Bonding device and bonding method

Abstract

The invention provides a bonding apparatus and a bonding method, which can properly correct the height of the peripheral part of a substrate. This joining device is provided with a first holding unit, a second holding unit, a pushing unit, and a control unit. The first holding portion holds the first substrate from below the first substrate. The second holding portion is disposed above the first holding portion and holds the second substrate from above the second substrate. The pushing part is arranged on the second holding part and is used for pushing the central part of the second substrate downwards. The first holding portion has an outer suction portion, an inner suction portion, and a deformation portion. The outer adsorption portion adsorbs an outer peripheral portion of the first substrate. The inner adsorption portion adsorbs a portion of the first substrate inside of the outer peripheral portion. The deformation portion relatively deforms the outer suction portion and the inner suction portion. The control unit acquires information on the height of the outer peripheral portion of the first substrate from the reference surface, and controls the deformation unit on the basis of the acquired information.

Description

Technical Field

[0001] The present disclosure relates to a joining device and a joining method. Background Art

[0002] Conventionally, there is known a bonding apparatus for bonding substrates such as semiconductor wafers to each other (see Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2015-095579 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] The present disclosure provides a technology capable of appropriately correcting the height of the outer peripheral portion of a substrate.

[0008] Solutions for solving problems

[0009] A bonding device according to one embodiment of the present disclosure includes a first holding portion, a second holding portion, a pushing portion, and a control portion. The first holding portion holds the first substrate from below. The second holding portion is arranged above the first holding portion and holds the second substrate from above. The pushing portion is provided on the second holding portion and is used to push down the central portion of the second substrate. The first holding portion includes an outer adsorption portion, an inner adsorption portion, and a deformation portion. The outer adsorption portion adsorbs the outer peripheral portion of the first substrate. The inner adsorption portion adsorbs the portion of the first substrate that is closer to the inner side than the outer peripheral portion. The deformation portion deforms the outer adsorption portion relative to the inner adsorption portion. The control portion obtains information on the height of the outer peripheral portion of the first substrate from a reference plane and controls the deformation portion based on the obtained information.

[0010] Effects of the Invention

[0011] According to the present disclosure, the height of the outer peripheral portion of the substrate can be appropriately corrected. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic plan view showing the structure of the joining system according to the first embodiment.

[0013] Figure 2 It is a schematic side view showing the structure of the joining system according to the first embodiment.

[0014] Figure 3 It is a schematic side view of the upper wafer and the lower wafer according to the first embodiment.

[0015] Figure 4It is a schematic diagram showing the structure of the bonding apparatus according to the first embodiment.

[0016] Figure 5 It is a schematic diagram showing the structure of the bonding apparatus according to the first embodiment.

[0017] Figure 6 Schematic diagram showing the configuration of a first holding portion and a second holding portion according to the first embodiment.

[0018] Figure 7 This is a schematic cross-sectional view showing the structure of the first holding portion according to the first embodiment.

[0019] Figure 8 It is a schematic plan view showing the structure of the first holding portion according to the first embodiment.

[0020] Figure 9 This is a schematic plan view showing the position of the adsorption surface when the outer adsorption portion according to the first embodiment is expanded.

[0021] Figure 10 It is a schematic cross-sectional view showing the structure of the deformation portion according to the first embodiment.

[0022] Figure 11 This is a flowchart showing the procedure of processing executed by the joining system according to the first embodiment.

[0023] Figure 12 This is a flowchart showing an example of a specific procedure of the processing shown in step S109.

[0024] Figure 13 This is a schematic cross-sectional view showing a method of expanding the outer suction portion.

[0025] Figure 14 It is a schematic plan view showing the structure of a deformation portion according to the second embodiment. DETAILED DESCRIPTION

[0026] Below, with reference to the accompanying drawings, a method for implementing the joining device and joining method disclosed herein (hereinafter referred to as an "embodiment") is described in detail. The present disclosure is not limited by this embodiment. Furthermore, the various embodiments can be appropriately combined within the scope of not causing inconsistencies in the processing contents. In the various embodiments below, the same reference numerals are used for the same parts, and repeated descriptions are omitted.

[0027] In the following embodiments, terms such as "fixed," "orthogonal," "perpendicular," or "parallel" may be used. However, these terms do not necessarily mean "fixed," "orthogonal," "perpendicular," or "parallel." Specifically, these terms allow for variations in manufacturing accuracy, installation accuracy, and the like.

[0028] In the drawings referenced below, to facilitate understanding, an orthogonal coordinate system is sometimes shown, defining mutually orthogonal X-axis, Y-axis, and Z-axis directions, with the positive Z-axis direction being vertically upward. Furthermore, the direction of rotation about the vertical axis is sometimes referred to as the θ direction.

[0029] The bonding device described in Patent Document 1, when bonding substrates, pushes down the center of a first substrate held by a first holding portion, bringing it into contact with the center of a second substrate held by a second holding portion. This bonds the centers of the two substrates together through intermolecular forces, with the bonding area extending from the center of the substrates toward the outer edges.

[0030] Here, the thickness of the outer periphery of the first substrate or the second substrate sometimes becomes thinner than the thickness of other parts due to the previous process of bonding, such as chemical mechanical polishing (CMP) or etching. In such a case, the height of the outer periphery of the first substrate or the second substrate becomes lower. In this way, the reference point of the outer periphery of the first substrate and the reference point of the outer periphery of the second substrate are offset. For example, when the thickness of the outer periphery of the second substrate is thinner than the thickness of other parts, after the first substrate and the second substrate are bonded, a radially inward strain component is generated in the first substrate with respect to the second substrate. As a result, there is a risk of reduced bonding accuracy of the outer periphery.

[0031] Therefore, a technology for appropriately correcting the height of the outer peripheral portion of the substrate is desired.

[0032] (First embodiment)

[0033] <Structure of the joint system>

[0034] First, refer to Figures 1 to 3 The structure of the joining system 1 according to the first embodiment will be described. Figure 1 It is a schematic plan view showing the structure of the joining system 1 according to the first embodiment. Figure 2 It is a schematic side view showing the structure of the joining system 1 according to the first embodiment. Figure 3 It is a schematic side view of the upper wafer W1 and the lower wafer W2 according to the first embodiment.

[0035] Figure 1 and Figure 2The bonding system 1 shown forms a superposed wafer T by bonding a first substrate W1 and a second substrate W2 .

[0036] The first substrate W1 is a semiconductor substrate such as a silicon wafer or a compound semiconductor wafer on which a plurality of electronic circuits are formed. The second substrate W2 is a bare wafer without any electronic circuits formed thereon. The first substrate W1 and the second substrate W2 have substantially the same diameter.

[0037] Furthermore, an electronic circuit may be formed on the second substrate W2. As the compound semiconductor wafer, for example, a wafer including gallium arsenide, silicon carbide, gallium nitride, and indium phosphide can be used, but the present invention is not limited thereto.

[0038] Hereinafter, the first substrate W1 is referred to as the "upper wafer W1," and the second substrate W2 is referred to as the "lower wafer W2." That is, the upper wafer W1 is an example of the first substrate, and the lower wafer W2 is an example of the second substrate. Furthermore, when referring to the upper wafer W1 and the lower wafer W2 collectively, they are sometimes referred to as "wafer W."

[0039] In addition, in the following, Figure 3 As shown, the surface of the upper wafer W1 that is bonded to the lower wafer W2 is referred to as the "bonding surface W1j," and the surface opposite to the bonding surface W1j is referred to as the "non-bonding surface W1n." Furthermore, the surface of the lower wafer W2 that is bonded to the upper wafer W1 is referred to as the "bonding surface W2j," and the surface opposite to the bonding surface W2j is referred to as the "non-bonding surface W2n."

[0040] like Figure 1 As shown, the bonding system 1 includes a loading / unloading station 2 and a processing station 3. The loading / unloading station 2 and the processing station 3 are arranged in this order along the positive direction of the X-axis. The loading / unloading station 2 and the processing station 3 are integrally connected.

[0041] The loading / unloading station 2 includes a loading platform 10 and a transfer area 20. The loading platform 10 includes multiple loading plates 11. Cassettes C1, C2, and C3, which hold multiple (e.g., 25) substrates in a horizontal position, are placed on each loading plate 11. For example, cassette C1 holds an upper wafer W1, cassette C2 holds a lower wafer W2, and cassette C3 holds a stacked wafer T.

[0042] The conveyance area 20 is arranged adjacent to the X-axis positive direction side of the mounting table 10. The conveyance area 20 is provided with a conveyance path 21 extending in the Y-axis direction and a conveyance device 22 movable along the conveyance path 21.

[0043] The transfer device 22 is movable not only in the Y-axis direction but also in the X-axis direction and can rotate about the Z-axis. Furthermore, the transfer device 22 transfers the upper wafer W1, the lower wafer W2, and the overlapped wafer T between the cassettes C1 to C3 placed on the mounting plate 11 and the third processing block G3 of the processing station 3, which will be described later.

[0044] The number of cassettes C1 to C3 placed on the placement plate 11 is not limited to the number shown in the figure. In addition to the cassettes C1, C2, and C3, a cassette for collecting defective substrates may be placed on the placement plate 11.

[0045] The processing station 3 is provided with a plurality of processing blocks, for example, three processing blocks G1, G2, and G3, each equipped with various devices. Figure 1 The first processing block G1 is provided on the back side of the processing station 3 ( Figure 1 The second processing block G2 is provided on the negative side of the Y axis. Figure 1 A third processing block G3 is provided on the negative X-axis side.

[0046] The first processing block G1 is equipped with a surface modification device 30 for modifying the bonding surfaces W1j and W2j of the upper and lower wafers W1 and W2. The surface modification device 30 modifies the bonding surfaces W1j and W2j of the upper and lower wafers W1 and W2 by cleaving the SiO2 bonds in the bonding surfaces W1j and W2j of the upper and lower wafers W1 and W2 into single SiO bonds, thereby modifying the bonding surfaces W1j and W2j so that the bonding surfaces W1j and W2j can be easily hydrophilized.

[0047] Furthermore, the first processing block G1 is provided with a surface hydrophilizing device 40. The surface hydrophilizing device 40 hydrophilizes the bonding surfaces W1j and W2j of the upper wafer W1 and the lower wafer W2 using, for example, pure water, and cleans the bonding surfaces W1j and W2j.

[0048] In the surface hydrophilization device 40, for example, pure water is supplied onto the upper wafer W1 or the lower wafer W2 while rotating the upper wafer W1 or the lower wafer W2 held on a rotating holding plate. The pure water supplied onto the upper wafer W1 or the lower wafer W2 thus spreads over the bonding surfaces W1j and W2j of the upper wafer W1 or the lower wafer W2, thereby hydrophilizing the bonding surfaces W1j and W2j.

[0049] Here, an example is shown in which the surface modification device 30 and the surface hydrophilization device 40 are arranged in a horizontal arrangement. However, the surface hydrophilization device 40 may be stacked above or below the surface modification device 30 .

[0050] like Figure 2As shown, the second processing block G2 includes a bonding device 41, a first temperature control device 42, and a second temperature control device 43. The bonding device 41 bonds the hydrophilized upper wafer W1 and the lower wafer W2 by intermolecular force. Details of the bonding device 41 will be described later.

[0051] The first temperature adjustment device 42 adjusts the temperature distribution of the upper wafer W1 before forming the superposed wafer T. The second temperature adjustment device 43 adjusts the temperature distribution of the lower wafer W2 before forming the superposed wafer T. In addition, in this embodiment, the first temperature adjustment device 42 and the second temperature adjustment device 43 are provided separately from the bonding device 41, but they can also be provided as part of the bonding device 41.

[0052] In the third processing block G3, for example, a first position adjustment device 51, a second position adjustment device 52, and conveying devices 53 and 54 are sequentially arranged from top to bottom. In addition, the arrangement position of each device in the third processing block G3 is not limited to Figure 2 The configuration position is shown. The first position adjustment device 51 adjusts the horizontal orientation of the upper wafer W1 and flips the upper wafer W1 upside down so that the bonding surface W1j of the upper wafer W1 faces downward. The second position adjustment device 52 adjusts the horizontal orientation of the lower wafer W2. The conveyor device 53 temporarily mounts the upper wafer W1. The conveyor device 54 temporarily mounts the lower wafer W2 and the overlapped wafer T.

[0053] In addition, if Figure 1 As shown, a transfer area 60 is formed in an area surrounded by the first processing block G1, the second processing block G2, and the third processing block G3. A transfer device 61 is disposed in the transfer area 60. The transfer device 61 includes a transfer arm that is movable in the vertical direction, the horizontal direction, and around the vertical axis.

[0054] The transfer device 61 moves within the transfer area 60 and transfers the upper wafer W1 , the lower wafer W2 , and the overlapped wafer T to predetermined devices in the first processing block G1 , the second processing block G2 , and the third processing block G3 adjacent to the transfer area 60 .

[0055] Furthermore, the joining system 1 includes a control device 70. The control device 70 controls the operation of the joining system 1. The control device 70 controls the operation of the joining system 1 based on signals from switches, various sensors, and the like.

[0056] The control device 70 includes a microcomputer including a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), input / output ports, and various circuits. The control device 70 controls the operation of the bonding system 1 by, for example, reading and executing a program stored in a storage unit 72.

[0057] Next, refer to Figure 4 and Figure 5 An example of the bonding apparatus 41 according to the first embodiment will be described. Figure 4 and Figure 5 Schematic diagram showing the structure of the bonding device 41 according to the first embodiment. Figure 4 As shown, the bonding apparatus 41 includes a process container 210 whose interior can be sealed. A loading / unloading port 211 is formed on the side of the process container 210 on the transfer area 60 side, and an opening / closing gate 212 is provided at the loading / unloading port 211. The upper wafer W1, the lower wafer W2, and the overlapped wafer T are loaded and unloaded through the loading / unloading port 211.

[0058] like Figure 5 As shown, a first holding portion 230 and a second holding portion 231 are provided within the processing container 210. The first holding portion 230 holds the lower wafer W2 from below, with its bonding surface W2j facing upward. The second holding portion 231 is provided above the first holding portion 230 and holds the upper wafer W1 from above, with its bonding surface W1j facing downward. The first holding portion 230 and the second holding portion 231 are, for example, vacuum holding disks.

[0059] The first holding portion 230 is supported by a first moving portion 291 provided below the first holding portion 230 . On the other hand, the second holding portion 231 is supported by a supporting member 280 provided on the top surface of the processing container 210 .

[0060] The first moving portion 291 moves the first holding portion 230 in the horizontal direction (Y-axis direction) as described later. The first moving portion 291 is configured to allow the first holding portion 230 to be movable in the vertical direction and rotatable around the vertical axis.

[0061] The first moving portion 291 is attached to a pair of guide rails 295 provided on the lower surface side of the first moving portion 291 and extending in the horizontal direction (Y-axis direction). The first moving portion 291 is configured to be movable along the guide rails 295. The guide rails 295 are provided on the second moving portion 296.

[0062] The second moving portion 296 is attached to a pair of guide rails 297 provided on the lower surface of the second moving portion 296 and extending in the horizontal direction (X-axis direction). The second moving portion 296 is configured to be movable along the guide rails 297. The pair of guide rails 297 are provided on a mounting portion 298 provided on the bottom surface of the processing container 210.

[0063] The first moving portion 291 and the second moving portion 296 constitute a moving mechanism 290. The moving mechanism 290 moves the first holding portion 230 relative to the second holding portion 231. The moving mechanism 290 also moves the first holding portion 230 between a substrate transfer position and a bonding position.

[0064] The substrate handover position is a position where the second holding portion 231 receives the upper wafer W1 from the conveying device 61, and a position where the first holding portion 230 receives the lower wafer W2 from the conveying device 61 and the first holding portion 230 hands over the overlapping wafer T to the conveying device 61. The substrate handover position is a position where the overlapping wafer T produced in the nth (n is a natural number greater than 1) bonding is continuously carried out and the upper wafer W1 and the lower wafer W2 to be bonded in the n+1th bonding are continuously carried in. The substrate handover position is, for example, Figure 4 and Figure 5 Position shown.

[0065] When transferring the upper wafer W1 to the second holding section 231, the transfer device 61 enters directly below the second holding section 231. Furthermore, when receiving the overlapped wafer T from the first holding section 230 and transferring the lower wafer W2 to the first holding section 230, the transfer device 61 enters directly above the first holding section 230. The first holding section 230 and the second holding section 231 are laterally offset, and the vertical distance between the first holding section 230 and the second holding section 231 is also large, making it easier for the transfer device 61 to enter.

[0066] On the other hand, the bonding position is a position (opposing position) where the upper wafer W1 and the lower wafer W2 are facing each other with a predetermined distance therebetween. Figure 6 At the bonding position, the vertical spacing between the upper wafer W1 and the lower wafer W2 is narrower than at the substrate handover position. Furthermore, unlike at the substrate handover position, the upper wafer W1 and the lower wafer W2 overlap when viewed in the vertical direction at the bonding position.

[0067] The moving mechanism 290 moves the relative position between the first holding portion 230 and the second holding portion 231 in the horizontal direction (both the X-axis and the Y-axis) and the vertical direction. While the moving mechanism 290 in this embodiment moves the first holding portion 230, it can also move either or both. Furthermore, the moving mechanism 290 can also rotate the first holding portion 230 or the second holding portion 231 about the vertical axis.

[0068] Next, refer to Figure 6 The structures of the first holding portion 230 and the second holding portion 231 will be described. Figure 6 Schematic diagram showing the structure of the first holding portion 230 and the second holding portion 231 according to the first embodiment.

[0069] like Figure 6 As shown, the first retaining portion 230 is divided into multiple (e.g., two) regions 230a and 230b along its radial direction. These regions 230a and 230b are arranged sequentially from the center to the outer edge of the first retaining portion 230. Region 230a is formed into a perfect circle when viewed from above, while region 230b is formed into an annular ring when viewed from above. Region 230b may also have multiple arc-shaped areas (small regions) along the circumference.

[0070] Suction pipes 260a and 260b are independently provided in each region 230a and 230b. Each suction pipe 260a and 260b is connected to a different vacuum pump 261a and 261b. Thus, the first holding unit 230 can vacuum-absorb the lower wafer W2 in each region 230a and 230b.

[0071] The first holding portion 230 is provided with a plurality (eg, three) of holding pins 265 that are movable vertically. The lower wafer W2 is placed on the upper ends of the holding pins 265. Alternatively, the lower wafer W2 may be vacuum-adsorbed on the upper ends of the holding pins 265.

[0072] The plurality of holding pins 265 rises, protruding from the suction surface of the first holding unit 230. In this state, the plurality of holding pins 265 receive the lower wafer W2 from the transfer device 61. Thereafter, the plurality of holding pins 265 descends, causing the lower wafer W2 to contact the suction surface of the first holding unit 230. The first holding unit 230 then horizontally vacuum-suctions the lower wafer W2 at multiple locations on the suction surface.

[0073] like Figure 6As shown, the second retaining portion 231 is also divided into multiple (e.g., three) regions 231a, 231b, and 231c along the radial direction of the second retaining portion 231. These regions 231a, 231b, and 231c are arranged in order from the center to the outer edge of the second retaining portion 231. Region 231a is formed into a perfect circle when viewed from above, and regions 231b and 231c are formed into annular rings when viewed from above.

[0074] Suction pipes 240a, 240b, 240c are independently provided in each region 231a, 231b, 231c. Each suction pipe 240a, 240b, 240c is connected to a different vacuum pump 241a, 241b, 241c. The second holding unit 231 can vacuum-absorb the upper wafer W1 in each region 231a, 231b, 231c.

[0075] The second holding portion 231 is provided with a plurality of holding pins 245 that can be raised and lowered vertically. The holding pins 245 are connected to a vacuum pump 246, which operates to vacuum-absorb the upper wafer W1. The upper wafer W1 is vacuum-absorbed to the lower ends of the holding pins 245. Ring-shaped suction pads may also be used in place of the holding pins 245.

[0076] The plurality of holding pins 245 are lowered by a drive unit (not shown) and protrude from the suction surface of the second holding unit 231. In this state, the plurality of holding pins 245 vacuum-suction the upper wafer W1, receiving the upper wafer W1 from the transfer device 61. The plurality of holding pins 245 then ascend, bringing the upper wafer W1 into contact with the suction surface of the second holding unit 231. Next, the second holding unit 231 operates the vacuum pumps 241a, 241b, and 241c to horizontally vacuum-suction the upper wafer W1 in each of the regions 231a, 231b, and 231c.

[0077] The second holding portion 231 also includes a through hole 243 at its center that vertically penetrates the second holding portion 231. A pusher 250 is inserted through the through hole 243. The pusher 250 pushes down the center of the upper wafer W1, which is spaced apart from the lower wafer W2, to bring the upper wafer W1 into contact with the lower wafer W2.

[0078] The pushing portion 250 includes a pushing pin 251 and an outer cylinder 252 serving as an elevating guide for the pushing pin 251. The pushing pin 251 is inserted into the through hole 243 by a driving portion (not shown) having a built-in motor, for example, and protrudes from the suction surface of the second holding portion 231 to push down the center of the upper wafer W1.

[0079] Next, refer to Figures 7 to 10 Next, the structure of the first holding portion 230 according to the first embodiment will be described. Figure 7It is a schematic cross-sectional view showing the structure of the first holding portion 230 according to the first embodiment. Figure 8 It is a schematic plan view showing the structure of the first holding portion according to the first embodiment.

[0080] Figure 9 This is a schematic plan view showing the position of the adsorption surface when the outer adsorption portion according to the first embodiment is expanded. Figure 10 : is a schematic cross-sectional view showing the structure of the deformation portion involved in the first embodiment. The first holding portion 230 has a function of deforming the height (shape) of the outer peripheral side of the adsorption surface 300 of the first holding portion 230 and holding it to correct the height of the outer peripheral portion of the lower wafer W2. Figure 7 In the following figures, the suction surface 300 of the first holding portion 230 is depicted as being flat, but the suction surface 300 may also have a structure including a plurality of ribs extending in the radial direction and a plurality of ribs surrounding the circumferential direction.

[0081] Here, the thickness of the outer periphery of the upper wafer W1 or the lower wafer W2 sometimes becomes thinner than the thickness of other parts due to the previous process of bonding, such as chemical mechanical polishing or etching. In such a case, the height of the outer periphery of the upper wafer W1 or the lower wafer W2 becomes lower. This causes an offset between the reference point of the outer periphery of the upper wafer W1 and the reference point of the outer periphery of the lower wafer W2, posing a risk of reduced bonding accuracy. Therefore, the first holding portion 230 controls the height of the outer periphery of the suction surface 300 of the first holding portion 230 to expand and contract the bonding surface W2j according to the height of the outer periphery of the lower wafer W2, thereby reducing the offset of the reference point.

[0082] Specifically, the first holding portion 230 includes an outer holding portion 301 that holds the outer periphery of the lower wafer W2, and an inner holding portion 302 that holds the portion of the lower wafer W2 inwardly of the outer periphery. The inner holding portion 302 is formed into a true circle in a plan view, and the outer holding portion 301 is formed into a circular ring at an adjacent position outside the inner holding portion 302.

[0083] The inner adsorption portion 302 has the above-mentioned regions 230a and 230b (see Figure 6 The outer suction portion 301 overlaps a portion of the region 230b and is configured to apply the suction pressure of the region 230b to the outer periphery of the lower wafer W2. For example, the outer suction portion 301 includes a plurality of internal flow paths 305 extending radially outward from the suction tube 260b, and suction holes 306 connected from each internal flow path 305 to the suction surface 300. Thus, the first holding portion 230 suctions the inner region, including the center, of the lower wafer W2 via the inner suction portion 302, while suctioning the outer periphery of the lower wafer W2 via the outer suction portion 301.

[0084] Furthermore, the first holding portion 230 has the function of deforming the outer suction portion 301 and the inner suction portion 302 relative to each other, both inside and outside the first holding portion 230. Specifically, the first holding portion 230 includes a base member 310 mounted on the moving mechanism 290, and a holding member 320 stacked on the base member 310 and directly holding the lower wafer W2. Furthermore, the first holding portion 230 includes a deforming portion 321 inside the holding member 320 that deforms the outer suction portion 301. The deforming portion 321 is provided on the outer periphery of the holding member 320.

[0085] The base member 310 is viewed in a side cross-section along the vertical direction (see Figure 7 ) has a convex shape having a base 311 fixed to the moving mechanism 290 (the moving stage of the moving mechanism 290) and a protrusion 312 that protrudes shortly vertically upward from the center of the base 311. The base member 310 supports the entire holding member 320 in the horizontal direction by fixing the reverse side (back side) of the inner suction portion 302 of the holding member 320 to the upper end surface of the protrusion 312.

[0086] Therefore, a gap 313 is formed between the first retaining member 230, radially outward of the protrusion 312, between the upper surface of the base portion 311 of the base member 310 and the back surface (e.g., the lower surface) of the outer suction portion 301 of the retaining member 320. Here, the bonding device 41 includes a reflector 314 near the first retaining member 230 to reflect light from a displacement meter (not shown) used to measure horizontal position during three-dimensional movement by the moving mechanism 290. The reflector 314 is provided separately from the base member 310 on the moving stage of the moving mechanism 290. If the base member 310 were to deform in response to the deformation of the deformable portion 321 of the first retaining member 230, this could affect the reflection of the adjacent reflector 314.

[0087] Therefore, the first holding portion 230 does not support the back surface of the outer holding portion 301 via the base member 310, thereby preventing the influence of deformation of the outer holding portion 301 from being transmitted to the base member 310. In other words, even if the bonding device 41 is configured to deform the outer holding portion 301, it can stabilize the reflection of the reflective mirror 314 and improve the measurement accuracy near the first holding portion 230, thereby enabling stable positioning of the first holding portion 230.

[0088] Furthermore, the retaining member 320 according to this embodiment has a deformable space 322 constituting the deformable portion 321 on the lower side of the outer suction portion 301 (inside the portion vertically overlapping the outer suction portion 301). The deformable space 322 is a space enclosed by the lower wall 323, upper wall 324, outer peripheral wall 325, and inner peripheral wall 326 of the retaining member 320 when viewed in a vertical cross-section. The deformable space 322 is formed into a rectangular shape with long sides in the horizontal direction when under the same pressure as the outer side of the retaining member 320. The lower wall 323, upper wall 324, outer peripheral wall 325, and inner peripheral wall 326 may be integrally formed, or one portion of the wall may be formed from a different member than the other portions. For example, the retaining member 320 may have the lower wall 323 made of a material having a high elastic modulus (hard), and the upper wall 324 , the outer peripheral wall 325 , and the inner peripheral wall 326 made of a material having an elastic modulus lower than that of the lower wall 323 (soft).

[0089] The upper wall 324 that forms the deformation space 322 is provided with the aforementioned internal flow paths 305 and suction holes 306. Furthermore, the thickness of the upper wall 324 (between the surface (e.g., the upper surface) of the outer suction portion 301 and the deformation space 322) is thinner than the thickness of the lower wall 323 (between the back surface (e.g., the lower surface) of the outer suction portion 301 and the deformation space 322). Therefore, when the internal pressure within the deformation space 322 fluctuates, the upper wall 324 deforms significantly, while the lower wall 323, outer peripheral wall 325, and inner peripheral wall 326 hardly deform. Thus, the first retaining portion 230 deforms the upper wall 324 in response to fluctuations in the internal pressure of the deformation space 322, enabling stable and reliable deformation of the outer suction portion 301.

[0090] In addition, if Figure 8 As shown, the deformation space 322 is formed into a circular ring shape (annular) surrounding the interior of the holding member 320 constituting the suction surface 300. Therefore, the internal pressure of the deformation space 322 is uniformly applied around the circumference of the holding member 320. Consequently, the first holding portion 230 can uniformly deform the outer suction portion 301 along the entire circumference in response to fluctuations in the internal pressure of the deformation space 322.

[0091] For example, by increasing the internal pressure of the deformation space 322, as shown in FIG. Figure 9 As shown, the upper wall 324 bulges out over the entire circumference of the retaining member 320. Figure 9In the figure, white represents the vertical height (position) of the inner suction portion 302, which serves as a reference on the suction surface 300, and darker colors indicate higher heights of the suction surface 300. In this manner, the first holding portion 230 deforms the height of the outer suction portion 301 throughout the entire circumference as the deforming portion 321 deforms, thereby uniformly deforming the outer periphery of the lower wafer W2.

[0092] Return to Figure 7 The coupling device 41 connects the fluid supply and discharge portion 330 to a port on the side surface of the retaining member 320. The fluid supply and discharge portion 330 supplies and discharges the deformation fluid to the deformation space 322. In this embodiment, the deformation fluid is air. Furthermore, the deformation fluid is not limited to air; inert gases such as nitrogen (N2) or liquids such as water and oil may also be used.

[0093] The fluid supply and exhaust section 330 includes a supply and exhaust path 331 connected to a port of the holding member 320 and extending to the outside of the processing container 210. Furthermore, the fluid supply and exhaust section 330 includes, in order from the upstream side to the downstream side of the supply and exhaust path 331, a pump (a pressurizing pump 332 and a depressurizing pump 333), a regulator 334, a valve 335, and a pressure sensor 336.

[0094] The pressure-increasing pump 332 and the pressure-reducing pump 333 are branched, for example, at a position upstream of the regulator 334 and can operate independently under the control of the control device 70. The pressure-increasing pump 332 supplies air to the retaining member 320 to increase the internal pressure of the deformation space 322. The pressure-reducing pump 333 discharges air from the retaining member 320 to reduce the internal pressure of the deformation space 322.

[0095] The regulator 334 is, for example, an electropneumatic regulator, and adjusts the pressure of the air flowing through the supply and exhaust path 331 to a target pressure commanded by the control device 70. Furthermore, the fluid supply and exhaust unit 330 is not limited to using a single regulator 334; for example, a regulator 334 may be used for each of the pressure pump 332 and the pressure reducing pump 333.

[0096] Valve 335 opens and closes the flow path within supply and exhaust path 331 under the control of control device 70. For example, a pneumatically operated valve (AOV) can be used as valve 335, which has the function of opening and closing supply and exhaust path 331 and opening to the atmosphere to allow air to flow in and out. Thus, valve 335 can be opened to the atmosphere when deformation of outer suction portion 301 is complete, allowing deformed portion 321 to immediately return to its original shape. Furthermore, the use of valve 335 is not limited to a single one; for example, valve 335 can be applied to both pressure pump 332 and pressure reducing pump 333.

[0097] Pressure sensor 336 detects the pressure of air supplied to or exhausted from retaining member 320 and transmits this detection information to control device 70. Based on the detection information from pressure sensor 336, control device 70 adjusts the amount of air supplied to deformable portion 321 and closes valve 335 at an appropriate timing. With valve 335 closed, deformation space 322 is maintained at a predetermined internal pressure, allowing upper wall 324 to maintain its deformed state.

[0098] Furthermore, the bonding device 41 is provided with a displacement sensor 340 (an example of a measuring unit) at a position vertically above the first holding portion 230 to detect the height of the outer periphery of the lower wafer W2. The displacement sensor 340 is, for example, provided above the outer adsorption portion 301 of the first holding portion 230 that is arranged at the substrate handover position. The measurement method of the displacement sensor 340 is, for example, a confocal method, a spectroscopic interference method, or a triangulation method. The light source of the displacement sensor 340 is an LED or a laser. The displacement sensor 340 is connected to the control device 70, and the displacement sensor 340 measures the height of the outer periphery of the lower wafer W2 with respect to the adsorption surface 300 as a reference, and sends the measured measurement information to the control device 70.

[0099] The control device 70 can operate the deformation portion 321 based on the measurement information measured by the displacement sensor 340. For example, when the height of the outer peripheral portion of the lower wafer W2 is within the threshold range including the target height, the control device 70 stops the deformation of the deformation portion 321. In addition, when the height of the outer peripheral portion of the lower wafer W2 is outside the threshold range including the target height, the control device 70 deforms the deformation portion 321 according to the deviation from the target height. Figure 7 In the embodiment, a single displacement sensor 340 is provided at a position facing the outer suction portion 301. However, multiple displacement sensors 340 may be provided around the circumference of the outer suction portion 301. Furthermore, the displacement sensor 340 may utilize a first displacement meter for measuring the thickness of the lower wafer W2, described later. Alternatively, an imaging unit (not shown) that captures the side surface of the lower wafer W2 may be used in place of the displacement sensor 340. The height of the outer periphery of the lower wafer W2 may also be determined based on image data of the lower wafer W2 captured by the imaging unit.

[0100] In addition, when the bonding device 41 of this embodiment places the lower wafer W2 on the adsorption surface 300 of the first holding portion 230, the lower wafer W2 is deformed by the deformation of the middle portion in the width direction of the outer adsorption portion 301 (deformation space 322). Here, the so-called middle portion in the width direction of the outer adsorption portion 301 refers to the vicinity of the middle position 301c in the width direction of the outer adsorption portion 301, for example, the central area when the outer adsorption portion 301 is divided into three equal parts in the width direction. Therefore, as Figure 10As shown, the bonding device 41 positions the lower wafer W2 so that the outer edge of the lower wafer W2 is located near the middle position 301c in the width direction of the outer suction portion 301 when holding the lower wafer W2 on the suction surface 300. Figure 10 In FIG. 3 , the widthwise middle position 301 c of the outer suction portion 301 is simply indicated by a dashed line.

[0101] In order to arrange the outer edge of the lower wafer W2 near the middle position 301c in the width direction of the outer suction portion 301, the range of the deformation space 322 is designed to be sized according to the size of the lower wafer W2. For example, when the diameter of the lower wafer W2 is 300mm, the diameter φI of the inner peripheral wall 326 of the deformation space 322 is preferably set in the range of 270mm to 280mm, and the diameter φO of the outer peripheral wall 325 of the deformation space 322 is preferably set in the range of 340mm to 350mm (see Figure 8 ). In this embodiment, the diameter φI of the inner circumferential wall 326 is set to 276 mm, and the diameter φO of the outer circumferential wall 325 is set to 346 mm. Therefore, the width of the outer adsorption portion 301 (deformation space 322) is 70 mm, and the middle position 301c in the width direction of the outer adsorption portion 301 is 35 mm. The diameter from the center of the first retaining portion 230 to the middle position 301c in the width direction of the outer adsorption portion 301 is 276 mm + 35 mm = 311 mm. The boundary between the outer adsorption portion 301 and the inner adsorption portion 302 can be defined by the inner circumferential wall 326. The outer adsorption portion 301 can be understood as the entire portion of the retaining member 320 that is radially outward of the inner circumferential wall 326, and can also be understood as the formation range of the deformation space 322 (between the outer circumferential wall 325 and the inner circumferential wall 326). Alternatively, the boundary between the outer adsorption portion 301 and the inner adsorption portion 302 may be defined by the supporting portion (protrusion 312) and the non-supporting portion (gap 313) of the base member 310 (see Figure 7 ) For example, the ratio of the width of the outer adsorption portion 301 to the radius of the inner adsorption portion 302 is preferably set in a range of approximately 1 / 5 to 3 / 5.

[0102] The bonding device 41 can impart the influence of the deformation shape near the widthwise middle position 301c to the upper wafer W1 and the lower wafer W2 during the deformation of the deformation portion 321 by arranging the outer edge of the lower wafer W2 near the widthwise middle position 301c of the outer suction portion 301. For example, when the thickness of the outer periphery of the lower wafer W2 becomes thinner than the thickness of other portions and the height of the outer periphery of the lower wafer W2 becomes smaller than the threshold range including the target height, the deformation portion 321 (upper wall 324) of the deformation space 322 is bulged so that the height of the outer periphery of the bonding surface W2j falls within the threshold range (see FIG. Figure 13In this way, the bonding apparatus 41 can precisely correct the height of the outer periphery of the lower wafer W2 by utilizing the deformed shape of the center of the outer suction portion 301. By correcting the height of the outer periphery of the lower wafer W2, bonding is performed while also imparting a radially inward strain component to the upper wafer W1, thereby canceling out the strain components. As a result, a decrease in bonding accuracy can be suppressed.

[0103] <Specific Operations of the Joint System>

[0104] Next, refer to Figure 11 The specific operation of the joining system 1 according to the first embodiment will be described. Figure 11 This is a flowchart showing the procedure of processing executed by the joining system 1 according to the first embodiment. Figure 11 The various processes shown are executed based on the control of the control device 70 .

[0105] First, a cassette C1 containing a plurality of upper wafers W1, a cassette C2 containing a plurality of lower wafers W2, and an empty cassette C3 are placed on the loading and unloading station 2. The upper wafers W1 in the cassette C1 are then removed by the transfer device 22 and transferred to the conveyor device 53 located in the third processing block G3 of the processing station 3.

[0106] Next, the upper wafer W1 is transported by the transport device 61 to the surface modification device 30 of the first processing block G1. In the surface modification device 30, oxygen gas, serving as a processing gas, is excited into plasma and ionized in a predetermined reduced pressure atmosphere. These oxygen ions are irradiated onto the bonding surface of the upper wafer W1, thereby subjecting the bonding surface to plasma treatment. Thus, the bonding surface of the upper wafer W1 is modified (step S101).

[0107] Next, the upper wafer W1 is transported by the transport device 61 to the surface hydrophilization device 40 in the first processing block G1. In the surface hydrophilization device 40, pure water is supplied to the upper wafer W1 while rotating the upper wafer W1 held on the rotating holding plate. This hydrophilizes the bonding surface of the upper wafer W1. Furthermore, the bonding surface of the upper wafer W1 is cleaned with this pure water (step S102).

[0108] Next, the upper wafer W1 is transported by the transport device 61 to the first position adjustment device 51 of the third processing block G3. The upper wafer W1 is horizontally adjusted by the first position adjustment device 51 and flipped over (step S103). This positions the grooves of the upper wafer W1 in a predetermined orientation, with the bonding surface W1j of the upper wafer W1 facing downward.

[0109] Next, the upper wafer W1 is transferred by the transfer device 61 to the first temperature control device 42 of the second processing block G2. The temperature of the upper wafer W1 is adjusted by the first temperature control device 42 (step S104). The temperature of the upper wafer W1 is adjusted with the bonding surface W1j of the wafer W1 facing downward. Afterward, the upper wafer W1 is transferred by the transfer device 61 to the bonding device 41.

[0110] The lower wafer W2 is processed by repeating the processes of steps S101 to S104 for the upper wafer W1. First, the lower wafer W2 is taken out of the cassette C2 by the transfer device 22 and transferred to the conveyor device 53 disposed in the third processing block G3.

[0111] Next, the lower wafer W2 is transferred by the transfer device 61 to the surface modification device 30, where the bonding surface W2j of the lower wafer W2 is modified (step S105). Thereafter, the lower wafer W2 is transferred by the transfer device 61 to the surface hydrophilization device 40, where the bonding surface W2j of the lower wafer W2 is hydrophilized and cleaned (step S106).

[0112] Next, the lower wafer W2 is transferred to the second position adjusting device 52 by the transfer device 61. The lower wafer W2 is horizontally oriented by the second position adjusting device 52 (step S107).

[0113] Next, the lower wafer W2 is transferred by the transfer device 61 to the second temperature control device 43 of the second processing block G2. The temperature of the lower wafer W2 is adjusted by the second temperature control device 43 (step S108). The temperature of the lower wafer W2 is adjusted with the bonding surface W2j of the lower wafer W2 facing upward. Afterwards, the lower wafer W2 is transferred by the transfer device 61 to the bonding device 41.

[0114] Next, the upper wafer W1 and the lower wafer W2 are bonded by the bonding device 41 to form a superposed wafer T (step S109). The details of the process of step S109 will be described later. Thereafter, the superposed wafer T is transported by the transport device 61 to the transfer device 54 of the third processing block G3.

[0115] Thereafter, the superimposed wafer T is transferred to the cassette C3 on the mounting table 10 by the transfer device 22. Thus, a series of processes are completed.

[0116] Next, refer to Figure 12 and Figure 13 Come to Figure 11 An example of a specific process of the step of producing the superimposed wafer T in step S109 will be described. Figure 12 This is a flowchart showing an example of a specific procedure of the processing shown in step S109. Figure 13 It is a schematic cross-sectional view showing a method of expanding the outer suction portion 301 .

[0117] First, the control unit 71 controls the first holding unit 230 to suck and hold the lower wafer W2 from below the lower wafer W2 that has been loaded into the bonding device 41. Similarly, the control unit 71 controls the second holding unit 231 to suck and hold the upper wafer W1 that has been loaded into the bonding device 41 from above (step S201). In this case, the relative position between the first holding unit 230 and the second holding unit 231 is Figure 5 The substrate interface position is shown.

[0118] Next, the control unit 71 obtains information on the height of the outer periphery of the lower wafer W2 relative to the adsorption surface 300 from the displacement sensor 340 (step S202). For example, the control unit 71 controls the moving mechanism 290 (see Figure 4 、 Figure 5 ) to move the first holding unit 230 horizontally so that any position on the outer periphery of the lower wafer W2 is positioned directly below the displacement sensor 340. The control unit 71 then obtains height information at any position from the displacement sensor 340. By repeating this process of moving the first holding unit 230 and obtaining height information from the displacement sensor 340, the control unit 71 can obtain height information for the entire circumference of the outer periphery of the lower wafer W2. For example, the control unit 71 uses the average value of the height of the entire circumference of the outer periphery of the lower wafer W2 for subsequent processing.

[0119] Next, the control unit 71 determines whether the height of the outer periphery of the lower wafer W2 relative to the suction surface 300 is within a threshold range that includes a target height (step S203). The target height is determined by measuring the thickness of the lower wafer W2 before it is loaded into the bonding system 1 using a measuring device (not shown). For example, the target height can be determined by measuring the thickness of the center portion of the lower wafer W2 or the average thickness of multiple locations on the lower wafer W2 as measured by the measuring device.

[0120] Then, when the height of the outer periphery of the lower wafer W2 is outside the threshold range including the target height (step S203 : No), the control unit 71 performs the deformation operation of the deformation unit 321 (step S204 ).

[0121] In the deformation operation, first, the control unit 71 releases the suction of the lower wafer W2 by the first holding unit 230 .

[0122] Next, the control unit 71 performs a pressurization process to increase the internal pressure of the deformation space 322 according to the deviation between the height of the outer periphery of the lower wafer W2 and the target height. Specifically, the control unit 71 supplies air to the deformation space 322 using the fluid supply and exhaust unit 330. Figure 13As shown, the upper wall 324 is raised (bulged) vertically upward. At this point, the upper wall 324 is curved into an arched shape with the widthwise middle position 301c as its apex. Therefore, after the first holding portion 230 is deformed, the lower wafer W2, whose outer edge is attracted to the outer holding portion 301 radially inward of the widthwise middle position 301c, is held on the first holding portion 230 in a shape that tilts radially outward and vertically upward.

[0123] The control unit 71 may obtain the amount of air supplied to the deformation space 322 based on a table pre-stored in the storage unit 72 , for example, which associates the deviation between the height of the outer periphery of the lower wafer W2 and the target height with the amount of supplied air.

[0124] Thus, for example, when the thickness of the outer periphery becomes thinner than that of other parts in the front process of bonding and the height of the outer periphery of the lower wafer W2 becomes lower, the height of the outer periphery of the lower wafer W2 can be appropriately corrected and the lower wafer W2 can be maintained during adsorption.

[0125] During the deformation operation of the deformation section 321 in step 204, the control section 71 monitors the height of the outer periphery of the lower wafer W2 by repeating steps S202 and S203. Then, in step S203, when the height of the outer periphery of the lower wafer W2 is within a threshold range including the target height (step S203: "Yes"), the control section 71 stops the deformation operation of the deformation section 321, and again adsorbs and holds the lower wafer W2 by the first holding section 230, and proceeds to step S205. When the outer adsorption section 301 bulges as described above, the lower wafer W2 is held in a state in which the outer periphery of the lower wafer W2 is deformed. In addition, when the height of the outer periphery of the lower wafer W2 is within the threshold range including the target height as initially measured by the displacement sensor 340, the deformation operation of the deformation section 321 is not performed, and the process proceeds to step S205.

[0126] Next, the control unit 71 moves the relative position between the first holding unit 230 and the second holding unit 231 from the substrate transfer position to the substrate transfer position through the moving mechanism 290. Figure 6 The bonding position shown is shown (step S205 ). In step S205 , the control unit 71 adjusts the positions of the upper wafer W1 and the lower wafer W2 in the horizontal direction.

[0127] A plurality of predetermined reference points are formed on the bonding surface W1j of the upper wafer W1. Furthermore, a plurality of predetermined reference points are also formed on the bonding surface W2j of the lower wafer W2. These reference points can be, for example, patterns formed on the upper wafer W1 and the lower wafer W2, respectively. The number of reference points can be arbitrarily set.

[0128] The horizontal positions of the upper wafer W1 and the lower wafer W2 are adjusted using, for example, a first imaging unit and a second imaging unit (not shown). The first imaging unit photographs the reference points formed on the lower surface (joining surface W1j) of the upper wafer W1, and the second imaging unit photographs the reference points formed on the upper surface (joining surface W2j) of the lower wafer W2.

[0129] The image data captured by the first and second camera units is output to the control unit 71. Based on this image data, the control unit 71 controls the moving mechanism 290 to move the first holding unit 230 horizontally so that the reference points of the upper wafer W1 and the lower wafer W2 are aligned. Furthermore, the control unit 71 uses the moving mechanism 290 to rotate the first holding unit 230 about the vertical axis so that the reference points of the upper wafer W1 and the lower wafer W2 are aligned. This adjusts the horizontal positions of the first and second holding units 230, 231, and thereby the horizontal positions of the upper and lower wafers W1 and W2.

[0130] In addition, in step S205, the control unit 71 adjusts the positions of the upper wafer W1 and the lower wafer W2 in the vertical direction. Specifically, the control unit 71 controls the moving mechanism 290 to move the first holding unit 230 vertically upward. As a result, the gap G between the bonding surface W2j of the lower wafer W2 and the bonding surface W1j of the upper wafer W1 (see FIG. 2 ) is increased. Figure 6 ) becomes a predetermined distance, for example, 80 μm to 200 μm. The gap G is adjusted using, for example, a first displacement gauge and a second displacement gauge (not shown). The first displacement gauge measures the thickness of the lower wafer W2 held by the first holding portion 230. The second displacement gauge measures the thickness of the upper wafer W1 held by the second holding portion 231. The thickness measurement is performed, for example, when the moving mechanism 290 moves the second holding portion 231 in the horizontal direction.

[0131] The data measured by the first and second displacement gauges are output to the control unit 71. The control unit 71 controls the moving mechanism 290 based on the data measured by the first and second displacement gauges to adjust the vertical position of the first holding unit 230 so that the gap G becomes the set value.

[0132] Next, the control unit 71 stops the operation of the vacuum pump 241a, and releases the upper wafer W1 from the region 231a (see FIG. Figure 5 ). The control unit 71 then lowers the push pins 251 of the push unit 250 to push down the center of the upper wafer W1, thereby bringing the upper wafer W1 into contact with the lower wafer W2 (step S206). As a result, the centers of the upper wafer W1 and the lower wafer W2 are brought into contact with each other.

[0133] Since the bonding surface W1j of the upper wafer W1 and the bonding surface W2j of the lower wafer W2 have been modified, van der Waals forces (intermolecular forces) are generated between the bonding surfaces W1j and W2j, bonding the bonding surfaces W1j and W2j to each other. Furthermore, since the bonding surface W1j of the upper wafer W1 and the bonding surface W2j of the lower wafer W2 have been hydrophilized, the hydrophilic groups (e.g., OH groups) hydrogen bond, firmly bonding the bonding surfaces W1j and W2j to each other.

[0134] Next, the control unit 71 stops the vacuum pump 241 b to release the upper wafer W1 from being sucked in the region 231 b . Next, the control unit 71 stops the vacuum pump 241 c to release the upper wafer W1 from being sucked in the region 231 c .

[0135] In this way, the vacuum suction of the upper wafer W1 is released in stages from the center to the periphery of the upper wafer W1, and the upper wafer W1 falls toward the lower wafer W2 in stages and abuts against it. Moreover, the bonding of the upper wafer W1 and the lower wafer W2 is sequentially advanced from the center to the periphery (step S207). As a result, the bonding surface W1j of the upper wafer W1 and the bonding surface W2j of the lower wafer W2 abut with their entire surfaces, bonding the upper wafer W1 and the lower wafer W2 to obtain a superimposed wafer T. Afterwards, the control unit 71 causes the push pin 251 to rise to its original position.

[0136] After the stacked wafer T is formed, the control unit 71 controls the moving mechanism 290 to change the relative position between the first holding unit 230 and the second holding unit 231 from Figure 6 The engagement position shown moves to Figure 4 and Figure 5 The substrate transfer position shown is obtained (step S208). For example, the control unit 71 controls the moving mechanism 290 to first lower the first holding unit 230 to increase the vertical distance between the first holding unit 230 and the second holding unit 231. The control unit 71 then controls the moving mechanism 290 to move the first holding unit 230 laterally to offset the first holding unit 230 from the second holding unit 231 in the horizontal direction.

[0137] The control unit 71 then controls the transport device 61 to remove the overlapped wafer T (step S209). Specifically, the control unit 71 first releases the suction of the overlapped wafer T by the first holding unit 230. Next, the control unit 71 raises the plurality of holding pins 265 to transfer the overlapped wafer T to the transport device 61. The control unit 71 then lowers the plurality of holding pins 265 to their original positions.

[0138] As described above, the bonding apparatus 41 according to this embodiment can appropriately correct the height of the outer periphery of the lower wafer W2 by using the deforming portion 321 to relatively deform the outer suction portion 301 and the inner suction portion 302. Thus, for example, if the outer periphery of the bonding surface W2j of the lower wafer W2 is low, the height of the outer periphery of the lower wafer W2 can be sufficiently corrected to bond the lower wafer W2 to the upper wafer W1. As a result, the bonding apparatus 41 can produce an overlapped wafer T with reduced offset between the reference points of the upper wafer W1 and the lower wafer W2.

[0139] In addition, the control unit 71 controls the first holding unit 230 to make the first holding unit 230 hold the lower wafer W2. Thereafter, the control unit 71 obtains the height information of the outer peripheral portion of the lower wafer W2 based on the adsorption surface 300 from the displacement sensor 340, and controls the deformation unit 321 based on the obtained information to deform the outer adsorption unit 301. Thereafter, the control unit 71 controls the outer adsorption unit 301 and the inner adsorption unit 302 to make the outer adsorption unit 301 and the inner adsorption unit 302 adsorb the lower wafer W2.

[0140] In this manner, the control unit 71 temporarily releases the suction of the lower wafer W2, then performs the deformation process on the first holding unit 230 using the deformation unit 321, and then re-adsorbs the lower wafer W2. Therefore, during the deformation process, pressure is less likely to be applied to the lower wafer W2 from the first holding unit 230. Alternatively, the control unit 71 may raise the plurality of holding pins 265 after releasing the suction of the lower wafer W2, thereby performing the deformation process without contact between the lower wafer W2 and the first holding unit 230.

[0141] In addition, here, the example of measuring the height of the outer periphery of the lower wafer W2 is described, but it is not limited to this. The height of the outer periphery of the upper wafer W1 can also be measured. For example, the bonding device 41 can also be equipped with a displacement sensor (not shown) for measuring the height of the outer periphery of the upper wafer W1. In this case, it can also be set to Figure 12 In step S202, the control unit 71 obtains information about the height of the outer periphery of the upper wafer W1 from the displacement sensor. In step S203, the control unit 71 determines whether the total value of the height of the outer periphery of the lower wafer W2 and the height of the outer periphery of the upper wafer W1 is within a threshold range that includes a target total height. Specifically, the control unit 71 may control the deformation unit 321 based on information about the height of the outer periphery of the upper wafer W1 and the height of the outer periphery of the lower wafer W2. Alternatively, the control unit 321 may be controlled using only information about the height of the outer periphery of the upper wafer W1.

[0142] Furthermore, a correction process corresponding to the amount of deviation between the height of the outer peripheral portion of the lower wafer W2 and the target height may be performed not only in the bonding process but also in the subsequent photolithography process.

[0143] (Second embodiment)

[0144] Figure 14 : is a schematic top view showing the structure of the deformation portion 321 involved in the second embodiment. Figure 14 As shown, the deformation portion 321 that deforms the outer adsorption portion 301 may also be of the following structure: a plurality of divided deformation spaces 322A are provided along the circumference of the second holding portion 231, and air is supplied or exhausted to each of the plurality of deformation spaces 322A. Thus, the first holding portion 230 can individually adjust the circumferential deformation of the outer adsorption portion 301 according to the heights measured at multiple locations on the outer periphery of the lower wafer W2. That is, Figure 12 In step S202, when the heights of multiple locations on the outer periphery of the lower wafer W2 are measured, in subsequent steps S203 and S204, the control unit 71 supplies air to the deformation space 322A corresponding to the measured locations according to the deviation between the height of the locations and the target height. In other words, the bonding device 41 can appropriately perform corrections based on the relative difference in the height of the outer periphery of the lower wafer W2. In addition, Figure 14 While the structure is shown as being divided into eight deformation spaces 322A, it goes without saying that the number of divisions and the volume of each space can be freely designed. Furthermore, while the example described here measures the height at multiple locations on the outer periphery of the lower wafer W2, the method for measuring the height of the outer periphery of the lower wafer W2 is not limited to this. For example, the height of the outer periphery of the lower wafer W2 can also be measured while the lower wafer W2 is rotated 360°.

[0145] (Third embodiment)

[0146] In the first embodiment, the case where the height of the outer periphery of the lower wafer W2 is measured in the bonding device 41 is described, but the invention is not limited thereto, and the height of the outer periphery of the lower wafer W2 may also be measured outside the bonding device 41. For example, the height of the outer periphery of the lower wafer W2 may also be measured in a measuring device not shown in the figure in the bonding system 1. The measuring device outputs the information of the measured height of the outer periphery of the lower wafer W2 to the control device 70, and the control device 70 controls the deformation part 321 based on the acquired information. In addition, the height of the outer periphery of the lower wafer W2 may also be measured in a measuring device not shown in the figure outside the bonding system 1. The measuring device outputs the information of the measured height of the outer periphery of the lower wafer W2 to the control device 70 via the network, and the control device 70 controls the deformation part 321 based on the acquired information.

[0147] In this case, it is possible to omit Figure 12 The processing of step S202 can be performed, thereby improving the processing throughput.

[0148] (Fourth embodiment)

[0149] In the first embodiment, the following situation is described: in the deformation action performed by the deformation portion 321, the control portion 71 temporarily releases the adsorption of the lower wafer W2 and then performs deformation processing of the first holding portion 230 by the deformation portion 321, and then adsorbs the lower wafer W2 again, but is not limited to this, and the deformation processing by the first holding portion 230 may also be performed while still adsorbing the lower wafer W2.

[0150] Specifically, the control unit 71 may control the first holding unit 230 to hold the lower wafer W2, and then control the outer suction unit 301 and the inner suction unit 302 to suction the lower wafer W2, and then obtain the height information of the outer peripheral portion of the lower wafer W2 based on the suction surface 300 from the displacement sensor 340, and control the deformation unit 321 based on the obtained information to deform the outer suction unit 301. That is, it may also be that Figure 12 In step 204 , the control unit 71 does not perform the process of releasing suction and re-suction of the lower wafer W2 , but only controls the deforming unit 321 .

[0151] Thus, compared with the case where the lower wafer W2 is released from adsorption and then adsorbed again, the time required for the bonding process can be shortened.

[0152] It should be understood that all aspects of the embodiments disclosed herein are illustrative and non-restrictive. In fact, the above embodiments can be implemented in a variety of ways. In addition, the above embodiments may be omitted, replaced, or modified in various ways without departing from the appended claims and their subject matter.

[0153] Furthermore, the present disclosure can take the following structures. (1)

[0155] A joining device comprising:

[0156] a first holding portion that holds the first substrate from below;

[0157] a second holding portion disposed above the first holding portion and configured to hold the second substrate from above the second substrate;

[0158] a pushing portion, provided on the second holding portion, for pushing down the central portion of the second substrate; and

[0159] Control Department,

[0160] Wherein, the first holding portion has:

[0161] an outer adsorption portion for adsorbing an outer periphery of the first substrate;

[0162] an inner suction portion configured to suction a portion of the first substrate that is located inner than the outer peripheral portion; and

[0163] a deformation portion that deforms the outer suction portion relative to the inner suction portion,

[0164] The control unit acquires information on the height of the outer peripheral portion of the first substrate from a reference surface, and controls the deformation unit based on the acquired information. (2)

[0166] The bonding device according to (1), wherein:

[0167] When the height of the outer peripheral portion of the first substrate from the reference surface is outside a threshold range including a target height, the control unit controls the deforming unit according to an amount of deviation from the target height. (3)

[0169] The bonding device according to (2), wherein:

[0170] The deforming portion has a deformation space at a portion located inside the first holding portion and located at the outer adsorption portion.

[0171] When the height of the outer peripheral portion of the first substrate from the reference surface is outside a threshold range including a target height, the control unit controls the deformation unit to supply fluid to the deformation space so as to cause the outer adsorption unit to bulge relative to the inner adsorption unit. (4)

[0173] The bonding device according to any one of (1) to (3), wherein:

[0174] The bonding apparatus further includes a measuring unit configured to measure a height of the outer peripheral portion of the first substrate with reference to a suction surface of the outer suction unit.

[0175] The control unit controls the deformation unit based on the information acquired from the measurement unit. (5)

[0177] The bonding device according to any one of (1) to (4), wherein:

[0178] The outer edge of the first substrate is arranged at a middle portion in the width direction of the outer adsorption portion. (6)

[0180] The bonding device according to (4), wherein:

[0181] The control unit controls the first holding unit to make the first holding unit hold the first substrate. Thereafter, the control unit obtains information on the height of the outer peripheral portion of the first substrate based on the adsorption surface of the outer adsorption unit from the measuring unit, and controls the deformation unit based on the obtained information to deform the outer adsorption unit. Thereafter, the control unit controls the outer adsorption unit and the inner adsorption unit to make the outer adsorption unit and the inner adsorption unit adsorb the first substrate. (7)

[0183] The bonding device according to (4), wherein:

[0184] The control unit controls the first holding unit to make the first holding unit hold the first substrate. Thereafter, the control unit controls the outer adsorption unit and the inner adsorption unit to make the outer adsorption unit and the inner adsorption unit adsorb the first substrate. Thereafter, the control unit obtains information on the height of the outer peripheral portion of the first substrate based on the adsorption surface of the outer adsorption unit from the measuring unit, and controls the deformation unit based on the obtained information to deform the outer adsorption unit. (8)

[0186] A joining method includes the following steps:

[0187] holding the first substrate from below the first substrate using a first holding portion that holds the first substrate from below the first substrate;

[0188] holding the second substrate from above the second substrate using a second holding portion that is disposed above the first holding portion and holds the second substrate from above the second substrate;

[0189] Acquiring information on the height of the outer periphery of the first substrate from a reference plane;

[0190] Based on the acquired information, deforming the outer adsorption portion using a deforming portion that deforms the outer adsorption portion relative to the inner adsorption portion, wherein the outer adsorption portion adsorbs the outer peripheral portion of the first substrate and the inner adsorption portion adsorbs a portion of the first substrate that is inner than the outer peripheral portion;

[0191] adsorbing the first substrate using the outer adsorption portion and the inner adsorption portion; and

[0192] The center portion of the second substrate held by the second holding portion is pushed down using a pushing portion provided on the second holding portion and configured to push down the center portion of the second substrate.

[0193] Description of Reference Numerals

[0194] 1: bonding system; 41: bonding device; 70: control device; 71: control unit; 72: storage unit; 230: first holding unit; 231: second holding unit; 250: pushing unit; 301: outer adsorption unit; 302: inner adsorption unit; 321: deformation unit; W1: upper wafer; W2: lower wafer.

Claims

1. A bonding device comprising: a first holding portion that holds the first substrate from below; a second holding portion disposed above the first holding portion and configured to hold the second substrate from above the second substrate; a pushing portion, provided on the second holding portion, for pushing down the central portion of the second substrate; and Control Department, in, The first holding portion has: an outer adsorption portion for adsorbing an outer periphery of the first substrate; an inner suction portion configured to suction a portion of the first substrate that is located inner than the outer peripheral portion; and a deformation portion that deforms the outer suction portion relative to the inner suction portion, The control unit acquires information on the height of the outer peripheral portion of the first substrate from a reference surface, and controls the deformation unit based on the acquired information.

2. The joining device according to claim 1, wherein When the height of the outer peripheral portion of the first substrate from the reference surface is outside a threshold range including a target height, the control unit controls the deforming unit according to an amount of deviation from the target height.

3. The joining device according to claim 2, wherein: The deforming portion has a deformation space at a portion located inside the first holding portion and located at the outer adsorption portion. When the height of the outer peripheral portion of the first substrate from the reference surface is outside a threshold range including a target height, the control unit controls the deformation unit to supply fluid to the deformation space so as to cause the outer adsorption unit to bulge relative to the inner adsorption unit.

4. The joining device according to claim 1, wherein: The bonding apparatus further includes a measuring unit configured to measure a height of the outer peripheral portion of the first substrate with reference to a suction surface of the outer suction unit. The control unit controls the deformation unit based on the information acquired from the measurement unit.

5. The joining device according to claim 1, wherein The outer edge of the first substrate is arranged at a middle portion in the width direction of the outer adsorption portion. The joining device according to claim 4 , wherein: The control unit controls the first holding unit to make the first holding unit hold the first substrate. Thereafter, the control unit obtains information on the height of the outer peripheral portion of the first substrate based on the adsorption surface of the outer adsorption unit from the measuring unit, and controls the deformation unit based on the obtained information to deform the outer adsorption unit. Thereafter, the control unit controls the outer adsorption unit and the inner adsorption unit to make the outer adsorption unit and the inner adsorption unit adsorb the first substrate.

7. The joining device according to claim 4, wherein: The control unit controls the first holding unit to make the first holding unit hold the first substrate. Thereafter, the control unit controls the outer adsorption unit and the inner adsorption unit to make the outer adsorption unit and the inner adsorption unit adsorb the first substrate. Thereafter, the control unit obtains information on the height of the outer peripheral portion of the first substrate based on the adsorption surface of the outer adsorption unit from the measuring unit, and controls the deformation unit based on the obtained information to deform the outer adsorption unit.

8. A joining method comprising the following steps: holding the first substrate from below the first substrate using a first holding portion that holds the first substrate from below the first substrate; holding the second substrate from above the second substrate using a second holding portion that is disposed above the first holding portion and holds the second substrate from above the second substrate; Acquiring information on the height of the outer periphery of the first substrate from a reference plane; Based on the acquired information, deforming the outer adsorption portion using a deforming portion that deforms the outer adsorption portion relative to the inner adsorption portion, wherein the outer adsorption portion adsorbs the outer peripheral portion of the first substrate and the inner adsorption portion adsorbs a portion of the first substrate that is inner than the outer peripheral portion; adsorbing the first substrate using the outer adsorption portion and the inner adsorption portion; and The center portion of the second substrate held by the second holding portion is pushed down using a pushing portion provided on the second holding portion and configured to push down the center portion of the second substrate.

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