Sensing structure

Abstract

The application discloses a sensing structure; wherein, the sensing structure comprises: a substrate, a humidity sensing layer, a first electrode, a second electrode and a gas sensing layer. The humidity sensing layer is arranged on the substrate. The first electrode is arranged on the humidity sensing layer. The second electrode is arranged on the humidity sensing layer. The first electrode and the second electrode are separated from each other. The gas sensing layer is arranged on the first electrode and the second electrode. The gas sensing layer is electrically connected with the first electrode and the second electrode. The sensing structure of the application can reduce water vapor noise in the sensing process.

Description

Technical Field

[0001] This application relates to a sensing structure, and more particularly to an integrated sensing structure with humidity sensing and gas sensing functions. Background Technology

[0002] Gas sensors, such as volatile organic compound (VOC) sensors, may include a gas sensing layer. During sensing, the gas to be measured is passed through the gas sensor, and the gas sensing layer detects it. However, when the gas to be measured is introduced, it typically includes not only VOCs but also water from the environment. This results in the gas sensor simultaneously receiving electrical signals from both the organic gases and the water from the environment when sensing the electrical signal of the gas to be measured. Furthermore, because the electrical signal from the organic gases changes linearly, while the electrical signal from the water changes exponentially, the electrical signal from the water significantly reduces the accuracy of organic gas sensing.

[0003] In other words, removing sensing noise caused by water in the environment is extremely important. However, currently, the only ways to reduce sensing noise caused by water in the environment are to remove water from the gas being measured by adding an additional heating element; directly introducing an anhydrous gas; or adding an additional humidity sensor to correct the electrical signal generated by water in the environment. However, all of these methods result in difficulties in miniaturizing the sensing device.

[0004] Therefore, although existing sensing structures have gradually met their intended uses, they are not yet completely satisfactory in all aspects, so there are still some issues to be overcome regarding sensing structures. Summary of the Invention

[0005] In view of the above problems, some embodiments of this application obtain a sensing structure capable of simultaneously sensing humidity and gas by providing a humidity sensing layer; an electrode layer including a first electrode and a second electrode; and a gas sensing layer in a stacked structure. Specifically, gas is sensed by electrical changes in the electrically connected first electrode, second electrode, and gas sensing layer, while water vapor is sensed by electrical changes generated by the deformation of the first electrode and / or the second electrode, thereby forming an integrated sensing structure.

[0006] According to some embodiments, a sensing structure is provided. The aforementioned sensing structure includes: a substrate, a humidity sensing layer, a first electrode, a second electrode, and a gas sensing layer. The humidity sensing layer is disposed on the substrate. The first electrode is disposed on the humidity sensing layer. The second electrode is disposed on the humidity sensing layer. The first electrode and the second electrode are separate from each other. The gas sensing layer is disposed on the first electrode and the second electrode. The gas sensing layer is electrically connected to the first electrode and the second electrode.

[0007] The sensing structure of this application can reduce water vapor noise during the sensing process.

[0008] The sensing structures of some embodiments of this application can be applied to various types of sensing devices and / or semiconductor devices. To make the features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0009] The following detailed description, in conjunction with the accompanying drawings, will provide a better understanding of the embodiments of this application. It is worth noting that, according to industry standard practice, some features may not be drawn to scale. In fact, for clarity of discussion, the dimensions of different features may be increased or decreased.

[0010] Figures 1A to 1D These are, respectively, a three-dimensional schematic diagram, a cross-sectional schematic diagram, a gas sensing schematic diagram, and a humidity sensing schematic diagram illustrating a sensing structure according to some embodiments of this application.

[0011] Figures 2A to 2D These are, respectively, a three-dimensional schematic diagram, a cross-sectional schematic diagram, a gas sensing schematic diagram, and a humidity sensing schematic diagram illustrating a sensing structure according to some embodiments of this application.

[0012] Figures 3A to 3D These are, respectively, a three-dimensional schematic diagram, a cross-sectional schematic diagram, a gas sensing schematic diagram, and a humidity sensing schematic diagram illustrating a sensing structure according to some embodiments of this application.

[0013] Figure Labels

[0014] 1,2,3: Sensing Structure

[0015] 100:Substrate

[0016] 110: Conductive layer

[0017] 200: Humidity sensing layer

[0018] 201: First contact plug

[0019] 202: Second contact plug

[0020] 310: First electrode

[0021] 311: Bending section

[0022] 312: First end

[0023] 313: Second end

[0024] 314: Circular section

[0025] 315: Connection part

[0026] 320: Second electrode

[0027] 321: Closed part

[0028] 322: Extension

[0029] 323: Circular section

[0030] 324: Connecting pad

[0031] 400: Gas Sensing Layer

[0032] A: Cross-sectional area

[0033] C1: First contact object

[0034] C2: Second contact material

[0035] C3: Third contact material

[0036] D1: First Direction

[0037] D2: Second Direction

[0038] L: Length Detailed Implementation

[0039] The following disclosure provides many different embodiments or examples for implementing various elements of the provided sensing structure. Specific examples of each element and its configuration are described below to simplify the embodiments of this application. Of course, these are merely examples and are not intended to limit this application. For example, if the description refers to a first element formed on a second element, it may include embodiments where the first and second elements are in direct contact, or embodiments where an additional element is formed between the first and second elements so that they are not in direct contact.

[0040] Furthermore, in embodiments described in different figures and illustrations, the same or similar component symbols are used to identify the same or similar components. Moreover, the terms "first" and "second" used herein are used only to distinguish one component from another.

[0041] Furthermore, reference numerals and / or letters may be repeated in different embodiments of this application. Such repetition is for brevity and clarity, and not intended to indicate a relationship between the different embodiments and / or forms discussed. It is understood that additional operations may be provided before, during, and after the method, and some described operations may be replaced or deleted for other embodiments of the method.

[0042] Reference Figure 1A The sensing structure 1 may include a substrate 100, a humidity sensing layer 200, a first electrode 310, a second electrode 320, and a gas sensing layer 400.

[0043] In some embodiments, the substrate 100 may include glass fiber, epoxy resin, aluminum nitride (AlN), silicon carbide (SiC), printed circuit board (PCB) substrate, combinations thereof, or other suitable substrates, but this application is not limited thereto. In some embodiments, actual or virtual dots, such as ink or etched marks, may be formed on the substrate 100 as positioning points to improve the accuracy of the subsequent placement of components formed on the substrate 100, thereby improving the reliability of the sensing structure.

[0044] In some embodiments, the humidity sensing layer 20 may include a water-absorbing and swelling material. In some embodiments, the degree of swelling of the aforementioned water-absorbing and swelling material changes with the degree of water absorption, for example, exhibiting a linear change. In some embodiments, the water-absorbing and swelling material may include: photoresist materials, polyimide, sodium polystyrene sulfonate, benzocyclobutene, cellulose acetate-butyrate, poly(methyl methacrylate), analogs, combinations thereof, or other suitable materials, but this application is not limited thereto. In some embodiments, the humidity sensing layer 200 may be formed on the substrate 100 by spin coating or deposition.

[0045] In some embodiments, the humidity sensing layer 200 may have a water absorption swelling rate between greater than 0% and less than or equal to 20% (>0% and ≤20%). In some embodiments, the water absorption swelling rate of the humidity sensing layer 200 may be less than or equal to 5%, 10%, 15%, 20%, or any value between therewith, to reduce or avoid the probability of irreversible deformation of the first electrode 310 and the second electrode 320 disposed on the humidity sensing layer 200. In some embodiments, the water absorption swelling direction of the humidity sensing layer 200 may be three-dimensional; however, the water absorption swelling rate that mainly affects the deformation of the first electrode 310 and / or the second electrode 320 is the swelling rate in the thickness direction. Therefore, the water absorption swelling rate of the humidity sensing layer 200 may be the water absorption thickness swelling rate. It should be noted that in some embodiments, the water absorption swelling rate refers to the volume change before and after water absorption. For example, the water absorption swelling rate is obtained by measuring the difference in mass of the material of the humidity sensing layer 200 before and after water absorption (e.g., the weight difference before and after water absorption), and calculating the increased volume of the material of the humidity sensing layer 200 using the density of water. Furthermore, the water absorption thickness swelling rate can be obtained by calculating the change in thickness from the increased volume of the material of the humidity sensing layer 200 and the area of ​​the material.

[0046] In some embodiments, the humidity sensing layer 200 has an upwardly convex top surface. For example, the top surface of the humidity sensing layer 200 protrudes in a direction away from the substrate 100. Because the humidity sensing layer 200 has a convex top surface, the degree of water absorption and expansion in the thickness direction can be increased, thereby improving the accuracy of the sensing structure.

[0047] In some embodiments, the first electrode 310 and / or the second electrode 320 may include a conductive material. The aforementioned conductive material may be a metal, metal alloy, conductive metal oxide, or other suitable material such as gold (Au), silver (Ag), copper (Cu), aluminum (Al), platinum (Pt), or the like, but this application is not limited thereto. In some embodiments, the first electrode 310 and the second electrode 320 may be metal electrodes. In some embodiments, the first electrode 310 and the second electrode 320 may be disposed on the humidity sensing layer 200 by a deposition process.

[0048] In some embodiments, the aforementioned deposition process may be a chemical vapor deposition (CVD) process. The aforementioned CVD process may be low-pressure chemical vapor deposition (LPCVD), low-temperature chemical vapor deposition (LTCVD), rapid thermal chemical vapor deposition (RTCVD), PECVD, atomic layer deposition (ALD) of atomic layer chemical vapor deposition, or other suitable CVD processes, but this application is not limited thereto.

[0049] In some embodiments, the gas sensing layer 400 may include carbon black, tin dioxide (SnO2), zinc oxide (ZnO), titanium dioxide (TiO2), nickel oxide (NiO), iron oxide (Fe2O3), tungsten oxide (WO3), copper oxide (CuO), a solid electrolyte material such as yttrium-stabilized zirconia (YSZ), or other suitable sensing materials, but this application is not limited thereto. In some embodiments, the appropriate gas sensing layer 400 may be selected according to the type of gas to be measured. In some embodiments, the gas to be measured may include carbon monoxide (CO), nitrogen dioxide (NO2), or other gases, but this application is not limited thereto. For example, if the user expects the sensing structure to be able to distinguish whether the gas to be measured includes carbon monoxide, the gas sensing layer 400 may include tin dioxide. In some embodiments, the gas sensing layer 400 may be formed by 3D printing, single-point coating, multi-point coating, or deposition processes.

[0050] like Figure 1A As shown, in some embodiments, a humidity sensing layer 200 may be disposed on a substrate 100. A first electrode 310 may be disposed on the humidity sensing layer 200. A second electrode 320 may be disposed on the humidity sensing layer 200. In some embodiments, the first electrode 310 and the second electrode 320 may be disposed on the same layer. In some embodiments, the first electrode 310 and the second electrode 320 are physically separated from each other. A distance may exist between the first electrode 310 and the second electrode 320. In some embodiments, a gas sensing layer 400 is disposed on the first electrode 310 and the second electrode 320. The gas sensing layer 400 may directly contact the first electrode 310 and the second electrode 320. The gas sensing layer 400 may be electrically connected to the first electrode 310 and the second electrode 320.

[0051] In some embodiments, the humidity sensing layer 200 and the gas sensing layer 400 overlap in the normal direction of the substrate 100. In other words, the humidity sensing layer 200 and the gas sensing layer 400 overlap in the vertical direction. In some embodiments, the projection of the gas sensing layer 400 onto the substrate 100 is within the projection of the humidity sensing layer 200 onto the substrate 100. In some embodiments, the projected area of ​​the gas sensing layer 400 onto the substrate 100 is less than or equal to the projected area of ​​the humidity sensing layer 200 onto the substrate 100.

[0052] In some embodiments, the first electrode 310 and the second electrode 320 are disposed between the humidity sensing layer 200 and the gas sensing layer 400. In other words, the humidity sensing layer 200 and the gas sensing layer 400 share the first electrode 310 and the second electrode 320.

[0053] In some embodiments, a substrate 100, a humidity sensing layer 200, a first electrode 310 and a second electrode 320, and a gas sensing layer 400 may be formed sequentially. In some embodiments, the first electrode 310 and the second electrode 320 may be formed in the same or different processes.

[0054] In some embodiments, since the first electrode 310 and the second electrode 320 are used to apply voltage to provide a conductive path, the first electrode 310 and the second electrode 320 herein may be interchangeable. In some embodiments, at least a portion of the first electrode 310 may surround at least a portion of the second electrode 320. In other embodiments, at least a portion of the second electrode 320 may surround at least a portion of the first electrode 310. In still other embodiments, the second electrode 320 may completely surround the first electrode 310.

[0055] Reference Figure 1B , which is along in Figure 1A The diagram shows a cross-sectional view taken by line segment XX'. In some embodiments, a portion of the gas sensing layer 400 may be located in the gap between the first electrode 310 and the second electrode 320. In some embodiments, the gas sensing layer 400 may be in direct contact with the humidity sensing layer 200. In some embodiments, the gas sensing layer 400 exposes a portion of the second electrode 320. In some embodiments, the gas sensing layer 400 covers a portion of the top surface of the second electrode 320, the side surface of the second electrode 320, and the top and side surfaces of the first electrode 310, and the gas sensing layer 400 exposes another portion of the top surface of the second electrode 320. Therefore, a subsequently formed contact can be disposed on the exposed top surface of the second electrode 320 to improve the process margin when forming the contact.

[0056] The following is borrowed Figure 1C and Figure 1D The following are schematic diagrams of gas sensing and humidity sensing of some embodiments disclosed herein.

[0057] Reference Figure 1C For the sake of brevity, the first electrode 310, the second electrode 320, and the gas sensing layer 400 are mainly shown.

[0058] like Figure 1C As shown, in some embodiments, the first electrode 310 may further include a line segment portion and a curved portion 311. In some embodiments, the line segment portion may include a portion extending along a first direction D1, a portion extending along a second direction D2 perpendicular to the first direction D1, and a portion extending along a direction having an angle with the first direction D1. In some embodiments, the edge of the line segment portion may be a straight line, a curve, or an irregular shape. In some embodiments, the line segment portion may have an I-shaped portion, an L-shaped portion, or other portions with similar shapes.

[0059] In some embodiments, the bending portions 311 can be provided in multiple ways to give the shape of the first electrode 310 greater variability. In some embodiments, the first electrode 310 may have C-shaped portions, U-shaped portions, V-shaped portions, S-shaped portions, Z-shaped portions, serrated portions, or other portions with similar shapes. In some embodiments, since the first electrode 310 may include bending portions 311, the total length of the first electrode 310 can be increased, thereby reducing the resistance and / or capacitance of the first electrode 310 itself, thus improving the accuracy of sensing.

[0060] like Figure 1C As shown, in some embodiments, the second electrode 320 may further include a closed portion 321 and an extended portion 322 connected to each other. In some embodiments, the closed portion 321 of the second electrode 320 may surround the first electrode 310. For example, the closed portion 321 of the second electrode 320 may completely surround the first electrode 310.

[0061] In some embodiments, the closed portion 321 may be a ring such as a hollow circle, a hollow ellipse, a frame such as a hollow rectangle, a hollow polygon, or other similar shapes. In some embodiments, because the second electrode 320 has the closed portion 321, the process margin of the gas sensing layer 400 deposited on the second electrode 320 by the deposition process can be increased. For example, the edge shape of the gas sensing layer 400 can be more easily controlled, and overflow problems generated during the formation of the gas sensing layer 400 can be reduced or avoided, thereby reducing unnecessary conductive paths generated during the formation of the gas sensing layer 400 and improving reliability.

[0062] In some embodiments, the extension portion 322 of the second electrode 320 may extend into the opening of the curved portion of the first electrode 310. In some embodiments, since the second electrode 320 may include the extension portion 322, the total length of the second electrode 320 can be increased, thereby reducing the resistance of the second electrode 320 itself, and thus improving the accuracy of sensing.

[0063] like Figure 1C As shown, in some embodiments, the first electrode 310 may be a serpentine electrode, and the second electrode 320 may include a frame-shaped portion and an extension portion 322 connected to each other. The frame-shaped portion of the second electrode 320 completely surrounds the serpentine electrode, that is, the frame-shaped portion of the second electrode 320 completely surrounds the first electrode 310. The extension portion 322 of the second electrode 320 extends into the opening of the curved portion of the serpentine electrode. In some embodiments, the second electrode 320 may be an interdigitated electrode (IDE).

[0064] like Figure 1C As shown, the sensing structure 1 may further include a first contact C1 and a second contact C2. In some embodiments, the first contact C1 is disposed on the first electrode 310, for example, it may be disposed at any point on the first electrode 310. In some embodiments, the second contact C2 is disposed on the second electrode 320, for example, it may be disposed at any point on the second electrode 320. In some embodiments, the first contact C1 and the second contact C2 may be electrically connected to an external power source. In some embodiments, the first contact C1 and / or the second contact C2 comprises a conductive material. The aforementioned conductive material may be a metal, metal alloy, conductive metal oxide, or other suitable material such as gold (Au), silver (Ag), copper (Cu), aluminum (Al), platinum (Pt), or similar materials, but this application is not limited thereto. The material and forming process of the first contact C1 and / or the second contact C2 may be the same as or different from those of the first electrode 310 and / or the second electrode 320, and therefore will not be described in detail.

[0065] In some embodiments, since the gas sensing layer 400 exposes a portion of the top surface of the second electrode 320, the second contact C2 can be disposed on the exposed top surface of the second electrode 320 to maintain the integrity and reliability of the second electrode 320. In other embodiments, the gas sensing layer 400 can completely cover the top surface of the second electrode 320. In this embodiment, the first electrode 310 and the second electrode 320 can be connected to the first contact C1 and the second contact C2 respectively by forming vias on the bodies of the first electrode 310 and / or the second electrode 320.

[0066] In some embodiments, the first electrode 310 and / or the second electrode 320 may further include a pad to facilitate the setting of the first contact C1, the second contact C2 and the third contact C3 and / or to facilitate wire bonding.

[0067] like Figure 1C As shown, in some embodiments, since the first electrode 310, the second electrode 320 and the gas sensing layer 400 are connected to each other to form a conductive path, the type, concentration or combination of the gas to be measured can be obtained by measuring the resistance difference before and after the gas to be measured is introduced into the sensing structure.

[0068] For example, before introducing the target gas (containing moisture from the environment), a first resistance value of the gas sensing layer 400 is obtained by applying a voltage to the first contact C1 on the first electrode 310 and the second contact C2 on the second electrode 320. After introducing the target gas, the target gas is adsorbed onto the gas sensing layer 400. A second resistance value of the gas sensing layer 400 is then obtained by applying a voltage to the first contact C1 and the second contact C2 again. Therefore, the type and / or concentration of the adsorbed target gas can be identified by calculating the resistance difference between the first and second resistance values. In other words, the smaller the resistance value of the first electrode 310 and the second electrode 320 when sensing the type and / or concentration of the target gas, the more accurately the resistance change of the gas sensing layer 400 can be sensed, thereby improving the accuracy of the sensing structure.

[0069] Reference Figure 1D For the sake of brevity, the main components are shown: substrate 100, humidity sensing layer 200, and first electrode 310.

[0070] like Figure 1D As shown, the sensing structure 1 may further include a third contact C3. In some embodiments, the third contact C3 is disposed on the first electrode 310, for example, it may be disposed at any point on the first electrode 310. In some embodiments, the first contact C1 and the third contact C3 on the first electrode 310 may be electrically connected to an external power source. The material and forming process of the third contact C3 may be the same as or different from those of the first contact C1 and / or the second contact C2.

[0071] like Figure 1D As shown, in some embodiments, relative humidity is obtained by measuring the resistance difference before and after deformation caused by the expansion of the water-absorbing and swelling material of the first electrode 310 corresponding to the humidity sensing layer 200.

[0072] For example, before introducing the test gas (containing moisture from the environment), a third resistance value of the first electrode 310 body is obtained by applying a voltage to the first contact C1 and the third contact C3 on the first electrode 310. After the test gas is introduced, the moisture in the test gas is adsorbed into the humidity sensing layer 200, causing the humidity sensing layer 200 to expand in the thickness direction, thereby causing the first electrode 310 disposed on the humidity sensing layer 200 to be deformed by tensile or compressive stress. A fourth resistance value of the first electrode 310 body is obtained again by applying a voltage to the first contact C1 and the third contact C3. Therefore, the moisture content and relative humidity can be identified by calculating the resistance difference between the third and fourth resistance values. In other words, sensing the moisture content and relative humidity is performed by sensing the change in the resistance value of the first electrode 310 body.

[0073] In some embodiments, relative humidity can be obtained by deformation of a portion of the first electrode 310 or by deformation of the entire first electrode 310. For example, such as Figure 1D As shown, a portion of the first electrode 310 may have a length L and a cross-sectional area A. According to the formulas for resistance, length, and cross-sectional area, the resistance is directly proportional to the length L and inversely proportional to the cross-sectional area A. Therefore, when the humidity sensing layer 200 below the first electrode 310 absorbs water and expands, the length L of the first electrode 310 is stretched and becomes longer, and the cross-sectional area A of the first electrode 310 is stretched and decreases, thus causing the resistance of the first electrode 310 to increase. Furthermore, the relative humidity is obtained by comparing the resistance values ​​of the first electrode 310 before and after deformation.

[0074] In other embodiments, relative humidity can be obtained by compressing the first electrode 310 to induce deformation. In some embodiments, the larger the dimension of the first electrode 310, such as its length, the more significant the deformation, thus further increasing the difference in resistance before and after deformation, thereby improving the accuracy of humidity sensing.

[0075] Continuing from the above, in some embodiments, a total signal of the gas to be measured can be obtained by calculating the resistance difference between the first resistance value and the second resistance value, wherein the total signal of the gas to be measured includes a VOC gas signal and a water vapor signal. Simultaneously, a water vapor signal can be obtained by calculating the resistance difference between the third resistance value and the fourth resistance value. In some embodiments, the total signal of the gas to be measured and the water vapor signal are corrected to obtain the VOC gas signal. For example, the water vapor signal can be subtracted from the total signal of the gas to be measured; the total signal of the gas to be measured can be divided by the water vapor signal (total signal of the gas to be measured / water vapor signal); or the total signal of the gas to be measured and the water vapor signal can be substituted into a suitable fitting curve to obtain the VOC gas signal.

[0076] In some embodiments, such as Figure 1C The illustrated gas sensing diagram can be considered a chemical sensor, and as... Figure 1D The humidity sensing diagram shown can be considered as a mechanical sensor. Therefore, this application can integrate a chemical sensor and a mechanical sensor into one integrated sensing structure. In some embodiments, this application can provide a calibrated VOC gas signal without the need for additional heating elements to remove water vapor from the gas to be measured, nor without the need for a costly pre-dehydration system.

[0077] It should be noted that even Figure 1DUsing the first electrode 310 as an example of obtaining relative humidity, the second electrode 320 can also be used to obtain relative humidity. In embodiments where the second electrode 320 is used to obtain relative humidity, the third contact C3 can be disposed at any point on the second electrode 320.

[0078] It should also be noted that, according to Figure 1C and Figure 1D Since at least one contact can be shared when sensing both gas and water vapor, the number of contact elements in the sensing structure can be effectively reduced, thereby reducing manufacturing costs, improving reliability, and / or increasing miniaturization. For example, the sensing structure may only have three contact elements. Two of the aforementioned three contact elements are respectively disposed on the first electrode 310 and the second electrode 320, and the third of the aforementioned three contact elements is disposed on the electrode used for sensing relative humidity, that is, the third of the aforementioned three contact elements is disposed on either the first electrode 310 or the second electrode 320.

[0079] Reference Figures 2A to 2D These are, respectively, perspective views, cross-sectional views, gas sensing diagrams, and humidity sensing diagrams of the sensing structure 2 illustrated according to other embodiments of this application. For the sake of brevity, as... Figures 2A to 2D The structure shown is similar to... Figures 1A to 1D The structures shown are identical or similar, and will not be described again.

[0080] like Figure 2A As shown, in some embodiments, the first electrode 310 may include a closed portion. For example, the closed portion may be an annular shape such as a hollow circle, a hollow ellipse, a frame shape such as a hollow rectangle, a hollow square, a hollow rhombus, a hollow polygon, or other similar shapes. In some embodiments, the first electrode 310 may include an annular portion 314. Because the first electrode 310 may include a closed portion, the process margin and reliability of the gas sensing layer 400 can be improved.

[0081] In some embodiments, the second electrode 320 may include a central portion. For example, the central portion may be a solid shape such as a circle, ellipse, triangle, rectangle, cross, polygon, irregular shape, or other similar shape. In some embodiments, the second electrode 320 may include a circular portion 323. In some embodiments, the annular portion 314 of the first electrode 310 surrounds the circular portion 323 of the second electrode 320. In some embodiments, the circular portion 323 of the second electrode 320 may be located at a virtual center of the annular portion 314 of the first electrode 310. In some embodiments, the projection of the circular portion 323 of the second electrode 320 onto the substrate 100 lies within the inner boundary of the projection of the annular portion 314 of the first electrode 310 onto the substrate 100.

[0082] like Figure 2A As shown, in some embodiments, the sensing structure 2 may further include a conductive layer 110. In some embodiments, the conductive layer 110 is disposed between the substrate 100 and the humidity sensing layer 200. The material and forming process of the conductive layer 110 may be the same as or different from those of the first electrode 310 and / or the second electrode 320. In some embodiments, the conductive layer 110 is a metal layer.

[0083] In some embodiments, the second electrode 320 further includes a connecting pad 324. In some embodiments, the connecting pad 324 may be disposed on the humidity sensing layer 200. In some embodiments, the connecting pad 324 may be disposed on the same layer as the circular portion 323. In some embodiments, the connecting pad 324 is electrically connected to the circular portion 323. In some embodiments, the material and forming process of the connecting pad 324 may be the same as or different from those of the circular portion 323. In some embodiments, the connecting pad 324 may include a line segment portion. In some embodiments, the line segment portion may have an I-shaped portion, an L-shaped portion, or other portions with similar shapes. In some embodiments, the connecting pad 324 may be any shape suitable for wire bonding.

[0084] In some embodiments, the sensing structure 2 may further include a first contact plug 201 and a second contact plug 202. The first contact plug 201 penetrates the humidity sensing layer 200 and is electrically connected to the circular portion 323 of the second electrode 320 and the conductive layer 110. The second contact plug 202 penetrates the humidity sensing layer 200 and is electrically connected to the connecting pad 324 of the second electrode 320 and the conductive layer 110. That is, through the first contact plug 201, the second contact plug 202, and the conductive layer 110, the circular portion 323 of the second electrode 320 is spaced apart from the connecting pad 324 of the second electrode 320 when viewed in a top view, but the circular portion 323 of the second electrode 320 is electrically connected to the connecting pad 324 of the second electrode 320.

[0085] In some embodiments, the first contact plug 201 and / or the second contact plug 202 may include a conductive material. The aforementioned conductive material may be a metal, metal alloy, conductive metal oxide, or other suitable material such as gold (Au), silver (Ag), copper (Cu), aluminum (Al), platinum (Pt), or the like, but this application is not limited thereto. The material and forming process of the first contact plug 201 and / or the second contact plug 202 may be the same as or different from those of the first electrode 310 and / or the second electrode 320.

[0086] In some embodiments, after providing the substrate 100, a conductive layer 110 is formed on the substrate 100. Next, the conductive layer 110 is etched to form vias, and then a first contact plug 201 and a second contact plug 202 are formed in the vias. Then, a patterned humidity sensing layer 200 is formed on the conductive layer 110. Subsequently, a first electrode 310 and a second electrode 320 are formed on the humidity sensing layer 200, and then a gas sensing layer 400 is formed on the first electrode 310, the second electrode 320, the first contact plug 201, and the humidity sensing layer 200.

[0087] In other embodiments, after the substrate 100 is provided, a conductive layer 110 and a humidity sensing layer 200 are sequentially formed on the substrate 100. Next, vias are formed in the conductive layer 110 and the humidity sensing layer 200, and a first contact plug 201 and a second contact plug 202 are formed in the vias. Then, a first electrode 310 and a second electrode 320 are formed on the humidity sensing layer 200, and a gas sensing layer 400 is formed on the first electrode 310, the second electrode 320, the first contact plug 201, and the humidity sensing layer 200.

[0088] like Figure 2B As shown, the first contact plug 201 can penetrate the humidity sensing layer 200. The top surface of the first contact plug 201 contacts the circular portion 323, and the bottom surface of the first contact plug 201 contacts the conductive layer 110. In some embodiments, the humidity sensing layer 200 can also serve as an insulating layer between the first electrode 310 and the second electrode 320 to prevent short circuits between the first electrode 310 and the second electrode 320. Figure 2B As shown, the second contact plug 202 can penetrate the humidity sensing layer 200. The top surface of the second contact plug 202 contacts the connecting pad 324, and the bottom surface of the second contact plug 202 contacts the conductive layer 110.

[0089] Similar to Figure 1C , Figure 2C This is a schematic diagram of gas sensing, and is similar to... Figure 1D , Figure 2D This is a schematic diagram of gas sensing, so descriptions that are the same as or similar to those described above are omitted here.

[0090] like Figure 2C As shown, in some embodiments, the first electrode 310 may further include a first end 312, a second end 313, and a connecting portion 315. In some embodiments, the first end 312 is located at one end of the first electrode 310, and the second end 313 is located at the other end of the first electrode 310. In some embodiments, the connecting portion 315 may connect the first end 312, the second end 313, and the annular portion 314. That is, the connecting portion 315 allows the first end 312, the second end 313, and the annular portion 314 to be connected to each other.

[0091] In some embodiments, the first end portion 312 and / or the second end portion 313 may extend along a first direction D1, and the connecting portion 315 may extend along a second direction D2 perpendicular to the first direction D1. In some embodiments, multiple connecting portions 315 may be provided. In some embodiments, the first end portion 312, the connecting portion 315, the annular portion 314, the connecting portion 315, and the second end portion 313 are sequentially connected to each other. In some embodiments, the connecting portion 315 may further include a bent portion. In other words, the connecting portion 315 may cause the extension direction of the first electrode 310 to change from along one direction to along another direction.

[0092] like Figure 2C As shown, the first contact C1 may be disposed on the second end 313 of the first electrode 310. The second contact C2 may be disposed on the connecting pad 324 of the second electrode 320. In some embodiments, the shape of the gas sensing layer 400 may correspond to the annular portion 314 of the first electrode 310. For example, the gas sensing layer 400 may have a circular shape. Furthermore, the gas sensing layer 400 may expose a portion of the top surface of the annular portion 314 of the first electrode 310. When the shape of the gas sensing layer 400 corresponds to the annular portion 314 of the first electrode 310, the degree of deformation of the gas sensing layer 400 itself caused by the expansion of the humidity sensing layer 200 below the gas sensing layer 400 after absorbing water and expanding will be reduced. In other words, by adjusting the shape and area of ​​the gas sensing layer 400, the risk of deformation of the gas sensing layer 400 and changes in its electrical characteristics can be reduced.

[0093] like Figure 2D As shown, the first contact C1 and the third contact C3 can be respectively disposed on the first end and the second end of the first electrode 310. In other words, the first contact C1 can be used as one of the contact materials during gas sensing, or it can be used as one of the contact materials during humidity sensing. In some embodiments, relative humidity can be obtained by the degree of deformation of the first electrode 310.

[0094] like Figure 2C and Figure 2DAs shown, in this embodiment, since the first electrode 310 has an annular portion 314, it can provide measurement data with a small standard deviation, thereby improving accuracy. In some embodiments, relative humidity can be sensed primarily by the degree of deformation of the first electrode 310. Therefore, the dimensions between the annular portion 314 of the first electrode 310 and the circular portion 323 of the second electrode 320 located below the gas sensing layer 400 can be adjusted to reduce the size of the circular portion 323 of the second electrode 320, thereby facilitating the miniaturization of the overall gas sensing structure. Furthermore, the circular portion 323 of the second electrode 320 can be further connected to the connecting pad 324 of the second electrode 320 via the first contact plug 201, the conductive layer 110, and the second contact plug 202 to improve the wire bonding process margin.

[0095] Reference Figures 3A to 3D These are, respectively, perspective views, cross-sectional views, gas sensing views, and humidity sensing views of the sensing structure 3 illustrated according to other embodiments of this application. For the sake of brevity, as... Figures 3A to 3D The structure shown is similar to... Figures 1A to 1D and / or Figures 2A to 2D The structures shown are identical or similar, and will not be described again.

[0096] like Figure 3A As shown, in some embodiments, the first electrode 310 may have substantially S-shaped, Z-shaped, serrated, or chain-like portions. In some embodiments, because the first electrode 310 has the above-described shape, the total electrode length of the first electrode 310 per unit area can be increased, thereby improving the degree of deformation during subsequent humidity sensing and thus improving the accuracy of humidity sensing. Figure 3B As shown, in some embodiments, the first contact plug 201 may be provided in multiple forms.

[0097] like Figure 3C As shown, in some embodiments, the annular portion 314 of the first electrode 310 may be provided in multiple ways, and the multiple annular portions 314 may be arranged at intervals from each other. The multiple annular portions 314 may be arranged in a matrix. The multiple annular portions 314 may be arranged in an S-shape, a Z-shape, a serpentine shape, a sawtooth shape, and / or a chain shape. The multiple annular portions 314 are electrically connected to each other, for example, they are conductive to each other. In some embodiments, the circular portion 323 of the second electrode 320 may also be provided in multiple ways. The multiple circular portions 323 of the second electrode 320 are correspondingly disposed with respect to the multiple annular portions 314 of the first electrode 310. One of the multiple annular portions 314 surrounds a corresponding circular portion 323 of the multiple circular portions 323.

[0098] In some embodiments, the gas sensing layer 400 is also provided as a plurality of gas sensing layers 400. One of the plurality of gas sensing layers 400 is connected to a corresponding annular portion 314 of a plurality of annular portions 314 and a corresponding circular portion 323 of a plurality of circular portions 323.

[0099] In some embodiments, the sensing structure 3 can be considered as a plurality of sensing structures 2 arranged in series. Specifically, the annular portion 314 of the first electrode 310 and the circular portion 323 of the second electrode 320 in the sensing structure 2 can be considered as a unit, and the aforementioned unit can be arranged in series. Therefore, the sensing structure 3 can increase the sheet resistance of the first electrode 310, thereby reducing the capacitance of the first electrode 310 itself. In addition, the first electrode 310 having multiple units can provide a longer electrode length to increase the degree of deformation of the first electrode 310, thereby improving the accuracy of humidity sensing.

[0100] Furthermore, multiple gas sensing layers 400 can increase the total area of ​​the gas sensing layers 400, thereby improving the accuracy of gas sensing. Moreover, compared to a single gas sensing layer with the same total area, multiple gas sensing layers 400 can reduce the risk of deformation altering the electrical characteristics of a single-piece gas sensing layer. Specifically, a single-piece gas sensing layer is more significantly affected by the underlying humidity sensing layer 200, resulting in greater deformation, which degrades its electrical characteristics and hinders gas sensing. However, this application improves the accuracy of gas sensing by using multiple gas sensing layers 400 while maintaining the same sensing area, thus reducing deformation.

[0101] In summary, according to some embodiments of this application, this application provides an integrated sensing structure by vertically arranging a humidity sensing layer, an electrode layer including a first electrode and a second electrode, and a gas sensing layer. In this application, the principles of chemical sensors (e.g., VOC sensors) and mechanical sensors (e.g., humidity sensors) are simultaneously applied to achieve a miniaturized sensing structure. For example, gas is sensed using a gas sensing layer, a first electrode, and a second electrode, and water vapor is sensed by arbitrarily selecting either the first or second electrode and based on its deformation. This achieves both gas and water vapor sensing within a smaller unit area, increasing the unit density of the element and thus improving the performance of the sensing device. Therefore, this application can provide a sensing structure that reduces water vapor noise.

[0102] While the embodiments and advantages of this application have been disclosed above, it should be understood that those skilled in the art can make modifications, substitutions, and refinements without departing from the spirit and scope of this application. Furthermore, the scope of protection of this application is not limited to the processes, machines, manufacturing methods, material compositions, apparatuses, methods, and steps described in the specific embodiments herein. Those skilled in the art can understand, from the disclosure of some embodiments of this application, current or future developed processes, machines, manufacturing methods, material compositions, apparatuses, methods, and steps, as long as they can perform substantially the same function or obtain substantially the same results in the embodiments described herein, they can be used according to some embodiments of this application. Therefore, the scope of protection of this application includes the aforementioned processes, machines, manufacturing methods, material compositions, apparatuses, methods, and steps. In addition, each claim constitutes an individual embodiment, and the scope of protection of this application also includes combinations of various claims and embodiments.

[0103] The above outlines several embodiments to enable those skilled in the art to better understand the viewpoints of the embodiments described herein. Those skilled in the art should understand that they can design or modify other processes and structures based on the embodiments of this application to achieve the same purpose and / or advantages as the embodiments described herein. Those skilled in the art should also understand that such equivalent processes and structures do not depart from the spirit and scope of this application, and that various changes, substitutions, and replacements can be made without departing from the spirit and scope of this application.

Claims

1. A sensing structure, characterized in that, include: One substrate; A humidity sensing layer is disposed on the substrate; A first electrode is disposed above the humidity sensing layer; A second electrode is disposed above the humidity sensing layer, and the first electrode and the second electrode are separate from each other; and A gas sensing layer is disposed above the first electrode and the second electrode and electrically connected to the first electrode and the second electrode, wherein the humidity sensing layer is located between the substrate and the gas sensing layer; The humidity sensing layer and the gas sensing layer share the first electrode and the second electrode. The humidity sensing layer includes a water-absorbing and swelling material, and at least one of the first electrode and the second electrode undergoes a deformation according to the degree of expansion of the water-absorbing and swelling material. The relative humidity is obtained based on the resistance difference before and after the deformation.

2. The sensing structure as described in claim 1, characterized in that, A portion of the first electrode surrounds a portion of the second electrode.

3. The sensing structure as described in claim 1, characterized in that, The gas sensing layer exposes a portion of the second electrode, and a contact is disposed on that portion of the second electrode.

4. The sensing structure as described in claim 1, characterized in that, The first electrode is a serpentine electrode, and the second electrode includes a frame-shaped portion and an extension portion connected to each other. The frame-shaped portion surrounds the serpentine electrode, and the extension portion extends into the opening of the curved portion of the serpentine electrode.

5. The sensing structure as described in claim 1, characterized in that, The first electrode includes an annular portion, and the second electrode includes a circular portion, with the annular portion surrounding the circular portion.

6. The sensing structure as described in claim 5, characterized in that, The first electrode further includes: A first end, located at one end of the first electrode: A second end, located at the other end of the first electrode; and A connecting portion connects the first end, the second end, and the annular portion.

7. The sensing structure as described in claim 5, characterized in that, The second electrode further includes: a connecting pad disposed on the humidity sensing layer and electrically connected to the circular portion, and the sensing structure further includes: A conductive layer is disposed between the substrate and the humidity sensing layer; A first contact plug penetrates the humidity sensing layer and is electrically connected to the circular portion of the second electrode and the conductive layer; and A second contact plug penetrates the humidity sensing layer and is electrically connected to the connection pad and the conductive layer of the second electrode.

8. The sensing structure as described in claim 5, characterized in that, The annular portion is provided in multiple ways, and the multiple annular portions are arranged at intervals or in a matrix, and the multiple annular portions are electrically connected to each other.

9. The sensing structure as described in claim 8, characterized in that, The circular portion is provided in multiple ways, and one of the multiple annular portions surrounds a corresponding circular portion among the multiple circular portions.

10. The sensing structure as described in claim 9, characterized in that, The gas sensing layer is provided in multiple forms, and one of the gas sensing layers is connected to a corresponding annular portion and a corresponding circular portion among the multiple annular portions.

11. The sensing structure as described in claim 1, characterized in that, The gas sensing layer adsorbs a gas to be tested, and the type, concentration, or combination of the gas to be tested is obtained based on the resistance difference before and after the adsorption of the gas to be tested.

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