Amorphous silicon infrared detector pixel, chip, movement and equipment

Abstract

The present disclosure relates to the technical field of infrared detection, and particularly relates to an amorphous silicon infrared detector pixel, a chip, a movement and equipment, the amorphous silicon infrared detector pixel comprising an absorption sensing part; the absorption sensing part comprises an amorphous silicon thermal sensitive layer and a metal electrode layer; the amorphous silicon thermal sensitive layer comprises a thermal sensitive working area and a non-thermal sensitive working area, the thermal sensitive working area has a first thickness, the non-thermal sensitive working area has a second thickness, the first thickness is greater than the second thickness, and the effective value of the second thickness is less than 2000 angstroms; the metal electrode layer is in contact with the non-thermal sensitive working area and at least the side surface of the thermal sensitive working area; wherein an adjacent pair of metal electrode layers located on the side surface of the thermal sensitive working area form quasi-parallel electrodes. Thus, the first thickness of the amorphous silicon thermal sensitive layer in the thermal sensitive working area is greater than the second thickness of the non-thermal sensitive working area, the thickness of the amorphous silicon thermal sensitive layer between the quasi-parallel electrodes is relatively thick, noise can be reduced, and the performance of the device is improved.

Description

Technical Field

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

[0002] Infrared detection is a technology that uses infrared radiation emitted or reflected by objects to detect, identify, and locate them. Amorphous silicon infrared detection equipment is a device that uses the infrared radiation characteristics of objects for detection and can operate without a cooling system.

[0003] Specifically, amorphous silicon 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 the detection chip, the detection chip causes a change in its own physical parameters based on the infrared signal, and converts it into an electrical signal. After being read out by the circuit and processed, the infrared signal is finally detected and imaged.

[0004] In related technologies, amorphous silicon infrared detectors exhibit relatively high 1 / f noise, primarily stemming from the noise of the amorphous silicon thermistor layer material. As a semiconductor material, thicker amorphous silicon corresponds to more conductive channels. Since amorphous silicon is a thermistor, temperature changes cause fluctuations in the conductivity at the contact points between these channels. These fluctuations in conductivity at the contact points generate 1 / f noise. The thicker the amorphous silicon layer, the more pronounced these fluctuations at the contact points, resulting in greater 1 / f noise and poorer device performance. Utility Model Content

[0005] To solve the above-mentioned technical problems, or at least partially solve them, this disclosure provides an amorphous silicon infrared detector pixel, chip, core, and device.

[0006] This disclosure provides an amorphous silicon infrared detector pixel, including an absorption sensing unit; the absorption sensing unit includes an amorphous silicon thermistor layer and a metal electrode layer.

[0007] The amorphous silicon thermistor layer includes a thermistor working area and a non-thermistor working area. The thermistor working area has a first thickness, and the non-thermistor working area has a second thickness. The first thickness is greater than the second thickness, and the effective value of the second thickness is less than 2000 angstroms. The thermistor working area generates a change in resistance in response to the received thermal signal.

[0008] The metal electrode layer is in contact with the non-thermal working area and at least with the side of the thermal working area; wherein, a pair of adjacent metal electrode layers located on the side of the thermal working area form quasi-parallel electrodes.

[0009] This disclosure also provides an amorphous silicon infrared detector pixel, including an absorption sensing part as described in any of the above-described amorphous silicon infrared detector pixels, a beam structure and a readout circuit, and an interconnection structure connecting the beam structure, the absorption sensing part and the readout circuit.

[0010] This disclosure also provides an amorphous silicon infrared detector chip, comprising an array structure of multiple amorphous silicon infrared detector pixels as described above.

[0011] This disclosure also provides an amorphous silicon infrared detector core, which includes any of the aforementioned amorphous silicon infrared detector chips; the core also includes a lens for focusing infrared signals onto the amorphous silicon infrared detector chip.

[0012] This disclosure also provides an amorphous silicon infrared detection device, which includes any of the aforementioned mechanisms.

[0013] The technical solution provided in this disclosure has the following advantages compared with the prior art:

[0014] In the amorphous silicon infrared detector pixel, chip, core, and device provided in the embodiments of this disclosure, the amorphous silicon infrared detector pixel includes an absorption sensing part; the absorption sensing part includes an amorphous silicon thermistor layer and a metal electrode layer; the amorphous silicon thermistor layer includes a thermistor working area and a non-thermistor working area, the thermistor working area has a first thickness, the non-thermistor working area has a second thickness, the first thickness is greater than the second thickness, and the effective value of the second thickness is less than 2000 angstroms; wherein, the thermistor working area generates a resistance change in response to the received thermal signal; the metal electrode layer is in contact with the non-thermistor working area and at least in contact with the side of the thermistor working area; wherein, a pair of adjacent metal electrode layers located on the side of the thermistor working area form quasi-parallel electrodes. Therefore, by setting the first thickness of the amorphous silicon thermistor layer in the thermistor working region to be greater than the second thickness in the non-thermistor working region, and the effective value of the second thickness being less than 2000 angstroms, the thickness of the amorphous silicon thermistor layer between the quasi-parallel electrodes is made thicker, which can directly reduce the formation of different conductive channels. The metal material of the metal electrode layer corresponding to the non-thermistor working region can diffuse into the amorphous silicon thermistor layer, thereby also preventing the formation of the corresponding conductive channels, 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. Attached Figure Description

[0015] 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.

[0016] 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.

[0017] Figure 1 A schematic diagram of the structure of the absorption sensing section of an amorphous silicon infrared detector pixel provided in an embodiment of this disclosure;

[0018] Figure 2 This is a schematic diagram of the absorption sensing section of an amorphous silicon infrared detector pixel in related technologies.

[0019] Figure 3 A schematic diagram of the structure of the absorption sensing section of another amorphous silicon infrared detector pixel provided in an embodiment of this disclosure;

[0020] Figure 4 for Figure 3 The diagram shows the working principle of the absorption sensing unit of an amorphous silicon infrared detector pixel.

[0021] Figure 5 This is a schematic diagram illustrating the working principle of the absorption sensing unit of another amorphous silicon infrared detector pixel in related technologies.

[0022] Figure 6 A schematic diagram of the structure of the absorption sensing section of another amorphous silicon infrared detector pixel provided in this embodiment of the present disclosure;

[0023] Figure 7 A physical schematic diagram of the absorption sensing section of an amorphous silicon infrared detector pixel provided in an embodiment of this disclosure;

[0024] Figure 8 A schematic diagram of the structure of the absorption sensing section of another amorphous silicon infrared detector pixel provided in this embodiment of the present disclosure;

[0025] Figure 9 A schematic diagram of the absorption sensing part and beam structure of another amorphous silicon infrared detector pixel provided in this embodiment of the present disclosure;

[0026] Figure 10 A schematic diagram of the structure of another amorphous silicon infrared detector pixel provided in this embodiment of the present disclosure;

[0027] Figure 11 A schematic diagram of the structure of another amorphous silicon infrared detector pixel provided in this embodiment of the present disclosure;

[0028] Figure 12 A schematic diagram of the structure of another amorphous silicon infrared detector pixel provided in this embodiment of the present disclosure;

[0029] Figure 13 A schematic flowchart illustrating a method for fabricating an amorphous silicon infrared detector pixel according to an embodiment of this disclosure;

[0030] Figure 14 for Figure 13 The schematic diagram of the structure after S21 in the preparation method shown;

[0031] Figure 15 for Figure 13 The schematic diagram of the structure after S22 in the preparation method shown;

[0032] Figure 16 for Figure 13 The schematic diagram of the structure after S23 in the preparation method shown;

[0033] Figure 17 for Figure 13 The schematic diagram of the structure after S24 in the preparation method shown;

[0034] Figure 18 This is a schematic diagram of the structure of an amorphous silicon infrared detection chip provided in an embodiment of this disclosure;

[0035] Figure 19 This is a schematic diagram of the structure of an amorphous silicon infrared detector core provided in an embodiment of this disclosure. Detailed Implementation

[0036] 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.

[0037] 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.

[0038] Figure 1 This is a partial structural diagram of an amorphous silicon infrared detector pixel provided in an embodiment of the present disclosure, showing the film structure of the absorption sensing part; Figure 2 This is a partial structural diagram of an amorphous silicon infrared detector pixel in related technologies, which also shows the structure of the absorption sensing section; Figure 1 and Figure 2 The comparison illustrates the improvement of the film structure of the absorption sensing portion of the amorphous silicon infrared detector pixel provided in the embodiments of this disclosure compared to the film structure of the absorption sensing portion of the amorphous silicon infrared detector pixel in the related art. (Reference) Figure 1The amorphous silicon infrared detector pixel 10 provided in this embodiment may include: an absorption sensing unit 11; the absorption sensing unit 11 includes an amorphous silicon thermistor layer 111 and a metal electrode layer 112; the amorphous silicon thermistor layer 111 includes a thermistor working region 1111 and a non-thermistor working region 1112, wherein the thermistor working region 1111 generates a resistance change based on the received thermal signal, that is, the amorphous silicon thermistor layer 111 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 111 of the thermistor working region 1111 is the effective resistive portion, and the amorphous silicon thermistor layer 111 of the non-thermistor working region 1112 is the non-resistive portion. The metal electrode layer 112 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 detector pixel.

[0039] The thermal working area 1111 has a first thickness H1, and the non-thermal working area 1112 has a second thickness H2, with the first thickness H1 being greater than the second thickness H2. Therefore, the thermal working area 1111 is higher than the non-thermal working area 1112. The effective value of the second thickness H2 is less than 2000 angstroms. Figure 1 The thermal working area 1111 forms a raised structure relative to the non-thermal working area 1112.

[0040] The metal electrode layer 112 is in contact with the non-thermosensitive working area 1112 and at least with the side surface of the thermosensitive working area 1111. Adjacent pairs of metal electrode layers 112 located on the side surface of the thermosensitive working area 1111 form quasi-parallel electrodes. That is, a pair of metal electrodes 112 in contact with the side surface of the same thermosensitive working area 1111 form quasi-parallel electrodes. Figure 1 Within the thermal working area 1111, a pair of metal electrodes 112 corresponding to the beginning and end of the arrows form quasi-parallel electrodes. Quasi-parallel electrodes refer to a pair of metal electrode layers 112 that may deviate during the manufacturing process due to process reasons. They may not be a pair of electrodes that are strictly parallel in a mathematical sense, but may have a small angular deviation. Therefore, in this embodiment, the pair of metal electrodes is referred to as quasi-parallel electrodes.

[0041] The greater the difference in thickness between the first thickness H1 and the second thickness H2, 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 the conductivity of the contact point between different conductive channels caused by temperature fluctuations. This is more conducive to eliminating additional noise. When the conductive channel is a single channel, the contact point conductivity will not exist, and no additional noise will be generated.

[0042] contrast Figure 2In the amorphous silicon 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, creating 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. Simultaneously, the overall amorphous silicon thin-film structure results in a large heat capacity, long thermal response time, and poor NETD (thermal sensitivity) performance. Furthermore, due to the high sheet resistance of amorphous silicon, a thicker amorphous silicon layer is required to achieve the designed resistance value. Reducing the overall thickness of the amorphous silicon layer would further increase the sheet resistance, requiring a longer effective amorphous silicon resistor and a larger area for the absorption sensing element. This leads to a more complex structural design and hinders pixel miniaturization.

[0043] In the amorphous silicon infrared detector pixel 10 provided in this embodiment, by setting the first thickness H1 of the amorphous silicon thermistor layer 111 in the thermistor working area 1111 to be greater than its second thickness H2 in the non-thermistor working area 1112, quasi-parallel electrodes can be formed using a pair of adjacent metal electrode layers 112 located on the side of the thermistor working area 1111. These quasi-parallel electrodes improve the uniformity of the conductive channels, directly reducing the formation of different conductive channels and decreasing 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.

[0044] In some embodiments, the amorphous silicon thermistor layer 111 includes an amorphous silicon layer doped with one or more elements selected from boron, phosphorus, hydrogen, germanium, vanadium, and oxygen.

[0045] Specifically, the thermistor working area 1111 can generate a resistance change based on the received thermal signal. The amorphous silicon thermistor layer 111 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.

[0046] In some embodiments, continue to refer to Figure 1 The thermal working area 1111 includes a first bottom 111B and a first top 111T, and the non-thermal working area 1112 includes a second bottom 112B and a second top 112T, respectively. The first bottom 111B and the second bottom 112B are located on the same plane, and the height of the first top 111T is greater than the height of the second top 112T, so that the first thickness H1 of the thermal working area 1111 is greater than the second thickness H2 of the non-thermal working area 1112.

[0047] It is understood that the first bottom 111B and the second bottom 112B in the embodiments of this disclosure are located on the same plane, which is not a strictly mathematical plane, but a plane that allows for process errors.

[0048] In some embodiments, the non-thermal working area 1112 is thinned to a second thickness H2 by etching.

[0049] 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 thickness of the non-thermal working area 1112 can be reduced by etching, so that the second thickness H2 of the thinned amorphous silicon thermal layer 111 in the non-thermal working area 1112 is smaller than its first thickness H1 in the thermal working area 1111. The process is simple, mature and controllable, which is conducive to ensuring device yield.

[0050] In other embodiments, the thermistor working area 1111 and the non-thermistor working area 1112 of the amorphous silicon thermistor layer 111 can also be formed in other ways, which are not limited here.

[0051] In some embodiments, continue to refer to Figure 1 The metal electrode layer 112 is located on the side of the amorphous silicon thermistor layer 111 that is opposite to the first bottom layer 111B and the second bottom layer 112B.

[0052] by Figure 1 Taking the orientation shown as an example, the metal electrode layer 112 is located above the amorphous silicon thermistor layer 111 and covers part of the first top 111T, the second top 112T, and the side of the thermistor working area 1111 (i.e., the adjacent side of the first top 111T and the second top 112T). It can transmit the infrared detection electrical signal converted from the thermistor working area 1111 of the amorphous silicon thermistor layer 111 to the substrate (e.g., the readout circuit) through the beam structure in the infrared detector.

[0053] In some embodiments, the metal electrode layer 112 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 metal electrode layer 112 and are commonly used conductive metal materials in CMOS processes.

[0054] In some embodiments, material from the metal electrode layer 112 located in the non-thermal working region 1112 diffuses into the non-thermal working region 1112, which is equivalent to metallizing a portion of the amorphous silicon layer in the non-thermal working region 1112 of the amorphous silicon thermistor layer 111 that contacts the metal electrode layer 112, increasing the area of ​​the quasi-parallel electrodes. Referring to the preceding text, the effective value of the second thickness H2 of the non-thermal working region 1112 does not include the thickness of the material diffused into the metal electrode layer 112, but can be understood as the thickness of the amorphous silicon layer that is not metallized. This further reduces the formation of different conductive channels and lowers noise, which will be discussed later in conjunction with... Figure 4 Detailed explanation.

[0055] In some embodiments, Figure 3 This is a schematic diagram of the absorption sensing section of another amorphous silicon infrared detector pixel provided in an embodiment of this disclosure. Figure 1 Based on, refer to Figure 3 In the amorphous silicon infrared detector pixel 10, the absorption sensing part 11 further includes a dielectric layer 113; the dielectric layer 113 covers the thermal working area 1111 of the amorphous silicon thermistor layer 111; and the dielectric layer 113 is located between the metal electrode layer 112 and the amorphous silicon thermistor layer 111.

[0056] by Figure 3 Taking the orientation shown as an example, the dielectric layer 113 is located above the amorphous silicon thermistor layer 111, and the metal electrode layer 112 is located above the dielectric layer 113. The dielectric layer 113 can isolate the amorphous silicon thermistor layer 111 and the metal electrode layer 112 of the thermistor working area 1111, protect the resistance of the thermistor working area 1111 of the amorphous silicon thermistor layer 111 from forming metal silicides, and at the same time prevent the metal electrode layer 112 from affecting the thermistor working area 1111 of the amorphous silicon thermistor layer 111 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.

[0057] For example, the dielectric layer 113 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 111 does not form metal silicides.

[0058] Specifically, the dielectric layer 113 is located on the thermistor working area 1111 of the amorphous silicon thermistor layer 111, and between the metal electrode layer 112 and the amorphous silicon thermistor layer 111. The dielectric layer 113 separates the metal electrode layer 112 and the amorphous silicon thermistor layer 111, thus preventing the thermistor working area 1111 of the amorphous silicon thermistor layer 111 from being affected by the metal in the metal electrode layer 112. Using silicon oxide, silicon nitride, or silicon oxynitride as the dielectric layer 113 satisfies the requirement that the thermistor working area 1111 of the amorphous silicon thermistor layer 111 is not affected by the metal electrode layer 112. Furthermore, the metal used to form the metal silicide layer will not react with silicon oxide, silicon nitride, or silicon oxynitride, protecting 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.

[0059] For example, Figure 4 and Figure 5 The comparison illustrates the improvement in the working principle of the amorphous silicon infrared detector pixel 10 provided in this disclosure embodiment compared to the amorphous silicon infrared detector pixel 01 in related technologies. Specifically, in conjunction with... Figure 1 or Figure 3 By setting the first thickness H1 of the amorphous silicon thermistor layer 111 in the thermistor working region 1111 to be greater than its second thickness H2 in the non-thermistor working region 1112, quasi-parallel electrodes can be formed on opposite sides of the thermistor working region 1111, as reference. Figure 4 In section ①, the quasi-parallel electrode can directly reduce the formation of different conductive channels, which is beneficial for reducing noise; at the same time, in the non-thermosensitive working area 1112, the metal material of the metal electrode layer 112 can diffuse into the amorphous silicon thermistor layer 111, further preventing the formation of conductive channels, corresponding to Figure 4 Therefore, noise will be significantly reduced. The effective thickness of the corresponding second thickness H2 does not include the thickness diffused into by the metal electrode layer. Specifically, the conductive channels of the amorphous silicon thermistor layer (corresponding to...) Figure 5 ④) will be greatly reduced, which can be regarded as the unification of some conductive channels (corresponding to Figure 4 (③) This significantly reduces noise. Simultaneously, because the thickness of the amorphous silicon thermistor layer is reduced in the non-thermal working area, the heat capacity is also greatly reduced, the thermal response time is shortened, and the thermal sensitivity performance is improved. Furthermore, without being limited by heat capacity, the thickness of the amorphous silicon layer can be adjusted over a wide range, fully meeting the design requirements of the resistor and facilitating pixel miniaturization.

[0060] In some embodiments, Figure 6 This is a schematic diagram of the absorption sensing section of another amorphous silicon infrared detector pixel provided in an embodiment of this disclosure. Figure 1 Based on, refer to Figure 6In this amorphous silicon infrared detector pixel 10, the absorption sensing unit 11 further includes a protective layer 114; the protective layer 114 is located on the side of the amorphous silicon thermistor layer 111 opposite to the metal electrode layer 112, and on the side of the metal electrode layer 112 opposite to the amorphous silicon thermistor layer 111. Figure 6 Taking the orientation shown as an example, the protective layer 114 may be located below the amorphous silicon thermistor layer 111 and above the metal electrode layer 112 and the dielectric layer 113.

[0061] In other embodiments, the protective layer 114 may be located only on the side of the amorphous silicon thermistor layer 111 away from the metal electrode layer 112, or the protective layer 114 may be located only on the side of the metal electrode layer 112 away from the amorphous silicon thermistor layer 111, which is not limited here.

[0062] For example, Figure 7 This is a schematic diagram of the absorption sensing section of an amorphous silicon infrared detector pixel provided in an embodiment of this disclosure. (Reference) Figure 7 In the amorphous silicon infrared detector pixel 10, the absorption sensing unit 11 includes an amorphous silicon thermistor layer 111, a metal electrode layer 112, a dielectric layer 113, and a protective layer 114, so as to... Figure 7 Taking the orientation shown as an example, the dielectric layer 113 is located above the thermistor working area 1111 of the amorphous silicon thermistor layer 111, and the metal electrode layer 112 is located above the non-thermosensitive working area 1112, the side of the thermistor working area 1111, the side of the dielectric layer 113, and its edge area. The amorphous silicon thermistor layer 111 includes the thermistor working area 1111 and the non-thermosensitive working area 1112. The metal electrode layer 112 covers the non-thermosensitive working area 1112, the side of the thermistor working area 1111, and the edge area of ​​the dielectric layer 113 located on top of the thermistor working area 1111. The dielectric layer 113 covers the top of the thermistor working area 1111 to isolate the metal electrode layer 112 from the thermistor working area 1111 of the amorphous silicon thermistor layer 111. The protective layer 114 is located below the amorphous silicon thermistor layer 111, above the metal electrode layer 112, and above the dielectric layer 113 not covered by the metal electrode layer 112.

[0063] In the amorphous silicon infrared detector pixel 10 provided in this embodiment, by providing a protective layer 114 located on the side of the amorphous silicon thermistor layer 111 facing away from the metal electrode layer 112, and / or located on the side of the metal electrode layer 112 facing away from the amorphous silicon thermistor layer 111, the amorphous silicon thermistor layer 111 and / or the metal electrode layer 112 can be protected from oxidation or corrosion during the fabrication of the absorption sensing part 11, for example, preventing VHF corrosion and improving the stability of the absorption sensing part 11 structure. Exemplarily, the protective layer 114 may include at least one or more of silicon nitride, aluminum oxide, amorphous silicon, silicon carbide, and amorphous carbon.

[0064] In some embodiments, Figure 8 This is a schematic diagram of the absorption sensing section of another amorphous silicon 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 structure (i.e., the structure along cross-section A1-A2) of the absorption sensing section of the pixel. (Refer to...) Figure 8 In the amorphous silicon infrared detector pixel 10, the absorption sensing part 11 further includes a through hole 110; the through hole 110 is in the thickness direction (i.e., Figure 8 The absorption sensor 11 is penetrated in the Z direction (as shown in the diagram). This configuration improves the absorption rate and enhances the accuracy of infrared detection.

[0065] The through hole 110 can be a circular hole, a square hole, a polygonal hole, or an irregularly shaped hole, and is not limited thereto. Furthermore, the number of through holes 110 is not limited in this embodiment.

[0066] In this embodiment, by providing the absorption sensing part 11 with a through hole 110, which at least penetrates the absorption sensing part 11, 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 110 on the absorption sensing part 11 helps to release the internal stress of the absorption sensing part 11, optimizes the flatness of the absorption sensing part 11, and improves the structural stability of the absorption sensing part 11, thereby improving the structural stability of the entire infrared detector.

[0067] In some embodiments, Figure 9 A schematic diagram of the absorption sensing section and beam structure of another amorphous silicon infrared detector pixel provided in this embodiment of the present disclosure. (See reference) Figure 9 The amorphous silicon infrared detector pixel also includes a beam structure 12; the beam structure 12 is disposed on the same layer as the absorption sensing unit 11; the infrared detection electrical signal obtained by the absorption sensing unit 11 in response to the infrared temperature detection signal is transmitted to the substrate (e.g., readout circuit) through the beam structure 12.

[0068] In the amorphous silicon thermistor layer 111 of the absorption sensing section 11, a portion of the amorphous silicon thermistor layer 111 in the non-thermal working area 1112 serves as the dielectric layer 120 of the beam structure 12.

[0069] In this way, film layer reuse can be achieved, that is, different structures can be formed by using different regions of the same amorphous silicon layer, thereby reducing the number of film layers and simplifying the device structure.

[0070] In some embodiments, Figure 10 This is a schematic diagram of the structure of another amorphous silicon infrared detector pixel provided in an embodiment of this disclosure. Figure 11 This is a schematic diagram illustrating the structure of another amorphous silicon infrared detector pixel provided in an embodiment of this disclosure. (See reference...) Figure 10or Figure 11 The amorphous silicon infrared detector pixel 10 also includes a beam structure 12; the beam structure 12 is disposed in a different layer from the absorption sensing part 11.

[0071] refer to Figure 11 The absorption sensing unit 11 may also include an absorption layer 115, which is located on the side of the metal electrode layer 112 away from the amorphous silicon thermistor layer 111 and forms a suspended structure to enhance infrared absorption and improve the accuracy of infrared detection.

[0072] In some embodiments, Figure 12 This is a schematic diagram illustrating the structure of another amorphous silicon infrared detector pixel provided in an embodiment of this disclosure. (See reference...) Figure 12 The amorphous silicon infrared detector pixel 10 includes the absorption sensing part 11 of any of the amorphous silicon infrared detector pixels 10 provided in the above embodiments, and also includes a beam structure 12 and a readout circuit 13, as well as an interconnection structure 14 connecting the beam structure 12, the absorption sensing part 11 and the readout circuit 13.

[0073] The infrared detection electrical signal obtained by the absorption sensing unit 11 in response to the conversion of the infrared temperature detection signal is transmitted to the readout circuit 13 through the beam structure 12 and the interconnection structure 14.

[0074] What is understandable is that Figure 12 The present invention only illustrates one structural form of the absorption sensing unit 11, the beam structure 12, the interconnection structure 14, and the readout circuit 13. In other embodiments, the absorption sensing unit 11 and the beam structure 12 may also adopt other structural forms provided in the embodiments of the present disclosure, and the interconnection structure 14 and the readout circuit 13 may also be implemented in other structural forms known to those skilled in the art, which are not limited herein.

[0075] This disclosure also provides a method for preparing an amorphous silicon infrared detector pixel, which is used to form any of the amorphous silicon infrared detector pixels provided in the above embodiments, and can achieve the corresponding beneficial effects, which will not be elaborated here.

[0076] For example, Figure 13 This is a schematic flowchart illustrating a method for fabricating an amorphous silicon infrared detector pixel according to an embodiment of this disclosure. (Reference) Figure 13 The fabrication method of the amorphous silicon infrared detector pixel includes the following steps.

[0077] S21, Form an amorphous silicon thermistor layer.

[0078] For example, Figure 14 for Figure 13The schematic diagram of the structure after S21 in the illustrated fabrication method only shows the amorphous silicon thermistor layer 111. It is important to note that this amorphous silicon thermistor layer 111 is an amorphous silicon thermistor layer with a uniform thickness; subsequent steps are required to form amorphous silicon thermistors with different partitions. It is understood that this amorphous silicon thermistor layer 111 can be formed on top of other previously formed structures within the amorphous silicon infrared detector pixel, which will not be elaborated upon here.

[0079] In this step, the amorphous silicon thermistor layer 111 can be formed in any manner known to those skilled in the art, and is not limited here.

[0080] S22. A dielectric layer is formed on one side of the amorphous silicon thermistor layer.

[0081] For example, Figure 15 for Figure 13 The diagram shows the structure after step S22 in the preparation method shown. (Reference) Figure 15 In the orientation shown, a dielectric layer 113 is formed above the amorphous silicon thermistor layer 111 (i.e., on the side opposite to other structures formed earlier in the amorphous silicon infrared detector pixel).

[0082] In this step, the dielectric layer 113 can be formed in any manner known to those skilled in the art, and is not limited here.

[0083] S23. Photolithography and etching are performed on the dielectric layer and the amorphous silicon thermistor layer to pattern the structure of the thermistor working area and the non-thermistor working area.

[0084] The thermistor working area has a first thickness, and the non-thermal working area has a second thickness. The first thickness is greater than the second thickness, and the effective value of the second thickness is less than 2000 angstroms. The thermistor working area generates a change in resistance in response to the received thermal signal.

[0085] For example, Figure 16 for Figure 13 The diagram shows the structure after step S23 in the preparation method shown. (Reference) Figure 16 and combined Figure 1 After a patterning process, the thickness of the amorphous silicon thermistor layer 111 in the non-thermal working area 1112 is etched to a second thickness H2, and the dielectric layer 113 corresponding to the non-thermal working area 1112 is removed; the thickness of the amorphous silicon thermistor layer 111 in the thermistor working area 1111 is retained to a first thickness H1, and the dielectric layer 113 corresponding to the thermistor working area 1111 is retained.

[0086] In this step, the dielectric layer 113 corresponding to the non-thermal working area 1112 is removed by photolithography and etching, and the thickness of the amorphous silicon thermistor layer 111 in the non-thermal working area 1112 is reduced, thereby patterning an amorphous silicon thermistor layer 111 including a thicker thermistor working area and a thinner non-thermal working area.

[0087] In some implementations, the medium layer of the beam structure can also be formed simultaneously in this step, which is not limited here.

[0088] S24. Deposit a metal electrode layer on the side of the dielectric layer away from the amorphous silicon thermistor layer.

[0089] For example, Figure 17 for Figure 13 The diagram shows the structure after step S24 in the preparation method shown. (Reference) Figure 17 A metal electrode layer 112 is formed above the dielectric layer 113, on the side of the amorphous silicon thermistor layer 111 not covered by the dielectric layer 113 and above it (i.e., on the side away from other structures formed earlier in the amorphous silicon infrared detector pixel). The metal electrode layer 112 is a whole-layer structure covering the dielectric layer 113 and the amorphous silicon thermistor layer 111.

[0090] In this step, the specific formation method of the metal electrode layer 112 can be any method known to those skilled in the art, and is not limited here.

[0091] S25. Photolithography and etching are performed on the metal electrode layer to form an absorption sensing element.

[0092] For example, Figure 1 This can be understood as a structural schematic diagram after S25 in this preparation method. The metal electrode layer is in contact with the non-thermosensitive working area and at least with the side surface of the thermosensitive working area; wherein, a pair of adjacent metal electrode layers located on the side surface of the thermosensitive working area form quasi-parallel electrodes.

[0093] In the method for fabricating amorphous silicon infrared detector pixels provided in this disclosure, photolithography and etching are used to make the first thickness of the amorphous silicon thermistor layer in the thermistor working region greater than its second thickness in the non-thermistor working region. The effective value of the second thickness is less than 2000 angstroms. This allows for the formation of quasi-parallel electrodes using a pair of adjacent metal electrode layers located on the side of the thermistor working region. These quasi-parallel electrodes improve the uniformity of the conductive channels, directly reducing the formation of different conductive channels and decreasing 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.

[0094] In some embodiments, the fabrication method of amorphous silicon infrared detector pixels may also include steps such as forming a protective layer, through holes, interconnect structures, etc., which will not be elaborated or limited here.

[0095] Based on the above embodiments, this disclosure also provides an amorphous silicon infrared detection chip.

[0096] For example, Figure 18 This is a schematic diagram of the structure of an amorphous silicon infrared detection chip provided in an embodiment of this disclosure. (Reference) Figure 18 The amorphous silicon infrared detector chip 30 may include an array structure composed of multiple amorphous silicon infrared detector pixels 10 provided in the above embodiments, and a readout circuit 13.

[0097] Based on the above embodiments, this disclosure also provides a mechanism for amorphous silicon infrared detection, which includes any of the amorphous silicon infrared detection chips provided in the above embodiments.

[0098] For example, Figure 19 This is a schematic diagram of the structure of an amorphous silicon infrared detector core provided in an embodiment of this disclosure. (Reference) Figure 19 The mechanism 40 includes an amorphous silicon infrared detection chip 30; the mechanism 40 also includes a lens 41, which is used to focus the infrared signal onto the amorphous silicon infrared detection chip 30 to improve the intensity of the infrared signal and improve the signal-to-noise ratio.

[0099] In other embodiments, the movement 40 may also include other structural and functional components, which are not described in detail or limited herein.

[0100] In other embodiments, the movement may also include other structural and functional components, which are not described in detail or limited herein.

[0101] Based on the above embodiments, this disclosure also provides an amorphous silicon infrared detection device, which may include any of the mechanisms provided in the above embodiments.

[0102] In other embodiments, the amorphous silicon infrared detection device may also include other structural and functional components, which are not described in detail or limited herein.

[0103] 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.

[0104] 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 amorphous silicon infrared detector pixel, characterized by, Includes an absorption sensing unit; the absorption sensing unit includes an amorphous silicon thermistor layer and a metal electrode layer; The amorphous silicon thermistor layer includes a thermistor working area and a non-thermistor working area. The thermistor working area has a first thickness, and the non-thermistor working area has a second thickness. The first thickness is greater than the second thickness, and the effective value of the second thickness is less than 2000 angstroms. The thermistor working area generates a resistance change in response to a received thermal signal. The metal electrode layer is in contact with the non-thermal working area and at least with the side of the thermal working area; wherein, a pair of adjacent metal electrode layers located on the side of the thermal working area form quasi-parallel electrodes.

2. The amorphous silicon infrared detector pixel of claim 1, wherein, The thermal working area includes a first bottom and a first top opposite each other, and the non-thermal working area includes a second bottom and a second top opposite each other; The first bottom and the second bottom are located on the same plane, and the height of the first top is greater than the height of the second top.

3. The amorphous silicon infrared detector pixel of claim 1, wherein, The non-thermal working area is thinned to the second thickness by etching.

4. The amorphous silicon infrared detector pixel of claim 2, wherein, The metal electrode layer is located on the side of the amorphous silicon thermistor layer opposite to the first bottom and the second bottom.

5. The amorphous silicon infrared detector pixel of claim 1, wherein, The material of the metal electrode layer located in the non-thermal working area diffuses into the non-thermal working area, increasing the area of ​​the quasi-parallel electrode. The effective value of the second thickness of the non-thermal working area does not include the thickness diffused into by the metal electrode layer.

6. The amorphous silicon infrared detector pixel of claim 1, wherein, 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 metal electrode layer and the amorphous silicon thermistor layer.

7. The amorphous silicon infrared detector pixel of claim 1, wherein, The absorption sensing unit also includes a protective layer; The protective layer is located on the side of the amorphous silicon thermistor layer opposite to the metal electrode layer, and / or on the side of the metal electrode layer opposite to the amorphous silicon thermistor layer.

8. The amorphous silicon infrared detector pixel of claim 1, wherein, The absorption sensing part further includes a through hole; the through hole extends through the absorption sensing part in the thickness direction.

9. The amorphous silicon infrared detector pixel of claim 1, wherein, It also includes beam structures; The beam structure is disposed on the same layer as the absorption and sensing unit; In the amorphous silicon thermistor layer of the absorption sensing unit, a portion of the amorphous silicon thermistor layer in the non-thermal working area serves as the dielectric layer of the beam structure. or, The beam structure is disposed on a different layer from the absorption and sensing unit; The absorption sensing unit further includes an absorption layer located on the side of the metal electrode layer away from the amorphous silicon thermistor layer, forming a suspended structure to enhance infrared absorption.

10. An amorphous silicon infrared detector pixel, characterized in that, The amorphous silicon infrared detector pixel, as described in any one of claims 1-9, includes an absorption sensing section, a beam structure, a readout circuit, and an interconnection structure connecting the beam structure, the absorption sensing section, and the readout circuit.

11. An amorphous silicon infrared detection chip, characterized in that, An array structure comprising multiple amorphous silicon infrared detector pixels as described in any one of claims 1-9.

12. A mechanism for amorphous silicon infrared detection, characterized in that, The device includes the amorphous silicon infrared detection chip as described in claim 11; the mechanism further includes a lens for focusing infrared signals onto the amorphous silicon infrared detection chip.

13. An amorphous silicon infrared detection device, characterized in that, The amorphous silicon infrared detection device includes the mechanism as described in claim 12.

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