A non-cooled infrared detector and a manufacturing method thereof

Abstract

The application discloses a non-refrigeration infrared detector and a manufacturing method thereof, and belongs to the field of infrared detector technology.The non-refrigeration infrared detector comprises a substrate, a micro-bridge structure and a first capacitor, wherein the micro-bridge structure is arranged above the substrate; and the first capacitor is used for storing the charge output by the infrared detector, and is arranged at the upper end of the substrate and below the bridge surface layer of the micro-bridge structure.The application integrates the readout circuit, the storage capacitor for storing the electric signal and the micro-bridge structure of the infrared detector in one pixel by using the MEMS manufacturing technology, reduces the readout circuit device, increases the readout circuit array wiring space, optimizes the overall layout and wiring of the readout circuit, stores the collected signal in place, reduces the layout wiring, reduces the signal crosstalk, improves the performance of the detector, greatly reduces the area of the detector chip, and reduces the cost of the detector.

Description

Technical Field

[0001] This invention belongs to the field of infrared detection technology, specifically relating to an uncooled infrared detector and its manufacturing method. Background Technology

[0002] The working principle of an uncooled infrared detector is that thermal radiation is focused onto the focal plane array of the detector through an infrared optical system. After each pixel absorbs the infrared radiation, its thermally sensitive temperature changes. This change is collected by the detector's readout circuit, stored, and processed before being output to finally obtain a visualized electronic image reflecting the temperature distribution of the target.

[0003] Currently, the storage capacitor of uncooled infrared detectors is located in the readout circuit within the substrate and is not integrated with the pixel. Furthermore, the data acquisition and data storage of uncooled infrared detectors currently require passing through the pixel area and using very long wiring connections, which increases signal crosstalk and makes layout and wiring difficult. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide an uncooled infrared detector and its manufacturing method. By using MEMS manufacturing technology, the storage capacitor for storing signals in the readout circuit is integrated with the microbridge structure of the infrared detector into a single pixel. This reduces the number of readout circuit components, increases the wiring space of the readout circuit array, optimizes the overall layout and wiring of the readout circuit, stores the acquired signals locally, reduces layout traces, reduces signal crosstalk, improves detector performance, significantly reduces the area of ​​the detector chip, and simultaneously reduces the cost of the detector.

[0005] The technical solution of this invention is implemented as follows: This invention discloses an uncooled infrared detector, characterized in that it comprises:

[0006] Substrate;

[0007] Microbridge structures are arranged above the substrate;

[0008] The first capacitor is used to store the charge output by the infrared detector;

[0009] The first capacitor is disposed on the upper end of the substrate and is located below the bridge layer of the microbridge structure.

[0010] Furthermore, a first capacitor is disposed below the bridge surface layer of each microbridge structure, and the first capacitor stores the charge output by the infrared detector pixel corresponding to the microbridge structure.

[0011] Furthermore, a reflective layer is provided below the bridge deck layer, and a resonant cavity is formed between the reflective layer and the bridge deck layer. The reflective layer is one of the plates of the first capacitor.

[0012] Furthermore, the reflective layer is connected to a fixed potential.

[0013] Furthermore, an insulating layer is disposed on the upper surface of the substrate, and the first capacitor is formed on the insulating layer.

[0014] Furthermore, the first capacitor includes a first electrode plate, a second electrode plate, and a capacitor dielectric layer located between the first electrode plate and the second electrode plate. The first electrode plate and the capacitor dielectric layer, as well as the second electrode plate and the capacitor dielectric layer, are separated by an insulating layer material.

[0015] Furthermore, the first plate and the second plate of the first capacitor are electrically connected to the readout circuit in the substrate through the first conductive post and the second conductive post located in the insulating layer, respectively.

[0016] Furthermore, the first and second electrically conductive anchors of the microbridge structure are located at two opposite corners of the corresponding pixel, and the first and second conductive posts are located at the other two opposite corners of the corresponding pixel.

[0017] Furthermore, the first and second electrically conductive anchors of the microbridge structure are supported on the insulating layer and electrically connected to the readout circuit in the substrate through conductive pillars located within the insulating layer.

[0018] This invention discloses a method for manufacturing an uncooled infrared detector, comprising the following steps:

[0019] Provide substrate;

[0020] Fabricate the first capacitor on the substrate;

[0021] Fabrication of microbridge structures;

[0022] The first capacitor is used to store the charge output by the infrared detector, and the first capacitor is located below the bridge surface layer of the microbridge structure.

[0023] The present invention has at least the following beneficial effects: The present invention utilizes MEMS manufacturing technology to integrate the storage capacitor for storing signals in the readout circuit with the microbridge structure of the infrared detector into a single pixel, thereby reducing readout circuit components, increasing the wiring space of the readout circuit array, optimizing the overall layout and wiring of the readout circuit, storing the acquired signals locally, reducing layout traces, reducing signal crosstalk, improving detector performance, significantly reducing the area of ​​the detector chip, and simultaneously reducing the cost of the detector.

[0024] The reflective layer of the microbridge structure in the infrared detector can not only increase infrared absorption of the reflected thermal radiation of the microbridge structure, but also serve as the second plate of the MIM capacitor, reducing the number of manufacturing steps and improving production efficiency.

[0025] This invention uses the reflective layer in the microbridge structure as the second plate of the MIM capacitor in the readout circuit. By connecting the readout circuit to a fixed potential, the noise of the detector can be reduced, thereby improving the detector performance. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram showing the integration of a first capacitor and a microbridge structure into a single pixel process according to an embodiment of the present invention;

[0028] Figure 2 This is a schematic diagram showing the integration of a first capacitor and a microbridge structure into a single pixel process according to an embodiment of the present invention, after specific step b.

[0029] Figure 3 This is a schematic diagram showing the integration of a first capacitor and a microbridge structure into a single pixel process according to an embodiment of the present invention, after specific step c.

[0030] Figure 4 This is a schematic diagram showing the specific steps d after integrating a first capacitor and a microbridge structure into a single pixel process according to an embodiment of the present invention.

[0031] Figure 5 This is a schematic diagram showing the specific step e of integrating a first capacitor and a microbridge structure into a single pixel process according to an embodiment of the present invention.

[0032] Figure 6 This is a schematic diagram showing the specific steps f after integrating a first capacitor and a microbridge structure into a single pixel process according to an embodiment of the present invention.

[0033] Figure 7 This is a schematic diagram showing the specific steps g of the process for integrating a first capacitor and a microbridge structure into a single pixel in one embodiment of the present invention.

[0034] Figure 8 Schematic diagram of the readout circuit for an uncooled infrared detector;

[0035] Figure 9 A three-dimensional image of a first capacitor and a microbridge structure integrated into a single pixel, as provided in another embodiment of the present invention.

[0036] In the attached figures, 1 is the substrate, 2 is the microbridge structure, 21 is the bridge surface layer, 22 is the first bridge leg, 23 is the second bridge leg, 24 is the first electrically conductive anchor post, 25 is the second electrically conductive anchor post, 3 is the first capacitor, 31 is the reflective layer, 32 is the capacitor dielectric layer, 33 is the first electrode plate, 34 is the first insulating layer, 35 is the third insulating layer, 36 is the fifth insulating layer, 37 is the second insulating layer, 38 is the fourth insulating layer, 4 is the first conductive post, 5 is the second conductive post, 6 is the third conductive post, 7 is the fourth conductive post, 8 is the third electrode plate, and 9 is the fourth electrode plate. Detailed Implementation

[0037] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0039] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature; in the description of this invention, unless otherwise stated, "a plurality of" or "several" means two or more.

[0040] Example 1

[0041] See Figures 1 to 9 This invention provides an uncooled infrared detector, comprising:

[0042] Substrate 1 has a built-in readout circuit;

[0043] Microbridge structure 2 is arranged above substrate 1;

[0044] The first capacitor 3 is used to store the charge output by the infrared detector;

[0045] The first capacitor 3 is disposed on the upper end of the substrate 1 and is located below the bridge layer 21 of the microbridge structure 2.

[0046] Furthermore, a first capacitor 3 is disposed below the bridge surface layer of each microbridge structure 2, and the first capacitor 3 stores the charge output by the infrared detector pixel corresponding to the microbridge structure 2.

[0047] Furthermore, the bridge deck layer 21 is provided with a heat-sensitive material for absorbing infrared radiation. A reflective layer 31 is located below the bridge deck layer 21, forming a resonant cavity between the reflective layer 31 and the bridge deck layer 21. The reflective layer 31 is one of the plates of the first capacitor 3, i.e., the second plate. The reflective layer 31 is parallel to the bridge deck layer 21.

[0048] The reflective layer of the microbridge structure in the infrared detector can not only increase infrared absorption of the reflected thermal radiation of the microbridge structure, but also serve as the second plate of the MIM capacitor, reducing the number of manufacturing steps and improving production efficiency.

[0049] In one embodiment, the microbridge structure 2 is a MEMS microbridge structure, and the substrate 1 is a CMOS substrate.

[0050] The target emits infrared radiation containing its own temperature information. When the heat-sensitive material of the infrared detector absorbs this radiation, its temperature changes. This temperature change is converted into a change in electrical charge through a certain conversion mechanism and output. The first capacitor is used to store this charge. For example, when the temperature of the thermistor in a calorimeter changes, its resistance value changes accordingly. Applying a bias current converts this change in resistance into a change in voltage, thereby outputting a corresponding charge stored in the first capacitor. The charge stored in the first capacitor is further processed and output by a readout circuit. Subsequently, the intensity of the infrared radiation is determined by measuring the magnitude of the charge.

[0051] This invention utilizes MEMS manufacturing technology to integrate the storage capacitor for the readout circuit and the microbridge structure of the infrared detector into a single pixel. This reduces the number of readout circuit components, increases the wiring space for the readout circuit array, optimizes the overall layout and wiring of the readout circuit, allows for on-site storage of the acquired signals, reduces layout traces, lowers signal crosstalk, improves detector performance, significantly reduces the area of ​​the detector chip, and simultaneously reduces the cost of the detector.

[0052] Furthermore, the reflective layer 31 is connected to a fixed potential, specifically to the ground potential of the readout circuit. By grounding the reflective layer 31, the parasitic capacitance and resistance are reduced, which can reduce the noise of the detector and thus improve the detector performance. In addition, since a large amount of charge accumulates in the etching process of the reflective layer 31, it will affect the device structure. By connecting the reflective layer 31 to the ground potential through the readout circuit, the large amount of charge accumulated in the etching process can also be released by grounding, which improves the performance of the detector and the stability of the device structure, while increasing the production yield of the detector.

[0053] Furthermore, the microbridge structure 2 includes a bridge deck layer 21, a first bridge leg 22, and a second bridge leg 23. One end of the bridge deck layer 21 is supported on a first electrically conductive anchor post 24 via the first bridge leg 22, and one end of the first bridge leg 22 is electrically connected to one end of the bridge deck layer 21. The other end of the first bridge leg 22 is electrically connected to the upper end of the first electrically conductive anchor post 24, and the lower end of the first electrically conductive anchor post 24 is electrically connected to the substrate 1 via a third conductive post 6.

[0054] The other end of the bridge deck layer 21 is supported on the second electrically conductive anchor post 25 via the second bridge leg 23, and one end of the second bridge leg 23 is electrically connected to the other end of the bridge deck layer 21. The other end of the second bridge leg 23 is electrically connected to the upper end of the second electrically conductive anchor post 25, and the lower end of the second electrically conductive anchor post 25 is electrically connected to the substrate 1 via the fourth conductive post 7.

[0055] In one embodiment, the bridge deck layer 21 and the bridge leg layer are located on the same plane. Of course, the microbridge structure 2 of the present invention is not limited to the above embodiment, and the microbridge structure 2 can be adjusted as needed.

[0056] An insulating layer is provided on the upper surface of the substrate 1, and the first capacitor 3 is formed on the insulating layer.

[0057] The first capacitor 3 includes a first electrode 33, a second electrode, and a capacitor dielectric layer 32 located between the first electrode 33 and the second electrode. The first electrode and the capacitor dielectric layer, as well as the second electrode and the capacitor dielectric layer, are separated by an insulating layer material. The first electrode 33 is located directly below the capacitor dielectric layer 32, and the second electrode, i.e., the reflective layer 31, is located directly above the capacitor dielectric layer 32. These three components constitute a MIM capacitor.

[0058] Furthermore, the first electrode 33 is electrically connected to the readout circuit in the substrate 1 through the first conductive post 4 located in the insulating layer, and the second electrode, i.e. the reflective layer 31, is electrically connected to the readout circuit in the substrate 1 through the second conductive post 5 located in the insulating layer.

[0059] Furthermore, a third electrode plate 8 and a fourth electrode plate 9 are also disposed on the insulating layer. The reflective layer is spaced apart from the third electrode plate 8 and serves as two electrode plates of the capacitor, together forming a second capacitor. The reflective layer and the fourth electrode plate 9 are spaced apart and serve as two electrode plates of the capacitor, together forming a third capacitor. This invention can use the second capacitor, the third capacitor, or a combination of the second and third capacitors in parallel as the sample-and-hold capacitor of the readout circuit.

[0060] Furthermore, the reflective layer 31 can be made of materials such as aluminum, titanium, or titanium nitride. The capacitor dielectric layer 32 can be made of materials such as silicon nitride. The first electrode plate 33 can be made of materials such as aluminum, titanium, or titanium nitride. The insulating layer can be made of materials such as silicon dioxide or silicon oxide.

[0061] Furthermore, a first insulating layer 3 is provided at the lower end of the first electrode plate 33, a first insulating layer 34 is located at the upper end of the substrate 1, a third insulating layer 35 is provided at the upper end of the first electrode plate 33, the lower end of the capacitor dielectric layer 32 is the third insulating layer 35, and the upper end of the capacitor dielectric layer 32 is the fifth insulating layer 36. The reflective layer 31 is located at the upper end of the fifth insulating layer 36.

[0062] Furthermore, the insulating layer includes a first insulating layer 34, a second insulating layer 37, a third insulating layer 35, a fourth insulating layer 38, and a fifth insulating layer 36 arranged sequentially from bottom to top. A first groove is provided on the second insulating layer 37, and a capacitor electrode material (such as aluminum, titanium, or titanium nitride) is deposited in the first groove to form a first electrode 33. A second groove is provided on the fourth insulating layer 38, and a capacitor dielectric material (such as silicon nitride) is deposited in the second groove to form the capacitor dielectric layer 32.

[0063] Furthermore, the third electrode plate 8 and the fourth electrode plate 9 are disposed on the fifth insulating layer 36.

[0064] In one embodiment, the first electrically conductive anchor post 24 and the second electrically conductive anchor post 25 of the microbridge structure 2 are supported on the insulating layer (such as the fifth insulating layer 36) and are electrically connected to the readout circuit in the substrate 1 through the third conductive post and the fourth conductive post located in the insulating layer, respectively.

[0065] Another embodiment is as follows: the first conductive anchor of the microbridge structure is supported on the third electrode plate 8, and the first conductive anchor is electrically connected to the third electrode plate 8. The third electrode plate 8 is electrically connected to the readout circuit in the substrate through a third conductive post located in the insulating layer. The second conductive anchor of the microbridge structure is supported on the fourth electrode plate 9, and the second conductive anchor is electrically connected to the fourth electrode plate 9. The fourth electrode plate 9 is electrically connected to the readout circuit in the substrate through a fourth conductive post located in the insulating layer.

[0066] In other embodiments, the first electrically conductive anchor post 24 and the second electrically conductive anchor post 25 of the microbridge structure 2 can also be directly supported on the substrate 1 and electrically connected to the readout circuit in the substrate 1 through metal electrodes.

[0067] Furthermore, the first electrically conductive anchor post 24 and the second electrically conductive anchor post 25 of the microbridge structure 2 are located at two opposite corners of the corresponding pixel, and the first conductive post 4 and the second conductive post 5 of the first capacitor 3 are located at the other two opposite corners of the corresponding pixel.

[0068] The two ends of the microbridge structure 2 of each uncooled infrared detector pixel are electrically connected to the corresponding readout circuit, and the two ends of the first capacitor 3 of each uncooled infrared detector pixel are electrically connected to the corresponding readout circuit, serving as the storage capacitor C1 of the readout circuit.

[0069] Further, the readout circuit includes a first transistor Q1, a second transistor Q2, and a first operational amplifier. The source of the first transistor is connected to one end of the microbridge structure 2 of the uncooled infrared detector pixel, and the other end of the microbridge structure 2 of the uncooled infrared detector pixel is connected to the power supply voltage Vdet. The drain of the first transistor is connected to the drain of the second transistor. The gate of the first transistor is connected to a first bias voltage. The source of the second transistor is connected to a second bias voltage via a resistor. The gate of the second transistor is connected to a third bias voltage. The inverting input of the first operational amplifier is connected to the drains of the first transistor and the second transistor. The inverting input of the first operational amplifier is connected to one end of the first capacitor 3 of the uncooled infrared detector pixel. The other end of the first capacitor 3 of the uncooled infrared detector pixel is connected to the output of the first operational amplifier. The non-inverting input of the first operational amplifier is connected to a reference voltage. The output of the first operational amplifier is the output of the readout circuit.

[0070] Furthermore, the readout circuit also includes a sample-and-hold capacitor C2. This sample-and-hold capacitor C2 can be a commercially available capacitor, or it can be the second capacitor or the third capacitor described in Embodiment 3, or a combination of the second and third capacitors in parallel. This invention utilizes MEMS manufacturing technology to integrate the sample-and-hold capacitor C2 of the readout circuit with the microbridge structure of the infrared detector into a single pixel, reducing the number of readout circuit components and increasing the wiring space of the readout circuit array.

[0071] In one embodiment, one end of the sample-and-hold capacitor C2 is connected to the output of the first operational amplifier, and the other end of the sample-and-hold capacitor C2 is grounded.

[0072] Based on the working principle of uncooled infrared detectors, this invention integrates the storage capacitor for the readout circuit signal into the infrared detector pixel using MEMS manufacturing technology. The microbridge structure 2 is defined by its reflective layer 31 (also a mirror); above the reflective layer 31 is the microbridge structure 2, and below it is the MIM capacitor. That is, the MIM capacitor is directly below the microbridge structure 2. In this integrated pixel, the reflective layer 31 of the infrared detector's microbridge structure 2 not only increases infrared absorption by reflecting thermal radiation from the microbridge structure 2, but also serves as the second plate of the MIM capacitor.

[0073] The first and second electrical contact holes are used for CMOS connection to both ends of the MIM capacitor; the third and fourth electrical contact holes are used for CMOS connection to both ends of the microbridge structure 2.

[0074] The working principle of an uncooled infrared detector is that thermal radiation is focused onto the focal plane array of the detector through an infrared optical system. After each pixel absorbs the infrared radiation, its thermally sensitive temperature changes. This change is collected by the detector's readout circuit, stored, and processed before being output to finally obtain a visualized electronic image reflecting the temperature distribution of the target.

[0075] Each pixel absorbs infrared radiation, causing a change in its thermally sensitive temperature. This change is captured, stored, and processed by the detector's readout circuit before being output, such as... Figure 8 As shown.

[0076] Example 2

[0077] See Figures 1 to 7 The present invention also discloses a method for manufacturing an uncooled infrared detector, comprising the following steps:

[0078] Substrate 1 is provided;

[0079] Fabricate the first capacitor 3 on substrate 1;

[0080] Fabrication of microbridge structure 2;

[0081] The first capacitor 3 is used to store the charge output by the infrared detector, and the first capacitor 3 is located below the bridge layer 21 of the microbridge structure 2.

[0082] Further, a first capacitor 3 is fabricated on the substrate 1, and a microbridge structure 2 is fabricated, specifically including the following steps:

[0083] a) A first insulating layer 34 is formed on the substrate 1, and etching is performed from the surface of the first insulating layer 34 and extends downward to the surface of the substrate 1. A first electrical contact hole is etched at a set position, and conductive material is deposited in the first electrical contact hole.

[0084] b) A second insulating layer 37 is formed on the first insulating layer 34. The second insulating layer 37 is etched from its surface and extends downward to the surface of the first insulating layer 34. A first groove is etched at a set position. Capacitor plate material is deposited in the first groove to form a first plate 33. The first plate partially covers the corresponding first electrical contact hole, so that the first plate is electrically connected to the readout circuit in the substrate 1 through the conductive material in the corresponding first electrical contact hole.

[0085] c) A third insulating layer 35 is formed on the first electrode plate;

[0086] d) A fourth insulating layer 38 is formed on the third insulating layer 35. The fourth insulating layer 38 is etched from its surface and extends downward to the surface of the third insulating layer 35. A second groove is etched at a set position. Dielectric material is deposited in the second groove to form a capacitor dielectric layer 32. The capacitor dielectric layer 32 is located directly above the corresponding first electrode plate.

[0087] e) A fifth insulating layer 36 is formed on the capacitor dielectric layer 32. The fifth insulating layer 36 is etched from its surface and extends downward to the surface of the substrate 1. A second electrical contact hole, a third electrical contact hole, and a fourth electrical contact hole are etched at set positions. Conductive material is deposited in the second electrical contact hole, the third electrical contact hole, and the fourth electrical contact hole.

[0088] f) A reflective layer 31 is formed on the fifth insulating layer 36. The reflective layer 31 partially covers the corresponding second electrical contact hole, so that the reflective layer is electrically connected to the readout circuit in the substrate 1 through the conductive material in the corresponding second electrical contact hole. The reflective layer and the first electrode plate serve as the two electrode plates of the capacitor, and together they constitute the first capacitor.

[0089] g) A microbridge structure 2 is fabricated on the fifth insulating layer 36. There is a gap between the reflective layer and the bridge surface layer 21 of the microbridge structure 2. The reflective layer is located directly below the bridge surface layer 21 of the microbridge structure 2. The first electrically conductive anchor 24 of the microbridge structure 2 covers the third electrical contact hole, and the second electrically conductive anchor 25 of the microbridge structure 2 covers the fourth electrical contact hole, so that the two ends of the bridge surface layer 21 of the microbridge structure 2 are electrically connected to the substrate 1 through the conductive material in the third electrical contact hole and the fourth electrical contact hole, respectively.

[0090] Furthermore, the reflective layer 31 can be made of materials such as aluminum, titanium, or titanium nitride. The capacitor dielectric layer 32 can be made of materials such as silicon nitride. The first electrode plate 33 can be made of materials such as aluminum, titanium, or titanium nitride. The insulating layer can be made of materials such as silicon dioxide or silicon oxide.

[0091] By employing the above-described process of the present invention, the storage capacitor for storing signals in the readout circuit and the microbridge structure of the infrared detector are integrated into a single pixel using MEMS manufacturing technology. This reduces the number of readout circuit components, increases the wiring space of the readout circuit array, optimizes the overall layout and wiring of the readout circuit, allows for on-site storage of the acquired signals, reduces layout traces, lowers signal crosstalk, improves detector performance, significantly reduces the area of ​​the detector chip, and simultaneously reduces the cost of the detector.

[0092] Figure 7 This is for illustrative purposes only and is not intended to define the specific locations of the first, second, third, and fourth electrical contact holes. The specific locations of the first, second, third, and fourth electrical contact holes shall be set as needed.

[0093] Furthermore, the first and second electrical contact holes of the same pixel are located at two opposite corners of the corresponding pixel, and the third and fourth electrical contact holes of the same pixel are located at two opposite corners of the corresponding pixel. The straight line containing the first and second electrical contact holes of the same pixel intersects with the straight line containing the third and fourth electrical contact holes.

[0094] Example 3

[0095] In another embodiment, step f) further includes: a third electrode plate 8 and a fourth electrode plate 9 are respectively formed on the fifth insulating layer 36. The third electrode plate 8 and the fourth electrode plate 9 are spaced apart from the reflective layer. The third electrode plate 8 partially covers the corresponding third electrical contact hole, so that the third electrode plate 8 is electrically connected to the substrate 1 through the conductive material in the corresponding third electrical contact hole. The fourth electrode plate 9 partially covers the corresponding fourth electrical contact hole, so that the fourth electrode plate 9 is electrically connected to the substrate 1 through the conductive material in the corresponding fourth electrical contact hole. The reflective layer and the third electrode plate 8 serve as two electrode plates of the capacitor, forming a second capacitor together. The reflective layer and the fourth electrode plate 9 serve as two electrode plates of the capacitor, forming a third capacitor together. The first electrically conductive anchor post 24 is formed on the third electrode plate 8, and the second electrically conductive anchor post 25 is formed on the fourth electrode plate 9. The third electrode plate 8 and the fourth electrode plate 9 can be made of the same material as the reflective layer and fabricated at the same time, and the reflective layer, the third electrode plate 8, and the fourth electrode plate 9 are deposited and patterned in one step.

[0096] The third electrode plate 8 can be made of materials such as aluminum, titanium, or titanium nitride. The fourth electrode plate 9 can be made of materials such as aluminum, titanium, or titanium nitride.

[0097] This invention can use a second capacitor, a third capacitor, or a combination of the second and third capacitors in parallel as the sample-and-hold capacitor of the readout circuit. By using MEMS manufacturing technology, the sample-and-hold capacitor of the readout circuit and the microbridge structure of the infrared detector can be integrated into a single pixel, reducing the number of readout circuit components and increasing the wiring space of the readout circuit array.

[0098] The other technical features of this embodiment are the same as those of Embodiment 2.

[0099] This invention utilizes MEMS fabrication technology to integrate the microbridge structure 2 of the infrared detector and the storage capacitor for storing signals in the readout circuit into a single pixel. This increases the wiring space of the readout circuit array, optimizes the overall layout and wiring of the readout circuit, allows for on-site storage of the acquired signals, reduces layout traces, lowers signal crosstalk, and improves detector performance. The reflective layer 31 in the microbridge structure 2 serves as the second plate of the MIM capacitor in the readout circuit, connected to a fixed potential, which reduces detector noise and thus improves detector performance.

[0100] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An uncooled infrared detector, characterized in that, include: Substrate; Microbridge structures are arranged above the substrate; The first capacitor is used to store the charge output by the infrared detector; The first capacitor is disposed on the upper end of the substrate and is located below the bridge layer of the microbridge structure. Below the bridge deck layer is a reflective layer, and a resonant cavity is formed between the reflective layer and the bridge deck layer. The reflective layer is one of the plates of the first capacitor and is connected to a fixed potential.

2. The uncooled infrared detector as described in claim 1, characterized in that: Each of the microbridge structures has a first capacitor disposed below the bridge surface layer, and the first capacitor stores the charge output by the infrared detector pixel corresponding to the microbridge structure.

3. The uncooled infrared detector as described in claim 1, characterized in that: An insulating layer is disposed on the upper surface of the substrate, and the first capacitor is formed on the insulating layer.

4. The uncooled infrared detector as described in claim 1 or 3, characterized in that: The first capacitor includes a first plate, a second plate, and a capacitor dielectric layer located between the first plate and the second plate. The first plate and the capacitor dielectric layer, as well as the second plate and the capacitor dielectric layer, are separated by an insulating layer material.

5. The uncooled infrared detector as described in claim 3, characterized in that: The first plate and the second plate of the first capacitor are electrically connected to the readout circuit in the substrate through the first conductive post and the second conductive post located in the insulating layer, respectively.

6. The uncooled infrared detector as described in claim 5, characterized in that: The first and second electrically conductive anchors of the microbridge structure are located at two opposite corners of the corresponding pixel, and the first and second conductive anchors are located at the other two opposite corners of the corresponding pixel.

7. The uncooled infrared detector as described in claim 3, characterized in that: The first and second electrically conductive anchors of the microbridge structure are supported on the insulating layer and electrically connected to the readout circuit in the substrate through conductive pillars located in the insulating layer.

8. A method for manufacturing an uncooled infrared detector, characterized in that: Includes the following steps: Provide substrate; Fabricate the first capacitor on the substrate; Fabrication of microbridge structures; The first capacitor is used to store the charge output by the infrared detector, and the first capacitor is located below the bridge surface layer of the microbridge structure. Below the bridge deck layer is a reflective layer, and a resonant cavity is formed between the reflective layer and the bridge deck layer. The reflective layer is one of the plates of the first capacitor and is connected to a fixed potential.

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