Uncooled infrared detector chip

Abstract

The utility model relates to an uncooled infrared detector chip, which comprises a substrate, an effective element area is arranged on the substrate, effective elements are arranged in the effective element area, effective element dummy areas are arranged on the periphery of the effective element area, dummy effective elements are arranged in the effective element dummy areas, and at least one dummy effective element is used as a blind element corresponding to the effective element. And the read-out circuit is electrically connected with the read-out circuit on the substrate. According to the chip layout, a dummy effective element is adopted to replace a blind element, a dummy effective element preparation method adopts a protection layer mode, it is guaranteed that the dummy effective element is changed into a substrate hot short mode from an original suspended structure, the preparation technology is not changed, and the manufacturing cost is reduced. The design of the blind pixel working resistor is changed from the original parallel connection of a single blind pixel or a plurality of blind pixels to the electrical connection of n * n dummy effective elements used as the blind pixels, and every n dummy effective elements used as the blind pixels are connected in series and then connected in parallel. According to the design of the utility model, the utilization rate of the chip area and the uniformity of the blind pixel resistance are effectively improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of non-refrigerated infrared detectors, and in particular relates to a non-refrigerated infrared detector chip. Background Art

[0002] Uncooled infrared thermal imagers are widely used in defense industry, security monitoring, human body temperature monitoring and smart home. As the civilian market gradually expands, the demand for uncooled infrared thermal imagers will gradually expand. The demand for uncooled infrared detectors, the core components of uncooled infrared thermal imagers, will also expand simultaneously. However, the high cost of uncooled infrared detectors limits its application in the civilian market. At the same time, the size, weight, performance and cost (SWaP) of uncooled infrared detectors will develop in the direction of smaller (size, weight), better (performance) and lower (cost). Among them, cost is particularly critical. Cost reduction will help expand the application field of uncooled infrared detectors. The expansion of demand will further reduce the cost of production, thereby popularizing and widely using uncooled infrared detectors.

[0003] The cost of uncooled infrared detectors includes the cost of uncooled infrared detector packaging and chips. Uncooled infrared chips are mainly produced using semiconductor process methods. The mainstream of semiconductor production is the eight-inch silicon wafer production line. If the area of ​​each chip is reduced, the number of chips concentrated on a silicon wafer will increase, and the cost of each chip will be reduced. At the same time, if the area of ​​the chip is reduced, the volume and weight of the detector will also be reduced, which is conducive to the application of the detector.

[0004] The uncooled infrared chip is made by preparing a MEMS chip on the structure of the readout circuit. The layout of the MEMS chip mainly includes three parts: effective element, reference element and blind element. Effectively reducing the area of ​​these three parts will play a key role in the size of the uncooled infrared chip. However, the area size of the effective element and the reference element is mainly determined by the pixel size and the array specifications. These two have a direct impact on the performance of the uncooled infrared detector and are difficult to reduce. Blind pixels have no direct impact on performance. Reducing the area of ​​blind pixels to reduce the area of ​​the chip will be an effective way. Utility Model Content

[0005] The utility model aims to solve at least one of the technical problems existing in the prior art, and proposes a non-cooling infrared detector chip, which has a smaller volume, lighter weight and lower cost.

[0006] The technical solution of the utility model is implemented as follows: a non-cooled infrared detector chip includes a substrate, an effective element area is provided on the substrate, effective elements are arranged in the effective element area, effective element dummy areas are provided around the effective element area, dummy effective elements are arranged in the effective element dummy area, at least one dummy effective element is used as a blind element, and is electrically connected to a readout circuit on the substrate, and the dummy effective element used as a blind element adopts a substrate thermal short structure.

[0007] Furthermore, the effective element adopts a microbridge suspended structure, and a sacrificial layer is provided between the dummy effective element used as a blind element and the substrate.

[0008] Furthermore, isolation grooves are arranged around the dummy effective element used as the blind element, and the isolation grooves are configured to prevent the sacrificial layer of the dummy effective element used as the blind element from being released.

[0009] Furthermore, the thermal sensitive element pattern of the dummy effective element used as a blind element is consistent with the thermal sensitive element pattern of the effective element, and the absorption layer material pattern of the dummy effective element used as a blind element is configured so that the absorption layer material covers the entire surface of the sacrificial layer.

[0010] Furthermore, a light shielding layer is added on the dummy effective element used as a blind element.

[0011] Furthermore, the resistance value of a single dummy effective element is the same as the resistance value of an effective element.

[0012] Furthermore, a readout circuit is provided on the substrate, and the readout circuit includes an amplifying circuit and a blind element branch and an effective element branch. The blind element branch includes a blind element working resistor and a first transistor connected in series, and the effective element branch includes an effective element resistor and a second transistor. One end of the blind element branch is connected to one end of the power supply, and the other end of the blind element branch is connected to one end of the effective element branch and the input end of the amplifying circuit. One end of the effective element branch is connected to the input end of the amplifying circuit, and the other end of the effective element branch is connected to the other end of the power supply. The blind element working resistor is formed by electrically connecting at least one dummy effective element used as a blind element.

[0013] Furthermore, the resistance value of the blind element working resistance is consistent with the resistance value of the effective element resistance.

[0014] Furthermore, the amplifying circuit includes an integrating capacitor and an amplifier, one end of the integrating capacitor is connected to the input end of the amplifier, and the other end of the integrating capacitor is connected to the output end of the amplifier, the input end of the amplifier is the input end of the amplifying circuit, and the output end of the amplifier is the output end of the amplifying circuit.

[0015] Furthermore, the blind pixel working resistor is formed by electrically connecting n*n dummy effective elements used as blind pixels, wherein every n dummy effective elements used as blind pixels are connected in series and then in parallel with each other.

[0016] Furthermore, a reference element region is provided on the substrate, the reference element region is provided with a reference element, a reference element dummy region is provided around the reference element region, the reference element dummy region is provided with a dummy reference element, and at least one dummy reference element is used as a blind element corresponding to the reference element.

[0017] The embodiments of the present invention have at least the following beneficial effects:

[0018] The non-cooled infrared detector chip of the utility model replaces blind elements with dummy effective elements, thereby reducing the chip area and increasing the number of chips. The number of dummy effective elements does not change, thereby ensuring the uniformity of the effective elements.

[0019] The dummy effective element of the non-cooling infrared detector chip of the utility model adopts the method of substrate thermal shorting to replace the original suspended structure, thereby ensuring the stability of circuit operation.

[0020] The dummy effective element of the uncooled infrared detector chip of the utility model adopts a non-bridge leg structure to replace the original bridge leg structure, thereby ensuring the thermal shorting of its substrate and the uniformity of the pixel, thereby reducing the occurrence of image non-uniformity caused by the defects of a single dummy effective element.

[0021] The dummy effective element substrate of the non-cooled infrared detector chip of the utility model is thermally shorted in a manner that ensures that the sacrificial layer of the dummy effective element is not released, that is, isolation grooves are designed around the dummy effective element to ensure that the substrate is thermally shorted.

[0022] The design value of a single blind element resistance of a traditional uncooled infrared detector chip is N times (such as 4 times) the effective element resistance value, and the blind element working resistance is formed by connecting N (such as 4) blind elements in parallel. The blind element working resistance of the uncooled infrared detector chip of the utility model is formed by electrically connecting n*n dummy effective elements used as blind elements, wherein every n dummy effective elements used as blind elements are connected in series and then in parallel with each other. The design of the dummy effective element resistance is consistent with the design of the effective element resistance, occupies a smaller area, and can improve the resistance non-uniformity brought by the process, and can ensure matching with the effective element resistance, while also reducing the resistance deviation caused by the process non-uniformity.

[0023] The blind pixels corresponding to the original reference pixels in the non-cooled infrared detector chip of the utility model will also be replaced by dummy reference pixels, which reduces the chip area and increases the utilization rate of the wafer area.

[0024] The non-cooling infrared detector chip of the utility model adopts the original dummy effective element to replace the blind element, and then adds a light shielding layer to the dummy effective element to reduce the absorption of infrared light. The light shielding layer adopts Al material.

[0025] The uncooled infrared detector chip of the utility model involves a change in chip layout, but the chip manufacturing process remains unchanged, and the time and cost of the manufacturing process are not increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 This is a working diagram of the non-cooling infrared chip of the utility model;

[0028] Figure 2 This is the layout diagram of the traditional uncooled infrared chip array;

[0029] Figure 3 It is a schematic diagram of the structure of the blind element;

[0030] Figure 4 It is a structural diagram of the effective element;

[0031] Figure 5 This is a planar layout diagram of the uncooled infrared chip of the utility model;

[0032] Figure 6 It is a schematic diagram of the structure of the substrate thermal short dummy effective element;

[0033] Figure 7 It is the design schematic diagram of the traditional blind resistor;

[0034] Figure 8 A schematic diagram of a design of an embodiment of a dummy effective element resistor;

[0035] Fig. 9 A schematic diagram of another embodiment of a dummy effective element resistor;

[0036] Fig.10 It is a schematic diagram of the design of the dummy effective element resistor reflective layer of the utility model. DETAILED DESCRIPTION

[0037] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0038] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, words such as "one", "one" or "the" do not indicate quantity restrictions, but indicate the existence of at least one. Words such as "include" or "comprise" mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described target changes, the relative positional relationship may also change accordingly.

[0039] In each of the accompanying drawings, identical elements are represented by similar reference numerals. For the sake of clarity, the various parts in the accompanying drawings are not all drawn to scale. In addition, some well-known parts may not be shown in the drawings.

[0040] Many specific details of the present invention are described below, such as the structure, materials, dimensions, processing techniques and technologies of the components, so as to more clearly understand the present invention. However, as those skilled in the art will appreciate, the present invention may be implemented without following these specific details.

[0041] The circuit working mode of the uncooled infrared detector chip uses the difference between the blind element current and the effective element current to form an image by integrating and amplifying the output voltage. When the detector is radiated by external infrared energy, because the blind element current remains unchanged and the effective element current changes, the output voltage is integrated and amplified for the changed effective element current to form an image corresponding to the infrared radiation energy. The blind element adopts the method of substrate thermal short, that is, the blind element resistance is not affected by external infrared radiation, that is, the blind element current remains unchanged before and after infrared radiation. The effective element adopts a microbridge suspended structure, and the effective element resistance is very sensitive to external infrared radiation, so the effective element current changes with the change of infrared radiation energy, thereby indirectly reflecting the infrared radiation energy. The microbridge suspended structure is also called a MEMS structure, which is realized by MEMS technology, including coating process, photolithography process, etching process, cleaning process and release process.

[0042] Figure 1Where Ra is the blind element working resistance, Rb is the effective element resistance, and the design values ​​of Ra and Rb resistance are consistent (such as Ra and Rb are 100K-500K). V is the blind element power supply, which can provide a power supply with a voltage of 3V-8V. M1 and M2 are the first transistor and the second transistor respectively. When the gate voltage is greater than the threshold voltage, the transistor is turned on, and the blind element current and the effective element current are turned on. GND is grounded to ensure the conduction of the effective element. C1 is an integral capacitor, and A1 is an amplifier. The blind element and the effective element bifurcated current are integrated and amplified through C1 and A1 to output the final required voltage signal Vout.

[0043] Figure 2 This is a normal planar layout diagram of a traditional uncooled infrared detector chip, where 1 is the effective element area, and its area is determined by the pixel size and array specifications. 2 is the blind element area, and each column of effective elements corresponds to a group of blind elements. Its corresponding area is not as large as the effective element area, but it also occupies a certain proportion of the chip area. The utility model focuses on reducing the area of ​​this area. 3 is the reference element area, and 4 is the blind element area corresponding to the reference element. It plays the role of providing a reference voltage to the effective element. Its area is relatively small and has not been changed in the utility model. The utility model changes the area of ​​2, that is, the utility model cancels the blind element area. Figure 2 2 and 4 in the figure. 5 is the effective element dummy area, which is used to ensure the uniformity of the pattern change of the effective element, that is, adding dummy effective elements can improve the uniformity of the edge effective elements and ensure the consistency of the pixel output voltage.

[0044] The blind pixel design of the traditional uncooled infrared chip is to mark out a certain area on the chip, and its number is consistent with the number of columns of effective pixels. At the same time, in order to improve the uniformity of the blind pixel resistance, several parallel connections are generally adopted, see Figure 7 As shown. The blind pixel structure generally adopts a long strip structure design, so the blind pixel occupies a larger area, increases the area of ​​the entire chip, and reduces the number of chips contained in the same wafer. For example, the blind pixel area of ​​a traditional non-cooled infrared detector chip generally occupies one-third to one-sixth of the chip area, and the proportion is related to the chip array specifications and the readout circuit design. Depending on the chip specifications, the number of chips contained in each eight-inch wafer ranges from dozens to hundreds. By reducing the area of ​​the blind pixel area, the number of chips on a single wafer can be increased from 30% to more than ten percent, and the manufacturing cost of a single chip can be reduced in the same proportion. The utility model adopts a method of replacing the blind pixel with an effective pixel, and at the same time sets the blind pixel in the dummy area of ​​the effective pixel, which can effectively reduce the area of ​​the blind pixel area, integrate the blind pixel area with the effective pixel area, reduce the area of ​​the overall chip, increase the number of chips on the same wafer, and reduce the manufacturing cost of the chip.

[0045] In order to improve the response rate of large-array detectors, a dual-channel method is adopted. The corresponding chip array area has two upper and lower blind element areas, and the corresponding dummy effective elements are also around the upper and lower effective elements. The utility model can also be applied to large-array detectors, saving two blind element areas, and the area utilization rate of the chip will be higher.

[0046] Figure 3 and Figure 4 The diagrams are of the structure of a single blind element and an effective element. The traditional blind element uses a rectangular structure substrate thermal short, which can ensure that the resistance remains constant under infrared radiation. The effective element uses a cantilever beam suspended structure, which ensures less heat loss. The height of the suspended structure is between (2.0um-2.2um), which is 1 / 4 of the long-wave infrared wavelength. According to the multiple absorption theory, it ensures the highest infrared absorption energy.

[0047] In the operation of uncooled infrared detectors, the design of blind element working resistance and effective element resistance is basically the same, which is conducive to improving the matching of blind element current and effective element current and improving the adjustable range of voltage. The traditional single blind element resistance is designed to be N times of a single effective element, and N (N can be 2 or more) parallel connections are used to form the blind element working resistance. The blind element working resistance is consistent with the effective element resistance. The use of N parallel connections can effectively improve the non-uniformity of resistance caused by the non-uniformity of the process and improve the matching with the effective element resistance. The Dummy effective element has the same resistance design as the effective element. In order to improve the non-uniformity of resistance caused by the process, several series and several parallel connections are used (2 series, 2 parallel connections, 3 series, 3 parallel connections...), which can ensure the matching with the effective element resistance and reduce the resistance deviation caused by the process non-uniformity.

[0048] See also Figure 5 An embodiment of the utility model provides a non-cooled infrared detector chip, including a substrate, an effective element area is provided on the substrate, an effective element is set in the effective element area, an effective element dummy area is provided around the effective element area, the effective element dummy area is provided with dummy effective elements, at least one dummy effective element is used as a blind element corresponding to the effective element, and is electrically connected to the readout circuit on the substrate. Figure 5 is the chip layout diagram of the utility model, and Figure 2 Compared with the traditional FPGA, the blind element area is reduced, the utilization rate of the chip area is improved, but the normal operation of the chip is guaranteed, and the performance remains unchanged. 01 and 03 are the effective element area and the reference element area respectively. Figure 2 The original structure is consistent with the layout. 05 and 06 are dummy valid elements and dummy reference elements respectively. Figure 5The function of the dummy effective element and the dummy reference element remains unchanged, ensuring the consistency of the edge effective element and the reference element. The surface structure of the dummy effective element and the dummy reference element is the same, which can ensure the consistency of the edge effective element and the reference element.

[0049] The effective element area refers to the area where the non-cooled infrared chip absorbs infrared, and it is composed of pixels of the surface array specification. In semiconductor technology, due to process characteristics, the uniformity of pixels is related to the surrounding graphics, that is, if the graphics around the pixels are consistent, the better its uniformity. The edge pixels are different from the middle pixels because of the surrounding graphics. In order to improve the consistency of the edge effective element pixels and the middle effective element pixels, dummy pixels are generally added around the surface array. These dummy pixels are consistent with the effective element design, which improves the consistency of the edge effective element and the middle effective element, but does not participate in the work. The utility model designs the dummy effective element in the effective element dummy area into a blind pixel, which ensures the consistency of the effective element and reduces the area of ​​the blind pixel area and the chip area.

[0050] In some embodiments, the effective element adopts a microbridge suspended structure. The microbridge structure can effectively reduce thermal conductivity and reduce the loss of infrared thermal energy. At the same time, the suspended structure is conducive to the secondary absorption of infrared energy, improves the absorption rate of infrared energy, and increases the sensitivity of the infrared chip.

[0051] The blind element of the traditional uncooled infrared chip does not adopt the microbridge suspended structure, that is, the blind element of the traditional uncooled infrared detector chip adopts the substrate thermal short method, which can effectively reduce the self-heating effect of the blind element and maintain the stability of the blind element resistance. Because when the detector is working, the blind element always keeps the current passing through, the self-heating effect will increase, and the blind element temperature will rise. According to the resistance-temperature characteristics of the heat-sensitive element material, the blind element resistance will also change with the temperature rise. However, through the substrate thermal short method, the heat will quickly disappear, the blind element temperature will remain constant, and then the blind element resistance will also remain constant, ensuring the stability of the output current.

[0052] The traditional dummy effective element adopts a suspended structure. If the dummy effective element is used as a blind element, because the blind element needs to avoid the influence of infrared radiation energy and ensure the stability of the resistor, the suspended structure needs to be changed to a substrate thermal short structure, that is, the dummy effective element used as a blind element in the utility model needs to adopt a substrate thermal short method, and the dummy effective element bridge surface interconnection method is adopted to ensure that the dummy effective element substrate material PI is not released, so as to achieve the substrate thermal short method. In order to further ensure that the edge pixel is not released, an isolation groove can be added around the dummy effective element, and the purpose of PI not being released is achieved by the thin film in the isolation groove. The bridge surface interconnection method adopts a pixel non-division method, which only requires the mask design to be inconsistent with the effective element design, and the process can be completely consistent, without adding process steps and process conditions. There is no cost change and process change for the manufacture and production of the chip, so that the utility model is convenient and easy to implement. The isolation groove solution also only requires the mask to add an isolation groove design around the dummy effective element. The original isolation groove is designed around the blind element. The process scheme and process flow are consistent with the original one, and there is no increase in manufacturing and production costs.

[0053] The sacrificial layer material of the suspended structure is PI material, which is released through the chemical reaction of O2 plasma. The dummy effective element with thermal short substrate adopts a non-suspended structure. The entire surface of the sacrificial layer (the entire surface of the sacrificial layer includes the upper surface and side walls of the sacrificial layer) is covered by the absorption layer material (SIN) to avoid reaction with O2 plasma. The non-release method is adopted to ensure the thermal short substrate structure and function of the dummy effective element. Figure 6 This is a design schematic diagram of a substrate thermal short dummy effective element, in which the patterns of the conductive and thermal sensitive elements are consistent with the effective element, but the pattern of the absorption layer material is inconsistent. The absorption layer material pattern of the substrate thermal short dummy effective element is configured as the absorption layer material covering the sacrificial layer material. The effective element pattern adopts a bridge leg structure while the substrate thermal short dummy effective element adopts a non-bridge leg structure.

[0054] In some embodiments, a readout circuit is provided on the substrate, and the readout circuit includes an amplifying circuit and a blind element branch and an effective element branch. The blind element branch includes a blind element working resistor Ra and a first transistor M1 connected in series, and the effective element branch includes an effective element resistor Rb and a second transistor M2. One end of the blind element branch is connected to one end of the power supply (i.e., the power supply voltage), and the other end of the blind element branch is connected to one end of the effective element branch and the input end of the amplifying circuit, one end of the effective element branch is connected to the input end of the amplifying circuit, and the other end of the effective element branch is connected to the other end of the power supply (i.e., ground).

[0055] In this embodiment, one end of the blind element working resistor Ra is connected to one end of the power supply (i.e., the power supply voltage), the other end of the blind element working resistor Ra is connected to the input end of the amplifier circuit via the first transistor M1, one end of the effective element resistor Rb is connected to the input end of the amplifier circuit via the second transistor M2, and the other end of the effective element resistor Rb is connected to the other end of the power supply (i.e., ground).

[0056] The uncooled infrared detector chip applies voltage to one end of the blind element working resistor Ra, and then passes through a first field effect transistor. The first field effect transistor corresponds to a gate voltage, which controls the opening and closing of the first field effect transistor. After the blind element current passes through the first field effect transistor, it is divided into two paths. One path passes through the effective element resistor of the effective element branch and the second field effect transistor. The second field effect transistor controls the opening and closing of the effective element branch, and then the end of the second field effect transistor is grounded; the other path is connected to the amplifier and integration capacitor of the readout circuit, outputs an effective voltage, and finally converted into a recognizable image.

[0057] In some embodiments, the amplifying circuit includes an integrating capacitor and an amplifier, one end of the integrating capacitor is connected to the input end of the amplifier, and the other end of the integrating capacitor is connected to the output end of the amplifier, the input end of the amplifier is the input end of the amplifying circuit, and the output end of the amplifier is the output end of the amplifying circuit.

[0058] In some embodiments, the blind pixel working resistor Ra is formed by electrically connecting n*n dummy effective elements used as blind pixels, wherein every n dummy effective elements used as blind pixels are connected in series and then connected in parallel. That is, every n dummy effective elements used as blind pixels are connected in series to form n branches, and the n branches are connected in parallel to form the blind pixel working resistor Ra. n is a positive integer, such as n in this embodiment is 2 or 3.

[0059] The blind cell working resistance of the traditional uncooled infrared detector chip is constructed by parallel blind cells, which is used to improve the uniformity of the blind cell resistance. After multiple blind cells are connected in parallel, the resistance is equivalent to the effective cell resistance. Then the resistance of a single blind cell is a multiple of the effective cell resistance, and the multiple is related to the number of blind cells in parallel. In this case, the resistance of a single blind cell will be relatively large, and its length will be relatively long. The area of ​​the blind cell region will also increase. In addition, with the number of blind cells in parallel, the area of ​​the blind cell region will occupy a certain area of ​​the chip. After the dummy effective cell is designed as a blind cell, because the dummy effective cell resistance is consistent with the effective cell resistance and occupies a smaller area, in order to improve the uniformity of resistance and maintain the consistency between the blind cell working resistance and the effective cell resistance, a series connection plus parallel connection is adopted to achieve the required resistance. See Figure 8 If the number of dummy effective elements is four, the blind element working resistance is composed of four dummy effective elements connected in series and then in parallel, see Fig. 9, if the number of dummy effective elements is nine, the blind element working resistance is composed of three dummy effective elements connected in series and then in parallel, and so on. The series and parallel modes are implemented through the readout circuit. The number of dummy effective elements is determined according to the area of ​​the effective element region and the size of the effective element array. In principle, the larger the dummy effective element, the better the consistency of the boundary effective element, but the area occupied will become larger. In order to further improve the uniformity of the dummy effective element, the edge row can still be designed as a traditional dummy effective element and does not participate in the work.

[0060] In some embodiments, a light shielding layer is added on the dummy effective element used as a blind element. Fig.10 It is designed for dummy effective element with reflective layer. In the traditional blind element design, a reflective layer is added to prevent the blind element from absorbing infrared energy. The reflective layer is generally made of metal AL. The dummy effective element is replaced by the blind element. A reflective layer (metal AL) can also be added to the dummy effective element to reduce the absorption of infrared energy and ensure the stability of resistance. The process production method is consistent with the traditional blind element. Fig.10 6 is a metal (AL) reflective layer.

[0061] In some embodiments, a reference element region is provided on the substrate, and a reference element is provided in the reference element region. A reference element dummy region is provided around the reference element region, and a dummy reference element is provided in the reference element dummy region. The reference element adopts a structural design consistent with the effective element, but adopts a substrate thermal shorting method, that is, the reference element is consistent with the effective element resistance, but is insensitive to infrared absorption and self-heating effects. A reference current is provided to the effective element by the reference element, which can effectively reduce the influence of the substrate temperature on the effective element resistance, thereby achieving higher sensitivity.

[0062] The dummy reference element has the same structure as the effective reference element, and the blind element corresponding to the reference element has the same function as the blind element corresponding to the effective element.

[0063] The reference element provides a reference voltage to the effective element, and can provide feedback on the temperature of the chip substrate. The utility model does not need to change the design and process of the reference element, and can maintain the consistency of the traditional method. However, if the original design of the reference element corresponds to a blind element, the utility model can change the blind element design corresponding to the reference element to a dummy reference element, and the utility model is still applicable. After adopting the utility model, the blind element position corresponding to the reference element is effectively saved, and the corresponding area is saved.

[0064] In some embodiments, at least one dummy reference element is used as a blind element corresponding to the reference element.

[0065] The blind pixel part of the conventional uncooled infrared chip is designed to be large in size, occupying a large area of ​​the chip, thereby increasing the area of ​​a single chip and the manufacturing cost. However, the utility model effectively reduces the blind pixel area, thereby reducing the chip area and reducing the manufacturing cost.

[0066] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An uncooled infrared detector chip, comprising a substrate, wherein an effective element region is provided on the substrate, and effective elements are arranged in the effective element region, characterized in that: An effective element dummy area is arranged around the effective element area, and the effective element dummy area is provided with dummy effective elements. At least one dummy effective element is used as a blind element and is electrically connected to the readout circuit on the substrate. The dummy effective element used as a blind element adopts a substrate thermal short structure.

2. The uncooled infrared detector chip according to claim 1, characterized in that: The effective element adopts a microbridge suspended structure, and a sacrificial layer is provided between the dummy effective element used as a blind element and the substrate.

3. The uncooled infrared detector chip according to claim 2, characterized in that: Isolation grooves are arranged around the dummy effective element used as a blind element, and the isolation grooves are configured to prevent the sacrificial layer of the dummy effective element used as a blind element from being released.

4. The uncooled infrared detector chip according to claim 1, 2 or 3, characterized in that: The thermal sensitive element pattern of the dummy effective element used as a blind element is consistent with the thermal sensitive element pattern of the effective element, and the absorption layer material pattern of the dummy effective element used as a blind element is configured so that the absorption layer material covers the entire surface of the sacrificial layer.

5. The uncooled infrared detector chip according to claim 1, characterized in that: A shading layer is added to the dummy effective element used as a blind element.

6. The uncooled infrared detector chip according to claim 1, characterized in that: The resistance value of a single dummy effective element is the same as the resistance value of a single effective element.

7. The uncooled infrared detector chip according to claim 1, characterized in that: The readout circuit includes an amplifier circuit and a blind element branch and an effective element branch. The blind element branch includes a blind element working resistor and a first transistor connected in series. The effective element branch includes an effective element resistor and a second transistor. One end of the blind element branch is connected to one end of a power supply, and the other end of the blind element branch is connected to one end of an effective element branch and an input end of the amplifier circuit. One end of the effective element branch is connected to the input end of the amplifier circuit, and the other end of the effective element branch is connected to the other end of the power supply. The blind element working resistor is formed by electrically connecting at least one dummy effective element used as a blind element.

8. The uncooled infrared detector chip according to claim 7, characterized in that: The amplifying circuit includes an integrating capacitor and an amplifier, one end of the integrating capacitor is connected to the input end of the amplifier, and the other end of the integrating capacitor is connected to the output end of the amplifier. The input end of the amplifier is the input end of the amplifying circuit, and the output end of the amplifier is the output end of the amplifying circuit.

9. The uncooled infrared detector chip according to claim 7, characterized in that: The blind pixel working resistor is formed by electrically connecting n*n dummy effective elements used as blind pixels, wherein every n dummy effective elements used as blind pixels are connected in series and then in parallel.

10. The uncooled infrared detector chip according to claim 1, characterized in that: A reference element region is provided on the substrate, a reference element is provided in the reference element region, a reference element dummy region is provided around the reference element region, a dummy reference element is provided in the reference element dummy region, and at least one dummy reference element is used as a blind element corresponding to the reference element.

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