Laminated structure micromirror chip, array system and manufacturing method

Abstract

The invention relates to a laminated structure micromirror chip, which is characterized in that a mirror surface support (10) is carried by a combined structure in which an outer annular structure (2) and an inner annular structure (9) are sleeved with each other, and aiming at the edge of the mirror surface structure, the longitudinal direction between the lower surface of the mirror surface support (10) and the upper surface of a substrate (1); an out-of-mirror upper comb tooth structure (3), an out-of-mirror lower comb tooth structure (4), an in-mirror upper comb tooth structure (11) and an in-mirror lower comb tooth structure (12) with upper and lower comb teeth staggered in parallel are designed, multi-angle rotation of a mirror surface support (10) is driven by acting force between the upper and lower comb teeth after the upper and lower comb teeth are electrified, a single micro-mirror occupies a smaller size space, and the size of the micro-mirror is reduced. The gap between the mirror surfaces is effectively reduced, the mirror surface rotation angle is reduced, a large-scale micro-mirror array system is realized, and the requirements of an optical communication system are met; and a corresponding micro-mirror chip manufacturing method is designed, so that the manufacturing process is simplified, the processing cost and the processing difficulty are reduced, and the rate of finished products is improved.

Description

Technical Field

[0001] The invention relates to a stacked structure micromirror chip, an array system and a manufacturing method, and belongs to the technical field of micro-electromechanical systems. Background Art

[0002] With the rapid development of optical communication technology, OCS (Optical circuit switches), or optical switches, are used to dynamically configure interconnection topology at the optical transmission layer, similar to the role of traditional switches in electrical layer switching. In the process of building data centers, due to higher requirements in terms of deployment scale, modular deployment, security, power consumption and performance, traditional electrical switching does not meet the relevant interconnection needs, so OCS is introduced to form a new solution. When building a TPU cluster, compared with traditional switch solutions, OCS solutions have lower costs, lower power consumption, and faster deployment. The cost of OCS and other optical components accounts for less than 5% of the total system cost, and power consumption accounts for less than 3%.

[0003] MEMS micromirror arrays are used for switching optical paths in OCS. Existing drive combs occupy a large chip space, which makes the micromirror unit larger and thus the entire micromirror array larger. In order to achieve optical path switching, a larger mirror angle is required, which makes the processing more difficult. At the same time, a larger drive voltage leads to high control costs. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a stacked structure micromirror chip, so that a single micromirror occupies a smaller space, effectively reducing the gap size between mirror surfaces, reducing the mirror angle, and realizing a large-scale micromirror array.

[0005] The present invention adopts the following technical solution to solve the above technical problems: the present invention designs a stacked structure micromirror chip, comprising a substrate, an outer ring structure, an upper comb tooth structure outside the mirror, a lower comb tooth structure outside the mirror, and a mirror structure comprising a mirror reflection layer; wherein the outer ring structure is arranged on the upper surface of the substrate in a posture parallel to the upper surface of the substrate, the mirror structure is located in the outer ring structure, two edge positions of the mirror structure connected to each other through the center position thereof are respectively connected to the inner side of the outer ring structure through an outer rotating shaft, and the straight lines where the two outer rotating shafts are respectively located are collinear with each other, and the collinear line passes through the center position of the mirror structure; The outer upper comb-tooth structure of the mirror includes comb teeth that are distributed on both sides of the straight line where the outer rotating shaft is located and are fixedly connected to the edge of the mirror structure. Based on defining each area on the upper surface of the substrate corresponding to the distribution of the outer upper comb-tooth structure as each outer mirror area, the outer lower comb-tooth structure includes comb teeth that are respectively fixedly connected to each outer mirror area on the upper surface of the substrate. Along the projection direction perpendicular to the upper surface of the substrate, the projections of each comb tooth in the outer upper comb-tooth structure are respectively parallel to the projections of each comb tooth in the outer lower comb-tooth structure on the upper surface of the substrate corresponding to the outer mirror area, and are interlaced with each other. A driving electrode and a grounding electrode are arranged on the upper surface of the substrate, and are electrically connected to each comb tooth in the upper comb tooth structure outside the mirror for power supply; a driving electrode and a grounding electrode are arranged on the lower surface of the substrate, and are electrically connected to each comb tooth in the lower comb tooth structure outside the mirror for power supply through the substrate upward; based on respectively supplying power to the driving electrode on the upper surface of the substrate and the driving electrode on the lower surface of the substrate, under the interaction force between each comb tooth in the upper comb tooth structure outside the mirror and each comb tooth in the lower comb tooth structure outside the mirror in the corresponding mirror area on the upper surface of the substrate, the mirror structure is driven to rotate around the straight line where the outer rotating shaft is located, thereby completing the drive adjustment of the mirror structure angle.

[0006] As a preferred technical solution of the present invention: one end of each comb tooth in the comb tooth structure on the outside of the mirror is fixedly connected to the edge of the mirror structure, the other end of each comb tooth does not contact the inner side edge of the outer annular structure, and the edge of each comb tooth surface facing the substrate does not contact the upper surface of the substrate. Based on the straight line passing through the center position and edge of the mirror structure and perpendicular to the straight line where the outer rotation axis is located as the reference line, along the projection direction perpendicular to the surface where the edge of the mirror structure is located, the projections of each comb tooth in the comb tooth structure on the outside of the mirror are axially symmetrically distributed relative to the reference line, and the projections of each comb tooth in the comb tooth structure on the outside of the mirror are axially symmetrically distributed relative to the straight line where the outer rotation axis is located; Based on defining the regions on the upper surface of the substrate corresponding to the distribution of the upper comb-tooth structure outside the mirror as the respective extra-mirror regions, the length edges on the surface of each comb tooth in the lower comb-tooth structure outside the mirror are respectively fixedly connected to the respective extra-mirror regions on the upper surface of the substrate corresponding to the respective extra-mirror regions; along the projection direction perpendicular to the upper surface of the substrate, the projections of each comb tooth in the upper comb-tooth structure outside the mirror are respectively parallel to the projections of each comb tooth in the lower comb-tooth structure outside the mirror in the extra-mirror regions corresponding to the upper surface of the substrate, and are interlaced with each other.

[0007] As a preferred technical solution of the present invention: the straight lines along the length directions of the comb teeth in the comb tooth structure outside the mirror are parallel to the straight line along which the outer rotating shaft is located, or the straight lines along the length directions of the comb teeth in the comb tooth structure outside the mirror are perpendicular to the straight line along which the outer rotating shaft is located.

[0008] As a preferred technical solution of the present invention: the mirror structure also includes an inner ring structure, a mirror support, an upper comb tooth structure inside the mirror, and a lower comb tooth structure inside the mirror, wherein the mirror support is located in the inner ring structure, and two edge positions of the mirror support whose connecting lines pass through the center position thereof are respectively connected to the inner side of the inner ring structure through inner rotating shafts, and the straight lines where the two inner rotating shafts are respectively located are collinear with each other, and the collinear lines pass through the center position of the mirror support, and the straight line where the inner rotating shaft is located is perpendicular to the straight line where the outer rotating shaft is located, and the mirror reflection layer is arranged on the surface of the mirror support facing away from the substrate; The mirror inner upper comb tooth structure includes comb teeth that are fixedly connected to the surface of the mirror support facing the substrate and distributed on both sides of the straight line where the inner rotation axis is located. Based on defining each area on the upper surface of the substrate corresponding to the distribution of the mirror inner upper comb tooth structure as each mirror inner area, the mirror inner lower comb tooth structure includes comb teeth that are respectively fixedly connected to each mirror inner area on the upper surface of the substrate. Along the projection direction perpendicular to the upper surface of the substrate, the projections of each comb tooth in the mirror inner upper comb tooth structure are respectively parallel to the projections of each comb tooth in the mirror inner lower comb tooth structure on the upper surface of the substrate corresponding to the mirror inner area, and are interlaced with each other. The driving electrode and the grounding electrode arranged on the upper surface of the substrate are electrically connected to each comb tooth in the upper comb tooth structure inside the mirror for power supply; the driving electrode and the grounding electrode arranged on the lower surface of the substrate pass upward through the substrate and then electrically connected to each comb tooth in the lower comb tooth structure inside the mirror for power supply; based on respectively supplying power to the driving electrode on the upper surface of the substrate and the driving electrode on the lower surface of the substrate, under the interaction force between each comb tooth in the upper comb tooth structure inside the mirror and each comb tooth in the lower comb tooth structure inside the mirror in the corresponding mirror area on the upper surface of the substrate, the mirror support is driven to rotate around the straight line where the inner rotating shaft is located, thereby completing the drive adjustment of the mirror support angle.

[0009] As a preferred technical solution of the present invention: each comb tooth in the comb tooth structure inside the mirror is fixedly connected to the surface of the mirror support facing the substrate with its length edge on the surface, the edge on the surface of each comb tooth facing the substrate does not contact the upper surface of the substrate, along the projection direction perpendicular to the mirror support, the projection of each comb tooth in the comb tooth structure inside the mirror is axially symmetrical with respect to the straight line where the inner rotation axis is located, and along the projection direction perpendicular to the surface where the inner annular structure is located, the projection of each comb tooth in the comb tooth structure inside the mirror is axially symmetrical with respect to the straight line where the outer rotation axis is located; Based on defining the various areas on the upper surface of the substrate corresponding to the distribution of the upper comb-tooth structure inside the mirror as various in-mirror areas, each comb tooth in the lower comb-tooth structure inside the mirror is fixedly connected to the corresponding in-mirror area on the upper surface of the substrate with its length edge on the surface; along the projection direction perpendicular to the upper surface of the substrate, the projection of each comb tooth in the upper comb-tooth structure inside the mirror is parallel to the projection of each comb tooth in the lower comb-tooth structure inside the mirror in the corresponding in-mirror area on the upper surface of the substrate, and is interlaced with each other.

[0010] As a preferred technical solution of the present invention: the straight lines along the length directions of the comb teeth in the upper comb tooth structure inside the mirror are parallel to the straight line along which the inner rotating shaft is located, or the straight lines along the length directions of the comb teeth in the upper comb tooth structure inside the mirror are perpendicular to the straight line along which the inner rotating shaft is located.

[0011] Accordingly, the technical problem that the present invention needs to solve is to provide an array system based on a stacked structure micromirror chip, which can quickly realize a large-scale micromirror array with a single small-sized spatial micromirror, effectively reduce the overall structural space occupancy, and provide practical application efficiency.

[0012] In order to solve the above technical problems, the present invention adopts the following technical scheme: the present invention designs an array system of stacked structure micromirror chips, including stacked structure micromirror chips with the same structure and size as each other, the stacked structure micromirror chips are distributed in an array position, the upper surfaces of the substrates of the stacked structure micromirror chips are coplanar, and the upper surfaces of adjacent substrates are butt-jointed with each other.

[0013] Corresponding to the above, the technical problem that the present invention needs to solve is to provide a method for manufacturing a stacked structure micromirror chip, which can stably and efficiently realize the designed micromirror chip and improve the yield rate.

[0014] In order to solve the above technical problems, the present invention adopts the following technical solutions: The present invention designs a method for manufacturing a stacked structure micromirror chip, based on two SOI silicon wafers respectively including a top silicon layer, a buried layer, and a bottom silicon layer from top to bottom, and performs the following steps to realize the manufacturing of the stacked structure micromirror chip; Step A. Take a first SOI silicon wafer, set an insulating layer on the lower surface of the bottom silicon layer in the first SOI silicon wafer, etch a deep hole penetrating the buried layer from the lower surface of the insulating layer upward, fill the deep hole with metal, and lead a metal wire in the deep hole to the edge of the insulating layer on the lower surface of the bottom silicon layer; Step B. for the first SOI silicon wafer, etching downward from the upper surface of the top silicon layer in the first SOI silicon wafer to obtain individual comb teeth, forming a mirror outer lower comb tooth structure and a mirror inner lower comb tooth structure; Step C. taking a second SOI silicon wafer, and etching upward to a preset depth a local area of ​​the non-mirror inner upper comb structure of the lower surface of the bottom silicon layer in the second SOI silicon wafer corresponding to the mirror support, to form a local gap space below the mirror support; Step D. performing silicon-silicon bonding between the second SOI silicon wafer and the first SOI silicon wafer, with the bottom silicon layer in the second SOI silicon wafer facing the top silicon layer in the first SOI silicon wafer, and removing the top silicon layer and the buried layer in the second SOI silicon wafer to expose the upper surface of the bottom silicon layer in the second SOI silicon wafer; Step F. performing deep silicon etching with a photoresist as a mask on the surfaces where the driving electrodes and the grounding electrodes are located to obtain patterned insulating grooves around the electrodes, and depositing an OXD oxide layer on the upper surface of the bottom silicon layer in the second SOI silicon wafer, the surfaces where the driving electrodes and the grounding electrodes are located, and the insulating grooves; Step G. Performing photolithography on the OXD oxide layer to pattern each electrode region, the outer annular structure region, the outer shaft region, the inner annular structure region, the mirror support region, the inner shaft region, and each comb tooth region corresponding to the comb tooth structure on the outer side of the mirror and the comb tooth structure on the inner side of the mirror, and performing metal deposition etching on each electrode region and the mirror support region to obtain each electrode and the mirror reflection layer; Step H. For the outer annular structure area, the outer shaft area, the inner annular structure area, the mirror support area, the inner shaft area, and the comb tooth areas corresponding to the mirror outer comb tooth structure and the mirror inner comb tooth structure, deep silicon etching is performed using photoresist as a mask to obtain the outer annular structure, the outer shaft, the inner annular structure, the inner shaft, the mirror support, and the comb teeth constituting the mirror outer comb tooth structure and the mirror inner comb tooth structure.

[0015] As a preferred technical solution of the present invention: in the step F, the OXD oxide layer is deposited by plasma enhanced chemical vapor deposition (PECVD).

[0016] The stacked structure micromirror chip, array system and manufacturing method of the present invention adopt the above technical solution and have the following technical effects compared with the prior art: The stacked structure micromirror chip designed by the present invention is based on the design of an outer ring structure carrying a mirror structure, and the mirror structure is specifically designed to carry a mirror support with an inner ring structure. For the longitudinal direction between the edge of the mirror structure, the lower surface of the mirror support and the upper surface of the substrate, an upper comb tooth structure outside the mirror and a lower comb tooth structure outside the mirror, and an upper comb tooth structure inside the mirror and a lower comb tooth structure inside the mirror are designed. The upper comb tooth structure and the lower comb tooth structure inside the mirror are parallel and staggered with each other. The power supply drive to each comb tooth is applied through the electrode. Through the force between the upper and lower corresponding comb teeth, the mirror support is driven to rotate about two mutually orthogonal axes respectively, so as to realize multi-angle driven rotation of the mirror support. The design solves the problem of too large spacing of the MEMS micromirror array in the prior art, so that a single micromirror occupies a smaller space, effectively reduces the gap between the mirrors, reduces the mirror rotation angle, realizes a large-scale micromirror array system, and meets the needs of the optical communication system. In the stacked structure micromirror chip and array system designed by the present invention, the comb tooth structure design that is parallel and staggered from top to bottom does not take up more space, so that the overall size is smaller. Under the power supply drive to each comb tooth through the electrode, a larger driving range and a larger driving force can be obtained; and the design effectively reduces the weight of the mirror support structure, increases the resonant frequency, and has higher seismic resistance; in addition, the present invention designs a corresponding micromirror chip manufacturing method, simplifies the manufacturing process, reduces processing costs and processing difficulty, and improves the yield rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a top view of an embodiment of a stacked structure micromirror chip designed by the present invention; Figure 2 It is a top perspective view of the embodiment 1 of the stacked structure micromirror chip designed by the present invention regarding the upper comb tooth structure inside the mirror and the lower comb tooth structure inside the mirror; Figure 3 It is a top perspective view of the second embodiment of the stacked structure micromirror chip designed by the present invention regarding the upper comb tooth structure inside the mirror and the lower comb tooth structure inside the mirror; Figure 4 The present invention designs a stacked structure micromirror chip about Figure 1 and Figure 3 A cross-sectional view of a combined embodiment; Figure 5 It is a schematic diagram of the SOI silicon wafer structure; Figure 6 Schematic diagram of step A in the method for manufacturing a micromirror chip with a stacked structure according to the present invention; Figure 7 It is a schematic diagram of step B in the manufacturing method of designing a stacked structure micromirror chip of the present invention; Figure 8 Schematic diagram of step G in the method for manufacturing a micromirror chip with a stacked structure according to the present invention; Fig. 9 It is a schematic diagram of step H in the method for manufacturing a stacked structure micromirror chip of the present invention.

[0018] Among them, 1. substrate, 2. outer ring structure, 3. upper comb-tooth structure outside the mirror, 4. lower comb-tooth structure outside the mirror, 5. mirror reflection layer, 6. outer shaft, 7. drive electrode, 8. ground electrode, 9. inner ring structure, 10. mirror support, 11. upper comb-tooth structure inside the mirror, 12. lower comb-tooth structure inside the mirror, 13. inner shaft, 14. top silicon layer, 15. buried layer, 16. bottom silicon layer, 17. metal. DETAILED DESCRIPTION

[0019] The specific implementation modes of the present invention will be further described in detail below in conjunction with the accompanying drawings.

[0020] The present invention designs a stacked structure micromirror chip. In practical applications, the specific design includes a substrate 1, an outer ring structure 2, an upper comb tooth structure 3 outside the mirror, a lower comb tooth structure 4 outside the mirror, and a mirror structure including a mirror reflection layer 5; wherein the outer ring structure 2 is arranged on the upper surface of the substrate 1 in a posture parallel to the upper surface of the substrate 1, the mirror structure is located in the outer ring structure 2, and the two edge positions of the mirror structure connected to each other through the center position thereof are respectively connected to the inner side of the outer ring structure 2 through an outer rotating shaft 6, and the straight lines where the two outer rotating shafts 6 are respectively located are collinear with each other, and the collinear line passes through the center position of the mirror structure.

[0021] The upper comb tooth structure 3 outside the mirror includes comb teeth fixedly connected to the edge of the mirror structure distributed on both sides of the straight line where the outer rotating shaft 6 is located. Based on the definition that the areas on the upper surface of the substrate 1 corresponding to the distribution of the upper comb tooth structure 3 outside the mirror are each outside the mirror area, the lower comb tooth structure 4 outside the mirror includes comb teeth fixedly connected to each outside mirror area on the upper surface of the substrate 1. Along the projection direction perpendicular to the upper surface of the substrate 1, the projections of each comb tooth in the upper comb tooth structure 3 outside the mirror are respectively parallel to the projections of each comb tooth in the lower comb tooth structure 4 outside the mirror in the corresponding outside mirror area on the upper surface of the substrate 1, and are intertwined with each other.

[0022] Regarding the above-mentioned upper comb-tooth structure 3 and lower comb-tooth structure 4 outside the mirror, in a specific application, one end of each comb-tooth structure 3 outside the mirror is designed to be fixedly connected to the edge of the mirror structure, and the other end of each comb-tooth does not contact the inner side edge of the outer annular structure 2, and the edge of each comb-tooth surface facing the substrate 1 does not contact the upper surface of the substrate 1. Based on the straight line defined as a reference line passing through the center position of the mirror structure and the edge and perpendicular to the straight line where the outer rotating shaft 6 is located, along the projection direction perpendicular to the surface where the edge of the mirror structure is located, the upper comb-tooth structure 3 outside the mirror is The projections of each comb tooth are axially symmetrical relative to the reference line, and the projections of each comb tooth in the upper comb tooth structure 3 outside the mirror are axially symmetrical relative to the straight line where the outer rotating axis 6 is located; the length edges on the surface of each comb tooth in the lower comb tooth structure 4 outside the mirror are fixedly connected to the upper surface of the substrate 1 corresponding to each mirror outer area; under the above-mentioned design structure, along the projection direction perpendicular to the upper surface of the substrate 1, the projections of each comb tooth in the upper comb tooth structure 3 outside the mirror are respectively parallel to the projections of each comb tooth in the lower comb tooth structure 4 outside the mirror in the corresponding mirror outer area on the upper surface of the substrate 1, and are intertwined with each other.

[0023] In actual applications, it can be specifically designed that the straight lines where the length directions of the comb teeth of the upper comb tooth structure 3 outside the mirror are located are parallel to the straight line where the outer rotating shaft 6 is located, or the straight lines where the length directions of the comb teeth of the upper comb tooth structure 3 outside the mirror are located are perpendicular to the straight line where the outer rotating shaft 6 is located, and based on the comb teeth in the upper comb tooth structure 3 outside the mirror, combined with the upper and lower corresponding comb teeth being parallel to each other and staggered with each other, the corresponding structures of the comb teeth in the lower comb tooth structure 4 outside the mirror are designed for application.

[0024] According to the above-mentioned outer comb tooth structure 3 and the outer comb tooth structure 4, the specific implementation is as follows. Figure 1 As shown, the comb tooth structure 3 on the outside of the mirror includes comb teeth distributed on both sides of the straight line where the outer rotating shaft 6 is located, each of which is fixedly connected to the edge of the mirror structure with one end thereof, the straight line where the length direction of each comb tooth is located is parallel to the straight line where the outer rotating shaft 6 is located, and the other end of each comb tooth does not contact the inner side edge of the outer annular structure 2, the surface of each comb tooth is perpendicular to the surface where the edge of the mirror structure is located, and the edge of each comb tooth surface facing the substrate 1 does not contact the upper surface of the substrate 1, based on defining a straight line passing through the center position of the mirror structure and the edge and perpendicular to the straight line where the outer rotating shaft 6 is located as a reference line, along the projection direction perpendicular to the surface where the edge of the mirror structure is located, the projections of each comb tooth in the comb tooth structure 3 on the outside of the mirror are axially symmetrically distributed relative to the reference line. , and the projections of each comb tooth in the outer comb tooth structure 3 are axially symmetrically distributed relative to the straight line where the outer rotation axis 6 is located; based on the definition that each area on the upper surface of the substrate 1 corresponding to the distribution of the outer comb tooth structure 3 is each outer mirror area, the outer lower comb tooth structure 4 includes comb teeth respectively fixedly connected to each outer mirror area on the upper surface of the substrate 1 with their length edges on the surface, the straight lines where the length directions of each comb tooth are located are parallel to the straight line where the outer rotation axis 6 is located, and the surfaces of each comb tooth are respectively perpendicular to the upper surface of the substrate 1; along the projection direction perpendicular to the upper surface of the substrate 1, the projections of each comb tooth in the outer comb tooth structure 3 are respectively parallel to the projections of each comb tooth in the outer lower comb tooth structure 4 in the upper surface of the substrate 1 corresponding to the outer mirror area, and are staggered with each other.

[0025] The mirror structure involved in the design of the above technical solution, in actual application, is based on the mirror reflection layer 5, and the design also includes an inner ring structure 9, a mirror support 10, an upper comb tooth structure 11 inside the mirror, and a lower comb tooth structure 12 inside the mirror, wherein the mirror support 10 is located in the inner ring structure 9, and the two edge positions of the mirror support 10 connected to each other through the center position thereof are respectively connected to the inner side of the inner ring structure 9 through the inner rotating shaft 13, and the straight lines where the two inner rotating shafts 13 are respectively located are collinear with each other, and the collinearity passes through the center position of the mirror support 10, and the straight line where the inner rotating shaft 13 is located is perpendicular to the straight line where the outer rotating shaft 6 is located, and the mirror reflection layer 5 is arranged on the surface of the mirror support 10 facing away from the substrate 1. The design of the mirror structure here effectively reduces the weight of the mirror support 10 structure, improves the resonance frequency, and has higher seismic resistance.

[0026] Among them, the upper comb tooth structure 11 inside the mirror includes comb teeth fixedly connected to the surface of the mirror support 10 facing the substrate 1 on both sides of the straight line where the inner rotating shaft 13 is located, based on the definition that the various areas on the upper surface of the substrate 1 corresponding to the distribution of the upper comb tooth structure 11 inside the mirror are various mirror areas, the lower comb tooth structure 12 inside the mirror includes comb teeth fixedly connected to the various mirror areas on the upper surface of the substrate 1, along the projection direction perpendicular to the upper surface of the substrate 1, the projections of each comb tooth in the upper comb tooth structure 11 inside the mirror are respectively parallel to the projections of each comb tooth in the lower comb tooth structure 12 inside the mirror in the corresponding mirror area on the upper surface of the substrate 1, and are intertwined with each other.

[0027] Regarding the above-mentioned upper comb-tooth structure 11 and lower comb-tooth structure 12 inside the mirror, in a specific application, each comb tooth in the upper comb-tooth structure 11 is designed to be fixedly connected to the surface of the mirror support 10 facing the substrate 1 by the length edge on its surface, and the edge on the surface of each comb tooth facing the substrate 1 does not contact the upper surface of the substrate 1, along the projection direction perpendicular to the mirror support 10, the projection of each comb tooth in the upper comb-tooth structure 11 is axially symmetrical with respect to the straight line where the inner rotation axis 13 is located, and along the projection direction perpendicular to the surface where the inner annular structure 9 is located, the projection of each comb tooth in the upper comb-tooth structure 11 is axially symmetrical with respect to the straight line where the outer rotation axis 6 is located; each comb tooth in the lower comb-tooth structure 12 is fixedly connected to the upper surface of the substrate 1 corresponding to each mirror inner region by the length edge on its surface; under the above-mentioned design structure, along the projection direction perpendicular to the upper surface of the substrate 1, the projection of each comb tooth in the upper comb-tooth structure 11 is parallel to each other and staggered with the projection of each comb tooth in the lower comb-tooth structure 12 in the mirror inner region corresponding to the upper surface of the substrate 1.

[0028] And in actual application, it can be specifically designed that the straight line where the length direction of each comb tooth in the upper comb tooth structure 11 inside the mirror is parallel to the straight line where the inner rotation axis 13 is located, or the straight line where the length direction of each comb tooth in the upper comb tooth structure 11 inside the mirror is perpendicular to the straight line where the inner rotation axis 13 is located, and based on each comb tooth in the upper comb tooth structure 11 inside the mirror, combined with the upper and lower corresponding comb teeth being parallel to each other and staggered with each other, the corresponding structure of each comb tooth in the lower comb tooth structure 12 inside the mirror is designed for application.

[0029] According to the above-mentioned structure design of the upper comb tooth structure 11 and the lower comb tooth structure 12, the specific implementation is as follows: Figure 2As shown, the comb tooth structure 11 inside the mirror includes comb teeth distributed on both sides of the straight line where the inner rotating shaft 13 is located, and the length edges on their surfaces are respectively fixedly connected to the surface of the mirror support 10 facing the substrate 1, the straight line where the length direction of each comb tooth is located is parallel to the straight line where the inner rotating shaft 13 is located, the surface where the surface of each comb tooth is located is perpendicular to the surface of the mirror support 10, the edge on the surface of each comb tooth facing the substrate 1 does not contact the upper surface of the substrate 1, along the projection direction perpendicular to the mirror support 10, the projection of each comb tooth in the comb tooth structure 11 inside the mirror is axially symmetrical with respect to the straight line where the inner rotating shaft 13 is located, and along the projection direction perpendicular to the surface where the inner annular structure 9 is located, each comb tooth in the comb tooth structure 11 inside the mirror is axially symmetrical with respect to the straight line where the inner rotating shaft 13 is located. The projections are axially symmetrical relative to the straight line where the outer rotation axis 6 is located; based on the definition that each area on the upper surface of the substrate 1 corresponding to the distribution of the upper comb tooth structure 11 inside the mirror is each mirror inner area, the lower comb tooth structure 12 inside the mirror includes comb teeth that are fixedly connected to each mirror inner area on the upper surface of the substrate 1 with their length edges on the surface, and the straight lines where the length directions of each comb tooth are located are parallel to the straight line where the inner rotation axis 13 is located, and the surfaces of each comb tooth are perpendicular to the upper surface of the substrate 1; along the projection direction perpendicular to the upper surface of the substrate 1, the projections of each comb tooth in the upper comb tooth structure 11 inside the mirror are parallel to each other and interlaced with the projections of each comb tooth in the lower comb tooth structure 12 inside the mirror in the corresponding mirror inner area on the upper surface of the substrate 1.

[0030] According to the above Figure 2 In the embodiment 1 shown, there is also Figure 3 In the embodiment shown in the figure, if the embodiment shown in the figure is combined with Figure 3 The second embodiment shown is Figure 1 Combining the embodiments shown in FIG. Figure 4 A cross-sectional view of the structure of the illustrated embodiment.

[0031] The above technical solution designs a comb tooth structure that is parallel and staggered from top to bottom. In actual applications, it does not take up more space, making the overall size smaller. At the same time, it can obtain a larger driving range and greater driving force when the power is driven by the electrodes to each comb tooth.

[0032] In actual application, the driving electrode 7 and the grounding electrode 8 are respectively arranged on the upper surface and the lower surface of the substrate 1, and the driving electrode 7 and the grounding electrode 8 on the upper surface of the substrate 1 are electrically connected to each comb tooth in the upper comb tooth structure 11 inside the mirror for power supply, and the driving electrode 7 and the grounding electrode 8 on the lower surface of the substrate 1 are electrically connected to each comb tooth in the lower comb tooth structure 12 inside the mirror for power supply. The interaction between each comb tooth in the upper comb tooth structure 11 inside the mirror and each comb tooth in the lower comb tooth structure 12 inside the mirror in the corresponding mirror area on the upper surface of the substrate 1 drives the mirror support 10 to rotate around the straight line where the inner rotating shaft 13 is located, thereby completing the drive adjustment of the angle of the mirror support 10, that is, the drive adjustment of the angle of the mirror reflection layer 5.

[0033] At the same time, the driving electrode 7 on the upper surface of the substrate 1 and the grounding electrode 8 are electrically connected to each comb tooth in the outer upper comb tooth structure 3 for power supply, and the driving electrode 7 on the lower surface of the substrate 1 and the grounding electrode 8 are electrically connected to each comb tooth in the outer lower comb tooth structure 4 for power supply. The interaction between each comb tooth in the outer upper comb tooth structure 3 and each comb tooth in the outer lower comb tooth structure 4 in the corresponding outer mirror area on the upper surface of the substrate 1 drives the mirror structure to rotate around the straight line where the outer rotating shaft 6 is located, thereby completing the drive adjustment of the mirror structure angle. According to the above application, the mirror reflection layer 5 is driven to rotate with the straight line where the inner rotation axis 13 is located as the axis, and the outer rotation axis 6 is driven to rotate with the straight line where the outer rotation axis 6 is located as the axis.

[0034] The stacked structure micromirror chips designed above can be further combined to construct an array system in actual applications, specifically using stacked structure micromirror chips with the same structure and size as each other. Specifically, the stacked structure micromirror chips are distributed in an array position, and the upper surfaces of the substrates 1 of the stacked structure micromirror chips are coplanar, and the upper surfaces of adjacent substrates 1 are butt-jointed with each other.

[0035] In practical applications, the above-mentioned stacked structure micromirror chip is specifically based on two pieces such as Figure 5 The SOI silicon wafer shown includes a top silicon layer, a buried layer, and a bottom silicon layer in order from top to bottom. The following steps are performed to realize the manufacture of the stacked structure micromirror chip.

[0036] Step A. Take the first SOI silicon wafer, set an insulating layer on the lower surface of the bottom silicon layer in the first SOI silicon wafer, etch a deep hole penetrating the buried layer from the lower surface of the insulating layer upward, fill the deep hole with metal, and lead the metal in the deep hole to the edge of the insulating layer surface on the lower surface of the bottom silicon layer, such as Figure 6 shown.

[0037] Step B. For the first SOI silicon wafer, the upper surface of the top silicon layer in the first SOI silicon wafer is etched downward to obtain each comb tooth, forming a mirror outer lower comb tooth structure 4 and a mirror inner lower comb tooth structure 12, such as Figure 7 shown.

[0038] Step C: Take a second SOI silicon wafer, and etch upward to a preset depth a local area of ​​the lower surface of the bottom silicon layer in the second SOI silicon wafer corresponding to the non-mirror inner upper comb structure 11 of the mirror support 10 to form a local gap space below the mirror support 10 .

[0039] Step D. With the bottom silicon layer in the second SOI silicon wafer facing the top silicon layer in the first SOI silicon wafer, the second SOI silicon wafer is silicon-bonded to the first SOI silicon wafer, and the top silicon layer and the buried layer in the second SOI silicon wafer are removed to expose the upper surface of the bottom silicon layer in the second SOI silicon wafer.

[0040] Step F. For the surfaces where the driving electrode 7 and the grounding electrode 8 are located, deep silicon etching is performed using a photoresist as a mask to obtain patterned insulating grooves around each electrode, and for the upper surface of the bottom silicon layer in the second SOI silicon wafer, the surfaces where the driving electrode 7 and the grounding electrode 8 are located, and the insulating grooves, an OXD oxide layer is deposited using a plasma enhanced chemical vapor deposition (PECVD) method.

[0041] Step G. Perform photolithography on the OXD oxide layer to pattern each electrode region, the outer annular structure 2 region, the outer shaft 6 region, the inner annular structure 9 region, the mirror support 10 region, the inner shaft 13 region, and each comb tooth region corresponding to the mirror outer comb tooth structure 3 and the mirror inner comb tooth structure 11, and perform metal deposition etching on each electrode region and the mirror support 10 region to obtain each electrode and the mirror reflection layer 5, as shown in FIG. Figure 8 shown.

[0042] Step H. For the outer annular structure 2 region, the outer rotating shaft 6 region, the inner annular structure 9 region, the mirror support 10 region, the inner rotating shaft 13 region, and the respective comb tooth regions corresponding to the mirror outer upper comb tooth structure 3 and the mirror inner upper comb tooth structure 11, deep silicon etching is performed using a photoresist as a mask to obtain the outer annular structure 2, the outer rotating shaft 6, the inner annular structure 9, the inner rotating shaft 13, the mirror support 10, and the respective comb teeth constituting the mirror outer upper comb tooth structure 3 and the mirror inner upper comb tooth structure 11, as shown in FIG. Fig. 9 shown.

[0043] The design of the manufacturing method above simplifies the manufacturing process, reduces processing cost and difficulty, and improves the yield rate in practical applications.

[0044] The above technical scheme is based on the design of an outer ring structure 2 carrying a mirror structure, and the mirror structure is specifically designed as an inner ring structure 9 carrying a mirror support 10. For the longitudinal direction between the edge of the mirror structure, the lower surface of the mirror support 10 and the upper surface of the substrate 1, an upper comb tooth structure 3 outside the mirror and a lower comb tooth structure 4 outside the mirror are parallel and staggered with upper and lower comb teeth, as well as an upper comb tooth structure 11 inside the mirror and a lower comb tooth structure 12 inside the mirror are designed. The power supply drive to each comb tooth is applied through the electrode. Through the force between the upper and lower corresponding comb teeth, the mirror support 10 is driven to rotate about two mutually orthogonal axes respectively, thereby realizing multi-angle driven rotation of the mirror support 10. The design solves the problem of excessively large spacing of the MEMS micromirror array in the prior art, so that a single micromirror occupies a smaller space, effectively reduces the gap between the mirrors, reduces the mirror rotation angle, and realizes a large-scale micromirror array system to meet the needs of optical communication systems.

[0045] 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 stacked structure micromirror chip, characterized in that: The mirror structure comprises a substrate (1), an outer annular structure (2), an outer upper comb tooth structure (3), an outer lower comb tooth structure (4), and a mirror structure comprising a mirror reflection layer (5); wherein the outer annular structure (2) is arranged on the upper surface of the substrate (1) in a posture parallel to the upper surface of the substrate (1), the mirror structure is located in the outer annular structure (2), two edge positions of the mirror structure whose connecting line passes through the center position thereof are connected to the inner side of the outer annular structure (2) through outer rotating shafts (6), and the straight lines on which the two outer rotating shafts (6) are located are collinear with each other, and the collinear line passes through the center position of the mirror structure; The outer mirror upper comb tooth structure (3) comprises comb teeth that are distributed on both sides of the straight line where the outer rotating shaft (6) is located and are fixedly connected to the edge of the mirror structure. Based on the definition that each area on the upper surface of the substrate (1) corresponding to the distribution of the outer mirror upper comb tooth structure (3) is each outer mirror area, the outer mirror lower comb tooth structure (4) comprises comb teeth that are respectively fixedly connected to each outer mirror area on the upper surface of the substrate (1). Along the projection direction perpendicular to the upper surface of the substrate (1), the projections of each comb tooth in the outer mirror upper comb tooth structure (3) are respectively parallel to the projections of each comb tooth of the outer mirror lower comb tooth structure (4) in the outer mirror area corresponding to the upper surface of the substrate (1), and are interlaced with each other. A driving electrode (7) and a grounding electrode (8) are arranged on the upper surface of the substrate (1), and are electrically connected to each comb tooth in the upper comb tooth structure (3) outside the mirror for power supply; a driving electrode (7) and a grounding electrode (8) are arranged on the lower surface of the substrate (1), and are electrically connected to each comb tooth in the lower comb tooth structure (4) outside the mirror for power supply through the substrate (1) upward; based on the power supply to the driving electrode (7) on the upper surface of the substrate (1) and the driving electrode (7) on the lower surface of the substrate (1), the mirror structure is driven to rotate about the straight line where the outer rotation axis (6) is located, thereby completing the drive adjustment of the angle of the mirror structure.

2. The stacked structure micromirror chip according to claim 1, characterized in that: One end of each comb tooth in the comb tooth structure (3) outside the mirror is fixedly connected to the edge of the mirror structure, the other end of each comb tooth does not contact the inner side edge of the outer annular structure (2), and the edge of each comb tooth surface facing the substrate (1) does not contact the upper surface of the substrate (1). Based on a straight line that passes through the center position and edge of the mirror structure and is perpendicular to the straight line where the outer rotation axis (6) is located as a reference line, along the projection direction perpendicular to the surface where the edge of the mirror structure is located, the projections of each comb tooth in the comb tooth structure (3) outside the mirror are axially symmetrically distributed relative to the reference line, and the projections of each comb tooth in the comb tooth structure (3) outside the mirror are axially symmetrically distributed relative to the straight line where the outer rotation axis (6) is located; Based on the definition that each area on the upper surface of the substrate (1) corresponding to the distribution of the upper comb-tooth structure (3) outside the mirror is each outer mirror area, the length edges on the surface of each comb tooth in the lower comb-tooth structure (4) outside the mirror are respectively fixedly connected to each outer mirror area on the upper surface of the substrate (1); along the projection direction perpendicular to the upper surface of the substrate (1), the projections of each comb tooth in the upper comb-tooth structure (3) outside the mirror are respectively parallel to the projections of each comb tooth of the lower comb-tooth structure (4) outside the mirror in the outer mirror area on the upper surface of the substrate (1), and are interlaced with each other.

3. The stacked structure micromirror chip according to claim 2, characterized in that: The straight lines along which the length directions of the comb teeth of the comb tooth structure (3) are located are parallel to the straight line along which the outer rotation axis (6) is located, or the straight lines along which the length directions of the comb teeth of the comb tooth structure (3) are located are perpendicular to the straight line along which the outer rotation axis (6) is located.

4. The stacked structure micromirror chip according to claim 1, characterized in that: The mirror structure also includes an inner ring structure (9), a mirror support (10), an upper comb tooth structure (11) and a lower comb tooth structure (12), wherein the mirror support (10) is located in the inner ring structure (9), two edge positions of the mirror support (10) connected to each other through the center position thereof are connected to the inner side of the inner ring structure (9) through inner rotation shafts (13), the straight lines on which the two inner rotation shafts (13) are located are collinear with each other, and the collinear lines pass through the center position of the mirror support (10), and the straight line on which the inner rotation shaft (13) is located is perpendicular to the straight line on which the outer rotation shaft (6) is located, and the mirror reflection layer (5) is arranged on the surface of the mirror support (10) facing away from the substrate (1); The mirror inner upper comb tooth structure (11) comprises comb teeth distributed on both sides of the straight line where the inner rotation axis (13) is located and fixedly connected to the surface of the mirror support (10) facing the substrate (1). Based on the definition that each area on the upper surface of the substrate (1) corresponding to the distribution of the mirror inner upper comb tooth structure (11) is each mirror inner area, the mirror inner lower comb tooth structure (12) comprises comb teeth fixedly connected to each mirror inner area on the upper surface of the substrate (1). Along the projection direction perpendicular to the upper surface of the substrate (1), the projections of each comb tooth in the mirror inner upper comb tooth structure (11) are parallel to the projections of each comb tooth in the mirror inner lower comb tooth structure (12) in the mirror inner area on the upper surface of the substrate (1), and are interlaced with each other. The driving electrode (7) and the grounding electrode (8) provided on the upper surface of the substrate (1) are electrically connected to each comb tooth in the upper comb tooth structure (11) in the mirror for power supply; the driving electrode (7) and the grounding electrode (8) provided on the lower surface of the substrate (1) pass through the substrate (1) upwards and are electrically connected to each comb tooth in the lower comb tooth structure (12) in the mirror for power supply; based on the power supply to the driving electrode (7) on the upper surface of the substrate (1) and the driving electrode (7) on the lower surface of the substrate (1), the mirror support (10) is driven to rotate about the straight line where the inner rotation axis (13) is located, thereby completing the drive adjustment of the angle of the mirror support (10).

5. The stacked structure micromirror chip according to claim 4, characterized in that: Each comb tooth in the mirror internal upper comb tooth structure (11) is fixedly connected to the surface of the mirror support (10) facing the substrate (1) with its length edge on the surface, the edge on the surface of each comb tooth facing the substrate (1) does not contact the upper surface of the substrate (1), along the projection direction perpendicular to the mirror support (10), the projection of each comb tooth in the mirror internal upper comb tooth structure (11) is axially symmetrical with respect to the straight line where the inner rotation axis (13) is located, and along the projection direction perpendicular to the surface where the inner annular structure (9) is located, the projection of each comb tooth in the mirror internal upper comb tooth structure (11) is axially symmetrical with respect to the straight line where the outer rotation axis (6) is located; Based on defining each region on the upper surface of the substrate (1) corresponding to the distribution of the upper comb-tooth structure (11) in the mirror as each region in the mirror, each comb tooth in the lower comb-tooth structure (12) in the mirror is fixedly connected to each region in the upper surface of the substrate (1) corresponding to the mirror by its length edge on the surface; along the projection direction perpendicular to the upper surface of the substrate (1), the projection of each comb tooth in the upper comb-tooth structure (11) in the mirror is parallel to the projection of each comb tooth of the lower comb-tooth structure (12) in the mirror region on the upper surface of the substrate (1), and they are interlaced with each other.

6. The stacked structure micromirror chip according to claim 5, characterized in that: The straight lines along which the length directions of the comb teeth in the upper comb tooth structure (11) are located are parallel to the straight line along which the inner rotation axis (13) is located, or the straight lines along which the length directions of the comb teeth in the upper comb tooth structure (11) are located are perpendicular to the straight line along which the inner rotation axis (13) is located.

7. An array system of a stacked structure micromirror chip according to any one of claims 1 to 6, characterized in that: It comprises stacked structure micromirror chips of the same structure and size, each stacked structure micromirror chip is distributed in an array position, the upper surfaces of the substrates (1) of each stacked structure micromirror chip are coplanar, and the upper surfaces of adjacent substrates (1) are butted against each other.

8. A method for manufacturing a stacked structure micromirror chip according to any one of claims 4 to 6, characterized in that: Based on two SOI silicon wafers respectively including a top silicon layer, a buried layer, and a bottom silicon layer from top to bottom, the following steps are performed to realize the manufacture of the stacked structure micromirror chip; Step A. Take a first SOI silicon wafer, set an insulating layer on the lower surface of the bottom silicon layer in the first SOI silicon wafer, etch a deep hole penetrating the buried layer from the lower surface of the insulating layer upward, fill the deep hole with metal, and lead a metal wire in the deep hole to the edge of the insulating layer on the lower surface of the bottom silicon layer; Step B. For the first SOI silicon wafer, the upper surface of the top silicon layer in the first SOI silicon wafer is etched downward to obtain individual comb teeth, forming a mirror outer lower comb tooth structure (4) and a mirror inner lower comb tooth structure (12); Step C. taking a second SOI silicon wafer, etching upwards to a preset depth a local area of ​​the non-mirror inner upper comb structure (11) of the mirror support (10) on the lower surface of the bottom silicon layer in the second SOI silicon wafer, to form a local gap space below the mirror support (10); Step D. performing silicon-silicon bonding between the second SOI silicon wafer and the first SOI silicon wafer, with the bottom silicon layer in the second SOI silicon wafer facing the top silicon layer in the first SOI silicon wafer, and removing the top silicon layer and the buried layer in the second SOI silicon wafer to expose the upper surface of the bottom silicon layer in the second SOI silicon wafer; Step F. performing deep silicon etching with a photoresist as a mask on the surfaces provided by the driving electrode (7) and the grounding electrode (8) to obtain patterned insulating grooves around each electrode, and depositing an OXD oxide layer on the upper surface of the bottom silicon layer in the second SOI silicon wafer, the surfaces provided by the driving electrode (7) and the grounding electrode (8), and the insulating grooves; Step G. Performing photolithography on the OXD oxide layer to pattern each electrode region, the outer annular structure (2) region, the outer shaft (6) region, the inner annular structure (9) region, the mirror support (10) region, the inner shaft (13) region, and each comb tooth region corresponding to the mirror outer upper comb tooth structure (3) and the mirror inner upper comb tooth structure (11), and performing metal deposition etching on each electrode region and the mirror support (10) region to obtain each electrode and the mirror reflection layer (5); Step H. For the outer annular structure (2) region, the outer rotating shaft (6) region, the inner annular structure (9) region, the mirror support (10) region, the inner rotating shaft (13) region, and the respective comb tooth regions corresponding to the mirror outer comb tooth structure (3) and the mirror inner comb tooth structure (11), deep silicon etching is performed using a photoresist as a mask to obtain the outer annular structure (2), the outer rotating shaft (6), the inner annular structure (9), the inner rotating shaft (13), the mirror support (10), and the respective comb teeth constituting the mirror outer comb tooth structure (3) and the mirror inner comb tooth structure (11).

9. The method for manufacturing a stacked structure micromirror chip according to claim 8, characterized in that: In the step F, the OXD oxide layer is deposited by plasma enhanced chemical vapor deposition (PECVD).

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