Air pressure sensor, preparation method thereof and electronic equipment

Abstract

An air pressure sensor and a preparation method thereof, and an electronic device, the air pressure sensor comprising: a substrate (10) and a first capacitor (C1) arranged on one side of the substrate (10), the first capacitor (C1) comprising: a first bottom electrode (11) arranged close to the substrate (10); the first insulating layer (12) is arranged on one side, deviating from the substrate (10), of the first bottom electrode (11); the first top electrode (13) is arranged on the side, away from the substrate (10), of the first insulating layer (12), a first opening (H1) is formed in the first top electrode (13), and the first opening (H1) is used for exposing the first insulating layer (12) at the corresponding position; wherein the first insulating layer (12) can change the dielectric constant of the first insulating layer (12) in environments with different humidity, so as to change the capacitance value of the first capacitor (C1). The air pressure sensor has the functions of air pressure testing and humidity testing, integration of the MEMS hygrometer and the barometer is achieved, integration and miniaturization of the sensor are achieved, the steps of the manufacturing process and the packaging process are saved, cost is saved, and the air pressure sensor can be used for monitoring environmental pressure and humidity of different scenes.

Description

Air pressure sensor, preparation method thereof, and electronic device Technical Field

[0001] The present disclosure relates to the field of sensor technology, and in particular to an air pressure sensor, a preparation method thereof, and an electronic device. Background Art

[0002] The Internet of Things (IoT) era is a product of humanity's perception and transformation of its surroundings. Multiple sensors are placed within objects to collect real-time physical, chemical, biological, and location information. These sensors connect objects to one another and to people through networks, enabling intelligent identification and management of objects and processes. The development of the IoT allows for multifaceted environmental monitoring, including industrial, domestic, and natural environments, creating a vast market.

[0003] Overview

[0004] The present disclosure provides an air pressure sensor, comprising: a substrate, and a first capacitor arranged on one side of the substrate, wherein the first capacitor comprises:

[0005] A first bottom electrode is arranged close to the base substrate;

[0006] a first insulating layer, disposed on a side of the first bottom electrode facing away from the substrate; and

[0007] a first top electrode, disposed on a side of the first insulating layer facing away from the base substrate, wherein the first top electrode is provided with a first opening, the first opening being used to expose the first insulating layer at a corresponding position;

[0008] The first insulating layer can change its dielectric constant in environments with different humidity, so as to change the capacitance of the first capacitor.

[0009] In some embodiments, a surface of the first insulating layer facing away from the base substrate and a surface of the first top electrode close to the base substrate are in contact with each other.

[0010] In some embodiments, the first capacitor further includes:

[0011] A first cavity is located between the first insulating layer and the first top electrode, the orthographic projection of the first cavity on the base substrate at least partially overlaps with the orthographic projection of the first opening on the base substrate, and the orthographic projection area of ​​the first cavity on the base substrate is larger than the orthographic projection area of ​​the first opening on the base substrate.

[0012] In some embodiments, the air pressure sensor further comprises:

[0013] The heating electrode is insulated from the first bottom electrode and the first top electrode respectively, and the orthographic projection of the heating electrode on the base substrate does not overlap with the orthographic projection of the first bottom electrode on the base substrate and the orthographic projection of the first top electrode on the base substrate, and the orthographic projection of the heating electrode on the base substrate is located within the orthographic projection range of the first insulating layer on the base substrate.

[0014] In some embodiments, the heating electrode and the first bottom electrode are provided in the same layer and are made of the same material, and the heating electrode is a closed structure surrounding the first bottom electrode; and / or

[0015] The heating electrode is provided in the same layer as the first top electrode and is made of the same material. The heating electrode is a closed structure surrounding the first top electrode.

[0016] In some embodiments, the air pressure sensor includes a plurality of heating electrodes separated from each other in a first direction parallel to the base substrate, wherein the first direction is a direction from a center of the first insulating layer to an edge of the first insulating layer.

[0017] In some embodiments, the first opening has at least one of the following characteristics:

[0018] On a plane parallel to the base substrate, a plurality of the first openings are evenly distributed on the first top electrode;

[0019] On a plane parallel to the base substrate, a plurality of the first openings are arranged in an array along a row direction and / or a column direction;

[0020] A ratio of an orthographic projection area of ​​the first opening on the base substrate to an orthographic projection area of ​​the first top electrode on the base substrate is greater than or equal to 5% and less than or equal to 10%; and

[0021] The orthographic projection shape of the first opening on the base substrate includes at least one of the following: a sector shape, an ellipse shape, a polygon shape, and an irregular shape.

[0022] In some embodiments, in an orthographic projection on the base substrate, the first insulating layer covers the first bottom electrode and the first top electrode respectively, and the first bottom electrode at least partially overlaps with the first top electrode.

[0023] In some embodiments, the air pressure sensor further includes: a second capacitor located on the same side of the substrate as the first capacitor, the second capacitor including:

[0024] A second bottom electrode is disposed close to the base substrate;

[0025] a second cavity, disposed on a side of the second bottom electrode facing away from the substrate; and

[0026] a second top electrode, disposed on a side of the second cavity facing away from the substrate;

[0027] The second cavity is a sealed chamber, and the second top electrode can be deformed under the action of external air pressure to change the capacitance of the second capacitor.

[0028] In some embodiments, the air pressure sensor further comprises:

[0029] a third cavity, provided on a side of the second top electrode facing away from the substrate; and

[0030] a third top electrode, disposed on a side of the third cavity facing away from the substrate;

[0031] The second top electrode, the third cavity and the third top electrode constitute a third capacitor, and a second opening is provided on the third top electrode, and the second opening is used to connect the external environment with the third cavity.

[0032] In some embodiments, the second opening has at least one of the following characteristics:

[0033] On a plane parallel to the base substrate, a plurality of the second openings are evenly distributed on the third top electrode;

[0034] On a plane parallel to the base substrate, a plurality of the second openings are arranged in an array along a row direction and / or a column direction;

[0035] A ratio of an orthographic projection area of ​​the second opening on the base substrate to an orthographic projection area of ​​the third top electrode on the base substrate is greater than or equal to 5% and less than or equal to 10%; and

[0036] The orthographic projection shape of the second opening on the base substrate includes at least one of the following: a sector shape, an ellipse shape, a polygon shape, and an irregular shape.

[0037] In some embodiments, the first bottom electrode and the second top electrode are disposed in the same layer.

[0038] In some embodiments, the second capacitor is located between the first capacitor and the base substrate, and an orthographic projection of the first capacitor on the base substrate at least partially overlaps with an orthographic projection of the second capacitor on the base substrate.

[0039] In some embodiments, the second top electrode and the first bottom electrode share the same electrode or are independently provided.

[0040] In some embodiments, an orthographic projection of the first capacitor on the substrate does not overlap with an orthographic projection of the second capacitor on the substrate.

[0041] In some embodiments, in an orthographic projection on the base substrate, both the second bottom electrode and the second top electrode cover the second cavity, and the second bottom electrode at least partially overlaps the second top electrode.

[0042] In some embodiments, in an orthographic projection on the substrate, the second top electrode covers the third cavity, the third cavity is located within the outer contour of the third top electrode, and the second top electrode at least partially overlaps the third top electrode.

[0043] In some embodiments, the air pressure sensor further includes at least one of the following:

[0044] a second insulating layer, disposed between the first bottom electrode and the first insulating layer, wherein an orthographic projection of the second insulating layer on the base substrate at least covers the first bottom electrode; and

[0045] A third insulating layer is provided on a side of the first top electrode facing away from the base substrate. A third opening is provided on the third insulating layer. The orthographic projection of the third opening on the base substrate at least partially overlaps with the orthographic projection of the first opening on the base substrate.

[0046] In some embodiments, a material of the first insulating layer includes at least one of the following: polyimide, positive photoresist, negative photoresist, and polydimethylsiloxane.

[0047] The present disclosure provides an electronic device, comprising:

[0048] An air pressure sensor as described in any embodiment; and

[0049] The detection circuit is connected to the air pressure sensor and is used to determine the ambient humidity around the air pressure sensor according to the capacitance of the first capacitor.

[0050] The present disclosure provides a method for preparing an air pressure sensor, comprising:

[0051] providing a substrate;

[0052] A first bottom electrode, a first insulating layer and a first top electrode are formed in sequence on one side of the base substrate, wherein the first bottom electrode, the first insulating layer and the first top electrode constitute a first capacitor, and a first opening is provided on the first top electrode, the first opening is used to expose the first insulating layer at a corresponding position, and the first insulating layer can change its own dielectric constant in environments with different humidity to change the capacitance of the first capacitor.

[0053] In some embodiments, the step of sequentially forming a first bottom electrode, a first insulating layer, and a first top electrode on one side of the substrate includes:

[0054] forming the first bottom electrode on one side of the base substrate;

[0055] Using a first patterning process, forming a first insulating layer pattern on a side of the first bottom electrode facing away from the base substrate;

[0056] performing plasma bombardment on the first insulating layer pattern to form a nanofiber body in the first insulating layer pattern, thereby obtaining the first insulating layer;

[0057] The first top electrode is formed on a side of the first insulating layer facing away from the base substrate.

[0058] In some embodiments, after the step of obtaining the first insulating layer, the method further includes:

[0059] forming a first sacrificial layer material on a side of the first insulating layer facing away from the base substrate, wherein the orthographic projection of the first sacrificial layer material on the base substrate at least covers the orthographic projection of the first insulating layer on the base substrate;

[0060] The step of forming the first top electrode on a side of the first insulating layer facing away from the base substrate comprises:

[0061] Using a second patterning process, forming the first top electrode on a side of the first sacrificial layer material facing away from the base substrate;

[0062] The first sacrificial layer material is etched through the first opening on the first top electrode to form a first cavity and a first sacrificial layer between the first insulating layer and the first top electrode, the orthographic projection of the first cavity on the base substrate at least partially overlaps with the orthographic projection of the first opening on the base substrate, and the orthographic projection area of ​​the first cavity on the base substrate is larger than the orthographic projection area of ​​the first opening on the base substrate.

[0063] The above description is only an overview of the technical solution of the present disclosure. In order to more clearly understand the technical means of the present disclosure, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present disclosure more obvious and easy to understand, the specific implementation methods of the present disclosure are listed below.

[0064] BRIEF DESCRIPTION OF THE DRAWINGS

[0065] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure or related technologies, the following is a brief introduction to the drawings required for the description of the embodiments or related technologies. Obviously, the drawings described below are some embodiments of the present disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without inventive efforts. It should be noted that the scales in the drawings are for illustration only and do not represent the actual scale.

[0066] FIG1 exemplarily shows a schematic cross-sectional structure diagram of a first air pressure sensor;

[0067] FIG2 exemplarily shows a schematic cross-sectional structure diagram of a second air pressure sensor;

[0068] FIG3 exemplarily shows a schematic cross-sectional structure diagram of a third air pressure sensor;

[0069] FIG4 exemplarily shows a schematic cross-sectional structure diagram of a fourth air pressure sensor;

[0070] FIG5 exemplarily shows a schematic planar structural diagram of a first top electrode;

[0071] FIG6 exemplarily shows a schematic planar structural diagram of a third top electrode;

[0072] FIG7 exemplarily shows a schematic diagram of the preparation process of the first air pressure sensor;

[0073] FIG8 exemplarily shows a schematic diagram of the preparation process of the third air pressure sensor.

[0074] Detailed description

[0075] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present disclosure, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present disclosure without making any creative efforts shall fall within the scope of protection of the present disclosure.

[0076] To save space and achieve multi-point, all-encompassing monitoring, sensors are becoming increasingly miniaturized and highly integrated. Therefore, multifunctional sensors capable of measuring multiple physical quantities hold great promise for future applications. However, sensors with different functions often utilize different manufacturing and packaging processes, often subject to process constraints. Therefore, the integration of multifunctional sensors has become a hot topic of research.

[0077] Referring to Figures 1 to 4, schematic cross-sectional structures of several air pressure sensors provided by the present disclosure are exemplarily shown. As shown in any one of Figures 1 to 4, the air pressure sensor includes: a base substrate 10, and a first capacitor C1 arranged on one side of the base substrate 10, the first capacitor C1 includes: a first bottom electrode 11, arranged close to the base substrate 10; a first insulating layer 12, arranged on the side of the first bottom electrode 11 away from the base substrate 10; and a first top electrode 13, arranged on the side of the first insulating layer 12 away from the base substrate 10, a first opening H1 is provided on the first top electrode 13, and the first opening H1 is used to expose the first insulating layer 12 at the corresponding position. Among them, the first insulating layer 12 can change its own dielectric constant in environments with different humidity to change the capacitance value of the first capacitor C1.

[0078] Exemplarily, the material of the first insulating layer 12 includes at least one of the following: a humidity-sensitive material whose dielectric constant changes with humidity, such as polyimide, positive photoresist, negative photoresist, and polydimethylsiloxane.

[0079] In the present disclosure, in the normal direction of the base substrate 10 , the first opening H1 is a through hole penetrating the first top electrode 13 , so that gas from the external environment can enter the first capacitor C1 through the first opening H1 and then come into contact with the first insulating layer 12 .

[0080] As shown in any of Figures 1 to 4 , the first insulating layer 12 is equivalent to the dielectric layer of the first capacitor C1. When the first insulating layer 12 comes into contact with the external ambient gas, it can absorb moisture from the gas, thereby changing the dielectric constant, causing the capacitance of the first capacitor C1 to change. The humidity of the external environment can be obtained based on the corresponding relationship between the capacitance change of the first capacitor C1 and the humidity value. Therefore, the first capacitor C1 is equivalent to a micro-electro-mechanical systems (MEMS) hygrometer, which can be used to detect the humidity of the external environment.

[0081] The air pressure sensor provided by this disclosure combines air pressure and humidity measurement functions, integrating a MEMS hygrometer with a barometer. This allows for sensor integration and miniaturization, saving manufacturing and packaging steps and reducing costs. The air pressure sensor provided by this disclosure can be used to monitor ambient pressure and humidity in various scenarios.

[0082] Illustratively, the substrate 10 may be a silicon substrate, which is not limited in the present disclosure.

[0083] For example, the main material of the first bottom electrode 11 may be doped polysilicon or metal, etc., wherein the metal may include but is not limited to aluminum, copper, silver, gold, etc., or alloys thereof.

[0084] For example, the first bottom electrode 11 can be prepared and patterned by a bonding process or a deposition process, wherein the deposition process can include magnetron sputtering, chemical vapor deposition, etc.

[0085] Exemplarily, the main material of the first bottom electrode 11 is doped polysilicon, which can be formed by in-situ doping low pressure chemical vapor deposition (LPCVD) process and annealing, or by depositing polysilicon by LPCVD process, followed by ion implantation and annealing.

[0086] For example, the first insulating layer 12 can be formed by spin coating and photolithography to form a pattern of the first insulating layer 12. Furthermore, the pattern of the first insulating layer 12 can be subjected to plasma bombardment to form the material of the first insulating layer 12 into a nanofiber body.

[0087] For example, on a plane parallel to the base substrate 10 , the plurality of first openings H1 may be evenly distributed on the first top electrode 13 .

[0088] For example, on a plane parallel to the base substrate 10, the plurality of first openings H1 are arranged in an array along the row direction and / or the column direction. That is, on a plane parallel to the base substrate 10, the plurality of first openings H1 may be arranged in an array along the row direction (as shown in FIG. 5 a), or in an array along the column direction, or in an array along both the row and column directions (as shown in FIG. 5 b and FIG. 5 c).

[0089] For example, on a plane parallel to the base substrate 10 , the plurality of first openings H1 may be irregularly arranged on the first top electrode 13 .

[0090] For example, the ratio of the orthographic projection area of ​​the first opening H1 on the base substrate 10 to the orthographic projection area of ​​the first top electrode 13 on the base substrate 10 is greater than or equal to 5% and less than or equal to 10%. In this way, while ensuring that the first insulating layer 12 has sufficient contact area with the external ambient air, the first opening H1 is prevented from being too large, which would result in an excessively small overlapping area between the first top electrode 13 and the first bottom electrode 11, thereby reducing the impact on the capacitance of the first capacitor C1.

[0091] For example, the orthographic projection shape of the first opening H1 on the base substrate 10 includes at least one of the following: a sector, an ellipse, a polygon (such as a rectangle as shown in FIG. 5 a, and a square as shown in FIG. 5 c), and other regular and irregular shapes. The ellipse may include a circle (as shown in FIG. 5 b). The polygon may include a triangle, a quadrilateral, and a pentagon. The polygon may be a chamfered polygon or a non-chamfered polygon.

[0092] For example, the main material of the first top electrode 13 may be doped polysilicon or metal, etc., wherein the metal may include but is not limited to aluminum, copper, silver, gold, etc., or alloys thereof.

[0093] Illustratively, the first top electrode 13 can be prepared and patterned by a bonding process or a deposition process.

[0094] According to the above description, the first bottom electrode 11 , the first insulating layer 12 and the first top electrode 13 can all be manufactured using mature process solutions, thereby improving product yield.

[0095] In some embodiments, as shown in FIG. 1 , a surface of the first insulating layer 12 facing away from the base substrate 10 is in contact with a surface of the first top electrode 13 close to the base substrate 10 .

[0096] In FIG1 , the surface of the first insulating layer 12 close to the first top electrode 13 is in direct contact with the surface of the first top electrode 13 close to the first insulating layer 12. Since there is no gap between the first insulating layer 12 and the first top electrode 13, the contact area of ​​the first insulating layer 12 with the external environment is the exposed area of ​​the first insulating layer 12 at the first opening H1.

[0097] In order to increase the contact area between the first insulating layer 12 and the external environment, in other embodiments, as shown in any one of Figures 2 to 4, the first capacitor C1 further includes: a first cavity 21, located between the first insulating layer 12 and the first top electrode 13, the orthographic projection of the first cavity 21 on the base substrate 10 and the orthographic projection of the first opening H1 on the base substrate 10 at least partially overlap, and the orthographic projection area of ​​the first cavity 21 on the base substrate 10 is greater than the orthographic projection area of ​​the first opening H1 on the base substrate 10.

[0098] As shown in any one of Figures 2 to 4, the first cavity 21 is connected to the external environment through the first opening H1, and the external environment gas enters the first cavity 21 through the first opening H1. The first insulating layer 12 serves as the cavity wall of the first cavity 21 and is in contact with the external environment gas. This can increase the contact area between the first insulating layer 12 and the external environment, thereby improving the test accuracy and sensitivity.

[0099] During specific implementation, a first sacrificial layer material can be first formed on the side of the first insulating layer 12 facing away from the base substrate 10, and the first sacrificial layer material at least completely covers the first insulating layer 12; then a first top electrode 13 having a first opening H1 can be formed on the side of the first sacrificial layer material facing away from the base substrate 10; and then an etching solution is poured through the first opening H1 on the first top electrode 13 to etch the first sacrificial layer material, thereby forming a first cavity 21 and a first sacrificial layer 22 between the first insulating layer 12 and the first top electrode 13.

[0100] For example, the material of the first sacrificial layer 22 may include silicon dioxide. The first sacrificial layer 22 may be prepared by using a LPCVD process or a plasma enhanced chemical vapor deposition (PECVD) process.

[0101] In some embodiments, as shown in any one of Figures 1 to 4, the air pressure sensor further includes: a heating electrode 14, which is insulated from the first bottom electrode 11 and the first top electrode 13, respectively; the orthographic projection of the heating electrode 14 on the base substrate 10 does not overlap with the orthographic projection of the first bottom electrode 11 on the base substrate 10 and the orthographic projection of the first top electrode 13 on the base substrate 10, and the orthographic projection of the heating electrode 14 on the base substrate 10 is located within the orthographic projection range of the first insulating layer 12 on the base substrate 10.

[0102] As shown in any one of Figures 1 to 4, in the normal direction of the base substrate 10, the heating electrode 14 does not overlap with the first bottom electrode 11, and the heating electrode 14 does not overlap with the first top electrode 13. This can avoid the heating electrode 14 from affecting the capacitance of the first capacitor C1, thereby improving the accuracy of humidity detection.

[0103] The heating electrode 14 is equivalent to a resistor. When the resistor is electrically heated, the heat it dissipates can evaporate the moisture in the first insulating layer 12, thereby achieving active dehumidification and eliminating the hysteresis effect of natural dehumidification. In specific implementations, the heating electrode 14 can be heated periodically, and the heating cycle can be set according to actual needs.

[0104] In some embodiments, as shown in any one of Figures 1 to 4, the heating electrode 14 can be provided in the same layer as the first bottom electrode 11 and made of the same material. In this way, the heating electrode 14 and the first bottom electrode 11 can be formed simultaneously using the same process, thereby improving preparation efficiency and simplifying the preparation process steps.

[0105] For example, as shown in any of Figures 1 to 4 , the heating electrode 14 is a closed structure surrounding the first bottom electrode 11. That is, the heating electrode 14 is a closed ring structure located outside the first bottom electrode 11. This allows the first insulating layer 12 to be uniformly heated in the annular direction.

[0106] In some embodiments, the heating electrode 14 can be provided in the same layer and made of the same material as the first top electrode 13. In this way, the heating electrode 14 and the first top electrode 13 can be formed simultaneously using the same process, thereby improving the manufacturing efficiency and simplifying the manufacturing process steps.

[0107] Exemplarily, the heating electrode 14 is a closed structure surrounding the first top electrode 13. That is, the heating electrode 14 is a closed ring structure located outside the first top electrode 13. In this way, the first insulating layer 12 can be uniformly heated in the ring direction.

[0108] In some embodiments, as shown in any one of Figures 1 to 4, the air pressure sensor includes a plurality of heating electrodes 14 separated from each other in a first direction f1 parallel to the plane of the base substrate 10, wherein the first direction f1 is a direction from the center of the first insulating layer 12 to the edge of the first insulating layer 12.

[0109] By arranging a plurality of heating electrodes 14 spaced apart from each other in the first direction f1 , the dehumidification efficiency of the first insulating layer 12 can be improved, thereby improving the accuracy of humidity detection.

[0110] For example, as shown in any of Figures 1 to 4 , the air pressure sensor includes a plurality of mutually separated closed structures in a first direction f1 parallel to the plane of the base substrate 10. In Figures 1 to 4 , the heater electrode 14 is a closed ring structure, and two mutually separated ring structures are provided around the first bottom electrode 11.

[0111] In some embodiments, as shown in any one of FIG. 1 to FIG. 4 , in an orthographic projection on the base substrate 10 , the first insulating layer 12 covers the first bottom electrode 11 and the first top electrode 13 , respectively, and the first bottom electrode 11 at least partially overlaps the first top electrode 13 .

[0112] For example, in Figures 1 to 4, the orthographic projection of the first bottom electrode 11 on the base substrate 10 is located within the boundary range of the orthographic projection of the first insulating layer 12 on the base substrate 10, and the orthographic projection of the first top electrode 13 on the base substrate 10 is located within the boundary range of the orthographic projection of the first insulating layer 12 on the base substrate 10.

[0113] For example, in FIG. 1 to FIG. 4 , the orthographic projection boundary of the first bottom electrode 11 on the base substrate 10 is substantially aligned with the orthographic projection outer contour of the first top electrode 13 on the base substrate 10 , which is not limited in the present disclosure.

[0114] In some embodiments, as shown in any one of Figures 1 to 4 , the air pressure sensor further includes: a second capacitor C2, located on the same side of the base substrate 10 as the first capacitor C1. The second capacitor C2 includes: a second bottom electrode 15, located near the base substrate 10; a second cavity 16, located on a side of the second bottom electrode 15 facing away from the base substrate 10; and a second top electrode 17, located on a side of the second cavity 16 facing away from the base substrate 10. The second cavity 16 is a sealed chamber, and the second top electrode 17 can deform under the action of external air pressure to change the capacitance of the second capacitor C2.

[0115] Under the action of external air pressure, the second top electrode 17 deforms toward or away from the second bottom electrode 15, causing the distance between the second top electrode 17 and the second bottom electrode 15 to change, that is, the distance between the two plates of the second capacitor C2 changes. Among them, the second cavity 16 provides space for the second top electrode 17 to deform. Since the capacitance of the second capacitor C2 is negatively correlated with the distance between the two plates, that is, as the distance between the second top electrode 17 and the second bottom electrode 15 becomes smaller, the capacitance of the second capacitor C2 increases, and as the distance between the second top electrode 17 and the second bottom electrode 15 increases, the capacitance of the second capacitor C2 decreases. Therefore, the external air pressure value can be obtained based on the corresponding relationship between the capacitance change of the second capacitor C2 and the pressure value.

[0116] Exemplarily, the second cavity 16 may be a vacuum cavity, which is not limited in the present disclosure.

[0117] For example, the main material of the second bottom electrode 15 may be doped polysilicon or metal, etc., wherein the metal may include but is not limited to aluminum, copper, silver, gold, etc., or alloys thereof.

[0118] In some examples, the base substrate 10 is a silicon substrate, and a predetermined region of the base substrate 10 is doped to form the second bottom electrode 15 . In this way, the second bottom electrode 15 is embedded in the base substrate 10 .

[0119] In other examples, the second bottom electrode 15 can be prepared and patterned using a bonding process or a deposition process. In this way, the second bottom electrode 15 is located between the base substrate 10 and the second cavity 16 .

[0120] Illustratively, the main material of the second bottom electrode 15 is doped polysilicon, which can be formed by an in-situ doping LPCVD process and annealing, or by depositing polysilicon by an LPCVD process, followed by ion implantation and annealing.

[0121] For example, the main material of the second top electrode 17 may be doped polysilicon or metal, etc., wherein the metal may include but is not limited to aluminum, copper, silver, gold, etc., or alloys thereof.

[0122] Illustratively, the second top electrode 17 can be prepared and patterned by a bonding process or a deposition process.

[0123] Illustratively, the main material of the second top electrode 17 is doped polysilicon, which can be formed by an in-situ doping LPCVD process and annealing, or by depositing polysilicon by an LPCVD process and then performing ion implantation and annealing.

[0124] For example, as shown in any one of Figures 1 to 4, a second sacrificial layer material can be first formed on the side of the second bottom electrode 15 facing away from the base substrate 10, and the second sacrificial layer material at least completely covers the second bottom electrode 15; then, an initial second top electrode having an etched hole is formed on the side of the second sacrificial layer material facing away from the base substrate 10; then, an etching solution is poured through the etched hole to etch the second sacrificial layer material to form a second cavity 16 and a second sacrificial layer 18, and then the etched hole on the initial second top electrode is sealed to form a closed second cavity 16 and a second top electrode 17.

[0125] For example, the material of the second sacrificial layer 18 may include silicon dioxide. The second sacrificial layer 18 may be prepared by using a process such as LPCVD or PECVD.

[0126] In some embodiments, as shown in FIG4 , the air pressure sensor further includes: a third cavity 31 disposed on a side of the second top electrode 17 facing away from the base substrate 10; and a third top electrode 32 disposed on a side of the third cavity 31 facing away from the base substrate 10. The second top electrode 17, the third cavity 31, and the third top electrode 32 constitute a third capacitor C3. A second opening H2 is disposed on the third top electrode 32, and the second opening H2 is used to connect the external environment to the third cavity 31.

[0127] As shown in FIG. 4 , in the normal direction of the base substrate 10 , the second opening H2 is a through hole penetrating the third top electrode 32 , so that gas from the external environment can enter the third cavity 31 through the second opening H2 , thereby causing external air pressure to act on the second top electrode 17 .

[0128] As shown in Figure 4, the third cavity 31 is connected to the outside world through the second opening H2. This allows the upper and lower air pressures of the third top electrode 32 to be balanced and not deform, while the second top electrode 17 deforms under the action of air pressure. When the second top electrode 17 deforms toward the second bottom electrode 15, the spacing between the two plates of the second capacitor C2 decreases, while the spacing between the two plates of the third capacitor C3 increases, causing the capacitance of the second capacitor C2 to increase and the capacitance of the third capacitor C3 to decrease. When the second top electrode 17 deforms away from the second bottom electrode 15, the spacing between the two plates of the second capacitor C2 increases, while the spacing between the two plates of the third capacitor C3 decreases, causing the capacitance of the second capacitor C2 to decrease and the capacitance of the third capacitor C3 to increase. When the second top electrode 17 deforms, the capacitance of the second capacitor C2 and the third capacitor C3 change in opposite directions. Therefore, the external air pressure value can be determined based on the difference in capacitance between the second and third capacitors C2 and C3. This eliminates the influence of noise and improves detection sensitivity and accuracy.

[0129] In some embodiments, on a plane parallel to the base substrate 10 , the plurality of second openings H2 are evenly distributed on the third top electrode 32 .

[0130] In some embodiments, the plurality of second openings H2 are arranged in an array along the row direction and / or the column direction on a plane parallel to the base substrate 10. That is, on a plane parallel to the base substrate 10, the plurality of second openings H2 may be arranged in an array along the row direction (as shown in FIG. 6 a), or in an array along the column direction, or in an array along both the row direction and the column direction (as shown in FIG. 6 b and FIG. 6 c).

[0131] It should be noted that, on a plane parallel to the base substrate 10 , the plurality of second openings H2 may also be irregularly arranged on the third top electrode 32 .

[0132] In some embodiments, the ratio of the orthographic projection area of ​​the second opening H2 on the base substrate 10 to the orthographic projection area of ​​the third top electrode 32 on the base substrate 10 is greater than or equal to 5% and less than or equal to 10%. In this way, while ensuring that the third cavity 31 is connected to the outside, the second opening H2 is prevented from being too large, which would result in an excessively small overlapping area between the second top electrode 17 and the third top electrode 32, thereby reducing the impact on the capacitance of the third capacitor C3.

[0133] In some embodiments, the orthographic projection shape of the second opening H2 on the base substrate 10 includes at least one of the following: a sector, an ellipse, a polygon (such as a rectangle as shown in Figure 6a, and a square as shown in Figure 6c), and other regular and irregular shapes. The ellipse may include a circle (as shown in Figure 6b). The polygon may include a triangle, a quadrilateral, and a pentagon. The polygon may be a chamfered polygon or a non-chamfered polygon.

[0134] For example, the main material of the third top electrode 32 may be doped polysilicon or metal, etc., wherein the metal may include but is not limited to aluminum, copper, silver, gold, etc., or alloys thereof.

[0135] Illustratively, the third top electrode 32 can be prepared and patterned by a bonding process or a deposition process.

[0136] Illustratively, the main material of the third top electrode 32 is doped polysilicon, which can be formed by an in-situ doping LPCVD process and annealing, or by depositing polysilicon by an LPCVD process and then performing ion implantation and annealing.

[0137] For example, a third sacrificial layer material can first be formed on the side of the second top electrode 17 facing away from the base substrate 10, and the third sacrificial layer material at least completely covers the second top electrode 17; then, a third top electrode 32 having a second opening H2 is formed on the side of the third sacrificial layer material facing away from the base substrate 10; and then, an etching solution is poured through the second opening H2 on the third top electrode 32 to etch the third sacrificial layer material, thereby forming a second cavity 16 and a third sacrificial layer 33 between the second top electrode 17 and the third top electrode 32.

[0138] For example, the material of the third sacrificial layer 33 may include silicon dioxide. The third sacrificial layer 33 may be prepared by using a process such as LPCVD or PECVD.

[0139] Exemplarily, as shown in FIG. 4 , the first sacrificial layer 22 and the third sacrificial layer 33 may be provided in the same layer and made of the same material, so that the first cavity 21 and the second cavity 16 may be formed simultaneously.

[0140] In some embodiments, as shown in any one of Figures 1 to 4 , the first bottom electrode 11 and the second top electrode 17 are disposed in the same layer. Furthermore, the first bottom electrode 11 and the second top electrode 17 may be made of the same material.

[0141] For example, in FIG. 1 and FIG. 2 , the first bottom electrode 11 and the second top electrode 17 share the same electrode, which can reduce the preparation of one film layer, thereby simplifying the process and improving the preparation efficiency.

[0142] For example, in Figure 3 or Figure 4, the first bottom electrode 11 and the second top electrode 17 are two electrodes located in the same layer and separated from each other. This can avoid signal interference that may be caused by the shared electrodes and improve the accuracy of air pressure and humidity detection.

[0143] It should be noted that the first bottom electrode 11 and the second top electrode 17 may also be provided in different layers, which is not limited in the present disclosure.

[0144] In some embodiments, as shown in FIG1 or FIG2 , the second capacitor C2 is located between the first capacitor C1 and the base substrate 10, and the orthographic projection of the first capacitor C1 on the base substrate 10 at least partially overlaps with the orthographic projection of the second capacitor C2 on the base substrate 10. That is, in the normal direction of the base substrate 10, the first capacitor C1 and the second capacitor C2 may partially overlap or completely overlap.

[0145] In this way, the first capacitor C1 and the second capacitor C2 are integrated in the vertical direction, which can further reduce the size of the air pressure sensor and is conducive to device miniaturization.

[0146] 1 or 2 , the second top electrode 17 and the first bottom electrode 11 may share the same electrode. The second top electrode 17 and the first bottom electrode 11 may also be independently provided, for example, the second top electrode 17 and the first bottom electrode 11 may be located in different film layers.

[0147] In FIG. 1 and FIG. 2 , the second top electrode 17 and the first capacitor C1 located thereon are deformed as a whole under the action of external air pressure.

[0148] In some embodiments, as shown in FIG3 or FIG4 , the orthographic projection of the first capacitor C1 on the base substrate 10 does not overlap with the orthographic projection of the second capacitor C2 on the base substrate 10. That is, in the normal direction of the base substrate 10, the first capacitor C1 and the second capacitor C2 may not overlap.

[0149] In this way, the first capacitor C1 and the second capacitor C2 are integrated in the horizontal direction, which can further reduce the thickness of the air pressure sensor, avoid mutual interference between humidity detection and air pressure detection, and improve detection accuracy.

[0150] The second capacitor C2 shown in Figures 1 to 3 constitutes a single-film barometer, while the second capacitor C2 and third capacitor C3 shown in Figure 4 constitute a differential-film barometer. The hygrometer formed by the first capacitor C1 can be located above (as shown in Figures 1 and 2) or to the side (as shown in Figure 3) of the single-film barometer, while the hygrometer formed by the first capacitor C1 can be located to the side of the differential-film barometer (as shown in Figure 4).

[0151] In some embodiments, as shown in any one of FIG. 1 to FIG. 4 , in an orthographic projection on the base substrate 10 , the second bottom electrode 15 and the second top electrode 17 both cover the second cavity 16 , and the second bottom electrode 15 and the second top electrode 17 at least partially overlap.

[0152] As shown in any one of Figures 1 to 4, the orthographic projection of the second cavity 16 on the base substrate 10 is located within the orthographic projection boundary of the second bottom electrode 15 on the base substrate 10, and the orthographic projection of the second cavity 16 on the base substrate 10 is located within the orthographic projection boundary of the second top electrode 17 on the base substrate 10.

[0153] For example, in FIG. 1 to FIG. 4 , the orthographic projection of the second bottom electrode 15 on the base substrate 10 completely overlaps with the orthographic projection of the second top electrode 17 on the base substrate 10 , which is not limited in the present disclosure.

[0154] In some embodiments, as shown in FIG. 4 , in the orthographic projection on the base substrate 10 , the second top electrode 17 covers the third cavity 31 , the third cavity 31 is located within the outer contour of the third top electrode 32 , and the second top electrode 17 at least partially overlaps the third top electrode 32 .

[0155] As shown in Figure 4, the orthographic projection of the third cavity 31 on the base substrate 10 is located within the orthographic projection boundary of the second top electrode 17 on the base substrate 10, and the orthographic projection of the third cavity 31 on the base substrate 10 is located within the orthographic projection outer contour of the third top electrode 32 on the base substrate 10.

[0156] In some embodiments, as shown in any one of Figures 1 to 4, the air pressure sensor further includes: a second insulating layer 19, disposed between the first bottom electrode 11 and the first insulating layer 12, wherein the orthographic projection of the second insulating layer 19 on the base substrate 10 at least covers the first bottom electrode 11.

[0157] In Figures 1 to 4, the second insulating layer 19 completely covers the first bottom electrode 11 and the heater electrode 14. The second insulating layer 19 also fills the gap between the first bottom electrode 11 and the heater electrode 14, as well as the gap between adjacent heater electrodes 14. The provision of the second insulating layer 19 can prevent short circuits between different electrodes and appropriately reduce the lateral spacing between adjacent electrodes, which is conducive to further miniaturization of the sensor.

[0158] In FIG. 3 , the second insulating layer 19 further extends to above the second capacitor C2 and is located on the side of the second top electrode 17 facing away from the base substrate 10 .

[0159] In FIG. 4 , the second insulating layer 19 further extends to above the second capacitor C2 and is located between the second top electrode 17 and the third cavity 31 , thereby preventing the second top electrode 17 and the third top electrode 32 from short-circuiting.

[0160] In some embodiments, as shown in any one of Figures 1 to 4, the pressure sensor further includes: a third insulating layer 110, which is arranged on the side of the first top electrode 13 facing away from the base substrate 10, and a third opening H3 is provided on the third insulating layer 110, and the orthographic projection of the third opening H3 on the base substrate 10 at least partially overlaps with the orthographic projection of the first opening H1 on the base substrate 10.

[0161] As shown in any one of FIG. 1 to FIG. 4 , in the normal direction of the base substrate 10 , the third opening H3 is a through hole penetrating the third insulating layer 110 .

[0162] For example, as shown in any one of Figures 1 to 4 , in the normal direction of the base substrate 10, the third opening H3 completely covers the first opening H1 and the first top electrode 13 around the first opening H1. This ensures that the gas from the external environment can enter the first insulating layer 12 through the first opening H1 without hindrance.

[0163] For example, in FIG. 3 and FIG. 4 , the orthographic projection of the third opening H3 on the base substrate 10 at least partially overlaps with the orthographic projection of the second top electrode 17 on the base substrate 10 .

[0164] As shown in any one of Figures 1 to 4, the pressure sensor may further include: a first signal connection area 111, arranged in the same layer as the second bottom electrode 15; a second signal connection area 112, arranged in the same layer as the first bottom electrode 11 and the second top electrode 17; and a plurality of wire bonding areas 113, arranged in the same layer as the first top electrode 13. In Figure 4, the pressure sensor also includes: a third signal connection area 34, arranged in the same layer as the third top electrode 32 and interconnected. As shown in Figures 1 to 4, the plurality of wire bonding areas 113 are directly connected to different signal connection areas or connected vias. The via area can be made of metal or polysilicon filled vias.

[0165] Among them, the wire bonding area 113 can be connected to the detection circuit, which can determine the ambient humidity around the pressure sensor based on the capacitance of the first capacitor C1, and can also determine the air pressure around the pressure sensor based on the capacitance of the second capacitor C2, or the capacitance of the second capacitor C2 and the third capacitor C3.

[0166] As shown in any one of Figures 1 to 4, the second insulating layer 19 and the third insulating layer are respectively provided with openings at positions corresponding to the first signal connection area 111, the second signal connection area 112, and the third signal connection area 34, so as to connect to the wire bonding area 113. In addition, the second insulating layer 19 and the third insulating layer are also respectively provided with openings at the position of the wire bonding area 113 so as to connect to the detection circuit.

[0167] For example, the materials of the second insulating layer 19 and the third insulating layer 110 may respectively include one or more insulating materials such as silicon nitride, silicon oxide, or silicon oxynitride.

[0168] For example, the orthographic projection shapes of the first bottom electrode 11, the first insulating layer 12, the first top electrode 13, the first cavity 21, the second bottom electrode 15, the second cavity 16, the second top electrode 17, the third cavity 31, and the third top electrode 32 on the substrate 10 may include at least one of the following: a regular shape such as a circle, a sector, an ellipse, a rectangle, or a chamfered rectangle, as well as an irregular shape. In FIG5 , the orthographic projection shape of the first top electrode 13 on the substrate 10 is a rectangle. In FIG6 , the orthographic projection shape of the third top electrode 32 on the substrate 10 is a rectangle.

[0169] The present disclosure also provides an electronic device, including: an air pressure sensor as provided in any embodiment; and a detection circuit connected to the air pressure sensor, for determining the ambient humidity around the air pressure sensor based on the capacitance of the first capacitor C1.

[0170] Those skilled in the art will appreciate that the electronic device has the advantages of the aforementioned air pressure sensor.

[0171] In some embodiments, the electronic device may include, for example, a mobile phone, a smart home device, an unmanned driving device, a digital camera, a tablet computer, a laptop computer, a navigation device, a portable camcorder, a viewfinder, a vehicle, a large wall, a theater screen, or a stadium sign.

[0172] The present disclosure also provides a method for preparing an air pressure sensor, comprising:

[0173] Step S01: providing a base substrate 10 .

[0174] Step S02: A first bottom electrode 11, a first insulating layer 12 and a first top electrode 13 are formed in sequence on one side of the base substrate 10, wherein the first bottom electrode 11, the first insulating layer 12 and the first top electrode 13 constitute a first capacitor C1, and a first opening H1 is provided on the first top electrode 13, and the first opening H1 is used to expose the first insulating layer 12 at a corresponding position. The first insulating layer 12 can change its own dielectric constant in environments with different humidity to change the capacitance of the first capacitor C1.

[0175] The air pressure sensor provided in any embodiment can be prepared using the preparation method provided in the present disclosure.

[0176] In some implementations, step S02 may specifically include the following steps:

[0177] Step S11 : forming a first bottom electrode 11 on one side of the base substrate 10 .

[0178] For example, the first bottom electrode 11 can be prepared and patterned by a bonding process or a deposition process, wherein the deposition process can include magnetron sputtering, chemical vapor deposition, etc.

[0179] Step S12 : using a first patterning process to form a pattern of the first insulating layer 12 on the side of the first bottom electrode 11 facing away from the base substrate 10 .

[0180] Illustratively, the first patterning process may include a spin coating process and a photolithography process, which is not limited in the present disclosure.

[0181] Step S13 : performing plasma bombardment on the pattern of the first insulating layer 12 to form a nanofiber body in the pattern of the first insulating layer 12 , thereby obtaining the first insulating layer 12 .

[0182] Step S14 : forming a first top electrode 13 on a side of the first insulating layer 12 facing away from the base substrate 10 .

[0183] Exemplarily, the first top electrode 13 can be prepared and patterned by a bonding process or a deposition process.

[0184] In some implementations, after step S13, the method further includes:

[0185] Step S21 : forming a first sacrificial layer material on a side of the first insulating layer 12 facing away from the base substrate 10 , wherein the orthographic projection of the first sacrificial layer material on the base substrate 10 at least covers the orthographic projection of the first insulating layer 12 on the base substrate 10 .

[0186] Accordingly, step S14 may specifically include:

[0187] Step S22 : using a second patterning process to form a first top electrode 13 on the side of the first sacrificial layer material facing away from the base substrate 10 .

[0188] Illustratively, the second patterning process may include a deposition process and a photolithography process, which is not limited in the present disclosure.

[0189] Step S23: Etching the first sacrificial layer material through the first opening H1 on the first top electrode 13 to form a first cavity 21 and a first sacrificial layer 22 between the first insulating layer 12 and the first top electrode 13, wherein the orthographic projection of the first cavity 21 on the base substrate 10 at least partially overlaps with the orthographic projection of the first opening H1 on the base substrate 10, and the orthographic projection area of ​​the first cavity 21 on the base substrate 10 is greater than the orthographic projection area of ​​the first opening H1 on the base substrate 10.

[0190] Exemplarily, an etching solution may be injected into the first opening H1 to etch the first sacrificial layer material.

[0191] The following is an exemplary description of the preparation process of the air pressure sensor shown in FIG1 , with reference to FIG6 , which specifically includes the following steps:

[0192] Step S31 : forming a second bottom electrode 15 and a first signal connection region 111 on the substrate 10 by an implantation process, or a deposition and photolithography process.

[0193] Step S32 : forming a second sacrificial layer material on the surface of the second bottom electrode 15 facing away from the base substrate 10 .

[0194] Step S33 : preparing and patterning by a bonding process or a deposition process to form an initial second top electrode 17 (with an etched hole), a heating electrode 14 and a second signal connection area 112 on the surface of the second sacrificial layer material facing away from the base substrate 10 .

[0195] Step S34: injecting etching solution through the etching hole to etch the second sacrificial layer material to form a second cavity 16 and a second sacrificial layer 18, and sealing the etching hole to obtain a second top electrode 17 (or first bottom electrode 11).

[0196] Step S35: Using low-temperature chemical vapor deposition and photolithography, a second insulating layer 19 is formed on the surface of the second top electrode 17 and the heating electrode 14 facing away from the base substrate 10. FIG7 a shows a cross-sectional structure diagram of the pressure sensor after completing this step.

[0197] Step S36: Spin-coating the first insulating layer material onto the surface of the second insulating layer 19 facing away from the base substrate 10 and performing photolithography to form a pattern for the first insulating layer 12. The pattern of the first insulating layer 12 is then plasma bombarded to form a nanofiber structure in the first insulating layer 12. FIG. 7 b shows a schematic cross-sectional structure of the air pressure sensor after completing this step.

[0198] Step S37: sputtering and patterning a metal layer on the surface of the first insulating layer 12 facing away from the base substrate 10 to form a first top electrode 13 and a wire bonding area 113. FIG7 c shows a cross-sectional view of the pressure sensor after completing this step.

[0199] Step S38: Using low-temperature chemical vapor deposition and photolithography, form a third insulating layer 110 on the surface of the first top electrode 13 facing away from the substrate 10. FIG. 7 d shows a schematic cross-sectional structure diagram of the pressure sensor after completing this step.

[0200] The following is an exemplary description of the preparation process of the air pressure sensor shown in FIG3 , with reference to FIG8 , which specifically includes the following steps:

[0201] Step S41 : forming a second bottom electrode 15 and a first signal connection region 111 on the base substrate 10 by adopting an implantation process, or a deposition and photolithography process.

[0202] Step S42 : forming a second sacrificial layer material on the surface of the second bottom electrode 15 facing away from the base substrate 10 .

[0203] Step S43 : Prepare and pattern the second sacrificial layer material by a bonding process or a deposition process to form an initial second top electrode 17 (with an etched hole), a first bottom electrode 11 , a heating electrode 14 and a second signal connection area 112 on the surface of the second sacrificial layer material facing away from the base substrate 10 .

[0204] Step S44 : injecting an etching solution through the etching hole to etch the second sacrificial layer material to form a second cavity 16 and a second sacrificial layer 18 , and sealing the etching hole to obtain a second top electrode 17 .

[0205] Step S45: Using low-temperature chemical vapor deposition and photolithography, a second insulating layer 19 is formed on the surface of the second top electrode 17, the first bottom electrode 11, and the heating electrode 14 facing away from the substrate 10. FIG8 a shows a cross-sectional structure diagram of the pressure sensor after completing this step.

[0206] Step S46: The first insulating layer material is spin-coated on the surface of the second insulating layer 19 facing away from the base substrate 10, and then photolithographically etched to form a pattern of the first insulating layer 12. The pattern of the first insulating layer 12 is then plasma bombarded to form a nanofiber structure in the first insulating layer 12. FIG. 8(b) shows a schematic cross-sectional structure of the air pressure sensor after completing this step.

[0207] Step S47: forming a first sacrificial layer material on the surface of the first insulating layer 12 facing away from the base substrate 10. Referring to Figure c in Figure 8 , there is shown a schematic cross-sectional structure diagram of the air pressure sensor after completing this step.

[0208] Step S48: sputtering and patterning a metal layer on the surface of the first sacrificial layer material facing away from the base substrate 10 to form a first top electrode 13 and a wire bonding area 113. FIG. 8 d shows a schematic cross-sectional structure diagram of the pressure sensor after completing this step.

[0209] Step S49: Using low-temperature chemical vapor deposition and photolithography, form a third insulating layer 110 on the surface of the first top electrode 13 facing away from the substrate 10. FIG8 e shows a schematic cross-sectional structure of the pressure sensor after completing this step.

[0210] Step S410: Etching solution is injected through the third opening H3 in the third insulating layer 110 and the first opening H1 in the first top electrode 13 to etch the first sacrificial layer material, forming a first cavity 21 and a first sacrificial layer 22. FIG8(f) shows a schematic cross-sectional structure of the pressure sensor after this step. The first sacrificial layer material above the second top electrode 17 can be etched away simultaneously.

[0211] It should be noted that the preparation method may also include more steps, which can be determined according to actual needs and is not limited by the present disclosure. The detailed description of the preparation method and the technical effects can be referred to the description of the air pressure sensor above, which will not be repeated here.

[0212] In the present disclosure, “a plurality of” means two or more, and “at least one” means one or more, unless otherwise clearly defined.

[0213] In the present disclosure, the orientation or positional relationship indicated by the terms "upper" and "lower" is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present disclosure and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it should not be understood as a limitation on the present disclosure.

[0214] As used herein, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, product, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not preclude the presence of additional identical elements in the process, method, commodity, or apparatus that includes the element.

[0215] References herein to "one embodiment," "some embodiments," "exemplary embodiments," "one or more embodiments," "an example," "an example," "some examples," and the like are intended to indicate that a particular feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of the present disclosure. Schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be included in any one or more embodiments or examples in any suitable manner.

[0216] In this document, relational terms such as first and second, etc. are used merely to distinguish one entity or operation from another entity or operation, but do not necessarily require or imply any actual relationship or order between these entities or operations.

[0217] When describing some embodiments, the expressions "coupled" and "connected" may be used. For example, when describing some embodiments, the term "connected" may be used to indicate that two or more components are in direct physical or electrical contact with each other. For another example, when describing some embodiments, the term "coupled" may be used to indicate that two or more components are in direct physical or electrical contact. However, the term "coupled" or "communicatively coupled" may also mean that two or more components are not in direct contact with each other, but still cooperate or interact with each other. The embodiments disclosed herein are not necessarily limited to the contents of this document.

[0218] “At least one of A, B and C” has the same meaning as “at least one of A, B or C” and both include the following combinations of A, B and C: A only, B only, C only, the combination of A and B, the combination of A and C, the combination of B and C, and the combination of A, B and C.

[0219] “A and / or B” includes the following three combinations: A only, B only, and a combination of A and B.

[0220] As used herein, the term "if" is optionally interpreted to mean "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrases "if it is determined that" or "if [stated condition or event] is detected" are optionally interpreted to mean "upon determining" or "in response to determining" or "upon detecting [stated condition or event]" or "in response to detecting [stated condition or event]," depending on the context.

[0221] The use of "for" or "configured to" herein is intended to be open and inclusive language that does not exclude devices adapted or configured to perform additional tasks or steps.

[0222] The use of "based on" or "according to" in this document is intended to be open and inclusive. A process, step, calculation, or other action based on one or more stated conditions or values ​​may, in practice, be based on other conditions or values ​​beyond the stated values. A process, step, calculation, or other action based on one or more stated conditions or values ​​may, in practice, be based on other conditions or values ​​beyond the stated values.

[0223] As used herein, "about," "substantially," or "approximately" includes the stated value and an average value that is within an acceptable range of deviation from the particular value as determined by one of ordinary skill in the art taking into account the measurements in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system).

[0224] As used herein, "parallel", "perpendicular", "equal", and "flush" include the situations described and situations similar to the situations described, the range of which is within an acceptable deviation range, wherein the acceptable deviation range is as determined by a person of ordinary skill in the art taking into account the measurement in question and the errors associated with the measurement of the specific quantity (i.e., the limitations of the measurement system). For example, "parallel" includes absolute parallelism and approximate parallelism, wherein the acceptable deviation range of approximate parallelism can be, for example, a deviation within 5°; "perpendicular" includes absolute perpendicularity and approximate perpendicularity, wherein the acceptable deviation range of approximate perpendicularity can also be, for example, a deviation within 5°. "Equal" includes absolute equality and approximate equality, wherein the acceptable deviation range of approximate equality can be, for example, the difference between the two being equal is less than or equal to 5% of either one. "Flush" includes absolute equality and approximate flushness, wherein the acceptable deviation range of approximate flushness can be, for example, the distance between the two being flush is less than or equal to 5% of either one's size.

[0225] It will be understood that when a layer or element is referred to as being on another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may be present therebetween.

[0226] Exemplary embodiments are described herein with reference to cross-sectional and / or plan views that are idealized exemplary drawings. In the drawings, the thicknesses of layers and regions are exaggerated for clarity. Therefore, variations in shape relative to the drawings due to, for example, manufacturing techniques and / or tolerances are contemplated. Therefore, the exemplary embodiments should not be construed as limited to the shapes of the regions shown herein, but rather include deviations in shape due to, for example, manufacturing. For example, an etched region shown as a rectangle will typically have curved features. Therefore, the regions shown in the drawings are schematic in nature, and their shapes are not intended to illustrate the actual shape of regions of the device and are not intended to limit the scope of the exemplary embodiments.

[0227] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present disclosure.

Claims

1. An air pressure sensor, comprising: A substrate, and a first capacitor disposed on one side of the substrate, wherein the first capacitor comprises: A first bottom electrode is disposed close to the substrate; A first insulating layer is disposed on a side of the first bottom electrode facing away from the substrate; and A first top electrode is disposed on a side of the first insulating layer away from the base substrate, and a first opening is disposed on the first top electrode, and the first opening is used to expose the first insulating layer at a corresponding position; The first insulating layer can change its dielectric constant in environments with different humidity to change the capacitance of the first capacitor.

2. The air pressure sensor according to claim 1, wherein: A surface of the first insulating layer facing away from the substrate is in contact with a surface of the first top electrode close to the substrate.

3. The air pressure sensor according to claim 1, wherein: The first capacitor also includes: A first cavity is located between the first insulating layer and the first top electrode, an orthographic projection of the first cavity on the base substrate at least partially overlaps with an orthographic projection of the first opening on the base substrate, and an orthographic projection area of ​​the first cavity on the base substrate is larger than an orthographic projection area of ​​the first opening on the base substrate.

4. The air pressure sensor according to any one of claims 1 to 3, wherein: The air pressure sensor also includes: The heating electrode is insulated from the first bottom electrode and the first top electrode respectively, the orthographic projection of the heating electrode on the base substrate has no overlap with the orthographic projection of the first bottom electrode on the base substrate and the orthographic projection of the first top electrode on the base substrate, and the orthographic projection of the heating electrode on the base substrate is located within the orthographic projection range of the first insulating layer on the base substrate.

5. The air pressure sensor according to claim 4, wherein: The heating electrode is disposed in the same layer as the first bottom electrode and is made of the same material, and the heating electrode is a closed structure surrounding the first bottom electrode; and / or The heating electrode is disposed in the same layer as the first top electrode and is made of the same material. The heating electrode is a closed structure surrounding the first top electrode.

6. The air pressure sensor according to claim 4 or 5, wherein: In a first direction parallel to the base substrate, the air pressure sensor includes a plurality of heating electrodes separated from each other, wherein the first direction is a direction from a center of the first insulating layer to an edge of the first insulating layer.

7. The air pressure sensor according to any one of claims 1 to 6, wherein: The first opening has at least one of the following characteristics: On a plane parallel to the substrate, a plurality of the first openings are evenly distributed on the first top electrode; On a plane parallel to the base substrate, a plurality of the first openings are arranged in an array along a row direction and / or a column direction; A ratio of an orthographic projection area of ​​the first opening on the substrate to an orthographic projection area of ​​the first top electrode on the substrate is greater than or equal to 5% and less than or equal to 10%; as well as The orthographic projection shape of the first opening on the base substrate includes at least one of the following: a sector shape, an ellipse shape, a polygon shape, and an irregular shape.

8. The air pressure sensor according to any one of claims 1 to 7, wherein: In an orthographic projection on the base substrate, the first insulating layer covers the first bottom electrode and the first top electrode respectively, and the first bottom electrode at least partially overlaps with the first top electrode.

9. The air pressure sensor according to any one of claims 1 to 8, wherein: The air pressure sensor further includes: a second capacitor located on the same side of the substrate as the first capacitor, the second capacitor including: A second bottom electrode is disposed close to the base substrate; A second cavity is provided on a side of the second bottom electrode away from the base substrate; and A second top electrode is disposed on a side of the second cavity away from the substrate; The second cavity is a closed chamber, and the second top electrode can be deformed under the action of external air pressure to change the capacitance of the second capacitor.

10. The air pressure sensor according to claim 9, wherein: The air pressure sensor also includes: A third cavity is disposed on a side of the second top electrode away from the substrate; and A third top electrode is disposed on a side of the third cavity away from the substrate; The second top electrode, the third cavity and the third top electrode constitute a third capacitor, and a second opening is provided on the third top electrode, and the second opening is used to connect the external environment with the third cavity.

11. The air pressure sensor according to claim 10, wherein: The second opening has at least one of the following features: On a plane parallel to the base substrate, a plurality of the second openings are evenly distributed on the third top electrode; On a plane parallel to the base substrate, a plurality of the second openings are arranged in an array along a row direction and / or a column direction; A ratio of an orthographic projection area of ​​the second opening on the base substrate to an orthographic projection area of ​​the third top electrode on the base substrate is greater than or equal to 5% and less than or equal to 10%; as well as The orthographic projection shape of the second opening on the base substrate includes at least one of the following: a sector shape, an ellipse shape, a polygon shape, and an irregular shape.

12. The air pressure sensor according to any one of claims 9 to 11, wherein: The first bottom electrode and the second top electrode are arranged in the same layer.

13. The air pressure sensor according to claim 9, wherein: The second capacitor is located between the first capacitor and the substrate, and an orthographic projection of the first capacitor on the substrate at least partially overlaps with an orthographic projection of the second capacitor on the substrate.

14. The air pressure sensor according to claim 13, wherein: The second top electrode and the first bottom electrode share the same electrode or are independently arranged.

15. The air pressure sensor according to any one of claims 9 to 12, wherein: The orthographic projection of the first capacitor on the substrate has no overlap with the orthographic projection of the second capacitor on the substrate.

16. The air pressure sensor according to any one of claims 9 to 15, wherein: In an orthographic projection on the base substrate, both the second bottom electrode and the second top electrode cover the second cavity, and the second bottom electrode at least partially overlaps the second top electrode.

17. The air pressure sensor according to claim 10 or 11, wherein: In the orthographic projection on the substrate, the second top electrode covers the third cavity, the third cavity is located within the range of the outer contour of the third top electrode, and the second top electrode at least partially overlaps with the third top electrode.

18. The air pressure sensor according to any one of claims 1 to 17, wherein: The air pressure sensor further includes at least one of the following: A second insulating layer is disposed between the first bottom electrode and the first insulating layer, wherein an orthographic projection of the second insulating layer on the base substrate at least covers the first bottom electrode; as well as A third insulating layer is arranged on a side of the first top electrode away from the base substrate. A third opening is arranged on the third insulating layer. The orthographic projection of the third opening on the base substrate at least partially overlaps with the orthographic projection of the first opening on the base substrate.

19. The air pressure sensor according to any one of claims 1 to 18, wherein: The material of the first insulating layer includes at least one of the following: polyimide, positive photoresist, negative photoresist and polydimethylsiloxane.

20. An electronic device, comprising: An air pressure sensor as claimed in any one of claims 1 to 19; as well as The detection circuit is connected to the air pressure sensor and is used to determine the ambient humidity around the air pressure sensor according to the capacitance of the first capacitor.

21. A method for preparing an air pressure sensor, comprising: providing a substrate base plate; A first bottom electrode, a first insulating layer and a first top electrode are sequentially formed on one side of the base substrate, wherein the first bottom electrode, the first insulating layer and the first top electrode constitute a first capacitor, a first opening is provided on the first top electrode, the first opening is used to expose the first insulating layer at a corresponding position, and the first insulating layer can change its own dielectric constant in environments with different humidity to change the capacitance of the first capacitor.

22. The preparation method according to claim 21, wherein The step of sequentially forming a first bottom electrode, a first insulating layer and a first top electrode on one side of the base substrate comprises: forming the first bottom electrode on one side of the base substrate; Using a first patterning process, forming a first insulating layer pattern on a side of the first bottom electrode away from the base substrate; Plasma bombarding is performed on the first insulating layer pattern to form a nanofiber body into the first insulating layer pattern, thereby obtaining the first insulating layer; The first top electrode is formed on a side of the first insulating layer facing away from the base substrate.

23. The preparation method according to claim 22, wherein: After the step of obtaining the first insulating layer, the method further includes: Forming a first sacrificial layer material on a side of the first insulating layer away from the base substrate, wherein an orthographic projection of the first sacrificial layer material on the base substrate at least covers an orthographic projection of the first insulating layer on the base substrate; The step of forming the first top electrode on a side of the first insulating layer away from the base substrate comprises: Using a second patterning process, forming the first top electrode on a side of the first sacrificial layer material facing away from the substrate; The first sacrificial layer material is etched through the first opening on the first top electrode to form a first cavity and a first sacrificial layer between the first insulating layer and the first top electrode, the orthographic projection of the first cavity on the substrate at least partially overlaps with the orthographic projection of the first opening on the substrate, and the orthographic projection area of ​​the first cavity on the substrate is greater than the orthographic projection area of ​​the first opening on the substrate.

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