MEMS device limiting structure

Abstract

The MEMS device limiting structure comprises an upper limiting structure and a lower limiting structure, the upper limiting structure is used for providing a reverse force for the device structure when the device structure moves towards the first direction, the third direction and the fourth direction, so that the impact resistance of the device structure in the X / Y direction is improved; the lower limiting structure is used for providing a reverse force for the device structure when the device structure moves towards the second direction so as to prevent the deformation quantity of the device structure from exceeding the maximum allowable deformation quantity; glue grooves are formed in the periphery of the limiting structure, the limiting structure is combined with the device structure in a gluing mode, the gap between the limiting structure and the device structure is accurately controlled within 10 micrometers, and therefore the product yield of the MEMS device is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of semiconductor, and particularly relates to a MEMS device limiting structure. BACKGROUND

[0002] Micro devices (MEMS, Micro-electro-mechanical-system) integrate micro mechanical structures, micro sensors, micro actuators and electrical systems on a chip, and play a vital role in modern technology, and are widely used in consumer electronics, medical devices, aerospace and Internet of Things (IoT) and other industries.

[0003] Micro devices are small in size, delicate in structure and sensitive to external impact, so their impact resistance is directly related to the stability and service life of the device; in the automotive industry, micro devices such as sensors / actuators need to resist shocks, vibrations and other impacts during vehicle operation to ensure the stable operation of the automotive electronic system, for example, vehicle sensors need to ensure normal operation under long-term vibration; in the aerospace and military fields, micro devices often need to work in extreme environments, such as high acceleration and high vibration, and impact resistance is a key factor to ensure mission success and equipment safety; for example, micro devices on satellites need to withstand the huge acceleration during launch.

[0004] As shown in Figure 1 , the existing limiting structure has no X / Y direction limiting, and the gap between the micromirror and the limiting structure is mainly controlled by two methods: one is to rely on the size of the silicon particles in the glue, as shown in Figure 1 (a), since particle stacking may occur, and the stacking has randomness, which may cause inconsistent glue thickness at different places, resulting in inconsistent gap size; and the thickness of the commonly used silicon particles in the industry is often a multiple of 10um, so the error of the gap at different places is also a multiple of 10um; the other is the etching step structure as shown in Figure 1 (b), the etching step still needs to be connected with the micromirror and the limiting structure through glue, and the consistency of the glue thickness is greatly affected by the equipment during die bonding, and the thickness error is generally at the level of 10um; considering the etching error on the limiter (1 (better level in the industry) ~ 5 (general level in the industry) um), the error of the gap at different places is at least >11um; The movement stroke of the micro device itself is at the um level, if the gap is smaller than the design value, it may cause the normal movement of the micro device to be blocked, and the function cannot be completed; if the gap is larger than the design value, the limiting device may not be able to prevent the micro device from moving too much.

[0005] Therefore, how to improve the shock resistance of MEMS devices in the X / Y direction and control the gap error within 10µm has become an urgent problem to be solved. Summary of the Invention

[0006] This application provides a MEMS device limiting structure, including an upper limiting structure and a lower limiting structure. The upper limiting structure provides a reverse force to the device structure when it moves in the first, third, and fourth directions, further improving the impact resistance of the device structure in the X / Y directions. The lower limiting structure provides a reverse force to the device structure when it moves in the second direction, so as to prevent the deformation of the device structure from exceeding the maximum allowable deformation. Furthermore, adhesive grooves are provided around the limiting structure, which is bonded to the device structure by adhesive bonding, precisely controlling the gap between the limiting structure and the device structure within 10µm, thereby improving the product yield of the MEMS device.

[0007] Other objects and advantages of the present invention can be further understood from the technical features disclosed herein.

[0008] To achieve one or more of the above objectives or other objectives, the present invention provides a MEMS device limiting structure.

[0009] A MEMS device limiting structure includes: an upper limiting structure and a lower limiting structure; The upper limit structure is used to provide a reverse force to the device structure when it moves toward the first direction, the third direction, and the fourth direction; the lower limit structure is used to provide a reverse force to the device structure when it moves toward the second direction, so as to prevent the deformation of the device structure from exceeding the maximum allowable deformation. The limiting structure is provided with adhesive grooves on all four sides, and is bonded to the device structure by adhesive bonding.

[0010] The upper limit structure is glued to the top of the device structure and includes a surrounding limit post. The left and right sides of the limit post are respectively etched to form a first step and a second step. The first step includes a first step and an adhesive groove, and the second step includes a second step. The lower limit structure is glued to the bottom of the device structure, and a first groove is provided at the center position, and an adhesive groove is provided on the outside of the first groove.

[0011] The first step of the first step portion is close to the limiting post, and the glue groove of the first step portion is disposed at the edge of the upper limit structure.

[0012] The device structure includes a rigid structure, a flexible structure, and a frame. The flexible structure is used to drive the rigid structure to move, and the frame is used to support and drive the flexible structure.

[0013] The limiting post is inserted into the gap between the rigid structure and the frame, and is used to provide a reverse force to the device structure when the device structure moves in the third and fourth directions; and the height of the limiting post is less than the depth of the gap.

[0014] The width of the first groove is at least the same as the width of the flexible structure, the depth of the first groove is the same as the depth of the adhesive groove, and the depth of the first groove is not greater than 2 / 3 of the height of the lower limit structure.

[0015] The adhesive groove is a quadrilateral structure and is located at the edge of the limiting structure.

[0016] Several columnar structures are symmetrically arranged at the center of the glue tank.

[0017] The lower limiting structure is etched to form a second groove arranged in a circumferential shape, and an adhesive groove is provided at the edge. The depth of the second groove is the same as the depth of the adhesive groove, and the depth of the second groove is not greater than 2 / 3 of the height of the lower limiting structure.

[0018] A through hole penetrating the lower limiting structure is etched at the center of the first groove.

[0019] Several protruding structures covering the edge of the rigid structure are symmetrically arranged at the center of the upper limit structure to provide a reverse force when the MEMS device moves toward the first direction.

[0020] The upper limit structure is provided with several elastic beam structures, which connect the protruding structure. The upper limit structure and the rigid structure achieve flexible contact through the elastic beam structures.

[0021] Compared with the prior art, the beneficial effects of the present invention mainly include: This application provides a MEMS device limiting structure, including an upper limiting structure and a lower limiting structure. The upper limiting structure provides a reverse force to the device structure when it moves in the first, third, and fourth directions, further improving the impact resistance of the device structure in the X / Y directions. The lower limiting structure provides a reverse force to the device structure when it moves in the second direction, so as to prevent the deformation of the device structure from exceeding the maximum allowable deformation. Furthermore, adhesive grooves are provided around the limiting structure, which is bonded to the device structure by adhesive bonding, precisely controlling the gap between the limiting structure and the device structure within 10µm, thereby improving the product yield of the MEMS device.

[0022] To make the above and other objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the specific embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 A schematic diagram of the micromirror limiting structure provided for the background technology of this application.

[0025] Figure 2 This is a cross-sectional view of the MEMS device structure provided in Embodiment 1 of this application.

[0026] Figure 3 This is a top view of the MEMS device structure provided in Embodiment 1 of this application.

[0027] Figure 4 This is a cross-sectional view of the upper limit structure provided in Embodiment 1 of this application.

[0028] Figure 5 This is a cross-sectional view of the lower limit structure provided in Embodiment 1 of this application.

[0029] Figure 6 Top view of the upper limit structure provided in Embodiment 1 of this application Figure 1 .

[0030] Figure 7 Top view of the upper limit structure provided in Embodiment 1 of this application Figure 2 .

[0031] Figure 8 Top view of the upper limit structure provided in Embodiment 1 of this application Figure 3 .

[0032] Figure 9 This is a flowchart illustrating the fabrication process of the lower limit structure provided in Embodiment 1 of this application.

[0033] Figure 10 The flowchart shows the preparation process of the upper limit structure provided in Embodiment 1 of this application.

[0034] Figure 11 This is a flowchart illustrating the fabrication process of the lower limit structure provided in Embodiment 2 of this application.

[0035] Figure 12 The flowchart for the preparation of the upper limit structure provided in Embodiment 2 of this application is shown.

[0036] Figure 13 This is a flowchart illustrating the preparation process of the lower limit structure provided in Embodiment 3 of this application.

[0037] Figure 14 This is a flowchart illustrating the preparation process of the lower limit structure provided in Embodiment 4 of this application.

[0038] Figure 15 This is a top view of the MEMS device structure provided in Embodiment 5 of this application.

[0039] Figure 16 This is a top view of the MEMS device structure provided in Embodiment 6 of this application.

[0040] Figure 17 The flowchart for the preparation of the upper limit structure provided in Embodiment 7 of this application is shown. Detailed Implementation

[0041] The foregoing and other technical contents, features, and effects of the present invention will be clearly presented in the following detailed description of a preferred embodiment with reference to the accompanying drawings. The directional terms mentioned in the following embodiments, such as up, down, left, right, front, or back, are merely for reference to the accompanying drawings. Therefore, the directional terms used are for illustrative purposes and not for limiting the present invention.

[0042] The embodiments of this application will now be described in detail with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the embodiments of this application to facilitate a better understanding of the application. However, the technical solutions claimed in this application can be implemented even without these technical details and various variations and modifications based on the following embodiments.

[0043] Example 1 like Figure 2 As shown, a MEMS device limiting structure includes: an upper limiting structure 4 and a lower limiting structure 5; the upper limiting structure 4 is used to provide a reverse force to the device structure when it moves toward the first direction, the third direction and the fourth direction, and the lower limiting structure 5 is used to provide a reverse force to the device structure when it moves toward the second direction, so as to prevent the deformation of the device structure from exceeding the maximum allowable deformation; adhesive grooves 6 are provided around the limiting structure, and the limiting structure is bonded to the device structure by adhesive method.

[0044] Specifically, such as Figure 2 As shown, there are adhesive grooves 6 on the edges of both the upper limit structure 4 and the lower limit structure 5. When bonding, the adhesive is applied in the adhesive grooves 6. During bonding, due to capillary effect, most of the adhesive will move to the edge, and the final error caused by the adhesive thickness is <5um. At the same time, considering the etching error of the upper limit structure (1 (good level in the industry) ~ 5um (general level in the industry)), the error of the gaps at various places can often be controlled within 10um.

[0045] like Figure 3As shown, the device structure includes a rigid structure 1, a flexible structure 2, and a frame 3. The flexible structure 2 is used to drive the rigid structure 1 to deflect, and the frame 3 is used to support and drive the flexible structure 2. When an impact occurs, the flexible structure 2 deforms, which in turn causes the rigid structure 1 to deform. The greater the deformation, the greater the stress generated, and the easier it is for the material to break. The presence of the limiting structure can limit the deformation of each component of the device structure, so that the stress is controlled within a safe range, thereby ensuring the integrity of the device structure.

[0046] The limiting structure is made of semiconductor material, preferably silicon. In the embodiments of this application, the first direction is the +Z direction, the second direction is the -Z direction, and the third and fourth directions are the X / Y directions. Among them, the upper limiting structure 4 mainly improves the impact resistance in the +Z direction and the X / Y direction, and the lower limiting structure 5 mainly improves the impact resistance in the -Z direction.

[0047] The first direction is the direction in which the flexible structure 2 moves toward the rigid structure 1; the maximum allowable deformation is the maximum deformation of the stress concentration area when the flexible structure 2 causes the rigid structure 1 to deform.

[0048] Specifically, the frame 3 is used to support the remaining structures and may contain circuit structures to drive the flexible structure 2 or transmit electrical signals. It often has high stiffness and is not easily deformed. The flexible structure 2 is often composed of a combination of beams, membranes, and other structures. It often has low stiffness and is easily deformed. The rigid structure 1 is often composed of a structure with a certain mass to accomplish a specific purpose. For example, the deflection of the flexible structure 2 causes the mirror of the rigid structure 1 to deflect; or the deflection of the flexible structure 2 causes the rigid structure 1, which acts as a mass block, to deflect, thereby forming stress concentration areas in some parts of the flexible structure 2. The device structure is made of semiconductor materials, preferably silicon. There may be metals for electrical connection with the outside world, such as aluminum, gold, platinum, molybdenum, copper, titanium, etc. There may be different driving methods to actuate the flexible structure 2, such as piezoelectric, electrostatic, electromagnetic, and electrothermal driving. There may also be a passivation layer to protect specific structures, which is composed of a single layer of silicon dioxide / silicon nitride or a composite silicon dioxide / silicon nitride film.

[0049] like Figure 4 As shown, the upper limit structure 4 is glued to the top of the device structure and includes a limit post 40 arranged in a ring. A first step portion and a second step portion are respectively etched on the left and right sides of the limit post. The first step portion includes a first step 41 and a glue groove 6, and the second step portion includes a second step 42. The first step 41 is close to the limit post 40, and the glue groove 6 is disposed at the edge of the upper limit structure 4. like Figure 2 As shown, the limiting post 40 passes through the gap between the rigid structure 1 and the frame 3, and is used to provide a reverse force to the device structure when the device structure moves in the third and fourth directions; and the height of the limiting post 40 is less than the depth of the gap.

[0050] like Figure 5 As shown, the lower limit structure 5 is glued to the bottom of the device structure, and a first groove 51 is provided at the center position. A glue groove 6 is provided on the outside of the first groove 51. The width of the first groove 51 is at least the same as the width of the flexible structure 2, and the depth is the same as the depth of the glue groove 6. The depth of the first groove 51 is not greater than 2 / 3 of the height of the lower limit structure 5.

[0051] like Figure 6 As shown, in a preferred embodiment of the present invention, the shape of the glue groove 6 in this embodiment can be designed in various ways, with multiple trapezoidal / rectangular structures arranged around the limiting structure, all of which can play a similar role.

[0052] like Figure 7 As shown, in a preferred embodiment of the present invention, the limiting structure retains several un-etched portions in the middle, thereby forming a columnar structure in the adhesive groove 6. The un-etched portions can be regular structures such as circles or squares, or irregular structures.

[0053] like Figure 8 As shown, in a preferred embodiment of the present invention, the edge of the limiting structure is cut open to form a ring of adhesive groove 6.

[0054] A method for fabricating a MEMS device constraint structure, comprising: The lower limit structure 5 and the upper limit structure 4 are prepared, and the upper limit structure 4, the device structure and the lower limit structure 5 are glued together simultaneously or stepwise. like Figure 9 As shown, the fabrication process of the lower limit structure 5 is as follows: Step S1: Provide a semiconductor substrate 10; Step S2: An oxide layer 11 is formed on the surface of the semiconductor substrate 10 by thermal oxidation, LPCVD, and PECVD processes. The oxide layer 11 is silicon dioxide and has a thickness of <3µm. Step S3: Photolithography and etching are performed on the front side of the semiconductor substrate 10 to form the first groove 51 and the adhesive groove 6; Step S4: Remove oxide layer 11; like Figure 10 As shown, the fabrication process of the upper limit structure 4 is as follows: Step S1: Provide a semiconductor substrate 10; Step S2: An oxide layer 11 is formed on the surface of the semiconductor substrate 10 by thermal oxidation, LPCVD, and PECVD processes. The oxide layer 11 is silicon dioxide and has a thickness of <3µm. Steps S3-S4: Photolithography and etching are performed multiple times on the front side of the semiconductor substrate 10 to form a first step portion and a second step portion; the first step portion includes a first step 41 and a glue groove 6, and the second step portion includes a second step 42; the first step 41 is close to the limiting post 40, and the glue groove 6 is disposed at the edge of the upper limit structure 4. Step S5: Perform photolithography and etching on the back side of the semiconductor substrate 10 to etch through the semiconductor substrate 10; Step S6: Remove oxide layer 11.

[0055] Example 2 The limiting structure can be fabricated from an SOI wafer, which includes a bottom silicon layer 7, a buried oxide layer 8, and a device layer 9 arranged sequentially from bottom to top. The buried oxide layer 8 is a silicon dioxide layer with a thickness of typically <3µm. During the fabrication of the SOI wafer itself, the thickness error of the device layer 9 can be controlled to <1µm. During the etching process of fabricating the limiting structure, the buried oxide layer 8 itself acts as a barrier layer to prevent over-etching. Therefore, the etching depth can be defined by defining the thickness of the device layer 9. Finally, considering the gap error caused by the adhesive bonding method (<5µm), the overall gap error can be controlled to <6µm.

[0056] The preparation process of the lower limit structure 5 is as follows: Figure 11 As shown, it includes: Step S1: Provide SOI wafers; Step S2: An oxide layer 11 is formed on the surface of the SOI wafer through thermal oxidation, LPCVD, and PECVD processes. The oxide layer 11 is silicon dioxide with a thickness of <3µm. Step S3: Photolithography and etching are performed on the front side of the SOI wafer to form the first groove 51 and the resist groove 6; Step S4: Remove oxide layer 11; The preparation process of upper limit structure 4 is as follows Figure 12 As shown, it includes: Step S1: Provide SOI wafers; Step S2: An oxide layer 11 is formed on the surface of the SOI wafer through thermal oxidation, LPCVD, and PECVD processes. The oxide layer 11 is silicon dioxide with a thickness of <3µm. Steps S3-S4: Multiple photolithography and etching processes are performed on the front side of the SOI wafer to form a first step portion and a second step portion; the first step portion includes a first step 41 and a resist groove 6, the first step 41 is close to the limiting post 40, and the resist groove 6 is disposed at the edge of the upper limit structure 4; the first step 41 is etched and formed on the device layer 9, and the resist groove 6 is etched and stopped at the buried oxide layer 8; the second step portion includes a second step 42, and the second step 42 is etched and stopped at the buried oxide layer 8; Step S5: Perform photolithography and etching on the back side of the SOI wafer to etch through the SOI wafer; Step S6: Remove oxide layer 11.

[0057] Example 3 The preparation process of the lower limit structure 5 is as follows: Figure 13 As shown, the lower limit structure 5 is etched to form a second groove 52 arranged in a ring shape, and an adhesive groove 6 is provided on the edge. The depth of the second groove 52 is the same as the depth of the adhesive groove 6, and the depth of the second groove 52 is not greater than 2 / 3 of the height of the lower limit structure 5. This structure is suitable for flexible structures 2 that are relatively fragile and cannot be directly hard contacted, such as beams and membrane structures.

[0058] Example 4 The preparation process of the lower limit structure 5 is as follows: Figure 14 As shown, the lower limit structure 5 is glued to the bottom of the device structure. A first groove 51 is provided at the center position. Adhesive grooves 6 are symmetrically provided on the outer side of the first groove 51. A through hole 53 penetrating the lower limit structure is etched at the center position of the first groove 51.

[0059] This structure is applicable to the following three situations: 1. Align the lower limit structure 5 with the device structure; 2. The flexible structure is easy to observe during use; 3. Reduce the stiffness of the lower limit structure 5 so that the contact between the lower limit structure 5 and the flexible structure 2 is a soft contact.

[0060] Example 5 Upper limit structure 4, as shown Figure 15 As shown, several protruding structures 40 covering the edge of the rigid structure 1 are symmetrically arranged at the center of the upper limit structure 4, providing a reverse force when the MEMS device moves toward the first direction.

[0061] Specifically, the upper limit structure 4 does not completely wrap the edge of the rigid structure 1, but uses a protruding structure 40 to cover part of the edge of the rigid structure 1. The number of protruding structures 40 can be determined according to actual needs. The protruding structure 40 can be a conventional structure or an irregular structure such as a square, rectangle, triangle, or semicircle. It only needs to cover the edge of the rigid structure 1 to play a blocking role.

[0062] This structure is applicable in the following two situations: 1. Align the upper limit structure 4 with the device structure; 2. The rigid structure 1 should be kept as unobstructed as possible.

[0063] Example 6 Upper limit structure 4, as shown Figure 16As shown, the upper limit structure 4 uses several flexible and discontinuous elastic beam structures 42. The elastic beam structures 42 connect the main body of the upper limit structure 4 and the protruding structure 40. The elastic beam structures 42 are made of flexible materials, which reduces stiffness and allows the upper limit structure 4 and the rigid structure 1 to make flexible contact through the elastic beam structures 42, reducing the possibility of damage to both. The length, width and shape of the elastic beam structures 42 can be designed according to actual needs.

[0064] Example 7 The upper limit structure 4 does not undergo back-side photolithography or etching processes, completely covering the underlying rigid structure 1. This makes it suitable for devices that do not require contact with the outside environment, and the fully enclosed structure can maximize resistance to the impact forces of the rigid structure 1. The fabrication process of the upper limit structure 4 is as follows: Figure 17 As shown, it includes: Step S1: Provide SOI wafers; Step S2: An oxide layer 11 is formed on the surface of the SOI wafer through thermal oxidation, LPCVD, and PECVD processes. The oxide layer 11 is silicon dioxide with a thickness of <3µm. Steps S3-S4: Multiple photolithography and etching processes are performed on the front side of the SOI wafer to form a first step portion and a second step portion; the first step portion includes a first step 41 and a resist groove 6, the first step 41 is close to the limiting post 40, and the resist groove 6 is disposed at the edge of the upper limit structure 4; the first step 41 is etched and formed on the device layer 9, and the resist groove 6 is etched and stopped at the buried oxide layer 8; the second step portion includes a second step 42, and the second step 42 is etched and stopped at the buried oxide layer 8; Step S5: Remove oxide layer 11.

[0065] In summary, this application provides a MEMS device limiting structure, including an upper limiting structure and a lower limiting structure. The upper limiting structure provides a reverse force to the device structure when it moves in the first, third, and fourth directions, further improving the impact resistance of the device structure in the X / Y directions. The lower limiting structure provides a reverse force to the device structure when it moves in the second direction to prevent the deformation of the device structure from exceeding the maximum allowable deformation. Furthermore, adhesive grooves are provided around the limiting structure, which is bonded to the device structure by adhesive bonding, precisely controlling the gap between the limiting structure and the device structure to within 10µm, thereby improving the product yield of the MEMS device.

[0066] The common English terms or letters used in this invention for clarity of description are for illustrative purposes only and are not limiting interpretations or specific uses. They should not be used to limit the scope of protection of this invention based on their possible Chinese translations or specific letters.

[0067] It should also be noted that in this article, relational terms such as “first” and “second” are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

Claims

1. A MEMS device limiting structure, characterized in that, The application relates to a MEMS device limiting structure. The upper limiting structure provides reverse force for the device structure when the device structure moves towards the first direction, the third direction and the fourth direction. The lower limiting structure provides reverse force for the device structure when the device structure moves towards the second direction, so as to avoid the deformation of the device structure exceeding the maximum allowable deformation. The limiting structure is provided with a glue groove around the limiting structure, and the limiting structure is combined with the device structure through the glue groove. The upper limiting structure is glued to the upper side of the device structure, and the upper limiting structure is provided with a limiting column in a surrounding manner.

2. The MEMS device stop structure of claim 1, wherein, The lower limiting structure is glued to the lower side of the device structure, and the lower limiting structure is provided with a first groove at a central position. The first step of the first step part is close to the limiting column, and the glue groove of the first step part is arranged at the edge of the upper limiting structure.

3. The MEMS device stop structure of claim 2, wherein, The device structure comprises a rigid structure, a flexible structure and a frame.

4. The MEMS device stop structure of claim 2, wherein, The limiting column is arranged in the gap between the rigid structure and the frame, and the limiting column provides reverse force for the device structure when the device structure moves towards the third direction and the fourth direction.

5. The MEMS device stop structure of claim 4, wherein, The height of the limiting column is smaller than the depth of the gap. The width of the first groove is at least the same as the width of the flexible structure.

6. The MEMS device stop structure of claim 4, wherein, The glue groove is a quadrilateral structure and is arranged at the edge of the limiting structure.

7. The MEMS device stop structure of claim 1, wherein, A plurality of columnar structures are symmetrically arranged at the central position of the glue groove.

8. The MEMS device stop structure of claim 7, wherein, The lower limiting structure is etched and provided with a second groove in a surrounding manner.

9. The MEMS device stop structure of claim 1, wherein, A through hole is etched at the central position of the first groove and penetrates the lower limiting structure.

10. The MEMS device stop structure of claim 2, wherein, The upper limiting structure is symmetrically provided with a plurality of protruding structures covering the edges of the rigid structure at the central position of the upper limiting structure.

11. The MEMS device stop structure of claim 4, wherein, The upper limiting structure is provided with a plurality of elastic beam structures.

12. The MEMS device stop structure of claim 11, wherein, The elastic beam structures connect the protruding structures, and the upper limiting structure and the rigid structure are flexibly contacted through the elastic beam structures.

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