Wafer bonding device and wafer bonding method

Abstract

The invention provides a wafer bonding device and a wafer bonding method, and relates to the technical field of semiconductor processing. The wafer bonding device comprises a carrying seat, a driving structure arranged on the carrying seat, and a target chuck and a bearing chuck which are arranged along the Z direction, at least one of the target chuck and the bearing chuck is in transmission connection with the driving structure, and the driving structure is configured to be capable of driving the target chuck and the bearing chuck to relatively move along the X-Y direction and the Z direction; a plurality of notches are formed in the edge of the target chuck; the carrying base is provided with a plurality of visual systems, the visual systems are located on the side, away from the bearing chuck, of the target chuck, the axial direction of the visual systems is consistent with the Z direction, the visual systems correspond to the notches one to one, and the visual systems are configured to shoot images, corresponding to the notches, of the wafers loaded on the target chuck and the bearing chuck. The wafer bonding device is good in wafer bonding quality, high in yield, small in size and small in occupied space.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor processing technology, and in particular to a wafer bonding device and a wafer bonding method. Background Art

[0002] Wafer bonding technology is to tightly combine two wafers with clean surfaces into a whole under the action of external force. Among them, the alignment accuracy of the wafer is an important characterization parameter of the bonding technology.

[0003] In the wafer bonding device of the related technology, a C-shaped arm is generally used and a visual system is arranged at its upper and lower ends to realize the shooting of the upper and lower wafers. Three process positions, namely the wafer transfer position, the middle position and the alignment position, are arranged in the horizontal direction. When in use, the upper chuck and the lower chuck are driven by the driving structure to move between the three process positions, and the C-shaped arm is driven to move laterally to cooperate to complete the alignment operation of the upper and lower wafers; wherein, the displacement of the C-shaped arm and the driving structure is large, which will not only introduce measurement errors, resulting in poor alignment accuracy, and correspondingly poor wafer bonding quality; it also leads to a long interaction time of each process and a high time consumption, resulting in low bonding efficiency and yield of the wafer bonding device; at the same time, the wafer bonding device requires three process positions in the horizontal direction, with a complex structure, a large volume, and a large occupation of space. Summary of the invention

[0004] The object of the present invention is to provide a wafer bonding device and a wafer bonding method to solve the technical problems in the related art that the wafer bonding device has poor wafer bonding quality, low yield, large size and large occupied space.

[0005] In order to solve the above problems, the present invention provides a wafer bonding device, comprising a carrier, a driving structure provided on the carrier, and a target chuck and a carrier chuck arranged along the Z direction, wherein the target chuck and / or the carrier chuck are connected to the driving structure by transmission, and the driving structure is configured to: be able to drive the target chuck and the carrier chuck to move relative to each other along the XY direction and the Z direction;

[0006] The edge of the target chuck is provided with multiple notches; the carrier is provided with multiple visual systems, and the multiple visual systems are located on the side of the target chuck away from the carrier chuck. The axial directions of the multiple visual systems are consistent with the Z direction and correspond one-to-one to the multiple notches, and are configured to capture images of the wafers loaded on the target chuck and the carrier chuck corresponding to the notches.

[0007] Optionally, the target chuck has an X-direction translational freedom and a Y-direction translational freedom under the drive of the drive structure.

[0008] Optionally, one of the notches corresponds to a notch position of a wafer loaded on the target chuck, and the driving structure is configured to drive the target chuck and the carrier chuck to rotate relative to each other around a Z axis.

[0009] Optionally, one of the chucks is used as a lifting chuck, and the lifting chuck has a Z-direction translational freedom when driven by the driving structure; and the ejector pin structure corresponding to the lifting chuck is relatively fixedly connected to the carrier.

[0010] Optionally, the driving structure comprises a hexapod, a fixed end of the hexapod is fixedly connected to the carrier, and a movable end of the hexapod is connected to one of the chucks.

[0011] The present invention also provides a wafer bonding method, using the above-mentioned wafer bonding device, the wafer bonding method comprises:

[0012] Determine the film transmission order of the target chuck and the carrier chuck according to the X-direction translational freedom and the Y-direction translational freedom of the target chuck;

[0013] Transferring a first wafer to a chuck that is at the front of the determined wafer transfer sequence, and capturing a first image of the first wafer at a bonding position;

[0014] Transferring the second wafer to the chuck that is later in the determined wafer transfer sequence, adjusting the first wafer to avoid the shooting path in the XY directions, and capturing a second image of the second wafer at the bonding position;

[0015] Acquire the center offset of the first wafer and the second wafer in the XY direction according to the first image and the second image;

[0016] Adjusting and aligning the target chuck and the carrier chuck located at the bonding position according to the circle center offset;

[0017] The first wafer and the second wafer are bonded together.

[0018] Optionally, the step of determining the film transmission order of the target chuck and the carrier chuck according to the X-direction translational freedom and the Y-direction translational freedom of the target chuck comprises:

[0019] Determining whether the target chuck has an X-direction translational degree of freedom and / or a Y-direction translational degree of freedom;

[0020] If yes, then determine that the transmission sequence of the target chuck is before the transmission sequence of the carrier chuck, or determine that the transmission sequence of the carrier chuck is before the transmission sequence of the target chuck;

[0021] If not, it is determined that the film transmission sequence of the carrier chuck is before the film transmission sequence of the target chuck.

[0022] Optionally, when the wafer transmission sequence of the target chuck is before the wafer transmission sequence of the carrier chuck, the step of adjusting the first wafer to avoid the shooting path in the XY direction includes: driving the target chuck and the carrier chuck to move relative to each other along the XY direction, so that the first wafer moves to a position avoiding the shooting path;

[0023] When the film transmission sequence of the carrier chuck is before the film transmission sequence of the target chuck, the step of adjusting the first wafer to avoid the shooting path in the XY direction includes: keeping the carrier chuck fixed in the XY direction so that the first wafer avoids the shooting path in the XY direction.

[0024] Optionally, the step of capturing a first image of the first wafer at the bonding position includes:

[0025] Determining whether the chuck loaded with the first wafer has a Z-direction translational freedom;

[0026] If yes, driving the chuck to move up and down along the Z direction to a bonding position, and taking a first image of the first wafer;

[0027] If not, directly capture the first image of the first wafer.

[0028] Optionally, the wafer bonding method further includes:

[0029] Acquire deflection amounts of the first wafer and the second wafer around the Z axis according to the first image and the second image;

[0030] The target chuck and the carrier chuck located at the bonding position are aligned according to the deflection amount; and then the step of bonding the first wafer and the second wafer is performed.

[0031] In the wafer bonding device and wafer bonding method provided by the present invention, multiple visual systems are arranged on one side of the target chuck. During operation, the visual system does not need to be displaced. In the XY direction, the target chuck and the carrier chuck do not need to be displaced or only need to be moved laterally with a small stroke under the drive of the driving structure to avoid the gap at the edge of the target chuck. In the Z direction, the target chuck and the carrier chuck only need to be moved up and down with a small stroke under the drive of the driving structure to reach the bonding position or the avoidance position. It can be seen that during operation, the displacement of the visual system and the driving component is small, and the error introduced is small. The smaller the displacement of the visual system, the target chuck and the carrier chuck, the smaller the displacement of the visual system, the target chuck and the carrier chuck, and the smaller the displacement of the visual system, the target chuck and the carrier chuck, and the smaller the displacement of the visual system, the target chuck and the carrier chuck, and the smaller the displacement of the visual system, the target chuck and the carrier chuck, and the smaller the displacement of the visual system, the smaller the displacement of ... BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 An axonometric diagram of a wafer bonding device provided by an embodiment of the present invention;

[0034] Figure 2 A longitudinal cross-sectional view of a wafer bonding device provided by an embodiment of the present invention;

[0035] Figure 3 for Figure 1 Axonometric view of the wafer bonding device with the carrier chuck and upper ejector structure removed;

[0036] Figure 4 for Figure 1 A top view of the wafer bonding device with the carrier chuck and upper ejector pin structure removed;

[0037] Figure 5 A first schematic diagram of a wafer bonding method provided by an embodiment of the present invention;

[0038] Figure 6 A second schematic diagram of a wafer bonding method provided by an embodiment of the present invention;

[0039] Figure 7A third flow chart of the wafer bonding method provided in an embodiment of the present invention.

[0040] Description of reference numerals:

[0041] 100-carrier; 200-driving structure; 300-target chuck; 310-notch; 400-carrying chuck; 40A-through hole; 500-visual system; 510-focusing assembly; 520-camera assembly; 600-base; 700-vibration isolation assembly; 810-upper ejector structure; 820-lifting component; 900-lower ejector structure. DETAILED DESCRIPTION

[0042] 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.

[0043] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the 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 limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0044] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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 it can be indirectly connected 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.

[0045] This embodiment provides a wafer bonding device, such as Figure 1-Figure 4As shown, it includes a carrier 100, a driving structure 200 arranged on the carrier 100, and a target chuck 300 and a carrier chuck 400 arranged along the Z direction, at least one of the target chuck 300 and the carrier chuck 400 is transmission-connected to the driving structure 200, and the driving structure 200 is configured to: be able to drive the target chuck 300 and the carrier chuck 400 to move relative to each other along the XY direction and the Z direction; the edge of the target chuck 300 is provided with a plurality of notches 310; the carrier 100 is provided with a plurality of visual systems 500, the plurality of visual systems 500 are located on a side of the target chuck 300 away from the carrier chuck 400, the axial directions of the plurality of visual systems 500 are consistent with the Z direction and correspond one-to-one to the plurality of notches 310, and are configured to: capture images of the wafers loaded on the target chuck 300 and the carrier chuck 400 corresponding to the notches 310.

[0046] In the wafer bonding device provided in this embodiment, one of the target chuck 300 and the carrier chuck 400 serves as an upper chuck, and the other serves as a lower chuck, and the two are arranged at intervals along the Z direction, and the two can perform relative translational movement along the XY directions and relative lifting movement along the Z direction under the drive of the driving structure 200. Specifically, the target chuck 300 and the carrier chuck 400 can both be connected to the driving structure 200; or, the target chuck 300 is connected to the driving structure 200, and the carrier chuck 400 is fixed on the carrier 100; or, the target chuck 300 is fixed on the carrier 100, and the carrier chuck 400 is transmission-connected to the driving structure 200.

[0047] The chuck adjacent to the vision system 500 serves as the target chuck 300, the number of the vision systems 500 is at least three, and the multiple vision systems 500 are arranged at intervals along the circumference of the target chuck 300. Preferably, the multiple vision systems 500 are arranged at even intervals along the circumference of the target chuck 300. When in use, the shooting area of ​​the vision system 500 includes the extension area of ​​the corresponding notch 310 along the Z direction. When the wafer is loaded on the target chuck 300 or the carrier chuck 400, the edge area corresponding to the wafer and the notch 310 is located in the shooting area of ​​the vision system 500. When there is no obstruction between the target chuck 300 and the carrier chuck 400 and the vision system 500, the vision system 500 can capture the image of the edge area of ​​the wafer at the corresponding notch 310.

[0048] With respect to the wafer bonding device, this embodiment further provides a wafer bonding method. Figure 5 The first process diagram of the wafer bonding method provided by the embodiment of the present invention is shown in FIG. Figure 5 As shown, the wafer bonding method includes the following steps:

[0049] S502 determines the film transfer sequence of the target chuck 300 and the carrier chuck 400 according to the X-direction translational freedom and the Y-direction translational freedom of the target chuck 300 .

[0050] Along the Z direction, the target chuck 300 is located between multiple vision systems 500 and the carrier chuck 400, and the target chuck 300 and the carrier chuck 400 are approximately coaxially arranged along the Z direction. When the target chuck 300 transfers the film before the carrier chuck 400, the wafer loaded on the target chuck 300 will block the gap 310 and affect the vision system 500 to shoot the edge area of ​​the wafer loaded on the carrier chuck 400 through the gap 310. Therefore, according to whether the target chuck 300 has one of the X-direction translational freedom and the Y-direction translational freedom, it is determined whether the target chuck 300 can move translationally after the wafer is loaded in front to avoid blocking the vision system 500, and the film transfer order of the target chuck 300 and the carrier chuck 400 is set accordingly to ensure that the vision system 500 shoots the edge area of ​​the wafer loaded on the target chuck 300 and the carrier chuck 400. Specifically, under this condition, the target chuck 300 may have only the X-direction translational freedom, only the Y-direction translational freedom, both the X-direction translational freedom and the Y-direction translational freedom, or neither the X-direction translational freedom nor the Y-direction translational freedom.

[0051] S504: Transfer the first wafer to the chuck with the first wafer transfer sequence determined, and capture a first image of the first wafer at the bonding position.

[0052] The wafer that is transferred first is taken as the first wafer. After the chuck at the front in the transfer sequence receives the first wafer, it can remain in place or move along the Z direction under the drive of the driving structure 200 to reach the bonding position. At this time, the notch 310 is not blocked. After focusing, multiple visual systems 500 take images of the first wafer in the corresponding edge areas of each notch 310 as the first image.

[0053] S506: Transfer the second wafer to the chuck with the determined wafer transfer sequence at the rear, adjust the first wafer in the XY direction to avoid the shooting path, and shoot a second image of the second wafer at the bonding position.

[0054] The wafer transferred later is used as the second wafer. The chuck with the earlier wafer transfer sequence can be kept in the bonding position as needed or moved away from the chuck with the later wafer transfer sequence to the avoidance position under the drive of the driving structure 200 to ensure smooth wafer transfer from the robot to the chuck with the later wafer transfer sequence. After receiving the second wafer, the chuck with the later wafer transfer sequence can remain in place or move along the Z direction under the drive of the driving structure 200 to reach the bonding position. When the target chuck 300 is at the later wafer transfer sequence, the visual system 500 is not blocked when photographing the second wafer. The target chuck 300 and the carrier chuck 400 remain in place in the XY direction so that the visual system 500 can capture the second image; when the carrier chuck 400 is in the latter film transfer order, the first wafer loaded on the target chuck 300 will block the notch 310, and the target chuck 300 is driven by the driving component to translate in the XY direction so that the first wafer no longer blocks the shooting area of ​​the visual system 500; after focusing, multiple visual systems 500 capture images of the corresponding edge areas of the second wafer as the second image.

[0055] S508 obtains the center offset of the first wafer and the second wafer in the XY direction according to the first image and the second image.

[0056] Each first image has an outline of an edge area of ​​the first wafer at different circumferential positions, and the first center coordinates of the first wafer can be calculated based on the outline; similarly, each second image has an outline of an edge area of ​​the second wafer at different circumferential positions, and the second center coordinates of the second wafer can be calculated based on the outline, and the center offset of the first wafer and the second wafer in the XY plane can be calculated based on the first center coordinates and the second center coordinates.

[0057] S510: aligning the target chuck 300 and the carrier chuck 400 located at the bonding position according to the center offset.

[0058] S512 performs a bonding process on the first wafer and the second wafer.

[0059] The first wafer and the second wafer are both located at their respective bonding positions. According to the calculated center offset, the driving structure 200 is controlled to drive the target chuck 300 and the carrier chuck 400 to move relative to each other along the XY direction to perform deviation compensation of the corresponding displacement, thereby realizing the translation alignment operation of the first wafer and the second wafer; then the first wafer and the second wafer are bonded to obtain a bonded wafer.

[0060] In the wafer bonding device and wafer bonding method provided in the present embodiment, by setting a plurality of visual systems 500 on one side of the target chuck 300, during operation, the visual system 500 does not need to be displaced, and in the XY direction, the target chuck 300 and the carrier chuck 400 do not need to be displaced or only need to perform a small stroke lateral movement under the drive of the driving structure 200 to avoid the notch 310 located at the edge of the target chuck 300; in the Z direction, the target chuck 300 and the carrier chuck 400 only need to perform a small stroke lifting movement under the drive of the driving structure 200 to reach the bonding position or the avoidance position; it can be seen that during operation, the visual system 500, The displacement of the driving component is small, and the error introduced is small, thereby improving the accuracy of the measured center offset, and correspondingly improving the alignment accuracy and bonding quality of the first bonded wafer and the second bonded wafer; at the same time, it can also reduce the interaction time of the operation process, can reduce the time consumption during the operation process, and improve the bonding efficiency and yield; in addition, the displacement of the visual system 500, the target chuck 300 and the carrier chuck 400 is small, and only one bonding position and one process position are required in the XY direction, and the structural simplicity of the wafer bonding device can be improved, the volume of the wafer bonding device and its space occupancy can be reduced, and the integration flexibility of the wafer bonding device can be improved.

[0061] Specifically, in the wafer bonding device provided in this embodiment, the Z-axis displacement of the target chuck 300 and the carrier chuck 400 by the driving structure 200 is approximately 20 mm, and the lateral displacement is larger than the radial dimension of the notch 310 along the corresponding chuck. Both the lateral displacement and the longitudinal displacement are much smaller than the large stroke displacement of approximately 500 mm between the three process positions in the related technology.

[0062] Specifically, in this embodiment, step S502 determines the film transmission order of the target chuck 300 and the carrier chuck 400 according to the X-direction translational freedom and the Y-direction translational freedom of the target chuck 300, including: judging whether the target chuck 300 has the X-direction translational freedom and / or the Y-direction translational freedom; if so, determining that the film transmission order of the target chuck 300 is before the film transmission order of the carrier chuck 400, or determining that the film transmission order of the carrier chuck 400 is before the film transmission order of the target chuck 300; if not, determining that the film transmission order of the carrier chuck 400 is before the film transmission order of the target chuck 300.

[0063] When the target chuck 300 does not have the X-axis translational freedom and the Y-axis translational freedom, it indicates that the target chuck 300 is relatively fixedly connected to the carrier 100. If the target chuck 300 is loaded with a wafer before the carrier chuck 400, the wafer loaded on the target chuck 300 will block the notch 310 and affect the visual system 500's shooting of the edge area of ​​the wafer loaded on the carrier chuck 400 through the notch 310. Therefore, under this condition, it is necessary to limit the film transmission sequence of the target chuck 300 to be after the film transmission sequence of the carrier chuck 400 to ensure that the visual system 500 can shoot the wafers loaded on the target chuck 300 and the carrier chuck 400.

[0064] When the target chuck 300 has at least one of the X-direction translational freedom and the Y-direction translational freedom under the drive of the driving structure 200, it is characterized that the target chuck 300 can perform translational movement relative to the visual system 500 under the drive of the driving structure 200 to avoid the shooting area of ​​the visual system 500, thereby solving the problem of the wafer loaded on the target chuck 300 blocking the notch 310. Under this condition, the order of transferring the wafers to the target chuck 300 and the carrier chuck 400 is not restricted, and the wafer transfer order of the target chuck 300 can be prior to the wafer transfer order of the carrier chuck 400, and the wafer transfer order of the carrier chuck 400 can also be prior to the wafer transfer order of the target chuck 300.

[0065] Optionally, in this embodiment, the target chuck 300 has the X-direction translation freedom and the Y-direction translation freedom under the drive of the driving structure 200. On the one hand, during operation, the film transmission sequence of the target chuck 300 and the carrier chuck 400 is not restricted, and the applicability is higher; specifically, when the parallelism of the target chuck 300 and the carrier chuck 400 has reached the standard, the film transmission sequence of the carrier chuck 400 can be set to precede the film transmission sequence of the target chuck 300, then during the alignment process, the target chuck 300 does not need to be displaced in the XY direction, and the visual system 500 can realize the image capture of the first bonded wafer and the second bonded wafer, thereby further reducing the XY displacement of the target chuck 300 and the carrier chuck 400 during the operation process, and correspondingly further improving the alignment accuracy and bonding quality of the wafer bonding device, and further reducing time consumption, improving bonding efficiency and productivity. When it is necessary to detect the parallelism of the target chuck 300 and the carrier chuck 400, the film transmission order of the target chuck 300 or the carrier chuck 400 can be determined according to the installation position of the parallelism detection element. On this basis, the shooting of the first image and the second image can be realized, and the alignment operation and the bonding operation can be realized accordingly to ensure the normal operation of the wafer bonding device.

[0066] On the other hand, when the target chuck 300 is transmitted before the carrier chuck 400, after taking the first image, the driving structure 200 can drive the target chuck 300 to move laterally in the XY plane in sequence along the direction away from each notch 310, and through a smaller lateral displacement, the first bonded wafer avoids the obstruction of each notch 310, thereby further reducing the lateral displacement of the target chuck 300 and the carrier chuck 400 in the XY direction during the alignment process, and correspondingly further reducing the error introduced by the driving structure 200, further improving the alignment accuracy and bonding quality of the wafer bonding device, and at the same time, it can further reduce the lateral volume occupied by the wafer bonding device, and further improve the structural compactness of the wafer bonding device.

[0067] In this embodiment, when the film transmission sequence of the target chuck 300 is before the film transmission sequence of the carrier chuck 400, the first wafer will block the notch 310, affecting the visual system 500's shooting of the second wafer. Accordingly, the step of adjusting the first wafer to avoid the shooting path in the XY direction includes: driving the target chuck 300 and the carrier chuck 400 to move relative to each other along the XY direction, so that the first wafer moves to a position that avoids the shooting path, thereby ensuring that the visual system 500 shoots the second wafer to obtain a second image.

[0068] Specifically, Figure 4As shown, the wafer bonding device includes three vision systems 500, and the three vision systems 500 are evenly spaced around the circumference of the target chuck 300; the target chuck 300 is provided with six notches 310, and the six notches 310 are evenly spaced along the circumference of the target chuck 300, wherein three notches 310 are used as reserved openings, and the other three notches 310 correspond one-to-one to the three vision systems 500; when the target chuck 300 receives the first wafer, there is no obstruction between the first wafer and the vision system 500, and when the target chuck 300 is located in the bonding position, the vision system 500 takes pictures of the edge of the first wafer through the corresponding notches 310 to obtain three groups of first images, and feeds the first images back to the control component of the wafer bonding device, and the control component can calculate the first center coordinates of the first wafer according to the edge contour of the first wafer in the three groups of first images; then, the second wafer is transferred to the carrier chuck 400, and when the carrier chuck 400 is located in the bonding position , the first wafer blocks the three notches 310, and the three sets of vision systems 500 cannot take pictures of the edge of the second wafer through the three notches 310. Then the driving structure 200 can drive the target chuck 300 and the carrier chuck 400 to move relatively in translation along the XY direction, so that the initial positions of the three notches 310 of the target chuck 300 corresponding to the vision system 500 are successively unblocked, that is, the first wafer no longer blocks the shooting path of the vision system 500 at the corresponding notches 310. Accordingly, the unblocked vision system 500 successively takes second images of the corresponding edges of the second wafer, and the vision system 500 feeds back the three sets of second images to the control component of the wafer bonding device. The control component can calculate the second center coordinates of the second wafer according to the edge contour of the second wafer in the three sets of second images; then the center offset of the first wafer and the second wafer in the XY plane is calculated according to the first center coordinates and the second center coordinates.

[0069] Specifically, the driving structure 200 can drive the target chuck 300 and the carrier chuck 400 to move away from each other along the straight line connecting each notch 310 and the center of the target chuck 300, and avoidance of the shooting path of the corresponding visual system 500 can be achieved by a displacement not greater than the depth of the notch 310; on the basis of ensuring effective avoidance, the lateral driving displacement of the driving structure 200 is further reduced, and accordingly the error introduced by the driving structure 200 is further reduced, thereby further improving the alignment accuracy of the wafer bonding device and further reducing its lateral volume.

[0070] Among them, when the film transmission order of the carrier chuck 400 is before the film transmission order of the target chuck 300, the step of adjusting the first wafer to avoid the shooting path in the XY direction includes: keeping the carrier chuck 400 fixed in the XY direction so that the first wafer avoids the shooting path in the XY direction. First, the first wafer is transferred to the carrier chuck 400. When the carrier chuck 400 is located in the bonding position, the first wafer will not block the notch 310. The driving structure 200 does not need to adjust the positions of the carrier chuck 400 and the target chuck 300 in the XY direction. It only needs to adjust the Z-direction interval between the carrier chuck 400 and the target chuck 300 according to the Z-direction space required for the robot to transfer the second wafer, so that the visual system 500 can shoot the first wafer; then, the second wafer is transferred to the target chuck 300. Neither the first wafer nor the second wafer will block the notch 310. The driving structure 200 does not need to adjust the positions of the carrier chuck 400 and the target chuck 300 in the XY plane, so that the visual system 500 can shoot the second wafer; the alignment process is simpler, the interaction time is shorter, and the error introduced by the driving structure 200 is smaller, and the wafer bonding device is more efficient and has a higher yield.

[0071] Optionally, in this embodiment, one of the notches 310 corresponds to the notch position of the wafer loaded on the target chuck 300, and the driving structure 200 is configured to be able to drive the target chuck 300 and the carrier chuck 400 to rotate relative to each other around the Z axis. Accordingly, the wafer bonding method further includes: obtaining the deflection amount of the first wafer and the second wafer around the Z axis according to the first image and the second image; adjusting the alignment of the target chuck 300 and the carrier chuck 400 located at the bonding position according to the deflection amount; and then performing the step of bonding the first wafer and the second wafer.

[0072] The edge of the wafer is provided with a notch for characterizing its circumferential orientation. When the target chuck 300 and the carrier chuck 400 receive the wafer, the notch of the wafer corresponds to the position of one of the notches 310. The vision system 500 can obtain the notch contours of the first wafer and the second wafer respectively from a set of first images and a set of second images taken through the notch 310. The control component can calculate the angular offset of the two along the circumferential direction according to the notch contour of the first wafer and the notch contour of the second wafer, thereby obtaining the deflection of the first wafer and the second wafer around the Z axis; continuously, when the first wafer and the second wafer are both in the bonding position, the driving structure 200 can compensate for the circumferential offset of the first wafer and the second wafer according to the deflection amount. Without increasing the operating steps, the circumferential angles of the first wafer and the second wafer can be aligned, thereby further improving the alignment accuracy and bonding quality of the wafer bonding device.

[0073] In this embodiment, one of the target chuck 300 and the carrier chuck 400 is relatively fixed to the carrier 100 along the Z direction, and the other one serves as a lifting chuck and has the freedom of translation along the Z direction under the drive of the driving structure 200. The lifting chuck needs to move up and down under the drive of the lifting structure to reach the initial position, the avoidance position or the bonding position; the initial position and the bonding position of the other chuck are the same position.

[0074] The step of S504 of capturing a first image of the first wafer at the bonding position includes: determining whether the chuck loaded with the first wafer has a Z-direction translational freedom; if so, driving the chuck to move up and down along the Z-direction to the bonding position, and capturing a first image of the first wafer; if not, representing that the initial position of the chuck is also the bonding position, and directly capturing a first image of the first wafer.

[0075] S506 takes a second image of the second wafer at the bonding position, which is similar to the step of S504 taking a first image of the first wafer at the bonding position. When the chuck loaded with the second wafer has the Z-direction translational freedom, the chuck is driven to move up and down along the Z-direction to the bonding position, and the second image of the second wafer is taken. When the chuck loaded with the second wafer does not have the Z-direction translational freedom, the initial position of the chuck is also the bonding position, and the second image of the second wafer is directly taken.

[0076] Among them, for the lifting chuck with Z-direction translational freedom, the ejector structure corresponding to the lifting chuck is relatively fixedly connected to the carrier 100. When in use, the position of the ejector structure is fixed, and the lifting chuck can be lifted and lowered relative to the ejector structure to realize that the ejector structure extends out of the lifting chuck through the through hole 40A of the lifting chuck along the Z direction to receive the transferred wafer, or retracts into the lifting chuck along the Z direction to place the received wafer on the lifting chuck, thereby realizing the ejector structure and the lifting chuck receiving the wafer through a simpler structure.

[0077] Specifically, the driving structure 200 can adopt a hexapod displacement table, the fixed end of the hexapod displacement table is fixedly connected to the carrier 100, and the movable end of the hexapod displacement table is connected to one of the chucks. The hexapod displacement table has the degrees of freedom of translation in the X direction, the degrees of freedom of translation in the Y direction, the degrees of freedom of translation in the Z direction, the degrees of freedom of rotation around the X axis, the degrees of freedom of rotation around the Y axis, and the degrees of freedom of rotation around the Z axis. The use of six sets of translation tables can better achieve the position and angle adjustment of the target chuck 300 relative to the carrier chuck 400 in various directions, and can achieve the alignment operation and bonding operation of the wafer bonding device, with a simple structure and strong functionality.

[0078] In this embodiment, as 1 and Figure 2As shown, the wafer bonding device further includes a base 600, and the carrier 100 is connected to the base 600 via a vibration isolation assembly 700. When in use, the carrier 100 carries components for alignment and bonding, such as the driving structure 200, the visual system 500, the target chuck 300, and the carrier chuck 400, and the base 600 is placed on the bottom surface or the base, and the carrier 100 and the base 600 are connected via the vibration isolation assembly 700, which can effectively reduce the vibration effect caused by the operation of external devices on the carrier 100 and the components loaded thereon, thereby ensuring the accuracy of the alignment operation and the bonding operation, and correspondingly further improving the bonding quality of the wafer bonding device.

[0079] like Figure 1 and Figure 2 As shown, the driving structure 200 adopts a hexapod displacement platform, which is connected to the carrier 100, and its top moving end is connected to the lower chuck, which can drive the lower chuck to move so that it has six degrees of freedom; the upper chuck is fixedly connected to the carrier 100; the visual system 500 is divided into three groups, and the three groups of visual systems 500 are all connected to the carrier 100 and located below the lower chuck, then the lower chuck is close to the visual system 500 as the target chuck 300, and the upper chuck is far away from the visual system 500 as the bearing chuck 400, and the lower chuck has the Z-direction translation freedom as a lifting component. The ejector structure corresponding to the lower chuck is relatively fixedly connected to the carrier 100 as the lower ejector structure 900, and the ejector structure corresponding to the upper chuck is an upper ejector structure 810, which can be driven by the lifting component 820 to move relative to the upper chuck through the through hole 40A of the upper chuck to receive the upper wafer.

[0080] Specifically, each visual system 500 may include a focusing assembly 510 fixed to the carrier 100 and a camera assembly 520 connected to the focusing assembly 510. The camera assembly 520 may specifically include a camera, a light source and a lens. The axial direction of the lens extends along the Z direction and corresponds to one of the notches 310. The camera assembly 520 may use visible light or infrared light. When in use, the focusing assembly 510 may automatically focus the camera assembly 520 to capture an image of the lower wafer that is lifted and lowered to the bonding position and an image of the upper wafer that remains in the bonding position.

[0081] The lifting component 820 and the focusing assembly 510 may specifically be an electric slide table.

[0082] Figure 6 A second schematic diagram of the wafer bonding method provided by an embodiment of the present invention. When one of the notches corresponds to the notch position of the wafer, such as Figure 6 As shown, the wafer bonding method includes:

[0083] S601 determines whether the target chuck has the X-direction translational freedom and / or the Y-direction translational freedom; if so, executes step S602 or S603; if not, executes step S603.

[0084] S602 determines that the film transmission sequence of the target chuck is before the film transmission sequence of the carrier chuck; and proceeds to step S604.

[0085] S603 determines that the film transmission sequence of the carrier chuck is before the film transmission sequence of the target chuck; and proceeds to step S606.

[0086] S604: transferring the first wafer to the target chuck, and capturing a first image of the first wafer at the bonding position.

[0087] S605: transfer the second wafer to the carrier chuck, drive the target chuck and the carrier chuck to move relative to each other along the XY direction, so that the first wafer moves to a position avoiding the shooting path, and captures a second image of the second wafer at the bonding position; and continue to execute step S608.

[0088] S606: Transfer the first wafer to the carrier chuck, and take a first image of the first wafer at the bonding position.

[0089] S607: transfer the second wafer to the target chuck, keep the carrier chuck fixed in the XY direction, so that the first wafer avoids the shooting path in the XY direction, and take a second image of the second wafer at the bonding position; continue to execute step S608.

[0090] S608: Obtain the center offset of the first wafer and the second wafer in the XY direction and the deflection around the Z axis according to the first image and the second image.

[0091] S609: aligning the target chuck and the carrier chuck located at the bonding position according to the center offset and the deflection around the Z axis.

[0092] S610 performs a bonding process on the first wafer and the second wafer.

[0093] Figure 7 A second schematic flow chart of a wafer bonding method provided by an embodiment of the present invention. Figure 1 and Figure 2 As shown, the upper chuck is relatively fixedly connected to the carrier, the driving structure adopts a six-legged displacement table, and six groups of displacement tables are connected to the lower chuck, so that the lower chuck has the X-direction translation freedom, the Y-direction translation freedom and the Z-direction translation freedom. Accordingly, the lower chuck serves as a lifting chuck; the target chuck is provided with three notches, one of which corresponds to the notch position of the wafer, and there are three visual systems, all of which are arranged below the lower chuck, so that the lower chuck serves as the target chuck and the upper chuck serves as the carrying chuck; the wafer transmission order of the target chuck is first; as shown Figure 7As shown, the wafer bonding method includes:

[0094] S701 determines the film transmission order of the target chuck first according to the X-direction translational freedom and the Y-direction translational freedom of the target chuck.

[0095] S702 transfers the first wafer to the target chuck.

[0096] S703 drives the target chuck to rise from the initial position to the bonding position, and captures a first image of the first wafer.

[0097] S704 drives the target chuck to the bonding position and descends to the avoidance position, and transfers the second wafer to the carrier chuck.

[0098] S705 drives the target chuck to move in a direction away from the openings of the three notches in sequence, so that the first wafer sequentially avoids the shooting paths of the visual systems corresponding to the three notches, and the three avoided visual systems sequentially capture the second image of the second wafer.

[0099] S706: Obtain the center offset of the first wafer and the second wafer in the XY direction and the deflection around the Z axis according to the first image and the second image.

[0100] S707 drives the target chuck to rise from the avoidance position to the bonding position, and adjusts the alignment between the target chuck and the carrier chuck according to the center offset and the deflection around the Z axis.

[0101] S708 performs bonding processing on the first wafer and the second wafer.

[0102] 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 bonding device, characterized in that: The invention comprises a carrier (100), a driving structure (200) arranged on the carrier (100), and a target chuck (300) and a carrier chuck (400) arranged along the Z direction, wherein the target chuck (300) and / or the carrier chuck (400) are connected to the driving structure (200) by transmission, and the driving structure (200) is configured to: be able to drive the target chuck (300) and the carrier chuck (400) to move relative to each other along the XY direction and the Z direction; The edge of the target chuck (300) is provided with a plurality of notches (310); the carrier (100) is provided with a plurality of visual systems (500), the plurality of visual systems (500) are located on a side of the target chuck (300) away from the carrier chuck (400), the axial directions of the plurality of visual systems (500) are consistent with the Z direction and correspond one-to-one to the plurality of notches (310), and are configured to capture images of the wafers loaded on the target chuck (300) and the carrier chuck (400) corresponding to the notches (310).

2. The wafer bonding device according to claim 1, characterized in that: The target chuck (300) has an X-direction translational freedom and a Y-direction translational freedom under the drive of the drive structure (200).

3. The wafer bonding device according to claim 1, characterized in that: One of the notches (310) corresponds to a notch position of a wafer loaded on the target chuck (300), and the driving structure (200) is configured to be able to drive the target chuck (300) and the carrier chuck (400) to rotate relative to each other around a Z axis.

4. The wafer bonding device according to claim 1, characterized in that: The target chuck (300) or the carrier chuck (400) serves as a lifting chuck, and the lifting chuck has a Z-direction translational freedom when driven by the driving structure (200); and the ejector pin structure corresponding to the lifting chuck is relatively fixedly connected to the carrier (100).

5. The wafer bonding device according to claim 1, characterized in that: The driving structure (200) comprises a hexapod displacement platform, the fixed end of the hexapod displacement platform is fixedly connected to the carrier (100), and the movable end of the hexapod displacement platform is connected to the target chuck (300) or the carrier chuck (400).

6. A wafer bonding method, characterized in that: Using the wafer bonding device according to claims 1 to 5, the wafer bonding method comprises: Determining the film transmission sequence of the target chuck (300) and the carrier chuck (400) according to the X-direction translational freedom and the Y-direction translational freedom of the target chuck (300); Transferring a first wafer to a chuck that is at the front of the determined wafer transfer sequence, and capturing a first image of the first wafer at a bonding position; Transferring the second wafer to the chuck that is later in the determined wafer transfer sequence, adjusting the first wafer to avoid the shooting path in the XY directions, and capturing a second image of the second wafer at the bonding position; Acquire the center offset of the first wafer and the second wafer in the XY direction according to the first image and the second image; Adjusting and aligning the target chuck (300) and the carrier chuck (400) located at the bonding position according to the circle center offset; The first wafer and the second wafer are bonded together.

7. The wafer bonding method according to claim 6, characterized in that: The step of determining the film transmission order of the target chuck (300) and the carrier chuck (400) according to the X-direction translational freedom and the Y-direction translational freedom of the target chuck (300) comprises: Determining whether the target chuck (300) has an X-direction translational degree of freedom and / or a Y-direction translational degree of freedom; If so, it is determined that the transmission sequence of the target chuck (300) is located before the transmission sequence of the carrier chuck (400), or it is determined that the transmission sequence of the carrier chuck (400) is located before the transmission sequence of the target chuck (300); If not, it is determined that the film transmission sequence of the carrier chuck (400) is located before the film transmission sequence of the target chuck (300).

8. The wafer bonding method according to claim 7, characterized in that: When the wafer transmission sequence of the target chuck (300) is located before the wafer transmission sequence of the carrier chuck (400), the step of adjusting the first wafer to avoid the shooting path in the XY direction comprises: driving the target chuck (300) and the carrier chuck (400) to move relative to each other along the XY direction so that the first wafer moves to a position avoiding the shooting path; When the film transmission sequence of the carrier chuck (400) is before the film transmission sequence of the target chuck (300), the step of adjusting the first wafer to avoid the shooting path in the XY direction includes: keeping the carrier chuck (400) fixed in the XY direction so that the first wafer avoids the shooting path in the XY direction.

9. The wafer bonding method according to claim 6, characterized in that: The step of capturing a first image of the first wafer at the bonding position includes: Determining whether the chuck loaded with the first wafer has a Z-direction translational freedom; If yes, driving the chuck to move up and down along the Z direction to the bonding position, and taking a first image of the first wafer; If not, directly capture the first image of the first wafer.

10. The wafer bonding method according to claim 6, characterized in that: The wafer bonding method further comprises: Acquire deflection amounts of the first wafer and the second wafer around the Z axis according to the first image and the second image; The target chuck (300) and the carrier chuck (400) located at the bonding position are aligned according to the deflection amount; and then the step of bonding the first wafer and the second wafer is performed.

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