Coating unit and substrate joining device comprising the same

Abstract

To provide a coating unit which can precisely control an amount of a filling liquid to be supplied to two joined substrates.SOLUTION: A coating unit comprises: a chuck that, while holding a joint substrate W indicating two joined substrates W1, W2, rotates about an axis which is orthogonal to a main surface of the joint substrate and which passes through a center of the main surface; and a filling liquid nozzle 49 that, by ejecting multiple droplets of a filling liquid FL which changes to a solid or semisolid filler toward the joint substrate held by the chuck, supplies the filling liquid FL to an annular groove WG formed between outer peripheral parts of the two joined substrates W1, W2.SELECTED DRAWING: Figure 11C

Description

[Technical field]

[0001] The present invention relates to an application unit that applies a filling liquid to two bonded substrates and a substrate bonding device including the application unit. The substrates include, for example, semiconductor wafers, substrates for FPDs (Flat Panel Displays) such as liquid crystal displays and organic EL (electroluminescence) displays, substrates for optical disks, substrates for magnetic disks, substrates for magneto-optical disks, substrates for photomasks, ceramic substrates, and substrates for solar cells. [Background technology]

[0002] Patent Document 1 discloses an edge condition checking device capable of determining the presence or absence of internal defects in a protective member formed on the outer peripheral edge of a substrate. Paragraph 0087 of Patent Document 1 states, "As shown in Figs. 10 and 11, an edge condition checking device 1 according to a second embodiment includes, in addition to the configuration of the edge condition checking device 1 according to the first embodiment, a protective member forming unit LN for forming a protective member w4 on the outer peripheral edge of a bonded substrate W. The protective member forming unit LN is connected to a supply system (not shown) that supplies a coating liquid for the protective member, and includes a nozzle member capable of ejecting the coating liquid supplied from the supply system." [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-43003 A Summary of the Invention [Problem to be solved by the invention]

[0004] Patent Document 1 only describes "a nozzle member capable of ejecting a coating liquid supplied from a supply system," and does not clarify in what form the coating liquid is ejected from the nozzle member.

[0005] Therefore, one object of the present invention is to provide a coating unit that can precisely control the amount of filler liquid supplied to two bonded substrates, and a substrate bonding apparatus equipped with the same. [Means for solving the problem]

[0006] One embodiment of the present invention provides an application unit including a chuck that holds a bonded substrate, which is two bonded substrates, and rotates about an axis that is perpendicular to a main surface of the bonded substrate and passes through the center of the main surface, and a filling liquid nozzle that supplies the filling liquid to an annular groove formed between the outer peripheries of the two bonded substrates by spraying a plurality of droplets of the filling liquid, which changes into a solid or semi-solid filling body, toward the bonded substrate held by the chuck. The bonded substrate includes two planes that are parallel to each other. The two planes of the bonded substrate are non-bonded surfaces of the two bonded substrates. The main surface of the bonded substrate may be any of the two planes of the bonded substrate.

[0007] In the embodiment, at least one of the following features may be added to the application unit:

[0008] The filler fluid nozzle is an inkjet nozzle that sprays multiple droplets of the filler fluid in substantially the same direction toward the annular groove.

[0009] The coating unit further includes a position detector that detects the position of the outer periphery of the bonded substrate held by the chuck, and a nozzle actuator that moves the filling liquid nozzle in accordance with the position of the outer periphery detected by the position detector.

[0010] The application unit further includes a control device that performs at least one of position control, which causes the nozzle actuator to move the filling liquid nozzle in accordance with the position of the outer periphery detected by the position detector while causing the position detector to detect the position of the outer periphery, and flow rate control, which changes the amount of the filling liquid sprayed from the filling liquid nozzle per unit time in accordance with the position of the outer periphery detected by the position detector while causing the position detector to detect the position of the outer periphery.

[0011] The coating unit further includes a void detector that detects voids within the filling liquid or filling body in the annular groove and voids between the bonding surfaces of the two bonded substrates when the chuck is holding the bonded substrates.

[0012] The filling liquid nozzle includes a large-diameter nozzle that sprays multiple droplets of the filling liquid from a spray orifice toward the bonded substrate held by the chuck, and a small-diameter nozzle that sprays multiple droplets of the filling liquid from a spray orifice having an area smaller than the spray orifice of the large-diameter nozzle toward the bonded substrate held by the chuck.

[0013] Another embodiment of the present invention provides a substrate bonding apparatus including: a bonding unit that bonds two substrates together; and an application unit that applies a filling liquid that changes into a solid or semi-solid filling body to a bonded substrate, which is the two substrates bonded by the bonding unit, wherein the application unit includes a chuck that holds the bonded substrate and rotates about an axis that is perpendicular to a main surface of the bonded substrate and passes through a center of the main surface; and a filling liquid nozzle that supplies the filling liquid to an annular groove formed between the outer peripheries of the two bonded substrates by spraying a plurality of droplets of the filling liquid toward the bonded substrate held by the chuck.

[0014] In the above embodiment, at least one of the following features may be added to the substrate bonding apparatus.

[0015] The bonding unit includes a first chuck and a second chuck that respectively hold the two substrates before being bonded, and a bonding actuator that brings the two substrates held by the first chuck and the second chuck into contact by moving the first chuck and the second chuck relatively, and the coating unit further includes a chamber that accommodates the chuck, the filling liquid nozzle, and the first chuck and the second chuck.

[0016] The bonding unit further includes a void detector for detecting voids between the bonding surfaces of the two bonded substrates and voids within the filler liquid or filler body in the annular groove. [Brief description of the drawings]

[0017] [Figure 1A] 1 is a schematic diagram showing an example of the appearance of two substrates before and after bonding. [Figure 1B] 1A and 1B are schematic diagrams showing an example of cross sections of two substrates before and after bonding. [Figure 1C] 4A and 4B are schematic diagrams showing an example of cross sections of two bonded substrates before and after a filling liquid is supplied to the outer periphery of the two substrates. [Figure 1D] 3A and 3B are schematic diagrams showing an example of cross sections of two bonded substrates before and after the two substrates are thinned. [Diagram 2] 1A to 1C are process diagrams illustrating a substrate bonding method according to an embodiment of the present invention. [Diagram 3] 1 is a schematic plan view of a substrate bonding apparatus according to an embodiment of the present invention; [Figure 4A] FIG. 1 is a schematic diagram showing a horizontal view of the inside of an aligner before activation. [Figure 4B] A schematic diagram showing the inside of an aligner from above before activation. [Figure 5A] FIG. 2 is a schematic diagram showing the inside of the activation unit viewed horizontally. [Figure 5B] FIG. 2 is a schematic diagram showing the inside of the activation unit as viewed from directly above. [Figure 6A] FIG. 2 is a schematic diagram showing the inside of the pre-bonding cleaning unit as viewed horizontally. [Figure 6B] FIG. 2 is a schematic view showing the inside of the pre-bonding cleaning unit as viewed from directly above. [Figure 7A] FIG. 2 is a schematic diagram showing the inside of the coating unit as viewed horizontally. [Figure 7B] FIG. 2 is a schematic view showing the inside of the coating unit as viewed from directly above. [Figure 7C-D] FIG. 2 is a schematic diagram of a filling fluid nozzle. [Figure 8A] FIG. 2 is a schematic diagram showing the inside of the joint unit as viewed horizontally. [Figure 8B] FIG. 2 is a schematic diagram showing the inside of the joint unit as viewed horizontally. [Figure 9A] FIG. 2 is a schematic diagram showing the inside of the grinding unit as viewed horizontally. [Figure 9B] FIG. 2 is a schematic view showing the inside of the grinding unit as viewed from directly above. [Figure 10] FIG. 2 is a block diagram showing an electrical configuration of the substrate bonding apparatus. [Figure 11A] 3 is a schematic cross-sectional view of the outer periphery of a substrate. [Figure 11B] FIG. 2 is a schematic view showing the inside of the coating unit as viewed from directly above. [Figure 11C] 10 is a schematic cross-sectional view showing a state in which a fill liquid is being supplied to an annular groove formed between the outer peripheries of two bonded substrates. FIG. [Figure 11D] FIG. 11 is a schematic cross-sectional view showing a state in which a void between two bonded substrates is detected by a void detector. [Figure 12A] FIG. 10 is a horizontal schematic view of the inside of a coating unit according to another embodiment of the present invention. [Figure 12B] 1 is a schematic diagram showing a state in which the bonded substrates, the filling liquid, and the voids in the filling body are photographed. FIG. [Figure 13] FIG. 2 is a schematic plan view of a substrate showing device and non-device regions. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0019] In the following description, a bonded substrate W refers to two bonded substrates W, a pre-bonded substrate W refers to one substrate W before bonding, and a bonded substrate W refers to one substrate W after bonding. Bonding is synonymous with bonding.

[0020] The first substrate W1 refers to a pre-bonded substrate W. The second substrate W2 refers to another pre-bonded substrate W. The bonded first substrate W1 and second substrate W2 refer to a bonded substrate W. The two bonded substrates W also refer to a bonded substrate W. When it does not matter whether it is a bonded substrate W, a pre-bonded substrate W, or a bonded substrate W, it is simply referred to as a substrate W.

[0021] Fig. 1A is a schematic diagram showing an example of the appearance of two substrates W before and after bonding. Fig. 1B is a schematic diagram showing an example of the cross section of two substrates W before and after bonding. Fig. 1C is a schematic diagram showing an example of the cross section of two substrates W before and after supplying a filling liquid FL to the outer periphery of the two bonded substrates W. Fig. 1D is a schematic diagram showing an example of the cross section of two bonded substrates W before and after thinning the two bonded substrates W.

[0022] As shown in FIG. 1A, the first substrate W1 and the second substrate W2 are flat disks with the same diameter. The diameters of the first substrate W1 and the second substrate W2 may be 300 mm or other. The thermal expansion coefficient of the first substrate W1 may be equal to or different from the thermal expansion coefficient of the second substrate W2. The first substrate W1 includes a disk-shaped substrate WD1, and the second substrate W2 includes a disk-shaped substrate WD2. The substrates WD1 and WD2 are made of a semiconductor such as a single crystal of silicon. The substrates WD1 and WD2 may be made of a material other than a semiconductor.

[0023] Both the substrate WD1 and the substrate WD2 include a circular front surface and a rear surface that are parallel to each other, and an annular end surface that connects the outer edges of the front surface and the rear surface. The front surface and the rear surface of the substrate WD1 are flat surfaces that are parallel to each other. The front surface and the rear surface of the substrate WD2 are similar. The front surfaces of the substrate WD1 and the substrate WD2 are device formation surfaces on which devices such as transistors are formed. The rear surfaces of the substrate WD1 and the substrate WD2 are non-device formation surfaces on which devices are not formed. Both the front surface and the rear surface of the substrate WD1 or the substrate WD2 may be device formation surfaces.

[0024] The outer periphery of the substrate WD1 forms a V-shaped notch that opens at the end face of the substrate WD1 when the substrate WD1 is viewed in a direction perpendicular to the surface of the substrate WD1. The outer periphery of the substrate WD1 may form an orientation flat (so-called orientation flat) instead of a notch. The notch and orientation flat indicate the crystal orientation of the substrate WD1 or the substrate WD2. The first substrate W1 is positioned in the circumferential direction of the first substrate W1 based on the notch or orientation flat of the first substrate W1. The same applies to the second substrate W2.

[0025] As shown in FIG. 1B, the first substrate W1 includes a device layer WC1 covering the surface of the base material WD1 and a bonding layer WB1 covering the surface of the device layer WC1. The second substrate W2 includes a device layer WC2 covering the surface of the base material WD2 and a bonding layer WB2 covering the surface of the device layer WC2. Devices such as transistors are disposed in the device layer WC1 and the device layer WC2. The devices are covered by the bonding layer WB1 and the bonding layer WB2. The bonding layer WB1 and the bonding layer WB2 are transparent or semi-transparent insulating layers. The bonding layer WB1 and the bonding layer WB2 may be silicon oxide films or thin films of materials other than silicon oxide. In the former case, the bonding layer WB1 and the bonding layer WB2 may be silicon oxide films made using TEOS (tetraethoxysilane).

[0026] The surface of the bonding layer WB1 of the first substrate W1 is the bonding surface WA1 of the first substrate W1. The surface of the bonding layer WB2 of the second substrate W2 is the bonding surface WA2 of the second substrate W2. The first substrate W1 and the second substrate W2 are bonded so that the bonding surface WA1 of the first substrate W1 and the bonding surface WA2 of the second substrate W2 face each other. The surface of the first substrate W1 is the bonding surface WA1 that contacts the atmosphere in the space in which the first substrate W1 is placed. The surface of the second substrate W2 is the bonding surface WA2 that contacts the atmosphere in the space in which the second substrate W2 is placed.

[0027] 2 is a process diagram for explaining a substrate bonding method according to an embodiment of the present invention. When bonding the first substrate W1 and the second substrate W2, an activation process (step S1 in FIG. 2) is performed to activate the bonding surface WA1 of the first substrate W1 and the bonding surface WA2 of the second substrate W2, and a cleaning process (step S2 in FIG. 2) is performed to clean and dry the two activated substrates W. Then, an inversion process (step S3 in FIG. 2) is performed to invert one of the first substrate W1 and the second substrate W2.

[0028] After one of the first substrate W1 and the second substrate W2 is inverted, an alignment confirmation process (step S4 in FIG. 2) is performed to confirm the alignment representing the relative position and angle of the first substrate W1 and the second substrate W2, an alignment adjustment process (step S5 in FIG. 2) is performed to adjust the alignment of the first substrate W1 and the second substrate W2 based on the confirmed alignment, and a substrate contact process (step S6 in FIG. 2) is performed to bond the first substrate W1 and the second substrate W2 by contacting the first substrate W1 and the second substrate W2 whose alignment has been adjusted. Then, an inspection process (step S7 in FIG. 2) is performed to inspect the bonding accuracy of the first substrate W1 and the second substrate W2, that is, the amount of misalignment of the positions of the two bonded substrates W and the amount of misalignment of the angles of the two bonded substrates W (angles around the center of the substrates W).

[0029] The activation step may be a plasma treatment in which plasma such as oxygen plasma is applied to the bonding surface WA1 of the first substrate W1 and the bonding surface WA2 of the second substrate W2. In this case, moisture in the air or moisture supplied to the substrate W in the cleaning step contacts the bonding surface WA1 of the first substrate W1 and the bonding surface WA2 of the second substrate W2 that have been irradiated with the plasma, and hydrophilic groups such as hydroxyl groups (OH groups) are formed on the bonding surface WA1 of the first substrate W1 and the bonding surface WA2 of the second substrate W2. The plasma treatment is an example of surface modification that modifies the surface of the substrate W. The activation step may be a wet treatment in which a hydrophilizing liquid that forms hydrophilic groups is supplied to the bonding surface WA1 of the first substrate W1 and the bonding surface WA2 of the second substrate W2.

[0030] The substrate contacting step may be a step of directly bonding two substrates W in the atmosphere at room temperature (e.g., 20 to 30° C.). The substrate contacting step may be a step of performing face-to-face bonding in which the two substrates W are bonded so that their surfaces face each other. In this case, the surfaces of the two substrates W correspond to the bonding surface WA1 of the first substrate W1 and the bonding surface WA2 of the second substrate W2. The substrate contacting step may be a step of bonding two substrates W without pressing one of the two substrates W against the other of the two substrates W, or by pressing one of the two substrates W against the other of the two substrates W with a pressure that does not damage devices formed on the two substrates W.

[0031] FIG. 1B shows a cross section of the first substrate W1 and the second substrate W2 cut along a plane perpendicular to the first substrate W1 and the second substrate W2. The ratio of the thickness of the device layer WC1 and the device layer WC2 to the thickness of the bonding layer WB1 and the bonding layer WB2 shown in FIG. 1B is not necessarily the same as the actual ratio. FIG. 1B shows an example in which a hydroxyl group, which is an example of a hydrophilic group, is formed on the bonding surface WA1 of the first substrate W1 and the bonding surface WA2 of the second substrate W2 before bonding. In this example, an oxygen atom (O) in the hydroxyl group is bonded to a silicon atom (Si) in the bonding layer WB1 and the bonding layer WB2.

[0032] Before bonding, the bonding surface WA1 of the first substrate W1 and the bonding surface WA2 of the second substrate W2 are terminated with multiple hydroxyl groups. When the bonding surface WA1 of the first substrate W1 and the bonding surface WA2 of the second substrate W2 are brought into contact with each other, the first substrate W1 and the second substrate W2 are bonded together by the intermolecular force acting between the two hydroxyl groups. In some cases, water molecules are released from the two hydroxyl groups, and silicon atoms in the bonding layer WB1 of the first substrate W1 and silicon atoms in the bonding layer WB2 of the second substrate W2 are bonded together via oxygen atoms. In this way, the first substrate W1 and the second substrate W2 are bonded together.

[0033] As shown in FIG. 1C, after the first substrate W1 and the second substrate W2 are bonded, a coating process (step S8 in FIG. 2) is performed in which a filling liquid FL is applied to the annular groove WG formed between the outer peripheries of the bonded first substrate W1 and the second substrate W2. Thereafter, as shown in FIG. 1D, a grinding process (step S9 in FIG. 2) is performed in which one of the bonded first substrate W1 and the second substrate W2 is ground to thin the bonded first substrate W1 and the second substrate W2, i.e., the bonded substrate W, and a cleaning process (step S10 in FIG. 2) is performed in which the thinned bonded substrate W is cleaned and dried. FIG. 1D shows an example in which the thickness of the bonded substrate W is reduced by grinding the first substrate W1. Instead of reducing the thickness of the first substrate W1, the thickness of the second substrate W2 may be reduced.

[0034] The inspection process (step S7 in FIG. 2) may be performed after the coating process (step S8 in FIG. 2) rather than before. In this case, the inspection process may be performed before the grinding process (step S9 in FIG. 2) or after the grinding process. The inspection process may be performed before and after the grinding process. In this case, the bonding accuracy before and after the grinding process may be compared. A pass / fail judgment may be made based on whether the change in bonding accuracy exceeds a threshold value. A pass rate may be calculated based on the pass / fail judgment, or a pass map may be created that shows the relationship between the substrate W on which the pass / fail judgment was made and the substrate W that passed, and at least one of the pass rate and the pass map may be recorded or displayed.

[0035] As shown in FIG. 1C and FIG. 1D, the filling liquid FL is a liquid that changes into a solid or semi-solid filler FS. The filling liquid FL may be a solution in which the filler FS corresponding to the solute is dissolved in a solvent, or a liquid of the filler FS (a liquid in which the concentration of the filler FS is 100% or nearly 100%), or may be a liquid other than these. When the filling liquid FL is a solution containing the filler FS and a solvent, the solvent may be a liquid of a substance that is more volatile than water, such as IPA (isopropyl alcohol). For example, the filling liquid FL may be a SOG (spin-on-glass) liquid containing a siloxane component corresponding to the solute and an alcohol corresponding to the solvent.

[0036] When the grinding process is started, the filling liquid FL in the annular groove WG has changed into a filling body FS. If necessary, a process for causing or promoting the change from the filling liquid FL to a filling body FS may be performed before the grinding process. For example, when the filling liquid FL changes into a filling body FS by evaporation of the filling liquid FL, a part of the filling liquid FL may be evaporated by at least one of heating the filling liquid FL and lowering the air pressure. When the filling liquid FL changes into a filling body FS by hardening of the filling liquid FL, the filling liquid FL may be hardened by at least one of heating the filling liquid FL and irradiating the filling liquid FL with light. These processes may be performed while the filling liquid FL is being supplied, or after the supply of the filling liquid FL is stopped, or both.

[0037] Next, the substrate bonding apparatus 1 that bonds two substrates W as described above will be described.

[0038] 3 is a schematic plan view of a substrate bonding apparatus 1 according to one embodiment of the present invention. In the following description, the up-down direction, the left-right direction, and the front-rear direction refer to the up-down direction, the left-right direction, and the front-rear direction of the substrate bonding apparatus 1 unless otherwise specified. The up-down direction is the vertical direction. The left-right direction and the front-rear direction are two horizontal directions that are perpendicular to each other. The left-right direction is the arrangement direction of multiple carriers CA held by multiple load ports LP. Each carrier CA is held by the load port LP with the opening of the carrier CA facing backward.

[0039] The substrate bonding apparatus 1 is an apparatus for bonding two disk-shaped substrates W. The substrate bonding apparatus 1 includes a plurality of load ports LP on which a plurality of carriers CA, each of which accommodates a plurality of substrates W such as a FOUP (Front-Opening Unified Pod), are placed, a plurality of processing units 2 for processing the substrates W transported from the plurality of load ports LP, a transport system TS for transporting the substrates W between the plurality of load ports LP and the plurality of processing units 2, and an outer wall 1a forming an enclosed space accommodating the plurality of processing units 2 and the transport system TS. The substrate bonding apparatus 1 further includes a control device 3 for controlling the substrate bonding apparatus 1.

[0040] 3 shows an example in which three load ports LP are provided. The three load ports LP include a first load port LP1 on which a carrier CA accommodating a first substrate W1 is placed, a second load port LP2 on which a carrier CA accommodating a second substrate W2 is placed, and a third load port LP3 on which a carrier CA accommodating the bonded first substrate W1 and second substrate W2 is placed. The first load port LP1 and the second load port LP2 are loading ports on which a carrier CA accommodating a substrate W to be bonded in the substrate bonding apparatus 1 is placed. The third load port LP3 is an unloading port on which a carrier CA accommodating two substrates W bonded in the substrate bonding apparatus 1 is placed.

[0041] The multiple processing units 2 include a pre-activation aligner 10, an activation unit 20, a pre-bonding cleaning unit 30, a pre-bonding aligner, a coating unit 40, a bonding unit 50, a grinding unit 60, and a post-grinding cleaning unit 70. Fig. 3 shows an example in which two each of the pre-activation aligner 10, the activation unit 20, the pre-bonding cleaning unit 30, the pre-bonding aligner, and the coating unit 40 are provided, and the pre-bonding aligner is integrated with the coating unit 40.

[0042] The pre-activation aligner 10 is a unit that positions the substrate W in the circumferential direction of the substrate W based on the notch or the orientation flat. The pre-bonding aligner is similar. The activation unit 20 is a unit that performs plasma processing to activate the front or back surface of the substrate W by bringing plasma into contact with the front or back surface of the substrate W. The pre-bonding cleaning unit 30 is a unit that cleans the substrate W by supplying a cleaning liquid to the substrate W.

[0043] The bonding unit 50 is a unit that bonds two substrates W by bringing them into contact with each other. The coating unit 40 is a unit that supplies a filling liquid to an annular groove WG (see FIG. 1C) formed between the outer peripheries of the two bonded substrates W. The grinding unit 60 is a unit that thins the two bonded substrates W by grinding the two bonded substrates W. The post-grinding cleaning unit 70 is a unit that cleans the two substrates W by supplying a cleaning liquid to the two substrates W that have been thinned by grinding.

[0044] The transfer system TS transfers the substrate W from the first load port LP1 and the second load port LP2 to the multiple processing units 2, and transfers the substrate W from the multiple processing units 2 to the third load port LP3. The transfer system TS further transfers the substrate W between the multiple processing units 2. The transfer system TS may include at least one transfer robot TR that transfers one or more substrates W in a horizontal position on a transfer path TP indicated by a thick line in FIG.

[0045] The transport robot TR includes at least one hand TH that holds one substrate W in a horizontal position. The transport robot TR moves along the transport path TP while holding the substrate W horizontally with the hand TH. Fig. 3 shows an example in which the transport path TP extends from each of the first load port LP1 and the second load port LP2 to a plurality of processing units 2, and returns from the plurality of processing units 2 to the third load port LP3.

[0046] The following describes the multiple processing units 2. First, the pre-activation aligner 10 will be described.

[0047] Fig. 4A is a schematic diagram showing the inside of the aligner 10 as viewed horizontally before activation, and Fig. 4B is a schematic diagram showing the inside of the aligner 10 as viewed from directly above before activation.

[0048] 4A and 4B, the pre-activation aligner 10 includes a chamber 11 that forms an internal space in which the substrate W is placed and a passage opening through which the substrate W passes to enter and exit the internal space, and a chuck 14 that holds the substrate W horizontally within the chamber 11. The chamber 11 includes a partition wall 12 that forms the internal space and the passage opening, and a door 13 that moves relative to the partition wall 12 to open and close the passage opening.

[0049] The pre-activation aligner 10 further includes an electric motor 15 that rotates the chuck 14 to rotate the substrate W around a vertical center of rotation A1 passing through the center of the substrate W held by the chuck 14, an outer periphery position sensor 16 that identifies the orientation of the notch or orientation flat by detecting the contour shape of the substrate W, and a control device 3 that stops the substrate W at a position where the orientation of the notch or orientation flat matches a reference direction by rotating the chuck 14 with the electric motor 15 based on the detection value of the outer periphery position sensor 16.

[0050] The chuck 14 may be a mechanical chuck that holds the substrate W horizontally by pressing a plurality of chuck pins horizontally against the edge surface of the substrate W, or may be a vacuum chuck that holds the substrate W horizontally by adsorbing the lower surface of the substrate W to the upper surface of a spin base arranged below the substrate W. FIGS. 4A and 4B show an example of the latter. In the latter case, the outer periphery position sensor 16 may identify the position of the center of the substrate W by detecting the contour shape of the substrate W. In this case, the pre-activation aligner 10 may further include a centering actuator that moves the chuck 14 horizontally to bring the center of the substrate W closer to the rotation center A1 of the substrate W.

[0051] An actuator is a device that converts driving energy, which may be electrical, fluid, magnetic, thermal, or chemical energy, into mechanical work, i.e., the motion of a tangible object. Actuators include electric motors (rotary motors), linear motors, air cylinders, and other devices. When the motion of the actuator is different from the motion of the object, a motion converter may be provided to convert the motion of the actuator into linear motion or rotation. For example, when the actuator is an electric motor and moves the object in a linear motion, the rotation of the electric motor may be converted into linear motion by a motion converter such as a ball screw and ball nut.

[0052] Next, the activation unit 20 will be described.

[0053] Fig. 5A is a schematic diagram showing the inside of the activation unit 20 as viewed horizontally. Fig. 5B is a schematic diagram showing the inside of the activation unit 20 as viewed from directly above.

[0054] 5A and 5B, the activation unit 20 includes a chamber 21 that forms an internal space in which the substrate W is placed and a passage port through which the substrate W passes to enter and exit the internal space, a lower electrode 24L that horizontally supports the substrate W in the chamber 21, an upper electrode 24u that is placed above the substrate W held by the lower electrode 24L, a gas pipe 25p that supplies a processing gas between the upper electrode 24u and the lower electrode 24L, a gas valve 25v that opens and closes the gas pipe 25p, a power source 26 that changes the processing gas between the upper electrode 24u and the lower electrode 24L into plasma, and a vacuum pump 27 that exhausts gas from the internal space. The chamber 21 includes a partition wall 22 that forms the internal space and the passage port, and a door 23 that moves relative to the partition wall 22 to open and close the passage port.

[0055] Although not shown, the gas valve 25v includes a valve body provided with an annular valve seat through which gas passes, a valve element movable relative to the valve seat, and an actuator that moves the valve element between a closed position in which the valve element contacts the valve seat and an open position in which the valve element is separated from the valve seat. The actuator may be a pneumatic actuator, an electric actuator, or an actuator other than these. The control device 3 (see FIG. 3) opens and closes the gas valve 25v by controlling the actuator.

[0056] Next, the pre-bonding cleaning unit 30 will be described.

[0057] Fig. 6A is a schematic diagram of the inside of the pre-bonding cleaning unit 30 viewed horizontally. Fig. 6B is a schematic diagram of the inside of the pre-bonding cleaning unit 30 viewed from directly above.

[0058] 6A and 6B, the pre-bonding cleaning unit 30 includes a chamber 31 that forms an internal space in which the substrate W is placed and a passage port through which the substrate W passes entering and exiting the internal space, a chuck 34 that horizontally holds the substrate W in the chamber 31, an electric motor 35 that rotates the chuck 34 to rotate the substrate W about a vertical rotation center A1 passing through the center of the substrate W held by the chuck 34, and one or more processing liquid nozzles 36 that eject a processing liquid such as a cleaning liquid toward the substrate W held by the chuck 34. The chamber 31 includes a partition wall 32 that forms an internal space and a passage port, and a door 33 that moves relative to the partition wall 32 to open and close the passage port. The cleaning liquid may be pure water (deionized water (DIW)) or a liquid other than pure water.

[0059] Although not shown, the post-grinding cleaning unit 70 (see FIG. 3) has a similar configuration to the pre-bonding cleaning unit 30. Thus, the post-grinding cleaning unit 70 includes a chamber 31, a chuck 34, an electric motor 35, and a processing liquid nozzle 36. The chamber 31 includes a partition wall 32 and a door 33. The pre-bonding cleaning unit 30 and the post-grinding cleaning unit 70 are different from each other in that the pre-bonding cleaning unit 30 cleans the first substrate W1 or the second substrate W2, whereas the post-grinding cleaning unit 70 cleans the first substrate W1 or the second substrate W2 that has been bonded and ground.

[0060] Next, the coating unit 40 will be described.

[0061] Fig. 7A is a schematic diagram of the inside of the coating unit 40 as viewed horizontally. Fig. 7B is a schematic diagram of the inside of the coating unit 40 as viewed from directly above. Figs. 7C and 7D are schematic diagrams of the filling liquid nozzle 49.

[0062] The application unit 40 includes a pre-bonding aligner. The pre-bonding aligner has a configuration similar to that of the pre-activation aligner 10 (see FIGS. 4A and 4B). Thus, the application unit 40 includes a chamber 11, a partition 12, a door 13, a chuck 14, an electric motor 15, and an outer periphery position sensor 16. In the following, in order to distinguish the configuration of the pre-activation aligner 10 from that of the application unit 40, the chamber 11, the partition 12, the door 13, the chuck 14, the electric motor 15, and the outer periphery position sensor 16 for the application unit 40 will be referred to as a chamber 41, a partition 42, a door 43, a chuck 44, an electric motor 45, and an outer periphery position sensor 46. The chuck 44 is the above-mentioned vacuum chuck.

[0063] The coating unit 40 includes at least one filling liquid nozzle 49 that ejects filling liquid toward the substrate W held by the chuck 44. FIG. 7B shows an example in which two filling liquid nozzles 49 are provided. The two filling liquid nozzles 49 are arranged at an interval in the rotation direction Dr of the chuck 44. The two filling liquid nozzles 49 eject filling liquid toward two target positions spaced apart in the rotation direction Dr of the chuck 44. Each target position is a position within the annular groove WG (see FIG. 1C).

[0064] Filler liquid nozzle 49 is a droplet nozzle that generates multiple droplets of filler liquid that are sprayed toward the object to be coated. The droplet nozzle may be a mist nozzle that ejects liquid in a mist, or an inkjet nozzle that forms a line of multiple droplets, or may be other than these. Figures 7C and 7D show an example in which filler liquid nozzle 49 is an inkjet nozzle.

[0065] The mist nozzle may be an external mixing or internal mixing type two-fluid nozzle that generates mist by colliding liquid and gas, or it may be a spray nozzle that generates mist by ejecting compressed liquid from an orifice or by utilizing the Venturi effect.

[0066] The inkjet nozzle may be a piezoelectric or thermal inkjet nozzle, or may be an inkjet nozzle other than a piezoelectric or thermal type. The inkjet nozzle may be a large-diameter nozzle 49X having a relatively large diameter nozzle 49x for ejecting droplets, or a small-diameter nozzle 49Y having a relatively small diameter nozzle 49y for ejecting droplets.

[0067] FIG. 7C shows an example of a large diameter nozzle 49X. FIG. 7D shows an example of a small diameter nozzle 49Y. The diameter of the injection port 49x of the large diameter nozzle 49X may be within any of the ranges of 10 μm or less, 8 μm or less, and 3 μm or less, or may be outside these ranges. The same applies to the diameter of the injection port 49y of the small diameter nozzle 49Y. The area of ​​the injection port 49y of the small diameter nozzle 49Y is smaller than the area of ​​the injection port 49x of the large diameter nozzle 49X. When the diameter of the injection port 49x of the large diameter nozzle 49X exceeds 10 μm, the diameter of the injection port 49y of the small diameter nozzle 49Y may be within the range of 0.01 μm to 10 μm.

[0068] The filling liquid nozzle 49 may be fixed to the partition 42 or may be movable relative to the partition 42. When a plurality of filling liquid nozzles 49 are provided in one coating unit 40, at least one filling liquid nozzle 49 may be fixed to the partition 42 and the remaining at least one filling liquid nozzle 49 may be movable relative to the partition 42.

[0069] 7A and 7B, when the filling liquid nozzle 49 is movable relative to the partition 42, the application unit 40 may include a nozzle actuator 49a that operates the filling liquid nozzle 49 relative to the partition 42. One nozzle actuator 49a may be provided for each filling liquid nozzle 49, or one nozzle actuator 49a may be provided for each of the multiple filling liquid nozzles 49. FIGS. 7A and 7B show an example of the former.

[0070] The nozzle actuator 49a may include at least one of a horizontal actuator that moves the filling liquid nozzle 49 horizontally, a vertical actuator that moves the filling liquid nozzle 49 vertically, and a posture-changing actuator that changes the posture of the filling liquid nozzle 49. When the filling liquid nozzle 49 is moved in the horizontal and vertical directions, the filling liquid nozzle 49 may be directly or indirectly connected to the horizontal actuator, and the horizontal actuator may be directly or indirectly connected to the vertical actuator.

[0071] 7A and 7B, the coating unit 40 includes a height sensor 47 that measures the height of the substrate W held by the chuck 44. The height sensor 47 measures the height of the upper or lower surface of the substrate W held by the chuck 44. Fig. 7A shows an example in which the height sensor 47 is disposed above the substrate W held by the chuck 44 and measures the height of the upper surface of the substrate W. The height sensor 47 may be a laser sensor or another sensor.

[0072] The height sensor 47 is an optical non-contact sensor that detects the position of the substrate W in the vertical direction. When the chuck 44 rotates around the rotation center A1 of the chuck 44 while holding the substrate W, the substrate W moves in the rotation direction Dr of the chuck 44 relative to the height sensor 47, and the position detected by the height sensor 47 moves in the opposite direction to the rotation direction Dr of the chuck 44 relative to the substrate W. Therefore, when the substrate W and the chuck 44 are rotated 360 degrees or more while the height sensor 47 is measuring the height of the substrate W, the height of the substrate W is measured around the entire circumference of the substrate W.

[0073] By measuring the height of the upper surface of the substrate W over the entire circumference thereof, it is possible to measure the shape of the upper surface of the substrate W over the entire circumference thereof. For example, by measuring the height of the outer periphery of the upper surface of the substrate W, more specifically, the height of the range from the edge of the substrate W to a position inside the edge, over the entire circumference of the substrate W, it is possible to measure the shape of the outer periphery of the upper surface of the substrate W including the edge of the substrate W. Since the shape of the outer periphery of the upper surface of the substrate W is measured for each rotation angle about the rotation center A1 of the chuck 44, it is also possible to measure how the shape of the outer periphery of the upper surface of the substrate W changes depending on the position in the circumferential direction of the substrate W.

[0074] The outer periphery position sensor 46 is an optical non-contact sensor that detects the outer periphery position of the substrate W in the horizontal direction. When the chuck 44 rotates around the rotation center A1 of the chuck 44 while holding the substrate W, the substrate W moves in the rotation direction Dr of the chuck 44 relative to the outer periphery position sensor 46, and the position detected by the outer periphery position sensor 46 moves in the opposite direction to the rotation direction Dr of the chuck 44 relative to the substrate W. Therefore, if the substrate W and the chuck 44 are rotated 360 degrees or more while the outer periphery position sensor 46 is detecting the outer periphery position of the substrate W, the outer periphery position of the substrate W in the horizontal direction can be detected all around the substrate W. This makes it possible to measure the outer periphery shape of the substrate W.

[0075] By measuring the shape of the outer periphery of the substrate W held by the chuck 44, it is possible to measure the amount and direction of eccentricity of the substrate W relative to the rotation center A1 of the chuck 44. It is also possible to measure the orientation of the notch or orientation flat relative to the chuck 44. In addition, because the position of the outer periphery of the substrate W is measured for each rotation angle about the rotation center A1 of the chuck 44, it is also possible to measure how the position of the outer periphery of the substrate W in the horizontal direction changes depending on the position of the substrate W in the circumferential direction.

[0076] The coating unit 40 includes a void detector 48 that captures an image of voids in at least one of the filling liquid and the filling body in the annular groove WG (see FIG. 1C) of the bonded substrate W (two bonded substrates W) held by the chuck 44. As long as it can capture an image of the voids in the filling liquid and the filling body, the void detector 48 may be an infrared camera or a camera other than an infrared camera. When the void detector 48 is a camera, the image sensor may be either a CCD (Charge Coupled Device) sensor or a CMOS (Complementary Metal Oxide Semiconductor).

[0077] When the void detector 48 is an infrared camera, the coating unit 40 may include a light source 48s (see FIG. 7A) that irradiates the outer periphery of the bonded substrate W with infrared light. The light source 48s may be disposed inside the coating unit 40 or outside the coating unit 40. In the latter case, the light from the light source 48s may be guided into the coating unit 40 by a guide such as an optical fiber. If the presence or absence of voids in the filling liquid and the filling body can be detected without the light source 48s, the light source 48s is not necessary.

[0078] 7B shows an example in which one void detector 48 is provided for each filling liquid nozzle 49. Therefore, in this example, two void detectors 48 are provided. This is not limited to the above, and one void detector 48 may be provided for each of a plurality of filling liquid nozzles 49. In the example shown in FIG. 7B, the void detector 48 is disposed upstream of the filling liquid nozzle 49 in the rotation direction Dr of the chuck 44. The filling liquid nozzle 49 and the void detector 48 may be disposed within a range of less than 45 degrees with respect to an angle around the rotation center A1 of the chuck 44.

[0079] The void detector 48 photographs the inside of the annular groove WG of the bonded substrate W. When at least one of the filling liquid and the filling body is present in the annular groove WG, the void detector 48 also photographs at least one of the filling liquid and the filling body. When the substrate W and the chuck 44 are rotated 360 degrees or more while the void detector 48 photographs the substrate W, the annular groove WG and the like are photographed over the entire circumference of the substrate W. This makes it possible to inspect the presence or absence of voids in the filling liquid or filling body supplied to the bonded substrate W over the entire circumference of the substrate W. Furthermore, the void detector 48 can be used to observe how the shape of the annular groove WG and the shapes of the filling liquid and the filling body in the annular groove WG change depending on the position in the circumferential direction of the substrate W.

[0080] Next, a description will be given of the bonding unit 50. Unless otherwise specified, the bonding unit 50 described in this specification bonds substrates under atmospheric pressure.

[0081] 8A and 8B are horizontal schematic diagrams of the inside of the bonding unit 50. Fig. 8A shows the state before the first substrate W1 and the second substrate W2 are bonded, and Fig. 8B shows the state after the first substrate W1 and the second substrate W2 have been bonded.

[0082] 8A and 8B, the bonding unit 50 includes a chamber 51 that forms a passage opening through which the first substrate W1 and the second substrate W2 pass before and after bonding and an internal space in which the first substrate W1 and the second substrate W2 that have passed the passage opening are disposed, a first chuck 54A that holds the first substrate W1 horizontally within the chamber 51, and a second chuck 54B that holds the second substrate W2 horizontally within the chamber 51. The chamber 51 includes a partition 52 that forms the internal space and the passage opening, and a door 53 that moves relative to the partition 52 to open and close the passage opening.

[0083] The bonding unit 50 further includes a plurality of bonding actuators 55 that bond the first substrate W1 and the second substrate W2 by moving the first chuck 54A and the second chuck 54B relatively while they are holding the first substrate W1 and the second substrate W2, and at least one camera 56 that detects the alignment of the first substrate W1 and the second substrate W2 at least either before or after bonding the first substrate W1 and the second substrate W2 by photographing at least one of the first substrate W1 and the second substrate W2.

[0084] The multiple joining actuators 55 may include a horizontal actuator that moves the first chuck 54A and the second chuck 54B relatively in a horizontal direction, a vertical actuator that moves the first chuck 54A and the second chuck 54B relatively in a vertical direction, and a rotational actuator that rotates the first chuck 54A and the second chuck 54B relatively around a vertical line.

[0085] The multiple bonding actuators 55 may include an inversion actuator that rotates the first chuck 54A about a horizontal straight line to invert the first substrate W1 held by the first chuck 54A up and down. The inversion actuator may also invert the first substrate W1 held by a chuck other than the first chuck 54A up and down. The inversion actuator may also invert the first substrate W1 up and down outside the bonding unit 50. When the hand TH (see FIG. 3) of the transport robot TR can hold the first substrate W1 horizontally facing downward (when the hand TH is a vacuum hand, a Bernoulli hand, or the like), the inversion actuator may be part of the transport robot TR.

[0086] At least one camera 56 may include a first camera 56A for photographing the first substrate W1 before it is bonded to the second substrate W2, a second camera 56B for photographing the second substrate W2 before it is bonded to the first substrate W1, and a third camera 56C for photographing the bonded first substrate W1 and second substrate W2. The first camera 56A may photograph the first substrate W1 held by the first chuck 54A, or may photograph the first substrate W1 held by a chuck other than the first chuck 54A. The same applies to the second camera 56B. The third camera 56C may photograph the bonded substrate W (bonded first substrate W1 and second substrate W2) held by the first chuck 54A or the second chuck 54B, or may photograph the bonded substrate W held by a chuck other than the first chuck 54A and the second chuck 54B. At least one camera 56 may capture an image of at least one of the first substrate W1 and the second substrate W2 outside the joining unit 50.

[0087] The first camera 56A and the second camera 56B are alignment cameras used to check and adjust the alignment of the first substrate W1 and the second substrate W2 before they are bonded. The third camera 56C is an inspection camera used to check the alignment of the bonded first substrate W1 and the second substrate W2. The inspection camera is an infrared camera that converts infrared rays into electrical signals to generate electronic data of still images or videos. The alignment camera may be an infrared camera or a visible light camera that converts visible light into electrical signals to generate electronic data of still images or videos.

[0088] Next, the grinding unit 60 will be described.

[0089] Fig. 9A is a schematic diagram of the inside of the grinding unit 60 as viewed horizontally. Fig. 9B is a schematic diagram of the inside of the grinding unit 60 as viewed from directly above.

[0090] 9A and 9B, grinding unit 60 includes a chamber 61 forming a passage opening through which bonded substrate W, i.e., bonded first substrate W1 and second substrate W2, passes and an internal space in which bonded substrate W that has passed the passage opening is disposed, a chuck 64 that holds bonded substrate W horizontally within chamber 61, and an electric motor 65 that rotates chuck 64 to rotate bonded substrate W about a vertical rotation center A1 passing through the center of bonded substrate W held by chuck 64. Chamber 61 includes a partition 62 that forms the internal space and the passage opening, and a door 63 that moves relative to partition 62 to open and close the passage opening.

[0091] Grinding unit 60 further includes a grindstone 66 that is pressed against the upper surface of bonded substrate W held by chuck 64, a horizontal disk-shaped wheel 67 that holds grindstone 66, an electric motor 68 that rotates grindstone 66 and wheel 67 around a vertical rotation center that passes through the center of wheel 67, and an elevation actuator 69 that vertically moves grindstone 66 and wheel 67. When grindstone 66 is brought into contact with the upper surface of bonded substrate W while rotating chuck 64 and wheel 67, the entire upper surface of bonded substrate W is ground by grindstone 66.

[0092] Next, the electrical configuration of the substrate bonding apparatus 1 will be described.

[0093] 10 is a block diagram showing an electrical configuration of the substrate bonding apparatus 1. The substrate bonding apparatus 1 includes a control device 3 that controls the electric and electronic devices included in the substrate bonding apparatus 1. The control device 3 controls the substrate bonding apparatus 1 to operate the substrate bonding apparatus 1 as described below. In other words, the control device 3 is programmed to perform the operations described below.

[0094] The control device 3 includes at least one computer. The computer includes a computer main body 3a and a peripheral device 3d connected to the computer main body 3a. The computer main body 3a includes a CPU 3b (central processing unit) that executes various commands, and a memory 3c that stores information. The peripheral device 3d includes a storage 3e that stores information to be transmitted and received between the memory 3c, such as a program P, a reader 3f that reads information from a removable medium RM, and a communication device 3g that communicates with other devices, such as a host computer HC.

[0095] The control device 3 is connected to an input device 3h and a display device 3i. The input device 3h is operated when an operator such as a user or a maintenance person inputs information to the substrate bonding apparatus 1. The information is displayed on the screen of the display device 3i. The input device 3h may be any one of a keyboard, a pointing device, and a touch panel, or may be a device other than these. The substrate bonding apparatus 1 may be provided with a touch panel display that serves as both the input device 3h and the display device 3i.

[0096] The CPU 3b executes a program P stored in the storage 3e. The program P in the storage 3e may be one that has been pre-installed in the control device 3, may be one that has been sent from the removable medium RM to the storage 3e via the reader 3f, or may be one that has been sent from an external device such as a host computer HC to the storage 3e via a communication device 3g.

[0097] The memory 3c is a volatile memory that retains its memory only when power is supplied. The storage 3e and the removable medium RM are non-volatile memories that retain their memory even when power is not supplied. The storage 3e is, for example, a magnetic storage device such as a hard disk drive. The removable medium RM is, for example, an optical disk such as a compact disk or a semiconductor memory such as a memory card. The removable medium RM is an example of a computer-readable recording medium on which the program P is recorded. The removable medium RM is a non-transitory tangible recording medium.

[0098] The storage 3e stores a plurality of recipes RC. The recipe RC is information that specifies the processing content, processing conditions, and processing procedure of the substrate W. The plurality of recipes RC differ from each other in at least one of the processing content, processing conditions, and processing procedure of the substrate W. The control device 3 controls the substrate bonding apparatus 1 so that the substrate W is processed according to the recipe RC specified by the host computer HC. The control device 3 is programmed to execute each process described below.

[0099] The recipe RC includes the application amount (total amount of filling liquid supplied to one substrate W), the application start position (position where supply of filling liquid to the substrate W starts), and the application end position (position where supply of filling liquid to the substrate W starts to end). In other words, the application amount, etc. are specified in the recipe RC. When the filling liquid nozzle 49 is moved, the path through which the filling liquid nozzle 49 passes is also included in the recipe RC. The user can change the application amount, etc. by editing the recipe RC. The recipe RC may be edited by the user operating the input device 3h, or may be edited by the user operating a device other than the substrate bonding apparatus 1, such as a personal computer. In the latter case, the edited recipe RC can be sent to the control device 3 via the communication device 3g.

[0100] Next, a description will be given of the application of the filling liquid to the substrate W. First, the shape of the substrate W will be described, and then the application of the filling liquid to the substrate W will be described.

[0101] Fig. 11A is a schematic cross-sectional view of the outer periphery of a substrate W. Fig. 11B is a schematic view of the inside of a coating unit 40 as viewed from directly above. Fig. 11C is a schematic cross-sectional view showing a state in which a filling liquid FL is being supplied to an annular groove WG formed between the outer peripheries of two bonded substrates W. Fig. 11D is a schematic cross-sectional view showing a state in which a void V1 and a void V2 between two bonded substrates W are being detected by a void detector 48.

[0102] As described above, after two substrates W are bonded together, a filler liquid FL is applied to the outer periphery of the two bonded substrates W. The outer periphery of the substrate W is also called a bevel portion. FIG. 11A shows an example in which the cross section of the outer periphery of the substrate W is semicircular or parabolic. The cross section of the outer periphery of the substrate W may have a shape other than semicircular or parabolic, such as a trapezoid. The following describes a state in which the front and back surfaces of the substrate W are horizontal.

[0103] The outer surface of the substrate W includes a bonding surface WA that contacts another substrate W, a non-bonding surface WN that does not contact another substrate W, and a tip WE that is located on the outermost side of the outer surface of the substrate W. The tip WE of the substrate W is a circular line or surface that connects the outer periphery of the bonding surface WA and the outer periphery of the non-bonding surface WN. The edge surface of the substrate W is a region of a predetermined range that includes the tip WE of the substrate W.

[0104] The bonding surface WA of the substrate W includes a horizontal, flat, circular flat portion F1 and an annular outer peripheral portion O1 extending from the outer periphery of the flat portion F1 to the tip WE so as to descend as it approaches the tip WE. The non-bonding surface WN of the substrate W includes a horizontal, flat, circular flat portion F2 and an annular outer peripheral portion O2 extending from the outer periphery of the flat portion F2 to the tip WE so as to ascend as it approaches the tip WE.

[0105] The flat portion F1 of the bonding surface WA corresponds to a device formation region where a device is formed. The flat portion F1 of the bonding surface WA is parallel to the flat portion F2 of the non-bonding surface WN. The center of the flat portion F1 of the bonding surface WA is located on the center line of the substrate W. The center of the flat portion F2 of the non-bonding surface WN is also located on the center line of the substrate W. The diameter of the flat portion F1 of the bonding surface WA is equal to or approximately equal to the diameter of the flat portion F2 of the non-bonding surface WN. When the cross section of the outer periphery of the substrate W is semicircular or parabolic, the cross sections of the outer periphery O1 and the outer periphery O2 are arc-shaped. When the cross section of the outer periphery of the substrate W is trapezoidal, the cross sections of the outer periphery O1 and the outer periphery O2 are linear.

[0106] When two substrates W as shown in FIG. 11A are bonded together, the outer peripheries of the two bonded substrates W form an annular groove WG that opens at the end faces of the two substrates W. The annular groove WG is formed between the two bonded substrates W by the outer peripheries of the two substrates W. The annular groove WG is continuous around the entire circumference of the bonded substrates W. The thickness direction of the two bonded substrates W corresponds to the width direction of the annular groove WG, and the radial direction of the two bonded substrates W (the direction perpendicular to the center line of the substrates W) corresponds to the depth direction of the annular groove WG. The depth of the annular groove WG increases continuously or stepwise as it approaches the center of the annular groove WG in the width direction of the annular groove WG.

[0107] As described above, after two substrates W are bonded together, the bonded substrate W, i.e., one of the two bonded substrates W, is ground and thinned by a grindstone 66 (see FIG. 9A). The thickness of the outer periphery of the substrate W decreases toward the end face of the substrate W. Near the end face of the substrate W, the outer peripheries of the two bonded substrates W are separated from each other, forming a gap corresponding to the annular groove WG. If the bonded substrate W is ground without a filler FS (see FIG. 11D) in the annular groove WG, a force is applied to the outer periphery of the substrate W from the grindstone 66, and the outer periphery of one substrate W may bend toward the outer periphery of the other substrate W. To alleviate this, it is necessary to supply a filler liquid FL, which changes into a solid or semi-solid filler FS, to the annular groove WG.

[0108] When the filling liquid FL is supplied to the annular groove WG of the bonded substrate W, as shown in Fig. 11B, the bonded substrate W is carried into the coating unit 40 by the transport robot TR (see Fig. 3) and held horizontally by the chuck 44. This allows the substrate W to be held horizontally with the front surface of the substrate W, which is the bonding surface WA, facing upward. In this state, the substrate W is rotated by the chuck 44 while the filling liquid nozzle 49 is caused to discharge the filling liquid FL toward the annular groove WG of the bonded substrate W.

[0109] The filling liquid FL discharged from the filling liquid nozzle 49 is applied to the inner surface of the annular groove WG. FIG. 11C shows an example in which the filling liquid nozzle 49 is an inkjet nozzle. In this example, multiple droplets of the filling liquid FL sprayed from the filling liquid nozzle 49 scatter in approximately the same direction toward the annular groove WG of the bonded substrate W. These droplets enter the annular groove WG and collide with the bonded substrate W in the annular groove WG. As a result, the filling liquid FL is applied to the inner surface of the annular groove WG.

[0110] The droplets of the filling liquid FL applied to the bonded substrate W remain at or near the position where they collided with the bonded substrate W due to the viscosity of the filling liquid FL and the force acting on the filling liquid FL from the bonded substrate W. Subsequent droplets of the filling liquid FL collide with at least one of the inner surface of the annular groove WG and the filling liquid FL adhering to the inner surface of the annular groove WG, and remain at or near the position where they collided. By repeating this phenomenon, the filling liquid FL gradually reduces the space in the annular groove WG, i.e., the space between the outer peripheries of the two bonded substrates W.

[0111] The filler liquid FL in the annular groove WG changes into a solid or semi-solid filler FS in the annular groove WG. If the filler liquid FL has changed into a filler FS when grinding of the bonded substrate W is started, the filler liquid FL may change into a filler FS while the filler liquid nozzle 49 is discharging the filler liquid FL, or may change into a filler FS after the filler liquid nozzle 49 stops discharging the filler liquid FL. In either case, a process may be performed to cause or promote the change from the filler liquid FL to the filler FS.

[0112] The filling liquid nozzle 49 may be kept stationary or may be kept moving from the start to the end of the discharge of the filling liquid FL from the filling liquid nozzle 49. There may be a period in which the filling liquid nozzle 49 is caused to discharge the filling liquid FL while the filling liquid nozzle 49 is kept stationary, and a period in which the filling liquid nozzle 49 is caused to discharge the filling liquid FL while the filling liquid nozzle 49 is moving.

[0113] The radial distance from the center of rotation A1 of the bonded substrate W to the outer periphery of the bonded substrate W can change depending on the angle around the center of rotation A1 of the bonded substrate W. The height of the outer periphery of the bonded substrate W can also change depending on the angle around the center of rotation A1 of the bonded substrate W. Therefore, the position of the annular groove WG can change in at least one of the radial and vertical directions depending on the angle around the center of rotation A1 of the bonded substrate W.

[0114] 11C , the control device 3 may reduce the change in the distance from the filling liquid nozzle 49 to the annular groove WG of the bonded substrate W by having the nozzle actuator 49a move the filling liquid nozzle 49 in response to a change in the position of the annular groove WG in at least one of the radial and vertical directions. In this case, after measuring the change in the position of the annular groove WG over the entire circumference of the bonded substrate W, the control device 3 may cause the filling liquid nozzle 49 to start discharging the filling liquid FL toward the rotating bonded substrate W, or may cause the filling liquid nozzle 49 to discharge the filling liquid FL toward the rotating bonded substrate W while measuring the change in the position of the annular groove WG.

[0115] The outer periphery position sensor 46, the height sensor 47, and the void detector 48 are examples of position detectors that detect the position of the outer periphery of the bonded substrate W. The change in the position of the annular groove WG may be detected by any one of the outer periphery position sensor 46, the height sensor 47, and the void detector 48, or by two or more of them. The void detector 48 can also detect the change in the position of the annular groove WG in the radial and vertical directions by detecting the change in the shape of the annular groove WG relative to the angle around the rotation center A1 of the bonded substrate W.

[0116] 11B shows an example in which the filling liquid nozzle 49 is caused to discharge the filling liquid FL toward the rotating bonded substrate W while the change in the position and shape of the annular groove WG is measured by the void detector 48. In this example, the void detector 48 is disposed upstream of the filling liquid nozzle 49 in the rotation direction Dr of the bonded substrate W. Since the difference in rotation angle between the void detector 48 and the filling liquid nozzle 49 (the difference in angle about the rotation center A1 of the bonded substrate W) and the rotation speed of the bonded substrate W are known, the filling liquid nozzle 49 can be moved relative to the bonded substrate W in accordance with these and the amount and direction of change in the position of the annular groove WG.

[0117] Not only the position of the annular groove WG but also the shape of the annular groove WG may change depending on the angle around the rotation center A1 of the bonded substrate W. When the change in the position and shape of the annular groove WG is measured by the void detector 48, the flow rate of the filling liquid FL discharged from the filling liquid nozzle 49 (the amount of filling liquid FL discharged from the filling liquid nozzle 49 per unit time) may be changed depending on the change. In this way, it is possible to reduce the change in the radial distance from the rotation center A1 of the bonded substrate W to the outer end of the filling liquid FL in the annular groove WG. Regardless of whether or not the change in the position and shape of the annular groove WG is measured, the control device 3 may change the flow rate of the filling liquid FL.

[0118] When the filling liquid FL is applied to a plurality of bonded substrates W, the position of the annular groove WG may change in the same manner between these bonded substrates W. Therefore, the control device 3 may cause the nozzle actuator 49a to move the filling liquid nozzle 49 in response to the change in the position of the annular groove WG of another bonded substrate W. In other words, the control device 3 may store measurement data D1 obtained when the change in the position of the annular groove WG of another bonded substrate W is measured, and cause the nozzle actuator 49a to move the filling liquid nozzle 49 based on this measurement data D1. Alternatively, the control device 3 may cause the void detector 48 or the like to measure the change in the position and shape of the annular groove WG every time the bonded substrate W held by the chuck 44 is changed.

[0119] In this manner, the filling liquid FL is applied to the inner surface of the annular groove WG. The presence or absence of a coating defect may be detected by observing the inside of the annular groove WG with the void detector 48 after stopping the supply of the filling liquid FL. As shown in FIG. 11D, the void detector 48 can detect a void V1 in the filling liquid FL or the filling body FS in the annular groove WG of the bonded substrate W held by the chuck 44. The void detector 48 may be configured to detect a void V2 between the bonding surface WA1 and the bonding surface WA2. When detecting the void V2, the void detector 48 may be moved above or below the bonded substrate W held by the chuck 44, or another void detector 48 may be disposed above or below the bonded substrate W held by the chuck 44.

[0120] When two substrates W are bonded together, a gap corresponding to the annular groove WG is formed between the outer peripheries of the two substrates W. When two substrates W without a filler FS in the annular groove WG are being ground, a force is applied from the grindstone to the outer periphery of the substrate W, which may cause the outer periphery of the substrate W to bend toward the annular groove WG. By disposing a filler FS in the annular groove WG, such bending can be reduced. The gap V1 in the filler FS (see FIG. 11D) may cause stress concentration in the filler FS when the two substrates W are being ground. The gap V1 can be reduced or made smaller by supplying droplets of the filler liquid FL to the annular groove WG.

[0121] After the annular groove WG is filled with the filler liquid FL, the bonded substrate W is ground. When grinding of the bonded substrate W starts, the filler liquid FL in the annular groove WG has changed to a solid or semi-solid filler FS. When the bonded substrate W, that is, one of the two bonded substrates W, is ground with a grindstone 66 (see FIG. 9A), the outer periphery of the bonded substrate W is supported by the filler FS. Therefore, chipping, in which the edge of the thinned substrate W is chipped, and the generation of particles associated with this can be prevented or reduced. As a result, the number of particles adhering to devices can be reduced, and the device yield can be increased.

[0122] Next, the effects of this embodiment will be described.

[0123] In this embodiment, while rotating the bonded substrate W, multiple droplets of the filling liquid are sprayed toward the annular groove WG formed between the outer peripheries of the two bonded substrates W. This allows the filling liquid to be supplied to the annular groove WG. In addition, by controlling the rotation angle of the chuck 44 that holds the bonded substrate W, the range in which the filling liquid is supplied to the annular groove WG can be controlled. The filling liquid changes into a solid or semi-solid filling body. Therefore, the relative movement of the outer peripheries of the two bonded substrates W can be regulated by the filling body. Furthermore, since multiple droplets of the filling liquid are sprayed, the amount of filling liquid supplied to the annular groove WG can be precisely controlled compared to the case in which the filling liquid is continuously discharged.

[0124] In this embodiment, droplets of the filling liquid are intermittently sprayed from the filling liquid nozzle 49, which is an inkjet nozzle. A plurality of droplets of the filling liquid sprayed from the filling liquid nozzle 49 scatter in the same or almost the same direction toward the annular groove WG. Therefore, the position to which the filling liquid is supplied can be controlled with higher precision than in the case where a plurality of droplets of the filling liquid scatter in various directions.

[0125] In this embodiment, the position of the outer periphery of the bonded substrate W held by the chuck 44 is detected, and the nozzle actuator 49a is caused to move the filling liquid nozzle 49 in accordance with the detected position. As a result, the filling liquid nozzle 49 moves in at least one of the horizontal and vertical directions in accordance with the change in the position of the outer periphery of the bonded substrate W, so that the change in the distance from the filling liquid nozzle 49 to the bonded substrate W that occurs with the rotation of the bonded substrate W can be reduced. Therefore, the position to which the filling liquid is supplied can be controlled with high precision. When the amount of filling liquid FL discharged from the filling liquid nozzle 49 per unit time is changed in accordance with the detected position, the change in the radial distance from the rotation center A1 of the bonded substrate W to the outer end of the filling liquid FL in the annular groove WG can be reduced.

[0126] In this embodiment, the nozzle actuator 49a moves the filling liquid nozzle 49 while detecting the position of the outer periphery of the bonded substrate W, not after detecting the position of the outer periphery of the bonded substrate W. Therefore, the time until the supply of the filling liquid to the annular groove WG is completed can be shortened compared to the case where the nozzle actuator 49a moves the filling liquid nozzle 49 after the detection of the position of the outer periphery of the bonded substrate W has been completed but before the detection is being performed.

[0127] In this embodiment, while the chuck 44 holds the bonded substrates W, the void detector 48 detects voids in the filling liquid or filler in the annular groove WG. This makes it possible to detect voids in the filling liquid or filler in the annular groove WG while the filling liquid is being supplied to the annular groove WG. In addition, the void detector 48 can be configured to detect not only voids in the filling liquid or filler but also voids between the bonding surfaces WA of the two bonded substrates W, so that the time required to complete void detection can be shortened compared to the case where the voids between the bonding surfaces WA of the two substrates W are detected after the bonded substrates W are moved from the chuck 44.

[0128] In this embodiment, a coating unit 40 is provided in a substrate bonding apparatus 1 that bonds two substrates W. The coating unit 40 coats the two substrates W bonded by the bonding unit 50 with a filling liquid. As described above, the coating unit 40 sprays a plurality of droplets of the filling liquid toward the annular groove WG formed between the outer peripheries of the two bonded substrates W while rotating the bonded substrates W. This not only shortens the time from bonding the two substrates W to supplying the filling liquid to the two bonded substrates W, but also allows for precise control of the amount of filling liquid supplied to the annular groove WG.

[0129] In this embodiment, the substrate bonding apparatus 1 is provided with not only the bonding unit 50 and the coating unit 40, but also a grinding unit 60 that grinds the bonded substrates W coated with the filling liquid. This makes it possible to shorten the time from bonding two substrates W to grinding the two bonded substrates W. The filling liquid applied to the bonded substrates W changes into a solid or semi-solid filling material. This makes it possible to grind the bonded substrates W while preventing the outer periphery of the substrates W from being bent by the force applied from the grindstone 66.

[0130] Next, another embodiment will be described.

[0131] As shown in FIG. 12A, the application unit 40 may be integral with the bonding unit 50 rather than being a pre-bonding aligner.

[0132] 12A includes the configuration of the bonding unit 50 shown in FIGS. 8A and 8B. Thus, the coating unit 40 includes a first chuck 54A, a second chuck 54B, a bonding actuator 55, and the like. The first chuck 54A, the second chuck 54B, the chuck 44, and the like are disposed in the chamber 41 of the coating unit 40.

[0133] In the case where the coating unit 40 is integrated with the bonding unit 50, when the first substrate W1 held by the first chuck 54A and the second substrate W2 held by the second chuck 54B are bonded, the first substrate W1 and the second substrate W2 are held by the second chuck 54B so that the first substrate W1 is located above the second substrate W2. The bonding actuator 55 moves the second chuck 54B horizontally between an image capturing position (center position) where the bonded substrate W held by the second chuck 54B is captured by the third camera 56C, a bonding position (left position) where the first substrate W1 held by the first chuck 54A is bonded to the second substrate W2 held by the second chuck 54B, and a receiving position (right position) where the bonded substrate W is received by the second chuck 54B or the chuck 44.

[0134] The chuck 44 has an adsorption surface that contacts the bonded substrate W facing downward. The coating unit 40 includes a chuck lift actuator 44a that moves the chuck 44 vertically. The chuck lift actuator 44a moves the chuck 44 vertically between a receiving position where the substrate W is received by the second chuck 54B or the chuck 44, and an application position (position shown in FIG. 12A) where the filling liquid is applied to the bonded substrate W held by the chuck 44. The application position is a position above the receiving position. The receiving position of the chuck 44 is a position above the receiving position of the second chuck 54B.

[0135] The bonded substrate W held by the second chuck 54B is received by the chuck 44 when the second chuck 54B and the chuck 44 are located at the receiving position. The chuck 44 rises from the receiving position to the application position while holding the bonded substrate W. Thereafter, the filling liquid is supplied to the annular groove WG of the bonded substrate W held by the chuck 44. When the supply of the filling liquid starts, the second chuck 54B may be located at the receiving position or may be retracted from the receiving position.

[0136] The supply of the filling liquid to the annular groove WG is the same as that described above, except that the bonded substrate W is disposed below the chuck 44. If necessary, the position of the outer periphery of the bonded substrate W held by the chuck 44 may be detected by at least one of the outer periphery position sensor 46, the height sensor 47, and the void detector 48 shown in Figures 7A and 7B. After the supply of the filling liquid to the annular groove WG is completed, the transfer robot TR (see Figure 3) may receive the bonded substrate W from the chuck 44 located at any position within the range from the receiving position to the application position, or may receive the bonded substrate W from the second chuck 54B located at any position within the range from the receiving position to the imaging position.

[0137] As shown in Fig. 12B, after the filling liquid FL is supplied to the annular groove WG, the bonded substrate W held by the second chuck 54B may be photographed by the third camera 56C, which is an infrared camera. Specifically, after the bonded substrate W held by the chuck 44 is received by the second chuck 54B, the second chuck 54B may be moved from the receiving position to the photographing position. Then, the bonded substrate W held by the second chuck 54B may be photographed by the third camera 56C. In this case, not only the gap V2 between the bonding surfaces WA1 and WA2 but also the gap V1 in the filling liquid FL or the filler FS in the annular groove WG may be detected by the third camera 56C.

[0138] 12A, the chamber 41 of the coating unit 40 accommodates not only the chuck 44 and the filling liquid nozzle 49, but also the first chuck 54A and the second chuck 54B of the bonding unit 50. This allows the substrate bonding apparatus 1 to be made smaller in size than when a dedicated chamber 51 is provided for the bonding unit 50. In addition, since the filling liquid is supplied to the bonded substrate W held by a chuck 44 other than the first chuck 54A and the second chuck 54B, the filling liquid nozzle 49 can be kept away from the first chuck 54A and the second chuck 54B, making it difficult for the filling liquid to adhere to the first chuck 54A and the second chuck 54B.

[0139] 12B, the void detector 48 detects not only the gap between the bonding surfaces WA of the two bonded substrates W, but also the gap in the filling liquid or filler in the annular groove WG. In other words, the void detector 48 that detects the gap between the two substrates W can be used as the void detector 48 that detects the gap in the filling liquid or filler. Therefore, it is not necessary to provide a dedicated void detector 48 that detects only the gap in the filling liquid or filler in the annular groove WG.

[0140] As shown in Fig. 13, filling liquid may be applied only to a partial area in the circumferential direction of the substrate W, rather than to the entire circumference of the substrate W. The area surrounded by the two-dot chain line in Fig. 13 indicates the area to which filling liquid is applied. In this example, filling liquid is applied only to four areas spaced apart in the circumferential direction of the substrate W.

[0141] Devices such as transistors are formed on the surface of the substrate W, which corresponds to the device formation surface. The device region and non-device region are both regions within the surface of the substrate W. In FIG. 13, the outer edge of the device region is indicated by a thick line. The device region is a region where devices such as transistors and patterns exist. The non-device region is a region where no devices or patterns exist. The non-device region is a ring-shaped region around the device region.

[0142] The shortest distance from the outer periphery of the substrate W to the outer edge of the device region may vary depending on the position on the outer periphery of the substrate W. If the shortest distance is relatively short, a relatively large force is likely to be applied from the grindstone 66 (see FIG. 9A) to the device located at the edge of the device region when the bonded substrate W is ground. If a crack or chip that occurs on the outer periphery of the bonded substrate W during grinding of the bonded substrate W reaches a device located at the edge of the device region, the device (the device including the crack, etc.) becomes defective. The shorter the shortest distance, the more likely the device is to become defective. As shown in FIG. 13, the filling liquid may be applied only to a plurality of ranges (ranges surrounded by two-dot chain lines) where the shortest distance is relatively short. In this way, it is possible to prevent a large force from being applied to the device located at the edge of the device region, while shortening the time required to apply the filling liquid compared to applying the filling liquid to the entire circumference of the substrate W.

[0143] The filling liquid nozzle 49 may continuously discharge the filling liquid so that a continuous liquid column is formed from the filling liquid nozzle 49 to the substrate W, or may spray a plurality of droplets of the filling liquid toward the substrate W, and then continuously discharge the filling liquid so that a continuous liquid column is formed from the filling liquid nozzle 49 to the substrate W. In the latter case, a droplet nozzle that sprays a plurality of droplets of the filling liquid toward the substrate W, and a liquid column nozzle that continuously discharges the filling liquid so that a continuous liquid column is formed from the filling liquid nozzle 49 to the substrate W may be provided.

[0144] If the filling liquid is continuously discharged so as to form a continuous liquid column from the filling liquid nozzle 49 to the substrate W after a plurality of droplets of the filling liquid are ejected toward the substrate W, the position to which the filling liquid is supplied can be precisely controlled at first, and the filling liquid can be supplied at high speed thereafter. Therefore, the time required to complete the supply of the filling liquid can be shortened compared to the case where a plurality of droplets of the filling liquid are ejected from start to finish.

[0145] The filling liquid nozzle 49 may be composed of a large-diameter nozzle 49X and a small-diameter nozzle 49Y shown in Fig. 7C and Fig. 7D. In this case, droplets of the filling liquid jetted from the jet port 49y of the small-diameter nozzle 49Y may be supplied to the bottom (rear) of the annular groove WG, that is, a position where the filling liquid is difficult to reach. Then, droplets of the filling liquid jetted from the jet port 49x of the large-diameter nozzle 49X may be supplied to the annular groove WG. In this way, it is possible to prevent voids from occurring at the bottom of the annular groove WG and to shorten the time required to apply the filling liquid.

[0146] Grinding unit 60 may be omitted from substrate bonding apparatus 1. Coating unit 40 may be omitted from substrate bonding apparatus 1. In other words, coating unit 40 may be a device separate from substrate bonding apparatus 1 and disposed outside outer wall 1a of substrate bonding apparatus 1.

[0147] The substrate bonding apparatus 1 is not limited to an apparatus for bonding two disk-shaped substrates W, but may be an apparatus for bonding two polygonal substrates W.

[0148] Any two or more of the above mentioned features may be combined. Any two or more of the above mentioned steps may be combined.

[0149] Although the embodiments of the present invention have been described in detail, these are merely examples used to clarify the technical contents of the present invention, and the present invention should not be construed as being limited to these examples. The spirit and scope of the present invention are limited only by the appended claims. [Explanation of symbols]

[0150] 1: substrate bonding device, 3: control device, 40: coating unit, 41: chamber, 44: chuck, 46: outer periphery position sensor, 47: height sensor, 48: void detector, 49: filling liquid nozzle, 49X: large diameter nozzle, 49Y: small diameter nozzle, 49a: nozzle actuator, 50: bonding unit, 54A: first chuck, 54B: second chuck, 55: bonding actuator, 60: grinding unit, A1: rotation center, FL: filling liquid, FS: filling body, W: substrate, WA, WA1, WA2: bonding surface, WG: annular groove

Claims

1. a chuck that holds a bonded substrate, which is two bonded substrates, and rotates about an axis that is perpendicular to a main surface of the bonded substrate and passes through a center of the main surface; a filling liquid nozzle that supplies the filling liquid to an annular groove formed between the outer peripheries of the two bonded substrates by spraying a plurality of droplets of the filling liquid that changes into a solid or semi-solid filler toward the bonded substrates held by the chuck.

2. The application unit according to claim 1 , wherein the filler liquid nozzle is an inkjet nozzle that sprays a plurality of droplets of the filler liquid in substantially the same direction toward the annular groove.

3. a position detector for detecting a position of an outer periphery of the bonded substrate held by the chuck; The coating unit according to claim 1 , further comprising: a nozzle actuator that moves the filling liquid nozzle in accordance with the position of the outer periphery detected by the position detector.

4. The application unit according to claim 3, further comprising a control device that performs at least one of a position control that causes the nozzle actuator to move the filling liquid nozzle in accordance with the position of the outer periphery detected by the position detector while causing the position detector to detect the position of the outer periphery, and a flow rate control that changes the amount of the filling liquid sprayed from the filling liquid nozzle per unit time in accordance with the position of the outer periphery detected by the position detector while causing the position detector to detect the position of the outer periphery.

5. The coating unit of claim 1 or 2, further comprising a void detector that detects voids within the filling liquid or filling body in the annular groove and voids between the bonding surfaces of the two bonded substrates when the chuck is holding the bonded substrates.

6. 3. The coating unit according to claim 1, wherein the filling liquid nozzle includes a large-diameter nozzle that sprays a plurality of droplets of the filling liquid from a spray opening toward the bonded substrate held by the chuck, and a small-diameter nozzle that sprays a plurality of droplets of the filling liquid from a spray opening having an area smaller than that of the spray opening of the large-diameter nozzle toward the bonded substrate held by the chuck.

7. The method includes: a joining unit that joins two substrates together; and an application unit that applies a filler liquid that changes into a solid or semi-solid filler to the joined substrate, which is the two substrates joined by the joining unit; The application unit includes: a chuck that holds the bonded substrate and rotates about an axis that is perpendicular to a main surface of the bonded substrate and passes through a center of the main surface; a filling liquid nozzle that supplies the filling liquid to an annular groove formed between the outer peripheries of the two bonded substrates by spraying a plurality of droplets of the filling liquid toward the bonded substrate held by the chuck.

8. the bonding unit includes a first chuck and a second chuck that respectively hold the two substrates before being bonded, and a bonding actuator that brings the two substrates held by the first chuck and the second chuck into contact with each other by moving the first chuck and the second chuck relatively; The substrate bonding apparatus of claim 7 , wherein the coating unit further includes a chamber that houses the chuck, the filling liquid nozzle, the first chuck, and the second chuck.

9. The substrate bonding apparatus of claim 7 or 8, wherein the bonding unit further includes a void detector that detects voids between the bonding surfaces of the two bonded substrates and voids within the filling liquid or filling body in the annular groove.

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