CN111952394B

CN111952394B - Infrared detector and preparation method thereof

Info

Publication number: CN111952394B
Application number: CN202010639304.8A
Authority: CN
Inventors: 魏斌; 翟光杰; 潘辉; 武佩
Original assignee: Beijing North Gaoye Technology Co ltd
Current assignee: Beijing North Gaoye Technology Co ltd
Priority date: 2020-07-06
Filing date: 2020-07-06
Publication date: 2021-04-23
Anticipated expiration: 2040-07-06
Also published as: CN111952394A

Abstract

The invention relates to an infrared detector and a preparation method thereof, wherein the infrared detector comprises a plurality of detector pixels arranged in an array, each detector pixel comprises an electrode layer, a plurality of patterned hollow structures arranged in an array are arranged on the electrode layer, and the patterned hollow structures are in a regular hexagon shape; the infrared absorption spectrum band of the infrared detector is 3-30 microns. Through the technical scheme, the wide-spectrum absorption of the infrared detector is realized, the absorption rate of the infrared detector to the infrared radiation energy of the temperature of the target object is greatly improved, and the infrared detector has high detection sensitivity.

Description

Infrared detector and preparation method thereof

Technical Field

The disclosure relates to the technical field of infrared detection, in particular to an infrared detector and a preparation method thereof.

Background

The non-contact infrared detector comprises a non-contact temperature measuring sensor, for example, and the detection principle is that the infrared detector converts an infrared radiation signal emitted by a target object to be measured into a thermal signal, the thermal signal is converted into an electrical signal through a detector sensitive element, and the electrical signal is processed and output through a circuit chip. The absorption value of the infrared detector to the infrared radiation signal is very important as the initial signal of the infrared detector, and the larger the signal value is, the higher the sensitivity of the infrared detector is, so that the absorption rate of the infrared detector to the infrared radiation is an extremely important parameter for evaluating the performance of the infrared detector.

At present, a spectrum section of infrared radiation absorbed by a non-contact infrared detector, such as a non-contact temperature measurement sensor, is almost in a 8-14 micron wave band, that is, the infrared absorption spectrum section mostly shows a high absorption rate in the 8-14 micron wave band, the infrared absorption in the wave band range only accounts for about 37% of the total target emissivity, and a great part of infrared radiation cannot be absorbed by the infrared detector, so that the infrared absorption rate of the infrared detector is poor, and the sensitivity of the infrared detector is poor.

Disclosure of Invention

In order to solve the technical problem or at least partially solve the technical problem, the present disclosure provides an infrared detector and a manufacturing method thereof, which implement wide spectrum absorption of the infrared detector, greatly improve the absorption rate of the infrared detector to the infrared radiation energy of the target object at the temperature, and further enable the infrared detector to have higher detection sensitivity.

The disclosed embodiment provides an infrared detector, including:

the array type detector comprises a plurality of detector pixels arranged in an array, wherein each detector pixel comprises an electrode layer, a plurality of patterned hollow structures arranged in an array are arranged on the electrode layer, and the patterned hollow structures are in a regular hexagon shape;

the infrared absorption spectrum band of the infrared detector is 3-30 microns.

Optionally, the electrode layer includes a bulk electrode structure and a beam electrode structure, the bulk electrode structure is electrically insulated from the beam electrode structure, and the patterned hollow structure is disposed on the bulk electrode structure;

the detector pixel further comprises a thermosensitive layer, and an isolating layer is arranged between the blocky electrode structure and the thermosensitive layer.

Optionally, the electrode layer comprises a first bulk electrode structure and a second bulk electrode structure, and a first beam electrode structure and a second beam electrode structure;

the first bulk electrode structure is connected with the first beam-like electrode structure, the second bulk electrode structure is connected with the second beam-like electrode structure, and the first bulk electrode structure is electrically insulated from the second bulk electrode structure;

the patterning hollow-out structure is arranged on the first blocky electrode structure and the second blocky electrode structure.

Optionally, the detector pixel comprises:

the device comprises an integrated circuit substrate, and a reflecting layer, a supporting layer, a thermosensitive layer and a passivation layer which are sequentially arranged on the integrated circuit substrate;

the electrode layer is located on one side, close to the passivation layer, of the thermosensitive layer, or the electrode layer is located on one side, close to the supporting layer, of the thermosensitive layer.

Optionally, a cavity between the reflective layer and the passivation layer forms a resonant cavity, and a height of the resonant cavity is greater than or equal to 1 micrometer and less than or equal to 2.5 micrometers.

Optionally, the thickness of the electrode layer is less than or equal to 50 nm.

Optionally, the side length of the patterned hollow structures of the regular hexagon is greater than or equal to 0.1 micrometer and less than or equal to 2 micrometers, and the minimum distance between the patterned hollow structures of adjacent regular hexagons is greater than or equal to 0.1 micrometer and less than or equal to 1 micrometer.

Optionally, the detector pixel comprises:

the device comprises an integrated circuit substrate, and a supporting layer, an electrode layer and a passivation layer which are sequentially arranged on the integrated circuit substrate;

the detector pixel comprises at least two beam structures, and each beam structure is respectively connected with an absorption plate and a micro bridge column;

in the at least two beam structures, two parallel beam structures which are intersected at the same node in the beam path from the absorption plate to the corresponding micro-bridge column are respectively a first half-bridge structure and a second half-bridge structure, and the first half-bridge structure and the second half-bridge structure form a thermally symmetrical structure;

the first half-bridge structure comprises a support layer, an electrode layer and a passivation layer, the second half-bridge structure comprises a support layer, the length of the first half-bridge structure in the thermally symmetric structure is greater than that of the second half-bridge structure, and the unbalanced difference in thermal conductivity between the first half-bridge structure and the second half-bridge structure in the thermally symmetric structure is less than or equal to 20%;

each of the beam structures has two connection points with the absorber plate.

Optionally, the beam structure including the thermally symmetric structure includes at least one folded structure, at least one of the folded structures is provided with a support rod, the support rod includes a support layer, and the support rod and the folded part of the folded structure form a rectangle;

the thermal conductance of the supporting rod is the same as that of the other three-side structure of the rectangle in which the supporting rod is positioned.

The embodiment of the present disclosure further provides a method for manufacturing an infrared detector, which is used for manufacturing the infrared detector according to the first aspect, and the method for manufacturing an infrared detector includes:

forming an entire electrode layer;

and etching the electrode layer to form a block pattern and a beam pattern in the electrode layer and form the regular hexagonal patterned hollow structure.

Optionally, the preparation method of the detector specifically includes:

sequentially forming a reflecting layer, a sacrificial layer, a supporting layer and a thermosensitive layer on an integrated circuit substrate;

forming an entire electrode layer on the thermosensitive layer;

etching the electrode layer to form a block pattern and a beam pattern in the electrode layer and form the regular hexagonal patterned hollow structure;

forming a passivation layer on the electrode layer;

releasing the sacrificial layer; alternatively, the first and second electrodes may be,

the preparation method of the detector specifically comprises the following steps:

sequentially forming a reflecting layer, a sacrificial layer and a supporting layer on an integrated circuit substrate;

forming an entire electrode layer on the support layer;

forming a thermosensitive layer and a passivation layer on one side of the electrode layer;

and releasing the sacrificial layer.

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

the infrared detector comprises a plurality of detector pixels arranged in an array, each detector pixel comprises an electrode layer, a plurality of patterned hollow structures arranged in an array are arranged on the electrode layer, the patterned hollow structures are in regular hexagons, a metamaterial layer formed by the regular hexagons on the electrode layer is combined with a microbridge detector structure, infrared electromagnetic waves absorbed by the metamaterial layer formed by the regular hexagons on the electrode layer are overlapped with infrared electromagnetic waves absorbed by the microbridge detector structure, namely, the intensity of infrared electromagnetic wave signals absorbed by the whole infrared detector is increased by the arrangement of the metamaterial layer formed by the regular hexagons on the electrode layer, so that the absorption rate of incident infrared electromagnetic waves is improved, and the infrared absorption spectrum section of the infrared detector reaches a wave band of 3-30 microns, the infrared detector realizes the super-strong absorption of a wide spectrum from 3 micrometers to 30 micrometers, so that the detector has good absorption characteristics in a wave band from 3 micrometers to 30 micrometers, the absorption rate of the infrared detector to the infrared radiation energy of the target object temperature is greatly improved, and the infrared detector has high detection sensitivity.

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 description of the embodiments or prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive exercise.

Fig. 1 is a schematic perspective view of an infrared detector according to an embodiment of the present disclosure;

FIG. 2 is a schematic structural diagram of a detector pixel according to an embodiment of the present disclosure;

fig. 3 is an exploded perspective view of a detector pixel according to an embodiment of the present disclosure;

fig. 4 is an absorption rate simulation diagram of an infrared detector provided in an embodiment of the present disclosure;

fig. 5 to 9 are exploded perspective views of detector pixels provided in the embodiments of the present disclosure;

FIG. 10 is an exploded perspective view of another detector pixel provided in the embodiments of the present disclosure;

fig. 11 is a schematic flow chart illustrating a method for manufacturing an infrared detector according to an embodiment of the present disclosure;

FIG. 12 is a schematic perspective view of another detector pixel provided in the embodiments of the present disclosure;

FIG. 13 is a schematic diagram of a partial top view structure of a detector pixel according to an embodiment of the present disclosure;

FIG. 14 is a schematic perspective exploded view of another detector pixel provided by embodiments of the present disclosure;

FIG. 15 is a schematic perspective view of another detector pixel provided in the embodiments of the present disclosure;

FIG. 16 is a schematic perspective view of another detector pixel provided in the embodiments of the present disclosure;

FIG. 17 is a schematic perspective view of another detector pixel provided in the embodiments of the present disclosure;

FIG. 18 is a schematic perspective view of another detector pixel provided in the embodiments of the present disclosure;

FIG. 19 is a schematic perspective view of another detector pixel provided in the embodiments of the present disclosure;

FIG. 20 is a schematic perspective view of another detector pixel provided in the embodiments of the present disclosure;

FIG. 21 is a schematic perspective view of another detector pixel provided in the embodiments of the present disclosure;

FIG. 22 is a schematic perspective view of another detector pixel provided in the embodiments of the present disclosure;

FIG. 23 is a schematic perspective view of another detector pixel provided in the embodiments of the present disclosure;

FIG. 24 is a schematic perspective view of a microbridge structure used in the prior art;

FIG. 25 is a schematic perspective view of another detector pixel provided in the embodiments of the present disclosure;

FIG. 26 is a schematic diagram of a partial top view of another detector pixel provided by embodiments of the present disclosure;

fig. 27 is a schematic perspective view of another detector pixel 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 in other ways than those 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 perspective structure diagram of an infrared detector provided in an embodiment of the present disclosure, fig. 2 is a schematic perspective structure diagram of a detector pixel provided in an embodiment of the present disclosure, and fig. 3 is an exploded perspective structure diagram of a detector pixel provided in an embodiment of the present disclosure. With reference to fig. 1 to 3, the infrared detector includes a plurality of detector pixels 1 arranged in an array, and fig. 1 exemplarily shows that the infrared detector includes three rows and three columns of detector pixels 1, and the specific number of detector pixels 1 in the infrared detector is not limited in the embodiments of the present disclosure. The detector pixels are semiconductor devices that are sensitive to infrared radiation and are specially adapted to convert radiant energy into electrical energy.

Each detector pixel 1 comprises an electrode layer 25, a plurality of patterned hollow structures 5 arranged in an array are arranged on the electrode layer 25, the patterned hollow structures 5 are regular hexagons, specifically, the metamaterial is a material which is based on the generalized Snell's law and performs electromagnetic/optical beam regulation and control by controlling wave front phase, amplitude and polarization, the regular hexagonal patterned hollow structures 5 on the electrode layer 25 form a metamaterial layer, which can also be called a super surface or a super structure, the super surface or the super structure is an ultrathin two-dimensional array plane, and the phase, polarization mode, propagation mode and other characteristics of electromagnetic waves can be flexibly and effectively controlled. The regular-hexagon patterned hollow-out structures 5 on the super electrode layer 25 are arranged to form the super material layer, the regular-hexagon patterned hollow-out structures 5 on the electrode layer 25 are used for forming electromagnetic super material structures, and artificial composite structures or composite materials with supernormal electromagnetic properties are formed, so that cutting of electromagnetic waves and light wave performance is achieved, and special electromagnetic wave absorption devices are obtained.

The metamaterial layer formed by the regular-hexagon patterned hollow structures 5 on the electrode layer 25 is combined with the microbridge type detector structure, infrared electromagnetic waves absorbed by the infrared detector can be enhanced by the infrared electromagnetic waves absorbed by the electrode layer 25 with the regular-hexagon patterned hollow structures 5, the infrared electromagnetic waves absorbed by the metamaterial layer formed by the regular-hexagon patterned hollow structures 5 on the electrode layer 25 are superposed with the infrared electromagnetic waves absorbed by the microbridge type detector structure, the infrared electromagnetic waves absorbed by the metamaterial layer formed by the regular-hexagon patterned hollow structures 5 on the electrode layer 25 are coupled with components of incident infrared electromagnetic waves, that is, the intensity of the absorbed infrared electromagnetic wave signals is increased by the arrangement of the metamaterial layer formed by the regular-hexagon patterned hollow structures 5 on the electrode layer 25, and therefore the absorption rate of the infrared detector to the incident infrared electromagnetic waves is improved.

In addition, the regular hexagonal patterned hollow structures 5 arranged in an array on the electrode layer 25 form the metamaterial layer in the embodiment of the disclosure, so that the wide-spectrum absorption of the infrared detector can be realized on the basis of the existing preparation process of the infrared detector, the metal electrodes in the electrode layer 25 can play a role in electrical connection and can also be used as the metamaterial layer, namely, the metamaterial surface structure layer, the formation of the metamaterial layer does not increase the difficulty of the preparation process of the infrared detector, and an additional film layer is not required to be added to realize the metamaterial layer, thereby being beneficial to the miniaturization of the volume of the infrared detector. The metamaterial layer formed by the regular-hexagon patterned hollow structures 5 on the electrode layer 25 is combined with the infrared detector, electromagnetic wave signals absorbed by the metamaterial layer formed by the regular-hexagon patterned hollow structures 5 on the electrode layer 25 can be enhanced, the two electromagnetic wave signals are superposed together, and therefore the intensity of the electromagnetic wave signals absorbed by the infrared detector is increased. In addition, the reading circuit in the infrared detector can process the electric signal obtained by converting the infrared electromagnetic signal without adding an extra circuit and a corresponding algorithm, and the infrared detector is combined with the metamaterial layer, namely a super-surface structure, so that the additional heat capacity of the infrared detector is favorably reduced, and the infrared detection sensitivity of the infrared detector is further improved.

For the shape of the patterned structure included in the metamaterial layer and the corresponding structure size, the following maxwell equations can be used for derivation:

wherein H represents an auxiliary magnetic field, E represents an electric field of an incident electromagnetic wave, B represents a magnetic field of an incident electromagnetic wave, D represents an electric displacement, μ represents a permeability, ε represents a permittivity,

representing a vector operator, wherein t represents time, and based on the above, the regular hexagonal patterned hollow structures 5 on the electrode layer 25 are arranged to form a metamaterial layer, and the sizes of the regular hexagonal patterned hollow structures 5 on the electrode layer 25 are correspondingly arranged, so that the infrared absorption rate of the infrared detector is greater than or equal to 80%, the infrared absorption spectrum band of the infrared detector is 3 micrometers to 30 micrometers, it should be noted that the infrared absorption rate of the infrared detector is greater than or equal to 80%, which means that the infrared detector is in the wave band range of 3 micrometers to 30 micrometers, and the infrared detection is in the wave band range of 3 micrometers to 30 micrometersThe average infrared absorption rate of the detector is more than or equal to 80 percent.

Fig. 4 is an absorption rate simulation diagram of an infrared detector according to an embodiment of the disclosure. In fig. 4, the abscissa indicates the wavelength of the absorbed infrared signal in microns and the ordinate a indicates the infrared absorption rate. As shown in fig. 4, the metamaterial layer formed by the regular hexagonal patterned hollow-out structures 5 on the electrode layer 25 is utilized in the embodiment of the disclosure, so that the infrared absorption rate of the infrared detector is greater than or equal to 80%, the infrared absorption spectrum band of the infrared detector is 3 micrometers to 30 micrometers, that is, the infrared detector realizes super-strong absorption of a wide spectrum of 3 micrometers to 30 micrometers, that is, the detector has good absorption characteristics in 3 micrometers to 30 micrometers, the absorption rate of the infrared detector to the temperature radiant energy of the target object is greatly improved, and further, the infrared detector has high detection sensitivity.

Specifically, the absorption of electromagnetic waves by the metamaterial is mainly based on the combination of physical structure and material parameters, and the absorption structure with multiple functions can be realized by designing different structures and using different materials to combine with the structures. For example, the material forming the electrode layer 25 may include one or both of titanium and titanium nitride, that is, the material forming the electrode layer 25 may include titanium or titanium nitride, or a mixture of titanium and titanium nitride in a predetermined ratio. Through setting up electrode layer 25, the concrete material that the metamaterial layer adopted promptly, combine regular hexagon's that electrode layer 25 includes patterning hollow out construction 5, on the basis of guaranteeing that electrode layer 25 can accurately carry out signal transmission, realize infrared detector's infrared absorption rate more than or equal to 80%, infrared detector's infrared absorption spectral band is 3 microns to 30 microns wave bands, improves infrared detector and to the absorption rate of target object temperature radiant energy, and then makes infrared detector have higher detectivity.

Illustratively, the number of the patterned hollow structures 5 arranged in the array can be adjusted according to the specific area of the detector pixel 1 in the infrared detector, and the number of the patterned hollow structures 5 included in the detector pixel 1 is not specifically limited in the embodiment of the present disclosure. For example, fig. 3 exemplarily sets all regular hexagonal patterned hollow structures 5 to have the same size, and the regular hexagonal patterned hollow structures 5 to have the same arrangement direction, or may set the patterned hollow structures 5 to be a combination of the patterned hollow structures 5 with different sizes, and the regular hexagonal patterned hollow structures 5 to have different arrangement directions.

Fig. 5 to 9 are exploded perspective views of detector pixels provided in the embodiments of the present disclosure. With reference to fig. 1 to 9, the detector cell 1 comprises an integrated circuit substrate 21 and, arranged on the integrated circuit substrate 21 in this order, a reflective layer 22, a support layer 23, a thermally sensitive layer 24 and a passivation layer 26, with reference to fig. 3 and 9, an electrode layer 25 is exemplarily arranged on the side of the thermally sensitive layer 24 adjacent to the passivation layer 26. Specifically, fig. 5 to 9 are respectively exploded views of a film layer from bottom to top in a detector pixel 1, fig. 3 is an exploded perspective view of the detector pixel after forming the structure of fig. 8, wherein an integrated circuit substrate 21 includes a readout circuit for implementing signal acquisition and data processing, a reflective layer 22 is used for reflecting infrared rays to an absorption plate in the detector pixel 1, and matching with a resonant cavity to implement secondary absorption of infrared rays, a support layer 23 is used for supporting a microbridge structure and also has an effect of absorbing infrared radiation, a thermosensitive layer 24 is used for converting a temperature signal into an electrical signal, an electrode layer 25 is used for transmitting the electrical signal converted by the thermosensitive layer 24 to the readout circuit in the integrated circuit substrate 21 through a beam structure 27 having an L-shaped left side and a right side, the electrode layer 25 forms a metamaterial layer by using a regular hexagonal patterned hollow structure 5 arranged in an array, and the two beam structures 27 respectively transmit positive and negative signals of the electrical, the readout circuit performs non-contact infrared temperature detection by analysis of the acquired electrical signals, and the passivation layer 26 serves to protect the electrode layer 25 and the thermosensitive layer 24 from oxidation or corrosion.

The absorption plate in the detector pixel 1 comprises a supporting layer 23, a thermosensitive layer 24, an electrode layer 25 and a passivation layer 26, after absorbing infrared radiation, the absorption plate transmits heat to the integrated circuit substrate 21 through beam structures 27 on two sides to dissipate heat, so that preparation is made for next temperature measurement, transmission of an electric signal in the infrared detector is accompanied with transmission of a thermal signal, and the transmission of the thermal signal is slower than that of the electric signal by utilizing the beam structures 27. The infrared detector provided by the embodiment of the disclosure can be a focal plane detector with a regular hexagon super-surface infrared absorption characteristic, namely, an uncooled infrared focal plane detector, and the uncooled infrared focal plane detector can be divided into three technical modules, namely, a microbolometer, a reading circuit and a vacuum package, from design to manufacture, wherein the microbolometer is an mems (micro Electro Mechanical systems) structure described in the embodiment of the disclosure.

On a silicon substrate, picture elements, also called microbridges, are grown by MEMS technology, which are very similar to the bridge deck structure, which is made of a multilayer material, comprising an absorbing plate for absorbing infrared radiation energy and a heat sensitive layer 24 for converting temperature changes into voltage or current changes, the bridge arms, i.e. the beam structure 27 and the microbridge columns 28, serving to support the deck and to electrically connect. The temperature of the absorption plates of the micro-bridges changes after absorbing infrared energy, the different micro-bridges receive heat radiation with different energy, the temperature changes of the micro-bridges are different, accordingly, the resistance value of the thermosensitive layer 24 of each micro-bridge is changed correspondingly, the change is converted into an electric signal through a reading circuit inside the infrared detector to be output, and finally a visual electronic image reflecting the target temperature condition is obtained through a signal acquisition and data processing circuit outside the infrared detector.

Referring to fig. 1 to 9, the electrode layer 25 may include a bulk electrode structure 251 and a beam electrode structure 252, the bulk electrode structure 251 is electrically insulated from the beam electrode structure 252, that is, the bulk electrode structure 251 is not in contact with the beam electrode structure 252, the patterned hollow structure 5 is disposed on the bulk electrode structure 251, and referring to fig. 8 and 3, the isolation layer 29 is disposed between the bulk electrode structure 251 and the thermosensitive layer 24, and exemplarily, the isolation layer 29 may include one or more of silicon oxide, silicon nitride, silicon carbide, or silicon oxynitride.

Specifically, set up patterned hollow out construction 5 on massive electrode structure 251, massive electrode structure 251 no longer plays the effect of signal transmission this moment, but utilizes regular hexagon's patterned hollow out construction 5 on it to form the metamaterial layer, make the intensity of the infrared electromagnetic wave signal of whole infrared detector absorption increase, thereby the absorptivity of incident infrared electromagnetic wave has been improved, make the detector have fine absorption characteristic in 3 microns to 30 microns wave band, the absorptivity of infrared detector to target object temperature radiant energy has been improved greatly, and then make infrared detector have higher detection sensitivity.

The beam-shaped electrode structure 252 is used for transmitting the electrical signal converted from the thermosensitive layer 24 to the integrated circuit substrate 21, the upper and right patterned electrodes form a beam-shaped electrode structure 252, the lower and left patterned electrodes form a beam-shaped electrode structure 252, and the two beam-shaped electrode structures 252 are respectively used for transmitting positive and negative electrical signals. In addition, an isolating layer 29 is required to be arranged between the block-shaped electrode structure 251 and the thermosensitive layer 24, and the isolating layer 29 is used for insulating the block-shaped electrode structure 251 and the thermosensitive layer 24, so that the block-shaped electrode structure 251 is prevented from influencing the resistance of the thermosensitive layer 24 and further influencing the process of temperature signal and electric signal conversion of the thermosensitive layer 24. Specifically, the isolation layer 29 may be formed in a partial region of the thermosensitive layer 24 after the thermosensitive layer 24 is formed, that is, the isolation layer 29 is formed only in a region corresponding to the block electrode structure 251 on the thermosensitive layer 24, and the isolation layer 29 is not formed in a region corresponding to the beam electrode structure 252 on the thermosensitive layer 24, so that the isolation layer 29 can effectively insulate the block electrode structure 251 from the thermosensitive layer 24, and the arrangement of the isolation layer 29 does not affect the transmission of the electric signal from the thermosensitive layer 24 to the beam electrode structure 252.

Fig. 10 is an exploded perspective view of another detector pixel provided in the embodiments of the present disclosure. Fig. 10 corresponds to fig. 3, and, unlike the detector pixel of the structure shown in fig. 3, in the detector pixel of the structure shown in fig. 10, the electrode layer 25 comprises a first bulk electrode structure 253 and a second bulk electrode structure 254, and a first beam-like electrode structure 255 and a second beam-like electrode structure 256, the first block-like electrode structure 253 being connected to the first beam-like electrode structure 255, the second block-like electrode structure 254 being connected to the second beam-like electrode structure 256, the first block-like electrode structure 253 being electrically insulated from the second block-like electrode structure 254, that is, the first bulk electrode structure 253 is not in contact with the second bulk electrode structure 254, and no isolation layer is required to be disposed between the electrode layer 25 and the thermosensitive layer 24, and the first bulk electrode structure 253 and the first beam-shaped electrode structure 255 are integrated, and the second bulk electrode structure 254 and the second beam-shaped electrode structure 256 are integrated, respectively, for transmitting positive and negative electrical signals.

In addition, the patterned hollow-out structures 5 are arranged on the first block-shaped electrode structure 253 and the second block-shaped electrode structure 254, and infrared electromagnetic waves absorbed by a metamaterial layer formed by the regular hexagonal patterned hollow-out structures 5 on the electrode layer 25 can be overlapped with infrared electromagnetic waves absorbed by the microbridge type detector structure, so that the detector has good absorption characteristics in a wave band of 3 micrometers to 30 micrometers, and the absorption rate of the infrared detector to the temperature radiation energy of a target object and the detection sensitivity of the infrared detector are greatly improved.

Alternatively, in conjunction with fig. 1 to 10, an electrode layer 25 may also be provided on the side of the thermosensitive layer 24 adjacent to the support layer 23. Specifically, can form electrode layer 25 after forming supporting layer 23, and form patterning hollow out construction 5 on electrode layer 25, then form heat-sensitive layer 24 on electrode layer 25, the infrared electromagnetic wave that the metamaterial layer that regular hexagon's patterning hollow out construction 5 formed on electrode layer 25 formed absorbs can be utilized with the infrared electromagnetic wave stack of microbridge formula detector structure self absorption equally, make the detector have fine absorption characteristic in 3 microns to 30 microns wave band, infrared detector has improved the absorptivity to target object temperature radiant energy greatly, and then make infrared detector have higher detectivity.

Alternatively, with reference to fig. 1 to 10, a cavity between the reflective layer 22 and the passivation layer 26 may be configured to form a resonant cavity, and the height of the resonant cavity is greater than or equal to 1 micron and less than or equal to 2.5 microns. Specifically, the optical resonant cavity in the infrared detector comprises a reflecting layer 22, an absorbing plate and a cavity between the reflecting layer 22 and the absorbing plate, the absorbing plate comprises a supporting layer 23, a thermosensitive layer 24, an electrode layer 25 and a passivation layer 26, and the height of the resonant cavity is the sum of the thickness of the reflecting layer 22, the thickness of the absorbing plate and the height of the cavity between the reflecting layer 22 and the absorbing plate.

Specifically, the absorption rate of the infrared detector to infrared radiation can be improved by adjusting the height of the optical resonant cavity, part of incident infrared radiation energy can penetrate through the absorption plate of the microbridge structure, an infrared reflection layer 22 is manufactured below the microbridge, and the infrared reflection layer 22 can reflect infrared radiation energy projected from the upper side back to the plate for secondary absorption. The distance between the absorbing plate and the reflective layer 22 has a large influence on the effect of the secondary absorption. Set up the high more than or equal to 1 micron of resonant cavity, less than or equal to 2.5 microns, can effectively increase the absorption rate of absorption board to the infrared radiant energy of reflection back, reinforcing infrared detector is to specific wave band infrared radiation's absorption rate, combine the metamaterial layer that regular hexagon's patterning hollow out construction 5 constitutes on the electrode layer 25, make infrared detector's infrared absorption rate more than or equal to 80%, infrared detector's infrared absorption spectrum section is 3 microns to 30 microns wave band, even make infrared detector realize 3 microns to 30 microns's wide spectrum super absorption, the absorption rate of infrared detector to target object temperature radiant energy has been improved greatly, and then make infrared detector have higher detectivity.

Alternatively, with reference to fig. 1 to 10, the thickness of the electrode layer 25 may be set to be 50 nm or less, that is, the thickness of the electrode layer 25 in the direction perpendicular to the integrated circuit substrate 21 may be set to be 50 nm or less. Specifically, the characteristics of the electrode layer 25, i.e., the metamaterial layer, can be regulated and controlled by the structural order design of the key physical dimensions, and the infrared electromagnetic waves absorbed by the metamaterial layer can be coupled with the electromagnetic components of the incident infrared electromagnetic waves by adjusting the physical dimensions and material parameters of the metamaterial layer. The thickness of the electrode layer 25 is set to be less than or equal to 50 nanometers, so that the infrared absorption rate of the infrared detector is greater than or equal to 80%, and the infrared absorption spectrum section of the infrared detector is a 3-30-micrometer wave band, and the phenomenon that the detection sensitivity of the infrared detector is influenced due to the fact that the thickness of the electrode layer 25 is too large, namely the infrared absorption spectrum section of the infrared detector is influenced due to the fact that the thickness of the metamaterial layer is too large is avoided. In addition, the thickness of the electrode layer 25 is set to be less than or equal to 50 nanometers, which is beneficial to reducing the thickness of the electrode layer 25 on the beam structure 27, and is further beneficial to reducing the thermal conductance on the beam structure 27.

Optionally, with reference to fig. 1 to 10, the side length of the patterned hollow structures 5 of the regular hexagon is greater than or equal to 0.1 micrometer and less than or equal to 2 micrometers, and the minimum distance d between the patterned hollow structures of adjacent regular hexagons is greater than or equal to 0.1 micrometer and less than or equal to 1 micrometer. Similarly, the characteristics of the metamaterial layer can be regulated and controlled by the ordered structure design of the key physical dimensions, and by adjusting the electrode layer 25, namely the physical dimensions and material parameters of the metamaterial layer, the infrared electromagnetic waves absorbed by the metamaterial layer can be coupled with the electromagnetic components of the incident infrared electromagnetic waves, so that most of the incident electromagnetic waves of a specific frequency band are coupled, the infrared absorption rate of the infrared detector is more than or equal to 80%, and the infrared absorption spectrum band of the infrared detector is 3-30 μm.

The embodiment of the disclosure also provides a preparation method of the infrared detector. Fig. 11 is a schematic flow chart of a method for manufacturing an infrared detector according to an embodiment of the present disclosure, where the method for manufacturing an infrared detector can be used to manufacture the infrared detector according to the above embodiment. As shown in fig. 11, the method for manufacturing the infrared detector includes:

and S1, forming an electrode layer on the whole surface.

And S2, etching the electrode layer to form a block pattern and a beam pattern in the electrode layer, and forming a regular hexagonal patterned hollow structure.

Optionally, taking the detector pixel with the structure shown in fig. 3 as an example to embody the preparation process of the infrared detector, the preparation method of the detector may specifically include sequentially forming the reflective layer 22, the sacrificial layer (not shown in fig. 3), the supporting layer 23, and the thermal layer 24 on the integrated circuit substrate 21, forming the electrode layer 25 on the entire surface of the thermal layer 24, etching the electrode layer 25 to form the block pattern and the beam pattern in the electrode layer 25, that is, to form the block electrode structure 251 and the beam electrode structure 252, and to form the regular hexagonal patterned hollow structure 5, etching the electrode pattern at the same time, etching the metal array patterned hollow structure 5 together, forming the passivation layer 26 on the electrode layer 25, and releasing the sacrificial layer, that is, removing the sacrificial layer.

Optionally, the method for manufacturing the detector may further specifically include sequentially forming a reflective layer 22, a sacrificial layer, and a support layer 23 on the integrated circuit substrate 21, forming an entire surface of the electrode layer 25 on the support layer 23, etching the electrode layer 25 to form a block pattern and a beam pattern in the electrode layer, and forming the regular-hexagonal patterned hollow structure 5, forming a thermal sensitive layer 24 and a passivation layer 26 on one side of the electrode layer 25, that is, disposing the electrode layer 25 on one side of the thermal sensitive layer 24 adjacent to the support layer 23, and finally releasing the sacrificial layer.

Thus, the metamaterial layer formed by the regular hexagonal patterned hollow structure on the electrode layer is combined with the micro-bridge detector structure, infrared electromagnetic waves absorbed by the metamaterial layer formed by the regular hexagonal patterned hollow structure on the electrode layer are superposed with the infrared electromagnetic waves absorbed by the micro-bridge detector structure, namely, the intensity of infrared electromagnetic wave signals absorbed by the whole infrared detector is increased by the arrangement of the metamaterial layer formed by the regular hexagonal patterned hollow structure on the electrode layer, so that the absorptivity of incident infrared electromagnetic waves is improved, the infrared absorptivity of the infrared detector is more than or equal to 80%, the infrared absorption spectrum band of the infrared detector reaches 3-30-micron wave band, namely, the infrared detector realizes 3-30-micron wide-spectrum super-absorption, so that the detector has good absorption characteristics in 3-30-micron wave band, the absorption rate of the infrared detector to the infrared radiation energy of the target object temperature is greatly improved, and the infrared detector has high detection sensitivity.

The existing infrared focal plane detector has the problems that the thermal conductivity of the infrared detector is large, and the performance of the infrared detector is poor, for example, a microbridge structure with a geometric symmetry design is adopted, two half bridges in the microbridge structure are geometrically symmetric, and the length of a half bridge with an electric transmission function is equal to that of a half bridge without the electric transmission function. However, because the mechanical strength and the thermal conductivity of the electrode material and the supporting layer material are different, the difference between the speed of the heat reaching the two corresponding micro-bridge columns from the absorption plate is large, the thermal conductivity of the whole micro-bridge structure is large, and the detection performance of the infrared detector formed by the micro-bridge structure is poor. In addition, the micro-bridge structure with the geometric symmetry design is subjected to large stress and deformation, so that the mechanical stability and the impact resistance of the micro-bridge structure are poor, and the structural stability of the whole infrared detector is poor. Therefore, how to further reduce the thermal conductance of the infrared detector, improve the infrared detection performance of the infrared detector, and further improve the structural stability of the infrared detector becomes a problem to be solved urgently.

On the basis of the foregoing embodiment, fig. 12 is a schematic perspective structure diagram of another detector pixel provided in the embodiment of the present disclosure, fig. 13 is a schematic partial top-view structure diagram of a detector pixel provided in the embodiment of the present disclosure, and fig. 14 is a schematic perspective exploded view of another detector pixel provided in the embodiment of the present disclosure. With reference to fig. 12 to 14, the detector pixel comprises at least two beam structures 27, where the detector pixel is exemplarily arranged to comprise two beam structures 27, each beam structure 27 connecting an absorber plate 6 and a micro-bridge post 28, respectively.

In particular, the detector pixel comprises an integrated circuit substrate 21, an absorber plate 6 and a beam structure 27, the integrated circuit substrate 21 comprising a readout circuit for reading and processing electrical signals and a reflective layer 22 on the integrated circuit substrate 21 for secondary reflection of infrared radiation, the absorber plate 6 comprising a support layer 23, an electrode layer 25, a heat sensitive layer 24 and a passivation layer 26, the electrode layer 25 being on the support layer 23, the heat sensitive layer 24 being on the electrode layer 25, the passivation layer 26 being on the heat sensitive layer 24 and the electrode layer 25. The absorber plate 6 is used to absorb infrared radiation energy of a target object, and the beam structure 27 includes a support layer 23, an electrode layer 25, and a passivation layer 26 thereon, and the beam structure 27 is a member for performing electrical and thermal conduction. Wherein the support layer 23 serves as a structural support, the thermo-sensitive layer 24 is only located on the absorbent plate 6 for converting temperature signals into electrical signals, the electrode layer 25 is used for adjusting the electrical resistance of the thermo-sensitive layer 24 and for transferring electrical signals of the thermo-sensitive layer 24 via the beam structure 27 to a read-out circuit of the integrated circuit substrate, and the passivation layer 26 is used for protecting the thermo-sensitive layer 24 and the electrode layer 25.

Illustratively, the material constituting the thermosensitive layer 24 may be vanadium oxide, silicon, or titanium oxide, and correspondingly, the infrared detector may be a vanadium oxide sensor, an amorphous silicon sensor, or a titanium oxide sensor, and the infrared detector may also be a thermopile sensor or a diode sensor. Illustratively, the material forming the support layer 23 may include one or more of silicon oxide, silicon nitride, silicon oxynitride, or amorphous carbon, and the material forming the passivation layer 26 may include one or more of silicon oxide, silicon nitride, silicon oxynitride, or amorphous carbon.

In addition, fig. 12 to 14 only exemplarily set the electrode layer 25 at a side of the heat-sensitive layer 24 adjacent to the integrated circuit substrate 21, and also may set the electrode layer 25 at a side of the heat-sensitive layer 24 adjacent to the passivation layer 26, and fig. 14 exemplarily sets the electrode layer 25 to be distributed as two block-shaped large-area patterned electrodes 251 on the absorbing plate 6, and the area of the patterned electrodes is not particularly limited by the embodiment of the present disclosure.

In at least two beam structures 27, two parallel beam structures that intersect at the same node in the beam path from the absorber plate 6 to the corresponding micro-bridge column 28 are a first half-bridge structure 71 and a second half-bridge structure 72, respectively, the first half-bridge structure 71 and the second half-bridge structure 72 form a thermally symmetric structure 7, fig. 12 to 14 set the detector pixel to include two beam structures 27, in the beam path from the absorber plate 6 to the corresponding micro-bridge column 28, two parallel beam structures that intersect at the same node are a first half-bridge structure 71 and a second half-bridge structure 72, respectively, and the first half-bridge structure 71 and the second half-bridge structure 72 form the thermally symmetric structure 7.

With reference to fig. 12 to 14, referring mainly to fig. 13, the parallel beam structure a and the parallel beam structure B meet at the same node a, the parallel beam structure C and the parallel beam structure D meet at the node B and the node C, and the parallel beam structure e and the parallel beam structure f meet at the same node D. The length of the first half-bridge structure 71 in the thermally symmetric structure 7 is greater than the length of the second half-bridge structure 72, so that the parallel beam structure a is the first half-bridge structure 71, and the parallel beam structure b is the second half-bridge structure 72, and the two structures form a thermally symmetric structure 7; the parallel beam structure c is a first half-bridge structure 71, the parallel beam structure d is a second half-bridge structure 72, and the first half-bridge structure and the second half-bridge structure form a thermally symmetric structure 7; the parallel beam structure e is a first half-bridge structure 71 and the parallel beam structure f is a second half-bridge structure 72, which form a thermally symmetric structure 7.

The heat of the detector picture elements is conducted from the central absorber plate 6 to the two micro-bridge columns 28 connected to the same beam structure 27, the first half-bridge structure 71 comprises a support layer 23, an electrode layer 25 and a passivation layer 26, the second half-bridge structure 72 comprises a support layer 23, i.e. the thickness of the first half-bridge structure 71 is greater than that of the second half-bridge structure 72, and in the case that the lengths of the first half-bridge structure 71 and the second half-bridge structure 72 are equal, the heat conduction speed of the first half-bridge structure 71 is faster than that of the second half-bridge structure 72 due to the greater thickness thereof. The length of the first half-bridge structure 71 and the length of the second half-bridge structure 72 are asymmetrically designed, that is, the length of the first half-bridge structure 71 is longer than the length of the second half-bridge structure 72, so that the heat conduction speed of the first half-bridge structure 71 with a fast heat conduction speed caused by a thickness factor is slowed down, and further, the heat conduction unbalanced difference between the first half-bridge structure 71 and the second half-bridge structure 72 in the thermally symmetric structure 7 is less than or equal to 20%, that is, the difference between the heat conduction speeds of the first half-bridge structure 71 and the second half-bridge structure 72 in the thermally symmetric structure 7 is less than or equal to 20%, taking the heat conduction speed of the first half-bridge structure 71 as an example, the heat conduction speed of the second half-bridge structure 72 is greater than or equal to 0.8, and less than or equal to 1.2.

Referring to fig. 12 to 14, the thermal conductivities of the parallel beam structure a and the parallel beam structure b are similar, the thermal conductivities of the parallel beam structure c and the parallel beam structure d are similar, the thermal conductivities of the parallel beam structure e and the parallel beam structure f are similar, the heat on the absorption plate 6 is synchronously transferred to the two end points of the beam structure 27 connected with the absorption plate 6, then the heat is basically and synchronously transferred to the parallel beam structure c and the parallel beam structure d after passing through the parallel beam structure a and the parallel beam structure b, the heat is basically and synchronously transferred to the parallel beam structure e and the parallel beam structure f after passing through the parallel beam structure c and the parallel beam structure d, and the heat is basically and synchronously transferred to the upper micro bridge column 28 and the lower micro bridge column 28 after passing through the parallel beam structure e and the parallel beam structure f and is radiated by the integrated circuit substrate 21.

Thus, the time for the heat from the absorption plate 6 to reach the lower micro-bridge column 28 through the first half-bridge structure 71 is similar to the time for the heat to reach the upper micro-bridge column 28 through the second half-bridge structure 72, so as to further realize the heat balance on the beam structure 27, reduce the total thermal conductance of the detector pixel, and optimize the infrared detection performance of the infrared detector composed of the detector pixel, such as an infrared focal plane detector, so that the NETD (Noise Equivalent Temperature Difference) of the infrared detector is improved by more than 15%.

In addition, the length of the first half-bridge structure 71 with the larger thickness is set in the embodiment of the disclosure, the length of the second half-bridge structure 72 with the smaller thickness is larger than that of the first half-bridge structure 71 with the smaller thickness, and compared with symmetrical structures with the same length of the first half-bridge structure 71 and the second half-bridge structure 72, the stress and deformation of the detector pixel under the same force are reduced, under the same acting force, the stress of the detector pixel is reduced by at least 10%, the deformation is reduced by at least 50%, the stability and the impact resistance of the detector pixel are improved, the structural stability of the whole infrared detector is further improved, and the mechanical strength of the infrared detector is enhanced.

It should be noted that fig. 12 to 14 only exemplarily set up that a detector pixel includes three thermally symmetric structures 7 formed by three first half-bridge structures 71 and three second half-bridge structures 72, and the specific number of thermally symmetric structures 7 included in the detector pixel is not limited by the embodiments of the present disclosure, and it is sufficient to ensure that the detector pixel includes at least one thermally symmetric structure 7.

In addition, a plurality of patterned hollow structures arranged in an array are arranged on the electrode layer 25, which is not shown in fig. 12 to 14, the patterned hollow structures are regular hexagons, or a plurality of patterned hollow structures 5 arranged in an array are arranged on the electrode layer 25 of each detector pixel as shown in fig. 3, the patterned hollow structures 5 are regular hexagons, so that the infrared absorption rate of the infrared detector is greater than or equal to 80%, and the infrared absorption spectrum band of the infrared detector is 3 micrometers to 30 micrometers.

Alternatively, the equivalent thickness of the support layer 23 may be set to 100 angstroms or more and 2000 angstroms or less, and the thickness of the passivation layer 26 may be set to 50 angstroms or more and 2000 angstroms or less. Specifically, by setting the thicknesses of the support Layer 23, the electrode Layer 25 and the passivation Layer 26 on the beam structure 27, the thermal conductivity of the beam structure 27 is optimized, and then the thermal conductivity of the detector pixel is optimized, and the support Layer 23, the electrode Layer 25 and the passivation Layer 26 on the beam structure 27 may be formed by a PECVD (Plasma Enhanced Chemical Vapor Deposition) or ALD (Atomic Layer Deposition) process.

Optionally, fig. 12 to 14 exemplarily set the overall thickness of the support layer 23 to be the same, that is, the thickness of the support layer 23 included in the first half-bridge structure 71 is the same as the thickness of the support layer 23 included in the second half-bridge structure 72, and the thickness of the support layer 23 included in the first half-bridge structure 71 may also be set to be different from the thickness of the support layer 23 included in the second half-bridge structure 72, for example, the thickness of the support layer 23 included in the first half-bridge structure 71 is set to be greater than the thickness of the support layer 23 included in the second half-bridge structure 72, or the thickness of the support layer 23 included in the first half-bridge structure 71 is set to be less than the thickness of the support layer 23 included in the second half-bridge structure 72, and the thickness of the support layer 23 included in the first half-bridge structure 71 is set to be different from the thickness of the support layer.

Preferably, the thermal conductance of the first half-bridge structure 71 and the second half-bridge structure 72 in the thermally symmetric structure 7 may be set to be the same. Specifically, with reference to fig. 12 to 14, the heat on the absorption plate 6 is synchronously transferred to the beam structure 27 connecting the two end points of the absorption plate 6, then after passing through the parallel beam structure a and the parallel beam structure b, the heat is synchronously transferred to the parallel beam structure c and the parallel beam structure d, after passing through the parallel beam structure c and the parallel beam structure d, the heat is synchronously transferred to the parallel beam structure e and the parallel beam structure f, after passing through the parallel beam structure e and the parallel beam structure f, the heat is synchronously transferred to the upper micro-bridge column 28 and the lower micro-bridge column 28, and is dissipated by the integrated circuit substrate 21. In this way, the time for the heat from the absorption plate 6 to reach the lower micro-bridge column 28 through the first half-bridge structure 71 is the same as the time for the heat to reach the upper micro-bridge column 28 through the second half-bridge structure 72, so that the heat balance on the beam structure 27 is realized to the maximum extent, the total heat conduction of the detector pixel is reduced to the minimum, and the infrared detection performance of the infrared detector composed of the detector pixels, such as an infrared focal plane detector, is optimized to the maximum extent.

Alternatively, in conjunction with fig. 12 to 14, the length l of the first half-bridge structure 71 in the thermally symmetric structure 7 may be set₁The second half-bridge structure 72 has a length l₂，l₁And l₂The following formula is satisfied:

wherein k is₁Is the thermal conductivity, k, of the support layer 23₂Is the thermal conductivity, k, of the electrode layer 25₃Thermal conductivity, w, of the passivation layer 26₁Width, w, of the support layer 23 on the beam structure₂Width, w, of the electrode layer 25 on the beam structure₃Is the width, t, of the passivation layer 26 on the beam structure₁Is the equivalent thickness, t, of the support layer 23₂Is the thickness, t, of the electrode layer 25₃Is the thickness of the passivation layer 26.

Specifically, with reference to fig. 12-14, thermal conductance G of first half-bridge structure 71₁The following calculation formula is satisfied:

thermal conductance G of the second half-bridge structure 72₂The following calculation formula is satisfied:

to achieve minimum thermal conductance of the detector pixel, G₁And G₂The sum of (a) is minimal, since the total length of the microbridge is constant and the thermal conductance is inversely proportional to the length, only if the thermal conductance of the first half-bridge structure 71 is the same as the second half-bridge structure 72, i.e. G₁Is equal to G₂When the total thermal conductance of the detector pixel reaches the minimum value, which can be obtained from the above formula, G₁Is equal to G₂When l is turned on₁And l₂The following formula is satisfied:

it should be noted that, in the equivalent thickness of the support layer 23 described in the embodiment of the present disclosure, when the thickness of the support layer 23 included in the first half-bridge structure 71 is equal to the thickness of the support layer 23 included in the second half-bridge structure 72, the thickness of the entire film layer of the support layer 23 is the same, and the equivalent thickness of the support layer 23 is the original thickness of the support layer 23. When the thickness of the support layer 23 included in the first half-bridge structure 71 is not equal to the thickness of the support layer 23 included in the second half-bridge structure 72, the thickness of the entire film layer of the support layer 23 is not uniform, and the equivalent thickness of the support layer 23 is the average thickness of the support layer 23.

Alternatively, in combination with fig. 12 to 14, it may be provided that the beam structure 27 comprising the thermally symmetric structure 7 further comprises at least one connection bar 8, the connection bar 8 being used to separate the first half-bridge structure 71 and the second half-bridge structure 72 of the thermally symmetric structure 7, the first half-bridge structure 71 and the second half-bridge structure 72 being located on either side of the connection bar 8 in a direction perpendicular to the connection bar 8, the connection bar 8 comprising the support layer 23, the electrode layer 25 and the passivation layer 26.

In particular, fig. 12 to 14 exemplarily provide that the two beam structures 27 each comprise a connecting rod 8, each beam structure 27 comprises two connecting rods 8, the connecting rod 8 is used for dividing the first half-bridge structure 71 and the second half-bridge structure 72 in the thermally symmetric structure 7, and the first half-bridge structure 71 and the second half-bridge structure 72 are respectively located on two sides of the connecting rod 8 in a direction perpendicular to the connecting rod 8, i.e. the first half-bridge structure 71 and the second half-bridge structure 72 in the thermally symmetric structure 7 are separated by the connecting rod 8 and connected by the connecting rod 8. The tie bar 8 comprises a support layer 23, an electrode layer 25 and a passivation layer 26 for spacing apart a first half-bridge structure 71 comprising the support layer 23, the electrode layer 25 and the passivation layer 26 and a second half-bridge structure 72 comprising only the support layer 23. Similarly, the first half-bridge structure 71 and the second half-bridge structure 72 with the thermal conductivity non-equilibrium difference value less than or equal to 20% form the thermal symmetric structure 7, so that the total thermal conductivity of the detector pixel is reduced, the infrared detection performance of the infrared detector is improved, the stress and deformation of the micro-bridge structure under the same force are reduced, the stability and the impact resistance of the detector pixel are improved, the structural stability of the whole infrared detector is improved, and the mechanical strength of the infrared detector is enhanced.

It should be noted that the number of the connecting rods 8 is not limited in the embodiment of the present disclosure, and the positions and the specific number of the connecting rods 8 may be set according to the number of the folds in the beam structure 27 and the distribution of the first half-bridge structure 71 and the second half-bridge structure 72.

Fig. 12 to 14 exemplarily show that a single beam structure 27 is folded back 6 times, the single beam structure 27 includes three thermally symmetric structures 7, or as shown in fig. 15, a single beam structure is folded back 1 time, the single beam structure includes one thermally symmetric structure, wherein a parallel beam structure g is a first half-bridge structure 71, a parallel beam structure h is a second half-bridge structure 72, which meet at a node E, the first half-bridge structure 71 and the second half-bridge structure 72 form one thermally symmetric structure, and the single beam structure includes one connecting rod 8. Or as shown in fig. 16, a single beam structure is folded back 3 times, the single beam structure includes two thermally symmetric structures, where the parallel beam structure i and the parallel beam structure j form one thermally symmetric structure, the parallel beam structure i is a first half-bridge structure 71, the parallel beam structure j is a second half-bridge structure 72, the parallel beam structure k and the parallel beam structure l form another thermally symmetric structure, the parallel beam structure k is the first half-bridge structure 71, the parallel beam structure l is the second half-bridge structure 72, and the single beam structure includes one connecting rod 8. Or as shown in fig. 17, a single beam structure is folded back 5 times, the single beam structure includes two thermally symmetric structures, where a parallel beam structure m and a parallel beam structure n form one thermally symmetric structure, the parallel beam structure m is a first half-bridge structure 71, the parallel beam structure n is a second half-bridge structure 72, the parallel beam structure p and the parallel beam structure q form another thermally symmetric structure, the parallel beam structure p is the first half-bridge structure 71, the parallel beam structure q is the second half-bridge structure 72, and the single beam structure includes two connecting rods 8.

Alternatively, the detector pixel may be configured to include one or two sets of two micro-bridge pillars 28 arranged diagonally, as shown in fig. 12 to 17, and the detector pixel may be configured to include two sets of two micro-bridge pillars 28 arranged diagonally, that is, the detector pixel is configured to include four micro-bridge pillars 28, or the detector pixel may be configured to include one set of two micro-bridge pillars 28 arranged diagonally, that is, the detector pixel is configured to include two micro-bridge pillars 28.

Illustratively, as shown in fig. 18, the detector pixel may be configured to include two beam structures, and the single beam structure includes a thermally symmetric structure, where the parallel beam structure s is a first half-bridge structure 71, and the parallel beam structure t is a second half-bridge structure 72, and a junction node of the two is F. As shown in fig. 19, the detector pixel may also include two beam structures, and the single beam structure includes a thermally symmetric structure, where the parallel beam structure u is a first half-bridge structure 71, the parallel beam structure v is a second half-bridge structure 72, and a junction node of the two is H. As shown in fig. 20, the detector pixel may also include two beam structures, and a single beam structure includes a thermally symmetric structure, where the parallel beam structure w is the first half-bridge structure 72, the parallel beam structure x is the second half-bridge structure 72, and a junction node of the two is K.

In addition, as shown in fig. 12 to 17, four micro-bridge columns 28 are arranged symmetrically, that is, four micro-bridge columns 28 are located at four top corners of a rectangle, or as shown in fig. 21, four micro-bridge columns 28 are arranged asymmetrically, a detector pixel includes two beam structures, and a single beam structure includes one thermally symmetric structure, where a parallel beam structure y is a first half-bridge structure 71, a parallel beam structure z is a second half-bridge structure 72, and a junction node of the two is M.

Optionally, with reference to fig. 12 to fig. 21, the beam structure 27 may be linearly lapped on the corresponding micro bridge pillar 28, that is, the outermost beam of the beam structure 27 away from the absorption plate 6 is linearly and directly lapped on the corresponding micro bridge pillar 28, so as to improve the stability of lapping between the beam structure 27 and the micro bridge pillar 28, and further improve the mechanical strength and the structural stability of the detector pixel. As shown in fig. 22, the beam structure may be connected to the corresponding micro bridge column 28 through a small segment of the overlapping structure 100, and to improve the stability of the beam structure, the width of the overlapping structure 100 may be increased, for example, the line width of the overlapping structure 100 is increased to reduce the stress on the beam structure, so as to improve the structural strength of the beam structure.

Fig. 23 is a schematic perspective view of another detector pixel provided in the embodiment of the present disclosure. As shown in fig. 23, the detector pixel may be arranged to include four beam structures, i.e., the detector pixel includes a first beam structure 271 and a second beam structure 272 arranged in a first direction XX ', and a third beam structure 273 and a fourth beam structure 274 arranged in a second direction YY', the first direction XX 'being perpendicular to the second direction YY'. The first and

second beam structures

271, 272 comprise thermally symmetrical structures, the positions of which can be seen in fig. 12 to 14, the third and

fourth beam structures

273, 274 comprise only the support layer 23, i.e. the third and

fourth beam structures

273, 274 do not comprise thermally symmetrical structures, the first and

second beam structures

271, 272 satisfy a thermally symmetrical relationship, and the third and

fourth beam structures

273, 274 satisfy a thermally symmetrical relationship.

As shown in fig. 23, the thermal conductance of the third beam structure 273 is set to be less than or equal to that of the first beam structure 271 or that of the second beam structure 272, and the thermal conductance of the fourth beam structure 274 is set to be less than or equal to that of the first beam structure 271 or that of the second beam structure 272, which is favorable for reducing the total thermal conductance of the detector pixel and optimizing the infrared detection performance of the infrared detector formed by the detector pixel.

Alternatively, it is possible to provide each beam structure 27 with two connection points to the absorber plate 6, as shown in fig. 12 to 14, 16, 18 to 20, and 22, each beam structure 27 with two connection points to the absorber plate 6, and two beam structures 27 located above and below the absorber plate 6 in fig. 23 each with two connection points to the absorber plate 6.

Fig. 24 is a schematic perspective view of a microbridge structure used in the prior art. As shown in fig. 24, the microbridge structure of the standing structure adopts a half-bridge arrangement, and all the beam structures include a supporting layer, an electrode layer and a passivation layer, so that the structural stability is poor, because the uniform ends of the two beam structures are connected to an absorption plate, and the other ends of the two beam structures are connected to a microbridge column, the structural freedom is high, and the stability is poor. In order to improve the structural stability of the infrared detector, a thickened beam structure is required, however, the beam structure and the absorption plate are manufactured at the same time, the thickness of the absorption plate is increased due to the thickness of the beam structure, the thermal capacity of the micro-bridge structure is increased due to the thickening of the beam structure, and the performance of the infrared detector is poor. Alternatively, the thickness of the beam structure may be set to be large, and the thickness of the absorption plate may be different from that of the beam structure, which may lead to a complicated process of the microbridge structure and a reduction in the yield of the infrared detector.

The embodiment of the disclosure sets each beam structure 27 and the absorption plate 6 to have two connection points, thereby effectively reducing the degree of freedom of the beam structure 27, improving the mechanical stability of the beam structure 27, further improving the stability of the detector pixel, and having simple manufacturing process without adding extra manufacturing process.

Alternatively, in combination with fig. 12 to 23, it is possible to arrange thermally symmetrical structures 7 on opposite sides of the absorber plate 6, with the first half-bridge structure 71 and the second half-bridge structure 72 distributed in opposite positions. Specifically, taking fig. 12 to 17 and 21 to 23 as examples, the first half-bridge structure 71 is located above and the second half-bridge structure 72 is located below in the thermally symmetric structure 7 located on the left side of the absorber plate 6, and the first half-bridge structure 71 is located below and the second half-bridge structure 72 is located above in the thermally symmetric structure 7 located on the right side of the absorber plate 6. Taking fig. 18 and 19 as an example, in the thermally symmetrical structure 7 located above the absorber plate 6, the first half-bridge structure 71 is on the left and the second half-bridge structure 72 is on the right, and in the thermally symmetrical structure 7 located below the absorber plate 6, the first half-bridge structure 71 is on the right and the second half-bridge structure 72 is on the left. Taking fig. 20 as an example, in the thermally symmetrical structure 7 located above the absorber plate 6, the first half-bridge structure 71 is on top and the second half-bridge structure 72 is on bottom, and in the thermally symmetrical structure 7 located below the absorber plate 6, the first half-bridge structure 71 is on bottom and the second half-bridge structure 72 is on top.

Like this, lie in the relative thermal symmetry structure 7 that sets up both sides of absorbing plate 6 through the setting, first half-bridge structure 71 and second half-bridge structure 72's distribution position is opposite, has further reduced stress and the deformation that the microbridge structure received under the effect of the same power, has improved the stability and the shock resistance of detector pixel, and then has improved whole infrared detector's structural stability, has strengthened infrared detector's mechanical strength.

Fig. 25 is a schematic perspective view of another detector pixel provided by an embodiment of the disclosure, and fig. 26 is a schematic partial top view of another detector pixel provided by an embodiment of the disclosure. On the basis of the above-mentioned embodiment, with reference to fig. 12 to 14 and fig. 25 and 26, when the beam structure 27 including the thermally symmetric structure 7 includes at least one folded structure, at least one folded structure is correspondingly provided with the support rod 9, the support rod 9 includes the support layer 23, and the support rod 9 and the folded portion of the folded structure form a rectangle.

Fig. 12 to 14 and fig. 25 and 26 exemplarily set up that the beam structures 27 on the left and right sides all include the thermally symmetric structure 7, exemplarily set up that the beam structure 27 includes three folded structures corresponding to the first half-bridge structure 71, three folded structures are respectively and correspondingly provided with the supporting rod 9, the supporting rod 9 includes only the supporting layer 23, the supporting rod 9 and the folded portion of the corresponding folded structure form a rectangle, for example, form rectangles a1, a2 and a3, thus, the supporting rod 9 formed by using the supporting layer 23 improves the mechanical strength of the beam structure 27, the supporting rod 9 plays a role in enhancing the stability of the detector pixel, and further improves the structural stability of the infrared detector formed by the detector pixel. In addition, the support bar 9 may be provided corresponding to the folded structure of the second half-bridge structure 72, for example, in fig. 14 and 15, the support bar 91, the support bar 92, and the support bar 93 may be provided corresponding to the folded structure 94 of the second half-bridge structure 72, so that the stability of the thermally symmetric micro-bridge structure can be further enhanced. In summary, as long as the beam structure 27 including the thermally symmetric structure 7 includes the folded structure, the support rod 9 can be correspondingly disposed at the folded structure.

For example, in combination with fig. 12 to 14 and fig. 25 and 26, the beam structures 27 on two opposite sides of the absorption plate 6 may be arranged, and the distribution positions of the support rods 9 are diagonally symmetrical, for example, in the beam structure 27 on the left side of the absorption plate 6, there is one support rod 9 above, there are two support rods 9 below, in the beam structure 27 on the right side of the absorption plate 6, there are two support rods 9 above, and there is one support rod 9 below, so as to further improve the structural stability of the infrared detector formed by the detector pixels.

In addition, with regard to fig. 16, 17, 22 and 23, when the beam structure 27 including the thermally symmetric structure 7 includes at least one folded structure corresponding to the first half-bridge structure 71, the supporting rod 9 may also be disposed at the at least one folded structure corresponding to the first half-bridge structure 71, in analogy to the disposing manner of the supporting rod 9 in fig. 25 and 26, so as to further improve the structural stability of the infrared detector formed by the detector pixel.

Alternatively, the difference between the unbalanced thermal conductivities of the support bar 9 and the other three-sided structure of the rectangle in which the support bar 9 is located may be set to be less than or equal to 20%, that is, the difference between the thermal conduction speeds of the support bar 9 and the other three-sided structure of the rectangle in which the support bar 9 is located is set to be less than or equal to 20%, and taking the thermal conduction speed of the support bar 9 as 1 as an example, the thermal conduction speed of the other three-sided structure of the rectangle in which the support bar 9 is located is greater than or equal to 0.8 and less than or equal to 1. Preferably, the thermal conductance of the supporting rod 9 is the same as that of the other three-sided structure of the rectangle in which the supporting rod 9 is located.

Specifically, the support bar 91 may be provided to have the same thermal conductance as the support bar 91 of the three-sided structure corresponding to the rectangle a1, the support bar 92 may be provided to have the same thermal conductance as the support bar 92 of the three-sided structure corresponding to the rectangle a2, and the support bar 93 may be provided to have the same thermal conductance as the support bar 93 of the three-sided structure corresponding to the rectangle a 3. Thus, the supporting rod 9 satisfies the aforementioned heat balance relationship, the heat conductance of the supporting rod 9 and the partial beam structure 27 corresponding to the supporting rod 9 and having the same heat flow direction is the same or similar, so that the heat conductance increased by the supporting rod 9 is the minimum, the influence of the supporting rod 9 on the total heat conductance of the detector pixel is the minimum, that is, the supporting rod 9 is a structure designed on the basis of the thermal symmetric structure 7, and the supporting rod 9 can improve the local stress distribution of the beam structure 27 and form heat balance with the partial beam structure 27.

Therefore, the detector pixel provided by the embodiment of the disclosure can realize the thermal balance of the whole structure or the local structure of the microbridge, the thermal conductivity unbalanced difference range of the thermal conductivity of the two parts in each thermal symmetric structure 7 and the support rod 9 is within 20%, the total thermal conductivity of the combined detector pixel reaches the minimum value, and meanwhile, the support rod 9 can effectively improve the mechanical strength of the detector pixel.

Alternatively, at least one corner of the beam structure 27 may be configured as a rounded corner; and/or the width of the supporting rod 9 is more than or equal to the set width. Each corner of the beam structure 27 is exemplarily arranged to be a right-angle corner in combination with fig. 12 to 14 and fig. 25 and 26, and at least one corner of the beam structure 27 may be arranged to be an arc-shaped corner, so as to reduce stress and deformation of the beam structure 27 when subjected to an external force, and improve stability of the detector pixel. In addition, the width of the supporting rod 9 can be set to be larger than or equal to a set width, namely, the supporting rod 9 is widened to reduce stress and deformation of the beam structure 27 when the beam structure 27 is subjected to external force, so that stability of the detector pixel is improved, and the connecting rod 8 or the inflection structures at two ends of the beam structure 27 can be widened to reduce stress and deformation of the beam structure 27 when the beam structure 27 is subjected to external force, so that stability of the detector pixel is improved. Exemplarily, as shown in fig. 27, the triangular structure 200 shown in fig. 27 may also be disposed at the stress concentration position to reduce stress and deformation of the beam structure 27 when an external force is applied, so as to improve stability of the detector pixel.

The first half-bridge structure and the second half-bridge structure with the thermal conductivity non-equilibrium difference value being less than or equal to 20% are utilized to form the thermal symmetry structure, the total thermal conductivity of the detector pixel is further reduced, the infrared detection performance of the infrared detector is further improved, the stress and deformation of the micro-bridge structure under the same force are reduced, the stability and the impact resistance of the detector pixel are improved, the structural stability of the whole infrared detector is further improved, and the mechanical strength of the infrared detector is enhanced.

It is noted that, in this document, relational terms such as "first" and "second," and the like, may be 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 phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The foregoing are merely exemplary embodiments of the present disclosure, which 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, comprising:

the infrared absorption spectrum band of the infrared detector is 3-30 microns;

the detector pixel comprises:

the first half-bridge structure comprises a support layer, an electrode layer and a passivation layer, the second half-bridge structure comprises a support layer, the length of the first half-bridge structure in the thermally symmetric structure is greater than that of the second half-bridge structure, and the unbalanced difference in thermal conductivity between the first half-bridge structure and the second half-bridge structure in the thermally symmetric structure is less than or equal to 20%.

2. The infrared detector as claimed in claim 1, wherein the electrode layer comprises a bulk electrode structure and a beam electrode structure, the bulk electrode structure is electrically insulated from the beam electrode structure, and the patterned hollow structure is disposed on the bulk electrode structure;

3. The infrared detector as set forth in claim 1, wherein the electrode layer includes first and second bulk electrode structures, and first and second beam electrode structures;

4. The infrared detector of claim 2 or 3, characterized in that the detector pixels comprise:

5. The infrared detector as claimed in claim 4, wherein the cavity from the reflective layer to the passivation layer forms a resonant cavity, and the height of the resonant cavity is greater than or equal to 1 micron and less than or equal to 2.5 microns.

6. The infrared detector as claimed in any one of claims 1 to 3, wherein the thickness of said electrode layer is 50 nm or less.

7. The infrared detector as claimed in any one of claims 1 to 3, wherein the side length of the patterned hollow structures of regular hexagon is 0.1 micron or more and 2 microns or less, and the minimum distance between the patterned hollow structures of adjacent regular hexagon is 0.1 micron or more and 1 micron or less.

8. The infrared detector as set forth in claim 1, wherein each of said beam structures has two connection points with said absorber plate.

9. The infrared detector as claimed in claim 8, wherein the beam structure including the thermally symmetric structure includes at least one folded structure, at least one of the folded structures is correspondingly provided with a support rod, the support rod includes a support layer, and the support rod and the folded portion of the folded structure form a rectangle;

10. A method for manufacturing an infrared detector, which is used for manufacturing the infrared detector as claimed in any one of claims 1 to 9, the method comprising:

forming an entire electrode layer;