Heating assembly and gas sensor

Abstract

The application relates to a heating assembly and a gas sensor. The heating assembly comprises a substrate, a conductive layer located on the upper surface of the substrate, a first insulating layer located on the upper surface of the conductive layer, the sidewall of the conductive layer and the upper surface of the substrate, a sidewall structure located on the sidewall of the first insulating layer, wherein the sidewall of the first insulating layer corresponds to the sidewall of the conductive layer, a first heating electrode in contact with one end of the sidewall structure, and a second heating electrode in contact with the other end of the sidewall structure. The heating assembly can save the device design area.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and in particular to a heating component and a gas sensor. Background Technology

[0002] With the development of semiconductor technology, gas sensors have emerged. Gas sensors have significant potential for development in fields such as gas sensing components, micro-calorimeters, gas flow meters, infrared light sources, and the collection of minute particles. Gas sensors have advantages such as low heat loss, low heating power, simple manufacturing processes, short response times, and ease of integration with other microelectronic devices, making their applications very wide-ranging.

[0003] Currently, gas sensors are typically integrated with micro-electro-mechanical systems (MEMS) sensing components via heating elements. In traditional technologies, gas sensors are usually constructed by interleaving the heating layer of the heating element with the conductive layer of the sensing element. However, because the heating layer and conductive layer are located on the same plane and a certain distance needs to be maintained between them, traditional technologies suffer from a large device design area. Summary of the Invention

[0004] Therefore, it is necessary to provide a heating component and a gas sensor to address the problem of large device design area in traditional technologies.

[0005] To achieve the above objectives, in one aspect, the present invention provides a heating assembly, comprising:

[0006] Base;

[0007] A conductive layer is located on the upper surface of the substrate;

[0008] A first insulating layer is located on the upper surface of the conductive layer, the sidewall of the conductive layer, and the upper surface of the substrate;

[0009] A sidewall structure is located on the sidewall of the first insulating layer; wherein the sidewall of the first insulating layer corresponds to the sidewall of the conductive layer;

[0010] The first heating electrode is disposed in contact with one end of the sidewall structure;

[0011] The second heating electrode is positioned in contact with the other end of the sidewall structure.

[0012] The aforementioned heating assembly includes: a substrate; a conductive layer located on the upper surface of the substrate; a first insulating layer located on the upper surface of the conductive layer, the sidewall of the conductive layer, and the upper surface of the substrate; a sidewall structure located on the sidewall of the first insulating layer; wherein the sidewall of the first insulating layer corresponds to the sidewall of the conductive layer; a first heating electrode contacting one end of the sidewall structure; and a second heating electrode contacting the other end of the sidewall structure. Because the sidewall structure, serving as the heating layer of the heating assembly, is designed on the sidewall of the conductive layer, it saves device design area.

[0013] In one embodiment, the conductive layer includes a first comb-tooth structure and a second comb-tooth structure, wherein the comb-tooth portions of the first comb-tooth structure and the comb-tooth portions of the second comb-tooth structure are arranged alternately; wherein...

[0014] The first heating electrode is respectively in contact with the first sidewall located on the sidewall of the first comb structure and the second sidewall located on the sidewall of the second comb structure, wherein the first sidewall is the sidewall structure of the first end of the comb tooth portion of the first comb structure, and the second sidewall is the sidewall structure of the second end of the comb tooth portion of the second comb structure.

[0015] The second heating electrode is respectively in contact with the third sidewall located on the sidewall of the first comb structure and the fourth sidewall located on the sidewall of the second comb structure, wherein the third sidewall is the sidewall structure of the second end of the comb tooth portion of the first comb structure, and the fourth sidewall is the sidewall structure of the first end of the comb tooth portion of the second comb structure.

[0016] In one embodiment, the comb tooth portion of the first comb tooth structure includes a first main comb tooth, a first branch comb tooth, and a plurality of second branch comb teeth arranged at intervals. Each second branch comb tooth is connected to the first main comb tooth. The first end of the first main comb tooth serves as the first end of the comb tooth portion of the first comb tooth structure. The first branch comb tooth is connected to the second branch comb tooth near the second end of the first main comb tooth. The free end of the first branch comb tooth serves as the second end of the comb tooth portion of the first comb tooth structure.

[0017] The comb tooth portion of the second comb tooth structure includes a second main comb tooth, a third branch comb tooth, and a plurality of fourth branch comb teeth arranged at intervals. Each of the fourth branch comb teeth is connected to the third main comb tooth. The first end of the second main comb tooth serves as the first end of the comb tooth portion of the second comb tooth structure. The third branch comb tooth is connected to the fourth branch comb tooth near the second end of the second main comb tooth. The free end of the third branch comb tooth serves as the second end of the comb tooth portion of the second comb tooth structure.

[0018] In one embodiment, the first main comb tooth and the first branch comb tooth both extend along a first direction, and each second branch comb tooth extends along a second direction, wherein the first direction and the second direction intersect.

[0019] The second main comb tooth and the third branch comb tooth both extend along the first direction, and each of the fourth branch comb teeth extends along the second direction.

[0020] In one embodiment, the first end of the first main comb tooth is aligned with the free end of the third branch comb tooth; the first end of the second main comb tooth is aligned with the free end of the first branch comb tooth.

[0021] In one embodiment, the first heating electrode includes a first sub-electrode and a second sub-electrode, and the second heating electrode includes a third sub-electrode and a fourth sub-electrode. The first sub-electrode is connected to a first end of the first main comb tooth, the second sub-electrode is connected to a free end of the first branch comb tooth, the third sub-electrode is connected to a first end of the second main comb tooth, and the fourth sub-electrode is connected to a free end of the third branch comb tooth.

[0022] In one embodiment, the main body portion of the first main comb tooth and the first branch comb tooth both extend along a first direction, and the connecting portion of the first main comb tooth and each of the second branch comb teeth both extend along a second direction, wherein the first direction and the second direction intersect.

[0023] The main body of the second main comb tooth and the third branch comb tooth both extend along the first direction, and the connecting part of the second main comb tooth and each of the fourth branch comb teeth both extend along the second direction.

[0024] In one embodiment, the sidewall structure at the intersection of the comb teeth portion of the first comb structure and the comb teeth portion of the second comb structure overlaps.

[0025] In one embodiment, the first comb structure further includes a first comb electrode connected to a first end of the comb portion of the first comb structure, and the second comb structure further includes a second comb electrode connected to a first end of the comb portion of the second comb structure.

[0026] On the other hand, this application also provides a gas sensor, the gas sensor including a heating component as described in any of the above embodiments, wherein a back hole is formed on the lower surface of the substrate, and the gas sensor further includes:

[0027] The first oxide layer is located on the upper surface of the first insulating layer and on the surface of part of the sidewall structure;

[0028] An opening, penetrating the first oxide layer and the first insulating layer located on top of the conductive layer, is provided to expose the top of the conductive layer.

[0029] The first sensing electrode is disposed in contact with one end of the conductive layer;

[0030] The second sensing electrode is disposed in contact with the other end of the conductive layer;

[0031] A sensitive material layer is located above the conductive layer and is in contact with at least a portion of the conductive layer, and the sensitive material layer fills a portion of the opening.

[0032] The aforementioned gas sensor includes a heating component as described in any of the above embodiments, wherein a back hole is formed on the lower surface of the substrate, and the gas sensor further includes: a first oxide layer located on the substrate.

[0033] The upper surface of the first insulating layer and a portion of the surface of the sidewall structure; an opening penetrating the first oxide layer and the first insulating layer located on top of the conductive layer to expose the top of the conductive layer; a first sensing electrode in contact with one end of the conductive layer; a second sensing electrode in contact with the other end of the conductive layer; and a sensitive material layer located above the conductive layer and in contact with at least a portion of the conductive layer, the sensitive material layer filling a portion of the opening. Because the sidewall structure, serving as the heating layer of the heating assembly, is designed on the sidewall of the conductive layer, device design area can be saved.

[0034] In one embodiment, the gas sensor further includes:

[0035] The second insulating layer is located on the upper surface of the substrate;

[0036] The second oxide layer is located on the upper surface of the second oxide layer; the conductive layer is formed on the upper surface of the second oxide layer.

[0037] The third insulating layer is located on the lower surface of the substrate;

[0038] A third oxide layer is located on the lower surface of the third insulating layer; wherein the back hole penetrates a portion of the third oxide layer, a portion of the third insulating layer, and a portion of the substrate to expose a portion of the lower surface of the second insulating layer. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of this application or the conventional technology, the drawings used in the description of the embodiments or the conventional technology will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a top view of the heating assembly provided in one embodiment;

[0041] Figure 2 for Figure 1 A schematic diagram of the cross-sectional structure along the A-A' direction;

[0042] Figure 3 for Figure 1 A schematic diagram of the cross-sectional structure along the B-B' direction;

[0043] Figure 4 This is a top view of the heating assembly provided in another embodiment;

[0044] Figure 5 This is a top view of the heating assembly provided in another embodiment;

[0045] Figure 6 This is a top view of the heating assembly provided in another embodiment;

[0046] Figure 7 This is a top view of the heating assembly provided in another embodiment;

[0047] Figure 8 This is a top view of the heating assembly provided in another embodiment;

[0048] Figure 9 for Figure 8 A schematic diagram of the cross-sectional structure along the C-C' direction;

[0049] Figure 10 This is a top view of the structure of a gas sensor provided in one embodiment;

[0050] Figure 11 for Figure 10 A schematic diagram of the cross-sectional structure along the D-D' direction;

[0051] Figure 12 for Figure 10 A schematic diagram of the cross-sectional structure along the E-E' direction;

[0052] Figure 13 This is a schematic cross-sectional view of the substrate of a gas sensor provided in another embodiment;

[0053] Figure 14 This is a schematic cross-sectional view of the heating assembly provided in another embodiment;

[0054] Figure 15 This is a schematic diagram of the cross-sectional structure of a gas sensor provided in another embodiment.

[0055] Explanation of reference numerals in the attached drawings: 1-Substrate, 11-Second insulating layer, 12-Third insulating layer, 13-Second oxide layer, 14-Third oxide layer, 15-Back hole, 2-Conductive layer, 21-First comb tooth structure, 211-First main comb tooth, 2111-Main body of the first main comb tooth, 2112-Connecting part of the first main comb tooth, 212-First branch comb tooth, 213-Second branch comb tooth, 214-First comb tooth electrode, 22-Second comb tooth structure, 221-Second main comb tooth, 2211-Main body of the second main comb tooth, 2212-Second main comb tooth electrode. Connecting part, 222-third branch comb tooth, 223-fourth branch comb tooth, 224-second comb tooth electrode, 23-sensitive material layer, 3-first insulating layer, 4-sidewall structure, 41-first sidewall, 42-second sidewall, 43-third sidewall, 44-fourth sidewall, 401-initial sidewall structure, 5-first heating electrode, 51-first sub-electrode, 52-second sub-electrode, 6-second heating electrode, 61-third sub-electrode, 62-fourth sub-electrode, 7-first oxide layer, 71-opening, 8-first sensing electrode, 9-second sensing electrode. Detailed Implementation

[0056] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings, which illustrate embodiments of the present application. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this application will be thorough and complete.

[0057] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0058] It should be understood that when an element or layer is referred to as "on," "adjacent to," "connected to," or "coupled to" other elements or layers, it may be directly on, adjacent to, connected to, or coupled to other elements or layers, or there may be intervening elements or layers. Conversely, when an element is referred to as "directly on," "directly adjacent to," "directly connected to," or "directly coupled to" other elements or layers, there are no intervening elements or layers. It should be understood that although the terms first, second, third, etc., may be used to describe various elements, parts, regions, layers, doping types, and / or portions, these elements, parts, regions, layers, doping types, and / or portions should not be limited by these terms. These terms are only used to distinguish one element, part, region, layer, doping type, or portion from another element, part, region, layer, doping type, or portion. Therefore, without departing from the teachings of this invention, the first element, component, region, layer, doping type or portion discussed below may be represented as the second element, component, region, layer or portion; for example, the first doping type may be P-type and the second doping type may be N-type, or the first doping type may be N-type and the second doping type may be P-type.

[0059] Spatial relation terms such as “below,” “under,” “below,” “under,” “above,” “above,” etc., are used herein to describe the relationship between one element or feature shown in the figure and other elements or features. It should be understood that, in addition to the orientation shown in the figure, spatial relation terms also include different orientations of the device in use and operation. For example, if the device in the figure is flipped, the element or feature described as “below,” “under,” or “below” will be oriented “above” the other element or feature. Therefore, the exemplary terms “below” and “under” can include both above and below orientations. Furthermore, the device may also include other orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptive terms used herein will be interpreted accordingly.

[0060] When used herein, the singular forms of “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising / including” or “having,” etc., specify the presence of the stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. Meanwhile, in this specification, the term “and / or” includes any and all combinations of the associated listed items.

[0061] Please see Figure 1The present invention provides a heating assembly, comprising: a substrate 1, a conductive layer 2, a first insulating layer 3, a sidewall structure 4, a first heating electrode 5, and a second heating electrode 6; wherein the conductive layer 2 is located on the upper surface of the substrate 1, the first insulating layer 3 is located on the upper surface of the conductive layer 2, the sidewall of the conductive layer 2, and the upper surface of the substrate 1, and the sidewall structure 4 is located on the sidewall of the first insulating layer 3, wherein the sidewall of the first insulating layer 3 corresponds to the sidewall of the conductive layer 2; the first heating electrode 5 is in contact with one end of the sidewall structure 4, and the second heating electrode 6 is in contact with the other end of the sidewall structure 4.

[0062] The material of substrate 1 can be any suitable substrate material known in the art, such as at least one of the following: silicon (Si), germanium (Ge), red phosphorus, silicon germanium (SiGe), silicon carbide (SiC), silicon germanium carbon (SiGeC), indium arsenide (InAs), gallium arsenide (GaAs), indium phosphide (InP), or other III / V compound semiconductors, including multilayer structures composed of these semiconductors, or silicon on insulator (SOI), silicon on insulator (SSOI), silicon on insulator (S-SiGeOI), silicon on insulator (SiGeOI), and germanium on insulator (GeOI), or it can also be a double-side polished wafer (DSP), or a ceramic substrate such as alumina, quartz, or glass substrate, etc., which are not limited in this embodiment.

[0063] Here, conductive layer 2 refers to the main sensing component in the sensing assembly used to realize the sensing function. The shape of conductive layer 2 can be determined according to the design shape of the specific sensing assembly, for example, Figure 1 As shown, the shape of conductive layer 2 can be an interlaced comb shape, or, as... Figure 4 As shown, the shape of the conductive layer 2 can also be rectangular, or for example, it can also be a square, a circle, or other suitable shapes. This embodiment does not impose any limitations on this.

[0064] Taking the shape of conductive layer 2 as an example, which is an interlaced comb shape, such as Figure 1 , Figure 2 as well as Figure 3 As shown, Figure 1 This can be viewed as a top view of the heating assembly when the conductive layer 2 is comb-shaped. Figure 2 It can be regarded as Figure 1 A schematic diagram of the cross-sectional structure along the A-A' direction. Figure 3 It can be regarded as Figure 1The diagram shows a cross-sectional view of the structure along the B-B' direction. The material of the conductive layer 2 can be polycrystalline silicon or metal; this embodiment is not limited thereto. Furthermore, the polycrystalline silicon can be P-type or N-type conductive; this embodiment is not limited thereto. The first insulating layer 3 can include a silicon nitride layer.

[0065] The sidewall structure 4 can serve as a heating layer in the heating assembly. The material of the sidewall structure 4 can include polycrystalline silicon or metal; this embodiment is not limited thereto. Furthermore, the polycrystalline silicon can be P-type or N-type conductive; this embodiment is not limited thereto. Since the sidewall structure 4 is located on the sidewall of the conductive layer 2, it does not occupy excessive device design area. Simultaneously, because the sidewall structure 4 is separated from the conductive layer 2 by the first insulating layer 3, the conductive layer 2 and the sidewall structure 4 can operate independently of each other.

[0066] like Figure 1 or Figure 4 As shown, the materials of the first heating electrode 5 and the second heating electrode 6 can be any suitable metal electrode material in the art, such as aluminum. Since the first heating electrode 5 and the second heating electrode 6 can be connected by the sidewall structure 4, a complete heating assembly can be formed by the first heating electrode 5, the second heating electrode 6, and the sidewall structure 4, thereby realizing the heating function.

[0067] Additionally, it should be noted that in the actual fabrication process, depending on the specific shape of the conductive layer and the specific fabrication process of the gas sensor, it can be determined whether the first heating electrode 5 and the second heating electrode 6 are fabricated simultaneously. For example, still taking the conductive layer 2 as having an interlaced comb-like shape as an example, see [reference needed]. Figure 1 Since the first heating electrode 5 and the second heating electrode 6 are located on the same layer, the photolithography pattern can be appropriately modified in the same step to simultaneously fabricate the first heating electrode 5 and the second heating electrode 6. Of course, it is understandable that the first heating electrode 5 and the second heating electrode 6 can also be fabricated without using the same step.

[0068] The aforementioned heating assembly includes: a substrate 1, a conductive layer 2, a first insulating layer 3, a sidewall structure 4, a first heating electrode 5, and a second heating electrode 6. The conductive layer 2 is located on the upper surface of the substrate 1. The first insulating layer 3 is located on the upper surface of the conductive layer 2, the sidewall of the conductive layer 2, and the upper surface of the substrate 1. The sidewall structure 4 is located on the sidewall of the first insulating layer 3, with the sidewall of the first insulating layer 3 corresponding to the sidewall of the conductive layer 2. The first heating electrode 5 is in contact with one end of the sidewall structure 4, and the second heating electrode 6 is in contact with the other end of the sidewall structure 4. Because the sidewall structure 4, serving as the heating layer of the heating assembly, is designed on the sidewall of the conductive layer 2, it saves on device design area.

[0069] Optionally, a self-aligned sidewall process can be used to form the sidewall structure 4. An initial sidewall structure is formed before the upper surface of the first insulating layer. Then, without photolithography, the initial sidewall structure can be directly etched using the self-aligned sidewall process, removing part of the initial sidewall structure entirely. The portion of the initial sidewall structure located on the sidewall of the first insulating layer 3 will be retained as the sidewall structure 4. This eliminates the need for cumbersome photolithography steps, thus saving costs.

[0070] Furthermore, by controlling the etching time of the self-aligned sidewall process, the size and dimensions of the sidewall structure 4 can be controlled, thereby controlling the heating resistance of the sidewall structure 4 as a heating component. For example, see... Figure 3 In the diagram, the cross-sectional view of sidewall structure 4 resembles a quarter circle. It can be understood that a longer etching time results in a smaller diameter quarter circle, while a shorter etching time results in a larger diameter quarter circle. In other words, by controlling the etching time of the self-aligned sidewall process, the dimensions of sidewall structure 4 can be controlled, allowing for flexible adjustment of the heating resistor in the heating assembly according to actual application requirements.

[0071] In one embodiment, such as Figure 1 As shown, the conductive layer 2 includes a first comb tooth structure 21 and a second comb tooth structure 22, wherein the comb tooth portions of the first comb tooth structure 21 and the comb tooth portions of the second comb tooth structure 22 are arranged alternately. The first heating electrode 5 is in contact with a first sidewall 41 located on the sidewall of the first comb tooth structure 21 and a second sidewall 42 located on the sidewall of the second comb tooth structure 22, respectively. The first sidewall 41 is the sidewall structure 4 at the first end of the comb tooth portion of the first comb tooth structure 21, and the second sidewall 42 is the sidewall structure 4 at the second end of the comb tooth portion of the second comb tooth structure 22. The second heating electrode 6 is in contact with a third sidewall 43 located on the sidewall of the first comb tooth structure 21 and a fourth sidewall 44 located on the sidewall of the second comb tooth structure 22, respectively. The third sidewall 43 is the sidewall structure 4 at the second end of the comb tooth portion of the first comb tooth structure 21, and the fourth sidewall 44 is the sidewall structure 4 at the first end of the comb tooth portion of the second comb tooth structure 22.

[0072] To facilitate understanding of this solution, Figure 1In the first comb structure 21, the first end of the comb tooth portion is a portion of the comb tooth structure located at the right end of the first comb structure 21, and the second end of the comb tooth portion of the first comb structure 21 is a portion of the comb tooth structure located at the left end of the first comb structure 21; similarly, the first end of the comb tooth portion of the second comb structure 22 is a portion of the comb tooth structure located at the left end of the second comb structure 22, and the second end of the comb tooth portion of the second comb structure 22 is a portion of the comb tooth structure located at the right end of the second comb structure 22. At this time, by... Figure 1 As can be seen, since the first heating electrode 5 is in contact with the first sidewall 41 and the second sidewall 42, and the second heating electrode 6 is in contact with the third sidewall 43 and the fourth sidewall 44, the first heating electrode 5 and the second heating electrode 6 can be electrically connected through the sidewall structure 4, thereby forming a complete heating assembly to achieve the heating function. Furthermore, since the sidewall structure 4, which serves as the heating layer of the heating assembly, is designed on the sidewall of the conductive layer 2, it can save device design area.

[0073] In one embodiment, such as Figure 5 As shown, the comb tooth portion of the first comb tooth structure 21 includes a first main comb tooth 211, a first branch comb tooth 212, and a plurality of spaced-apart second branch comb teeth 213. Each second branch comb tooth 213 is connected to the first main comb tooth 211. The first end of the first main comb tooth 211 serves as the first end of the comb tooth portion of the first comb tooth structure 21. The first branch comb teeth 212 are connected to the second branch comb teeth 213 near the second end of the first main comb tooth 211. The free end of the first branch comb tooth 212 serves as the second end of the comb tooth portion of the first comb tooth structure 21. The second comb tooth structure 22 includes a second main comb tooth 221, a third branch comb tooth 222, and a plurality of spaced fourth branch comb teeth 223. Each fourth branch comb tooth 223 is connected to the third main comb tooth. The first end of the second main comb tooth 221 serves as the first end of the comb tooth portion of the second comb tooth structure 22. The third branch comb tooth 222 is connected to the fourth branch comb tooth 223 near the second end of the second main comb tooth 221. The free end of the third branch comb tooth 222 serves as the second end of the comb tooth portion of the second comb tooth structure 22.

[0074] Based on the above embodiments, in one embodiment, please continue to refer to... Figure 5 The first main comb tooth 211 and the first branch comb tooth 212 both extend along the first direction, and each second branch comb tooth 213 extends along the second direction, wherein the first direction and the second direction intersect; the second main comb tooth 221 and the third branch comb tooth 222 both extend along the first direction, and each fourth branch comb tooth 223 extends along the second direction.

[0075] The first direction can be, for example: Figure 5The first direction is shown as a horizontal direction. Of course, in other manufacturing processes and application environments, the first direction can be other suitable directions, and this embodiment is not limited thereto; the second direction can be perpendicular to the first direction, and the second direction can be as shown in the figure. Figure 5 The vertical direction is shown in the figure. Of course, in other manufacturing processes and application environments, the second direction can be other suitable directions, and this embodiment is not limited to them.

[0076] Based on the above embodiments, in one embodiment, please continue to refer to... Figure 5 The first end of the first main comb tooth 211 is aligned with the free end of the third branch comb tooth 222; the first end of the second main comb tooth 221 is aligned with the free end of the first branch comb tooth 212. It is understandable that adopting an alignment method can further reduce the device design area.

[0077] Based on the above embodiments, in one embodiment, such as Figure 6 As shown, the first heating electrode 5 includes a first sub-electrode 51 and a second sub-electrode 52, and the second heating electrode 6 includes a third sub-electrode 61 and a fourth sub-electrode 62. The first sub-electrode 51 is connected to the first end of the first main comb tooth 211, the second sub-electrode 52 is connected to the free end of the first branch comb tooth 212, the third sub-electrode 61 is connected to the first end of the second main comb tooth 221, and the fourth sub-electrode 62 is connected to the free end of the third branch comb tooth 222.

[0078] Based on the above embodiments, in one embodiment, such as Figure 7 As shown, the main body portion 2111 of the first main comb tooth and the first branch comb tooth 212 both extend along the first direction, and the connecting portion 2112 of the first main comb tooth and each of the second branch comb teeth 213 both extend along the second direction, wherein the first direction and the second direction intersect; the main body portion 2211 of the second main comb tooth and the third branch comb tooth 222 both extend along the first direction, and the connecting portion 2212 of the second main comb tooth and each of the fourth branch comb teeth 223 both extend along the second direction.

[0079] In one embodiment, such as Figure 8 and Figure 9 As shown, the sidewall structure 4 at the intersection of the comb teeth of the first comb tooth structure 21 and the comb teeth of the second comb tooth structure 22 overlaps.

[0080] in, Figure 9 It can be regarded as Figure 8 A schematic diagram of the cross-sectional structure along the C-C' direction is shown. Through appropriate layout design, the distance between the comb teeth of the first comb structure 21 and the comb teeth of the second comb structure 22 is minimized. At this point, as shown... Figure 9As shown, the sidewall structure 4 will fill the gap between the comb teeth of the first comb tooth structure 21 and the comb teeth of the second comb tooth structure 22, thereby further reducing the layout design area.

[0081] In one embodiment, such as Figure 5 , Figure 6 or Figure 7 As shown, the first comb structure 21 further includes a first comb electrode 214, which is connected to the first end of the comb portion of the first comb structure 21. The second comb structure 22 further includes a second comb electrode 224, which is connected to the first end of the comb portion of the second comb structure 22.

[0082] Optional, such as Figure 14 As shown, the heating assembly further includes: a second insulating layer 11, a second oxide layer 13, a third insulating layer 12, and a third oxide layer 14. The second insulating layer 11 is located on the upper surface of the substrate 1, the second oxide layer 13 is located on the upper surface of the second oxide layer 11, the conductive layer 2 is formed on the upper surface of the second oxide layer 13, the third insulating layer 12 is located on the lower surface of the substrate 1, and the third oxide layer 14 is located on the lower surface of the third insulating layer 12. A back hole 15 penetrates a portion of the third oxide layer 14, a portion of the third insulating layer 12, and a portion of the substrate 1 to expose a portion of the lower surface of the second insulating layer 11.

[0083] The materials of the second insulating layer 11 and the third insulating layer 12 can be the same, for example, both can be silicon nitride; the second insulating layer 11 and the third insulating layer 12 can be prepared by the same fabrication process. The materials of the second oxide layer 13 and the third oxide layer 14 can be the same, for example, both can be silicon oxide; the second oxide layer 13 and the third oxide layer 14 can be prepared by the same fabrication process. The second insulating layer 11 and the second oxide layer 13 serve to insulate the conductive layer 2 from the substrate 1. The third insulating layer 12 and the third oxide layer 14 can be used as a hard mask layer to etch back vias.

[0084] like Figures 10-12As shown, this application also provides a gas sensor, which includes a heating component as described in any of the above embodiments. A back hole 15 is formed on the lower surface of the substrate 1. The gas sensor further includes a first oxide layer 7, an opening 71, a first sensing electrode 8, a second sensing electrode 9, and a sensitive material layer 23. The first oxide layer 7 is located on the upper surface of the first insulating layer 3 and on the surface of a portion of the sidewall structure 4. The opening 71 penetrates the first oxide layer 7 and the first insulating layer 3 located at the top of the conductive layer 2 to expose the upper surface of the conductive layer 2. The first sensing electrode 8 is in contact with one end of the conductive layer 2, and the second sensing electrode 9 is in contact with the other end of the conductive layer 2. The sensitive material layer 23 is located above the conductive layer 2 and in contact with at least a portion of the conductive layer 2, and the sensitive material layer 23 fills a portion of the opening 71.

[0085] For example, the structure of the gas sensor is described with the conductive layer 2 having an interlaced comb-like shape, wherein, as Figure 10 As shown, the conductive layer 2 may include a first comb-tooth structure 21 and a second comb-tooth structure 22, with the comb teeth of the first comb-tooth structure 21 and the comb teeth of the second comb-tooth structure 22 arranged alternately. Of course, in other suitable applications, the shape of the conductive layer 2 can also be other suitable shapes. In this case, the shape of the gas sensor can also be adaptively adjusted based on the shape designed for the conductive layer 2. This embodiment does not impose any limitations on this. Figure 11 It can be regarded as Figure 10 A schematic diagram of the cross-sectional structure along the D-D' direction. Figure 12 It can be regarded as Figure 10 The diagram shows a cross-sectional view of the structure along the E-E' direction. The first oxide layer 7 may include a silicon oxide layer. The first oxide layer 7 serves to protect the sidewall structure 4. The materials of the first sensing electrode 8, the second sensing electrode 9, the first heating electrode 5, and the second heating electrode 6 can all be metallic electrode materials, such as copper, gold, titanium, silver, aluminum, etc., or multilayer metals composed of the above-mentioned materials, or metal alloys, etc. This embodiment does not impose any limitations.

[0086] Additionally, it should be noted that in the actual fabrication process, depending on the specific shape of the conductive layer and the specific fabrication process of the gas sensor, it can be determined whether the first heating electrode 5, the second heating electrode 6, the first sensing electrode 8, and the second sensing electrode 9 are fabricated simultaneously. For example, still taking the conductive layer 2 as having an interlaced comb-like shape as an example, see [reference needed]. Figure 10Since the first heating electrode 5, the second heating electrode 6, the first sensing electrode 8, and the second sensing electrode 9 are located on the same layer, the photolithography pattern can be appropriately modified in the same step to simultaneously fabricate the first heating electrode 5, the second heating electrode 6, the first sensing electrode 8, and the second sensing electrode 9. Of course, it is understandable that the first heating electrode 5, the second heating electrode 6, the first sensing electrode 8, and the second sensing electrode 9 can also be fabricated without using the same step.

[0087] Furthermore, when designing the shape of the conductive layer 2, in order to facilitate the connection between the conductive layer 2 and the first sensing electrode 8 and the second sensing electrode 9 to form a sensing assembly, the area of ​​the end portion of the conductive layer 2 can usually be designed to be larger. For example, still taking the shape of the conductive layer 2 as an interlaced comb shape as an example, please refer to... Figure 4 as well as Figure 10 ,exist Figure 10 In this process, by appropriately designing the layout, the end of the conductive layer 2 is made larger. This allows the first sensing electrode 8 and the second sensing electrode 9 to fill part of the opening 71 and more easily contact the larger end of the conductive layer 2 during the formation of the first sensing electrode 8 and the second sensing electrode 9 in step S209. Of course, depending on the specific fabrication process, it is also possible to design the end of the conductive layer 2 to be smaller, as long as the first sensing electrode 8 and the second sensing electrode 9 maintain contact with the conductive layer 2.

[0088] To facilitate understanding of this solution, Figure 10 The circular dashed box in the figure indicates the coating area of ​​the sensitive material layer 23. Of course, the coating area and shape of the sensitive material layer 23 are not limited to this area. Figure 10 The scheme shown can be applied in practical applications by determining the coating range and shape of the sensitive material layer 23 according to the specific manufacturing process. The goal is simply to connect the toothed portions of the first comb structure 21 and the second comb structure 22 using the sensitive material layer 23. This embodiment does not impose any limitations on this. A resistance is formed by coating the sensitive material layer 23 between the toothed portions of the first and second comb structures 21 and 22, resulting in different resistance changes depending on the application scenario, thus achieving the sensing function of the corresponding sensing component. For example, the coated sensitive material layer 23 can react to a specific gas, causing a resistance change. The first sensing electrode 8 and the second sensing electrode 9 monitor the resistance change of the sensitive material layer 23, ultimately realizing the sensing function of the sensing component.

[0089] The sensitive material layer 23 can be made of tin oxide or titanium oxide, or other suitable sensitive materials. Different sensitive materials can be applied to achieve the corresponding sensing functions depending on the application scenario. The process of applying the sensitive material layer 23 can include dispensing, inkjet printing, or printing.

[0090] The aforementioned gas sensor includes a heating component as described in any of the above embodiments. A back hole 15 is formed on the lower surface of the substrate 1. The gas sensor further includes a first oxide layer 7, an opening 71, a first sensing electrode 8, a second sensing electrode 9, and a sensitive material layer 23. The first oxide layer 7 is located on the upper surface of the first insulating layer 3 and part of the sidewall structure 4. The opening 71 penetrates the first oxide layer 7 and the first insulating layer 3 located at the top of the conductive layer 2 to expose the upper surface of the conductive layer 2. The first sensing electrode 8 is in contact with one end of the conductive layer 2, and the second sensing electrode 9 is in contact with the other end of the conductive layer 2. The sensitive material layer 23 is located above the conductive layer 2 and in contact with at least part of the conductive layer 2, filling part of the opening 71. Because the sidewall structure 4, which serves as the heating layer of the heating component, is designed on the sidewall of the conductive layer 2, it saves device design area.

[0091] Optionally, a self-aligned sidewall process can be used to form the sidewall structure 4. An initial sidewall structure is formed before the upper surface of the first insulating layer. Then, without photolithography, the initial sidewall structure can be directly etched using the self-aligned sidewall process, removing part of the initial sidewall structure entirely. The portion of the initial sidewall structure located on the sidewall of the first insulating layer 3 will be retained as the sidewall structure 4. This eliminates the need for cumbersome photolithography steps, thus saving costs.

[0092] Furthermore, by controlling the etching time of the self-aligned sidewall process, the size and dimensions of the sidewall structure 4 can be controlled, thereby controlling the heating resistance of the sidewall structure 4 as a heating component. For example, see... Figure 3 In the diagram, the cross-sectional view of sidewall structure 4 resembles a quarter circle. It can be understood that a longer etching time results in a smaller diameter quarter circle, while a shorter etching time results in a larger diameter quarter circle. In other words, by controlling the etching time of the self-aligned sidewall process, the dimensions of sidewall structure 4 can be controlled, allowing for flexible adjustment of the heating resistor in the heating assembly according to actual application requirements.

[0093] In one embodiment, such as Figure 13As shown, the gas sensor further includes: a second insulating layer 11, a second oxide layer 13, a third insulating layer 12, and a third oxide layer 14. The second insulating layer 11 is located on the upper surface of the substrate 1, the second oxide layer 13 is located on the upper surface of the second oxide layer 11, the conductive layer 2 is formed on the upper surface of the second oxide layer 13, the third insulating layer 12 is located on the lower surface of the substrate 1, and the third oxide layer 14 is located on the lower surface of the third insulating layer 12. A back aperture 15 penetrates a portion of the third oxide layer 14, a portion of the third insulating layer 12, and a portion of the substrate 1 to expose a portion of the lower surface of the second insulating layer 11.

[0094] The materials of the second insulating layer 11 and the third insulating layer 12 can be the same, for example, both can be silicon nitride; the second insulating layer 11 and the third insulating layer 12 can be prepared by the same fabrication process. The materials of the second oxide layer 13 and the third oxide layer 14 can be the same, for example, both can be silicon oxide; the second oxide layer 13 and the third oxide layer 14 can be prepared by the same fabrication process. The second insulating layer 11 and the second oxide layer 13 serve to insulate the conductive layer 2 from the substrate 1. The third insulating layer 12 and the third oxide layer 14 can be used as a hard mask layer to etch and form the back via 15.

[0095] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features of the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0096] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A heating assembly, characterized in that, include: Base; A conductive layer is located on the upper surface of the substrate; A first insulating layer is located on the upper surface of the conductive layer, the sidewall of the conductive layer, and the upper surface of the substrate; A sidewall structure is located on the sidewall of the first insulating layer; wherein the sidewall of the first insulating layer corresponds to the sidewall of the conductive layer; the sidewall structure serves as a heating layer in the heating assembly, and the sidewall structure is formed using a self-aligned sidewall process; The first heating electrode is disposed in contact with one end of the sidewall structure; The second heating electrode is disposed in contact with the other end of the sidewall structure; the first heating electrode, the second heating electrode, and the sidewall structure constitute a complete heating assembly to realize the heating function. The conductive layer includes a first comb structure and a second comb structure, wherein the comb teeth of the first comb structure and the comb teeth of the second comb structure are arranged alternately. All sidewalls of the first comb tooth structure are correspondingly provided with the sidewall structure, and all sidewalls of the second comb tooth structure are correspondingly provided with the sidewall structure. The width of the sidewall structure is smaller than the width of the comb teeth of the first comb tooth structure and smaller than the width of the comb teeth of the second comb tooth structure. The comb tooth portion of the first comb tooth structure includes a first main comb tooth, a first branch comb tooth, and a plurality of spaced second branch comb teeth. Each second branch comb tooth is connected to the first main comb tooth, and the first branch comb tooth is connected to the second branch comb tooth near the second end of the first main comb tooth. The comb tooth portion of the second comb tooth structure includes a second main comb tooth, a third branch comb tooth, and a plurality of spaced fourth branch comb teeth. Each fourth branch comb tooth is connected to the third main comb tooth, and the third branch comb tooth is connected to the fourth branch comb tooth near the second end of the second main comb tooth. The first main comb tooth and the first branch comb tooth both extend along a first direction, and each second branch comb tooth extends along a second direction, wherein the first direction and the second direction intersect; the second main comb tooth and the third branch comb tooth both extend along the first direction, and each fourth branch comb tooth extends along the second direction; the first end of the first main comb tooth is aligned with the free end of the third branch comb tooth; the first end of the second main comb tooth is aligned with the free end of the first branch comb tooth; or, the main body of the first main comb tooth and the first branch comb tooth both extend along the first direction, and the connecting portion of the first main comb tooth and each second branch comb tooth both extend along the second direction; the main body of the second main comb tooth and the third branch comb tooth both extend along the first direction, and the connecting portion of the second main comb tooth and each fourth branch comb tooth both extend along the second direction.

2. The heating assembly according to claim 1, characterized in that, The first heating electrode is respectively in contact with the first sidewall located on the sidewall of the first comb structure and the second sidewall located on the sidewall of the second comb structure, wherein the first sidewall is the sidewall structure of the first end of the comb tooth portion of the first comb structure, and the second sidewall is the sidewall structure of the second end of the comb tooth portion of the second comb structure. The second heating electrode is respectively in contact with the third sidewall located on the sidewall of the first comb structure and the fourth sidewall located on the sidewall of the second comb structure, wherein the third sidewall is the sidewall structure of the second end of the comb tooth portion of the first comb structure, and the fourth sidewall is the sidewall structure of the first end of the comb tooth portion of the second comb structure.

3. The heating assembly according to claim 2, characterized in that, The first end of the first main comb tooth serves as the first end of the comb tooth portion of the first comb tooth structure, and the free end of the first branch comb tooth serves as the second end of the comb tooth portion of the first comb tooth structure. The first end of the second main comb tooth serves as the first end of the comb tooth portion of the second comb tooth structure, and the free end of the third branch comb tooth serves as the second end of the comb tooth portion of the second comb tooth structure.

4. The heating assembly according to claim 3, characterized in that, The first heating electrode includes a first sub-electrode and a second sub-electrode, and the second heating electrode includes a third sub-electrode and a fourth sub-electrode. The first sub-electrode is connected to the first end of the first main comb tooth, the second sub-electrode is connected to the free end of the first branch comb tooth, the third sub-electrode is connected to the first end of the second main comb tooth, and the fourth sub-electrode is connected to the free end of the third branch comb tooth.

5. The heating assembly according to claim 2, characterized in that, The sidewall structure overlaps at the intersection of the comb teeth portion of the first comb structure and the comb teeth portion of the second comb structure.

6. The heating assembly according to claim 2, characterized in that, The first comb structure further includes a first comb electrode, which is connected to a first end of the comb portion of the first comb structure. The second comb structure further includes a second comb electrode, which is connected to a first end of the comb portion of the second comb structure.

7. A gas sensor, characterized in that, The gas sensor includes a heating component as described in any one of claims 1-6, wherein a back hole is formed on the lower surface of the substrate, and the gas sensor further includes: The first oxide layer is located on the upper surface of the first insulating layer and on the surface of part of the sidewall structure; An opening, penetrating the first oxide layer and the first insulating layer located on top of the conductive layer, is provided to expose the upper surface of the conductive layer. The first sensing electrode is disposed in contact with one end of the conductive layer; The second sensing electrode is disposed in contact with the other end of the conductive layer; A sensitive material layer is located above the conductive layer and is in contact with at least a portion of the conductive layer, and the sensitive material layer fills a portion of the opening.

8. The gas sensor according to claim 7, characterized in that, The gas sensor also includes: The second insulating layer is located on the upper surface of the substrate; The second oxide layer is located on the upper surface of the second oxide layer; the conductive layer is formed on the upper surface of the second oxide layer. The third insulating layer is located on the lower surface of the substrate; A third oxide layer is located on the lower surface of the third insulating layer, wherein the back hole penetrates a portion of the third oxide layer, a portion of the third insulating layer, and a portion of the substrate to expose a portion of the lower surface of the second insulating layer.

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