Preparation method of light reflection device and light reflection device

Abstract

The invention provides a preparation method of a light reflection device and the light reflection device, and relates to the technical field of semiconductors, and the preparation method comprises the steps: providing a substrate with a control circuit, patterning a first metal layer to form a metal interconnection layer, patterning a second metal layer to form a light reflection array, and enabling the metal interconnection layer to be electrically connected with the control circuit, and at least one light reflection structure of the light reflection array is electrically connected. According to the preparation method, the first metal layer and the second metal layer are sequentially deposited on the substrate and are patterned to obtain the metal interconnection layer and the light reflection array, so that the preparation of the light reflection device can be completed by adopting the MEMS technology based on the preparation method, the process is simple, the cost is low, and the reliability of the device can be ensured. The patterning of the metal interconnection layer and the patterning of the light reflection array do not influence each other, diversification of light reflection structures can be achieved, meanwhile, the number of the light reflection structures of the light reflection array is not limited, the size can be very small, and the size of the light reflection device is reduced.

Description

Technical Field

[0001] The present application relates to the field of semiconductor technology, and in particular to a method for preparing a light reflecting device and a light reflecting device. Background Art

[0002] Light reflectors are an indispensable part of the optical field and are used in many optical devices, such as astronomical telescopes, searchlights, movie projectors, periscopes, etc. In addition, light reflectors also play an important role in the field of optical information science and technology, and are used to control, adjust or convert the propagation direction, intensity, frequency, phase and other characteristics of light. Therefore, for those skilled in the art, providing a low-cost and low-difficulty preparation method has become a key research topic. Summary of the invention

[0003] In view of this, the present application provides a method for preparing a light reflective device and a light reflective device, and the scheme is as follows:

[0004] A method for preparing a light reflecting device, comprising:

[0005] Providing a substrate, wherein the substrate has a control circuit, wherein the control circuit is a CMOS control circuit;

[0006] Depositing a first metal layer, patterning the first metal layer to form a metal interconnection layer, wherein the metal interconnection layer is located on the surface of the substrate and is electrically connected to the control circuit;

[0007] Depositing a second metal layer and patterning the second metal layer to form a light reflection array, wherein the light reflection array is located on a side of the metal interconnect layer away from the substrate; the light reflection array includes a plurality of light reflection structures, and the metal interconnect layer is also electrically connected to the light reflection structures, so that the control circuit controls at least one of the light reflection structures in the light reflection array through the metal interconnect layer;

[0008] When the light reflective device is working, the control circuit sends a first control signal to the light reflective array through the metal interconnection layer to control at least one of the light reflective structures in the light reflective array to undergo a first deflection, or the control circuit sends a second control signal to the light reflective array through the metal interconnection layer to control at least one of the light reflective structures in the light reflective array to undergo a second deflection;

[0009] Among them, the light reflecting structure has a light reflecting surface, the first deflection is that the first side of the light reflecting surface is deflected along a first direction, the second deflection is that the second side of the light reflecting surface is deflected along the first direction, the first side and the second side are different sides of the light reflecting surface, and the first direction is the direction in which the light reflecting surface points to the substrate.

[0010] Optionally, the metal interconnect layer includes a first metal interconnect layer and a second metal interconnect layer, the second metal interconnect layer is located between the first metal interconnect layer and the light reflection array, the first metal interconnect layer is electrically connected to the control circuit, the second metal interconnect layer is electrically connected to the first metal interconnect layer, and the second metal interconnect layer is also electrically connected to the light reflection structure; forming the metal interconnect layer includes:

[0011] Depositing a first isolation layer on the surface of the substrate, wherein the first isolation layer has a first through hole, and the first through hole exposes the control circuit;

[0012] Depositing a first sub-metal layer on a side of the first isolation layer away from the substrate, and patterning the first sub-metal layer to form a first metal interconnection layer, wherein the first metal interconnection layer has a first preset pattern, covers the first isolation layer, and fills the first through hole;

[0013] Depositing a second isolation layer on a side of the first metal interconnection layer away from the substrate, wherein the second isolation layer has a second through hole, and the second through hole exposes a portion of the first metal interconnection layer;

[0014] A second sub-metal layer is deposited on the side of the second isolation layer away from the substrate, and the second sub-metal layer is patterned to form a second metal interconnection layer having a second preset pattern, covering the second isolation layer, and filling the second through hole.

[0015] Optionally, the light reflecting structure comprises an electrode layer and a supporting base located on a side of the second metal interconnection layer away from the substrate, the electrode layer is electrically connected to the second metal interconnection layer, the supporting base is also electrically connected to the second metal interconnection layer, and the light reflecting surface is connected to a side of the supporting base away from the substrate;

[0016] When the light reflecting device is working, the control circuit sends the first control signal to the electrode layer through the metal interconnection layer to control the light reflecting surface to undergo a first deflection, or the control circuit sends the second control signal to the electrode layer through the metal interconnection layer to control the light reflecting surface to undergo a second deflection.

[0017] Optionally, the electrode layer includes a first electrode and a second electrode, the first electrode and the second electrode are symmetrically distributed relative to the support base, and the first electrode corresponds to a first side of the light reflecting surface, and the second electrode corresponds to a second side of the light reflecting surface;

[0018] When the light reflecting device is working, the control circuit sends the first control signal to the electrode layer through the metal interconnection layer, so that the first electrode attracts the first side of the light reflecting surface and the second electrode repels the second side of the light reflecting surface, so as to control the light reflecting surface to undergo a first deflection, or the control circuit sends the second control signal to the electrode layer through the metal interconnection layer, so that the first electrode repels the first side of the light reflecting surface and the second electrode attracts the second side of the light reflecting surface, so as to control the light reflecting surface to undergo a second deflection.

[0019] Optionally, the support base includes a support bottom layer located on a side of the second metal interconnection layer away from the substrate, the support bottom layer includes a first support layer, a second support layer and a third support layer, the first support layer connects the second support layer and the third support layer to form an H-shaped support bottom layer; the first electrode and the second electrode are respectively located on both sides of the first support layer and are symmetrically distributed;

[0020] The support base further includes a support column, the support column is located on a side of the first support layer away from the substrate, and the light reflecting surface is located on a side of the support column away from the substrate.

[0021] Optionally, forming the light reflecting structure includes:

[0022] Depositing a third isolation layer on a side of the second metal interconnection layer away from the substrate, wherein the third isolation layer has a third through hole, and the third through hole exposes a portion of the second metal interconnection layer;

[0023] A third sub-metal layer is deposited on the side of the third isolation layer away from the substrate, and the third sub-metal layer is patterned to form the first electrode, the second electrode and the supporting bottom layer; wherein the first electrode has a third preset pattern and fills the corresponding third through hole; the second electrode has a fourth preset pattern and fills the corresponding third through hole; the supporting bottom layer has a fifth preset pattern and fills the corresponding third through hole;

[0024] A first sacrificial layer is formed on the electrode layer and the supporting bottom layer at a side away from the substrate, wherein the first sacrificial layer has a fourth through hole, and the fourth through hole exposes a portion of the first supporting layer;

[0025] Depositing a fourth sub-metal layer on the side of the first sacrificial layer away from the substrate, patterning the fourth sub-metal layer to form the support column and the light reflecting surface, wherein the support column is located in the fourth through hole, and the light reflecting surface covers the side of the fourth isolation layer away from the substrate and is connected to the support column;

[0026] The first sacrificial layer is removed, and a gap is formed between the light reflecting surface and the supporting bottom layer.

[0027] Optionally, forming the light reflecting structure further includes:

[0028] A limiting column is formed on a side of the supporting bottom layer away from the base, and the limiting column is located on a deflection path of the light reflecting surface and is used to limit a deflection angle of the light reflecting surface;

[0029] Forming a limiting column on the side of the supporting bottom layer away from the base includes:

[0030] After forming the electrode layer and the supporting bottom layer and before forming the first sacrificial layer, a second sacrificial layer is deposited on the side of the electrode layer and the supporting bottom layer away from the substrate, the second sacrificial layer having a fifth through hole, the fifth through hole being located on the deflection path of the light reflecting surface, and the fifth through hole exposing a portion of the supporting bottom layer;

[0031] A fifth sub-metal layer is deposited in the fifth through hole, and the second sacrificial layer is removed to form the limiting column.

[0032] Optionally, the limiting column includes a first limiting column, a second limiting column, a third limiting column and a fourth limiting column;

[0033] The first limiting column and the second limiting column are respectively located at two ends of the second supporting layer, and the third limiting column and the fourth limiting column are respectively located at two ends of the third supporting layer.

[0034] A light reflecting device, comprising:

[0035] a substrate having a control circuit therein;

[0036] A metal interconnection layer, the metal interconnection layer covers the surface of the substrate and is electrically connected to the control circuit;

[0037] a light reflection array, the light reflection array being located on a side of the metal interconnect layer away from the substrate; the light reflection array comprising a plurality of light reflection structures, the metal interconnect layer being also electrically connected to the light reflection structures, so that the control circuit controls at least one of the light reflection structures in the light reflection array through the metal interconnect layer;

[0038] When the light reflective device is working, the control circuit sends a first control signal to the light reflective array through the metal interconnection layer to control at least one of the light reflective structures in the light reflective array to undergo a first deflection, or the control circuit sends a second control signal to the light reflective array through the metal interconnection layer to control at least one of the light reflective structures in the light reflective array to undergo a second deflection;

[0039] Among them, the light reflecting structure has a light reflecting surface, the first deflection is that the first side of the light reflecting surface is deflected along a first direction, the second deflection is that the second side of the light reflecting surface is deflected along the first direction, the first side and the second side are different sides of the light reflecting surface, and the first direction is the direction in which the light reflecting surface points to the substrate.

[0040] Optionally, the metal interconnect layer includes a first metal interconnect layer and a second metal interconnect layer, the second metal interconnect layer is located between the first metal interconnect layer and the light reflection array, the second metal interconnect layer is electrically connected to the first metal interconnect layer, and the second metal interconnect layer is also electrically connected to the light reflection structure;

[0041] The light reflecting structure comprises an electrode layer and a supporting base located on a side of the second metal interconnection layer away from the substrate, the electrode layer is electrically connected to the second metal interconnection layer, the supporting base is also electrically connected to the second metal interconnection layer, and the light reflecting surface is connected to a side of the supporting base away from the substrate;

[0042] The electrode layer includes a first electrode and a second electrode, the first electrode and the second electrode are symmetrically distributed relative to the support base, and the first electrode corresponds to the first side of the light reflecting surface, and the second electrode corresponds to the second side of the light reflecting surface; the support base includes a support bottom layer located on the side of the second metal interconnection layer away from the substrate, the support bottom layer includes a first support layer, a second support layer and a third support layer, the first support layer connects the second support layer and the third support layer to form an H-shaped support bottom layer; the first electrode and the second electrode are respectively located on both sides of the first support layer and are symmetrically distributed; the support column is located on the side of the first support layer away from the substrate, and the light reflecting surface is located on the side of the support column away from the substrate;

[0043] When the light reflecting device is working, the control circuit sends the first control signal to the electrode layer through the metal interconnection layer to control the light reflecting surface to undergo a first deflection along the first direction, or the control circuit sends the second control signal to the electrode layer through the metal interconnection layer to control the light reflecting surface to undergo a second deflection.

[0044] Compared with the prior art, the technical solution of this application has the following beneficial effects:

[0045] The preparation method includes: providing a substrate with a control circuit, patterning a first metal layer to form a metal interconnection layer, and patterning a second metal layer to form a light reflection array. The metal interconnection layer is electrically connected to the control circuit, and the metal interconnection layer is also electrically connected to at least one light reflection structure of the light reflection array. It can be seen that the preparation method deposits the metal interconnection layer and the metal layer corresponding to the light reflection array on the substrate in sequence, and patterns the metal layer, so as to obtain the metal interconnection layer electrically connected to the control circuit and the light reflection array electrically connected to the metal interconnection layer, thus completing the preparation of the light reflection device. In other words, based on the preparation method provided in the present application, the preparation of the light reflection device can be completed by using MEMS technology, and there is no need to use special processes and design special equipment. Therefore, the preparation method provided in the present application is simple in process and low in cost, has strong operability, can ensure the reliability of the device, and has broad application prospects.

[0046] In addition, the patterning of the metal interconnect layer and the light reflection array does not affect each other, and it is sufficient to ensure that the control circuit, the metal interconnect layer and the light reflection array are electrically connected in sequence. Therefore, the light reflection structure of the light reflection array prepared by the preparation method can be diversified. Specifically, according to the performance requirements of the light reflection array, reflection arrays with different structures can be reasonably prepared, which can be applied to more application scenarios and has strong practicality. At the same time, the light reflection array is obtained by patterning the second metal layer using MEMS technology, and the number of light reflection structures of the light reflection array is not limited, and millions of them can be obtained, and the size can be very small. On the basis of ensuring the number of light reflection structures in the light reflection device, the volume of the light reflection device can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the related technologies, 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.

[0048] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which this application can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by this application, should still fall within the scope of the technical contents disclosed in this application.

[0049] Figure 1 A flow chart of a method for preparing a light reflective device provided in the present application;

[0050] Figure 2-Figure 8 A schematic diagram of the structure corresponding to each process step of a method for preparing a light reflective device provided in this application;

[0051] Fig. 9 This is a flow chart of a specific embodiment of a method for preparing a light reflecting device provided in the present application. DETAILED DESCRIPTION

[0052] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the embodiments in the present application. Obviously, the described embodiments are only embodiments of one area of ​​the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0053] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0054] As described in the background technology section, in order to facilitate the development of light reflective devices, providing a low-cost and easy-to-prepare preparation method has become a key issue for those skilled in the art.

[0055] Based on this, the present application provides a method for preparing a light reflective device, such as Figure 1 As shown, the preparation method comprises:

[0056] S1: Figure 2 As shown, a substrate 100 is provided, and a control circuit (not shown in the figure) is provided in the substrate 100. It should be noted that the control circuit can adopt an SRAM unit manufactured by a mature standard COMS process, that is, the control circuit can be a CMOS control circuit, which helps to reduce the power consumption of the manufactured light reflective device. However, this application does not limit this, and it depends on the specific situation.

[0057] S2: Figure 3As shown in d-3h, the first metal layer 10 is deposited, and the first metal layer 10 is patterned to form a metal interconnection layer 200, which is located on the surface of the substrate 100, and the metal interconnection layer 200 is electrically connected to the control circuit. Specifically, the first metal layer 10 is deposited on the surface of the substrate 100 by a deposition process, and the first metal layer 10 is patterned by photolithography or mechanical processing to form the metal interconnection layer 200. It should be noted that the above-mentioned deposition process can be a deposition process such as physical vapor deposition (such as evaporation, sputtering, laser pulse deposition PLD), chemical vapor deposition (such as LPCVD, PECVD, ALD), electrochemical deposition (such as electroplating), etc., and this application does not limit this, and it depends on the specific situation. It should also be noted that the metal interconnection layer 200 is located on the surface of the substrate 100, and specifically the metal interconnection layer 200 is located on the upper surface of the substrate 100.

[0058] S3: Figure 4 As shown, a second metal layer 20 is deposited and patterned to form a light reflection array. The light reflection array is located on the side of the metal interconnect layer 200 away from the substrate 100, and the light reflection array includes a plurality of light reflection structures 310. The metal interconnect layer 200 is also electrically connected to the light reflection structure 310, so that the control circuit can be electrically connected to the light reflection structure 310 through the metal interconnect layer 200, and then the control circuit can control at least one light reflection structure 310 in the light reflection array through the metal interconnect layer 200.

[0059] Specifically, when the light reflective device is working, the control circuit sends a first control signal to the light reflective array through the metal interconnection layer 200 to control at least one light reflective structure 310 in the light reflective array to undergo a first deflection, or the control circuit sends a second control signal to the light reflective array through the metal interconnection layer 200 to control at least one light reflective structure 310 in the light reflective array to undergo a second deflection. It should be noted that the control circuit does not directly control millions of light reflective structures 310, but addresses the corresponding light reflective structure 301 through the metal interconnection layer and sends a control signal thereto.

[0060] The light reflecting structure 310 has a light reflecting surface 301. Figure 5 As shown, the first deflection is that the first side of the light reflecting surface 301 deflects along the first direction, and the second deflection is that the second side of the light reflecting surface 301 deflects along the first direction. The first side and the second side are different sides of the light reflecting surface 301, and the first direction is the direction in which the light reflecting surface 301 points to the substrate 100. For example, Figure 4As shown, the light reflecting surface 301 is a rectangular plane, and the first side and the second side can be the opposite sides of the rectangular plane respectively. The first deflection is that the first side of the light reflecting surface 301 deflects in the direction toward the substrate 100, and the second side of the light reflecting surface 301 deflects in the direction away from the substrate 100, that is, the first deflection makes the light reflecting surface 301 tilt toward the substrate 100 in the direction from the second side to the first side, and the second deflection is that the second side of the light reflecting surface 301 deflects in the direction toward the substrate 100, and the first side of the light reflecting surface 301 deflects in the direction away from the substrate 100, that is, the first deflection makes the light reflecting surface 301 tilt toward the substrate 100 in the direction from the first side to the second side.

[0061] As can be seen from the above, when using the preparation method provided by the present application to prepare a light reflective device, a substrate 100 with a control circuit is provided, and a metal interconnection layer 200 and a metal layer corresponding to the light reflective array are sequentially deposited on the substrate 100, and the metal layer is patterned, so that the metal interconnection layer 200 electrically connected to the control circuit and the light reflective array electrically connected to the metal interconnection layer 200 can be obtained, and the preparation of the light reflective device is completed. In other words, the preparation method provided by the present application can be used to complete the preparation of the light reflective device by using MEMS technology. Since metal deposition and patterning in MEMS technology are both quite mature technical means, and do not require the use of special processes and the design of special equipment, the preparation method provided by the present application is simple in process and low in cost, has strong operability, can ensure the reliability of the device, and has a wide range of application prospects.

[0062] In addition, it can be seen from the above that the patterning of the metal interconnect layer 200 and the light reflection array does not affect each other, and it is sufficient to ensure that the control circuit, the metal interconnect layer 200 and the light reflection array are electrically connected in sequence. Therefore, the light reflection structure 310 of the light reflection array prepared by the preparation method can be diversified. Specifically, according to the performance requirements of the light reflection array, a reflection array with different structures can be reasonably prepared, which can be applied to more application scenarios and has strong practicality. At the same time, the light reflection array is obtained by patterning the second metal layer 20 using MEMS technology, and the number of light reflection structures of the light reflection array is not limited, and millions of them can be obtained, and the size can be very small. On the basis of ensuring the number of light reflection structures in the light reflection device, the volume of the light reflection device can be reduced.

[0063] In summary, the light reflective device manufactured by the preparation method provided in the present application has the characteristics of small size, low power consumption, high reliability, etc., and has broad application prospects.

[0064] In order to achieve insulation isolation between the control circuit, the metal interconnection layer 200 and the light reflection array except for the electrical connection area, based on the above embodiments, in one embodiment of the present application, the metal interconnection layer 200 includes a first metal interconnection layer 201 and a second metal interconnection layer 202, and the second metal interconnection layer 201 is located between the first metal interconnection layer 201 and the light reflection array, that is, the first metal interconnection layer 201, the second metal interconnection layer 202 and the light reflection array are arranged in sequence along the direction away from the substrate 100. Among them, the first metal interconnection layer 201 is electrically connected to the control circuit, the second metal interconnection layer 202 is electrically connected to the first metal interconnection layer 201, and the second metal interconnection layer 202 is also electrically connected to the light reflection structure 310.

[0065] Based on the above, for step S2, forming the metal interconnection layer 200 includes:

[0066] like Figure 3 As shown in a-3c, a first isolation layer 31 is deposited on the surface of the substrate 100, and the first isolation layer 31 has a first through hole 1. The first through hole 1 exposes the control circuit, and specifically, the first through hole 1 can expose the output port of the control circuit located on the surface of the substrate 100. Specifically, silicon dioxide or other insulating materials are deposited on the surface of the substrate 100 to form the first isolation layer 31, and photoresist is spin-coated, then exposed and developed to define the position of the first through hole 1, the first isolation layer 31 is etched to form the first through hole 1, and the side of the first isolation layer 31 away from the substrate 100 is flattened by chemical mechanical polishing.

[0067] like Figure 3 As shown in d-3f, the first sub-metal layer 11 is deposited on the side of the first isolation layer 31 away from the substrate 100, and the first sub-metal layer 11 is patterned to form a first metal interconnection layer 201, the first metal interconnection layer 201 having a first preset pattern, and the first metal interconnection layer 201 covers the first isolation layer 31 and fills the first through hole 1. Specifically, the first sub-metal layer 11 is deposited on the side of the first isolation layer 31 away from the substrate 100 after the planarization, and the photoresist is spin-coated, then exposed and developed to define the first pre-pattern, the first sub-metal layer 11 is etched to form the first metal interconnection layer 201, the photoresist is removed, or the first sub-metal layer 11 is processed by mechanical processing technology to form the first metal interconnection layer 201. It should be noted that the subsequent formation process of other isolation layers and sacrificial layers is the same as the formation process of the first isolation layer 31, and the subsequent formation process of other sub-metal layers is the same as the formation process of the first sub-metal layer 11, which will not be repeated.

[0068] Since the first through hole 1 exposes the control circuit, the first metal interconnection layer 201 covers the first isolation layer 31 and fills the first through hole 1, so that the first metal interconnection layer 201 can be electrically connected to the control circuit through the first through hole 1, while other areas are insulated and isolated.

[0069] like Figure 3 As shown in g-3h, a second isolation layer 32 is deposited on the side of the first metal interconnection layer 201 away from the substrate 100, and the second isolation layer 32 has a second through hole 2, and the first through hole 2 exposes a portion of the first metal interconnection layer 201. The process steps for forming the second isolation layer 32 are the same as the process steps for forming the first isolation layer 31, and will not be repeated here.

[0070] A second sub-metal layer 12 (not shown in the figure) is deposited on the side of the second isolation layer 32 facing away from the substrate 100, and the second sub-metal layer 12 is patterned to form a second metal interconnection layer 202. The second metal interconnection layer 202 has a second preset pattern, and the second metal interconnection layer 202 covers the second isolation layer 32 and fills the second through hole 2, so that the second metal interconnection layer 202 can be electrically connected to the first metal interconnection layer 201 through the second through hole 2, while other areas are insulated and isolated.

[0071] Based on the foregoing embodiments, in one embodiment of the present application, Figure 6 As shown, Figure 4 c is Figure 6 In the cross-sectional view along AA1, the light reflecting structure 310 includes an electrode layer 311 and a supporting base 312 located on the side of the second metal interconnection layer 202 away from the substrate 100. Specifically, the light reflecting structure 310 includes an electrode layer 311 and a supporting base 312 located on the side of the second isolation layer 32 away from the substrate 100. The electrode layer 311 is electrically connected to the second metal interconnection layer 202, the supporting base 312 is also electrically connected to the second metal interconnection layer 202, and the light reflecting surface 301 is connected to the side of the supporting base 312 away from the substrate 100.

[0072] Specifically, when the light reflecting device is working, the control circuit sends a first control signal to the electrode layer 311 through the metal interconnection layer 200, that is, through the first metal interconnection layer 201 and the second metal interconnection layer 202 in sequence, to control the light reflecting surface 301 to undergo a first deflection along a first direction, or the control circuit sends a second control signal to the electrode layer 311 through the metal interconnection layer 200, that is, through the first metal interconnection layer 201 and the second metal interconnection layer 202 in sequence, to control the light reflecting surface 301 to undergo a second deflection.

[0073] It should be noted that, since the support base 213 is electrically connected to the second metal interconnection layer 202, the light reflecting surface 301 is connected to the side of the support base 312 away from the substrate 100, so that the potentials of the support base 213, the second metal interconnection layer 202 and the light reflecting surface 301 are the same. The control circuit sends a first control signal to the electrode layer 311 through the metal interconnection layer 200, so that the electrode layer 311 has an electrostatic force on the first side and the second side of the light reflecting surface. Specifically, the electrode layer 311 attracts the first side of the light reflecting surface 301 and repels the second side of the light reflecting surface 301, so that the light reflecting surface 301 undergoes a first deflection. On the contrary, the control circuit sends a second control signal to the electrode layer 311 through the metal interconnection layer 200, so that the electrode layer 311 repels the first side of the light reflecting surface 301 and attracts the second side of the light reflecting surface 301, so that the light reflecting surface 301 undergoes a second deflection.

[0074] As can be seen from the above, when the light reflective device prepared by the preparation method is working, the deflection of the light reflective surface 301 is achieved through the electrostatic force of the electrode layer 311, so that the speed of the first deflection and the second deflection of the light reflective surface 301 is very fast, that is, the reaction speed of the light reflective device is relatively fast. In addition, it is known from the above that the light reflective device also has the advantages of small size and low power consumption, so the light reflective device prepared by the preparation method can be applied to projection display (such as DLP projector), imaging printing, precision lighting (such as surgical microscope, endoscope), spectral analysis (such as programmable grating), interactive display (such as virtual display, augmented reality, etc.) and optical interconnection and other fields. It should be noted that when the above light reflective device is applied to projection display, the density of the light reflective array can be increased according to the needs to improve the resolution of the projection device, and the color image display can also be realized by combining the color wheel or the rapid alternating projection of the three primary colors.

[0075] Based on the above, in one embodiment of the present application, Figure 6 As shown, the electrode layer 311 includes a first electrode 3111 and a second electrode 3112, the first electrode 3111 and the second electrode 3112 are symmetrically distributed relative to the support base 312, and the first electrode 3111 corresponds to the first side of the light reflecting surface 301, and the second electrode 3112 corresponds to the second side of the light reflecting surface 301. Specifically, the first electrode 3111 and the second electrode 3112 are symmetrically distributed relative to the support base 312, and when the light reflecting surface 301 is not deflected, the orthographic projection of the area where the first side of the light reflecting surface 301 is located coincides with the orthographic projection of the first electrode 3111, and the orthographic projection of the area where the second side of the light reflecting surface 301 is located coincides with the orthographic projection of the second electrode 3112. It should be noted that the shapes of the first electrode layer 3111 and the second electrode layer 3112 can be the same, for example, the shapes of the first electrode layer 3111 and the second electrode layer 3112 are rectangular.

[0076] When the light reflection device is working, the control circuit sends a first control signal to the electrode layer 311 through the metal interconnection layer 200, so that the first electrode 3111 attracts the first side of the light reflection surface 301, and the second electrode 3112 repels the second side of the light reflection surface 301, so as to control the light reflection surface 301 to undergo a first deflection. Alternatively, the control circuit sends a second control signal to the electrode layer 311 through the metal interconnection layer 200, so that the first electrode 3111 repels the first side of the light reflection surface 301, and the second electrode 3112 attracts the second side of the light reflection surface 301, so as to control the light reflection surface 301 to undergo a second deflection.

[0077] Based on the above, the electrode layer 311 includes a first electrode 3111 and a second electrode 3112. When the light reflecting device is working, the first electrode layer 3111 responds to the first control signal to attract the first side of the light reflecting surface 301, and the second electrode layer 3112 responds to the first control signal to repel the first side of the light reflecting surface 301, or the first electrode layer 3111 responds to the first control signal to repel the first side of the light reflecting surface 301, and the second electrode layer 3112 responds to the first control signal to attract the first side of the light reflecting surface 301. In other words, the first electrode layer 3111 and the second electrode layer 3112 work in coordination to achieve the deflection of the light reflecting surface 301, which helps to further improve the response speed of the light reflecting device, so that the obtained light reflecting device has a faster response speed.

[0078] Based on the foregoing embodiments, in one embodiment of the present application, Figure 6 As shown, the support base 312 includes a support bottom layer 3121 located on the side of the second metal interconnection layer 202 away from the substrate 100, and the support bottom layer 3121 includes a first support layer 31211, a second support layer 31212 and a third support layer 31213. The first support layer 31211 connects the second support layer 31212 and the third support layer 31213. Specifically, one end of the first support layer 31211 is connected to the midpoint of the second support layer 31212, and the other end of the first support layer 31211 is connected to the midpoint of the third support layer 31213 to form an H-shaped support bottom layer. Based on this, in this embodiment, the first electrode 3111 and the second electrode 3112 are respectively located on two layers of the first support layer 31211, and are symmetrically distributed relative to the first support layer 31211.

[0079] like Figure 5 As shown, the support base 312 also includes a support column 3122 . Specifically, the support column 3122 is located on the side of the first support layer 31211 away from the substrate 100 , and the light reflecting surface 301 is located on the side of the support column 3122 away from the substrate 100 to support the light reflecting surface 301 .

[0080] Based on the above, since the first support layer 31211, the second support layer 31212 and the third support layer 31213 of the support bottom layer 3121 form an H-shaped support bottom layer, and the first electrode 3111 and the second electrode 3112 are respectively located on two layers of the first support layer 31211 and are symmetrically distributed relative to the first support layer 31211, the first electrode 3111 and the second electrode 3112 are symmetrically distributed relative to the support bottom layer 3121. At the same time, the light reflecting surface 301 is located on the side of the support column 3122 away from the substrate 100, so that the first electrode 3111 and the second electrode 3112 can respectively apply electrostatic forces of the same strength and opposite directions to the light reflecting surface 301, which helps to ensure the smooth deflection of the light reflecting surface 301, and also helps to avoid damage to the light reflecting surface 301 due to uneven force.

[0081] Based on the foregoing embodiments, in one embodiment of the present application, Figure 4 As shown, for step S3, forming the light reflecting structure 310 includes:

[0082] A third isolation layer 33 is deposited on the side of the second metal interconnection layer 202 facing away from the substrate 100 . The third isolation layer 33 has a third through hole 3 . The third through hole 3 exposes a portion of the second metal interconnection layer 202 .

[0083] A third sub-metal layer 13 is deposited on the side of the third isolation layer 33 away from the substrate 100, and the third sub-metal layer 13 is patterned to form a first electrode 3111, a second electrode 3112, and a supporting bottom layer 3121. The first electrode 3111 has a third preset pattern and fills the corresponding third through hole 3, specifically the first electrode 3111 has a third preset pattern and fills the third through hole 3 below it. The second electrode 3112 has a fourth preset pattern and fills the corresponding third through hole 3, specifically the second electrode 3112 has a fourth preset pattern and fills the third through hole 3 below it. The supporting bottom layer 3121 has a fifth preset pattern and fills the corresponding third through hole 3, specifically the supporting bottom layer 3121 has a fifth preset pattern and fills the third through hole 3 below it.

[0084] like Figure 7 As shown, Figure 4 g is Figure 7 In the cross-sectional view along line BB1 ​​, a first sacrificial layer 34 is formed on the side of the electrode layer 311 and the supporting bottom layer 3121 away from the substrate 100 . The first sacrificial layer 34 has a fourth through hole 4 . The fourth through hole 4 exposes a portion of the first supporting layer 31211 .

[0085] A fourth sub-metal layer 14 is deposited on the side of the first sacrificial layer 34 away from the substrate 100, and the fourth sub-metal layer 14 is patterned to form a support column 3122 and a light reflecting surface 301, the support column 3122 is located in the fourth through hole 4, and the light reflecting surface 301 covers the side of the fourth isolation layer 34 away from the substrate 100 and is connected to the support column 3122.

[0086] The first sacrificial layer 34 is removed. At this time, there is a gap between the light reflecting surface 301 and the supporting bottom layer 3121 . The height of the gap is equal to the height of the supporting column 3122 .

[0087] It should be noted that, for light reflective devices, the deflection angles of the light reflective surfaces are usually different for different light reflective devices or different application scenarios. Therefore, during the design and preparation process, the deflection angles of the light reflective surfaces need to be limited according to actual conditions. Based on this, in one embodiment of the present application, forming the light reflective structure 310 also includes:

[0088] A limiting column 313 is formed on the side of the supporting bottom layer 3121 away from the base 100 . The limiting column 313 is located on the deflection path of the light reflecting surface 301 , and the height of the limiting column 313 is less than the height of the supporting column 3122 , so as to limit the deflection angle of the light reflecting surface 301 .

[0089] Specifically, Figure 4 e-4f, forming a limiting column 313 on the side of the supporting bottom layer 3121 away from the base 100 includes:

[0090] After forming the electrode layer 311 and the supporting bottom layer 3121 and before forming the first sacrificial layer 34, a second sacrificial layer 35 is deposited on the side of the electrode layer 311 and the supporting bottom layer 3121 away from the substrate 100. The second sacrificial layer 35 has a fifth through hole 5 (such as Figure 8 As shown, Figure 4 e is Figure 8 (a cross-sectional view along CC1 ) the fifth through hole 5 is located on the deflection path of the light reflecting surface, and an exposed portion of the fifth through hole 5 supports the bottom layer 3121 .

[0091] The fifth sub-metal layer 15 is deposited in the fifth through hole 5 , and the second sacrificial layer 35 is removed to form a limiting column 313 .

[0092] Based on the above, in a specific embodiment of the present application, Figure 5 As shown, the limiting column 313 includes a first limiting column 3131, a second limiting column 3132, a third limiting column 3133 and a fourth limiting column 3134. The first limiting column 3131 and the second limiting column 3132 are respectively located at two ends of the second support layer 31212, and the third limiting column 3133 and the fourth limiting column 3134 are respectively located at two ends of the third support layer 31213.

[0093] It should be noted that the above-mentioned limiting columns 313 and supporting columns 3122 are hollow structures, which can reduce the weight of the manufactured light reflection device and contribute to the lightweight during light reflection.

[0094] It should also be noted that the first metal layer 10 and the second metal layer 20 can be highly conductive metals or metal-like materials, such as metal aluminum, gold, nickel, molybdenum, chromium, cobalt, palladium, titanium, platinum, copper, rhenium, hafnium, tungsten, platinum-silicon alloy, iron-copper alloy, graphene, etc. The materials of the above-mentioned first isolation layer 31, the second isolation layer 32, and the third isolation layer 33 can be insulating materials such as silicon dioxide, and the first sacrificial layer 34 and the second sacrificial layer 35 can be polycrystalline silicon, single crystal silicon, silicon nitride, aluminum oxide, silicon dioxide, PMMA, photoresist, metal film, polyimide, etc. In other words, the preparation method uses easily available metal materials, sacrificial layer materials and isolation layer materials, which further reduces the cost and manufacturing difficulty.

[0095] In order to more clearly understand the method for preparing a light reflective device provided in the present application, a specific embodiment is described in detail below.

[0096] like Fig. 9 As shown, a substrate is provided, in which a CMOS control circuit is provided; a first isolation layer is deposited, etched to form a first through hole and flattened; a first sub-metal layer is deposited, and a first metal interconnection layer is patterned to form; a second isolation layer is deposited, etched to form a second through hole and flattened; a second sub-metal layer is deposited, and a second metal interconnection layer is patterned to form; a third isolation layer is deposited, etched to form a third through hole and flattened; a third sub-metal layer is deposited, and an electrode layer and a supporting bottom layer are patterned to form; a second sacrificial layer is deposited, etched to form a fifth through hole and flattened; a fifth sub-metal layer is deposited, and the fifth metal layer fills the fifth through hole, and excess metal layers and the second sacrificial layer are removed to form a limiting column; a first sacrificial layer is deposited, and a fourth through hole is etched to form and flattened; a fourth sub-metal layer is deposited, and the fourth metal layer covers the first sacrificial layer and fills the fourth through hole to form a supporting column and a light reflecting surface, and the first sacrificial layer is removed.

[0097] Based on the above, the present application also provides a light reflecting device, which is prepared by the preparation method described in any of the above embodiments, such as Figure 4 As shown in FIG. 1 , the light reflecting device comprises:

[0098] The substrate 100 has a control circuit (not shown in the figure), and the control circuit can be an SRAM unit manufactured by a mature standard CMOS process, that is, the control circuit can be a CMOS control circuit, which helps to reduce the power consumption of the manufactured light reflective device. However, this application does not limit this, and it depends on the specific situation.

[0099] The metal interconnection layer 200 is located on the surface of the substrate 100 and is electrically connected to the control circuit.

[0100] A light reflection array is located on a side of the metal interconnect layer 200 away from the substrate 100, and the light reflection array includes a plurality of light reflection structures 310. The metal interconnect layer 200 is also electrically connected to the light reflection structure 310, so that the control circuit can be electrically connected to the light reflection structure 310 through the metal interconnect layer 200, and then the control circuit can control at least one light reflection structure 310 in the light reflection array through the metal interconnect layer 200.

[0101] Specifically, when the light reflecting device is working, the control circuit sends a first control signal to the light reflecting array through the metal interconnection layer 200 to control at least one light reflecting structure 310 in the light reflecting array to undergo a first deflection, or the control circuit sends a second control signal to the light reflecting array through the metal interconnection layer 200 to control at least one light reflecting structure 310 in the light reflecting array to undergo a second deflection.

[0102] The light reflecting structure 310 has a light reflecting surface 301. Figure 5 As shown, the first deflection is that the first side of the light reflecting surface 301 deflects along the first direction, and the second deflection is that the second side of the light reflecting surface 301 deflects along the first direction. The first side and the second side are different sides of the light reflecting surface 301, and the first direction is the direction in which the light reflecting surface 301 points to the substrate 100. It should be noted that, for the light reflecting device described in the present application, when it is working, at least one light reflecting structure 310 in the light reflecting array can respond to the first control instruction to undergo a first deflection to achieve a first function, or at least one light reflecting structure 310 in the light reflecting array can respond to the second control instruction to undergo a second deflection to achieve a second function, such as the on-off of the light path or the brightness and darkness of the pixel. Specifically, for example, the light reflecting device is used as an optical switch studio, and at least one light reflecting structure 310 in the light reflecting array responds to the first control instruction to undergo a first deflection, and the light cannot be transmitted to the target position through the light reflecting surface 301, and the optical switch is closed at this time, and at least one light reflecting structure 310 in the light reflecting array responds to the second control instruction to undergo a second deflection, and the light cannot be transmitted to the target position through the light reflecting surface 301, and the optical switch is opened at this time.

[0103] As can be seen from the above, the metal interconnect layer 200 and the light reflection array belong to different metal layers. Therefore, the patterning of the metal interconnect layer 200 and the light reflection array does not affect each other. It is sufficient to ensure that the control circuit, the metal interconnect layer 200 and the light reflection array are electrically connected in sequence. Therefore, the light reflection structure 310 of the light reflection array can be diversified. Specifically, according to the performance requirements of the light reflection array, reflection arrays of different structures can be reasonably prepared, which can be applicable to more application scenarios and has strong practicality.

[0104] Based on the above embodiments, in one embodiment of the present application, the metal interconnection layer 200 includes a first metal interconnection layer 201 and a second metal interconnection layer 202, and the second metal interconnection layer 201 is located between the first metal interconnection layer 201 and the light reflection array, that is, the first metal interconnection layer 201, the second metal interconnection layer 202 and the light reflection array are arranged in sequence along a direction away from the substrate 100. Among them, the first metal interconnection layer 201 is electrically connected to the control circuit, the second metal interconnection layer 202 is electrically connected to the first metal layer interconnection layer 201, and the second metal interconnection layer 202 is also electrically connected to the light reflection structure 310.

[0105] The light reflection structure 310 includes an electrode layer 311 and a support base 312 located on the side of the second metal interconnection layer 202 away from the substrate 100. Specifically, the light reflection structure 310 includes an electrode layer 311 and a support base 312 located on the side of the second isolation layer 32 away from the substrate 100. The electrode layer 311 is electrically connected to the second metal interconnection layer 202, the support base 312 is also electrically connected to the second metal interconnection layer 202, and the light reflection surface 301 is connected to the side of the support base 312 away from the substrate 100.

[0106] The electrode layer 311 includes a first electrode 3111 and a second electrode 3112, the first electrode 3111 and the second electrode 3112 are symmetrically distributed relative to the support base 312, and the first electrode 3111 corresponds to the first side of the light reflecting surface 301, and the second electrode 3112 corresponds to the second side of the light reflecting surface 301. Specifically, the first electrode 3111 and the second electrode 3112 are symmetrically distributed relative to the support base 312, and when the light reflecting surface 301 is not deflected, the orthographic projection of the area where the first side of the light reflecting surface 301 is located coincides with the orthographic projection of the first electrode 3111, and the orthographic projection of the area where the second side of the light reflecting surface 301 is located coincides with the orthographic projection of the second electrode 3112. It should be noted that the shapes of the first electrode layer 3111 and the second electrode layer 3112 can be the same, for example, the shapes of the first electrode layer 3111 and the second electrode layer 3112 are rectangular.

[0107] The support base 312 includes a support bottom layer 3121 located on the side of the second metal interconnection layer 202 away from the substrate 100, and the support bottom layer 3121 includes a first support layer 31211, a second support layer 31212 and a third support layer 31213. The first support layer 31211 connects the second support layer 31212 and the third support layer 31213. Specifically, one end of the first support layer 31211 is connected to the midpoint of the second support layer 31212, and the other end of the first support layer 31211 is connected to the midpoint of the third support layer 31213 to form an H-shaped support bottom layer. Based on this, in this embodiment, the first electrode 3111 and the second electrode 3112 are respectively located on two layers of the first support layer 31211, and are symmetrically distributed relative to the first support layer 31211.

[0108] The support base 312 further includes a support column 3122 . Specifically, the support column 3122 is located on a side of the first support layer 31211 away from the substrate 100 . The light reflecting surface 301 is located on a side of the support column 3122 away from the substrate 100 to support the light reflecting surface 301 .

[0109] When the light reflecting device is working, the first electrode layer 3111 responds to the first control signal to attract the first side of the light reflecting surface 301, and the second electrode layer 3112 responds to the first control signal to repel the first side of the light reflecting surface 301, or the first electrode layer 3111 responds to the first control signal to repel the first side of the light reflecting surface 301, and the second electrode layer 3112 responds to the first control signal to attract the first side of the light reflecting surface 301. In other words, the first electrode layer 3111 and the second electrode layer 3112 work in coordination to achieve the deflection of the light reflecting surface 301, which helps to improve the response speed of the light reflecting device, so that the manufactured light reflecting device has a faster response speed.

[0110] It should be noted that, for a light reflector, the deflection angle of the light reflector surface is usually different for different light reflectors or different application scenarios. Therefore, during the design and preparation process, it is necessary to limit the deflection angle of the light reflector surface according to the actual situation, so that the light reflector device also includes a limit column 313, the limit column 313 is located on the deflection path of the light reflector surface 301, and the height of the limit column 313 is less than the height of the support column 3122, and is used to limit the deflection angle of the light reflector surface 301. Specifically, the limit column 313 includes a first limit column 3131, a second limit column 3132, a third limit column 3133 and a fourth limit column 3134. Among them, the first limit column 3131 and the second limit column 3132 are respectively located at the two ends of the second support layer 31212, and the third limit column 3133 and the fourth limit column 3134 are respectively located at the two ends of the third support layer 31213.

[0111] In summary, the present application provides a method for preparing a light reflective device and a light reflective device, the preparation method comprising: providing a substrate with a control circuit, patterning a first metal layer to form a metal interconnection layer, and patterning a second metal layer to form a light reflective array. The metal interconnection layer is electrically connected to the control circuit, and the metal interconnection layer is also electrically connected to at least one light reflective structure of the light reflective array. It can be seen that the preparation method deposits the metal interconnection layer and the metal layer corresponding to the light reflective array on the substrate in sequence, and patterns the metal layer, so as to obtain the metal interconnection layer electrically connected to the control circuit and the light reflective array electrically connected to the metal interconnection layer, thus completing the preparation of the light reflective device. In other words, based on the preparation method provided by the present application, the preparation of the light reflective device can be completed by using MEMS technology, and there is no need to use special processes and design special equipment, so that the preparation method provided by the present application is simple in process and low in cost, has strong operability, can ensure the reliability of the device, and has broad application prospects.

[0112] In addition, the patterning of the metal interconnect layer and the light reflection array does not affect each other, and it is sufficient to ensure that the control circuit, the metal interconnect layer and the light reflection array are electrically connected in sequence. Therefore, the light reflection structure of the light reflection array prepared by the preparation method can be diversified. Specifically, according to the performance requirements of the light reflection array, reflection arrays with different structures can be reasonably prepared, which can be applied to more application scenarios and has strong practicality. At the same time, the light reflection array is obtained by patterning the second metal layer using MEMS technology, and the number of light reflection structures of the light reflection array is not limited, and millions of them can be obtained, and the size can be very small. On the basis of ensuring the number of light reflection structures in the light reflection device, the volume of the light reflection device can be reduced.

[0113] In this specification, each embodiment is described in a progressive, parallel, or progressive and parallel manner. Each embodiment focuses on the differences from other embodiments, and the same or similar areas between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method area description.

[0114] It should be noted that in the description of the present application, it should be understood that the terms "upper", "lower", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. When a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a centrally arranged component at the same time.

[0115] It should also be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that an article 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 article or device. In the absence of further restrictions, the elements defined by the sentence "comprising a ..." do not exclude the existence of other identical elements in the article or device including the above elements.

[0116] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for preparing a light reflecting device, characterized in that: include: Providing a substrate, wherein the substrate has a control circuit, wherein the control circuit is a CMOS control circuit; Depositing a first metal layer, patterning the first metal layer to form a metal interconnection layer, wherein the metal interconnection layer is located on the surface of the substrate and is electrically connected to the control circuit; Depositing a second metal layer and patterning the second metal layer to form a light reflection array, wherein the light reflection array is located on a side of the metal interconnect layer away from the substrate; the light reflection array includes a plurality of light reflection structures, and the metal interconnect layer is also electrically connected to the light reflection structures, so that the control circuit controls at least one of the light reflection structures in the light reflection array through the metal interconnect layer; When the light reflective device is working, the control circuit sends a first control signal to the light reflective array through the metal interconnection layer to control at least one of the light reflective structures in the light reflective array to undergo a first deflection, or the control circuit sends a second control signal to the light reflective array through the metal interconnection layer to control at least one of the light reflective structures in the light reflective array to undergo a second deflection; Among them, the light reflecting structure has a light reflecting surface, the first deflection is that the first side of the light reflecting surface is deflected along a first direction, the second deflection is that the second side of the light reflecting surface is deflected along the first direction, the first side and the second side are different sides of the light reflecting surface, and the first direction is the direction in which the light reflecting surface points to the substrate.

2. The method for preparing a light reflecting device according to claim 1, characterized in that: The metal interconnection layer includes a first metal interconnection layer and a second metal interconnection layer, the second metal interconnection layer is located between the first metal interconnection layer and the light reflection array, the first metal interconnection layer is electrically connected to the control circuit, the second metal interconnection layer is electrically connected to the first metal interconnection layer, and the second metal interconnection layer is also electrically connected to the light reflection structure; forming the metal interconnection layer includes: Depositing a first isolation layer on the surface of the substrate, wherein the first isolation layer has a first through hole, and the first through hole exposes the control circuit; Depositing a first sub-metal layer on a side of the first isolation layer away from the substrate, and patterning the first sub-metal layer to form a first metal interconnection layer, wherein the first metal interconnection layer has a first preset pattern, covers the first isolation layer, and fills the first through hole; Depositing a second isolation layer on a side of the first metal interconnection layer away from the substrate, wherein the second isolation layer has a second through hole, and the second through hole exposes a portion of the first metal interconnection layer; A second sub-metal layer is deposited on the side of the second isolation layer away from the substrate, and the second sub-metal layer is patterned to form a second metal interconnection layer having a second preset pattern, covering the second isolation layer, and filling the second through hole.

3. The method for preparing a light reflecting device according to claim 2, characterized in that: The light reflecting structure comprises an electrode layer and a supporting base located on a side of the second metal interconnection layer away from the substrate, the electrode layer is electrically connected to the second metal interconnection layer, the supporting base is also electrically connected to the second metal interconnection layer, and the light reflecting surface is connected to a side of the supporting base away from the substrate; When the light reflecting device is working, the control circuit sends the first control signal to the electrode layer through the metal interconnection layer to control the light reflecting surface to undergo a first deflection, or the control circuit sends the second control signal to the electrode layer through the metal interconnection layer to control the light reflecting surface to undergo a second deflection.

4. The method for preparing a light reflecting device according to claim 3, characterized in that: The electrode layer includes a first electrode and a second electrode, the first electrode and the second electrode are symmetrically distributed relative to the support base, and the first electrode corresponds to a first side of the light reflecting surface, and the second electrode corresponds to a second side of the light reflecting surface; When the light reflecting device is working, the control circuit sends the first control signal to the electrode layer through the metal interconnection layer, so that the first electrode attracts the first side of the light reflecting surface and the second electrode repels the second side of the light reflecting surface, so as to control the light reflecting surface to undergo a first deflection, or the control circuit sends the second control signal to the electrode layer through the metal interconnection layer, so that the first electrode repels the first side of the light reflecting surface and the second electrode attracts the second side of the light reflecting surface, so as to control the light reflecting surface to undergo a second deflection.

5. The method for preparing a light reflecting device according to claim 4, characterized in that: The support base comprises a support bottom layer located on a side of the second metal interconnection layer away from the substrate, the support bottom layer comprises a first support layer, a second support layer and a third support layer, the first support layer connects the second support layer and the third support layer to form an H-shaped support bottom layer; the first electrode and the second electrode are respectively located on both sides of the first support layer and are symmetrically distributed; The support base further includes a support column, the support column is located on a side of the first support layer away from the substrate, and the light reflecting surface is located on a side of the support column away from the substrate.

6. The method for preparing a light reflecting device according to claim 5, characterized in that: Forming the light reflecting structure includes: Depositing a third isolation layer on a side of the second metal interconnection layer away from the substrate, wherein the third isolation layer has a third through hole, and the third through hole exposes a portion of the second metal interconnection layer; A third sub-metal layer is deposited on the side of the third isolation layer away from the substrate, and the third sub-metal layer is patterned to form the first electrode, the second electrode and the supporting bottom layer; wherein the first electrode has a third preset pattern and fills the corresponding third through hole; the second electrode has a fourth preset pattern and fills the corresponding third through hole; the supporting bottom layer has a fifth preset pattern and fills the corresponding third through hole; A first sacrificial layer is formed on the electrode layer and the supporting bottom layer at a side away from the substrate, wherein the first sacrificial layer has a fourth through hole, and the fourth through hole exposes a portion of the first supporting layer; Depositing a fourth sub-metal layer on the side of the first sacrificial layer away from the substrate, patterning the fourth sub-metal layer to form the support column and the light reflecting surface, wherein the support column is located in the fourth through hole, and the light reflecting surface covers the side of the fourth isolation layer away from the substrate and is connected to the support column; The first sacrificial layer is removed, and a gap is formed between the light reflecting surface and the supporting bottom layer.

7. The method for preparing a light reflecting device according to claim 6, characterized in that: Forming the light reflecting structure further includes: A limiting column is formed on a side of the supporting bottom layer away from the base, and the limiting column is located on a deflection path of the light reflecting surface and is used to limit a deflection angle of the light reflecting surface; Forming a limiting column on the side of the supporting bottom layer away from the base includes: After forming the electrode layer and the supporting bottom layer and before forming the first sacrificial layer, a second sacrificial layer is deposited on the side of the electrode layer and the supporting bottom layer away from the substrate, the second sacrificial layer having a fifth through hole, the fifth through hole being located on the deflection path of the light reflecting surface, and the fifth through hole exposing a portion of the supporting bottom layer; A fifth sub-metal layer is deposited in the fifth through hole, and the second sacrificial layer is removed to form the limiting column.

8. The method for preparing a light reflecting device according to claim 7, characterized in that: The limiting columns include a first limiting column, a second limiting column, a third limiting column and a fourth limiting column; The first limiting column and the second limiting column are respectively located at two ends of the second supporting layer, and the third limiting column and the fourth limiting column are respectively located at two ends of the third supporting layer.

9. A light reflecting device, characterized in that: include: a substrate having a control circuit therein; A metal interconnection layer, the metal interconnection layer covers the surface of the substrate and is electrically connected to the control circuit; a light reflection array, the light reflection array being located on a side of the metal interconnect layer away from the substrate; the light reflection array comprising a plurality of light reflection structures, the metal interconnect layer being also electrically connected to the light reflection structures, so that the control circuit controls at least one of the light reflection structures in the light reflection array through the metal interconnect layer; When the light reflective device is working, the control circuit sends a first control signal to the light reflective array through the metal interconnection layer to control at least one of the light reflective structures in the light reflective array to undergo a first deflection, or the control circuit sends a second control signal to the light reflective array through the metal interconnection layer to control at least one of the light reflective structures in the light reflective array to undergo a second deflection; Among them, the light reflecting structure has a light reflecting surface, the first deflection is that the first side of the light reflecting surface is deflected along a first direction, the second deflection is that the second side of the light reflecting surface is deflected along the first direction, the first side and the second side are different sides of the light reflecting surface, and the first direction is the direction in which the light reflecting surface points to the substrate.

10. The light reflecting device according to claim 9, characterized in that: The metal interconnect layer comprises a first metal interconnect layer and a second metal interconnect layer, the second metal interconnect layer is located between the first metal interconnect layer and the light reflection array, the second metal interconnect layer is electrically connected to the first metal interconnect layer, and the second metal interconnect layer is also electrically connected to the light reflection structure; The light reflecting structure comprises an electrode layer and a supporting base located on a side of the second metal interconnection layer away from the substrate, the electrode layer is electrically connected to the second metal interconnection layer, the supporting base is also electrically connected to the second metal interconnection layer, and the light reflecting surface is connected to a side of the supporting base away from the substrate; The electrode layer includes a first electrode and a second electrode, the first electrode and the second electrode are symmetrically distributed relative to the support base, and the first electrode corresponds to the first side of the light reflecting surface, and the second electrode corresponds to the second side of the light reflecting surface; the support base includes a support bottom layer located on the side of the second metal interconnection layer away from the substrate, the support bottom layer includes a first support layer, a second support layer and a third support layer, the first support layer connects the second support layer and the third support layer to form an H-shaped support bottom layer; the first electrode and the second electrode are respectively located on both sides of the first support layer and are symmetrically distributed; the support column is located on the side of the first support layer away from the substrate, and the light reflecting surface is located on the side of the support column away from the substrate; When the light reflecting device is working, the control circuit sends the first control signal to the electrode layer through the metal interconnection layer to control the light reflecting surface to undergo a first deflection along the first direction, or the control circuit sends the second control signal to the electrode layer through the metal interconnection layer to control the light reflecting surface to undergo a second deflection.

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