CN113447150B

CN113447150B - Infrared detector with microbridge structure

Info

Publication number: CN113447150B
Application number: CN202110713220.9A
Authority: CN
Inventors: 翟光杰; 潘辉; 武佩; 翟光强
Original assignee: Beijing North Gaoye Technology Co ltd
Current assignee: Beijing North Gaoye Technology Co ltd
Priority date: 2021-06-25
Filing date: 2021-06-25
Publication date: 2023-01-10
Anticipated expiration: 2041-06-25
Also published as: CN113447150A

Abstract

The utility model relates to a microbridge structure infrared detector, a CMOS measuring circuit system and a CMOS infrared sensing structure in the microbridge structure infrared detector are both prepared by a CMOS process, the CMOS manufacturing process comprises a metal interconnection process, a through hole process, an IMD process and an RDL process, a columnar structure in the microbridge structure infrared detector is a hollow columnar structure, the columnar structure at least comprises an electrode layer, and an absorption plate and a beam structure both at least comprise a first dielectric layer, an electrode layer and a second dielectric layer; the infrared detector with the microbridge structure also comprises a metamaterial structure and/or a polarization structure. Through the technical scheme, the problems of low performance, low pixel scale, low yield, poor consistency and the like of the traditional MEMS process infrared detector are solved, the absorption rate of the infrared detector with the microbridge structure to incident infrared electromagnetic waves is improved, the performance of the infrared detector with the microbridge structure is optimized, and the difficulty of the optical design of the infrared detector with the microbridge structure is reduced.

Description

Infrared detector with microbridge structure

Technical Field

The disclosure relates to the technical field of infrared detection, in particular to an infrared detector with a microbridge structure.

Background

The fields of monitoring markets, vehicle and auxiliary markets, home markets, intelligent manufacturing markets, mobile phone applications and the like have strong demands on uncooled high-performance chips, certain requirements are provided for the performance of the chips, the performance consistency and the product price, the potential demands of more than one hundred million chips are predicted every year, and the current process scheme and architecture cannot meet the market demands.

At present, the infrared detector with a microbridge structure adopts a mode of combining a measuring circuit and an infrared sensing structure, the measuring circuit is prepared by adopting a Complementary Metal-Oxide-Semiconductor (CMOS) process, and the infrared sensing structure is prepared by adopting a Micro-Electro-Mechanical System (MEMS) process, so that the following problems are caused:

(1) The infrared sensing structure is prepared by adopting an MEMS (micro-electromechanical systems) process, polyimide is used as a sacrificial layer, and the infrared sensing structure is incompatible with a CMOS (complementary metal oxide semiconductor) process.

(2) Polyimide is used as a sacrificial layer, so that the problem that the vacuum degree of a detector chip is influenced due to incomplete release exists, the growth temperature of a subsequent film is limited, and the selection of materials is not facilitated.

(3) Polyimide can cause the height of the resonant cavity to be inconsistent, and the working dominant wavelength is difficult to guarantee.

(4) The control of the MEMS process is far worse than that of the CMOS process, and the performance consistency and the detection performance of the chip are restricted.

(5) MEMS has low productivity, low yield and high cost, and can not realize large-scale batch production.

(6) The existing process capability of the MEMS is not enough to support the preparation of a detector with higher performance, and the MEMS has smaller line width and thinner film thickness, thereby being not beneficial to realizing the miniaturization of a chip.

Disclosure of Invention

In order to solve the technical problems or at least partially solve the technical problems, the present disclosure provides an infrared detector with a microbridge structure, which solves the problems of low performance, low pixel scale, low yield, poor consistency, etc. of the infrared detector in the conventional MEMS process, improves the absorption rate of the infrared detector with the microbridge structure to incident infrared electromagnetic waves, optimizes the performance of the infrared detector with the microbridge structure, and reduces the difficulty of the optical design of the infrared detector with the microbridge structure.

The present disclosure provides a microbridge structure infrared detector, including:

the CMOS infrared sensing structure comprises a CMOS measuring circuit system and a CMOS infrared sensing structure, wherein the CMOS measuring circuit system and the CMOS infrared sensing structure are both prepared by using a CMOS process, and the CMOS infrared sensing structure is directly prepared on the CMOS measuring circuit system;

the CMOS measurement circuit system comprises at least one layer of closed release isolation layer above the CMOS measurement circuit system, wherein the closed release isolation layer is used for protecting the CMOS measurement circuit system from being influenced by a process in the release etching process of manufacturing the CMOS infrared sensing structure;

the CMOS manufacturing process of the CMOS infrared sensing structure comprises a metal interconnection process, a through hole process, an IMD (in-mold decoration) process and an RDL (remote description language) process, wherein the CMOS infrared sensing structure comprises at least two metal interconnection layers, at least two dielectric layers and a plurality of interconnection through holes, the metal interconnection layers at least comprise a reflecting layer and an electrode layer, and the dielectric layers at least comprise a sacrificial layer and a heat-sensitive dielectric layer; the thermal sensitive medium layer is used for converting temperature change corresponding to infrared radiation absorbed by the thermal sensitive medium layer into resistance change, and further converting an infrared target signal into a signal capable of realizing electric reading through the CMOS measuring circuit system;

the CMOS infrared sensing structure comprises a resonant cavity formed by the reflecting layer and the heat sensitive medium layer, a suspended micro-bridge structure for controlling heat transfer and a columnar structure with electric connection and support functions, the columnar structure is a hollow columnar structure, the suspended micro-bridge structure comprises an absorption plate and a plurality of beam structures, the columnar structure at least comprises the electrode layer, the absorption plate and the beam structures at least comprise a first medium layer, the electrode layer and a second medium layer, the electrode layer is positioned between the first medium layer and the second medium layer, and the first medium layer is positioned on one side of the electrode layer close to the CMOS measuring circuit system;

the infrared detector with the microbridge structure further comprises a metamaterial structure and/or a polarization structure, wherein the metamaterial structure or the polarization structure is at least one metal interconnection layer on one side of the first dielectric layer close to the CMOS measurement circuit system, or at least one metal interconnection layer on one side of the second dielectric layer far away from the CMOS measurement circuit system, or at least one metal interconnection layer which is arranged between the first dielectric layer and the second dielectric layer and electrically insulated from the electrode layer, or the electrode layer is used as a metamaterial structure layer or a polarization structure layer;

the CMOS measuring circuit system is used for measuring and processing an array resistance value formed by one or more CMOS infrared sensing structures and converting an infrared signal into an image electric signal; the CMOS measuring circuit system comprises a bias voltage generating circuit, a column-level analog front-end circuit and a row-level circuit, wherein the input end of the bias voltage generating circuit is connected with the output end of the row-level circuit, the input end of the column-level analog front-end circuit is connected with the output end of the bias voltage generating circuit, the row-level circuit comprises row-level mirror image pixels and row selection switches, and the column-level analog front-end circuit comprises blind pixels; the row-level circuit is distributed in each pixel, selects a signal to be processed according to a row strobe signal of the time sequence generating circuit, and outputs a current signal to the column-level analog front-end circuit under the action of the bias voltage generating circuit so as to perform current-voltage conversion and output;

the column-level analog front-end circuit obtains two paths of currents according to the first bias voltage and the second bias voltage, performs transimpedance amplification on the difference between the two paths of generated currents and outputs the amplified current as an output voltage.

Optionally, the CMOS infrared sensing structure is fabricated on an upper layer or a same layer of a metal interconnection layer of the CMOS measurement circuitry.

Optionally, the sacrificial layer is used for enabling the CMOS infrared sensing structure to form a hollow structure, the material forming the sacrificial layer is silicon oxide, and the sacrificial layer is etched by using a post-CMOS process.

Optionally, the absorption plate is configured to absorb the infrared target signal and convert the infrared target signal into an electrical signal, the beam structure and the pillar structure are configured to transmit the electrical signal and to support and connect the absorption plate, the reflection layer is configured to reflect the infrared signal and form the resonant cavity with the thermal sensitive dielectric layer, the reflection layer includes at least one metal interconnection layer, and the pillar structure connects the beam structure and the CMOS measurement circuitry by using the metal interconnection process and the via process;

the absorption plate and the film layer of the beam structure are the same in composition, the absorption plate and the corresponding film layer of the beam structure are manufactured at the same time, the absorption plate sequentially comprises a first dielectric layer, an electrode layer and a second dielectric layer along the direction far away from the CMOS measuring circuit system, the material for forming the first dielectric layer comprises at least one of materials with the resistance temperature coefficient larger than a set value and prepared by amorphous silicon, amorphous germanium silicon or amorphous carbon, and the material for forming the second dielectric layer comprises at least one of materials with the resistance temperature coefficient larger than the set value and prepared by amorphous silicon, amorphous germanium silicon or amorphous carbon; alternatively, the first and second electrodes may be,

along the direction far away from the CMOS measuring circuit system, the beam structure sequentially comprises a first dielectric layer, an electrode layer and a second dielectric layer, the absorption plate sequentially comprises the first dielectric layer, the electrode layer, the heat sensitive dielectric layer and the second dielectric layer or the absorption plate sequentially comprises the first dielectric layer, the heat sensitive dielectric layer, the electrode layer and the second dielectric layer, the material for forming the first dielectric layer comprises at least one of amorphous silicon, amorphous germanium silicon, amorphous carbon or aluminum oxide, the material for forming the second dielectric layer comprises at least one of amorphous silicon, amorphous germanium-silicon, amorphous carbon or aluminum oxide, and the material for forming the heat sensitive dielectric layer comprises at least one of materials with the resistance temperature coefficient larger than a set value, which are prepared from titanium oxide, vanadium oxide, amorphous silicon, amorphous germanium-silicon, amorphous germanium-oxygen-silicon, germanium-silicon, germanium-oxygen-silicon, graphene, barium strontium titanate film, copper or platinum;

the electrode layer is made of at least one of titanium, titanium nitride, tantalum nitride, titanium-tungsten alloy, nickel-chromium alloy, nickel-platinum alloy, nickel-silicon alloy, nickel, chromium, platinum, tungsten, aluminum or copper.

Optionally, at least one hole-shaped structure is formed on the absorption plate, and the hole-shaped structure at least penetrates through the medium layer in the absorption plate; and/or at least one hole-shaped structure is formed on the beam structure, and the hole-shaped structure at least penetrates through the medium layer in the beam structure.

Optionally, the infrared detector with the microbridge structure further comprises a reinforcing structure, the reinforcing structure is arranged at a position corresponding to the columnar structure, and the reinforcing structure is used for enhancing the connection stability between the columnar structure and the suspended microbridge structure and between the columnar structure and the reflecting layer.

Optionally, the reinforcement structure is located on a side of the electrode layer adjacent to or remote from the CMOS measurement circuitry.

Optionally, the hermetic release barrier is located at an interface between the CMOS measurement circuitry and the CMOS infrared sensing structure and/or in the CMOS infrared sensing structure.

Optionally, the closed release isolation layer is located on the reflection layer and is arranged in contact with the reflection layer, and the electrode layer in the columnar structure is electrically connected with the reflection layer through a through hole penetrating through the closed release isolation layer;

the closed release isolation layer comprises at least one dielectric layer, and the material for forming the closed release isolation layer comprises at least one of silicon carbide, silicon carbonitride, silicon nitride, amorphous silicon, amorphous germanium-silicon, germanium, silicon-germanium alloy, amorphous carbon or aluminum oxide.

Optionally, the microbridge structure infrared detector is based on a 3nm, 7nm, 10nm, 14nm, 22nm, 28nm, 32nm, 45nm, 65nm, 90nm, 130nm, 150nm, 180nm, 250nm or 350nm CMOS process;

the metal connecting wire material forming the metal interconnection layer comprises at least one of aluminum, copper, tungsten, titanium, nickel, chromium, platinum, silver, ruthenium or cobalt.

Compared with the prior art, the technical scheme provided by the embodiment of the disclosure has the following advantages:

the CMOS measurement circuit system and the CMOS infrared sensing structure are integrally prepared on the CMOS production line by utilizing the CMOS process, compared with the MEMS process, the CMOS does not have the process compatibility problem, the technical difficulty of the MEMS process is solved, and the transportation cost and the risk caused by the problems of transportation and the like can be reduced by adopting the CMOS process production line process to prepare the microbridge structure infrared detector; the infrared detector with the microbridge structure takes silicon oxide as a sacrificial layer, the silicon oxide is completely compatible with a CMOS (complementary metal oxide semiconductor) process, the preparation process is simple and easy to control, the CMOS process does not have the problem that polyimide of the sacrificial layer is not released cleanly to influence the vacuum degree of a detector chip, the subsequent film growth temperature is not limited by the material of the sacrificial layer, the multilayer process design of the sacrificial layer can be realized, the process is not limited, the planarization can be easily realized by using the sacrificial layer, and the process difficulty and the possible risks are reduced; the infrared detector with the microbridge structure prepared by the integrated CMOS process can realize the aims of high yield, low cost, high yield and large-scale integrated production of chips, and provides a wider application market for the infrared detector with the microbridge structure; the infrared detector with the microbridge structure based on the CMOS process can realize smaller size and thinner film thickness of the characteristic structure of the infrared detector with the microbridge structure, so that the infrared detector with the microbridge structure has larger duty ratio, lower thermal conductivity and smaller thermal capacity, and the infrared detector with the microbridge structure has higher detection sensitivity, longer detection distance and better detection performance; the infrared detector with the microbridge structure based on the CMOS process can enable the size of a pixel of the detector to be smaller, realize smaller chip area under the same array pixel and be more beneficial to realizing the miniaturization of a chip; the infrared detector with the microbridge structure based on the CMOS process has the advantages of mature process production line, higher process control precision, better meeting of design requirements, better product consistency, better contribution to circuit piece adjustment performance and industrial batch production. In addition, the infrared detector with the microbridge structure also comprises a metamaterial structure and/or a polarization structure, so that the absorption rate of the infrared detector with the microbridge structure to incident infrared electromagnetic waves is effectively improved, and the performance of the infrared detector with the microbridge structure is optimized.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the disclosure.

In order to more clearly illustrate the embodiments or technical solutions in the prior art of the present disclosure, the drawings used in the embodiments or technical solutions in the prior art description will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without inventive labor.

Fig. 1 is a schematic perspective structure diagram of an infrared detector pixel with a microbridge structure provided in an embodiment of the present disclosure;

fig. 2 is a schematic cross-sectional structure diagram of an infrared detector pixel with a microbridge structure provided in an embodiment of the present disclosure;

fig. 3 is a schematic cross-sectional structure diagram of another infrared detector pixel with a microbridge structure provided in an embodiment of the present disclosure;

FIG. 4 is a schematic cross-sectional structure diagram of an infrared detector pixel with another microbridge structure provided in an embodiment of the present disclosure;

fig. 5 is a schematic cross-sectional structure diagram of another infrared detector pixel with a microbridge structure provided in an embodiment of the present disclosure;

FIG. 6 is a schematic cross-sectional structure diagram of an infrared detector pixel with another microbridge structure provided in an embodiment of the present disclosure;

FIG. 7 is a schematic perspective view of an infrared detector pixel with another microbridge structure according to an embodiment of the present disclosure;

fig. 8 is a schematic perspective structure diagram of another infrared detector pixel with a microbridge structure provided in an embodiment of the present disclosure;

fig. 9 is a schematic perspective structure diagram of an infrared detector pixel with another microbridge structure provided in the embodiment of the present disclosure;

fig. 10 is a schematic perspective structure diagram of another infrared detector pixel with a microbridge structure provided in an embodiment of the present disclosure;

fig. 11 is a schematic top view of a polarization structure provided in an embodiment of the present disclosure;

fig. 12 is a schematic top view of another polarization structure provided in the embodiments of the present disclosure;

fig. 13 is a schematic top view of another polarization structure provided in an embodiment of the disclosure;

fig. 14 is a schematic cross-sectional structure diagram of an infrared detector pixel with another micro-bridge structure provided in an embodiment of the present disclosure;

FIG. 15 is a schematic cross-sectional structure diagram of an infrared detector pixel with another microbridge structure provided in an embodiment of the present disclosure;

fig. 16 is a schematic cross-sectional structure diagram of an infrared detector pixel with another microbridge structure provided in an embodiment of the present disclosure;

fig. 17 is a schematic cross-sectional structure diagram of an infrared detector pixel with another microbridge structure provided in an embodiment of the present disclosure;

FIG. 18 is a schematic cross-sectional structure diagram of an infrared detector pixel with another micro-bridge structure provided in an embodiment of the present disclosure;

fig. 19 is a schematic cross-sectional structure diagram of an infrared detector pixel with another microbridge structure provided in an embodiment of the present disclosure;

fig. 20 is a schematic structural diagram of a CMOS measurement circuitry according to an embodiment of the disclosure;

fig. 21 is a schematic cross-sectional structure diagram of an infrared detector pixel with another microbridge structure provided in the embodiment of the present disclosure;

fig. 22 is a schematic perspective structure diagram of another infrared detector pixel with a microbridge structure provided in the embodiment of the present disclosure.

Detailed Description

In order that the above objects, features and advantages of the present disclosure may be more clearly understood, aspects of the present disclosure will be further described below. It should be noted that the embodiments and features of the embodiments of the present disclosure may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present disclosure, but the present disclosure may be practiced otherwise than as described herein; it is to be understood that the embodiments disclosed in the specification are only a few embodiments of the present disclosure, and not all embodiments.

Fig. 1 is a schematic three-dimensional structure diagram of an infrared detector pixel with a microbridge structure provided in an embodiment of the present disclosure, and fig. 2 is a schematic cross-sectional structure diagram of an infrared detector pixel with a microbridge structure provided in an embodiment of the present disclosure. Referring to fig. 1 and 2, the microbridge structure infrared detector comprises a plurality of microbridge structure infrared detector pixels arranged in an array, the microbridge structure infrared detector based on the CMOS process comprises a CMOS measurement circuit system 1 and a CMOS infrared sensing structure 2, the CMOS measurement circuit system 1 and the CMOS infrared sensing structure 2 are both prepared by using the CMOS process, and the CMOS infrared sensing structure 2 is directly prepared on the CMOS measurement circuit system 1.

Specifically, the CMOS infrared sensing structure 2 is used for converting an external infrared signal into an electric signal and transmitting the electric signal to the CMOS measuring circuit system 1, and the CMOS measuring circuit system 1 reflects temperature information of a corresponding infrared signal according to the received electric signal, so that the temperature detection function of the infrared detector with the microbridge structure is realized. The CMOS measuring circuit system 1 and the CMOS infrared sensing structure 2 are both prepared by using a CMOS process, and the CMOS infrared sensing structure 2 is directly prepared on the CMOS measuring circuit system 1, namely, the CMOS measuring circuit system 1 is prepared by adopting the CMOS process, and then the CMOS infrared sensing structure 2 is continuously prepared by utilizing the CMOS process by utilizing parameters of various processes compatible with a CMOS production line and the production line.

Therefore, the CMOS measurement circuit system 1 and the CMOS infrared sensing structure 2 are integrally prepared on the CMOS production line by utilizing the CMOS process, compared with the MEMS process, the CMOS process has no process compatibility problem, the technical difficulty of the MEMS process is solved, and the transportation cost and the risk caused by the problems of transportation and the like can be reduced by adopting the CMOS production line process to prepare the microbridge structure infrared detector; the infrared detector with the microbridge structure takes silicon oxide as a sacrificial layer, the silicon oxide is completely compatible with a CMOS (complementary metal oxide semiconductor) process, the preparation process is simple and easy to control, the CMOS process does not have the problem that polyimide of the sacrificial layer is not released cleanly to influence the vacuum degree of a detector chip, the subsequent film growth temperature is not limited by the material of the sacrificial layer, the multilayer process design of the sacrificial layer can be realized, the process is not limited, the planarization can be easily realized by using the sacrificial layer, and the process difficulty and the possible risks are reduced; the infrared detector with the microbridge structure prepared by the integrated CMOS process can realize the aims of high yield, low cost, high yield and large-scale integrated production of chips, and provides a wider application market for the infrared detector with the microbridge structure; the infrared detector with the microbridge structure based on the CMOS process can realize smaller size and thinner film thickness of the characteristic structure, and the infrared detector with the microbridge structure has larger duty ratio, lower thermal conductivity and smaller thermal capacity, so that the infrared detector with the microbridge structure has higher detection sensitivity, longer detection distance and better detection performance; the infrared detector with the microbridge structure based on the CMOS process can enable the pixel size of the detector to be smaller, realize smaller chip area under the same array pixel and be more beneficial to realizing chip miniaturization; the micro-bridge structure infrared detector based on the CMOS process has the advantages of mature process production line, higher process control precision, better meeting design requirements, better product consistency, more contribution to circuit piece adjustment performance and more contribution to industrialized batch production.

Referring to fig. 1 and 2, the cmos infrared sensing structure 2 includes a resonant cavity formed by a reflective layer 4 and a heat sensitive dielectric layer, a suspended microbridge structure 40 controlling heat transfer, and a pillar structure 6 having an electrical connection and support function, the suspended microbridge structure 40 including an absorption plate 10 and a plurality of beam structures 11. Specifically, the CMOS infrared sensing structure 2 includes a reflective layer 4, a suspended micro-bridge structure 40 and a columnar structure 6 which are located on the CMOS measurement circuit system 1, the columnar structure 6 is located between the reflective layer 4 and the suspended micro-bridge structure 40, the reflective layer 4 includes a reflective plate 41 and a supporting base 42, and the suspended micro-bridge structure 40 is electrically connected with the CMOS measurement circuit system 1 through the columnar structure 6 and the supporting base 42.

Specifically, the columnar structure 6 is located between the reflective layer 4 and the suspended microbridge structure 40, and is used for supporting the suspended microbridge structure 40 after a sacrificial layer on the CMOS measurement circuit system 1 is released, the sacrificial layer is located between the reflective layer 4 and the suspended microbridge structure 40, the suspended microbridge structure 40 transmits an electrical signal converted from an infrared signal to the CMOS measurement circuit system 1 through the corresponding columnar structure 6 and the corresponding supporting base 42, the CMOS measurement circuit system 1 processes the electrical signal to reflect temperature information, and non-contact infrared temperature detection of the infrared detector of the microbridge structure is achieved. The CMOS infrared sensing structure 2 outputs a positive electric signal and a ground electric signal through different electrode structures, the positive electric signal and the ground electric signal are transmitted to a supporting base 42 electrically connected with the columnar structures 6 through different columnar structures 6, fig. 1 and 2 exemplarily show that the direction parallel to the CMOS measuring circuit system 1 is along, the CMOS infrared sensing structure 2 comprises two columnar structures 6, one columnar structure 6 can be arranged for transmitting the positive electric signal, the other columnar structure 6 is arranged for transmitting the ground electric signal, the CMOS infrared sensing structure 2 also comprises four columnar structures 6, the four columnar structures 6 can be pairwise arranged into a group to respectively transmit the positive electric signal and the ground electric signal, the micro-bridge infrared detector comprises a plurality of micro-bridge infrared detector pixels arranged in an array, the four columnar structures 6 can also select two columnar structures 6 to respectively transmit the positive electric signal and the ground electric signal, and the other two columnar structures 6 supply the adjacent micro-bridge infrared detector pixels to transmit the electric signals. In addition, the reflecting layer 4 includes a reflecting plate 41 and a supporting base 42, a part of the reflecting layer 4 is used as a dielectric medium electrically connected with the CMOS measuring circuit system 1 through the columnar structure 6, that is, the supporting base 42, the reflecting plate 41 is used for reflecting infrared rays to the suspended microbridge structure 40, and the secondary absorption of the infrared rays is realized by matching with a resonant cavity formed between the reflecting layer 4 and the suspended microbridge structure 40, so as to improve the infrared absorption rate of the microbridge structure infrared detector and optimize the infrared detection performance of the microbridge structure infrared detector.

Combine fig. 1 and fig. 2, columnar structure 6 is hollow columnar structure, forms hollow structure at columnar structure 6 position promptly, and hollow columnar structure is favorable to reducing columnar structure 6's thermal conductance, and then reduces the influence of the heat-conduction that columnar structure 6 produced to the signal of telecommunication that unsettled microbridge structure 40 generated, is favorable to promoting microbridge structure infrared detector pixel and including this microbridge structure infrared detector pixel's infrared detection performance. Referring to fig. 1 and 2, the suspended micro-bridge structure 40 may include an absorption plate 10 and a plurality of beam structures 11, and fig. 1 and 2 exemplarily set the suspended micro-bridge structure 40 to include two beam structures 11, the absorption plate 10 being used to convert an infrared signal into an electrical signal and being electrically connected to the corresponding pillar structures 6 through the corresponding beam structures 11. The suspended micro-bridge structure 40 comprises an absorption plate 10 and a plurality of beam structures 11, the columnar structure 6 at least comprises an electrode layer 14, the absorption plate 10 and the beam structures 11 at least comprise a first medium layer 13, an electrode layer 14 and a second medium layer 15, the electrode layer 14 is located between the first medium layer 13 and the second medium layer 15, and the first medium layer 13 is located on one side, close to the CMOS measurement circuit system 1, of the electrode layer 14.

Exemplarily, as shown in fig. 2, the film structures of the absorption plate 10 and the beam structure 11 may be set to be the same and the corresponding films of the absorption plate 10 and the beam structure 11 are simultaneously fabricated, the absorption plate 10 is set to sequentially include a first dielectric layer 13, an electrode layer 14 and a second dielectric layer 15 along a direction away from the CMOS measurement circuit system 1, that is, along a direction away from the CMOS measurement circuit system 1, the beam structure 11 sequentially includes a first dielectric layer 13, an electrode layer 14 and a second dielectric layer 15, fig. 2 is exemplarily set to be along a direction away from the CMOS measurement circuit system 1, the column structure 6 also sequentially includes a first dielectric layer 13, an electrode layer 14 and a second dielectric layer 15, the first dielectric layer 13 in the beam structure 11, the first dielectric layer 13 in the absorption plate 10 and the first dielectric layer 13 in the column structure 6 may be simultaneously fabricated, the second dielectric layer 15 in the beam structure 11, the second dielectric layer 15 in the absorption plate 10 and the second dielectric layer 15 in the column structure 6 may be simultaneously fabricated, the electrode layer 14 in the beam structure 11, the electrode layer 14 in the column structure 10 and the electrode layer 14 in the column structure 6 may be simultaneously fabricated to simplify the fabrication process of the infrared detector. In addition, the electrode layer 14 in the absorber plate 10 is electrically connected with the electrode layer 14 in the beam structure 11, the electrode layer 14 in the columnar structure 6, and the support pedestal 42 to ensure that the electrical signal generated by the suspended micro-bridge structure 40 is transmitted to the CMOS measurement circuitry 1.

The material constituting the first dielectric layer 13 includes at least one of materials having a temperature coefficient of resistance greater than a set value, which are made of amorphous silicon, amorphous germanium, amorphous silicon germanium, or amorphous carbon, and the material constituting the second dielectric layer 15 includes at least one of materials having a temperature coefficient of resistance greater than a set value, which is made of amorphous silicon, amorphous germanium, amorphous silicon germanium, or amorphous carbon, and the set value may be, for example, 0.015/K. Therefore, the first dielectric layer 13 serves as a support layer and a heat sensitive dielectric layer, and the second dielectric layer 15 serves as a passivation layer and a heat sensitive dielectric layer, so that the thickness of the absorption plate 10 is reduced, the heat conductivity of the beam structure 11 is reduced, and the preparation process of the infrared detector with the microbridge structure is simplified. Specifically, the supporting layer is used for supporting an upper film layer in the suspended micro-bridge structure 40 after the sacrificial layer is released, the heat sensitive medium layer is used for converting infrared temperature detection signals into infrared detection electric signals, the electrode layer 14 is used for transmitting the infrared detection electric signals converted by the heat sensitive medium layer to the CMOS measurement circuit system 1 through the beam structures 11 on the left side and the right side, the two beam structures 11 respectively transmit positive and negative signals of the infrared detection electric signals, a reading circuit in the CMOS measurement circuit system 1 realizes non-contact infrared temperature detection through analysis of the acquired infrared detection electric signals, and the passivation layer is used for protecting the electrode layer 14 from oxidation or corrosion. In addition, corresponding to the absorption plate 10 and the beam structure 11, the electrode layer 14 is located in a closed space formed by the first dielectric layer 13, namely the support layer, and the second dielectric layer 15, namely the passivation layer, so that the protection of the electrode layer 14 in the absorption plate 10 and the beam structure 11 is realized.

Illustratively, as shown in fig. 2, the thickness of the first medium layer 13 in the beam structure 11 may be set to be not more than the thickness of the first medium layer 13 in the absorber plate 10; and/or the thickness of the second dielectric layer 15 in the beam structure 11 is not greater than the thickness of the second dielectric layer 15 in the absorption plate 10, that is, the thickness of the first dielectric layer 13 in the beam structure 11 is set to be less than or equal to the thickness of the first dielectric layer 13 in the absorption plate 10, or the thickness of the second dielectric layer 15 in the beam structure 11 is set to be less than or equal to the thickness of the second dielectric layer 15 in the absorption plate 10, or the thickness of the first dielectric layer 13 in the beam structure 11 is set to be less than or equal to the thickness of the first dielectric layer 13 in the absorption plate 10 and the thickness of the second dielectric layer 15 in the beam structure 11 is set to be less than or equal to the thickness of the second dielectric layer 15 in the absorption plate 10.

Specifically, the first dielectric layer 13 in the beam structure 11 may be etched more with respect to the first dielectric layer 13 in the absorber plate 10 when etching the first dielectric layer 13 in the beam structure 11, or may be made thicker with respect to the first dielectric layer 13 in the beam structure 11 when making the first dielectric layer 13 in the absorber plate 10, so that the thickness of the first dielectric layer 13 in the beam structure 11 is smaller than the thickness of the first dielectric layer 13 in the absorber plate 10. Likewise, the second dielectric layer 15 in the beam structure 11 is etched slightly with respect to the second dielectric layer 15 in the absorber plate 10 when etching the second dielectric layer 15 in the beam structure 11, or the second dielectric layer 15 in the beam structure 11 is made thicker when making the second dielectric layer 15 in the absorber plate 10, so that the thickness of the second dielectric layer 15 in the beam structure 11 is smaller than the thickness of the second dielectric layer 15 in the absorber plate 10. Thus, by setting the thickness of the first medium layer 13 in the beam structure 11 to be not more than the thickness of the first medium layer 13 in the absorber plate 10; and/or, the thickness of the second dielectric layer 15 in the beam structure 11 is not greater than the thickness of the second dielectric layer 15 in the absorption plate 10, so that the total thickness of the beam structure 11 is not greater than the total thickness of the absorption plate 10, which is beneficial to further reducing the thermal conductivity of the beam structure 11, further reducing the influence of the thermal conductivity generated by the beam structure 11 on the electrical signal generated by the suspended micro-bridge structure 40, and being beneficial to improving the infrared detection performance of the micro-bridge structure infrared detector pixel and the micro-bridge structure infrared detector comprising the micro-bridge structure infrared detector pixel.

Fig. 3 is a schematic cross-sectional structure diagram of another infrared detector pixel with a microbridge structure provided in the embodiment of the present disclosure. Different from the infrared detector pixel with the micro-bridge structure shown in fig. 2, the infrared detector pixel with the micro-bridge structure shown in fig. 3 is arranged along a direction away from the CMOS measurement circuit system 1, the beam structure 11 sequentially includes a first dielectric layer 13, an electrode layer 14 and a second dielectric layer 15, the absorption plate 10 sequentially includes the first dielectric layer 13, the electrode layer 14, a sensitive dielectric layer 12 and the second dielectric layer 15, or the absorption plate 10 sequentially includes the first dielectric layer 13, the heat sensitive dielectric layer 12, the electrode layer 14 and the second dielectric layer 15, that is, the heat sensitive dielectric layer 12 of the absorption plate 10 may be arranged at a side of the electrode layer 14 away from the CMOS measurement circuit system 1, the heat sensitive dielectric layer 12 of the absorption plate 10 may also be arranged at a side of the electrode layer 14 close to the CMOS measurement circuit system 1, fig. 3 is exemplarily arranged along a direction away from the CMOS measurement circuit system 1, the absorption plate 10 sequentially includes the first dielectric layer 13, the electrode layer 14, the sensitive dielectric layer 12 and the second dielectric layer 15, the first dielectric layer 13 in the beam structure 11 and the first dielectric layer 13 in the absorption plate 10 may be arranged at the same time as the first dielectric layer 13 in the absorption plate 10, the beam structure 15 and the second dielectric layer 15 in the absorption plate 10, and the infrared detector pixel structure 14 are manufactured at the same time, and the infrared detector pixel structure 14 are simplified, and the infrared detector are manufactured in the infrared detector. In addition, the electrode layer 14 in the absorber plate 10 is electrically connected with the electrode layer 14 in the beam structure 11, the electrode layer 14 in the columnar structure 6, and the support pedestal 42 to ensure that the electrical signal generated by the suspended micro-bridge structure 40 is transmitted to the CMOS measurement circuitry 1.

As shown in fig. 3, the material forming the first dielectric layer 13 includes at least one of amorphous silicon, amorphous germanium, amorphous silicon germanium, amorphous carbon or aluminum oxide, the material forming the second dielectric layer 15 includes at least one of amorphous silicon, amorphous germanium, amorphous silicon germanium, amorphous carbon or aluminum oxide, the material forming the thermally sensitive dielectric layer 12 includes at least one of materials having a temperature coefficient of resistance greater than a predetermined value, which is prepared from titanium oxide, vanadium oxide, amorphous silicon, amorphous germanium, amorphous silicon germanium oxide, silicon, germanium, silicon germanium oxide, graphene, a barium strontium titanate film, copper or platinum, and the predetermined value may be, for example, 0.015/K. Specifically, the first dielectric layer 13 serves as a supporting layer, the second dielectric layer 15 serves as a passivation layer, the supporting layer is used for supporting an upper film layer in the suspended micro-bridge structure 40 after the sacrificial layer is released, the heat-sensitive dielectric layer 12 is used for converting infrared temperature detection signals into infrared detection electric signals, the electrode layer 14 is used for transmitting the infrared detection electric signals converted from the heat-sensitive dielectric layer 12 to the CMOS measurement circuit system 1 through the beam structures 11 on the left side and the right side, the two beam structures 11 respectively transmit positive and negative signals of the infrared detection electric signals, a reading circuit in the CMOS measurement circuit system 1 realizes non-contact infrared temperature detection through analysis of the acquired infrared detection electric signals, and the passivation layer is used for protecting the electrode layer 14 from oxidation or corrosion. In addition, corresponding to the absorption plate 10 and the beam structure 11, the electrode layer 14 is located in a closed space formed by the first dielectric layer 13, namely the support layer, and the second dielectric layer 15, namely the passivation layer, so that the protection of the electrode layer 14 in the absorption plate 10 and the beam structure 11 is realized.

As shown in fig. 3, since the beam structure 11 includes the first dielectric layer 13, the electrode layer 14 and the second dielectric layer 15, the absorption plate 10 includes the first dielectric layer 13, the electrode layer 14, the heat sensitive dielectric layer 12 and the second dielectric layer 15, and under the condition that the thicknesses of the same films are the same, the total thickness of the beam structure 11 is smaller than that of the absorption plate 10, which is beneficial to further reducing the thermal conductivity of the beam structure 11, further reducing the influence of the thermal conductivity generated by the beam structure 11 on the electrical signal generated by the suspended microbridge structure 40, and being beneficial to improving the infrared detection performance of the microbridge structure infrared detector pixel and the microbridge structure infrared detector including the microbridge structure infrared detector pixel. Exemplarily, as shown in fig. 3, the thickness of the first medium layer 13 in the beam structure 11 may also be set not more than the thickness of the first medium layer 13 in the absorber plate 10; and/or the thickness of the second medium layer 15 in the beam structure 11 is not greater than the thickness of the second medium layer 15 in the absorption plate 10, that is, the thickness of the first medium layer 13 in the beam structure 11 is set to be less than or equal to the thickness of the first medium layer 13 in the absorption plate 10, or the thickness of the second medium layer 15 in the beam structure 11 is set to be less than or equal to the thickness of the second medium layer 15 in the absorption plate 10, or the thickness of the first medium layer 13 in the beam structure 11 is set to be less than or equal to the thickness of the first medium layer 13 in the absorption plate 10 and the thickness of the second medium layer 15 in the beam structure 11 is set to be less than or equal to the thickness of the second medium layer 15 in the absorption plate 10. Specifically, the first dielectric layer 13 in the beam structure 11 may be etched more with respect to the first dielectric layer 13 in the absorber plate 10 when etching the first dielectric layer 13 in the beam structure 11, or may be made thicker with respect to the first dielectric layer 13 in the beam structure 11 when making the first dielectric layer 13 in the absorber plate 10, so that the thickness of the first dielectric layer 13 in the beam structure 11 is smaller than the thickness of the first dielectric layer 13 in the absorber plate 10. Likewise, the second dielectric layer 15 in the beam structure 11 is etched with respect to the second dielectric layer 15 in the absorber plate 10 when etching the second dielectric layer 15 in the absorber plate 10, or the second dielectric layer 15 in the beam structure 11 is made thicker when making the second dielectric layer 15 in the absorber plate 10, so that the thickness of the second dielectric layer 15 in the beam structure 11 is smaller than the thickness of the second dielectric layer 15 in the absorber plate 10. Thereby, the thickness of the first medium layer 13 in the beam structure 11 is set to be not more than the thickness of the first medium layer 13 in the absorber plate 10; and/or, the thickness of second dielectric layer 15 is not more than the thickness of second dielectric layer 15 in the absorption board 10 in beam structure 11, in order to further ensure that the gross thickness of beam structure 11 is less than the gross thickness of absorption board 10, be favorable to further reducing beam structure 11's thermal conductance, and then reduce the influence of the thermal conductance that beam structure 11 produced to the signal of telecommunication that unsettled microbridge structure 40 generated, be favorable to promoting microbridge structure infrared detector pixel and including the infrared detector's of microbridge structure infrared detector's infrared detection performance.

Illustratively, the material constituting the electrode layer 14 may be at least one of titanium, titanium nitride, tantalum nitride, titanium tungsten alloy, nickel chromium alloy, nickel platinum alloy, nickel silicon alloy, nickel, chromium, platinum, tungsten, aluminum or copper, and particularly when at least one of titanium, titanium nitride, tantalum or tantalum nitride is used as the material of the electrode layer 14, it is preferable to provide that the electrode layer 14 is covered by the first dielectric layer 13 and the second dielectric layer 15, so as to prevent the electrode layer 14 from being affected by the etching process.

Fig. 4 is a schematic cross-sectional structure diagram of another infrared detector pixel with a microbridge structure provided in an embodiment of the present disclosure. Different from the micro-bridge structure infrared detector pixel with the structure shown in fig. 2 and 3, the micro-bridge structure infrared detector pixel with the structure shown in fig. 4 is exemplarily arranged along a direction away from the CMOS measurement circuit system 1, the columnar structure 6 sequentially includes the electrode layer 14 and the second dielectric layer 15, the second dielectric layer 15 in the beam structure 11, the second dielectric layer 15 in the absorption plate 10 and the second dielectric layer 15 in the columnar structure 6 can be simultaneously manufactured, and the electrode layer 14 in the beam structure 11, the electrode layer 14 in the absorption plate 10 and the electrode layer 14 in the columnar structure 6 are simultaneously manufactured, so that the manufacturing process of the micro-bridge structure infrared detector pixel is simplified, and the manufacturing process of the micro-bridge structure infrared detector is further simplified. In addition, the electrode layer 14 in the absorber plate 10 is electrically connected with the electrode layer 14 in the beam structure 11, the electrode layer 14 in the pillar structure 6, and the support pedestal 42 to ensure that the electrical signal generated by the suspended micro-bridge structure 40 is transmitted to the CMOS measurement circuitry 1.

Fig. 5 is a schematic cross-sectional structure diagram of another infrared detector pixel with a microbridge structure provided in an embodiment of the present disclosure. Different from the micro-bridge structure infrared detector pixel with the structure shown in fig. 2 to 4, the micro-bridge structure infrared detector pixel with the structure shown in fig. 5 is exemplarily arranged along a direction away from the CMOS measurement circuit system 1, the columnar structure 6 sequentially includes the first dielectric layer 13 and the electrode layer 14, the first dielectric layer 13 in the beam structure 11, the first dielectric layer 13 in the absorption plate 10 and the first dielectric layer 13 in the columnar structure 6 can be simultaneously manufactured, and the electrode layer 14 in the beam structure 11, the electrode layer 14 in the absorption plate 10 and the electrode layer 14 in the columnar structure 6 are simultaneously manufactured, so as to simplify a manufacturing process of the micro-bridge structure infrared detector pixel and further simplify a manufacturing process of the micro-bridge structure infrared detector. In addition, the electrode layer 14 in the absorber plate 10 is electrically connected with the electrode layer 14 in the beam structure 11, the electrode layer 14 in the columnar structure 6, and the support pedestal 42 to ensure that the electrical signal generated by the suspended micro-bridge structure 40 is transmitted to the CMOS measurement circuitry 1.

Fig. 6 is a schematic cross-sectional structure diagram of another infrared detector pixel with a microbridge structure provided in an embodiment of the present disclosure. Different from the micro-bridge structure infrared detector pixel with the structure shown in fig. 2 to 5, the micro-bridge structure infrared detector pixel with the structure shown in fig. 6 exemplarily sets that the columnar structure 6 only includes the electrode layer 14, and can set that the electrode layer 14 in the beam structure 11, the electrode layer 14 in the absorption plate 10 and the electrode layer 14 in the columnar structure 6 are simultaneously manufactured, so as to simplify the manufacturing process of the micro-bridge structure infrared detector pixel and further simplify the manufacturing process of the micro-bridge structure infrared detector. In addition, the electrode layer 14 in the absorber plate 10 is electrically connected with the electrode layer 14 in the beam structure 11, the electrode layer 14 in the columnar structure 6, and the support pedestal 42 to ensure that the electrical signal generated by the suspended micro-bridge structure 40 is transmitted to the CMOS measurement circuitry 1. It should be noted that, the film included in the pillar structure 6 is not specifically limited in the embodiments of the present disclosure, and it is sufficient to ensure that the pillar structure 6 at least includes the electrode layer 14 to realize the transmission of the electrical signal from the suspended micro-bridge structure 40 to the supporting base 42.

The infrared detector with the microbridge structure further includes a metamaterial structure and/or a polarization structure, the metamaterial structure is at least one metal interconnection layer, and the polarization structure is at least one metal interconnection layer, with reference to fig. 1 to 6, the metamaterial structure or the polarization structure may be at least one metal interconnection layer on a side of the first dielectric layer 13 close to the CMOS measurement circuit system 1, for example, the metal interconnection layer forming the metamaterial structure or the polarization structure may be located on a side of the first dielectric layer 13 close to the CMOS measurement circuit system 1 and in contact with the first dielectric layer 13, that is, the metal interconnection layer is located at the lowest part of the suspended microbridge structure 40. For example, the meta-material structure or the polarization structure may also be at least one metal interconnection layer on the side of the second dielectric layer 15 away from the CMOS measurement circuitry 1, and for example, the metal interconnection layer constituting the meta-material structure or the polarization structure may be located on the side of the second dielectric layer 15 away from the CMOS measurement circuitry 1 and in contact with the second dielectric layer 15, that is, the metal interconnection layer is located at the uppermost portion of the suspended microbridge structure 40. Illustratively, the metamaterial structure or the polarization structure may also be at least one metal interconnection layer located between the first dielectric layer 13 and the second dielectric layer 15 and electrically insulated from the electrode layer 14, for example, the metal interconnection layer constituting the metamaterial structure or the polarization structure may be located between the first dielectric layer 13 and the electrode layer 14 and electrically insulated from the electrode layer 14 or located between the second dielectric layer 15 and the electrode layer 14 and electrically insulated from the electrode layer 14. Illustratively, the electrode layer 14 may also be provided as a metamaterial structure layer or a polarization structure, i.e., a patterned structure of the metamaterial structure or the polarization structure may be formed on the electrode layer 14.

Exemplarily, fig. 7 is a schematic perspective view of a pixel of another infrared detector with a microbridge structure according to an embodiment of the present disclosure, and as shown in fig. 7, a metal interconnection layer forming a metamaterial structure may include a plurality of metal repeating units 20 arranged in an array, each metal repeating unit 20 includes two L-shaped patterned structures 21 arranged diagonally, and an infrared absorption spectrum band of the infrared detector with a microbridge structure is in a 3-30 μm band. As shown in fig. 8, a plurality of patterned hollow structures 22 arranged in an array are disposed on the metal interconnection layer forming the metamaterial structure, the patterned hollow structures 22 are in an open ring shape, and at this time, the infrared absorption spectrum band of the infrared detector with the microbridge structure is in a band of 3 micrometers to 30 micrometers. As shown in fig. 9, a plurality of straight-line strip structures 23 and a plurality of folded strip structures 24 are disposed on the metal interconnection layer forming the metamaterial structure, and the straight-line strip structures 23 and the folded strip structures 24 are alternately arranged in a direction perpendicular to the straight-line strip structures 23, where an infrared absorption spectrum band of the microbridge structure infrared detector is a band from 8 micrometers to 24 micrometers. Or as shown in fig. 10, a plurality of patterned hollow structures 25 arranged in an array are disposed on the metal interconnection layer forming the metamaterial structure, the patterned hollow structures 25 are regular hexagons, and the infrared absorption spectrum band of the infrared detector with the microbridge structure is 3-30 μm. It should be noted that, in the embodiments of the present disclosure, specific patterns on the metal interconnection layer constituting the metamaterial structure are not limited, and it is sufficient to ensure that repeated patterns can realize functions of the metamaterial structure or the polarization structure.

Specifically, the metamaterial is a material which is based on the generalized snell's law and performs electromagnetic or optical beam regulation and control by controlling wave front phase, amplitude and polarization, and can be also called as a super surface or a super structure, wherein the super surface or the super structure is an ultrathin two-dimensional array plane, and the characteristics of electromagnetic waves such as phase, polarization mode, propagation mode and the like can be flexibly and effectively manipulated. The present disclosure forms an electromagnetic metamaterial structure by using the patterned structure as shown in fig. 7 to fig. 10, that is, an artificial composite structure or a composite material having an extraordinary electromagnetic property is formed, so as to implement clipping of electromagnetic waves and light waves, thereby obtaining an electromagnetic wave absorption special device.

Fig. 11 is a schematic top view of a polarization structure according to an embodiment of the present disclosure. As shown in fig. 11, the polarization structure 26 may include a plurality of gratings 27 arranged in sequence, an interval between adjacent gratings 27 is 10nm to 500nm, the gratings 27 may be linear as shown in fig. 11, or may be curved as shown in fig. 12 and 13, the gratings 27 in the polarization structure 26 may be rotated or combined at any angle, and the polarization structure 26 may be disposed such that the CMOS sensing structure absorbs polarized light in a specific direction. Illustratively, the grating 27 may be a structure formed by etching a metal thin film, i.e., a metal interconnection layer. Specifically, polarization is an important information of light, and polarization detection can expand the information quantity from three dimensions, such as light intensity, light spectrum and space, to seven dimensions, such as light intensity, light spectrum, space, polarization degree, polarization azimuth angle, polarization ellipse ratio and rotation direction, and since the polarization degree of the ground object background is far less than that of the artificial target, the infrared polarization detection technology has very important application in the field of space remote sensing. In the existing polarization detection system, a polarization element is independent from a detector, and a polarizing film needs to be added on a lens of the whole machine or a polarization lens needs to be designed. The existing polarization detection system, which acquires polarization information by rotating a polarization element, has disadvantages of complicated optical elements and complicated optical path system. In addition, the polarization image acquired by combining the polarizer and the detector needs to be processed by an image fusion algorithm, which is not only complex but also relatively inaccurate.

According to the embodiment of the disclosure, the polarization structure 26 and the uncooled microbridge structure infrared detector are monolithically integrated, so that monolithic integration of the polarization-sensitive microbridge structure infrared detector can be realized, difficulty of optical design is greatly reduced, an optical system is simplified, optical elements are reduced, and cost of the optical system is reduced. In addition, the image collected by the single-chip integrated polarized uncooled infrared detector with the micro-bridge structure is original infrared image information, and the CMOS measuring circuit system 1 can obtain accurate image information only by processing signals detected by the infrared detector with the micro-bridge structure without carrying out image fusion of the existing detector, so that the authenticity and the effectiveness of the image are greatly improved. In addition, polarization structure 26 also can be located above absorption plate 10 and not set up with absorption plate 10 contact, namely polarization structure 26 can be for being located the unsettled structure of unsettled microbridge structure 40 top, polarization structure 26 and unsettled microbridge structure 40 can adopt the mode of post connection support or the mode that adopts the bonding to support, polarization structure 26 can the one-to-one correspondence bonding with microbridge structure infrared detector pixel, also can adopt the mode of whole chip bonding. Therefore, the independent suspended metal grating structure cannot cause deformation of the infrared sensitive micro-bridge structure and cannot influence the heat-sensitive characteristic of the sensitive film. With reference to fig. 1 to 13, at least one hole structure may be formed on the absorption plate 10, wherein the hole structure penetrates through at least the medium layer in the absorption plate 10; and/or, at least one hole-shaped structure is formed on the beam structure 11, and the hole-shaped structure at least penetrates through the medium layer in the beam structure 11, that is, only the absorption plate 10, or only the beam structure 11, or both the absorption plate 10 and the beam structure 11 may be provided with the hole-shaped structure. For example, whether the hole structures on the absorption plate 10 or the beam structures 11 are circular hole structures, square hole structures, polygonal hole structures or irregular pattern hole structures, the shape of the hole structures on the absorption plate 10 and the beam structures 11 is not specifically limited in the embodiments of the present disclosure, and the number of the hole structures on the absorption plate 10 and the beam structures 11 is not specifically limited in the embodiments of the present disclosure.

Therefore, at least one hole-shaped structure is formed on the absorption plate 10, the hole-shaped structure at least penetrates through the medium layer in the absorption plate 10, a sacrificial layer which needs to be released finally is arranged between the reflection layer 4 and the absorption plate 10, the sacrificial layer needs to be corroded by chemical reagents at the end of the manufacturing process of the infrared detector with the microbridge structure when the sacrificial layer is released, the hole-shaped structure on the absorption plate 10 is beneficial to increasing the contact area between the chemical reagents for releasing and the sacrificial layer, and the release rate of the sacrificial layer is accelerated. In addition, the area of the absorption plate 10 is larger than that of the beam structure 11, the hole-shaped structure on the absorption plate 10 is beneficial to releasing the internal stress of the absorption plate 10, optimizing the planarization degree of the absorption plate 10, and being beneficial to improving the structural stability of the absorption plate 10, so that the structural stability of the whole infrared detector with the microbridge structure is improved. In addition, at least one hole-shaped structure is formed on the beam structure 11 and penetrates through the medium layer in the beam structure 11 at least, so that the thermal conductance of the beam structure 11 is further reduced, and the infrared detection sensitivity of the infrared detector with the microbridge structure is improved.

With reference to fig. 2, fig. 4, fig. 5, and fig. 6, the hole structures on the absorber plate 10 may be disposed to penetrate through the first dielectric layer 13 and the second dielectric layer 15 in the absorber plate 10, or the hole structures on the absorber plate 10 may be disposed to penetrate through the first dielectric layer 13, the electrode layer 14, and the second dielectric layer 15 in the absorber plate 10, and the hole structures on the beam structure 11 may penetrate through the first dielectric layer 13 and the second dielectric layer 15 in the beam structure 11 where the electrode layer 14 is not disposed, or the hole structures on the beam structure 11 may penetrate through the first dielectric layer 13, the electrode layer 14, and the second dielectric layer 15 in the beam structure 11. As shown in fig. 3, the hole structures on the absorber plate 10 may be provided through the first dielectric layer 13 and the second dielectric layer 15 in the absorber plate 10, or the hole structures on the absorber plate 10 may be provided through the first dielectric layer 13, the electrode layer 14, the heat-sensitive dielectric layer 12 and the second dielectric layer 15 in the absorber plate 10, or the hole structures on the beam structure 11 may be provided through the first dielectric layer 13 and the second dielectric layer 15 at positions where the electrode layer 14 is not provided in the beam structure 11, or the hole structures on the beam structure 11 may be provided through the first dielectric layer 13, the electrode layer 14 and the second dielectric layer 15 in the beam structure 11.

Fig. 14 is a schematic cross-sectional structure view of an infrared detector pixel with another micro-bridge structure provided in an embodiment of the disclosure, and fig. 15 is a schematic cross-sectional structure view of an infrared detector pixel with another micro-bridge structure provided in an embodiment of the disclosure. With reference to fig. 1 to 15, the infrared detector with micro-bridge structure may further include a reinforcing structure 16, the reinforcing structure 16 is disposed at a position corresponding to the pillar structure 6, the reinforcing structure 16 is configured to enhance the connection stability between the pillar structure 6 and the suspended micro-bridge structure 40, especially, between the pillar structure 11, and is configured to enhance the connection stability between the pillar structure 6 and the reflective layer 4, especially, between the pillar structure 6 and the supporting base 42, that is, the reinforcing structure 16 may effectively enhance the mechanical stability between the pillar structure 6 and the suspended micro-bridge structure 40, especially, between the pillar structure 11, and enhance the mechanical stability between the pillar structure 6 and the reflective layer 4, especially, between the pillar structure 42, thereby enhancing the structural stability of the pixel of the infrared detector with micro-bridge structure and the infrared detector with micro-bridge structure including the pixel of the infrared detector with micro-bridge structure, and optimizing the electrical connection characteristics of the infrared detector with micro-bridge structure including the pixel of the infrared detector with micro-bridge structure.

Alternatively, the reinforcing structure 16 may be provided on a side of the electrode layer 14 remote from or adjacent to the CMOS measurement circuitry 1. Taking the infrared detector pixel with the structure shown in fig. 2 as an example, the reinforcing structure 16 may be located on a side of the second dielectric layer 15 away from the electrode layer 14; or the reinforcing structure 16 is arranged on one side of the second dielectric layer 15 adjacent to the electrode layer 14; or reinforcing structure 16 may be provided on the side of electrode layer 14 adjacent to first dielectric layer 13. Illustratively, as shown in fig. 14, the reinforcing structure 16 is disposed on a side of the second dielectric layer 15 away from the electrode layer 14, and the reinforcing structure 16 is disposed in contact with the second dielectric layer 15, where the reinforcing structure 16 may form a hollow structure in the hollow columnar structure as shown in fig. 14, and the reinforcing structure 16 may also form a solid structure in the hollow columnar structure as shown in fig. 15, that is, the reinforcing structure 16 may also fill the inner space surrounded by the second dielectric layer 15. Therefore, the reinforcing structure 16 covers the connecting position of the columnar structure 6 and the suspended micro-bridge structure 40, that is, covers the connecting position of the columnar structure 6 and the beam structure 11, which is equivalent to that a negative weight is added at the connecting position of the columnar structure 6 and the beam structure 11, and then the connecting stability between the columnar structure 6 and the suspended micro-bridge structure 40 is enhanced by the reinforcing structure 16. In addition, the reinforcing structure 16 also covers the connecting position of the columnar structure 6 and the supporting base 42, which is equivalent to that a negative weight is added at the connecting position of the columnar structure 6 and the supporting base 42, so that the reinforcing structure 16 is utilized to enhance the connection stability between the columnar structure 6 and the reflecting layer 4, especially the supporting base 42, further the electrical connection characteristic of the whole infrared detector with the microbridge structure is optimized, and the infrared detection performance of the infrared detector with the microbridge structure is optimized.

Fig. 16 is a schematic cross-sectional structure diagram of another infrared detector pixel with a microbridge structure provided in an embodiment of the present disclosure. Different from the micro-bridge infrared detector pixel with the structure shown in fig. 14 and 15, the micro-bridge infrared detector pixel with the structure shown in fig. 16 is provided with the reinforcing structure 16 on one side of the second dielectric layer 15 close to the electrode layer 14, that is, the reinforcing structure 16 can be arranged above the electrode layer 14, the reinforcing structure 16 is arranged in contact with the electrode layer 14, the reinforcing structure 16 is arranged between the electrode layer 14 and the second dielectric layer 15, and at this time, the reinforcing structure 16 forms a hollow structure in the hollow columnar structure. Similarly, the reinforcing structure 16 covers the connecting position of the columnar structure 6 and the suspended micro-bridge structure 40, that is, the connecting position of the columnar structure 6 and the beam structure 11, which is equivalent to adding a negative weight at the connecting position of the columnar structure 6 and the beam structure 11, so that the connecting stability between the columnar structure 6 and the suspended micro-bridge structure 40 is enhanced by the reinforcing structure 16. In addition, the reinforcing structure 16 also covers the connecting position of the columnar structure 6 and the supporting base 42, which is equivalent to that a negative weight is added at the connecting position of the columnar structure 6 and the supporting base 42, so that the reinforcing structure 16 is utilized to enhance the connection stability between the columnar structure 6 and the reflecting layer 4, especially the supporting base 42, further the electrical connection characteristic of the whole infrared detector with the microbridge structure is optimized, and the infrared detection performance of the infrared detector with the microbridge structure is optimized.

Fig. 17 is a schematic cross-sectional structure diagram of another infrared detector pixel with a microbridge structure provided in the embodiment of the present disclosure. Unlike the micro-bridge structure infrared detector pixel of the structures shown in fig. 14 to 16, the micro-bridge structure infrared detector pixel of the structure shown in fig. 17 is provided with the reinforcing structure 16 on the side of the electrode layer 14 adjacent to the first dielectric layer 13, that is, the reinforcing structure 16 may be located between the electrode layer 14 and the first dielectric layer 13 and the reinforcing structure 16 is provided in contact with the electrode layer 14. Similarly, the reinforcing structure 16 covers the connecting position of the columnar structure 6 and the suspended micro-bridge structure 40, that is, the connecting position of the columnar structure 6 and the beam structure 11, which is equivalent to adding a negative weight at the connecting position of the columnar structure 6 and the beam structure 11, so that the connecting stability between the columnar structure 6 and the suspended micro-bridge structure 40 is enhanced by the reinforcing structure 16. In addition, the reinforcing structure 16 also covers the connecting position of the columnar structure 6 and the supporting base 42, which is equivalent to that a negative weight is added at the connecting position of the columnar structure 6 and the supporting base 42, so that the reinforcing structure 16 is utilized to enhance the connection stability between the columnar structure 6 and the reflecting layer 4, especially the supporting base 42, further the electrical connection characteristic of the whole infrared detector with the microbridge structure is optimized, and the infrared detection performance of the infrared detector with the microbridge structure is optimized.

Illustratively, the material that may be provided to form reinforcing structure 16 includes at least one of amorphous silicon, amorphous germanium, amorphous silicon germanium, amorphous carbon, silicon carbide, aluminum oxide, silicon nitride, silicon carbonitride, silicon oxide, silicon, germanium, silicon germanium, aluminum, copper, tungsten, gold, platinum, nickel, chromium, titanium tungsten alloy, nickel-chromium alloy, nickel-platinum alloy, or nickel-silicon alloy. Specifically, the reinforcing structure 16 may be a single-layer structure deposited by a medium or a metal, or may be a multi-layer structure formed by stacking two, three, or more single-layer structures, where amorphous silicon, amorphous germanium, amorphous silicon germanium, amorphous carbon, silicon carbide, aluminum oxide, silicon nitride, silicon carbonitride, silicon, germanium, silicon germanium, aluminum, copper, tungsten, gold, platinum, nickel, chromium, titanium tungsten alloy, nickel-chromium alloy, nickel-platinum alloy, and nickel-silicon alloy are not corroded by gas-phase hydrogen fluoride, carbon tetrafluoride, or trifluoromethane, so that the reinforcing structure 16 is not affected during the process of corroding the sacrificial layer to release the sacrificial layer by gas-phase hydrogen fluoride, carbon tetrafluoride, or trifluoromethane, thereby ensuring that the mechanical strength of the joint between the columnar structure 6 and the suspended micro-bridge structure 40, and the joint between the columnar structure 6 and the reflective layer 4 is enhanced by the reinforcing structure 16, and the falling off between the beam structure 11 and the columnar structure 6 and between the reflective layer 4 due to loose connection is prevented, thereby improving the structural stability of the micro-bridge detector. In addition, when the material constituting the reinforcing structure 16 includes silicon oxide, since silicon oxide may be corroded by gas-phase hydrogen fluoride, carbon tetrafluoride, or trifluoromethane, it is preferable that the reinforcing structure 16 is disposed in a closed space surrounded by the first dielectric layer 13 and the second dielectric layer 15. It should be noted that, whether reinforcing structure 16 is a metal structure or a non-metal structure, it is necessary to ensure that the arrangement of reinforcing structure 16 does not affect the electrical connection relationship in the infrared detector with microbridge structure.

In addition, for the infrared detector pixel with the structure shown in fig. 4 to 6, it is also possible to arrange the reinforcing structure 16 on the side of the electrode layer 14 away from the CMOS measurement circuitry 1 with reference to fig. 14 to 16, or arrange the reinforcing structure 16 on the side of the electrode layer 14 adjacent to the CMOS measurement circuitry 1 with reference to fig. 17, which is not illustrated here any more, and the reinforcing structure 16 can also enhance the connection stability between the pillar structure 6 and the suspended microbridge structure 40 and between the pillar structure 6 and the reflective layer 4.

With reference to fig. 1 to 17, at least one hermetic release isolation layer 3 may be included above the CMOS measurement circuitry 1, and the hermetic release isolation layer 3 is used to protect the CMOS measurement circuitry 1 from process influence during the release etching process for fabricating the CMOS infrared sensing structure 2. Optionally, the hermetic release isolation layer 3 is located at an interface between the CMOS measurement circuit system 1 and the CMOS infrared sensing structure 2 and/or located in the CMOS infrared sensing structure 2, that is, the hermetic release isolation layer 3 may be located at an interface between the CMOS measurement circuit system 1 and the CMOS infrared sensing structure 2, or the hermetic release isolation layer 3 is located in the CMOS infrared sensing structure 2, or the hermetic release isolation layer 3 is located at an interface between the CMOS measurement circuit system 1 and the CMOS infrared sensing structure 2 and is provided with the hermetic release isolation layer 3 in the CMOS infrared sensing structure 2, the hermetic release isolation layer 3 is configured to protect the CMOS measurement circuit system 1 from erosion when the sacrificial layer is released by performing a corrosion process, the hermetic release isolation layer 3 at least includes one dielectric layer, and a dielectric material constituting the hermetic release isolation layer 3 includes at least one of silicon carbide, silicon carbonitride, silicon nitride, amorphous silicon, amorphous germanium, silicon, germanium, silicon germanium, a silicon germanium alloy, amorphous carbon, or aluminum oxide.

Fig. 2 to 17 exemplarily set the hermetic release barrier layer 3 in the CMOS infrared sensing structure 2, the hermetic release barrier layer 3 may be, for example, a dielectric layer or multiple dielectric layers above the metal interconnection layer of the reflective layer 4, where exemplarily set the hermetic release barrier layer 3 as a dielectric layer, the hermetic release barrier layer 3 is located on the reflective layer 4 and is disposed in contact with the reflective layer 4, and the electrode layer 14 in the pillar structure 6 is electrically connected to the reflective layer 4, i.e., the supporting base 42, through a through hole penetrating through the hermetic release barrier layer 3. Illustratively, the material constituting the hermetic release barrier layer 3 may include at least one of silicon carbide, silicon carbonitride, silicon nitride, amorphous silicon, amorphous germanium, amorphous silicon germanium, silicon, germanium, a silicon germanium alloy, amorphous carbon, or aluminum oxide, and the thickness of the hermetic release barrier layer 3 is smaller than that of the sacrificial layer. The resonant cavity of the infrared detector with the microbridge structure is realized by releasing the vacuum cavity after the silicon oxide sacrifice layer is released, the reflecting layer 4 is used as the reflecting layer of the resonant cavity, the sacrifice layer is positioned between the reflecting layer 4 and the suspended microbridge structure 40, and when at least one layer of closed release isolating layer 3 positioned on the reflecting layer 4 is arranged to select silicon carbide, silicon carbonitride, silicon nitride, amorphous silicon, amorphous germanium, amorphous silicon germanium, silicon, germanium, silicon germanium alloy, amorphous carbon or aluminum oxide and other materials as one part of the resonant cavity, the reflecting effect of the reflecting layer 4 is not influenced, the height of the resonant cavity can be reduced, the thickness of the sacrifice layer is further reduced, and the release difficulty of the sacrifice layer formed by silicon oxide is reduced. In addition, the sealing release isolation layer 3 and the columnar structure 6 are arranged to form a sealing structure, so that the CMOS measurement circuit system 1 is completely separated from the sacrificial layer, and the protection of the CMOS measurement circuit system 1 is realized.

Fig. 18 is a schematic cross-sectional structure diagram of another infrared detector pixel with a microbridge structure provided in the embodiment of the present disclosure. On the basis of the above embodiment, fig. 18 also sets the hermetic release isolation layer 3 in the CMOS infrared sensing structure 2, the hermetic release isolation layer 3 may be, for example, one or more dielectric layers located above the metal interconnection layer of the reflection layer 4, here, the hermetic release isolation layer 3 is exemplarily shown to be one dielectric layer, the hermetic release isolation layer 3 is located on the reflection layer 4 and is disposed in contact with the reflection layer 4, the electrode layer 14 in the pillar structure 6 is electrically connected to the reflection layer 4, that is, the supporting base 42, through a through hole penetrating through the hermetic release isolation layer 3, and the hermetic release isolation layer 3 covers the pillar structure 6, at this time, the material constituting the hermetic release isolation layer 3 may include at least one of silicon carbide, silicon carbonitride, silicon nitride, amorphous silicon, amorphous germanium, amorphous silicon germanium, silicon, germanium, silicon germanium alloy, amorphous carbon or aluminum oxide, and the thickness of the hermetic release isolation layer 3 is also smaller than the thickness of the sacrificial layer. Through setting up airtight release insulating layer 3 cladding columnar structure 6, can utilize airtight release insulating layer 3 as the support of columnar structure 6 department on the one hand, improve columnar structure 6's stability, guarantee columnar structure 6 and unsettled microbridge structure 40 and support base 42's electricity and be connected. On the other hand, the airtight release insulating layer 3 coating the columnar structure 6 can reduce the contact between the columnar structure 6 and the external environment, reduce the contact resistance between the columnar structure 6 and the external environment, further reduce the noise of the pixel of the infrared detector with the microbridge structure, improve the detection sensitivity of the infrared detection sensor, and simultaneously prevent the electrical breakdown of the exposed metal of the columnar structure 6. Similarly, the resonant cavity of the infrared detector with microbridge structure is realized by releasing the vacuum cavity after the silicon oxide sacrificial layer is released, the reflective layer 4 is used as the reflective layer of the resonant cavity, the sacrificial layer is positioned between the reflective layer 4 and the suspended microbridge structure 40, and when at least one layer of airtight release isolation layer 3 positioned on the reflective layer 4 is arranged to select silicon carbide, silicon carbonitride, silicon nitride, amorphous silicon, amorphous germanium, amorphous silicon germanium, silicon, germanium, silicon-germanium alloy, amorphous carbon or aluminum oxide and other materials as a part of the resonant cavity, the reflection effect of the reflective layer 4 is not affected, the height of the resonant cavity can be reduced, the thickness of the sacrificial layer is further reduced, and the release difficulty of the sacrificial layer formed by silicon oxide is reduced. In addition, the sealed release isolation layer 3 and the columnar structure 6 are arranged to form a sealed structure, so that the CMOS measurement circuit system 1 is completely separated from the sacrificial layer, and the CMOS measurement circuit system 1 is protected.

Fig. 19 is a schematic cross-sectional structure diagram of another infrared detector pixel with a microbridge structure provided in the embodiment of the disclosure. Unlike the infrared detector with the microbridge structure having the structure shown in the above embodiment, in the infrared detector with the microbridge structure having the structure shown in fig. 19, the hermetic release isolation layer 3 is located at the interface between the CMOS measurement circuit system 1 and the CMOS infrared sensing structure 2, for example, the hermetic release isolation layer 3 is located between the reflective layer 4 and the CMOS measurement circuit system 1, that is, the hermetic release isolation layer 3 is located below the metal interconnection layer of the reflective layer 4, and the supporting base 42 is electrically connected to the CMOS measurement circuit system 1 through a through hole penetrating through the hermetic release isolation layer 3. Specifically, since the CMOS measurement circuit system 1 and the CMOS infrared sensing structure 2 are both formed by using a CMOS process, after the CMOS measurement circuit system 1 is formed, a wafer including the CMOS measurement circuit system 1 is transferred to a next process to form the CMOS infrared sensing structure 2, since silicon oxide is a most commonly used dielectric material in the CMOS process, and silicon oxide is mostly used as an insulating layer between metal layers on the CMOS circuit, if no insulating layer is used as a barrier when silicon oxide with a thickness of about 2um is corroded, the circuit will be seriously affected, and in order to ensure that the silicon oxide medium on the CMOS measurement circuit system is not corroded when the silicon oxide of a sacrificial layer is released, a closed release insulating layer 3 is provided at an interface between the CMOS measurement circuit system 1 and the CMOS infrared sensing structure 2 according to the embodiment of the present disclosure. After the CMOS measuring circuit system 1 is prepared and formed, a closed release isolation layer 3 is prepared and formed on the CMOS measuring circuit system 1, the CMOS measuring circuit system 1 is protected by the closed release isolation layer 3, in order to ensure the electric connection between the support base 42 and the CMOS measuring circuit system 1, after the closed release isolation layer 3 is prepared and formed, a through hole is formed in the area of the closed release isolation layer 3 corresponding to the support base 42 by adopting an etching process, and the support base 42 is electrically connected with the CMOS measuring circuit system 1 through the through hole. In addition, the closed release isolation layer 3 and the support base 42 are arranged to form a closed structure, so that the CMOS measurement circuit system 1 is completely separated from the sacrificial layer, and the CMOS measurement circuit system 1 is protected.

Illustratively, the material provided to form hermetic release barrier layer 3 includes at least one of silicon carbide, silicon carbonitride, silicon nitride, amorphous silicon, amorphous germanium, amorphous silicon germanium, silicon, germanium, a silicon germanium alloy, amorphous carbon, or aluminum oxide. Specifically, silicon carbide, silicon carbonitride, silicon nitride, amorphous silicon, amorphous germanium, amorphous silicon germanium, silicon, germanium, a silicon germanium alloy, amorphous carbon, or aluminum oxide are all CMOS process corrosion-resistant materials, i.e., these materials are not corroded by the sacrificial layer release agent, so the hermetic release barrier layer 3 can be used to protect the CMOS measurement circuitry 1 from corrosion when the corrosion process is performed to release the sacrificial layer. In addition, the closed release isolation layer 3 covers the CMOS measurement circuit system 1, and the closed release isolation layer 3 can also be used for protecting the CMOS measurement circuit system 1 from being influenced by the process in the release etching process for manufacturing the CMOS infrared sensing structure 2. In addition, when being provided with at least one deck airtight release insulating layer 3 on reflection stratum 4, the material that sets up to constitute airtight release insulating layer 3 includes silicon, germanium, silicon germanium alloy, amorphous silicon, amorphous germanium, amorphous silicon germanium, amorphous carbon, carborundum, aluminium oxide, at least one in silicon nitride or the silicon carbonitride, when setting up airtight release insulating layer 3 and improving the stability of columnar structure 6, airtight release insulating layer 3 can hardly influence the reflection course in the resonant cavity, can avoid airtight release insulating layer 3 to influence the reflection course of resonant cavity, and then avoid airtight release insulating layer 3 to the influence of microbridge structure infrared detector detection sensitivity.

With reference to fig. 1 to 19, a CMOS fabrication process of the CMOS infrared sensing structure 2 includes a Metal interconnection process, a via process, an IMD (Inter Metal Dielectric) process, and an RDL (redistribution layer) process, where the CMOS infrared sensing structure 2 includes at least two Metal interconnection layers, at least two Dielectric layers, and a plurality of interconnection vias, the Dielectric layers include at least one sacrificial layer and one heat-sensitive Dielectric layer, the Metal interconnection layers include at least a reflective layer 4 and an electrode layer, the heat-sensitive Dielectric layer includes a thermal sensitive material having a resistance temperature coefficient greater than a predetermined value, for example, the resistance temperature coefficient may be greater than or equal to 0.015/K, the thermal sensitive material having a resistance temperature coefficient greater than the predetermined value forms the heat-sensitive Dielectric layer, and the heat-sensitive Dielectric layer is configured to convert a temperature change corresponding to infrared radiation absorbed by the thermal sensitive Dielectric layer into a resistance change, and further convert an infrared target signal into a signal capable of being electrically read through the CMOS measurement circuit system 1. In addition, the heat-sensitive medium layer comprises a heat-sensitive material with a resistance temperature coefficient larger than a set value, and the resistance temperature coefficient can be larger than or equal to 0.015/K, so that the detection sensitivity of the infrared detector with the microbridge structure can be improved.

Specifically, the metal interconnection process is used to achieve electrical connection between upper and lower metal interconnection layers, for example, to achieve electrical connection between the electrode layer 14 in the pillar structure 6 and the supporting base 42, the via process is used to form an interconnection via for connecting the upper and lower metal interconnection layers, for example, to form an interconnection via for connecting the electrode layer 14 in the pillar structure 6 and the supporting base 42, the IMD process is used to achieve isolation between the upper and lower metal interconnection layers, that is, electrical insulation, for example, electrical insulation between the absorbing plate 10 and the electrode layer 14 in the beam structure 11 and the reflective plate 41, the RDL process is a rewiring layer process, that is, a process in which a layer of metal is re-laid on top of the top metal of the circuit and has metal pillars, for example, tungsten pillars are electrically connected, the reflective layer 4 in the infrared detector with the microbridge structure can be re-prepared on the top metal of the CMOS measurement circuit system 1 by using the RDL process, and the supporting base 42 on the reflective layer 4 is electrically connected with the top metal of the CMOS measurement circuit system 1. In addition, as shown in fig. 2, the CMOS manufacturing process of the CMOS measurement circuit system 1 may also include a metal interconnection process and a via process, the CMOS measurement circuit system 1 includes metal interconnection layers 101, dielectric layers 102 and a silicon substrate 103 at the bottom, which are arranged at intervals, and the upper and lower metal interconnection layers 101 are electrically connected through vias 104.

With reference to fig. 1 to 19, the CMOS measurement circuit system 1 is configured to measure and process an array resistance value formed by one or more CMOS infrared sensing structures 2 and convert an infrared signal into an electrical image signal, and the microbridge structure infrared detector includes a plurality of microbridge structure infrared detector pixels arranged in an array, where each microbridge structure infrared detector pixel includes one CMOS infrared sensing structure 2. Specifically, the resonant cavity may be formed by a cavity between the reflective layer 4 and the heat-sensitive medium layer in the absorption plate 10, for example, the infrared light is reflected back and forth in the resonant cavity through the absorption plate 10, so as to improve the detection sensitivity of the infrared detector with microbridge structure, and due to the arrangement of the columnar structure 6, the beam structure 11 and the absorption plate 10 form the suspended microbridge structure 10 for controlling the heat transfer, and the columnar structure 6 is electrically connected to the supporting base 42 and the corresponding beam structure 11, and is used for supporting the suspended microbridge structure 40 located on the columnar structure 6.

Fig. 20 is a schematic structural diagram of a CMOS measurement circuit system according to an embodiment of the present disclosure. With reference to fig. 1 to 20, the cmos measurement circuit system 1 includes a bias generation circuit 7, a column-level analog front-end circuit 8 and a row-level circuit 9, an input end of the bias generation circuit 7 is connected to an output end of the row-level circuit 9, an input end of the column-level analog front-end circuit 8 is connected to an output end of the bias generation circuit 7, the row-level circuit 9 includes row-level mirror image elements Rsm and row selection switches K1, and the column-level analog front-end circuit 8 includes blind image elements RD; the row-level circuit 9 is distributed in each pixel, selects a signal to be processed according to a row strobe signal of the timing sequence generating circuit, and outputs a current signal to the column-level analog front-end circuit 8 under the action of the bias generating circuit 7 to perform current-voltage conversion output; the row-level circuit 9 outputs a third bias voltage VRsm to the bias generation circuit 7 when being controlled by the row selection switch K1 to be gated, the bias generation circuit 7 outputs a first bias voltage V1 and a second bias voltage V2 according to the input constant voltage and the third bias voltage VRsm, and the column-level analog front-end circuit 8 obtains two currents according to the first bias voltage V1 and the second bias voltage V2, performs transimpedance amplification on the difference between the two generated currents, and outputs the amplified currents as an output voltage.

Specifically, the row-level circuit 9 includes a row-level mirror image element Rsm and a row selection switch K1, and the row-level circuit 9 is configured to generate a third bias voltage VRsm according to a gating state of the row selection switch K1. Illustratively, the row-level image elements Rsm may be subjected to a shading process, so that the row-level image elements Rsm are subjected to a fixed radiation of a shading sheet having a temperature constantly equal to the substrate temperature, the row selection switch K1 may be implemented by a transistor, the row selection switch K1 is closed, and the row-level image elements Rsm are connected to the bias generation circuit 7, that is, the row-level circuit 9 outputs the third bias voltage VRsm to the bias generation circuit 7 when being controlled by the row selection switch K1 to be turned on. The bias generating circuit 7 may include a first bias generating circuit 71 and a second bias generating circuit 72, the first bias generating circuit 71 being configured to generate a first bias voltage V1 according to an input constant voltage, which may be, for example, a positive power supply signal with a constant voltage. The second bias generating circuit 72 may include a bias control sub-circuit 721 and a plurality of gate driving sub-circuits 722, the bias control sub-circuit 721 controlling the gate driving sub-circuits 722 to generate the corresponding second bias voltages V2, respectively, according to the third bias voltage VRsm.

The column-level analog front-end circuit 8 includes a plurality of column control sub-circuits 81, the column control sub-circuits 81 are disposed in correspondence with the gate driving sub-circuits 722, and exemplarily, the column control sub-circuits 81 may be disposed in one-to-one correspondence with the gate driving sub-circuits 722, and the gate driving sub-circuits 722 are configured to provide the second bias voltage V2 to the corresponding column control sub-circuits 81 according to their own gate states. For example, it may be set that when the gate driving sub-circuit 722 is gated, the gate driving sub-circuit 722 supplies the second bias voltage V2 to the corresponding column control sub-circuit 81; when the gate driving sub-circuit 722 is not gated, the gate driving sub-circuit 722 stops supplying the second bias voltage V2 to the corresponding column control sub-circuit 81.

The column-level analog front-end circuit 8 comprises an effective pixel RS and a blind pixel RD, the column control sub-circuit is used for generating a first current I1 according to a first bias voltage V1 and the blind pixel RD, generating a second current I2 according to a second bias voltage V2 and the effective pixel RS, performing transimpedance amplification on a difference value of the first current I1 and the second current I2 and outputting the difference value, and the row-level image pixel Rsm and the effective pixel RS have the same temperature drift amount under the same environment temperature.

Illustratively, the row-level image elements Rsm are thermally insulated from the CMOS measurement circuitry 1 and are shaded, and the row-level image elements Rsm are subjected to a fixed radiation from a shade sheet having a temperature constantly equal to the substrate temperature. The absorption plate 10 of the active pixel RS is thermally insulated from the CMOS measurement circuitry 1 and the active pixel RS receives external radiation. The absorbing plates 10 of the row-level mirror image elements Rsm and the effective elements RS are thermally insulated from the CMOS measuring circuit system 1, so that the row-level mirror image elements Rsm and the effective elements RS have a self-heating effect.

When the corresponding row-level mirror image element Rsm is gated by the row selection switch K1, the resistance value of both the row-level mirror image element Rsm and the effective pixel RS changes due to joule heat, but when the row-level mirror image element Rsm and the effective pixel RS are subjected to the same fixed radiation, the resistance value of the row-level mirror image element Rsm and the resistance value of the effective pixel RS are the same, the temperature coefficients of the row-level mirror image element Rsm and the temperature coefficient of the effective pixel RS are also the same, the temperature drift amounts of the row-level mirror image element Rsm and the effective pixel RS at the same environmental temperature are the same, the changes of the row-level mirror image element Rsm and the effective pixel RS at the same environmental temperature are synchronized, the characteristic that the temperature drift amounts of the row-level mirror image element Rsm and the effective pixel RS at the same environmental temperature are the utilized is favorable for effectively compensating the resistance value changes of the row-level mirror image element Rsm and the effective pixel RS due to the self-heating effect, and realizing the stable output of the CMOS measurement circuit system 1.

In addition, by arranging the second bias generating circuit 72 to include a bias control sub-circuit 721 and a plurality of gate driving sub-circuits 722, the bias control sub-circuit 721 is configured to control the gate driving sub-circuits 722 to generate corresponding second bias voltages V2 respectively according to the row control signal, so that each row of pixels has one path to drive the whole row of pixels in the row independently, the requirement for the second bias voltage V2 is reduced, that is, the driving capability of the bias generating circuit 7 is improved, and the CMOS measuring circuit system 1 is advantageously used to drive a larger-scale pixel array of the infrared detector with the microbridge structure. In addition, the specific detailed operation principle of the CMOS measurement circuit system 1 is well known to those skilled in the art and will not be described herein.

Alternatively, the CMOS infrared sensing structure 2 may be disposed on a metal interconnect layer of the CMOS measurement circuitry 1 or fabricated on the same layer. Specifically, the metal interconnection layer of the CMOS measurement circuitry 1 may be a top metal layer in the CMOS measurement circuitry 1, and in conjunction with fig. 1 to 19, the CMOS infrared sensing structure 2 may be fabricated on the top metal interconnection layer of the CMOS measurement circuitry 1, and the CMOS infrared sensing structure 2 is electrically connected to the CMOS measurement circuitry 1 through a supporting base 42 on the top metal interconnection layer of the CMOS measurement circuitry 1, so as to transmit the electrical signal converted by the infrared signal to the CMOS measurement circuitry 1.

Fig. 21 is a schematic cross-sectional structure diagram of another infrared detector pixel with a microbridge structure provided in an embodiment of the present disclosure. As shown in fig. 21, the CMOS infrared sensing structure 2 may also be prepared on the same layer as the metal interconnection layer of the CMOS measurement circuitry 1, that is, the CMOS measurement circuitry 1 and the CMOS infrared sensing structure 2 are arranged on the same layer, for example, as shown in fig. 21, the CMOS infrared sensing structure 2 may be arranged on one side of the CMOS measurement circuitry 1, and the top of the CMOS measurement circuitry 1 may also be provided with a hermetic release isolation layer 3 to protect the CMOS measurement circuitry 1.

Optionally, in conjunction with fig. 1 to 21, the sacrificial layer is used to form the CMOS infrared sensing structure 2 into a hollow structure, the material constituting the sacrificial layer is silicon oxide, and the sacrificial layer is etched by using a post-CMOS process. For example, the post-CMOS process may etch the sacrificial layer using at least one of gases having corrosive properties to silicon oxide, such as gaseous hydrogen fluoride, carbon tetrafluoride, and trifluoromethane. Specifically, a sacrificial layer (not shown in fig. 1 to 21) is provided between the reflective layer 4 and the suspended microbridge structure 40, and when the hermetic release isolation layer 3 is provided on the reflective layer 4, the sacrificial layer is provided between the hermetic release isolation layer 3 and the suspended microbridge structure 40, and the material constituting the sacrificial layer is silicon oxide, so as to be compatible with a CMOS process, and a post-CMOS process can be adopted, that is, the post-CMOS process corrodes the sacrificial layer to release the sacrificial layer in the final infrared detection chip product.

Optionally, the absorption plate 10 is used for absorbing the infrared target signal and converting the infrared target signal into an electrical signal, the absorption plate 10 includes a metal interconnection layer and at least one thermal sensitive medium layer, the metal interconnection layer in the absorption plate 10 is an electrode layer 14 in the absorption plate 10 for transmitting the electrical signal converted from the infrared signal. The beam structures 11 and the columnar structures 6 are used for transmitting electrical signals and for supporting and connecting the absorption plates 10, the electrode layer 14 in the absorption plates 10 includes two patterned electrode structures, the two patterned electrode structures output positive electrical signals and ground electrical signals respectively, and the positive electrical signals and the ground electrical signals are transmitted to the supporting base 42 electrically connected with the columnar structures 6 through the different beam structures 11 and the different columnar structures 6, and then transmitted to the CMOS measurement circuit system 1. The beam structure 11 comprises at least a metal interconnection layer, the metal interconnection layer in the beam structure 11 is an electrode layer 14 in the beam structure 11, and the electrode layer 14 in the beam structure 11 and the electrode layer 14 in the absorber plate 10 are electrically connected. The beam structure 11 and the CMOS measurement circuit system 1 are connected by the columnar structure 6 through a metal interconnection process and a through hole process, the upper side of the columnar structure 6 needs to be electrically connected to the electrode layer 14 in the beam structure 11 through a through hole penetrating through the sacrificial layer, the lower side of the columnar structure 6 needs to be electrically connected to the corresponding supporting base 42 through a through hole penetrating through the dielectric layer on the supporting base 42, and thus the electrode layer 14 in the beam structure 11 is electrically connected to the corresponding supporting base 42 through the corresponding columnar structure 6. The reflective plate 41 is used for reflecting infrared signals and forms a resonant cavity with the heat-sensitive medium layer, that is, the reflective plate 41 is used for reflecting infrared signals and forms a resonant cavity with the heat-sensitive medium layer, and the reflective layer 4 includes at least one metal interconnection layer, which is used for forming the supporting base 42 and also used for forming the reflective plate 41.

Optionally, with reference to fig. 1 to 21, at least one patterned metal interconnection layer may be disposed between the reflective layer 4 and the suspended micro-bridge structure 40, the patterned metal interconnection layer is located above or below the hermetic release isolation layer 3 and is electrically insulated from the reflective layer 4, and the patterned metal interconnection layer is used for adjusting a resonant mode of the infrared detector of the micro-bridge structure. Specifically, a Bragg reflector (Bragg reflector) is an optical device for enhancing reflection of light with different wavelengths by utilizing constructive interference of reflected light with different interfaces, and the Bragg reflector is composed of a plurality of 1/4 wavelength reflectors to realize efficient reflection of incident light with a plurality of wavelengths.

Illustratively, at least one patterned metal interconnect layer may be disposed on a side of the hermetic release barrier 3 away from the CMOS measurement circuitry 1 and/or at least one patterned metal interconnect layer may be disposed on a side of the hermetic release barrier 3 adjacent to the CMOS measurement circuitry 1. Illustratively, the patterned metal interconnection layer may include a plurality of metal repeating units arranged in an array, each metal repeating unit may include at least one of an L-shaped patterned structure, a circular structure, a sector-shaped structure, an oval structure, a circular ring structure, an open ring structure, or a polygonal structure arranged at two opposite corners, or the patterned metal interconnection layer may include a plurality of patterned hollow structures arranged in an array, and the patterned hollow structures may include at least one of a circular hollow structure, an open ring-shaped hollow structure, or a polygonal hollow structure.

Alternatively, it may be provided that the beam structure 11 and the absorber plate 10 are electrically connected at least at two ends, the CMOS infrared sensing structure 2 includes at least two columnar structures 6 and at least two support bases 42, and the electrode layer 14 includes at least two electrode terminals. Specifically, as shown in fig. 1, the beam structures 11 are electrically connected to two ends of the absorption plate 10, each beam structure 11 is electrically connected to one end of the absorption plate 10, the CMOS infrared sensing structure 2 includes two pillar structures 6, the electrode layer 14 includes at least two electrode terminals, at least a portion of the electrode terminals transmit positive electrical signals, and at least a portion of the electrode terminals transmit negative electrical signals, and the signals are transmitted to the supporting base 42 through the corresponding beam structures 11 and pillar structures 6.

Fig. 22 is a schematic perspective structure diagram of another infrared detector pixel with a microbridge structure provided in the embodiment of the present disclosure. As shown in fig. 22, the beam structures 11 may be electrically connected to four ends of the absorption plate 10, each beam structure 11 is electrically connected to two ends of the absorption plate 10, the CMOS infrared sensing structure 2 includes four pillar structures 6, one beam structure 11 connects two pillar structures 6, and the beam structure 11 may adopt a thermal symmetry structure, which is well known to those skilled in the art and will not be discussed herein. It should be noted that, in the embodiment of the present disclosure, the number of the connecting ends of the beam structure 11 and the absorbing plate 10 is not particularly limited, and it is sufficient that the beam structure 11 and the electrode terminal are respectively present, and the beam structure 11 is used for transmitting the electrical signal output by the corresponding electrode terminal.

Alternatively, the infrared detector with the microbridge structure can be configured based on a 3nm, 7nm, 10nm, 14nm, 22nm, 28nm, 32nm, 45nm, 65nm, 90nm, 130nm, 150nm, 180nm, 250nm or 350nm CMOS process, and the above dimensions represent process nodes of the integrated circuit, i.e., feature dimensions during the integrated circuit processing.

Alternatively, the metal wiring material constituting the metal interconnection layer in the microbridge structure infrared detector may be configured to include at least one of aluminum, copper, tungsten, titanium, nickel, chromium, platinum, silver, ruthenium, or cobalt, and for example, the material constituting the reflective layer 4 may be configured to include at least one of aluminum, copper, tungsten, titanium, nickel, chromium, platinum, silver, ruthenium, or cobalt. In addition, the CMOS measuring circuit system 1 and the CMOS infrared sensing structure 2 are both prepared by using a CMOS process, the CMOS infrared sensing structure 2 is directly prepared on the CMOS measuring circuit system 1, the radial side length of the columnar structure 6 can be more than or equal to 0.5um and less than or equal to 3um, the width of the beam structure 11, namely the width of a single line in the beam structure 11 is less than or equal to 0.3um, and the height of the resonant cavity is less than or equal to 2.5um.

It is noted that, in this document, relational terms such as "first" and "second," and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrases "comprising a component of' 8230; \8230;" does not exclude the presence of additional identical elements in the process, method, article, or apparatus that comprises the element.

The foregoing are merely exemplary embodiments of the present disclosure, which will enable those skilled in the art to understand or practice the present disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the disclosure. Thus, the present disclosure is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An infrared detector with a microbridge structure, comprising:

the CMOS manufacturing process of the CMOS infrared sensing structure comprises a metal interconnection process, a through hole process, an IMD (in-mold decoration) process and an RDL (remote description language) process, wherein the CMOS infrared sensing structure comprises at least two metal interconnection layers, at least two dielectric layers and a plurality of interconnection through holes, the two metal interconnection layers comprise a reflecting layer and an electrode layer, and the two dielectric layers comprise a sacrificial layer and a heat-sensitive dielectric layer; the thermal sensitive dielectric layer is used for converting temperature change corresponding to infrared radiation absorbed by the thermal sensitive dielectric layer into resistance change, and further converting an infrared target signal into a signal capable of realizing electric reading through the CMOS measuring circuit system;

the infrared detector with the microbridge structure further comprises a metamaterial structure and a polarization structure, wherein the metamaterial structure or the polarization structure is at least one metal interconnection layer on one side of the first dielectric layer close to the CMOS measuring circuit system, or at least one metal interconnection layer on one side of the second dielectric layer far away from the CMOS measuring circuit system, or at least one metal interconnection layer which is arranged between the first dielectric layer and the second dielectric layer and is electrically insulated from the electrode layer, or the electrode layer is used as a metamaterial structure layer or a polarization structure layer; wherein the polarization structure is monolithically integrated with the microbridge structure infrared detector;

at least one patterned metal interconnection layer is arranged between the reflection layer and the suspended micro-bridge structure, the patterned metal interconnection layer is positioned above or below the closed release isolation layer and is electrically insulated from the reflection layer, and the patterned metal interconnection layer is used for adjusting the resonance mode of the infrared detector of the micro-bridge structure;

2. The microbridge structure infrared detector of claim 1, wherein the CMOS infrared sensing structure is fabricated on top of or at the same level as a metal interconnect layer of the CMOS measurement circuitry.

3. The infrared detector with the microbridge structure according to claim 1, wherein the sacrificial layer is used for enabling the CMOS infrared sensing structure to form a hollow structure, the material of the sacrificial layer is silicon oxide, and the sacrificial layer is etched by a post-CMOS process.

4. The microbridge structure infrared detector of claim 1, wherein the absorption plate is used for absorbing the infrared target signal and converting the infrared target signal into an electrical signal, the beam structure and the pillar structure are used for transmitting the electrical signal and for supporting and connecting the absorption plate, the reflection layer is used for reflecting the infrared signal and forming the resonant cavity with the heat sensitive dielectric layer, the reflection layer comprises at least one metal interconnection layer, and the pillar structure connects the beam structure and the CMOS measurement circuitry by using the metal interconnection process and the via process;

the absorption plate and the film layer of the beam structure are the same in composition, the absorption plate and the corresponding film layer of the beam structure are manufactured at the same time, the absorption plate sequentially comprises a first dielectric layer, an electrode layer and a second dielectric layer along the direction far away from the CMOS measuring circuit system, the material for forming the first dielectric layer comprises at least one of materials with the resistance temperature coefficient larger than a set value and prepared by amorphous silicon, amorphous germanium silicon or amorphous carbon, and the material for forming the second dielectric layer comprises at least one of materials with the resistance temperature coefficient larger than the set value and prepared by amorphous silicon, amorphous germanium silicon or amorphous carbon; alternatively, the first and second liquid crystal display panels may be,

the beam structure sequentially comprises a first dielectric layer, an electrode layer and a second dielectric layer along the direction far away from the CMOS measuring circuit system, the absorption plate sequentially comprises the first dielectric layer, the electrode layer, the heat sensitive dielectric layer and the second dielectric layer or the absorption plate sequentially comprises the first dielectric layer, the heat sensitive dielectric layer, the electrode layer and the second dielectric layer, the material for forming the first dielectric layer comprises at least one of amorphous silicon, amorphous germanium silicon, amorphous carbon or aluminum oxide, the material for forming the second dielectric layer comprises at least one of amorphous silicon, amorphous germanium silicon, amorphous carbon or aluminum oxide, and the material for forming the heat sensitive dielectric layer comprises at least one of materials prepared from titanium oxide, vanadium oxide, silicon, germanium silicon, germanium oxide, graphene, barium strontium titanate film, copper or platinum, wherein the resistance temperature coefficient of the materials is larger than a set value;

the electrode layer is made of a material including at least one of titanium, titanium nitride, tantalum nitride, titanium tungsten alloy, nickel-chromium alloy, nickel-platinum alloy, nickel-silicon alloy, nickel, chromium, platinum, tungsten, aluminum, or copper.

5. The microbridge structure infrared detector according to claim 1, wherein the absorption plate is formed with at least one hole structure, and the hole structure penetrates through at least a medium layer in the absorption plate; and/or at least one hole-shaped structure is formed on the beam structure, and the hole-shaped structure at least penetrates through the medium layer in the beam structure.

6. The infrared detector with a micro-bridge structure according to claim 1, further comprising a reinforcing structure, wherein the reinforcing structure is disposed at a position corresponding to the position of the columnar structure, and the reinforcing structure is used for enhancing the connection stability between the columnar structure and the suspended micro-bridge structure and between the columnar structure and the reflective layer.

7. The microbridge structure infrared detector of claim 6, wherein the reinforcing structure is located on a side of the electrode layer that is adjacent to or remote from the CMOS measurement circuitry.

8. The microbridge structure infrared detector of claim 1, wherein the hermetic release barrier is located at an interface between the CMOS measurement circuitry and the CMOS infrared sensing structure and/or in the CMOS infrared sensing structure.

9. The infrared detector with the micro-bridge structure according to claim 8, wherein the close release isolation layer is disposed on the reflection layer and is in contact with the reflection layer, and the electrode layer in the columnar structure is electrically connected to the reflection layer through a through hole penetrating through the close release isolation layer;

the closed release isolation layer comprises at least one dielectric layer, and the material for forming the closed release isolation layer comprises at least one of silicon carbide, silicon carbonitride, silicon nitride, silicon, germanium, silicon-germanium alloy, amorphous carbon or aluminum oxide.

10. The microbridge structure infrared detector of claim 1, wherein the microbridge structure infrared detector is based on a 3nm, 7nm, 10nm, 14nm, 22nm, 28nm, 32nm, 45nm, 65nm, 90nm, 130nm, 150nm, 180nm, 250nm, or 350nm CMOS process;