Metal-dielectric-metal structure, thermosensitive infrared sensing unit and detector
By adopting a patterned metal layer suction design with metal-dielectric-metal structure in the thermal infrared sensing unit, the problem of space occupation and performance is solved, and high sensitivity and anti-aging capabilities are improved.
Patent Information
- Application Number
- CN202421870606.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-05
- Publication Date
- 2025-07-11
- Estimated Expiration
- 2034-08-05
AI Technical Summary
The prior art is difficult to reduce space occupation while taking into account excellent vacuum aging resistance, high infrared absorption efficiency and wide absorption bandwidth.
The metal-dielectric-metal structure is adopted, and the patterned metal layer is an getter metal layer, which is used for gettering and enhancing infrared band absorption, and a wideband absorption is formed by combining resonant absorbers of various sizes.
The sensitivity and accuracy of the thermal infrared sensing unit are improved, the detector's anti-vacuum aging ability is enhanced, and the package area and volume are reduced.
Smart Images
Figure CN223094137U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of infrared detection, and particularly to a metal-dielectric-metal structure, a thermosensitive infrared sensing unit and a detector. Background Art
[0002] A thermosensitive infrared detector is a technology that can sense and analyze infrared radiation in the surrounding environment, and perform tasks such as target detection and temperature measurement based on the thermal radiation characteristics of the target, including microbolometers, thermopile detectors, pyroelectric detectors, etc. Among them, the thermosensitive element, as the key part of the sensor, absorbs infrared radiation to cause its own temperature change, thereby changing its physical properties to achieve infrared detection.
[0003] To reduce the temperature change of the detector caused by heat exchange with air, the thermosensitive infrared sensor usually adopts vacuum packaging, that is, the thermosensitive unit is encapsulated in a closed structure in a vacuum environment, and means such as high-temperature baking are used to remove the residual gas during the packaging process to ensure a high vacuum degree in the closed structure. However, there will inevitably be residual gas during the vacuum packaging process, and the gas leaked, degassed during the device life and released by the device itself during operation will all reduce the vacuum life of the device. Therefore, an getter is usually introduced during its packaging process to keep a good vacuum degree for a long time. At the same time, a certain infrared absorption structure, such as a metal-dielectric-metal (MIM) structure, will be used to improve the absorption efficiency of the detector for infrared radiation and broaden the absorption bandwidth. However, the additional infrared absorption structure itself will occupy a large space. At this time, introducing a getter will greatly increase the area and volume of the vacuum packaging, which is not conducive to the miniaturization of the device.
[0004] Therefore, how to reduce the space occupation while taking into account excellent anti-vacuum aging performance, high infrared absorption efficiency and wide absorption bandwidth is an urgent problem to be solved by those skilled in the art. Summary of the Utility Model
[0005] The purpose of the utility model is to provide a metal-dielectric-metal structure, a thermosensitive infrared sensing unit and a thermosensitive infrared detector to solve the problem in the prior art that it is impossible to reduce the space occupation while taking into account excellent anti-vacuum aging performance, high infrared absorption efficiency and wide absorption bandwidth.
[0006] To solve the above technical problems, the utility model provides a metal-dielectric-metal structure for a thermosensitive infrared sensing unit, which sequentially includes a continuous metal layer, a dielectric layer and a patterned metal layer from bottom to top;
[0007] The patterned metal layer is a getter metal layer for gas absorption and enhancing infrared band absorption.
[0008] Optionally, in the metal-dielectric-metal structure, the continuous metal layer is a gettering metal layer and / or the dielectric layer is a patterned dielectric layer.
[0009] Optionally, in the metal-dielectric-metal structure, the gettering metal layer is at least one of a titanium metal layer, a cobalt metal layer, a vanadium metal layer, and a zirconium metal layer.
[0010] Optionally, in the metal-dielectric-metal structure, the patterned metal layer is a continuous covering layer including a hollow pattern;
[0011] or the patterned metal layer is a continuous covering layer including a groove pattern;
[0012] or the patterned metal layer is a layer composed of a plurality of separately arranged resonant absorbers.
[0013] Optionally, in the metal-dielectric-metal structure, the patterned metal layer includes a plurality of periodically arranged array units;
[0014] A single one of the array units includes a plurality of separately arranged resonant absorbers;
[0015] The centers of all the resonant absorbers in a single one of the array units are equally spaced on a preset circumference;
[0016] The patterned metal layer includes resonant absorbers of multiple sizes.
[0017] Optionally, in the metal-dielectric-metal structure, a single one of the array units includes resonant absorbers of multiple sizes.
[0018] A thermosensitive infrared sensing unit sequentially includes a readout circuit substrate layer, a thermistor sensing layer, an insulating layer, a continuous metal layer, a dielectric layer, and a patterned metal layer from bottom to top;
[0019] The thermistor sensing layer is electrically isolated from the continuous metal layer by the insulating layer;
[0020] The patterned metal layer is a gettering metal layer.
[0021] Optionally, in the thermosensitive infrared sensing unit, the thermistor sensing layer includes at least one of a vanadium oxide layer, a silicon oxide layer, and an amorphous silicon layer;
[0022] and / or
[0023] The insulating layer includes at least one of a silicon dioxide layer, an aluminum oxide layer, a silicon nitride layer, and a boron nitride layer.
[0024] A thermosensitive infrared detector, the thermosensitive infrared detector includes the thermosensitive infrared sensing unit according to any one of the above;
[0025] A plurality of the thermosensitive infrared sensing unit arrays are arranged in an array.
[0026] Optionally, in the thermosensitive infrared detector, the thermosensitive infrared detector is at least one of a metal-packaged infrared detector, a ceramic-packaged infrared detector, a wafer-level packaged infrared detector, and a pixel-level packaged infrared detector.
[0027] The metal-dielectric-metal structure provided by the present invention is used for a thermosensitive infrared sensing unit, and sequentially includes a continuous metal layer, a dielectric layer, and a patterned metal layer from bottom to top; the patterned metal layer is a getter metal layer for gas absorption and enhanced infrared band absorption. By setting the patterned metal layer as a metal material layer with gas absorption ability, the MIM (metal-dielectric-metal) structure on the top of the thermosensitive infrared sensing unit has both the functions of enhancing infrared band absorption and gas absorption, while improving the sensitivity and accuracy of the thermosensitive infrared sensing unit, and also improving the anti-vacuum aging ability of the detector, and avoiding arranging a getter separately except for the MIM structure, greatly reducing the packaging area and volume of the thermosensitive infrared sensing unit. The present invention also provides a thermosensitive infrared sensing unit and a thermosensitive infrared detector having the above beneficial effects. Description of the Drawings
[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.
[0029] Figure 1 It is a schematic structural diagram of a specific embodiment of the metal-dielectric-metal structure provided by the present invention;
[0030] Figure 2 , Figure 3 , Figure 4 They are all schematic structural diagrams of the patterned metal layer of a specific embodiment of the metal-dielectric-metal structure provided by the present invention;
[0031] Figure 5 It is a top view schematic diagram of the patterned metal layer of a specific embodiment of the metal-dielectric-metal structure provided by the present invention;
[0032] Figure 6 It is a schematic structural diagram of a single array unit of a specific embodiment of the metal-dielectric-metal structure provided by the present invention;
[0033] Figure 7 , Figure 8 , Figure 9 are absorption spectrograms of a specific embodiment of the metal-dielectric-metal structure corresponding to the thermosensitive infrared sensing unit provided by the present utility model;
[0034] Figure 10 is a schematic structural diagram of a specific embodiment of the thermosensitive infrared sensing unit provided by the present utility model;
[0035] Figure 11 is a schematic structural diagram of a specific embodiment of the thermosensitive infrared detector provided by the present utility model.
[0036] In the figure, it includes 01 - readout circuit substrate layer, 02 - support layer, 03 - thermistor sensing layer, 04 - insulating layer, 05 - continuous metal layer, 06 - dielectric layer, 07 - patterned metal layer, 07a - array unit, 07b - resonant absorber, 10 - thermosensitive infrared sensing unit, 20 - thermal insulation microbridge. Specific Embodiment
[0037] In order to enable those skilled in the art to better understand the solution of the present utility model, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model.
[0038] The core of the present utility model is to provide a metal-dielectric-metal structure for a thermosensitive infrared sensing unit, and a schematic structural diagram of a specific embodiment thereof is as Figure 1 shown, which is called Specific Embodiment 1, and successively includes a continuous metal layer 05, a dielectric layer 06, and a patterned metal layer 07 from bottom to top;
[0039] The patterned metal layer 07 is a getter metal layer for gas absorption and enhancing infrared band absorption.
[0040] As a preferred embodiment, the continuous metal layer 05 is a getter metal layer and / or the dielectric layer 06 is a patterned dielectric layer.
[0041] In this preferred embodiment, the continuous metal layer 05 is also defined as a getter metal layer, which increases the contact area between the getter metal and the environment and the maximum gas absorption amount, thereby improving the anti-vacuum aging ability of the detector.
[0042] Similarly, the dielectric layer 06 can also be a dielectric layer 06 with a groove pattern or a hollow pattern. By changing the pattern morphology of the dielectric layer 06, it can better cooperate with the patterned metal layer 07 to achieve the broadening of the working band and the improvement of the infrared absorption effect.
[0043] As a specific implementation manner, the gettering metal layer is at least one of a metal titanium layer, a metal cobalt layer, a metal vanadium layer, and a metal zirconium layer. The gettering metal layer can be a single metal layer as described above, or an alloy layer corresponding to the above metal layer. Each of the above metals has good gettering ability and good plasticity, and at the same time has strong infrared absorption and consumption ability, which can improve the infrared absorption ability while enhancing the anti-vacuum aging ability.
[0044] As a specific implementation manner, the patterned metal layer 07 is a continuous covering layer including a hollow pattern;
[0045] Or the patterned metal layer 07 is a continuous covering layer including a groove pattern;
[0046] Or the patterned metal layer 07 is a layer composed of a plurality of separately arranged resonant absorbers 07b.
[0047] In this specific implementation manner, three specific structures of the patterned metal layer 07 are provided, which can further improve the flexibility of the working band setting of the thermal infrared sensing unit, and at the same time can improve the infrared absorption effect according to the actual situation. Refer to Figure 2 , Figure 3 and Figure 4 . The above three figures are side views of three cases of the three patterned metal layers 07 in this specific implementation manner. The dotted lines are the hollowed-out parts blocked. Among them, Figure 2 corresponds to the case of "a continuous covering layer including a hollow pattern", Figure 3 corresponds to the case of "a continuous covering layer including a groove pattern", Figure 4 corresponds to the case of "a layer composed of a plurality of separately arranged resonant absorbers 07b".
[0048] As a preferred implementation manner, the patterned metal layer 07 includes a plurality of periodically arranged array units 07a;
[0049] Each single array unit 07a includes a plurality of separately arranged resonant absorbers 07b;
[0050] The centers of all the resonant absorbers 07b in each single array unit 07a are equally spaced on a preset circumference;
[0051] The patterned metal layer 07 includes resonant absorbers 07b of various sizes.
[0052] In this preferred embodiment, the patterned metal layer 07 is divided into a plurality of periodically arranged array units 07a. At the same time, it is disclosed that a plurality of resonant absorbers 07b with centers equally spaced on a circumference are provided in a single array unit 07a. The size of the resonant absorber 07b corresponds to the wavelength of the working band. This structure can further improve the absorption efficiency of the patterned metal layer 07 for infrared rays in the working band and ensure that the infrared rays are uniformly absorbed in the patterned metal layer 07. Of course, this preferred embodiment further points out that the patterned metal layer 07 includes resonant absorbers 07b of various sizes. Different resonant absorbers 07b have different resonant absorption wavelengths. As the size of the resonant absorber 07b increases, the corresponding absorption wavelength also increases. Thus, by setting resonant absorbers 07b of various sizes, multiple narrow-band absorption peaks are coupled to form a broadband absorption, greatly increasing the working band width of the thermosensitive infrared sensing unit.
[0053] Furthermore, a single array unit 07a includes resonant absorbers 07b of various sizes.
[0054] In this preferred embodiment, in each array unit 07a, resonant absorbers 07b of various sizes are provided. That is, each array unit 07a has the ability to absorb infrared rays of multiple wavelengths, and the absorption spectrum of each array unit 07a is relatively wide. This avoids the loss of part of the working band in the case where a local area of the thermosensitive infrared sensing unit is damaged due to a temporary failure of the equipment or external collision during the production process. In this preferred embodiment, even if a part of the thermosensitive infrared sensing unit is damaged, the working band can still meet the design expectations, greatly improving the working stability of the thermosensitive infrared sensing unit.
[0055] Please see Figure 5 , Figure 5 FIG. 13 is a top view schematic diagram of the patterned metal layer 07 in a specific embodiment. It can be seen that in this specific embodiment, this column of units is a hexagonal array unit 07a, which is periodically arranged in the patterned metal layer 07, and the dielectric layer 06 below the patterned metal layer 07 is the same size as the patterned metal layer 07 and is in corresponding positions.
[0056] Furthermore, referring again to Figure 6 , Figure 6FIG. 0 is a schematic structural diagram of a single array unit 07a. In a hexagonal period shown in the figure, 6 polygonal resonant absorbers 07b are integrated. The centers of these 6 polygons are evenly distributed on a circle with a radius of R0. The sizes of each polygon are different, namely D1, D2, D3, D4, D5, and D6, and the sizes increase in sequence. Different sizes of the resonant absorber 07b correspond to different resonant absorption wavelengths. As the size of the resonant absorber 07b increases, the corresponding absorption wavelength also increases. When multiple resonant absorbers 07b with different sizes are integrated in an array unit 07a, multiple narrowband absorption peaks can be coupled to form broadband absorption. Of course, by adjusting the radius R0 of the circle, the shape and size (side length a) of the array unit 07a, the sizes D1, D2, D3, D4, D5, and D6 of the resonant absorber 07b, and the material and shape of the resonant absorber 07b, the selective absorption of the polarization direction and frequency of infrared electromagnetic waves can be controlled, thereby realizing broadband absorption and polarization-selective absorption.
[0057] The materials that the continuous metal layer 05 can select include metal materials such as gold, silver, copper, aluminum, and titanium. The materials that the getter metal layer can select include metal materials with getter functions such as titanium and zirconium. The materials that the dielectric layer 06 can select include dielectric materials such as zinc sulfide, zinc selenide, germanium, and silicon. The thickness range of the continuous metal layer 05 is 0.05 μm - 0.3 μm. The thickness range of the dielectric layer 06 is 0.1 μm - 1 μm. The thickness range of the patterned metal layer 07 is 0.05 μm - 0.3 μm. When the array unit 07a is hexagonal, the range of the side length a of the array unit 07a is 3 μm - 30 μm, and the selectable range of the radius R0 of the circle is 3 μm - 20 μm. The selectable range of the sizes D1 - D6 of the resonant absorber 07b is 0.5 μm - 5 μm. Using the COMSOL software based on the finite element method for simulation calculation, the absorption spectrum of this specific embodiment is as Figure 7 shown. Further, when the sizes of each resonant absorber 07b are adjusted, the absorption bandwidth can be expanded, and the corresponding absorption spectrum is as Figure 8 shown. Still further, when the material of the patterned metal layer 07 is changed, the in-band absorption can be more stable, and the corresponding absorption spectrum at this time is as Figure 9 shown.
[0058] The metal-dielectric-metal structure provided by the utility model is used for the thermal infrared sensor unit, and includes a continuous metal layer 05, a dielectric layer 06 and a pattern metal layer 07 from bottom to top; the pattern metal layer 07 is an air-absorbing metal layer, which is used for air absorption and enhanced infrared band absorption. The utility model sets the pattern metal layer 07 as a metal material layer with air absorption ability, so that the MIM (metal-dielectric-metal) structure on the top of the thermal infrared sensor unit 10 has the functions of enhancing infrared band absorption and air absorption. While improving the sensitivity and accuracy of the thermal infrared sensor unit 10, it also improves the anti-vacuum aging ability of the detector, and avoids arranging an air-absorbing agent separately in addition to the MIM structure, which greatly reduces the packaging area and volume of the thermal infrared sensor unit 10.
[0059] The utility model also provides a thermal infrared sensor unit, a structural schematic diagram of a specific implementation method thereof is shown in FIG. Figure 10 As shown, it is called the specific implementation mode 2, which includes, from bottom to top, a readout circuit substrate layer 01, a thermistor sensing layer 03, an insulating layer 04, a continuous metal layer 05, a dielectric layer 06 and a pattern metal layer 07;
[0060] The thermistor sensing layer 03 and the continuous metal layer 05 are electrically isolated by the insulating layer 04;
[0061] The patterned metal layer 07 is a getter metal layer.
[0062] The patterned metal layer 07, the dielectric layer 06 and the continuous metal layer 05 in the present invention together constitute the MIM (metal-dielectric-metal) structure of the infrared sensing unit, which corresponds to the metal-dielectric-metal structure in the previous text and can be understood in comparison with the previous text. Some technical details will not be repeated here.
[0063] Of course, in combination with the application scenario, the thickness of the continuous metal layer 05 is not less than the skin depth of the electromagnetic waves within the working band, which can ensure that the infrared electromagnetic waves within the working band will not transmit the MIM structure, so as to achieve a better absorption effect on the electromagnetic waves within the working band. Of course, the thickness of the continuous metal layer 05 should not be too large, which will increase the overall space occupancy of the device, and can be adjusted according to actual conditions.
[0064] Of course, in actual production, in order to maintain the working stability of the thermal infrared sensor unit, a support layer 02 is usually provided between the readout circuit substrate layer 01 and the thermistor sensor layer 03 (please refer to Figure 10 ), maintaining the structural stability of the thermal infrared sensing unit.
[0065] Wherein, the thermistor sensing layer 03 includes at least one of a vanadium oxide layer, a silicon oxide layer and an amorphous silicon layer;
[0066] and / or
[0067] The insulating layer 04 includes at least one of a silicon dioxide layer, an aluminum oxide layer, a silicon nitride layer, and a boron nitride layer.
[0068] The vanadium oxide layer, the silicon dioxide layer, and the amorphous silicon layer are all material layers with a high linear correlation between temperature and resistivity change within the operating temperature of the thermosensitive infrared sensing unit. After receiving infrared rays in the operating wavelength band, they can promptly reflect the change in resistivity. Of course, other types of material layers can also be selected as the thermistor sensing layer 03 according to actual needs, and the present invention does not limit this here. Similarly, due to their dense structure and good chemical stability, the silicon dioxide layer, the aluminum oxide layer, the silicon nitride layer, and the boron nitride layer can play a protective role for other underlying structural layers while playing an insulating role, and thus can be used as the preferred material layers for the insulating layer 04. Of course, other material layers can also be selected as the insulating layer 04, and the present invention does not limit this here.
[0069] Further, the thermistor sensing layer 03 is a silicon dioxide layer and / or an amorphous silicon layer;
[0070] The insulating layer 04 is a silicon dioxide layer and / or a silicon nitride layer.
[0071] The resistivity of both the silicon dioxide layer and the amorphous silicon layer will change significantly with temperature, and they can well perform the function of the thermistor sensing layer 03. Based on these two types of thermistor sensing layers 03, through simple surface treatment and epitaxial layer growth, the silicon dioxide layer and / or the silicon nitride layer used as the insulating layer 04 can be obtained. The process is simple and the cost is low, and the thermistor sensing layer 03 and the insulating layer 04 are tightly combined. The dense silicon dioxide layer and / or silicon nitride layer can play a good protective role for the thermistor sensing layer 03. Of course, the thermistor sensing layer 03 can also be made of other materials, such as vanadium oxide, etc.
[0072] The following takes an actual production as an example to illustrate the specific implementation method for manufacturing the thermosensitive infrared sensing unit, including:
[0073] Step 1: Prepare a sacrificial layer on the integrated readout circuit substrate layer 01 using a polyimide material or an oxidized porous silicon material. The sacrificial layer covers the upper surface of the readout circuit substrate layer 01. Use a photolithography mask plate to etch the sacrificial layer to prepare holes, and the readout electrodes are exposed through the holes to obtain a patterned sacrificial layer.
[0074] Step 2: Prepare a support layer 02 on the patterned sacrificial layer using a silicon nitride material. Use a photolithography mask plate and etch the support layer 02 to obtain a first support and a second support, and the holes are exposed.
[0075] The first support and the second support are patterned support layers 02, including a support area where the thermosensitive infrared sensing unit will be arranged later and an area connected to the hole.
[0076] Step 3: Form a photoresist pattern of the electrode structure on the first support and the second support, deposit metal on the photoresist pattern of the electrode structure, and strip the photoresist pattern of the electrode structure to obtain a bridge electrode layer, a first electrode layer, and a second electrode layer.
[0077] The bridge electrode layer, the first electrode layer, and the second electrode layer are all directly or indirectly electrically connected to the subsequent thermistor sensing layer 03, so as to obtain corresponding electrical signals from the thermistor sensing layer 03 to measure the infrared reception situation.
[0078] Step 4: Form a contact hole photoresist pattern on the hole, deposit metal aluminum on the contact hole photoresist pattern, and strip the contact hole photoresist pattern to obtain a contact hole.
[0079] Step 5: Form a thermistor photoresist pattern on the bridge electrode layer, grow a thermistor material, and strip the thermistor photoresist pattern to obtain a thermistor sensing layer 03. The thermistor material is silicon oxide or amorphous silicon.
[0080] Step 6: Prepare a passivation insulating layer 04 on the thermistor sensing layer 03. The material of the passivation insulating layer 04 is silicon dioxide, aluminum oxide, silicon nitride, or boron nitride.
[0081] Step 7: Prepare a continuous metal layer 05 on the passivation insulating layer 04. The material of the continuous metal layer 05 is gold, silver, copper, aluminum, titanium, or tungsten.
[0082] Step 8: Prepare a dielectric layer 06 on the continuous metal layer 05. The material of the dielectric layer 06 is silicon, germanium, aluminum oxide, or zinc sulfide.
[0083] Step 9: Prepare a patterned metal layer 07 on the dielectric layer 06. The patterned metal layer 07 is a gettering metal layer. The material of the gettering metal layer is a metal single-layer or alloy layer with a gettering function, such as titanium, cobalt, vanadium, zirconium, etc.
[0084] Step 10: Attach the infrared focal plane array made in the previous steps to a ceramic package, and perform wire bonding and vacuum packaging.
[0085] Step 11: Apply a bias current or place it in a high-temperature environment to break the surface oxide layer of the patterned metal layer 07 and activate it, and the thermosensitive infrared sensing unit is completed.
[0086] The thermal infrared sensing unit provided by the present utility model sequentially includes a readout circuit substrate layer 01, a thermistor sensing layer 03, an insulating layer 04, a continuous metal layer 05, a dielectric layer 06, and a patterned metal layer 07 from bottom to top; the thermistor sensing layer 03 is electrically isolated from the continuous metal layer 05 by the insulating layer 04; the patterned metal layer 07 is a gettering metal layer. By setting the patterned metal layer 07 as a metal material layer with gettering ability, the MIM (metal-dielectric-metal) structure at the top of the thermal infrared sensing unit 10 has both functions of enhancing infrared band absorption and gettering. While improving the sensitivity and accuracy of the thermal infrared sensing unit 10, it also improves the anti-vacuum aging ability of the detector, and avoids arranging a getter separately besides the MIM structure, greatly reducing the packaging area and volume of the thermal infrared sensing unit 10.
[0087] The present utility model also provides a thermal infrared detector. The structural schematic diagram of a specific embodiment is as Figure 11 shown, which is called the third specific embodiment. The thermal infrared detector includes the thermal infrared sensing unit 10 described in any one of the above;
[0088] Multiple thermal infrared sensing units 10 are arranged in an array.
[0089] The thermal infrared detector provided by the present utility model corresponds to the thermal infrared sensing unit 10 in the foregoing. For specific technical details, reference can be made to the foregoing, and details will not be repeated here.
[0090] Certainly, the thermal infrared detector is at least one of a metal-packaged infrared detector, a ceramic-packaged infrared detector, a wafer-level packaged infrared detector, and a pixel-level packaged infrared detector. The thermal infrared detector provided by the present utility model has excellent compatibility and can be compatible with various packaging methods, having good versatility.
[0091] In the thermal infrared detector, adjacent thermal infrared sensing units 10 are thermally isolated by a thermal insulation microbridge 20. By setting the thermal insulation microbridge 20, the thermal infrared sensing units 10 do not interfere with each other, greatly improving the detection accuracy.
[0092] The thermal infrared detector provided by the present utility model includes the thermal infrared sensing unit 10 as described in any one of the above; a plurality of the thermal infrared sensing units 10 are arranged in an array. The thermal infrared sensing unit 10 successively includes a readout circuit substrate layer 01, a thermistor sensing layer 03, an insulating layer 04, a continuous metal layer 05, a dielectric layer 06, and a patterned metal layer 07 from bottom to top; the thermistor sensing layer 03 is electrically isolated from the continuous metal layer 05 by the insulating layer 04; the patterned metal layer 07 is a gettering metal layer. By setting the patterned metal layer 07 as a metal material layer with gettering ability, the MIM (metal-dielectric-metal) structure at the top of the thermal infrared sensing unit 10 has both the functions of enhancing infrared band absorption and gettering, while improving the sensitivity and accuracy of the thermal infrared sensing unit 10, also improving the anti-vacuum aging ability of the detector, and avoiding arranging a getter separately except for the MIM structure, greatly reducing the packaging area and volume of the thermal infrared sensing unit 10.
[0093] In this specification, each embodiment is described in a progressive manner. The key point of each embodiment is to illustrate the differences from other embodiments. For the same or similar parts among the embodiments, reference can be made to each other. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple. For the relevant parts, reference can be made to the description in the method part.
[0094] It should be noted that in this specification, relative terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of another identical element in the process, method, article or device including the element.
[0095] The above has introduced in detail the metal-dielectric-metal structure, the thermosensitive infrared sensing unit, and the thermosensitive infrared detector provided by the present utility model. Specific examples are used in this article to elaborate on the principle and implementation manner of the present utility model. The description of the above embodiments is only used to help understand the method and its core idea of the present utility model. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present utility model, several improvements and modifications can be made to the present utility model, and these improvements and modifications also fall within the protection scope of the claims of the present utility model.
Claims
1. A metal-dielectric-metal structure for a thermosensitive infrared sensing unit, characterized in that, It includes a continuous metal layer (05), a dielectric layer (06), and a patterned metal layer (07) in sequence from bottom to top; The patterned metal layer (07) is a gettering metal layer for gettering and enhancing infrared band absorption.
2. The metal-dielectric-metal structure according to claim 1, characterized in that, The continuous metal layer (05) is a gettering metal layer and / or the dielectric layer (06) is a patterned dielectric layer.
3. The metal-dielectric-metal structure according to claim 1, wherein, The gettering metal layer is at least one of a titanium metal layer, a cobalt metal layer, a vanadium metal layer, and a zirconium metal layer.
4. The metal-dielectric-metal structure according to any one of claims 1 to 3, characterized in that The patterned metal layer (07) is a continuous covering layer including a hollow pattern; Or the patterned metal layer (07) is a continuous covering layer including a groove pattern; Or the patterned metal layer (07) is a layer composed of a plurality of separately arranged resonant absorbers (07b).
5. The metal-dielectric-metal structure according to claim 4, characterized in that The patterned metal layer (07) includes a plurality of periodically arranged array units (07a); A single array unit (07a) includes a plurality of separately arranged resonant absorbers (07b); The centers of all the resonant absorbers (07b) in a single array unit (07a) are equally spaced on a preset circumference; The patterned metal layer (07) includes resonant absorbers (07b) of various sizes.
6. The metal-dielectric-metal structure according to claim 5, characterized in that, A single array unit (07a) includes resonant absorbers (07b) of various sizes.
7. A thermosensitive infrared sensing unit, characterized in that, It includes a readout circuit substrate layer (01), a thermistor sensing layer (03), an insulating layer (04), a continuous metal layer (05), a dielectric layer (06), and a patterned metal layer (07) in sequence from bottom to top; The thermistor sensing layer (03) is electrically isolated from the continuous metal layer (05) by the insulating layer (04); The patterned metal layer (07) is a gettering metal layer.
8. The thermal infrared sensing unit according to claim 7, characterized in that, The thermistor sensing layer (03) includes at least one of a vanadium oxide layer, a silicon oxide layer, and an amorphous silicon layer; And / or The insulating layer (04) includes at least one of a silicon dioxide layer, an aluminum oxide layer, a silicon nitride layer, and a boron nitride layer.
9. A thermosensitive infrared detector, characterized in that, The thermal infrared detector includes a thermal infrared sensing unit (10) as described in claim 7 or 8; A plurality of the thermal infrared sensing units (10) are arranged in an array.
10. The thermosensitive infrared detector according to claim 9, wherein, The thermal infrared detector is at least one of a metal-packaged infrared detector, a ceramic-packaged infrared detector, a wafer-level-packaged infrared detector, and a pixel-level-packaged infrared detector.