Bonding apparatus and bonding method

Abstract

The bonding apparatus of the embodiment includes a first chuck (LC) and a second chuck (UC) and a press pin (30). The second chuck (UC) is disposed above the first chuck (LC). The press pin (30) is provided at a center portion of the second chuck (UC), has a front end portion extending in a first direction, and is provided in a manner capable of ascending and descending in the first direction. The first chuck (LC) has a first rib (42) separating a first region (NSA) including a region overlapping the front end portion of the press pin (30) and a second region (SA) surrounding the outer periphery of the first region (NSA) in plan view. The first chuck (LC) has a plurality of pins (43) provided in a manner having intervals, respectively, in the second region (SA) in a surface of the first chuck (LC) opposite to the second chuck (UC), and does not have the pins (43) in a region of the first region (NSA) overlapping the front end portion in plan view.

Description

[0001] This application is based on and pursues the priority of Japanese Patent Application No. 2021-152246, filed on September 17, 2021, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The implementation methods involve a joining device and a joining method. Background Technology

[0003] Three-dimensional stacking technology is known to be used to stack semiconductor circuit substrates in three dimensions. Summary of the Invention

[0004] One implementation improves the yield of semiconductor devices.

[0005] The bonding device of this embodiment performs a bonding process to bond a first surface of a first substrate and a second surface of a second substrate. The bonding device includes a first chuck, a second chuck, and a pressing pin. The first chuck is capable of holding a third surface of the first substrate facing the first surface. The second chuck is capable of holding a fourth surface of the second substrate facing the second surface and is disposed above the first chuck. The pressing pin is disposed at the center of the second chuck, has a front end portion extending in a first direction, and is configured to be movable in the first direction. The first chuck has a first rib that, when viewed from above, separates a first region including a region overlapping the front end portion of the pressing pin and a second region surrounding the outer periphery of the first region. On the fifth surface of the first chuck facing the second chuck, a plurality of pins are provided in the second region in a spaced-apart manner, while no pins are present in the region of the first region overlapping the front end portion when viewed from above.

[0006] Based on the above structure, the yield of semiconductor devices can be improved. Attached Figure Description

[0007] Figure 1 This is a side view showing an example of the state of two wafers before and after being joined by a joining device.

[0008] Figure 2 This is a block diagram illustrating an example of the structure of the coupling device according to the first embodiment.

[0009] Figure 3 This is a schematic diagram showing an example of the structure of the upper suction cup and impact unit included in the coupling device of the first embodiment.

[0010] Figure 4 This is a schematic diagram showing an example of the structure of the lower suction cup included in the coupling device of the first embodiment.

[0011] Figure 5This is a flowchart illustrating an example of the joining process of the joining device according to the first embodiment.

[0012] Figure 6 This is a schematic diagram illustrating a specific example of the joining process in the joining device of the comparative example.

[0013] Figure 7 This is a schematic diagram showing a specific example of the joining process in the joining device of the first embodiment.

[0014] Figure 8 This is a schematic diagram showing an example of the structure of the lower suction cup included in the coupling device 1 of the second embodiment.

[0015] Figure 9 This is a schematic diagram showing a specific example of the joining process in the joining device of the second embodiment.

[0016] Figure 10 This is a schematic diagram showing an example of the structure of the lower suction cup included in the coupling device 1 of the third embodiment.

[0017] Figure 11 This is a schematic diagram illustrating a specific example of the joining process in the joining device of the third embodiment.

[0018] Figure 12 This is a schematic diagram illustrating a specific example of the joining process of a joining device according to a modified example of the first embodiment. Detailed Implementation

[0019] Hereinafter, embodiments will be described with reference to the accompanying drawings. Each embodiment illustrates an apparatus and method for embodying the technical concept of the invention. The drawings are schematic or conceptual. The dimensions, scales, etc., of each drawing may not be identical to reality. Structural illustrations are appropriately omitted to facilitate observation. The shading lines added to the drawings may not be related to the materials or properties of the constituent elements. In this specification, the X, Y, and Z directions indicate intersecting directions. Furthermore, constituent elements having substantially the same function and structure are labeled with the same reference numerals. Characters, etc., added to the reference numerals are used to distinguish similar elements labeled with the same reference numerals from one another.

[0020] [1] First Embodiment

[0021] The bonding apparatus 1 according to the first embodiment will now be described. The bonding apparatus 1 of the first embodiment is a device for bonding two semiconductor circuit boards, and has a structure that improves the overlap of the two semiconductor circuit boards to be bonded. In this specification, the semiconductor circuit board is referred to as a "wafer". Furthermore, of the two wafers bonded by the bonding apparatus 1, the wafer disposed on the lower side is referred to as the "lower wafer LW", and the wafer disposed on the upper side is referred to as the "upper wafer UW". "Upper" and "lower" are defined based on the direction along the Z-direction.

[0022] [1-1] Overview of the coupling device 1

[0023] Figure 1 This is a side view showing an example of the state of the two wafers before and after bonding using bonding device 1. Figure 1 (A) and (B) correspond to the states before and after joining, respectively. For example... Figure 1 As shown in (A), the bonding device 1 arranges the upper wafer UW and the lower wafer LW facing each other. The upper surface of the upper wafer UW is the back surface of the upper wafer UW and is held in the bonding device 1. The lower surface of the upper wafer UW is the surface of the upper wafer UW, corresponding to the bonding surface. The surface and back surface of the upper wafer UW face each other. The upper surface of the lower wafer LW is the surface of the lower wafer LW, corresponding to the bonding surface. The lower surface of the lower wafer LW is the back surface of the lower wafer LW and is held in the bonding device 1. The surface and back surface of the lower wafer LW face each other. Furthermore, the bonding device 1 adjusts the overlap position of the upper wafer UW and the lower wafer LW. Then, as... Figure 1 As shown in (B), the bonding device 1 bonds the lower surface (bonding surface) of the upper wafer UW and the upper surface (bonding surface) of the lower wafer LW.

[0024] In this specification, the two joined wafers are referred to as "joined wafers BW". Joined wafers BW include semiconductor devices such as NAND flash memory. When the semiconductor device is NAND flash memory, for example, control circuitry is arranged on the lower wafer LW, and memory cells are arranged on the upper wafer UW. Details regarding the joining process will be described later.

[0025] [1-2] Structure of the coupling device 1

[0026] Figure 2 This is a block diagram illustrating an example of the structure of the coupling device 1 according to the first embodiment. Figure 2 As shown, the joining device 1 includes, for example, a control device 10, an upper loading platform 11, a lower loading platform 12, a vacuum pump 13, and a conveying device 14.

[0027] The control device 10 is a computer or similar device that controls the overall operation of the bonding device 1. The control device 10 controls the loading stage 11, the unloading stage 12, the vacuum pump 13, and the transport device 14. Although not shown in the figures, the control device 10 includes, for example, a CPU (Central Processing Unit), ROM (Read Only Memory), and RAM (Random Access Memory). The CPU is a processor that executes various programs related to the control of the bonding device 1. The ROM is a non-volatile storage device that stores the control programs for the bonding device 1. The RAM is a volatile storage device used as the CPU's working area. The control device 10 can also execute programs installed from an externally connected storage medium.

[0028] The upper stage 11 is a wafer mounting stage that has the function of adsorbing and holding a wafer UW and adjusting the position of the upper stage 11. The upper stage 11 includes an upper chuck UC and a striker unit SU. The upper chuck UC is a wafer chuck that uses vacuum adsorption to fix the wafer, such as a pin chuck. The upper chuck UC holds the wafer UW by adsorbing it from its lower side. The striker unit SU is a device that has the function of pressing down on the upper surface of the center portion of the wafer UW held on the upper chuck UC.

[0029] The download stage 12 is a wafer carrier stage with the functions of adsorbing the lower wafer (LW) and adjusting the position of the download stage 12. The download stage 12 includes a lower chuck LC. The lower chuck LC is a wafer chuck that uses vacuum adsorption to fix the wafer, such as a pin chuck. The lower chuck LC holds the lower wafer (LW) by adsorbing it above the upper chuck UC. The upper loading stage 11 and the download stage 12 are configured to allow the upper wafer (UW) held on the upper chuck UC and the lower wafer (LW) held on the lower chuck LC to be arranged facing each other. That is, the upper chuck UC can be positioned above the lower chuck LC.

[0030] Vacuum pump 13 is a pump with the function of discharging gas. Vacuum pump 13 is connected to at least one suction port provided on each of the upper suction cup UC and the lower suction cup LC. Vacuum pump 13 can independently perform vacuuming through each suction port of the plurality of suction ports based on the control of control device 10.

[0031] The transport device 14 is an apparatus equipped with a transport arm capable of transporting wafers, a transfer device for temporarily holding multiple wafers, etc. The transport device 14 processes upper wafers (UW), lower wafers (LW), and bonding wafers (BW). For example, the transport device 14 transports the upper wafers (UW) and lower wafers (LW) received from an external preprocessing unit to the upper suction cup (UC) and lower suction cup (LC), respectively. Furthermore, after the bonding process, the transport device 14 transports the bonding wafers (BW) held at the lower suction cup (LC) to the outside of the bonding unit 1. The transport device 14 may also include a mechanism for flipping the wafers vertically.

[0032] Furthermore, the aforementioned "pretreatment apparatus" is an apparatus that modifies and hydrophilizes the bonding surfaces of the upper wafer UW and the lower wafer LW in a way that enables them to bond before the bonding process of the bonding apparatus 1. In short, the pretreatment apparatus first performs plasma treatment on the surfaces of the upper wafer UW and the lower wafer LW to modify their surfaces. During plasma treatment, oxygen ions or nitrogen ions are generated based on oxygen or nitrogen as the treatment gas under a predetermined reduced pressure atmosphere, and the generated oxygen ions or nitrogen ions are irradiated onto the bonding surfaces of each wafer. Afterward, the pretreatment apparatus supplies pure water to the surfaces of the upper wafer UW and the lower wafer LW. As a result, hydroxyl groups are attached to the surfaces of the upper wafer UW and the lower wafer LW, thus hydrophilizing the surfaces. In the bonding process of the bonding apparatus 1, the upper wafer UW and the lower wafer LW with their bonding surfaces thus modified and hydrophilized are used. The bonding apparatus 1 can also be combined with the pretreatment apparatus to form a bonding system.

[0033] (Structure of the upper suction cup UC)

[0034] Figure 3 This is a schematic diagram showing an example of the structure of the upper suction cup UC and the impact unit SU provided in the coupling device 1 of the first embodiment. Figure 3 (A) shows the planar layout of the upper suction cup UC and the impact unit SU. Figure 3 (B) shows the cross-sectional structure of the upper suction cup UC and the impact unit SU. For example... Figure 3 As shown, the upper suction cup UC has a main body 20. The diameter of the main body 20 is at least larger than that of the upper wafer UW when viewed from above. Ribs 21, 22, 23 and 24, multiple pins 25, multiple suction ports 26, 27 and 28, and a through hole 29 are provided on the main body 20. The impact unit SU has a pressing pin 30, an actuator part 31, and a drive part 32.

[0035] Ribs 21, 22, 23, and 24, and multiple pins 25 are each disposed on the lower surface of the main body 20. The lower surface of the main body 20 corresponds to the suction surface of the upper suction cup UC. The heights of ribs 21, 22, 23, and 24, and multiple pins 25 are approximately uniform. Ribs 21, 22, 23, and 24 are arranged, for example, in a concentric circle pattern. Specifically, ribs 21, 22, 23, and 24 are each arranged in a ring shape. Rib 21 is disposed on the outer periphery of the main body 20. The diameter of rib 22 is smaller than that of rib 21. The diameter of rib 23 is smaller than that of rib 22. The diameter of rib 24 is smaller than that of rib 23.

[0036] Hereinafter, the area between ribs 21 and 22 will be referred to as the "edge region EA". The area between ribs 22 and 23 will be referred to as the "middle region MA". The area between ribs 23 and 24 will be referred to as the "center region CA". Furthermore, the edge region EA, the middle region MA, and the center region CA can each be referred to as an "attraction region". Figure 3 As shown in (A), the upper suction cup UC preferably has multiple attraction areas extending from the inner periphery to the outer periphery. Each attraction area can also be further divided or can be of other shapes.

[0037] Multiple pins 25 are arranged independently across the entirety of the central region CA, the intermediate region MA, and the edge region EA. The arrangement of the multiple pins 25 can be changed as appropriate. Suction ports 26, 27, and 28 are each independently connected to the vacuum pump 13. Suction ports 26, 27, and 28 are each connected to the lower surface of the upper suction cup UC. Multiple suction ports 26 are located in the edge region EA. Multiple suction ports 27 are located in the intermediate region MA. Multiple suction ports 28 are located in the central region CA. At least one suction port is required for each suction region.

[0038] like Figure 3 As shown in (A), the through hole 29 is located in the center of the main body 20, that is, in the area surrounded by the central region CA. Figure 3 As shown in (B), the through hole 29 is provided so that the main body 20 passes through along the Z direction. The center portion of the main body 20 is provided so that it faces the center portion of the upper wafer UW held on the upper chuck UC. Furthermore, the through hole 29 is formed so that the front end portion of the pressing pin 30 can be inserted and moved up and down along the Z direction.

[0039] The pressing pin 30 is a pin having a portion extending in the Z direction. An actuator section 31 supports the pressing pin 30. The actuator section 31 can generate a certain pressure in the Z direction using air supplied from an electro-pneumatic pressure regulating valve (not shown in the figure). A drive section 32 supports the actuator section 31. The drive section 32, for example, has a built-in motor, enabling the actuator section 31 to move in the Z direction.

[0040] In the upper suction cup UC described above, the vacuum pump 13 can depressurize the edge region EA, the middle region MA, and the center region CA respectively through the suction ports 26, 27, and 28. The wafer UW is attracted and held towards the main body 20 according to the depressurization of each suction region and the external atmosphere, such as atmospheric pressure. The control device 10 can independently turn on / off (ON / OFF) the adsorption of wafers in the center region CA, the middle region MA, and the edge region EA by controlling the vacuum pump 13.

[0041] Furthermore, when the upper suction cup UC adsorbs the upper wafer UW, rib 21 supports the outer periphery of the upper surface of the upper wafer UW, and ribs 22, 23, and 24, as well as multiple pins 25, each support a portion of the upper surface of the upper wafer UW. Because the upper surface of the upper wafer UW is supported by multiple pins 25, the upper wafer UW is held in a flat shape, suppressing deformation (warping) in the Z direction. Additionally, the influence of particles remaining on the upper surface of the upper wafer UW on the flatness of the adsorbed upper wafer UW can be suppressed. Moreover, since the contact area between the upper suction cup UC and the upper wafer UW is reduced, the upper wafer UW is easily detached from the upper suction cup UC when the adsorption of the upper wafer UW by the upper suction cup UC is released.

[0042] In the impact unit SU described above, the control device 10, by controlling the actuator unit 31 and the drive unit 32, can cause the pressing pin 30 to move up and down in the Z direction, so that the front end portion of the pressing pin 30 contacts the center portion of the upper surface of the upper wafer UW adsorbed on the upper suction cup UC. Furthermore, the control device 10 can control the load on the pressing pin 30 pressing against the center portion of the upper wafer UW. The pressing pin 30 can also be referred to as an "impactor". The outer diameter D1 of the front end portion of the pressing pin 30 (i.e., the portion of the pressing pin 30 that contacts the upper surface of the upper wafer UW) is designed, for example, in the range of 1.0 to 10.0 mm.

[0043] (Structure of the lower suction cup LC)

[0044] Figure 4 This is a schematic diagram showing an example of the structure of the lower suction cup LC included in the coupling device 1 of the first embodiment. Figure 4 (A) shows the planar layout of the lower suction cup LC in the first embodiment, and also shows the portion where the pressing pin 30 is configured in the engagement process. Figure 4 (B) shows the cross-sectional structure of the lower suction cup LC in the first embodiment. Figure 4 As shown, the lower suction cup LC has a main body 40. The diameter of the main body 40 is at least larger than that of the lower wafer LW when viewed from above. Ribs 41 and 42, a plurality of pins 43, and a plurality of suction ports 44 are provided on the main body 40.

[0045] Ribs 41 and 42, and a plurality of pins 43, are each disposed on the upper surface of the main body 40. The upper surface of the main body 40 corresponds to the adsorption surface of the lower suction cup LC. The heights of ribs 41 and 42 and the plurality of pins 43 are approximately uniform. Ribs 41 and 42 are arranged in a concentric circle. Specifically, ribs 41 and 42 are each arranged in a ring. Rib 41 is disposed on the outer periphery of the main body 40. The inner diameter D2 of rib 42 is smaller than that of rib 41 and larger than the outer diameter D1 of the front end portion of the pressing pin 30. The inner diameter D2 of rib 42 is designed, for example, to be in the range of 1.0 to 15.0 mm.

[0046] Hereinafter, the area between ribs 41 and 42 will be referred to as the "attraction area SA". The attraction area SA may also be divided or have other shapes. The part surrounded by rib 42 will be referred to as the "non-attraction area NSA". Rib 42 may also be referred to as the "partition". Furthermore, the shape of rib 42 is not limited to a ring shape. Rib 42 may be provided in such a way that it surrounds the part that overlaps with the pressing pin 30 during the joining process when viewed from above.

[0047] Multiple pins 43 are arranged separately from each other, covering the entire suction area SA. The arrangement of the multiple pins 43 can be appropriately changed. Multiple suction ports 44 are each connected to the upper surface of the lower suction cup LC. The multiple suction ports 44 are connected to the vacuum pump 13. When the suction area SA is divided into multiple areas by ribs, at least one suction port is provided for each suction area. When the suction area SA is divided into multiple areas by ribs, the lower suction cup LC and the vacuum pump 13 can also be configured to independently evacuate each of the divided areas.

[0048] Regarding the structure of the lower suction cup LC, in other words, on the upper side of the lower suction cup LC facing the upper suction cup UC, there are a plurality of pins 25 arranged at intervals in the suction area SA. On the other hand, the lower suction cup LC does not have pins 25 in the area of ​​the non-suction area NSA that overlaps with the front end of the pressing pin 30 when viewed from above (the non-suction area NSA).

[0049] In the lower suction cup LC described above, the vacuum pump 13 can depressurize the suction area SA through multiple suction ports 44. The lower wafer LW is attracted and held towards the main body 40 due to the depressurization of the suction area SA and the external atmosphere, such as atmospheric pressure. On the other hand, the non-suction area NSA is open to the atmosphere, thus maintaining atmospheric pressure. Therefore, the portion of the lower wafer LW in contact with the non-suction area NSA is not attracted towards the main body 40. In other words, the lower suction cup LC has a structure that does not attract the portion of the lower wafer LW located directly below the impactor (pressing pin 30) and becomes hollow (e.g., at atmospheric pressure).

[0050] Furthermore, when the lower chuck LC adsorbs the lower wafer LW, rib 41 supports the outer periphery of the lower surface of the lower wafer LW, and rib 42 and multiple pins 43 each support a portion of the lower surface of the lower wafer LW. Because the lower surface of the lower wafer LW is supported by the multiple pins 43, the lower wafer LW is held in a flat shape, suppressing deformation (warping) in the Z direction. Additionally, the influence of particles remaining on the lower surface of the lower wafer LW on the flatness of the adsorbed lower wafer LW can be suppressed. Moreover, since the contact area between the lower chuck LC and the lower wafer LW is reduced, the lower wafer LW is easily peeled off from the lower chuck LC when the adsorption of the lower chuck LC on the lower wafer LW is released.

[0051] [1-3] Joining treatment

[0052] Figure 5 This is a flowchart illustrating an example of the joining process of the joining device 1 according to the first embodiment. Hereinafter, refer to... Figure 5 An example of the joining process of the joining device 1 as a joining method of the first embodiment will be described.

[0053] If the bonding device 1 receives the upper wafer UW and the lower wafer LW after the bonding surfaces have been hydrophilized, the bonding process begins (start).

[0054] First, the control device 10 holds the upper wafer UW on the upper suction cup UC (S1). Specifically, the mating surface of the upper wafer UW received by the transport device 14 faces upward. Therefore, first, the transport device 14 flips the upper wafer UW so that the mating surface of the upper wafer UW faces downward. Then, the transport device 14 transports the flipped upper wafer UW below the upper suction cup UC. Afterward, the control device 10 operates the vacuum pump 13 to depressurize the center region CA, the middle region MA, and the edge region EA of the upper suction cup UC, causing the upper suction cup UC (upper stage 11) to adsorb and hold the upper surface of the upper wafer UW.

[0055] Next, the control device 10 holds the lower wafer LW on the lower suction cup LC (S2). Specifically, the mating surface of the lower wafer LW received by the transport device 14 faces upward. Therefore, the transport device 14 does not flip the lower wafer LW, but transports the lower wafer LW above the lower suction cup LC. Afterward, the control device 10 operates the vacuum pump 13 to depressurize the suction area SA of the lower suction cup LC, causing the lower suction cup LC (lower stage 12) to attract and hold the lower surface of the lower wafer LW. Furthermore, the order of processing S1 and S2 can be reversed, and the processing of S1 and S2 can be performed in parallel.

[0056] Next, the control device 10 positions the upper wafer UW and the lower wafer LW facing each other (S3). Specifically, the control device 10 adjusts the positions of the upper mounting stage 11 holding the upper wafer UW and the lower mounting stage 12 holding the lower wafer LW so that the upper wafer UW and the lower wafer LW face each other. For example, the control device 10 can capture at least one alignment mark from the bonding surface of the upper wafer UW and the bonding surface of the lower wafer LW, and adjust the overlap position of the upper wafer UW and the lower wafer LW based on the capture results. The structure for capturing the alignment marks can be provided on the upper mounting stage 11 and the lower mounting stage 12, or it can be provided in other parts of the bonding device 1. The distance between the facing upper wafer UW and the lower wafer LW is adjusted by the processing in S5 described later to a length that allows the upper wafer UW and the lower wafer LW to contact and bond.

[0057] Next, the control device 10 shuts off the adsorption in the central region CA of the upper suction cup UC (S4). Specifically, the control device 10 controls the vacuum pump 13 to stop the depressurization in the central region CA of the upper suction cup UC. At this time, the depressurization in the middle region MA and the edge region EA of the upper suction cup UC is maintained, and therefore the adsorption of the upper wafer UW in the middle region MA and the edge region EA is maintained. That is, the upper wafer UW is held by the middle region MA and the edge region EA of the upper suction cup UC.

[0058] Next, the control device 10 lowers the pressing pin 30, pressing the center of the upper wafer UW against the center of the lower wafer LW (S5). Specifically, the control device 10 controls the actuator unit 31 and the drive unit 32 to lower the pressing pin 30, causing the front end of the pressing pin 30 to press down the center of the upper surface of the upper wafer UW. At this time, the actuator unit 31 uses air supplied from the electro-pneumatic pressure regulating valve to apply a predetermined pressing load to the upper wafer UW via the pressing pin 30. As a result, the center of the upper wafer UW deforms, and the center of the upper wafer UW and the center of the lower wafer LW come into contact and are pressed. Thus, bonding begins between the pressed center of the upper wafer UW and the center of the lower wafer LW. In short, van der Waals forces (intermolecular forces) are generated between the bonding surfaces of the modified upper wafer UW and the modified lower wafer LW, and the contact portions of the upper wafer UW and the lower wafer LW are bonded. Furthermore, since the bonding surfaces of the upper wafer UW and the lower wafer LW are hydrophilized, the hydrophilic groups at the contact portions of the upper wafer UW and the lower wafer LW form hydrogen bonds (intermolecular forces), and the contact portions of the upper wafer UW and the lower wafer LW are bonded more firmly.

[0059] Next, the control device 10 shuts off the adsorption in the middle region MA of the upper suction cup UC (S6). Specifically, the control device 10 controls the vacuum pump 13 to stop the depressurization in the middle region MA of the upper suction cup UC. At this time, the depressurization in the edge region EA of the upper suction cup UC is maintained, and therefore the adsorption of the upper wafer UW in the edge region EA is maintained. That is, the upper wafer UW is held by the edge region EA of the upper suction cup UC. As a result, the portion of the upper wafer UW held in the middle region MA of the upper suction cup UC gradually peels off from the central region CA side and falls, contacting the upper surface of the lower wafer LW. Thus, in both the upper wafer UW and the lower wafer LW, the portions facing the middle region MA are bonded together by intermolecular forces in the same way as in the process of S5.

[0060] Next, the control device 10 shuts off the adsorption in the edge region EA of the upper suction cup UC (S7). Specifically, the control device 10 controls the vacuum pump 13 to stop the depressurization in the edge region EA of the upper suction cup UC. As a result, the portion of the upper wafer UW held in the edge region EA of the upper suction cup UC gradually peels off from the center region CA side and falls, contacting the upper surface of the lower wafer LW. Thus, the portions of the upper wafer UW and the lower wafer LW facing the edge region EA are bonded together by intermolecular forces in the same way as in the process of S5. If the process of S7 is completed, the bonding surfaces of the upper wafer UW and the lower wafer LW are fully bonded, forming the bonded wafer BW.

[0061] Next, the control device 10 raises the pressing pin 30 and closes the suction of the lower suction cup LC (S8). Specifically, the control device 10 controls the actuator unit 31 and the drive unit 32 to raise the pressing pin 30, causing the front end of the pressing pin 30 to separate from the upper surface of the upper wafer UW. In addition, the control device 10 controls the vacuum pump 13 to stop the depressurization in the suction area SA of the lower suction cup LC. As a result, the lower surface of the lower wafer LW, i.e., the lower surface of the bonded wafer BW, is easily peeled off from the lower suction cup LC.

[0062] If the processing of S8 is completed, the control device 10 causes the transport device 14 to transport the bonding wafer BW on the lower suction cup LC to the outside, thus ending the process. Figure 5 The series of processes (end).

[0063] (Joint treatment in the comparative example)

[0064] Figure 6 This is a schematic diagram illustrating a specific example of the joining process in the joining device of the comparative example. Figure 6(A), (B), (C), and (D) respectively show the states of the upper loading stage 11 and the lower loading stage 12, which are arranged opposite each other, and the states of the upper wafer UW and the lower wafer LW after a certain step of the bonding process in the comparative example. Furthermore, the bonding apparatus of the comparative example differs from the first embodiment only in the structure of the lower suction cup LC. Specifically, the lower suction cup LC of the comparative example has a structure in which the partition wall portion of the lower suction cup LC of the first embodiment is omitted, and a plurality of pins 43 are arranged in the center portion. Hereinafter, refer to... Figure 6 Specific examples of the joining process in the comparative examples will be explained.

[0065] If performed by the coupling device of the comparative example Figure 5 The processing of S1 to S3 is as follows: Figure 6 As shown in (A), the upper chuck UC adsorbs and holds the upper wafer UW, and the lower chuck LC adsorbs and holds the lower wafer LW, with the upper wafer UW and the lower wafer LW arranged opposite to each other. In the comparative example, the entire lower surface of the lower wafer LW is adsorbed and supported by a plurality of pins 43.

[0066] If performed by the coupling device of the comparative example Figure 5 The S4 and S5 treatments shut down the adsorption of CA in the central region and caused the pressing pin 30 to drop, thus, as Figure 6 As shown in (B), the center portion of the upper wafer UW is deformed into a concave shape by pressure applied by the front end portion of the pressing pin 30, and the concave portion is pressed against the center portion of the lower wafer LW. At this time, the center portion of the upper wafer UW deforms along the shape of the front end portion of the pressing pin 30, resulting in deformation. On the other hand, the portion of the lower wafer LW to which pressure is applied via the upper wafer UW is supported by multiple pins 43 accompanied by the adsorption of the lower suction cup LC. Therefore, in the processing of S5 in the comparative example, the deformation of the center portion of the lower wafer LW is suppressed.

[0067] If performed by the coupling device of the comparative example Figure 5 In the S6 process, the adsorption in the intermediate region MA is turned off, thereby peeling off the portion of the upper wafer UW adsorbed in the intermediate region MA from the central region CA side. Furthermore, as... Figure 6 As shown in (C), the formation (progress) of covalent bonds between the bonding surfaces of the upper wafer UW and the lower wafer LW proceeds from the central region CA side.

[0068] If the bonding apparatus of the comparative example performs the S7 process, the adsorption in the edge region EA is turned off, thereby peeling off a portion of the upper wafer UW adsorbed in the edge region EA from the middle region MA side. Furthermore, from the center region CA side, covalent bonds are formed between the bonding surfaces of the upper wafer UW and the lower wafer LW. Thus, as... Figure 6As shown in (D), the bonding surfaces of the upper wafer UW and the lower wafer LW are bonded together to form a bonded wafer BW.

[0069] (Jointing process in the first embodiment)

[0070] Figure 7 This is a schematic diagram showing a specific example of the joining process in the joining device 1 of the first embodiment. Figure 7 (A), (B), (C), and (D) respectively show the states of the opposing upper loading stage 11 and lower loading stage 12, and the upper wafer UW and lower wafer LW, after a certain step of the bonding process in the first embodiment. Hereinafter, refer to... Figure 7 A specific example of the joining process of the joining device 1 as a first embodiment will be described.

[0071] If performed by the joining device 1 of the first embodiment Figure 5 The processing of S1 to S3 is as follows: Figure 7 As shown in (A), the upper chuck UC adsorbs and holds the upper wafer UW, and the lower chuck LC adsorbs and holds the lower wafer LW, with the upper wafer UW and the lower wafer LW arranged opposite to each other. In the first embodiment, the lower surface of the lower wafer LW is adsorbed in the attraction region SA, while the non-attraction region NSA surrounded by the rib 42 (partition wall portion) is not adsorbed. The non-attraction region is not evacuated, and is therefore maintained at atmospheric pressure, for example. Thus, in the first embodiment, the following state is achieved: on the lower surface of the lower wafer LW, the portion facing the attraction region SA is supported by a plurality of pins 43, etc., while the portion facing the non-attraction region NSA is not supported by pins 43, etc.

[0072] If performed by the joining device 1 of the comparative example of the first embodiment. Figure 5 The S4 and S5 treatments shut down the adsorption of CA in the central region and caused the pressing pin 30 to drop, thus... Figure 7 As shown in (B), the center portion of the upper wafer UW is deformed into a concave shape by the pressure applied by the pressing pin 30, and the concave portion is pressed against the center portion of the lower wafer LW. At this time, the center portion of the upper wafer UW deforms along the shape of the front end portion of the pressing pin 30, resulting in deformation. In addition, the portion of the lower wafer LW to which pressure is applied via the upper wafer UW is not supported by the pin 43, etc., and therefore deforms along the shape of the deformed portion of the upper wafer UW, resulting in deformation. In other words, in the process of S5 in the first embodiment, as the center portion of the upper wafer UW deforms into a concave shape, the center portion of the lower wafer LW also deforms into a concave shape in the same way.

[0073] If performed by the joining device 1 of the first embodiment Figure 5The S6 process is shut down by adsorption in the intermediate region MA, thereby peeling off the portion of the upper wafer UW adsorbed in the intermediate region MA from the central region CA side. Furthermore, as... Figure 7 As shown in (C), the formation (progress) of covalent bonds between the bonding surfaces of the upper wafer UW and the lower wafer LW proceeds from the central region CA side.

[0074] If performed by the joining device 1 of the first embodiment Figure 5 In the S7 process, the adsorption in the edge region EA is turned off, thereby peeling off a portion of the upper wafer UW adsorbed in the edge region EA from the middle region MA side. Furthermore, covalent bonds are formed between the bonding surfaces of the upper wafer UW and the lower wafer LW from the center region CA side. Thus, as... Figure 7 As shown in (D), the bonding surfaces of the upper wafer UW and the lower wafer LW are bonded together to form a bonded wafer BW.

[0075] [1-4] Effects of the first embodiment

[0076] As explained above, the bonding device initiates the bonding process between the upper wafer UW and the lower wafer LW by impacting the upper wafer UW with the impact of the impactor (pressing pin 30). However, under the influence of the impactor, local deformation may occur in the center of the upper wafer UW. In a structure where the lower wafer LW is held and held by the entire surface of the lower chuck LC, including the center, as in the bonding device of the comparative example, deformation of the center of the lower wafer LW, which faces the center of the upper wafer UW, is suppressed when pressed by the impactor. Therefore, in the comparative example, bonding occurs with an overlap position offset between the center of the upper wafer UW and the center of the lower wafer LW. Consequently, in a semiconductor device disposed at the center of the bonding wafer BW, defects caused by the overlap position offset may occur.

[0077] In contrast, the bonding apparatus 1 of the first embodiment provides a non-attractive region (NSA) in the lower suction cup LC, which, in conjunction with the concave deformation of the upper wafer UW caused by the impactor, deforms the lower wafer LW into a concave shape. Therefore, the bonding apparatus 1 of the first embodiment can reduce the offset of the overlap position between the upper wafer UW and the lower wafer LW at the center of the bonded wafer BW. Consequently, the bonding apparatus 1 of the first embodiment can suppress defects caused by the offset of the overlap position at the center of the bonded wafer BW, thereby improving the yield of the semiconductor device.

[0078] [2] Second Embodiment

[0079] The bonding apparatus 1 of the second embodiment has the same structure as that of the first embodiment, except that the lower suction cup LC adsorbs and holds the center portion of the lower wafer LW in a concave shape. Furthermore, the bonding apparatus 1 of the second embodiment can perform the same bonding process as that of the first embodiment. Hereinafter, the differences between the bonding apparatus 1 of the second embodiment and that of the first embodiment will be described.

[0080] [2-1] Structure of the lower suction cup LCA

[0081] Figure 8 This is a schematic diagram showing an example of the structure of the lower suction cup LCa provided in the coupling device 1 of the second embodiment. Figure 8 (A) shows the planar layout of the lower suction cup LCa. Figure 8 (B) shows the cross-sectional structure of the lower suction cup LCa. For example... Figure 8 As shown, the lower suction cup LCa has a structure in which the rib 42 is omitted and a plurality of pins 43a are added in the lower suction cup LC of the first embodiment. Hereinafter, the central part of the lower suction cup LCa in top view will be referred to as the "central part CPa".

[0082] The suction area SA of the lower suction cup LCa includes a central portion CPa, which is disposed in the entire area surrounded by ribs 41. The central portion CPa is disposed in the area opposite to the central area CA described in the first embodiment. When the central portion CPa corresponds to the area that is surrounded in a ring shape, the diameter D3 of the central portion CPa is designed, for example, in the range of 1.0 to 15.0 mm.

[0083] A plurality of pins 43a are disposed in the central portion CPa. The height of each of the plurality of pins 43a is designed to be lower than that of the pins 43 disposed in the peripheral region of the central portion CPa (i.e., the region between the central portion CPa and the rib 41). In addition, the height of each of the plurality of pins 43a is designed, for example, to increase from the portion overlapping with the pressing pin 30 in top view toward the outer periphery of the lower suction cup LCa. More specifically, the height of each of the plurality of pins 43a is designed such that the deformation generated in the center of the upper wafer UW by the pressing pin 30 during the bonding process (i.e., the amount of concave deformation at the center of the upper wafer UW) is approximately the same as the deformation generated in the center of the lower wafer LW adsorbed and held in the lower suction cup LCa (i.e., the amount of concave deformation at the center of the lower wafer LW adsorbed along the central portion CPa).

[0084] The other structures of the joining device 1 in the second embodiment are the same as those in the first embodiment.

[0085] [2-2] Joining process in the second embodiment

[0086] Figure 9This is a schematic diagram showing a specific example of the joining process in the joining device 1 of the second embodiment. Figure 9 (A), (B), and (C) respectively show the states of the opposing upper loading stage 11 and lower loading stage 12, and the states of the upper wafer UW and lower wafer LW, after a certain step of the bonding process in the second embodiment. Hereinafter, refer to... Figure 9 A specific example of the joining process of the joining device 1 as a second embodiment will be described.

[0087] If performed by the joining device 1 of the second embodiment Figure 5 The processing of S1 to S3 is as follows: Figure 9 As shown in (A), the upper chuck UC adsorbs and holds the upper wafer UW, and the lower chuck LC adsorbs and holds the lower wafer LW, with the upper wafer UW and the lower wafer LW arranged opposite to each other. In the second embodiment, the lower chuck LC adsorbs the entire surface of the lower wafer LW. Furthermore, since the plurality of pins 43a disposed at the center CPa of the lower wafer LW are set lower than the pins 43a disposed in other areas, the center of the lower wafer LW is deformed into a concave shape by vacuum adsorption and supported by the plurality of pins 43a. That is, in the second embodiment, at the point when the lower chuck LC adsorbs the lower wafer LW, a concave deformation occurs at the center of the lower wafer LW.

[0088] If performed by the joining device 1 of the second embodiment Figure 5 The S4 and S5 treatments shut down the adsorption of CA in the central region and caused the pressing pin 30 to drop, thus... Figure 9 As shown in (B), the center portion of the upper wafer UW is deformed into a concave shape by pressure applied by the front end portion of the pressing pin 30, and the concave portion is pressed against the center portion (the concave portion) of the lower wafer LW. At this time, the center portion of the upper wafer UW deforms along the shape of the front end portion of the pressing pin 30, resulting in deformation. On the other hand, the portion of the lower wafer LW that is pressure applied via the upper wafer UW is supported by multiple pins 43a in conjunction with the adsorption of the lower suction cup LC. Therefore, in the process of S5 in the second embodiment, the deformation of the center portion of the lower wafer LW is suppressed.

[0089] If performed by the joining device 1 of the second embodiment Figure 5 During the S6 and S7 processes, the adsorption in the intermediate region MA and the edge region EA is shut off, thereby peeling off portions of the upper wafer UW adsorbed in the intermediate region MA and the edge region EA from the central region CA side. Thus, similar to the first embodiment, covalent bond formation (progress) occurs between the bonding surfaces of the upper wafer UW and the lower wafer LW from the central region CA side. Therefore, as in the first embodiment... Figure 9As shown in (C), the bonding surfaces of the upper wafer UW and the lower wafer LW are bonded together to form a bonded wafer BW.

[0090] [2-3] Effects of the second embodiment

[0091] As explained above, in the second embodiment, the bonding device 1 generates a concave deformation at the center of the lower wafer LW at the time when the lower suction cup LC adsorbs the lower wafer LW. Furthermore, the concave deformation generated in the lower wafer LW is adjusted to be approximately the same as the concave deformation at the center of the upper wafer UW caused by the impact of the impactor.

[0092] Therefore, the bonding apparatus 1 of the second embodiment, like that of the first embodiment, can reduce the offset of the overlapping position of the upper wafer UW and the lower wafer LW at the center of the bonding wafer BW. Thus, the bonding apparatus 1 of the second embodiment, like that of the first embodiment, can suppress the generation of defects caused by the offset of the overlapping position at the center of the bonding wafer BW, thereby improving the yield of the semiconductor device.

[0093] [3] Third embodiment

[0094] The bonding apparatus 1 of the third embodiment has the same structure as that of the first embodiment, except that the lower suction cup LC adsorbs and holds the center portion of the lower wafer LW in a convex shape. Furthermore, the bonding apparatus 1 of the third embodiment can perform the same bonding process as that of the first embodiment. Hereinafter, the differences between the bonding apparatus 1 of the third embodiment and that of the first embodiment will be described.

[0095] [3-1] Structure of the lower suction cup LCb

[0096] Figure 10 This is a schematic diagram showing an example of the structure of the lower suction cup LCb included in the coupling device 1 of the third embodiment. Figure 10 (A) shows the planar layout of the lower suction cup LCb. Figure 10 (B) shows the cross-sectional structure of the lower suction cup LCb. Figure 10 As shown, the lower suction cup LCb has a structure in which the rib 42 is omitted and a plurality of pins 43b are added in the lower suction cup LC of the first embodiment. Hereinafter, the central part of the lower suction cup LCb in top view will be referred to as the "central part CPb".

[0097] The suction area SA of the lower suction cup LCb includes a central portion CPb, which is disposed in the entire area surrounded by ribs 41. The central portion CPb is disposed in the area opposite to the central area CA described in the first embodiment. When the central portion CPb corresponds to the area that is surrounded in a ring shape, the diameter D4 of the central portion CPb is designed, for example, in the range of 1.0 to 15.0 mm.

[0098] A plurality of pins 43b are disposed in the central portion CPb. The height of each of the plurality of pins 43b is designed to be higher than that of the pins 43 disposed in the peripheral area of ​​the central portion CPb (i.e., the area between the central portion CPb and the rib 41). In addition, the height of each of the plurality of pins 43b is designed, for example, to decrease from the portion overlapping with the pressing pin 30 in top view toward the outer periphery of the lower suction cup LCb. More specifically, the height of each of the plurality of pins 43b is designed such that the deformation generated in the center of the upper wafer UW by the pressing pin 30 during the bonding process (i.e., the amount of concave deformation at the center of the upper wafer UW) is approximately the same as the deformation generated in the center of the lower wafer LW adsorbed and held in the lower suction cup LCb (i.e., the amount of convex deformation at the center of the lower wafer LW adsorbed along the central portion CPb).

[0099] The other structures of the coupling device 1 in the third embodiment are the same as those in the first embodiment.

[0100] [3-2] Joining process in the third embodiment

[0101] Figure 11 This is a schematic diagram showing a specific example of the joining process in the joining device 1 of the third embodiment. Figure 11 (A), (B), and (C) respectively show the states of the opposing upper loading stage 11 and lower loading stage 12, and the upper wafer UW and lower wafer LW, after a certain step of the bonding process in the third embodiment. Hereinafter, refer to... Figure 11 A specific example of the joining process of the joining device 1 as a joining method in the third embodiment will be described.

[0102] If performed by the coupling device 1 of the third embodiment Figure 5 The processing of S1 to S3 is as follows: Figure 11 As shown in (A), the upper chuck UC adsorbs and holds the upper wafer UW, and the lower chuck LC adsorbs and holds the lower wafer LW, with the upper wafer UW and the lower wafer LW arranged opposite to each other. In the third embodiment, the lower chuck LC adsorbs the entire surface of the lower wafer LW. Furthermore, since the plurality of pins 43b disposed at the center CPb of the lower wafer LW are set higher than the pins 43b disposed in other areas, the center of the lower wafer LW is deformed into a convex shape by vacuum adsorption and supported by the plurality of pins 43b. That is, in the third embodiment, at the time when the lower chuck LC adsorbs the lower wafer LW, deformation occurs at the center of the lower wafer LW.

[0103] If performed by the coupling device 1 of the third embodiment Figure 5 The S4 and S5 treatments shut down the adsorption of CA in the central region and caused the pressing pin 30 to drop, thus... Figure 11As shown in (B), the center portion of the upper wafer UW is deformed into a concave shape by pressure applied by the front end portion of the pressing pin 30, and the concave portion is pressed against the center portion of the lower wafer LW (the convex portion). At this time, the center portion of the upper wafer UW deforms along the shape of the front end portion of the pressing pin 30, resulting in deformation. On the other hand, the portion of the lower wafer LW that is pressure applied via the upper wafer UW is supported by multiple pins 43b accompanied by the adsorption of the lower suction cup LC. Therefore, in the process of S5 in the third embodiment, the deformation of the center portion of the lower wafer LW is suppressed.

[0104] If performed by the coupling device 1 of the third embodiment Figure 5 During the S6 and S7 processes, the adsorption in the intermediate region MA and the edge region EA is shut off, thereby peeling off portions of the upper wafer UW adsorbed in the intermediate region MA and the edge region EA from the central region CA side. Thus, similar to the first embodiment, covalent bond formation (progress) occurs between the bonding surfaces of the upper wafer UW and the lower wafer LW from the central region CA side. Therefore, as in the first embodiment... Figure 11 As shown in (C), the bonding surfaces of the upper wafer UW and the lower wafer LW are bonded together to form a bonded wafer BW.

[0105] [3-3] Effects of the third embodiment

[0106] As explained above, at the moment when the lower chuck LC picks up the lower wafer LW, the bonding device 1 of the third embodiment generates a convex deformation at the center of the lower wafer LW. Furthermore, the convex deformation generated in the lower wafer LW is adjusted to be approximately the same as the concave deformation at the center of the upper wafer UW caused by the impact of the impactor.

[0107] Therefore, the bonding apparatus 1 of the third embodiment, like that of the first embodiment, can reduce the offset of the overlapping position of the upper wafer UW and the lower wafer LW at the center of the bonding wafer BW. Thus, the bonding apparatus 1 of the third embodiment, like that of the first embodiment, can suppress defects caused by the offset of the overlapping position at the center of the bonding wafer BW, thereby improving the yield of the semiconductor device.

[0108] [4] Other

[0109] The above-described embodiments can be modified in a wide variety of ways.

[0110] Figure 12 This is a schematic diagram illustrating a specific example of the joining process of the joining device 1 in a modified example of the first embodiment, showing an example of the cross-sectional structure of the lower suction cup LC included in the joining device 1 in the modified example of the first embodiment. Figure 12As shown, in a variation of the first embodiment, the lower suction cup LC has a structure that adds at least one pin 42c to the lower suction cup LC of the first embodiment. The height of the pin 42c is designed so that no contact occurs when the pressing pin 30 presses the center of the lower wafer LW via the upper wafer UW. In this way, the lower suction cup LC can also have a pin 42c that does not contribute to the support of the lower wafer LW.

[0111] In this specification, the bonding apparatus 1 is used to bond two wafers, but it is not limited to this. For example, the lower wafer LW and the upper wafer UW may each be wafers obtained by bonding multiple wafers. That is, the bonded wafer formed by the bonding apparatus 1 may also have a structure in which three or more wafers are bonded.

[0112] In this specification, the upper suction cup UC and the lower suction cup LC are illustrated as pin suction cups, but they can each be other types of suction cups. The upper suction cup UC preferably has the function of sequentially closing the suction from the inside to the outside of the upper wafer UW. The lower suction cup LC can have a structure similar to the partition portion SP or the center portion CP. For example, in the first embodiment, the lower suction cup LC has a structure that does not suction and support the inner portion of the partition portion SP when viewed from above, but suctions and supports the outer portion. In the second embodiment, the lower suction cup LC has a support member that, when a wafer is suctioned, transforms the portion of the lower wafer LW located in the center portion CP into a concave shape. In the third embodiment, the lower suction cup LC has a support member that, when the lower wafer LW is suctioned, transforms the portion of the lower wafer LW located in the center portion CP into a convex shape.

[0113] In this specification, the "pins" and "ribs" of the upper suction cup UC and the lower suction cup LC are formed, for example, by machining the main body. A "region" can also be considered as a structure included by the upper suction cup UC or the lower suction cup LC. For example, if the lower suction cup LC is defined as including an attraction region SA and a non-attraction region NSA, the attraction region SA and the non-attraction region NSA are respectively associated with different regions above the main body 40. "Height" is measured with the main body 20 or 40 as a reference. Structures other than the main body 20 or 40 can also be used as a reference for "height." "Top view" corresponds, for example, to the state of viewing the XY plane (a plane parallel to the surface of the main body 20 or 40) formed by the X and Y directions from the Z direction.

[0114] While some embodiments of the invention have been described, these embodiments are given by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in a wide variety of other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and / or variations thereof are included in the scope and spirit of the invention, and are included within the scope of the invention as set forth in the claims and their equivalents.

Claims

1. A bonding apparatus for performing a bonding process of bonding a first surface of a first substrate and a second surface of a second substrate, comprising: The first suction cup is capable of holding the third surface of the first substrate that is opposite to the first surface; The second suction cup, capable of holding the fourth surface of the second substrate opposite to the second surface, is disposed above the first suction cup; and A pressing pin is located at the center of the second suction cup, has a front end portion extending in the first direction, and is configured to be able to move up and down in the first direction. The first suction cup has a first rib, which, when viewed from above, separates a first region including a region overlapping the front end portion of the pressing pin and a second region surrounding the outer periphery of the first region. The first suction cup, on its fifth surface opposite to the second suction cup, has a plurality of pins arranged at intervals in the second region. The area in the first region that overlaps with the front end portion in a top view does not have these pins. The outer diameter of the front end portion of the pressing pin is in the range of 1.0~10.0 mm. The inner diameter of the first rib is in the range of 1.0~15.0 mm.

2. The joining device according to claim 1, The first suction cup has a suction port connected to the fifth surface in the second region. When the first suction cup holds the third surface of the first substrate, the portion of the fifth surface of the first suction cup corresponding to the first region is open to the atmosphere, and the portion corresponding to the second region is evacuated through the suction port.

3. The joining device according to claim 1, The fifth surface of the first suction cup has a second rib, which is arranged to surround each of the first region and the second region. Viewed from above, the outer diameter of the front end portion of the pressing pin is smaller than the inner diameter of the first rib.

4. A bonding apparatus for performing a bonding process of bonding a first surface of a first substrate and a second surface of a second substrate, comprising: The first suction cup is capable of holding the third surface of the first substrate that is opposite to the first surface; The second suction cup, capable of holding the fourth surface of the second substrate opposite to the second surface, is disposed above the first suction cup; and A pressing pin is located at the center of the second suction cup, has a front end portion extending in the first direction, and is configured to be able to move up and down in the first direction. The first suction cup has a first region, which, when viewed from above, includes a region overlapping with the front end portion of the pressing pin, and a second region surrounding the outer periphery of the first region. The first suction cup has a plurality of pins arranged at intervals on its fifth surface opposite to the second suction cup, and the height of the pins in the first region is lower than the height of the pins in the second region.

5. A joining method, Using the bonding device according to claim 1 or 4, the first substrate is held by the first suction cup, the second substrate is held by the second suction cup, and the first substrate and the second substrate are bonded together.

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