MEMS device, cantilever beam structure and preparation method of cantilever beam structure

Abstract

The invention provides an MEMS device, a cantilever beam structure and a preparation method thereof, and relates to the technical field of semiconductors. The cantilever beam structure comprises a supporting seat and a cantilever beam, the supporting seat is provided with a first through cavity, the first through cavity penetrates through two opposite surfaces of the supporting seat, a part of area of the cantilever beam is attached to the upper surface of the supporting seat, and the other part of area of the cantilever beam is suspended above the first through cavity. A gap is formed between the side surface of the cantilever beam and the supporting seat and / or the other cantilever beam; the side wall of the first through cavity comprises an arc side wall, the arc side wall is connected with the surface, facing the first through cavity, of the cantilever beam, and the included angle between the tangent line of the connecting point of the arc side wall and the cantilever beam and the surface, facing the first through cavity, of the cantilever beam ranges from 90 degrees to 180 degrees. According to the cantilever beam structure, the fracture probability of the cantilever beam during upward deflection can be remarkably reduced.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a MEMS device, a cantilever beam structure and a preparation method thereof. Background Art

[0002] Micro-Electro-Mechanical Systems (MEMS) piezoelectric cantilever beams are the key basic structures in MEMS devices and systems and can be used in switches, resonators, sensors, etc. From a structural point of view, please refer to Figure 1 One end of the MEMS piezoelectric cantilever beam 10 is fixed on the fixed support base 20, defined as the fixed end 11, and the other end is suspended above the cavity 21 of the fixed support base 20 and can vibrate or bend freely, defined as the free end 12.

[0003] Affected by the morphology of the cavity sidewall, the angle between the MEMS piezoelectric cantilever beam 10 and the fixed support base 20 in the prior art is not a right angle under the ideal design state, but an acute angle. Figure 2 When the MEMS piezoelectric cantilever beam 10 is impacted by the vertical airflow from the cavity 21 and deflected upward, it will break to varying degrees. Summary of the Invention

[0004] The purpose of the present application is to provide a MEMS device, a cantilever beam structure and a preparation method thereof, in order to address the deficiencies in the above-mentioned prior art, which can reduce the probability of the cantilever beam breaking when it deflects upward.

[0005] To achieve the above objectives, the technical solutions adopted in the embodiments of the present application are as follows:

[0006] According to a first aspect of an embodiment of the present application, a cantilever beam structure is provided, comprising: a support seat and a cantilever beam, wherein a first through-cavity is provided on the support seat, the first through-cavity passes through two opposite surfaces of the support seat, a partial area of ​​the cantilever beam is in contact with the upper surface of the support seat, and another partial area is suspended above the first through-cavity, and a gap is provided between the side surface of the cantilever beam and the support seat and / or another cantilever beam; the side wall of the first through-cavity comprises an arc side wall, the arc side wall is connected to the surface of the cantilever beam facing the first through-cavity, and the angle between the tangent of the connection point between the arc side wall and the cantilever beam and the surface of the cantilever beam facing the first through-cavity is 90° to 180°.

[0007] Optionally, the arc sidewall has a first edge connected to the cantilever beam and a second edge opposite to the first edge, and the orthographic projection of the first edge on the cantilever beam is located within the orthographic projection of the second edge on the cantilever beam.

[0008] Optionally, the arc sidewall has a first edge connected to the cantilever beam and a second edge opposite to the first edge, and the orthographic projection of the first edge on the cantilever beam is outside the orthographic projection of the second edge on the cantilever beam.

[0009] Optionally, the arc side wall is tangent to the surface of the cantilever beam facing the first through cavity.

[0010] Optionally, an angle between a tangent line of a connection point between the arc side wall and the cantilever beam and a surface of the cantilever beam facing the first through cavity is 110° to 165°.

[0011] Optionally, it also includes a base, which is connected to the lower surface of the support base. A second through cavity is provided on the base, and the second through cavity passes through two opposite surfaces of the base. The edge of the second through cavity on the lower surface of the support base is located within the edge of the first through cavity on the lower surface of the support base.

[0012] According to a second aspect of an embodiment of the present application, a method for preparing a cantilever beam structure is provided, comprising: providing a support layer and forming a cantilever beam pattern on the upper surface of the support layer; etching the support layer to obtain a support seat having a first through-cavity, wherein the first through-cavity releases the cantilever beam pattern to obtain a cantilever beam, wherein a gap is provided between the side surface of the cantilever beam and the support seat and / or another cantilever beam; the side wall of the first through-cavity comprises an arc side wall, which is connected to the surface of the cantilever beam facing the first through-cavity; the angle between the tangent of the connection point between the arc side wall and the cantilever beam and the surface of the cantilever beam facing the first through-cavity is 90° to 180°.

[0013] Optionally, etching the support layer includes: etching the support layer using an isotropic etching process to obtain a first through cavity having an arc sidewall.

[0014] Optionally, providing a support layer and forming a cantilever beam pattern on the upper surface of the support layer includes: providing a base layer, and sequentially forming a support layer and a cantilever beam pattern on the base layer; etching the support layer to obtain a support seat having a first through-cavity includes: etching the base layer to obtain a base having a second through-cavity, wherein the second through-cavity passes through two opposite surfaces of the base layer; etching the support layer through the second through-cavity to obtain a support seat having a first through-cavity.

[0015] According to a third aspect of the embodiments of the present application, a MEMS device is provided, comprising a cantilever beam structure as described above.

[0016] The beneficial effects of this application include:

[0017] The present application provides a cantilever beam structure, comprising: a support base and a cantilever beam, wherein the support base is provided with a first through-hole, the first through-hole extending through two opposing surfaces of the support base; a portion of the cantilever beam is in contact with the upper surface of the support base, while another portion is suspended above the first through-hole; a gap is provided between the side surface of the cantilever beam and the support base and / or another cantilever beam; the sidewalls of the first through-hole include arcuate sidewalls, which are connected to the surface of the cantilever beam facing the first through-hole, and the angle between the tangent of the arcuate sidewall and the surface of the cantilever beam facing the first through-hole is between 90° and 180°. This arrangement can significantly improve the cantilever beam's resistance to airflow from the first through-hole and reduce the probability of the cantilever beam breaking when it deflects upward. Furthermore, the larger the angle between the tangent of the arcuate sidewall at the connection point and the surface of the cantilever beam facing the first through-hole, the stronger the cantilever beam's resistance to airflow impact. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 A schematic diagram of a cantilever beam structure in the prior art;

[0020] Figure 2 A schematic diagram of a cantilever beam structure in the prior art bending upward after being impacted by airflow;

[0021] Figure 3 One of the structural schematic diagrams of the cantilever beam structure provided in an embodiment of the present application;

[0022] Figure 4 The second structural diagram of the cantilever beam structure provided in the embodiment of the present application;

[0023] Figure 5 The third structural diagram of the cantilever beam structure provided in the embodiment of the present application;

[0024] Figure 6 The fourth structural diagram of the cantilever beam structure provided in the embodiment of the present application;

[0025] Figure 7 The fifth structural diagram of the cantilever beam structure provided in the embodiment of the present application;

[0026] Figure 8 The sixth structural diagram of the cantilever beam structure provided in the embodiment of the present application;

[0027] Figure 9 for Figure 1 、 Figure 3 and Figure 8 Schematic diagram of the maximum stress generated at the stress concentration point when the three structures are impacted by the same airflow;

[0028] Figure 10 One of the topographic images of the cantilever beam structure provided in an embodiment of the present application;

[0029] Figure 11 A schematic structural diagram of a support seat in a cantilever beam structure provided in an embodiment of the present application;

[0030] Figure 12 The second morphology diagram of the cantilever beam structure provided in the embodiment of the present application;

[0031] Figure 13 One of the preparation flow charts of the cantilever beam structure provided in the embodiment of the present application;

[0032] Figure 14 One of the schematic diagrams of the preparation process of the cantilever beam structure provided in the embodiment of the present application;

[0033] Figure 15 The seventh structural diagram of the cantilever beam structure provided in the embodiment of the present application;

[0034] Figure 16 The second flow chart of the preparation of the cantilever beam structure provided in the embodiment of the present application;

[0035] Figure 17 The second schematic diagram of the preparation process of the cantilever beam structure provided in the embodiment of the present application;

[0036] Figure 18 The third schematic diagram of the preparation process of the cantilever beam structure provided in the embodiment of the present application.

[0037] Icon: 10-MEMS piezoelectric cantilever; 11-fixed end; 12-free end; 20-fixed support seat; 21-cavity; 100-cantilever beam structure; 110-support seat; 111-first through-cavity; 1111-arc sidewall; 1111a-first edge; 1111b-second edge; 120-cantilever beam; 121-fixed area; 122-free area; 130-gap; 140-base; 141-second through-cavity; 200-support layer; 300-cantilever beam pattern; 400-base layer; β-angle between the tangent of the connection point between the arc sidewall and the cantilever and the surface of the cantilever beam facing the first through-cavity. DETAILED DESCRIPTION

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Generally, the components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0039] Therefore, the following detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application as claimed, but merely represents selected embodiments of the present application. It should be noted that, unless there is a conflict, the various features of the embodiments of the present application may be combined with each other, and the combined embodiments are still within the scope of protection of the present application.

[0040] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0041] In the description of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the product of this application is typically placed when in use. These terms are intended only to facilitate the description of this application and simplify the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this application. Furthermore, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0042] It should also be noted that, in the description of this application, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0043] In one aspect of the embodiment of this application, please refer to Figure 3 and Figure 4, provides a cantilever beam structure 100, comprising: a support base 110 and a cantilever beam 120. A first through cavity 111 is provided on the support base 110, and the first through cavity 111 passes through two opposite surfaces of the support base 110. Part of the cantilever beam 120 is in contact with the upper surface of the support base 110, and the other part is suspended above the first through cavity 111. A gap 130 is provided between the side surface of the cantilever beam 120 and the support base 110 and / or another cantilever beam 120. The side wall of the first through cavity 111 comprises an arc side wall 1111, which is connected to the surface of the cantilever beam 120 facing the first through cavity 111, and the angle β between the tangent of the connection point between the arc side wall and the cantilever beam and the surface of the cantilever beam facing the first through cavity is 90° to 180°.

[0044] It should be noted that the arrangement of the first through cavity 111 makes the support seat 110 annular, and the cantilever beam 120 is arranged on the upper surface of the support seat 110. The support seat 110 is a structure that directly fits the cantilever beam 120. The support seat 110 can be a single film layer structure, that is, it only includes one film layer; the support seat 110 can also be a composite film layer structure, that is, it includes two or more stacked film layers. The arc side wall 1111 can be located in one film layer or can span two or more film layers. Please refer to Figure 5 Other structures, such as a base 140 , may also be provided below the support seat 110 .

[0045] Cantilever beam 120 is divided into a fixed area 121 and a free area 122. Fixed area 121 is attached to and fixedly connected to the upper surface of support base 110, while free area 122 is suspended above first through cavity 111 of support base 110 and can vibrate up and down. Like support base 110, cantilever beam 120 can also have a single-layer or composite membrane structure.

[0046] The number of cantilever beams 120 can be one, two or more. Figure 6 As shown, when there is only one cantilever beam 120, a gap 130 is provided between the side of the free area 122 of the cantilever beam 120 and the support base 110 to allow air to flow. It can be understood that the free area 122 of the cantilever beam 120 has two opposite surfaces and a side surface connecting the two surfaces, one of which is arranged toward the first through cavity 111 and the other is arranged away from the first through cavity 111. Figure 4 As shown, when there are two or more cantilever beams 120, the two or more cantilever beams 120 are arranged in the same layer. If two or more cantilever beams 120 are arranged in a circle along the first surface of the support base 110, a gap 130 is provided between the side surfaces of the cantilever beams 120 and the side surfaces of the other cantilever beams 120. Figure 7As shown, if two or more cantilever beams 120 are arranged in parallel, a gap 130 is provided between the side surface of a cantilever beam 120 and the side surface of another cantilever beam 120, and a gap 130 is also provided between the side surface of the cantilever beam 120 and the support base 110. Of course, Figures 3 to 7 These are only a few embodiments for disposing the cantilever beam 120 . The cantilever beam 120 may also be disposed on the first surface of the support base 110 in other ways.

[0047] Please refer to Figure 3 and Figure 8 At least part of the sidewall of the first through-hole 111 is a circular arc sidewall 1111, and the longitudinal cross-section of the circular arc sidewall 1111 is in the shape of a circular arc. The circular arc sidewall 1111 is connected to the surface of the cantilever beam 120 facing the first through-hole 111, and the intersection between the two is the connection point of the circular arc sidewall 1111 and the cantilever beam 120. The angle β between the tangent of the circular arc sidewall and the cantilever beam at the connection point and the surface of the cantilever beam facing the first through-hole is 90° to 180° (inclusive). This arrangement can significantly improve the cantilever beam 120's ability to resist the impact of airflow from the first through-hole 111 and reduce the probability of the cantilever beam 120 breaking when it deflects upward. Moreover, the larger the angle between the tangent of the circular arc sidewall 1111 at the connection point and the surface of the cantilever beam 120 facing the first through-hole 111, the stronger the cantilever beam 120's ability to resist airflow impact. Preferably, the angle β between the tangent of the connection point between the arc side wall and the cantilever beam and the surface of the cantilever beam facing the first through cavity is 110° to 165°. The arc side wall 1111 with an angle β within this range is easier to process and has better impact resistance.

[0048] Please refer to Figure 9 , Figure 9 Shown Figure 1 、 Figure 3 and Figure 8 When the three structures are impacted by the same airflow from the first through cavity 111, the maximum stress generated at the stress concentration point is shown in the red line in the figure. Figure 1 The blue lines correspond to the structure in Figure 3 The gray lines correspond to the structure in Figure 8 Similarly, the stress values ​​at the stress concentration points of the three structures are normalized by the maximum stress that the device can withstand. It can be seen that, using the cantilever beam structure 100 provided in the embodiment of the present application, under the maximum airflow impact that the existing structure can withstand, its maximum stress point has not yet reached the tolerance limit of the device, which can indicate that the cantilever beam structure 100 provided in the embodiment of the present application has achieved the intended purpose.

[0049] The cantilever beam structure 100 is designed to shape the sidewall of the first through-hole 111 so that the sidewall connecting the first through-hole 111 and the cantilever beam 120 is a circular arc sidewall 1111, and the angle β between the tangent line at the connection point between the circular arc sidewall and the cantilever beam and the surface of the cantilever beam facing the first through-hole is between 90° and 180°. This configuration significantly improves the cantilever beam 120's ability to withstand the impact of airflow from the first through-hole 111 and reduces the probability of cantilever beam 120 fracturing when deflected upward. Furthermore, the larger the angle β between the tangent line at the connection point between the circular arc sidewall and the cantilever beam and the surface of the cantilever beam facing the first through-hole, the greater the cantilever beam 120's ability to withstand the impact of airflow.

[0050] Alternatively, see Figure 3 and Figure 10 The arc side wall 1111 has a first edge 1111a connected to the cantilever beam 120 and a second edge 1111b opposite to the first edge 1111a, and the orthographic projection of the first edge 1111a on the cantilever beam 120 is located within the orthographic projection of the second edge 1111b on the cantilever beam 120.

[0051] It can be understood that the connection point between the arcuate sidewall 1111 and the cantilever beam 120 is located on the first edge 1111a, and the edge of the arcuate sidewall 1111 away from the cantilever beam 120 is the second edge 1111b. The orthographic projection of the first edge 1111a on the cantilever beam 120 is located within the orthographic projection of the second edge 1111b on the cantilever beam 120. In other words, the size of the opening of the first through-hole 111 facing the cantilever beam 120 is smaller than the size of the opening of the cantilever beam 120 within the first through-hole 111.

[0052] Alternatively, see Figure 8 The arc side wall 1111 has a first edge 1111a connected to the cantilever beam 120 and a second edge 1111b opposite to the first edge 1111a. The orthographic projection of the first edge 1111a on the cantilever beam 120 is located outside the orthographic projection of the second edge 1111b on the cantilever beam 120. That is to say, the size of the opening of the first through cavity 111 facing the cantilever beam 120 is larger than the size of the opening of the cantilever beam 120 inside the first through cavity 111.

[0053] Figure 3 and Figure 8 The structures in the embodiment can significantly improve the ability of the cantilever beam 120 to resist the impact of the airflow in the first through cavity 111. When other etching parameters remain unchanged, Figure 3 The structure etching time is shorter, or the flow rate of the etching gas used is smaller.

[0054] Optionally, the arc sidewall 1111 is tangent to the surface of the cantilever beam 120 facing the first through cavity 111 .

[0055] In this way, the transition between the arc side wall 1111 and the cantilever beam 120 can be made smoother, and when the free area 122 of the cantilever beam 120 vibrates and bends downward, the cantilever beam 120 can be better protected.

[0056] Alternatively, see Figure 11 , the arc side wall 1111 is ring-shaped.

[0057] That is to say, the arc side walls 1111 are connected end to end in the horizontal direction to form a complete ring, but the cross section of the arc side walls 1111 can be rectangular, polygonal, etc. Figure 11 The embodiment shown in FIG. 1 is a rectangular cross-section of the arc side wall 1111. Figure 4 A circle of cantilever beams 120 can be set around the upper surface of the support base 110, and each cantilever beam 120 has strong airflow impact resistance.

[0058] Alternatively, see Figure 5 and Figure 12 The cantilever beam structure 100 also includes a base 140, which is connected to the lower surface of the support base 110. A second through cavity 141 is provided on the base 140. The second through cavity 141 passes through two opposite surfaces of the base 140. The edge of the second through cavity 141 on the lower surface of the support base 110 is located within the edge of the first through cavity 111 on the lower surface of the support base 110.

[0059] The base 140 is generally made of a substrate and may also include other film layers. The lateral dimension of the second through cavity 141 on the base 140 is smaller than the lateral dimension of the first through cavity 111 on the support base 110, thereby forming a gap between the base 140 and the cantilever beam 120. When the cantilever beam 120 is impacted by the first through cavity 111, the arc side wall 1111 can significantly reduce the probability of the cantilever beam 120 breaking when it deflects upward. When the cantilever beam 120 is impacted from above, the edge of the base 140 supports the cantilever beam 120, which can significantly reduce the probability of the cantilever beam 120 breaking when it deflects downward.

[0060] It can be understood that when the base 140 does not exist, the support base 110 can also be made of a substrate and can include other film layers.

[0061] For the second aspect of the embodiment of this application, please refer to Figure 13 , provides a method for preparing a cantilever beam structure, comprising:

[0062] S100: providing a support layer, and forming a cantilever beam pattern on an upper surface of the support layer.

[0063] Please refer to Figure 3 and Figure 14 The support layer 200 is used to form the support base 110 of the cantilever beam structure 100. After the cantilever beam pattern 300 is released, the cantilever beam 120 of the cantilever beam structure 100 is formed. As mentioned above, the support base 110 and the cantilever beam 120 can both be single-layer structures or composite-layer structures. Therefore, the support layer 200 and the cantilever beam pattern 300 can also be single-layer structures or composite-layer structures.

[0064] For example, a complete diaphragm layer is formed on the upper surface of the support layer 200 , and then the diaphragm layer is etched to obtain the desired cantilever beam pattern 300 .

[0065] S200: Etching the support layer to obtain a support seat having a first through-cavity, wherein the first through-cavity releases the cantilever beam pattern to obtain a cantilever beam, wherein a gap is provided between the side surface of the cantilever beam and the support seat and / or another cantilever beam. The sidewall of the first through-cavity includes an arc sidewall, which is connected to the surface of the cantilever beam facing the first through-cavity, and the angle between the tangent of the connection point between the arc sidewall and the cantilever beam and the surface of the cantilever beam facing the first through-cavity is 90° to 180°.

[0066] Please refer to Figure 15 The supporting layer 200 is etched on a side thereof away from the cantilever beam pattern 300, thereby forming a first through cavity 111 in the supporting layer 200, transforming the supporting layer 200 into a support base 110 for the cantilever beam structure 100. The first through cavity 111 penetrates two opposite surfaces of the supporting layer 200, releasing a portion of the cantilever beam pattern 300 and placing it in a suspended state, thereby obtaining a movable cantilever beam 120.

[0067] It should be noted that, in this embodiment, there is no limitation on the method of etching the support layer 200 and obtaining the cantilever beam pattern 300 , as long as the required support base 110 and cantilever beam 120 can be obtained.

[0068] The cantilever beam structure 100 prepared by the above-mentioned cantilever beam structure preparation method can significantly improve the impact resistance of the cantilever beam 120 to the airflow from the first through cavity 111 and reduce the probability of the cantilever beam 120 breaking when deflecting upward.

[0069] Optionally, etching the support layer includes: etching the support layer using an isotropic etching process to obtain a first through cavity having an arc sidewall.

[0070] Furthermore, the support layer is etched using an isotropic etching process with an etching gas, and the morphology of the etching cavity sidewall is controlled by controlling the etching time and / or the flow rate of the etching gas to obtain a first through cavity with arc sidewalls.

[0071] It is understood that after the etching cavity passes through the two opposite surfaces of the support layer 200, it becomes the first through cavity 111. The etching gas can be hydrogen fluoride gas, and other etching parameters include but are not limited to: temperature, etching gas flow rate, water / ethanol gas flow rate, cavity pressure and etching time.

[0072] When other etching parameters remain unchanged, by controlling the etching time, the first through cavity 111 with different arc sidewall 1111 morphologies can be obtained. For example, by increasing the etching time, the morphology of the arc sidewall 1111 can be changed from Figure 3 becomes Figure 8 .

[0073] When other etching parameters remain unchanged, by controlling the flow rate of the etching gas, the first through cavity 111 with different arc sidewall 1111 morphologies can be obtained. For example, by increasing the flow rate of the etching gas, the morphology of the arc sidewall 1111 can be changed from Figure 3 becomes Figure 8 .

[0074] Alternatively, the support layer is etched using wet chemicals in combination with an isotropic etching process, and the morphology of the etched cavity sidewall is controlled by controlling the etching time and / or the concentration of the wet chemicals to obtain a first through cavity with arc sidewalls.

[0075] Alternatively, see Figure 16 The method for preparing a cantilever beam structure includes providing a support layer and forming a cantilever beam pattern on the upper surface of the support layer.

[0076] S110: providing a base layer, and sequentially forming a support layer and a cantilever beam pattern on the base layer.

[0077] Etching the support layer to obtain a support base having a first through cavity includes:

[0078] S210: etching the base layer to obtain a base having a second through cavity, wherein the second through cavity penetrates two opposite surfaces of the base layer.

[0079] S220: Etching the support layer through the second through cavity to obtain a support base having a first through cavity.

[0080] Please refer to Figure 17 , a support layer 200 and a cantilever beam pattern 300 are sequentially stacked on the base layer 400, wherein the cantilever beam pattern 300 is laminated to the upper surface of the support layer 200, and the base layer 400 is laminated to the lower surface of the support layer 200. The base layer 400 may include a substrate and may also include other film layers. Figure 18 and Figure 5The base layer 400 is etched on a side of the base layer 400 facing away from the support layer 200 to form a second through cavity 141 on the base layer 400 that penetrates two opposing surfaces of the base layer 400, thereby obtaining the base 140. The support layer 200 is etched using the second through cavity 141 to form a first through cavity 111 on the support layer 200 that penetrates two opposing surfaces of the support layer 200, thereby obtaining the support base 110. The first through cavity 111 releases a portion of the cantilever beam pattern 300, thereby obtaining the cantilever beam 120.

[0081] It should be noted that, in this embodiment, there is no limitation on the method of etching the base layer 400 , the support layer 200 and forming the cantilever beam pattern 300 , as long as the required base 140 , the support base 110 and the cantilever beam 120 can be obtained.

[0082] According to a third aspect of the embodiments of the present application, a MEMS device is provided, comprising the cantilever beam structure 100 as described above.

[0083] The MEMS device includes the same structure and benefits as the cantilever beam structure 100 in the aforementioned embodiment. The structure and benefits of the cantilever beam structure 100 have been described in detail in the aforementioned embodiment and will not be repeated here.

[0084] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A cantilever beam structure, characterized in that: include: A support base and a cantilever beam, wherein the support base is provided with a first through-hole, the first through-hole penetrating two opposite surfaces of the support base, a portion of the cantilever beam is in contact with the upper surface of the support base, and another portion of the cantilever beam is suspended above the first through-hole, and a gap is provided between the side surface of the cantilever beam and the support base and / or another cantilever beam; The side wall of the first through cavity includes an arc side wall, which is connected to the surface of the cantilever beam facing the first through cavity, and the angle between the tangent of the connection point between the arc side wall and the cantilever beam and the surface of the cantilever beam facing the first through cavity is 90° to 180°.

2. The cantilever beam structure according to claim 1, wherein: The arc side wall has a first edge connected to the cantilever beam and a second edge opposite to the first edge, and the orthographic projection of the first edge on the cantilever beam is located within the orthographic projection of the second edge on the cantilever beam.

3. The cantilever beam structure according to claim 1, wherein: The arc side wall has a first edge connected to the cantilever beam and a second edge opposite to the first edge, and the orthographic projection of the first edge on the cantilever beam is outside the orthographic projection of the second edge on the cantilever beam.

4. The cantilever beam structure according to claim 1, wherein: The arc side wall is tangent to a surface of the cantilever beam facing the first through cavity.

5. The cantilever beam structure according to claim 1, wherein: An angle between a tangent line of a connection point between the arc side wall and the cantilever beam and a surface of the cantilever beam facing the first through cavity is 110° to 165°.

6. The cantilever beam structure according to any one of claims 1 to 5, characterized in that: It also includes a base, which is connected to the lower surface of the support base. The base is provided with a second through cavity, which runs through two opposite surfaces of the base. The edge of the second through cavity on the lower surface of the support base is located within the edge of the first through cavity on the lower surface of the support base.

7. A method for preparing a cantilever beam structure, characterized in that: include: providing a support layer, and forming a cantilever beam pattern on an upper surface of the support layer; The support layer is etched to obtain a support seat having a first through-cavity, wherein the first through-cavity releases the cantilever beam pattern to obtain a cantilever beam, wherein a gap is provided between the side surface of the cantilever beam and the support seat and / or another cantilever beam; the sidewall of the first through-cavity includes an arc sidewall, which is connected to the surface of the cantilever beam facing the first through-cavity; and the angle between the tangent of the connection point between the arc sidewall and the cantilever beam and the surface of the cantilever beam facing the first through-cavity is 90° to 180°.

8. The method for preparing a cantilever beam structure according to claim 7, wherein: The etching of the support layer comprises: The support layer is etched using an isotropic etching process to obtain a first through cavity with arc sidewalls.

9. The method for preparing a cantilever beam structure according to claim 7, wherein: The step of providing a support layer and forming a cantilever beam pattern on an upper surface of the support layer comprises: Providing a base layer, and sequentially forming a support layer and a cantilever beam pattern on the base layer; The etching of the support layer to obtain a support base having a first through cavity comprises: Etching the base layer to obtain a base having a second through cavity, wherein the second through cavity penetrates two opposite surfaces of the base layer; The support layer is etched through the second through cavity to obtain a support base having a first through cavity.

10. A MEMS device, characterized in that: The cantilever beam structure comprises the cantilever beam structure according to any one of claims 1 to 6.

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