Image sensing structure and manufacturing method thereof

Abstract

An image sensing structure is provided. The image sensing structure includes a substrate, an array of readout circuits, a photovoltaic layer, and a filter layer. The filter layer has a first spectrum defining a first wavelength. The photovoltaic layer has a second spectrum defining a second wavelength. The second wavelength is greater than the first wavelength. The first wavelength corresponds to a first line. The first line passes through a first point and a second point on a curve of the first spectrum of the filter layer. The first point aligns with an extinction coefficient of 0.9. The second point aligns with an extinction coefficient of 0.1. The second wavelength corresponds to a second line. The second line passes through a third point and a fourth point on a curve of the second spectrum of the photovoltaic layer. The third point aligns with an extinction coefficient of 0.9. The fourth point aligns with an extinction coefficient of 0.1.

Description

Technical Field

[0001] The present disclosure relates to an image sensing structure and a manufacturing method thereof, and more particularly to an image sensing structure having a filter layer and an absorption wavelength tunable-photoelectric layer and a manufacturing method thereof. Background Art

[0002] Infrared (IR) image sensors are a common technology used for facial recognition and three-dimensional (3D) sensing. These IR image sensors detect signals from laser light sources. Commonly used laser wavelengths are 850 nanometers (nm), 940 nm, 980 nm, 1310 nm, 1350 nm, and 1550 nm. They treat ambient broadband light sources as noise. To improve the signal-to-noise ratio (S / N), it is best to use a narrowband image sensor corresponding to the laser wavelength to sense the signal.

[0003] Currently, existing silicon-based image sensors typically operate at a wavelength of 940 nm but suffer from low quantum efficiency. This low quantum efficiency stems from relatively weak absorption efficiency in the near-infrared (NIR) region, between approximately 900 nm and 1100 nm. To improve the absorption efficiency of silicon-based image sensors in the NIR, ultra-deep (>5 μm) silicon-based photodiodes are recommended. However, this leads to higher manufacturing costs, high optical crosstalk between pixels, limited miniaturization, and lower image density. Furthermore, silicon lacks sensitivity above 1100 nm, limiting its application in the short-wave infrared (SWIR) region, between approximately 1100 nm and 1700 nm.

[0004] In addition, a complementary metal oxide semiconductor (CMOS) image sensor is integrated with an interference-type narrowband pass filter to serve as a narrowband IR image sensor. However, the aforementioned narrowband IR image sensor has a high-angle dependent peak shift when high-angle light is incident, and thus cannot be used at high incident angles, limiting the field of view (FOV) application. In addition, the manufacturing complexity, film thickness, and cost of the interference-type narrowband pass filter limit the prospects of integrating the image sensor with other components.

[0005] While the existing image sensing structures have generally met their intended purposes, these existing image sensing structures have not been entirely satisfactory in all respects, for example, the wavelength range to be improved. Therefore, there are still some problems to be solved regarding the search for image sensing structures with higher performance and the manufacturing method of the aforementioned image sensing structures. SUMMARY

[0006] In view of the above problems, some embodiments of the present disclosure include a filter layer having a first spectrum defining a first wavelength, and a wavelength tunable photoelectric layer having a second spectrum defining a second wavelength, wherein the second wavelength is greater than the first wavelength, to expand the sensing wavelength of a narrowband IR image sensor and / or improve the reliability of the narrowband IR image sensor.

[0007] According to some embodiments of the present disclosure, an image sensing structure is provided. The image sensing structure includes a substrate, a readout circuit array, a photoelectric layer, and a filter layer. The readout circuit array is located on the substrate. The photoelectric layer is disposed on the readout circuit array. The filter layer is disposed on the photoelectric layer. The filter layer has a first spectrum. The first spectrum defines a first wavelength. The photoelectric layer has a second spectrum. The second spectrum defines a second wavelength greater than the first wavelength. The first wavelength corresponds to a first line. The first line passes through a first point and a second point on a curve of the first spectrum of the filter layer. The first point is aligned with an extinction coefficient of 0.9. The second point is aligned with an extinction coefficient of 0.1. The second wavelength corresponds to a second line. The second line passes through a third point and a fourth point on the curve of the second spectrum of the photoelectric layer. The third point is aligned with an extinction coefficient of 0.9. The fourth point is aligned with an extinction coefficient of 0.1.

[0008] According to some embodiments of the present disclosure, a method for manufacturing an image sensing structure is provided. The method for manufacturing the image sensing structure includes forming a substrate, forming a readout circuit array on the substrate, forming a photoelectric layer on the readout circuit array, and forming a filter layer on the photoelectric layer. The filter layer has a first spectrum. The first spectrum defines a first wavelength. The photoelectric layer has a second spectrum. The second spectrum defines a second wavelength greater than the first wavelength. The first wavelength corresponds to a first line. The first line passes through a first point and a second point on a curve of the first spectrum of the filter layer. The first point is aligned with an extinction coefficient of 0.9. The second point is aligned with an extinction coefficient of 0.1. The second wavelength corresponds to a second line. The second line passes through a third point and a fourth point on the curve of the second spectrum of the photoelectric layer. The third point is aligned with an extinction coefficient of 0.9. The fourth point is aligned with an extinction coefficient of 0.1.

[0009] According to some embodiments of the present disclosure, the image sensing structure can be used in various types of devices and applications. In order to make the components and advantages of some embodiments of the present disclosure easier to understand, some embodiments are listed below in conjunction with the accompanying drawings and described in detail below. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The following detailed description, when combined with the accompanying drawings, will enable those skilled in the art to better understand the concepts of some embodiments of the present disclosure. It should be noted that, in accordance with standard industry practice, various components are not drawn to scale and are for illustrative purposes only. In fact, the dimensions of various components may be arbitrarily enlarged or reduced for clarity of description.

[0011] Figures 1A to 1Cis an illustrative cross-sectional view of an image sensing structure according to some embodiments of the present disclosure.

[0012] Figure 2A is a diagram of normalized extinction coefficient versus wavelength (nm) according to some embodiments of the present disclosure.

[0013] Figure 2B is a graph showing quantum efficiency (%) versus wavelength (nm) according to some embodiments of the present disclosure.

[0014] Figures 3A to 3F is a diagram illustrating normalized extinction coefficient and quantum efficiency (%) versus wavelength (nm) according to some embodiments of the present disclosure.

[0015] Figures 4A to 4D Schematic diagram of the energy gap of the first carrier transport layer, the photovoltaic layer, and the second carrier transport layer according to some embodiments of the present disclosure.

[0016] Figures 5A to 5H are illustrative cross-sectional views of image sensing structures at various stages of fabrication according to some embodiments of the present disclosure.

[0017] Figures 6A to 6H are illustrative cross-sectional views of image sensing structures at various stages of fabrication according to some embodiments of the present disclosure.

[0018] 7A to 7F are illustrative cross-sectional views of image sensing structures at various stages of fabrication according to some embodiments of the present disclosure.

[0019] Figure 8A is a schematic diagram of an image sensor according to some embodiments of the present disclosure.

[0020] Figure 8B is a schematic circuit diagram of an image sensor according to some embodiments of the present disclosure.

[0021] Description of reference numerals:

[0022] 1,2,3: Image sensing structure

[0023] 100: Substrate

[0024] 110: Readout circuit array

[0025] 111: Readout transistor unit

[0026] 112: Grassroots

[0027] 120: Bottom contact electrode

[0028] 121: Top contact electrode

[0029] 122: Insulation material

[0030] 200: Photovoltaic module

[0031] 210: First carrier transport layer

[0032] 210L: Minimum band gap

[0033] 210H: Maximum energy gap

[0034] 220: Photovoltaic layer

[0035] 220L: Minimum band gap

[0036] 220H: Maximum energy gap

[0037] 230: Second carrier transport layer

[0038] 230L: Minimum band gap

[0039] 230H: Maximum energy gap

[0040] 300: conductive layer

[0041] 310: conductive part

[0042] 400: Protective layer

[0043] 500: Microlens structure

[0044] 510: Microlens

[0045] 520: Filling material

[0046] 600: filter layer

[0047] 810: Image sensor array

[0048] 820: Column address decoder

[0049] 830: Line Circuit

[0050] 840: Row address decoder

[0051] 850: Analog-to-digital converter

[0052] L1: First Line

[0053] L2: Second Line

[0054] M1: Reset switch transistor

[0055] M2: Source follower transistor

[0056] M3: Column select switch transistor

[0057] P1: First point

[0058] P2: Second point

[0059] P3: The third point

[0060] P4: The fourth point

[0061] S1: First Spectrum

[0062] S2: Second Spectrum

[0063] W: distance

[0064] λ1: first wavelength

[0065] λ2: second wavelength

[0066] Δλ: difference DETAILED DESCRIPTION

[0067] The following disclosure provides many different embodiments or examples for implementing different components of the image sensing structure disclosed herein. Specific examples of each component and its configuration are described below to simplify the embodiments of the present disclosure. Of course, these are merely examples and are not intended to limit the present disclosure. For example, if the description refers to a first component being formed on a second component, it may represent an embodiment in which the first component is in direct contact with the second component, or it may represent an embodiment in which an additional component is formed between the first component and the second component so that the first component is not in direct contact with the second component. In addition, the embodiments of the present disclosure may repeat component symbols and / or characters in different examples. Such repetition is for simplicity and clarity, and is not intended to indicate a relationship between the different embodiments and / or implementations discussed herein.

[0068] The following describes some variations of the embodiments. Similar or identical reference numerals are used to designate similar or identical components in the various figures and illustrated embodiments. It should be understood that additional operations and / or processes may be provided before, during, or after the methods disclosed herein, and that in some embodiments, some of the disclosed operations may be replaced or deleted using other embodiments of the aforementioned methods.

[0069] Furthermore, spatially relative terms are used to facilitate description of the relationship of one component of the present disclosure to other components, for example, "on," "over," "upper," "lower," "above," "below," and the like. Spatially relative terms are intended to encompass different orientations of components in use or operation in addition to the orientations depicted in the drawings. When a component is oriented to another orientation (e.g., rotated 90 degrees or at other orientations), the spatially relative terms used herein should be interpreted based on that orientation.

[0070] Hereinafter, the terms "about," "approximately," and "substantially" generally mean within ±20% of a given value or a given range, for example, within ±10%, within ±5%, within ±3%, within ±2%, within ±1%, or within ±0.5%. It should be noted that the numerical values ​​provided in the specification are approximate values, that is, even if the terms "about," "approximately," and "substantially" are not specifically stated, the meanings of "about," "approximately," and "substantially" may still be implied.

[0071] Figures 1A to 1C is an illustrative cross-sectional view of an image sensing structure according to some embodiments of the present disclosure.

[0072] Reference Figure 1A An image sensing structure 1 is provided. The image sensing structure 1 includes a substrate 100, a readout circuit array 110, a photoelectric module 200, and a filter layer 600. The photoelectric module 200 includes a photoelectric layer 220. In some embodiments, the readout circuit array 110 is formed on the substrate 100. In some embodiments, the filter layer 600 is formed on the readout circuit array 110. In some embodiments, the photoelectric module 200 including the photoelectric layer 220 is formed between the readout circuit array 110 and the filter layer 600. In some embodiments, the readout circuit array 110, the photoelectric module 200, and the filter layer 600 are sequentially formed on the substrate 100. For clarity, the following description will be based on the stacking order of the image sensing structure 1.

[0073] In some embodiments, substrate 100 may be or include a bulk semiconductor substrate or a semiconductor-on-insulator (SOI) substrate. Substrate 100 may be doped using, for example, p-type dopants or n-type dopants, or may be undoped. Generally speaking, an SOI substrate includes a film layer of semiconductor material formed on an insulating layer. For example, the insulating layer may be a silicon oxide layer, a silicon nitride layer, a polysilicon layer, a combination thereof, or a stack of the foregoing film layers. The insulating layer is disposed on a substrate such as a silicon (Si) substrate. Other substrates, such as multi-layer substrates or gradient substrates, may also be used. In some embodiments, the semiconductor material of substrate 100 may include silicon having different crystal planes. In some embodiments, the substrate 100 may be a semiconductor substrate or a ceramic substrate, such as a gallium arsenide (GaAs) substrate, a gallium nitride (GaN) substrate, a silicon carbide (SiC) substrate, an aluminum nitride (AlN) substrate, or a sapphire substrate.

[0074] In some embodiments, the readout circuit array 110 includes a plurality of readout transistor units 111 arranged in a two-dimensional (2D) array on a base layer 112. Each readout transistor unit 111 includes a plurality of metal oxide semiconductor field effect transistors (MOSFETs) or thin film transistors (TFTs), or a combination thereof. The readout transistor unit 111 has one end in contact with a bottom contact pad 120, and the readout transistor unit 111 has a signal output end connected to an external circuit. Depending on the circuit design, the output signal can be an analog signal or a digital signal.

[0075] In some embodiments, the image sensing structure 1 further includes an insulating material 122 disposed between bottom contact electrodes 120, and the bottom contact electrodes 120 are formed on the readout circuit array 110. In some embodiments, the bottom contact electrodes 120 can serve as wiring in the readout circuit array 110 and / or as bottom electrodes of a subsequently formed optoelectronic module 200. For example, the bottom contact electrodes 120 can be disposed between the readout circuit array 110 and the subsequently formed optoelectronic module 200.

[0076] In some embodiments, the bottom contact electrode 120 may be or include a conductive material, such as a metal, a metal nitride, a conductive semiconductor material, one or more suitable conductive materials, or a combination thereof. In some embodiments, the metal may be gold (Au), nickel (Ni), platinum (Pt), palladium (Pd), iridium (Ir), titanium (Ti), chromium (Cr), tungsten (W), aluminum (Al), copper (Cu), or a combination thereof. The semiconductor material may be polycrystalline silicon (Si) or polycrystalline germanium (G). In some embodiments, the bottom contact electrode 120 may be a transparent conductive layer, such as indium tin oxide (ITO) or indium zinc oxide (ZnO).

[0077] In some embodiments, photovoltaic module 200 is formed on bottom contact electrode 120. In some embodiments, photovoltaic module 200 includes a first carrier transport layer 210, a photovoltaic layer 220 formed on first carrier transport layer 210, and a second carrier transport layer 230 formed on photovoltaic layer 220. In some embodiments, photovoltaic layer 220 is formed between first carrier transport layer 210 and second carrier transport layer 230. In some embodiments, first carrier transport layer 210 is formed between bottom contact electrode 120 and photovoltaic layer 220, and second carrier transport layer 230 is formed between photovoltaic layer 220 and a subsequently formed conductive layer 300.

[0078] In some embodiments, the first carrier transport layer 210 and the second carrier transport layer 230 are used to transport carriers, such as electrons or holes, into or out of the photovoltaic layer 220. That is, the first carrier transport layer 210 and the second carrier transport layer 230 can be electron transport layers (ETLs) and / or hole transport layers (HTLs). For example, both the first carrier transport layer 210 and the second carrier transport layer 230 can be electron transport layers or hole transport layers. Alternatively, the first carrier transport layer 210 is an electron transport layer, and the second carrier transport layer 230 is a hole transport layer. Alternatively, the first carrier transport layer 210 is a hole transport layer, and the second carrier transport layer 230 is an electron transport layer.

[0079] In some embodiments, the electron transport layer can be or include an electron transport material such as ZnO, TiO2, C 60 , its analogs, or one or more suitable electron transport materials. In some embodiments, the thickness of the electron transport layer can be between about 1 nm and about 200 nm. In some embodiments, the hole transport layer can be or include a hole transport material such as MoO3, WO3, poly-3,4-(ethylene-1,2-dioxy)thiophene (poly-3,4-Ethylenedioxythiophene, PEDOT), or one or more suitable hole transport materials. In some embodiments, the thickness of the hole transport layer can be between about 1 nm and about 200 nm.

[0080] In some embodiments, the photovoltaic layer 220 is configured to perform a photoelectric effect. In some embodiments, the photovoltaic layer 220 may be or include an organic material, a quantum dot (QD) material, a perovskite, one or more suitable photovoltaic materials, or a combination thereof. In some embodiments, the photovoltaic layer 220 may have a thickness ranging from approximately 100 nm to approximately 5000 nm.

[0081] like Figure 1A As shown, the image sensing structure 1 further includes a conductive layer 300. The conductive layer 300 is formed on the second carrier transport layer 230. In some embodiments, the conductive layer 300 serves as the upper electrode of the photovoltaic module 200 below the conductive layer 300. For example, the conductive layer 300 can be disposed between the photovoltaic module 200 and a subsequently formed protective layer.

[0082] In some embodiments, the material of the conductive layer 300 can be the same as or different from the material of the bottom contact electrode 120. In some embodiments, the conductive layer 300 can be or include a conductive material, such as a metal, a metal nitride, a conductive semiconductor material, one or more suitable conductive materials, or a combination thereof. In some embodiments, the metal can be gold, nickel, platinum, palladium, iridium, titanium, chromium, tungsten, aluminum, copper, one or more suitable materials, or a combination thereof. The semiconductor material can be polycrystalline silicon or polycrystalline germanium. In some embodiments, the conductive layer 300 is a transparent conductive layer.

[0083] In some embodiments, the image sensing structure 1 further includes a protective layer 400 formed on the conductive layer 300. In some embodiments, the protective layer 400 is formed between the optoelectronic module 200 and the subsequently formed filter layer 600 to protect the components beneath the protective layer 400. In some embodiments, the filter layer 600 may be an absorptive filter layer. The filtering capability of the absorptive filter layer is based on the absorption properties of the material comprising the absorptive filter layer. Because absorptive filters are nearly angle-independent, they can effectively reduce the blue-shift phenomenon that occurs when using multi-film interference filters. Furthermore, the thickness of the absorptive filter layer is smaller than that of the interference filter layer. Therefore, when incident light at a large oblique angle strikes the image sensing structure, the blue-shift of the image sensing structure can be reduced. The image sensing structure can be easily miniaturized. In some embodiments, the filter layer 600 is a long-pass filter layer.

[0084] In some embodiments, the image sensing structure 1 further comprises a microlens 510. In some embodiments, the microlens 510 is formed on the filter layer 600. In some other embodiments, the microlens 510 is formed on the protective layer 400. In some other embodiments, the microlens 510 is formed between the protective layer 400 and the filter layer 600. In some embodiments, the microlens 510 serves as a concentrator element, which can increase the light collection efficiency of the photovoltaic module 200. In some embodiments, the material of the microlens 510 can comprise an acrylic such as polymethyl methacrylate (PMMA) or polyglycidyl methacrylate (PGMA), a high refractive index (n) material, one or more suitable optically transparent microlens materials, or a combination thereof. In some embodiments, the shape of the microlens 510 is hemispherical. In some embodiments, the curvature of the microlens 510 can be adjusted. In some embodiments, a filler material with a low refractive index value is formed between each microlens 510. In some embodiments, the microlens 510 is formed corresponding to the readout transistor unit 111. In some embodiments, the boundary between adjacent microlenses 510 is aligned with the axis of symmetry of the readout transistor unit 111 in the readout circuit array 110. In other words, the distance W between the axes of symmetry of adjacent readout transistor units 111 is substantially the same as the width of the microlens 510.

[0085] For the sake of brevity, the same or similar descriptions will not be repeated below.

[0086] Reference is made to Figure 1BThe image sensing structure 2 includes a microlens 510 formed between the protective layer 400 and the filter layer 600. A filling material 520 is formed on the microlens 510. The filling material 520 may include or be phosphosilicate glass (PSG), borophosphosilicate glass (BPSG), a low dielectric constant (low-k) dielectric material, or one or more suitable dielectric materials. Examples of low dielectric constant dielectric materials include fluorinated silica glass (FSG), carbon doped silicon oxide, amorphous fluorinated carbon, parylene, bis-benzocyclobutenes (BCB), polyimides, and combinations thereof. The microlens 510 and the filling material 520 may be formed into a microlens structure 500. Therefore, the protective layer 400 can protect the components below the protective layer 400, such as the optoelectronic module 220 and the readout circuit array 110. In some embodiments, the filling material 520 provides a flat top surface, and the filter layer 600 is formed on the flat top surface of the microlens structure 500 and on the microlenses 510. Therefore, the filling material 520 provides more flexible manufacturing steps and methods for forming the image sensing structure 2.

[0087] Reference Figure 1C According to some other embodiments, the microlens 510 in the image sensing structure 3 is formed on the protective layer 400, and the protective layer 400 is formed on the filter layer 600. Therefore, the protective layer 400 can protect the components below the protective layer 400, such as the filter layer 600, the optoelectronic module 200, and the readout circuit array 110.

[0088] The image sensing structure disclosed in this disclosure can be applied to narrow-band infrared cameras for face sensing, motion detection, and / or machine vision. The image sensing structure disclosed in this disclosure can also be applied to narrow-band time-of-flight (TOF) sensors for augmented reality (AR) and / or virtual reality (VR) applications. The image sensor can be a front-side image (FSI) sensor or a back-side image (BSI) sensor.

[0089] Hereinafter, the detailed relationship between the filter layer 600 and the photoelectric layer 220 will be described.

[0090] Reference Figure 2A , which is a graph of normalized extinction coefficient versus wavelength (nm) according to some embodiments. It is noteworthy that according to some embodiments of the present disclosure, by selecting a specific combination of the photoelectric layer 220 and the filter layer 600, the optical performance of the image sensor can be improved, thereby improving the quantum efficiency (QE), peak shift, and field of view (FOV).

[0091] like Figure 2A As shown, the x-axis represents the normalized extinction coefficient of the photoelectric layer 220 and the filter layer 600, and the y-axis represents the wavelength (nm) corresponding to the normalized extinction coefficient. In other words, Figure 2A The normalized extinction coefficient spectra of the photoelectric layer 220 and the filter layer 600 are shown. Hereinafter, the normalized extinction coefficient spectrum of the filter layer 600 is referred to as the "first spectrum S1," and the normalized extinction coefficient spectrum of the photoelectric layer 220 is referred to as the "second spectrum S2." Generally speaking, the term "normalized" means scaling a numerical value to a range of 0 to 1 while maintaining the original distribution of the numerical value. For example, after normalization, the maximum extinction coefficient among all extinction coefficients can be scaled to 1, and the minimum extinction coefficient among all extinction coefficients can be scaled to 0. In the present disclosure, the extinction coefficient is normalized by the maximum extinction coefficient of the peak of the first spectrum S1 or the second spectrum S2, wherein the peak of the first spectrum S1 or the second spectrum S2 may have the maximum wavelength among all peaks. In other words, the extinction coefficient is normalized by the peak corresponding to the maximum wavelength.

[0092] In some embodiments, the first spectrum S1 of the filter layer 600 defines a first wavelength λ1 corresponding to the first line L1, while the second spectrum S2 of the photoelectric layer 220 defines a second wavelength λ2 corresponding to the second line L2. In some embodiments, the second wavelength λ2 is greater than the first wavelength λ1. In some embodiments, the second wavelength λ2 is greater than the first wavelength λ1 by approximately 10 nm to approximately 150 nm.

[0093] In detail, Figure 2A As shown, the first wavelength λ1 corresponds to a first line L1 passing through a first point P1 and a second point P2 on the curve of the first spectrum S1 of the filter layer 600. In some embodiments, the first point P1 is aligned with an extinction coefficient of 0.9, and the second point P2 is aligned with an extinction coefficient of 0.1. In some embodiments, the values ​​of the extinction coefficients aligned with the first point P1 and the second point P2 can be adjusted.

[0094] In particular, there may be many points aligned with an extinction coefficient of 0.9. Therefore, the first point P1 is a point aligned with an extinction coefficient of 0.9 and falls in the longest wavelength segment of the first spectrum S1. In some embodiments, the first point P1 falls in the right segment of the peak with the longest wavelength of the first spectrum S1. Similarly, there may be many points aligned with an extinction coefficient of 0.1. Therefore, the second point P2 is a point aligned with an extinction coefficient of 0.1 and falls in the longest wavelength segment of the first spectrum S1. In some embodiments, the second point P2 falls in the right segment of the peak with the longest wavelength of the first spectrum S1. In some embodiments, the first wavelength λ1 is defined by a first line L1 extending to a position of an extinction coefficient of 0. In other words, the first wavelength λ1 is defined by the cross point of the first line L1 and a line with an extinction coefficient of 0.

[0095] Similarly, the second wavelength λ2 corresponds to a second line L2 passing through a third point P3 and a fourth point P4 on the curve of the second spectrum S2 of the photovoltaic layer 220. In some embodiments, the third point P3 is aligned with an extinction coefficient of 0.9, and the fourth point P4 is aligned with an extinction coefficient of 0.1. In some embodiments, the values ​​of the extinction coefficients aligned with the third point P3 and the fourth point P4 can be adjusted as needed.

[0096] In particular, there may be many points aligned with an extinction coefficient of 0.9. Therefore, the third point P3 is a point aligned with an extinction coefficient of 0.9 and falls within the longest wavelength segment of the second spectrum S2. In some embodiments, the third point P3 falls within the right band of the peak with the longest wavelength of the second spectrum S2. Similarly, there may be many points aligned with an extinction coefficient of 0.1. Therefore, the fourth point P4 is a point aligned with an extinction coefficient of 0.1 and falls within the longest wavelength segment of the second spectrum S2. In some embodiments, the fourth point P4 falls within the right band of the peak with the longest wavelength of the second spectrum S2. In some embodiments, the second wavelength λ2 is defined by the second line L2 extending to the position of the extinction coefficient of 0. In other words, the second wavelength λ2 is defined by the intersection of the second line L2 and the line with an extinction coefficient of 0.

[0097] Reference Figure 2B , which is a graph of quantum efficiency (%) versus wavelength (nm) according to some embodiments. In some embodiments, filter layer 600 is a long-pass filter, so only light with a wavelength greater than the critical wavelength of filter layer 600 can pass through filter layer 600. Furthermore, the extinction coefficient of photoelectric layer 220 can affect the quantum efficiency of the image sensing structure and the wavelength of the sensing light. In some embodiments, some photons (e.g., IR photons) can reach photoelectric layer 220, while other photons (e.g., visible light photons) are blocked by filter layer 600. Accordingly, the difference Δλ between the first wavelength λ1 of filter layer 600 and the second wavelength λ2 of photoelectric layer 220 represents the wavelength range of the sensing light of the image sensing structure. In some embodiments, the sensing light represents light that can be sensed by the image sensing structure.

[0098] To achieve narrow band imaging, the materials of the photoelectric layer 220 and the filter layer 600 need to be well selected. There are many photoelectric layers that can provide a tunable spectral range from visible light wavelength (400 nm ~ 700 nm) to infrared light (IR) wavelength (700 nm ~ 2000 nm). The aforementioned photoelectric layers are such as organic bulk heterojunction (BHJ) photodetector, perovskite photodetector, quantum dot (QD) sensor or a combination thereof. The organic bulk heterojunction photodetector includes blends of conjugated polymers and / or small molecules. The quantum dot material is PbS, PbSe, CdS, CdSe, InP, InAs, InGaP, InGaAs, the like or a combination thereof. The size of the quantum dot is in the range from 2 nm to 15 nm. Each quantum dot is surrounded by an organic ligand or an inorganic ligand to maintain the quantum confinement effect and at the same time allow carrier transport between quantum dots. The aforementioned organic ligand can include 3- Mercaptopropionic acid (MPA), 1,2-Ethanedithiol (EDT), Ethylenediamine (EDA), the like or a combination thereof. The aforementioned inorganic ligand can be iodide, bromide and chloride. The aforementioned perovskite material can be inorganic-organic hybrid or pure inorganic material. The aforementioned inorganic-organic hybrid is MAPbBr3, MAPbI3, FAPbI3, MAPbSnI3, MASnI3, the like or a combination thereof. The inorganic material can be CsPbI3, CsSnI3, respectively. The pixelated bottom contact electrode 120 is a conductive material such as Al, Cu, AlCu, Ti / Al / Ti, W, Ag, Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), Graphene, Carbon Nanotube (CNT), Ag nanowire or a combination thereof.The first carrier transport layer 210 and the second carrier transport layer 230 can be made of ZnO, AZO, MoO3, WO3, NiO, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) doped with polystyrenesulfonic acid, poly[(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN), or ethoxylated polyethyleneimine (PEIE). The conductive layer 300 is a transparent conductive layer such as ITO, IZO, Ag nanowires, carbon nanotubes, or graphene. The protective layer 400 is a multilayer film, wherein the multilayer film includes a pure inorganic film or an organic / inorganic stacked film. The aforementioned inorganic film is SiO2, SiN, SiON, SiH, Al2O3, TiO2, the like, or a combination thereof. The filter layer 600 is an absorption filter layer, such as an organic metal complex dye or an inorganic thin film.

[0099] For example, when the material of the filter layer 600 is an organic long-wave pass filter layer (for example, the material of the above-mentioned organic long-wave pass filter layer); and the material of the photoelectric layer 220 is an organic bulk heterojunction photodiode or a perovskite photodiode or a QD photodiode (for example, the material of the above-mentioned photoelectric layer), as Figure 2A As shown, the first wavelength λ1 is 900nm, the second wavelength λ2 is 950nm, and the difference Δλ is 50nm. Therefore, the wavelength range of the sensing light of the image sensing structure is 920nm to 970nm, and the quantum efficiency of the sensing light is maximum when the wavelength of the sensing light is 940nm.

[0100] Reference Figures 3A to 3F , which is a graph of normalized extinction coefficient and quantum efficiency (%) versus wavelength (nm) according to some embodiments of the present disclosure. In other words, Figures 3A to 3F Each graph in is an overlay of a graph of normalized extinction coefficient versus wavelength (nm) and a graph of quantum efficiency (%) versus wavelength (nm). For example, Figure 3A yes Figure 2A and Figure 2B Overlay. Figure 3A As shown, the difference Δλ substantially corresponds to the wavelength range of the sensed light. In the present disclosure, the materials for the filter layer 600 and the photoelectric layer 220 can be selected based on requirements to meet the desired wavelength range. For example, the materials for the filter layer 600 and the photoelectric layer 220 can be selected based on a predetermined desired wavelength range.

[0101] like Figure 3BFor example, when the filter layer 600 is made of an organic long-wavelength pass filter, the photoelectric layer 220 is made of an organic bulk heterojunction photodiode, the first wavelength λ1 is 810 nm, the second wavelength λ2 is 860 nm, and the difference Δλ is 50 nm, the image sensor structure can sense light in a wavelength range of 830 nm to 880 nm, and the quantum efficiency reaches its maximum when the wavelength is 850 nm.

[0102] like Figure 3C For example, when the filter layer 600 is made of an organic long-wavelength pass filter, the photoelectric layer 220 is made of an organic hybrid heterojunction photodiode, the first wavelength λ1 is 940 nm, the second wavelength λ2 is 990 nm, and the difference Δλ is 50 nm, the image sensor structure can sense light in a wavelength range of 960 nm to 1100 nm, and the quantum efficiency reaches its maximum when the wavelength is 980 nm.

[0103] like Figure 3D For example, when the filter layer 600 is made of an organic long-wavelength pass filter, the photoelectric layer 220 is made of an organic hybrid heterojunction photodiode, the first wavelength λ1 is 1270 nm, the second wavelength λ2 is 1320 nm, and the difference Δλ is 50 nm, the image sensor structure can sense light in a wavelength range of 1290 nm to 1340 nm, and the quantum efficiency reaches its maximum when the wavelength is 1310 nm.

[0104] like Figure 3E For example, when the filter layer 600 is made of an organic long-wavelength pass filter, the photoelectric layer 220 is made of an organic hybrid heterojunction photodiode, the first wavelength λ1 is 1310 nm, the second wavelength λ2 is 1360 nm, and the difference Δλ is 50 nm, the image sensor structure can sense light in a wavelength range of 1330 nm to 1380 nm, and the quantum efficiency reaches its maximum when the wavelength is 1350 nm.

[0105] like Figure 3F For example, when the filter layer 600 is made of an organic long-wavelength pass filter, the photoelectric layer 220 is made of an organic hybrid heterojunction photodiode, the first wavelength λ1 is 1510 nm, the second wavelength λ2 is 156 nm, and the difference Δλ is 50 nm, the image sensor structure can sense light in a wavelength range of 1530 nm to 1580 nm, and the quantum efficiency reaches its maximum when the wavelength is 1550 nm.

[0106] Accordingly, the image sensing structure of the present disclosure can provide high quantum efficiency when the wavelength of the sensing light is greater than 800 nm, 850 nm, 900 nm, 950 nm, 1000 nm, 1050 nm, 1100 nm, 1150 nm, 1200 nm, 1250 nm, 1300 nm, 1350 nm, 1400 nm, 1450 nm, 1500 nm, 1550 nm, or one or more wavelengths suitable for use with the long-wave pass filter layer 600. In some embodiments, the image sensing structure provides high quantum efficiency in the near-infrared region. The image sensing structure can extend the wavelength of the sensing light from 850 nm to 1550 nm by selecting different materials for the optoelectronic layer 220 and the corresponding filter layer 600.

[0107] Figures 4A to 4D Schematic diagram of the energy gap of the first carrier transport layer 210, the photovoltaic layer 220, and the second carrier transport layer 230 according to some embodiments. Figures 4A to 4D , the x-axis represents the energy gaps of the first carrier transport layer 210 , the photovoltaic layer 220 , and the second carrier transport layer 230 .

[0108] like Figure 4A As shown, the first carrier transport layer 210 is an HTL, and the second carrier transport layer 230 is an ETL. The first carrier transport layer 210 has an energy gap between a maximum energy gap 210H and a minimum energy gap 210L. The photovoltaic layer 220 has an energy gap between a maximum energy gap 220H and a minimum energy gap 220L. The second carrier transport layer 230 has an energy gap between a maximum energy gap 230H and a minimum energy gap 230L. In some embodiments, the maximum energy gap 210H is higher than the maximum energy gap 220H, and the maximum energy gap 220H is higher than the maximum energy gap 230H. In some embodiments, the minimum energy gap 210L is higher than the minimum energy gap 220L, and the minimum energy gap 220L is higher than the minimum energy gap 230L. Therefore, in some embodiments, the average energy gap of the first carrier transport layer 210, the photovoltaic layer 220, and the second carrier transport layer 230 gradually decreases.

[0109] like Figure 4B As shown, the first carrier transport layer 210 is an ETL, and the second carrier transport layer 230 is an HTL, so the average energy gaps of the first carrier transport layer 210 , the photovoltaic layer 220 , and the second carrier transport layer 230 gradually increase.

[0110] like Figure 4C As shown, the first carrier transport layer 210 and the second carrier transport layer 230 are ETLs, and thus the average energy gap of the photovoltaic layer 220 is higher than the average energy gap of the first carrier transport layer 210 and the second carrier transport layer 230 .

[0111] like Figure 4DAs shown, the first carrier transport layer 210 and the second carrier transport layer 230 are ETLs, and thus the average energy gaps of the first carrier transport layer 210 and the second carrier transport layer 230 are higher than the average energy gap of the photovoltaic layer 220 .

[0112] Figures 5A to 5H are illustrative cross-sectional views of image sensing structures at various stages of fabrication according to some embodiments of the present disclosure. Figures 5A to 5H Display as Figure 1A The image sensing structure 1 is shown as an exemplary cross-sectional view.

[0113] Reference Figure 5A A substrate 100 is formed, and a readout circuit array 110 is formed on the substrate 100. A pixelated bottom contact electrode 120 is defined on each readout transistor unit 111. An insulating material 122 is disposed between each bottom contact electrode 120. In some embodiments, a top contact electrode 121 is formed on the substrate 100 and adjacent to the insulating material 122. In some embodiments, the bottom contact electrode 120 is formed on the readout circuit array 110. In some embodiments, the readout circuit array 110 is formed on the substrate 100. The readout circuit array 110 includes a plurality of transistors, capacitors, or resistors. The manufacturing process used to form the readout circuit array 110 and / or the bottom contact electrode 120 and the top contact electrode 121 can be physical vapor deposition (PVD), chemical vapor deposition (CVD), atomic layer deposition (ALD), similar processes, other suitable processes, or combinations thereof, followed by photoresist deposition, photolithography, development, dry etching, and / or wet etching.

[0114] Reference Figure 5B , a first carrier transport layer 210 is formed on the bottom contact electrode 120, a photovoltaic layer 220 is formed on the first carrier transport layer 210, and a second carrier transport layer 230 is formed on the photovoltaic layer 220. In some embodiments, the first carrier transport layer 210, the photovoltaic layer 220, and the second carrier transport layer 230 can be formed by a deposition process. The deposition process for forming the first carrier transport layer 210, the photovoltaic layer 220, and / or the second carrier transport layer 230 can be spin coating, doctor blading, screen printing, physical vapor deposition (PVD), chemical vapor deposition (CVD), atomic layer deposition (ALD), similar processes, other suitable processes, or combinations thereof.

[0115] Reference Figure 5C A patterned photoresist layer 330 is formed on the second carrier transport layer 230, and the area of ​​the patterned photoresist layer 330 is the same as the area of ​​the readout circuit array 110, or the area of ​​the patterned photoresist layer 330 is slightly larger than the area of ​​the readout circuit array 110. In some embodiments, the patterned photoresist layer 330 partially covers the second carrier transport layer 230. In some embodiments, a photoresist material (not shown) is formed on the second carrier transport layer 230, and then the photoresist material is patterned to form the patterned photoresist layer 330. In some embodiments, further processes such as an exposure process, an annealing process, a development process, the like, other suitable processes, or a combination thereof may be performed.

[0116] Reference Figure 5D , the second carrier transport layer 230, the photovoltaic layer 220, and the first carrier transport layer 210 are etched by a dry etching process using the patterned photoresist layer 330 as an etching mask to expose the top surface of the top contact electrode 121. In some embodiments, the patterned photoresist layer 330 defines the active area of ​​the image sensor. In some embodiments, the patterned photoresist layer 330 is then removed by a stripping process, such as an ashing process. In some embodiments, the photovoltaic layer 220 and the patterned photoresist layer 330 are made of different materials. In some embodiments, the photovoltaic material and the photoresist material are orthogonal. In other words, the photovoltaic material is immiscible with the photoresist material during the deposition, development, and removal processes. Therefore, after the removal process, the patterned photoresist layer 330 is completely removed with little or no damage to the photovoltaic layer 220.

[0117] Reference Figure 5E, a conductive layer 300 is formed on the second carrier transport layer 230 by a deposition process. The deposition process for forming the conductive layer 300 can be spin coating, doctor blade forming, screen printing or physical vapor deposition (PVD), chemical vapor deposition (CVD), atomic layer deposition (ALD), similar processes, other suitable processes or combinations thereof. In some embodiments, the conductive layer 300 is formed on the top surface of the second carrier transport layer 230, and the conductive layer 300 is in contact with the exposed top contact electrode 121. At this stage, the bottom contact electrode (bottom contact) and the top contact electrode (top contact) of the photoelectric layer 220 are fully formed. The pixel size is defined by the contact area of ​​each bottom contact electrode 120 with the first carrier transport layer 210. All bottom contact electrodes 120 and top contact electrodes 121 are connected to the readout circuit array 110 via wires under each bottom contact electrode 120 and top contact electrode 121. The analog signal read from each pixel is further converted into a digital signal by an analog-to-digital converter (ADC).

[0118] Reference Figure 5F , a protective layer 400 is formed on the conductive layer 300 by a deposition process. The deposition process used to form the protective layer 400 can be physical vapor deposition (PVD), chemical vapor deposition (CVD), atomic layer deposition (ALD), similar processes, other suitable processes, or combinations thereof. In some embodiments, the protective layer 400 is formed on the top surface of the conductive layer 300 and on both side surfaces of the conductive layer 300.

[0119] Reference Figure 5G The filter layer 600 is formed on the protective layer 400 by a deposition process. The deposition process used to form the filter layer 600 can be spin coating, doctor blade forming, screen printing, metal-organic chemical vapor deposition (MOCVD), atomic layer deposition (ALD), molecular beam epitaxy (MBE), liquid phase epitaxy (LPE), similar processes, other suitable processes, or combinations thereof.

[0120] Reference Figure 5HThe microlens 510 is formed on the filter layer 600 by a deposition process. The deposition process for forming the microlens 510 can be a spin-coating litho-type transparent photoresist followed by performing a UV exposure, development and thermal reflow process, similar processes, other suitable processes, or a combination thereof. Thus, the image sensor is obtained by the above processes. However, one or more suitable processes can be performed.

[0121] Figures 6A to 6H Exemplary cross-sectional views of an image sensing structure according to some other embodiments of the present disclosure at various stages of fabrication. Figures 6A to 6H Exemplary cross-sectional views of an image sensing structure 1 as shown in Figure 1A Exemplary cross-sectional views of an image sensing structure 1 as shown in

[0122] Referring to Figure 6A The structure as shown in Figure 6A is similar to the structure as shown in Figure 5A Two top contact electrodes 121 are disposed on the readout circuit array 110. For the sake of clarity, the same or similar descriptions will not be repeated.

[0123] Referring to Figure 6B A photoresist material is formed on the bottom contact electrode 120 and the top contact electrode 121 by a deposition process. The deposition process for forming the photoresist material can be a spin-coating process followed by a hot back or UV exposure process, similar processes, other suitable processes, or a combination thereof.

[0124] Referring to Figure 6C The photoresist material is patterned to form a patterned photoresist layer 330 on the top contact electrode 121 and expose a top surface of the bottom contact electrode 120. The patterned photoresist layer 330 covers the top contact electrode 121 and defines an active area of the image sensing structure.

[0125] Referring to Figure 6D The first carrier transport layer 210, the photoelectric layer 220, and / or the second carrier transport layer 230 are sequentially formed on the top surface of the bottom contact electrode 120 by a deposition process, respectively. The first carrier transport layer 210, the photoelectric layer 220, and / or the second carrier transport layer 230 are formed conformally. The deposition process for forming the first carrier transport layer 210, the photoelectric layer 220, and / or the second carrier transport layer 230 can be spin-coating, blade forming, screen printing, similar processes, other suitable processes, or a combination thereof.

[0126] Referring to Figure 6EThe patterned photoresist layer 330, the second carrier transport layer 230, the photoelectric layer 220, and the first carrier transport layer 210 on the top contact electrode 121 are removed by a lift-off process. The aforementioned lift-off process such as immersing the substrate into a hot dimethyl sulfoxide based (DMSO-based) solvent to expose the top surface of the top contact electrode 121. Thus, the second carrier transport layer 230, the photoelectric layer 220, and the first carrier transport layer 210 remaining on the bottom contact electrode 120.

[0127] Referring to Figures 6F to 6H The structures as shown in FIGS. 1A-1C are similar to the structures as shown in FIGS. 2A-2C, respectively, so the same description will not be repeated. Thus, the image sensor is obtained by the aforementioned processes. Figures 6F to 6H Figures 5F to 5H The structures as shown in FIGS. 1A-1C are similar to the structures as shown in FIGS. 2A-2C, respectively, so the same description will not be repeated. Thus, the image sensor is obtained by the aforementioned processes.

[0128] 7A to 7F are exemplary cross-sectional views of an image sensing structure according to some other embodiments of the present disclosure at various stages of fabrication. 7A to 7F Exemplary cross-sectional views are also shown with the image sensing structure 1 as shown in FIGS. 1A-1C as an example. Figure 1A

[0129] Referring to Figure 7A The structures as shown in FIGS. 1A-1C are similar to the structures as shown in FIGS. 2A-2C, respectively, so the same description will not be repeated. Thus, the image sensor is obtained by the aforementioned processes. Figure 7A Figure 5A The structures as shown in FIGS. 1A-1C are similar to the structures as shown in FIGS. 2A-2C, respectively, so the same description will not be repeated. Thus, the image sensor is obtained by the aforementioned processes.

[0130] Referring to Figure 7B The first carrier transport layer 210, the photoelectric layer 220, and the second carrier transport layer 230 are sequentially formed on the bottom contact electrode 120 and / or the top contact electrode 121.

[0131] Referring to Figure 7C The conductive layer 300 is directly formed on the second carrier transport layer 230 by an evaporation process. The aforementioned evaporation process is capable of selectively depositing the material of the conductive layer 300 on the second carrier transport layer 230. The conductive layer 300 corresponds to the bottom contact electrode 120 and the insulating material 122. The conductive layer 300 defines the active area of the sensor.

[0132] Referring to Figure 7D The first carrier transport layer 210, the photoelectric layer 220, and the second carrier transport layer 230 are etched to expose the top surface of the top contact electrode 121 by using the conductive layer 300 as an etch mask. Since the conductive layer 300 on the second carrier transport layer 230 serves as an etch mask, there is no need to form an additional mask or photoresist as an etch mask. Thus, the fabrication method of the image sensor can be simplified. ​​​

[0133] Reference Figure 7E The conductive portion 310 is formed on the top surface of the conductive layer 300 by spin coating, doctor blade forming, screen printing, physical vapor deposition (PVD), chemical vapor deposition (CVD), atomic layer deposition (ALD), similar processes, other suitable processes, or combinations thereof. The conductive portion 310 can be any type of conductive material, such as a metal, a heavily doped semiconductor, and a conductive polymer. Because the scale may not be drawn to scale, the total thickness of the first carrier transport layer 210, the photovoltaic layer 220, and the second carrier transport layer 230 is less than 2 microns. The conductive portion 310 connects the conductive layer 300 to the top contact electrode 121.

[0134] Reference Figure 7F ,like Figure 7F The structure shown is similar to Figure 6H The structure shown is similar. The same description will not be repeated. Therefore, the image sensor is obtained by the above process. Figure 7F The protective layer 400 can be conformally formed on the conductive layer 300 through a deposition process. The filter layer 600 can be formed on the protective layer 400 through a deposition process. In addition, the filter layer 600 can be planarized through a planarization process.

[0135] Figure 8A The structure of the image sensor is shown. The image sensor includes an image sensor array 810, a row address decoder 820, a column address decoder 840, a column circuit 830, and an analog-to-digital converter (ADC) 850. The image sensor array 810 includes a first carrier transport layer, a photovoltaic layer, a second carrier transport layer, a top conductive layer, a filter layer, and microlenses.

[0136] Reference Figure 8BThe image sensing array circuitry includes a bottom contact electrode 120, a first carrier transport layer 210, a photovoltaic layer 220, a second carrier transport layer 230, and a top conductive layer 300. Top conductive layer 300 is connected to top contact electrode 121. The circuitry beneath bottom contact electrode 120 and top contact electrode 121 is the readout circuitry. Each pixel includes a reset switch transistor M1, a source follower transistor M2, and a row-select switch transistor M3. The analog readout voltage can be further transmitted to ADC 850 for further image processing.

[0137] In summary, according to some embodiments, an image sensing structure integrates the readout circuit array 110, bottom contact electrode 120, first carrier transport layer 210, photovoltaic layer 220, second carrier transport layer 230, top conductive layer 300, and filter layer 600 to provide a monolithic IR narrow-band image sensor. By appropriately selecting the materials of the sensing array and the filter layer 600 to define the wavelength of the sensing light, the image sensing structure provides narrow-band sensing. Furthermore, because the filter layer 600 and photovoltaic layer 220 are selected based on their normalized extinction coefficients, these image sensing structures exhibit relatively low angle-dependent quantum efficiency peak shift. Therefore, these image sensing structures are suitable for high-FOV image sensing applications.

[0138] The scope of protection of the present disclosure is not limited to the processes, machines, manufactures, material components, devices, methods, structures and steps in the specific embodiments described in the specification. Any person skilled in the art can understand the processes, machines, manufactures, material components, devices, methods, structures and steps currently or in the future developed from the contents disclosed in some embodiments of the present disclosure, and as long as they can implement substantially the same functions or obtain substantially the same results as in the embodiments described herein, they can all be used according to some embodiments of the present disclosure. Therefore, the scope of protection of the present disclosure includes the above-mentioned processes, machines, manufactures, material components, devices, methods, structures and steps. In addition, each claim constitutes an individual embodiment, and the scope of protection of the present disclosure also includes the combination of each claim and embodiment.

[0139] The above summarizes several embodiments of the present disclosure so that those skilled in the art to which the present disclosure belongs can better understand the implementation methods of the embodiments of the present disclosure. Although some embodiments and the advantages of those embodiments have been disclosed in the present disclosure, it should be understood by those skilled in the art to which the present disclosure belongs that they can change, replace, substitute and / or modify other processes and structures based on the embodiments of the present disclosure to achieve the same purposes and / or advantages as the embodiments introduced herein. It should also be understood by those skilled in the art to which the present disclosure belongs that such equivalent constructions do not deviate from the concept and scope of the present disclosure, and they can make various changes, replacements, substitutions and / or modifications herein without violating the concept and scope of the present disclosure.

Claims

1. An image sensing structure, comprising: a substrate; a readout circuit array located on the substrate; a photoelectric layer disposed on the readout circuit array; as well as a filter layer disposed on the photoelectric layer; wherein the filter layer has a first spectrum of normalized extinction coefficient versus wavelength, the first spectrum defining a first wavelength, the first wavelength corresponding to a first line, the first line passing through a first point and a second point on a curve of the first spectrum of the filter layer, the first point and the second point falling within a longest wavelength band of the first spectrum relative to a peak of the longest wavelength of the first spectrum, the first point being aligned with an extinction coefficient of 0.9, and the second point being aligned with an extinction coefficient of 0.1, wherein the first wavelength is defined by the first line extending to a position where the extinction coefficient is 0; wherein the photovoltaic layer has a second spectrum of normalized extinction coefficient versus wavelength, the second spectrum defining a second wavelength, the second wavelength corresponding to a second line, the second line passing through a third point and a fourth point on a curve of the second spectrum of the photovoltaic layer, the third point and the fourth point falling within a longest wavelength band of the second spectrum relative to a peak of the longest wavelength of the second spectrum, the third point being aligned with an extinction coefficient of 0.9, and the fourth point being aligned with an extinction coefficient of 0.1, wherein the second wavelength is defined by the second line extending to a position where the extinction coefficient is 0; and The extinction coefficient is normalized by a maximum extinction coefficient of a peak of the first spectrum or the second spectrum, and the second wavelength is greater than the first wavelength. 2 . The image sensing structure as claimed in claim 1 , wherein the second wavelength is 10-150 nm greater than the first wavelength.

3. The image sensing structure according to claim 1, further comprising: a bottom contact electrode on the readout circuit array; a conductive layer on the photovoltaic layer; a first carrier transport layer disposed between the bottom contact electrode and the photovoltaic layer; and a second carrier transport layer disposed between the photoelectric layer and the conductive layer; The first carrier transport layer or the second carrier transport layer is an electron transport layer or a hole transport layer.

4. The image sensing structure according to claim 1 , further comprising: a protective layer disposed between the photoelectric layer and the filter layer; as well as A micro lens is arranged between the protection layer and the filter layer, and the filter layer is an absorption filter layer.

5. The image sensing structure according to claim 1 , further comprising: a protective layer disposed between the photoelectric layer and the filter layer; as well as A micro lens is arranged on the filter layer, and the filter layer is an absorption filter layer.

6. The image sensing structure according to claim 1, further comprising: a protective layer disposed on the filter layer; as well as A micro lens is arranged on the protection layer, and the filter layer is an absorption filter layer.

7. A method for manufacturing an image sensing structure, comprising: forming a substrate; forming a readout circuit array on the substrate; forming a photoelectric layer on the readout circuit array; as well as forming a filter layer on the photoelectric layer; wherein the filter layer has a first spectrum of normalized extinction coefficient versus wavelength, the first spectrum defining a first wavelength, the first wavelength corresponding to a first line, the first line passing through a first point and a second point on a curve of the first spectrum of the filter layer, the first point and the second point falling within a longest wavelength band of the first spectrum relative to a peak of the longest wavelength of the first spectrum, the first point being aligned with an extinction coefficient of 0.9, and the second point being aligned with an extinction coefficient of 0.1, wherein the first wavelength is defined by the first line extending to a position where the extinction coefficient is 0; wherein the photovoltaic layer has a second spectrum of normalized extinction coefficient versus wavelength, the second spectrum defining a second wavelength, the second wavelength corresponding to a second line, the second line passing through a third point and a fourth point on a curve of the second spectrum of the photovoltaic layer, the third point and the fourth point falling within a longest wavelength band of the second spectrum relative to a peak of the longest wavelength of the second spectrum, the third point being aligned with an extinction coefficient of 0.9, and the fourth point being aligned with an extinction coefficient of 0.1, wherein the second wavelength is defined by the second line extending to a position where the extinction coefficient is 0; and The extinction coefficient is normalized by a maximum extinction coefficient of a peak of the first spectrum or the second spectrum, and the second wavelength is greater than the first wavelength.

8. The manufacturing method according to claim 7, further comprising: forming a bottom contact electrode on the readout circuit array; forming a first carrier transport layer between the bottom contact electrode and the photovoltaic layer; forming a conductive layer on the photovoltaic layer; and forming a second carrier transport layer between the photoelectric layer and the conductive layer, The first carrier transport layer is an electron transport layer or a hole transport layer, and the second carrier transport layer is an electron transport layer or a hole transport layer.

9. The manufacturing method according to claim 7, further comprising: forming a protective layer between the photoelectric layer and the filter layer; and A micro lens is formed between the protection layer and the filter layer, and the filter layer is an absorption filter layer.

10. The manufacturing method according to claim 7, further comprising: forming a protective layer between the photoelectric layer and the filter layer; as well as A micro lens is formed on the filter layer, and the filter layer is an absorption filter layer.

11. The manufacturing method according to claim 7, further comprising: forming a protective layer on the filter layer; as well as A micro lens is formed on the protection layer, and the filter layer is an absorption filter layer.

12. The manufacturing method according to claim 7, wherein forming the photoelectric layer on the readout circuit array further comprises: forming a photoelectric material on the readout circuit array; forming a patterned photoresist layer on the optoelectronic material; etching the optoelectronic material; as well as The patterned photoresist layer is removed to form the photovoltaic layer, wherein the photovoltaic layer and the patterned photoresist layer are made of different materials.

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