A micro-mechanical stacking structure and connecting rod structure and preparation method thereof

Abstract

The present invention relates to a micromechanical stacking structure and a connecting rod structure and a preparation method thereof; the stacking structure comprises an upper structural layer, a lower structural layer, and an intermediate film layer; the intermediate film layer is deposited on the lower structural layer, an annular groove is etched to form, the upper structural layer is deposited, a contact channel is formed in the groove, the upper structural layer is patterned, and the intermediate film layer outside the contact channel is released. The connecting rod structure comprises at least one first stacking structure; the first stacking structure comprises an upper structural layer, a lower structural layer, and an intermediate film layer; the intermediate film layer is deposited on the lower structural layer, an annular groove is etched to form, the upper structural layer is deposited, a contact channel is formed in the groove, the upper structural layer is patterned, and the intermediate film layer outside the contact channel is released. The connecting rod structure further comprises a first stacking structure, a second stacking structure, a column, and / or a traditional structure; the second stacking structure comprises an upper structure, a filling structure, a stop layer, and a lower structure. The present invention reduces the influence of residual stress in the thin film of the connecting rod composite film layer material.

Description

Technical Field

[0001] The present invention relates to the field of MEMS (micro-electro-mechanical system) structure connection, and in particular to a micro-mechanical stacking structure and a connecting rod structure and a preparation method thereof. Background Art

[0002] MEMS (micro-electro-mechanical system) multi-layer motion structures sometimes require the upper and lower membrane layers to be connected by connecting rods to achieve the effect of joint motion.

[0003] The film linkage structure formed by traditional film processing after release is prone to slight upward or downward deformation of the vertical corner structure due to the residual stress of the film itself after the structure is released. Applications that require film flatness can easily affect component performance and the consistency of the finished product. In addition, when the vertical corner structure is movable after release, it is easy to form a structural stress concentration point here, making the structure relatively fragile and prone to structural fracture and damage when exposed to external forces. Summary of the Invention

[0004] The purpose of the present invention is to overcome the problem that thin films formed by existing thin film processes are prone to deformation, resulting in insufficient flatness and even breakage, thereby providing a micromechanical stacking structure and connecting rod structure and their preparation methods.

[0005] In order to solve the above technical problems, the technical solution of the present invention provides a micro-mechanical stacking structure 1, wherein the stacking structure 1 includes an upper structural layer 1-1, a lower structural layer 1-2 and an intermediate thin film layer 1-3;

[0006] The intermediate film layer 1-3 is deposited on the lower structural layer 1-2 and etched to form an annular groove, and then the upper structural layer 1-1 is deposited. The contact channel 1-4 is deposited in the groove, and the unnecessary part of the upper structural layer 1-1 is graphically removed, and the intermediate film layer 1-3 outside the contact channel 1-4 is released.

[0007] As one of the improvements of the above technical solution, the intermediate film layers 1-3 are single material film layers or composite film layers formed by randomly stacking multiple materials.

[0008] As one of the improvements of the above technical solution, the annular groove is in the shape of a circular ring, a square ring or a polygonal ring.

[0009] The present invention also provides a micro-mechanical connecting rod structure, wherein the connecting rod structure comprises at least a first stacking structure 1;

[0010] The first stacking structure 1 includes an upper structural layer 1-1, a lower structural layer 1-2 and an intermediate thin film layer 1-3; the intermediate thin film layer 1-3 is deposited on the lower structural layer 1-2, and after etching to form an annular groove, the upper structural layer 1-1 is deposited, and a contact channel 1-4 is deposited in the groove, and non-essential parts of the upper structural layer 1-1 are graphically removed, and the intermediate thin film layer 1-3 outside the contact channel 1-4 is released; the intermediate thin film layer 1-3 is a single material film layer or a composite film layer randomly stacked by multiple materials; the annular groove is in the shape of a circular ring, a square ring or a polygonal ring.

[0011] As one of the improvements of the above technical solution, the connecting rod structure further includes a first stacking structure 1, a second stacking structure 2, a column 3 and / or a traditional structure 4;

[0012] The second stacked structure 2 includes an upper structure 2-1, a filling structure 2-4, a stop layer 2-3 and a lower structure 2-2; after a sacrificial layer is deposited on the lower structure 2-2, a pit is formed by patterning, and then a film layer of the stop layer 2-3 is deposited, and a layer of the filling structure 2-4 is deposited to fill the pit formed by the film layer of the stop layer 2-3. Chemical mechanical polishing (CMP) is performed to remove the filling structure 2-4 material above the upper surface of the top layer 2-3-1 of the stop layer 2-3 to expose the upper surface of the top layer 2-3-1 of the stop layer 2-3. The top layer 2-3-1 of the stop layer 2-3 is patterned and non-essential parts of the stop layer 2-3 are removed to form the stop layer 2-3. The upper structure 2-1 is deposited and non-essential parts of the film layer of the upper structure 2-1 are patterned to release the sacrificial layer outside the stop layer 2-3.

[0013] The pillar 3 is a thin film layer formed by direct deposition;

[0014] The conventional structure 4 includes two thin film layers, an upper thin film layer and a lower thin film layer, wherein the upper thin film layer is stacked on the lower thin film layer in a concave shape.

[0015] As one of the improvements of the above technical solution, the inner bottom of the pit formed by the stop layer 2-3 of the second stacked structure 2 is set to a right-angle or stepped step shape, and the stepped step shape is a right-angle step or an oblique step.

[0016] The present invention also provides a method for preparing the micromechanical stacked structure provided by the present invention, comprising the following steps:

[0017] a) depositing thin film materials of the lower structural layer 1-2;

[0018] b) depositing sacrificial material of the intermediate thin film layers 1-3;

[0019] c) defining a contact area pattern on the surface of the intermediate film layer 1-3 by photolithography, and removing a portion of the intermediate film defined by the pattern by dry etching to form contact channels 1-4, wherein the pattern of the contact channels 1-4 is defined as a ring;

[0020] d) depositing a thin film material of the upper structural layer 1-1, interconnecting the upper structural layer 1-2 through the contact channel 1-4, and patterning and removing unnecessary parts of the upper structural layer 1-1;

[0021] e) releasing the sacrificial film material outside the contact channels 1 - 4 to form a stacked structure 1 .

[0022] As one of the improvements of the above technical solution, the ring shape of the contact channel in step c) includes a circular ring, a square ring or a polygonal ring.

[0023] As one of the improvements of the above technical solution, the material of the upper structure layer 1-1 film layer and the lower structure layer 1-2 film layer is a single material of silicon, polycrystalline silicon, amorphous silicon or silicon nitride, or a composite layer of polycrystalline silicon and silicon nitride, or a composite layer of amorphous silicon and silicon nitride;

[0024] As one of the improvements of the above technical solution, the thin film material of the intermediate sacrificial layer 1-3 is a single material of silicon oxide, borosilicate glass, phosphosilicate glass or borosilicate glass, or a composite material of at least two of them randomly stacked, and its deposition method is chemical vapor deposition CVD; the CVD includes low-pressure chemical vapor deposition LPCVD, atmospheric pressure chemical vapor deposition APCVD, sub-atmospheric pressure chemical vapor deposition SACVD or plasma enhanced chemical vapor deposition PECVD; when the thin film material of the intermediate sacrificial layer 1-3 is silicon oxide, its deposition method can also be thermal oxidation.

[0025] The present invention uses composite film layers to manufacture connecting rods. The film layers are stacked in sequence to improve strength and can also realize the production of small-sized graphics on each layer. At the same time, by optimizing the film layer stacking method and process, a relatively flat surface structure is formed. The stress of the connecting rod composite film layer can also be matched by selecting a combination of connecting rod composite film layer materials to reduce the influence of the residual stress of the connecting rod composite film layer material film, which can make the film structure connected to the connecting rod smoother, reduce the interference of the connecting rod residual stress, and improve the sensitivity performance of the component and the consistency of the finished product.

[0026] The micromechanical connecting rod proposed in the present invention can achieve the following technical effects:

[0027] 1. While achieving interconnection between the upper and lower thin films, the step height difference can be reduced to obtain a relatively flat surface structure, which is convenient for subsequent film flattening deposition and easy to achieve small line patterning.

[0028] 2. The first stacking structure and the second stacking structure are both composed of a structural layer material wrapped around a sacrificial layer material. While ensuring the flatness of the anchor area surface, the connecting rod cross-sectional area can be flexibly set according to the device structure design requirements and reused as a release stop structure to achieve precise stopping of release corrosion.

[0029] 3. The connecting rod is made of composite layer material, and the film layers are stacked in sequence. The first stacking structure and the second stacking structure process make the center area of ​​the connecting rod all solid film materials. The whole structure is relatively strong and reliable.

[0030] 4. By selecting a combination of connecting rod composite film materials to match the connecting rod composite film stress to reduce the influence of the connecting rod composite film material film residual stress, the film structure connected to the connecting rod can be made smoother, reducing the interference of the connecting rod residual stress, and improving the sensitivity performance of the component and the consistency of the finished product. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic cross-sectional view of the first stacking structure proposed by the present invention;

[0032] Figure 2 Three schematic cross-sectional views of the contact channel of the first stacked structure proposed by the present invention;

[0033] Figure 3 This is a cross-sectional schematic diagram of a second stacking structure included in the connecting rod structure proposed in the present invention;

[0034] FIG4 is a schematic cross-sectional view of a conventional structure and a first stacking structure proposed in the present invention, wherein FIG4(a) is a schematic cross-sectional view of the conventional structure, and FIG4(b) is a schematic cross-sectional view of the first stacking structure proposed in the present invention;

[0035] Figure 5 This is a cross-sectional schematic diagram of a first stacking structure proposed by the present invention, wherein the middle film layer is a composite layer;

[0036] Figure 6 Schematic diagram of the preparation process of the traditional structure;

[0037] Figure 7 A schematic diagram of the preparation process of the first stacking structure proposed in the present invention;

[0038] Figure 8 This is a schematic diagram of the preparation process of the second stacking structure included in the connecting rod structure proposed in the present invention;

[0039] FIG9 is a schematic cross-sectional view of a first embodiment of a second stacked structure included in the connecting rod structure proposed in the present invention. In this embodiment, a right-angled stepped step is provided inside the recess formed by the stop layer. FIG9(a) is a cross-sectional view before the sacrificial layer is released, and FIG9(b) is a cross-sectional view after the sacrificial layer is released.

[0040] FIG10 is a schematic cross-sectional view of a second embodiment of a second stacked structure included in the connecting rod structure proposed in the present invention. In this embodiment, an oblique stepped step is provided inside the recess formed by the stop layer. FIG10( a ) is a cross-sectional view before the sacrificial layer is released, and FIG10( b ) is a cross-sectional view after the sacrificial layer is released.

[0041] FIG11 is a schematic cross-sectional view of a connecting rod formed by stacking the first stacking structure with the column, the second stacking structure, and the traditional structure;

[0042] FIG12 is a schematic cross-sectional view of a connecting rod formed by stacking two first stacking structures and a second stacking structure;

[0043] FIG13 is a schematic cross-sectional view of a connecting rod formed by stacking any two of the columns, the second stacking structure, and the conventional structure with the first stacking structure;

[0044] FIG14 is a schematic cross-sectional view of a connecting rod formed by stacking a first stacking structure, a column, a second stacking structure, and a conventional structure;

[0045] Figures 15-19 This is a cross-sectional schematic diagram of the application of the connecting rod proposed in the present invention in a silicon microphone.

[0046] Figure ID

[0047] 1. First stacking structure 2. Second stacking structure 3. Column 4. Traditional structure

[0048] 1-1, upper structural layer 1-2, lower structural layer 1-3, middle film layer 1-4, contact channel

[0049] 2-1, upper structure 2-2, lower structure 2-3, stop layer 2-3-1, stop layer top

[0050] 2-4. Filling structure DETAILED DESCRIPTION

[0051] The technical solution provided by the present invention is further illustrated below with reference to embodiments.

[0052] The present invention proposes: a stacking structure and a composite film layer connecting rod structure, which improves the strength of the connecting rod and forms a relatively flat surface structure by introducing two stacking manufacturing processes; it can also match the composite film layer stress through the combination of composite film layer materials to reduce the influence of the residual stress of the connecting rod composite film layer material film, so that the film structure connected to the connecting rod can be smoother, reduce the interference of the connecting rod residual stress, and improve the sensitivity performance of the component and the consistency of the finished product.

[0053] like Figure 1As shown, a cross-sectional schematic diagram of the first stacking structure proposed in the present invention; the stacking structure 1 includes an upper structure layer 1-1, a lower structure layer 1-2 and an intermediate film layer 1-3; the intermediate film layer 1-3 is deposited on the lower structure layer 1-2, and after etching to form an annular groove, the upper structure layer 1-1 is deposited, and a contact channel 1-4 is deposited in the groove, and non-essential parts of the upper structure layer 1-1 are graphically removed, and the intermediate film layer 1-3 outside the contact channel 1-4 is released.

[0054] like Figure 2 1 and 2 are three schematic cross-sectional views of the contact channel of the first stacked structure proposed in the present invention; a) is a circular ring, b) is a square ring, and c) is a hexagonal ring.

[0055] like Figure 7 FIG. 1 is a schematic diagram of a preparation process of a first stacking structure proposed in the present invention;

[0056] The key processes and sequences are as follows:

[0057] a) depositing thin film materials of the lower structural layer;

[0058] b) depositing an intermediate sacrificial layer thin film material;

[0059] c) defining a contact area pattern on the surface of the intermediate film by photolithography, and removing the portion of the intermediate film defined by the pattern by dry etching to form a contact channel;

[0060] d) depositing an upper structural layer thin film material, interconnecting with the lower thin film through contact channels, and patterning and removing unnecessary parts of the upper structural layer;

[0061] e) releasing to form a first stacking structure.

[0062] Preferably, the contact area pattern is annular;

[0063] Preferably, the upper film is formed by LPCVD or PECVD.

[0064] Preferably, the upper film and the lower film are structural layers.

[0065] Preferably, the intermediate film layer is a sacrificial layer of silicon oxide, borosilicate glass (BSG), phosphosilicate glass (PSG), borophosphosilicate glass (BPSG) or a composite material randomly stacked by at least two of them, and its deposition method is chemical vapor deposition CVD, and the CVD includes low-pressure chemical vapor deposition LPCVD, atmospheric pressure chemical vapor deposition APCVD, sub-atmospheric pressure chemical vapor deposition SACVD or plasma enhanced chemical vapor deposition PECVD; when the sacrificial layer is silicon oxide, its deposition method can also be thermal oxidation; the corrosion rate of the sacrificial layer is greater than or much greater than the structural layer, and the sacrificial layer is corroded and released, retaining the structural layer material in the contact area to form an anchor area structure, and the anchor area structure is the structural layer material wrapping the sacrificial layer material. While ensuring the flatness of the anchor area surface, the anchor area area can be flexibly set according to the device structure design requirements, and the anchor area size can be precisely controlled after release.

[0066] The middle film layer is a single material film layer or a composite film layer stacked with multiple materials. Figure 5 FIG. 1 is a cross-sectional schematic diagram of a first stacking structure proposed by the present invention, wherein the middle film layer is a double-layer composite layer.

[0067] The first stacked structure features a ring-shaped etched contact area pattern, forming interconnecting channels between the upper and lower layers, followed by deposition of the upper film. Compared to traditional structures, this optimized etch pattern reduces the area requiring film filling, effectively minimizing step height differences and reducing processing complexity, resulting in a relatively flat surface structure. Furthermore, the central solid area is thicker, resulting in higher strength.

[0068] The traditional structure has disadvantages in terms of step height difference, which can easily cause large step height problems in the later layers. It is not suitable for the front layers in the product process flow, and will bring difficulties to the process processing of the later layers. However, it can be used in the later or final layers, because when it comes to the later layers, the step height difference on the chip surface will be relatively large, and the graphic plane size at the connection between the traditional structure and the lower structure layer can be made relatively large. Thick glue can be used to make larger graphics to achieve this, and the difficulty of photolithography will be relatively low. Therefore, in the embodiments of the present application, some connecting rod structures are formed by combining and stacking the first stacking structure proposed in the present invention with the traditional structure according to specific needs.

[0069] FIG4 is a schematic diagram showing a cross-sectional comparison of a conventional structure and a first stacking structure proposed in the present invention, wherein FIG4(a) is a schematic diagram showing a cross-sectional view of the conventional structure, and FIG4(b) is a schematic diagram showing a cross-sectional view of the first stacking structure proposed in the present invention;

[0070] like Figure 6 As shown, it is a schematic diagram of the preparation process of the traditional structure;

[0071] The key processes and sequences are as follows:

[0072] a) depositing the lower structural layer;

[0073] b) depositing a sacrificial layer on the lower structure;

[0074] c) etching the sacrificial layer to form a contact area pit;

[0075] d) depositing a thin film material for an upper structural layer and patterning and removing unnecessary portions of the upper structural layer;

[0076] e) Release the sacrificial layer to form a conventional structure.

[0077] In the traditional structure, due to the stress between the membrane layers, both sides of the upper membrane layer are prone to deformation, which affects the membrane layer structure. The first stacking structure proposed in the present invention effectively solves the problem that the upper membrane layer is prone to deformation or fracture.

[0078] like Figure 3 FIG. 2 is a cross-sectional schematic diagram of the second stacking structure included in the connecting rod structure proposed in the present invention;

[0079] The second stacked structure 2 includes an upper structure 2-1, a filling structure 2-4, a stop layer 2-3, and a lower structure 2-2; the filling structure 2-4 is filled in the pit formed by the stop layer 2-3, and is used to make the central part of the second stacked structure 2 solid, so as to connect the upper structure 2-1 and the lower structure 2-2;

[0080] The second stacked structure fills the etched contact area with a release-stop film material. The bottom layer is the interconnect material and also serves as a release corrosion barrier. It is then filled and smoothed with CMP material, and then the upper structural layer film is deposited. Compared to traditional methods, after filling and CMP, the surface structure is smoother, while the central solid area is thicker and stronger.

[0081] like Figure 8 FIG. 1 is a schematic diagram of a preparation process of the second stacking structure included in the connecting rod structure proposed in the present invention;

[0082] The key processes and sequences are as follows:

[0083] a) depositing a sacrificial layer on the underlying structural film, and etching the sacrificial layer to form a contact area pit;

[0084] b) depositing a release stop layer thin film material;

[0085] c) depositing the contact area pit filling material, followed by CMP to flatten the surface;

[0086] d) Graphically remove unnecessary areas of the stop layer;

[0087] e) depositing a superstructure thin film material and patterning and removing unnecessary portions of the superstructure film layer;

[0088] f) releasing to form a second stacking structure.

[0089] Preferably, the material of the lower structural film is silicon, polysilicon, amorphous silicon, a composite layer of polysilicon and silicon nitride, or a composite layer of amorphous silicon and silicon nitride;

[0090] Preferably, the material of the sacrificial layer is silicon oxide, which is formed by LPCVD, APCVD, SACVD, PECVD, etc.

[0091] Preferably, the release stop layer thin film material is silicon nitride, formed by LPCVD or PECVD;

[0092] Preferably, the contact area pit filling material is silicon oxide, borosilicate glass, phosphosilicate glass, borophosphosilicate glass, or a composite material of at least two of them stacked randomly;

[0093] Preferably, the material of the upper structure film is silicon, polysilicon, amorphous silicon, a composite layer of polysilicon and silicon nitride, or a composite layer of amorphous silicon and silicon nitride, or a composite material of at least two of them randomly stacked.

[0094] FIG9 is a cross-sectional view of a first embodiment of a second stacked structure included in the connecting rod structure proposed in the present invention. In this embodiment, a right-angled stepped step is provided inside the recess formed by the stop layer. FIG9( a ) is a cross-sectional view before the sacrificial layer is released, and FIG9( b ) is a cross-sectional view after the sacrificial layer is released.

[0095] As shown in Figure 10, it is a cross-sectional schematic diagram of a second embodiment of a second stacking structure included in the connecting rod structure proposed in the present invention. In this embodiment, an oblique stepped step is provided on the inner side of the pit formed by the stop layer, wherein Figure 10(a) is a cross-sectional diagram before the sacrificial layer is released, and Figure 10(b) is a cross-sectional diagram after the sacrificial layer is released; when preparing the oblique stepped step, during the sacrificial layer etching step, the angle of the etched side wall of the sacrificial layer can be kept inclined.

[0096] As shown in FIG11 , a schematic cross-sectional view of a connecting rod formed by stacking the first stacking structure with a column, a second stacking structure, a conventional structure, and the first stacking structure is shown; wherein the connecting rod in FIG11( a ) is formed by stacking the first stacking structure 1 and a column 3, the connecting rod in FIG11( b ) is formed by stacking the first stacking structure 1 and the second stacking structure 2, the connecting rod in FIG11( c ) is formed by stacking the first stacking structure 1 and the conventional structure 4, and the connecting rod in FIG11( d ) is formed by stacking two first stacking structures 1;

[0097] FIG12 is a schematic cross-sectional view of a connecting rod formed by stacking two first stacking structures and one second stacking structure, wherein the stop layer pit of the second stacking structure in FIG12(a) is a right-angled stepped step shape, and the stop layer pit of the second stacking structure in FIG12(b) is an oblique-angled stepped step shape;

[0098] As shown in FIG13 , it is a schematic cross-sectional view of a connecting rod formed by stacking any two of the columns, the second stacking structure, and the conventional structure with the first stacking structure, wherein the connecting rod in FIG13( a ) is formed by stacking the first stacking structure 1, the columns 3, and the conventional structure 4, the connecting rod in FIG13( b ) is formed by stacking the first stacking structure 1, the second stacking structure 2, and the columns 3, and the connecting rod in FIG13( c ) is formed by stacking the first stacking structure 1, the second stacking structure 2, and the conventional structure 4;

[0099] As shown in FIG14 , a schematic cross-sectional view of a connecting rod formed by stacking a first stacking structure 1, a column 3, a second stacking structure 2, and a conventional structure 4 is shown. The stop layer pit of the second stacking structure 2 in FIG14( a ) is in the shape of a right-angled stepped step, while the stop layer pit of the second stacking structure 2 in FIG14( b ) is in the shape of an oblique-angled stepped step.

[0100] like Figures 15-19 FIG. 1 is a cross-sectional schematic diagram of the application of the connecting rod proposed by the present invention in a silicon microphone, wherein: Figure 15 The connecting rod structure is formed by stacking two first stacking structures 1; Figure 16 The connecting rod structure is formed by stacking a first stacking structure 1, a column 3, and a traditional structure 4; Figure 17 The connecting rod structure is formed by stacking a first stacking structure 1 and two columns 3; Figure 18 The connecting rod structure is formed by stacking a first stacking structure 1 and a traditional structure 4, wherein the middle film layer of the first stacking structure is a composite layer; Figure 19 The connecting rod structure is formed by stacking two first stacking structures 1 and a column 3. The connecting rod in the three-layer structure has a flat surface, reduces the height difference, and has a stronger overall structure.

[0101] The internal composite film layer of the multi-layer connecting rod structure proposed by the present invention can match the film layer stress to reduce the interference and influence of the connecting rod on the residual stress of the film, thereby improving the sensitivity performance of the component and the consistency of the finished product.

[0102] The various structural stacking combinations provided by the present invention can match the stress of the film layer and achieve the goal of reducing the residual stress of the composite layer.

[0103] From the above specific description of the present invention, it can be seen that the micromechanical connecting rod structure of the present invention matches the connecting rod composite film stress by selecting a connecting rod composite film layer material combination, thereby reducing the influence of the residual stress of the connecting rod composite film layer material film, making the film structure connected to the connecting rod smoother, reducing the interference of the connecting rod residual stress, and improving the sensitivity performance of the component and the consistency of the finished product.

[0104] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions to the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention and are intended to be encompassed by the claims of the present invention.

Claims

1. A micromechanical stacked structure (1), comprising an upper structural layer (1-1), a lower structural layer (1-2) and an intermediate thin film layer (1-3), characterized in that: The intermediate film layer (1-3) is deposited on the lower structural layer (1-2), and after etching to form an annular groove, the upper structural layer (1-1) is deposited, a contact channel (1-4) is deposited in the groove, and the intermediate film layer (1-3) outside the contact channel (1-4) is released; The materials of the upper structural layer (1-1) and the lower structural layer (1-2) are single materials of silicon, polycrystalline silicon, amorphous silicon or silicon nitride, or composite layers of polycrystalline silicon and silicon nitride, or composite layers of amorphous silicon and silicon nitride; The film material of the intermediate film layer (1-3) is a single material of silicon oxide, borosilicate glass, phosphosilicate glass or borosilicate glass, or a composite material of at least two of them stacked randomly.

2. The micromechanical stacked structure according to claim 1, wherein: The intermediate film layer (1-3) is a single material film layer or a composite film layer formed by randomly stacking multiple materials.

3. The micromechanical stacked structure according to claim 1, wherein: The annular groove is in the shape of a circular ring, a square ring or a polygonal ring.

4. A micromechanical connecting rod structure, characterized in that: The connecting rod structure comprises at least a first stacking structure (1); The first stacked structure (1) comprises an upper structural layer (1-1), a lower structural layer (1-2) and an intermediate thin film layer (1-3); the intermediate thin film layer (1-3) is deposited on the lower structural layer (1-2), and after etching to form an annular groove, the upper structural layer (1-1) is deposited, a contact channel (1-4) is deposited in the groove, and the intermediate thin film layer (1-3) outside the contact channel (1-4) is released; the intermediate thin film layer (1-3) is a single material film layer or a composite film layer randomly stacked by multiple materials; the annular groove is in the shape of a circular ring, a square ring or a polygonal ring; The materials of the upper structural layer (1-1) and the lower structural layer (1-2) are single materials of silicon, polycrystalline silicon, amorphous silicon or silicon nitride, or composite layers of polycrystalline silicon and silicon nitride, or composite layers of amorphous silicon and silicon nitride; The film material of the intermediate film layer (1-3) is a single material of silicon oxide, borosilicate glass, phosphosilicate glass or borosilicate glass, or a composite material of at least two of them randomly stacked.

5. The micromechanical connecting rod structure according to claim 4, characterized in that: The connecting rod structure further comprises a first stacking structure (1), a second stacking structure (2), a column (3) and / or a traditional structure (4); The second stacking structure (2) comprises an upper structure (2-1), a filling structure (2-4), a stop layer (2-3) and a lower structure (2-2); after depositing a sacrificial layer on the lower structure (2-2), the sacrificial layer is patterned to form a pit, then a film layer of the stop layer (2-3) is deposited, a filling structure (2-4) layer is deposited and the pit formed by the stop layer (2-3) film layer is filled, chemical mechanical polishing is performed to remove the filling structure (2-4) material above the upper surface of the top layer (2-3-1) of the stop layer (2-3) film layer to expose the upper surface of the top layer (2-3-1) of the stop layer (2-3) film layer, the top layer (2-3-1) of the stop layer (2-3) film layer is patterned and non-essential parts of the stop layer (2-3) film layer are removed to form the stop layer (2-3), the upper structure (2-1) is deposited and the sacrificial layer outside the stop layer (2-3) is released; The column (3) is a thin film layer formed by direct deposition; The conventional structure (4) comprises two thin film layers, an upper thin film layer and a lower thin film layer, wherein the upper thin film layer is stacked on the lower thin film layer in a concave shape.

6. The micromechanical connecting rod structure according to claim 5, characterized in that: The inner bottom of the pit formed by the stop layer (2-3) of the second stacked structure (2) is arranged in a right-angle or stepped step shape, and the stepped step shape is a right-angle step or an oblique-angle step.

7. A method for preparing the micromechanical stacked structure according to claim 1, comprising the following steps: a) depositing thin film materials of the lower structural layer (1-2); b) depositing sacrificial material of the intermediate thin film layers (1-3); c) defining a contact area pattern on the surface of the intermediate film layer (1-3) by photolithography, and removing a portion of the intermediate film defined by the pattern by dry etching to form a contact channel (1-4), wherein the pattern of the contact channel (1-4) is defined as a ring; d) depositing a thin film material of an upper structural layer (1-1) interconnected with a lower structural layer (1-2) via contact channels (1-4); e) releasing the sacrificial film material outside the contact channels (1-4) to form a stacked structure (1).

8. The method for preparing a micromechanical stacked structure according to claim 7, wherein: The ring shape of the contact channel in step c) includes a circular ring shape, a square ring shape or a polygonal ring shape.

9. The method for preparing a micromechanical stacked structure according to claim 7, wherein: The thin film material of the intermediate thin film layer (1-3) is deposited by chemical vapor deposition (CVD); the CVD includes low-pressure chemical vapor deposition (LPCVD), atmospheric pressure chemical vapor deposition (APCVD), sub-atmospheric pressure chemical vapor deposition (SACVD) or plasma enhanced chemical vapor deposition (PECVD); when the thin film material of the intermediate thin film layer (1-3) is silicon oxide, its deposition method can also be thermal oxidation.

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