Infrared sensor and method of manufacturing the same

Abstract

This application provides an infrared sensor and its manufacturing method. The infrared sensor includes: a pixel microbridge structure, including a microbridge surface and a first driving circuit group. The microbridge surface is used to absorb infrared radiation, and the first driving circuit group outputs an electrical signal based on the infrared radiation to reflect the target temperature; and at least one dual-material thermally driven structure capable of deformation and contacting the lower surface of the microbridge surface to dissipate heat and support the microbridge surface. This technical solution, by providing at least one deformable dual-material thermally driven structure, allows the dual-material thermally driven structure to contact the surface of the microbridge surface near the first driving circuit group when high-temperature or high-energy target infrared radiation is incident, thereby increasing the heat dissipation path of the pixel microbridge structure and preventing burns to the pixel microbridge structure caused by heat conduction under strong radiation.

Description

Technical Field

[0001] This invention relates to the field of sensors, and more particularly to an infrared sensor and its manufacturing method. Background Technology

[0002] Infrared focal plane array sensors are one of the important sensors in industrial, Internet of Things, security, and home applications. They can be widely used in many fields with huge market demand and development potential, such as industrial inspection, home security, smart home, energy-saving control, medical care, flow counting, gas detection, fire monitoring, and consumer electronics.

[0003] Infrared focal plane array sensors commonly used in industrial and civilian applications are generally uncooled, also known as room-temperature infrared sensors. Uncooled infrared sensors operate at room temperature without cooling and offer advantages such as small size, low power consumption, low cost, and portability. Uncooled infrared sensors are typically thermal sensors, meaning they operate by detecting the thermal effects of infrared radiation. Commonly used infrared thermal sensors include thermopile sensors, pyroelectric sensors, and microbolometer focal plane array sensors.

[0004] Among these technologies, microbolometers employing pixel-scale microbridge structures are increasingly becoming the dominant uncooled infrared focal plane array (FLAS) technology. Microbolometer FLAS sensors detect radiation intensity by sensing changes in the resistance of thermistors caused by the thermal effect of infrared radiation. To improve sensitivity, the performance requirements for the pixel-scale microbridge structure of uncooled microbolometer FLAS sensors are as follows: First, it must possess excellent thermal insulation properties to maximize the conversion of absorbed infrared radiation into temperature changes; second, it must have low thermal mass to maintain a sufficiently small thermal time constant under high adiabatic conditions, thus meeting certain imaging frequency requirements; third, it must have high infrared absorptivity. Therefore, the pixel-scale microbridge structure of microbolometer FLAS sensors commonly employs a bridge-like microstructure supported by slender cantilever beams, fabricated using surface micromachining processes, and suspended above a CMOS readout circuit (ROIC) substrate—a structure commonly referred to in the industry as a microbridge structure. Each microbridge structure forms a pixel-scale microbridge structure.

[0005] While the aforementioned thermally adiabatic microbridge structure design significantly improves the conversion efficiency between incident radiation and temperature changes in the pixel microbridge structure, thus substantially enhancing sensor sensitivity, it also reduces the pixel microbridge structure's ability to withstand higher-energy incident radiation. For example, after being exposed to high-temperature or high-energy objects such as the sun, molten steel, or lasers, the temperature of the radiated sensor pixel microbridge structure will rise significantly. This high-temperature radiation can "burn" the pixel microbridge structure, manifesting as residual bright lines or spots on the image. These bright lines or spots cannot be completely corrected or eliminated through image processing methods; in severe cases, they may remain on the image for months, or even cause permanent damage and failure of the sensor.

[0006] On the other hand, the pixel microbridge structure supported by slender cantilever beams has poor resistance to mechanical shock. When subjected to strong external vibrations and impacts during use, it is prone to deformation, twisting, and breakage, resulting in blind pixels and dead spots in infrared images. This limits the application of uncooled microbolometer focal plane array sensors in high-impact scenarios such as gun aiming and smart guided projectiles.

[0007] Therefore, providing an infrared sensor that can avoid being "burned" by high-temperature radiation and is resistant to mechanical impact is a technical problem that needs to be solved. Summary of the Invention

[0008] The technical problem to be solved by this application is to provide an infrared sensor and its manufacturing method, which can avoid being "burned" by high temperature radiation and is resistant to mechanical impact.

[0009] To address the aforementioned issues, this application provides an infrared sensor, comprising: a pixel microbridge structure, including a microbridge surface and a first driving circuit group, wherein the microbridge surface is used to absorb infrared radiation, and the first driving circuit group outputs an electrical signal based on the infrared radiation to reflect the temperature of the target; and at least one dual-material thermally driven structure capable of deformation, which contacts the lower surface of the microbridge surface during deformation to dissipate heat and provide support for the microbridge surface.

[0010] In some embodiments, the dual-material thermally driven structure includes a first deformation structure and a second deformation structure that are of the same shape and are stacked on top of each other. The coefficient of thermal expansion of the second deformation structure is less than that of the first deformation structure. When deformation occurs, the upper surface of the second deformation structure contacts the lower surface of the microbridge deck.

[0011] In some embodiments, the infrared sensor further includes: a second driving circuit electrically connected to the dual-material thermally driven structure, wherein the second driving circuit applies current to the dual-material thermally driven structure to drive the dual-material thermally driven structure to deform.

[0012] In some embodiments, the shape of the first deformable structure is strip-shaped, cross-shaped, circular, rhomboid, or elliptical.

[0013] In some embodiments, the pixel microbridge structure further includes: a substrate, multiple piers, multiple microcantilever beams, and a resonant absorption cavity; piers and microcantilever beams are respectively disposed on opposite sides of the microbridge surface. The first driving circuit group includes two first driving circuits located at opposite ends of the substrate; the first end of the pier is connected to a first driving circuit, and the second end is connected to the microbridge surface through the corresponding microcantilever beam, forming the resonant absorption cavity between the microbridge surface and the substrate, wherein the resonant absorption cavity is a 1 / 4 wavelength resonant cavity.

[0014] In some embodiments, the microbridge deck includes: an infrared thermally sensitive layer, a first electrode layer, and a first support layer, wherein the first support layer is coupled to the corresponding bridge pier via the microcantilever beam; the infrared thermally sensitive layer is placed on the surface of the first support layer away from the first drive circuit group, for absorbing infrared radiation and converting it into an electrical signal; the first electrode layer is coupled to all the first drive circuits to transmit the electrical signal.

[0015] In some embodiments, the microcantilever beam includes a second electrode layer and a second support layer, wherein the first electrode layer is connected to the first driving circuit through the second electrode layer, and the first support layer is connected to the bridge pier through the second support layer.

[0016] In some embodiments, the infrared sensor includes at least one set of symmetrically distributed dual-material thermally driven structures.

[0017] This application also provides a method for manufacturing an infrared sensor, the method comprising: providing a substrate; forming a first driving circuit group within the substrate; forming a deformable dual-material thermally driven structure on the substrate; forming a suspended microbridge surface on the dual-material thermally driven structure, wherein when the dual-material thermally driven structure deforms, the upper surface of the dual-material thermally driven structure contacts the lower surface of the microbridge surface to dissipate heat and support the microbridge surface, the microbridge surface is used to absorb infrared radiation, and the first driving circuit group outputs an electrical signal based on the infrared radiation to reflect the temperature of the target.

[0018] In some embodiments, the step of forming a first driving circuit group in the substrate further includes: forming a second driving circuit in the substrate, the second driving circuit being used to apply current to the dual-material thermal driving structure to drive the dual-material thermal driving structure to deform; the step of forming a deformable dual-material thermal driving structure on the substrate further includes: forming a first sacrificial layer on the substrate, and forming a first connection structure in the first sacrificial layer; sequentially depositing a first coefficient of thermal expansion material and a second coefficient of thermal expansion material on the surface of the first sacrificial layer away from the substrate and patterning them to form a dual-material driving structure having a first deformation structure and a second deformation structure, the first deformation structure being connected to the second driving circuit through the first connection structure, wherein the second coefficient of thermal expansion is smaller than the first coefficient of thermal expansion, and when deformation occurs, the upper surface of the second deformation structure contacts the lower surface of the microbridge surface.

[0019] In some embodiments, the step of forming a suspended microbridge over the dual-material thermally driven structure further includes: forming a second sacrificial layer on the upper surface of the dual-material thermally driven structure and the remaining first sacrificial layer; etching a portion of the second sacrificial layer and the first sacrificial layer to expose the first driving circuit group and forming a second connection structure; forming a microbridge on the upper surface of the remaining second sacrificial layer, the microbridge being connected to the first driving circuit group through the second connection structure.

[0020] The above technical solution, by setting at least one deformable dual-material thermal drive structure, allows the dual-material thermal drive structure to contact the surface of the microbridge near the first drive circuit group when high-temperature or high-energy target infrared radiation is incident, thereby increasing the heat dissipation path of the pixel microbridge structure and avoiding burning of the pixel microbridge structure due to heat conduction under strong radiation.

[0021] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this application. Techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and apparatus should be considered part of the specification. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the specific implementation of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1This is a cross-sectional view of an infrared sensor in one embodiment of this application;

[0024] Figure 2 This is a top view of a dual-material thermally driven structure in one embodiment of this application;

[0025] Figure 3 This is a top view of a dual-material thermally driven structure in another embodiment of this application;

[0026] Figure 4 This is a flowchart of a method for manufacturing an infrared sensor according to an embodiment of this application. Detailed Implementation

[0027] The technical solutions of the specific embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described specific embodiments are only a part of the specific embodiments of this application, and not all of the specific embodiments. Based on the specific embodiments of this application, all other specific embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0028] Figure 1 This is a cross-sectional view of an infrared sensor according to an embodiment of this application. Please refer to the following... Figure 1 The infrared sensor includes a pixel microbridge structure 1 and at least one dual-material thermally driven structure 4. The pixel microbridge structure 1 includes a microbridge surface 2 and a first driving circuit group 3. The microbridge surface 2 absorbs infrared radiation, and the first driving circuit group 3 outputs an electrical signal based on the infrared radiation to reflect the target temperature. The dual-material thermally driven structure 4 is deformable and contacts the lower surface of the microbridge surface 2 during deformation to dissipate heat and provide support for the microbridge surface 2. In this embodiment, when the dual-material thermally driven structure 4 deforms and contacts the lower surface of the microbridge surface 2, the dual-material thermally driven structure 4 can become a heat dissipation path for the pixel microbridge structure 1.

[0029] Please continue reading below. Figure 1In this embodiment, the dual-material thermally driven structure 4 includes a first deformation structure 41 and a second deformation structure 42 with the same shape and stacked on top of each other. The coefficient of thermal expansion of the second deformation structure 42 is smaller than that of the first deformation structure 41. When deformation occurs, the upper surface of the second deformation structure 42 (the surface away from the first driving circuit group 3) contacts the lower surface of the microbridge surface 2 (the surface close to the first driving circuit group 3). When high-temperature or high-energy target infrared radiation is incident, the dual-material thermally driven structure 4 will also absorb the incident strong infrared radiation and cause its own temperature to rise. At this time, since the coefficient of thermal expansion of the second deformation structure 42 is smaller than that of the first deformation structure 41, the bending deflection generated by the second deformation structure 42 is smaller than that generated by the first deformation structure 41. When the intensity of incident infrared radiation exceeds a certain threshold, the dual-material thermally driven structure 4 bends and deflects to a certain extent, causing the upper surface of the second deformation structure 42 to contact the lower surface of the microbridge surface 2, thereby increasing the heat dissipation path of the pixel microbridge structure 1 and preventing the pixel microbridge structure 1 from being burned due to heat conduction under strong radiation. In some embodiments, the material of the first deformation structure 41 can be a metal with a high coefficient of thermal expansion such as gold or aluminum, and the material of the second deformation structure 42 can be a medium with a low coefficient of thermal expansion such as silicon oxide or silicon nitride.

[0030] Please continue reading below. Figure 1 In this embodiment, the infrared sensor further includes a second driving circuit 5, electrically connected to the dual-material thermally driven structure 4. The second driving circuit 5 applies current to the dual-material thermally driven structure 4 to drive it to deform. When the pixel microbridge structure 1 is applied to a high-impact scenario, the second driving circuit 5 applies current to the dual-material thermally driven structure 4, causing it to heat up, thereby supporting and reinforcing the pixel microbridge structure 1 and improving its impact resistance. Specifically, when the dual-material thermally driven structure 4 heats up and bends due to the current applied by the second driving circuit 5, it comes into contact with the microbridge surface 2 of the pixel microbridge structure 1, providing support and reinforcement in a high-impact scenario. When the second driving circuit 5 stops energizing the dual-material thermally driven structure 4, the dual-material thermally driven structure 4 returns to its original shape, and the pixel microbridge structure 1 returns to its original thermal sensitivity, thus protecting the infrared sensor.

[0031] In some embodiments, the first deformable structure 41 is strip-shaped, cross-shaped, circular, rhomboid, or elliptical. The second deformable structure 42 has the same shape as the first deformable structure 41.

[0032] Please continue reading below. Figure 1In this embodiment, the pixel microbridge structure 1 further includes: a substrate 6, multiple bridge piers 72, multiple microcantilever beams 8, and a resonant absorption cavity 9; bridge piers 72 and microcantilever beams 8 are respectively arranged on opposite sides of the microbridge surface 2. The first driving circuit group 3 includes two first driving circuits 31 located at opposite ends of the substrate 6; the first end of the bridge pier 72 is connected to one of the first driving circuits 31, and the second end is connected to the microbridge surface 2 through the corresponding microcantilever beam 8, forming the resonant absorption cavity 9 between the microbridge surface 2 and the substrate 6. Preferably, the resonant absorption cavity is a 1 / 4 wavelength resonant cavity. The material of the bridge pier 72 can be a conductive material such as metal.

[0033] Following the above embodiment, the microbridge deck 2 includes: an infrared thermally sensitive layer 21, a first electrode layer 22, and a first support layer 23; the first support layer 23 is coupled to the corresponding bridge pier 72 through the microcantilever beam 8; the infrared thermally sensitive layer 21 is placed on the surface of the first support layer 23 away from the first driving circuit group 3, and is used to absorb infrared radiation and convert it into an electrical signal; the first electrode layer 22 is coupled to all the first driving circuits 31 to transmit the electrical signal. The material of the infrared thermally sensitive layer 21 can be amorphous silicon or vanadium oxide, the material of the first electrode layer 22 can be titanium or titanium nitride, etc., and the material of the first support layer 23 can be silicon oxide, silicon nitride, etc.

[0034] In this embodiment, the pixel microbridge structure 1 is a single layer. In other embodiments, the pixel microbridge structure 1 can be a double-layer or multi-layer structure. The double-layer pixel microbridge structure includes two microbridge surfaces 2 with consistent orthographic projection, and the multi-layer pixel microbridge structure includes multiple microbridge surfaces 2 with consistent orthographic projection.

[0035] In some embodiments, the microcantilever beam 8 includes a second electrode layer 81 and a second support layer 82. The first electrode layer 22 is connected to the corresponding first driving circuit 31 through the second electrode layer 81, and the first support layer 23 is connected to the corresponding pier 72 through the second support layer 82. The material of the second electrode layer 81 is the same as the material of the first electrode layer 22, and the material of the second support layer 82 is the same as the material of the first support layer 23.

[0036] Figure 2 This is a top view of a dual-material thermally driven structure in one embodiment of this application. (See image below.) Figure 2 As shown, the infrared sensor includes a set of symmetrically distributed dual-material thermally driven structures 4, which symmetrically dissipate heat and support the microbridge surface 2. Figure 3 This is a top view of a dual-material thermally driven structure in another embodiment of this application. (See attached image.) Figure 3As shown, the infrared sensor includes two symmetrically distributed dual-material thermally driven structures 4 to enhance heat dissipation and support for the microbridge surface 2. In other embodiments, multiple symmetrical dual-material thermally driven structures 4 can be arranged according to the area of ​​the microbridge surface 2 to provide heat dissipation and support for the microbridge surface 2.

[0037] The above technical solution, by setting at least one deformable dual-material thermally driven structure 4, allows the dual-material thermally driven structure 4 to deform and contact the surface of the microbridge surface 2 near the first driving circuit group 3 when subjected to high-temperature or high-energy infrared radiation. This increases the heat dissipation path of the pixel microbridge structure 1 and avoids burns to the pixel microbridge structure 1 caused by heat conduction under strong radiation. Furthermore, by setting a second driving circuit 5 to apply current to the dual-material thermally driven structure 4, the dual-material thermally driven structure 4 heats up, bends, and deflects, contacting the microbridge surface 2 of the pixel microbridge structure 1. This provides support and reinforcement for the pixel microbridge structure 1 under strong impact, thereby protecting the infrared sensor.

[0038] Based on the same inventive concept, this application also provides a method for manufacturing an infrared sensor, used to manufacture the aforementioned infrared sensor.

[0039] Figure 4 This is a flowchart of a method for manufacturing an infrared sensor according to an embodiment of this application. Please refer to the following... Figure 4 The method for manufacturing the infrared sensor includes: step S401, providing a substrate; step S402, forming a first driving circuit group in the substrate; step S403, forming a deformable dual-material thermally driven structure on the substrate; step S404, forming a suspended microbridge surface on the dual-material thermally driven structure, wherein when the dual-material thermally driven structure deforms, the upper surface of the dual-material thermally driven structure contacts the lower surface of the microbridge surface to dissipate heat and support the microbridge surface, the microbridge surface is used to absorb infrared radiation, and the first driving circuit group outputs an electrical signal according to the infrared radiation to reflect the temperature of the target.

[0040] The first driving circuit 3 can be a CMOS readout circuit. Generally, the readout circuit is made using standard CMOS technology. Its manufacturing method and process should already be familiar to mainstream suppliers in the industry, so it will not be described in detail here.

[0041] Please refer to the following as well. Figure 4 and Figure 1The step of forming the first driving circuit group 3 within the substrate 6 further includes: forming a second driving circuit 5 within the substrate 6, the second driving circuit 5 being used to apply current to the dual-material thermal driving structure 4 to drive the dual-material thermal driving structure 4 to deform. The step of forming a deformable dual-material thermal driving structure 4 on the substrate 6 further includes: forming a first sacrificial layer (not shown) on the substrate 6, and forming a first connection structure within the first sacrificial layer; sequentially depositing a first coefficient of thermal expansion material and a second coefficient of thermal expansion material on the surface of the first sacrificial layer away from the substrate 6 and patterning them to form a dual-material driving structure 4 having a first deformation structure 41 and a second deformation structure 42, the first deformation structure 41 being connected to the second driving circuit 5 through the first connection structure; wherein, the first coefficient of thermal expansion is greater than the second coefficient of thermal expansion, and when deformation occurs, the upper surface of the second deformation structure 42 contacts the lower surface of the microbridge surface 2.

[0042] In this embodiment, the material of the first deformable structure 41 can be a metal with a high coefficient of thermal expansion such as gold or aluminum, and the material of the second deformable structure 42 can be a medium with a low coefficient of thermal expansion such as silicon oxide or silicon nitride.

[0043] The first connection structure 71 can be configured as a support pillar. The method for forming the support pillar is as follows: deposit the first sacrificial layer on the upper surface of the substrate 6, and pattern the first sacrificial layer by photolithography and etching to form a through hole. The through hole is used to connect the dual-material thermal drive structure 4 and the second drive circuit 5. Deposit conductive metal materials such as Al, Cu, W and Ti in the through hole to form a support pillar. The support pillar can support the dual-material thermal drive structure 4, and the dual-material thermal drive structure 4 is electrically connected to the second drive circuit 5 through the support pillar. Current can be applied to the dual-material thermal drive structure 4 through the second drive circuit 5 to drive the dual-material thermal drive structure 4 to deform. For details, please refer to the previous text, which will not be repeated here.

[0044] In some embodiments, the step of forming a suspended microbridge surface on the dual-material thermally driven structure further includes: forming a second sacrificial layer (not shown) on the upper surface of the dual-material thermally driven structure and the remaining first sacrificial layer; etching a portion of the second sacrificial layer and the first sacrificial layer to expose the first driving circuit group 3 and forming a second connection structure; forming a microbridge surface 2 on the upper surface of the remaining second sacrificial layer, the microbridge surface 2 being connected to the first driving circuit group 3 through the second connection structure.

[0045] The etching of the second sacrificial layer and the first sacrificial layer to expose the first driving circuit group 3 and form the second connection structure further includes: forming through holes in the second sacrificial layer and the first sacrificial layer, the through holes being used to connect the microbridge deck 2 and the first driving circuit 3; depositing silicon nitride or silicon oxide in the through holes to form a third support layer and depositing titanium or titanium nitride in the through holes to form a third electrode layer, the third support layer and the third electrode layer constituting the second connection structure, the second connection structure being able to support the microbridge deck 2. The second connection structure can be configured as a bridge pier 72. In some embodiments, forming the second connection structure further includes forming a micro cantilever beam 8, the micro cantilever beam 8 including a second electrode layer 81 and a second support layer 82, the micro cantilever beam 8 being used to connect the microbridge deck 2 to the bridge pier 72. The material of the second connection structure is a thermal insulation material.

[0046] The above technical solution, by setting at least one deformable dual-material thermally driven structure 4, allows the dual-material thermally driven structure 4 to contact the surface of the microbridge surface 2 near the first driving circuit group 3 when high-temperature or high-energy infrared radiation is incident. This increases the heat dissipation path of the pixel microbridge structure 1, preventing burns to the pixel microbridge structure 1 caused by heat conduction under strong radiation. Furthermore, by setting a second driving circuit 5 to apply current to the dual-material thermally driven structure 4, the structure heats up, bends, and deflects, contacting the microbridge surface 2 of the pixel microbridge structure 1. This provides support and reinforcement for the pixel microbridge structure 1 under strong impact, thereby protecting the infrared sensor.

[0047] It should be noted that, in this document, relational terms such as "second" and "second" are used only 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 "also includes a..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0048] The various specific embodiments in this specification are described in a related manner. Similar or identical parts between different specific embodiments can be referred to interchangeably. Each specific embodiment focuses on its differences from other specific embodiments. In particular, for the specific embodiment described above, since it is fundamentally similar to the specific embodiment described above, the description is relatively simple; relevant parts can be found in the description of the specific embodiment described above.

[0049] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of protection of this invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. An infrared sensor, characterized in that, include: A pixel microbridge structure includes a microbridge surface and a first driving circuit group. The microbridge surface is used to absorb infrared radiation, and the first driving circuit group outputs an electrical signal according to the infrared radiation to reflect the temperature of the target. At least one dual-material thermally driven structure is capable of deformation and, upon deformation, contacts the lower surface of the microbridge surface to dissipate heat and provide support for the microbridge surface. The dual-material thermally driven structure includes a first deformation structure and a second deformation structure placed on top of each other. The coefficient of thermal expansion of the second deformation structure is less than that of the first deformation structure. Upon deformation, the upper surface of the second deformation structure contacts the lower surface of the microbridge surface.

2. The infrared sensor according to claim 1, characterized in that, The first deformable structure and the second deformable structure have the same shape.

3. The infrared sensor according to claim 1, characterized in that, Also includes: The second driving circuit is electrically connected to the dual-material thermal driving structure. The second driving circuit applies current to the dual-material thermal driving structure to drive the dual-material thermal driving structure to deform.

4. The infrared sensor according to claim 2, characterized in that, The shape of the first deformable structure is strip-shaped, cross-shaped, circular, rhomboid, or elliptical.

5. The infrared sensor according to claim 1, characterized in that, The pixel microbridge structure further includes: a substrate, multiple piers, multiple microcantilever beams, and a resonant absorption cavity. Piers and microcantilever beams are respectively provided on opposite sides of the microbridge surface. The first driving circuit group includes two first driving circuits located at opposite ends of the substrate. The first end of the pier is connected to a first driving circuit, and the second end is connected to the microbridge surface through the corresponding microcantilever beam, forming the resonant absorption cavity between the microbridge surface and the substrate. The resonant absorption cavity is a 1 / 4 wavelength resonant cavity.

6. The infrared sensor according to claim 5, characterized in that, The microbridge deck includes an infrared thermally sensitive layer, a first electrode layer, and a first support layer. The first support layer is coupled to the corresponding bridge pier via the microcantilever beam. The infrared thermally sensitive layer is placed on the surface of the first support layer away from the first drive circuit group, and is used to absorb infrared radiation and convert it into an electrical signal. The first electrode layer is coupled to all the first drive circuits to transmit the electrical signal.

7. The infrared sensor according to claim 6, characterized in that, The microcantilever beam includes a second electrode layer and a second support layer. The first electrode layer is connected to the first driving circuit through the second electrode layer, and the first support layer is connected to the bridge pier through the second support layer.

8. The infrared sensor according to claim 1, characterized in that, It includes at least one set of symmetrically distributed dual-material thermally driven structures.

9. A method for manufacturing an infrared sensor, characterized in that, The method includes: providing a substrate; forming a first driving circuit group within the substrate; forming a deformable dual-material thermally driven structure on the substrate; forming a suspended microbridge surface above the dual-material thermally driven structure, wherein when the dual-material thermally driven structure deforms, the upper surface of the dual-material thermally driven structure contacts the lower surface of the microbridge surface to dissipate heat and support the microbridge surface, the microbridge surface is used to absorb infrared radiation, and the first driving circuit group outputs an electrical signal based on the infrared radiation to reflect the temperature of the target; The dual-material thermally driven structure includes a first deformation structure and a second deformation structure placed on top of each other. The coefficient of thermal expansion of the second deformation structure is smaller than that of the first deformation structure. When deformation occurs, the upper surface of the second deformation structure contacts the lower surface of the microbridge surface.

10. The method according to claim 9, characterized in that, The step of forming a first driving circuit group in the substrate further includes: forming a second driving circuit in the substrate, the second driving circuit being used to apply current to the dual-material thermal driving structure to drive the dual-material thermal driving structure to deform; the step of forming a deformable dual-material thermal driving structure on the substrate further includes: forming a first sacrificial layer on the substrate, and forming a first connection structure in the first sacrificial layer; sequentially depositing a first thermal expansion coefficient material and a second thermal expansion coefficient material on the surface of the first sacrificial layer away from the substrate and patterning them to form a dual-material thermal driving structure having a first deformation structure and a second deformation structure, the first deformation structure being connected to the second driving circuit through the first connection structure, wherein the second thermal expansion coefficient is smaller than the first thermal expansion coefficient, and when deformation occurs, the upper surface of the second deformation structure contacts the lower surface of the microbridge surface.

11. The method according to claim 10, characterized in that, The step of forming a suspended microbridge surface on the dual-material thermally driven structure further includes: forming a second sacrificial layer on the upper surface of the dual-material thermally driven structure and the remaining first sacrificial layer; etching a portion of the second sacrificial layer and the first sacrificial layer to expose the first driving circuit group and forming a second connection structure; forming a microbridge surface on the upper surface of the remaining second sacrificial layer, wherein the microbridge surface is connected to the first driving circuit group through the second connection structure.

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