A differential capacitive MEMS pressure sensor and method of manufacturing the same

Abstract

This application discloses a differential capacitive MEMS pressure sensor and its manufacturing method. The pressure sensor includes: a movable electrode comprising a first upper electrode and a second upper electrode, the first and second upper electrodes being an integral structure; the movable electrode being connected to the other end of a support body such that the first upper electrode is positioned above the first lower electrode, forming a first cavity; a gap exists between the first upper electrode and the substrate; the first upper electrode and the first lower electrode constitute a first capacitor; the second upper electrode is positioned above the second lower electrode, forming a second cavity, the second cavity being a sealed cavity; the second upper electrode and the second lower electrode constitute a second capacitor; under applied pressure load, the first and second upper electrodes move in opposite directions.

Description

Technical Field

[0001] This application relates to the field of microelectronics technology, and more specifically, to a differential capacitive MEMS pressure sensor and a method for manufacturing the same. Background Technology

[0002] MEMS pressure sensors can be categorized based on their operating principles into strain gauge, piezoresistive, piezoelectric, frequency-modulated, and capacitive pressure sensors. Additionally, there are photoelectric, ultrasonic, and fiber optic pressure sensors. Pressure sensors can directly convert the measured pressure into various forms of electrical signals, facilitating centralized monitoring and control in systems. Therefore, they are widely used in consumer electronics, smart homes, automotive electronics, and industrial control.

[0003] Currently, most mainstream MEMS capacitive pressure sensors are designed using a planar capacitor approach. A sensitive capacitor is formed by upper and lower plates. When test pressure is applied to the plate surface, it causes deformation. The change in the distance between the upper and lower plates triggers a linear change in capacitance. However, due to the inherent characteristics of the principle, planar capacitor pressure sensors suffer from poor linearity and are prone to damage from overload.

[0004] Therefore, there is an urgent need to propose a new technical solution to solve the above-mentioned technical problems. Summary of the Invention

[0005] One objective of this application is to provide a new technical solution for a differential capacitive MEMS pressure sensor.

[0006] According to a first aspect of this application, a differential capacitive MEMS pressure sensor is provided. The pressure sensor includes:

[0007] A substrate, wherein a first receiving cavity with one end open is provided inside the substrate;

[0008] A support body, one end of which is connected to the bottom of the first receiving cavity, and divides the first receiving cavity into a second receiving cavity and a third receiving cavity;

[0009] A fixed electrode, comprising a first lower electrode and a second lower electrode, wherein the first lower electrode is located at the bottom of the second receiving cavity and the second lower electrode is located at the bottom of the third receiving cavity;

[0010] The movable electrode includes a first upper electrode and a second upper electrode, which are integrally formed. The movable electrode is connected to the other end of the support body to allow...

[0011] The first upper electrode is located above the first lower electrode and forms a first cavity. There is a gap between the first upper electrode and the substrate. The first upper electrode and the first lower electrode constitute a first capacitor.

[0012] The second upper electrode is located above the second lower electrode and forms a second cavity. The second cavity is a closed cavity, and the second upper electrode and the second lower electrode constitute a second capacitor.

[0013] Under pressure load, the first upper electrode and the second upper electrode move in opposite directions.

[0014] Optionally, the second cavity is a vacuum cavity.

[0015] Optionally, the second and third accommodating cavities have the same volume.

[0016] Optionally, the support and the movable electrode are integrally formed.

[0017] Optionally, the substrate is made of at least one of sapphire, silicon carbide, and single-crystal silicon.

[0018] Optionally, the fixed electrode is made of polycrystalline silicon.

[0019] Optionally, the gap includes a first gap and a second gap. The first gap is the gap formed between the first upper electrode and the substrate along the length direction of the substrate, and the second gap is the gap formed between the first upper electrode and the substrate along the width direction of the substrate. The second gap is distributed on both sides of the first upper electrode.

[0020] Optionally, the size of the first gap is 10 μm, and the size of the second gap is 3 μm.

[0021] Optionally, it also includes pads, which include fixed electrode pads and movable electrode pads;

[0022] A first metallized via is provided in the substrate, and a second metallized via is provided in the support body. The fixed electrode is electrically connected to the fixed electrode pad through a first circuit in the first metallized via, and the first upper electrode is electrically connected to the movable electrode pad through a second circuit in the first metallized via and a third circuit in the second metallized via.

[0023] According to a second aspect of this application, a method for manufacturing a differential capacitive MEMS pressure sensor is provided. The method includes the following steps:

[0024] A substrate is provided, and a first receiving cavity is etched on the substrate;

[0025] A first metal layer is deposited and etched at the bottom of the first receiving cavity to form a first lower electrode and a second lower electrode that are independent of each other.

[0026] A second oxide layer is deposited and etched between the first lower electrode and the second lower electrode to form a support, which divides the first accommodating cavity into a second accommodating cavity and a third accommodating cavity.

[0027] A sacrificial layer is deposited within the second and third accommodating cavities;

[0028] A third oxide layer is deposited and etched on the sacrificial layer to form a first upper electrode and a second upper electrode;

[0029] The sacrificial layer is released so that the first upper electrode is positioned above the first lower electrode, forming a first cavity. A gap exists between the first upper electrode and the substrate. The first upper electrode and the first lower electrode constitute a first capacitor.

[0030] The second upper electrode is located above the second lower electrode and forms a second cavity. The second cavity is a closed cavity, and the second upper electrode and the second lower electrode constitute a second capacitor.

[0031] In this embodiment, the movable electrode is supported above the fixed electrode by a support body to form a first capacitor and a second capacitor. Under applied pressure load, the first upper electrode and the second upper electrode of the movable electrode move in opposite directions, so that the plate distance d1 between the first upper electrode and the first lower electrode and the plate distance d2 between the second upper electrode and the second lower electrode will change in opposite values. The first capacitor and the second capacitor will output differential capacitance signals, which greatly improves the linearity and sensitivity of the pressure sensor. Compared with the traditional single-capacitor pressure sensor, the output signal is effectively enhanced, which can effectively improve the testing accuracy of the pressure sensor.

[0032] Other features and advantages of the invention will become clear from the following detailed description of exemplary embodiments of the invention with reference to the accompanying drawings. Attached Figure Description

[0033] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the invention and, together with their description, serve to explain the principles of the invention.

[0034] Figure 1 This is a first schematic diagram of a differential capacitive MEMS pressure sensor according to an embodiment of the present disclosure.

[0035] Figure 2 This is a second schematic diagram of a differential capacitive MEMS pressure sensor according to an embodiment of the present disclosure.

[0036] Figure 3 This is a top view of a differential capacitive MEMS pressure sensor according to an embodiment of the present disclosure.

[0037] Explanation of reference numerals in the attached figures:

[0038] 1. Substrate; 2. Support; 3. Fixed electrode; 31. First lower electrode; 32. Second lower electrode; 4. Movable electrode; 41. First upper electrode; 42. Second upper electrode; 5. Gap; 51. First gap; 52. Second gap; 6. Pad; 61. Fixed electrode pad; 62. Movable electrode pad. Detailed Implementation

[0039] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention.

[0040] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use.

[0041] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0042] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0043] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0044] According to the first embodiment of this disclosure, as Figure 1 As shown, a differential capacitive MEMS pressure sensor is provided. The pressure sensor includes a substrate 1, a support 2, a fixed electrode 3, and a movable electrode 4.

[0045] The substrate 1 has a first receiving cavity with one end open.

[0046] One end of the support 2 is connected to the bottom of the first receiving cavity, and the first receiving cavity is divided into a second receiving cavity and a third receiving cavity.

[0047] The fixed electrode 3 includes a first lower electrode 31 and a second lower electrode 32. The first lower electrode 31 is located at the bottom of the second receiving cavity. The second lower electrode 32 is located at the bottom of the third receiving cavity.

[0048] The movable electrode 4 includes a first upper electrode 41 and a second upper electrode 42. The first upper electrode 41 and the second upper electrode 42 are integrally formed. The movable electrode 4 is connected to the other end of the support 2, so that...

[0049] The first upper electrode 41 is located above the first lower electrode 31 and forms a first cavity. A gap 5 exists between the first upper electrode 41 and the substrate 1. The first upper electrode 41 and the first lower electrode 31 constitute a first capacitor.

[0050] The second upper electrode 42 is located above the second lower electrode 32 and forms a second cavity. The second cavity is a closed cavity. The second upper electrode 42 and the second lower electrode 32 constitute a second capacitor.

[0051] Under the condition of applied pressure load, the first upper electrode 41 and the second upper electrode 42 move in opposite directions.

[0052] It should be noted that the working principle of the differential capacitive MEMS pressure sensor is as follows:

[0053] When a pressure load is applied, the first upper electrode 41 and the second upper electrode 42 move in opposite directions, that is, they deform in opposite directions. The electrode distance d1 between the first upper electrode 41 and the first lower electrode 31 and the electrode distance d2 between the second upper electrode 42 and the second lower electrode 32 will change in opposite values. The first capacitor and the second capacitor will output differential capacitance signals.

[0054] The capacitance calculation method is C = ε * ε0 * S / d. In this design, ε, ε0, and S are fixed values. When a pressure load is applied, d1 increases and d2 decreases, and the capacitance C1 of the first capacitor and the capacitance C2 of the second capacitor change in opposite directions to form a differential signal.

[0055] For example, the substrate 1 can be a cuboid. A first receiving cavity with one end open is provided inside the substrate 1.

[0056] The support 2 can be a cuboid. The dimensions of the support 2 are adapted to the first receiving cavity. When the support 2 is located in the first receiving cavity, one end of the support 2 is connected to the bottom of the first receiving cavity, dividing the first receiving cavity into a second receiving cavity and a third receiving cavity.

[0057] Of course, the shapes of the substrate 1 and the support 2 can also be other suitable shapes such as circles or rhombuses. There are no restrictions here, and those skilled in the art can choose according to actual needs.

[0058] The fixed electrode 3 includes a first lower electrode 31 and a second lower electrode 32. The first lower electrode 31 is located at the bottom of the second receiving cavity. The second lower electrode 32 is located at the bottom of the third receiving cavity.

[0059] The movable electrode 4 includes a first upper electrode 41 and a second upper electrode 42. The first upper electrode 41 and the second upper electrode 42 are integrally formed. The movable electrode 4 is connected to the other end of the support 2, so that...

[0060] The first upper electrode 41 is located above the first lower electrode 31 and forms a first cavity. A gap 5 exists between the first upper electrode 41 and the substrate 1. The first upper electrode 41 and the first lower electrode 31 constitute a first capacitor.

[0061] The second upper electrode 42 is located above the second lower electrode 32 and forms a second cavity. The second cavity is a closed cavity. The second upper electrode 42 and the second lower electrode 32 constitute a second capacitor.

[0062] Under the condition of applied pressure load, the first upper electrode 41 and the second upper electrode 42 move in opposite directions.

[0063] For example, the first upper electrode 41 and the second upper electrode 42 are an integral structure. This allows the first upper electrode 41 to move in the opposite direction to the second upper electrode 42 when a pressure load is applied to the second upper electrode 42. Consequently, the electrode distance d1 between the first upper electrode 41 and the first lower electrode 31 and the electrode distance d2 between the second upper electrode 42 and the second lower electrode 32 will change in opposite values, and the first capacitor and the second capacitor will output a differential capacitance signal.

[0064] For example, the first upper electrode 41 is located above the first lower electrode 31 and forms a first cavity. A gap 5 exists between the first upper electrode 41 and the substrate 1. The first upper electrode 41 and the first lower electrode 31 constitute a first capacitor. The gap 5 between the first upper electrode 41 and the substrate 1 allows the first cavity to communicate with the external environment, thereby ensuring that the air pressure inside the first cavity is equal to the external air pressure. Under conditions where the second upper electrode 42 is not subjected to pressure load, the first upper electrode 41 does not deform.

[0065] For example, the second upper electrode 42 is located above the second lower electrode 32 and forms a second cavity. The second cavity is a sealed cavity. The second upper electrode 42 and the second lower electrode 32 constitute a second capacitor. The second cavity is a sealed cavity. This prevents the second cavity from communicating with the external environment. Under pressure load, the external air pressure can drive the second upper electrode 42 to move closer to the second lower electrode 32, thereby causing the first upper electrode 41 to move away from the first lower electrode 31. Ultimately, this causes the first capacitor and the second capacitor to output a differential capacitance signal.

[0066] In the embodiments disclosed herein, such as Figure 2 As shown, the movable electrode 4 is supported above the fixed electrode 3 by the support body 2 to form a first capacitor and a second capacitor. Under the condition of applied pressure load, the first upper electrode 41 and the second upper electrode 42 of the movable electrode 4 move in opposite directions, so that the plate distance d between the first upper electrode 41 and the first lower electrode 31 and the plate distance d between the second upper electrode 42 and the second lower electrode 32 will change in opposite values. The first capacitor and the second capacitor will output differential capacitance signals, which greatly improves the linearity and sensitivity of the pressure sensor. Compared with the traditional single-capacitor pressure sensor, the output signal is effectively enhanced, which can effectively improve the test accuracy of the pressure sensor.

[0067] In one example, the second cavity is a vacuum cavity.

[0068] For example, setting the second cavity as a vacuum cavity makes it easier to obtain absolute air pressure, eliminates the influence of temperature changes in the sealed cavity on the detection accuracy of the second capacitor, and further improves the detection accuracy of the pressure sensor.

[0069] In one example, the second and third cavities have the same volume.

[0070] For example, the second and third accommodating cavities have the same volume. This ensures that the first and second capacitors have essentially the same initial capacitance, avoiding a difference in initial capacitance between the first and second capacitors under conditions without pressure load, and further improving the detection accuracy of the pressure sensor.

[0071] Of course, the volumes of the second and third receiving cavities may also be different, and this is not a limitation. Those skilled in the art can choose according to actual needs.

[0072] In one example, the support and the movable electrode 4 are integrally formed.

[0073] For example, the support body and the movable electrode 4 are integrally formed. This simplifies the manufacturing process of the support body and the movable electrode 4 and avoids the problem of unstable connection between the support body and the movable electrode 4.

[0074] In one example, the substrate 1 is made of at least one of silicon dioxide, silicon carbide, and silicon nitride.

[0075] For example, the material of substrate 1 can be selected as at least one of silicon dioxide, silicon carbide, and silicon nitride. All of these materials are non-conductive and have high hardness, which helps to improve the structural strength of the pressure sensor, thereby enabling substrate 1 to provide good and effective support for the fixed electrode 3, the support 2, and the movable electrode 4.

[0076] In one example, the material of the fixed electrode 3 is polycrystalline silicon.

[0077] For example, the material of the fixed electrode 3 is selected as polycrystalline silicon. Polycrystalline silicon is a conductive material and has high hardness, which allows the fixed electrode 3 to be stably fixed in the first receiving cavity and is not easily deformed. At the same time, the fixed electrode 3 can cooperate with the movable electrode 4 to form a capacitor to output a capacitance signal.

[0078] In one example, the gap 5 includes a first gap 51 and a second gap 52. The gap 5 formed between the first upper electrode 41 and the substrate 1 along the length direction of the substrate 1 is the first gap 51. The gap 5 formed between the first upper electrode 41 and the substrate 1 along the width direction of the substrate 1 is the second gap 52. The second gap 52 is distributed on both sides of the first upper electrode 41.

[0079] For example, such as Figure 3 As shown, the substrate 1 can be a cuboid. A first receiving cavity with one end open is provided inside the substrate 1. The receiving cavity is rectangular.

[0080] When the movable electrode 4 is positioned above the fixed electrode 3 via the support 2, the gap 5 formed between the first upper electrode 41 and the substrate 1 along the length direction of the substrate 1 is called the first gap 51. The gap 5 formed between the first upper electrode 41 and the substrate 1 along the width direction of the substrate 1 is called the second gap 52. The second gap 52 is distributed on both sides of the first upper electrode 41. This gap 5 allows the first cavity to communicate with the external environment, thereby ensuring that the air pressure inside the first cavity is equal to the external air pressure, and that the first upper electrode 41 does not deform under pressure load. At the same time, the arrangement of the first gap 51 and the second gap 52 ensures that, under the condition that the second upper electrode 42 moves, the first upper electrode 41 can move in the opposite direction to the direction of movement of the second upper electrode 42, thereby enabling the first capacitor and the second capacitor to output differential signals.

[0081] In one example, the size of the first gap 51 is 10 μm, and the size of the second gap 52 is 3 μm.

[0082] For example, the size of the first gap 51 is 10 μm, and the size of the second gap 52 is 3 μm. By controlling the sizes of the first gap 51 and the second gap 52 within this range, while ensuring that the first cavity is connected to the external environment, the area difference between the first upper electrode 41 and the second upper electrode 42 will not be too large. This avoids the problem of excessively large differences in initial capacitance caused by the difference in electrode area between the first upper electrode 41 and the second upper electrode 42, and thus improves the measurement accuracy of the pressure sensor.

[0083] In one example, the pressure sensor also includes pad 6. Pad 6 includes a fixed electrode pad 61 and a movable electrode pad 62.

[0084] A first metallized via is provided in the substrate 1. A second metallized via is provided in the support body. The fixed electrode 3 is electrically connected to the fixed electrode pad 61 through a first circuit in the first metallized via. The first upper electrode 41 is electrically connected to the movable electrode pad 62 through a second circuit in the first metallized via and a third circuit in the second metallized via.

[0085] For example, a first circuit and a second circuit are provided in the first metallized via. A third circuit is provided in the second metallized via. The fixed electrode 3 is electrically connected to the fixed electrode pad 61 through the first circuit in the first metallized via. The first upper electrode 41 is electrically connected to the movable electrode pad 62 through the second circuit in the first metallized via and the third circuit in the second metallized via.

[0086] For example, a fourth circuit is also provided in the first metallized via, and the second upper electrode 42 is electrically connected to the movable electrode pad 62 through the fourth circuit in the first metallized via.

[0087] The movable electrode 4 is supported above the fixed electrode 3 by the support body 2, and is electrically connected to the fixed electrode pad 61 and the movable electrode pad 62 through different circuits to form a first capacitor and a second capacitor. Under the condition of applied pressure load, the first upper electrode 41 and the second upper electrode 42 of the movable electrode 4 move in opposite directions, so that the electrode distance d1 between the first upper electrode 41 and the first lower electrode 31 and the electrode distance d2 between the second upper electrode 42 and the second lower electrode 32 will change in opposite values. The first capacitor and the second capacitor will output differential capacitance signals, which greatly improves the linearity and sensitivity of the pressure sensor. Compared with the traditional single-capacitor pressure sensor, the output signal is effectively enhanced, which can effectively improve the testing accuracy of the pressure sensor.

[0088] According to a second embodiment of this disclosure, a method for manufacturing a differential capacitive MEMS pressure sensor is provided. The method includes the following steps:

[0089] A substrate 1 is provided. A first receiving cavity is formed by etching on the substrate 1.

[0090] A first metal layer is deposited and etched at the bottom of the first receiving cavity to form a first lower electrode 31 and a second lower electrode 32 that are independent of each other.

[0091] A second oxide layer is deposited and etched between the first lower electrode 31 and the second lower electrode 32 to form a support 2. The support 2 divides the first receiving cavity into a second receiving cavity and a third receiving cavity.

[0092] Sacrificial layers are deposited in the second and third containment cavities.

[0093] A third oxide layer is deposited and etched on the sacrificial layer to form a first upper electrode 41 and a second upper electrode 42.

[0094] The sacrificial layer is released so that the first upper electrode 41 is positioned above the first lower electrode 31, forming a first cavity. A gap 5 exists between the first upper electrode 41 and the substrate 1. The first upper electrode 41 and the first lower electrode 31 constitute a first capacitor; and

[0095] The second upper electrode 42 is located above the second lower electrode 32 and forms a second cavity. The second cavity is a closed cavity. The second upper electrode 42 and the second lower electrode 32 constitute a second capacitor.

[0096] In this embodiment, the movable electrode 4 is supported above the fixed electrode 3 by the support body 2 to form a first capacitor and a second capacitor. Under the condition of applied pressure load, the first upper electrode 41 and the second upper electrode 42 of the movable electrode 4 move in opposite directions, so that the electrode distance d1 between the first upper electrode 41 and the first lower electrode 31 and the electrode distance d2 between the second upper electrode 42 and the second lower electrode 32 will produce opposite changes in value. The first capacitor and the second capacitor will output differential capacitance signals, which greatly improves the linearity and sensitivity of the pressure sensor. Compared with the traditional single-capacitor pressure sensor, the output signal is effectively enhanced, which can effectively improve the testing accuracy of the pressure sensor.

[0097] The above embodiments mainly describe the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. For the sake of brevity, they will not be elaborated here.

[0098] While specific embodiments of the invention have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of the invention. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims

1. A method of manufacturing a differential capacitive MEMS pressure sensor, characterized by, The method comprises the following steps: providing a substrate, etching a first accommodating cavity on the substrate; depositing and etching a first metal layer on the bottom of the first accommodating cavity to form a first lower electrode and a second lower electrode which are independent of each other; depositing and etching a second oxide layer between the first lower electrode and the second lower electrode to form a support body, the support body separating the first accommodating cavity into a second accommodating cavity and a third accommodating cavity; depositing a sacrificial layer in the second accommodating cavity and the third accommodating cavity; depositing and etching a third oxide layer on the sacrificial layer to form a first upper electrode and a second upper electrode; releasing the sacrificial layer to make the first upper electrode located above the first lower electrode and form a first cavity, the first upper electrode and the first lower electrode constituting a first capacitor; and the second upper electrode is located above the second lower electrode and forms a second cavity, the second cavity being a sealed cavity, the second upper electrode and the second lower electrode constituting a second capacitor. The differential capacitive MEMS pressure sensor comprises:

2. The method of manufacturing a differential capacitive MEMS pressure sensor according to claim 1, characterized in that, a substrate, an inner part of the substrate being provided with a first accommodating cavity with one end being open; a support body, one end of the support body being connected with the bottom of the first accommodating cavity and separating the first accommodating cavity into a second accommodating cavity and a third accommodating cavity; a fixed electrode, the fixed electrode comprising a first lower electrode and a second lower electrode, the first lower electrode being located at the bottom of the second accommodating cavity, and the second lower electrode being located at the bottom of the third accommodating cavity; a movable electrode, the movable electrode comprising a first upper electrode and a second upper electrode, the first upper electrode and the second upper electrode being an integral structure, the movable electrode being connected with the other end of the support body so that the first upper electrode is located above the first lower electrode and forms a first cavity, the first upper electrode and the first lower electrode constituting a first capacitor; the second upper electrode is located above the second lower electrode and forms a second cavity, the second cavity being a sealed cavity, the second upper electrode and the second lower electrode constituting a second capacitor; under the condition of applying a pressure load, the movement directions of the first upper electrode and the second upper electrode are opposite. The second cavity is a vacuum cavity.

3. The method of manufacturing a differential capacitive MEMS pressure sensor according to claim 2, characterized in that, The volumes of the second accommodating cavity and the third accommodating cavity are the same.

4. The method of manufacturing a differential capacitive MEMS pressure sensor according to claim 2, wherein, The support body and the movable electrode are integrally formed.

5. The method of manufacturing a differential capacitive MEMS pressure sensor according to claim 2, wherein, The material of the substrate is at least one of sapphire, silicon carbide and monocrystalline silicon.

6. The method of manufacturing a differential capacitive MEMS pressure sensor according to claim 2, wherein, The material of the fixed electrode is polysilicon.

7. The method of manufacturing a differential capacitive MEMS pressure sensor according to claim 2, wherein, The gap comprises a first gap and a second gap, the gap formed between the first upper electrode and the substrate along the length direction of the substrate being the first gap, and the gap formed between the first upper electrode and the substrate along the width direction of the substrate being the second gap, the second gap being distributed on both sides of the first upper electrode.

8. The method of manufacturing a differential capacitive MEMS pressure sensor according to claim 2, wherein, The size of the first gap is 10 μm, and the size of the second gap is 3 μm.

9. The method of manufacturing a differential capacitive MEMS pressure sensor according to claim 8, characterized in that, The method further comprises a pad, the pad comprising a fixed electrode pad and a movable electrode pad.

10. The method of manufacturing a differential capacitive MEMS pressure sensor according to claim 2, wherein, ​ A first metallized via is arranged in the substrate, a second metallized via is arranged in the support body, the fixed electrode is electrically connected to the fixed electrode pad through a first circuit in the first metallized via, and the first upper electrode is electrically connected to the movable electrode pad through a second circuit in the first metallized via and a third circuit in the second metallized via.

Images