Infrared focal plane detector, preparation method thereof and plane detection device

Abstract

The embodiment of the present application discloses an infrared focal plane detector, a preparation method thereof and a plane detection device. The infrared focal plane detector comprises a substrate, a readout circuit layer and a detection layer which are stacked on the substrate. The readout circuit layer comprises readout circuits of each detection unit. The detection layer comprises a first electrode, a second electrode which is oppositely arranged with the first electrode, and a photoelectric conversion layer which is arranged between the first electrode and the second electrode. The first electrode comprises a first functional layer which is arranged on the readout circuit layer and a second functional layer which covers the first functional layer. The first functional layer of each detection unit is electrically connected with the readout circuit, and the first functional layer comprises a plurality of openings which penetrate through the first functional layer. The embodiment provided by the present application increases the light transmittance on the basis of ensuring the conductivity of the first electrode, effectively improves the imaging quality of the infrared focal plane detector, and has practical application value.

Description

Technical Field

[0001] This invention relates to the field of semiconductors. More specifically, it relates to an infrared focal plane detector, its fabrication method, and a planar detection device. Background Technology

[0002] In nature, any object with a temperature above absolute zero continuously radiates infrared rays. Different parts of the object have different temperatures and emissivity, resulting in different radiation characteristics. The radiation emitted by an object must be transmitted through the atmosphere to reach an infrared receiving device. Because gases such as carbon dioxide and water vapor in the atmosphere selectively absorb and scatter infrared radiation through particles, the infrared radiation is attenuated to varying degrees. Typically, the infrared atmospheric window is divided into near-infrared (0.76–1.1 μm), short-wave infrared (1–3 μm), mid-wave infrared (3–6 μm), long-wave infrared (6–15 μm), even long-wave infrared (15–30 μm), far-infrared (30–100 μm), and submillimeter wave (100–1000 μm). The infrared spectrum lies between the visible spectrum and the microwave spectrum. Infrared imaging technology uses an infrared photoelectric system to convert the received infrared radiation into an image perceptible to the human eye. Short-wave infrared imaging technology combines the characteristics of visible light uniform reflection imaging (showing the shadows and contrast of objects) and long-wave infrared imaging (containing molecular vibration information and object thermal information), and has broad application prospects in fields such as low-light night vision, fog and haze imaging, food color sorting, and semiconductor detection.

[0003] Traditional infrared focal plane array sensors use indium gallium arsenide (IGaAs) material. The fabricated detector array is interconnected with silicon-based readout circuits through indium pillar flip-chip bonding. The high cost of semiconductor epitaxial growth and the low power of flip-chip bonding result in high production costs, which limit its application to military and scientific research purposes. Summary of the Invention

[0004] The purpose of this invention is to provide an infrared focal plane detector and its preparation method, as well as a planar detection device, to solve at least one of the problems existing in the prior art.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A first aspect of the present invention provides an infrared focal plane detector, comprising a plurality of detection units arranged in an array, each detection unit comprising a substrate, a readout circuit layer and a detection layer stacked on the substrate, wherein,

[0007] The readout circuit layer includes the readout circuits for each detection unit;

[0008] The detection layer includes a first electrode, a second electrode disposed opposite to the first electrode, and a photoelectric conversion layer disposed between the first electrode and the second electrode. The first electrode includes a first functional layer disposed on the readout circuit layer and a second functional layer covering the first functional layer. The first functional layer of each detection unit is electrically connected to the readout circuit, and the first functional layer includes a plurality of through openings therethrough.

[0009] Optionally, the shape and / or area of ​​the opening may be the same or different.

[0010] Optionally, the area of ​​the opening is greater than or equal to 262 square micrometers and less than or equal to 351 square micrometers;

[0011] and / or

[0012] The shape of the opening is at least one of rectangle, circle, triangle and rhombus.

[0013] Optionally, in the direction perpendicular to the substrate, the thickness of the first functional layer is greater than or equal to 300 nm and less than or equal to 500 nm;

[0014] and / or

[0015] The first functional layer is made of aluminum and molybdenum.

[0016] Optionally, the material of the second functional layer is indium tin oxide;

[0017] and / or

[0018] The photoelectric conversion layer is made of colloidal quantum dots.

[0019] Optionally, the material of the second electrode is at least one of gold, platinum, silver, aluminum, and copper;

[0020] and / or

[0021] The substrate is a glass substrate.

[0022] The second aspect of this invention provides a method for fabricating the infrared focal plane detector provided in the first aspect of this invention, comprising:

[0023] A readout circuit layer is formed on the substrate, including the readout circuit of each pixel unit;

[0024] A detection layer is formed on the readout circuit layer. The detection layer includes a first electrode, a second electrode, and a photoelectric conversion layer disposed between the first electrode and the second electrode. The first electrode includes a first functional layer disposed on the readout circuit layer and a second functional layer covering the first functional layer. The first functional layer of each detection unit is electrically connected to the readout circuit, and the first functional layer includes a plurality of through-holes.

[0025] The step of forming a probe layer on the readout circuit layer further includes:

[0026] A first functional layer is patterned on the readout circuit, wherein,

[0027] The thickness of the first functional layer in the direction perpendicular to the substrate is greater than or equal to 300 nm and less than or equal to 500 nm;

[0028] A second functional layer is deposited on the first functional layer to form the second functional layer;

[0029] A photoelectric conversion layer is formed on the second functional layer by spin coating or spray coating.

[0030] A second electrode is deposited on the photoelectric conversion layer.

[0031] Optionally, the step of patterning the first functional layer on the readout circuit further includes:

[0032] A first functional layer material is deposited on the readout circuit layer;

[0033] The first functional layer is formed by patterning the first functional layer material, wherein the area of ​​the opening is greater than or equal to 262 square micrometers and less than or equal to 351 square micrometers, and the shape of the opening is at least one of rectangle, circle, triangle and rhombus.

[0034] A third aspect of the present invention provides a planar detection device, including the planar detector described in the first aspect of the present invention.

[0035] The beneficial effects of this invention are as follows:

[0036] The infrared focal plane detector provided by this invention includes a readout circuit layer and a detection layer stacked on a substrate, realizing infrared detection and imaging of external objects. By setting multiple through-holes on the first functional layer of its first electrode, the light transmittance is increased while ensuring the conductivity of the first electrode, effectively improving the imaging quality of the infrared focal plane detector and having practical application value. Attached Figure Description

[0037] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0038] Figure 1 The diagram shows a structural schematic of an infrared focal plane detector according to an embodiment of the present invention.

[0039] Figure 2 This image shows a top view of an infrared focal plane detector provided in one embodiment of the present invention.

[0040] Figure 3 A schematic diagram of another infrared focal plane detector provided in one embodiment of the present invention is shown.

[0041] Figure 4 The diagram illustrates a structural schematic of an embodiment of the present invention after the formation of the first functional layer.

[0042] Figure 5 A top view of another infrared focal plane detector provided by another embodiment of the present invention is shown.

[0043] Figure 6 An equivalent circuit diagram of an infrared focal plane detector provided in another embodiment of the present invention is shown.

[0044] Figure 7 This diagram illustrates a fabrication process for an infrared focal plane detector according to another embodiment of the present invention. Detailed Implementation

[0045] To more clearly illustrate the present invention, the following description, in conjunction with embodiments and accompanying drawings, further explains the invention. Similar components in the drawings are indicated by the same reference numerals. Those skilled in the art should understand that the specific description below is illustrative rather than restrictive and should not be construed as limiting the scope of protection of the present invention.

[0046] Unless the context otherwise requires, throughout the specification and claims, the term "comprise" and its other forms, such as the third-person singular "comprises" and the present participle "comprising," are interpreted as open-ended and encompassing, meaning "including, but not limited to." In the description of the specification, terms such as "one embodiment," "some embodiments," "exemplary embodiments," "example," "specific example," or "some examples," etc., are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of this disclosure. The illustrative representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics mentioned may be included in any suitable manner in any one or more embodiments or examples.

[0047] This document describes exemplary embodiments with reference to cross-sectional views and / or plan views, which are idealized exemplary drawings. In the drawings, the thickness of layers and regions is enlarged for clarity. Therefore, variations in shape relative to the drawings are contemplated due to, for example, manufacturing techniques and / or tolerances. Thus, exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but rather include shape deviations due to, for example, manufacturing processes. For example, etched regions shown as rectangular would typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to show the actual shapes of the regions of the device, nor are they intended to limit the scope of the exemplary embodiments.

[0048] In this invention, the patterning process may include photolithography, or may include both photolithography and etching steps, and may also include other processes for forming a predetermined pattern, such as printing or inkjet printing. Photolithography refers to a process that uses photoresist, photomasks, and an exposure machine to form a pattern, including processes such as film formation, exposure, and development. The appropriate patterning process can be selected based on the structure formed according to this invention.

[0049] In related technologies, colloidal quantum dot materials have gradually entered the field of infrared focal plane array detectors. When fabricating infrared focal plane arrays using colloidal quantum dots, material synthesis is achieved through a single hot injection process. Liquid-phase coupling technology interconnects the colloidal quantum dots with the readout circuit, significantly reducing process difficulty and cost. This is of great significance for opening up a low-cost civilian market for short-wave infrared detectors. After absorbing infrared energy, colloidal quantum dots generate photocarriers, which are collected by electrodes under the influence of a built-in electric field to form a photocurrent.

[0050] One embodiment of the present invention provides an infrared focal plane detector based on colloidal quantum dot materials, such as... Figure 1 As shown, the infrared focal plane detector includes a readout circuit layer 10 and a detector layer 11 disposed on a substrate. The detector layer includes a first electrode 12, a second electrode 14, and a photoelectric conversion layer 13 disposed between the first electrode 12 and the second electrode 14. The photoelectric conversion layer 13 is made of glass-based colloidal quantum dots. External light passes through the readout circuit layer 10 from the substrate to the detector layer 11.

[0051] Meanwhile, in order to improve the conductivity of the first electrode 12 and increase the concentration of charge carriers, the first electrode 12 includes a first functional layer laid across the entire surface and a second functional layer covering the first functional layer.

[0052] This embodiment effectively improves the conductivity of the first electrode 12. However, the inventors have discovered that while improving conductivity, this embodiment also reduces the transparency of the detector to some extent. Specifically, for example... Figure 2The image shown is a top view of the infrared focal plane detector along the incident light side. The inventors pointed out that because the first functional layer is laid out across the entire surface, only a portion of the external light passes through the first electrode 12 to reach the photoelectric conversion layer 13, resulting in a weak photocurrent generated by the colloidal quantum dots, and the imaging accuracy of the infrared focal plane detector cannot be guaranteed. However, if the first functional layer is removed, the conductivity of the first electrode will be reduced.

[0053] Based on the above considerations, one embodiment of the present invention provides an infrared focal plane detector, including multiple detection units arranged in an array, such as... Figure 3 As shown, the infrared focal plane detector includes a substrate 101, a readout circuit layer 102 and a detector layer 103 stacked on the substrate, wherein,

[0054] The readout circuit layer 102 includes readout circuits for each detection unit;

[0055] The detection layer 103 includes a first electrode 1031, a second electrode 1032 disposed opposite to the first electrode 1031, and a photoelectric conversion layer 1033 disposed between the first electrode 1031 and the second electrode 1032. The first electrode 1031 includes a first functional layer 10311 disposed on the readout circuit layer 102 and a second functional layer 10312 covering the first functional layer 10311. The first functional layer 10311 of each detection unit is electrically connected to the readout circuit 102, and the first functional layer 10311 includes a plurality of through openings 103111.

[0056] This solution includes a readout circuit layer and a detection layer stacked on a substrate, enabling infrared detection and imaging of external objects. By setting multiple through-holes in the first functional layer of the first electrode, the light transmittance is increased while ensuring the conductivity of the first electrode, effectively improving the imaging quality of the infrared focal plane detector.

[0057] In one specific embodiment, the openings 103111 of the first functional layer 10311 have the same shape and area, the openings 103111 of the first functional layer 10311 of the first electrode 1031 are all square, and the area of ​​the openings 103111 is 280 square micrometers.

[0058] In this embodiment, as Figure 5The image shows a 2x2 pixel top view of the infrared focal plane sensor. The openings 103111 in the first functional layer 10311 corresponding to each sensor are rectangular, with an area of ​​320 square micrometers. This embodiment increases light transmittance while ensuring the conductivity of the first electrode by setting multiple openings 103111 that penetrate the first functional layer. The openings 103111 in the first functional layer have the same shape and area, simplifying the manufacturing process and saving manufacturing costs.

[0059] It should be noted that this application does not specifically limit the shape and area of ​​the openings 103111 in the first functional layer 10311, and is not limited to rectangles. For example, the openings 103111 in the first functional layer 10311 are all rhomboid in shape, and their areas are all 300 square micrometers. Those skilled in the art should understand that appropriate opening shapes and areas are selected according to actual application requirements. For example, the corresponding opening shape and area are selected according to the film layer design or display area design of the infrared focal plane sensor, so as to increase the light transmittance while ensuring the conductivity of the first electrode as a design criterion. This will not be elaborated further here.

[0060] In one specific embodiment, the openings 103111 of the first functional layer 10311 have the same shape but different areas. Specifically, some of the openings 103111 of the first functional layer are triangular in shape with an area of ​​300 square micrometers, while the remaining openings 103111 of the first functional layer are triangular in shape with an area of ​​298 square micrometers.

[0061] In one specific embodiment, the openings 103111 of the first functional layer 10311 have different shapes but the same area. Specifically, some of the openings 103111 of the first functional layer are triangular in shape with an area of ​​300 square micrometers, while the remaining openings 103111 of the first functional layer are rhomboid in shape with an area of ​​300 square micrometers.

[0062] In one specific embodiment, the shape and area of ​​the openings 103111 in the first functional layer are different. Specifically, some of the openings 103111 in the first functional layer are circular with an area of ​​269 square micrometers, while the remaining openings 103111 in the first functional layer are rectangular with an area of ​​320 square micrometers.

[0063] In this embodiment, by setting multiple openings that penetrate the first functional layer, the light transmittance is increased while ensuring the conductivity of the first electrode. The openings in the first functional layer have different shapes and areas, which can realize the wiring arrangement of the display area and non-display area of ​​the infrared focal plane detector without changing the layout of the detector layer.

[0064] This application does not impose specific limitations on this, and those skilled in the art should select appropriate opening shapes and areas according to actual application needs.

[0065] To ensure the conductivity of the first electrode, in one possible implementation, the area of ​​the opening is greater than or equal to 262 square micrometers and less than or equal to 351 square micrometers; the shape of the opening is at least one of rectangle, circle, triangle and rhombus, which can be set according to the actual application requirements and is not limited here.

[0066] In one specific embodiment, the ratio of the area of ​​the opening 103111 to the area of ​​the first functional layer is greater than or equal to 1.38 and less than or equal to 1.5.

[0067] This embodiment defines the area of ​​the opening 103111 in the first functional layer of the first electrode and its ratio to the area of ​​the first functional layer. When the ratio of the area of ​​the opening 103111 to the area of ​​the first functional layer is greater than or equal to 1.38 and less than or equal to 1.5, the light transmittance of the infrared focal plane detector and the charge transfer of the first electrode are both guaranteed to be at a high level. That is, while ensuring the conductivity of the first electrode, the light transmittance is increased, and the imaging quality of the detector is improved.

[0068] In one specific embodiment, the first functional layer 10311 is made of aluminum and molybdenum, specifically, it is a sandwich structure formed by sequentially stacking a molybdenum metal layer, an aluminum metal layer and a molybdenum metal layer.

[0069] In one specific embodiment, the substrate 101 is a glass substrate. Since the glass substrate has high hardness and transparency, it can prevent the infrared focal plane detector from being scratched while ensuring light transmittance.

[0070] In a specific embodiment, the infrared focal plane detector of this embodiment is described as an example. The infrared focal plane detector includes a readout circuit layer 102 and a detector layer 103 formed on a substrate 101. The readout circuit layer 102 includes at least one thin film transistor disposed on the substrate 101.

[0071] In one specific embodiment, the thin-film transistor employs a top-gate structure or a bottom-gate structure. A top-gate structure refers to a thin-film transistor with the gate located above the active layer, while a bottom-gate structure refers to a thin-film transistor with the gate located below the active layer.

[0072] In one specific embodiment, to produce as Figure 3 The following steps are used as an example of the infrared focal plane detector shown:

[0073] The first step is to form a readout circuit layer 102 on the substrate 101, including the readout circuit of each pixel unit.

[0074] In this embodiment, the readout circuit layer 102 includes at least one thin-film transistor, which is a bottom-gate structure. Forming at least one thin-film transistor includes the following steps:

[0075] A gate layer 1021 is formed on the substrate 101; in the embodiment, the gate layer is made of metal, such as aluminum or copper.

[0076] A gate insulating layer 1022 is formed on the gate layer 1021 to cover the gate layer 1021. For example, the gate insulating layer is made of an organic insulating layer, such as silicon nitride or silicon oxynitride.

[0077] An active layer 1024 and source / drain layers 1023 located on both sides of the active layer are formed on the gate insulating layer 1022.

[0078] An insulating passivation layer 1025 is formed covering the source / drain layer 1023 and the active layer 1024; the insulating passivation layer 1025 includes a first insulating passivation layer 10251, a second insulating passivation layer 10252, and a third insulating passivation layer 10253. The first insulating passivation layer 10251 is made of, for example, an inorganic insulating layer, such as a silicon nitride layer or a silicon oxynitride layer; the second insulating passivation layer 10252 is an organic insulating layer, such as a ring-shaped resin insulating layer; and the third insulating passivation layer 10253 is made of, for example, a silicon nitride layer or a silicon oxynitride layer.

[0079] Silicon nitride and ring resin have good insulation properties, ensuring the separation between the source or drain and the detector. In addition, silicon nitride and ring resin have good light transmittance, preventing the insulating passivation layer from affecting the light irradiation, thus effectively improving the imaging quality of the infrared focal plane detector.

[0080] Interconnects and / or channels are formed in the insulating passivation layer 1025 such that the at least one thin-film transistor is connected to each other; the thin-film transistor also includes a first via penetrating the insulating passivation layer to realize the electrode of the detector layer formed on the thin-film transistor and to connect it to the source or drain.

[0081] According to the circuit design requirements, different thin-film transistors can be separated by an insulating passivation layer and connected by interconnects formed in the insulating passivation layer. For bottom gate structure array substrates, the residues of the active layer can be effectively blocked from connecting the data lines and pixel electrodes and other first conductive layers, thus avoiding TFT electrical process defects.

[0082] In an optional embodiment, the thin-film transistor is a top-gate structure, wherein forming a thin-film transistor includes the following steps:

[0083] An active layer is formed on a substrate, and a gate insulating layer covering the active layer is formed on top of the active layer;

[0084] Forming a gate layer. Specifically, this includes: depositing a first metal thin film on a substrate with the aforementioned pattern, and patterning the first metal thin film using a patterning process to form a gate layer disposed on the gate insulating layer. The gate layer is made of metal, such as aluminum or copper.

[0085] Forming an interlayer dielectric layer. Specifically, this includes forming an interlayer dielectric layer on the gate electrode using plasma-enhanced chemical vapor deposition on the substrate on which the aforementioned pattern is formed, wherein the material of the interlayer dielectric layer is silicon oxide or silicon nitride.

[0086] Forming source and drain layers. Specifically, this includes: based on the aforementioned pattern, using magnetron sputtering equipment, depositing a second metal thin film on the interlayer dielectric layer to form source and drain electrodes disposed on the interlayer dielectric layer, wherein the source and drain layers are made of metal, for example, aluminum or copper.

[0087] The second step is to form a detection layer on the readout circuit layer. The detection layer includes a first electrode, a second electrode, and a photoelectric conversion layer disposed between the first electrode and the second electrode. The first electrode includes a first functional layer disposed on the readout circuit layer and a second functional layer covering the first functional layer. The first functional layer of each detection unit is electrically connected to the readout circuit, and the first functional layer includes a plurality of through-holes 103111.

[0088] In this embodiment, forming the detector layer includes: patterning a first functional layer 10311 on the readout circuit 102, wherein the thickness of the first functional layer 10311 in the direction perpendicular to the substrate is greater than or equal to 300 nm and less than or equal to 500 nm.

[0089] In this embodiment, the step of preparing the first functional layer 10311 includes:

[0090] A first metal layer is formed by depositing molybdenum metal in the direction away from the substrate of the readout circuit layer 102, a second metal layer is formed by depositing aluminum metal on the first metal layer, and a third metal layer is formed by depositing molybdenum metal on the second metal layer.

[0091] A photoresist layer is coated on the third metal layer, and exposed and developed using a photomask to form a retention area and a removal area. The removal area corresponds to the location of the opening 103111. Wet etching is used to remove the first metal layer, second metal layer, third metal layer, and photoresist corresponding to the removal area, forming a patterned first functional layer 10311. Figure 4 As shown.

[0092] A second functional layer 10312 is deposited on the first functional layer 10311;

[0093] In this embodiment, the material of the second functional layer 10312 of the first electrode 1031 is indium tin oxide (ITO). The ITO thin film is deposited on the surface of the first functional layer by electron beam evaporation, physical vapor deposition, or sputtering deposition, and has a thickness greater than or equal to 800 nm and less than or equal to 1200 nm.

[0094] In this embodiment, the second functional layer is prepared using indium tin oxide (ITO). The ITO film has high transparency, and the first electrode formed by combining it with the first functional layer has high transparency while ensuring high conductivity, thus improving the performance of the infrared focal plane detector.

[0095] A photoelectric conversion layer 1033 is formed on the second functional layer 10312 by spin coating or spray coating.

[0096] A second electrode 1032 is deposited on the photoelectric conversion layer 1033.

[0097] In this embodiment, a second electrode 1032 is disposed on the photoelectric conversion layer 1033, and the material of the second electrode 1032 is at least one selected from gold, platinum, silver, aluminum, and copper. This application does not specifically limit the choice of material; those skilled in the art should select appropriate materials based on actual application requirements, and further details will not be elaborated here.

[0098] In this embodiment, by setting multiple openings that penetrate the first functional layer, the light transmittance is increased while ensuring the conductivity of the first electrode. At the same time, the thickness of the first functional layer is set to be greater than or equal to 300 nm and less than or equal to 500 nm to ensure the conductivity and light transmittance of the first electrode.

[0099] In one possible implementation, since the material of the first functional layer 10311 has high conductivity, in order to avoid electrostatic breakdown during the etching of the first functional layer, a passivation layer (PVX layer) needs to be deposited on the third metal layer during the fabrication of the first functional layer. Photoresist is coated on the passivation layer, and exposure and development are performed through a mask to form retention areas and removal areas respectively. Dry etching is then used to retain the first metal layer, second metal layer, and third metal layer corresponding to the retention areas, thereby forming a patterned first functional layer.

[0100] This embodiment avoids electrostatic breakdown during etching by forming a passivation layer on the first functional layer before etching, thereby further improving product yield.

[0101] In one specific embodiment, the photoelectric conversion layer 1033 is formed of a colloidal quantum dot material capable of absorbing infrared light of a specified wavelength.

[0102] In this embodiment, the photoelectric conversion layer 1033 is prepared using colloidal quantum dot material, which greatly reduces the difficulty and cost of the process and is of great significance for opening up a low-cost civilian market for short-wave infrared detectors.

[0103] In one specific embodiment, the colloidal quantum dot material includes tin sulfide, tin selenide, tin telluride, lead sulfide, lead selenide, lead telluride, indium arsenide, indium antimonide, mercuric selenide, mercuric telluride, and their alloyed quantum dots. The photoelectric conversion layer 1033 can be made of the same material or can be divided into several groups, with different groups of photoelectric conversion layers 1033 each made of different materials. This allows the photoelectric conversion layer 1033 to not only achieve single-band photoelectric detection but also extended wavelength or multi-band photoelectric detection on the same readout circuit. When the quantum dot material forming the quantum dot film is lead selenide, the absorption band edge of the quantum dot film is tunable in the range of 1800nm-2300nm; when the quantum dot material forming the quantum dot film is lead sulfide, the absorption band edge of the quantum dot film is tunable in the range of 900nm-1300nm; and when the quantum dot material forming the quantum dot film is tin selenide, the absorption band edge of the quantum dot film is tunable in the range of 800nm-900nm. The absorption band edge of 1800nm ​​indicates that light with an incident wavelength less than 1800nm ​​can be absorbed.

[0104] In one possible implementation, a photoelectric conversion layer 1033 is formed on the first electrode 1031 using methods such as low-temperature drop coating, spin coating, blade coating, and inkjet printing. The photoelectric conversion layer 1033 has a thickness of 400-500 nm.

[0105] In one specific embodiment, a P-type doped layer 1034 is further disposed on the photoelectric conversion layer 1033 to form a PI junction, thereby enhancing conductivity.

[0106] In one possible implementation, mercury telluride colloidal quantum dots with a thickness of 500 nm are coated on the first electrode 1031 using methods such as low-temperature drop coating, spin coating, blade coating, and inkjet printing to obtain the photoelectric conversion layer 1033.

[0107] In one specific embodiment, a P-type doped layer 1034 is further disposed on the photoelectric conversion layer 1033. Specifically, silver telluride with a thickness of 200 nm is coated on the photoelectric conversion layer 1033 by spin coating, and the silver telluride is treated with mercuric chloride. After a chemical reaction, a P-type doped layer 1034 comprising silver chloride and mercuric telluride is obtained to form a PI junction, which functions as a PN junction and has the properties of forward conduction and reverse cutoff.

[0108] In one specific embodiment, the infrared focal plane detector further includes a bias electrode 104, such as... Figure 3 As shown, the bias electrode 104 is connected to the second electrode to output a bias voltage, which is used to achieve photoelectric conversion.

[0109] It should be noted that the infrared focal plane detector includes an active area and a non-display area, such as... Figure 6 As shown, the bias electrode 104 of the infrared focal plane detector is located in the non-display area and its surface is encapsulated by a chip-on-film (COF) film.

[0110] In this embodiment, a bias voltage is output by setting a bias electrode. The bias voltage is used to achieve photoelectric conversion, and the bias electrode is located in the non-display area, which further ensures the display effect of the detector.

[0111] Based on the infrared focal plane detector provided in the above embodiments, one embodiment of the present invention provides a method for fabricating an infrared focal plane detector, wherein the focal plane detector includes multiple pixel units arranged in an array, such as... Figure 7 As shown, the preparation method includes the following steps:

[0112] A readout circuit layer is formed on the substrate, including the readout circuit of each pixel unit;

[0113] A detection layer is formed on the readout circuit layer. The detection layer includes a first electrode, a second electrode, and a photoelectric conversion layer disposed between the first electrode and the second electrode. The first electrode includes a first functional layer disposed on the readout circuit layer and a second functional layer covering the first functional layer. The first functional layer of each detection unit is electrically connected to the readout circuit, and the first functional layer includes a plurality of through-holes 103111.

[0114] The infrared focal plane detector prepared by the above-described method in this embodiment has the advantages of simple structure and low cost. By setting multiple through-holes on the first functional layer of its first electrode, the light transmittance is increased while ensuring the conductivity of the first electrode, effectively improving the imaging quality and sensitivity of the infrared focal plane detector. Specific implementation details of this embodiment are found in the foregoing embodiments and will not be repeated here.

[0115] In one possible implementation, the substrate is a glass substrate. Because glass substrates have high hardness and transparency, they can prevent the infrared focal plane detector from being scratched while ensuring light transmittance.

[0116] In one specific embodiment, forming a probe layer on the readout circuit layer further includes:

[0117] A first functional layer is patterned on the readout circuit, and the first functional layer is in contact with the source or drain through the first via.

[0118] The thickness of the first functional layer in the direction perpendicular to the substrate is greater than or equal to 300 nm and less than or equal to 500 nm;

[0119] A second functional layer is deposited on the first functional layer to form the second functional layer;

[0120] A photoelectric conversion layer is formed on the second functional layer by spin coating or spray coating.

[0121] A second electrode is deposited on the photoelectric conversion layer.

[0122] Specifically, the step of patterning the first functional layer on the readout circuit further includes:

[0123] A first functional layer material is deposited on the readout circuit layer;

[0124] The first functional layer material is patterned to form the first functional layer 10311, wherein the area of ​​the opening 103111 is greater than or equal to 262 square micrometers and less than or equal to 351 square micrometers, and the shape of the opening 103111 is at least one of rectangle, circle, triangle and rhombus.

[0125] In this embodiment, the first functional layer is made of aluminum and molybdenum. Specifically, it is a sandwich structure formed by sequentially stacking a molybdenum metal layer, an aluminum metal layer, and a molybdenum metal layer, which effectively improves the stability of the detection layer.

[0126] In one specific embodiment, since the material of the first functional layer has high conductivity, in order to avoid electrostatic breakdown of the product during the etching of the first functional layer, a passivation layer (PVX layer) needs to be deposited on the third metal layer during the preparation of the first functional layer. Photoresist is coated on the passivation layer, and exposure and development are performed through a mask to form retention areas and removal areas respectively. Dry etching is used to process the first metal layer, second metal layer and third metal layer corresponding to the retention areas, forming a patterned first functional layer.

[0127] It should be noted that the principle and workflow of the infrared focal plane detector fabrication method provided in this embodiment are similar to the principle of the infrared focal plane detector described above. The relevant parts can be referred to the above description and will not be repeated here.

[0128] One embodiment of the present invention provides a planar detection device, the planar detection device including the above-described infrared focal plane detector.

[0129] In this embodiment, the infrared focal plane detector of the planar detection device increases the light transmittance while ensuring the conductivity of the first electrode by setting multiple through-holes on the first functional layer of its first electrode, thereby effectively improving the imaging quality of the infrared focal plane detector.

[0130] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0131] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A method for fabricating a planar detector, the planar detector comprising a plurality of pixel units arranged in an array, characterized in that, include A readout circuit layer is formed on the substrate, including the readout circuit of each pixel unit; A detection layer is formed on the readout circuit layer. The detection layer includes a first electrode, a second electrode, and a photoelectric conversion layer disposed between the first electrode and the second electrode. The first electrode includes a first functional layer disposed on the readout circuit layer and a second functional layer covering the first functional layer. The first functional layer of each detection unit is electrically connected to the readout circuit, and the first functional layer includes a plurality of through-holes.

2. The preparation method according to claim 1, characterized in that, The step of forming a probe layer on the readout circuit layer further includes: A first functional layer is patterned on the readout circuit, wherein the thickness of the first functional layer in the direction perpendicular to the substrate is greater than or equal to 300 nm and less than or equal to 500 nm. A second functional layer is deposited on the first functional layer to form the second functional layer; A photoelectric conversion layer is formed on the second functional layer by spin coating or spray coating. A second electrode is deposited on the photoelectric conversion layer.

3. The preparation method according to claim 1 or 2, characterized in that, The step of patterning the first functional layer on the readout circuit further includes: A first functional layer material is deposited on the readout circuit layer; The first functional layer is formed by patterning the first functional layer material, wherein the area of ​​the opening is greater than or equal to 262 square micrometers and less than or equal to 351 square micrometers, and the shape of the opening is at least one of rectangle, circle, triangle and rhombus.

4. A planar detector prepared using the preparation method of claim 1 or 2, comprising a plurality of detector units arranged in an array, characterized in that, Includes a substrate, a readout circuit layer and a probe layer stacked on the substrate, wherein, The readout circuit layer includes the readout circuits for each detection unit; The detection layer includes a first electrode, a second electrode disposed opposite to the first electrode, and a photoelectric conversion layer disposed between the first electrode and the second electrode. The first electrode includes a first functional layer disposed on the readout circuit layer and a second functional layer covering the first functional layer. The first functional layer of each detection unit is electrically connected to the readout circuit, and the first functional layer includes a plurality of through openings therethrough.

5. The planar detector according to claim 4, characterized in that, The shapes and / or areas of the openings may be the same or different.

6. The planar detector according to claim 5, characterized in that, The area of ​​the opening is greater than or equal to 262 square micrometers and less than or equal to 351 square micrometers; and / or The shape of the opening is at least one of rectangle, circle, triangle and rhombus.

7. The planar detector according to claim 4, characterized in that, In the direction perpendicular to the substrate, the thickness of the first functional layer is greater than or equal to 300 nm and less than or equal to 500 nm; and / or The first functional layer is made of aluminum and molybdenum.

8. The planar detector according to claim 4, characterized in that, The material of the second functional layer is indium tin oxide; and / or The photoelectric conversion layer is made of colloidal quantum dots.

9. The planar detector according to claim 4, characterized in that, The material of the second electrode is at least one of gold, platinum, silver, aluminum, and copper; and / or The substrate is a glass substrate.

10. A planar detection device, characterized in that, Including the planar detector as described in claim 4.

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