Micro-electro-mechanical structure, MEMS sensor and electronic device

Abstract

A micro-electro-mechanical structure, a MEMS sensor and an electronic device. The micro-electro-mechanical structure comprises a structural layer; the structural layer comprises a sensing layer and an electrode layer which are stacked; a gap is formed between the sensing layer and the electrode layer; in a cross-section perpendicular to the height direction of the micro-electro-mechanical structure, the sensing layer comprises a first area, a second area and a first isolation gap; the first isolation gap separates the first area from the second area; the first area is provided with a first electrical connection point; the second area is used for sensing an external signal; a second electrical connection point is provided on the side of the electrode layer opposite to the first area; the first electrical connection point and the second electrical connection point are used for forming an electrical connection with the interior and / or the exterior of the micro-electro-mechanical structure.

Description

Microelectromechanical structures, MEMS sensors and electronic devices

[0001] This disclosure claims priority to Chinese patent application number 202410338002.5, filed with the Patent Office of China on March 22, 2024, entitled “Microelectromechanical structures, MEMS sensors and electronic devices,” the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present disclosure relates to a micro-electromechanical structure, a MEMS sensor and an electronic device. Background Art

[0003] In related technologies, MEMS inertial sensors, formed using micro-electromechanical systems (MEMS) technology, are widely used in electronic devices. In existing MEMS inertial sensors, to prevent wire bonding from interfering with the active MEMS structure, the bonding electrodes are typically placed a safe distance away from the active MEMS structure. This results in a non-functional area between the active MEMS structure and the bonding electrodes, resulting in wasted space. Summary of the Invention

[0004] In view of the above-mentioned shortcomings of the prior art, the purpose of the present disclosure is to provide a new technical solution for micro-electromechanical structures, MEMS sensors and electronic devices.

[0005] According to one aspect of the present disclosure, a micro-electromechanical structure is provided.

[0006] The micro-electromechanical structure comprises:

[0007] A structural layer, wherein the structural layer includes a stacked sensing layer and an electrode layer, a gap is provided between the sensing layer and the electrode layer, and along a cross section perpendicular to the height direction of the micro-electromechanical structure, the sensing layer includes a first region, a second region and a first isolation groove, the first isolation groove separates the first region and the second region, the first region is provided with a first electrical connection point, the second region is used to sense an input signal, the electrode layer is provided with a second electrical connection point on a side opposite to the first region, the first electrical connection point and the second electrical connection point are used to form an electrical connection with the interior and / or exterior of the micro-electromechanical structure, and the first region, the electrode layer and the gap together form a parallel plate capacitor.

[0008] Optionally, the structural layer further includes an insulating layer, wherein the insulating layer is provided between the sensing layer and the electrode layer, and the insulating layer forms the gap.

[0009] Optionally, the insulating layer is formed by a thinning process.

[0010] Optionally, the sensing layer is located above the electrode layer, the electrode layer includes at least one electrode area, and the second electrical connection point is provided in the electrode area.

[0011] Optionally, the electrode layer includes a plurality of electrode regions, and the plurality of electrode regions are arranged at intervals along a cross section perpendicular to a height direction of the micro-electromechanical structure.

[0012] Optionally, the electrode layer includes a third region and a fourth region connected to each other, the third region is opposite to the first region, the fourth region is opposite to the second region, and the first region, the third region and the gap together form a parallel plate capacitor.

[0013] Optionally, the electrode layer includes a third region, a fourth region and a second isolation groove, the second isolation groove separates the third region and the fourth region, the third region is opposite to the first region, the fourth region is opposite to the second region, and the first region, the third region and the gap together form a parallel plate capacitor.

[0014] Optionally, the third region has a different structure from the first region.

[0015] Optionally, the third area and / or the first area includes a plurality of rectangular strips arranged at intervals.

[0016] Optionally, the third region and / or the first region are in the shape of discrete points, S-shaped curves or spirals.

[0017] Optionally, the first electrical connection point is electrically connected to an electrical connection point in the second region, and / or the second electrical connection point is electrically connected to an electrical connection point in the fourth region.

[0018] Optionally, a substrate is further included, and the structural layer is arranged on the substrate.

[0019] Optionally, a cover plate is further included, wherein the cover plate is arranged on a side of the structural layer away from the substrate, and the cover plate covers the second area.

[0020] Optionally, the sensing layer includes but is not limited to a mass block and a diaphragm.

[0021] According to another aspect of the present disclosure, a MEMS sensor is provided, comprising the above-mentioned micro-electromechanical structure.

[0022] Optionally, the MEMS sensor is a MEMS inertial sensor, and along a cross section perpendicular to a height direction of the MEMS sensor, an area of ​​the structural layer is larger than an area of ​​the cover plate.

[0023] According to another aspect of the present disclosure, an electronic device is provided, comprising the above-mentioned micro-electromechanical structure or the above-mentioned MEMS sensor.

[0024] One technical effect of the embodiments of the present disclosure is:

[0025] The micro-electromechanical structure includes a structural layer, the structural layer includes a stacked sensing layer and an electrode layer, a gap is formed between the sensing layer and the electrode layer, along a cross section perpendicular to the height direction of the micro-electromechanical structure, the sensing layer includes a first region, a second region and a first isolation groove, the first isolation groove separates the first region and the second region, the first region is provided with a first electrical connection point, the second region is used to sense external signals, the electrode layer is provided with a second electrical connection point on a side opposite to the first region, the first electrical connection point and the second electrical connection point are used to form an electrical connection with the interior and / or exterior of the micro-electromechanical structure, and the first region, the electrode layer and the gap together form a parallel plate capacitor, which can be used as a bias voltage for the micro-electromechanical structure to save the setting of an external power supply. Moreover, since the parallel plate capacitor is located in the non-working area of ​​the structural layer, it can also avoid wasting space in the structural layer, thereby improving the space utilization rate of the structural layer.

[0026] Other features and advantages of the present disclosure will become apparent from the following detailed description of exemplary embodiments of the present disclosure with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0028] FIG1 is a top view of a micro-electromechanical structure according to an embodiment of the present disclosure;

[0029] FIG2 is a cross-sectional view at BB in FIG1 ;

[0030] FIG3 is a cross-sectional view at CC in FIG1 ;

[0031] FIG4 is a schematic diagram of an electrode layer according to an embodiment of the present disclosure;

[0032] FIG5 is a schematic diagram of another electrode layer according to an embodiment of the present disclosure;

[0033] FIG6 is an equivalent circuit diagram of a micro-electromechanical structure using an embodiment of the present disclosure;

[0034] FIG7 is another equivalent circuit diagram of a micro-electromechanical structure using an embodiment of the present disclosure;

[0035] FIG8 is a schematic diagram of another micro-electromechanical structure according to an embodiment of the present disclosure;

[0036] FIG9 is a schematic diagram of the electrode layer in FIG8 ;

[0037] FIG10 is a schematic diagram of another micro-electromechanical structure according to an embodiment of the present disclosure;

[0038] FIG11 is a top view of another micro-electromechanical structure according to an embodiment of the present disclosure;

[0039] FIG12 is a cross-sectional view at EE in FIG11 ;

[0040] FIG13 is a schematic diagram of the electrode layer in FIG12 .

[0041] Explanation of the accompanying drawings: 1. Sensing layer; 11. First region; 12. Second region; 13. First isolation trench; 2. Electrode layer; 21. Third region; 22. Fourth region; 23. Second isolation trench; 3. Insulating layer; 4. Substrate; 5. Cover plate. DETAILED DESCRIPTION

[0042] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that unless otherwise specifically stated, the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present disclosure.

[0043] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present disclosure, its application, or uses.

[0044] Techniques and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the techniques and equipment should be considered part of the specification.

[0045] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0046] It should be noted that like reference numerals and letters refer to like items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0047] As shown in FIG1 to FIG13 , the micro-electromechanical structure provided by the embodiment of the present disclosure includes:

[0048] A structural layer, wherein the structural layer includes a stacked sensing layer 1 and an electrode layer 2, with a gap between the sensing layer 1 and the electrode layer 2. Along a cross section perpendicular to the height direction of the microelectromechanical structure, the sensing layer 1 includes a first region 11, a second region 12 and a first isolation groove 13, the first isolation groove 13 separates the first region 11 and the second region 12, the first region 11 is provided with a first electrical connection point, and the second region 12 is used to sense an input signal, the electrode layer 2 is provided with a second electrical connection point on a side opposite to the first region 11, the first electrical connection point and the second electrical connection point are used to form an electrical connection with the interior and / or exterior of the microelectromechanical structure, and the first region 11, the electrode layer 2 and the gap together form a parallel plate capacitor.

[0049] As shown in Figures 2 and 3, the sensing layer 1 and the electrode layer 2 are typically stacked along the height direction of the MEMS structure and form the structural layer of the MEMS structure. The sensing layer 1, also known as the vibration layer, can be a mass or a diaphragm that vibrates in response to an input signal, and the electrode layer 2 can be a back plate.

[0050] In particular, along a cross section perpendicular to the height direction of the microelectromechanical structure, the sensing layer 1 may include a first region 11, a second region 12, and a first isolation trench 13. The second region 12 is the working region, and the first region 11 is the non-working region (the shaded area in FIG3 ). The first region 11 and the second region 12 may be separated and isolated by the first isolation trench 13, facilitating the use of the first region 11 as an upper or lower plate to form an independent capacitor. The second region 12 of the sensing layer 1 cooperates with the electrode layer 2 to respond to input signals, thereby realizing the sensing function of the MEMS sensor using this microelectromechanical structure.

[0051] On this basis, the embodiment of the present disclosure is provided with a first electrical connection point on the first region 11, and a second electrical connection point is provided on the side of the electrode layer 2 opposite to the first region 11. That is, the first electrical connection point and the second electrical connection point are opposite to each other, and both are located in the non-working area of ​​the micro-electromechanical structure, thereby forming an independent parallel plate capacitor, and facilitating the use of the first electrical connection point and the second electrical connection point to form an electrical connection with the inside and / or outside of the micro-electromechanical structure. In addition, the provision of the first isolation groove 13 can also isolate the parallel plate capacitor formed in the non-working area from the parallel plate capacitor in the working area, thereby improving the performance of the micro-electromechanical structure.

[0052] Furthermore, since the first region 11 is a non-operating area, the first and second electrical connection points are also located in the non-operating area of ​​the structural layer. This arrangement, on the one hand, avoids wasting space in the structural layer, improves space utilization, and enhances the performance of the MEMS structure; on the other hand, it prevents interference of circuit wiring with the operating area of ​​the structural layer, ensuring the operational reliability of the MEMS structure.

[0053] The first region 11, the region opposite to the electrode layer 2 and the first region 11, and the gap therebetween can form a parallel plate capacitor. The parallel plate capacitor can be used as a bias voltage for the micro-electromechanical structure and can save the need for an external power supply, thereby reducing the resistance and inductance caused by multiple external power supplies and improving the high-frequency noise filtering performance of the micro-electromechanical structure, as shown in FIG6 . One plate of the parallel plate capacitor is connected to an electrode inside the micro-electromechanical structure, and the other plate of the parallel plate capacitor is grounded to ensure safety. Furthermore, the parallel plate capacitor can also be used as a voltage divider impedance to meet the needs of multiple bias voltages, simplifying the circuit layout and reducing costs, as shown in FIG7 .

[0054] According to actual design requirements, the electrode layer 2 can be configured to include a complete electrode region, and the first region 11, the portion of the electrode layer 2 opposite the first region 11, and the gap therebetween can form an independent parallel plate capacitor. Alternatively, the electrode layer 2 can be configured to include two separate regions, and the first region 11, the region of the electrode layer 2 opposite the first region 11, and the gap therebetween can also form an independent parallel plate capacitor.

[0055] Optionally, the structural layer further includes an insulating layer 3 , which is disposed between the sensing layer 1 and the electrode layer 2 , and the insulating layer 3 forms the gap.

[0056] As shown in Figure 2, during the structural layer formation process, the electrode layer 2 is typically first deposited and etched, followed by the insulating layer 3 deposited and etched on the electrode layer 2, and finally, the sensing layer 1 is deposited and etched on the insulating layer 3. Insulating layer 3 is sandwiched between sensing layer 1 and electrode layer 2, providing isolation and support. While ensuring electrical insulation between the first electrical connection point of sensing layer 1 and the second electrical connection point of electrode layer 2, insulating layer 3 can also directly serve as the dielectric layer of a parallel plate capacitor.

[0057] Optionally, the insulating layer 3 is formed by a thinning process.

[0058] Specifically, since the capacitance value is negatively correlated with the distance between the two plates (i.e., the thickness of the dielectric layer), the insulating layer 3 is formed by a thinning process, that is, reducing the thickness of the insulating layer 3 (as shown in FIG10 ), which can correspondingly increase the capacitance value of the parallel plate capacitor, thereby improving the performance of the micro-electromechanical structure. During the thinning process, factors such as the voltage drop between the two layers and the breakdown electric field strength need to be considered to ensure that the insulating layer 3 formed after thinning has stable electrical properties and good mechanical strength.

[0059] Optionally, the sensing layer 1 is located above the electrode layer 2 , and the electrode layer 2 includes at least one electrode region, and the second electrical connection point is provided in the electrode region.

[0060] Specifically, the sensing layer 1 is located above the electrode layer 2. The sensing layer 1 is typically a vibrating element such as a mass or diaphragm that vibrates in response to an input signal. The electrode layer 2 is typically a backplate. The electrode layer 2 may include one, two, or even multiple electrode regions, each of which is provided with at least one second electrical connection point. These second electrical connection points enable the electrode layer 2 to be electrically connected to the interior and / or exterior of the microelectromechanical structure, saving circuit wiring design while ensuring the performance of the microelectromechanical structure.

[0061] Optionally, the electrode layer 2 includes a plurality of electrode regions, and the plurality of electrode regions are arranged at intervals along a cross section perpendicular to a height direction of the micro-electromechanical structure.

[0062] As shown in FIG5 , the electrode area on electrode layer 2 is partitioned to form multiple independent sub-electrode areas. Each sub-electrode area can be electrically connected to the interior and / or exterior of the micro-electromechanical structure via a second electrical connection point. This simplifies the wiring process while ensuring the performance of the micro-electromechanical structure. It also facilitates the independent operation of the multiple sub-electrode areas to avoid mutual interference. For example, as shown in FIG5 , in an acceleration MEMS sensor using this micro-electromechanical structure, the X-axis and Z-axis can be connected separately to form a shield between them.

[0063] Optionally, the electrode layer 2 includes a third region 21 and a fourth region 22 connected to each other, the third region 21 is opposite to the first region 11, and the fourth region 22 is opposite to the second region 12, and the first region 11, the third region 21 and the gap together form a parallel plate capacitor.

[0064] Specifically, according to actual design requirements, the electrode layer 2 can be set to include a connected third region 21 and a fourth region 22, that is, there is no need to separate and isolate the third region 21 and the fourth region 22, and the first region 11, the third region 21 and the gap between the two can form an independent parallel plate capacitor.

[0065] Among them, the connected third region 21 and fourth region 22 can be different parts of the same electrode region on the electrode layer 2, that is, there is no need to divide the electrode layer 2; the connected third region 21 and fourth region 22 can also be two different electrode regions separated on the electrode layer 2, and the two electrode regions are electrically connected, such as Figure 13.

[0066] Optionally, the electrode layer 2 includes a third region 21, a fourth region 22 and a second isolation groove 23, the second isolation groove 23 separates the third region 21 and the fourth region 22, the third region 21 is opposite to the first region 11, the fourth region 22 is opposite to the second region 12, and the first region 11, the third region 21 and the gap together form a parallel plate capacitor.

[0067] As shown in Figures 3 to 5, along a cross section perpendicular to the height of the microelectromechanical structure, the electrode layer 2 can include a third region 21, a fourth region 22, and a second isolation trench 23. The fourth region 22 is the working area, and the third region 21 is the non-working area (the shaded area in the figure). The third region 21 and the fourth region 22 can be separated and isolated by the second isolation trench 23, facilitating the use of the third region 21 as the upper or lower plate to form an independent capacitor. The fourth region 22 of the electrode layer 2 cooperates with the second region 12 of the sensing layer 1 to respond to input signals, thereby realizing the sensing function of the MEMS sensor using this microelectromechanical structure.

[0068] The first region 11 , the third region 21 and the gap therebetween can form an independent parallel plate capacitor, which can be used as a bias voltage for the micro-electromechanical structure and save the need for an external power supply.

[0069] Optionally, the third region 21 has a different structure from the first region 11 .

[0070] Specifically, the third region 21 is configured to have a different structure from the first region 11, for example, one of the third region 21 and the first region 11 is in the shape of a flat plate and the other is in the shape of a rectangular strip; or one of the third region 21 and the first region 11 is in the shape of a flat plate and the other is in the shape of a discrete point. Both of these can increase the area of ​​the effective electrode of the parallel plate capacitor, thereby increasing the capacitance value of the parallel plate capacitor and improving the performance of the microelectromechanical structure.

[0071] Optionally, the third area 21 and / or the first area 11 includes a plurality of rectangular strips arranged at intervals.

[0072] As shown in Figures 8 and 9, the third region 21 or the first region 11 can be configured to include a plurality of spaced rectangular strips, or the third region 21 and the first region 11 can each include a plurality of spaced rectangular strips. Both can fully utilize their side areas to increase the effective electrode area of ​​the parallel plate capacitor, thereby increasing the capacitance of the parallel plate capacitor and improving the performance of the microelectromechanical structure. Depending on the actual wiring method, the plurality of spaced rectangular strips can extend along the length or width of the electrode layer 2.

[0073] Optionally, the third region 21 and / or the first region 11 are in the shape of discrete points, S-shaped bends or spirals.

[0074] Specifically, the third region 21 can be set to be in the shape of discrete points, S-shaped bends or spirals, and the first region 11 can be set to be in the shape of discrete points, S-shaped bends or spirals. The first region 11 and the third region 21 can also be set to be in the shape of discrete points, S-shaped bends or spirals respectively, all of which can increase the area of ​​the effective electrode of the parallel plate capacitor, thereby increasing the capacitance value of the parallel plate capacitor, and also improving the performance of the microelectromechanical structure.

[0075] Optionally, the first electrical connection point is electrically connected to an electrical connection point in the second region 12 , and / or the second electrical connection point is electrically connected to an electrical connection point in the fourth region 22 .

[0076] As shown in Figures 11 to 13, the first electrical connection point can be set to be directly electrically connected to the electrical connection point (electrode) in the second area 12, and the second electrical connection point can be set to be directly electrically connected to the electrical connection point (electrode) in the fourth area 22. The first electrical connection point can also be set to be directly electrically connected to the electrical connection point (electrode) in the second area 12, and the second electrical connection point can be directly electrically connected to the electrical connection point (electrode) in the fourth area 22. Both can form electrical connections inside the structural layer and the electrodes inside its working area, saving solder joints and external wiring design, thereby reducing inductance and resistance, and improving the performance of the microelectromechanical structure.

[0077] In addition, by directly forming an electrical connection between the structural layer and its working area, the space on the structural layer can be fully utilized, which facilitates the miniaturization of the micro-electromechanical structure.

[0078] Optionally, as shown in FIG2 , a substrate 4 is further included, and the structural layer is provided on the substrate 4. The substrate 4 is used to support the structural layer above, and the substrate 4 provides a stable support and fixed platform for the MEMS structure, which helps to ensure the stability and reliability of the MEMS structure.

[0079] Optionally, a cover plate 5 is further included. The cover plate 5 is arranged on a side of the structural layer away from the substrate 4 , and the cover plate 5 covers the second area 12 .

[0080] As shown in FIG2 , the provision of the cover plate 5 not only protects the MEMS structure and prevents external contamination and damage, but also provides a closed environment for the working area of ​​the MEMS structure, thereby reducing the impact of environmental factors and improving its structural stability.

[0081] Furthermore, the cover plate 5 covers the second region 12, effectively sealing and protecting the working area formed by the second region 12 and the fourth region 22, ensuring that the MEMS structure effectively senses input signals. The first electrical connection point is located on the first region 11 outside the cover plate 5, preventing interference with the connection between the cover plate 5 and the structural layer, thereby improving the structural reliability of the MEMS structure.

[0082] Optionally, the sensing layer 1 includes but is not limited to a mass block and a diaphragm, so that different MEMS sensors can be formed accordingly.

[0083] The present disclosure also provides a MEMS sensor, including the above-mentioned micro-electromechanical structure. The MEMS sensor should have all the technical effects of the above-mentioned micro-electromechanical structure.

[0084] Optionally, the MEMS sensor is a MEMS inertial sensor, and along a cross section perpendicular to a height direction of the MEMS sensor, an area of ​​the structural layer is larger than an area of ​​the cover plate 5 .

[0085] Specifically, the MEMS sensor can be a capacitive MEMS inertial sensor, such as a capacitive accelerometer, a capacitive gyroscope, etc. Capacitive MEMS inertial sensors often require bonding multiple wafers to form a vacuum environment required for the device structure to work, that is, the area covered by the cover plate 5.

[0086] Wire bonding (i.e., setting electrical connection points) is typically used to connect the devices. The area of ​​the structural layer, along a cross section perpendicular to the height of the MEMS sensor, is larger than that of the cover plate 5. This facilitates the placement of electrical connection points outside the cover plate 5, preventing the fabrication process from interfering with the working area of ​​the MEMS sensor. This improves the reliability of the MEMS sensor and allows for full utilization of the internal space within the MEMS sensor.

[0087] The present disclosure also provides an electronic device including the aforementioned microelectromechanical structure or the aforementioned MEMS sensor, wherein the electronic device includes but is not limited to a mobile phone, a tablet, a computer, and the like.

[0088] The above embodiments focus on 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. Considering the simplicity of the text, they will not be repeated here.

[0089] Although some specific embodiments of the present disclosure have been described in detail by way of examples, those skilled in the art will appreciate that the above examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Those skilled in the art will appreciate that modifications may be made to the above embodiments without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. A micro-electromechanical structure comprising: A structural layer, the structural layer comprising a stacked sensing layer (1) and an electrode layer (2), a gap being provided between the sensing layer (1) and the electrode layer (2), the sensing layer (1) comprising a first region (11), a second region (12) and a first isolation groove (13) along a cross section perpendicular to the height direction of the micro-electromechanical structure, the first isolation groove (13) separating the first region (11) and the second region (12), the first region (11) being provided with a first electrical connection point, the second region (12) being used for sensing an input signal, the electrode layer (2) being provided with a second electrical connection point on a side opposite to the first region (11), the first electrical connection point and the second electrical connection point being used to form an electrical connection with the interior and / or exterior of the micro-electromechanical structure, and the first region (11), the electrode layer (2) and the gap forming a parallel plate capacitor together.

2. The micro-electromechanical structure according to claim 1, wherein: The structural layer further comprises an insulating layer (3), wherein the insulating layer (3) is arranged between the sensing layer (1) and the electrode layer (2), and the insulating layer (3) forms the gap.

3. The micro-electromechanical structure according to claim 2, wherein: The insulating layer (3) is formed through a thinning process.

4. The micro-electromechanical structure according to any one of claims 1 to 3, wherein: The sensing layer (1) is located above the electrode layer (2), and the electrode layer (2) comprises at least one electrode region, wherein the second electrical connection point is provided in the electrode region.

5. The micro-electromechanical structure according to claim 4, wherein: The electrode layer (2) comprises a plurality of electrode regions, and the plurality of electrode regions are arranged at intervals along a cross section perpendicular to the height direction of the micro-electromechanical structure.

6. The micro-electromechanical structure according to any one of claims 1 to 5, wherein: The electrode layer (2) comprises a third region (21) and a fourth region (22) connected to each other, the third region (21) being opposite to the first region (11), the fourth region (22) being opposite to the second region (12), and the first region (11), the third region (21) and the gap together forming a parallel plate capacitor.

7. The micro-electromechanical structure according to any one of claims 1 to 5, wherein: The electrode layer (2) comprises a third region (21), a fourth region (22) and a second isolation groove (23); the second isolation groove (23) separates the third region (21) and the fourth region (22); the third region (21) is positioned opposite to the first region (11); the fourth region (22) is positioned opposite to the second region (12); the first region (11), the third region (21) and the gap together form a parallel plate capacitor.

8. The micro-electromechanical structure according to claim 7, wherein: The third region (21) has a different structure from the first region (11).

9. The micro-electromechanical structure according to claim 7 or 8, wherein: The third area (21) and / or the first area (11) comprises a plurality of rectangular strips arranged at intervals.

10. The micro-electromechanical structure according to any one of claims 7 to 9, wherein: The third region (21) and / or the first region (11) are in the form of discrete points, S-shaped bends or spirals.

11. The micro-electromechanical structure according to any one of claims 6 to 10, wherein: The first electrical connection point is electrically connected to an electrical connection point in the second region (12), and / or the second electrical connection point is electrically connected to an electrical connection point in the fourth region (22).

12. The micro-electromechanical structure according to any one of claims 1 to 11, wherein: It also includes a substrate (4), and the structural layer is arranged on the substrate (4).

13. The micro-electromechanical structure according to claim 12, wherein: It also includes a cover plate (5), which is arranged on a side of the structural layer away from the substrate (4), and covers the second area (12).

14. The micro-electromechanical structure according to any one of claims 1 to 13, wherein: The sensing layer (1) includes but is not limited to a mass block and a diaphragm.

15. A MEMS sensor comprising the micro-electromechanical structure according to any one of claims 1 to 14.

16. The MEMS sensor according to claim 15, wherein: The MEMS sensor is a MEMS inertial sensor, and along a cross section perpendicular to the height direction of the MEMS sensor, the area of ​​the structural layer is larger than the area of ​​the cover plate (5).

17. An electronic device comprising the microelectromechanical structure according to any one of claims 1 to 14 or the MEMS sensor according to any one of claims 15 to 16.

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