Uncooled infrared detection pixel, chip, movement and device

Abstract

The present disclosure relates to the technical field of infrared detection, and particularly relates to a non-cooled infrared detection pixel, a chip, a movement and equipment, the non-cooled infrared detection pixel comprises one or more interconnection structures connected with a readout circuit and an infrared sensing structure; wherein each interconnection structure comprises: a first aluminum connecting part, a tungsten structure and a second aluminum connecting part; wherein the tungsten structure is connected between the first aluminum connecting part and the second aluminum connecting part, and the first aluminum connecting part and / or the second aluminum connecting part comprises an aluminum layer and a titanium layer and / or a titanium nitride layer located on a side of the aluminum layer away from the readout circuit and / or a side of the aluminum layer facing the readout circuit, so that the interconnection structure can solve the problem of unstable noise caused by interconnection of the infrared detection chip, and can improve the process stability.

Description

Technical Field

[0001] This disclosure relates to the field of infrared detection technology, and in particular to an uncooled infrared detection pixel, chip, mechanism, and device. Background Technology

[0002] Infrared detection is a technology that uses the infrared radiation emitted or reflected by objects to detect, identify, and locate them. Uncooled infrared detection equipment is a device that uses the infrared radiation characteristics of objects for detection and can operate without a cooling system. Specifically, uncooled infrared detection equipment mainly works based on the principle of thermal effect. When an infrared signal shines on the sensitive element of the detector, such as a detection chip, the detection chip changes its own physical parameters based on the infrared signal, converts it into an electrical signal, and then reads it out through circuitry and performs subsequent processing to ultimately detect and image the infrared signal.

[0003] In related technologies, infrared detection pixels often employ a hollow columnar structure of single-layer metal as the interconnect structure to connect the readout circuit and the infrared sensing structure, achieving both electrical connection and mechanical support. A single-layer metal interconnect structure (such as patent CN202110138398.5) is shown below. Figure 18 The microbridge pillar 7 shown is formed by etching through-holes in the sacrificial layer 9 and then filling them with a metal layer 4 to create a hollow pillar structure. The defects of this process include:

[0004] 1) Through-holes formed by etching may have residual media due to incomplete removal during the etching, resist removal, and cleaning processes (e.g.) Figure 18 The outer side of the dielectric layer 3 and the sacrificial layer 9 at the location of the micro-bridge pillar 7 and the bottom of the reflective layer are in contact, and the residual condition of each via is not the same, making it difficult to ensure process consistency; at the same time, the temporarily retained particles will have a great impact on the noise of the pixel, so it will lead to unstable pixel noise. Pixels with relatively clean residual particles will have low noise, while pixels with incomplete residual particle removal will have high noise, so the noise consistency between pixels will be poor.

[0005] 2) The metal layer 4 inside the through hole has poor coverage, which may lead to the risk of electrical connection breakage; and the step coverage will vary, resulting in poor process consistency and resistance consistency.

[0006] 3) Through-hole processing requires two photolithography etching steps to form ( Figure 18At the bottom of the contact between the dielectric layer 3 and the metal layer 4 at the position of the micro-bridge pillar 7 and the reflective layer, the two via processes have high requirements for photolithography overlay and there is a risk of large overlay deviation. The resulting two vias have inconsistent positions and sizes, different areas and shapes of filling metal, and different interface characteristics with the readout circuit, resulting in poor consistency of contact resistance. Moreover, the two via processes mean that the size of the interconnect structure will inevitably not be too small, making it difficult to design small-sized pixels.

[0007] 4) Hollow columnar structure ( Figure 18 The design of the micro-bridge pillar 7) will result in an uneven surface during the fabrication process. Strict process control is required in the series of processes such as film growth, coating, photolithography, etching and cleaning. The process requirements are quite stringent.

[0008] 5) For infrared detector pixels with multi-layer structures, i.e., beam structures and absorption sensing parts with different or multiple layers of beam structures and absorption sensing parts, chemical mechanical polishing (CMP) is used to make the surface flat. However, in the design of hollow columnar structures, the hollow structure makes CMP more difficult and the surface flatness varies.

[0009] 6) Currently, the sacrificial layer 9 of traditional hollow columnar interconnect structures all adopt polyimide (PI) technology. The planarization process is not mature, making it difficult to accurately control the thickness of the sacrificial layer, which may deviate from the design requirements.

[0010] 7) There will be differences between the individual pixels made of hollow columnar structure, resulting in poor consistency of the entire infrared detection chip and greatly affecting the detection performance; at the same time, there will be differences between each chip and each wafer produced in batches, making it difficult to guarantee process stability and repeatability, and making it difficult to achieve large-scale mass production.

[0011] 8) Chips made from hollow columnar structures have a low yield and high processing costs. Utility Model Content

[0012] In order to solve the above-mentioned technical problems, or at least partially solve the above-mentioned technical problems, this disclosure provides an uncooled infrared detection pixel, chip, mechanism, and device.

[0013] This disclosure provides an uncooled infrared detection pixel, including multiple interconnected structures connecting readout circuits and infrared sensing structures; wherein each interconnected structure includes: a first aluminum connection portion, a tungsten structure, and a second aluminum connection portion; wherein the tungsten structure is connected between the first aluminum connection portion and the second aluminum connection portion;

[0014] The first aluminum connection portion and / or the second aluminum connection portion includes an aluminum layer and a titanium layer and / or a titanium nitride layer located on the side of the aluminum layer away from the readout circuit and / or on the side facing the readout circuit.

[0015] This disclosure also provides an uncooled infrared detection chip, including an array structure composed of multiple uncooled infrared detector pixels as described above and a readout circuit.

[0016] This disclosure also provides an uncooled infrared detection mechanism, which includes any of the above-mentioned uncooled infrared detection chips; the mechanism also includes a lens for focusing infrared signals onto the uncooled infrared detection chip.

[0017] This disclosure also provides an uncooled infrared detection device, which includes any of the aforementioned mechanisms.

[0018] The technical solution provided in this disclosure has the following advantages compared with the prior art:

[0019] In the uncooled infrared detection pixel, chip, core, and device provided in the embodiments of this disclosure, the uncooled infrared detection pixel includes multiple interconnect structures connecting readout circuits and infrared sensing structures; wherein each interconnect structure includes: a first aluminum connection portion, a tungsten structure, and a second aluminum connection portion; wherein the tungsten structure is connected between the first aluminum connection portion and the second aluminum connection portion, and the first aluminum connection portion and / or the second aluminum connection portion includes an aluminum layer and a titanium layer and / or a titanium nitride layer located on the side of the aluminum layer away from the readout circuit and / or on the side facing the readout circuit. Therefore, by setting the above interconnection structure, the connection between the readout circuit and the infrared sensing structure is realized. Compared with the traditional hollow columnar structure with a single layer of metal as the interconnection, the fabrication process of the interconnection structure in the uncooled infrared detection pixel provided in this disclosure is mature, with good process stability, no noise instability caused by residual particles, and good noise consistency. At the same time, it avoids the problem of poor electrical contact caused by high steps, with low contact resistance and good uniformity. In addition, the planarization process is mature and stable, and can perfectly meet the design requirements. Furthermore, the interconnection structure size can be made very small, enabling smaller pixel designs. Moreover, in the infrared detection chip formed by the infrared detection pixel including this interconnection structure, the consistency between different pixels is good and the performance is stable. In addition, the interconnection process can achieve efficient and low-cost production, so the infrared detection chip can achieve the goal of low processing cost, high yield, and mass production. Attached Figure Description

[0020] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0021] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of an uncooled infrared detection pixel provided in an embodiment of the present disclosure;

[0023] Figure 2 This is a schematic diagram of another uncooled infrared detection pixel provided in an embodiment of the present disclosure;

[0024] Figure 3 A partially enlarged structural schematic diagram of another uncooled infrared detection pixel provided in an embodiment of this disclosure;

[0025] Figure 4 This is a schematic diagram of the structure of another uncooled infrared detection pixel provided in an embodiment of the present disclosure;

[0026] Figure 5 This is a schematic diagram of the structure of another uncooled infrared detection pixel provided in an embodiment of the present disclosure;

[0027] Figure 6 This is a schematic diagram of the structure of another uncooled infrared detection pixel provided in an embodiment of the present disclosure;

[0028] Figure 7 This is a schematic diagram of the structure of another uncooled infrared detection pixel provided in an embodiment of the present disclosure;

[0029] Figure 8 This is a schematic diagram of the structure of another uncooled infrared detection pixel provided in an embodiment of the present disclosure;

[0030] Figure 9 This is a schematic diagram of the structure of another uncooled infrared detection pixel provided in an embodiment of the present disclosure;

[0031] Figure 10 This is a schematic diagram of the structure of another uncooled infrared detection pixel provided in an embodiment of the present disclosure;

[0032] Figure 11 This is a schematic diagram of the structure of another uncooled infrared detection pixel provided in an embodiment of the present disclosure;

[0033] Figure 12 This is a schematic diagram of the structure of another uncooled infrared detection pixel provided in an embodiment of the present disclosure;

[0034] Figure 13 This is a schematic diagram of the structure of another uncooled infrared detection pixel provided in an embodiment of the present disclosure;

[0035] Figure 14 A partial structural photograph of another uncooled infrared detection pixel provided in an embodiment of this disclosure;

[0036] Figure 15 A partial structural photograph of another uncooled infrared detector pixel provided in an embodiment of this disclosure;

[0037] Figure 16 This is a schematic diagram of the structure of an uncooled infrared detection chip provided in an embodiment of the present disclosure;

[0038] Figure 17 This is a schematic diagram of the structure of an uncooled infrared detector core provided in an embodiment of the present disclosure;

[0039] Figure 18 A schematic diagram of the structure of an infrared detection pixel is provided for related technologies. Detailed Implementation

[0040] To better understand the above-mentioned objectives, features, and advantages of this disclosure, the solutions disclosed herein will be further described below. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0041] Numerous specific details are set forth in the following description in order to provide a full understanding of this disclosure, but this disclosure may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only some, and not all, of the embodiments of this disclosure.

[0042] Figure 1 This is a schematic diagram of the structure of an uncooled infrared detector pixel provided in an embodiment of the present disclosure, illustrating a film structure of the uncooled infrared detector pixel. (Reference) Figure 1 The uncooled infrared detector pixel 10 may include: a readout circuit 100, an infrared sensing structure 110, and a plurality of interconnection structures 120 connecting the readout circuit 100 and the infrared sensing structure 110. For example, Figure 1 The number of interconnection structures 120 shown is two. In other embodiments, the number of readout circuits 120 connecting the readout circuit 100 and the infrared sensing structure 110 may be three, four or more, which is not limited here.

[0043] Each interconnect structure 120 includes: a first aluminum connection portion 121, a tungsten structure 122, and a second aluminum connection portion 123; wherein the tungsten structure 122 is connected between the first aluminum connection portion 121 and the second aluminum connection portion 123; the first aluminum connection portion 121 and / or the second aluminum connection portion 123 includes an aluminum layer 12A and a titanium layer 12Ti and / or a titanium nitride layer 12TiN located on the side of the aluminum layer 12A away from the readout circuit 100 and / or on the side of the aluminum layer 12A facing the readout circuit 100.

[0044] Both the first aluminum connecting part 121 and the second aluminum connecting part 123 can be referred to as aluminum connecting parts.

[0045] The aluminum connector includes an aluminum layer 12A, and at least one aluminum connector further includes at least one of a titanium layer and a titanium nitride layer, located on the side of the aluminum layer facing away from and / or towards the readout circuit. Figure 1 Taking the first aluminum connection portion 121 as an example, the first aluminum connection portion 121 includes an aluminum layer 12A, a titanium layer 12Ti, and a titanium nitride layer 12TiN; wherein, the titanium layer 12Ti is located on the side of the aluminum layer 12A away from the readout circuit 100, and the titanium nitride layer 12TiN is located on the side of the aluminum layer 12A facing the readout circuit 100. For example, taking... Figure 1 Taking the orientation shown as an example, aluminum layer 12A is located above readout circuit 100, titanium layer 12Ti is located above aluminum layer 1A, and titanium nitride layer 12TiN is located below aluminum layer 12A.

[0046] In other embodiments, the aluminum connector may include an aluminum layer and a titanium layer, with the titanium layer located on the side of the aluminum layer facing away from and / or towards the readout circuit; or, the aluminum connector may include an aluminum layer and a titanium nitride layer, with the titanium nitride layer located on the side of the aluminum layer facing away from and / or towards the readout circuit; or, the aluminum connector may include an aluminum layer, a titanium layer, and a titanium nitride layer, with the titanium layer located on the side of the aluminum layer facing away from and / or towards the readout circuit, and the titanium nitride layer located on the side of the aluminum layer facing away from and / or towards the readout circuit. When the titanium layer and the titanium nitride layer are located on the same side of the aluminum layer, the titanium layer is located between the aluminum layer and the titanium nitride layer, or the titanium nitride layer is located between the aluminum layer and the titanium layer, which is not limited herein.

[0047] The device also includes a titanium layer and / or a titanium nitride layer located on the side of the aluminum layer facing away from and / or towards the readout circuit, provided that at least one aluminum connection portion is provided. The titanium layer and / or titanium nitride layer can act as a diffusion barrier layer to prevent diffusion between the aluminum layer and the dielectric, thereby improving the stability and reliability of the device. Simultaneously, the titanium layer and / or titanium nitride layer can act as an adhesion layer to increase the adhesion between the aluminum layer and the dielectric and the tungsten structure, preventing film peeling that could affect the process and performance. Furthermore, the titanium layer and / or titanium nitride layer can act as an anti-reflection layer, significantly reducing reflectivity during photolithography and ensuring clear edges of the exposed pattern. Additionally, the titanium layer and / or titanium nitride layer can act as an etching barrier layer to prevent corrosion and damage to the aluminum layer during etching and cleaning. Finally, the titanium layer and / or titanium nitride layer can act as a protective layer to protect the aluminum layer surface from external environmental erosion and damage, thereby improving device performance and stability.

[0048] Continue to refer to Figure 1 In the uncooled infrared detection pixel 10, the interconnection structure 120 is connected between the infrared sensing structure 110 and the readout circuit 100. Based on this connection, the interconnection structure 120 can realize the transmission of electrical signals between the infrared sensing structure 110 and the readout circuit 100.

[0049] In the interconnection structure 120, the two ends of the tungsten structure 122 are respectively connected to the first aluminum connection portion 121 and the second aluminum connection portion 123. The first aluminum connection portion 121 is connected to the readout circuit 100, and the second aluminum connection portion 123 is connected to the infrared sensing structure 110. Specifically, with... Figure 1 For example, taking the connection path between the readout circuit 100 and the infrared sensing structure 110 as the sequence, the readout circuit 100 is connected to the first aluminum connection part 121, the first aluminum connection part 121 is connected to the tungsten structure 122, the tungsten structure 122 is connected to the second aluminum connection part 123, and the second aluminum connection part 123 is connected to the infrared sensing structure 110. This achieves the connection between the infrared sensing structure 110 and the readout circuit 100. This connection includes electrical connection and mechanical connection, which are not limited here, and will be illustrated by example later.

[0050] Specifically, the interconnection structure 120 includes a first aluminum connection portion 121 and a second aluminum connection portion 123 disposed opposite to each other, and a tungsten structure 122 disposed between the first aluminum connection portion 121 and the second aluminum connection portion 123.

[0051] For example, in the interconnect structure 120, along the direction away from the readout circuit 100, reference Figure 1 The direction shown in the image is from bottom to top. Figure 1(As shown to Z by a third party), the first aluminum connection 121, the tungsten structure 122 and the second aluminum connection 123 are stacked and connected in sequence, and the first aluminum connection 121 located on the lower layer is connected to the readout circuit 100, and the second aluminum connection 123 located on the upper layer is connected to the infrared sensing structure 110, so as to realize the transmission of electrical signals between the infrared sensing structure 110 and the readout circuit 100 based on the interconnection structure 120.

[0052] Specifically, the infrared sensing structure 110 converts infrared signals into electrical signals. The electrical signals are transmitted to the readout circuit 100 via the second aluminum connector 123, the tungsten structure 122, and the first aluminum connector 121, which are connected in sequence. The readout circuit 100 receives the electrical signals. The readout circuit 100 can reflect the temperature information of the corresponding infrared signal based on the received electrical signals, thereby realizing the temperature detection function of the infrared detection device.

[0053] In the uncooled infrared detector pixel 10 provided in this embodiment, the connection between the readout circuit 100 and the infrared sensing structure 110 is realized by setting the above-mentioned interconnection structure 120. Compared with the traditional hollow columnar structure with a single layer of metal as the interconnection, the interconnection structure 120 in the uncooled infrared detector pixel 10 provided in this embodiment has a mature manufacturing process, good process stability, no noise instability caused by residual particles, and good noise consistency. At the same time, it avoids the problem of poor electrical contact caused by high steps, with low contact resistance and good uniformity. In addition, the planarization process is mature and stable, and can perfectly meet the design requirements. Furthermore, the interconnection structure size can be made very small, enabling smaller pixel designs. Moreover, in the infrared detector chip formed by the infrared detector pixel including the interconnection structure, the consistency between different pixels is good and the performance is stable. In addition, the interconnection process can achieve efficient and low-cost production, so the infrared detector chip can achieve the goal of low processing cost, high yield, and mass production.

[0054] It should be noted that, Figure 1 The diagram illustrates, by way of example, that a tungsten structure 122 in a single interconnect structure 120 includes two tungsten pillars, but this does not constitute a limitation on the number of tungsten pillars in the tungsten structure 122. In other implementations, the number of tungsten pillars in a single tungsten structure 122 may be one or more, and is not limited herein.

[0055] In some embodiments, within the same interconnect structure 120, the plane containing the first aluminum connection portion 121 is parallel to the plane containing the second aluminum connection portion 123 and perpendicular to the tungsten structure 122.

[0056] In the same interconnect structure 120, the first aluminum connection portion 121 and the second aluminum connection portion 123 are arranged opposite to each other, and their planes are parallel; Figure 1Taking the shown orientation as an example, it can be understood that the planes containing the first aluminum connector 121 and the second aluminum connector 123 are both parallel to the plane. Figure 1 The plane containing the first direction X and the second direction Y shown in the figure is perpendicular to the tungsten structure 122. That is, the tungsten structure 122 is perpendicularly connected between the first aluminum connection part 121 and the second aluminum connection part 123. This arrangement is beneficial to shorten the transmission path of the electrical signal, improve the response speed, reduce signal attenuation, and improve the signal-to-noise ratio.

[0057] In some embodiments, Figure 2 A schematic diagram of another uncooled infrared detector pixel provided in an embodiment of this disclosure. (See reference...) Figure 2 In the uncooled infrared detector pixel 10, the interconnect structure 120 contains one tungsten pillar 12W in the tungsten structure 122. In other embodiments, the tungsten pillar 12W in the tungsten structure 122 may also have multiple pillars, see reference. Figure 1 The tungsten structure 122 contains two tungsten pillars. That is, the tungsten structure 122 has at least one tungsten pillar 12W. Specifically, the number of tungsten pillars 12W in the same tungsten structure 122 can be one, two, three, four, or more. When there are multiple tungsten pillars 12W in the same tungsten structure 122, the multiple tungsten pillars 12W can be arranged in a row, a column, an array, or any other pattern, without limitation. Regarding the number of tungsten pillars 12W, this embodiment does not limit the number, as long as it meets the thermal conductivity, electrical conductivity, and support requirements of the uncooled infrared detection pixel 10.

[0058] In some embodiments, Figure 3 This is a partially enlarged structural schematic diagram of another uncooled infrared detector pixel provided in an embodiment of this disclosure. (See reference) Figure 3 In the uncooled infrared detector pixel 10, the tungsten structure 122 includes an adhesion layer 12N, which at least covers the sides and bottom of the tungsten pillar 12W. The adhesion layer 12N includes a titanium layer and / or a titanium nitride layer. The bottom of the tungsten pillar 12W faces the bottom of the readout circuit 100. Figure 3 Taking the orientation shown in the figure as an example, the bottom of the tungsten column 12W is the lower part of the tungsten column 12W.

[0059] When the adhesion layer 12N is disposed at the bottom of the tungsten pillar 12W, it can enhance the connection performance between the tungsten structure 122 and the corresponding aluminum connector, including enhancing its mechanical connection performance and improving structural stability, as well as enhancing its electrical connection performance, reducing contact resistance, reducing loss during electrical signal transmission, and improving detection performance.

[0060] The adhesion layer 12N surrounds the side of the tungsten pillar 12W, which increases the contact area between the adhesion layer 12N and the tungsten pillar 12W. This is equivalent to widening the transmission channel of the electrical signal and reducing its transmission resistance, thereby further reducing the transmission loss of the electrical signal and improving the detection performance. It also increases the adhesion characteristics with the medium, which can ensure that the tungsten pillar 12W can be completely deposited in the through hole to form a tungsten pillar. Furthermore, it can prevent diffusion between the tungsten pillar 12W and the medium, thereby improving the stability and reliability of the device.

[0061] The adhesion layer 12N may include a titanium layer and / or a titanium nitride layer to form an adhesion layer based on a conductive layer, which can enhance the mechanical and electrical connection performance between the tungsten structure 122 and the corresponding aluminum connector by means of the adhesion layer 12N.

[0062] In some embodiments, Figure 1 Based on this, in the uncooled infrared detection pixel 10, the aluminum layer 12A of the first aluminum connection portion 121 and / or the second aluminum connection portion 123 is a pure aluminum layer or an aluminum alloy layer.

[0063] The aluminum layer 12A of the aluminum connector can be a pure aluminum material layer or an aluminum alloy material layer, so as to flexibly meet the needs of process preparation as well as the performance requirements of electrical signal transmission and mechanical support.

[0064] In some embodiments, Figure 1 Based on this, in the uncooled infrared detection pixel 10, the first aluminum connection part 121 is the top metal layer of the readout circuit 100, or the first aluminum connection part 121 is a metal layer with rewiring above the readout circuit 100.

[0065] The first aluminum connector 121 serves as an interface for the readout circuit 100, enabling the transmission of electrical signals to the readout circuit 100. This first aluminum connector 121 can be configured as the top metal layer of the readout circuit 100, utilizing the film layer within the readout circuit 100 as a structure within the first interconnect structure 1201, thereby reducing the total number of film layers and simplifying the overall structure of the uncooled infrared detector pixel 10. Alternatively, the first aluminum connector 121 can be positioned above the readout circuit 100 (to...). Figure 1 (Taking the orientation shown in the figure as an example), specifically, it is a rewiring metal layer on the readout circuit 100 to reduce the impact on the readout circuit 100 and ensure the stability and accuracy of the electrical signal.

[0066] In some embodiments, in the uncooled infrared detector pixel 10, the same-layer aluminum structure of the first aluminum connector 121 serves as the reflective layer of the uncooled infrared detector pixel 10, and / or the same-layer structure of at least one metal layer in the readout circuit 100 serves as the reflective layer of the uncooled infrared detector pixel 10. This reflective layer is used to reflect infrared signals and, together with the infrared sensing unit 110, forms a resonant cavity structure to improve the infrared absorption characteristics of the uncooled infrared detector pixel 10.

[0067] In some embodiments, Figure 4 This is a schematic diagram of the structure of another uncooled infrared detection pixel provided in an embodiment of this disclosure. Figure 5 This is a schematic diagram of the structure of another uncooled infrared detection pixel provided in an embodiment of this disclosure. Figure 6 This is a schematic diagram of the structure of another uncooled infrared detector pixel provided in an embodiment of this disclosure. (See reference...) Figures 4-6 In the uncooled infrared detection pixel 10, the infrared sensing structure 110 includes at least one beam structure 111 and / or at least one absorption plate structure 112. Figures 4-6 The infrared sensing structure 110 is shown by way of example, including a beam structure 111 and an absorption plate structure 112. In other embodiments, the beam structure 111 in the infrared sensing structure 110 may also have two or more layers, and the absorption plate structure 112 may also have two or more layers. The number of layers of the absorption plate structure 112 and the number of layers of the beam structure 111 may be equal or unequal, and are not limited here.

[0068] In some embodiments, continue to refer to Figure 4 The beam structure 111 is located on the side of the absorption plate structure 112 facing the readout circuit 100, that is, the beam structure 111 can be located between the absorption plate structure 112 and the readout circuit 100.

[0069] In some embodiments, continue to refer to Figure 5 The beam structure 111 is located on the side of the absorption plate structure 112 away from the readout circuit 100, that is, the absorption plate structure 112 can be located between the beam structure 111 and the readout circuit 100.

[0070] In some embodiments, continue to refer to Figure 6 The beam structure 111 and the absorption plate structure 112 can be set on the same floor.

[0071] In some embodiments, continue to refer to Figure 4 or Figure 5 In the uncooled infrared detector pixel 10, the interconnection structure 120 includes a first interconnection structure 1201 and a second interconnection structure 1202. The first interconnection structure 1201 connects the readout circuit 100 and the beam structure 111, and the second interconnection structure 1202 connects the beam structure 111 and the absorption plate structure 112.

[0072] Therefore, the absorption plate structure 112 can be connected to the beam structure 111 through the second interconnection structure 1202, and the beam structure 111 can be connected to the readout circuit 100 through the first interconnection structure 1201. Thus, the connection between the absorption plate structure 112 and the readout circuit 100 is realized by using the second interconnection structure 1202, the beam structure 111 and the first interconnection structure 1201, which facilitates the transmission of electrical signals on the absorption plate structure 112 to the readout circuit 100.

[0073] In some embodiments, Figure 1 Based on, combined Figure 4 or Figure 5 In the uncooled infrared detector pixel 10, the infrared sensing structure 110 includes a beam structure 111 and an absorption plate structure 112. The second aluminum connection portion 123 in the first interconnection structure 1201 and the first aluminum connection portion 121 in the second interconnection structure 1202 are disposed on the same layer. Both the second aluminum connection portion 123 in the first interconnection structure 1201 and the first aluminum connection portion 121 in the second interconnection structure 1202 are directly connected to the beam structure 111. For example, the second aluminum connection portion 123 in the first interconnection structure 1201 and the first aluminum connection portion 121 in the second interconnection structure 1202 are located on the side of the beam structure 111 facing the readout circuit 100. In other embodiments, the second aluminum connection portion 123 in the first interconnection structure 1201 and the first aluminum connection portion 121 in the second interconnection structure 1202 may also be located on the side of the beam structure 111 away from the readout circuit 100; this is not limited here.

[0074] By setting the aluminum connection part connected to the same beam structure 111 in the same layer, the same layer can be obtained by patterning the aluminum layer formed in the same process, thereby simplifying the process and the connection structure.

[0075] In some embodiments, Figure 7 This is a schematic diagram of the structure of another uncooled infrared detector pixel provided in an embodiment of this disclosure. (See reference...) Figure 7 In the uncooled infrared detection pixel 10, the multi-layer beam structure 111 is connected by one or more interconnecting structures 120. Figure 7 An example is shown in the uncooled infrared detection pixel 10, in which the infrared sensing structure 110 includes two beam structures 111 and one absorption plate structure 112, wherein the beam structures 111 of different layers are connected by an interconnection structure 120.

[0076] In some embodiments, Figure 8 This is a schematic diagram of the structure of another uncooled infrared detector pixel provided in an embodiment of this disclosure. (See reference...) Figure 8 In the uncooled infrared detector pixel 10, multiple absorption plate structures 112 are connected by one or more interconnection structures 120. Figure 8 An example is shown in the uncooled infrared detection pixel 10, in which the infrared sensing structure 110 includes a beam structure 111 and two absorption plate structures 112, wherein the absorption plate structures 112 of different layers are connected by an interconnection structure 120.

[0077] In some embodiments, Figure 9 This is a schematic diagram of the structure of another uncooled infrared detector pixel provided in an embodiment of this disclosure. (See reference...) Figure 9 In the uncooled infrared detector pixel 10, the beam structure 111 includes at least an insulating layer 11G and a first metal layer 11S; the first metal layer 11S is connected to the interconnect structure 120, for example, to the aluminum connection portion of the interconnect structure 120, and the insulating layer 11G is located on the side of the first metal layer 11S facing away from the readout circuit 100. In other embodiments, the insulating layer 11G may also be located on the side of the first metal layer 11S facing the readout circuit 100, which is not limited here.

[0078] In the preceding paragraph, "connection" refers to either electrical connection or non-electrical connection (i.e., support connection). The second aluminum connection 123 is at least partially electrically connected to the beam structure 111. When the second aluminum connection 123 is partially electrically connected to the beam structure 111, the non-electrically connected second aluminum connection 123, together with the tungsten structure 112 and the first aluminum connection 111, provides structural support for the beam structure 111. Specifically, the first metal layer 11S in the beam structure 111 provides the electrical connection. When the first metal layer 11S is connected to the interconnecting structure, it provides electrical connection between the beam structure 111 and the interconnecting structure 120. When the first metal layer 11S is not connected to the interconnecting structure 120 and only the insulating layer 11G is connected to the interconnecting structure 120, the beam structure 111 only provides structural support.

[0079] In some embodiments, the tungsten pillar 12W of the tungsten structure 122 passes through the insulating layer 11G and is electrically connected to the first aluminum connection 121 and / or the second aluminum connection 123.

[0080] Specifically, at least the insulating layer 11G includes a hollow area; either only the insulating layer 11G includes a hollow area, or both the insulating layer 11G and the first metal layer 11S include hollow areas, meaning the beam structure 111 includes a hollow area. The tungsten structure 122 is electrically connected to the first aluminum connection portion 121 within the hollow area. The area of ​​this hollow area is larger than the bottom area of ​​the tungsten structure 122. By etching away the insulating layer 11G or both the insulating layer 11G and the first metal layer 11S above the first aluminum connection portion 121, the tungsten structure 122 can be prevented from being non-conductive at the first aluminum connection portion 121, ensuring the stability and reliability of the electrical connection.

[0081] Alternatively, the area of ​​the hollowed-out region in the beam structure 111 can be equal to the bottom area of ​​the tungsten structure 122, with the tungsten structure 122 passing through the beam structure 111 and electrically connected to the first aluminum connector 121 within this hollowed-out region. This design is simple and eliminates the need to consider the corrosion and damage to the first aluminum connector 121 caused by large-area etching of the beam structure 111.

[0082] In some embodiments, Figure 10 This is a schematic diagram of the structure of another uncooled infrared detector pixel provided in an embodiment of this disclosure. (See reference...) Figure 10 In the uncooled infrared detector pixel 10, the absorption plate structure 112 includes at least a heat-sensitive layer 12R and a second metal layer 12S. The second metal layer 12S is connected to the first metal layer 11S in the beam structure 111 (not shown in the figure), or the second metal layer 12S is connected to the interconnection structure 120, such as... Figure 10 The heat-sensitive layer 12R is located on the side of the second metal layer 12S facing or away from the readout circuit 100. Figure 10 The diagram only shows the heat-sensitive layer 12R located on the side of the second metal layer 12S facing the readout circuit 100; in other embodiments, the heat-sensitive layer 12R may also be located on the side of the second metal layer 12S away from the readout circuit 100, which is not limited here.

[0083] The heat-sensitive layer 12R is used to convert infrared signals into electrical signals, that is, to convert infrared temperature detection signals into infrared detection electrical signals, and transmits them to the readout circuit 100 through the second metal layer 12S, the beam structure 111, and the interconnection structure. The heat-sensitive layer 12R may include at least one of amorphous silicon, amorphous germanium-silicon oxide, vanadium oxide, titanium oxide, amorphous germanium, amorphous germanium-silicon, silicon, germanium, germanium-silicon, germanium-silicon oxide, graphene, barium strontium titanate film, copper, and platinum.

[0084] The second metal layer 12S serves as an electrode layer for transmitting electrical signals. The second metal layer 12S may include at least one of titanium, titanium nitride, tantalum, tantalum nitride, nickel, chromium, platinum, tungsten, aluminum, copper, titanium alloys, and nickel-based alloys.

[0085] In some embodiments, Figure 11 This is a schematic diagram of the structure of another uncooled infrared detector pixel provided in an embodiment of this disclosure. (See reference...) Figure 11 The uncooled infrared detector pixel 10 also includes a release blocking layer 130, which is located at least on the side of the readout circuit 100 facing the infrared sensing structure 110.

[0086] The release barrier layer 130 is used at least to protect the readout circuit 100 from process influences during the release etching process for fabricating the interconnect structure and during the etching process for the sacrificial layer. Optionally, the release barrier layer 130 is located at the interface between the readout circuit 100 and the interconnect structure and / or within the interconnect structure. That is, the release barrier layer 130 can be located at the interface between the readout circuit 100 and the interconnect structure, or it can be located within the interconnect structure, or the interface between the readout circuit 100 and the interconnect structure has a release barrier layer 130 and the interconnect structure also has a release barrier layer 130. The release barrier layer 130 is used to protect the readout circuit 100 from erosion during the etching process to release the sacrificial layer. The release barrier layer 130 includes at least one dielectric layer, and the dielectric material constituting the release barrier layer 130 includes at least one of silicon carbide, silicon carbonitride, silicon nitride, amorphous silicon, amorphous germanium, amorphous germanium silicon, silicon, germanium, silicon-germanium alloy, amorphous carbon, or alumina.

[0087] Among them, at least the release barrier layer 130 includes a hollow area, such as Figure 11 As shown at the location of the interconnect structure 120 on the left side, the release barrier layer 130 includes a hollow area at the corresponding position of the tungsten structure 122. The tungsten structure 122 is electrically connected to the first aluminum connection portion 121 within this hollow area, and the area of ​​this hollow area is larger than the bottom area of ​​the tungsten structure 122. Etching away the release barrier layer 130 first ensures the electrical connection between the tungsten structure 122 and the first aluminum connection portion 121, avoiding electrical continuity problems and additional noise issues caused by etching processes.

[0088] Alternatively, the area of ​​the hollowed-out region in the release barrier layer 130 can be equal to the bottom area of ​​the tungsten structure 122, such as... Figure 11 As shown at the location of the interconnect structure 120 on the right side, the tungsten structure 122 passes through the release barrier layer 130 and is electrically connected to the first aluminum connector 121 in this hollowed-out area. The structural design is simple and does not require consideration of the impact of large-area etching of the release barrier layer 130 on the corrosion and damage to the first aluminum connector 121.

[0089] In some embodiments, Figure 12 This is a schematic diagram of the structure of another uncooled infrared detector pixel provided in an embodiment of this disclosure. (See reference...) Figure 12 The uncooled infrared detector pixel 10 also includes at least one sacrificial layer 140 located between the release blocking layer 130 and the infrared sensing structure 110.

[0090] For example, the sacrificial layer 140 may be located within the space where the interconnect structure 120 is located; the sacrificial layer 140 may be released by vapor phase corrosion. Figure 12The image shows the intermediate state of the uncooled infrared detector pixel 10. The sacrificial layer 140 is used as the process material for preparing the uncooled infrared detector pixel 10, ensuring that the interconnect structures 120 can be stacked sequentially. The hollow structure of the sacrificial layer 140 is removed by vapor phase etching (see reference). Figures 1-11 This is the final display state of the uncooled infrared detector pixel 10.

[0091] The sacrificial layer 140 may be silicon oxide, and the gaseous corrosive gas may be at least one of hydrogen fluoride, carbon tetrafluoride, and trifluoromethane; or the sacrificial layer 140 may be silicon, and the gaseous corrosive gas may be at least one of silicon tetrafluoride, sulfur hexafluoride, carbon tetrafluoride, and xenon fluoride; or the sacrificial layer 140 may be polyimide (PI), and the gaseous corrosive gas may be at least one of oxygen, ozone, hydrogen fluoride, and hydrogen chloride.

[0092] In some embodiments, the fabrication steps of the interconnect structure 120 may include: a first step, fabricating a first aluminum interconnect, specifically including: sequentially depositing a titanium layer and / or a titanium nitride layer, depositing an aluminum layer, depositing a titanium layer and / or a titanium nitride layer, and photolithographically etching to form a patterned first aluminum interconnect; a second step, fabricating a tungsten structure, specifically including: depositing a silicon oxide sacrificial layer, planarizing it by chemical mechanical polishing (CMP), photolithographically etching the silicon oxide to form tungsten pillar vias, depositing a titanium layer and / or a titanium nitride layer, depositing a tungsten layer, and then CMP to form a patterned tungsten structure; The third step is to prepare the second aluminum interconnect, which may include: depositing a titanium layer and / or a titanium nitride layer sequentially, depositing an aluminum layer, depositing another titanium layer and / or a titanium nitride layer, and photolithographically etching to form a patterned second aluminum interconnect; the first aluminum interconnect of the second interconnect structure is also formed simultaneously. The fourth step is to prepare the infrared sensing structure, which may include: depositing a first metal layer, photolithographically etching to form a patterned first metal layer structure, depositing a heat-sensitive layer, and photolithographically etching the heat-sensitive layer and the first metal layer to form a patterned infrared sensing structure with a beam structure and an absorption plate structure.

[0093] In some embodiments, the method for preparing the uncooled infrared detector pixel may further include: preparing a hollow structure, specifically including: VHF etching of a silicon oxide sacrificial layer.

[0094] In some embodiments, Figure 13 This is a schematic diagram of the structure of another uncooled infrared detector pixel provided in an embodiment of this disclosure. (See reference...) Figure 13 The uncooled infrared detector pixel 10 also includes a dielectric layer 150, which covers the exposed surfaces of the interconnect structure 120 and / or readout circuit 100 after release. The dielectric layer 150 is used at least to insulate and protect the interconnect structure 120 and / or readout circuit 100.

[0095] The dielectric layer 150 is used to prevent low-pressure metal discharge. The dielectric layer 150 includes at least one of aluminum oxide layer, silicon oxide layer, hafnium oxide layer, silicon nitride layer, amorphous silicon layer, silicon carbide layer and amorphous carbon layer. It can enhance the mechanical strength of the connection and prevent the upper structure (i.e. the corresponding aluminum connection part) from falling off due to poor connection with the tungsten structure, thereby enhancing the structural stability. At the same time, it can protect the entire structure from corrosion and influence from the external environment.

[0096] Furthermore, the dielectric layer 150 is provided on the side of the tungsten structure. This dielectric layer 150 serves as electrical insulation, reducing electrical connection abnormalities caused by metal discharge under low-pressure environments and mitigating the introduction of additional noise signals. This slows down the performance degradation of the tungsten structure and extends the service life of the corresponding detection equipment. In addition, while protecting the tungsten structure, the dielectric layer 150 also acts as an auxiliary support structure, improving the mechanical stability of the interconnect structure and thus enhancing the overall structural stability of the uncooled infrared detection pixel 10. Specifically, when an adhesion layer 2B is also provided on the side of the tungsten structure, the dielectric layer 150 can cover the outside of the adhesion layer 2B.

[0097] In some implementations, the dielectric layer 150 also covers the surface of the aluminum connector that does not correspond to the tungsten structure, in order to further enhance structural stability and resist the influence of the external environment.

[0098] In some embodiments, Figure 14 This is a partial structural diagram of another uncooled infrared detector pixel provided in an embodiment of the present disclosure, showing the first interconnect structure 1201 and beam structure 111 of the uncooled infrared detector pixel with the sacrificial layer 140 not released. (See reference...) Figure 14 The first interconnect structure 1201 may include a first aluminum connection portion 121, a tungsten structure 122, and a second aluminum connection portion 123. The first aluminum connection portion 121 includes an aluminum layer 12A, a titanium nitride layer 12TiN on the side of the aluminum layer 12A facing away from the readout circuit, and a titanium nitride layer 12TiN on the side facing the readout circuit. The tungsten structure 122 includes a tungsten pillar 12W and a titanium nitride layer 12TiN covering the periphery and bottom of the tungsten pillar 12W. The second aluminum connection portion 123 includes an aluminum layer 12A, a titanium nitride layer 12TiN on the side of the aluminum layer 12A facing away from the readout circuit, and a titanium nitride layer 12TiN on the side facing the readout circuit. The beam structure 111 includes a first metal layer 11S and an insulating layer 11G.

[0099] In some embodiments, Figure 15 This is a partial structural diagram of another uncooled infrared detector pixel provided in an embodiment of the present disclosure, showing the second interconnect structure 1202 and the absorber plate structure 112 after the sacrificial layer is released. (See reference...) Figure 15The second interconnect structure 1202 includes a first aluminum connection portion 121, a tungsten structure 122, and a second aluminum connection portion 123. The first aluminum connection portion 121 includes an aluminum layer 12A and a titanium nitride layer 12TiN on the side of the aluminum layer 12A away from the readout circuit and a titanium nitride layer 12TiN on the side facing the readout circuit. The tungsten structure 122 includes a tungsten pillar and a titanium nitride layer covering the periphery and bottom of the tungsten pillar (in the figure, the tungsten pillar is covered inside the titanium nitride layer and is not visible; only the titanium nitride layer is visible). The second aluminum connection portion 123 includes an aluminum layer 12A and a titanium nitride layer 12TiN on the side of the aluminum layer 12A away from the readout circuit and a titanium nitride layer 12TiN on the side facing the readout circuit. The absorption plate structure 112 includes a second metal layer 12S and a heat-sensitive layer 12R.

[0100] In other embodiments, the first interconnection structure, beam structure, second interconnection structure, and absorption plate structure in the uncooled infrared detection pixel can also be implemented using other structural forms provided in the embodiments of this application, which are not limited here.

[0101] Based on the above embodiments, this disclosure also provides an uncooled infrared detection chip.

[0102] For example, Figure 16 This is a schematic diagram of the structure of an uncooled infrared detection chip provided in an embodiment of this disclosure. (Reference) Figure 16 The uncooled infrared detection chip 20 may include an array structure composed of multiple uncooled infrared detection pixels 10 provided in any of the above embodiments, and includes a readout circuit 100.

[0103] Based on the above embodiments, this disclosure also provides a mechanism for uncooled infrared detection, which includes any of the uncooled infrared detection chips provided in the above embodiments.

[0104] For example, Figure 17 This is a schematic diagram of the structure of an uncooled infrared detector core provided in an embodiment of this disclosure. (Reference) Figure 17 The mechanism 30 includes an uncooled infrared detection chip 20; the mechanism 30 also includes a lens 31, which is used to focus the infrared signal onto the uncooled infrared detection chip 20 to improve the intensity of the infrared signal and improve the signal-to-noise ratio.

[0105] In other embodiments, the movement 20 may also include other structural and functional components, which are not described in detail or limited herein.

[0106] Based on the above embodiments, this disclosure also provides an uncooled infrared detection device, which may include any of the mechanisms provided in the above embodiments.

[0107] In other embodiments, the uncooled infrared detection device may also include other structural and functional components, which are not described in detail or limited herein.

[0108] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0109] The above description is merely a specific embodiment of this disclosure, enabling those skilled in the art to understand or implement it. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this disclosure. Therefore, this disclosure is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An uncooled infrared detection pixel, characterized in that, An interconnection structure comprising multiple readout circuits and infrared sensing structures; wherein each of the interconnection structures includes: a first aluminum connection portion, a tungsten structure, and a second aluminum connection portion; wherein the tungsten structure is connected between the first aluminum connection portion and the second aluminum connection portion; The first aluminum connection portion and / or the second aluminum connection portion includes an aluminum layer and a titanium layer and / or a titanium nitride layer located on the side of the aluminum layer away from the readout circuit and / or on the side facing the readout circuit.

2. The uncooled infrared detection pixel according to claim 1, characterized in that, Within the same interconnect structure, the plane containing the first aluminum connection portion is parallel to the plane containing the second aluminum connection portion and perpendicular to the tungsten structure.

3. The uncooled infrared detection pixel according to claim 1, characterized in that, Within the interconnection structure, the number of tungsten pillars in the tungsten structure is at least one.

4. The uncooled infrared detection pixel according to claim 3, characterized in that, The tungsten structure includes an adhesion layer that covers at least the sides and bottom of the tungsten pillars of the tungsten structure, and the adhesion layer includes a titanium layer and / or a titanium nitride layer.

5. The uncooled infrared detection pixel according to claim 1, characterized in that, The aluminum layer of the first aluminum connector and / or the second aluminum connector is a pure aluminum layer or an aluminum alloy layer; The aluminum layer of the first aluminum connector is the top metal layer of the readout circuit, or the aluminum layer of the first aluminum connector is the aluminum layer above the readout circuit that has been rewired. The same layer aluminum structure of the first aluminum connector serves as the reflective layer of the uncooled infrared detector pixel, and / or the same layer structure of at least one metal layer in the readout circuit serves as the reflective layer of the uncooled infrared detector pixel.

6. The uncooled infrared detection pixel according to claim 1, characterized in that, The infrared sensing structure includes at least one beam structure and / or at least one absorption plate structure; the beam structure is located on the side of the absorption plate structure facing or away from the readout circuit, or the beam structure and the absorption plate structure are arranged on the same layer.

7. The uncooled infrared detection pixel according to claim 6, characterized in that, The interconnection structure includes a first interconnection structure and a second interconnection structure. The first interconnection structure connects the readout circuit and the beam structure, and the second interconnection structure connects the beam structure and the absorption plate structure.

8. The uncooled infrared detection pixel according to claim 6, characterized in that, The plurality of beam structures are connected by one or more of the interconnecting structures; the plurality of absorption plate structures are connected by one or more of the interconnecting structures.

9. The uncooled infrared detection pixel according to claim 6, characterized in that, The beam structure includes at least an insulating layer and a first metal layer; the first metal layer is connected to a second aluminum connection portion of the interconnect structure, and the insulating layer is located on the side of the first metal layer facing or away from the readout circuit.

10. The uncooled infrared detection pixel according to claim 6, characterized in that, The absorption plate structure includes at least a heat-sensitive layer and a second metal layer, the second metal layer being connected to a first metal layer in the beam structure, or the second metal layer being connected to the interconnect structure; the heat-sensitive layer is located on the side of the second metal layer facing or away from the readout circuit.

11. The uncooled infrared detection pixel according to any one of claims 1-10, characterized in that, It also includes a release blocking layer, which is located at least on the side of the readout circuit facing the infrared sensing structure.

12. The uncooled infrared detection pixel according to claim 11, characterized in that, It also includes at least one sacrificial layer located between the release blocking layer and the infrared sensing structure.

13. The uncooled infrared detection pixel according to claim 1, characterized in that, It also includes a dielectric layer that covers the exposed surfaces of the interconnect structure and / or the readout circuit after release, the dielectric layer serving at least to provide insulation protection for the interconnect structure and / or the readout circuit.

14. An uncooled infrared detection chip, characterized in that, It includes an array structure consisting of multiple uncooled infrared detector pixels as described in any one of claims 1-13 and the readout circuit.

15. A mechanism for uncooled infrared detection, characterized in that, The mechanism includes the uncooled infrared detection chip as described in claim 14; the mechanism also includes a lens for focusing infrared signals onto the uncooled infrared detection chip.

16. An uncooled infrared detection device, characterized in that, The uncooled infrared detection device includes the mechanism as described in claim 15.

Images