Gas-driven MEMS micromirror and forming method thereof

Abstract

The invention relates to a gas-driven MEMS (Micro Electro Mechanical System) micromirror which comprises a micromirror structure and a micromirror substrate, and a micromirror moving cavity is formed in the micromirror substrate and is used for providing a moving space and mechanical support for the micromirror structure. Wherein the micro-mirror structure further comprises a mirror surface, which is used for reflecting light; one end of the torsion beam is connected with the mirror surface, and the other end of the torsion beam is connected with the side wall of the micro-mirror moving cavity; one end of the torsion stress surface is connected with the mirror surface, the other end of the torsion stress surface is a free end, and the micro-mirror moving cavity is provided with an air inlet channel outlet above the torsion stress surface. Power is provided through an external air source, an additional chip driving module is not needed, the structure is simple and reliable, stable operation can be achieved in a high-temperature environment, a large torsion angle is achieved, and better reliability and economical efficiency are achieved.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of semiconductor technology, and in particular to a gas-driven MEMS micromirror and a method for forming the same. Background Art

[0002] MEMS micromirror (Micro-Electro-Mechanical Systems Mirror) is a miniature drivable reflector manufactured based on micro-electromechanical system technology. The basic principle of MEMS micromirror is: the laser emitted by a laser or other light source is projected onto a rotatable MEMS micromirror, which then rotates and reflects the laser to a specific target area. MEMS micromirrors can precisely control the direction of reflected light and are widely used in optical and electronic equipment, such as lidar, projectors, and fiber-optic communication systems.

[0003] Existing MEMS micromirror driving methods mainly include electrostatic driving, electromagnetic driving and thermal driving, etc. The above driving methods usually require the integration of corresponding driving circuits on the chip. The integration process not only increases the complexity and cost of the manufacturing process, but also may limit the use of MEMS micromirrors in certain environments. For example, in high temperature, strong electromagnetic interference or other environments that are not suitable for circuit operation, traditional driving methods face reliability and stability issues. Summary of the invention

[0004] The technical problem solved by the embodiments of the present application is to provide a gas-driven MEMS micromirror and a method for forming the same, so as to improve the performance of the MEMS micromirror in extreme environments.

[0005] To solve the above problems, an embodiment of the present application provides a gas-driven MEMS micromirror, comprising: a micromirror structure and a micromirror substrate, wherein a micromirror active cavity is formed inside the micromirror substrate, for providing an active space and mechanical support for the micromirror structure; wherein the micromirror structure further comprises: a mirror surface for reflecting light; a torsion beam, one end of which is connected to the mirror surface, and the other end is connected to the side wall of the micromirror active cavity; a torsion force surface, one end of which is connected to the mirror surface, and the other end is a free end, and the micromirror active cavity is provided with an air inlet channel outlet above the torsion force surface.

[0006] Optionally, the mirror surface, the torsion beam, and the torsion force bearing surface are coplanar.

[0007] Optionally, the micromirror structure includes: two torsion beams and two torsion force bearing surfaces, the two torsion beams are symmetrically arranged on both sides of the mirror surface along a first direction, and the two torsion force bearing surfaces are symmetrically arranged on both sides of the mirror surface along a second direction, and the first direction is perpendicular to the second direction.

[0008] Optionally, an air inlet channel is formed inside the micromirror substrate for introducing airflow outside the micromirror into the micromirror active cavity. The air inlet channel inlet is arranged on the outer surface of the micromirror substrate, and the air inlet channel outlet is arranged on the surface of the micromirror active cavity and is located above the torsional force surface.

[0009] Optionally, the micromirror substrate is further provided with an exhaust port for exhausting the gas in the micromirror active cavity.

[0010] Optionally, the micromirror substrate is further provided with a light channel located directly above the mirror surface.

[0011] Optionally, the micromirror substrate is further provided with a torsion limit block, and the torsion limit block is arranged between the outlet of the air inlet channel and the light channel.

[0012] On the other hand, an embodiment of the present application provides a method for forming a gas-driven MEMS micromirror, comprising the following steps: providing an SOI silicon wafer, wherein the SOI silicon wafer comprises a first silicon layer, a second silicon layer, and a first buried oxide layer buried between the first silicon layer and the second silicon layer; patterning the second silicon layer to form a micromirror structure to be released; providing a composite silicon wafer, wherein the composite silicon wafer is formed with a light channel, a gas channel, and a first part of a micromirror active cavity; bonding the second silicon layer to the composite silicon wafer by a bonding process, such that the micromirror structure to be released is located in the first part of the micromirror active cavity; removing at least part of the first silicon layer and the first buried oxide layer, such that the bottom of the micromirror structure to be released is suspended in the air.

[0013] Optionally, the method for forming the composite silicon wafer includes: providing a first silicon wafer, forming the first part of the micromirror active cavity, the first part of the light channel, and the first part of the gas channel on the first silicon wafer; providing a second silicon wafer, forming the second part of the light channel and the second part of the gas channel on the second silicon wafer; bonding the first silicon wafer to the second silicon wafer by a bonding process, so that the first part of the light channel and the second part of the light channel together form the light channel, and the first part of the gas channel and the second part of the gas channel together form the gas channel.

[0014] Optionally, the first silicon wafer and the second silicon wafer are double-sided polished silicon wafers.

[0015] Compared with the prior art, the technical solution of the embodiment of the present application has the following advantages:

[0016] The gas-driven MEMS micromirror provided in the present application is powered by an external gas source and does not require an additional chip driving module. It has a simple and reliable structure, can operate stably in a high-temperature environment, achieve a larger torsion angle, and has better reliability and economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0018] Figure 1 An application scenario of a MEMS micromirror is shown.

[0019] Figure 2 A schematic structural diagram of a gas-driven MEMS micromirror provided by the present invention.

[0020] Figure 3 for Figure 2 A cross-sectional view of the gas-driven MEMS micromirror along line Y-Y' is shown.

[0021] Figure 4 A schematic diagram of the structure of the gas-driven MEMS micromirror provided by the present invention from another perspective.

[0022] Figure 5-Figure 19 This is a schematic structural diagram corresponding to each step in the gas-driven MEMS micromirror formation method provided by the present invention.

[0023] Fig. 20 A schematic structural diagram of a gas-driven MEMS micromirror provided by the present invention in which the mirror surface rotates under gas driving. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the present disclosure clearer, the present disclosure will be further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0025] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a product or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such product or device. In the absence of more restrictions, the elements defined by the sentence "comprises a" do not exclude the presence of other identical elements in the product or device including the elements.

[0026] In the related technology, MEMS micromirror is a miniature drivable reflector manufactured based on micro-electromechanical system technology. Figure 1The application scenario of MEMS micromirrors is schematically shown. A light source (such as a laser) emits a light beam through a lens. After passing through a beam splitter, part of the light is guided to the MEMS micromirror. The MEMS micromirror rotates and reflects the laser, and can accurately control the angle of the reflected light beam, guide the reflected light beam to the lens, and finally irradiate the reflective target.

[0027] In the prior art, MEMS micromirrors are generally driven by electrostatic, electromagnetic or thermal means. The above-mentioned MEMS micromirror driving methods have problems such as complex manufacturing, high cost, and limited reliability in extreme environments. For example, the existing electrostatic drive uses electrostatic force to drive the rotation of the micromirror, which requires the processing of complex drive circuits on the chip; the electromagnetic drive controls the rotation of the micromirror through the interaction between current and magnetic field, which also requires the processing of complex drive circuits on the chip, and electromagnetic interference may affect the stability of the micromirror system; thermal drive causes thermal expansion or deformation of the material through local heating, thereby realizing the rotation of the micromirror, but this drive method is sensitive to temperature changes and has low reliability in high temperature environments.

[0028] In order to solve the above technical problems, an embodiment of the present invention further provides a gas-driven MEMS micromirror, comprising: a micromirror structure and a micromirror substrate, wherein a micromirror activity cavity is formed inside the micromirror substrate to provide an activity space and mechanical support for the micromirror structure; wherein the micromirror structure further comprises:

[0029] Mirror surface, used to reflect light;

[0030] A torsion beam, one end of which is connected to the mirror surface, and the other end of which is connected to the side wall of the micromirror active cavity;

[0031] The torsion force-bearing surface has one end connected to the mirror surface and the other end being a free end. The micromirror active cavity is provided with an air inlet channel outlet above the torsion force-bearing surface.

[0032] In order to solve the above technical problems, an embodiment of the present invention provides a method for forming a gas-driven MEMS micromirror, comprising the following steps:

[0033] Providing an SOI silicon wafer, the SOI silicon wafer comprising a first silicon layer, a second silicon layer, and a first buried oxide layer buried between the first silicon layer and the second silicon layer; patterning the second silicon layer to form a micromirror structure to be released;

[0034] Providing a composite silicon wafer, the composite silicon wafer is formed with a light channel, a gas channel, and a first part of a micromirror active cavity;

[0035] Bonding the second silicon layer to the composite silicon wafer by using a bonding process, so that the micromirror structure to be released is located in the first part of the micromirror active cavity;

[0036] At least a portion of the first silicon layer and the first buried oxide layer is removed, so that the bottom of the micromirror structure to be released is suspended.

[0037] The gas-driven MEMS micromirror provided in this embodiment is powered by an external gas source and does not require an additional chip driving module. It has a simple and reliable structure, can operate stably in a high temperature environment, achieve a larger torsion angle, and has better reliability and economy.

[0038] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0039] For reference Figure 2-Figure 4 The present invention provides a gas-driven MEMS micromirror 100, comprising: a micromirror structure 110 and a micromirror substrate 120 providing mechanical support and an air flow channel for the micromirror structure 110.

[0040] The micromirror structure 110 further includes: a mirror surface 111, a torsion beam 112, and a torsion force bearing surface 113. In some embodiments, the mirror surface 111, the torsion beam 112, and the torsion force bearing surface 113 can be an integrated structure. In some embodiments, the mirror surface 111, the torsion beam 112, and the torsion force bearing surface 113 can be coplanar.

[0041] A micromirror activity cavity 121 is formed inside the micromirror substrate 120 to provide a space for the micromirror structure 110 to move. The micromirror structure 110 is located in the micromirror activity cavity 121 formed by the micromirror substrate 120 and is connected to the side wall of the micromirror activity cavity 121 via a torsion beam 112 .

[0042] As a specific example, the micromirror structure 110 includes a mirror surface 111, two torsion beams 112 symmetrically arranged relative to the mirror surface 111, and two torsion force surfaces 113 symmetrically arranged relative to the mirror surface 111, wherein the two torsion beams 112 are respectively located on both sides of the mirror surface 111 along the X direction, and the two torsion force surfaces 113 are respectively located on both sides of the mirror surface 111 along the Y direction, and the torsion beams 112 and the torsion force surfaces 113 are perpendicular to each other in the XY plane, forming a cross-shaped distribution. The mirror surface 111, the torsion beam 112, and the torsion force surface 113 can be an integral structure and are arranged in the same plane.

[0043] The mirror 111 is used to reflect or regulate light. The mirror 111 is connected to the side wall of the micromirror active cavity 121 through a torsion beam 112 and is suspended relative to the micromirror base 120 to ensure that the mirror 111 has a certain rotation ability.

[0044] The torsion beam 112 is used to support the mirror surface 111. One end of the torsion beam 112 is connected to the mirror surface 111, and the other end is connected to the side wall of the micromirror active cavity 121. The rotation axis of the torsion beam 112 and the mirror surface 111 are colinear. When the micromirror is acted upon by airflow, the torsion beam 112 undergoes elastic torsion deformation, so that the mirror surface 111 rotates around the rotation axis under the restraint of the torsion beam 112 and tilts, thereby achieving high-precision angle control of the micromirror structure 110. In some embodiments, two torsion beams 112 are symmetrically arranged on both sides of the mirror surface 111 along a first direction (e.g., the X direction in the figure), and are respectively a first torsion beam and a second torsion beam.

[0045] One end of the torsion force-bearing surface 113 is connected to the mirror surface 111, and the other end is a free end. The micromirror active cavity 121 is provided with an airflow outlet above the torsion force-bearing surface 113, namely, an air inlet channel outlet 124. When the gas blows from the air inlet channel outlet 124 to the torsion force-bearing surface 113, the airflow exerts a force on the torsion force-bearing surface 113, so that the mirror surface 111 generates a rotational motion around the torsion beam 112. In some embodiments, the two torsion force-bearing surfaces 113 are symmetrically arranged on both sides of the mirror surface 111 along the second direction (e.g., the Y direction in the figure), and are respectively the first torsion force-bearing surface and the second torsion force-bearing surface.

[0046] The micromirror substrate 120 provides support and airflow control for the micromirror structure 110. A micromirror activity cavity 121 is formed inside the micromirror substrate 120 to provide an activity space and mechanical support for the micromirror structure 110.

[0047] An air inlet channel is also formed inside the micromirror base 120. Specifically in the present embodiment, the air inlet channel is further divided into two sections that are perpendicular and connected to each other, namely, a first channel 122a extending in the horizontal direction and a second channel 122b extending in the vertical direction. The air inlet channel is used to introduce the airflow outside the micromirror into the micromirror active cavity 121. The air inlet channel has two openings, namely, an air inlet channel inlet 123 arranged on the outer surface of the micromirror base 120, and an air inlet channel outlet 124 arranged in the micromirror active cavity 121 and facing the torsion force surface 113. The airflow enters from the air inlet channel inlet 123, flows out from the air inlet channel outlet 124, and blows directly to the torsion force surface 113. In some embodiments, the air inlet channel inlet 123 is arranged on the outer side wall of the micromirror base 120, and the air inlet channel outlet 124 is arranged on the upper surface of the micromirror active cavity 121, and is located above the torsion force surface 113. The number of the air intake channels is the same as the torsional stress surface 113 , that is, one air intake channel corresponds to one torsional stress surface 113 . In some embodiments, there are two torsional stress surfaces 113 , and the number of corresponding air intake channels is also two.

[0048] The micromirror base 120 is also provided with an exhaust port 126 for exhausting the gas in the micromirror active cavity 121 to ensure smooth airflow circulation. The airflow enters from the air inlet channel inlet 123, passes through the air inlet channel and is ejected from the air inlet channel outlet 124, directly acts on the torsional force bearing surface 113, and is finally exhausted from the exhaust port 126.

[0049] The micromirror substrate 120 is also provided with a light channel 128 located directly above the mirror surface 111 to ensure smooth transmission of light signals.

[0050] The micromirror base 120 is also provided with a torsion limiter 127 for limiting the maximum rotation angle of the mirror surface 111. The torsion limiter 127 can be provided at the upper part of the micromirror active cavity, and specifically, can be a downward convex structure provided between the air inlet channel outlet 124 and the light channel 128.

[0051] The micromirror design of the present application avoids complex driving circuits and is powered by an external gas source, without the need for an additional chip driving module, thus reducing structural complexity and potential failure risks. In addition, the gas drive method can operate stably in a high temperature environment and is not easily affected by temperature changes. And because the pressure and flow of the gas source can be precisely controlled, the MEMS micromirror of the present application can achieve a larger torsion angle, breaking through the limitations of traditional electrostatic drive.

[0052] Compared with the prior art, the gas-driven MEMS micromirror provided in the present application is powered by an external gas source and does not require an additional chip driving module. It has a simple and reliable structure, can operate stably in a high temperature environment, achieve a larger torsion angle, and has better reliability and economy.

[0053] Figures 5 to 19 It is a schematic structural diagram corresponding to each step in an embodiment of a method for forming a gas-driven MEMS micromirror provided by the present invention.

[0054] refer to Figure 5-Figure 7 ,in, Figure 7 yes Figure 6 S100, providing an SOI silicon wafer 10, the SOI silicon wafer 10 comprising a first silicon layer 11, a second silicon layer 13 and a first buried oxide layer 12 buried between the first silicon layer 11 and the second silicon layer 13; patterning the second silicon layer 13 to form a micromirror structure 110 to be released.

[0055] In this step, a micromirror structure 110 to be released is formed on the SOI silicon wafer 1. The micromirror structure 110 to be released in this step is a micromirror structure 110 that has not yet been released, and the bottom of the micromirror structure 110 to be released is not suspended, but is in contact with the buried oxide layer 12. In subsequent steps, the buried oxide layer 12 and the first silicon layer 11 at the bottom of the micromirror structure 110 to be released will be removed. With the removal of the bottom buried oxide layer 12 and the first silicon layer 11, the micromirror structure 110 to be released will be in a truly suspended state, forming a suspended micromirror structure 110.

[0056] refer to Figure 8-Figure 16 , S200, provide a composite silicon wafer 40, which is formed with a light channel 128, an air inlet channel 122, and a first part 1211 of the micromirror active cavity.

[0057] In some embodiments, step S200 may further include:

[0058] refer to Figure 8-Figure 11 ,in, Fig. 9 yes Figure 8 Section along BB', Fig.11 yes Fig.10 Cross-sectional view along line BB′ S210 , providing a first silicon wafer 20 , and forming the first micromirror active cavity portion 1211 , the first light channel portion 1281 , and the first air inlet channel portion 1221 on the first silicon wafer 20 .

[0059] In this step, the first silicon wafer 20 can be a double-sided polished (DSP) silicon wafer, and both sides of the DSP silicon wafer are polished to improve its surface flatness and smoothness. The silicon material of part of the first silicon wafer 20 can be removed by etching process to form the above-mentioned micromirror active cavity first part 1211, the light channel first part 1281, and the air intake channel first part 1221 and other structures.

[0060] refer to Figure 12-Figure 15 ,in, Fig.13 yes Fig.12 Cross-section along CC', Fig.15 yes Fig.14 Cross-sectional view along CC′ S220 , providing a second silicon wafer 30 , and forming the light channel second portion 1282 and the air inlet channel second portion 1222 on the second silicon wafer 30 .

[0061] In this step, the second silicon wafer 30 can be a double-sided polished (DSP) silicon wafer, and both sides of the DSP silicon wafer are polished to improve its surface flatness and smoothness. The silicon material of the second silicon wafer 30 can be removed by etching process to form the above-mentioned structure of the second part 1282 of the light channel and the second part 1222 of the air inlet channel.

[0062] refer to Fig.16 , S230, using a bonding process to bond the first silicon wafer 20 and the second silicon wafer 30, so that the first part 1281 of the light channel and the second part 1282 of the light channel together form the light channel 128, and the first part 1221 of the air inlet channel and the second part 1222 of the air inlet channel together form the air inlet channel 122.

[0063] In this step, the first silicon wafer 20 and the second silicon wafer 30 are formed into an integrated structure by a bonding process, and the composite silicon wafer 40 is formed after the first silicon wafer 20 and the second silicon wafer 30 are bonded.

[0064] refer to Fig.17 S300, using a bonding process to bond the second silicon layer 13 to the composite silicon wafer 40, so that the micromirror structure 110 to be released is located in the first part 1211 of the micromirror active cavity. In this step, the SOI silicon wafer 10 and the composite silicon wafer 40 are formed into an integrated structure using a bonding process.

[0065] refer to Fig.18 and Fig.19 , S400, removing at least a portion of the first silicon layer 11 and the first buried oxide layer 12, so that the bottom of the micromirror structure 110 to be released is suspended.

[0066] Fig. 20 The figure shows the situation in which the mirror surface of the gas-driven MEMS micromirror provided by the present invention rotates under gas drive. Specifically, the airflow blows toward the micromirror structure 110 through the gas channel 112, and the pressure of the airflow causes the micromirror structure 110 to rotate downward from position A to position B. The precise regulation of the flow rate and pressure of the gas enables the rotation angle of the micromirror to be accurately controlled, thereby achieving the desired optical adjustment effect. Furthermore, the air inlet channels 122 on the left and right sides can cooperate with each other, and by adjusting the pressure and flow rate of the airflow, different torsion angles and rotation frequencies can be achieved, thereby accurately controlling the movement of the micromirror.

[0067] In addition to being a driving source, the airflow also has a cooling function. When the airflow passes through the micromirror structure 110, it can not only drive the mirror surface 111 to rotate, but also take away some heat, thereby effectively reducing the temperature of the micromirror structure 110 and its surrounding components to prevent overheating, so that the gas-driven MEMS micromirror of the present invention exhibits better stability and reliability in a high temperature environment.

[0068] It should be noted that each embodiment in this specification is described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the embodiments can be referred to each other. For the device embodiment, since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0069] Although the embodiments of the present application are disclosed above, the present application is not limited thereto. Any person skilled in the art may make various changes and modifications without departing from the spirit and scope of the present application. Therefore, the scope of protection of the present application shall be subject to the scope defined by the claims.

Claims

1. A gas-driven MEMS micromirror, characterized in that: include: A micromirror structure and a micromirror substrate, wherein a micromirror activity cavity is formed inside the micromirror substrate to provide an activity space and mechanical support for the micromirror structure; wherein the micromirror structure further comprises: Mirror surface, used to reflect light; A torsion beam, one end of which is connected to the mirror surface, and the other end of which is connected to the side wall of the micromirror active cavity; The torsion force-bearing surface has one end connected to the mirror surface and the other end being a free end. The micromirror active cavity is provided with an air inlet channel outlet above the torsion force-bearing surface.

2. The gas-driven MEMS micromirror according to claim 1, characterized in that: The mirror surface, the torsion beam, and the torsion force bearing surface are coplanar.

3. The gas-driven MEMS micromirror according to claim 1 or 2, characterized in that: The micromirror structure includes: two torsion beams and two torsion force-bearing surfaces, the two torsion beams are symmetrically arranged on both sides of the mirror surface along a first direction, and the two torsion force-bearing surfaces are symmetrically arranged on both sides of the mirror surface along a second direction, and the first direction is perpendicular to the second direction.

4. The gas-driven MEMS micromirror according to claim 1, wherein: An air inlet channel is formed inside the micromirror substrate for introducing airflow outside the micromirror into the micromirror active cavity. The air inlet channel inlet is arranged on the outer surface of the micromirror substrate, and the air inlet channel outlet is arranged on the surface of the micromirror active cavity and is located above the torsional force surface.

5. The gas-driven MEMS micromirror according to claim 4, characterized in that: The micromirror substrate is also provided with an exhaust port for exhausting the gas in the micromirror active cavity.

6. The gas-driven MEMS micromirror according to claim 1 or 5, characterized in that: The micromirror substrate is also provided with a light channel located just above the mirror surface.

7. The gas-driven MEMS micromirror according to claim 6, characterized in that: The micromirror substrate is also provided with a torsion limiting block, which is arranged between the outlet of the air inlet channel and the light channel.

8. A method for forming a gas-driven MEMS micromirror as claimed in claim 1, characterized in that: The following steps are involved: Providing an SOI silicon wafer, the SOI silicon wafer comprising a first silicon layer, a second silicon layer, and a first buried oxide layer buried between the first silicon layer and the second silicon layer; patterning the second silicon layer to form a micromirror structure to be released; Providing a composite silicon wafer, the composite silicon wafer is formed with a light channel, an air intake channel, and a first part of a micromirror active cavity; Bonding the second silicon layer to the composite silicon wafer by using a bonding process, so that the micromirror structure to be released is located in the first part of the micromirror active cavity; At least a portion of the first silicon layer and the first buried oxide layer is removed, so that the bottom of the micromirror structure to be released is suspended.

9. The method for forming a gas-driven MEMS micromirror according to claim 8, wherein: The method for forming the composite silicon wafer comprises: Providing a first silicon wafer, on which the first part of the micromirror active cavity, the first part of the light channel, and the first part of the air inlet channel are formed; Providing a second silicon wafer, forming the second portion of the light channel and the second portion of the air inlet channel on the second silicon wafer; The first silicon wafer is bonded to the second silicon wafer by using a bonding process, so that the first part of the light channel and the second part of the light channel together form the light channel, and the first part of the air inlet channel and the second part of the air inlet channel together form the air inlet channel.

10. The method for forming a gas-driven MEMS micromirror according to claim 9, wherein: The first silicon wafer and the second silicon wafer are double-sided polished silicon wafers.

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