PN 1  is disposed on the active layer  200  and between the active layer  200  and the sensing elements  100 U. The sensing elements  100 U are disposed on the planarization layer PN 1 , and are electrically connected to a conductive layer MA in the active layer  200  through a conductive layer MB, and thereby electrically connected to the thin-film transistor TR 1 , the thin-film transistor TR 2 , and the thin-film transistor TR 3 . 
     In some embodiments, the conductive layer MB may penetrate through the planarization layer PN 1  to be electrically connected to the conductive layer MA, and the conductive layer MA may, for example, penetrate through the gate dielectric layer (not labeled) and the dielectric layer (not labeled) to be electrically connected to the semiconductor layer of the thin-film transistor TR 1 , but it is not limited thereto. Specifically, in some embodiments, a part of the planarization layer PN 1  may be removed by a patterning process to form a through hole PN 1 -V, then a passivation layer  202  may be formed on the planarization layer PN 1  and in the through hole PN 1 -V, and then the conductive layer MB may be formed on the passivation layer  202 . In addition, the conductive layer MB may also be formed in the through hole PN 1 -V, and then the passivation layer  202  may be formed on the conductive layer MB. 
     In some embodiments, the material of the planarization layer PN 1  may include organic materials, inorganic materials, another suitable material, or a combination thereof, but it is not limited thereto. For example, the inorganic material may include, but is not limited to, silicon nitride, silicon oxide, silicon oxynitride, aluminum oxide, another suitable material, or a combination thereof. For example, the organic material may include, but is not limited to, epoxy resins, silicone resins, acrylic resins (such as polymethylmetacrylate (PMMA)), polyimide, perfluoroalkoxy alkane (PFA), another suitable material, or a combination thereof. 
     In some embodiments, the planarization layer PN 1  may be formed using a chemical vapor deposition process, a physical vapor deposition process, a coating process, a printing process, another suitable process, or a combination thereof. The chemical vapor deposition process may include, for example, a low pressure chemical vapor deposition (LPCVD) process, a low temperature chemical vapor deposition (LTCVD) process, a rapid thermal chemical vapor deposition (RTCVD) process, a plasma enhanced chemical vapor deposition (PECVD) process, an atomic layer deposition (ALD) process, but it is not limited thereto. The physical vapor deposition process may include, for example, a sputtering process, an evaporation process, a pulsed laser deposition process, but it is not limited thereto. 
     Furthermore, the planarization layer PN 1  may be patterned by a photolithography process and/or an etching process. In some embodiments, the photolithography process may include photoresist coating (e.g., spin coating), soft baking, hard baking, mask alignment, exposure, post-exposure baking, photoresist development, washing and drying, etc., but it is not limited thereto. The etching process may include a dry etching process or a wet etching process, but it is not limited thereto. 
     In some embodiments, the conductive layer MA and the conductive layer MB may include conductive materials, such as metal conductive materials, transparent conductive materials, other suitable conductive materials, or a combination thereof, but they are not limited thereto. For example, the metal conductive material may include, but is not limited to, copper (Cu), silver (Ag), gold (Au), tin (Sn), aluminum (Al), molybdenum (Mo), tungsten (W), chromium (Cr), nickel (Ni), platinum (Pt), titanium (Ti), alloys of the foregoing metals, another suitable material, or a combination thereof. The transparent conductive material may include transparent conductive oxide (TCO), for example, indium tin oxide (ITO), antimony zinc oxide (AZO), tin oxide (SnO), zinc oxide (ZnO), indium zinc oxide (IZO), indium gallium zinc oxide (IGZO), indium tin zinc oxide (ITZO), antimony tin oxide (ATO), another suitable transparent conductive material, or a combination thereof, but it is not limited thereto. 
     In some embodiments, the conductive layer MA and the conductive layer MB may be formed using a chemical vapor deposition process, a physical vapor deposition process, an electroplating process, an electroless plating process, another suitable process, or a combination thereof. 
     In some embodiments, the passivation layer  202  may have a single-layer structure or a multiple-layer structure, and the material of the passivation layer  202  may include an inorganic material, an organic material, or a combination thereof, but it is not limited thereto. For example, the inorganic material may include, but is not limited to, silicon nitride, silicon oxide, silicon oxynitride, another suitable material, or a combination thereof. For example, the organic material may include, but is not limited to, polyethylene terephthalate (PET), polyethylene (PE), polyethersulfone (PES), polycarbonate (PC), polymethylmethacrylate (PMMA), polyimide (PI), another suitable material, or a combination thereof. 
     In some embodiments, the passivation layer  202  may be formed using a coating process, a chemical vapor deposition process, a physical vapor deposition process, a printing process, an evaporation process, a sputtering process, another suitable process, or a combination thereof. 
     Furthermore, in some embodiments, the sensing device  10  further includes a planarization layer PN 2  disposed on the passivation layer  202 , and parts of the planarization layer PN 2  are disposed between the sensing elements  100 U. That is, the planarization layer PN 2  is disposed on the passivation layer  202 , and parts of the planarization layer PN 2  are removed by a patterning process to form a plurality of through holes PN 2 -V, and a plurality of sensing elements  100 U are respectively disposed in the through holes PN 2 -V. In this way, the sensing elements  100 U are separated from each other. In addition, it should be understood that although the sensing device  10  in the figure has four sensing elements  100 U, the present disclosure is not limited thereto. In accordance with different embodiments, the sensing device  10  may have another suitable number of sensing elements  100 U. 
     Specifically, in some embodiments, a first electrode layer material, a body region material, and a second electrode layer material may be sequentially formed on the passivation layer  202  using a chemical vapor deposition process, a physical vapor deposition process, or an ion implantation process, and then parts of the first electrode layer material, the body region material, and the second electrode layer material may be removed by a photolithography process and/or an etching process to form a plurality of separate sensing elements  100 U. Next, the planarization layer PN 2  may be formed to cover the sensing elements  100 U. The material and method for forming the planarization layer PN 2  are similar to those of the aforementioned planarization layer PN 1 , and thus will not be repeated here. 
     In addition, the sensing elements  100 U are disposed on the passivation layer  202 . The sensing elements  100 U can receive lights and convert the received lights into electrical signals. The generated electrical signals can be transmitted to the active layer  200 , and processed and analyzed by the sensing circuit SC in the active layer  200 . In some embodiments, the sensing element  100 U includes a photodiode, other elements that can convert optical signals to electrical signals, or a combination thereof, but it is not limited thereto. 
     In some embodiments, the sensing element  100 U has a first doped layer  100   a , an intrinsic layer  100   b , and a second doped layer  100   c , and the intrinsic layer  100   b  may be disposed between the first doped layer  100   a  and the second doped layer  100   c . In some embodiments, the sensing element  100 U has a P-I-N structure, an N-I-P structure, or another suitable structure, but it is not limited thereto. 
     In some embodiments, the first doped layer  100   a  may be, for example, an N-type doped region, the second doped layer  100   c  may be, for example, a P-type doped region, and they may be combined with the intrinsic layer  100   b  to form an N-I-P structure. The material of the element  100 U may include a semiconductor material, for example, may include silicon or another suitable material. 
     In some embodiments, when lights irradiate the sensing elements  100 U having the aforementioned structure, pairs of electrons and electron holes are generated to produce photocurrents, but it is not limited thereto. 
     In some embodiments, the first doped layer  100   a  and the intrinsic layer  100   b , and the second doped layer  100   c  may be formed using a chemical vapor deposition process, a physical vapor deposition process, an electroplating process, an electroless plating process, another suitable process, or a combination thereof. In some embodiments, the conductive layer MC is disposed on the sensing elements  100 U, the second doped layers  100   c  of the sensing elements  100 U are electrically connected to the conductive layer MC, and the first doped layers  100   a  are electrically connected to the conductive layer MB. In some embodiments, the conductive layer MC penetrates through the passivation layer  204  and be electrically connected to the second doped layer  100   c . In detail, in some embodiments, parts of the passivation layer  204  may be removed by a patterning process to form through holes  204   b  above the sensing elements  100 U. Specifically, the passivation layer  204  may be formed on the planarization layer PN 2  and in the through holes PN 2 -V, and then the conductive layer MC may be formed on the passivation layer  204 . In addition, the conductive layer MC also may be formed in the through holes PN 2 -V, and then the passivation layer  204  may be formed on the conductive layer MC. 
     The materials and methods for forming the conductive layer MC are similar to those of the aforementioned conductive layer MA and conductive layer MB, and the materials and methods for forming the passivation layer  204  are similar to those of the aforementioned passivation layer  202 , and thus will not be repeated here. In addition, in some embodiments, the material of the conductive layer MC is a transparent conductive material, which can reduce the influence on the photosensitive efficiency of the sensing element  100 U. 
     Still referring to  FIG. 1 , light-collecting elements  400  are disposed above the sensing elements  100 U. The light-collecting elements  400  are used to collect lights to the sensing elements  100 U. It should be noted that the sensing elements  100 U are configured to generate a plurality of sensing signals according to the lights that are collected by the light-collecting elements  400 , and the sensing elements  100 U can output the sensing signals as a whole to the sensing circuit SC. The circuit diagram regarding the signal transmission will be described in  FIG. 3 . As shown in  FIG. 1 , the sensing elements  100 U are electrically connected to the conductive layer MB, and the conductive layer MB is used as a signal transmission terminal of the sensing elements  100 U, for example, a terminal FD shown in  FIG. 3 . 
     In some embodiments, in a normal direction of the substrate  102  (for example, the Z direction in the figure), the sensing element  100 U and the light-collecting element  400  at least partially overlap. In some embodiments, in the normal direction of the substrate  102  (for example, the Z direction in the figure), the part of the planarization layer PN 2  disposed between the sensing elements  100 U also at least partially overlaps the light-collecting element  400 . In some embodiments, the number of sensing elements  100 U is less than or equal to the number of light-collecting elements  400 . According to the present disclosure, “overlap”, “partially overlap” or “at least partially overlap” means that two elements have overlapping parts with each other. That is, a part of element A and a part of element B overlap each other. Alternatively, in the normal direction of  102  (for example, the Z direction in the figure), a projection of element A on the substrate  102  overlaps a projection of element B on the substrate  102 . 
     In some embodiments, the light-collecting elements  400  may be a micro-lens or other structure with a light-collecting effect. In some embodiments, the material of the light-collecting element  400  may include silicon oxide, polymethylmethacrylate (PMMA), cycloolefin polymer (COP), polycarbonate (PC), another suitable material, or a combination thereof, but it is not limited thereto. 
     In addition, in some embodiments, the light-collecting element  400  may be formed by a chemical vapor deposition process, a physical vapor deposition process, a coating process, a printing process, another suitable process, or a combination thereof. In addition, the light-collecting element  400  may be patterned to have a suitable shape and profile by a photolithography process and/or an etching process. 
     In accordance with the embodiments of the present disclosure, the arrangement of the light-collecting elements  400  helps to concentrate the lights on a specific area, for example, the lights can be collected on a plurality of sensing elements  100 U. It should be noted that according to the present disclosure, parts of the planarization layer PN 2  are removed through a patterning process to form a plurality of through holes PN 2 -V, and a plurality of sensing elements  100 U are respectively disposed in the through holes PN 2 -V, so that a plurality of sensing elements  100 U are arranged in a discontinuous manner. In other words, two adjacent sensing elements  100 U among the sensing elements  100 U may be separated by parts of the planarization layer PN 2 . In some embodiments, portions that are irradiated by the lights collected from the light-collecting elements  400  are provided with the sensing elements  100 U, and portions that are not irradiated by the light collected from the light-collecting elements  400  are provided with the planarization layer (for example, the planarization layer PN 2  may be disposed at the portion between two adjacent sensing elements  100 U that are not irradiated by light collected from the light-collecting elements  400 ), thereby reducing the portions of the sensing elements  100 U that may not be irradiated by light. For example, when several sensing elements  100 U are integrated into a large sized sensing element  100 U (that is, when the planarization layer PN 2  is reduced or deleted), many areas of the sensing element  100 U may not be irradiated by light. In this way, the photocurrent produced by the sensing elements  100 U will be affected by parasitic capacitance in a greater degree, thereby reducing the photoelectric conversion efficiency or sensitivity. In accordance with the embodiments of the present disclosure, the areas that are not irradiated by the lights collected from the light-collecting elements  400  may not be provided with the sensing element  100 U (for example, the planarization layer PN 2  is provided), thereby reducing the chance that the photocurrents of the sensing element  100 U being affected by parasitic capacitance. Accordingly, the sensitivity of the sensing element  100 U can be improved, or the overall performance of the sensing device  10  can be enhanced. 
     Still referring to  FIG. 1 , in some embodiments, the sensing device  10  further includes a planarization layer PN 3  and a light-shielding layer  302  disposed on the sensing elements  100 U. The planarization layer PN 3  and the light-shielding layer  302  are disposed between the sensing elements  100 U and the light-collecting elements  400 , and the light-shielding layer  302  has a plurality of openings  300   p . In some embodiments, the opening  300   p  overlaps the sensing element  100 U in the normal direction of the substrate  102  (for example, the Z direction in the figure). In some embodiments, the opening  300   p  overlaps the light-collecting element  400  in the normal direction of the substrate  102  (for example, the Z direction in the figure). 
     The light-shielding layer  302  can reduce the reflectivity of light. For example, the light-shielding layer  302  can absorb the light reflected by the conductive layer MB or the light reflected back and forth between conductive layers to achieve the effect of anti-reflection or reducing light noise. In some embodiments, the light-shielding layer  302  may include a metal material, and the metal material may include copper (Cu), aluminum (Al), molybdenum (Mo), indium (In), ruthenium (Ru), tin (Sn), gold (Au)), platinum (Pt), zinc (Zn), silver (Ag), titanium (Ti), lead (Pb), nickel (Ni), chromium (Cr), magnesium (Mg), palladium (Pd), alloys of the foregoing metals, another suitable metal material, or a combination thereof, but it is not limited thereto. 
     Furthermore, in some embodiments, the light-shielding layer  302  may be formed by a chemical vapor deposition process, a physical vapor deposition process, an electroplating process, an electroless plating process, another suitable process, or a combination thereof. In addition, the light-shielding layer  302  may be patterned by a photolithography process and/or an etching process to have the opening  300   p . The opening  300   p  has an opening width. For example, the opening width of the opening  300   p  may be greater than or equal to 2 micrometers (μm) and less than or equal to 6 micrometers (μm) (i.e. 2 μm≤opening width of the opening  300   p≤ 6 μm), such as 3 μm, 4 μm, or 5 μm. 
     Specifically, in some embodiments, a passivation layer  206  may be formed on the planarization layer PN 3  before the light-shielding layer  302  is formed, and then parts of the light-shielding layer  302  may be removed by a patterning process to form the openings  300   p . Next, the passivation layer  206  may be formed on the light-shielding layer  302  and in the openings  300   p . Furthermore, the material and method for forming the passivation layer  206  are similar to those of the aforementioned passivation layer  202 , and thus will not be repeated here. 
     Furthermore, in some embodiments, the sensing device optionally includes a color filter layer disposed on the passivation layer  206 . In some embodiments, the color filter layer may include a red filter unit, a green filter unit, a blue filter unit, a white filter unit, or other color filter units, but it is not limited thereto. According to different embodiments, the color filter layer may have any suitable number or color of color filter units. 
     In some embodiments, the sensing device  10  further includes a dielectric layer  208 , a light-shielding layer  302 - 1 , and a passivation layer  210 . The dielectric layer  208  is disposed on the passivation layer  206 , and the light-shielding layer  302 - 1  has a plurality of openings  300   p - 1 . The opening  300   p - 1  has an opening width. For example, the opening width of the opening  300   p - 1  may be greater than or equal to 6 μm and less than or equal to 10 μm (i.e. 6 μm≤opening width of the opening  300   p - 1 ≤10 μm), such as 7 μm, 8 μm, or 9 μm. Alternatively, the opening width of the opening  300   p - 1  may be greater than or equal to 0.5 times the opening width of the opening  300   p , and less than or equal to 2.5 times the opening width of the opening  300   p . In some embodiments, the opening  300   p - 1  overlaps the sensing element  100 U in the normal direction of the substrate  102  (for example, the Z direction in the figure). In some embodiments, the opening  300   p - 1  overlaps the light-collecting element  400  in the normal direction of the substrate  102  (for example, the Z direction in the figure). 
     Furthermore, in some embodiments, the opening  300   p - 1  overlaps the opening  300   p  in the normal direction of the substrate  102  (for example, the Z direction in the figure). In some embodiments, the width of the opening  300   p - 1  is greater than the width of the opening  300   p . Specifically, in some embodiments, the width of the opening  300   p - 1  may be, for example, 8 μm and the width of the opening  300   p  may be, for example, 4 μm, but it is not limited thereto. In accordance with the embodiments of the present disclosure, the width of the opening of the light-shielding layer  302  refers to the maximum width of the bottom of the opening in a direction perpendicular to the normal direction of the substrate  102  (for example, the X direction in the figure). 
     In some embodiments, the dielectric layer  208  may include an organic dielectric material or an inorganic dielectric material. For example, the organic insulating material may include, but is not limited to, perfluoroalkoxy alkane (PFA), polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), polyethylene, another suitable material, or a combination thereof. For example, the inorganic insulating material may include, but is not limited to, silicon oxide, silicon nitride, silicon oxynitride, other high-k dielectric materials, or a combination thereof. 
     Furthermore, the materials and methods for forming the light-shielding layer  302 - 1  are similar to those of the aforementioned light-shielding layer  302 , and the materials and methods for forming the passivation layer  210  are similar to those of the aforementioned passivation layer  202 , and thus will not be repeated here. 
     As shown in  FIG. 1 , in some embodiments, the sensing device  10  further includes a dielectric layer  212 , a light-shielding layer  302 - 2 , and a passivation layer  214 . The dielectric layer  212  is disposed on the passivation layer  210 , and the light-shielding layer  302 - 2  has a plurality of openings  300   p - 2 . The opening  300   p - 2  has an opening width. For example, the opening width of the opening  300   p - 2  may be greater than or equal to 12 μm and less than or equal to 16 μm (i.e. 12 μm≤opening width of the opening  300   p - 2 ≤16 μm), such as 13 μm, 14 μm, or 15 μm. Alternatively, the opening width of the opening  300   p - 2  may be greater than or equal to 2 times the opening width of the opening  300   p , and less than or equal to 4 times the opening width of the opening  300   p . In some embodiments, the opening  300   p - 2  overlaps the sensing element  100 U in the normal direction of the substrate  102  (for example, the Z direction in the figure). In some embodiments, the opening  300   p - 2  overlaps the light-collecting element  400  in the normal direction of the substrate  102  (for example, the Z direction in the figure). 
     Moreover, in some embodiments, the opening  300   p - 2  overlaps the opening  300   p - 1  and the opening  300   p  in the normal direction of the substrate  102  (for example, the Z direction in the figure). In some embodiments, the width of the opening  300   p - 2  is greater than the width of the opening  300   p - 1 . For example, the width of the opening  300   p - 2  may be 14 μm, and the width of the opening  300   p - 1  may be 8 μm, but it is not limited thereto. In some embodiments, when the opening width of the opening  300   p - 2  is greater than or equal to 2 times the opening width of the opening  300   p , and less than or equal to 4 times the opening width of the opening  300   p , and when the opening width of the opening  300   p - 1  is greater than or equal to 0.5 times the opening width of the opening  300   p , and less than or equal to 2.5 times the opening width of the opening  300   p , the angles of the lights incident on the sensing element  100 U are substantially the same. In other words, through the above design, the sensing device  10  can have a collimator-like structure so that the lights incident on the sensing element  100 U are substantially parallel to the normal direction of the substrate  102  (for example, the Z direction in the figure). Therefore, the sensitivity of the sensing device can be improved. Especially, it is helpful to improve the sensitivity of the sensing devices that are applied to in-display fingerprint recognition, but it is not limited thereto. 
     Next, refer to  FIG. 2 , which is a top-view diagram of the sensing element  100 U, the bottom surface of the opening  204   b  of the passivation layer  204  and the opening  300   p  in the partial sensing device  10  in accordance with some embodiments of the present disclosure.  FIG. 2  schematically illustrates the width relationship among a set of sensing element  100 U, the bottom surface of the opening  204   b  of the passivation layer  204 , and the opening  300   p . It should be understood that the same or similar components (or elements) in the following paragraph will be denoted by the same or similar reference numbers, and their materials, manufacturing methods and functions are the same or similar to those described above, and thus they will not be repeated in the following context. 
     As shown in  FIG. 2 , in some embodiments, the width of the bottom surface of the opening  204   b  of the passivation layer  204  is smaller than the width of the sensing element  100 U, and the width of the opening  300   p  is smaller than the width of the sensing element  100 U. The width of the bottom surface  204   b  may be, for example, greater than or equal to 2 μm and less than or equal to 5 μm (i.e. 2 μm≤width of the bottom surface  204   b≤ 5 μm), such as 3 μm, or 4 μm. The width of the sensing element  100 U may be, for example, greater than or equal to 8 μm and less than or equal to 12 μm (i.e. 8 μm≤width of the sensing element  100 U≤12 μm), such as 9 μm, 10 μm, or 11 μm. The bottom surface of the opening  204   b  of the passivation layer  204  refers to the width of the bottommost part of the opening  204   b  of the passivation layer  204  that is disposed above the sensing element  100 U. With the design that the width of the bottom surface  204   b  of the passivation layer  204  being smaller than the width of the sensing element  100 U, and the width of the opening  300   p  being smaller than the width of the sensing element  100 U, the lights incident on the sensing element  100 U are substantially parallel to the normal direction of the substrate  102  (for example, the Z direction in the figure). Therefore, the optical signals of the sensing element  100 U can be effectively increased, or the sensitivity of the sensing device can be improved. In accordance with the embodiments of the present disclosure, the width of the aforementioned element refers to the distance of the bottommost part of the element along the X direction in a plane that is perpendicular to the normal direction of the substrate  102  (for example, the X-Y plane in the drawing). 
     Furthermore, it should be understood that, in accordance with the embodiments of the present disclosure, an optical microscope (OM), a scanning electron microscope (SEM), a film thickness profiler (α-step), an ellipsometer or another suitable method may be used to measure the width, thickness, height or area of the element, or the distance or pitch between elements. Specifically, in some embodiments, a scanning electron microscope may be used to obtain a cross-sectional image including the elements to be measured, and the width, thickness, height or area of the element, or the distance or pitch between elements in the image can be measured. 
       FIG. 3  is an equivalent circuit diagram of a sensing circuit SC in accordance with some embodiments of the present disclosure. As shown in  FIG. 3 , in some embodiments, each of the sensing elements  100 U is electrically connected to a terminal FD of the sensing circuit SC, and the sensing elements  100 U are arranged discontinuously and electrically connected to each other in parallel. In some embodiments, the terminal FD is a floating diffusion node. As described above, a plurality of sensing elements  100 U that are arranged in a discontinuous manner generate a plurality of sensing signals according to the collected lights, and transmit these sensing signals as a whole to the terminal FD. Specifically, according to the present disclosure, “as a whole” refers to that, for example, the sensing signals of a plurality of parallel-connected sensing elements  100 U are integrated into a sensing signal before being transmitted to the terminal FD. According to the embodiments of the present disclosure, the configuration in which a plurality of sensing elements  100 U are arranged discontinuously and electrically connected to each other in parallel can reduce the equivalent capacitance of the sensing elements  100 U or improve the sensitivity and performance of the sensing device. 
     In some embodiments, the thin-film transistor TR 1  and the thin-film transistor TR 2  are electrically connected to the terminal FD, and the thin-film transistor TR 2  is further electrically connected to the thin-film transistor TR 3 . In some embodiments, the thin-film transistor TR 1  can reset the potential of the terminal FD to give an initial potential, and the photocurrents generated by the sensing elements  100 U can change the potential of the terminal FD, and the signals generated by the current can be transmitted by the thin-film transistor TR 2  and the thin-film transistor TR 3 . 
     Furthermore, as described above, the sensing circuit SC includes the thin-film transistor TR 1 , the thin-film transistor TR 2 , and the thin-film transistor TR 3 . In addition, a plurality of sensing elements  100 U are coupled to a system voltage line VCC 1 . 
     The thin-film transistor TR 1  includes a first terminal coupled to the system voltage line VCC 1 , a second terminal coupled to the terminal FD, and a control terminal coupled to a control signal DCGy. The thin-film transistor TR 1  can connect or disconnect the system voltage line VCC 1  according to the control signal DCGy. When the thin-film transistor TR 1  is connected to the system voltage line VCC 1 , the potential of the terminal FD can be reset. When the thin-film transistor TR 1  is disconnected from the system voltage line VCC 1 , the potential of the terminal FD is not reset. 
     The thin-film transistor TR 2  includes a first terminal coupled to the system voltage line VCC 2 , a second terminal coupled to the first terminal of the thin-film transistor TR 3 , and a control terminal coupled to the second terminal of the thin-film transistor TR 1  and the terminal FD. The thin-film transistor TR 2  is used to amplify the voltage of the terminal FD to generate an amplified current IAMP. 
     The thin-film transistor TR 3  includes a first terminal coupled to the second terminal of the thin-film transistor TR 2 , a second terminal coupled to a readout signal line ROx, and a control terminal coupled to the scan line signal SCNy. The thin-film transistor TR 3  can connect or disconnect the first terminal of the thin-film transistor TR 3  and the readout signal line ROx according to the scan line signal SCNy. When the first terminal of the thin-film transistor TR 3  is connected to the readout signal line ROx, it can output the amplified current IAMP to the readout signal line ROx. When the first terminal of the thin-film transistor TR 3  is disconnected from the readout signal line ROx, not amplified current IAMP is output to the readout signal line ROx. By collecting the amplified current IAMP generated by the sensing elements  100 U, a fingerprint can be pieced together, especially through a plurality of sensing elements  100 U that are electrically connected in parallel. 
     Next, refer to  FIGS. 4A-4C , which are top-view diagrams of the sensing elements  100 U and the light-collecting elements  400  of a sensing device in accordance with some embodiments of the present disclosure. It should be understood that, for clear description,  FIGS. 4A-4C  only illustrate the diagrams of partial sensing elements  100 U and light-collecting elements  400  to further describe their configuration. 
     In some embodiments, in a top-view perspective, the sensing element  100 U is rectangular, and the light-collecting element  400  is circular, but the present disclosure is not limited thereto. According to different embodiments, the sensing element  100 U and the light-collecting element  400  may have any other suitable shape. Furthermore, in some embodiments, the sensing device has a plurality of light-collecting elements  400 . For example, the light-collecting elements  400  may form an array in a 2×2 manner, and the array can be regarded as a light-collecting unit U. That is, the sensing device may have a plurality of light-collecting units U. In a light-collecting unit U, each of the sensing elements  100 U is electrically connected to the conductive layer MB (e.g., an anode) and the conductive layer MC (e.g., a cathode), and the sensing elements  100 U are electrically connected with each other in parallel. In addition, the conductive layer MB may be a patterned conductive layer MB, and the conductive layer MC may be a patterned conductive layer MC, but it is not limited thereto. When the sensing elements  100 U of the light-collecting unit U are irradiated by lights, the photocurrents generated by the sensing elements  100 U all can be derived through the conductive layer MB and the conductive layer MC of the light-collecting unit U. That is, a plurality of sensing signals are output as a whole, thereby reducing the impact of parasitic capacitance. However, it should be understood that the number and arrangement of the sensing elements  100 U and the light-collecting elements  400  are not limited to those shown in the figure. According to different embodiments, the sensing device may have any suitable number of sensing elements  100 U and light-collecting elements  400 . In addition, according to different embodiments, the sensing elements  100 U and the light-collecting elements  400  of the sensing device may be configured in another suitable arrangement. 
     As shown in  FIG. 4A , the number of sensing elements  100 U may be less than the number of light-collecting elements  400 . For example, one sensing element  100 U may correspond to two light-collecting elements  400 . That is, in the normal direction of the substrate  102  (for example, the Z direction in the figure), one sensing element  100 U may at least partially overlap two light-collecting elements  400 . In addition, a portion of the sensing element  100 U may not overlap the light-collecting element  400 . 
     As shown in  FIG. 4B , in some embodiments, the number of sensing elements  100 U may be equal to the number of light-collecting elements  400 . For example, one sensing element  100 U may correspond to one light-collecting element  400 . That is, in the normal direction of the substrate  102  (for example, the Z direction in the figure), one sensing element  100 U may at least partially overlap one light-collecting element  400 . In some embodiments, the light-collecting element  400  may entirely overlap the sensing element  100 U. 
     As shown in  FIG. 4C , in some embodiments, the number of sensing elements  100 U may be less than the number of light-collecting elements  400 . For example, in one light collecting unit U, part of the sensing elements  100 U may correspond to one light-collecting element  400 , that is, in the normal direction of the substrate  102  (for example, the Z direction in the figure), one sensing element  100 U may at least partially overlap one light-collecting element  400 ; in addition, part of the sensing elements  100 U may correspond to two light-collecting elements  400 , that is, in the normal direction of the substrate  102  (for example, the Z direction in the figure), one sensing element  100 U may at least partially overlap two light-collecting elements  400 . 
     Next, refer to  FIGS. 5A-5C , which are top-view diagrams of partial sensing elements  100 U and light-collecting elements  400  of a sensing device in accordance with some other embodiments of the present disclosure. It should be understood that, for clear description, some elements of the sensing device are omitted in the drawing, and only some elements are schematically drawn to further describe their configuration. 
     As shown in  FIGS. 5A-5C , in some embodiments, the sensing device may have, for example, seven light-collecting elements  400 , and the light-collecting elements  400  are arranged in a hexagonal array. For example, the first row may include two light-collecting elements  400 , the second row may include three light-collecting elements  400 , and the third row may include two light-collecting elements  400 , but the number of light-collecting elements  400  is not limited thereto. 
     As shown in  FIG. 5A  and  FIG. 5C , the number of sensing elements  100 U may be less than the number of light-collecting elements  400 . For example, part of the sensing elements  100 U may correspond to two light-collecting elements  400 , and part of the sensing elements  100 U may correspond to three light-collecting elements  400 . That is, in the normal direction of the substrate  102  (for example, the Z direction in the figure), one sensing element  100 U may at least partially overlap two or three light-collecting elements  400 . In addition, a portion of the sensing element  100 U may not overlap the light-collecting element  400 . Furthermore, as shown in  FIG. 5A , the extending direction of the sensing element  100 U may be the same as the direction in which the light-collecting elements  400  of the first row are arranged (for example, the X direction in the figure). Alternatively, as shown in  FIG. 5C , the extending direction of the sensing element  100 U may be different from the direction in which the first row of light-collecting elements  400  are arranged (for example, the X direction in the figure). 
     As shown in  FIG. 5B , in some embodiments, the number of sensing elements  100 U may be equal to the number of light-collecting elements  400 . For example, one sensing element  100 U may correspond to one light-collecting element  400 . That is, in the normal direction of the substrate  102  (for example, the Z direction in the figure), one sensing element  100 U may at least partially overlap one light-collecting element  400 . In some embodiments, the light-collecting element  400  may entirely overlap the sensing element  100 U. 
     Next, refer to  FIGS. 6A-6C , which are top-view diagrams of partial sensing elements  100 U and light-collecting elements  400  of a sensing device in accordance with some other embodiments of the present disclosure. It should be understood that, for clear description, some elements of the sensing device are omitted in the drawing, and only some elements are schematically drawn to further describe their configuration. 
     As shown in  FIGS. 6A-6C , in some embodiments, the sensing device may include, for example, nine light-collecting elements  400 , and the light-collecting elements  400  are arranged in a 3×3 array, but the number of light-collecting elements  400  is not limited thereto. As shown in  FIGS. 6A-6C , the number of sensing elements  100 U may be less than the number of light-collecting elements  400 . For example, one sensing element  100 U may correspond to three light-collecting elements  400 . That is, in the normal direction of the substrate  102  (for example, the Z direction in the figure), one sensing element  100 U may at least partially overlap three light-collecting elements  400 . In addition, a portion of the sensing element  100 U may not overlap the light-collecting element  400 . Furthermore, as shown in  FIG. 6C , in some embodiments, some of the sensing elements  100 U may have the same shape (e.g., a triangle), and some of the sensing elements  100 U may have a different shape (for example, a rectangle). In some other embodiments, the sensing elements  100 U may all have different shapes. 
     As shown in  FIG. 6B , the number of sensing elements  100 U may be equal to the number of light-collecting elements  400 . For example, one sensing element  100 U may correspond to one light-collecting element  400 . That is, in the normal direction of the substrate  102  (for example, the Z direction in the figure), one sensing element  100 U may at least partially overlap one light-collecting element  400 . In some embodiments, the light-collecting element  400  may entirely overlap the sensing element  100 U. 
     Next, refer to  FIGS. 7A-7C , which are top-view diagrams of partial sensing elements  100 U and light-collecting elements  400  of a sensing device in accordance with some other embodiments of the present disclosure. It should be understood that, for clear description, some elements of the sensing device are omitted in the drawing, and only some elements are schematically drawn to further describe their configuration. 
     As shown in  FIGS. 7A-7C , in some embodiments, the sensing device may have, for example, sixteen light-collecting elements  400 , and the light-collecting elements  400  are arranged in a 4×4 array, but the number of light-collecting elements  400  is not limited thereto. As shown in  FIG. 7A  and  FIG. 7C , the number of sensing elements  100 U may be less than the number of light-collecting elements  400 . For example, one sensing element  100 U may correspond to four light-collecting elements  400  (as shown in  FIG. 7A ) or two light-collecting elements  400  (as shown in  FIG. 7C ). In addition, a portion of the sensing element  100 U may not overlap the light-collecting element  400 . 
     As shown in  FIG. 7B , the number of sensing elements  100 U may be equal to the number of light-collecting elements  400 . For example, one sensing element  100 U may correspond to one light-collecting element  400 . That is, in the normal direction of the substrate  102  (for example, the Z direction in the figure), one sensing element  100 U may at least partially overlap one light-collecting element  400 . In some embodiments, the light-collecting element  400  may entirely overlap the sensing element  100 U. 
     Next, refer to  FIG. 8A  and  FIG. 8B , which are schematic diagrams of an electronic device  1  in accordance with some embodiments of the present disclosure. It should be understood that, for clear description, the drawings only schematically illustrate some of the components of the electronic device  1 . In accordance with some embodiments, additional features can be added to the electronic device  1  described below. 
     In some embodiments, the electronic device  1  includes the aforementioned sensing device  10  and a display device  20 , and the sensing device  10  is disposed opposite the display device  20 . In some embodiments, the electronic device  1  has functions such as touch-sensing or fingerprint recognition. For example, the electronic device  1  may be a touch display device, but it is not limited thereto. For example, the light L generated by the display device  20  is reflected by a finger FP to generate the reflected light RL, and the reflected light RL can be transmitted to the sensing device  10  after passing through the display device  20 . The sensing device  10  can sense the touch of the finger, and convert it into an electronic signal to the corresponding driving component or signal processing component for identification and analysis. Specifically, the sensing device  10  may be fixed to the display device  20  through an adhesive layer, or the sensing device  10  may be fixed to the display device  20  through a spacer SP. When the sensing device  10  is fixed to the display device  20  through the spacer SP, there may be air or other media between the sensing device  10  and the display device  20 . The light L generated by the display device  20  is reflected by the finger FP and then generates the reflected light RL. The reflected light RL can be transmitted to the sensing device  10  through the air, and the sensing device  10  can sense the touch of the finger. The adhesive layer or spacer may include a material with adhesiveness. In some embodiments, the adhesive layer may include a light-curable adhesive material, a heat-curable adhesive material, a light-heat-curable adhesive material, another suitable material, or a combination thereof, but it is not limited thereto. For example, in some embodiments, the adhesive layer may include, but is not limited to, optical clear adhesive (OCA), optical clear resin (OCR), pressure sensitive adhesive (PSA), another suitable material, or a combination thereof. 
     In some embodiments, the display device  20  may include, for example, a liquid-crystal display panel, a light-emitting diode display panel, such as an inorganic light-emitting diode display panel, an organic light-emitting diode (OLED) display panel, a mini light-emitting diode (mini LED) display panel, a micro light-emitting diode (micro LED) display panel, or a quantum dot (QD) light-emitting diode (e.g., QLED or QDLED) display panel, but it is not limited thereto. 
     To summarize the above, in accordance with some embodiments of the present disclosure, the provided sensing device can reduce the equivalent capacitance of the sensing elements through the configuration design of the sensing circuit and the sensing elements. Therefore, the sensitivity of the sensing elements can be improved, or the overall performance of the sensing device can be improved. The display quality and sensing performance of the electronic device can be further enhanced. 
     Although some embodiments of the present disclosure and their advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the disclosure as defined by the appended claims. The features of the various embodiments can be used in any combination as long as they do not depart from the spirit and scope of the present disclosure. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the present disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed, that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present disclosure. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods or steps. In addition, each claim constitutes an individual embodiment, and the claimed scope of the present disclosure includes the combinations of the claims and embodiments. The scope of protection of present disclosure is subject to the definition of the scope of the appended claims. Any embodiment or claim of the present disclosure does not need to meet all the purposes, advantages, and features disclosed in the present disclosure.