Uncooled infrared detection pixel, chip, movement and device

Abstract

This disclosure relates to the field of infrared detection technology, and more particularly to an uncooled infrared detection pixel, chip, core, and device. The uncooled infrared detection pixel includes a first interconnect structure and a second interconnect structure. The first interconnect structure includes a first aluminum connection portion, a first tungsten connection portion, a second aluminum connection portion, and a beam structure connected in sequence. The second interconnect structure includes a third aluminum connection portion, a second tungsten connection portion, a fourth aluminum connection portion, and an absorption sensing portion connected in sequence. The aluminum connection portion includes an aluminum layer, and at least one aluminum connection portion further 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 absorption sensing portion. The first interconnect structure connects the second interconnect structure and a readout circuit. The first aluminum connection portion in the first interconnect structure connects to the readout circuit. The second aluminum connection portion in the first interconnect structure and the third aluminum connection portion in the second interconnect structure connect to the beam structure. This interconnect structure can solve the noise instability problem caused by the interconnection of the infrared detection chip, and can reduce noise and improve 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 14 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 14 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 14At 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 14 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 lower yield and higher processing costs;

[0012] Furthermore, in related technologies, uncooled infrared detection devices can use amorphous silicon as the thermosensitive layer. However, the 1 / f noise of this amorphous silicon-based infrared detection device is relatively high, mainly due to the noise of the amorphous silicon thermosensitive layer material. Because amorphous silicon is a semiconductor material, the thicker the layer, the more conductive channels it corresponds to. Since amorphous silicon is a thermosensitive material, temperature changes cause fluctuations in the conductivity at the contact points between the conductive channels. These fluctuations in conductivity at the contact points create 1 / f noise. The thicker the amorphous silicon layer, the more pronounced the contact point fluctuations, resulting in greater 1 / f noise and poorer device performance. Utility Model Content

[0013] 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.

[0014] This disclosure provides an uncooled infrared detection pixel, including a first interconnection structure and a second interconnection structure. The first interconnection structure includes a first aluminum connector, a first tungsten connector, a second aluminum connector, and a beam structure. The second interconnection structure includes a third aluminum connector, a second tungsten connector, a fourth aluminum connector, and an absorption sensing part.

[0015] The aluminum connector includes an aluminum layer, 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 away from and / or towards the absorption sensing portion.

[0016] The first interconnect structure connects the second interconnect structure to the readout circuit;

[0017] In the first interconnection structure, the two ends of the first tungsten connector are respectively connected to the first aluminum connector and the second aluminum connector. The first aluminum connector is connected to the readout circuit, and the second aluminum connector is connected to the beam structure.

[0018] In the second interconnection structure, the two ends of the second tungsten connector are respectively connected to the third aluminum connector and the fourth aluminum connector. The third aluminum connector is connected to the beam structure, and the fourth aluminum connector is connected to the absorption sensing part.

[0019] The absorption sensing unit includes an amorphous silicon thermistor layer and a first metal layer; the first metal layer is located on the side of the amorphous silicon thermistor layer away from the readout circuit and is connected to the fourth aluminum connection portion;

[0020] The absorption sensing unit includes a thermistor working area and a non-thermistor working area. The amorphous silicon thermistor layer is located in the thermistor working area. The thermistor working area generates a resistance change in response to the received thermal signal.

[0021] The first metal layer is located in the non-thermal working area and is in contact with at least the side of the thermal working area; wherein, a pair of adjacent first metal layers located on the side of the thermal working area form quasi-parallel electrodes.

[0022] 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.

[0023] 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.

[0024] This disclosure also provides an uncooled infrared detection device, which includes any of the aforementioned mechanisms.

[0025] The technical solution provided in this disclosure has the following advantages compared with the prior art:

[0026] The uncooled infrared detection pixel, chip, core, and device provided in this disclosure include a first interconnect structure and a second interconnect structure. The first interconnect structure includes a first aluminum connection portion, a first tungsten connection portion, a second aluminum connection portion, and a beam structure. The second interconnect structure includes a third aluminum connection portion, a second tungsten connection portion, a fourth aluminum connection portion, and an absorption sensing portion. The aluminum connection portion includes an aluminum layer, and at least one aluminum connection portion further includes at least one layer selected from titanium and titanium nitride layers, located on the side of the aluminum layer facing away from and / or towards the absorption sensing portion. The first interconnect structure connects the second interconnect structure to a readout circuit. In the first interconnect structure, the two ends of the first tungsten connection portion are respectively connected to the first aluminum connection portion and the second aluminum connection portion, the first aluminum connection portion is connected to the readout circuit, and the second aluminum connection portion is connected to the beam structure. In the second interconnect structure, the two ends of the second tungsten connection portion are respectively connected to the third aluminum connection portion and the fourth aluminum connection portion, the third aluminum connection portion is connected to the beam structure, and the fourth aluminum connection portion is connected to the absorption sensing portion. Therefore, by setting the above interconnection structure, the connection between the readout circuit and the 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 detector 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 detector chip formed by the infrared detector 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 detector chip can achieve the goal of low processing cost, high yield, and mass production. Furthermore, the absorption sensing unit includes an amorphous silicon thermistor layer and a first metal layer; the absorption sensing unit includes a thermistor working area and a non-thermistor working area, the amorphous silicon thermistor layer is only located in the thermistor working area, that is, the amorphous silicon thermistor layer in the thermistor working area has a target thickness, and the amorphous silicon thermistor layer in the non-thermistor working area has zero thickness; wherein, the thermistor working area generates a resistance change in response to the received thermal signal; the first metal layer is located in the non-thermistor working area and is at least in contact with the side of the thermistor working area; wherein, a pair of adjacent first metal layers located on the side of the thermistor working area form quasi-parallel electrodes.Therefore, by setting the amorphous silicon thermistor layer to have a target thickness in the thermistor working area and zero thickness in the non-thermistor working area (i.e., removing the amorphous silicon thermistor layer in the non-thermistor working area), the thickness of the amorphous silicon thermistor layer between the quasi-parallel electrodes is made thicker. This directly reduces the formation of different conductive channels and forms a single conductive channel, thus significantly reducing noise. At the same time, it can significantly reduce heat capacity, shorten thermal response time, and improve device performance. Moreover, without being limited by heat capacity, the thickness of the amorphous silicon thermistor layer can be adjusted over a wide range, which can fully meet the design requirements of the resistor. The area of ​​the amorphous silicon thermistor working area is relatively small, which can meet the requirements of small-sized pixels and provides more sufficient conditions for the design of pixels below 12um. Attached Figure Description

[0027] 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.

[0028] 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.

[0029] Figure 1 This is a schematic diagram of the structure of an uncooled infrared detection pixel provided in an embodiment of the present disclosure;

[0030] Figure 2 This is a schematic diagram of another uncooled infrared detection pixel provided in an embodiment of the present disclosure;

[0031] Figure 3 A partially enlarged structural schematic diagram of another uncooled infrared detection pixel provided in an embodiment of this disclosure;

[0032] Figure 4 A partially enlarged structural schematic diagram of another uncooled infrared detection pixel provided in an embodiment of this disclosure;

[0033] Figure 5 A schematic diagram of the structure of an absorption sensor for another uncooled infrared detection pixel provided in an embodiment of this disclosure;

[0034] Figure 6 This is a schematic diagram of the structure of another uncooled infrared detection pixel provided in an embodiment of the present disclosure;

[0035] Figure 7 This is a schematic diagram of the structure of another uncooled infrared detection pixel provided in an embodiment of the present disclosure;

[0036] Figure 8This is a schematic diagram of the structure of another uncooled infrared detection pixel provided in an embodiment of the present disclosure;

[0037] Figure 9 This is a schematic diagram of the structure of another uncooled infrared detection pixel provided in an embodiment of the present disclosure;

[0038] Figure 10 This is a schematic diagram of the structure of another uncooled infrared detection pixel provided in an embodiment of the present disclosure;

[0039] Figure 11 A partial structural photograph of another uncooled infrared detection pixel provided in an embodiment of this disclosure;

[0040] Figure 12 This is a schematic diagram of the structure of an uncooled infrared detection chip provided in an embodiment of the present disclosure;

[0041] Figure 13 This is a schematic diagram of the structure of an uncooled infrared detector core provided in an embodiment of the present disclosure;

[0042] Figure 14 A schematic diagram of the structure of an infrared detection pixel provided for related technologies;

[0043] Figure 15 A schematic diagram of the absorption sensor section of another infrared detection pixel provided for related technologies. Detailed Implementation

[0044] 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.

[0045] 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.

[0046] 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 1The uncooled infrared detection pixel 10 may include a first interconnection structure 11 and a second interconnection structure 12; wherein, the first interconnection structure 11 includes a first aluminum connector 111, a first tungsten connector 112, a second aluminum connector 113 and a beam structure 114, and the second interconnection structure 12 includes a third aluminum connector 121, a second tungsten connector 122, a fourth aluminum connector 123 and an absorption sensing part 124; wherein, the first aluminum connector 111, the second aluminum connector 113, the third aluminum connector 121 and the fourth aluminum connector 123 may all be referred to as aluminum connectors.

[0047] The aluminum connector includes an aluminum layer 1A, 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 away from and / or towards the absorption sensing portion. Figure 1 Taking the first aluminum connector 111 as an example, the first aluminum connector 111 includes an aluminum layer 1A, a titanium layer 141, and a titanium nitride layer 142; wherein, the titanium layer 141 is located on the side of the aluminum layer 1A away from the absorption sensing portion 124, and the titanium nitride layer 142 is located on the side of the aluminum layer 1A facing the absorption sensing portion 124. For example, Figure 1 Taking the orientation shown as an example, the absorption sensor 124 is located above the aluminum layer 1A, the titanium layer 141 is located below the aluminum layer 1A, and the titanium nitride layer 142 is located above the aluminum layer 1A.

[0048] 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 absorption sensing portion; 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 absorption sensing portion; 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 absorption sensing portion, and the titanium nitride layer located on the side of the aluminum layer facing away from and / or towards the absorption sensing portion. 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 here.

[0049] The device further includes at least one titanium layer and one titanium nitride layer located on the side of the aluminum layer facing away from and / or towards the absorption sensing portion, 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 to ensure 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.

[0050] Continue to refer to Figure 1 In the uncooled infrared detector pixel 10, the first interconnection structure 11 connects the second interconnection structure 12 and the readout circuit 100. Specifically, the first interconnection structure 11 connects the second interconnection structure 12 and the readout circuit 100, and based on this connection, the first interconnection structure 11 enables electrical signal transmission between the second interconnection structure 12 and the readout circuit 100.

[0051] In the first interconnection structure 11, the two ends of the first tungsten connector 112 are respectively connected to the first aluminum connector 111 and the second aluminum connector 113. The first aluminum connector 111 is connected to the readout circuit 100, and the second aluminum connector 113 is connected to the beam structure 114. In the second interconnection structure 12, the two ends of the second tungsten connector 122 are respectively connected to the third aluminum connector 121 and the fourth aluminum connector 123. The third aluminum connector 121 is connected to the beam structure 114, and the fourth aluminum connector 123 is connected to the absorption sensor 124.

[0052] Specifically, taking the connection path between the readout circuit 100 and the absorption sensing unit 124 as an example, the readout circuit 100 is connected to the first aluminum connection part 111, the first aluminum connection part 111 is connected to the first tungsten connection part 112, the first tungsten connection part 112 is connected to the second aluminum connection part 113, the second aluminum connection part 113 is connected to the beam structure 114, the beam structure 114 is connected to the third aluminum connection part 121, the third aluminum connection part 121 is connected to the second tungsten connection part 122, the second tungsten connection part 122 is connected to the fourth aluminum connection part 123, and the fourth aluminum connection part 123 is connected to the absorption sensing plate 124. In this way, the connection between the absorption sensing unit 124 and the readout circuit 100 is realized. This connection includes electrical connection and mechanical connection, which are not limited here, but will be described by example later.

[0053] Specifically, the first interconnection structure 11 includes a first aluminum connection portion 111 and a second aluminum connection portion 113 disposed opposite to each other, a first tungsten connection portion 112 disposed between the first aluminum connection portion 111 and the second aluminum connection portion 113, and a beam structure 114 disposed on the side of the second aluminum connection portion 113 away from the first aluminum connection portion 111.

[0054] For example, in the first interconnect structure 11, 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 connector 111, the first tungsten connector 112, the second aluminum connector 113, and the beam structure 114 are stacked and connected in sequence. The first aluminum connector 111, located at the bottom, is connected to the readout circuit 100, and the beam structure 114, located at the top, is connected to the second interconnection structure 12, so as to realize the transmission of electrical signals between the second interconnection structure 12 and the readout circuit 100 based on the first interconnection structure 11.

[0055] Specifically, the second interconnection structure 12 includes a third aluminum connection portion 121 and a fourth aluminum connection portion 123 disposed opposite to each other, a second tungsten connection portion 122 disposed between the third aluminum connection portion 121 and the fourth aluminum connection portion 123, and an absorption sensing portion 124 disposed on the side of the fourth aluminum connection portion 123 away from the third aluminum connection portion 121.

[0056] For example, in the second interconnect structure 12, 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 third aluminum connection 121, the second tungsten connection 122, the fourth aluminum connection 123 and the absorption sensing part 124 are stacked and connected in sequence, and the third aluminum connection 121 located at the bottom layer is connected to the first interconnection structure 11, specifically connected to the beam structure 114 in the first interconnection structure 11, so as to transmit electrical signals to the readout circuit 100 through the first interconnection structure 11 including the beam structure 114.

[0057] Specifically, the absorption sensing unit 124 converts the infrared signal into an electrical signal. This electrical signal is transmitted to the readout circuit 100 via a series of sequentially connected components: a fourth aluminum connector 123, a second tungsten connector 122, a third aluminum connector 121, a beam structure 114, a second aluminum connector 113, a first tungsten connector 112, and a first aluminum connector 111. The readout circuit 100 receives the electrical signal. The readout circuit 100 can reflect the temperature information of the corresponding infrared signal based on the received electrical signal, thereby realizing the temperature detection function of the infrared detection device.

[0058] The absorption sensing unit 124 includes an amorphous silicon thermistor layer 1241 and a first metal layer 1242. The amorphous silicon thermistor layer 1241 includes a thermistor working region 1111 and a non-thermistor working region 1112. The thermistor working region 1111 generates a resistance change based on the received thermal signal, that is, the amorphous silicon thermistor layer 1241 of the thermistor working region 1111 is used to convert the infrared temperature signal into an infrared detection electrical signal. The amorphous silicon thermistor layer 1241 of the thermistor working region 1111 is the effective resistive portion, and the amorphous silicon thermistor layer 1241 of the non-thermistor working region 1112 is the non-resistive portion. The first metal layer 1242 is used to transmit the infrared detection electrical signal converted from the thermistor working region 1111 to the substrate (e.g., a readout circuit) through a beam structure in the amorphous silicon infrared detection pixel.

[0059] The absorption sensing unit 124 includes a thermistor working region and a non-thermistor working region, with an amorphous silicon thermistor layer located only in the thermistor working region. The thermistor working region generates a resistance change in response to the received thermal signal. A first metal layer is located in the non-thermistor working region and is in contact with the side of the amorphous silicon thermistor layer at least in the thermistor working region. Adjacent (opposite) pairs of first metal layers on the side of the amorphous silicon thermistor layer in the same thermistor working region form quasi-parallel electrodes. Alternatively, the amorphous silicon thermistor layer 1241 in the thermistor working region 1111 has a target thickness H0, while the amorphous silicon thermistor layer 1241 in the non-thermistor working region 1112 has a thickness of zero, meaning the material of the amorphous silicon thermistor layer 1241 in the non-thermistor working region 1112 is completely removed, thereby forming a bump in the thermistor working region 1111 that protrudes above the non-thermistor working region 1112. Figure 1 The thermal working area 1111 forms a raised structure relative to the non-thermal working area 1112.

[0060] The first metal layer 1242 is located in the non-thermosensitive working area 1112 and is in contact with at least one side of the thermosensitive working area 1111. Adjacent pairs of first metal layers 1242 located on the side of the thermosensitive working area 1111 form quasi-parallel electrodes; that is, a pair of metal electrodes 112 in contact with the side of the same thermosensitive working area 1111 form quasi-parallel electrodes. Figure 1 Within the thermistor working area 1111, a pair of metal electrodes 112 corresponding to the arrows at the beginning and end form quasi-parallel electrodes. Here, quasi-parallel electrodes refer to a pair of first metal layers 1242 that, due to process reasons, may deviate during the fabrication process and are not necessarily mathematically perfectly parallel electrodes; there may be a small angular deviation. Therefore, in this embodiment, the pair of metal electrodes is referred to as quasi-parallel electrodes.

[0061] The greater the difference in thickness between the target thickness H0 of the thermistor working area 1111 and the thickness of the non-thermistor working area 1112, the larger the area of ​​the quasi-parallel electrode, the fewer the conductive channels in the thermistor working area 1111, and the less the fluctuation in conductivity at the contact points between different conductive channels caused by temperature fluctuations, which is more conducive to eliminating additional noise. In this embodiment, by setting the thickness of the amorphous silicon thermistor layer 1241 in the non-thermistor working area 1112 to zero, the conductive channel is a single channel, the contact point conductivity does not exist, and therefore no additional noise is generated, thereby reducing noise.

[0062] contrast Figure 15 In the uncooled infrared detector pixel 01 of the related technology, the amorphous silicon layer 011 on the absorption plate is fully retained. The thickness of the amorphous silicon layer 011 directly affects the noise level of the device, and the thicker the layer, the greater the 1 / f noise, because a thicker amorphous silicon layer 011 provides more conductive channels, such as... Figure 2 As indicated by the arrow within the amorphous silicon layer 011, amorphous silicon has a thermistor temperature coefficient, meaning its resistance changes with temperature. Therefore, temperature fluctuations cause conductance fluctuations at the contact points between conductive channels, which generate 1 / f noise. The thicker the amorphous silicon layer 011, the more conductive channels there are, and the greater the noise caused by conductance fluctuations at the contact points between different conductive channels. Furthermore, the overall amorphous silicon thin-film structure results in a large heat capacity, long thermal response time, and poor NETD (thermal sensitivity) performance. Additionally, due to the high sheet resistance of amorphous silicon, a thicker amorphous silicon layer is required to achieve the designed resistance value. Reducing the amorphous silicon thickness increases the complexity of the structural design and hinders pixel miniaturization.

[0063] In the uncooled infrared detection pixel 10 provided in this embodiment, the amorphous silicon thermistor layer 1241 of the absorption sensing section 124 has a target thickness H0 in the thermistor working area 1111 and a thickness of zero in the non-thermistor working area 1112. This allows for the formation of quasi-parallel electrodes using a pair of adjacent first metal layers 1242 located on the side of the thermistor working area 1111. These quasi-parallel electrodes improve the uniformity of the conductive channels, ensuring that even if the conductive channel is a single channel, contact point conductivity is absent, thus eliminating additional noise and reducing noise. Simultaneously, it significantly reduces heat capacity, shortens thermal response time, and improves device performance. Furthermore, without being limited by heat capacity, the thickness of the amorphous silicon thermistor layer can be adjusted over a wide range, fully meeting the design requirements of the resistor and facilitating pixel miniaturization. Furthermore, by setting the first interconnect structure 11 and the second interconnect structure 12, the connection between the readout circuit 100 and the absorption sensing unit 124 is realized. Compared with the traditional hollow columnar structure with a single layer of metal as the interconnect, the fabrication process of the interconnect structure in the uncooled infrared detection pixel 10 provided in this embodiment is mature, the process stability is good, there is no noise instability caused by residual particles, and the noise consistency is good. At the same time, it avoids the problem of poor electrical contact caused by high steps, the contact resistance is small, and the uniformity is good. In addition, the planarization process is mature and stable, and can perfectly meet the design requirements. Furthermore, the interconnect structure size can be made very small, and smaller pixel designs can be realized. Furthermore, in the infrared detection chip formed by the infrared detection pixel including the interconnect structure, the consistency between different pixels is good and the performance is stable. Moreover, the interconnect 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.

[0064] It should be noted that, Figure 1 The illustration only shows, by way of example, that the first tungsten connector 112 in a single first interconnect structure 11 includes two tungsten pillars, and the second tungsten connector 122 in a single second interconnect structure 12 includes two tungsten pillars, but this does not constitute a limitation on the number of tungsten pillars in the first tungsten connector 112 and the second tungsten connector 122. In other implementations, the number of tungsten pillars in a single first tungsten connector 112 may be one or more; the number of tungsten pillars in a single second tungsten connector 122 may be one or more; and the number of tungsten pillars in a single second tungsten connector 122 may be equal to or unequal to the number of tungsten pillars in a single first tungsten connector 112, which is not limited here.

[0065] In some embodiments, continue to refer to Figure 1 In the uncooled infrared detector pixel 10, in the first interconnection structure 11, the plane where the first aluminum connection part 111 is located is parallel to the plane where the second aluminum connection part 113 is located, and is perpendicular to the first tungsten connection part 112.

[0066] In the same first interconnect structure 11, the first aluminum connection portion 111 and the second aluminum connection portion 113 are arranged opposite to each other, and their planes are parallel; Figure 1 Taking the shown orientation as an example, it can be understood that the planes containing the first aluminum connector 111 and the second aluminum connector 113 are both parallel to the planes shown. Figure 1 The plane containing the first direction X and the second direction Y shown in the figure is perpendicular to the first tungsten connector 112. That is, the first tungsten connector 112 is perpendicularly connected between the first aluminum connector 111 and the second aluminum connector 113. 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.

[0067] In some embodiments, continue to refer to Figure 1 In the uncooled infrared detector pixel 10, in the second interconnection structure 12, the plane where the third aluminum connection part 121 is located is parallel to the plane where the fourth aluminum connection part 123 is located, and is perpendicular to the second tungsten connection part 122.

[0068] In the same second interconnection structure 12, the third aluminum connection portion 121 and the fourth aluminum connection portion 123 are arranged opposite to each other, and their planes are parallel; Figure 1 Taking the shown orientation as an example, it can be understood that the planes containing the third aluminum connector 121 and the fourth aluminum connector 123 are both parallel to the plane shown. Figure 1 The plane containing the first direction X and the second direction Y shown in the figure is perpendicular to the second tungsten connector 122. That is, the second tungsten connector 122 is perpendicularly connected between the third aluminum connector 121 and the fourth aluminum connector 123. This helps to shorten the transmission path of the electrical signal, improve the response speed, reduce signal attenuation, and improve the signal-to-noise ratio.

[0069] In some embodiments, continue to refer to Figure 1 In the uncooled infrared detector pixel 10, the first interconnect structure 11 is located on the side of the second interconnect structure 12 facing the readout circuit 100. In other embodiments, the first interconnect structure 11 may also be located on the side of the second interconnect structure 12 away from the readout circuit 100.

[0070] Furthermore, the second aluminum connection portion 113 in the first interconnection structure 11 and the third aluminum connection portion 121 in the second interconnection structure 12 are disposed on the same layer.

[0071] In this configuration, the second aluminum connection portion 113 in the first interconnection structure 11 and the third aluminum connection portion 121 in the second interconnection structure 12 are both directly connected to the beam structure 114. For example, the second aluminum connection portion 113 in the first interconnection structure 11 and the third aluminum connection portion 121 in the second interconnection structure 12 are both located on the side of the beam structure 114 facing the readout circuit 100. In other embodiments, the second aluminum connection portion 113 in the first interconnection structure 11 and the third aluminum connection portion 121 in the second interconnection structure 12 may also be located on the side of the beam structure away from the readout circuit 114; this is not a limitation.

[0072] For example, with Figure 1 Taking the orientation shown as an example, the second aluminum connection 113 in the first interconnection structure 11 is the upper aluminum connection in the first interconnection structure 11, and the third aluminum connection 121 in the second interconnection structure 12 is the lower aluminum connection in the second interconnection structure 12. Both of these aluminum connections are directly connected to the beam structure 114. By setting these two aluminum connections to be at least partially on the same layer, for example, they can be patterned based on the aluminum layer formed in the same process to achieve the same layer, thereby simplifying the process and the connection structure.

[0073] In some embodiments, Figure 1 Based on this, in the uncooled infrared detector pixel 10, the aluminum layer 1A of the aluminum connector is a pure aluminum layer or an aluminum alloy layer.

[0074] The aluminum layer 1A 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.

[0075] In some embodiments, Figure 1 Based on this, in the uncooled infrared detection pixel 10, the aluminum layer 1A of the first aluminum connection portion 111 is the top metal layer of the readout circuit 100, or the aluminum layer 1A of the first aluminum connection portion 111 is an aluminum layer that has been rewired above the readout circuit 100.

[0076] The first aluminum connector 111 serves as an interface for the readout circuit 100, enabling the transmission of electrical signals to the readout circuit 100. This first aluminum connector 111 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 11, 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 111 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.

[0077] The same-layer aluminum structure of the first aluminum connection portion 111 can serve as a reflective layer for the uncooled infrared detection pixel; the same-layer structure of at least one metal layer in the readout circuit can also serve as a reflective layer for the uncooled infrared detection pixel. This reflective layer is used to reflect infrared signals and forms a resonant cavity structure together with the absorption sensing portion to improve the infrared absorption characteristics of the uncooled infrared detection pixel.

[0078] 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 this uncooled infrared detector pixel 10, the number of tungsten pillars 2A in the first tungsten connector 112 and the second tungsten connector 122 is one. In other embodiments, the number of tungsten pillars 2A in the first tungsten connector 112 and the second tungsten connector 122 may be multiple, see reference. Figure 1 The number of tungsten pillars 2A in the first tungsten connecting portion 112 and the second tungsten connecting portion 122 can be two, or the number of tungsten pillars 2A in the first tungsten connecting portion 112 and the second tungsten connecting portion 122 can be more than one; or the number of tungsten pillars 2A in the first tungsten connecting portion 112 is one, and the number of tungsten pillars 2A in the second tungsten connecting portion 122 is multiple; or the number of tungsten pillars 2A in the first tungsten connecting portion 112 is multiple, and the number of tungsten pillars 2A in the second tungsten connecting portion 122 is one. That is, the number of tungsten pillars 2A in the first tungsten connecting portion 112 and / or the second tungsten connecting portion 122 can be one or more, that is, the number of tungsten pillars 2A in the same tungsten connecting portion can be one, two, three, four or more. When the number of tungsten pillars 2A in the same tungsten connecting portion is multiple, the multiple tungsten pillars 2A can be arranged in a row, or in a column, or in an array, or in any pattern, which is not limited here. The number of tungsten pillars 2A is not limited in this embodiment, as long as it meets the thermal conductivity, electrical conductivity and support requirements of the uncooled infrared detection pixel 10.

[0079] 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 first tungsten connector 112 includes an adhesive layer 2B, and / or the second tungsten connector 122 includes an adhesive layer ( Figure 3 (Not shown in the image); the adhesion layer 2B at least covers the sides and bottom of the tungsten pillar 2A, and the adhesion layer 2B includes a titanium layer and / or a titanium nitride layer. The bottom of the tungsten pillar 2A is the bottom of the tungsten pillar 2A facing the readout circuit 100, so as to... Figure 3 Taking the orientation shown in the figure as an example, the bottom of tungsten column 2A is the lower part of tungsten column 2A.

[0080] When the adhesion layer 2B is disposed at the bottom of the tungsten pillar 2A, it can enhance the connection performance between the tungsten connector 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.

[0081] The adhesion layer 2B surrounds the side of the tungsten pillar 2A, which increases the contact area between the adhesion layer 2B and the tungsten pillar 2A. 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 2A can be completely deposited in the through hole to form a tungsten pillar. Furthermore, it can prevent diffusion between the tungsten pillar 2A and the medium, thereby improving the stability and reliability of the device.

[0082] It is understood that the adhesive layer 2B may cover the entire side of the tungsten pillar 2A or only part of the side of the tungsten pillar 2A, and this is not limited here.

[0083] The adhesion layer 2B 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 connector and the corresponding aluminum connector by using the adhesion layer 2B.

[0084] In some embodiments, Figure 4 This is a partially enlarged structural schematic diagram of another uncooled infrared detector pixel provided in an embodiment of this disclosure. (See reference) Figure 4 The uncooled infrared detector pixel 10 may also include a first protective layer 15, which covers the exposed surface of the interconnect structure (the first interconnect structure 11 is shown as an example in the figure, and the second interconnect structure is also included in the embodiment of this disclosure) and / or the readout circuit 100. The first protective layer 15 is at least used to insulate and protect the interconnect structure and / or the readout circuit 100.

[0085] The first protective layer 15 is used to prevent low-pressure metal discharge. The first protective layer 15 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 connection part, thereby enhancing the structural stability. At the same time, it can protect the entire structure from corrosion and influence from the external environment.

[0086] Furthermore, a first protective layer 15 is provided on the side of the tungsten connector. This first protective layer 15 serves as electrical insulation, reducing electrical connection abnormalities caused by metal discharge under low-pressure environments or the introduction of additional noise signals, thus mitigating performance degradation of the tungsten connector and extending the service life of the corresponding detection equipment. In addition, while protecting the tungsten connector, the first protective layer 15 also acts as an auxiliary support structure, improving the mechanical stability of the interconnect structure and thereby 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 connector, the first protective layer 15 can cover the outside of the adhesion layer 2B.

[0087] In some implementations, the first protective layer 15 also covers the surface of the aluminum connector that does not correspond to the tungsten connector, in order to further enhance structural stability and resist the influence of the external environment.

[0088] In some embodiments, the amorphous silicon thermistor layer 1241 includes an amorphous silicon layer doped with one or more elements selected from boron, phosphorus, hydrogen, germanium, vanadium, and oxygen.

[0089] Specifically, the thermistor working area 1111 can generate a resistance change based on the received thermal signal. The amorphous silicon thermistor layer 1241 includes an amorphous silicon material layer, which can be an amorphous silicon material layer doped with one or more elements such as boron (B), phosphorus (P), hydrogen (H), germanium (Ge), vanadium (V), and oxygen (O). Amorphous silicon materials have advantages such as large-area low-temperature film formation and compatibility with conventional IC processes, and are therefore widely used in the semiconductor field. Furthermore, amorphous silicon is not corroded by hydrogen fluoride gas, which is beneficial for the release of the sacrificial layer in infrared detectors.

[0090] In some embodiments, the non-thermal working area 1112 is removed by etching or stripping.

[0091] Specifically, the non-thermal working area 1112 and the thermal working area 1111 can be formed based on an amorphous silicon layer of a certain thickness. For example, the amorphous silicon layer of the non-thermal working area 1112 can be removed by etching or stripping, so that the thickness of the amorphous silicon thermal layer 1241 in the non-thermal working area 1112 is zero, and it has a target thickness H0 greater than zero in the thermal working area 1111. The process is simple, mature and controllable, which is conducive to ensuring device yield.

[0092] In other embodiments, the thermistor working area 1111 and the non-thermistor working area 1112 of the amorphous silicon thermistor layer 1241 may also be formed in other ways, which are not limited here.

[0093] In some embodiments, continue to refer to Figure 1 The first metal layer 1242 is located on one side of the amorphous silicon thermistor layer 1241.

[0094] by Figure 1 Taking the orientation shown as an example, the first metal layer 1242 is located above the amorphous silicon thermistor layer 1241, and covers the top part and the side of the thermistor working area 1111 (i.e. the adjacent side of the thermistor working area 1111 and the non-thermal working area 1112). It can transmit the infrared detection electrical signal converted from the thermistor working area 1111 of the amorphous silicon thermistor layer 1241 to the readout circuit 100 through the second interconnection structure 12 and the first interconnection structure 11.

[0095] In some embodiments, the first metal layer 1242 includes at least one selected from titanium-tungsten alloy (TiW), titanium (Ti), titanium nitride (TiN), aluminum (Al), nickel (Ni), chromium (Cr), platinum (Pt), nickel (Ni) alloy, and metal silicides (e.g., nickel silicide (NiSi)). These materials, as conductive materials, can effectively improve the oxidation resistance of the first metal layer 1242 and are commonly used conductive metal materials in CMOS processes.

[0096] In some embodiments, Figure 5 This is a schematic diagram of the absorption sensing section of another uncooled infrared detector pixel provided in this embodiment of the present disclosure. It shows the planar structure (i.e., the structure in the XY plane) and the cross-sectional film layer structure (i.e., the structure along cross-section A1-A2) of the absorption sensing section of the pixel. Figure 1 Based on, refer to Figure 5 In the uncooled infrared detector pixel 10, the absorption sensing part 124 also includes a through hole 1240; the through hole 1240 is in the thickness direction (i.e. Figure 5 The absorption sensor 124 (shown in the Z direction) penetrates through it. This configuration improves the absorption rate and enhances the accuracy of infrared detection.

[0097] The through hole 1240 can be a circular hole, a square hole, a polygonal hole, or an irregularly shaped hole, and is not limited herein. Furthermore, the number of through holes 1240 is not limited in this embodiment.

[0098] In this embodiment, by providing the absorption sensing part 124 with a through hole 1240, which at least penetrates the absorption sensing part 124, it is beneficial to increase the contact area between the chemical reagent used in the release of the sacrificial layer and the sacrificial layer, thereby accelerating the release rate of the sacrificial layer. Furthermore, the through hole 1240 on the absorption sensing part 124 helps to release the internal stress of the absorption sensing part 124, optimizes the flatness of the absorption sensing part 124, and improves the structural stability of the absorption sensing part 124, thereby improving the structural stability of the entire infrared detector.

[0099] In some embodiments, Figure 6 This is a schematic diagram of the structure of another uncooled infrared detection pixel provided in an embodiment of this disclosure. Figure 1Based on, refer to Figure 6 In the uncooled infrared detector pixel 10, the absorption sensing unit 124 further includes a dielectric layer 1243; the dielectric layer 1243 covers the thermal working area 1111 of the amorphous silicon thermistor layer 1241; and the dielectric layer 1243 is located between the first metal layer 1242 and the amorphous silicon thermistor layer 1241.

[0100] by Figure 6 Taking the orientation shown as an example, the dielectric layer 1243 is located above the amorphous silicon thermistor layer 1241, and the first metal layer 1242 is located above the dielectric layer 1243. The dielectric layer 1243 can isolate the amorphous silicon thermistor layer 1241 and the first metal layer 1242 in the thermistor working area 1111, protect the resistance of the thermistor working area 1111 of the amorphous silicon thermistor layer 1241 from forming metal silicide, and at the same time prevent the first metal layer 1242 from affecting the thermistor working area 1111 of the amorphous silicon thermistor layer 1241 during the etching process, avoid affecting the design resistance, and ensure that the resistance of the thermistor working area 1111 is consistent with the design value.

[0101] For example, the dielectric layer 1243 may include one or more of silicon oxide, silicon nitride, or silicon oxynitride to ensure that the effective resistive portion of the amorphous silicon thermistor layer 1241 does not form metal silicides.

[0102] Specifically, the dielectric layer 1243 is located on the thermistor working area 1111 of the amorphous silicon thermistor layer 1241, and between the first metal layer 1242 and the amorphous silicon thermistor layer 1241. The dielectric layer 1243 separates the first metal layer 1242 and the amorphous silicon thermistor layer 1241, which can prevent the thermistor working area 1111 of the amorphous silicon thermistor layer 1241 from being affected by the metal in the first metal layer 1242. Using silicon oxide, silicon nitride, or silicon oxynitride as the dielectric layer 1243 can meet the requirement that the thermistor working area 1111 of the amorphous silicon thermistor layer 1241 is not affected by the first metal layer 1242. Furthermore, the metal used to form the metal silicide layer will not react with silicon oxide, silicon nitride, or silicon oxynitride, which can protect the amorphous silicon thermistor working area 1111 from forming metal silicides. Moreover, the material preparation process is more mature and the price is relatively low, which helps to reduce the manufacturing cost of infrared detectors.

[0103] In some embodiments, Figure 7 This is a schematic diagram of the structure of another uncooled infrared detection pixel provided in an embodiment of this disclosure. Figure 6 Based on, refer to Figure 7 In this uncooled infrared detector pixel 10, the absorption sensing unit 124 further includes a second protective layer 1244; the second protective layer 1244 is located on the side of the amorphous silicon thermistor layer 1241 opposite to the first metal layer 1242, and on the side of the first metal layer 1242 opposite to the amorphous silicon thermistor layer 1241. Figure 7 Taking the orientation shown as an example, the second protective layer 1244 can be located below the amorphous silicon thermistor layer 1241 and above the first metal layer 1242 and the dielectric layer 1243.

[0104] In other embodiments, the second protective layer 1244 may be located only on the side of the amorphous silicon thermistor layer 1241 away from the first metal layer 1242, or the second protective layer 1244 may be located only on the side of the first metal layer 1242 away from the amorphous silicon thermistor layer 1241, which is not limited here.

[0105] In the uncooled infrared detector pixel 10 provided in this embodiment, by setting a second protective layer 1244 on the side of the amorphous silicon thermistor layer 1241 opposite to the first metal layer 1242, and / or on the side of the first metal layer 1242 opposite to the amorphous silicon thermistor layer 1241, the amorphous silicon thermistor layer 1241 and / or the first metal layer 1242 can be protected from oxidation or corrosion during the fabrication of the absorption sensing part 124, for example, preventing VHF corrosion and improving the stability of the absorption sensing part 124 structure. Exemplarily, the second protective layer 1244 may include at least one or more of silicon nitride, aluminum oxide, amorphous silicon, silicon carbide, and amorphous carbon.

[0106] 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, the beam structure 114 includes at least one insulating layer 1141 and one second metal layer 1142; the second metal layer 1142 is located on the side of the insulating layer 1141 facing the readout circuit 100, and is connected to at least the second aluminum connection portion 113 and the third aluminum connection portion 121. In other embodiments, the second metal layer 1142 may be located on the side of the insulating layer 1141 away from the readout circuit 100.

[0107] In the preceding paragraph, "connection" refers to either electrical connection or non-electrical connection (i.e., support connection). The second aluminum connection 113 is at least partially electrically connected to the beam structure 114. When the second aluminum connection 113 is partially electrically connected to the beam structure 114, the non-electrically connected second aluminum connection 113, together with the first tungsten connection 112 and the first aluminum connection 111, provides structural support for the beam structure 114. Specifically, the electrical connection is achieved by the second metal layer 1142 in the beam structure 114. When the second metal layer 1142 is connected to the interconnection structure, an electrical connection is achieved between the beam structure 114 and the interconnection structure. When the second metal layer 1142 is not connected to the interconnection structure and only the insulating layer 1141 is connected to the interconnection structure, the beam structure 114 only serves as structural support.

[0108] The insulating layer 1141 can be made of at least one of amorphous silicon, amorphous germanium, amorphous germanium silicon, aluminum oxide, silicon nitride, amorphous carbon, and silicon carbide, and the second metal layer 1142 can be made of at least one of titanium, titanium nitride, titanium-tungsten alloy, nickel, chromium, platinum, nickel-based alloy, and titanium-based alloy.

[0109] In some embodiments, continue to refer to Figure 8 In the uncooled infrared detector pixel 10, the second tungsten connector 122 is electrically connected to the third aluminum connector 121 through at least the insulating layer 1141.

[0110] Among them, at least the insulating layer 1141 includes a hollow area, such as Figure 8 As shown at the location of the second interconnection structure 12 on the left side, the insulating layer 1141 includes a hollow area, or both the insulating layer 1141 and the second metal layer 1142 include hollow areas, i.e., the beam structure 114 includes a hollow area. The second tungsten connector 122 is electrically connected to the third aluminum connector 121 within the hollow area; the area of ​​this hollow area is larger than the bottom area of ​​the second tungsten connector 122. By first etching away the insulating layer 1141 or the insulating layer 1141 and the second metal layer 1142 above the third aluminum connector 121, the second tungsten connector 122 can be prevented from being non-conductive in the third aluminum connector 121, ensuring the stability and reliability of the electrical connection.

[0111] Alternatively, the area of ​​the hollowed-out area in the beam structure 114 can be equal to the bottom area of ​​the second tungsten connection 122, such as... Figure 8 As shown at the location of the second interconnection structure 12 on the right side, the second tungsten connector 122 passes through the beam structure 114 in this hollowed-out area and is electrically connected to the third aluminum connector 121. The structural design is simple and does not require consideration of the impact of large-area etching of the beam structure 114 on the corrosion and damage of the third aluminum connector 121.

[0112] 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 The uncooled infrared detector pixel 10 may also include at least one release blocking layer 18, the release blocking layer 18 being located at least on the side of the readout circuit 100 facing the absorption sensing part 124; the first tungsten connection part 112 is electrically connected to the first aluminum connection part 111 through at least the release blocking layer 18.

[0113] The release barrier layer 18 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 18 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 18 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 18 and the interconnect structure also has a release barrier layer 18. The release barrier layer 18 is used to protect the readout circuit 100 from erosion during the etching process to release the sacrificial layer. The release barrier layer 18 includes at least one dielectric layer, and the dielectric material constituting the release barrier layer 18 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.

[0114] Among them, at least the release barrier layer 18 includes a hollow area, such as Figure 9 As shown at the location of the first interconnect structure 11 on the left side, the release barrier layer 18 and the titanium nitride layer 142 include a hollow area at the corresponding position of the first tungsten connector 112. The first tungsten connector 112 is electrically connected to the first aluminum connector 111 within this hollow area, and the area of ​​this hollow area is larger than the bottom area of ​​the first tungsten connector 112. Etching away the release barrier layer 18 first ensures the electrical connection between the first tungsten connector 112 and the first aluminum connector 111, avoiding electrical continuity problems and additional noise issues caused by etching processes.

[0115] Alternatively, the area of ​​the hollowed-out area in the release barrier layer 18 and the titanium nitride layer 142 can be equal to the bottom area of ​​the first tungsten connector 112, such as... Figure 9 As shown at the location of the first interconnect structure 11 on the right side, the first tungsten connector 112 passes through the release barrier layer 18 and the titanium nitride layer 142 in the hollowed-out area and is electrically connected to the first aluminum connector 111. The structural design is simple and does not need to consider the impact of large-area etching of the release barrier layer 18 on the corrosion and damage of the first aluminum connector 111.

[0116] 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 The uncooled infrared detector pixel 10 may also include two sacrificial layers 19 located between the release blocking layer 18 and the absorption sensing unit 124.

[0117] For example, the sacrificial layer 19 may be located within the space where the first interconnect structure 11 and the second interconnect structure 12 are located; the sacrificial layer 12 may be released by vapor phase corrosion. Figure 10The image shows the intermediate state of the uncooled infrared detector pixel. The sacrificial layer is used as the process material for preparing the uncooled infrared detector pixel to ensure that the first interconnect structure 11 and the second interconnect structure 12 can be stacked sequentially. The final display state of the uncooled infrared detector pixel is obtained by releasing the hollow structure with the sacrificial layer 12 removed through vapor phase corrosion (refer to the schematic diagram of the uncooled infrared detector pixel provided in the previous embodiment of this disclosure).

[0118] The sacrificial layer 19 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 19 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 19 may be polyimide (PI), and the gaseous corrosive gas may be at least one of oxygen, ozone, hydrogen fluoride, and hydrogen chloride.

[0119] In some embodiments, the fabrication steps of the first interconnect structure 11 may include: 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 first tungsten interconnect, 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 photolithographically etching to form a patterned first tungsten interconnect; a third step, fabricating a second 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 second aluminum interconnect; a third aluminum interconnect is also formed simultaneously; a fourth step, fabricating a beam structure, specifically including: depositing a second metal layer, photolithographically etching to form a patterned first metal layer structure, depositing an insulating layer, and photolithographically etching the insulating layer and the second metal layer to form a patterned beam structure.

[0120] In some embodiments, the fabrication steps of the second interconnect structure 12 may include: fabricating a second tungsten interconnect, specifically including: depositing a silicon oxide sacrificial layer, planarizing it using CMP, photolithographically etching to form tungsten pillar vias, depositing a titanium layer and / or a titanium nitride layer, depositing a tungsten layer, and using CMP to form a patterned second tungsten interconnect; fabricating a fourth aluminum interconnect, specifically including: 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 fourth aluminum interconnect; fabricating an absorption sensing portion, specifically including: forming an amorphous silicon thermistor layer (the amorphous silicon thermistor layer in this step is an amorphous silicon thermistor layer with a uniform thickness, which is formed through subsequent steps to form amorphous silicon thermistor layers with different partitions), forming a dielectric layer on the side of the amorphous silicon thermistor layer away from the readout circuit, and performing photolithography and etching or stripping on the dielectric layer and the amorphous silicon thermistor layer to form a pattern. A structure is formed that includes a thermistor working area and a non-thermistor working area. The amorphous silicon thermistor layer in the thermistor working area has a target thickness, while the amorphous silicon thermistor layer in the non-thermistor working area has zero thickness, meaning the amorphous silicon thermistor layer in the non-thermistor working area is completely removed. A first metal layer is deposited on the side of the dielectric layer away from the amorphous silicon thermistor layer (the first metal layer is formed above the dielectric layer, on the side of the amorphous silicon thermistor layer not covered by the dielectric layer, and on the side away from other structures formed earlier in the uncooled infrared detection pixel; the first metal layer in this step is a whole-layer structure covering the dielectric layer and the amorphous silicon thermistor layer). The first metal layer is photolithographically etched or stripped to form an absorption sensing part. The first metal layer is located in the non-thermistor working area and is in contact with at least the side of the thermistor working area. A pair of adjacent first metal layers located on the side of the thermistor working area form quasi-parallel electrodes.

[0121] 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.

[0122] In some embodiments, Figure 11 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 11 in the uncooled infrared detector pixel where the sacrificial layer 19 has not been released. (See reference...) Figure 11The first interconnection structure 11 may include a first aluminum connection portion 111, a first tungsten connection portion 112, a second aluminum connection portion 113, and a beam structure 114. The first aluminum connection portion 111 includes an aluminum layer 11A and a titanium nitride layer 142 on the side of the aluminum layer 11A away from the readout circuit and a titanium nitride layer 142 on the side of the aluminum layer 11A facing the readout circuit. The first tungsten connection portion 112 includes a tungsten pillar 2A and a titanium nitride layer (i.e., an adhesion layer 2B) covering the tungsten pillar around its perimeter and bottom. The second aluminum connection portion 113 includes an aluminum layer 11A and a titanium nitride layer 142 on the side of the aluminum layer 11A away from the readout circuit and a titanium nitride layer 142 on the side of the aluminum layer 11A facing the readout circuit. The beam structure 114 includes a second metal layer 1142 and an insulating layer 1141.

[0123] In other embodiments, the first interconnection structure and the second interconnection structure in the uncooled infrared detection pixel may also be implemented using other structural forms provided in the embodiments of this application, which are not limited here.

[0124] Based on the above embodiments, this disclosure also provides an uncooled infrared detection chip.

[0125] For example, Figure 12 This is a schematic diagram of the structure of an uncooled infrared detection chip provided in an embodiment of this disclosure. (Reference) Figure 12 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.

[0126] 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.

[0127] For example, Figure 13 This is a schematic diagram of the structure of an uncooled infrared detector core provided in an embodiment of this disclosure. (Reference) Figure 13 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.

[0128] In other embodiments, the movement 20 may also include other structural and functional components, which are not described in detail or limited herein.

[0129] 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.

[0130] 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.

[0131] 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.

[0132] 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, It includes a first interconnection structure and a second interconnection structure. The first interconnection structure includes a first aluminum connector, a first tungsten connector, a second aluminum connector, and a beam structure. The second interconnection structure includes a third aluminum connector, a second tungsten connector, a fourth aluminum connector, and an absorption sensing part. The aluminum connector includes an aluminum layer, and at least one of the aluminum connectors further includes at least one of a titanium layer and a titanium nitride layer, located on the side of the aluminum layer away from and / or towards the absorption sensing portion; The first interconnect structure connects the second interconnect structure and the readout circuit; In the first interconnection structure, the two ends of the first tungsten connector are respectively connected to the first aluminum connector and the second aluminum connector. The first aluminum connector is connected to the readout circuit, and the second aluminum connector is connected to the beam structure. In the second interconnection structure, the two ends of the second tungsten connector are respectively connected to the third aluminum connector and the fourth aluminum connector. The third aluminum connector is connected to the beam structure, and the fourth aluminum connector is connected to the absorption sensing part. The absorption sensing unit includes an amorphous silicon thermistor layer and a first metal layer; the first metal layer is located on the side of the amorphous silicon thermistor layer away from the readout circuit and is connected to the fourth aluminum connection portion; The absorption sensing unit includes a thermistor working area and a non-thermistor working area. The amorphous silicon thermistor layer is located in the thermistor working area. The thermistor working area generates a resistance change in response to the received thermal signal. The first metal layer is located in the non-thermal working area and is in contact with at least the side of the thermal working area; wherein, a pair of adjacent first metal layers located on the side of the thermal working area form quasi-parallel electrodes.

2. The uncooled infrared detection pixel according to claim 1, characterized in that, In the first interconnection structure, the plane containing the first aluminum connection portion is parallel to the plane containing the second aluminum connection portion and perpendicular to the first tungsten connection portion; In the second interconnection structure, the plane where the third aluminum connection portion is located is parallel to the plane where the fourth aluminum connection portion is located, and perpendicular to the second tungsten connection portion; The first interconnect structure is located on the side of the second interconnect structure that is opposite to or towards the readout circuit; The second aluminum connection portion in the first interconnection structure is disposed in the same layer as the third aluminum connection portion in the second interconnection structure.

3. The uncooled infrared detection pixel according to claim 1, characterized in that, The aluminum layer of the aluminum connector is a pure aluminum layer or an aluminum alloy layer; The first aluminum connection is the top metal layer of the readout circuit, or the first aluminum connection is an 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.

4. The uncooled infrared detection pixel according to claim 1, characterized in that, The number of tungsten pillars in the first tungsten connector and / or the second tungsten connector is one or more.

5. The uncooled infrared detection pixel according to claim 4, characterized in that, The first tungsten connector and / or the second tungsten connector include an adhesive layer that covers at least the sides and bottom of the tungsten pillar, and the adhesive layer includes a titanium layer and / or a titanium nitride layer.

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

7. The uncooled infrared detection pixel according to claim 1, characterized in that, The amorphous silicon thermistor layer in the non-thermal working area is removed by etching or stripping.

8. The uncooled infrared detection pixel according to claim 1, characterized in that, The absorption sensing part further includes a through hole; the through hole extends through the absorption sensing part in the thickness direction.

9. The uncooled infrared detection pixel according to claim 1, characterized in that, The absorption sensing unit also includes a dielectric layer; The dielectric layer covers the thermistor working area of ​​the amorphous silicon thermistor layer; and the dielectric layer is located between the first metal layer and the amorphous silicon thermistor layer.

10. The uncooled infrared detection pixel according to claim 1, characterized in that, The absorption sensing unit also includes a second protective layer; The second protective layer is located on the side of the amorphous silicon thermistor layer opposite to the first metal layer, and / or on the side of the first metal layer opposite to the amorphous silicon thermistor layer.

11. The uncooled infrared detection pixel according to claim 1, characterized in that, The beam structure includes at least one insulating layer and one second metal layer; the second metal layer is located on the side of the insulating layer facing or away from the readout circuit, and is connected to at least the second aluminum connection portion and the third aluminum connection portion; the second tungsten connection portion passes through the insulating layer and is electrically connected to the third aluminum connection portion.

12. The uncooled infrared detection pixel according to claim 1, characterized in that, It also includes at least one release barrier layer, which is located at least on the side of the readout circuit facing the absorption sensing part; the first tungsten connector passes through the release barrier layer and is electrically connected to the first aluminum connector.

13. The uncooled infrared detection pixel according to claim 12, characterized in that, It also includes two sacrificial layers located between the release barrier layer and the absorption sensing unit.

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.

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