Chip infrared spectrometer

Abstract

The utility model provides a chip infrared spectrometer. The chip infrared spectrometer comprises a readout integrated circuit wafer, a miniature bolometer array and a surface enhanced infrared nano antenna absorber array, the miniature bolometer array is composed of a plurality of miniature bolometers, and the miniature bolometer array is arranged on the surface of the readout integrated circuit wafer; the surface-enhanced infrared nano antenna absorber array is composed of the same number of surface-enhanced infrared nano antenna absorbers, and the surface-enhanced infrared nano antenna absorbers are correspondingly arranged on the surfaces of the miniature bolometers; the surface-enhanced infrared nano antenna absorber is of a plasmon structure of a metal-medium-metal three-layer structure. According to the utility model, the surface-enhanced infrared nano antenna absorber is directly formed on the surface of the miniature bolometer, so that the distance between the surface-enhanced infrared nano antenna absorber and the miniature bolometer is reduced to the greatest extent, the size of a unit is reduced, crosstalk of incident light on an infrared detector is reduced, higher spectral resolution is realized, and the packaging cost is reduced.

Description

Technical Field

[0001] The present application relates to the fields of semiconductor technology and spectral measurement technology, and in particular to a chip-based infrared spectrometer. Background Art

[0002] In many fields such as scientific research and industrial production, spectrometers have become one of the most important instruments for material characterization and chemical analysis. Based on semiconductor manufacturing methods and combined with micro-nano optical design, the technical solution of realizing chip-level spectrometers has received widespread attention.

[0003] At present, the main technical routes of spectral identification can be divided into four categories. The first is to decompose light into spatially separated detectors through devices with dispersive optical properties; the second is those that use narrowband filters to preferentially transmit specific spectral components to different detectors; the third is Fourier transform micro-spectrometers based on time or space interferometers; the fourth category is "reconstruction" or "computational" spectrometers that use computer processing power.

[0004] Based on the above technical directions of spectral recognition, various spectrometers of microchip size have been proposed in the past decade. The main technical problems currently exist are as follows. First, under the premise of meeting the performance requirements of the usage scenario, the manufacturing method of the spectrometer chip should meet the requirements of mass production and low cost. Second, the chip-level spectrometer should be as highly integrated as possible to meet the specific integration of the spectral recognition module, detector module, and readout circuit module. Third, in the application scenarios of spectrometers, the most important is the infrared band (2-20μm), also known as the fingerprint area. However, high-performance, low-cost infrared detectors are still relatively scarce, so chip-scale infrared spectrometers are difficult to meet the first two technical requirements. Utility Model Content

[0005] The utility model provides a chip-based infrared spectrometer to solve all or part of the problems of the prior art, so as to obtain a high-performance, low-cost chip-level infrared spectrometer.

[0006] In order to achieve the above-mentioned purpose, the utility model provides a chip-based infrared spectrometer, including a readout integrated circuit wafer, a micro-bolometer array and a surface-enhanced infrared nano-antenna absorber array; the micro-bolometer array is composed of a plurality of micro-bolometers, and the micro-bolometer array is arranged on the surface of the readout integrated circuit wafer; the surface-enhanced infrared nano-antenna absorber array is composed of the same number of surface-enhanced infrared nano-antenna absorbers, and the surface-enhanced infrared nano-antenna absorbers are correspondingly arranged on the surface of each micro-bolometer; the surface-enhanced infrared nano-antenna absorber is a plasmon structure of a metal-medium-metal three-layer structure. The present application adopts a plasmon structure of a metal-medium-metal three-layer structure as an infrared filtering and enhancement unit, and realizes the selective absorption of incident light of different narrowbands; by directly forming the surface-enhanced infrared nano-antenna absorber on the surface of the micro-bolometer, the function of the spectrometer is realized, and the distance between the two can be minimized to the greatest extent, achieving higher spectral resolution and reducing packaging costs.

[0007] The surface enhanced infrared nano antenna absorber is composed of a bottom metal layer, a dielectric layer and a top metal layer from bottom to top, wherein the top metal layer is a characteristic structure array formed by arranging a plurality of characteristic structures. The top metal layer adopts an array structure, which can be adjusted and adapted according to design requirements and has a wide range of applications.

[0008] The structural parameters of the different top metal layers can be the same or different. By optimizing the structural design of the top metal layer using an optical design method, a surface-enhanced infrared nano-antenna absorber with a high optical quality factor can be obtained, thereby improving the accuracy; in addition, the absorption spectrum of each surface-enhanced infrared nano-antenna absorber can be encoded and designed by changing the structure of the top metal layer, and the spectrum of the detected signal can be restored by combining machine learning and artificial intelligence algorithms, which can achieve a spectrometer function with ultra-high resolution and bandwidth compared to traditional narrow-band filtering methods.

[0009] The material of the bottom metal layer and the top metal layer is any one of gold, silver, titanium or aluminum, and the material of the dielectric layer is any one of silicon nitride, silicon dioxide, aluminum oxide or silicon carbide. Using a material that is easy to generate plasmons as the metal layer and a dielectric layer material with a high refractive index and low loss can reduce losses and further improve the accuracy of the spectrometer.

[0010] A conductive base is provided on the readout integrated circuit wafer, and the microbolometer is electrically connected to a readout circuit inside the readout integrated circuit wafer through the conductive base. By connecting the microbolometer to the readout circuit through the conductive base, the optical signal can be processed.

[0011] The microbolometer is a suspended microbridge structure, which is composed of two bridge legs and an infrared detector layer. The two bridge legs are respectively arranged on a conductive base, and the infrared detector layer is arranged on the two bridge legs to form a suspended structure. The infrared detector layer is suspended on the surface of the wafer, and an insulating air cavity is formed between the two, which can achieve thermal isolation of the infrared detector layer, greatly reduce the thermal conductivity and heat capacity of the microbolometer, and significantly improve the performance of the microbolometer.

[0012] The bridge leg is a multilayer structure consisting of a support layer, an electrode layer and a protective layer, and the infrared detector layer is a multilayer structure consisting of a support layer, a thermosensitive layer, an electrode layer and a protective layer. The structural stability and service life of the microbolometer can be ensured by the structural arrangement of the support layer and the protective layer, and the conversion of heat to an electrical signal can be realized through the thermosensitive layer and transmitted to the readout circuit through the electrode layer.

[0013] The upper surface of the readout integrated circuit wafer is also provided with a metal reflective layer, and the metal reflective layer is located below the infrared detector layer. The metal reflective layer is provided below the infrared detector layer, so that a resonant cavity can be formed between the metal reflective layer and the infrared detector layer, thereby improving the performance of the microbolometer.

[0014] A protective layer is formed on the surface of the surface enhanced infrared nano-antenna absorber array, and the material of the protective layer is a high-transmittance material. In order to protect the structural integrity and service life of the spectrometer, a protective layer can be formed on its upper surface.

[0015] Compared with the prior art, the beneficial effects of the utility model mainly include the following: the utility model provides a chip-based infrared spectrometer, which realizes the miniaturization requirement of the chip scale of the infrared spectrometer; the manufacturing method is reliable and compatible with the manufacturing of traditional MEMS bolometers, meeting the requirements of mass production and low cost; by directly manufacturing the surface-enhanced infrared nano-antenna absorber structure on the suspended detector film layer, the micro-bolometer and the surface-enhanced infrared nano-antenna absorber are matched one by one, which can minimize the distance between the two, achieve higher spectral resolution and reduce packaging costs; in addition, the performance of the spectrometer is scalable, based on narrowband The filter-based spectrometer can improve the overall working bandwidth of the spectrometer by increasing the number of micro-bolometers. By optimizing the film thickness and top pattern design of the surface-enhanced infrared nanoantenna absorber using optical design methods, a surface-enhanced infrared nanoantenna absorber with a high optical quality factor can be obtained, thereby improving the accuracy. Based on the computational or reconstructive spectrometer, by encoding the absorption spectrum of each surface-enhanced infrared nanoantenna absorber and combining machine learning and artificial intelligence algorithms to perform spectral restoration on the detected signal, a spectrometer function with ultra-high resolution and bandwidth can be achieved compared to traditional narrow-band filtering methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the specific embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 The utility model provides a schematic diagram of the cross-sectional structure of an infrared spectrometer.

[0018] Figure 2 This is a schematic diagram of the cross-sectional structure of a surface enhanced infrared nano-antenna absorber provided by the utility model.

[0019] Figure 3 This is a schematic diagram of the top view structure of a surface enhanced infrared nano-antenna absorber provided by the utility model.

[0020] Figure 4 The utility model provides a top view schematic diagram of an infrared spectrometer chip. DETAILED DESCRIPTION

[0021] The above and other technical contents, features and effects of the present invention will be clearly presented in the following detailed description of a preferred embodiment with reference to the drawings. The directional terms mentioned in the following embodiments, such as up, down, left, right, front or back, etc., are only referenced to the directions of the attached drawings. Therefore, the directional terms used are used to illustrate and not to limit the present invention.

[0022] The following will describe the various embodiments of the present application in detail with reference to the accompanying drawings. However, it will be appreciated by those skilled in the art that in the various embodiments of the present application, many technical details are provided in order to enable the reader to better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical solution claimed in the present application can be implemented.

[0023] Embodiment 1:

[0024] The utility model provides a chip-based infrared spectrometer, comprising a readout integrated circuit wafer, a micro-bolometer array and a surface-enhanced infrared nano-antenna absorber array; the micro-bolometer array is composed of a plurality of micro-bolometers, and the micro-bolometer array is arranged on the surface of the readout integrated circuit wafer; the surface-enhanced infrared nano-antenna absorber array is composed of the same number of surface-enhanced infrared nano-antenna absorbers as the micro-bolometer array, and each surface-enhanced infrared nano-antenna absorber is correspondingly arranged on the surface of each micro-bolometer; the surface-enhanced infrared nano-antenna absorber is a plasmon structure of a metal-medium-metal three-layer structure.

[0025] Figure 1 The utility model provides a schematic diagram of the cross-sectional structure of an infrared spectrometer.

[0026] In this embodiment, the substrate used is a readout integrated circuit wafer 121, and a conductive base 131 is provided on the upper surface of the readout integrated circuit wafer 121. The readout integrated circuit (ROIC) wafer can be used as one of the components of an infrared spectrometer, and can be used to process the output data of the infrared detector by connecting the infrared detector (i.e., microbolometer) to the driving circuit inside the ROIC wafer.

[0027] like Figure 1 As shown, a microbolometer array and a surface-enhanced infrared nano-antenna absorber array are sequentially arranged on the readout integrated circuit wafer 121; the microbolometer array is formed by a plurality of microbolometers (101, 102 ... 10N) arranged in a certain rule, and a corresponding surface-enhanced infrared nano-antenna absorber array is arranged on the upper surface of the microbolometer array, and the surface-enhanced infrared nano-antenna absorber array is also composed of a plurality of surface-enhanced infrared nano-antenna absorbers (111, 112 ... 11N) arranged in a certain rule (the number of surface-enhanced infrared nano-antenna absorbers is the same as the number of microbolometers). Each unit in the microbolometer array corresponds to each unit of the surface-enhanced infrared nano-antenna absorber array, that is, a corresponding surface-enhanced infrared nano-antenna absorber is arranged on each microbolometer, such as a surface-enhanced infrared nano-antenna absorber 111 is arranged on the upper surface of the microbolometer 101, a surface-enhanced infrared nano-antenna absorber 112 is arranged on the upper surface of the microbolometer 102, and so on.

[0028] The following is an illustration of the basic unit in the microbolometer array, namely the microbolometer, and the basic unit in the surface enhanced infrared nanoantenna absorber array, namely the surface enhanced infrared nanoantenna absorber.

[0029] like Figure 1As shown, in this embodiment, the microbolometer 101 is a suspended microbridge structure, which is specifically composed of two parts: a bridge leg 141 and an infrared detector layer 151. The two bridge legs 141 in opposite directions are respectively arranged on a corresponding conductive base 131, and are electrically connected to a readout circuit (not shown in the figure) in the readout integrated circuit wafer 121 through the conductive base 131; and the infrared detector layer 151 is arranged on the two bridge legs 141, and is suspended above the readout integrated circuit wafer 121 under the support of the bridge legs 141. Through the suspended structure, a heat-insulating air cavity can be formed between the readout integrated circuit wafer 121 and the infrared detector layer 151 to achieve thermal isolation of the infrared detector layer 151, thereby greatly reducing the thermal conductivity and heat capacity of the microbolometer, and significantly improving the performance of the microbolometer.

[0030] In this embodiment, a suspended microbridge structure of a microbolometer is provided, but the present invention is not limited to this structure. The micro-bolometer in the present embodiment is prepared by the following method: first, a plurality of conductive bases 131 are arranged on the readout integrated circuit wafer 121, and then a dielectric layer is formed on the wafer. The material of the dielectric layer can be selected from SiO2 or Si3N4. In the present embodiment, the dielectric layer is SiO2; a metal reflective layer is formed on the surface of the formed dielectric layer. The material of the metal reflective layer can be selected from one of metal materials such as aluminum, gold, silver, copper, titanium, titanium nitride, nickel chromium, etc. In the present embodiment, the material used for the metal reflective layer is aluminum; a sacrificial layer is formed on the surface of the readout integrated circuit wafer 121 and the reflective layer. In the present embodiment, the sacrificial layer material is polyimide; a through hole is formed on the surface of the sacrificial layer, and the through hole terminates on the conductive base 131; a multilayer structure of a support layer, a thermal sensitive layer, an electrode layer and a protective layer is formed in sequence on the surface of the sacrificial layer, and a multilayer structure of a support layer, an electrode layer and a protective layer is formed in sequence in the through hole; the support layer, the electrode layer and the protective layer formed on the surface of the sacrificial layer and in the through hole are formed in the same process. In order to prevent the thermal sensitive layer from tilting or contacting the substrate, stress balance is also required in the multi-layer thin film process; the material of the support layer and the protective layer can be selected from SiO2 or Si3N4. In this embodiment, both are SiO2; the material of the thermal sensitive layer is VO x, the thermosensitive layer can convert the received optical signal into an electrical signal; one end of the electrode layer is connected to the thermosensitive layer, and the other end is connected to the conductive base 131, so as to output the signal of the thermosensitive layer to the readout circuit inside the readout integrated circuit wafer 121; finally, the sacrificial layer is released to form a suspended microbridge structure. In this embodiment, the sacrificial layer is a polyimide layer, and the sacrificial layer is removed by plasma etching to obtain a suspended microbridge structure; wherein, the multilayer structure formed in the through hole is the bridge leg 141, and the multilayer structure formed on the surface of the sacrificial layer is the infrared detector layer 151. That is, in this embodiment, the bridge leg 141 of the micro-bolometer is a multilayer structure composed of three film layers of a support layer, an electrode layer and a protective layer, and the infrared detector layer 151 is a multilayer structure composed of four film layers of a support layer, a thermosensitive layer (the thermosensitive layer is generally a rectangular block structure), an electrode layer and a protective layer, the metal reflective layer is located below the infrared detector layer 151, and the bridge leg 141 is arranged on the conductive base 131.

[0031] The following describes the structure of the surface enhanced infrared nano-antenna absorber 111 as an example. The cross-sectional structure of the surface enhanced infrared nano-antenna absorber 111 is shown in FIG. Figure 2 The top view structure of the surface enhanced infrared nano-antenna absorber 111 is shown in FIG. Figure 3 In this embodiment, the surface enhanced infrared nano-antenna absorber 111 is a plasmon structure. The so-called plasmon structure is a structure that uses the interaction between electromagnetic oscillations formed by the interaction between free electrons and photons in the metal surface area and the electromagnetic field of light waves to modulate incident light.

[0032] Combination Figure 2 and Figure 3 As shown, the surface enhanced infrared nano-antenna absorber 111 is a three-layer film structure, that is, a metal-medium-metal three-layer structure from bottom to top, which are a bottom metal layer 1110, a dielectric layer 1111 and a top metal layer 1112. The bottom metal layer 1110 and the dielectric layer 1111 thereon have the same pattern. In this embodiment, both are rectangular structures with a size similar to that of the thermal sensitive layer in the micro-bolometer (here, the size refers to the length and width of the thermal sensitive layer). The bottom metal layer 1110 is a layered structure with a size similar to that of the thermosensitive layer (i.e., the length and width of the bottom metal layer 1110 are respectively similar to the length and width of the thermosensitive layer of the micro-bolometer), a thickness of 100 nm, and a constituent material thereof is gold; the dielectric layer 1111 is a layered structure with a size similar to that of the bottom metal layer 1110 and a thickness of 45 nm, and a constituent material thereof is aluminum oxide; a patterned top metal layer 1112 is located on the dielectric layer 1111, the thickness of the layer is 70 nm, and the constituent material thereof is also gold; Figure 2 and Figure 3As shown, in this embodiment, the top metal layer 1112 is a metal array structure, that is, a patterned structure formed by a number of characteristic structures 1113 arranged in a certain period. In this embodiment, the patterned structure formed by the arrangement of the characteristic structures 1113 is rectangular. In the top metal layer 1112, the characteristic structure 1113 is a rectangular parallelepiped structure, the length and width of which are both 720nm, and the thickness is 70nm (that is, the thickness of the top metal layer 1112). The spacing between two adjacent characteristic structures 1113 is 1200nm. The above-mentioned top metal layer 1112 is formed by spreading the characteristic structures 1113 as much as possible throughout the entire bottom metal layer 1110 area at the above spacing. In the attached Figure 2 and 3 In the figure, for convenience of representation, not all characteristic structures 1113 are shown, and the sizes in the figures are not in accordance with the actual proportions, which are not limitations on the size, quantity and array of the characteristic structures 1113. In other embodiments, the size, quantity and arrangement of the characteristic structures 1113 used to form the top metal layer 1112 can be reasonably designed according to the size of the bottom metal layer 1110.

[0033] In other embodiments, the shapes of the bottom metal layer 1110 and the dielectric layer 1111 thereon can be determined according to actual needs, and the specific shapes are not limited here; the sizes of the bottom metal layer 1110 and the dielectric layer 1111 can also be determined according to actual needs, and are not limited; similarly, the structural parameter design of the top metal layer 1112 (that is, the shape, size, number and array mode of the characteristic structure 1113 can be changed) can also be designed according to different goals. In other embodiments, the characteristic structure 1113 can be cylindrical, triangular prism, hollow cylindrical, hollow square, hollow triangular prism, cube, cuboid, pentagonal prism, hexagonal prism, heart-shaped prism, etc., and the shape is not limited; in other embodiments, the distribution mode of the characteristic structure 1113 can be any one of a tetragonal lattice arrangement, a hexagonal lattice arrangement, a random arrangement or a mixed arrangement, and this is not limited. The tetragonal lattice arrangement means that the characteristic structure 1113 is periodically arranged along the orthogonal direction, and has translational symmetry, two-fold symmetry and mirror symmetry; the hexagonal lattice arrangement means that the characteristic structure 1113 is periodically arranged along the non-orthogonal direction, and has translational symmetry, six-fold symmetry and mirror symmetry; the random arrangement means that the positions of the characteristic structures 1113 are randomly arranged; the mixed arrangement means that the shapes and positions of the characteristic structures 1113 are randomly arranged.

[0034] According to different working bands, the film materials of the above three layers can be selected. For the bottom metal layer and the top metal layer, any metal material can be used. Further, metals such as gold, silver, titanium or aluminum that can generate surface plasmons can be selected. The materials of the bottom metal layer and the top metal layer can be the same or different. As for the dielectric layer material, it is generally required to have a high refractive index and low loss, including but not limited to silicon nitride, silicon dioxide, silicon carbide, aluminum oxide, etc.

[0035] The above examples illustrate the micro-bolometer and the surface-enhanced infrared nano-antenna absorber. The overall structure of a chip-based infrared spectrometer provided by this embodiment is further introduced below. Figure 4 FIG. 1 is a top view of the chip-based infrared spectrometer provided in this embodiment. M rows and N columns, a total of M×N micro-bolometers (101, 102, ..., M0N) are arranged on the readout integrated circuit wafer 121, and each micro-bolometer (i.e. Figure 4 The rectangular area in the figure is provided with a surface enhanced infrared nano-antenna absorber (i.e. Figure 4 ), that is, there are M rows and N columns, and a total of MxN surface enhanced infrared nano-antenna absorbers (111, 112...M1N). It should be noted that Figure 4 The rectangle and circle in the figure are only used to represent the micro-bolometer and the surface-enhanced infrared nano-antenna absorber, respectively, and are not intended to limit the shape and size of the micro-bolometer and the surface-enhanced infrared nano-antenna absorber. Figure 4 The use of rectangles and circles is to better distinguish the two units for easier observation and understanding. By providing a one-to-one corresponding surface-enhanced infrared nanoantenna absorber on each microbolometer, that is, the surface-enhanced infrared nanoantenna absorber is correspondingly provided above the infrared detector layer 151 of the microbolometer, thereby ensuring a one-to-one correspondence between the microbolometer and the infrared nanoantenna absorber. In other embodiments, in order to provide better protection, a protective layer is also formed on the surface of the surface-enhanced infrared nanoantenna absorber array, and the material of the protective layer can be selected from highly transmittance materials such as silicon nitride, silicon oxide, and silicon oxynitride.

[0036] In the chip-based infrared spectrometer of the present embodiment, the structure of each micro-bolometer (101, 102, ..., M0N) forming the micro-bolometer array is consistent.

[0037] like Figure 4As shown, there are MxN surface-enhanced infrared nano-antenna absorbers (111, 112...M1N) in the surface-enhanced infrared nano-antenna absorber array, and the structure of each surface-enhanced infrared nano-antenna absorber can refer to the surface-enhanced infrared nano-antenna absorber 111, but the specific structural parameters of different surface-enhanced infrared nano-antenna absorbers may be different. Specifically, for different surface-enhanced infrared nano-antenna absorbers, the bottom metal layer and the dielectric layer are consistent, that is, in the same embodiment, the material, shape and thickness of the bottom metal layer of the MxN surface-enhanced infrared nano-antenna absorbers are the same, and the material, shape and thickness of all dielectric layers are also the same. For different surface-enhanced infrared nano-antenna absorbers, the material of the top metal layer is the same, and the structural parameters (that is, the shape, size, number and array method of the characteristic structure) may be the same or different. Specifically, in the same top metal layer, the shape and size of each characteristic structure should be consistent; for different top metal layers, the shape and size of the characteristic structures constituting each top metal layer can be the same or different, and the array of characteristic structures in each top metal layer can also be the same or different, and the top metal layer can be graphically designed according to the design goal. Different surface-enhanced infrared nanoantenna absorbers are sensitive to light wavelengths to achieve the spectrometer function of the thermal radiation meter array.

[0038] In this embodiment, a microbolometer array and a surface enhanced infrared nano-antenna absorber array are sequentially formed on the readout integrated circuit wafer 121, and the units of the microbolometer array and the surface enhanced infrared nano-antenna absorber array correspond one to one, and a chip-based infrared spectrometer is obtained. The implementation mechanism of the infrared spectrometer structure of the utility model is as follows: when light is irradiated, it will first be incident on the surface of the surface enhanced infrared nano-antenna absorber array. If the wavelength of the incident light satisfies the wave vector matching condition at the metal / dielectric material (in this embodiment, the dielectric material is air) interface, a surface plasmon will be generated at the interface. At this time, an extraordinary absorption phenomenon will occur, that is, the infrared light absorption efficiency near the surface plasmon excitation wavelength will be greatly enhanced, so that the incident infrared light of a specific narrow frequency will be absorbed by the surface plasmon resonance, converted into heat energy and conducted to the corresponding microbolometer surface below, that is, the surface enhanced infrared nano-antenna absorber has wavelength selectivity, can select light of a specific wavelength band and absorb it after enhancement, and then conduct the generated heat to the thermosensitive layer in the microbolometer. Therefore, according to this working principle, by changing the structure of the surface enhanced infrared nano-antenna absorber, the excitation wavelength of the surface plasmon can be adjusted, thereby changing the central wavelength of the absorption area, and realizing selective absorption of different incident light. After being absorbed by the surface enhanced infrared nano-antenna absorber, the incident light will be converted into heat and then absorbed by the thermistor of the infrared detector layer 151 in the micro-bolometer. The thermistor in the infrared detector layer 151 will change its resistance value due to the absorbed heat, and then output a corresponding voltage signal and transmit it to the readout circuit in the readout integrated circuit wafer 121 through the conductive base, thereby feeding back the intensity of the incident light and realizing the detection of infrared light.

[0039] The chip-based infrared spectrometer provided by the utility model can well realize the function of the spectrometer, and the performance of the spectrometer is scalable, and it can develop spectrometers with two different technical routes. The first is a spectrometer based on the narrowband filter route. By increasing the number of micro-bolometers, the overall working bandwidth of the spectrometer can be improved. By optimizing the film thickness and top pattern design of the surface-enhanced infrared nano-antenna absorber using optical design methods, a surface-enhanced infrared nano-antenna absorber with a high optical quality factor can be obtained, thereby improving the accuracy. The second is a computational or reconstructive spectrometer. By encoding the absorption spectrum of each surface-enhanced infrared nano-antenna absorber, combining machine learning and artificial intelligence algorithms to perform spectral restoration on the detected signal, it can achieve ultra-high resolution and bandwidth spectrometer functions relative to traditional narrowband filtering methods. The solution of the utility model directly forms the surface-enhanced infrared nano-antenna absorber on the surface of the micro-bolometer, which can minimize the distance between the two, achieve higher spectral resolution and reduce packaging costs.

[0040] Some commonly used English nouns or letters used in this application for the sake of clarity are only used for exemplary references rather than restrictive interpretations or specific usages, and the protection scope of this application should not be limited by their possible Chinese translations or specific letters. It should also be noted that, in this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

Claims

1. A chip-based infrared spectrometer, characterized in that: Includes readout integrated circuit wafers, microbolometer arrays, and surface-enhanced infrared nanoantenna absorber arrays; The microbolometer array is composed of a plurality of microbolometers, and the microbolometer array is arranged on the surface of the readout integrated circuit wafer; The surface enhanced infrared nano-antenna absorber array is composed of the same number of surface enhanced infrared nano-antenna absorbers, and the surface enhanced infrared nano-antenna absorbers are correspondingly arranged on the surface of each micro-bolometer; The surface enhanced infrared nano-antenna absorber is a plasmon structure of a metal-medium-metal three-layer structure.

2. The chip-based infrared spectrometer according to claim 1, characterized in that: The surface enhanced infrared nano-antenna absorber comprises a bottom metal layer, a dielectric layer and a top metal layer from bottom to top, and the top metal layer is a characteristic structure array formed by arranging a plurality of characteristic structures.

3. The chip-based infrared spectrometer according to claim 2, characterized in that: The structural parameters of the different top metal layers may be the same or different.

4. The chip-based infrared spectrometer according to claim 2, characterized in that: The material of the bottom metal layer and the top metal layer is any one of gold, silver, titanium or aluminum, and the material of the dielectric layer is any one of silicon nitride, silicon dioxide, aluminum oxide or silicon carbide.

5. The chip-based infrared spectrometer according to claim 1, characterized in that: A conductive base is arranged on the readout integrated circuit wafer, and the micro-bolometer is electrically connected to a readout circuit inside the readout integrated circuit wafer through the conductive base.

6. The chip-based infrared spectrometer according to claim 5, characterized in that: The micro-bolometer is a suspended micro-bridge structure, which is composed of two bridge legs and an infrared detector layer. The two bridge legs are respectively arranged on a conductive base, and the infrared detector layer is arranged on the two bridge legs to form a suspended structure.

7. The chip-based infrared spectrometer according to claim 6, characterized in that: The bridge leg is a multi-layer structure consisting of a support layer, an electrode layer and a protective layer, and the infrared detector layer is a multi-layer structure consisting of a support layer, a thermal sensitive layer, an electrode layer and a protective layer.

8. The chip-based infrared spectrometer according to claim 6, characterized in that: The upper surface of the readout integrated circuit wafer is also provided with a metal reflective layer, and the metal reflective layer is located below the infrared detector layer.

9. The chip-based infrared spectrometer according to claim 1, characterized in that: A protective layer is formed on the surface of the surface enhanced infrared nano-antenna absorber array, and the material of the protective layer is a high-transmittance material.

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