MEMS device

Abstract

The application discloses a MEMS device. The MEMS device comprises a substrate having opposite first and second surfaces; at least one first groove extending from a first image of the first surface into the substrate; and at least one second groove extending from a second image of the second surface into the substrate, the second groove being in communication with the corresponding first groove to form a through hole, wherein the bottom image of the second groove at least partially overlaps the bottom image of the first groove, and the width of the overlapping area is greater than a set value in the first direction. By limiting the position of the second groove, the structural misplacement or fracture caused by alignment deviation and etching angle fluctuation in the double-sided etching process can be avoided, and the formation of the through hole is ensured.

Description

Technical Field

[0001] This application relates to the field of semiconductor technology, and in particular to a MEMS device. Background Technology

[0002] MEMS (Micro-Electro-Mechanical Systems) are devices that integrate microelectronics and micromechanical technologies and are widely used in consumer electronics, automotive electronics and other fields.

[0003] MEMS devices typically incorporate high aspect ratio structures in their substrates to meet the mechanical response or isolation requirements of the devices in specific directions. These structures are usually formed in the substrate using deep etching processes. When a multilayer structure is already integrated on the front side of the substrate, it is no longer possible to use front-side deep etching to form a high aspect ratio structure, and it is necessary to switch to back-side deep etching or double-sided etching techniques.

[0004] Figure 1 The diagram shows a schematic structural diagram of a MEMS device in the prior art. Among them, (a) shows a schematic diagram of deep back etching under ideal conditions, (b) shows a schematic diagram of deep back etching with alignment deviation, and (c) shows a schematic diagram of double-sided etching with etching angle fluctuation.

[0005] As shown in Figure (a), under ideal alignment conditions, deep back etching can form vertically penetrating and precisely positioned vias 11a and 12a in the substrate 10, leaving a high aspect ratio structure in the substrate 10 between them. However, due to alignment errors in actual processes, as shown in Figure (b), the positions of vias 11b and 12b shift, causing the dimensions and positions of the high aspect ratio structure to deviate from the design values. As shown in Figure (c), although double-sided etching can minimize the impact of alignment errors, small fluctuations in the angle during etching can still cause the upper and lower etched areas to not be perfectly matched, resulting in a non-ideal morphology. Especially in cases of extremely high aspect ratios, this leads to misalignment of the high aspect ratio structure and low product yield. Utility Model Content

[0006] In view of the above problems, the purpose of this application is to provide a MEMS device that can improve product yield.

[0007] According to one aspect of the present invention, a MEMS device is provided, comprising: a substrate having opposing first and second surfaces; at least one first groove extending from a first image on the first surface into the substrate; and at least one second groove extending from a second image on the second surface into the substrate, the second groove communicating with a corresponding first groove to form a through-hole, wherein a bottom image of the second groove at least partially overlaps with a bottom image of the first groove, and in a first direction, the width of the overlapping area is greater than a predetermined value.

[0008] Optionally, at least a portion of the substrate is retained to form a high aspect ratio structure, the upper portion of which is adjacent to the first groove, and the lower portion of which is adjacent to the second groove.

[0009] Optionally, the first groove has at least one first boundary and at least one second boundary, and the second groove has at least one third boundary and at least one fourth boundary. In a first direction, the first boundary and the third boundary are located on a first side of the corresponding through-hole, and the second boundary and the fourth boundary are located on a second side of the corresponding through-hole. The substrate between at least partially adjacent first boundaries forms the upper portion, and the substrate between at least partially adjacent third boundaries forms the lower portion. In the first direction, the width of the upper portion is greater than or less than the width of the lower portion.

[0010] Optionally, the width of the upper portion is the distance between adjacent first boundaries, and the width of the lower portion is the distance between adjacent third boundaries.

[0011] Optionally, the distance between the first boundary and the set third boundary is greater than or equal to a set value.

[0012] Optionally, d = d1 + d2, where d is the set value, d1 is the maximum alignment deviation between the set position and the actual position of the second image, and d2 is the maximum offset between the actual bottom image of the second groove and the set bottom image when only etching angle fluctuation exists.

[0013] Optionally, it further includes: a structural layer, stacked with the substrate layer, the structural layer having at least one conductive layer and / or at least one dielectric layer.

[0014] Optionally, it further includes: a sacrificial layer located between the structural layer and the substrate, wherein the edge of the structural layer is connected to the substrate via the sacrificial layer.

[0015] Optionally, when the first groove and the second groove surround the high aspect ratio structure, the structural layer is also connected to the upper portion via the sacrificial layer.

[0016] Optionally, the sidewalls of the first groove and / or the second groove are vertical, sloping, or arc-shaped.

[0017] According to the MEMS device disclosed in this application, a double-sided etching method is used. A first groove is formed on a first surface, which helps to improve the accuracy of the position of the high aspect ratio structure on the first surface. A second groove is formed on a second surface, which helps to control the overall morphology and dimensional accuracy of the high aspect ratio structure. By limiting the position of the bottom image of the second groove by the bottom image of the first groove, structural misalignment or breakage caused by alignment deviation and etching angle fluctuation during the double-sided etching process can be avoided, ensuring the formation of vias and the continuity and stability of the high aspect ratio structure, thereby effectively improving the reliability and manufacturing yield of the device. Attached Figure Description

[0018] The above and other objects, features and advantages of this application will become clearer from the following description of embodiments with reference to the accompanying drawings, in which:

[0019] Figure 1 A schematic structural diagram of a MEMS device in the prior art is shown;

[0020] Figure 2 A schematic diagram of a substrate in a MEMS device according to some embodiments of this application is shown;

[0021] Figure 3 This application shows a two-dimensional schematic diagram of the substrate in a MEMS device in some of its embodiments;

[0022] Figure 4 A schematic diagram showing the first image;

[0023] Figure 5 A schematic diagram showing different sidewall shapes of the first groove;

[0024] Figure 6 This diagram shows a two-dimensional cross-sectional view of a MEMS device according to an embodiment of this application.

[0025] Figure 7 The diagram shows a cross-sectional view of a MEMS device according to an embodiment of this application under different deviations. Detailed Implementation

[0026] Various embodiments of the present application will now be described in more detail with reference to the accompanying drawings. In the various drawings, the same elements are indicated by the same or similar reference numerals. For clarity, the various parts in the drawings are not drawn to scale.

[0027] Furthermore, certain terms are used in this specification and claims to refer to specific components. Those skilled in the art will understand that manufacturers may use different names to refer to the same component. This specification and claims do not distinguish components based on differences in name, but rather on differences in function.

[0028] It should be understood that, in the following description, "circuit" may include single or combined hardware circuits, programmable circuits, state machine circuits, and / or elements capable of storing instructions executed by the programmable circuit. When an element or circuit is said to be "connected" to another element or "connected" between two nodes, it may be directly coupled or connected to the other element, or there may be intermediate elements; the connection between elements may be physical, logical, or a combination thereof. Conversely, when an element is said to be "directly coupled to" or "directly connected" to another element, it means that there are no intermediate elements between them.

[0029] Furthermore, it should be noted that in this document, 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. Moreover, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0030] According to the MEMS device disclosed in this application, its substrate has opposing first and second surfaces. A first groove extends from a first image on the first surface into the substrate; a second groove extends from a second image on the second surface into the substrate, and the second groove communicates with a corresponding first groove to form a through-hole. The bottom image of the second groove at least partially overlaps with the bottom image of the first groove, and in a first direction, the width of the overlapping area is greater than a predetermined value.

[0031] Furthermore, at least a portion of the substrate is retained to form a high aspect ratio structure. The upper end of the high aspect ratio structure is adjacent to the first groove, and the lower end of the high aspect ratio structure is adjacent to the second groove.

[0032] Specifically, the first groove has at least one first boundary and at least one second boundary, and the second groove has at least one third boundary and at least one fourth boundary. In a first direction, the first and third boundaries are located on a first side of the corresponding via, and the second and fourth boundaries are located on a second side of the corresponding via. The substrate retained between adjacent first boundaries forms the upper portion of a high aspect ratio structure, and the substrate retained between adjacent third boundaries forms the lower portion of a high aspect ratio structure. In the first direction, the width of the upper portion of the high aspect ratio structure is greater than or less than the width of the lower portion.

[0033] The first groove is formed on the first surface, which helps to improve the accuracy of the position of the high aspect ratio structure on the first surface; the second groove is formed on the second surface, which helps to control the overall morphology and dimensional accuracy of the high aspect ratio structure; by limiting the position of the second groove, structural misalignment or breakage caused by alignment deviation and etching angle fluctuation during double-sided etching can be avoided, ensuring the formation of vias and ensuring the continuity and stability of the high aspect ratio structure, thereby effectively improving the reliability and manufacturing yield of the device.

[0034] To facilitate understanding of the MEMS devices disclosed in this application, Figure 2 This diagram illustrates a substrate in a MEMS device according to some embodiments of this application. Figure 2 In the accompanying drawings, the first direction is the X direction; the second direction is the Z direction; and the third direction is the Y direction. The first, second, and third directions intersect each other, preferably perpendicular to each other. The second direction Y is the direction between the first and second surfaces, and the plane formed by the first direction X and the third direction Y is parallel to the first and / or second surfaces of the substrate.

[0035] Furthermore, in Figure 2 In the figure, (a) shows a three-dimensional structure of substrate 20 with the XZ plane as the cross-section, and (b) and (c) are two-dimensional schematic diagrams of this cross-section. Figure (b) mainly marks the relative positions of the grooves, and figure (c) mainly marks the distance relationships between the boundaries. It should be noted that... Figure 2 In the examples provided, the shapes of the first and second grooves are provided as examples based on predetermined configurations. In actual operation, alignment deviations and fluctuations in etching angles can cause changes in the shape of the first and / or second grooves. The semiconductor device provided in this application can avoid such changes, particularly avoiding low device yield due to shape variations during the formation of the second groove.

[0036] Combination Figure 2In Figures (a), (b), and (c), the MEMS device includes a substrate 20. The substrate 20 has a first surface I1 and a second surface I2 opposite to each other. The structural layer of the MEMS device can be formed on the first surface I1, and the packaging substrate or external circuitry can be connected to the second surface I2. The substrate 20 can be made of silicon or silicon-based materials.

[0037] At least one first groove is formed on the first surface I1. The first groove extends from the first image on the first surface I1 into the substrate 20. Figure 2 The image shows two first grooves 21 and 21' as examples. The bottom image of each first groove has a first boundary and a second boundary. Taking the first groove 21 as an example, as shown... Figure 2 As shown in Figure (b), the first boundary is the first sidewall 211 extending to the end of the substrate 20. Figure 2 In diagram (a), it is represented by the boundary FA, ​​and in diagram (c), it is represented by point A. For example... Figure 2 As shown in Figure (b), the second boundary is the second sidewall 212 extending to the end of the substrate 20, and the second boundary is in Figure 2 In diagram (a), it is represented by the boundary FB, and in diagram (c), it is represented by point B.

[0038] At least one second groove is formed on the second surface I2. The second groove extends from the second image on the second surface I2 into the substrate 20. Figure 2 The example uses two second grooves 22 and 22'. The bottom of each second groove has opposing third and fourth boundaries. Taking second groove 22 as an example, as... Figure 2 As shown in Figure (b), the third boundary is the third sidewall 213 of the second groove 22 extending to the end in the substrate 20. Figure 2 In diagram (a), it is represented by the boundary FC, and in diagram (c), it is represented by point C. For example... Figure 2 As shown in Figure (b), the fourth boundary is the fourth sidewall 214 of the second groove 22 extending to the end in the substrate 20, and the fourth boundary is in Figure 2 In diagram (a), it is represented by the boundary FD, and in diagram (c), it is represented by point D.

[0039] In a preferred embodiment, the etching depth of the second groove in the second direction Z is greater than that of the first groove.

[0040] Each second groove communicates with a corresponding first groove to form a through-hole penetrating the substrate 20. Figure 2 In this example, the first groove 21 and the second groove 22 form a first through hole, and the first groove 21' and the second groove 22' form a second through hole. Figure 2In the first direction X, these through holes are formed between the corresponding first boundary and fourth boundary, serving as airflow channels, liquid flow channels, etc. between the first surface I1 and the second surface I2.

[0041] In double-sided photolithography, after forming the first groove, the predetermined position of the second image is obtained based on the bottom image of the first groove. To ensure the formation of the via, in the MEMS device disclosed in this application, in the first direction X, the bottom image of the first groove and the predetermined bottom image of the second groove at least partially overlap, and the width of the overlapping area is greater than a predetermined value. After forming the first and second grooves, the connection point between them falls within this overlapping area. Figure 2 In diagram (c), Lw is represented as d, where Lw is the distance between the first boundary and the fourth boundary, and d is a set value.

[0042] In a preferred embodiment, the set value d = d1 + d2, where d1 is the maximum alignment deviation between the set position and the actual position of the second image, and d2 is the maximum offset between the actual image at the bottom of the second groove and the set image at the bottom when only the etching angle fluctuates.

[0043] The substrate 20, which is at least partially retained, forms a high aspect ratio structure. The upper portion of the high aspect ratio structure is adjacent to the first groove, and the lower portion of the high aspect ratio structure is adjacent to the second groove.

[0044] exist Figure 2 In this example, a high aspect ratio structure 30 is formed in the substrate 20 between the first and second vias. The high aspect ratio structure 30 serves as an isolation region to prevent crosstalk between adjacent vias in terms of airflow or liquid flow.

[0045] Specifically, the substrate 20 retained between the first grooves 21 and 21' forms the upper portion of the high aspect ratio structure 30, and the substrate 20 retained between the second grooves 22 and 22' forms the lower portion of the high aspect ratio structure 30. Figure 2 In the first direction, the width W1 of the upper part is greater than the width W2 of the lower part, thus forming a T-shaped cross-section with a high aspect ratio 30, which is beneficial to effectively improve the mechanical strength and deformation resistance of the structure.

[0046] In some embodiments, when there are multiple first grooves and / or each first groove has multiple first boundaries and multiple second boundaries, the width W1 of the upper portion can be the distance between adjacent first boundaries, and the width W2 of the lower portion can be the distance between adjacent third boundaries. Figure 2As shown, in the case of multiple first grooves and multiple second grooves, in order to form the high aspect ratio structure 30 of the T-shaped cross-section described above, the distance between the first boundary and the predetermined third boundary should be greater than or equal to the predetermined value d. The predetermined third boundary is the third boundary in the bottom predetermined image of the second groove. Furthermore, W1-W2≥2d should also be satisfied, where W1 is the distance between adjacent first boundaries and W2 is the distance between adjacent predetermined third boundaries.

[0047] It should be noted that this application does not limit the relative positional relationship between the first groove and the second groove, as long as the first groove and the second groove can communicate. As an example, Figure 3 Further embodiments are shown, illustrating the substrate structure with the XZ plane as the cross-section. In these embodiments, Figure 2 and Figure 3 Figure (a) shows structures with a high aspect ratio and a T-shaped cross-section. Figure 3 Figures (b) and (c) both show structures with a high aspect ratio forming an inverted T-shaped cross-section.

[0048] Specifically, taking the set form as an example, in the first direction:

[0049] Figure 2 The first groove 21 and the second groove 22 shown communicate between the first boundary and the fourth boundary. Figure 2 In diagram (c), this is represented by a connection between points A and D. Specifically, the width of the overlapping area between the bottom images of the first and second grooves is greater than a set value; this means the width between the first boundary and the fourth boundary in the bottom images of the second groove is greater than a set value. Simultaneously, to form a high aspect ratio T-shaped cross-section, the distance AC between the first boundary and the third boundary in the bottom images of the second groove needs to be greater than or equal to a set value. Correspondingly, the difference between the width W1 of the upper portion and the width W2 of the lower portion of the high aspect ratio structure is greater than or equal to twice the set value.

[0050] Figure 3 In Figure (a), the first groove 21 and the second groove 22 are connected between the first boundary and the second boundary. For example, they are connected between point A and point B. The width of the overlapping area between the bottom images of the first groove and the bottom set images of the second groove is greater than a set value, specifically meaning the width AB between the first boundary and the second boundary is greater than a set value. Simultaneously, to form a high aspect ratio structure with a T-shaped profile, the distance AC between the third boundary in the bottom set images of the first boundary and the second groove needs to be greater than or equal to a set value. Correspondingly, the difference between the width W1 of the upper portion and the width W2 of the lower portion of the high aspect ratio structure is greater than or equal to twice the set value.

[0051] Figure 3In Figure (b), the first groove 21 and the second groove 22 are connected between the second boundary and the third boundary. For example, this is represented by connecting points B and C. The width of the overlapping area between the bottom images of the first and second grooves is greater than a set value, specifically meaning the width BC between the second boundary and the third boundary in the bottom image of the second groove is greater than a set value. Simultaneously, to form a high aspect ratio structure with an inverted T-shaped profile, the distance AC between the first boundary and the third boundary in the bottom image of the second groove needs to be greater than or equal to a set value. Correspondingly, the difference between the width W2 of the lower portion and the width W1 of the upper portion of the high aspect ratio structure is greater than or equal to twice the set value.

[0052] Figure 3 In Figure (d), the first groove 21 and the second groove 22 are connected between the third boundary and the fourth boundary. For example, this is represented by connecting points D and C. The overlap width of the bottom image of the first groove and the bottom setting image of the second groove being greater than a set value specifically means that the width CD between the third and fourth boundaries in the bottom setting image of the second groove is greater than a set value. Simultaneously, in order to form a high aspect ratio structure with an inverted T-shaped cross-section, the distance AC between the third boundary in the bottom setting images of the first boundary and the second groove needs to be greater than or equal to a set value. Correspondingly, the difference between the width W2 of the lower portion and the width W1 of the upper portion of the high aspect ratio structure is greater than or equal to twice the set value.

[0053] It should be noted that this application does not limit the specific shapes of the first image, the second image, the first groove, and the second groove; they can be designed as rectangular, circular, or polygonal structures according to actual process requirements. For example... Figure 4 The diagram shows various shapes of the first image in the XY plane.

[0054] Specifically, in Figure 4 In figures (a) to (e), the first image is a single image, and a first groove is formed accordingly. In figures (f) to (i), the first image comprises multiple sub-images, and multiple first grooves are formed accordingly.

[0055] for Figure 2 Example of cross-section shown: In some embodiments, the corresponding first image may be as follows Figure 4 As shown in Figure (f). Figure 2 The cross-section can be obtained by cutting along the plane containing line P2-P2'. Meanwhile, in some embodiments, when the first image is... Figure 4 When looking at graph (f) in the diagram, one can also obtain results such as... Figure 3 Cross-sectional views of each figure.

[0056] In some other embodiments, the first groove 21 and the first groove 21' may be connected, and the second groove 22 and the second groove 22' may also be connected. That is, the first groove 21 and the first groove 21' are manifestations of the same groove at different positions, and the second groove 22 and the second groove 22' are also manifestations of the same groove at different positions. The first image in this case is, for example, [image of a first groove]. Figure 4 As shown in Figure (b). Figure 2 Each cross-section can be obtained by cutting along the plane containing line P1-P1'. Meanwhile, in some embodiments, when the first image is... Figure 4 When looking at Figure (b) in the diagram, one can also obtain results such as... Figure 3 Cross-sectional views of each figure.

[0057] The second image is similar, and will not be described in detail here.

[0058] Furthermore, when the first groove has multiple first boundaries and second boundaries, the second groove should have corresponding multiple third boundaries and fourth boundaries. In this case, the upper portion of the high aspect ratio structure can be located between adjacent first boundaries, and the lower portion of the high aspect ratio structure can be located between adjacent third boundaries. In some embodiments, the width W1 of the upper portion is the distance between adjacent first boundaries, and the width W2 of the lower portion is the distance between adjacent third boundaries. Still using... Figure 4 Taking Figure (b) as an example, the first groove formed according to the first image can have two first boundaries corresponding to F1 and F1' in the figure, and two second boundaries corresponding to F2 and F2' in the figure. Then, the upper end of the high aspect ratio structure 30 is specifically located between these two first boundaries. The lower end of the high aspect ratio structure 30 is similar.

[0059] It should be understood that, according to Figures 2 to 4 In various embodiments, the upper portion of the corresponding high aspect ratio structure may be formed on the substrate between any adjacent first boundaries, and the lower portion of the corresponding high aspect ratio structure may be formed on the substrate between any adjacent third boundaries. In still other embodiments, the upper portion of the corresponding high aspect ratio structure may be formed on the substrate between only a portion of the first boundaries, and the lower portion of the high aspect ratio structure may be formed on the substrate between the corresponding third boundaries.

[0060] Furthermore, this application does not impose excessive restrictions on the sidewall shapes of the first and second grooves. Figure 5 Two-dimensional cross-sectional schematic diagrams of the substrate are shown in some other embodiments. For example... Figure 5 As shown in Figures (a) and (b), the sidewall of the first groove can be inclined, forming a sloping sidewall; or as ...b), the sidewall of the first groove can be inclined, forming a sloping sidewall. Figure 5As shown in Figures (c) and (d), the first groove can be arc-shaped, forming an arc-shaped sidewall. During the etching process to form the first groove, different sidewall shapes can be formed by adjusting the etching rate and angle to adapt to different process requirements. That is, on the plane formed by the first and second directions, the projection of the high aspect ratio structure is T-shaped or T-like. Similarly, when the width of the upper part of the high aspect ratio structure is smaller than the width of the lower part in the first direction X, the projection of the high aspect ratio structure can also be an inverted T-shaped or inverted T-like.

[0061] Figure 6 This diagram shows a two-dimensional cross-sectional view of a MEMS device according to an embodiment of this application. Figure 6 In this context, the substrate of the MEMS device is used as the... Figure 2 The illustrated embodiment is provided as an example. However, it should be understood that in other embodiments, the MEMS device disclosed in this application may have any of the substrate structures described above.

[0062] like Figure 6 As shown in Figure (a), the MEMS device disclosed in this application, in addition to any of the substrates mentioned above, also includes a structural layer 24 stacked on the first surface. This structural layer 24 may include a conductive layer and / or a dielectric layer. Specifically, it may be one or more conductive layers, one or more dielectric layers, or a composite structural layer formed by alternating stacks of conductive and dielectric layers. The conductive layer may be made of polycrystalline silicon or amorphous silicon, and the dielectric layer may be made of materials such as silicon nitride; this application does not impose any restrictions. The structural layer 24 is patterned using deposition and photolithography etching processes to form the functional portion of the MEMS device.

[0063] Furthermore, a sacrificial layer 23 is provided between the structural layer 24 and the first surface of the substrate 20. The edge of the structural layer 24 is connected to the substrate 20 via the sacrificial layer 23. The sacrificial layer 23 serves to isolate the structural layer 24 from the substrate 20, thereby suspending the main body of the structural layer 24 above the first surface. In some embodiments, the sacrificial layer 23 can also restrict the active area of ​​the structural layer 24. The sacrificial layer 23 can be made of silicon dioxide and formed by thermal oxidation or chemical vapor deposition processes.

[0064] It should be noted that in some embodiments, for example when the first image is Figure 4 In Figures (e) and (i), the high aspect ratio structure 30 can be completely detached from the substrate. In this case, as shown... Figure 6 As shown in Figure (b), the high aspect ratio structure 30 also requires a sacrificial layer 23 retained between the upper part of the high aspect ratio structure 30 and the structural layer 24, so that the structural layer 24 can provide support for the high aspect ratio structure 30.

[0065] Figure 7The figures show schematic cross-sectional views of the MEMS device according to embodiments of this application under different deviations. Figure (a) shows a schematic diagram under ideal conditions, Figure (b) shows a schematic diagram when there is an alignment deviation during etching the second groove, and Figure (c) shows a schematic diagram when there is etching angle fluctuation during etching the second groove. In Figure (a), taking the case where both the first and second grooves are vertical sidewalls as an example, the first and second grooves are perfectly aligned. In Figures (b) and (c), even with alignment deviations or etching angle fluctuations, because the preset distance d has comprehensively considered the effects of alignment deviations and etching angle fluctuations, the first and second grooves can still form a continuous through-hole structure by retaining sufficient substrate material, and the complete connection between the upper and lower portions of the high aspect ratio structure can still be ensured, thereby improving product yield. It can be understood that although in Figure 7 Although not shown in the figure, even if alignment deviation and etching angle fluctuation exist simultaneously, they will not have a substantial impact on the MEMS device of this application.

[0066] According to the MEMS device disclosed in this application, a double-sided etching method is used. A first groove is formed on a first surface, which helps to improve the accuracy of the position of the high aspect ratio structure on the first surface. A second groove is formed on a second surface, which helps to control the overall morphology and dimensional accuracy of the high aspect ratio structure. By limiting the position of the bottom image of the second groove by the bottom image of the first groove, structural misalignment or breakage caused by alignment deviation and etching angle fluctuation during the double-sided etching process can be avoided, ensuring the formation of vias and the continuity and stability of the high aspect ratio structure, thereby effectively improving the reliability and manufacturing yield of the device.

[0067] The embodiments described above, as per the examples of this application, do not exhaustively describe all details, nor do they limit this application to the specific embodiments described above. Clearly, many modifications and variations can be made based on the above description. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of this application, thereby enabling those skilled in the art to effectively utilize this application and its modifications. The scope of protection of this application should be determined by the scope defined in the claims of this application.

Claims

1. A MEMS device, characterized in that, include: A substrate having opposing first and second surfaces; At least one first groove extends from a first image on the first surface into the substrate; as well as At least one second groove extends from a second image on the second surface into the substrate, and the second groove communicates with a corresponding first groove to form a through-hole. Wherein, the bottom image of the second groove at least partially overlaps with the bottom image of the first groove, and in the first direction, the width of the overlapping area is greater than a set value.

2. The MEMS device according to claim 1, characterized in that, The substrate, at least partially retained, forms a high aspect ratio structure, the upper portion of which is adjacent to the first groove, and the lower portion of which is adjacent to the second groove.

3. The MEMS device according to claim 2, characterized in that, The first groove has at least one first boundary and at least one second boundary, and the second groove has at least one third boundary and at least one fourth boundary. In a first direction, the first boundary and the third boundary are located on a first side of the corresponding through hole, and the second boundary and the fourth boundary are located on a second side of the corresponding through hole. The upper portion is formed by the substrate between at least partially adjacent first boundaries. The lower portion is formed by the substrate between at least partially adjacent third boundaries. In the first direction, the width of the upper portion is greater than or less than the width of the lower portion.

4. The MEMS device according to claim 3, characterized in that, The width of the upper portion is the distance between adjacent first boundaries, and the width of the lower portion is the distance between adjacent third boundaries.

5. The MEMS device according to claim 4, characterized in that, The distance between the first boundary and the set third boundary is greater than or equal to a set value.

6. The MEMS device according to any one of claims 1-5, characterized in that, d = d1 + d2, d is the set value. d1 represents the maximum alignment deviation between the set position and the actual position of the second image. d2 is the maximum offset between the actual bottom image of the second groove and the set bottom image when only etching angle fluctuation exists.

7. The MEMS device according to any one of claims 2-5, characterized in that, Also includes: The structural layer is stacked on top of the substrate layer. The structural layer has at least one conductive layer and / or at least one dielectric layer.

8. The MEMS device according to claim 7, characterized in that, Also includes: A sacrificial layer is located between the structural layer and the substrate, and the edge of the structural layer is connected to the substrate via the sacrificial layer.

9. The MEMS device according to claim 8, characterized in that, With the first and second grooves surrounding the high aspect ratio structure, the structural layer is also connected to the upper portion via the sacrificial layer.

10. The MEMS device according to any one of claims 1-5, characterized in that, The sidewalls of the first groove and / or the second groove are vertical, sloping, or arc-shaped.

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