Bonding apparatus and bonding method

Abstract

This bonding apparatus bonds a first substrate to a second substrate. The bonding apparatus comprises a first holding portion that holds the first substrate, a second holding portion that holds the second substrate, a movement mechanism that moves one of the first holding portion and the second holding portion relative to the other; and a control unit. The first holding portion holds the first substrate in a curved shape. The second holding portion holds the second substrate in a curved shape. The control unit controls the movement mechanism so that the centers of the curved first substrate and the curved second substrate are aligned by relative movement, and then causes the first holding portion and second holding portion to be positioned in close proximity, thereby bonding the first substrate to the second substrate.

Description

Joining device and joining method

[0001] This disclosure relates to a joining device and a joining method.

[0002] Patent Document 1 discloses a bonding system for forming a bonded substrate (polymerized substrate) by joining a first substrate and a second substrate via an adhesive. The bonded substrate thus formed is then ground on one side (the first substrate side) in a grinding apparatus in the next step, resulting in a thinner ground substrate. In the grinding process of the grinding apparatus, if the first and second substrates of the bonded substrate are bonded concentrically, it becomes easier to correct the inclination angle and grinding amount of the bonded substrate within the grinding apparatus, which has the advantage of improving the in-plane uniformity of the ground substrate.

[0003] Japanese Patent Publication No. 2015-46531

[0004] This disclosure provides a technology that enables the stable bonding of a first substrate and a second substrate in a concentric manner.

[0005] According to one aspect of the present disclosure, a bonding apparatus for joining a first substrate and a second substrate is provided, comprising: a first holding part for holding the first substrate; a second holding part for holding the second substrate; a moving mechanism for moving one of the first holding part and the second holding part relative to the other; and a control unit, wherein the first holding part holds the first substrate in a curved position, the second holding part holds the second substrate in a curved position, and the control unit controls the moving mechanism to align the center of the curved first substrate with the center of the curved second substrate by the relative movement, and then brings the first holding part and the second holding part closer to each other to bond the first substrate and the second substrate.

[0006] According to one embodiment, the first substrate and the second substrate can be stably bonded together in a concentric manner.

[0007] This is a block diagram showing the overall configuration of a semiconductor manufacturing system according to an embodiment. Figure 2(A) is a schematic cross-sectional view showing a bonded substrate formed by the semiconductor manufacturing system. Figure 2(B) is a schematic cross-sectional view showing a ground substrate formed by the semiconductor manufacturing system. This is a schematic plan view showing the overall configuration of the bonding apparatus. This is a flowchart showing the bonding method of the bonding apparatus. This is a side cross-sectional view showing the state before bonding in the bonding module. This is a flowchart showing the bonding method. Figure 7(A) is a first explanatory diagram showing the alignment of the processing substrate and the carrier substrate. Figure 7(B) is a second explanatory diagram showing the alignment of the processing substrate and the carrier substrate. Figure 7(C) is a third explanatory diagram showing the bonding of the processing substrate and the carrier substrate. This is a side cross-sectional view showing the state at the time of bonding in the bonding module. This is a side cross-sectional view showing a bonding module according to a first modified example. This is a side cross-sectional view showing a bonding module according to a second modified example.

[0008] The following describes embodiments for implementing this disclosure with reference to the drawings. In each drawing, the same reference numerals are used for identical components, and redundant explanations may be omitted.

[0009] As shown in Figure 1, the semiconductor manufacturing system includes a bonding apparatus 1 that forms a bonded substrate T by bonding a first substrate W1 and a second substrate W2, a grinding apparatus 6 that forms a ground substrate TG by grinding the bonded substrate T, and a management apparatus 9 that manages the entire system.

[0010] As shown in Figure 2(A), the first substrate W1 and the second substrate W2 are formed as discs of substantially the same shape (same diameter) and are joined to each other by being superimposed vertically by the joining device 1. The joined substrate T also has an adhesive layer G between the first substrate W1 and the second substrate W2, and the two substrates are joined together by the adhesive layer G.

[0011] The first substrate W1 is a processing substrate having multiple semiconductor devices (electronic circuits) on a semiconductor substrate such as a silicon wafer or a compound semiconductor wafer. Therefore, the first substrate W1 will also be referred to as the processing substrate W1 below. Of the surfaces of the processing substrate W1, the surface that has each semiconductor device and is joined to the second substrate W2 is called the "joining surface W1j", and the surface opposite to the joining surface W1j is called the "non-joining surface W1n".

[0012] The second substrate W2 is, for example, a carrier substrate (support substrate) that supports the processing substrate W1. Therefore, hereafter, the second substrate W2 will also be referred to as the carrier substrate W2. As this carrier substrate W2, for example, a bare wafer without semiconductor devices or a glass substrate can be used. Hereinafter, the surface of the carrier substrate W2 that is joined to the processing substrate W1 will be referred to as the "joining surface W2j", and the surface opposite to the joining surface W2j will be referred to as the "non-joining surface W2n". However, the second substrate W2 is not limited to a carrier substrate, but may also be a processing substrate having semiconductor devices.

[0013] Furthermore, the adhesive layer G (adhesive) that joins the processing substrate W1 and the carrier substrate W2 can be made of thermoplastic resin, photocurable resin, etc. Examples of thermoplastic resins include polyethylene-based, polyvinyl acetate-based, ethylene-vinyl acetate copolymer, polypropylene-based, polyamide-based, polyester-based, and acrylic-based resins. Examples of photocurable resins include acrylic-based and silicone-based resins.

[0014] The bonded substrate T, bonded by the bonding apparatus 1, has a configuration in which a carrier substrate W2, an adhesive layer G, and a processing substrate W1 are stacked in order from the lower vertical side to the upper vertical side. Furthermore, the processing substrate W1 of the bonded substrate T has a metal layer ML at the interface BS with the adhesive layer G, depending on the semiconductor device on the bonding surface W1j side. In addition, each semiconductor device on the processing substrate W1 has recesses Wh, such as trenches or holes, extending from the bonding surface W1j to the non-bonded surface W1n.

[0015] The bonded substrate T, bonded by the bonding device 1, has a total thickness AT which is the sum of the thickness of the processing substrate W1, the thickness of the carrier substrate W2, and the thickness of the adhesive layer G. Then, in the next step, this bonded substrate T is ground by the grinding device 6 to become a ground substrate TG with a thinner total thickness AT', as shown in Figure 2(B).

[0016] Specifically, after the formation of the bonding substrate T, the non-bonding surface W1n side of the processing substrate W1 is ground by the grinding device 6. As a result, the bottom surface of each recess Wh of the processing substrate W1 is in a state close to the non-bonding surface W1n. The ground substrate TG formed in this way is taken out as an appropriate semiconductor device chip, for example, by going through a dicing process which is a subsequent process.

[0017] <Configuration of Bonding Device> Next, the configuration of the bonding device 1 of the semiconductor manufacturing system that bonds the processing substrate W1 and the carrier substrate W2 will be described while referring to FIG. 3. In the following description, the positions of each component will be described based on the direction indications of the X-axis direction, Y-axis direction, and Z-axis direction shown in FIG. 3. The X-axis direction and the Y-axis direction are horizontal directions and are perpendicular to each other. The Z-axis direction is the vertical direction.

[0018] The bonding device 1 includes a loading / unloading station 2, a first processing station 3, and a second processing station 4. The loading / unloading station 2, the first processing station 3, and the second processing station 4 are installed in this order in the positive X-axis direction.

[0019] The loading / unloading station 2 of the bonding device 1 includes a mounting table 11 and a transfer area 12. On the mounting table 11, cassettes C ｗ１ 、C ｗ２ 、C ｔ are mounted. The cassette C ｗ１ is a cassette that houses the processing substrate W1, the cassette C ｗ２ is a cassette that houses the carrier substrate W2, and the cassette C ｔ is a cassette that houses the bonding substrate T. Note that the number of cassettes C ｗ１ 、C ｗ２ 、C ｔ mounted on the mounting table 11 is not particularly limited.

[0020] The transport area 12 is positioned adjacent to the mounting table 11 on the positive X-axis side. The transport area 12 is provided with a transport path 121 extending in the Y-axis direction and a transport device 122 that can move along this transport path 121. The transport device 122 is movable in the X-axis direction and the Z-axis direction, and is also rotatable around the Z-axis. The transport device 122 transports a cassette C placed on the mounting table 11. ｗ１ , C ｗ２ , C ｔ The processing substrate W1, carrier substrate W2, and bonding substrate T are transported between the first processing station 3 and the first processing station 3.

[0021] The first processing station 3 comprises a transfer block 13, a transport area 14, a plurality of coating devices 15, a plurality of heat treatment devices 16, and a plurality of removal devices 17. The transfer block 13 is positioned adjacent to the transport area 12 on the positive X-axis side. The transport area 14 is positioned adjacent to the transfer block 13 on the positive X-axis side. The coating devices 15 and removal devices 17 are positioned adjacent to the transport area 14 on the negative Y-axis side, and the heat treatment devices 16 are positioned adjacent to the transport area 14 on the positive Y-axis side. The removal devices 17 are stacked, for example, above the coating devices 15.

[0022] The transfer block 13 is configured to allow the processing substrate W1, carrier substrate W2, bonding substrate T, etc. to be temporarily placed between the transport area 12 and the transport area 14.

[0023] A transport device 141 is positioned in the transport area 14. The transport device 141 is movable in the horizontal direction (X-axis direction, Y-axis direction) and the vertical direction (Z-axis direction), and is rotatable around the Z-axis. The transport device 141 transports the processed substrate W1, carrier substrate W2, and bonded substrate T between the transfer block 13, coating device 15, heat treatment device 16, removal device 17, and the transfer block 18 of the second processing station 4, which will be described later.

[0024] The coating device 15 is a device that applies adhesive to the bonding surface W1j of the processing substrate W1. The heat treatment device 16 is a device that heats the processing substrate W1 to a predetermined temperature after the adhesive has been applied. The removal device 17 is a device that removes the adhesive from the peripheral edge of the processing substrate W1 by supplying an organic solvent to the peripheral edge of the processing substrate W1 to which the adhesive has been applied.

[0025] The second processing station 4 comprises a transfer block 18, a transport area 19, and a plurality of joining modules 20. The transfer block 18 is positioned adjacent to the transport area 14 on the positive X-axis side. The transport area 19 is positioned adjacent to the transfer block 18 on the positive X-axis side. The plurality of joining modules 20 are positioned adjacent to the transport area 19 on the positive Y-axis side and the negative Y-axis side, respectively.

[0026] The transfer block 18 is configured to temporarily hold the processing substrate W1, carrier substrate W2, and bonding substrate T, etc., between the transport area 14 and the transport area 19. The transfer block 18 also includes an aligner device with a reversing mechanism that can adjust the orientation of the processing substrate W1 (horizontal position, circumferential position, etc.) and reverse the upper and lower surfaces of the processing substrate W1 (bonding surface W1j, non-bonding surface W1n). Furthermore, the transfer block 18 includes an aligner device that can adjust the orientation of the carrier substrate W2 (horizontal position, circumferential position, etc.). For example, the aligner device with a reversing mechanism and the aligner device are stacked vertically on the transfer block 18.

[0027] A transport device 191 is positioned in the transport area 19. The transport device 191 is movable in the X-axis, Y-axis, and Z-axis directions, and is rotatable around the Z-axis. The transport device 191 transports the processing substrate W1, the carrier substrate W2, and the bonding substrate T between the transfer block 18 and the bonding module 20. The bonding module 20 bonds the processing substrate W1 and the carrier substrate W2.

[0028] Furthermore, the bonding apparatus 1 includes a control unit 5 (information processing unit) that controls each component of the apparatus. The control unit 5 is a computer having a processor 51, memory 52, an input / output interface (not shown), and a communication interface. The processor 51 is a combination of one or more of the following: a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), or a circuit consisting of multiple discrete semiconductors. The memory 52 includes a main memory and an auxiliary memory. In other words, in this disclosure, the control unit 5 is an electronic circuit having a CPU, GPU, ASIC, FPGA, etc., and performs various control operations described in this specification by executing instruction codes stored in the memory 52 or by circuit design for special applications.

[0029] <Joining Method> The control unit 5 controls each component of the joining device 1 and, for example, executes steps S101 to S109 of the joining method shown in Figure 4 to join the processing substrate W1 and the carrier substrate W2. In the joining method, the control unit 5 uses the transport device 122 of the transport area 12 to transfer the cassette C ｗ１ The processed substrate W1 is removed from the processing area and transported to the transfer block 13, and the transport device 141 in the transport area 14 removes the processed substrate W1 from the transfer block 13 and transports it to the coating device 15. At this time, the processed substrate W1 is transported by the transport devices 122 and 141 with the bonding surface W1j facing upwards and transported to the coating device 15.

[0030] Then, the coating device 15 applies adhesive to the bonding surface W1j of the incoming processing substrate W1 (step S101). The adhesive applied by the coating device 15 is liquid, and by discharging the adhesive from a nozzle (not shown) to the center of the processing substrate W1, it spreads radially from the center to the outer edge. After that, the control unit 5 controls the transport device 141 to transport the processing substrate W1 from the coating device 15 to the heat treatment device 16.

[0031] The heat treatment device 16 heats the processing substrate W1 inside while maintaining an inert atmosphere (step S102). As a result, the adhesive applied to the bonding surface W1j of the processing substrate W1 becomes harder than when it was applied as the solvent such as an organic solvent volatilizes. Thereafter, the control unit 5 controls the transfer device 141 to transfer the processing substrate W1 from the heat treatment device 16 to the removal device 17. [[ID=X]] [[ID=X]]

[0032] The removal device 17 removes the adhesive applied to the peripheral portion of the bonding surface W1j of the processing substrate W1 (step S103). Thereafter, the control unit 5 controls the transfer device 141 to transfer the processing substrate W1 from the removal device 17 to the delivery block 18. [[ID=X]] [[ID=X]]

[0033] The delivery block 18 adjusts the horizontal posture of the processing substrate W1 by an aligner device with an inversion mechanism (not shown) (step S104). Further, the delivery block 18 inverts the processing substrate W1 by an aligner device with an inversion mechanism so that the upward bonding surface W1j faces downward (step S105). [[ID=X]] [[ID=X]]

[0034] Thereafter, the control unit 5 controls the transfer device 191 in the transfer area 19 to take out the processing substrate W1 from the delivery block 18 and carry it into the bonding module 20 (step S106). [[ID=X]] [[ID=X]]

[0035] Also, the bonding device 1 conveys the carrier substrate W2 at the timing when the first substrate W1 is being processed by an appropriate device. The control unit 5 takes out the carrier substrate W2 from the cassette C [[ID=X]] ｗ２ by the transfer device 122 in the transfer area 12 and carries it into the delivery block 13, and takes out the carrier substrate W2 from the delivery block 13 by the transfer device 141 in the transfer area 14 and carries it into the delivery block 18. Then, the control unit 5 adjusts the horizontal posture of the carrier substrate W2 by an aligner device (not shown) (step S107). [[ID=X]]<![CDATA[ ]]>[[ID=X]]<![CDATA[

[0036] ]]> Thereafter, the control unit 5 controls the transfer device 191 in the transfer area 19 to take out the carrier substrate W2 from the delivery block 18 and carry it into the bonding module 20 (step S108). [[ID=X]] [[ID=X]]

[0037] After the processing substrate W1 and the carrier substrate W2 are each loaded, the bonding module 20 performs a bonding process for bonding the processing substrate W1 and the carrier substrate W2 to form a bonded substrate T (step S109). After the formation of the bonded substrate T, the control unit 5 transports the bonded substrate T from the bonding module 20 of the second processing station 4 to the cassette Ct of the loading / unloading station 2 by the transport devices 191, 141, and 122, and accommodates the bonded substrate T in the cassette Ct. Thereby, a series of processes of the bonding apparatus 1 are completed.

[0038] <Bonding Module> Next, the configuration of the bonding module 20 of the bonding apparatus 1 will be described with reference to FIG. 5. The bonding module 20 includes a processing container 21, a first holding unit 22, and a second holding unit 23 housed inside the processing container 21. The first holding unit 22 holds the processing substrate W1 on the ceiling side of the processing container 21. The second holding unit 23 is disposed vertically below the first holding unit 22 and holds the carrier substrate W2.

[0039] The processing container 21 is a processing container that can be sealed inside, and includes a first chamber portion 211 and a second chamber portion 212. The first chamber portion 211 is a container having a concave shape in a sectional view with an open lower portion, and houses the first holding unit 22 and the like inside. The second chamber portion 212 is a container having a concave shape in a sectional view with an open upper portion, and houses the second holding unit 23 and the like inside.

[0040] The first holding section 22 and the second holding section 23 have chucks 221 and 231 for adsorbing the processing substrate W1 and the carrier substrate W2, respectively. For example, the first holding section 22 has an adsorption device 225 and an adsorption path 226 for vacuum adsorption of the processing substrate W1. The adsorption device 225 is connected to the control unit 5 and performs adsorption operations based on the control of the control unit 5. The adsorption path 226 is wired inside the first chamber section 211. The adsorption device 225 independently applies adsorption pressure to each of the multiple adsorption regions set on the first holding surface 22s of the first holding section 22. On the other hand, the second holding section 23 has an adsorption device 235 and an adsorption path 236 for vacuum adsorption of the carrier substrate W2. The adsorption device 235 is connected to the control unit 5 and performs adsorption operations based on the control of the control unit 5. The adsorption path 236 is wired inside the second chamber section 212. The adsorption device 225 independently applies adsorption pressure to each of the multiple adsorption regions set on the second holding surface 23s of the second holding portion 23. However, the first holding portion 22 and the second holding portion 23 are not limited to a configuration that uses vacuum adsorption as a means of holding the substrate; for example, an electrostatic chuck, a mechanical mechanism, etc., may also be applied.

[0041] Furthermore, the first holding surface 22s of the chuck 221 and the second holding surface 23s of the chuck 231 are formed as curved surfaces, and hold the processing substrate W1 and the carrier substrate W2 in a curved state relative to each other. The significance of making the first holding surface 22s and the second holding surface 23s curved surfaces and their specific configuration will be described in detail later.

[0042] Furthermore, the first holding section 22 and the second holding section 23 each incorporate heating mechanisms 222 and 232, respectively. The heating mechanism 222 heats the processing substrate W1 held in the first holding section 22, and the heating mechanism 232 heats the carrier substrate W2 held in the second holding section 23. The second holding section 23 also includes a base 233 that supports the chuck 231.

[0043] In addition to the processing container 21, the first holding part 22, and the second holding part 23, the bonding module 20 also includes a base member 24, a pressurizing mechanism 25, a moving mechanism 26, a depressurizing mechanism 27, and an imaging unit 28.

[0044] The base member 24 is fixed to the bottom surface of the first chamber section 211 (the ceiling surface of the processing container 21) and supports the first holding section 22 by suspending it. A guide mechanism is provided between the first holding section 22 and the base member 24 to guide the vertical movement of the first holding section 22.

[0045] The pressurizing mechanism 25 has the function of bringing the processing substrate W1 into contact with the carrier substrate W2 by moving the first holding portion 22 vertically downward, and pressurizing the processing substrate W1 while it is in contact. For example, the pressurizing mechanism 25 comprises an expandable body 251, a gas flow path 252, and a gas supply and discharge source 253.

[0046] The expandable body 251 is made of a stainless steel bellows that is expandable and contractible in the vertical direction. The lower end of the expandable body 251 is connected to the upper surface of the first holding part 22. The upper end of the expandable body 251 is connected to the lower surface of the base member 24. The gas flow path 252 communicates with the space inside the expandable body 251 via the base member 24 and the first chamber part 211. This gas flow path 252 is connected to the gas supply and discharge source 253 via a gas path. The gas supply and discharge source 253 is connected to the control unit 5 and supplies and discharges gas based on the control of the control unit 5.

[0047] The pressurizing mechanism 25, configured in this way, supplies gas from the gas supply / discharge source 253 to the space inside the expandable body 251 via the gas flow path 252, thereby extending the expandable body 251 and lowering the first holding portion 22. As a result, the processing substrate W1 held by the first holding portion 22 comes into contact with the carrier substrate W2. The pressurizing mechanism 25 also adjusts the pressure exerted by the processing substrate W1 on the carrier substrate W2 after contact by adjusting the pressure of the gas supplied to the expandable body 251.

[0048] The moving mechanism 26 has the function of moving the first chamber portion 211 relative to the second chamber portion 212. For example, the moving mechanism 26 moves the first chamber portion 211 vertically, horizontally, and around the vertical axis based on the control of the control unit 5. The joining module 20 adjusts the horizontal and circumferential positions of the processing substrate W1 via the first chamber portion 211 and the first holding portion 22 using the moving mechanism 26, and then lowers the first chamber portion 211 to bring it into contact with the second chamber portion 212, thereby closing the processing container 21. As a result, the inside of the processing container 21 becomes a sealed space when the processing substrate W1 and the carrier substrate W2 are joined. It is preferable that one of the first chamber portion 211 and the second chamber portion 212 be provided with a sealing member 213 that hermetically closes the processing container 21. Furthermore, the moving mechanism 26 is not limited to a configuration that moves the first chamber portion 211, but may also be configured to move the second chamber portion 212. Alternatively, the moving mechanism 26 may be configured to move not only one of the first chamber section 211 and the second chamber section 212 relative to the other, but both relative to each other.

[0049] The pressure reduction mechanism 27 is provided, for example, at the bottom of the second chamber section 212 and reduces the pressure inside the processing container 21. The pressure reduction mechanism 27 includes an intake passage 271 that communicates with the inside of the processing container 21, and an intake device 272, such as a vacuum pump, connected to the intake passage 271 via an intake path. The intake device 272 generates an suction force in the intake passage 271 based on the control of the control unit 5, thereby sucking out the gas inside the processing container 21.

[0050] The imaging unit 28 includes a first imaging unit 281 and a second imaging unit 282. The first imaging unit 281 is positioned below the first holding unit 22 and images the bonding surface W1j (including adhesive) of the processing substrate W1 held by the first holding unit 22. The second imaging unit 282 is positioned above the second holding unit 23 and images the bonding surface W2j of the carrier substrate W2 held by the second holding unit 23. The first imaging unit 281 and the second imaging unit 282 may be wide-angle CCD cameras, CMOS cameras, etc.

[0051] The first imaging unit 281 and the second imaging unit 282 are movable horizontally by a moving mechanism (not shown), and before lowering the first chamber unit 211, they enter between the first holding unit 22 and the second holding unit 23 to image the processing substrate W1 and the carrier substrate W2. The imaging information from the first imaging unit 281 and the second imaging unit 282 is transmitted to the control unit 5. Based on this imaging information, the control unit 5 controls the operation of the moving mechanism 26 to adjust the horizontal position of the first chamber unit 211, and then lowers the moving mechanism 26.

[0052] The bonding module 20 is basically configured as described above. Conventionally, the bonding module held the processing substrate W1 with the first holding surface of the first holding part as a flat surface aligned horizontally, and also held the carrier substrate W2 with the second holding surface of the second holding part as a flat surface aligned horizontally. In this case, misalignment in the horizontal direction is likely to occur when bonding the processing substrate W1 and the carrier substrate W2. This misalignment between the processing substrate W1 and the carrier substrate W2 may affect the lower thickness LT of the bonding substrate T (see Figure 2(A)) and reduce the in-plane uniformity of the total thickness AT' of the substrate TG after grinding.

[0053] Therefore, the bonding device 1 is configured to suppress horizontal misalignment between the processing substrate W1 and the carrier substrate W2 by overlapping them concentrically and bonding them together. The grinding device 6 can easily adjust the inclination angle or grinding amount of the bonding substrate T during grinding by performing feedforward control using measurement data of the bonded substrate T of the concentrically overlapped processing substrate W1 and carrier substrate W2.

[0054] Specifically, as shown in Figure 5, the bonding module 20 of the bonding device 1 holds the processing substrate W1 in a curved position by the first holding portion 22 and holds the carrier substrate W2 in a curved position by the second holding portion 23, and bonds the processing substrate W1 and the carrier substrate W2 in this state. Note that the first holding surface 22s and the second holding surface 23s shown in Figure 5 are depicted with exaggerated curves to make their curved surfaces easier to understand. In reality, the difference in height between the center and the outer edge of the first holding surface 22s and the second holding surface 23s is about 0.1 mm to several mm.

[0055] The first holding surface 22s is formed in a circular shape with a diameter larger than the diameter of the processing substrate W1 in a plan view, and the entire surface is curved. The center of the first holding surface 22s coincides with the axis of the first chamber portion 211. The center of the first holding surface 22s is located at the highest position (vertically upward) relative to the other parts of the first holding surface 22s. In other words, in a cross-sectional view, the first holding portion 22 has a substantially concave first holding surface 22s as a whole, by recessing the center of the chuck 221 vertically upward from the outer edge of the disc-shaped chuck 221. The cross-sectional shape of the first holding surface 22s is an arc shape with a gentle (small) curvature, with the highest point at the center as the base point.

[0056] As described above, multiple adsorption regions are set on the first holding surface 22s, and adsorption holes of the adsorption path 226 are connected to each adsorption region. The first holding part 22 may have multiple ribs that protrude slightly from the adsorption holes, and the first holding surface 22s may be formed by multiple ribs. For example, when holding the processing substrate W1, the first holding part 22 can hold the processing substrate W1 in a state that follows the curvature of the first holding surface 22s by sequentially generating adsorption pressure from appropriate adsorption regions of the first holding surface 22s based on the operation of the adsorption device 225. The method of holding the processing substrate W1 by the first holding part 22 is not particularly limited, and the processing substrate W1 may be held by simultaneously applying adsorption pressure to each adsorption region of the first holding surface 22s.

[0057] On the other hand, the second retaining surface 23s is formed in a circular shape with a diameter larger than that of the carrier substrate W2 in a plan view, and the entire surface is curved. The center of the second retaining surface 23s coincides with the axis of the second chamber portion 212. The center of the second retaining surface 23s is located at the highest point (vertically upward) relative to the other parts of the second retaining surface 23s. In other words, in a cross-sectional view, the second retaining portion 23 has a second retaining surface 23s that is substantially convex overall, by causing the center of the disc-shaped chuck 231 to protrude vertically upward from the outer edge of the chuck 231. The cross-sectional shape of the second retaining surface 23s is an arc shape with a gentle (small) curvature, starting from the highest point at the center.

[0058] As described above, multiple adsorption regions are set on the second holding surface 23s, and the adsorption holes of the adsorption path 236 are connected to each adsorption region. The second holding portion 23 may also have multiple ribs that protrude slightly from the adsorption holes, and the second holding surface 23s may be formed by multiple ribs. For example, when holding the carrier substrate W2, the second holding portion 23 can hold the carrier substrate W2 in a state that follows the curvature of the second holding surface 23s by sequentially generating adsorption pressure from appropriate adsorption regions of the second holding surface 23s based on the operation of the adsorption device 235. The method of holding the carrier substrate W2 by the second holding portion 23 is not particularly limited, and the carrier substrate W2 may be held by simultaneously applying adsorption pressure to each adsorption region of the second holding surface 23s.

[0059] In this embodiment, the curved surfaces of the first holding surface 22s and the second holding surface 23s are set to have the same curvature. As a result, the processing substrate W1 held on the first holding surface 22s and the carrier substrate W2 held on the second holding surface 23s have the same curvature, allowing them to be properly superimposed during bonding. However, the curvature of the first holding surface 22s and the curvature of the second holding surface 23s may be different. For example, the curvature of the first holding surface 22s may be slightly smaller than the curvature of the second holding surface 23s. Even in this case, the processing substrate W1 and the carrier substrate W2 can be bonded together by applying pressure with the pressure mechanism 25 during bonding.

[0060] <Joining Process of the Joining Method> The joining module 20 is basically configured as described above and performs the joining process of the joining method to join the processing substrate W1 and the carrier substrate W2 based on the control of the control unit 5 (step S109 in Figure 4). The control unit 5 of the joining apparatus 1 controls, for example, steps S201 to S209 shown in Figure 6 in the joining method (joining process) to operate each component of the joining module 20.

[0061] Specifically, when the processing substrate W1 is transported below the first holding part 22 by the transport device 191 (see Figure 3), the bonding module 20 holds the processing substrate W1 in a curved manner by the first holding part 22 (step S201: step (A)). The first holding part 22 applies the suction pressure of the suction device 225 to the first holding surface 22s, thereby adsorbing the non-bonding surface W1n of the processing substrate W1 supported by the transport device 191. In this adsorption, the processing substrate W1 curves concavely in accordance with the curved surface of the first holding surface 22s and makes surface contact with the first holding surface 22s.

[0062] Furthermore, when the carrier substrate W2 is transported above the second holding portion 23 by the transport device 191, the bonding module 20 holds the carrier substrate W2 by bending it (step S202: step (B)). The second holding portion 23 applies the suction pressure of the suction device 235 to the second holding surface 23s, thereby adsorbing the non-bonding surface W2n of the carrier substrate W2 supported by the transport device 191. In this adsorption, the carrier substrate W2 curves convexly in accordance with the curved surface of the second holding surface 23s and makes surface contact with the second holding surface 23s. Note that the order of steps S201 and S202 may be reversed.

[0063] Subsequently, the bonding module 20 moves the first imaging unit 281 and the second imaging unit 282 horizontally to image the outer edge of the processing substrate W1 and the carrier substrate W2, respectively, and calculates the center of the processing substrate W1 and the center of the carrier substrate W2 (step S203). For example, the control unit 5 calculates the horizontal coordinates (X coordinate, Y coordinate) of the center W1o of the processing substrate W1 held in the first holding unit 22 based on the shape and position of the outer edge of the processing substrate W1 included in the imaging information (see Figure 7(A)). The control unit 5 also calculates the horizontal coordinates (X coordinate, Y coordinate) of the center W2o of the carrier substrate W2 held in the second holding unit 23 based on the shape and position of the outer edge of the carrier substrate W2 included in the imaging information (see Figure 7(A)).

[0064] Furthermore, the bonding module 20 operates the movement mechanism 26 so that the calculated horizontal coordinates of the center W1o of the processing substrate W1 and the calculated horizontal coordinates of the center W2o of the carrier substrate W2 coincide (step S204: (C)). As a result, as shown in Figures 7(A) and 7(B), the bonding module 20 can align the processing substrate W1 and the carrier substrate W2 concentrically before bonding. Alternatively, the control unit 5 may perform movement control to align the axis of the first chamber 211 with the axis of the second chamber 212 without using imaging information for horizontal alignment, and this movement control may align the center W1o of the processing substrate W1 with the center W2o of the carrier substrate W2.

[0065] Then, after the first imaging unit 281 and the second imaging unit 282 have exited the processing container 21, the bonding module 20 uses the moving mechanism 26 to lower the first chamber unit 211, bringing the first holding unit 22 and the second holding unit 23 closer together (step S205: (D)). As this lowering occurs, the lower end of the first chamber unit 211 comes into contact with the upper end of the second chamber unit 212, closing it and creating a sealed space inside the processing container 21 (see also Figure 8).

[0066] Furthermore, after the processing container 21 is closed, the bonding module 20 uses a depressurization mechanism 27 to suck out the gas inside the processing container 21, thereby reducing the internal pressure of the processing container 21 to a target pressure (step S206). The bonding module 20 also uses the heating mechanism 222 of the first holding part 22 and the heating mechanism 232 of the second holding part 23 to heat the processing substrate W1 and the carrier substrate W2 to a target temperature (for example, 200°C to 250°C) (step S207).

[0067] After the processing container 21 reaches the target pressure and the processing substrate W1 and carrier substrate W2 reach the target temperature, the bonding module 20 supplies gas via the pressurizing mechanism 25 to lower the first holding part 22, thereby bonding the processing substrate W1 and the carrier substrate W2 (step S208: step (D)). That is, as shown in Figures 7(C) and 8, the operation of the pressurizing mechanism 25 brings the processing substrate W1 of the first holding part 22 into contact with and pressurizes the carrier substrate W2 of the second holding part 23, thereby pressing the bonding surface W1j of the processing substrate W1 and the bonding surface W2j of the carrier substrate W2 together. As a result, the processing substrate W1 and the carrier substrate W2 are bonded together via the adhesive layer G to form a bonded substrate T.

[0068] In this configuration, the processing substrate W1 held on the first holding surface 22s and the carrier substrate W2 held on the second holding surface 23s are superimposed such that their centers W1o and W2o coincide, and are concentric and point-symmetric with approximately the same degree of curvature. As a result, horizontal displacement between the processing substrate W1 and the carrier substrate W2 is suppressed, promoting uniformity of the total thickness AT in the same circumferential direction.

[0069] After the bonding substrate T is formed, the bonding module 20 performs a bonding completion process (step S209). In the bonding completion process, the suction pressure by the first holding part 22 is released, and the gas is discharged from the space inside the expandable body 251 by the pressurizing mechanism 25, causing the first holding part 22 to rise. As a result, the bonding substrate T is placed on the second holding part 23. The bonding module 20 also stops the heating of the heating mechanisms 222 and 232, the depressurization of the depressurization mechanism 27, and opens the processing container 21 by raising the first chamber part 211 with the moving mechanism 26. The bonding device 1 then receives the bonding substrate T from the second holding part 23 by the transport device 191, and transports the bonding substrate T out of the bonding module 20.

[0070] The bonded substrates T discharged from the bonding module 20 are transported by the transport devices 191, 141, and 122 of the bonding apparatus 1 from the bonding module 20 at the second processing station 4 to the cassette Ct at the loading / unloading station 2, where they are stored. The cassette Ct containing multiple bonded substrates T is then discharged from the bonding apparatus 1 by an overhead transport mechanism (not shown) and loaded into the grinding apparatus 6 (see Figure 1).

[0071] In the grinding apparatus 6, the processing substrate W1 of the bonded substrate T is ground to form the ground substrate TG. Although the specific configuration is omitted, the grinding apparatus 6 rotates the bonded substrate T and brings the grinding tool into contact with the first substrate W1 of the bonded substrate T, thereby grinding the first substrate W1. At this time, the grinding apparatus 6 adjusts the inclination angle of the bonded substrate with respect to the rotation centerline of the grinding tool, thereby determining the total thickness AT' (thickness T of the processing substrate W1) of the ground substrate TG. ｗ１ The goal is to make the thickness of the bonded substrate T uniform, even if the center of the bonded substrate T protrudes vertically upward from the outer edge as described above, the thickness of the processed substrate W1 in the circumferential direction is equal to the thickness of the bonded substrate T. ｗ１ The carrier substrate W2 and the adhesive layer G are bonded together with approximately equal thickness. Therefore, the grinding device 6 rotates the bonded substrate T and grinds its circumferential direction with a grinding tool. In addition, the grinding device 6 changes the radial position of the bonded substrate T during grinding and adjusts the inclination angle of the bonded substrate T. As a result, the grinding device 6 grinds the thickness T of the processed substrate W1. ｗ１ This allows for obtaining a good substrate TG that is approximately constant after grinding.

[0072] As described above, the bonding apparatus 1 and bonding method according to the embodiment can stably bond the processing substrate W1 and the carrier substrate W2 in a concentric manner. This makes it easier for the semiconductor manufacturing system to correct the inclination angle and grinding amount of the bonded substrate T when forming the ground substrate TG in the next process. As a result, the in-plane uniformity of the ground substrate TG can be improved.

[0073] The bonding apparatus 1 according to this disclosure is not limited to the above-described embodiment and can take various modified forms. For example, the bonding substrate T formed by the bonding apparatus 1 and bonding method of this disclosure may be used in another process without being ground by the grinding apparatus 6. Even in this case, the processing substrate W1 and the carrier substrate W2 are precisely bonded in a concentric manner, making it possible to perform stable processing in another process.

[0074] Furthermore, in the above embodiment, a bonding apparatus 1 was described that forms a bonded substrate T having an adhesive (adhesive layer G) between a first substrate W1 and a second substrate W2. However, the bonding apparatus 1 does not necessarily have to have an adhesive between the first substrate W1 and the second substrate W2. For example, even when the bonding surface W1j of the first substrate W1 and the bonding surface W2j of the second substrate W2 are hydrophilized and the first substrate W1 and the second substrate W2 are bonded by hydrogen bonding, a similar configuration may be adopted.

[0075] Furthermore, the bonding apparatus 1 may be equipped with a measuring device for measuring the thickness of the formed bonded substrate T, and may be configured to output the measurement results to the grinding apparatus 6 or the control device 9. For example, the measuring device may be a displacement sensor integrally installed in the imaging unit 28, which detects changes in the upper surface of the bonded substrate T relative to the second holding surface 23s as the imaging unit 28 moves. Alternatively, the measuring device may be one or more infrared sensors installed in the second holding unit 23, which irradiate measurement light from the carrier substrate W2 side and receive the reflected light. The measurement results measured in the bonding apparatus 1 can be used as a profile when grinding the bonded substrate T in the grinding apparatus 6. In addition, the control device 9 manages the measurement results of the bonded substrate T from the bonding apparatus 1, the measurement results of the ground substrate TG from the grinding apparatus 6, etc., so that this data can be used in subsequent processes (for example, the dicing process).

[0076] Alternatively, the bonding device 1 may be configured to bond the processing substrate W1 held by the first holding part 22 and the carrier substrate W2 held by the second holding part 23 by vertical movement of the moving mechanism 26, without including a pressurizing mechanism 25.

[0077] <First Modification> For example, the bonding module 20A according to the first modification shown in Figure 9 differs from the bonding module 20 according to the embodiment in that the curvature of the processing substrate W1 and the curvature of the carrier substrate W2 are reversed. In detail, the first holding portion 22 is formed in a convex shape in cross-sectional view, with its center protruding vertically downward from the outer edge. The second holding portion 23 is formed in a concave shape in cross-sectional view, with its center recessed vertically downward from the outer edge.

[0078] As a result, the bonding module 20A can bond a processing substrate W1, which has a downward convex center, to a carrier substrate W2, which has a downward concave center, using the first holding portion 22. Even in this case, the processing substrate W1 and the carrier substrate W2, which are curved concentrically and point-symmetrically, can be bonded, and the bonded substrate T can be formed with high precision. The formed bonded substrate T will have a uniform thickness in the circumferential direction, and the in-plane uniformity of the substrate TG (processing substrate W1) after grinding by the grinding device 6 in the next step can be improved.

[0079] <Second Modification> For example, as shown in the second modification in Figure 10, the joining module 20B of the joining device 1 may be equipped with a deformable part 29 that can change the curvature of either one or both of the curved surfaces of the first holding part 22 and the second holding part 23. In the example in Figure 10, an actuator 291 is shown as the deformable part 29 of the first holding part 22, and a fluid supply and discharge unit 292 is shown as the deformable part 29 of the second holding part 23. The deformable part 29 is not limited to these, and various configurations that can change the curvature of the first holding surface 22s, the second holding surface 23s, etc., may be adopted. For example, a fluid supply and discharge unit 292 may be applied to the first holding part 22, and an actuator 291 may be applied to the second holding part 23.

[0080] The actuator 291 of the deformation section 29 is, for example, installed at the center of the first holding section 22, and changes the center of the first holding surface 22s by extending or contracting in the vertical direction. As a result, the first holding surface 22s of the first holding section 22 can hold the processing substrate W1 in a state in which the processing substrate W1 has been deformed to an appropriate curvature.

[0081] On the other hand, the supply and discharge unit 292 of the deformation section 29 has a cavity 292a inside the base 233, and the second holding surface 23s is displaced by supplying an appropriate fluid to this cavity 292a via the fluid supply and discharge path 292b. The type of fluid in the supply and discharge unit 292 is not particularly limited and may be a gas such as air or an inert gas, or a liquid such as water or oil. As a result, the second holding surface 23s of the second holding section 23 can hold the carrier substrate W2 in a state in which the carrier substrate W2 has been deformed to an appropriate curvature (such as a curvature that substantially matches that of the processing substrate W1).

[0082] When the bonding device 1 deforms the first holding surface 22s and the second holding surface 23s with the deformation part 29, it is preferable to measure the in-plane strain of the processing substrate W1 and the carrier substrate W2 in advance using a strain measuring device (not shown), and to control the deformation part 29 based on this in-plane strain. For example, the control unit 5 uses the measurement result of the one with the larger in-plane strain between the processing substrate W1 and the carrier substrate W2. As an example, if the processing substrate W1 is distorted relatively more than the carrier substrate W2, the deformation amount of the deformation part 29 is set to be larger in accordance with the strain of the processing substrate W1. Conversely, if the relative strain between the carrier substrate W2 and the processing substrate W1 is small, the deformation amount of the deformation part 29 is set to be smaller. In this way, the bonding device 1 can bond the processing substrate W1 and the carrier substrate W2 in a state where the processing substrate W1 and the carrier substrate W2 are appropriately deformed.

[0083] Alternatively, when the bonding device 1 deforms the first holding surface 22s and the second holding surface 23s with the deformation part 29, it may measure the state of the ground substrate TG (thickness of the ground substrate TG) after grinding by the grinding device 6 and feed back the measurement data. For example, the thickness T of the processed substrate W1 in the ground substrate TG. ｗ１If in-plane uniformity is not achieved, the bonding device 1 receives feedback of the measurement results (measurement data of the substrate TG after grinding). Based on these measurement results, the bonding device 1 can set the curvature when deforming the deformation portion 29 and appropriately adjust the amount of deformation of the first holding surface 22s and the second holding surface 23s (in other words, the curvature of the processed substrate W1 and the carrier substrate W2).

[0084] The joining apparatus and joining method according to the embodiments disclosed herein are illustrative and not restrictive in all respects. The embodiments can be modified and improved in various ways without departing from the scope and spirit of the appended claims. The matters described in the above embodiments can be otherwise configured and combined in a non-consistent manner.

[0085] This application claims priority to Japanese Patent Application No. 2024-161243, which was filed with the Japan Patent Office on September 18, 2024, and the entire contents of that application are incorporated herein by reference.

[0086] 1 Bonding device 5 Control unit 22 First holding unit 23 Second holding unit 26 Moving mechanism W1 First substrate (processing substrate) W2 Second substrate (carrier substrate)

Claims

1. A bonding apparatus for joining a first substrate and a second substrate, comprising: a first holding part for holding the first substrate; a second holding part for holding the second substrate; a moving mechanism for moving one of the first holding part and the second holding part relative to the other; and a control unit, wherein the first holding part holds the first substrate in a curved position, the second holding part holds the second substrate in a curved position, and the control unit controls the moving mechanism to align the center of the curved first substrate with the center of the curved second substrate by the relative movement, then brings the first holding part and the second holding part closer to each other, and bonds the first substrate and the second substrate.

2. The bonding apparatus according to claim 1, wherein the first holding portion has a first holding surface for holding the non-bonding surface of the first substrate, the second holding portion is positioned vertically below the first holding portion and has a second holding surface for holding the non-bonding surface of the second substrate, and the entire surface of the first holding surface and the second holding surface is curved because their centers are displaced in the same vertical direction.

3. The joining device according to claim 2, wherein the first retaining surface is formed in a concave shape, with its center recessed vertically upward from its outer edge in a cross-sectional view, and the second retaining surface is formed in a convex shape, with its center protruding vertically upward from its outer edge in a cross-sectional view.

4. The joining device according to claim 2, wherein the first retaining surface is formed in a convex shape in a cross-sectional view, with its center protruding vertically downward from the outer edge, and the second retaining surface is formed in a concave shape in a cross-sectional view, with its center recessed vertically downward from the outer edge.

5. The joining device according to any one of claims 2 to 4, wherein the curvature of the first holding surface and the curvature of the second holding surface are the same.

6. The joining device according to any one of claims 2 to 4, wherein the first holding portion and the second holding portion have deformable portions that can change either or both of the curvature of the first holding surface and the curvature of the second holding surface.

7. The bonding apparatus according to claim 6, wherein the control unit sets the curvature for the next deformation of the deformed portion based on the measurement result of the thickness of the ground substrate formed by grinding the bonded substrate into which the first substrate and the second substrate are joined, and changes the deformed portion.

8. The bonding apparatus according to claim 6, wherein the control unit sets the amount of deformation of the deformed portion based on the strain of the first substrate and the second substrate measured in advance, and controls the deformed portion based on the set amount of deformation to change the curvature of the first retaining surface and the curvature of the second retaining surface.

9. The bonding apparatus according to claim 1, wherein the control unit outputs the measurement result of the thickness of the bonded substrate formed by joining the first substrate and the second substrate to a grinding apparatus that forms a ground substrate by grinding the bonded substrate, or a management apparatus that manages the bonding apparatus and the grinding apparatus.

10. The bonding apparatus according to claim 1, comprising: a first chamber portion for housing the first holding portion; a second chamber portion for housing the second holding portion and forming a sealed space by closing off between itself and the first chamber portion based on the movement of the moving mechanism; and a pressurizing mechanism for pressurizing the first holding portion toward the second holding portion, wherein the control unit, after the first chamber portion and the second chamber portion have been closed off, operates the pressurizing mechanism to bring the first holding portion into contact with and pressurize the second holding portion, thereby bonding the first substrate and the second substrate.

11. A joining method for a joining apparatus for joining a first substrate and a second substrate, comprising: (A) holding the first substrate in a curved manner with a first holding part; (B) holding the second substrate in a curved manner with a second holding part; (C) moving one of the first holding part and the second holding part relative to the other so that the center of the curved first substrate coincides with the center of the curved second substrate; and (D) after step (C), bringing the first holding part and the second holding part closer to each other to join the first substrate and the second substrate.

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