Preparation system and preparation method of MEMS (Micro Electro Mechanical System) micromirror

Abstract

The invention discloses a preparation system and a preparation method of an MEMS micromirror, and the preparation system comprises a processing device which is used for processing the upper surface of a wafer before bonding of the wafer, and processing the lower surface of the wafer after bonding and before de-bonding of the wafer, so as to form a plurality of MEMS micromirror chips; the bonding device is used for bonding the wafer and the temporary bonding material, and the upper surface of the wafer is a bonding surface; the de-bonding device is used for separating the wafer and the temporary bonding material by adopting a dry-method de-bonding technology; the sorting device is used for automatically sorting the plurality of MEMS micromirror chips on the wafer after the wafer is de-bonded and distinguishing qualified chips from unqualified chips; wherein the processing device, the bonding device, the de-bonding device and the sorting device are all located in the same manufacturing facility. By adopting the preparation system to prepare the MEMS micromirror, the production process can be simplified, the cost can be reduced, and the product quality and the production automation level can be improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of micro-electro-mechanical system, and in particular to a preparation system and a preparation method of a MEMS micro-mirror. BACKGROUND

[0002] With the rapid development of micro-electro-mechanical system (MEMS) technology, MEMS micro-mirror devices show a wide application prospect in the fields of radar, image projection, augmented reality (AR) / virtual reality (VR) and optical communication.

[0003] However, in the manufacturing process of the traditional MEMS micro-mirror device, the front-end process and the back-end process are usually carried out in different manufacturing facilities in different factory areas. This separated production mode not only increases the product cost, but also reduces the controllability of product quality.

[0004] Therefore, how to simplify the manufacturing process of the MEMS micro-mirror device, reduce the cost, improve the product quality and the production automation level has become a technical problem to be solved at present. SUMMARY

[0005] In order to overcome the above problems or at least partially solve the above problems, the present application provides a preparation system and a preparation method of a MEMS micro-mirror to simplify the production process, reduce the cost, and improve the product quality and the production automation level.

[0006] In a first aspect, a preparation system of a MEMS micro-mirror is provided, characterized in that it comprises:

[0007] a processing device configured to process an upper surface of a wafer before wafer bonding, and process a lower surface of the wafer after wafer bonding and before debonding, so as to form a plurality of MEMS micro-mirror chips;

[0008] a bonding device configured to bond the wafer with a temporary bonding material, wherein the upper surface of the wafer is a bonding surface;

[0009] a debonding device configured to separate the wafer and the temporary bonding material by using a dry debonding technology;

[0010] a sorting device configured to automatically sort the plurality of MEMS micro-mirror chips on the wafer after wafer debonding, so as to distinguish between qualified chips and unqualified chips;

[0011] wherein the processing device, the bonding device, the debonding device and the sorting device are located in the same manufacturing facility.

[0012] In some implementations, the MEMS micro-mirror chip includes a mirror, a driving component, a frame, a partition connector and a mirror support; the driving component is configured to drive the mirror to rotate, the frame is arranged around the mirror and configured to support the driving component, the partition connector is located on the frame and is configured to connect adjacent MEMS micro-mirror chips; and the mirror support is located on the back of the mirror and configured to support the mirror.

[0013] The processing device includes:

[0014] A deposition device is configured to deposit a mirror material film layer on the upper surface of the wafer before the wafer is bonded, and to deposit a driving component material film layer on the upper surface of the wafer after the mirror is formed;

[0015] A photolithography device is configured to form a patterned photoresist layer on the mirror material film layer and the driving component material film layer respectively, and to form a required patterned photoresist layer on the lower surface of the wafer after the wafer is bonded and before the wafer is debonded.

[0016] An etching device is configured to etch the mirror material film layer to form the mirror, etch the driving component material film layer to form the driving component, and etch the lower surface of the wafer to form the frame, the partition connector and the mirror support after the wafer is bonded and before the wafer is debonded, using the corresponding patterned photoresist layer as a mask.

[0017] In some implementations, the etching device includes a dry etching machine and a wet etching machine.

[0018] In some implementations, the deposition device is further configured to:

[0019] deposit a mirror reflection layer on the surface of the mirror before the wafer is bonded after the mirror is etched on the wafer; or

[0020] deposit the mirror reflection layer on the surface of the mirror after the wafer and the temporary bonding material are separated.

[0021] In some implementations, the deposition device includes a tray for loading the wafer for depositing the mirror reflection layer, and a metal-made shadow mask is fixedly arranged on the side of the tray for loading the wafer, and the shadow mask is configured to cover the wafer.

[0022] In some implementations, the preparation system further includes:

[0023] A cleaning device is configured to clean the surface of the mirror to remove residues and impurities on the surface of the mirror before the mirror reflection layer is deposited.

[0024] In some implementations, the bonding device comprises:

[0025] a temporary bonding machine for coating a temporary bonding glue on a temporary bonding material or a wafer surface, aligning and bonding the temporary bonding material with the wafer;

[0026] wherein the temporary bonding glue is a bonding glue suitable for dry debonding.

[0027] In some implementations, the debonding device comprises:

[0028] a dry debonding machine for separating the wafer and the temporary bonding material by using a dry debonding technology, and temporarily fixing the separated wafer on a layer of flexible film;

[0029] wherein the dry debonding technology is a thermal slip debonding technology, a mechanical debonding technology or a laser debonding technology.

[0030] In some implementations, the sorting device comprises:

[0031] a visual detection mechanism for visually detecting a plurality of MEMS micro-mirror chips in the wafer after debonding, and identifying qualified chips and unqualified chips;

[0032] a sorting execution mechanism for automatically sorting the qualified chips and the unqualified chips according to the identification result of the visual detection mechanism.

[0033] In a second aspect, a preparation method of a MEMS micro-mirror is provided, which is prepared by using the preparation system of the first aspect, and the preparation method comprises:

[0034] providing a wafer, the wafer having opposite upper and lower surfaces;

[0035] processing the upper surface of the wafer by using a processing device to form mirror surfaces of a plurality of MEMS micro-mirror chips and driving components for driving the mirror surfaces to rotate;

[0036] providing a temporary bonding material;

[0037] bonding the wafer and the temporary bonding material by using a bonding device;

[0038] A processing device is used to process the lower surface of the wafer to form the outer frame, segmentation connectors, and mirror support for a plurality of MEMS micromirror chips. The outer frame is arranged around the mirror and is used to support the driving assembly. The segmentation connectors are located on the outer frame and adjacent MEMS micromirrors are connected by the segmentation connectors. The mirror support is located on the back of the mirror and is used to support the mirror.

[0039] A debonding device is used to separate the wafer and the temporary bonding material using dry debonding technology;

[0040] After wafer debonding, a sorting device is used to automatically sort multiple MEMS micromirror chips on the wafer to distinguish between qualified and unqualified chips.

[0041] The technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0042] This invention provides a method for manufacturing MEMS micromirror devices. By highly integrating processing, bonding, debonding, and sorting devices within the same manufacturing facility, it achieves ultimate integration of the manufacturing process. This completely avoids the cumbersome processes and increased costs associated with cross-plant and cross-facility operations for front-end and back-end processes in traditional manufacturing. It ensures continuity of the manufacturing process and environmental control, reducing the risk of impurity introduction. This not only significantly reduces redundant steps such as transportation and storage between different facilities, substantially lowering product costs, but also allows for precise control of the entire process within a single facility. This effectively eliminates the negative impact of process and environmental differences between different facilities on product quality, greatly improving the stability and controllability of product quality. Furthermore, the use of automated equipment to perform key operations such as processing, bonding, debonding, and sorting comprehensively improves the level of production automation, significantly reduces manual intervention, further compresses production costs, and increases production efficiency. The debonding device utilizes dry debonding technology to separate the wafer from the temporary bonding material, ensuring that the relative positions of each MEMS chip on the wafer remain consistent after debonding as before. This avoids the problem of disordered chip distribution in the chemical solution after wet debonding, greatly facilitating subsequent automated sorting. The introduction of the sorting device enables rapid automated chip sorting, overcoming the inefficiency and instability of existing manual sorting, and ensuring a high degree of cleanliness on the chip surface, providing strong assurance for product quality.

[0043] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0044] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0045] Figure 1 This is a block diagram of a MEMS micromirror fabrication system provided by related technologies;

[0046] Figure 2 This is a structural block diagram of a MEMS micromirror fabrication system provided in an embodiment of the present invention;

[0047] Figure 3 This is a schematic diagram of the structure of a MEMS micromirror chip provided in an embodiment of the present invention;

[0048] Figure 4 This is a flowchart of a method for fabricating a MEMS micromirror provided in an embodiment of the present invention. Detailed Implementation

[0049] To better understand the above technical solutions, the following will describe the above technical solutions in detail with reference to the accompanying drawings and specific implementation methods. It should be understood that the embodiments of this disclosure and the specific features in the embodiments are detailed descriptions of the technical solutions of this application, rather than limitations on the technical solutions of this application. Unless otherwise specified, the embodiments of this application and the technical features in the embodiments can be combined with each other.

[0050] To better understand this application, the following is a brief introduction to the fabrication system and method of MEMS micromirrors in related technologies:

[0051] Figure 1 This is a block diagram of a MEMS micromirror fabrication system provided by related technologies, such as... Figure 1As shown, the MEMS micromirror fabrication system 100 in the related technology includes a processing unit 111 and a bonding unit 112 located in a front-end fabrication facility 110, and a debonding unit 121 located in a back-end fabrication facility 120. The processing unit 111 processes the wafer to form multiple MEMS micromirror chips, and the bonding unit 112 bonds the wafer to temporary bonding material. After the processing and bonding of the MEMS micromirrors are completed in the front-end fabrication facility 110, the wafer can be packaged and transported to the back-end fabrication facility 120. The debonding unit 112 in the back-end fabrication facility 120 uses wet debonding technology to separate the wafer and the temporary bonding material. Subsequently, the multiple MEMS chips on the debonded wafer undergo manual mirror cleaning and manual sorting, transferring the multiple MEMS chips to a chip box for final packaging before transportation.

[0052] As mentioned above, MEMS micromirror devices often employ a process of front-end temporary bonding and back-end wet debonding to ensure a defect-free mirror surface. While this process can prevent mirror scratches and particle defects during packaging to some extent, the wet debonding steps are cumbersome, involving numerous manual or semi-automatic operations for wafer transfer and chip cleaning, resulting in low automation. This not only limits the rapid processing of chips but also reduces chip yield and reliability, thereby increasing the manufacturing costs of back-end processes and the overall chip manufacturing cost.

[0053] Furthermore, front-end processes primarily involve photolithography, thin-film deposition, and dry / wet etching, while back-end processes mainly involve wafer bonding / debonding and chip sorting. Significant differences exist between front-end and back-end processes in terms of equipment, environment, and facility layout, leading to complex wafer packaging and transportation processes during production. This not only increases product costs but also reduces the controllability of product quality.

[0054] Therefore, to address the aforementioned technical problems, this invention provides a MEMS micromirror fabrication system and method. By integrating processing, bonding, debonding, and sorting devices into the same manufacturing facility, it achieves ultimate integration of the manufacturing process, avoiding the cumbersome and costly operations of traditional cross-plant / facility operations, reducing transportation and storage links to lower costs, and precisely controlling the entire process, thereby improving product quality stability and controllability. Simultaneously, fully automated operation increases automation, reduces labor, compresses costs, and improves efficiency.

[0055] Figure 2 This is a structural block diagram of a MEMS micromirror fabrication system provided in an embodiment of the present invention, as shown below. Figure 2 As shown, the preparation system 200 includes a processing device 210, a bonding device 220, a debonding device 230, and a sorting device 240.

[0056] Processing unit 210 processes the upper surface of the wafer before wafer bonding and processes the lower surface of the wafer after wafer bonding and before debonding to form multiple MEMS micromirror chips. Bonding unit 220 bonds the wafer to temporary bonding material, wherein the upper surface of the wafer is the bonding surface. Debonding unit 230 separates the wafer and temporary bonding material using dry debonding technology. Sorting unit 240 automatically sorts the multiple MEMS micromirror chips on the wafer after wafer debonding, distinguishing between qualified and unqualified chips. The processing unit, bonding unit, debonding unit, and sorting unit are all located within the same manufacturing facility.

[0057] It should be noted that the same manufacturing facility refers to chip manufacturing cleanrooms located in the same location and having a continuous environment.

[0058] Figure 3 This is a schematic diagram of the structure of a MEMS micromirror chip provided in an embodiment of the present invention, as shown below. Figure 3 As shown, the MEMS micromirror chip 300 includes a mirror 310, a driving assembly 320, an outer frame 330, a segmented connector 340, and a mirror support (not shown in the figure). The driving assembly 320 drives the mirror 310 to rotate. The outer frame 330 is arranged around the mirror 310 and supports the driving assembly 320. The segmented connector 340 is located on the outer frame 330, and adjacent MEMS micromirror chips are connected through the segmented connector 340. The mirror support is located on the back of the mirror 310 and supports the mirror 310.

[0059] In some implementations, the outer frame 330 includes a frame body and a thickened layer. The frame body has opposing support surfaces and a bottom surface. The driving component 320 is located on the support surface, and the thickened layer protrudes from the bottom surface. The outer frame support structure is relatively thick, facilitating automatic wafer transfer during the manufacturing process. Dividing connectors 340 are evenly distributed around the frame body of the outer frame 330. Each dividing connector 340 has a dicing channel P, facilitating the separation of adjacent MEMS micromirror chips 300 using laser or mechanical methods along the dicing channel P. The driving component 320 includes a driving element 321, a rotating shaft 322, and an electrode 323. The driving element 321 is connected to the mirror surface 310 via the rotating shaft 322. The electrode 323 is connected to the driving element 321 and provides voltage or current to the driving element 321. The driving method of the driving component 320 can be electrostatic, electromagnetic, or piezoelectric; this invention does not limit this method.

[0060] In some implementations, the processing apparatus 210 includes:

[0061] Deposition equipment is used to deposit a mirror material film on the upper surface of a wafer before wafer bonding, and to deposit a drive component material film on the upper surface of the wafer after the mirror is formed.

[0062] Photolithography equipment is used to form patterned photoresist layers on the mirror material film layer and the drive component material film layer, respectively, and to form the required patterned photoresist layer on the lower surface of the wafer after wafer bonding and before debonding.

[0063] Etching equipment is used to etch mirror material films to form mirrors using corresponding patterned photoresist layers as masks, to etch drive component material films to form drive components, and to etch the lower surface of the wafer after wafer bonding and before debonding to form the outer frame, dividing connectors and mirror support components.

[0064] In the above implementation, the processing device 210 is used to process the upper surface of the wafer to form the mirror surface 310 and the driving component 320 of the MEMS micromirror chip 300.

[0065] For example, deposition equipment may include physical vapor deposition (PVD) equipment and / or chemical vapor deposition (CVD) equipment to deposit mirror material films and drive component material films via PVD and / or CVD methods. Photolithography equipment can transfer the desired pattern to the photoresist surface through photoresist coating, exposure, and development steps to form the desired patterned photoresist.

[0066] In some implementations, the etching equipment includes dry etching machines and / or wet etching machines.

[0067] For example, the mirror surface 310 is formed by dry etching, and the driving component 320 is formed by wet etching. Alternatively, the mirror surface 310 can be formed by both dry and wet etching, and the driving component 320 can be formed by both dry and wet etching, etc. In specific processing, the appropriate etching machine can be used to form the required MEMS micromirror chip according to the actual process, and the present invention does not limit this.

[0068] In some implementations, the MEMS micromirror chip also includes a specular light-reflecting layer located on the mirror surface, and the deposition equipment is also used for:

[0069] After etching a mirror surface on the wafer, a mirror reflection layer is deposited on the mirror surface before wafer bonding; or, after the wafer and temporary bonding material separate, a mirror reflection layer is deposited on the mirror surface.

[0070] Since all devices are located within the same manufacturing facility, the process flow can be flexibly adjusted. Therefore, in different application scenarios, the mirror reflection layer can be formed at different stages to meet actual production needs.

[0071] In one implementation, when the mirror reflection performance of the MEMS micromirror chip is required to be extremely high, and the mirror surface is easily contaminated or damaged during subsequent bonding processes, thus severely affecting the quality and performance of the reflective layer, a mirror reflection layer can be deposited on the mirror surface before wafer bonding. The advantage of this approach is that the mirror reflection layer can be deposited in a relatively independent environment with less external interference, ensuring that the reflective layer has a uniform and dense structure, thereby achieving excellent reflection performance. Simultaneously, it avoids the adverse effects of impurities and stresses that may be introduced during bonding, ensuring that the MEMS micromirror chip can stably and efficiently reflect light in subsequent use, improving the overall performance and reliability of the chip.

[0072] In another implementation, when the production process involves special steps that, if performed before wafer bonding, might damage the already deposited mirror reflective layer, or when the process flow arrangement would increase process complexity and cost by depositing the reflective layer before wafer bonding, the mirror reflective layer can be deposited on the mirror surface after the wafer and temporary bonding material are separated. At this point, the wafer has completed the necessary pre-processing such as bonding and is in a relatively stable state. Depositing the mirror reflective layer at this stage can avoid potential damage to the reflective layer from the pre-processing. Furthermore, based on the optimization of the overall process flow, choosing to deposit the reflective layer at this stage can simplify the process steps, reduce production costs, and still ensure that the mirror reflective layer has a good reflective effect, meeting the requirements for use in MEMS micromirror chips.

[0073] In the above implementation, the deposition equipment includes a tray for loading wafers and a tray for depositing the specular reflective layer. A metal shadow mask is fixedly disposed on the wafer-loading side of the tray, covering the wafer. The shadow mask precisely blocks and defines the deposition area, ensuring that the formed specular reflective layer only covers a predetermined specific area on the mirror surface, preventing reflective material from being deposited in non-target areas (such as wafer edges, tray surfaces, or other areas where a reflective layer is undesirable). Through the blocking effect of the shadow mask, the reflective layer material can be precisely deposited on the mirror surface according to a pre-designed pattern and size during the deposition process, ensuring that the shape, size, and position of the specular reflective layer meet design requirements. This improves the optical performance and reliability of the MEMS micromirror chip while reducing material waste and potentially complex subsequent cleaning processes.

[0074] In some implementations, the preparation system 200 also includes:

[0075] A cleaning device is used to clean the surface of a mirror before the deposition of a mirror reflective layer, in order to remove residues and impurities from the mirror surface.

[0076] In this implementation, cleaning the mirror surface before depositing the mirror reflection layer ensures that the mirror's optical performance meets high standards. Furthermore, the cleaned mirror surface creates ideal conditions for the deposition of the mirror reflection layer, allowing the reflection layer material to adhere uniformly, densely, and firmly to the mirror surface, thereby forming a high-quality mirror reflection layer. This significantly improves the reflection efficiency, stability, and lifespan of the reflection layer, thus ensuring the quality and reliability of the entire MEMS micromirror chip.

[0077] In some implementations, the debonding device 210 includes:

[0078] A dry debonding machine is used to separate wafers and temporary bonding materials using dry debonding technology, and temporarily fix the separated wafers onto a flexible thin film. The dry debonding technology can be thermal slip debonding, mechanical debonding, or laser debonding.

[0079] It should be noted that the dry debonding machine also has the function of temporarily fixing the separated wafer onto a flexible film. This flexible film typically has good flexibility and adhesion, enabling the wafer to be stably fixed on it without damaging the wafer surface. The dry debonding machine uses a precise mechanical structure and adsorption device to accurately place the wafer on the flexible film, and utilizes the adhesive properties of the film to ensure a tight bond between the wafer and the film. This temporary fixing method not only facilitates subsequent wafer transportation and processing operations, but also effectively protects the wafer surface from external contamination and damage during operation, providing a good guarantee for subsequent process steps.

[0080] In some implementations, the bonding device 220 includes:

[0081] A temporary bonding machine is used to coat temporary bonding material or wafer surface with temporary bonding adhesive, align the temporary bonding material with the wafer, and bond them together.

[0082] The temporary bonding adhesive is suitable for dry debonding. This type of temporary bonding adhesive provides sufficient adhesion during the bonding process, ensuring a tight bond between the wafer and the temporary bonding material. When debonding is required, it can be rapidly and cleanly separated under specific dry conditions (such as heating or laser irradiation), leaving no residue on the wafer surface. This provides a good foundation for subsequent process steps and helps improve the overall fabrication quality and production efficiency of MEMS micromirror chips.

[0083] For example, different temporary bonding adhesives can be selected for different dry debonding technologies. For instance, for thermal slip debonding technology, thermoplastic polymers can be used as temporary bonding adhesives. Thermoplastic polymers can soften at specific temperatures, allowing the wafer to separate from the carrier by thermal slip. For mechanical debonding technology, polymer bonding adhesives or peelable tapes can be used as temporary bonding adhesives. Polymer bonding adhesives or peelable tapes can be easily peeled off under specific conditions (such as heating or applying external force), achieving mechanical debonding. For laser debonding technology, photosensitive polymers can be used as temporary bonding adhesives. Photosensitive polymers undergo photochemical reactions under laser irradiation of a specific wavelength, leading to a decrease in adhesive strength and achieving debonding.

[0084] In practical operation, the temporary bonding machine can precisely and uniformly coat a layer of temporary bonding adhesive onto the temporary bonding material or wafer surface using methods such as spraying, spin coating, or screen printing. After the temporary bonding adhesive is applied, the temporary bonding machine performs a precise alignment operation. It is equipped with a high-precision alignment system that utilizes advanced image recognition and laser positioning technologies to quickly and accurately identify alignment marks on the temporary bonding material and the wafer, precisely aligning them to the preset positions. After alignment, the temporary bonding machine begins the bonding operation. By applying appropriate pressure, temperature, and other conditions, it causes the temporary bonding adhesive to cure, thereby achieving a strong bond between the temporary bonding material and the wafer.

[0085] In some implementations, the sorting device 240 includes:

[0086] A visual inspection unit is used to perform visual inspection on multiple MEMS micromirror chips in a debonded wafer to identify qualified and unqualified chips.

[0087] The sorting execution mechanism is used to automatically sort qualified chips from unqualified chips based on the identification results of the visual inspection mechanism.

[0088] Specifically, the visual inspection mechanism utilizes a high-precision optical imaging system, integrating a high-definition industrial camera, a high-performance lens, and professional lighting equipment. It can capture every detail on the surface of multiple MEMS micromirror chips on the wafer with ultra-high resolution. Then, with the help of advanced image processing algorithms and artificial intelligence technology trained on a large number of samples, it accurately analyzes scratches, cracks, and dirt on the chip's exterior, as well as the integrity of the electrodes and the normality of circuit connections in the internal structure. After a detailed comparison with preset quality standards, it quickly and accurately identifies qualified and unqualified chips and transmits the results as data signals to the sorting execution mechanism. The sorting execution mechanism consists of a robotic arm with high-precision motion control capabilities, a vacuum suction cup that conforms to the characteristics of the chip, a stable conveyor device, and an intelligent command and control system. Based on signals from the vision inspection mechanism, it quickly directs a robotic arm to move above the target chip, firmly adsorbs the chip using a vacuum suction cup, and then precisely places qualified and unqualified chips into their corresponding collection areas via a conveyor. Its sorting speed is flexibly adjustable and it can operate stably for extended periods, efficiently completing sorting tasks and providing high-quality chip raw materials for subsequent chip packaging and testing processes, significantly improving the efficiency and quality of the entire MEMS micromirror chip fabrication process. After the chips are transferred from the tray to the chip box by the sorting device 240, final packaging is completed, enabling chip transportation.

[0089] It should be understood that the above division of the devices is only presented as an example. In actual technical implementation, the division of each module has many possibilities and is not limited to the methods described above. The embodiments of the present invention do not limit the form of module division.

[0090] Based on the same inventive concept, this invention also provides a method for fabricating MEMS micromirrors, which are fabricated using the fabrication system described in the above embodiments.

[0091] Figure 4 This is a flowchart of a method for fabricating a MEMS micromirror provided in an embodiment of the present invention, as shown below. Figure 4 As shown, the preparation method includes:

[0092] Step S410: Provide a wafer having opposing upper and lower surfaces.

[0093] For example, the wafer can be a silicon-on-insulator (SOI) wafer. The SOI wafer includes a device layer, a buried oxide layer, and a substrate layer stacked sequentially.

[0094] Step S420: A processing device is used to process the upper surface of the wafer to form the mirror surface of multiple MEMS micromirror chips and a drive component for driving the mirror surface to rotate.

[0095] In some implementations, step S420 may include:

[0096] A dielectric layer is formed on the surface of the SOI wafer. This dielectric layer serves as an insulation layer. Specifically, an insulating material is deposited on the surface of the SOI wafer as a dielectric layer using the chemical vapor deposition (CVD) method.

[0097] The mirror surface of a MEMS micromirror and the driving components for rotating the mirror are formed on the surface of the SOI wafer. Specifically, the driving components, forming electrodes, driving structures, and rotation axes, can be fabricated using physical vapor deposition (PVD), photolithography, and dry etching methods. The mirror surface is fabricated using PVD, photolithography, and wet etching methods. In this embodiment, the groove-shaped region on the front of the micromirror and the connection region between adjacent micromirrors can also be defined using photolithography and deep silicon etching methods.

[0098] Step S430: Provide a temporary bonding material.

[0099] For example, the temporary bonding material can be glass or a quartz wafer.

[0100] Step S440: Use a bonding device to bond the wafer and the temporary bonding material.

[0101] Step S450: A processing device is used to process the lower surface of the wafer to form the outer frame, segmentation connector and mirror support of multiple MEMS micromirror chips.

[0102] The outer frame surrounds the mirror and supports the drive components. The segmented connectors are located on the outer frame, and adjacent MEMS micromirrors are connected by the segmented connectors. The mirror support is located on the back of the mirror and is used to support the mirror.

[0103] In some implementations, step S450 may include:

[0104] The lower surface of the wafer is thinned;

[0105] A shallow trench etching process is used to etch the wafer once, forming a patterned groove on the lower surface of the wafer to define the area where the outline and the split connectors are located;

[0106] A deep trench etching process is used to perform secondary etching on the lower surface of the wafer to remove other wafers outside the area where the outer frame and partition connectors are located, in order to form the outer frame and partition connectors.

[0107] In the aforementioned shallow trench etching process and deep trench etching process, patterned photoresist can be formed on the lower surface of the wafer by photolithography, and the corresponding patterned photoresist can be used as a mask to etch the desired structure.

[0108] Step S460: Use a debonding device to separate the wafer and temporary bonding material using dry debonding technology.

[0109] For example, the dry debonding technology can be thermal slip debonding, mechanical debonding, or laser debonding. In step S460, the separated wafer can also be temporarily fixed on a flexible thin film.

[0110] Step S470: After wafer debonding, a sorting device is used to automatically sort multiple MEMS micromirror chips on the wafer to distinguish between qualified and unqualified chips.

[0111] In this embodiment, the dividing section of the dividing connector can be cut along the dicing channel of the dividing connector using laser or mechanical methods to separate multiple MEMS micromirror chips. The separated MEMS micromirror chips are then transferred from the tray to a chip box, and after final packaging, the chips can be transported.

[0112] The specific details of each device involved in the above preparation method can be understood by referring to the relevant descriptions and effects in the gas preparation system embodiments shown above, and will not be repeated here.

[0113] The technical solutions provided in the above embodiments of this application have at least the following technical effects or advantages:

[0114] This invention provides a method for manufacturing MEMS micromirror devices. By highly integrating processing, bonding, debonding, and sorting devices within the same manufacturing facility, it achieves ultimate integration of the manufacturing process. This completely avoids the cumbersome processes and increased costs associated with cross-plant and cross-facility operations for front-end and back-end processes in traditional manufacturing. It ensures continuity of the manufacturing process and environmental control, reducing the risk of impurity introduction. This not only significantly reduces redundant steps such as transportation and storage between different facilities, substantially lowering product costs, but also allows for precise control of the entire process within a single facility. This effectively eliminates the negative impact of process and environmental differences between different facilities on product quality, greatly improving the stability and controllability of product quality. Furthermore, the use of automated equipment to perform key operations such as processing, bonding, debonding, and sorting comprehensively improves the level of production automation, significantly reduces manual intervention, further compresses production costs, and increases production efficiency. The debonding device utilizes dry debonding technology to separate the wafer from the temporary bonding material, ensuring that the relative positions of each MEMS chip on the wafer remain consistent after debonding as before. This avoids the problem of disordered chip distribution in the chemical solution after wet debonding, greatly facilitating subsequent automated sorting. The introduction of the sorting device enables rapid automated chip sorting, overcoming the inefficiency and instability of existing manual sorting, and ensuring a high degree of cleanliness on the chip surface, providing strong assurance for product quality.

[0115] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0116] Similarly, it should be understood that, in order to simplify this disclosure and aid in understanding one or more of the various aspects of the invention, in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof. However, this method of disclosure should not be construed as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as reflected in the following claims, inventive aspects lie in fewer than all features of a single foregoing disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into this detailed description, wherein each claim itself is a separate embodiment of the invention.

[0117] It should be noted that the above embodiments are illustrative of the invention and not restrictive of the invention, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims.

Claims

1. A system for fabricating MEMS micromirrors, characterized in that, include: A processing apparatus is used to process the upper surface of a wafer before wafer bonding and to process the lower surface of the wafer after wafer bonding and before debonding, so as to form multiple MEMS micromirror chips. A bonding apparatus for bonding the wafer to a temporary bonding material, wherein the upper surface of the wafer is the bonding surface; A debonding apparatus for separating the wafer and the temporary bonding material using a dry debonding technique; The sorting device is used to automatically sort multiple MEMS micromirror chips on the wafer after the wafer is debonded, and to distinguish between qualified chips and unqualified chips. The processing device, the bonding device, the debonding device, and the sorting device are all located in the same manufacturing facility.

2. The preparation system according to claim 1, characterized in that, The MEMS micromirror chip includes a mirror, a driving component, an outer frame, a segmented connector, and a mirror support component; the driving component is used to drive the mirror to rotate, the outer frame is arranged around the mirror and used to support the driving component, the segmented connector is located on the outer frame, and adjacent MEMS micromirror chips are connected through the segmented connector; The mirror support is located on the back of the mirror and is used to support the mirror. The processing apparatus includes: A deposition apparatus for depositing a mirror material film on the upper surface of a wafer before the wafer is bonded, and for depositing a drive component material film on the upper surface of the wafer after the mirror is formed; A photolithography apparatus is used to form patterned photoresist layers on the mirror material film layer and the driving component material film layer, respectively, and to form the required patterned photoresist layer on the lower surface of the wafer after wafer bonding and before debonding. An etching apparatus is used to etch the mirror material film layer to form the mirror using the corresponding patterned photoresist layer as a mask, to etch the driving component material film layer to form the driving component, and to etch the lower surface of the wafer after wafer bonding and before debonding to form the outer frame, the dividing connector and the mirror support.

3. The preparation system according to claim 2, characterized in that, The etching equipment includes dry etching machines and wet etching machines.

4. The preparation system according to claim 2, characterized in that, The deposition equipment is also used for: After etching the mirror surface onto the wafer, and before wafer bonding, a mirror reflection layer is deposited on the surface of the mirror surface; or... After the wafer and the temporary bonding material are separated, the mirror reflection layer is deposited on the mirror surface to form the mirror reflection layer.

5. The preparation system according to claim 4, characterized in that, The deposition apparatus includes a tray for loading the wafer and for depositing the specular reflection layer, and a metal shadow mask is fixedly disposed on one side of the tray for loading the wafer, the shadow mask being used to cover the wafer.

6. The preparation system according to claim 4, characterized in that, The preparation system further includes: A cleaning device is used to clean the surface of the mirror before the deposition of the mirror reflective layer, in order to remove residues and impurities from the surface of the mirror.

7. The preparation system according to claim 1, characterized in that, The bonding device includes: A temporary bonding machine is used to coat a temporary bonding material or wafer surface with temporary bonding adhesive, and to align and bond the temporary bonding material to the wafer. The temporary bonding adhesive is a bonding adhesive suitable for dry debonding.

8. The preparation system according to claim 1, characterized in that, The debonding device includes: A dry debonding machine is used to separate the wafer and the temporary bonding material using dry debonding technology, and temporarily fix the separated wafer onto a flexible film. The dry debonding technology mentioned above can be thermal slip debonding technology, mechanical debonding technology, or laser debonding technology.

9. The preparation system according to claim 1, characterized in that, The sorting device includes: A visual inspection mechanism is used to perform visual inspection on multiple MEMS micromirror chips in the debonded wafer to identify qualified chips and unqualified chips. The sorting execution mechanism is used to automatically sort the qualified chips from the unqualified chips based on the recognition results of the vision inspection mechanism.

10. A method for fabricating a MEMS micromirror, characterized in that, Prepared using the preparation system according to any one of claims 1 to 9, the preparation method comprising: A wafer is provided, the wafer having opposing upper and lower surfaces; The upper surface of the wafer is processed using a processing device to form the mirrors of multiple MEMS micromirror chips and a drive assembly for driving the mirrors to rotate. Provide a temporary bonding material; The wafer and the temporary bonding material are bonded using a bonding device; A processing device is used to process the lower surface of the wafer to form the outer frame, segmentation connectors, and mirror support for a plurality of MEMS micromirror chips. The outer frame is arranged around the mirror and is used to support the driving assembly. The segmentation connectors are located on the outer frame and adjacent MEMS micromirrors are connected by the segmentation connectors. The mirror support is located on the back of the mirror and is used to support the mirror. A debonding device is used to separate the wafer and the temporary bonding material using dry debonding technology; After wafer debonding, a sorting device is used to automatically sort multiple MEMS micromirror chips on the wafer to distinguish between qualified and unqualified chips.

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