A method for manufacturing a light reflecting device and a light reflecting device

Abstract

The application provides a light reflection device preparation method and a light reflection device, and relates to the technical field of semiconductors. The preparation method comprises the following steps: 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 with the control circuit and at least one light reflection structure of the light reflection array. The preparation method sequentially deposits the first metal layer and the second metal layer on the substrate and performs patterning, so that the metal interconnection layer and the light reflection array can be obtained. Therefore, the preparation of the light reflection device can be completed based on the preparation method by using MEMS technology, the process is simple, the cost is low, and the reliability of the device can be ensured. Moreover, the patterning of the metal interconnection layer and the light reflection array does not affect each other, the diversification of the light reflection structure can be realized, the number of the light reflection structure of the light reflection array is not limited, the size of the light reflection structure can be very small, and the volume of the light reflection device is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor, in particular to a light reflection device preparation method and a light reflection device. BACKGROUND

[0002] The light reflection device is an indispensable part in the field of optics, and is applied to many optical devices, such as astronomical telescopes, searchlights, movie projectors, periscopes, etc. In addition, in the field of optical information science and technology, the light reflection device also plays an important role in controlling, regulating or converting the propagation direction, intensity, frequency and phase of light. Therefore, for those skilled in the art, it is a key research topic to provide a low-cost and low-difficulty preparation method. SUMMARY

[0003] Therefore, the present application provides a light reflection device preparation method and a light reflection device, and the scheme is as follows:

[0004] A light reflection device preparation method comprises the following steps:

[0005] A substrate is provided, wherein the substrate has a control circuit, and the control circuit is a CMOS control circuit;

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

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

[0008] When the light reflection device works, the control circuit sends a first control signal to the light reflection array through the metal interconnection layer to control at least one light reflection structure in the light reflection array to occur a first deflection, or the control circuit sends a second control signal to the light reflection array through the metal interconnection layer to control at least one light reflection structure in the light reflection array to occur a second deflection;

[0009] Wherein, the light reflection structure has a light reflection surface, the first deflection is that the first side of the light reflection surface deflects in a first direction, the second deflection is that the second side of the light reflection surface deflects in the first direction, the first side and the second side are different sides of the light reflection surface, and the first direction is the direction in which the light reflection surface points to the substrate.

[0010] Optionally, the metal interconnection layer comprises 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 with the control circuit, the second metal interconnection layer is electrically connected with the first metal interconnection layer, and the second metal interconnection layer is also electrically connected with the light reflection structure; forming the metal interconnection layer comprises:

[0011] depositing a first isolation layer on the substrate surface, the first isolation layer has a first through hole, the first through hole exposes the control circuit;

[0012] depositing a first sub-metal layer on the side of the first isolation layer away from the substrate, patterning the first sub-metal layer to form the first metal interconnection layer, 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 the side of the first metal interconnection layer away from the substrate, the second isolation layer has a second through hole, the second through hole exposes part of the first metal interconnection layer;

[0014] depositing a second sub-metal layer on the side of the second isolation layer away from the substrate, patterning the second sub-metal layer to form the second metal interconnection layer, the second metal interconnection layer has a second preset pattern, covers the second isolation layer, and fills the second through hole.

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

[0016] When the light reflection device is working, the control circuit sends the first control signal to the electrode layer through the metal interconnection layer to control the light reflection surface to deflect in 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 reflection surface to deflect in the second direction.

[0017] Optionally, the electrode layer comprises a first electrode and a second electrode, the first electrode and the second electrode are symmetrically distributed with respect to the support base, and the first electrode corresponds to the first side of the light reflection surface, and the second electrode corresponds to the second side of the light reflection surface;

[0018] In operation, 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 to control the light reflecting surface to deflect in a first direction, 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 to control the light reflecting surface to deflect in a second direction.

[0019] Optionally, the support base comprises a support bottom layer on the 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 the two sides of the first support layer and are symmetrically distributed.

[0020] The support base further comprises a support column, 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.

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

[0022] A third isolation layer is deposited on the side of the second metal interconnection layer away from the substrate, the third isolation layer has third through holes, and the third through holes expose part 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 support 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; and the support bottom layer has a fifth preset pattern and fills the corresponding third through hole;

[0024] A first sacrificial layer is formed on the side of the electrode layer and the support bottom layer away from the substrate, the first sacrificial layer has fourth through holes, and the fourth through holes expose part of the first support layer;

[0025] A fourth sub-metal layer is deposited on the side of the first sacrificial layer away from the substrate, and the fourth sub-metal layer is patterned to form the support column and the light reflecting surface, 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 support bottom layer.

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

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

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

[0030] After the electrode layer and the support substrate are formed, and before the first sacrificial layer is formed, a second sacrificial layer is deposited on the side of the electrode layer and the support substrate away from the substrate. The second sacrificial layer has a fifth via located on the deflection path of the light-reflecting surface, and the fifth via exposes a portion of the support substrate.

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

[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 post and the second limiting post are located at both ends of the second support layer, and the third limiting post and the fourth limiting post are located at both ends of the third support layer.

[0034] A light-reflecting device, comprising:

[0035] A substrate having control circuitry;

[0036] A metal interconnect layer covers the surface of the substrate and is electrically connected to the control circuit.

[0037] A light-reflecting array is located on the side of the metal interconnect layer opposite to the substrate; the light-reflecting array includes a plurality of light-reflecting structures, and the metal interconnect layer is electrically connected to the light-reflecting structures so that the control circuit controls at least one of the light-reflecting structures in the light-reflecting array through the metal interconnect layer;

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

[0039] The light-reflecting structure has a light-reflecting surface. The first deflection is the deflection of a first side of the light-reflecting surface along a first direction, and the second deflection is the deflection of a second side of the light-reflecting surface 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 includes an electrode layer and a support base located on the side of the second metal interconnect layer away from the substrate. The electrode layer is electrically connected to the second metal interconnect layer, and the support base is also electrically connected to the second metal interconnect layer. The light-reflecting surface is connected to the side of the support base away from the substrate.

[0042] The electrode layer includes a first electrode and a second electrode, which are symmetrically distributed with respect to the support base. 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. The support base includes a support substrate located on the side of the second metal interconnect layer away from the substrate. The support substrate 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 substrate. The first electrode and the second electrode are located on opposite sides of the first support layer and are symmetrically distributed. The support pillar 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 pillar 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 interconnect 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 interconnect layer to control the light reflecting surface to undergo a second deflection.

[0044] Compared with the prior art, the beneficial effects of the technical solution of this application are as follows:

[0045] The fabrication method includes: providing a substrate with a control circuit; patterning a first metal layer to form a metal interconnect layer; and patterning a second metal layer to form a light-reflecting array. The metal interconnect layer is electrically connected to the control circuit and also electrically connected to at least one light-reflecting structure of the light-reflecting array. Thus, this fabrication method sequentially deposits a metal interconnect layer and a metal layer corresponding to the light-reflecting array on the substrate, and then patterns the metal layers to obtain the metal interconnect layer electrically connected to the control circuit and the light-reflecting array electrically connected to the metal interconnect layer, thereby completing the fabrication of the light-reflecting device. In other words, the fabrication method provided in this application can be used with MEMS technology to fabricate the light-reflecting device without the need for special processes or dedicated equipment. Therefore, the fabrication method provided in this application is simple, low-cost, highly operable, and can ensure the reliability of the fabricated device, showing broad application prospects.

[0046] Furthermore, the patterning of the metal interconnect layer and the optical reflective array does not affect each other, ensuring that the control circuit, metal interconnect layer, and optical reflective array are electrically connected sequentially. Therefore, the optical reflective structure of the optical reflective array fabricated using this method can be diversified. Specifically, different reflective array structures can be rationally fabricated according to the performance requirements of the optical reflective array, making it suitable for more application scenarios and highly practical. Simultaneously, the optical reflective array is obtained by patterning the second metal layer using MEMS technology, which also allows for an unlimited number of optical reflective structures in the array—up to millions—and enables very small sizes, reducing the size of the optical reflective device while maintaining the number of optical reflective structures. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments or prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this application. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0048] The structures, proportions, sizes, etc., shown in the accompanying drawings are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the implementation conditions of this application. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size should still fall within the scope of the technical content disclosed in this application, provided that they do not affect the effects and purposes that this application can produce.

[0049] Figure 1 A flowchart of a method for fabricating a light-reflecting device provided in this application;

[0050] Figures 2-8 A schematic diagram of the structure corresponding to each process step of the optical reflective device fabrication method provided in this application;

[0051] Figure 9 A flowchart illustrating a specific embodiment of a method for fabricating a light-reflecting device provided in this application. Detailed Implementation

[0052] The embodiments of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are merely one area of ​​this application, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0053] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, the application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0054] As described in the background section, in order to facilitate the development of optical reflective devices, providing a low-cost and easy-to-fabricate fabrication method has become a key topic for those skilled in the art.

[0055] Based on this, this application provides a method for fabricating a light-reflecting device, such as... Figure 1 As shown, the preparation method includes:

[0056] S1: As Figure 2 As shown, a substrate 100 is provided, which contains a control circuit (not shown in the figure). It should be noted that the control circuit can be an SRAM cell fabricated using mature standard CMOS technology; that is, the control circuit can be a CMOS control circuit, which helps reduce the power consumption of the resulting light-reflecting device. However, this application does not limit this; the specific choice depends on the circumstances.

[0057] S2: As Figure 3As shown in d-3h, a first metal layer 10 is deposited and patterned to form a metal interconnect layer 200. This metal interconnect layer 200 is located on the surface of the substrate 100 and is electrically connected to the control circuit. Specifically, a first metal layer 10 is deposited on the surface of the substrate 100 using a deposition process, and the first metal layer 10 is patterned by photolithography or mechanical processing to form the metal interconnect layer 200. It should be noted that the above deposition process can be 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. This application does not limit the specific process; the choice depends on the circumstances. It should also be noted that the metal interconnect layer 200 is located on the surface of the substrate 100, specifically on the upper surface of the substrate 100.

[0058] S3: As Figure 4 As shown, a second metal layer 20 is deposited and patterned to form a light-reflecting array. This light-reflecting array is located on the side of the metal interconnect layer 200 facing away from the substrate 100, and includes multiple light-reflecting structures 310. The metal interconnect layer 200 is also electrically connected to the light-reflecting structures 310, allowing a control circuit to control at least one light-reflecting structure 310 in the light-reflecting array via the metal interconnect layer 200.

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

[0060] The aforementioned light-reflecting structure 310 has a light-reflecting surface 301, such as Figure 5 As shown, the first deflection is the deflection of a first side of the light-reflecting surface 301 along a first direction, and the second deflection is the deflection of a second side of the light-reflecting surface 301 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 towards the substrate 100. For example, as... Figure 4As shown, the light reflecting surface 301 is a rectangular plane. The first side and the second side can be the opposite sides of the rectangular plane. The first deflection is that the first side of the light reflecting surface 301 is deflected in the direction toward the substrate 100, and the second side of the light reflecting surface 301 is deflected in the direction away from the substrate 100. That is, the first deflection makes the light reflecting surface 301 tilted toward the substrate 100 in the direction from the second side to the first side. The second deflection is that the second side of the light reflecting surface 301 is deflected in the direction toward the substrate 100, and the first side of the light reflecting surface 301 is deflected in the direction away from the substrate 100. That is, the first deflection makes the light reflecting surface 301 tilted toward the substrate 100 in the direction from the first side to the second side.

[0061] As described above, when fabricating a light-reflecting device using the method provided in this application, a substrate 100 with a control circuit is provided. A metal interconnect layer 200 and a metal layer corresponding to the light-reflecting array are sequentially deposited on the substrate 100. The metal layers are then patterned to obtain the metal interconnect layer 200 electrically connected to the control circuit and the light-reflecting array electrically connected to the metal interconnect layer 200, thus completing the fabrication of the light-reflecting device. In other words, the fabrication of a light-reflecting device can be completed using MEMS technology based on the method provided in this application. Since metal deposition and patterning in MEMS technology are mature techniques that do not require special processes or dedicated equipment, the fabrication method provided in this application is simple, low-cost, highly operable, and ensures the reliability of the fabricated device, thus having broad application prospects.

[0062] Furthermore, as mentioned above, the patterning of the metal interconnect layer 200 and the optical reflective array does not affect each other. It is sufficient to ensure that the control circuit, the metal interconnect layer 200, and the optical reflective array are electrically connected sequentially. Therefore, the optical reflective structure 310 of the optical reflective array fabricated using this method can be diversified. Specifically, different structures of reflective arrays can be rationally fabricated according to the performance requirements of the optical reflective array, making it suitable for more application scenarios and highly practical. Simultaneously, since the optical reflective array is obtained by patterning the second metal layer 20 using MEMS technology, the number of optical reflective structures in the optical reflective array is unlimited, potentially reaching millions, and the size can be made very small. This reduces the volume of the optical reflective device while maintaining the number of optical reflective structures.

[0063] In summary, the optical reflective device prepared by the method provided in this application has the characteristics of small size, low power consumption, and high reliability, and has broad application prospects.

[0064] To achieve insulation isolation between the control circuit, the metal interconnect layer 200, and the light reflection array, except for the electrical connection area, based on the aforementioned embodiments, in one embodiment of this application, the metal interconnect layer 200 includes a first metal interconnect layer 201 and a second metal interconnect layer 202. The second metal interconnect layer 201 is located between the first metal interconnect layer 201 and the light reflection array, that is, the first metal interconnect layer 201, the second metal interconnect layer 202, and the light reflection array are arranged sequentially along the direction away from the substrate 100. The first metal interconnect layer 201 is electrically connected to the control circuit, the second metal interconnect layer 202 is electrically connected to the first metal interconnect layer 201, and the second metal interconnect layer 202 is also electrically connected to the light reflection structure 310.

[0065] Based on the above, for step S2, forming the metal interconnect 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. The first isolation layer 31 has a first via 1, which exposes the control circuit. Specifically, the first via 1 can expose the output port of the control circuit located on the surface of the substrate 100. Specifically, silicon dioxide or other insulating material is 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 via 1. The first isolation layer 31 is etched to form the first via 1, and the side of the first isolation layer 31 facing away from the substrate 100 is planarized by chemical mechanical polishing.

[0067] like Figure 3 As shown in d-3f, a first sub-metal layer 11 is deposited on the side of the first isolation layer 31 facing away from the substrate 100, and the first sub-metal layer 11 is patterned to form a first metal interconnect layer 201. The first metal interconnect layer 201 has a first preset pattern, and the first metal interconnect layer 201 covers the first isolation layer 31 and fills the first via 1. Specifically, the first sub-metal layer 11 is deposited on the side of the planarized first isolation layer 31 facing away from the substrate 100, and 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 interconnect layer 201, and the photoresist is removed, or the first sub-metal layer 11 is processed by mechanical processing technology to form the first metal interconnect layer 201. It should be noted that the formation process of subsequent isolation layers and sacrificial layers is the same as the formation process of the first isolation layer 31, and the formation process of subsequent sub-metal layers is the same as the formation process of the first sub-metal layer 11, and will not be described again.

[0068] Since the control circuit is exposed in the first via 1, the first metal interconnect layer 201 covers the first isolation layer 31 and fills the first via 1, so that the first metal interconnect layer 201 can be electrically connected to the control circuit through the first via 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 interconnect layer 201 facing away from the substrate 100. The second isolation layer 32 has a second via 2, which exposes a portion of the first metal interconnect layer 201. The process steps for forming the second isolation layer 32 are the same as those for forming the first isolation layer 31, and will not be described again here.

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

[0071] Based on the foregoing embodiments, in one embodiment of this application, such as Figure 6 As shown, Figure 4 c is Figure 6 Along the cross-sectional view of AA1, the light-reflecting structure 310 includes an electrode layer 311 and a support base 312 located on the side of the second metal interconnect layer 202 facing away from the substrate 100. Specifically, the light-reflecting structure 310 includes an electrode layer 311 and a support base 312 located on the side of the second isolation layer 32 facing away from the substrate 100. The electrode layer 311 is electrically connected to the second metal interconnect layer 202, and the support base 312 is also electrically connected to the second metal interconnect layer 202. The light-reflecting surface 301 is connected to the side of the support base 312 facing 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 interconnect layer 200, that is, through the first metal interconnect layer 201 and the second metal interconnect layer 202 in sequence, to control the light reflecting surface 301 to undergo a first deflection along the first direction; or, the control circuit sends a second control signal to the electrode layer 311 through the metal interconnect layer 200, that is, through the first metal interconnect layer 201 and the second metal interconnect 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 interconnect layer 202, and the light-reflecting surface 301 is connected to the side of the support base 312 facing away from the substrate 100, the potentials of the support base 213, the second metal interconnect 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 interconnect layer 200, causing the electrode layer 311 to exert electrostatic forces on the first and second sides of the light-reflecting surface. Specifically, the electrode layer 311 can attract the first side of the light-reflecting surface 301 and repel the second side, causing the light-reflecting surface 301 to undergo a first deflection. Conversely, the control circuit sends a second control signal to the electrode layer 311 through the metal interconnect layer 200, which can cause the electrode layer 311 to repel the first side of the light-reflecting surface 301 and attract the second side, causing the light-reflecting surface 301 to undergo a second deflection.

[0074] As described above, when the light-reflecting device prepared by this method is in operation, the electrostatic force of the electrode layer 311 deflects the light-reflecting surface 301, resulting in rapid first and second deflections of the light-reflecting surface 301. In other words, the light-reflecting device has a fast response speed. Furthermore, as previously known, this light-reflecting device also possesses advantages such as small size and low power consumption. Therefore, the light-reflecting device prepared by this method can be applied to fields such as projection displays (e.g., DLP projectors), imaging printing, precision lighting (e.g., surgical microscopes, endoscopes), spectral analysis (e.g., programmable gratings), interactive displays (e.g., virtual displays, augmented reality), and optical interconnects. It should be noted that when the above-mentioned light-reflecting device is applied to projection displays, the density of the light-reflecting array can be increased to improve the resolution of the projection device, and it can also be combined with a color wheel or rapid alternating projection of the three primary colors to achieve color image display.

[0075] Based on the above, in one embodiment of this application, such as 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 with respect to the support base 312, and the first electrode 3111 corresponds to the first side of the light reflecting surface 301, while 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 with respect 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 first electrode layer 3111 and the second electrode layer 3112 can have the same shape, for example, the first electrode layer 3111 and the second electrode layer 3112 can be rectangular.

[0076] When the light-reflecting device is working, the control circuit sends a first control signal to the electrode layer 311 through the metal interconnect layer 200, causing the first electrode 3111 to attract the first side of the light-reflecting surface 301 and the second electrode 3112 to repel the second side of the light-reflecting surface 301, thereby controlling the light-reflecting surface 301 to undergo a first deflection. Alternatively, the control circuit sends a second control signal to the electrode layer 311 through the metal interconnect layer 200, causing the first electrode 3111 to repel the first side of the light-reflecting surface 301 and the second electrode 3112 to attract the second side of the light-reflecting surface 301, thereby controlling the light-reflecting 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 attracts the first side of the light reflecting surface 301 in response to the first control signal, and the second electrode layer 3112 repels the first side of the light reflecting surface 301 in response to the first control signal, or the first electrode layer 3111 repels the first side of the light reflecting surface 301 in response to the first control signal, and the second electrode layer 3112 attracts the first side of the light reflecting surface 301 in response to the first control signal. In other words, the first electrode layer 3111 and the second electrode layer 3112 work in coordination to deflect the light reflecting surface 301, which helps to further improve the response speed of the light reflecting device, making the fabricated light reflecting device have a faster response speed.

[0078] Based on the foregoing embodiments, in one embodiment of this application, such as Figure 6 As shown, the support base 312 includes a support substrate 3121 located on the side of the second metal interconnect layer 202 facing away from the substrate 100. This support substrate 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, forming an H-shaped support substrate. Based on this, in this embodiment, the first electrode 3111 and the second electrode 3112 are located on two separate 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 base 100, and the light reflecting surface 301 is located on the side of the support column 3122 away from the base 100, so as 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 supporting substrate 3121 form an H-shaped supporting substrate, and the first electrode 3111 and the second electrode 3112 are respectively located on the 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 supporting substrate 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 the first electrode 3111 and the second electrode 3112 can apply electrostatic forces of the same strength and opposite direction 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 caused by uneven force on the light reflecting surface 301.

[0081] Based on the foregoing embodiments, in one embodiment of this application, such as 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 interconnect layer 202 away from the substrate 100. The third isolation layer 33 has a third via 3, and the third via 3 exposes a portion of the second metal interconnect layer 202.

[0083] A third sub-metal layer 13 is deposited on the side of the third isolation layer 33 facing 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 support substrate 3121. The first electrode 3111 has a third preset pattern and fills a corresponding third via 3; specifically, the first electrode 3111 has a third preset pattern and fills the third via 3 below it. The second electrode 3112 has a fourth preset pattern and fills a corresponding third via 3; specifically, the second electrode 3112 has a fourth preset pattern and fills the third via 3 below it. The support substrate 3121 has a fifth preset pattern and fills a corresponding third via 3; specifically, the support substrate 3121 has a fifth preset pattern and fills the third via 3 below it.

[0084] like Figure 7 As shown, Figure 4 g is Figure 7 Along the cross-sectional view of BB1, a first sacrificial layer 34 is formed on the side of the electrode layer 311 and the support layer 3121 away from the substrate 100. The first sacrificial layer 34 has a fourth through hole 4, which exposes a portion of the first support 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. The fourth sub-metal layer 14 is patterned to form a support pillar 3122 and a light-reflecting surface 301. The support pillar 3122 is located in the fourth via 4. 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 pillar 3122.

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

[0087] It should be noted that, for light-reflecting devices, the deflection angle of the light-reflecting surface is usually different for different light-reflecting devices or different application scenarios. Therefore, during the design and fabrication process, it is necessary to limit the deflection angle of the light-reflecting surface according to the actual situation. Based on this, in one embodiment of this application, forming the light-reflecting structure 310 further 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, which is used to limit the deflection angle of the light reflecting surface 301.

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

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

[0091] A 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 post 313.

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

[0093] It should be noted that the aforementioned limiting column 313 and support column 3122 are hollow structures, which can reduce the weight of the manufactured light reflection device and contribute to lightweighting 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 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 first isolation layer 31, the second isolation layer 32, and the third isolation layer 33 can be insulating materials such as silicon dioxide. The first sacrificial layer 34 and the second sacrificial layer 35 can be polycrystalline silicon, monocrystalline silicon, silicon nitride, alumina, silicon dioxide, PMMA, photoresist, metal thin film, polyimide, etc. In other words, this preparation method uses readily available metal materials, sacrificial layer materials, and isolation layer materials, further reducing costs and manufacturing difficulties.

[0095] To gain a clearer understanding of the fabrication method of the optical reflective device provided in this application, a detailed description is provided below through a specific embodiment.

[0096] like Figure 9 As shown, a substrate is provided, in which a CMOS control circuit is formed; a first isolation layer is deposited, etched to form a first via and planarized; a first sub-metal layer is deposited and patterned to form a first metal interconnect layer; a second isolation layer is deposited, etched to form a second via and planarized; a second sub-metal layer is deposited and patterned to form a second metal interconnect layer; a third isolation layer is deposited, etched to form a third via and planarized; a third sub-metal layer is deposited and patterned to form an electrode layer and a support substrate; a second sacrificial layer is deposited, etched to form a fifth via and planarized; a fifth sub-metal layer is deposited, the fifth metal layer fills the fifth via, excess metal layer and second sacrificial layer are removed to form a limiting pillar; a first sacrificial layer is deposited, etched to form a fourth via and planarized; a fourth sub-metal layer is deposited, the fourth metal layer covers the first sacrificial layer and fills the fourth via to form a support pillar and a light reflecting surface, and the first sacrificial layer is removed.

[0097] Based on the above, this application also provides a light reflecting device, which is prepared using the fabrication method described in any of the above embodiments, such as... Figure 4 As shown in figure i, the light-reflecting device includes:

[0098] The substrate 100 contains a control circuit (not shown in the figure), which can be an SRAM cell fabricated using mature standard CMOS technology. In other words, the control circuit can be a CMOS control circuit, which helps reduce the power consumption of the resulting light-reflecting device. However, this application does not limit this; it depends on the specific circumstances.

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

[0100] A light-reflecting array is located on the side of the metal interconnect layer 200 opposite to the substrate 100, and the light-reflecting array includes a plurality of light-reflecting structures 310. The metal interconnect layer 200 is also electrically connected to the light-reflecting structures 310, so that a control circuit can be electrically connected to the light-reflecting structures 310 through the metal interconnect layer 200, and thus the control circuit can control at least one light-reflecting structure 310 in the light-reflecting 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 interconnect 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 interconnect layer 200 to control at least one light reflecting structure 310 in the light reflecting array to undergo a second deflection.

[0102] The aforementioned light-reflecting structure 310 has a light-reflecting surface 301, such as Figure 5 As shown, the first deflection is the deflection of the first side of the light reflecting surface 301 along the first direction, and the second deflection is the deflection of the second side of the light reflecting surface 301 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 towards the substrate 100. It should be noted that, for the light reflecting device described in this application, when it is working, at least one light reflecting structure 310 in the light reflecting array can respond to the first control command to undergo the first deflection and realize the first function, or at least one light reflecting structure 310 in the light reflecting array can respond to the second control command to undergo the second deflection and realize the second function, such as the opening and closing of the light path or the change of pixel brightness. Specifically, for example, if the light reflecting device is used as a light switch, at least one light reflecting structure 310 in the light reflecting array responds to the first control command to undergo the first deflection, and the light cannot be transmitted to the target position through the light reflecting surface 301. At this time, the light switch is closed. At least one light reflecting structure 310 in the light reflecting array responds to the second control command to undergo the second deflection, and the light cannot be transmitted to the target position through the light reflecting surface 301. At this time, the light switch is open.

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

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

[0105] The light-reflecting structure 310 includes an electrode layer 311 and a support base 312 located on the side of the second metal interconnect layer 202 facing away from the substrate 100. Specifically, the light-reflecting structure 310 includes an electrode layer 311 and a support base 312 located on the side of the second isolation layer 32 facing away from the substrate 100. The electrode layer 311 is electrically connected to the second metal interconnect layer 202, and the support base 312 is also electrically connected to the second metal interconnect layer 202. The light-reflecting surface 301 is connected to the side of the support base 312 facing 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 with respect to the support base 312, and the first electrode 3111 corresponds to the first side of the light reflecting surface 301, while 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 with respect 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 first electrode layer 3111 and the second electrode layer 3112 can have the same shape, for example, the first electrode layer 3111 and the second electrode layer 3112 can be rectangular.

[0107] The support base 312 includes a support substrate 3121 located on the side of the second metal interconnect layer 202 facing away from the substrate 100. This support substrate 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, forming an H-shaped support substrate. Based on this, in this embodiment, the first electrode 3111 and the second electrode 3112 are located on two separate layers of the first support layer 31211 and are symmetrically distributed relative to the first support layer 31211.

[0108] 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 base 100, and the light reflecting surface 301 is located on the side of the support column 3122 away from the base 100, so as to support the light reflecting surface 301.

[0109] When the light reflecting device is working, the first electrode layer 3111 attracts the first side of the light reflecting surface 301 in response to the first control signal, and the second electrode layer 3112 repels the first side of the light reflecting surface 301 in response to the first control signal, or the first electrode layer 3111 repels the first side of the light reflecting surface 301 in response to the first control signal, and the second electrode layer 3112 attracts the first side of the light reflecting surface 301 in response to the first control signal. In other words, the first electrode layer 3111 and the second electrode layer 3112 work in coordination to deflect the light reflecting surface 301, which helps to improve the response speed of the light reflecting device and makes the fabricated light reflecting device have a faster response speed.

[0110] It should be noted that for light-reflecting devices, the deflection angle of the light-reflecting surface is usually different for different devices or different application scenarios. Therefore, during the design and fabrication process, it is necessary to limit the deflection angle of the light-reflecting surface according to the actual situation. Thus, the light-reflecting device also includes a limiting post 313. The limiting post 313 is located on the deflection path of the light-reflecting surface 301, and the height of the limiting post 313 is less than the height of the support post 3122, which is used to limit the deflection angle of the light-reflecting surface 301. Specifically, the limiting post 313 includes a first limiting post 3131, a second limiting post 3132, a third limiting post 3133, and a fourth limiting post 3134. Among them, the first limiting post 3131 and the second limiting post 3132 are located at both ends of the second support layer 31212, and the third limiting post 3133 and the fourth limiting post 3134 are located at both ends of the third support layer 31213.

[0111] In summary, this application provides a method for fabricating a light-reflecting device and a light-reflecting device. The method includes: providing a substrate with a control circuit; patterning a first metal layer to form a metal interconnect layer; and patterning a second metal layer to form a light-reflecting array. The metal interconnect layer is electrically connected to the control circuit and also electrically connected to at least one light-reflecting structure of the light-reflecting array. Therefore, this fabrication method sequentially deposits a metal interconnect layer and a metal layer corresponding to the light-reflecting array on the substrate, and then patterns the metal layers to obtain the metal interconnect layer electrically connected to the control circuit and the light-reflecting array electrically connected to the metal interconnect layer, thus completing the fabrication of the light-reflecting device. In other words, the fabrication method provided in this application can be used with MEMS technology to fabricate the light-reflecting device without requiring special processes or dedicated equipment. Therefore, the fabrication method provided in this application is simple, low-cost, highly operable, and can ensure the reliability of the fabricated device, thus having broad application prospects.

[0112] Furthermore, the patterning of the metal interconnect layer and the optical reflective array does not affect each other, ensuring that the control circuit, metal interconnect layer, and optical reflective array are electrically connected sequentially. Therefore, the optical reflective structure of the optical reflective array fabricated using this method can be diversified. Specifically, different reflective array structures can be rationally fabricated according to the performance requirements of the optical reflective array, making it suitable for more application scenarios and highly practical. Simultaneously, the optical reflective array is obtained by patterning the second metal layer using MEMS technology, which also allows for an unlimited number of optical reflective structures in the array—up to millions—and enables very small sizes, reducing the size of the optical reflective device while maintaining the number of optical reflective structures.

[0113] The various embodiments in this specification are described in a progressive, parallel, or combined manner. Each embodiment focuses on its differences from other embodiments, and similar or identical areas between embodiments can be referred to interchangeably. For the apparatuses disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the descriptions are relatively simple, and relevant details can be found in the description of the method area.

[0114] It should be noted that, in the description of this application, the terms "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. When a component is considered to be "connected" to another component, it can be directly connected to the other component or there may be a component centrally located at the same time.

[0115] It should also be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or apparatus comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or apparatus that includes the aforementioned element.

[0116] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily 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 this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for fabricating a light-reflecting device, characterized in that, include: A substrate is provided, wherein the substrate has a control circuit, and the control circuit is a CMOS control circuit. A first metal layer is deposited, the first metal layer is patterned, and a metal interconnect layer is formed. The metal interconnect layer is located on the surface of the substrate and is electrically connected to the control circuit. A second metal layer is deposited and patterned to form a light reflection array, the light reflection array being located on the side of the metal interconnect layer facing 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; 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, and the second metal interconnect layer is electrically connected to the first metal interconnect layer and also electrically connected to the light reflection structure. Forming the metal interconnect layer includes: depositing a first isolation layer on the substrate surface, the first isolation layer having a first via exposed by the first via; depositing a first sub-metal layer on the side of the first isolation layer away from the substrate, and patterning the first sub-metal layer to form the first metal interconnect layer, the first metal interconnect layer having a first preset pattern covering the first isolation layer and filling the first via; depositing a second isolation layer on the side of the first metal interconnect layer away from the substrate, the second isolation layer having a second via exposed by the second via; depositing a second sub-metal layer on the side of the second isolation layer away from the substrate, and patterning the second sub-metal layer to form the second metal interconnect layer, the second metal interconnect layer having a second preset pattern covering the second isolation layer and filling the second via; The light-reflecting structure includes an electrode layer and a support base located on the side of the second metal interconnect layer away from the substrate. The electrode layer is electrically connected to the second metal interconnect layer, and the support base is also electrically connected to the second metal interconnect layer. The light-reflecting surface of the light-reflecting structure is connected to the side of the support base away from the substrate. When the light reflecting device is working, the control circuit sends a first control signal to the electrode layer of the light reflecting array through the metal interconnect layer to control at least one of the light reflecting structures in the light reflecting array to undergo a first deflection; or, the control circuit sends a second control signal to the electrode layer of the light reflecting array through the metal interconnect layer to control at least one of the light reflecting structures in the light reflecting array to undergo a second deflection. Wherein, the first deflection is the deflection of a first side of the light-reflecting surface along a first direction, the second deflection is the deflection of a second side of the light-reflecting surface 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 fabricating a light-reflecting device according to claim 1, characterized in that, The electrode layer includes a first electrode and a second electrode, which are symmetrically distributed with respect to the support base. 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 interconnect layer, causing the first electrode to attract the first side of the light reflecting surface and the second electrode to repel the second side of the light reflecting surface, thereby controlling 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 interconnect layer, causing the first electrode to repel the first side of the light reflecting surface and the second electrode to attract the second side of the light reflecting surface, thereby controlling the light reflecting surface to undergo a second deflection.

3. The method for fabricating a light-reflecting device according to claim 2, characterized in that, The support base includes a support substrate located on the side of the second metal interconnect layer opposite to the substrate. The support substrate 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 substrate. The first electrode and the second electrode are located on both sides of the first support layer and are symmetrically distributed. The support base also includes a support column, which 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.

4. The method for fabricating a light-reflecting device according to claim 3, characterized in that, Forming the light-reflecting structure includes: A third isolation layer is deposited on the side of the second metal interconnect layer away from the substrate, the third isolation layer having a third via, the third via exposing a portion of the second metal interconnect 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 support substrate; wherein, the first electrode has a third preset pattern and is filled with a corresponding third via; the second electrode has a fourth preset pattern and is filled with a corresponding third via; the support substrate has a fifth preset pattern and is filled with a corresponding third via. A first sacrificial layer is formed on the side of the electrode layer and the support layer away from the substrate. The first sacrificial layer has a fourth through hole, and the fourth through hole exposes a portion of the first support layer. A fourth sub-metal layer is deposited on the side of the first sacrificial layer away from the substrate, and the fourth sub-metal layer is patterned to form the support pillar and the light-reflecting surface. The support pillar is located in the fourth via, and the light-reflecting surface covers the side of the first sacrificial layer away from the substrate and is connected to the support pillar. After removing the first sacrificial layer, a gap is formed between the light-reflecting surface and the supporting substrate.

5. The method for fabricating a light-reflecting device according to claim 4, characterized in that, The formation of the light-reflecting structure further includes: A limiting post is formed on the side of the supporting bottom layer away from the base. The limiting post is located on the deflection path of the light reflecting surface and is used to limit the deflection angle of the light reflecting surface. The limiting column formed on the side of the supporting bottom layer away from the base includes: After the electrode layer and the support substrate are formed, and before the first sacrificial layer is formed, a second sacrificial layer is deposited on the side of the electrode layer and the support substrate away from the substrate. The second sacrificial layer has a fifth via located on the deflection path of the light-reflecting surface, and the fifth via exposes a portion of the support substrate. A fifth sub-metal layer is deposited in the fifth through hole, and the second sacrificial layer is removed to form the limiting post.

6. The method for fabricating a light-reflecting device according to claim 5, 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 post and the second limiting post are located at both ends of the second support layer, and the third limiting post and the fourth limiting post are located at both ends of the third support layer.

7. A light-reflecting device, characterized in that, The light-reflecting device is prepared according to the preparation method described in any one of claims 1-6, and the light-reflecting device comprises: A substrate having control circuitry; A metal interconnect layer covers the surface of the substrate and is electrically connected to the control circuit. A light-reflecting array is located on the side of the metal interconnect layer opposite to the substrate; the light-reflecting array includes a plurality of light-reflecting structures, and the metal interconnect layer is electrically connected to the light-reflecting structures so that the control circuit controls at least one of the light-reflecting structures in the light-reflecting array through the metal interconnect layer; 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 is also electrically connected to the light reflection structure. The light-reflecting structure includes an electrode layer and a support base located on the side of the second metal interconnect layer away from the substrate. The electrode layer is electrically connected to the second metal interconnect layer, and the support base is also electrically connected to the second metal interconnect layer. The light-reflecting surface of the light-reflecting structure is connected to the side of the support base away from the substrate. When the light reflecting device is working, the control circuit sends a first control signal to the electrode layer of the light reflecting array through the metal interconnect layer to control at least one of the light reflecting structures in the light reflecting array to undergo a first deflection; or, the control circuit sends a second control signal to the electrode layer of the light reflecting array through the metal interconnect layer to control at least one of the light reflecting structures in the light reflecting array to undergo a second deflection. Wherein, the first deflection is the deflection of a first side of the light-reflecting surface along a first direction, the second deflection is the deflection of a second side of the light-reflecting surface 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.

8. The light-reflecting device according to claim 7, characterized in that, The electrode layer includes a first electrode and a second electrode, which are symmetrically distributed with respect to the support base. 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. The support base includes a support substrate located on the side of the second metal interconnect layer away from the substrate. The support substrate 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 substrate. The first electrode and the second electrode are located on opposite sides of the first support layer and are symmetrically distributed. The support base also includes a support column 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.

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