Wafer alignment equipment and wafer alignment method

Abstract

The invention relates to the technical field of wafer alignment, in particular to wafer alignment equipment and a wafer alignment method. The wafer alignment equipment comprises a frame, an image acquisition assembly, a Z-direction driving mechanism, a first carrying table and a second carrying table, the first carrying table is connected with the frame through the Z-direction driving mechanism, the Z direction is perpendicular to the bearing face of the first carrying table, and the second carrying table is installed on the frame. The bearing surface of the first carrying table is used for bearing a first wafer, and the bearing surface of the second carrying table is used for bearing a second wafer; the image acquisition assembly is mounted on the frame and is used for acquiring an edge image of the first wafer and an edge image of the second wafer; the first carrying platform and the second carrying platform can form a multi-degree-of-freedom micro-motion structure. The wafer alignment method is applied to the wafer alignment equipment. The wafer alignment equipment and the wafer alignment method provided by the invention are high in efficiency and precision, convenient to control, small in size, light in structure and good in flexibility of whole machine integration.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer alignment, and in particular to a wafer alignment device and a wafer alignment method. Background Art

[0002] At present, all wafer alignment equipment are equipped with an upper and lower unloading platform, and the upper and lower unloading platforms move interactively between the wafer transfer position, the middle position and the alignment position to complete the wafer transfer and alignment.

[0003] Since the wafer transfer position, intermediate position and alignment position are arranged laterally in a direction parallel to the wafer surface, the lateral displacement of the upper and lower unloading stages is large, which easily introduces large repeatability errors and takes a long time, affecting the yield. In addition, it will also cause the wafer alignment equipment to be larger in size, heavier in structure, and less flexible in overall integration. Summary of the invention

[0004] The object of the present invention is to provide a wafer alignment device and a wafer alignment method to alleviate the technical problems of large size, large error and low yield existing in the wafer alignment device in the prior art.

[0005] The wafer alignment device provided by the present invention comprises a frame, an image acquisition component, a Z-direction driving mechanism, and a first carrier and a second carrier that are arranged opposite to each other.

[0006] The first stage is connected to the frame via the Z-direction driving mechanism, and the Z-direction driving mechanism is used to drive the first stage to move along the Z-direction, wherein the Z-direction is perpendicular to the carrying surface of the first stage, and the second stage is mounted on the frame; the carrying surface of the first stage is used to carry the first wafer, and the carrying surface of the second stage is used to carry the second wafer.

[0007] The image acquisition component is installed on the frame, and is used to acquire the edge image of the first wafer and the edge image of the second wafer; the first stage and the second stage can form a multi-degree-of-freedom micro-motion structure, and is used to align the first wafer and the second wafer according to the edge image of the first wafer and the edge image of the second wafer.

[0008] Preferably, as an implementation method, the second stage is located above the first stage, the image acquisition component is located above the second stage, the second stage is provided with a light-transmitting hole, and the image acquisition component can capture edge images of the first wafer and the second wafer through the light-transmitting hole.

[0009] Preferably, as an implementable embodiment, an ejection mechanism is installed at the bottom of the frame, and the first carrier is provided with a first through hole, and the first through hole is used for the ejection mechanism to pass through from bottom to top to receive the first wafer;

[0010] And / or, a vacuum adsorption mechanism is installed on the top of the frame, and the vacuum adsorption mechanism includes a hollow needle for adsorbing the wafer, and the second carrier is provided with a second through hole, and the second through hole is used to pass the hollow needle from top to bottom.

[0011] Preferably, as an implementable embodiment, the Z-direction driving mechanism includes a power mechanism and at least two groups of transmission components, each of the transmission components is arranged at intervals along the circumference of the first carrier and connected to the first carrier, and the power mechanism is connected to the transmission components for driving the first carrier to move along the Z direction through the transmission components.

[0012] Preferably, as an implementable embodiment, the transmission assembly includes a guide rail, a lead screw, a nut and a connecting plate, the guide rail is fixed to the frame, the lead screw is rotatably connected to the frame, and the guide rail and the lead screw are both arranged along the Z direction; the nut cooperates with the lead screw, and the nut is fixedly connected to the connecting plate; the connecting plate slidably cooperates with the guide rail, and the connecting plate is fixedly connected to the first carrier; the power mechanism is connected to the lead screw for driving the lead screw to rotate.

[0013] Preferably, as an implementable embodiment, the power mechanism includes a rotary drive, a driving pulley, a synchronous belt and a plurality of driven pulleys, the rotary output shaft of the rotary drive is coaxially fixedly connected to the driving pulley, and the driving pulley and each of the driven pulleys cooperate with the synchronous belt; the driven pulleys correspond one-to-one to the transmission components, and the driven pulleys are coaxially fixedly connected to the corresponding lead screw in the transmission component.

[0014] Preferably, as an implementable embodiment, the screw is a ball screw, and the nut is a ball nut.

[0015] Preferably, as an implementable embodiment, the image acquisition component includes a plurality of cameras, and the plurality of cameras are arranged at intervals along the edge of the second wafer.

[0016] Preferably, as an implementable embodiment, the first stage includes a first fine-motion stage, and the second stage includes a second fine-motion stage;

[0017] Alternatively, the first stage or the second stage comprises a multi-degree-of-freedom fine-motion stage.

[0018] The present invention also provides a wafer alignment method, which is applied to the wafer alignment device, and the method comprises:

[0019] transferring the first wafer to the first stage;

[0020] Controlling the Z-direction driving mechanism to drive the first stage to move to an alignment position;

[0021] Controlling the image acquisition component to acquire an edge image of the first wafer;

[0022] Controlling the Z-direction driving mechanism to drive the first stage to move to an avoidance position in a direction facing away from the second stage;

[0023] transferring the second wafer to the second stage;

[0024] Controlling the Z-direction driving mechanism to drive the first stage to move to the alignment position;

[0025] Controlling the image acquisition component to acquire an edge image of the second wafer;

[0026] Analyzing and obtaining a spatial deviation between the first wafer and the second wafer according to the edge image of the first wafer and the edge image of the second wafer;

[0027] According to the spatial deviation between the first wafer and the second wafer, the first stage and the second stage are controlled to perform multi-degree-of-freedom adjustment to align the first wafer with the second wafer.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] When two wafers (a first wafer and a second wafer) need to be aligned, the first wafer can be first transferred to the first stage, and then the Z-axis driving mechanism is controlled to drive the first stage to move to the alignment position along the Z direction, and the image acquisition component is controlled to acquire an edge image of the first wafer; after completing the acquisition of the edge image of the first wafer, the Z-axis driving mechanism is controlled to drive the first stage to move to an avoidance position in a direction facing away from the second stage to avoid the second wafer; the second wafer is transferred to the second stage, and when the second stage is in the corresponding alignment position, the image acquisition component is controlled to acquire an edge image of the second wafer; after completing the acquisition of the edge image of the second wafer, the first stage and the second stage are controlled to work together to adjust the relative position of the first wafer and the second wafer to align the first wafer with the second wafer.

[0030] It should be noted that when the wafer alignment device provided by the present invention aligns the wafer, it only needs the first carrier to perform a small stroke displacement along the Z direction to avoid the second wafer. On the one hand, it can shorten the process time, reduce the difficulty of controlling the moving parts, and reduce the repeatability error introduced by large-stroke movement; on the other hand, it can reduce the size of the equipment and make the wafer alignment equipment the same size as other process units, so as to more flexibly adjust the overall layout and unit quantity configuration.

[0031] Therefore, the wafer alignment device provided by the present invention has high efficiency and precision, is easy to control, has a small size, a light structure, and has better flexibility in overall machine integration.

[0032] The wafer alignment method provided by the present invention has all the advantages of the above-mentioned wafer alignment device because it is applied to the above-mentioned wafer alignment device, and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0034] Figure 1 A schematic structural diagram of a wafer alignment device provided by an embodiment of the present invention;

[0035] Figure 2 A schematic flow chart of a wafer alignment method provided in an embodiment of the present invention.

[0036] Description of reference numerals:

[0037] 110-lower mounting plate; 120-upper mounting plate; 130-column;

[0038] 210-motor; 220-driven pulley; 230-guide rail; 240-screw;

[0039] 310-first fine-motion stage; 320-first carrier plate; 330-fixed stage;

[0040] 410 - second micro-motion stage; 420 - second carrier plate;

[0041] 500- ejector mechanism;

[0042] 600-vacuum adsorption mechanism; 610-hollow needle;

[0043] 710-camera; 720-short cantilever. DETAILED DESCRIPTION

[0044] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0045] The present invention is further described in detail below through specific implementation examples in conjunction with the accompanying drawings.

[0046] See also Figure 1The present embodiment provides a wafer alignment device, which includes a frame, an image acquisition component, a Z-direction drive mechanism, and a first stage and a second stage arranged opposite to each other; the first stage is connected to the frame through the Z-direction drive mechanism, the Z-direction drive mechanism is used to drive the first stage to move along the Z-direction, the Z-direction is perpendicular to the bearing surface of the first stage, and the second stage is installed on the frame; the bearing surface of the first stage is used to bear the first wafer, and the bearing surface of the second stage is used to bear the second wafer; the image acquisition component is installed on the frame, and is used to acquire an edge image of the first wafer and an edge image of the second wafer; the first stage and the second stage can form a multi-degree-of-freedom micro-motion structure, and is used to align the first wafer and the second wafer according to the edge image of the first wafer and the edge image of the second wafer.

[0047] When two wafers (a first wafer and a second wafer) need to be aligned, the first wafer can be first transferred to the first stage, and then the Z-axis driving mechanism is controlled to drive the first stage to move to the alignment position along the Z direction, and the image acquisition component is controlled to acquire an edge image of the first wafer; after completing the acquisition of the edge image of the first wafer, the Z-axis driving mechanism is controlled to drive the first stage to move to an avoidance position in a direction facing away from the second stage to avoid the second wafer; the second wafer is transferred to the second stage, and when the second stage is in the corresponding alignment position, the image acquisition component is controlled to acquire an edge image of the second wafer; after completing the acquisition of the edge image of the second wafer, the first stage and the second stage are controlled to work together to adjust the relative position of the first wafer and the second wafer to align the first wafer with the second wafer.

[0048] It should be noted that when the wafer alignment equipment provided in this embodiment aligns the wafer, it only needs the first carrier to perform a small stroke displacement along the Z direction to avoid the second wafer. On the one hand, it can shorten the process time, reduce the difficulty of controlling the moving parts, and reduce the repeatability error introduced by large-stroke movement; on the other hand, it can reduce the size of the equipment and make the wafer alignment equipment the same size as other process units, so as to more flexibly adjust the overall layout and unit quantity configuration.

[0049] Therefore, the wafer alignment equipment provided in this embodiment has high efficiency and precision, is easy to control, and has a small size, a light structure, and better flexibility in overall machine integration.

[0050] Specifically, the second stage is arranged above the first stage so that the two stages are arranged relative to each other up and down; the image acquisition component is arranged above the second stage, and a light-transmitting hole is opened on the second stage so that the image acquisition component can acquire the edge image of the first wafer and the edge image of the second wafer through the light-transmitting hole. It should be noted that in the related art, a wafer alignment device using a C-arm is used, and upper and lower cameras are respectively fixed at the upper and lower ends of the C-arm, and the upper and lower cameras are used to respectively shoot the edge image of the upper wafer and the edge image of the lower wafer. The C-arm cantilever is relatively long, resulting in poor stability, high control requirements, and easy introduction of measurement errors; in the related art, a wafer alignment device using a beam structure is used, and a camera is fixed on the beam structure, and the camera is used to shoot and measure the edge image of the upper wafer and the edge image of the lower wafer respectively. The beam is made of marble, and the mass is too large, which causes the center of gravity of the equipment to be raised, and it is easy to introduce shaking problems. In this embodiment, the image acquisition component is arranged on the same side (above) of the first platform and the second platform. There is no need to set up a C-arm and a beam structure. The image acquisition component can be fixed with a short cantilever 720. Therefore, the stability is higher, the control requirements are lower, and the measurement error is smaller. In addition, the center of gravity of the equipment is lower and it is not easy to shake.

[0051] Furthermore, an ejection mechanism 500 can be installed at the bottom of the frame, and a first through hole can be correspondingly opened on the first stage. When the first stage descends, the ejection mechanism 500 can be ejected from bottom to top through the first through hole to receive the first wafer. After the first stage rises and resets, the first wafer received by the ejection mechanism 500 can be lifted by the bearing surface of the first stage. In this way, the first wafer can be stably placed on the bearing surface of the first stage, reducing the risk of damage to the first wafer. Specifically, the first stage includes a first carrier 320, the top surface of the first carrier 320 is the bearing surface, and the first through hole is opened in the first carrier 320.

[0052] A vacuum adsorption mechanism 600 can be installed on the top of the frame. The vacuum adsorption mechanism 600 has a hollow needle 610 (hollow PIN) for adsorbing the second wafer. A second through hole is correspondingly opened on the second carrier, so that the hollow needle 610 of the vacuum adsorption mechanism 600 can pass through the second through hole from top to bottom and adsorb the second wafer, so that the second wafer can be stably maintained on the bearing surface of the second carrier under the adsorption force of the hollow needle 610. It should be noted that the second wafer is adsorbed on the bearing surface of the second carrier by vacuum adsorption, which has a better fixing effect and can reduce the risk of damage to the second wafer. Specifically, the second carrier includes a second carrier 420, the bottom surface of the second carrier 420 is the bearing surface, and the second through hole is opened in the second carrier 420.

[0053] In the specific structure of the Z-direction driving mechanism, a power mechanism and at least two groups of transmission components can be provided, and each transmission component is arranged at intervals along the circumference of the first carrier, and each transmission component is connected to the first carrier, and the power mechanism is connected to the transmission component, so that the power mechanism can transmit power to the first carrier through the transmission component to drive the first carrier to move along the Z direction, and it is provided in at least two groups and arranged at intervals along the circumference of the first carrier, so that the force balance of the first carrier can be improved, so that the first carrier is not easy to be skewed; wherein, the transmission component can also serve as a supporting structure of the first carrier. Preferably, the transmission component is provided in more than three groups for easy implementation.

[0054] The above-mentioned transmission assembly may specifically include a guide rail 230, a lead screw 240, a nut and a connecting plate. The guide rail 230 is fixed to the frame and arranged along the Z direction. The connecting plate is slidably matched with the guide rail 230 and the connecting plate is fixedly connected to the first carrier. Thus, the guide rail 230 can guide the first carrier through the connecting plate, so that the first carrier can move smoothly along the Z direction, thereby improving the position accuracy of the first carrier; the lead screw 240 is rotatably connected to the frame and arranged along the Z direction. The nut is matched with the lead screw 240 and the nut is fixedly connected to the connecting plate. The power mechanism is connected to the lead screw 240 so as to utilize the power mechanism to drive the lead screw 240 to rotate. Under the combined action of the first carrier, the guide rail 230 and the connecting plate, the lead screw 240 can drive the nut to move along the Z direction, thereby driving the first carrier to move along the Z direction.

[0055] The above-mentioned power mechanism may specifically include a rotary driver, a driving pulley, a synchronous belt and a plurality of driven pulleys 220. The rotary output shaft of the rotary driver is coaxially fixedly connected with the driving pulley so as to use the rotary driver to drive the driving pulley to rotate; the driving pulley and each driven pulley are matched with a synchronous belt so as to use the synchronous belt to drive each driven pulley 220 to rotate; the driven pulley 220 is arranged one by one with the transmission assembly, and the driven pulley 220 is coaxially fixedly connected with the lead screw 240 in the corresponding transmission assembly so as to use the driven pulley 220 to drive each transmission assembly to operate, thereby realizing the driving of the first carrier. It should be noted that under the action of the driving pulley, the driven pulley 220 and the synchronous belt, a single rotary driver can drive each transmission assembly, which is conducive to reducing costs, improving structural compactness and reducing volume.

[0056] Furthermore, the rotary drive may be installed in the frame to fully utilize the space and improve the compactness of the structure.

[0057] The motor 210 may be used as the above-mentioned rotation driver.

[0058] The lead screw 240 is preferably configured as a ball screw and the nut is configured as a ball nut, which can reduce friction and obtain higher transmission efficiency and accuracy, so that the first carrier can be moved to the target position quickly and accurately.

[0059] In the specific structure of the above-mentioned image acquisition component, multiple cameras 710 can be set, and the multiple cameras 710 are arranged at intervals along the edge of the second wafer to take pictures of different parts of the edge of the first wafer and different parts of the edge of the second wafer, so as to obtain images of different parts of the edges of the two wafers, improve the accuracy of judging the spatial position of the wafer, and further improve the wafer alignment effect. Among them, the number and layout of the cameras 710 can be flexibly adjusted.

[0060] Preferably, multiple cameras 710 can be evenly arranged to further improve the accuracy of determining the spatial position of the wafer. Specifically, four cameras 710 can be set to obtain better accuracy of determining the spatial position of the wafer. Among them, the camera 710 can be a visible light camera or an infrared camera.

[0061] As an implementable embodiment, a first micro-motion stage 310 may be provided in the specific structure of the first carrier, and a second micro-motion stage 410 may be provided in the specific structure of the second carrier, and the first micro-motion stage 310 and the second micro-motion stage 410 constitute the above-mentioned multi-degree-of-freedom micro-motion structure, and the first micro-motion stage 310 is used to realize micro-motion of the first wafer, and the second micro-motion stage 410 is used to realize micro-motion of the second wafer, so that the two wafers are aligned. Specifically, the degree of freedom of one of the micro-motion stages (specifically, the first micro-motion stage 310) may include the z-direction translational degree of freedom, and the degree of freedom of the other micro-motion stage (specifically, the second micro-motion stage 410) may include the x-direction translational degree of freedom, the y-direction translational degree of freedom, and the θz rotational degree of freedom. The first carrier may also include a fixed platform 330, and the first micro-motion stage 310 is mounted on the fixed platform 330, and the fixed platform 330 is fixedly connected to the connecting plate.

[0062] As another possible implementation method, a multi-degree-of-freedom fine-motion stage may be provided in the specific structure of one of the carriers (the first carrier or the second carrier), and the multi-degree-of-freedom fine-motion of the wafers carried by the fine-motion stage may be achieved by using the fine-motion stage to align the two wafers.

[0063] It can be equipped with a large-stroke coarse motion structure as needed.

[0064] The above-mentioned frame may specifically include an upper mounting plate 120, a lower mounting plate 110 and a column 130, wherein the upper mounting plate 120 and the lower mounting plate 110 are arranged opposite to each other up and down, and the column 130 is connected between the upper mounting plate 120 and the lower mounting plate 110. The guide rail 230 is arranged vertically, and its two ends are respectively connected to the upper mounting plate 120 and the lower mounting plate 110. The lead screw 240 is arranged vertically, and its two ends are respectively rotatably connected to the upper mounting plate 120 and the lower mounting plate 110. The second carrier is inverted below the upper mounting plate 120. The image acquisition assembly is installed above the upper mounting plate 120. The motor 210 is installed above the lower mounting plate 110.

[0065] Figure 2 is a schematic flow chart of a wafer alignment method provided in this embodiment, the method comprising:

[0066] Step S102, transferring the first wafer to the first stage;

[0067] Step S104, controlling the Z-axis driving mechanism to drive the first stage to move to the alignment position;

[0068] Step S106, controlling the image acquisition component to acquire an edge image of the first wafer;

[0069] Specifically, each camera in the image acquisition component simultaneously photographs the edge of the first wafer.

[0070] Step S108, controlling the Z-axis driving mechanism to drive the first stage to move in a direction away from the second stage to an avoidance position;

[0071] Step S110, transferring the second wafer to the second stage;

[0072] Step S112, controlling the Z-axis driving mechanism to drive the first stage to move to the alignment position;

[0073] Step S114, controlling the image acquisition component to acquire an edge image of the second wafer;

[0074] Specifically, each camera in the image acquisition component simultaneously photographs the edge of the second wafer.

[0075] Step S116, analyzing and obtaining a spatial deviation between the first wafer and the second wafer according to the edge image of the first wafer and the edge image of the second wafer;

[0076] Step S118, controlling the first stage and the second stage to perform multi-degree-of-freedom adjustment according to the spatial deviation between the first wafer and the second wafer, so as to align the first wafer with the second wafer.

[0077] The wafer alignment method provided in this embodiment has all the advantages of the above-mentioned wafer alignment device because it is applied to the above-mentioned wafer alignment device, and has high efficiency and precision and is easy to control.

[0078] Specifically, the first stage can be controlled to complete position adjustment of z-axis translation; and the second stage can be controlled to complete x-axis translation, y-axis translation, and posture adjustment of rotation around the z-axis.

[0079] In the description of the present invention, it should be noted that the terms "upper", "lower", "vertical", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0080] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0081] Of course, those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing the control device through a computer, and the program can be stored in a computer-readable storage medium. When the program is executed, it may include the processes of the above-mentioned method embodiments, wherein the storage medium may be a memory, a disk, an optical disk, etc.

[0082] Although the present invention is disclosed as above, the present invention is not limited thereto. Any person skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the scope defined by the claims.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A wafer alignment device, characterized in that: It includes a frame, an image acquisition component, a Z-direction driving mechanism, and a first carrier and a second carrier that are arranged opposite to each other; The first stage is connected to the frame via the Z-direction driving mechanism, the Z-direction driving mechanism is used to drive the first stage to move along the Z-direction, the Z-direction is perpendicular to the bearing surface of the first stage, and the second stage is mounted on the frame; the bearing surface of the first stage is used to bear the first wafer, and the bearing surface of the second stage is used to bear the second wafer; The image acquisition component is installed on the frame, and is used to acquire the edge image of the first wafer and the edge image of the second wafer; the first stage and the second stage can form a multi-degree-of-freedom micro-motion structure, and is used to align the first wafer and the second wafer according to the edge image of the first wafer and the edge image of the second wafer.

2. The wafer alignment device according to claim 1, characterized in that: The second stage is located above the first stage, the image acquisition component is located above the second stage, the second stage is provided with a light-transmitting hole, and the image acquisition component can acquire edge images of the first wafer and the second wafer through the light-transmitting hole.

3. The wafer alignment device according to claim 2, characterized in that: An ejection mechanism (500) is installed at the bottom of the frame, and the first carrier is provided with a first through hole, the first through hole being used for the ejection mechanism (500) to pass through from bottom to top to receive the first wafer; And / or, a vacuum adsorption mechanism (600) is installed on the top of the frame, and the vacuum adsorption mechanism (600) includes a hollow needle (610) for adsorbing the wafer, and the second carrier is provided with a second through hole, and the second through hole is used to pass the hollow needle (610) from top to bottom.

4. The wafer alignment device according to claim 1, characterized in that: The Z-direction driving mechanism includes a power mechanism and at least two groups of transmission components, each of which is arranged at intervals along the circumference of the first carrier and connected to the first carrier. The power mechanism is connected to the transmission components and is used to drive the first carrier to move along the Z direction through the transmission components.

5. The wafer alignment device according to claim 4, characterized in that: The transmission assembly comprises a guide rail (230), a lead screw (240), a nut and a connecting plate; the guide rail (230) is fixed to the frame; the lead screw (240) is rotatably connected to the frame; the guide rail (230) and the lead screw (240) are both arranged along the Z direction; the nut cooperates with the lead screw (240), and the nut is fixedly connected to the connecting plate; the connecting plate is slidably cooperated with the guide rail (230), and the connecting plate is fixedly connected to the first carrier; the power mechanism is connected to the lead screw (240) and is used to drive the lead screw (240) to rotate.

6. The wafer alignment device according to claim 5, characterized in that: The power mechanism comprises a rotary drive, a driving pulley, a synchronous belt and a plurality of driven pulleys (220); the rotary output shaft of the rotary drive is coaxially fixedly connected to the driving pulley, and the driving pulley and each of the driven pulleys (220) cooperate with the synchronous belt; the driven pulleys (220) correspond to the transmission components one by one, and the driven pulleys (220) are coaxially fixedly connected to the lead screw (240) in the corresponding transmission component.

7. The wafer alignment device according to claim 5, characterized in that: The lead screw (240) is a ball screw, and the nut is a ball nut.

8. The wafer alignment device according to claim 1, characterized in that: The image acquisition component comprises a plurality of cameras (710), and the plurality of cameras (710) are arranged at intervals along the edge of the second wafer.

9. The wafer alignment device according to any one of claims 1 to 8, characterized in that: The first carrier includes a first fine-motion platform (310), and the second carrier includes a second fine-motion platform (410); Alternatively, the first stage or the second stage comprises a multi-degree-of-freedom fine-motion stage.

10. A wafer alignment method, characterized in that: Applied to the wafer alignment device according to any one of claims 1 to 9, the method comprising: transferring the first wafer to the first stage; Controlling the Z-direction driving mechanism to drive the first stage to move to an alignment position; Controlling the image acquisition component to acquire an edge image of the first wafer; Controlling the Z-direction driving mechanism to drive the first stage to move to an avoidance position in a direction facing away from the second stage; transferring the second wafer to the second stage; Controlling the Z-direction driving mechanism to drive the first stage to move to the alignment position; Controlling the image acquisition component to acquire an edge image of the second wafer; Analyzing and obtaining a spatial deviation between the first wafer and the second wafer according to the edge image of the first wafer and the edge image of the second wafer; According to the spatial deviation between the first wafer and the second wafer, the first stage and the second stage are controlled to perform multi-degree-of-freedom adjustment to align the first wafer with the second wafer.

Images