MEMS micromirror array and preparation method thereof

Abstract

The invention discloses an MEMS (micro-electromechanical system) micromirror array and a preparation method thereof, the MEMS micromirror array is formed by periodically arranging a plurality of MEMS micromirrors, each MEMS micromirror comprises two SOI (silicon-on-insulator) sheets which are parallel and opposite up and down, and the two SOI sheets are connected through silicon-silicon bonding; wherein the upper SOI sheet comprises a substrate, an upper comb tooth structure, a mirror surface, a rotating shaft structure and an electrode structure; the lower SOI chip comprises a lower comb tooth structure; the MEMS micro-mirror array is prepared by the preparation method designed by the invention, the MEMS micro-mirror array designed by the invention aims to solve the problems of complicated electrode lead arrangement, high cost and low yield of the MEMS micro-mirror array in the prior art, and the preparation method of the MEMS micro-mirror array is provided to reduce the process difficulty and simplify the manufacturing process so as to reduce the manufacturing cost.

Description

Technical Field

[0001] The present invention relates to the field of micro-electromechanical technology, in particular to a MEMS micro-mirror array, and also to a method for preparing the MEMS micro-mirror array. Background Art

[0002] With the rapid development of optical communication technology, especially driven by AI intelligence, the surge in data traffic and the complexity of network architecture have put forward higher requirements for the flexibility and efficiency of optical network nodes. As a key device in the optical network, the performance of optical cross-connect (OXC) directly affects the operating efficiency and stability of the entire optical network. OXC based on MEMS micromirror array has been widely used in modern optical communication networks due to its compact structure, low power consumption and fast response speed.

[0003] However, the existing MEMS micromirror array and its preparation process face many challenges in the layout of electrode leads. The traditional TSV (Through Silicon Via) process requires each electrode to be led out from the back and then connected to the wiring substrate using the flipchip process, which not only increases the complexity of the manufacturing process, but also leads to problems such as high cost and low yield. Summary of the invention

[0004] The purpose of the present invention is to provide a MEMS micromirror array and a preparation method thereof, so as to solve the problems of complex electrode lead arrangement, high cost and low yield of MEMS micromirror array in the prior art, and to achieve the technical effect of reducing process difficulty, simplifying manufacturing process and reducing manufacturing cost.

[0005] In order to realize the above functions, the present invention designs a MEMS micromirror array, which is composed of a plurality of MEMS micromirrors arranged periodically, each MEMS micromirror includes two parallel SOI sheets facing each other up and down, and the two SOI sheets are connected by silicon-silicon bonding; wherein the upper SOI sheet includes a substrate 1, an upper comb-tooth structure, a mirror surface 2, a rotating shaft structure, and an electrode structure; and the lower SOI sheet includes a lower comb-tooth structure;

[0006] The shaft structure of the upper SOI wafer includes a pair of outer shafts 3 and a pair of inner shafts 4, and a shaft frame 5 connected to the outer shaft 3 and the inner shaft 4 respectively; the shaft frame 5 is an annular structure, located at the center of the substrate 1, the mirror 2 is located inside the annular structure of the shaft frame 5, the straight lines where the pair of outer shafts 3 are located are collinear and are respectively located at the upper and lower ends of the outer side of the shaft frame 5, one end of the outer shaft 3 is respectively connected to the shaft frame 5, and the other end of the outer shaft 3 is respectively connected to the substrate 1, so that the shaft frame 5 generates axial rotation relative to the fixed substrate 1 with the pair of outer shafts 3 as the axis;

[0007] A pair of inner shaft rotating shafts 4 are collinear and located at the left and right ends of the inner side of the rotating shaft frame 5, one end of the inner shaft rotating shaft 4 is connected to the rotating shaft frame 5, and the other end of the inner shaft rotating shaft 4 is connected to the mirror surface 2, so that the mirror surface 2 is axially rotated relative to the fixed substrate 1 with the pair of inner shaft rotating shafts 4 as the axis;

[0008] The upper comb tooth structure includes a pair of outer shaft movable comb tooth groups 6 and a pair of inner shaft movable comb tooth groups 7. The outer shaft movable comb tooth groups 6 are axially symmetrical and are respectively located at the left and right ends of the outer side of the rotating shaft frame 5. The straight lines where the symmetry axes of the pair of outer shaft movable comb tooth groups 6 are located are collinear and collinear with the inner shaft rotating shaft 4. One end of the pair of outer shaft movable comb tooth groups 6 is respectively connected to the rotating shaft frame 5, and the other end is opposite to the substrate 1. The pair of outer shaft movable comb tooth groups 6 rotate axially with the rotating shaft frame 5.

[0009] The inner shaft movable comb tooth group 7 is in an axisymmetric shape and is respectively located at the upper and lower ends of the inner side of the rotating shaft frame 5. The straight line where the symmetry axes of the pair of inner shaft movable comb tooth groups 7 are located is collinear and is also collinear with the outer shaft rotating shaft 3. One end of the pair of inner shaft movable comb tooth groups 7 is respectively connected to the mirror surface 2, and the other end is opposite to the inner side of the rotating shaft frame 5. The pair of inner shaft movable comb tooth groups 7 rotate axially with the mirror surface 2.

[0010] The lower comb tooth structure includes a pair of outer-axis fixed comb tooth groups 8 and a pair of inner-axis fixed comb tooth groups 9, which are fixed on the lower SOI wafer and correspond to the outer-axis movable comb tooth group 6 and the inner-axis movable comb tooth group 7 in the upper comb tooth structure respectively;

[0011] The pattern formed by the upper comb structure, the mirror surface 2 and the rotating shaft structure on the substrate 1 is axially symmetrical.

[0012] As a preferred technical solution of the present invention: the outer-axis movable comb tooth group 6 and the inner-axis movable comb tooth group 7 in the upper comb tooth structure each include at least one comb tooth, and each comb tooth in the comb tooth group extends to both sides with the symmetry axis of the comb tooth group as the center; each comb tooth in the comb tooth group is parallel to each other, and adjacent comb teeth are equidistant; the outer-axis fixed comb tooth group 8 and the inner-axis fixed comb tooth group 9 in the lower comb tooth structure each include at least one comb tooth, and the projections of each comb tooth in the outer-axis fixed comb tooth group 8 and the inner-axis fixed comb tooth group 9 are respectively parallel to the projections of each comb tooth in the outer-axis movable comb tooth group 6 and the inner-axis movable comb tooth group 7 at the corresponding positions, and are staggered with each other.

[0013] As a preferred technical solution of the present invention: the electrode structure includes two pairs of positive electrode PAD10 and two pairs of GND PAD11, each positive electrode PAD10 has a positive electrode isolation groove 12 on the outside, the two pairs of positive electrode PAD10 are respectively located at the upper right corner and the lower left corner of the substrate 1, and the two pairs of GND PAD11 are respectively located at the upper left corner and the lower right corner of the substrate 1.

[0014] As a preferred technical solution of the present invention: the positive electrode isolation groove 12 and the non-patterned area on the surface of the substrate 1 are insulated by covering the oxide layer.

[0015] As a preferred technical solution of the present invention: the oxide layer is prepared by thermal oxidation or plasma enhanced chemical vapor deposition process.

[0016] As a preferred technical solution of the present invention: the positive electrode isolation groove 12 is patterned by deep silicon etching technology.

[0017] As a preferred technical solution of the present invention: a plurality of MEMS micromirrors are periodically arranged to form a MEMS micromirror array, the electrode structure of each MEMS micromirror is respectively connected to an electrode lead, the plane where the electrode structure is located is used as the front side of the MEMS micromirror, and each electrode lead is led out from the front side of the MEMS micromirror.

[0018] The present invention also provides a method for preparing a MEMS micromirror array, and performs the following steps S1 to S8 to complete the preparation of the MEMS micromirror array:

[0019] Step S1: for each MEMS micromirror in the MEMS micromirror array, a lower comb-tooth etching is performed on the lower SOI wafer by deep silicon etching technology to form a lower comb-tooth structure;

[0020] Step S2: performing silicon-silicon bonding between the upper SOI wafer and the lower SOI wafer on which the lower comb teeth etching has been completed;

[0021] Step S3: removing the handle layer and buried oxide layer of the upper SOI wafer after silicon-silicon bonding to expose the required structural part;

[0022] Step S4: On the upper SOI wafer, using a photoresist as a mask, patterning the positive electrode isolation groove 12 by deep silicon etching technology, and the width of the positive electrode isolation groove 12 is reduced as much as possible under the premise of satisfying the maximum etching depth-to-width ratio;

[0023] Step S5: preparing an oxide layer on the surface of the upper SOI wafer by thermal oxidation or plasma enhanced chemical vapor deposition process to form a substrate 1 on the surface of the upper SOI wafer;

[0024] Step S6: using photolithography technology to etch the oxide layer on the surface of the upper SOI wafer to pattern the electrode structure and the upper comb structure;

[0025] Step S7: forming an electrode structure, an electrode lead and a mirror 2 on the surface of the upper SOI wafer by metal deposition technology and etching technology;

[0026] Step S8: Using the photoresist as a mask, the upper SOI wafer is etched into upper comb teeth by deep silicon etching technology to form an upper comb tooth structure and a shaft structure, thereby completing the preparation of the MEMS micromirror. The MEMS micromirrors are periodically arranged to form a MEMS micromirror array.

[0027] Beneficial effects: Compared with the prior art, the advantages of the present invention include:

[0028] 1. Reduce process difficulty: By leading out the electrode leads from the front, the complexity of leading out the electrode from the back in the traditional TSV process is avoided, thus reducing the process difficulty;

[0029] 2. Simplify the manufacturing process: The solution of leading the electrode leads from the front simplifies the manufacturing process and improves production efficiency;

[0030] 3. Reduce manufacturing costs: Due to the simplification of process difficulty and manufacturing process, the manufacturing cost of the present invention is significantly reduced;

[0031] 4. Improve product yield: The simplified manufacturing process reduces potential manufacturing defects and improves product yield;

[0032] 5. Compact structure: The present invention ensures the compact structure of the micromirror array while achieving effective arrangement of electrode leads, thus meeting the requirements of the optical communication network for equipment performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic diagram of a top view of a MEMS micromirror provided according to an embodiment of the present invention;

[0034] Figure 2 is a schematic diagram of an oxide layer of a MEMS micromirror provided according to an embodiment of the present invention;

[0035] Figure 3 is a schematic diagram of a lower comb tooth structure provided according to an embodiment of the present invention;

[0036] Figure 4 is a schematic diagram of silicon-silicon bonding of two SOI wafers provided according to an embodiment of the present invention;

[0037] Figure 5 is a schematic diagram of an upper SOI wafer with a handle layer and a buried oxide layer removed according to an embodiment of the present invention;

[0038] Figure 6 is a schematic diagram of etching a positive electrode isolation groove according to an embodiment of the present invention;

[0039] Figure 7 is a schematic diagram of preparing an oxide layer according to an embodiment of the present invention;

[0040] Figure 8is a partial enlarged view of the filling effect of the positive electrode isolation groove provided in an embodiment of the present invention;

[0041] Fig. 9 is a schematic diagram of an etching electrode structure and an upper comb structure provided according to an embodiment of the present invention;

[0042] Fig.10 is a schematic diagram of forming an electrode structure, an electrode lead and a mirror surface according to an embodiment of the present invention;

[0043] Fig.11 is a schematic diagram of an etched upper comb structure and a rotating shaft structure provided according to an embodiment of the present invention;

[0044] Fig.12 Schematic diagram of a MEMS micromirror array provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0045] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0046] A MEMS micromirror array provided by an embodiment of the present invention is composed of a plurality of MEMS micromirrors arranged periodically, each MEMS micromirror includes two parallel SOI sheets facing each other vertically, and the two SOI sheets are connected by silicon-silicon bonding; Figure 1 , wherein the upper SOI sheet includes a substrate 1, an upper comb-tooth structure, a mirror 2, a rotating shaft structure, and an electrode structure; and the lower SOI sheet includes a lower comb-tooth structure;

[0047] The shaft structure of the upper SOI wafer includes a pair of outer shafts 3 and a pair of inner shafts 4, and a shaft frame 5 connected to the outer shaft 3 and the inner shaft 4 respectively; the shaft frame 5 is an annular structure, located at the center of the substrate 1, the mirror 2 is located inside the annular structure of the shaft frame 5, the straight lines where the pair of outer shafts 3 are located are collinear and are respectively located at the upper and lower ends of the outer side of the shaft frame 5, one end of the outer shaft 3 is respectively connected to the shaft frame 5, and the other end of the outer shaft 3 is respectively connected to the substrate 1, so that the shaft frame 5 generates axial rotation relative to the fixed substrate 1 with the pair of outer shafts 3 as the axis;

[0048] A pair of inner shaft rotating shafts 4 are collinear and located at the left and right ends of the inner side of the rotating shaft frame 5, one end of the inner shaft rotating shaft 4 is connected to the rotating shaft frame 5, and the other end of the inner shaft rotating shaft 4 is connected to the mirror surface 2, so that the mirror surface 2 is axially rotated relative to the fixed substrate 1 with the pair of inner shaft rotating shafts 4 as the axis;

[0049] The upper comb tooth structure includes a pair of outer shaft movable comb tooth groups 6 and a pair of inner shaft movable comb tooth groups 7. The outer shaft movable comb tooth groups 6 are axially symmetrical and are respectively located at the left and right ends of the outer side of the rotating shaft frame 5. The straight lines where the symmetry axes of the pair of outer shaft movable comb tooth groups 6 are located are collinear and collinear with the inner shaft rotating shaft 4. One end of the pair of outer shaft movable comb tooth groups 6 is respectively connected to the rotating shaft frame 5, and the other end is opposite to the substrate 1. The pair of outer shaft movable comb tooth groups 6 rotate axially with the rotating shaft frame 5.

[0050] The inner shaft movable comb tooth group 7 is in an axisymmetric shape and is respectively located at the upper and lower ends of the inner side of the rotating shaft frame 5. The straight line where the symmetry axes of the pair of inner shaft movable comb tooth groups 7 are located is collinear and is also collinear with the outer shaft rotating shaft 3. One end of the pair of inner shaft movable comb tooth groups 7 is respectively connected to the mirror surface 2, and the other end is opposite to the inner side of the rotating shaft frame 5. The pair of inner shaft movable comb tooth groups 7 rotate axially with the mirror surface 2.

[0051] The lower comb tooth structure includes a pair of outer-axis fixed comb tooth groups 8 and a pair of inner-axis fixed comb tooth groups 9, which are fixed on the lower SOI wafer and correspond to the outer-axis movable comb tooth group 6 and the inner-axis movable comb tooth group 7 in the upper comb tooth structure respectively;

[0052] The pattern formed by the upper comb structure, the mirror surface 2 and the rotating shaft structure on the substrate 1 is axially symmetrical.

[0053] The outer-axis movable comb tooth group 6 and the inner-axis movable comb tooth group 7 in the upper comb tooth structure each include at least one comb tooth, and each comb tooth in the comb tooth group extends to both sides with the symmetry axis of the comb tooth group as the center; each comb tooth in the comb tooth group is parallel to each other, and adjacent comb teeth are equally spaced; the outer-axis fixed comb tooth group 8 and the inner-axis fixed comb tooth group 9 in the lower comb tooth structure each include at least one comb tooth, and the projections of each comb tooth in the outer-axis fixed comb tooth group 8 and the inner-axis fixed comb tooth group 9 are respectively parallel to the projections of each comb tooth in the outer-axis movable comb tooth group 6 and the inner-axis movable comb tooth group 7 at the corresponding positions, and are staggered with each other.

[0054] The electrode structure includes two pairs of positive electrode PAD10 and two pairs of GND PAD11. Each positive electrode PAD10 has a positive electrode isolation groove 12 on the outside. The two pairs of positive electrode PAD10 are respectively located at the upper right corner and the lower left corner of the substrate 1, and the two pairs of GND PAD11 are respectively located at the upper left corner and the lower right corner of the substrate 1.

[0055] The positive electrode isolation groove 12 and the non-patterned area on the surface of the substrate 1 are insulated by covering the oxide layer. Figure 2 ,The shaded area in the figure is the oxide layer, which is prepared by thermal oxidation (TOX) or plasma enhanced chemical vapor deposition (PECVD) process.

[0056] The positive electrode isolation groove 12 is patterned by deep silicon etching technology, and the width of the isolation groove is reduced as much as possible under the premise of meeting the maximum etching depth-to-width ratio, so as to facilitate the filling of the insulation groove and the upper wiring requirements.

[0057] A plurality of MEMS micromirrors are arranged periodically to form a MEMS micromirror array. The electrode structure of each MEMS micromirror is connected to an electrode lead respectively. The plane where the electrode structure is located is used as the front side of the MEMS micromirror. Each electrode lead is led out from the front side of the MEMS micromirror, thus avoiding the complexity of leading out the electrode from the back side in the traditional TSV process, reducing the process difficulty, simplifying the manufacturing process, reducing the manufacturing cost, and improving the product yield.

[0058] The embodiment of the present invention further provides a method for preparing a MEMS micromirror array, and performs the following steps S1 to S8 to complete the preparation of the MEMS micromirror array:

[0059] Step S1: For each MEMS micromirror in the MEMS micromirror array, the SOI wafer below is etched with a lower comb tooth by deep silicon etching technology to form a lower comb tooth structure. Figure 3 ;

[0060] Step S2: perform silicon-silicon bonding between the upper SOI wafer and the lower SOI wafer on which the lower comb teeth etching has been completed. The schematic diagram of silicon-silicon bonding between the two SOI wafers is shown in FIG. Figure 4 ;

[0061] Step S3: Remove the handle layer and buried oxide layer of the upper SOI wafer after silicon-silicon bonding to expose the required structural parts, refer to Figure 5 ;

[0062] Step S4: On the upper SOI wafer, using the photoresist as a mask, the positive electrode isolation groove 12 is patterned by deep silicon etching technology. The width of the positive electrode isolation groove 12 is minimized as much as possible under the premise of meeting the maximum etching depth-to-width ratio. Figure 6 ;

[0063] Step S5: thermal oxidation or plasma enhanced chemical vapor deposition is used to prepare an oxide layer on the surface of the upper SOI wafer to form a substrate 1 on the surface of the upper SOI wafer. Figure 7 The positive electrode isolation groove 12 around the positive electrode PAD 10 has a large aspect ratio, so the top of the positive electrode isolation groove 12 will be filled first during filling, which can ensure the reliability of isolation between electrodes and connection of the wiring substrate; Figure 8 It is a partial enlarged view of the filling effect of the positive electrode isolation groove 12, and the shadow is the oxide layer;

[0064] Step S6: Using photolithography technology, the oxide layer on the surface of the upper SOI wafer is etched to pattern the electrode structure and the upper comb structure, referring to Fig. 9 ;

[0065] Step S7: Forming electrode structures, electrode leads and mirror 2 on the upper SOI wafer surface by metal deposition technology and etching technology, referring to Fig.10 ;

[0066] Step S8: Using the photoresist as a mask, the upper SOI wafer is etched by deep silicon etching technology to form an upper comb structure and a shaft structure, and the preparation of the MEMS micromirror is completed. Fig.11 , each MEMS micromirror is arranged periodically to form a MEMS micromirror array, refer to Fig.12 .

[0067] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, and various changes can be made within the knowledge scope of ordinary technicians in this field without departing from the purpose of the present invention.

Claims

1. A MEMS micromirror array, consisting of a plurality of MEMS micromirrors arranged periodically, It is characterized in that Each MEMS micromirror comprises two parallel SOI sheets facing each other vertically, and the two SOI sheets are connected by silicon-silicon bonding; the upper SOI sheet comprises a substrate (1), an upper comb-tooth structure, a mirror surface (2), a rotating shaft structure, and an electrode structure; and the lower SOI sheet comprises a lower comb-tooth structure. The rotating shaft structure of the upper SOI wafer comprises a pair of outer rotating shafts (3) and a pair of inner rotating shafts (4), and a rotating shaft frame (5) respectively connected to the outer rotating shafts (3) and the inner rotating shafts (4); the rotating shaft frame (5) is an annular structure and is located at the center of the substrate (1); the mirror (2) is located inside the annular structure of the rotating shaft frame (5); the straight lines where the pair of outer rotating shafts (3) are located are collinear and respectively located at the upper and lower ends of the outer side of the rotating shaft frame (5); one end of the outer rotating shaft (3) is respectively connected to the rotating shaft frame (5), and the other end of the outer rotating shaft (3) is respectively connected to the substrate (1), so that the rotating shaft frame (5) generates axial rotation relative to the fixed substrate (1) with the pair of outer rotating shafts (3) as the axis; A pair of inner shaft rotating shafts (4) are located on a collinear line and are respectively located at the left and right ends of the inner side of the rotating shaft frame (5); one end of the inner shaft rotating shaft (4) is respectively connected to the rotating shaft frame (5); the other end of the inner shaft rotating shaft (4) is respectively connected to the mirror surface (2), so that the mirror surface (2) generates axial rotation relative to the fixed substrate (1) with the pair of inner shaft rotating shafts (4) as the axis; The upper comb tooth structure comprises a pair of outer shaft movable comb tooth groups (6) and a pair of inner shaft movable comb tooth groups (7); the outer shaft movable comb tooth groups (6) are axially symmetrical and are respectively located at the left and right ends of the outer side of the rotating shaft frame (5); the straight lines where the symmetry axes of the pair of outer shaft movable comb tooth groups (6) are located are collinear and collinear with the inner shaft rotating shaft (4); one end of the pair of outer shaft movable comb tooth groups (6) is respectively connected to the rotating shaft frame (5), and the other end is opposite to the substrate (1); the pair of outer shaft movable comb tooth groups (6) generate axial rotation along with the rotating shaft frame (5); The inner shaft movable comb tooth groups (7) are axially symmetrical and are respectively located at the upper and lower ends of the inner side of the rotating shaft frame (5); the straight line where the symmetry axes of the pair of inner shaft movable comb tooth groups (7) are located is collinear and is also collinear with the outer shaft rotating shaft (3); one end of the pair of inner shaft movable comb tooth groups (7) is respectively connected to the mirror surface (2), and the other end is opposite to the inner side of the rotating shaft frame (5); the pair of inner shaft movable comb tooth groups (7) rotate axially with the mirror surface (2); The lower comb tooth structure comprises a pair of external fixed comb tooth groups (8) and a pair of internal fixed comb tooth groups (9), which are fixed on the lower SOI wafer and respectively correspond to the external movable comb tooth group (6) and the internal movable comb tooth group (7) in the upper comb tooth structure; The pattern formed by the upper comb tooth structure, the mirror surface (2) and the rotating shaft structure on the substrate (1) is axially symmetrical.

2. A MEMS micromirror array according to claim 1, It is characterized in that The outer shaft movable comb tooth group (6) and the inner shaft movable comb tooth group (7) in the upper comb tooth structure each include at least one comb tooth, and each comb tooth in the comb tooth group extends to both sides with the symmetry axis of the comb tooth group as the center; each comb tooth in the comb tooth group is parallel to each other, and adjacent comb teeth are equally spaced; the outer shaft fixed comb tooth group (8) and the inner shaft fixed comb tooth group (9) in the lower comb tooth structure each include at least one comb tooth, and the projections of each comb tooth in the outer shaft movable comb tooth group (6) and the inner shaft movable comb tooth group (7) at corresponding positions are respectively parallel to each other, and are staggered with each other.

3. A MEMS micromirror array according to claim 1, It is characterized in that The electrode structure comprises two pairs of positive electrode PADs (10) and two pairs of GND PADs (11), each positive electrode PAD (10) having a positive electrode isolation groove (12) on its outer side, the two pairs of positive electrode PADs (10) being respectively located at the upper right corner and the lower left corner of the substrate (1), and the two pairs of GND PADs (11) being respectively located at the upper left corner and the lower right corner of the substrate (1).

4. A MEMS micromirror array according to claim 3, It is characterized in that The positive electrode isolation groove (12) and the non-patterned area on the surface of the substrate (1) are insulated by covering with an oxide layer.

5. A MEMS micromirror array according to claim 3, It is characterized in that The oxide layer is prepared by thermal oxidation or plasma enhanced chemical vapor deposition process.

6. A MEMS micromirror array according to claim 3, It is characterized in that The positive electrode isolation groove (12) is patterned by deep silicon etching technology.

7. A MEMS micromirror array according to claim 1, It is characterized in that A plurality of MEMS micromirrors are periodically arranged to form a MEMS micromirror array. The electrode structure of each MEMS micromirror is respectively connected to an electrode lead. The plane where the electrode structure is located is used as the front side of the MEMS micromirror, and each electrode lead is led out from the front side of the MEMS micromirror.

8. A method for preparing a MEMS micromirror array, It is characterized in that Perform the following steps S1 to S8 to complete the preparation of a MEMS micromirror array as described in any one of claims 1 to 7: Step S1: for each MEMS micromirror in the MEMS micromirror array, a lower comb-tooth etching is performed on the lower SOI wafer by deep silicon etching technology to form a lower comb-tooth structure; Step S2: performing silicon-silicon bonding between the upper SOI wafer and the lower SOI wafer on which the lower comb teeth etching has been completed; Step S3: removing the handle layer and buried oxide layer of the upper SOI wafer after silicon-silicon bonding to expose the required structural part; Step S4: on the upper SOI wafer, using a photoresist as a mask, patterning the positive electrode isolation groove (12) by deep silicon etching technology, wherein the width of the positive electrode isolation groove (12) is reduced as much as possible while satisfying the maximum etching depth-to-width ratio; Step S5: preparing an oxide layer on the surface of the upper SOI wafer by thermal oxidation or plasma enhanced chemical vapor deposition process to form a substrate (1) on the surface of the upper SOI wafer; Step S6: using photolithography technology to etch the oxide layer on the surface of the upper SOI wafer to pattern the electrode structure and the upper comb structure; Step S7: forming an electrode structure, electrode leads and a mirror surface (2) on the upper SOI wafer surface by metal deposition technology and etching technology; Step S8: Using the photoresist as a mask, the upper SOI wafer is etched into upper comb teeth by deep silicon etching technology to form an upper comb tooth structure and a shaft structure, thereby completing the preparation of the MEMS micromirror. The MEMS micromirrors are periodically arranged to form a MEMS micromirror array.

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