Substrate bonding system and substrate bonding method

Abstract

To provide a substrate bonding system capable of improving bonding position accuracy in entire substrates which are bonded to each other, and a substrate bonding method.SOLUTION: A substrate bonding system calculates, on the basis of a picked-up image obtained by imaging a plurality of alignment marks using an imaging section of an inspection device, a positional displacement amount and a positional displacement direction of each of the plurality of alignment marks, separates an axial direction component and a rotation direction component in two axial directions, which cross each other, of a positional displacement vector determined by the calculated positional displacement amount and positional displacement direction and calculates, on the basis of the separated axial direction component and rotation direction component, a horizontal offset vector reflected with an axial direction offset amount which is an offset amount in an axial direction of the other substrate with respect to one substrate in bonding the substrates and a rotation direction offset amount which is an offset amount in a rotation direction.SELECTED DRAWING: Figure 18

Description

[Technical field]

[0001] The present invention relates to a system and method for bonding substrates. [Background technology]

[0002] An apparatus for bonding two substrates together, which includes a mounting device to which the substrates are attached during bonding, has been proposed (see, for example, Patent Document 1). The mounting device described in Patent Document 1 has an outer annular portion that holds the periphery of the substrate with a vacuum chuck, and a deformation means that deforms the substrate so that the center of the substrate protrudes from the mounting device. This apparatus brings the centers of the bonding surfaces of the two substrates into contact with each other, and then releases the suction and holding of the periphery of one substrate by the vacuum chuck. As a result, the restoring force and gravity acting on the periphery of one substrate causes the contact portion to expand radially outward from the center of the one substrate, reaching the periphery of the one substrate. In this manner, the two substrates are bonded together. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2013 / 023708 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the case of the device described in Patent Document 1, when releasing the suction and holding of the periphery of one of the substrates, even if the vacuum chuck that suctions and holds the periphery of the one of the substrates is stopped, the substrate may still stick to the mounting surface of the mounting device due to electrostatic forces generated on the periphery of the substrate. In this case, the magnitude of the force acting on one of the substrates becomes non-uniform, causing variations in the speed at which the contact area between the substrates spreads, which may result in a decrease in the accuracy of the joining position of the two substrates that are joined together.

[0005] The present invention has been made in consideration of the above-mentioned circumstances, and has an object to provide a substrate bonding system and a substrate bonding method that can improve the bonding position accuracy over the entire substrates bonded to each other. [Means for solving the problem]

[0006] In order to achieve the above object, a substrate bonding system according to the present invention comprises: A substrate bonding system for bonding a first substrate provided with a plurality of first alignment marks and a second substrate provided with a plurality of second alignment marks, comprising: a bonding device including a first substrate holding section that holds the first substrate, a second substrate holding section that holds the second substrate with the bonding surface of the second substrate facing the bonding surface of the first substrate, a first imaging section, and a holder driving section that moves at least one of the first substrate holding section and the second substrate holding section relatively to the other in a direction intersecting a direction in which the first substrate holding section and the second substrate holding section face each other; An inspection device having a second imaging unit; A control unit, the first substrate is provided with at least one third alignment mark different from the plurality of first alignment marks; the second substrate is provided with at least one fourth alignment mark different from the plurality of second alignment marks, the number of which is equal to the number of the at least one third alignment mark; the second imaging unit images all of the multiple first alignment marks, the multiple second alignment marks, the at least one third alignment mark, and the at least one fourth alignment mark of each of the first substrate and the second substrate bonded to each other; The control unit calculates a positional misalignment amount and a positional misalignment direction of each of the multiple first alignment marks and the multiple second alignment marks, and a positional misalignment amount and a positional misalignment direction of each of the at least one third alignment mark and the at least one fourth alignment mark based on an image obtained by imaging the multiple first alignment marks, the multiple second alignment marks, the at least one third alignment mark, and the at least one fourth alignment mark with the second imaging unit, separates axial components and rotational components along each of two intersecting axial directions of a misalignment vector determined by the calculated positional misalignment amount and positional misalignment direction, and calculates a horizontal offset amount reflecting an axial offset amount, which is the offset amount in the two axial directions of the second substrate relative to the first substrate when the first substrate and the second substrate are joined, and a rotational offset amount, which is the offset amount in the rotational direction of the second substrate, based on the separated axial components and rotational components.

[0007] The method for bonding substrates according to the present invention from another aspect comprises: A substrate bonding method for bonding a first substrate and a second substrate, comprising the steps of: the first substrate is provided with three or more first alignment marks; the second substrate is provided with three or more second alignment marks, the number of which is the same as the three or more first alignment marks; a step of imaging, by a first imaging unit, the three or more first alignment marks, the three or more second alignment marks, at least one third alignment mark different from the three or more first alignment marks, and at least one fourth alignment mark different from the three or more second alignment marks, the number of which is the same as that of the at least one third alignment mark, of each of the first substrate and the second substrate bonded to each other; calculating a positional misalignment amount and a positional misalignment direction of each of the three or more first alignment marks and the three or more second alignment marks and a positional misalignment amount and a positional misalignment direction of each of the at least one third alignment mark and the at least one fourth alignment mark based on an image obtained by imaging the three or more first alignment marks, the three or more second alignment marks, the at least one third alignment mark, and the at least one fourth alignment mark by a second imaging unit different from the first imaging unit, separating an axial component and a rotational component along each of two intersecting axial directions of a misalignment vector determined by the calculated positional misalignment amount and positional misalignment direction, and calculating a horizontal offset amount reflecting an axial offset amount that is an offset amount in the two axial directions of the second substrate relative to the first substrate when bonding the first substrate and the second substrate together and a rotational offset amount that is an offset amount in the rotational direction of the second substrate based on the separated axial component and rotational component; and moving at least one of the first substrate and the second substrate so that the positional misalignment amount between the three or more first alignment marks and second alignment marks corresponding to each of the three or more first alignment marks is offset by the horizontal offset amount. Effect of the Invention

[0008] According to the present invention, the first substrate and the second substrate can be bonded together without distortion and with high positional accuracy over the entire surfaces. [Brief description of the drawings]

[0009] [Figure 1] 1 is a schematic configuration diagram of a substrate bonding system according to a first embodiment of the present invention. [Diagram 2] 1 is a schematic front view of an activation treatment apparatus according to a first embodiment. [Diagram 3] 1 is a schematic front view of a substrate bonding apparatus according to a first embodiment. [Figure 4A]2 is a schematic perspective view showing the vicinity of a stage and a head according to the first embodiment. FIG. [Figure 4B] 5A to 5C are diagrams illustrating a method for fine-tuning the head according to the first embodiment. [Figure 5A] 2 is a schematic plan view of a stage and a head according to the first embodiment. FIG. [Figure 5B] 3 is an enlarged view of a portion of the stage and head according to the first embodiment. [Figure 6A] 3 is a plan view of a part of a first region of a stage and a head according to the first embodiment. FIG. [Figure 6B] 4 is a plan view of a portion of the stage and the second region of the head according to the first embodiment. FIG. [Figure 7A] 5B is a schematic cross-sectional view of the stage and head according to the first embodiment taken along line BB in FIG. 5A. [Figure 7B] 5B is a schematic cross-sectional view of the stage and head according to the first embodiment taken along line AA in FIG. 5A. [Figure 8] 2 is a schematic plan view of a position measurement unit according to the first embodiment. FIG. [Figure 9A] FIG. 2 shows three alignment marks provided on one of the two substrates to be joined. [Figure 9B] FIG. 13 is a diagram showing three alignment marks provided on the other of the two substrates to be joined. [Figure 10A] FIG. 2 is a schematic diagram showing a captured image of an alignment mark. [Figure 10B] FIG. 1 is a schematic diagram showing a state in which alignment marks are misaligned with each other. [Figure 11] 1 is a schematic diagram of an inspection device according to a first embodiment. [Figure 12] 4 is a flowchart showing a flow of a substrate bonding method executed by the substrate bonding system according to the first embodiment. [Figure 13A] 1 is a schematic plan view showing an electrostatic chuck and an alignment mark according to a first embodiment, illustrating a state in which the electrostatic chuck and the alignment mark overlap each other. FIG. [Figure 13B]1 is a schematic plan view showing an electrostatic chuck and an alignment mark according to a first embodiment, in which the electrostatic chuck and the alignment mark do not overlap with each other. FIG. [Figure 14] 4 is a flowchart showing a flow of a substrate bonding process performed by the substrate bonding apparatus in accordance with the first embodiment. [Figure 15A] 5 is a schematic cross-sectional view showing how the central portion of the substrate held by the stage and head in accordance with the first embodiment is released from the stage and head. FIG. [Figure 15B] 4 is a schematic cross-sectional view showing a state in which central portions of bonding surfaces of substrates held by a stage and a head according to the first embodiment are brought into contact with each other. FIG. [Figure 16A] 5 is a schematic cross-sectional view showing how substrates held by a stage and a head according to the first embodiment are brought closer to each other. FIG. [Figure 16B] 5 is a schematic cross-sectional view showing how substrates held by a stage and a head according to the first embodiment are brought closer to each other. FIG. [Figure 17A] 1 is a schematic cross-sectional view showing a state in which peripheral portions of bonding surfaces of substrates held by a stage and a head in the embodiment are brought into contact with each other. FIG. [Figure 17B] 5 is a schematic cross-sectional view showing how the head according to the first embodiment is removed from the stage. FIG. [Figure 18] FIG. 11 is a diagram showing the distribution of misalignment vectors obtained from images captured by the inspection device of embodiment 1, showing the case where no correction of the horizontal offset vector and protrusion offset amount is performed when joining substrates together, (A) is a diagram showing the misalignment vector indicating the misalignment amount and misalignment direction of each alignment mark, (B) is a diagram showing the XY direction components of the misalignment vector, (C) is a diagram showing the rotation direction components of the misalignment vector, (D) is a diagram showing the warp component of the misalignment vector, and (E) is a diagram showing the distortion component of the misalignment vector. [Figure 19A] 11A and 11B are diagrams for explaining offset vectors of alignment marks; [Figure 19B] 11A and 11B are diagrams for explaining offset vectors of alignment marks; [Figure 19C] 11A and 11B are diagrams for explaining offset vectors of alignment marks; [Figure 19D] 11A and 11B are diagrams for explaining offset vectors of alignment marks; [Figure 19E] 11A and 11B are diagrams for explaining offset vectors of alignment marks; [Figure 20A] 11 is a schematic plan view showing a state in which an electrostatic chuck and an alignment mark according to a comparative example overlap each other. FIG. [Figure 20B] FIG. 11 is a schematic plan view showing an electrostatic chuck and alignment marks according to a comparative example, illustrating a state after the attitude of the substrate has been changed. [Figure 21A] FIG. 11 is a schematic plan view of a stage and a head according to the second embodiment. [Figure 21B] 21B is a cross-sectional view of the stage and head according to the second embodiment taken along line CC in FIG. 21A. [Figure 22A] 13 is a schematic cross-sectional view showing a state in which central portions of bonding surfaces of substrates held by a stage and a head according to a second embodiment are brought into contact with each other. FIG. [Figure 22B] 10 is a schematic cross-sectional view showing a state in which a pressing member is brought into contact with a substrate held by a stage and a head according to a second embodiment. FIG. [Figure 23A] 10 is a schematic cross-sectional view showing how substrates held by a stage and a head according to the second embodiment are brought closer to each other. FIG. [Figure 23B] 13 is a schematic cross-sectional view showing a state in which peripheral portions of bonding surfaces of substrates held by a stage and a head according to a second embodiment are brought into contact with each other. FIG. [Figure 24A] FIG. 13 is a schematic plan view of a stage and a head according to a modified example. [Figure 24B] FIG. 13 is an enlarged view of a portion of a stage and a head according to a modified example. [Figure 25A] FIG. 13 is a schematic plan view of a stage and a head according to a modified example. [Figure 25B] FIG. 13 is an enlarged view of a portion of a stage and a head according to a modified example. [Figure 26A] FIG. 13 is a schematic plan view of a stage and a head according to a modified example. [Figure 26B] 26B is a schematic cross-sectional view taken along line DD in FIG. 26A of a stage and a head according to a modified example. [Figure 27A] 13 is a plan view of a part of the stage and the second region of the head according to a modified example. FIG. [Figure 27B] 26B is a schematic cross-sectional view of a stage and a head according to a modified example taken along line EE in FIG. 26A. [Figure 28] FIG. 13 is a schematic plan view of a stage and a head according to a modified example. [Figure 29] FIG. 11 is a cross-sectional view of a stage and a head according to a modified example. [Diagram 30] FIG. 13 is a schematic plan view of an imaging section according to a modified example. [Diagram 31] FIG. 13 is a schematic front view of an activation treatment apparatus according to a modified example. [Diagram 32] 10 is a flowchart showing a flow of a substrate bonding process executed by a substrate bonding apparatus according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] (Embodiment 1) Hereinafter, a substrate bonding apparatus according to an embodiment of the present invention will be described with reference to the drawings. The substrate bonding apparatus according to the present embodiment bonds two substrates together by bringing two substrates, the bonding surfaces of which have been subjected to an activation treatment, into contact with each other in a vacuum chamber having a vacuum level equal to or higher than a preset reference vacuum level.

[0011] As shown in FIG. 1, the substrate bonding system according to the present embodiment includes introduction ports 811 and 812, an unloading port 813, transport devices 82, 84, and 86, a cleaning device 3, an activation processing device 2, a substrate bonding device 1, load lock units 83 and 85, an inspection device 7, and a control unit 9 that controls the operations of the transport devices 82, 84, and 86, the cleaning device 3, the activation processing device 2, the substrate bonding device 1, the load lock units 83 and 85, and the inspection device 7. The transport device 82 includes a transport robot 821 having an arm with a holder at the tip thereof for holding a substrate. The transport robot 821 is movable along the direction in which the introduction ports 811 and 812 and the unloading port 813 are arranged, and can change the direction of the tip of the arm by rotating. The transport device 82 is provided with a HEPA (High Efficiency Particulate Air) filter (not shown). As a result, the inside of the transport device 82 is an atmospheric pressure environment with extremely few particles.

[0012] The cleaning device 3 cleans the substrates while discharging water, cleaning liquid, or N2 gas toward the substrates. The cleaning device 3 has a stage (not shown) that supports the substrates, a rotary drive unit (not shown) that rotates the stage in a plane perpendicular to the vertical direction, and a cleaning nozzle (not shown) that discharges water, cleaning liquid, or N2 gas to which ultrasonic or megasonic vibrations have been applied. The cleaning device 3 cleans the entire bonding surfaces of the substrates W1 and W2 by rotating the stage while spraying water to which ultrasonic waves have been applied from the cleaning nozzle onto the bonding surfaces of the substrates while swinging the cleaning nozzle in the radial direction of the substrates W1 and W2. The cleaning device 3 spin-dries the substrates W1 and W2 by rotating the stage while stopping the discharge of water from the cleaning nozzle. The cleaning device 3 is also provided with a HEPA filter (not shown) like the transport device 82.

[0013] The load lock unit 83 includes a chamber 831, an exhaust pipe (not shown) communicating with the inside of the chamber 831, a vacuum pump (not shown) for discharging gas from the chamber 831 through the exhaust pipe, and an exhaust valve (not shown) inserted in the exhaust pipe. The load lock unit 83 reduces (depressurizes) the air pressure in the chamber 831 by opening the exhaust valve and operating the vacuum pump to discharge the gas from the chamber 831 to the outside of the chamber 831 through the exhaust pipe. The load lock unit 83 also includes a gate 8331 disposed on the transfer device 82 side of the chamber 831, a gate 8321 disposed on the transfer device 84 side of the chamber 831, and gate drivers 8332 and 8322 for driving the gates 8331 and 8321 to open and close, respectively. The load lock unit 83 also includes an alignment mechanism (not shown) for adjusting the attitudes of the substrates W1 and W2 in the chamber 831. The gates 8331 and 8321 are provided so as to cover an opening (not shown) penetrating the chamber 831 on the transfer device 82 side and an opening (not shown) penetrating the chamber 831 on the transfer device 84 side, respectively. The load lock unit 83 includes a chamber 831, an exhaust pipe (not shown) communicating with the inside of the chamber 831, a vacuum pump (not shown) for discharging gas from the chamber 831 through the exhaust pipe, and an exhaust valve (not shown) inserted in the exhaust pipe. The load lock unit 83 reduces (depressurizes) the air pressure in the chamber 831 by opening the exhaust valve and operating the vacuum pump to discharge the gas from the chamber 831 to the outside of the chamber 831 through the exhaust pipe. The chamber 831 is connected to the transfer device 82 through the gate 8331, and is connected to the transfer device 84 through the gate 8321. The load lock unit 85 also includes a chamber 851, an exhaust pipe (not shown), a vacuum pump (not shown), and an exhaust valve (not shown), similar to the load lock unit 83. The chamber 851 is connected to the transfer apparatus 82 via a gate 8531 and to the transfer apparatus 86 via a gate 8521 .

[0014] The transfer device 84 includes a chamber 843, an exhaust pipe (not shown) communicating with the inside of the chamber 843, a vacuum pump (not shown) for discharging gas from the chamber 843 through the exhaust pipe, an exhaust valve (not shown) inserted in the exhaust pipe, and a transfer robot 841 for transferring the substrates W1 and W2. The transfer device 84 maintains the inside of the chamber 843 in a reduced pressure state by opening the exhaust valve and operating the vacuum pump to discharge the gas from the chamber 843 to the outside of the chamber 843 through the exhaust pipe. The chamber 843 is connected to the substrate bonding apparatus 1 via a gate 1211, and is connected to the load lock unit 83 via a gate 8321. The gate 1211 is in an open state when the transfer robot 841 transfers the substrates W1 and W2 into the substrate bonding apparatus 1. The transfer robot 841 has an arm having a holder at its tip for holding the substrate, and can change the direction of the tip of the arm by rotating. The holding unit is, for example, an electrostatic chuck, and attracts and holds the side of the substrates W1, W2 opposite to the joining surface side. The transport device 84 also has a transport device imaging unit 844 that images multiple points on the periphery of the substrates W1, W2.

[0015] The transfer device 86, like the transfer device 84, includes a chamber 863, an exhaust pipe (not shown), a vacuum pump (not shown), an exhaust valve (not shown), and a transfer robot 861. The chamber 863 is connected to the activation treatment device 2 via a gate 8621, and is connected to the load lock unit 85 via a gate 8521. Like the transfer robot 841, the transfer robot 861 has an arm provided with a holder for holding a substrate at its tip, and can change the orientation of the tip of the arm by rotating. The holder is, for example, an electrostatic chuck, and adsorbs and holds the substrates W1, W2 on the side opposite to the bonding surface.

[0016] The activation processing device 2 performs an activation process for activating the bonding surface of the substrate by performing at least one of reactive ion etching using nitrogen gas and irradiation with nitrogen radicals. The activation processing device 2 is a device that generates inductively coupled plasma (ICP), and as shown in FIG. 2, includes a stage 210, a processing chamber 212, a plasma chamber 213, an induction coil 215 wound around the outside of the plasma chamber 213, and a high-frequency power source 216 that supplies a high-frequency current to the induction coil 215. The plasma chamber 213 is formed of, for example, quartz glass. The activation processing device 2 also includes a nitrogen gas supply unit 220A and an oxygen gas supply unit 220B. The nitrogen gas supply unit 220A includes a nitrogen gas storage unit 221A, a supply valve 222A, and a supply pipe 223A. The oxygen gas supply unit 220B has an oxygen gas storage unit 221B, a supply valve 222B, and a supply pipe 223B. The substrates W1 and W2 are placed on the stage 210. The processing chamber 212 communicates with the inside of the plasma chamber 213. The processing chamber 212 is connected to a vacuum pump 201a via an exhaust pipe 201b and an exhaust valve 201c. The activation processing device 2 opens the exhaust valve 201c and operates the vacuum pump 201a to exhaust the gas in the processing chamber 212 to the outside of the processing chamber 212 through the exhaust pipe 201b, thereby reducing (decompressing) the air pressure in the processing chamber 212.

[0017] The high frequency power supply 216 may be one that supplies a high frequency current of, for example, 27 MHz to the induction coil 215. When a high frequency current is supplied to the induction coil 215 in a state where N2 gas is introduced into the plasma chamber 213, a plasma PLM is formed in the plasma chamber 213. Here, since ions contained in the plasma are trapped in the plasma chamber 213 by the induction coil 215, a configuration without a trap plate may be used between the plasma chamber 213 and the processing chamber 212. The induction coil 215, the high frequency power supply 216, and the nitrogen gas supply unit 220A constitute a plasma generation source that generates the plasma PLM in the plasma chamber 213 and supplies N2 radicals in the plasma to the bonding surfaces of the substrates W1 and W2 supported by the stage 210. Here, an example of the activation processing device 2 that generates an ICP and includes an induction coil 215 and a high-frequency power supply 216 has been described, but the present invention is not limited thereto. Instead, the activation processing device 2 may be a device that generates a capacitively coupled plasma (CCP) that includes a plate electrode disposed outside the plasma chamber 213, a high-frequency power supply electrically connected to the plate electrode, and a trap plate disposed between the plasma chamber 213 and the processing chamber 212 to trap ions in the plasma. In this case, the high-frequency power supply may be one that applies a high-frequency bias of, for example, 27 MHz. The power supplied from the high-frequency power supply to the inside of the plasma chamber is set to, for example, 250 W. The bias application unit 217 is a high-frequency power supply that applies a high-frequency bias to the substrates W1 and W2 supported by the stage 210. The bias application unit 217 may be one that generates a high-frequency bias of, for example, 13.56 MHz. In this manner, a sheath region where ions having kinetic energy repeatedly collide with the substrates W1 and W2 is generated near the bonding surfaces of the substrates W1 and W2 by applying a high frequency bias to the substrates W1 and W2 by the bias application unit 217. The bonding surfaces of the substrates W1 and W2 are etched by the ions having kinetic energy present in this sheath region.

[0018] As shown in FIG. 3, the substrate bonding apparatus 1 includes a chamber 120, a stage 141 as a first substrate holder, a head 142 as a second substrate holder, a stage driver 143, a head driver 144, substrate heaters 1481 and 1482, and a position measurement unit 500. The substrate bonding apparatus 1 also includes a distance measurement unit 1493 that measures the distance between the stage 141 and the head 142. In the following description, the ±Z direction in FIG. 1 is appropriately defined as the up-down direction, and the XY direction is appropriately defined as the horizontal direction. The chamber 120 maintains the region S1 in which the substrates W1 and W2 are disposed at a vacuum level equal to or higher than a preset reference vacuum level. The chamber 120 is connected to a vacuum pump 121a via an exhaust pipe 121b and an exhaust valve 121c. When the exhaust valve 121c is opened and the vacuum pump 121a is operated, the gas in the chamber 120 is exhausted to the outside of the chamber 120 through the exhaust pipe 121b, and the inside of the chamber 120 is maintained at a reduced pressure. Also, by adjusting the amount of exhaust by varying the opening / closing amount of the exhaust valve 121c, the air pressure (degree of vacuum) in the chamber 120 can be adjusted. Also, a window 120a that is used for measuring the relative position between the substrates W1 and W2 by the position measuring unit 500 is provided in a part of the chamber 120.

[0019] The stage driving unit 143 is a holder driving unit that can move the stage 141 in the XY directions and rotate it around the Z axis.

[0020] The head driving unit 144 has an elevation driving unit 146 that raises and lowers the head 142 vertically upward or vertically downward (see arrow AR1 in FIG. 1), an XY direction driving unit 145 that moves the head 142 in the XY directions, and a rotation driving unit 147 that rotates the head 142 in a rotation direction around the Z axis (see arrow AR2 in FIG. 1). The XY direction driving unit 145 and the rotation driving unit 147 constitute a holder driving unit that moves the head 142 in a direction perpendicular to the vertical direction (XY directions, rotation direction around the Z axis). The head driving unit 144 also has a piezo actuator 1456 for adjusting the inclination of the head 142 with respect to the stage 141, and a first pressure sensor 1457 for measuring the pressure applied to the head 142. The XY direction drive unit 145 and the rotation drive unit 147 move the head 142 relative to the stage 141 in the X direction, the Y direction, and in a rotational direction around the Z axis, thereby enabling alignment of the substrate W1 held by the stage 141 and the substrate W2 held by the head 142.

[0021] The lifting / lowering drive unit 146 moves the head 142 in the vertical direction to bring the stage 141 and the head 142 closer to each other or move the head 142 away from the stage 141. The lifting / lowering drive unit 146 moves the head 142 vertically downward, so that the substrate W1 held by the stage 141 and the substrate W2 held by the head 142 come into contact with each other. Then, when the lifting / lowering drive unit 146 applies a driving force to the head 142 in a direction to approach the stage 141 while the substrates W1 and W2 are in contact with each other, the substrate W2 is pressed against the substrate W1. The lifting / lowering drive unit 146 is provided with a pressure sensor 148 that measures the driving force applied by the lifting / lowering drive unit 146 to the head 142 in a direction to approach the stage 141. From the measured value of the pressure sensor 148, the pressure acting on the bonding surfaces of the substrates W1 and W2 when the substrate W2 is pressed against the substrate W1 by the lifting / lowering drive unit 146 can be detected. The pressure sensor 148 is composed of, for example, a load cell.

[0022] As shown in FIG. 4A, there are three piezo actuators 1456 and three first pressure sensors 1457. The three piezo actuators 1456 and the three first pressure sensors 1457 are disposed between the head 142 and the XY-direction drive unit 145. The three piezo actuators 1456 are fixed at three positions on the top surface of the head 142 that are not on the same line, and at three positions arranged at approximately equal intervals along the circumferential direction of the head 142 on the periphery of the top surface of the head 142, which is approximately circular in plan view. The three first pressure sensors 1457 connect the upper end of the piezo actuator 1456 to the lower surface of the XY-direction drive unit 145. The three piezo actuators 1456 can be individually extended and retracted in the vertical direction. The three piezo actuators 1456 are extended and retracted to finely adjust the inclination of the head 142 around the X-axis and the Y-axis and the vertical position of the head 142. For example, when the head 142 is tilted with respect to the stage 141 as shown by the dashed line in FIG. 4B, one of the three piezo actuators 1456 is extended (see arrow AR3 in FIG. 4B) to finely adjust the attitude of the head 142, so that the lower surface of the head 142 and the upper surface of the stage 141 can be brought into a substantially parallel state. In addition, the three pressure sensors 1457 measure the pressure forces at three positions on the lower surface of the head 142. Then, by driving each of the three piezo actuators 1456 so that the pressure forces measured by the three pressure sensors 1457 are equal, the substrates W1 and W2 can be brought into contact with each other while maintaining the lower surface of the head 142 and the upper surface of the stage 141 substantially parallel to each other.

[0023] The stage 141 and the head 142 are disposed in the chamber 120 so as to face each other in the vertical direction. The stage 141 is a first substrate holder that holds the substrate W1 on its upper surface, and the head 142 is a second substrate holder that holds the substrate W2 on its lower surface. Here, the stage 141 supports the substrate W1 with its upper surface in surface contact with the entire substrate W1, and the head 142 supports the substrate W2 with its lower surface in surface contact with the entire substrate W2. The stage 141 and the head 142 are formed of a light-transmitting material such as light-transmitting glass. As shown in FIG. 5A and FIG. 5B, the stage 141 and the head 142 are provided with electrostatic chucks 1411, 1412, 1413, 1421, 1422, and 1423 that hold the substrates W1 and W2. The electrostatic chucks 1411 and 1421 hold the peripheries of the substrates W1 and W2. Furthermore, through holes 141b and 142b having a circular shape in plan view are provided in the center of the stage 141 and the head 142. Furthermore, the stage 141 and the head 142 are provided with air pressure detection units (not shown) that detect the air pressure in the region between the stage 141 and the head 142 and the substrates W1 and W2 when gas is discharged from gas discharge holes 1411c and 1421c described below.

[0024] The electrostatic chucks 1411, 1412, 1421, and 1422 are first electrostatic chucks provided in annular first regions A1 facing peripheral portions of the substrates W1 and W2 on the stage 141 and head 142 when the substrates W1 and W2 are held on the stage 141 and head 142. The electrostatic chucks 1411 and 1412 are provided in two preset sub-annular regions A11 and A12 centered on the center of the stage 141 in the first region A1 of the stage 141. The electrostatic chucks 1411 and 1412 each hold a portion of the substrate W1 arranged at a preset substrate holding position on the stage 141 that faces the two sub-annular regions A11 and A12. Electrostatic chucks 1421 and 1422 are also provided in two preset sub-annular regions A11 and A12 centered on the central portion of the head 142 in the first region A1 of the head 142. The electrostatic chucks 1421 and 1422 hold portions of a substrate W2 disposed at a preset substrate holding position of the head 142 that face the two sub-annular regions A11 and A12, respectively. Here, the substrate holding position is set to a position that coincides with the first region A1 if, for example, the outer dimensions of the substrates W1 and W2 are the same as those of the first region A1.

[0025] The electrostatic chucks 1411 and 1421 each have, in the first region A1, a plurality of electrodes 1411b and 1412b extending radially from the center of the stage 141 and the head 142 toward the periphery of the stage 141 and the head 142, and two annular terminal electrodes 1411a and 1421a disposed along the circumferential direction of the stage 141 and the head 142. The plurality of electrodes 1411b and 1412b are first electrodes extending from each of the two terminal electrodes 1411a and 1421a toward the other terminal electrode 1421a and 1411a along the radial direction of each of the two terminal electrodes 1411a and 1421a. Here, terminal electrodes 1411a and 1421a correspond to a third terminal electrode and a fourth terminal electrode, and terminal electrode 1411a has a smaller diameter than terminal electrode 1421a and is disposed on the central side of stage 141 and head 142. A plurality of long electrode elements 1411b and 1421b are disposed in first region A1 of stage 141 and head 142 so as to be alternately arranged along the circumferential direction of first region A1. 6A, the terminal electrodes 1411a and 1421a each have a bent portion 1411ab and 1421ab bent so as to protrude in a direction away from the other terminal electrode 1411a and 1421a in a plan view, and a thin connecting portion 1411aa and 1421aa extending along the circumferential direction of the stage 141 and the head 142 and connecting ends of two adjacent bent portions 1411ab and 1421ab in the circumferential direction of the stage 141 and the head 142. A maximum width Wi4 between the bent portions 1411ab and 1421ab and the connecting portions 1411aa and 1421aa in the radial direction of the stage 141 and the head 142 is set to be longer than the width of an alignment mark, which will be described later, for example.

[0026] Moreover, the electrostatic chucks 1412 and 1422 also have, in the first region A1, a plurality of electrodes 1412b and 1422b extending radially from the center of the stage 141 and the head 142 toward the periphery of the stage 141 and the head 142, and two annular terminal electrodes 1412a and 1422a disposed along the circumferential direction of the stage 141 and the head 142. The plurality of electrodes 1412b and 1422b are first electrodes extending from each of the two terminal electrodes 1412a and 1422a toward the other terminal electrode 1422a and 1412a along the radial direction of each of the two terminal electrodes 1412a and 1422a. The terminal electrodes 1412a and 1422a correspond to a third terminal electrode and a fourth terminal electrode, and the terminal electrode 1412a has a smaller diameter than the terminal electrode 1422a and is disposed on the central side of the stage 141 and the head 142. In the first region A1, the electrostatic chucks 1412 and 1422 are disposed inside the electrostatic chucks 1411 and 1421. The multiple long electrode elements 1412b and 1422b are arranged alternately in the first region A1 of the stage 141 and the head 142 along the circumferential direction of the first region A1. The terminal electrodes 1411a, 1421a, 1422a, and 1412a and the multiple electrode elements 1411b, 1421b, 1412b, and 1422b are formed of, for example, a metal. In this manner, the electrostatic chucks 1411, 1412, 1421, and 1422 each have, in the first region A1, a plurality of electrodes 1411b, 1412b, 1421b, and 1422b extending radially from the center of the stage 141 and the head 142 toward the periphery of the stage 141 and the head 142. This allows the substrate bonding apparatus 1 to capture images of alignment marks MK1a, MK1b, MK1c, MK2a, MK2b, and MK2c provided on the substrates W1 and W2, which will be described later, through gaps between the plurality of electrodes 1411b, 1412b, 1421b, and 1422b, using the imaging units 501A, 501B, and 501C, which will be described later.

[0027] In addition, grooves 1411d and 1421d are formed in the sub-annular region A11 of the first region A1 in the stage 141 and the head 142, each having a portion extending radially from the center of the stage 141 and the head 142 toward the periphery of the stage 141 and the head 142. In addition, gas discharge holes 1411c and 1421c connected to the gas supply unit 1492 are provided in a portion of the grooves 1411d and 1421d. The gas discharge holes 1411c and 1421c correspond to the gas discharge unit that discharges gas, and the grooves 1411d and 1421d correspond to the second recess communicating with the gas discharge holes 1411c and 1412c. Here, the width of the grooves 1411d and 1421d is set to, for example, about 0.2 mm. The grooves 1411d and 1421d have portions extending along the extending direction of the plurality of electrode elements 1411b and 1412b, respectively. The grooves 1411d and 1421d are provided between the plurality of electrode elements 1411b electrically connected to the terminal electrode 1411a and the plurality of electrode elements 1412b connected to the terminal electrode 1421a in the electrostatic chucks 1411 and 1412. Also, a groove (not shown) having a portion extending radially from the center of the stage 141 and head 142 toward the periphery of the stage 141 and head 142 is formed in the sub-annular region A12 of the first region A1 in the stage 141 and head 142. Also, a gas discharge hole (not shown) connected to the gas supply unit 1492 is provided in a portion of the grooves 1411d and 1421d. The gas discharge holes provided in the sub-annular region A12 also correspond to a gas discharge portion that discharges gas, and the grooves provided in the sub-annular region A12 also correspond to a second groove that constitutes a second recess communicating with the gas discharge holes provided in the sub-annular region A12. The grooves also have portions that extend along the extending directions of the multiple electrode elements 1411b and 1412b. The grooves 1411d and 1421d are provided between the multiple electrode elements 1421b electrically connected to the terminal electrode 1411a and the multiple electrode elements 1412b connected to the terminal electrode 1421a in the electrostatic chucks 1421 and 1422.

[0028] The electrostatic chucks 1413 and 1423 are second electrostatic chucks provided in a second region A2 inside the first region A1 of the stage 141 and the head 142. As shown in Fig. 5B, the electrostatic chucks 1413 and 1423 have a plurality of electrodes 1413b and 1423b extending radially from the center of the stage 141 and the head 142 toward the periphery of the stage 141 and the head 142 in the second region A2, and two annular terminal electrodes 1413a and 1423a disposed along the circumferential direction of the stage 141 and the head 142. The plurality of electrodes 1413b and 1423b are second electrodes extending from the two terminal electrodes 1413a and 1423a toward the other terminal electrodes 1423a and 1413a along the radial direction of the stage 141 and the head 142. 6B, each of the multiple electrode elements 1413b, 1423b has a wedge-shaped shape in plan view whose width in a direction perpendicular to its extending direction in plan view becomes wider toward the periphery of the stage 141 and the head 142. The terminal electrodes 1413a, 1423a correspond to a first terminal electrode electrically connected to the multiple electrode elements 1413b and a second terminal electrode electrically connected to the multiple electrode elements 1423b, respectively.

[0029] In addition, grooves 1413d and 1423d are formed in the second area A2 of the stage 141 and the head 142, each having a portion extending radially from the center of the stage 141 and the head 142 toward the periphery of the stage 141 and the head 142. In addition, gas discharge holes 1413c and 1423c connected to the gas supply unit 1492 are provided in a portion of the grooves 1413d and 1423d in the stage 141 and the head 142. The gas discharge holes 1413c and 1423c correspond to the gas discharge unit that discharges gas, and the grooves 1413d and 1423d correspond to the first groove that constitutes the first recess that communicates with the gas discharge holes 1413c and 1423c. Here, the width Wi1 of the grooves 1413d and 1423d is set to, for example, about 0.2 mm. The grooves 1413d and 1423d have portions extending along the extension direction of the plurality of electrodes 1413b and 1423b. The grooves 1413d and 1423d are provided between the plurality of electrodes 1413b electrically connected to the terminal electrode 1413a and the plurality of electrodes 1423b connected to the terminal electrode 1423a in the electrostatic chucks 1413 and 1423. As shown in FIG. 7A, the width Wi3 between the surface of the stage 141 and the head 142 of the electrostatic chucks 1413 and 1423 is set shorter than the depth Wi2 of the grooves 1413d and 1423d, and is set to 0.05 mm or more and 0.1 mm or less when the substrates W1 and W2 are sapphire substrates or glass substrates, for example. When the substrates W1 and W2 are Si substrates, it can be set to about 5 mm. The terminal electrodes 1413a, 1423a and the plurality of electrode elements 1413b, 1423b are formed from a transparent conductive film containing a transparent conductive material such as ITO.

[0030] The electrostatic chucks 1411, 1412, 1413, 1421, 1422, and 1423 are connected to a chuck driving unit 1491. The chuck driving unit 1491 drives the electrostatic chucks 1411, 1412, 1413, 1421, 1422, and 1423 by applying voltages to the electrostatic chucks 1411, 1412, 1413, 1421, 1422, and 1423 based on control signals input from the control unit 9. The chuck driving unit 1491 also drives the electrostatic chucks 1411, 1412, 1413, 1421, 1422, and 1423 independently of one another based on control signals input from the control unit 9.

[0031] The chuck driving unit 1491 applies a pulse voltage between the two terminal electrodes 1411a, 1412a of the electrostatic chucks 1411, 1412 when removing the substrates W1, W2 from the electrostatic chucks 1411, 1412. The chuck driving unit 1491 also applies a pulse voltage between the two terminal electrodes 1421a, 1422a of the electrostatic chucks 1421, 1422 when removing the substrates W1, W2 from the electrostatic chucks 1421, 1422. The chuck driving unit 1491 also applies a pulse voltage between the two terminal electrodes 1431a, 1432a of the electrostatic chucks 1413, 1423 when removing the substrates W1, W2 from the electrostatic chucks 1431, 1432. Here, the chuck driving unit 1491 gradually reduces the amplitude of the pulse voltage while alternately applying pulse voltages of different polarities between the terminal electrodes 1411a, 1412a (1421a, 1422a, 1431a, 1432a). The pulse intervals of the pulse voltages are determined in consideration of the discharge time of the stage 141 and the head 142. The pulse widths of the pulse voltages may be set to be equal to each other, or may be set to become longer over time. Alternatively, the pulse widths of five or less arbitrarily selected pulse voltages may be set to be equal. Furthermore, the pulse intervals may be set to be equal to each other, or may be set to become longer over time. Alternatively, the pulse intervals of four or less arbitrarily selected pulse voltages may be set to be equal. The gas supply unit 1492 supplies gas to each of the gas discharge holes 1411c, 1421c, 1412c, 1422c, 1413c, and 1423c based on a control signal input from the control unit 9, thereby discharging gas from the gas discharge holes 1411c, 1421c, 1412c, 1422c, 1413c, and 1423c.

[0032] 7B, the stage 141 and the head 142 have a pressing mechanism 1441 that presses the center of the substrate W1 and a pressing mechanism 1442 that presses the center of the substrate W2. The pressing mechanism 1441 is provided in the center of the stage 141, and the pressing mechanism 1442 is provided in the center of the head 142. The pressing mechanism 1441 has a pressing part 1441a that can appear and disappear on the head 142 side through a through hole 141b of the stage 141, and a pressing drive part 1441b that drives the pressing part 1441a. The pressing mechanism 1442 has a pressing part 1442a that can appear and disappear on the stage 141 side through a through hole 142b of the head 142, and a pressing drive part 1442b that drives the pressing part 1442a. The pressing drive units 1441b and 1442b have, for example, voice coil motors. The pressing units 1441a and 1442a perform either pressure control to control so as to keep the pressure applied to the substrates W1 and W2 constant, or position control to control so as to keep the contact position of the substrates W1 and W2 constant. For example, the pressing unit 1441a is position-controlled and the pressing unit 1442a is pressure-controlled, so that the substrates W1 and W2 are pressed at a constant position with a constant pressure.

[0033] Returning to FIG. 1, the distance measurement unit 1493 is, for example, a laser distance meter, and measures the distance between the stage 141 and the head 142 without contacting the stage 141 and the head 142. The distance measurement unit 1493 measures the distance between the stage 141 and the head 142 from the difference between the reflected light on the upper surface of the stage 141 and the reflected light on the lower surface of the head 142 when a laser beam is irradiated from above the transparent head 142 toward the stage 141. As shown in FIG. 4A, the distance measurement unit 1493 measures the distance between three sites P11, P12, and P13 on the upper surface of the stage 141 and three sites P21, P22, and P23 on the lower surface of the head 142 that face the sites P11, P12, and P13 in the Z direction.

[0034] 8, the position measuring unit 500 has three imaging units 501A, 501B, and 501C, a reflecting member 502, and imaging unit position adjusting units 503A, 503B, and 503C, and measures the amount of positional deviation between the substrate W1 and the substrate W2 in a direction perpendicular to the vertical direction (XY direction, rotation direction around the Z axis). The three imaging units 501A, 501B, and 501C are arranged around the reflecting member 502 so that the acute angles DAB, DBC, and DCA formed by two adjacent optical axes JLA and JLB (JLB, ​​JLC and JLC, JLA) in the circumferential direction of the reflecting member 502 are equal. Reflecting surfaces 502a, 502b, and 502c are formed on the reflecting member 502 in the portions facing the three imaging units 501A, 501B, and 501C, respectively. The imaging units 501A, 501B, 501C and the reflecting member 502 are disposed on the side of the stage 141 opposite to the side holding the substrate W1. The imaging units 501A, 501B, 501C are all first imaging units having imaging elements 511A, 511B, 511C and a coaxial illumination system (not shown). As a light source for the coaxial illumination system, a light source that emits light (e.g., infrared light) that transmits through the substrates W1 and W2, the stage 141, and a window 120a provided in the chamber 120 is used.

[0035] For example, as shown in Figures 9A and 9B, at least three alignment marks MK1a, MK1b, and MK1c are provided on the substrate W1, and at least three alignment marks MK2a, MK2b, and MK2c are provided on the substrate W2. Either one of the alignment marks MK1a, MK1b, and MK1c and the alignment marks MK2a, MK2b, and MK2c corresponds to a first alignment mark, and the other corresponds to a second alignment mark. The substrate bonding apparatus 1 performs an alignment operation (alignment operation) of both substrates W1 and W2 while recognizing the positions of the alignment marks MK1a, MK1b, MK1c, MK2a, MK2b, and MK2c provided on both substrates W1 and W2 by the position measurement unit 500. More specifically, the substrate bonding apparatus 1 first performs a rough alignment operation (rough alignment operation) on the substrates W1 and W2 to face the two substrates W1 and W2 while recognizing the alignment marks MK1a, MK1b, NK1c, MK2a, MK2b, NK2c provided on the substrates W1 and W2 by the position measurement unit 500. Thereafter, the substrate bonding apparatus 1 performs a more precise alignment operation (fine alignment operation) while simultaneously recognizing the alignment marks MK1a, MK2a, (MK1b, MK2b and MK1c, MK2c) provided on the two substrates W1 and W2 by the position measurement unit 500.

[0036] 3, the light emitted from the light source of the coaxial illumination system of the imaging unit 501A is reflected by the reflecting surface 502a of the reflecting member 502 and travels upward, and passes through the window 120a of the chamber 120 and part or all of the substrates W1 and W2. The light that has passed through part or all of the substrates W1 and W2 is reflected by the alignment marks MK1a and MK2a of the substrates W1 and W2, travels downward, passes through the window 120a, is reflected by the reflecting surface 502a of the reflecting member 502, and enters the imaging element 511A of the imaging unit 501A. The light emitted from the light source of the coaxial illumination system of the imaging unit 501B is reflected by the reflecting surface 502b of the reflecting member 502 and travels upward, and passes through the window 120a of the chamber 120 and part or all of the substrates W1 and W2. The light that has been transmitted through a part or all of the substrates W1 and W2 is reflected by the alignment marks MK1b and MK2b of the substrates W1 and W2, travels downward, passes through the window 120a, is reflected by the reflecting surface 502b of the reflecting member 502, and enters the imaging element 511B of the imaging unit 501B. Although not shown in FIG. 3, the light emitted from the light source of the coaxial illumination system of the imaging unit 501C shown in FIG. 8 is reflected by the reflecting surface 502c of the reflecting member 502, travels upward, and passes through the window 120a of the chamber 120 and the substrates W1 and W2, or a part or all of the substrates W1 and W2. The light that has been transmitted through a part or all of the substrates W1 and W2 is reflected by the alignment marks MK1c and MK2c of the substrates W1 and W2, travels downward, passes through the window 120a, is reflected by the reflecting surface 502c of the reflecting member 502, and enters the imaging element 511C of the imaging unit 501C. In this manner, the position measurement unit 500 obtains a captured image GAa including the alignment marks MK1a and MK2a of the two substrates W1 and W2, a captured image GAb including the alignment marks MK1b and MK2b of the two substrates W1 and W2, and a captured image GAc including the alignment marks MK1c and MK2b of the two substrates W1 and W2, as shown in Fig. 10A and Fig. 10B. Note that the imaging operations of the imaging units 501A, 501B, and 501C to capture the captured images GAa, GAb, and GAc are performed substantially simultaneously.The three imaging units 501A, 501B, and 501C capture images of the alignment marks MK1a, MK1b, MK1c, MK2a, MK2b, and MK2c in the first area A1, which is made up of the stage 141 and the two sub-annular areas A11 and A12 of the head 142.

[0037] The imaging unit position adjustment units 503A, 503B, and 503C move the imaging units 501A, 501B, and 501C in the vertical direction or in a horizontal direction perpendicular to the optical axis and vertical direction of the imaging units 501A, 501B, and 501C, respectively. The imaging unit position adjustment units 503A, 503B, and 503C each have an imaging unit holding unit (not shown) that holds the imaging units 501A, 501B, and 501C, and an actuator (not shown) that drives the imaging unit holding unit in the vertical direction and the horizontal direction. The imaging unit position adjustment units 503A, 503B, and 503C can move the imaging positions on the substrates W1 and W2 in a direction perpendicular to the thickness direction of the substrates W1 and W2 by moving the imaging units 501A, 501B, and 501C in the vertical direction or the horizontal direction, respectively.

[0038] Returning to FIG. 3, the substrate heating units 1481 and 1482 are, for example, electric heaters, and are provided on the stage 141 and the head 142, respectively, as shown in FIG. 7B. The substrate heating units 1481 and 1482 transfer heat to the substrates W1 and W2 held on the stage 141 and the head 142 to heat them. The temperatures of the substrates W1 and W2 and their bonding surfaces can be adjusted by adjusting the heat generation amounts of the substrate heating units 1481 and 1482. The substrate heating units 1481 and 1482 are connected to a heating unit drive unit (not shown), and the heating unit drive unit causes the substrate heating units 1481 and 1482 to generate heat by supplying current to the substrate heating units 1481 and 1482 based on a control signal input from the control unit 9 shown in FIG. 1.

[0039] The inspection device 7 detects the amount of misalignment of all the alignment marks MK1a, MK1b, MK1c, MK2a, MK2b, and MK2c provided on the bonded substrates W1 and W2. The inspection device 7 includes a stage 71 on which the bonded substrates W1 and W2 are placed, a light source 72, an imaging unit 73, and a horizontal direction drive unit 74, as shown in FIG. 11. The stage 71 is made of a material transparent to the light emitted from the light source 72. The light source 72 emits light toward the substrates W1 and W2 from the side of the stage 71 opposite to the side on which the substrates W1 and W2 are placed. The imaging unit 73 is a second imaging unit having an imaging element 731 on which light emitted from the light source 72 that has passed through the stage 71 and the substrates W1 and W2 is incident. The horizontal direction drive unit 74 moves the stage 71 in a horizontal direction perpendicular to the thickness direction of the stage 71, as shown by an arrow AR3.

[0040] Returning to FIG. 1, the control unit 9 is a control system having, for example, a personal computer, and has a CPU (Central Processing Unit) and a memory. The memory stores a program executed by the CPU. The control unit 9 converts the measurement signals input from the pressure sensor 148 and the position measurement unit 150 into measurement information and acquires it. The control unit 9 also converts the captured image signals input from the imaging units 501A, 501B, and 501C of the substrate bonding apparatus 1, the imaging unit 73 of the inspection apparatus 7, and the transport device imaging unit 844 of the transport device 84 into captured image information and acquires it. Furthermore, the control unit 9 controls the operations of the chuck driving unit 1491, the gas supply unit 1492, the imaging unit position adjustment units 503A, 503B, and 503C, the piezo actuator 1456, the pressing driving units 1441b and 1432b, the heating unit driving unit, the stage driving unit 143, and the head driving unit 144 of the substrate bonding apparatus 1 by outputting control signals to each of them. As shown in Fig. 10B, the control unit 9 calculates the positional deviation amounts dxa, dya between a pair of alignment marks MK1a, MK2a provided on the substrates W1, W2 based on the captured image GAa acquired from the imaging unit 501A. Note that Fig. 10B shows a state in which the pair of alignment marks MK1a, MK2a are misaligned with each other. Similarly, the control unit 9 calculates the positional deviation amounts dxb, dyb, dxc, dyc between the other two pairs of alignment marks MK1b, MK2b, MK1c, MK2c provided on the substrates W1, W2 based on the captured images GAb, GAc acquired from the imaging units 501B, 501C. Then, the control unit 9 calculates the relative misalignment amounts dx, dy, and dθ of the two substrates W1 and W2 in the X direction, Y direction, and rotation direction around the Z axis based on the misalignment amounts dxa, dya, dxb, dyb, dxc, and dyc of these three sets of alignment marks and the geometric relationship between the three sets of marks. Then, the control unit 9 moves the head 142 in the X direction and Y direction and rotates it around the Z axis so as to reduce the calculated misalignment amounts dx, dy, and dθ. In this way, the substrate bonding apparatus 1 performs an alignment operation to correct the misalignment amounts dx, dy, and dθ of the two substrates W1 and W2 in the horizontal direction.The control unit 9 also outputs control signals to the activation processing device 2, the transport devices 82, 84, and 86, the cleaning device 3, and the inspection device 7 to control their operations.

[0041] In addition, when the control unit 9 brings the substrates W1 and W2 into contact with each other over their entire surfaces while the central portions of the bonding surfaces of the substrates W1 and W2 are in contact with each other and the peripheral portions of the substrates W1 and W2 are held by the electrostatic chucks 1411, 1412, 1421, and 1422, the control unit 9 first fills the entire groove provided in the sub-annular region A12 with gas from the gas discharge holes provided in the sub-annular region A12 of the first region A1, and then controls the chuck driving unit 1491 and the gas supply unit 1492 to release the substrates W1 and W2 from the electrostatic chucks 1421 and 1422. Next, the control unit 9 fills the entire grooves 1411d, 1412d provided in the sub-annular region A11 of the first region A1 with gas from the gas discharge holes 1411c, 1412c provided in the sub-annular region A11, and then controls the chuck driving unit 1491 and the gas supply unit 1492 to release the substrates W1, W2 held by the electrostatic chucks 1411, 1412, 1421, 1422. At this time, the control unit 9 controls the flow rate of the gas discharged from the gas discharge holes 1411c, 1421c, 1421c, 1422c based on the air pressure detected by the air pressure detection unit described above so that the air pressure is less than the critical pressure. As a result, the substrates W1, W2 come into contact with each other on their entire surfaces.

[0042] Furthermore, the control unit 9 calculates the positional deviation amount and positional deviation direction of each of the alignment marks of the substrates W1 and W2 based on the captured image obtained by capturing the alignment marks of the substrates W1 and W2 by the imaging unit 73. Then, the control unit 9 separates the axial components along the two mutually intersecting axial directions of the positional deviation vector determined by the calculated positional deviation amount and positional deviation direction, that is, the XY direction component and the rotation direction component, and calculates a horizontal offset vector that is a vector reflecting the axial offset amount, which is the offset amount in the XY direction of the substrate W2 relative to the substrate W1 when bonding the substrates W1 and W2, and the rotation direction offset amount, which is the offset amount in the rotation direction, based on the separated XY direction component and rotation direction component. In addition, the control unit 9 separates the warp component of the positional deviation vector determined by the calculated positional deviation amount and positional deviation direction, and calculates the protrusion offset amount, which is the offset amount of the protrusion amount of the central part of the substrate W1 toward the substrate W2 side relative to the peripheral part of the substrate W1 when bonding the substrates W1 and W2, based on the separated warp component. Here, the control unit 9 calculates a horizontal offset vector and a protruding offset amount based on statistical values ​​(e.g., average values ​​or median values) of the misalignment amounts and misalignment directions obtained for the plurality of bonded substrates W1, W2 each time a preset number of bonded substrates W1, W2 are produced. The control unit 9 also calculates a horizontal offset vector so that the misalignment amount of each of the plurality of sets of alignment marks imaged by the imaging unit 73 is minimized. Then, the control unit 9 stores information indicating the calculated horizontal offset vector and protruding offset amount in a memory.

[0043] The control unit 9 also calculates the amount and direction of misalignment of the alignment marks MK1a, MK1b, MK1c, MK2a, MK2b, MK2c based on the captured images obtained by capturing the alignment marks MK1a, MK1b, MK1c, MK2a, MK2b, MK2c with the substrates W1, W2 spaced apart using the imaging units 501A, 501B, 501C and the captured images obtained by capturing the alignment marks MK1a, MK1b, MK1c, MK2a, MK2b, MK2c of the substrates W1, W2 bonded together using the imaging units 501A, 501B, 501C. The control unit 9 then updates the horizontal offset vector based on the calculated amount and direction of misalignment. Specifically, the control unit 9 calculates the positional deviation error from the captured image obtained by capturing the alignment marks MK1a, MK1b, MK1c, MK2a, MK2b, and MK2c after the substrates W1 and W2 are separated and the alignment of the substrates W1 and W2 is completed. Then, the control unit 9 calculates the positional deviation amount at the time of bonding the substrates W1 and W2 by subtracting the above-mentioned positional deviation error from the positional deviation amount calculated from the captured image obtained by capturing the alignment marks MK1a, MK1b, MK1c, MK2a, MK2b, and MK2c of the substrates W1 and W2 bonded to each other. Here, since the positional deviation error is not 0, the offset direction and offset amount corresponding to the multiple alignment marks calculated from the captured image captured by the imaging unit 73 of the inspection device 7 cannot be adopted as they are. Here, the above-mentioned horizontal offset vector is calculated for each set of alignment marks MK1a and MK2a (MK1b, MK2b, MK1c, MK2c). The control unit 9 may obtain information on the misalignment amount and misalignment direction of the alignment marks MK1a, MK1b, MK1c, MK2a, MK2b, and MK2c of the bonded substrates W1 and W2 from the inspection device 7 to calculate the above-mentioned misalignment amount error. The calculation of the horizontal offset vector may be performed by the inspection device 7 or may be performed by the substrate bonding apparatus 1. When the horizontal offset vector is calculated by the inspection device 7, information indicating the misalignment amount error may be notified to the inspection device 7.In addition, the offset direction and offset amount calculated based on the image captured by the imaging section 73 of the inspection device 7 are offset direction and offset amount common to all pairs of alignment marks on substrates W1 and W2, while the horizontal offset vector reflecting the offset direction and offset amount corrected based on the above-mentioned positional misalignment error is determined separately for each pair of alignment marks MK1a, MK2a (MK1b, MK2b, MK1c, MK2c).

[0044] Next, the flow of operations from when the substrates W1 and W2 are introduced into the substrate bonding system according to this embodiment until the substrates W1 and W2 are bonded and removed from the substrate bonding system will be described with reference to Figs. 12 to 17B. Here, it is assumed that the substrates W1 and W2 are placed in advance in the introduction ports 811 and 812. The substrates W1 and W2 are, for example, any of a Si substrate, a glass substrate, an oxide substrate (e.g., a silicon oxide (SiO2) substrate, an alumina substrate (Al2O3), etc.), and a nitride substrate (e.g., silicon nitride (SiN), aluminum nitride (AlN)). At least one of the substrates W1 and W2 may have a metal portion and an insulating film exposed on the bonding surface. Alternatively, at least one of the substrates W1 and W2 may have an insulating film formed by depositing an oxide or nitride exposed on the bonding surface. Here, it is assumed that the substrate W1 is a glass substrate or an oxide substrate, and the substrate W2 is a Si substrate or a nitride substrate. Further, in the introduction port 811, for example, the substrate W2 held by the head 142 in the substrate bonding apparatus 1 is placed, and in the introduction port 812, for example, the substrate W1 placed on the stage 141 in the substrate bonding apparatus 1 is placed.

[0045] First, as shown in FIG. 12, the substrate bonding system transfers the substrates W1 and W2 from the introduction ports 811 and 812 to the load lock unit 85 by the transfer robot 821 of the transfer device 82 (step S101). Next, the substrate bonding system transfers the substrates W1 and W2 from the load lock unit 85 to the activation processing device 2 by the transfer robot 861 of the transfer device 86 (step S102). Next, the activation processing device 2 performs an activation processing step for activating the bonding surfaces by performing at least one of reactive ion etching using nitrogen gas and irradiation with nitrogen radicals on at least one of the bonding surfaces of the substrates W1 and W2 to be bonded to each other (step S103). Here, the activation processing device 2 has a different processing sequence depending on the type of substrates to be activated for the bonding surfaces. When activating the bonding surfaces of the substrate W1, i.e., a glass substrate or an oxide substrate, the activation processing device 2 first introduces N2 gas from the nitrogen gas storage unit 221A through the supply pipe 223A into the processing chamber 212 by opening the supply valve 222A shown in FIG. 2. Next, in the activation processing device 2, while the supply of high-frequency current from the high-frequency power supply 216 to the induction coil 215 is stopped, the bias application unit 217 applies a high-frequency bias to the substrates W1 and W2 placed on the stage 210. As a result, reactive ion etching (RIE) using N2 gas is performed on the bonding surface of the substrate W1. Next, the activation processing device 2 starts supplying a high-frequency current from the high-frequency power supply 216 to the induction coil 215 to generate plasma with N2 gas. At this time, the activation processing device 2 stops applying the high-frequency bias to the substrate W1 by the bias application unit 217. In this manner, N2 radicals are irradiated onto the bonding surface of the substrate W1.

[0046] On the other hand, when activating the bonding surface of the substrate W2, that is, the Si or nitride substrate, the activation processing device 2 first introduces O2 gas from the oxygen gas storage unit 221B through the supply pipe 223B into the processing chamber 212 by opening the supply valve 222B. Next, the activation processing device 2 applies a high-frequency bias to the substrate W2 placed on the stage 210 by the bias application unit 217 while stopping the supply of high-frequency current from the high-frequency power source 216 to the induction coil 215. This causes reactive ion etching (RIE) using O2 gas to be performed on the bonding surface of the substrate W2. Next, the activation processing device 2 closes the supply valve 222B to stop the supply of O2 gas from the oxygen gas storage unit 221B into the processing chamber 212, thereby exhausting the O2 gas from the processing chamber 212. After that, the activation processing device 2 opens the supply valve 222A to introduce N2 gas from the nitrogen gas storage unit 221A into the processing chamber 212 through the supply pipe 223A. Thereafter, the activation processing device 2 starts supplying a high-frequency current from the high-frequency power supply 216 to the induction coil 215 to generate plasma from the N2 gas. At this time, the activation processing device 2 stops applying the high-frequency bias to the substrate W2 by the bias application unit 217. In this manner, the bonding surface of the substrate W2 is irradiated with N2 radicals.

[0047] Returning to FIG. 12, the transport device 86 then transports the substrates W1 and W2 from the activation processing device to the load lock unit 85 (step S104). Next, the transport robot 821 of the transport device 82 transports the substrates W1 and W2 from the load lock unit 85 to the cleaning device 3 (step S105). Next, the cleaning device 3 executes a water cleaning process in which water is sprayed onto the bonding surfaces of the substrates W1 and W2 to clean the bonding surfaces (step S106). Here, the cleaning device 3 scans the stage on which the substrates W1 and W2 are placed in the XY directions while spraying ultrasonically applied water from the cleaning head onto the bonding surfaces of the substrates W1 and W2 to clean the entire bonding surfaces of the substrates W1 and W2. This removes foreign matter attached to the bonding surfaces of the substrates W1 and W2. Next, the cleaning device 3 stops the discharge of water from the cleaning head, and then rotates the stage to spin-dry the substrates, thereby completing the cleaning process. Thereafter, the transfer device 82 transfers the substrates W1, W2 from the cleaning device 3 to the load lock unit 83 (step S107). Next, the transfer device 84 removes the substrates W1, W2 from the load lock unit 83, and the transfer device imaging unit 844 images the peripheral portions of the substrates W1, W2 (step S108).

[0048] Next, the control unit 9 determines whether the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, and MK2c used to calculate the positional deviation amount overlap with the electrostatic chucks 1411, 1412, 1421, and 1422 based on the captured image acquired from the transport device imaging unit 844 (step S109). Specifically, the control unit 9 previously acquires information indicating the relative positional relationship between the positions of the stage 141 and the electrostatic chucks 1411 and 1421 of the head 142 of the substrate bonding apparatus 1 and the positions of the substrates W1 and W2 held by the transport device 84, and determines whether the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, and MK2c used to calculate the positional deviation amount overlap with the electrostatic chucks 1411, 1412, 1421, and 1422 based on this information. If the control unit 9 determines that none of the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, and MK2c used to calculate the amount of positional deviation overlap with the electrostatic chucks 1411, 1412, 1421, and 1422 (step S109: No), the processing proceeds to step S111 and subsequent steps.

[0049] On the other hand, it is assumed that the control unit 9 determines that at least one of the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, and MK2c used to calculate the amount of misalignment overlaps with the electrostatic chucks 1411, 1412, 1421, and 1422 (step S109: Yes). For example, it is assumed that the alignment marks MK1a and MK2a overlap with a part of the electrostatic chucks 1411 and 1421, as shown in FIG. 13A. In this case, the control unit 9 rotates the stage 141 and then receives the substrates W1 and W2, as shown in FIG. 12, thereby rotating the stage 141 so that all of the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, and MK2c used to calculate the amount of misalignment of the substrates W1 and W2 do not overlap with the electrostatic chucks 1411, 1412, 1421, and 1422 (step S110). For example, from the state shown in Fig. 13A, the stage 141 is rotated in the rotation direction shown by the arrow AR10 in Fig. 13A, and then the substrates W1 and W2 are received. Here, the control unit 9 rotates the stage 141 so that all of the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, and MK2c are positioned between the multiple electrodes 1411b, 1412b, 1421b, and 1422b of the electrostatic chucks 1411, 1412, 1421, and 1422. As a result, the alignment marks MK1a and MK2a used to calculate the amount of misalignment of the substrates W1 and W2 do not overlap the electrostatic chucks 1411 and 1421, as shown in Fig. 13B, for example. In addition, the control unit 9 controls the image capturing unit position adjustment units 503A, 503B, and 503C to move the image capturing units 501A, 501B, and 501C to positions where the image capturing units 501A, 501B, and 501C can capture the images of the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, and MK2c of the substrates W1 and W2, respectively. Returning to FIG. 12, thereafter, the transport device 84 transports the substrates W1 and W2 to the substrate bonding apparatus 1 (step S111). Next, the substrate bonding apparatus 1 executes the substrate bonding process (step S112).

[0050] Here, the substrate bonding process executed by the substrate bonding system will be described in detail with reference to Fig. 14. In Fig. 14, it is assumed that the substrate bonding apparatus 1 has already stored the measurement results of the thicknesses of the substrates W1 and W2 in the memory of the control unit 9. First, the substrate bonding apparatus 1 executes a distance measurement process in which the distance measurement unit 1493 measures the distances between the stage 141 and the head 142 at three points on the stage 141 and the head 142 (step S1).

[0051] Next, the substrate bonding apparatus 1 calculates the distance between the bonding surface of substrate W1 and the bonding surface of substrate W2 based on the measured distances between the stage 141 and the head 142 at three points on the stage 141 and the head 142 and the thicknesses of substrates W1 and W2. Then, based on the calculated distance, the substrate bonding apparatus 1 moves the head 142 vertically downward to bring substrates W1 and W2 closer to each other (step S2). Next, the substrate bonding apparatus 1 calculates the amount of positional deviation of substrate W1 with respect to substrate W2 in a state in which substrates W1 and W2 are spaced apart from each other (step S3). Here, the control unit 9 first acquires the captured images GAa, GAb, and GAc (see FIG. 10A) of the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, and MK2c provided in the portions of the two substrates W1 and W2 facing the first area A1 in a non-contact state from the imaging units 501A, 501B, and 501C of the position measurement unit 500. Then, the control unit 9 calculates the positional deviation amounts dx, dy, and dθ of the two substrates W1 and W2 in the X direction, the Y direction, and the rotation direction around the Z axis based on the three captured images GAa, GAb, and GAc as described above. Next, the substrate bonding apparatus 1 performs alignment by moving the substrate W2 relative to the substrate W1 so as to correct the calculated positional deviation amounts dx, dy, and dθ (step S4). Here, the substrate bonding apparatus 1 moves the stage 141 in the X direction, the Y direction, and the rotation direction around the Z axis so as to reduce the positional deviation amounts dx, dy, and dθ.

[0052] Thereafter, the substrate bonding apparatus 1 brings the head 142 even closer to the stage 141, thereby bringing the substrates W1 and W2 closer to each other (step S5). Here, the substrate bonding apparatus 1 positions the head 142 at a position where the gap between the substrates W1 and W2 is optimal for bringing the central portions of the substrates W1 and W2 into contact with each other while the substrates W1 and W2 are bent. In this state, the peripheral portions of the substrates W1 and W2 are spaced apart from each other by about 50 μm.

[0053] Next, the substrate bonding apparatus 1 performs a first contact step of contacting the center of the substrate W1 with the center of the substrate W2 by bending the substrates W1 and W2 while the substrates W1 and W2 are spaced apart from each other (step S6). The substrate bonding apparatus 1 first fills the entire grooves 1413d and 1423d provided in the second region A2 with gas from the gas discharge holes 1413c and 1423c provided in the second region A2 of the stage 141 and the head 142, as shown by the arrow AR11 in FIG. 15A. Thereafter, the substrate bonding apparatus 1 releases the holding of the substrate W1 by the electrostatic chucks 1413 and 1423 of the stage 141 and the head 142. At this time, the control unit 9 controls the gas supply unit 1492 so that gas is discharged from the gas discharge hole 1413c so that the pressure at which the substrate W1 contacts the substrate W2 is less than the critical pressure at which the substrates W1 and W2 are temporarily bonded. Specifically, the control unit 9 controls the flow rate of the gas discharged from the gas discharge holes 1413c, 1423c based on the air pressure detected by the air pressure detection unit described above so that the air pressure is less than the critical pressure. Next, the substrate bonding apparatus 1 presses the center of the substrate W1 toward the substrate W2 by the pressing unit 1441a while the electrostatic chucks 1411, 1412 of the stage 141 are holding the peripheral portion of the substrate W1. Here, the state in which the electrostatic chucks 1411, 1412 are holding the peripheral portion of the substrate W1 includes not only a state in which the chuck driving unit 1491 applies a voltage to the electrostatic chucks 1411, 1412 of the stage 141, but also a state in which no voltage is applied to the electrostatic chucks 1411, 1412 and the peripheral portion of the substrate W1 is in close contact with the electrostatic chucks 1411, 1412 due to the residual electrostatic force of the electrostatic chucks 1411, 1412. As a result, the substrate W1 is bent so that its central portion W1c protrudes toward the substrate W2, as shown in Fig. 15B. Furthermore, the substrate bonding apparatus 1 presses the central portion of the substrate W2 toward the substrate W1 with the pressing portion 1442a while the peripheral portion of the substrate W2 is held by the electrostatic chucks 1421 and 1422 of the head 142. As a result, the substrate W2 is bent so that its central portion protrudes toward the substrate W1, as shown in Fig. 15B.In this manner, the pressure of the gas discharged from the grooves 1413d, 1423d is effectively applied to the force of adhering the substrates W1, W2 to the stage 141 and head 142 due to the residual electrostatic force remaining between the electrodes 1413b, 1423b after the holding by the electrostatic chucks 1413, 1413 is released, thereby making the substrates W1, W2 free from the force of adhering to the stage 141 and head 142. In this state, the substrates W1, W2 are brought into contact with each other by pressurizing the central portions of the substrates W1, W2 with a pressure equal to or higher than the critical pressure, so that the substrates W1, W2 can be bonded from the central portions to the peripheral portions without being affected by the adhesion force to the stage 141 and head 142, and therefore the substrates W1, W2 can be bonded over the entire surfaces with high positional accuracy without distortion. Furthermore, if the pressing parts 1441a and 1432a press the central parts of the substrates W1 and W2 before they become free from the force of contacting the substrates W1 and W2 with the stage 141 and head 142, the distortion of the substrates W1 and W2 due to the influence of the contact force with the stage 141 and head 142 will become large. Furthermore, the control part 9 makes the pressing parts 1441a and 1432a protrude from the stage 141 and head 142 so that the protrusion amount of one of the pressing parts 1441a and 1432a is larger than the other by the protrusion offset amount based on the information indicating the protrusion offset amount stored in the memory. This makes it possible to reduce the amount of warping of the substrates W1 and W2 when the substrates W1 and W2 are bonded to each other.

[0054] 14, the substrate bonding apparatus 1 executes a second contact step of expanding the contact area of ​​the substrates W1 and W2 from the central portions W1c and W2c of the substrates W1 and W2 toward the peripheral portions W1s and W2s (step S7). Here, the substrate bonding apparatus 1 moves the pressing portion 1441a in a direction to sink into the stage 141 and moves the pressing portion 1442a in a direction to sink into the head 142, as shown by an arrow AR12 in FIG. 16A. At the same time, the substrate bonding apparatus 1 moves the head 142 in a direction approaching the stage 141, as shown by an arrow AR13. As a result, as shown by the arrow AR14, the contact portion of the substrates W1 and W2 spreads from the center toward the periphery of the substrates W1 and W2 due to the intermolecular force (van der Waals force) generated between the substrates W1 and W2 or the bonding force due to water or OH groups present on the bonding surfaces of the substrates W1 and W2, starting from the center portion that is point-pressurized by the pressing mechanisms 1441 and 1432. Then, when the substrate bonding apparatus 1 moves the head 142 close to a position spaced a preset distance from the stage 141, it releases the holding of the substrates W1 and W2 by the electrostatic chucks 1421 and 1422 as shown in FIG. 16B. At this time, the substrate bonding apparatus 1 first fills the entire grooves provided in the sub-annular region A12 of the first region A1 with gas from the gas discharge holes provided in the sub-annular region A12, and then releases the holding of the substrates W1 and W2 by the electrostatic chucks 1421 and 1422. At this time, the control unit 9 controls the flow rate of the gas discharged from the gas discharge holes 1412c, 1422c based on the air pressure detected by the air pressure detection unit so that the air pressure is less than the critical pressure. Next, the substrate bonding apparatus 1 fills the entire grooves 1411d, 1412d provided in the sub-annular region A11 of the first region A1 with gas from the gas discharge holes 1411c, 1412c provided in the sub-annular region A11, and then releases the holding of the substrates W1, W2 by the electrostatic chucks 1411, 1412, 1421, 1422. This releases the holding of the substrates W1, W2 by the electrostatic chucks 1421, 1422. Then, the contact portion of the substrates W1, W2 further spreads from the center to the periphery of the substrates W1, W2. Here, the bonding surfaces of the substrates W1 and W2 come into contact with each other, so that the substrates W1 and W2 are temporarily bonded to each other by hydrogen bonds between OH groups or water molecules.

[0055] 14, the substrate bonding apparatus 1 measures the amount of misalignment of the substrate W2 with respect to the substrate W1 while the bonding surface of the substrate W1 is in contact with the bonding surface of the substrate W2 (step S8). At this time, the substrate bonding apparatus 1 measures the amount of misalignment of the substrates W1 and W2 while the contact area between the substrates W1 and W2 is expanding, restricting the movement of the substrate W2 with respect to the substrate W1. Next, the substrate bonding apparatus 1 determines whether the calculated amounts of misalignment dx, dy, and dθ are all equal to or less than the preset thresholds of misalignment dxth, dyth, and dθth (step S9).

[0056] Here, it is assumed that the substrate bonding apparatus 1 determines that any one of the calculated positional deviation amounts dx, dy, and dθ is greater than the preset positional deviation amount thresholds dxth, dyth, and dθth (step S9: No). In this case, the substrate bonding apparatus 1 lifts the head 142 to separate the substrate W2 from the substrate W1 (step S10). At this time, the substrate bonding apparatus 1 lifts the head 142 to widen the distance between the substrates W1 and W2, moves the pressing portion 1441a in a direction to be immersed in the stage 141, and moves the pressing portion 1442a in a direction to be buried in the head 142. Here, the substrate bonding apparatus 1 controls the lift of the head 142 so that the tensile pressure of the substrate W2 when peeling the substrate W2 from the substrate W1 is constant. As a result, the substrate W2 is separated from the substrate W1, and the contact state of the substrates W1 and W2 is released.

[0057] Next, the substrate bonding apparatus 1 calculates the correction movement amount of the substrates W1 and W2 to make all the calculated positional deviation amounts dx, dy, and dθ equal to or less than the positional deviation amount thresholds dxth, dyth, and dθth (step S11). Here, the control unit 9 calculates the correction movement amount to move the substrates W1 and W2 by the movement amount corresponding to the difference between the positional deviation amounts dx, dy, and dθ between the substrates W1 and W2 when the substrate W2 is in contact with the substrate W1 and the positional deviation amounts between the substrates W1 and W2 when the substrate W2 is not in contact with the substrate W1. Then, the control unit 9 further adds the offset amounts in the XY directions and the rotation direction indicated by the horizontal offset vectors in the XY directions and the rotation direction stored in the memory to the correction movement amount. By offsetting by this correction movement amount and aligning the substrates W1 and W2, if a similar positional deviation occurs due to contact between the substrates W1 and W2 when the substrates W1 and W2 come into contact with each other again, the positional deviation of the substrates W1 and W2 will be eliminated.

[0058] Next, the substrate bonding apparatus 1 performs alignment so as to correct the relative positional deviation amounts dx, dy, and dθ of the two substrates W1 and W2 while the two substrates W1 and W2 are not in contact with each other (step S12). Here, the substrate bonding apparatus 1 moves the stage 141 in the X direction, the Y direction, and the rotation direction around the Z axis by the correction movement amount calculated in step S111. In this way, the substrate bonding apparatus 1 adjusts the relative position of the substrate W2 with respect to the substrate W1 so as to reduce the positional deviation amounts dx, dy, and dθ while the substrates W1 and W2 are spaced apart from each other. Then, the substrate bonding apparatus 1 performs the process of step S9 again.

[0059] On the other hand, it is assumed that the substrate bonding apparatus 1 determines that all of the calculated positional deviations dx, dy, and dθ are equal to or less than the preset positional deviation thresholds dxth, dyth, and dθth (step S9: Yes). In this case, the substrate bonding apparatus 1 further expands the contact portion of the substrates W1 and W2 from the center to the periphery of the substrates W1 and W2, so that the substrates W1 and W2 come into contact with each other over their entire surfaces (step S13). Here, as shown in FIG. 17A, the substrate bonding apparatus 1 moves the pressing portion 1441a of the pressing mechanism 1441 in a direction to make it sink into the stage 141, moves the pressing portion 1442a of the pressing mechanism 1442 in a direction to make it sink into the head 142, and at the same time, moves the head 142 further in a direction approaching the stage 141 as shown by the arrow AR16, thereby reducing the distance between the peripheries of the substrates W1 and W2. In this manner, the substrate bonding apparatus 1 brings the peripheral portion of the substrate W1 into contact with the peripheral portion of the substrate W2, so that the bonding surfaces of the substrates W1, W2 come into contact with each other over their entire surfaces.

[0060] Returning to FIG. 14, thereafter, the substrate bonding apparatus 1 performs a main bonding process in which the substrates W1 and W2 are pressed against the substrate W2 while the substrates W1 and W2 are in contact with each other, and then heated to bond the substrates W1 and W2 together (step S14). Next, the substrate bonding apparatus 1 stops the electrostatic chuck 1421 of the head 142 to release the holding of the substrate W2 (step S15). Next, the substrate bonding apparatus 1 lifts the head 142 to separate it from the substrate W2, as shown by the arrow AR17 in FIG. 17B. Next, the substrate bonding apparatus 1 measures the positional deviation of the substrate W2 with respect to the substrate W1 again while the substrates W1 and W2 are bonded to each other (step S16). Next, the control unit 9 calculates a horizontal offset vector of the substrate W2 with respect to the substrate W1 and a protrusion offset amount for the protrusion amount of the pressing parts 1441a, 1432a of the pressing mechanisms 1441, 1432, which are used when calculating a correction amount movement amount in the next bonding of the substrates W1, W2, based on the calculated positional deviation amount (step S17). Here, the control unit 9 stores information indicating the calculated horizontal offset vector and protrusion offset amount in the memory.

[0061] Returning to FIG. 12, the transport device 84 then transports the bonded substrates W1 and W2 from the substrate bonding apparatus 1 to the load lock unit 83 (step S113). The transport device 82 then removes the bonded substrates W1 and W2 from the load lock unit 83 and transports them to the inspection device 7 (step S114). After that, the inspection device 7 captures images of all alignment marks including the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, and MK2c provided on the bonded substrates W1 and W2 (step S115). Here, the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, and MK2c are used for alignment in the substrate bonding apparatus 1, and the inspection device 7 captures images of not only these alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, and MK2c but also all other alignment marks. The other alignment mark on one of the substrates W1 and W2 corresponds to the third alignment mark, and the other alignment mark on the other substrate corresponds to the fourth alignment mark. Here, the inspection device 7 sequentially captures images of all alignment marks including the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, and MK2c provided on the substrates W1 and W2 bonded to each other using the imaging unit 73. Next, the control unit 9 calculates the amount and direction of misalignment of each alignment mark from the images captured by the imaging unit 73 of the inspection device 7 (step S116).

[0062] Next, the control unit 9 calculates the horizontal offset vector of the substrate W2 relative to the substrate W1 and the protrusion offset amount for the protrusion amount of the pressing parts 1441a and 1432a of the pressing mechanisms 1441 and 1432, which are used when calculating the correction amount movement amount in the next bonding of the substrates W1 and W2, based on the calculated positional deviation amount (step S117). Specifically, the control unit 9 separates the positional deviation vector in each alignment mark specified by the calculated positional deviation amount and positional deviation direction into XY direction components, rotation direction components, warpage components, and distortion components. Here, when the control unit 9 obtains a distribution of positional deviation vectors as shown in, for example, FIG. 18(A), it separates the positional deviation vector into XY direction components, rotation direction components, warpage components, and distortion components as shown in FIG. 18(B) to (E), respectively. That is, the combination of the XY direction components, rotation direction components, warpage components, and distortion components in FIG. 18(B) to (E) is in a relationship that coincides with the positional deviation vector. Then, the control unit 9 calculates a horizontal offset vector, which is a vector reflecting the axial directions along each of the two intersecting axes of substrate W2 relative to substrate W1, i.e., the axial offset amount, which is the offset amount in the X and Y directions, and the rotational offset amount, which is the offset amount in the rotational direction, from only the X and Y direction components and the rotational direction components obtained by separating them.

[0063] Incidentally, it is preferable from the viewpoint of improving alignment accuracy to convert the calculated offset amount into a horizontal offset vector that reflects the axial offset amount, which is the offset amount in the XY direction, and the rotational offset amount, which is the offset amount in the rotational direction, of the substrate W2 relative to the substrate W1 at each position of the alignment marks MK1a, Mk1b, MK2a, MK2b, MK3a, and MK3b used in the bonding apparatus 1, which are respectively along two intersecting axes of the substrate W2 relative to the substrate W1 at each position of the alignment marks MK1a, Mk1b, MK2a, MK2b, MK3a, and MK3b used in the bonding apparatus 1, since the horizontal offset amount in the alignment marks MK1a, Mk1b, MK2a, MK2b, MK3a, and MK3b actually used is more reflected. First, the representative positions CE1a and CE2a of the alignment marks MK1a and MK2a shown in FIG. 19A are set to match in a state where the centers of the two alignment marks MK1a and MK1b are arranged to match as shown in FIG. 19B. Then, as shown in Fig. 19C, it is assumed that the representative position CE2a of the alignment mark MK2a is moved by an amount reflecting the direction and size indicated by the above-mentioned horizontal offset vector VEoffa. Then, as shown in Fig. 19D, the alignment marks MK1a and MK2a are aligned in a state shifted by the horizontal offset vector VEoffa. Then, as shown in Fig. 19E, it is assumed that the offset amounts in the X and Y directions of the substrate W2 relative to the substrate W1 are Δxoff and Δyoff, respectively, and the offset amount in the rotational direction is Δθoff. In this case, the horizontal offset vector VEoffa corresponding to the pair of alignment marks MK1a, MK2a imaged by the imaging unit 501A is represented by a vector starting from the representative position CE1a of alignment mark MK1a and ending at the representative position CE2a of alignment mark MK2a, and the horizontal offset vector VEoffb corresponding to the pair of alignment marks MK1b, MK2b imaged by the imaging unit 501B is represented by a vector starting from the representative position CE1b of alignment mark MK1b and ending at the representative position CE2b of alignment mark MK2b.Further, the horizontal offset vector VEoffc corresponding to the pair of alignment marks MK1c and MK2c captured by the imaging unit 501C is expressed as a vector starting from the representative position CE1c of the alignment mark MK1c and ending at the representative position CE2c of the alignment mark MK2c. Here, each horizontal offset vector VEoffa, VEoffb, and VEoffc is expressed as a vector having a different direction and magnitude. The control unit 9 calculates each horizontal offset vector VEoffa, VEoffb, and VEoffc. Then, the control unit 9 performs alignment between the substrates W1 and W2 using the representative positions CE2a, CE2b, and CE2c obtained by shifting the alignment marks MK1b, MK2b, and MK2c by the above-mentioned horizontal offset vectors VEoffa, VEoffb, and VEoffc.

[0064] Further, the control unit 9 calculates the protrusion offset amount of the pressing units 1441a and 1432a of the pressing mechanisms 1441 and 1432 based only on the warpage component. Here, the control unit 9 calculates the horizontal offset vector and the protrusion offset amount based on the average value or median value of the positional deviation amount and the positional deviation direction obtained for the plurality of bonded substrates W1 and W2 each time a predetermined number of bonded substrates W1 and W2 are produced. Then, the control unit 9 stores information indicating the calculated horizontal offset vector and the protrusion offset amount in the memory. As a result, the substrate bonding apparatus 1 corrects the calculated horizontal offset vector and the protrusion offset amount when bonding the substrates W1 and W2. Thereafter, the transport device 82 transports the bonded substrates W1 and W2 after the measurement from the inspection device 7 to the take-out port 813 (step S118). In this substrate bonding method, at least some of the series of processes of steps S101 to S104, the series of processes of steps S105 to S107, the series of processes of steps S108 to S113, and the series of processes of steps S115 to S117 may be performed in parallel on different substrates W1 and W2.

[0065] As described above, according to the substrate bonding apparatus 1 of the present embodiment, the substrates W1 and W2 are brought into contact with each other while gas is discharged between the stage 141 and the substrate W1 from the gas discharge holes 1413c and the groove 1413d in a state where the central portion W1c of the substrate W1 and the central portion W2c of the substrate W2 are in contact with each other and the peripheral portion W1s of the substrate W1 is held by the electrostatic chucks 1411 and 1412. As a result, the pressure of the gas discharged from the gas discharge holes 1413c and 1423c to the grooves 1413d and 1423d effectively acts against the force of the substrates W1 and W2 being in close contact with the stage 141 and the head 142 due to the residual electrostatic force remaining in the electrostatic chucks 1413 and 1423 after the holding by the electrostatic chucks 1413 and 1423 is released, thereby making the substrates W1 and W2 free from the force of the substrates being in close contact with the stage 141 and the head 142. In this state, by pressing the central portions of the substrates W1 and W2 together with a pressure equal to or greater than the critical pressure, bonding can be carried out from the central portions of the substrates W1 and W2 toward the periphery without being affected by the adhesion forces of the substrates W1 and W2 to the stage 141 and head 142, so that the substrates W1 and W2 can be bonded without distortion and with high positional accuracy over the entire surface.

[0066] Incidentally, if the stage 141 and the head 142 did not have the grooves 1413d and 1423d, only a portion of the substrates W1 and W2 would peel off from the stage 141 and the head 142, and there would be a risk that a portion of the substrates W1 and W2 that was in close contact with the stage 141 and the head 142 would remain inside the substrates W1 and W2. If this happens, there is a risk that the entire portion of the substrates W1 and W2, excluding their peripheries, will not be free from the force that causes them to be in close contact with the stage 141 and the head 142. In particular, as described above, in the case where gas is discharged from the gas discharge holes 1413c, 1423c before releasing the electrostatic chucks 1413, 1423, if the residual electrostatic force of the electrostatic chucks 1413, 1423 is relatively small, only the vicinity of the gas discharge holes 1413c, 1423c will be peeled off from the stage 141 and the head 142, and the gas pressure will not be able to effectively apply to the entire portion of the substrates W1, W2 except for their peripheral portions, and it may become impossible to free the entire portion of the substrates W1, W2 except for their peripheral portions from the stage 141 and the head 142. In contrast, the stage 141 and head 142 of this embodiment are provided with grooves 1413d and 1423d, which allows the entire substrates W1, W2 except for their peripheral portions to be free from the force of adhering them to the stage 141 and head 142. Therefore, bonding can be carried out from the center of the substrates W1, W2 toward their peripheral portions without being affected by the adhesion force of the substrates W1, W2 to the stage 141 and head 142.

[0067] Moreover, the grooves 1413d and 1423d formed in the second region A2 of the stage 141 and head 142 according to this embodiment have portions extending along the extending direction of the plurality of electrode elements 1413b and 1423b, respectively. The grooves 1413d and 1423d are provided between the plurality of electrode elements 1413b electrically connected to the terminal electrode 1413a of the stage 141 and head 142 and the plurality of electrode elements 1423b electrically connected to the terminal electrode 1423a. This allows the force of the gas discharged from the gas discharge holes 1413c and 1423c through the grooves 1413d and 1423d in the direction of peeling the substrates W1 and W2 from the stage 141 and head 142 to be uniformly applied to the entire substrates W1 and W2 in comparison with the force of the electrostatic chucks 1413 and 1423 for adhering the substrates to the stage 141 and head 142. Furthermore, by providing the grooves 1413d, 1423d between the electrodes 1413b, 1423b to which voltages of opposite polarities are applied, the pressure of the gas discharged from the grooves 1413d, 1423d can be effectively applied to the force caused by the electrostatic force generated between the electrodes 1413b, 1423b to bring the substrates W1, W2 into close contact with the stage 141 and the head 142. Therefore, the speed at which the contact areas between the substrates W1, W2 spread can be made uniform.

[0068] Furthermore, the stage 141 and head 142 according to this embodiment are provided in the sub-annular region A11 of the first region A1 and have grooves 1411d and 1421d that communicate with the gas discharge holes 1411c and 1411d. The stage 141 and head 142 are also provided in the sub-annular region A12 of the first region A1 and have grooves that communicate with the gas discharge holes. When bringing the substrates W1 and W2 into contact with each other over their entire surfaces from a state in which the central portions of the bonding surfaces of the substrates W1 and W2 are in contact with each other and the peripheral portions of the substrates W1 and W2 are held by the electrostatic chucks 1411, 1412, 1421, and 1422, the control unit 9 first fills the entire groove provided in the sub-annular region A12 with gas from the gas discharge holes provided in the sub-annular region A12 of the first region A1, and then controls the chuck driving unit 1491 and the gas supply unit 1492 to release the substrates W1 and W2 from the electrostatic chucks 1421 and 1422. Next, the control unit 9 fills the entire grooves 1411d, 1412d provided in the sub-annular region A11 of the first region A1 with gas from the gas discharge holes 1411c, 1412c provided in the sub-annular region A11, and then controls the chuck driving unit 1491 and the gas supply unit 1492 to release the substrates W1, W2 from the electrostatic chucks 1411, 1412, 1421, 1422. As a result, the state in which the peripheral portions of the substrates W1, W2 are held by the electrostatic chucks 1411, 1412, 1421, 1422 is released while a force is acting in a direction in which the substrates W1, W2 are peeled off from the stage 141 and the head 142 from the entire grooves 1411d, 1412d. Therefore, by applying a force to the entire substrates W1 and W2 in a direction in which the substrates are peeled off from the stage 141 and head 142, it is possible to prevent a portion of the substrates W1 and W2 from being preferentially peeled off from the stage 141 and head 142, and it is possible to make uniform the speed at which the contact areas between the substrates W1 and W2 spread.

[0069] In addition, by filling the entire grooves provided in the sub-annular region A12 of the first region A1 and the entire grooves 1411d and 1412d provided in the sub-annular region A11 of the first region A1 with gas while a voltage is applied between the multiple electrodes 1411b, 1421b, 1412b, and 1422b of the electrostatic chucks 1411, 1421, 1412, and 1422, respectively, it is possible to ionize a part of the gas filled in the grooves 1411d and 1412d. As a result, the residual electrostatic force of the electrostatic chucks 1411, 1421, 1412, and 1422 is neutralized by the ions contained in the gas, so that the substrates W1 and W2 are easily peeled off from the stage 141 and the head 142.

[0070] Now, suppose that the stage and the head are provided with electrostatic chucks 9411 and 9421 each having terminal electrodes 9411a and 9421a that are straight and without bends, and electrode elements 9411b and 9421b, as shown in Fig. 20A. Here, suppose that the alignment marks MK1a' and MK2a' used to calculate the amount of misalignment of the substrates W1 and W2 overlap with the electrode elements 9411b and 9421b of the electrostatic chucks 9411 and 9421, as shown in Fig. 20A. In this case, the substrate bonding apparatus 1 rotates the stage 141 and then receives the substrates W1 and W2, so that the alignment marks MK1a' and MK2a' do not overlap with the electrode elements 9411b and 9421b of the electrostatic chucks 9411 and 9421, as shown in Fig. 20B. However, for example, when the alignment marks MK1a, MK2a used to calculate the positional deviation amount of the substrates W1, W2 overlap with the terminal electrodes 9411a, 9421a of the electrostatic chucks 9411, 9421 as shown in FIG. 20A, even if the substrate bonding apparatus 1 rotates the stage 141 in the rotational direction indicated by the arrow AR10 in FIG. 20A and then receives the substrates W1, W2, the alignment marks MK1a, MK2a will overlap with the terminal electrodes 9411a, 9421a of the electrostatic chucks 1411, 1421 as shown in FIG. 20B. Furthermore, if the stage and head are moved in parallel so that the alignment marks MK1a, MK2a used to calculate the amount of positional deviation of the substrates W1, W2 do not overlap with the electrostatic chucks 1411, 1421, the position at which the pressing mechanism presses the substrates W1, W2 will be shifted from the center of the substrates W1, W2, and as a result, distortion will be more likely to occur in the substrates W1, W2 that are joined to each other.

[0071] In contrast, in the electrostatic chucks 1411 and 1421 according to the present embodiment, the terminal electrode 1411a has a plurality of bent portions 1411ab bent so as to protrude in a direction away from the other in a plan view, and a connecting portion 1411aa connecting the ends of two adjacent bent portions 1411ab in the circumferential direction. As a result, the substrate bonding apparatus 1 rotates the stage 141 before receiving the substrates W1 and W2, so that the alignment marks MK1a and MK2a used to calculate the positional deviation amount of the substrates W1 and W2 do not overlap with the electrostatic chucks 1411 and 1421 without moving the stage 141 and the head 142 in parallel. Therefore, the substrates W1 and W2 can be bonded to each other with high positional accuracy, and the distortion generated in the substrates W1 and W2 bonded to each other can be reduced.

[0072] In addition, the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, and MK2c of the substrates W1 and W2 are often provided at the corners of the regions on which the chips are based on the substrates W1 and W2, that is, on the periphery of the regions on which the chips are based. Here, the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, and MK2c must be arranged so as not to overlap with the dicing lines provided between the regions on which the chips are based adjacent to each other, so they must be arranged inside the regions on which the chips are based, and the area of ​​the regions on which the chips are based increases accordingly. In this case, the positions of the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, and MK2c are arranged closer to the center than the periphery of the substrates W1 and W2 by the amount of increase in the area of ​​the regions on which the chips are based. On the other hand, the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, and MK2c must be disposed in positions facing the first region A1 when the substrates W1 and W2 are disposed at the substrate holding positions of the stage 141 and the head 142. Therefore, if the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, and MK2c are disposed closer to the center of the substrates W1 and W2 than the periphery, the width of the first region A1 must be set wider accordingly. Here, if one electrostatic chuck is provided in the first region A1, when the substrates W1 and W2 are brought into contact with each other at their centers, the bonding between the substrates W1 and W2 stops at the portion facing the first region A1, and the bonding between the substrates W1 and W2 does not sufficiently extend to the vicinity of the periphery, which may cause distortion in the periphery of the substrates W1 and W2. In contrast, in the stage 141 and head 142 of this embodiment, two sub-annular regions A11 and A12 are predefined in the first region A1, and electrostatic chucks 1411, 1412, 1421, and 1422 are provided in the sub-annular regions A11 and A12, respectively.This allows the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, and MK2c of the substrates W1 and W2 to be captured even when they are located closer to the center than the periphery of the substrates W1 and W2. When the substrates W1 and W2 are brought into contact with each other at their centers to bond the substrates W1 and W2, the electrostatic chucks 1412 and 1422 provided in the sub-annular region A12 are released from the electrostatic chucks, so that the bonding of the substrates W1 and W2 can proceed to the vicinity of the periphery of the substrates W1 and W2. The electrostatic chucks 1412 and 1422 provided in the sub-annular region A12 may be driven simultaneously with the electrostatic chucks 1413 and 1423 provided in the second region A2. In this case, the electrostatic chucks 1412 and 1422 and the electrostatic chucks 1413 and 1423 can share a power source, so that the configuration of the substrate bonding apparatus 1 can be simplified.

[0073] Furthermore, the substrate bonding system according to the present embodiment includes an inspection device 7 having an imaging unit 73 that images all of the alignment marks of the substrates W1 and W2 bonded to each other. The control unit 9 calculates the positional deviation amount and positional deviation direction of each of the alignment marks of the substrates W1 and W2 based on the captured image obtained by imaging the alignment marks of the substrates W1 and W2 by the imaging unit 73. The control unit 9 then separates the axial components along the two intersecting axial directions of the positional deviation vector determined by the calculated positional deviation amount and positional deviation direction, i.e., the XY direction component and the rotation direction component, and calculates a horizontal offset vector that is a vector reflecting the axial directions along the two intersecting axes of the substrate W2 relative to the substrate W1 when bonding the substrates W1 and W2, i.e., the axial offset amount which is the offset amount in the XY direction and the rotation direction which is the offset amount in the rotation direction, based on the separated XY direction component and rotation direction component. The control unit 9 also separates the warpage component of the misalignment vector determined by the calculated misalignment amount and misalignment direction, and calculates a protrusion offset amount, which is an offset amount of the protrusion amount of the central part of the substrate W1 toward the substrate W2 side relative to the peripheral part of the substrate W1 when the substrates W1 and W2 are bonded, based on the separated warpage component. As a result, when the substrates W1 and W2 are bonded, for example, in a case where the substrates W1 and W2 are repeatedly bonded multiple times, the relative positions of the substrates W1 and W2 are corrected by an offset amount corresponding to the absolute value of the horizontal offset vector in the offset direction indicated by the horizontal offset vector calculated based on the misalignment amount of the alignment mark after the past substrate bonding process. Therefore, the bonding position accuracy of the substrates W1 and W2 can be improved. Here, when the pressing mechanism on the head 142 side is a position control mechanism and the pressing mechanism on the stage 141 side is a pressure control mechanism, if the protrusion offset amount on the head 142 side is increased, the peripheral parts of the bonded substrates W1 and W2 are warped toward the head 142 side relative to the central parts. On the other hand, if the amount of protrusion offset on the head 142 side is reduced, the peripheral portions of the joined substrates W1 and W2 warp toward the stage 141 side with respect to the central portions.

[0074] Incidentally, if the offset direction and offset amount are determined based only on the image captured by the imaging unit 73 of the inspection device 7 without considering the positional deviation error of the alignment marks MK1a, MK1b, MK1c, MK2a, MK2b, and MK2c described above, the alignment marks MK1a, MK1b, MK1c, MK2a, MK2b, and MK2c will be misaligned by the positional deviation error in the substrate bonding apparatus 1. In contrast, in this embodiment, the offset direction and offset amount are corrected by the positional deviation error of the alignment marks MK1a, MK1b, MK1c, MK2a, MK2b, and MK2c before and after bonding the substrates W1 and W2 in the substrate bonding apparatus 1 to calculate the horizontal offset vector. This can improve the accuracy of the horizontal offset vector required when bonding the substrates W1 and W2.

[0075] (Embodiment 2) The substrate bonding apparatus according to the present embodiment differs from the first embodiment in that it includes a plurality of pressing members that are annular with different inner diameters, are concentrically arranged in a second region inside the first region of the first substrate holding portion so that their centers coincide with the central portion of the first substrate holding portion, and press a portion of the first substrate arranged at the substrate holding position that faces the second region. The substrate bonding apparatus according to the present embodiment brings the first substrate and the second substrate into contact with each other while preferentially pressing the first substrate from the pressing member located on the central portion side of the first substrate holding portion among the plurality of pressing members, with the central portion of the first substrate being in contact with the central portion of the second substrate and the peripheral portion of the first substrate being held by the substrate holding portion.

[0076] The substrate bonding apparatus according to the present embodiment has a structure substantially similar to that of the substrate bonding apparatus 1 constituting the substrate bonding system described in the first embodiment, and as shown in FIG. 21A and FIG. 21B, only the structures of the stage 2141 and the head 2142 are different from those of the first embodiment. Note that in FIG. 21A and FIG. 21B, the same components as those in the first embodiment are given the same reference numerals as those in FIG. 5A and FIG. 5B. The substrate bonding apparatus according to the present embodiment includes the chamber 120, the stage 2141, the head 2142, the stage driving unit 143, the head driving unit 144, the substrate heating units 1481 and 1482, the position measuring unit 500, and the distance measuring unit 1493, as in the substrate bonding apparatus 1 described in the first embodiment. Note that in the following description, the same components as those in the first embodiment are described using the same reference numerals as those in the first embodiment, as appropriate.

[0077] The stage 2141 and the head 2142 are disposed in the chamber 120 so as to face each other in the vertical direction. The stage 2141 is a first substrate holder that holds the substrate W1 on its upper surface, and the head 2142 is a second substrate holder that holds the substrate W2 on its lower surface. Here, the stage 2141 supports the substrate W1 with its upper surface in surface contact with the entire substrate W1, and the head 2142 supports the substrate W2 with its lower surface in surface contact with the entire substrate W2. The stage 2141 and the head 2142 are formed of a light-transmitting material such as light-transmitting glass. As shown in FIG. 21A, the stage 2141 is provided with an electrostatic chuck 1411 that holds the substrate W1, a pressing mechanism 1441 that presses the center of the substrate W1, and a plurality of (32 in FIG. 21A) pressing members 21511, 21512, 21513, and 21514 that are circular in plan view. Also, as shown in Fig. 21B, the stage 2141 is provided with piezoelectric actuators 21611, 21612, 21613, and 21614. As shown in Fig. 21A, the head 2142 is provided with an electrostatic chuck 1421 that holds the substrate W2, a pressing mechanism 1442 that presses the center of the substrate W2, and a plurality of (32 in Fig. 21A) pressing members 21521, 21522, 21523, and 21524 that are circular in plan view. Also, as shown in Fig. 21B, the head 2142 is provided with piezoelectric actuators 21621, 21622, 21623, and 21624. The electrostatic chucks 1411 and 1421 are provided in an annular first region A1 facing the peripheries of the substrates W1 and W2 on the stage 141 and head 142 in a state in which the substrates W1 and W2 are held on the stage 2141 and head 2142. The electrostatic chucks 1411 and 1421 hold the peripheries of the substrates W1 and W2, respectively. Furthermore, the stage 141 and head 142 are provided in their central portions with through holes 141b and 142b that are circular in plan view.

[0078] The pressing members 21511, 21512, 21513, and 21514 are disposed in the second region A2 of the stage 2141 along four imaginary circles VC1, VC2, VC3, and VC4 whose centers coincide with the central portion of the stage 2141. The pressing members 21511, 21512, 21513, and 21514 press a portion of the substrate W1 disposed in a preset substrate holding position on the stage 2141 that faces the second region A2. The piezo actuators 21611, 21612, 21613, and 21614 are pressing member driving units that drive the pressing members 21511, 21512, 21513, and 21514 in a direction protruding from the stage 2141 or in a direction retracting into the stage 2141, respectively. The pressing members 21521, 21522, 21523, and 21524 are also arranged along four imaginary circles VC1, VC2, VC3, and VC4 whose centers coincide with the central portion of the head 2142 in the second region A2 of the head 2142. The pressing members 21521, 21522, 21523, and 21524 press a portion of the substrate W2 that faces the second region A2 and is arranged at a preset substrate holding position in the head 2142. The piezo actuators 21621, 21622, 21623, and 21624 are pressing member driving units that drive the pressing members 21521, 21522, 21523, and 21524 in a direction protruding from the head 2142 or in a direction retracting into the head 2142, respectively.

[0079] The control unit 9 controls the amount of movement of each of the pressing members 21511, 21512, 21513, and 21514 by controlling the amount of change in length of the piezoelectric actuators 21611, 21612, 21613, and 21614 in the opposing direction between the stage 2141 and the head 2142. The control unit 9 controls the piezoelectric actuators 21611, 21612, 21613, and 21614 so that the speed at which the multiple pressing members 21511, 21512, 21513, and 21514 come into contact with the substrate W1 in order from the side closest to the center of the stage 2141 is faster than the speed at which the temporary bonding of the substrates W1 and W2 progresses from a state in which the centers of the bonding surfaces of the substrates W1 and W2 are in contact with each other toward the periphery of the substrates W1 and W2. The control unit 9 also controls the amount of movement of each of the pressing members 21521, 21522, 21523, and 21524 by controlling the amount of change in length of the piezoelectric actuators 21621, 21622, 21623, and 21624 in the opposing direction between the stage 2141 and the head 2142. The control unit 9 controls the piezoelectric actuators 21611, 21612, 21613, and 21614 so that the speed at which the pressing members 21521, 21522, 21523, and 21524 bring the substrates W2 into contact with each other in sequence from the side closest to the center of the head 2142 is faster than the speed at which the temporary bonding of the substrates W1 and W2 progresses from a state in which the centers of the bonding surfaces of the substrates W1 and W2 are in contact with each other toward the peripheries of the substrates W1 and W2.

[0080] In the substrate bonding system according to the present embodiment, the flow of a series of operations from when substrates W1, W2 are loaded until substrates W1, W2 are bonded and removed from the substrate bonding system is substantially the same as in embodiment 1, and only a part of the operations in the substrate bonding process differs from embodiment 1. The substrate bonding process performed by the substrate bonding system according to the present embodiment will now be described with reference to Figs. 14, 22A to 23B.

[0081] First, as shown in FIG. 14, the substrate bonding apparatus executes a series of operations from steps S1 to S4. Next, the substrate bonding apparatus further moves the head 142 closer to the stage 141 to bring the substrates W1 and W2 closer to each other (step S5). Next, the substrate bonding apparatus executes a first contact step in which the substrates W1 and W2 are bent while the substrates W1 and W2 are spaced apart from each other, thereby bringing the center of the substrate W1 into contact with the center of the substrate W2 (step S6). At this time, the substrate bonding apparatus, for example, as shown in FIG. 22A, while holding the peripheral portion of the substrate W1 on the electrostatic chuck 1411, presses the center of the substrate W1 toward the substrate W2 with the pressing portion 1441a, thereby bending the substrate W1 so that the center portion W1c of the substrate W1 protrudes toward the substrate W2. Moreover, the substrate bonding apparatus, while holding the peripheral portion of the substrate W2 on the electrostatic chuck 1422, presses the central portion of the substrate W2 toward the substrate W1 with the pressing portion 1442a, thereby bending the substrate W2 so that the central portion of the substrate W2 protrudes toward the substrate W1. Then, as shown in Fig. 22B, the substrate bonding apparatus brings the pressing members 21511, 21512, 21513, and 21514 into contact with the substrate W1 with the piezoelectric actuators 21611, 21612, 21613, and 21614. Furthermore, the substrate bonding apparatus brings the pressing members 21521, 21522, 21523, and 21524 into contact with the substrate W2 with the piezoelectric actuators 21621, 21622, 21623, and 21624.

[0082] 14, the substrate bonding apparatus performs a second contact step of expanding the contact area of ​​the substrates W1 and W2 from the central portions W1c and W2c of the substrates W1 and W2 toward the peripheral portions W1s and W2s (step S7). Here, the substrate bonding apparatus moves the pressing portion 1441a in a direction to make it sink into the stage 2141 and moves the pressing portion 1442a in a direction to make it sink into the head 2142, as shown by the arrow AR22 in FIG. 23A. At the same time, the substrate bonding apparatus moves the head 2142 in a direction to approach the stage 2141, as shown by the arrow AR21. Then, the substrate bonding apparatus preferentially presses the substrate W1 from among the pressing members 21511, 21512, 21513, and 21514 that are located on the central side of the stage 2141. Furthermore, the substrate bonding apparatus preferentially presses substrate W2 from among the pressing members 21521, 21522, 21523, and 21524 that are located closer to the center of head 2142. As a result, as indicated by arrows AR23, the contact portions of substrates W1 and W2 start from the centers that are point-pressed by pressing mechanisms 1441 and 1432 and spread from the centers of substrates W1 and W2 toward the peripheries.

[0083] After that, a series of processes from step S8 to S12 are executed. Then, it is assumed that the substrate bonding apparatus determines that all of the calculated positional deviation amounts dx, dy, and dθ are equal to or less than the preset positional deviation amount thresholds dxth, dyth, and dθth (step S9: Yes). In this case, the substrate bonding apparatus 1 further expands the contact portion of the substrates W1 and W2 from the center to the periphery of the substrates W1 and W2, so that the substrates W1 and W2 come into contact with each other over their entire surfaces (step S13). Here, as shown in FIG. 23B, the substrate bonding apparatus 1 moves the pressing portion 1441a of the pressing mechanism 1441 in a direction to make it sink into the stage 2141 and moves the pressing portion 1442a of the pressing mechanism 1442 in a direction to make it sink into the head 2142, and at the same time, moves the head 142 further in a direction approaching the stage 141 as shown by the arrow AR24, thereby reducing the distance between the peripheries of the substrates W1 and W2. In this manner, the substrate bonding apparatus 1 brings the peripheral portion of the substrate W1 into contact with the peripheral portion of the substrate W2, so that the bonding surfaces of the substrates W1, W2 come into contact with each other over their entire surfaces.

[0084] 14, next, the substrate bonding apparatus 1 performs a main bonding process for bonding the substrates W1 and W2 together (step S14), and releases the holding of the substrate W2 by stopping the electrostatic chuck 1421 of the head 2142 (step S15). Then, the substrate bonding apparatus 1 performs the processes from step S16 onwards.

[0085] As described above, according to the substrate bonding apparatus of this embodiment, when the center of substrate W1 and the center of substrate W2 are in contact with each other and the periphery of substrate W1 is held by stage 2141, substrates W1 and W2 are brought into contact with each other while substrate W1 is pressed preferentially by one of pressing members 21511, 21512, 21513, 21514 located closer to the center of stage 2141. At this time, the substrate bonding apparatus preferentially presses substrate W2 by one of pressing members 21521, 21522, 21523, 21524 located closer to the center of head 2142. As a result, the pressure of the gas discharged from the grooves 1413d, 1423d is effectively applied to the force of adhering the substrates W1, W2 to the stage 141 and head 142 due to the residual electrostatic force remaining between the electrodes 1413b, 1423b after the holding by the electrostatic chucks 1413, 1413 is released, thereby making the substrates W1, W2 free from the force of adhering to the stage 141 and head 142. In this state, by pressurizing the centers of the substrates W1, W2 with a pressure equal to or higher than the critical pressure and bringing them into contact with each other, bonding can be advanced from the centers of the substrates W1, W2 toward the peripheries without being affected by the adhesion force to the stage 141 and head 142, so that the substrates W1, W2 can be bonded over the entire surfaces with high positional accuracy without distortion.

[0086] Although each embodiment of the present invention has been described above, the present invention is not limited to the configuration of each of the above-mentioned embodiments. For example, as shown in Fig. 24A, the stage 3141 and the head 3142 may have grooves 3413d and 3423d having a plurality of arc-shaped sub-grooves 34131d and 34231d that extend concentrically and have different diameters, and gas discharge holes 3413c and 3423c that communicate with the grooves 3413d and 3423d. In Fig. 24A, the same components as those in the first embodiment are denoted by the same reference numerals as those in Fig. 5A. Here, as shown in FIG. 24B, the multiple sub-grooves 34131d, 34231d are connected at both ends to adjacent sub-grooves 34131d, 34231d on one side of the radial direction of the stage 4141 and head 3142 via sub-grooves 34132d, 34232d extending in the radial direction of the stages 3141 and 4142.

[0087] Moreover, the electrostatic chucks 3413 and 3423 according to this modification each have, in the second region A2, a plurality of electrode elements 3413b and 3423b extending in an arc shape centered on the center of the stage 4141 and the head 4142, and a plurality of terminal electrodes 3413a and 3423a. The plurality of electrode elements 3413b and 3423b are arranged in a concentric shape centered on the center of the stage 4141 and the head 4142 and alternately arranged in the radial direction. The plurality of terminal electrodes 3413a each extend in the radial direction of the stage 4141 and the head 4142, and connect one end of each of two adjacent electrode elements 3413b across one electrode element 3423b in the radial direction of the stage 4141 and the head 4142. The multiple terminal electrodes 3423a also extend in the radial direction of the stage 4141 and head 4142, and connect one end of each of two adjacent electrode elements 3423b that sandwich one electrode element 3413b in the radial direction of the stage 4141 and head 4142.

[0088] Alternatively, for example, as shown in Fig. 25A, the stage 4141 and the head 4142 may have spiral grooves 4413d and 4423d, and a plurality of gas discharge holes 4413c and 4423c communicating with the grooves 4413d and 4423d, respectively. Note that in Fig. 25A, the same components as those in the first embodiment are denoted by the same reference numerals as those in Fig. 5A.

[0089] 25B, the electrostatic chucks 4413 and 4423 according to this modification each have two electrodes 4413b and 4423b that extend in a spiral shape centered on the central portion of the stage 4141 and the head 4142 in the second region A2. One of the two electrodes 4413b and 4423b is disposed on at least one side in the radial direction of the stage 4141 and the head 4142, while the other is disposed on the other side.

[0090] Also, as shown in FIG. 26A, for example, the second region A2 inside the first region A1 in the stage 5141 and the head 5142 may be provided with a plurality of radially extending elongated grooves 5413d, 5423d, and gas discharge holes 5413c, 5423c opening at the bottom of the end of the stage 5141 and the head 5142 on the central side of each groove 5413d, 5423d. Also, as shown in FIG. 26B, the first region A1 may not be provided with a groove. Note that in FIG. 26A and FIG. 26B, the same components as those in the first embodiment are denoted by the same reference numerals as those in FIG. 5A and FIG. 7A. In the stage 5141 and the head 5142 according to this modification, the electrostatic chucks 5413, 5423 are disposed between two adjacent grooves 5413d, 5423d in the circumferential direction of the stage 5141 and the head 5142 in the second region A2. Here, the width Wi51 of the grooves 5413d, 5423d is set to, for example, about 0.2 mm. As shown in Fig. 27A, the electrostatic chucks 5413, 5423 each have two arc-shaped terminal electrodes 5413a, 5423a extending in the circumferential direction of the stage 5141 and the head 5142, and a plurality of long electrode elements 5413b, 5423b extending from the two terminal electrodes 5413a, 5423a toward the other terminal electrodes 5423a, 5413a along the radial direction of the stage 5141 and the head 5142. Here, the electrode elements 5413b, 5423b each have a wedge-shaped shape in a plan view that becomes wider toward the peripheral edge side of the stage 5141 and the head 5142. Furthermore, as shown in FIG. 27B, the width Wi53 between the electrostatic chucks 5413 and 5423 and the surfaces of the stage 5141 and head 5142 is set to be shorter than the depth Wi52 of the grooves 5413d and 5423d.

[0091] In the first embodiment, an example has been described in which two circular sub-annular regions A11 and A12 are set in the first region A1 of the stage 141 and the head 142, and electrostatic chucks 1411, 1421, 1412, and 1422 are provided in the sub-annular regions A11 and A12, respectively. However, the number of sub-annular regions set in the first region A1 is not limited to two. For example, three or more circular sub-annular regions may be set in the first region A1, and an electrostatic chuck may be provided in each of the sub-annular regions.

[0092] In the first embodiment, an example has been described in which the substrate bonding apparatus 1 first fills the entire groove 1413d provided in the second region A2 with gas from the gas discharge holes 1413c provided in the second region A2 of the stage 141 and the head 142, and then releases the holding of the substrates W1 and W2 by the electrostatic chucks 1413 and 1423. However, this is not limiting, and for example, the substrate bonding apparatus 1 may discharge gas from the gas discharge holes 1413c and 1423c provided in the second region A2 of the stage 141 and the head 142 toward the grooves 1413d and 1423d provided in the second region A2 after releasing the holding of the substrates W1 and W2 by the electrostatic chucks 1413 and 1423. At this time, the control unit 9 may control the gas supply unit 1492 so that the gas is discharged from the gas discharge holes 1413c, 1423c so that the pressure at which the substrates W1, W2 contact each other is less than the critical pressure at which the substrates W1, W2 are temporarily bonded. This allows the pressure of the gas discharged from the gas discharge holes 1413c, 1423c through the grooves 1413d, 1423d to effectively act on the force that causes the substrates W1, W2 to adhere to the stage 141 and head 142 due to the residual electrostatic force remaining between the electrodes 1413b, 1423b after the holding by the electrostatic chucks 1413, 1413 is released. This makes the substrates W1, W2 free from the force that causes them to adhere to the stage 141 and head 142. In this state, the central portions of the substrates W1 and W2 are brought into contact with each other by applying pressure equal to or greater than the critical pressure, so that bonding can proceed from the central portion to the peripheral portion of the substrates W1 and W2 without being affected by the adhesion force to the stage 141 and the head 142, thereby enabling the substrates W1 and W2 to be bonded without distortion and with high positional accuracy over the entire surface.

[0093] In the first embodiment, the control unit 9 may calculate the horizontal offset vector without using captured images of the alignment marks captured by the imaging unit 73 of the inspection device 7. In this case, the control unit 9 calculates the positional deviation amount and positional deviation direction of each of the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, MK2c based on captured images obtained by capturing the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, MK2c by the imaging units 501A, 501B, 501C after the substrates W1, W2 are separated and the alignment of the substrates W1, W2 is completed, and on the basis of captured images obtained by capturing the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, MK2c of the substrates W1, W2 bonded to each other. Specifically, the control unit 9 calculates the positional deviation error from the captured image obtained by capturing the alignment marks MK1a, MK1b, MK1c, MK2a, MK2b, and MK2c after the substrates W1 and W2 are separated and the alignment of the substrates W1 and W2 is completed. Then, the control unit 9 calculates the positional deviation amount at the time of bonding the substrates W1 and W2 by subtracting the above-mentioned positional deviation error from the positional deviation amount calculated from the captured image obtained by capturing the alignment marks MK1a, MK1b, MK1c, MK2a, MK2b, and MK2c of the bonded substrates W1 and W2. Then, the control unit 9 may calculate the horizontal offset vector of the substrate W2 relative to the substrate W1 when bonding the substrates W1 and W2 based on the calculated positional deviation amount and positional deviation direction. Here, the horizontal offset amount is calculated for each set of alignment marks MK1a and MK2a (MK1b, MK2b, MK1c, MK2c).

[0094] In the second embodiment, an example has been described in which a plurality of pressing members 21511, 21512, 21513, and 21514 are arranged in the second region A2 of the stage 2141 along four virtual circles whose centers coincide with the center of the stage 2141, and a plurality of pressing members 21521, 21522, 21523, and 21524 are arranged in the second region A2 of the head 2142 along four virtual circles whose centers coincide with the center of the head 2142. However, this is not limited to the above, and for example, as shown in Fig. 28, a plurality of (four in Fig. 28) pressing members 61511, 61512, 61513, and 61514 arranged on the stage 6141 may be annular with different inner diameters, and a plurality of pressing members 61511, 61512, 61513, and 61514 arranged on the head 6142 may also be annular with different inner diameters. Here, the four pressing members 61511, 61512, 61513, and 61514 are concentrically arranged in the second region A2 of the stage 6141 so that their centers coincide with the center of the stage 6141. In addition, the four pressing members 61521, 61522, 61523, and 61524 are also concentrically arranged in the second region A2 of the head 6142 so that their centers coincide with the center of the head 6142.

[0095] In the second embodiment, an example has been described in which the piezoelectric actuators 21611, 21612, 21613, and 21614 drive the pressing members 21511, 21512, 21513, and 21514, respectively, and the piezoelectric actuators 21621, 21622, 21623, and 21624 drive the pressing members 21521, 21522, 21523, and 21524, respectively. However, the means for driving the pressing members 21511, 21512, 21513, 21514, 21521, 21522, 21523, and 21524 is not limited to this. For example, as in a stage 7141 shown in Fig. 29, pressing members 71511, 71512, 71513, and 71514 may respectively constitute pistons driven by air cylinders 71611, 71612, 71613, and 71614. Also, as in a head 7142 shown in Fig. 29, pressing members 71521, 71522, 71523, and 71524 may respectively constitute pistons driven by air cylinders 71621, 71622, 71623, and 71624. Here, the air cylinders 71611, 71612, 71613, and 71614 use air pressure to move the pressing members 21511, 21512, 21513, and 21514 individually in a direction toward the head 2142 or in a direction away from the head 2142. Furthermore, air cylinders 71621, 71622, 71623, and 71624 use air pressure to move the pressing members 21521, 21522, 21523, and 21524 individually in a direction approaching the stage 2141 or in a direction away from the head 2142.

[0096] In this case, the control unit 9 may control the air cylinders 71621, 71622, 71623, and 71624 so that the pressing members 21511, 21512, 21513, and 21514 press the substrate W1 so that the pressure at which the substrate W1 contacts the substrate W2 is less than the critical pressure at which the substrates W1 and W2 are temporarily bonded. In this case, the substrate bonding apparatus first presses the substrates W1 and W2 with the pressing members 21511, 21512, 21513, 21514, 21521, 21522, 21523, and 21524 so that the pressure at which the substrate W1 contacts the substrate W2 is less than the critical pressure at which the substrates W1 and W2 are temporarily bonded. Thereafter, the substrate bonding apparatus applies a voltage from the chuck driving unit 1491 to the electrostatic chucks 1411, 1412 of the stage 141 and the head 142, thereby causing the electrostatic chucks 1411, 1412 to hold the peripheral portions of the substrates W1, W2, while pressing the central portions of the substrates W1, W2 with the pressing units 1441a, 1432a.

[0097] In the first embodiment, an example has been described in which the position measurement unit 500 has three imaging units 501A, 501B, and 501C, but the number of imaging units is not limited to 3. For example, as in the case of a position measurement unit 8500 shown in Fig. 30, the position measurement unit 500 may have four imaging units 501A, 501B, 501C, and 501D, and a reflecting member 6502 on which four reflecting surfaces 6502a, 6502b, 6502c, and 6502d corresponding to the four imaging units 501A, 501B, 501C, and 501D, respectively, are formed. Here, the four imaging units 501A, 501B, 501C, and 501D are arranged around the reflecting member 6502 so that the acute angles DAB, DBC, DCD, and DDA formed by two adjacent optical axes JLA, JLB (JLB, ​​JLC, JLC, JLD, and JLD, JLA) in the circumferential direction of the reflecting member 6502 are equal.

[0098] In each embodiment, for example, a water gas supply unit (not shown) may be provided to supply water gas into the chamber 851 of the load lock unit 85 or into the chamber 863 of the transport device 86. The water gas supply unit generates and supplies water gas by mixing a carrier gas such as argon (Ar), nitrogen (N2), helium (He), or oxygen (O2) with vaporized water. The water gas supply unit is connected to the chamber 851 of the load lock unit 85 via a supply valve and a supply pipe. The flow rate of the water gas and carrier gas introduced into the chamber 851 is adjusted by controlling the opening of the supply valve. The water gas supply unit may be configured to accelerate water (H2O) molecules, clusters, etc., and irradiate them toward the bonding surfaces of the substrates W1 and W2. Here, the water gas supply unit may be configured as a particle beam source that emits accelerated water (H2O) particles. In this case, the particle beam source may be configured to generate water gas using, for example, an ultrasonic generating element. Alternatively, a mixed gas of carrier gas and water (H2O) generated by the above-mentioned bubbling or ultrasonic vibration may be introduced into the above-mentioned particle beam source to generate a water particle beam and irradiate the bonding surfaces of the substrates W1 and W2. In addition, in the process of step S104 in FIG. 12, for example, after the substrates W1 and W2 are transferred into the chamber 851 of the load lock unit 85, the substrate bonding system exposes the bonding surfaces of the substrates W1 and W2 to water gas without opening the chamber 851 to the atmosphere. Then, the substrate bonding system opens the chamber 851 to the atmosphere by opening the gate 8531 of the chamber 851 on the transfer device 82 side. In addition, instead of the water gas supply unit, a gas supply unit (not shown) that supplies a gas containing H or OH groups into the chamber 851 of the load lock unit 85 or the chamber 863 of the transfer device 86 may be provided.

[0099] In each embodiment, the substrate bonding system may include an activation processing device 10002 having a particle beam source for irradiating a particle beam onto the substrates W1 and W2 to activate the bonding surfaces of the substrates W1 and W2, as shown in FIG. 31. The activation processing device 10002 includes a chamber 10212, a stage 10210 for holding the substrates W1 and W2, a particle beam source 10061, and a beam source transport unit 10063. In FIG. 31, the same components as those in each embodiment are denoted by the same reference numerals as those in FIG. 2. The activation processing device 10002 also includes a plasma chamber 10213, an induction coil 215, and a high-frequency power supply 216. The activation processing device 10002 also includes a stage drive unit 10623 for rotating the stage 10210 around an axis perpendicular to the thickness direction, as shown by an arrow AR1003 in FIG. 31. Furthermore, the stage 10210 has, for example, a vacuum chuck, and when the substrates W1 and W2 are loaded, it adsorbs and holds the substrates W1 and W2.

[0100] The particle beam source 10061 is, for example, a fast atom beam (FAB) source, and includes a discharge chamber 10612, an electrode 10611 disposed in the discharge chamber 10612, a beam source driver 10613, and a gas supply unit 10614 that supplies nitrogen gas into the discharge chamber 10612. A FAB emission port 10612a that emits neutral atoms is provided on the peripheral wall of the discharge chamber 10612. The discharge chamber 10612 is formed of a carbon material. Here, the discharge chamber 10612 is in the shape of a long box, and a plurality of FAB emission ports 10612a are arranged in a straight line along the longitudinal direction of the discharge chamber 10612. The beam source driving unit 10613 has a plasma generating unit (not shown) that generates plasma of nitrogen gas in the discharge chamber 10612, and a DC power supply (not shown) that applies a DC voltage between the electrode 10611 and the peripheral wall of the discharge chamber 10612. The beam source driving unit 10613 applies a DC voltage between the peripheral wall of the discharge chamber 10612 and the electrode 10611 while the plasma of nitrogen gas is generated in the discharge chamber 10612. At this time, nitrogen ions in the plasma are attracted to the peripheral wall of the discharge chamber 10612. At this time, the nitrogen ions moving toward the FAB emission port 10612a receive electrons from the peripheral wall of the discharge chamber 10612 made of a carbon material at the outer periphery of the FAB emission port 10612a when passing through the FAB emission port 10612a. Then, these nitrogen ions become electrically neutralized nitrogen atoms and are emitted outside the discharge chamber 10612. However, some of the nitrogen ions cannot receive electrons from the peripheral wall of the discharge chamber 10612, and are emitted as nitrogen ions to the outside of the discharge chamber 10612. Also, a part or all of the inside of the FAB housing may be made of Si. In this way, Si particles are emitted at the same time as the Ar beam, so that Si is implanted into the interface, and OH groups are attached to the implanted Si, so that more OH groups can be generated, and the bonding strength can be increased.

[0101] The beam source transport unit 10063 has a long support rod 10631 that is inserted into a hole 10212a provided in the chamber 10212 and supports the particle beam source 10061 at one end, a support 10632 that supports the support rod 10631 at the other end of the support rod 10631, and a support drive unit 10633 that drives the support 10632. The beam source transport unit 10063 also has a bellows 10634 that is interposed between the outer periphery of the hole 10212a of the chamber 10212 and the support 10632 to maintain the degree of vacuum in the chamber 10212. The support driver 10633 drives the support 10632 in a direction in which the support rod 10631 is inserted into and removed from the chamber 10212, as shown by an arrow AR1001 in Fig. 31, thereby changing the position of the particle beam source 10061 in the chamber 10212, as shown by an arrow AR1002 in Fig. 31. Here, the beam source transporter 10063 moves the particle beam source 10061 in a direction perpendicular to the arrangement direction of the multiple FAB emission ports 10612a.

[0102] The activation processing device 10002 also has a nitrogen gas supply unit 220A that supplies nitrogen gas into the chamber 10212 via a supply pipe 223A. When a high-frequency current is supplied to the induction coil 215 with N2 gas introduced into the plasma chamber 10213, a plasma PLM2 is formed in the plasma chamber 10213. At this time, only radicals contained in the plasma PLM2 generated in the plasma chamber 10213 flow downward in the plasma chamber 10213. When irradiating the particle beam, the pressure in the chamber 10212 is adjusted to 100% by using, for example, a turbo molecular pump. -3 The chamber 10212 is evacuated to a vacuum of the order of Pa, but during radical processing, the pressure inside the chamber 10212 is increased to approximately several tens of Pa.

[0103] In the activation processing device 10002, first, the particle beam source 10061 is moved in the X-axis direction while irradiating the bonding surface of the substrates W1 and W2 with a particle beam. In this case, the activation processing device 10002 irradiates the bonding surface of the substrates W1 and W2 with a particle beam while moving the particle beam source 10061 in the +X direction, for example, and then irradiates the bonding surface of the substrates W1 and W2 with a particle beam while moving the particle beam source 10061 in the -X direction. In addition, the moving speed of the particle beam source 10061 is set to, for example, 1.2 to 14.0 mm / sec. In addition, the power supplied to the particle beam source 10061 is set to, for example, 1 kV and 100 mA. In addition, the flow rate of the nitrogen gas or oxygen gas introduced into the discharge chamber 10612 of the particle beam source 10061 is set to, for example, 100 sccm. Then, the activation processing device 10002 inverts the stage 10210 so that the bonding surfaces of the substrates W1 and W2 face vertically upward. Then, the activation processing device 10002 irradiates the bonding surfaces of the substrates W1 and W2 with nitrogen radicals generated in the plasma chamber 10213.

[0104] In each embodiment, the imaging units 501A, 501B, and 501C are described as being of a so-called reflective type having an imaging element and a coaxial illumination system, but the configuration of the imaging unit is not limited to this. For example, the imaging units may be of a so-called transmissive type, which includes an imaging element (not shown) and a light source (not shown) that are arranged at positions facing each other across the substrates W1 and W2 in the thickness direction of the substrates W1 and W2, and captures the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, and MK2c in an arrangement in which the imaging element receives light that is emitted from the light source and transmitted through the substrates W1 and W2.

[0105] In each embodiment, an example has been described in which the substrate bonding apparatus 1 captures the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, and MK2c, three of which are provided on each of the substrates W1 and W2, using the three imaging units 501A, 501B, and 501C. However, the number of imaging units is not limited to three, and the substrate bonding apparatus may, for example, be provided with two imaging units, and the two imaging units may capture the alignment marks, two of which are provided on each of the substrates W1 and W2. In this case, the substrate bonding apparatus may be provided with an imaging unit position adjustment unit that moves each of the two imaging units in the vertical direction and in the horizontal direction perpendicular to the optical axis direction and the vertical direction of each of the two imaging units. In this case, the substrate bonding apparatus receives the substrates W1 and W2 after rotating the stage 141 so that the two alignment marks are positioned between the multiple electrodes 1411b, 1412b, 1421b, and 1422b of the electrostatic chucks 1411, 1412, 1421, and 1422. The substrate bonding apparatus then moves the two imaging units to positions where the alignment marks of the substrates W1 and W2 can be imaged, and then causes the two imaging units to image the alignment marks. The substrate bonding apparatus may also include one imaging unit and an imaging unit position adjustment unit that moves the one imaging unit in the horizontal direction. In addition, when the imaging unit has a so-called transmission type configuration as described above, the substrate bonding apparatus may also include a light source position adjustment unit (not shown) that moves the light source according to the positions of the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, and MK2c.

[0106] In the first embodiment, the gas supply unit 1492 may supply a gas containing ions, and the gas discharge holes 1411c, 1412c, 1421c, 1422c, 1431c, and 1432c may discharge the gas containing ions. In this case, the residual electrostatic force of the electrostatic chucks 1411, 1421, 1412, and 1422 is neutralized by the ions contained in the gas, which has the advantage that the substrates W1 and W2 are easily peeled off from the stage 141 and the head 142.

[0107] In each embodiment, the substrate bonding apparatus 1 may determine whether or not at least one of the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, and MK2c overlaps with any of the electrostatic chucks 1411, 1412, 1421, and 1422. Here, the substrate bonding process performed by the substrate bonding system according to this modification will be described in detail with reference to FIG. 32. In FIG. 32, the same processes as those in the first embodiment are denoted by the same reference numerals as those in FIG. 14. First, the substrate bonding apparatus 1 performs a distance measurement process in which the distance measurement unit 1493 measures the distance between the stage 141 and the head 142 at three locations on the stage 141 and the head 142 (step S1). Next, the substrate bonding apparatus 1 calculates the distance between the bonding surface of the substrate W1 and the bonding surface of the substrate W2 based on the measured distance between the stage 141 and the head 142 at three locations on the stage 141 and the head 142 and the thicknesses of the substrates W1 and W2. Then, based on the calculated distance, the substrate bonding apparatus 1 moves the head 142 vertically downward to bring the substrates W1 and W2 closer to each other (step S2). Next, the substrate bonding apparatus 1 acquires captured images of the two substrates W1 and W2 from the imaging units 501A, 501B, and 501C of the position measurement unit 500. Based on the acquired captured images, the substrate bonding apparatus 1 determines whether or not at least one of the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, and MK2c used to calculate the amount of misalignment overlaps with any of the electrostatic chucks 1411, 1412, 1421, and 1422 (step S11001). Here, if the substrate bonding apparatus 1 determines that none of the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, and MK2c used to calculate the amount of misalignment overlaps with the electrostatic chucks 1411, 1412, 1421, and 1422 (step S11001: No), the processing from step S3 onward is executed. On the other hand, it is assumed that the substrate bonding apparatus 1 determines that at least one of the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, and MK2c used to calculate the amount of misalignment overlaps with the electrostatic chucks 1411, 1412, 1421, and 1422 (step S11001: Yes).In this case, the transport device 84 removes the substrates W1 and W2 from the substrate bonding apparatus 1 (step S11002). Next, the substrate bonding apparatus 1 rotates the stage 141 and the head 142 by a preset angle (step S11003). After that, the transport device 84 transports the substrates W1 and W2 back to the substrate bonding apparatus 1 (step S11004). Then, the process of step S1 is executed again.

[0108] According to this configuration, even if the conveying device 84 is not equipped with a conveying device imaging unit 844, the substrates W1 and W2 can be joined in a state in which all of the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, and MK2c used to calculate the amount of positional deviation do not overlap with the electrostatic chucks 1411, 1412, 1421, and 1422.

[0109] In each embodiment, the control unit 9 calculates the horizontal offset vector so that the positional deviation amount of each set of alignment marks captured by the imaging unit 73 of the inspection device 7 is minimized. However, the present invention is not limited to this. In the case where at least one of the substrates W1 and W2 has a plurality of chip formation regions that are the bases of chips, the control unit 9 may calculate the horizontal offset vector so that the ratio of chip formation regions that become defective due to the relative positional deviation of the substrates W1 and W2 among the plurality of chip formation regions is minimized. In addition, in the case where at least one of the substrates W1 and W2 has a plurality of chip formation regions that are the bases of chips, the control unit 9 may calculate the positional deviation amount and positional deviation direction of each chip formation region other than the chip formation region that becomes defective due to the positional deviation of the substrate W2 relative to the substrate W1 among the plurality of chip formation regions, separate the axial components along the two mutually intersecting axial directions of the positional deviation vector determined by the calculated positional deviation amount and positional deviation direction, i.e., the XY direction component and the rotation direction component, and calculate the above-mentioned horizontal offset vector based on the separated XY direction component and the rotation direction component.

[0110] In each embodiment, an example has been described in which both the stage 141 and the head 142 have the pressing mechanisms 1441 and 1432, respectively, but this is not limiting, and only either the stage 141 or the head 142 may have a pressing mechanism. Here, the electrostatic chuck 1413 provided on the stage 141 can be set to have a low holding force because the weight of the substrate W1 acts in a direction in which the substrate W1 adheres to the stage 141. For this reason, when the pressing mechanism 1441 is provided only on the stage 141, it is preferable because the substrate W1 can be prevented from sticking to the stage 141 due to the residual electrostatic force of the electrostatic chuck 1431 when the center of the substrate W1 is pressed.

[0111] In each embodiment and each of the above-mentioned modified examples, the substrate bonding system has been described as performing so-called hydrophilic bonding of the substrates W1 and W2, but is not limited thereto. For example, the substrate bonding system may be a system that performs so-called room temperature bonding, in which the bonding surfaces of the substrates W1 and W2 are brought into contact with each other and bonded via dangling bonds present on the bonding surfaces immediately after the bonding surfaces of the substrates W1 and W2 are activated by a particle beam in so-called ultra-high vacuum. Even in this case, in the substrate bonding device, bonding can proceed from the center to the periphery of the substrates W1 and W2 while the substrates W1 and W2 are free from the adhesion force to the stage and head. Therefore, the substrates W1 and W2 can be bonded with high positional accuracy over the entire surface without distortion. In addition, the substrate bonding system may be a system that performs so-called heat and pressure bonding, in which the substrates W1 and W2 are bonded via a solder portion or a metal portion, or a system that performs so-called anodic bonding, in which the substrates W1 and W2 are bonded by applying a voltage between the substrates W1 and W2.

[0112] In the embodiment, when the distribution of the positional deviation vector as shown in Fig. 18(A) is obtained, the positional deviation vector is separated into XY direction components, rotation direction components, warpage components and distortion components as shown in Fig. 18(B) to (E), respectively, and the horizontal offset amount of the substrate W2 with respect to the substrate W1 is calculated only from the XY direction components and rotation direction components obtained by separation. Here, the calculated horizontal offset amount may be directly taken into account when calculating the alignment of the substrate W2 with respect to the substrate W1 to calculate the correction movement amount.

[0113] In the first embodiment, an example has been described in which the inspection device 7 captures images of all of a plurality of alignment marks including the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, and MK2c. However, this is not limiting, and the inspection device 7 may capture images of all of the alignment marks other than the alignment marks MK1a, MK2a, MK1b, MK2b, MK1c, and MK2c used for alignment in the substrate bonding apparatus 1.

[0114] In embodiment 1, the bonding apparatus 1 may perform alignment of the substrate W2 with respect to the substrate W1 using representative positions of the alignment marks MK2a, MK2b, and MK2c shifted by an amount reflecting the direction and magnitude indicated by the previously calculated horizontal offset vector.

[0115] The present invention allows various embodiments and modifications without departing from the broad spirit and scope of the present invention. The above-described embodiments are for the purpose of explaining the present invention and do not limit the scope of the present invention. That is, the scope of the present invention is indicated by the claims, not the embodiments. Various modifications made within the scope of the claims and within the scope of the meaning of the invention equivalent thereto are considered to be within the scope of the present invention. [Industrial Applicability]

[0116] The present invention is suitable for the manufacture of, for example, CMOS image sensors, memories, computing elements, and MEMS. [Explanation of symbols]

[0117] 1: substrate bonding device, 2, 10002: activation processing device, 3: cleaning device, 7: inspection device, 9: control unit, 71, 141, 210, 2141, 3141, 3210, 4141, 5141, 6141, 7141, 10210: stage, 72: light source, 73, 501A, 501B, 501C, 501D: imaging unit, 74: horizontal direction drive unit, 82, 84, 86: conveying device, 83, 85: load lock unit, 120, 831, 843, 851, 863, 10212: chamber, 120a: window unit, 121a, 201a: vacuum pump, 121b, 201b: exhaust pipe, 121c, 20 1c: exhaust valve, 141b, 142b: through hole, 142, 2142, 3142, 4142, 5142, 6142, 7142: head, 143, 10623: stage drive unit, 144: head drive unit, 145: XY direction drive unit, 146: lift drive unit, 147: rotation drive unit, 148, 1457: pressure sensor, 212: processing chamber, 213, 10213: plasma chamber, 215: induction coil, 216: high frequency power supply, 217: bias application unit, 220A: nitrogen gas supply unit, 220B: oxygen gas supply unit, 221A: nitrogen gas storage unit, 221B: oxygen gas storage unit, 2 22A, 222B: supply valve, 223A, 223B: supply pipe, 500, 8500: position measurement unit, 502, 8502: reflection member, 502a, 502b, 502c, 8502a, 8502b, 8502c, 8502d: reflection surface, 503A, 503B, 503C: imaging unit position adjustment unit, 511A, 511B, 511C, 731: imaging element, 811, 812: introduction port, 813: removal port, 821, 841, 861: transport robot, 844: transport device imaging unit, 1211, 8321, 8331, 8521, 8531, 8621: gate, 1411, 1412, 14 13,1421,1422,1423,3413,3423,4413,4423,5413,5423: electrostatic chuck, 1411a,1412a,1413a,1421a,1422a,1423a,3413a,3423a,5413a,5423a: terminal electrode, 1411aa,1421aa: connecting portion, 1411ab,1421ab: bending portion, 1411b,1412b,1413b,1421b, 1422b,1423b,3413b,3423b,4413b,4423b,5413b,5423b: electrode, 1411c,1421c,3413c,3423c, 4413c, 4423c, 5413c, 5423c: gas discharge holes, 1411d, 1413d, 1423d, 3413d, 3423d, 4413d, 4423d, 5413d, 5423d: grooves, 1441, 1442: pressing mechanisms, 1441a, 1442a: pressing parts, 1441b, 1442b: pressing part drive parts, 1456, 21611, 21612, 21613, 21614, 21621, 21622, 21623, 21624: piezo actuators, 1481, 1482: substrate heating unit, 1491: chuck driving unit, 1492: gas supply unit, 1493: distance measurement unit, 10212a: hole, 10061: particle beam source, 10063: beam source transport unit, 10611: electrode, 10612: discharge chamber, 10612a: FAB radiation port, 10613: beam source driving unit, 10614: gas supply unit, 10631: support rod, 10632: support, 10633: support driving unit, 10634: bellows, 21511, 21512, 2151 3,21514,21521,21522,21523,21524,61511,61512,61513,61514,61521,61522,61523,61524,71511,71512,71513,71514,71521,71522,71523,71524: Pressing member, 34131d,34132d,34231d,34232d: Sub-groove, 71611,71612,71613,71614,71621,71622,71623 ,71624: Air cylinder, A1: First area, A2: Second area, A11, A12: Sub-annular area, GAa, GAb, GAc: Captured image, JLA, JLB, JLC: Optical axis, MK1a, MK1b, MK1c, MK2a, MK2b, MK2c: Alignment mark, P11, P12, P13, P21, P22, P23: Part, PLM, PLM2: Plasma, VC1, VC2, VC3: Virtual circle, W1, W2: Substrate, W1c, W2c: Center, W1s, W2s: Periphery,

Claims

1. A substrate bonding system for bonding a first substrate provided with a plurality of first alignment marks and a second substrate provided with a plurality of second alignment marks, comprising: a bonding device including a first substrate holding section that holds the first substrate, a second substrate holding section that holds the second substrate with the bonding surface of the second substrate facing the bonding surface of the first substrate, a first imaging section, and a holder driving section that moves at least one of the first substrate holding section and the second substrate holding section relatively to the other in a direction intersecting a direction in which the first substrate holding section and the second substrate holding section face each other; An inspection device having a second imaging unit; A control unit, the first substrate is provided with at least one third alignment mark different from the plurality of first alignment marks; the second substrate is provided with at least one fourth alignment mark different from the plurality of second alignment marks, the number of which is equal to the number of the at least one third alignment mark; the second imaging unit images all of the plurality of first alignment marks, the plurality of second alignment marks, the at least one third alignment mark, and the at least one fourth alignment mark of each of the first substrate and the second substrate bonded to each other; the control unit calculates a positional misalignment amount and a positional misalignment direction of each of the multiple first alignment marks and the multiple second alignment marks, and a positional misalignment amount and a positional misalignment direction of each of the at least one third alignment mark and the at least one fourth alignment mark, based on an image obtained by imaging the multiple first alignment marks, the multiple second alignment marks, the at least one third alignment mark, and the at least one fourth alignment mark with the second imaging unit, separates an axial component and a rotational component along each of two intersecting axial directions of a positional misalignment vector determined by the calculated positional misalignment amount and positional misalignment direction, and calculates a horizontal offset amount reflecting an axial offset amount which is an offset amount in the two axial directions of the second substrate relative to the first substrate when bonding the first substrate and the second substrate together, and a rotational offset amount which is an offset amount in the rotational direction of the second substrate relative to the first substrate, based on the separated axial component and rotational component. Substrate bonding system.

2. the control unit calculates the horizontal offset amount based on statistics of the positional deviation amounts and the positional deviation directions calculated for a preset number of the first substrate and the second substrate joined to each other. The substrate bonding system of claim 1 .

3. the control unit calculates the horizontal offset amount for each pair of a plurality of first alignment marks and a plurality of second alignment marks captured by the first imaging unit; The substrate bonding system according to claim 1 or 2.

4. the control unit calculates the horizontal offset amount so that a positional deviation amount of each pair of a plurality of first alignment marks and a plurality of second alignment marks imaged by the first imaging unit is minimized. The substrate bonding system of claim 3 .

5. At least one of the first substrate and the second substrate has a plurality of chip formation regions that become bases of chips; the control unit calculates the horizontal offset amount so as to minimize a ratio of chip formation areas that become defective due to a positional misalignment of the second substrate with respect to the first substrate among the plurality of chip formation areas. The substrate bonding system of claim 3 .

6. the control unit calculates the misalignment amount and the misalignment direction in each of the plurality of chip formation areas other than a chip formation area that becomes defective due to misalignment of the second substrate relative to the first substrate, separates an axial component and a rotational component along each of two intersecting axial directions of the misalignment vector determined by the calculated misalignment amount and the misalignment direction, and calculates the horizontal offset amount based on the separated axial component and the rotational component. The substrate bonding system of claim 5 .

7. the control unit controls the holding unit drive unit to move at least one of the first substrate holding unit and the second substrate holding unit so that a positional deviation amount between the plurality of first alignment marks and second alignment marks corresponding to each of the plurality of first alignment marks is offset by the horizontal offset amount. The substrate bonding system according to claim 1 or 2.

8. the first imaging unit is disposed on a side of the first substrate holding unit opposite to a side on which the first substrate is supported, the control unit calculates a positional deviation error, which is an error in the positional deviation of each of the plurality of first alignment marks and the plurality of second alignment marks, based on an image obtained by imaging the plurality of first alignment marks and the plurality of second alignment marks by the first imaging unit after the first substrate and the second substrate are separated from each other and alignment between the first substrate and the second substrate is completed, and updates the horizontal offset amount for each pair of the first alignment mark and the second alignment mark using the calculated positional deviation error. The substrate bonding system according to claim 1 or 2.

9. the first imaging unit is disposed on a side of the first substrate holding unit opposite to a side on which the first substrate is supported, the control unit calculates a positional deviation amount and a positional deviation direction of each of the plurality of first alignment marks and the plurality of second alignment marks based on an image obtained by imaging the plurality of first alignment marks and the plurality of second alignment marks with the first substrate and the second substrate separated from each other by the first imaging unit and an image obtained by imaging the plurality of first alignment marks and the plurality of second alignment marks of the first substrate and the second substrate bonded to each other by the first imaging unit, and calculates the horizontal offset amount based on the calculated positional deviation amount and positional deviation direction. The substrate bonding system according to claim 1 or 2.

10. the control unit calculates a positional deviation amount and a positional deviation direction of each of the at least one third alignment mark and the at least one fourth alignment mark based on an image obtained by imaging the at least one third alignment mark and the at least one fourth alignment mark, separates an axial component and a rotational component along each of two intersecting axial directions of a positional deviation vector determined by the calculated positional deviation amount and positional deviation direction, and calculates the horizontal offset amount corresponding to the pair of the first alignment mark and the second alignment mark imaged by the first imaging unit based on the separated axial component and rotational component. The substrate bonding system according to claim 1 or 2.

11. The control unit calculates a horizontal offset vector reflecting the horizontal offset amount. The substrate bonding system according to claim 1 or 2.

12. A substrate bonding system for bonding a first substrate provided with a plurality of first alignment marks and a second substrate provided with a plurality of second alignment marks, comprising: a bonding device including a first substrate holding section that holds the first substrate, a second substrate holding section that holds the second substrate with the bonding surface of the second substrate facing the bonding surface of the first substrate, a first imaging section, and a holder driving section that moves at least one of the first substrate holding section and the second substrate holding section relatively to the other in a direction intersecting a direction in which the first substrate holding section and the second substrate holding section face each other; A control unit, the control unit separates an axial component and a rotational component along each of two intersecting axial directions of a positional deviation vector determined by the calculated positional deviation amounts and positional deviation directions of each of the plurality of first alignment marks and the plurality of second alignment marks, and performs alignment of the second substrate with respect to the first substrate using representative positions of the plurality of second alignment marks shifted by a horizontal offset vector reflecting an axial offset amount, which is an offset amount in the two axial directions of the second substrate with respect to the first substrate when bonding the first substrate and the second substrate, and a rotational offset amount, which is an offset amount in the rotational direction of the second substrate with respect to the first substrate, based on the separated axial component and rotational component. Substrate bonding system.

13. A substrate bonding system for bonding a first substrate provided with a plurality of first alignment marks and a second substrate provided with a plurality of second alignment marks, comprising: a bonding device including a first substrate holding section that holds the first substrate, a second substrate holding section that holds the second substrate with the bonding surface of the second substrate facing the bonding surface of the first substrate, a first imaging section, and a holder driving section that moves at least one of the first substrate holding section and the second substrate holding section relatively to the other in a direction intersecting a direction in which the first substrate holding section and the second substrate holding section face each other; An inspection device having a second imaging unit; A control unit, the first substrate is provided with at least one third alignment mark different from the plurality of first alignment marks; the second substrate is provided with at least one fourth alignment mark different from the plurality of second alignment marks, the number of which is equal to the number of the at least one third alignment mark; the second imaging unit images all of the plurality of first alignment marks, the plurality of second alignment marks, the at least one third alignment mark, and the at least one fourth alignment mark of each of the first substrate and the second substrate bonded to each other; the control unit calculates a positional shift amount and a positional shift direction of each of the multiple first alignment marks and the multiple second alignment marks and a positional shift amount and a positional shift direction of each of the at least one third alignment mark and the at least one fourth alignment mark based on an image obtained by imaging the multiple first alignment marks, the multiple second alignment marks, the at least one third alignment mark, and the at least one fourth alignment mark with the second imaging unit, separates a warp component of a positional shift vector determined by the calculated positional shift amount and positional shift direction, and calculates a protrusion offset amount, which is an offset amount of a protrusion amount of a central portion of the first substrate toward the second substrate side with respect to a peripheral portion of the first substrate when the first substrate and the second substrate are bonded together, based on the separated warp component; Substrate bonding system.

14. the control unit calculates the protrusion offset amount so that the warpage amounts of the first substrate and the second substrate bonded to each other become zero. The substrate bonding system of claim 13.

15. the control unit calculates the protrusion offset amount based on statistics of the misalignment amounts and the misalignment directions calculated for a preset number of the first substrate and the second substrate joined to each other.

15. A substrate bonding system according to claim 13 or 14.

16. A substrate bonding method for bonding a first substrate and a second substrate, comprising the steps of: the first substrate is provided with three or more first alignment marks; the second substrate is provided with three or more second alignment marks, the number of which is equal to the three or more first alignment marks; a step of imaging, by a first imaging unit, the three or more first alignment marks, the three or more second alignment marks, at least one third alignment mark different from the three or more first alignment marks, and at least one fourth alignment mark different from the three or more second alignment marks, the number of which is the same as that of the at least one third alignment mark, on each of the first substrate and the second substrate bonded to each other; calculating a positional deviation amount and a positional deviation direction of each of the three or more first alignment marks and the three or more second alignment marks and a positional deviation amount and a positional deviation direction of each of the at least one third alignment mark and the at least one fourth alignment mark based on an image obtained by imaging the three or more first alignment marks, the three or more second alignment marks, the at least one third alignment mark, and the at least one fourth alignment mark by a second imaging unit different from the first imaging unit, separating an axial component and a rotational component along each of two intersecting axial directions of a positional deviation vector determined by the calculated positional deviation amount and positional deviation direction, and calculating a horizontal offset amount reflecting an axial offset amount which is an offset amount in the two axial directions of the second substrate relative to the first substrate when bonding the first substrate and the second substrate together and a rotational offset amount which is an offset amount in the rotational direction of the second substrate based on the separated axial component and rotational component; moving at least one of the first substrate and the second substrate so that a positional deviation amount between the three or more first alignment marks and second alignment marks corresponding to each of the three or more first alignment marks is offset by the horizontal offset amount; Board bonding method.

17. In the step of calculating the horizontal offset amount, the horizontal offset amount is calculated based on statistics of the positional deviation amounts and the positional deviation directions calculated for a preset number of the first substrate and the second substrate bonded to each other. The method of claim 16.

18. In the step of calculating the horizontal offset amount, the horizontal offset amount is calculated for each pair of a plurality of first alignment marks and a plurality of second alignment marks imaged by the first imaging unit.

18. The method for bonding substrates according to claim 16 or 17.

19. In the step of calculating the horizontal offset amount, the horizontal offset amount is calculated so that a positional deviation amount of each pair of a plurality of first alignment marks and a plurality of second alignment marks imaged by the first imaging unit is minimized.

20. The method of claim 18.

20. At least one of the first substrate and the second substrate has a plurality of chip formation regions that become bases of chips; and calculating the horizontal offset amount so as to minimize a ratio of chip formation areas that become defective due to a positional misalignment of the second substrate with respect to the first substrate among the plurality of chip formation areas in the step of calculating the horizontal offset amount.

20. The method of claim 18.

21. calculating the misalignment amount and the misalignment direction in each of the plurality of chip formation areas other than a chip formation area that becomes defective due to misalignment of the second substrate relative to the first substrate, separating an axial component and a rotational component along each of two intersecting axial directions of the misalignment vector determined by the calculated misalignment amount and the misalignment direction, and calculating the horizontal offset amount based on the separated axial component and the rotational component; 21. The method of claim 20.

22. and moving at least one of the first substrate and the second substrate so that the three or more first alignment marks and three or more second alignment marks corresponding to the three or more first alignment marks are offset by the horizontal offset amount.

18. The method for bonding substrates according to claim 16 or 17.

23. in the step of calculating the horizontal offset amount, a positional deviation error, which is an error in the positional deviation amount of each of the three or more first alignment marks and the three or more second alignment marks, is calculated based on an image obtained by imaging the three or more first alignment marks and the three or more second alignment marks by a first imaging unit arranged on the opposite side to the side on which the first substrate is supported in a first substrate holding unit that holds the first substrate, after the first substrate and the second substrate are separated from each other and alignment between the first substrate and the second substrate is completed, and the horizontal offset amount for each pair of the first alignment mark and the second alignment mark is updated using the calculated positional deviation error.

18. The method for bonding substrates according to claim 16 or 17.

24. and in the step of calculating the horizontal offset amount, a positional deviation amount and a positional deviation direction of each of the three or more first alignment marks and the three or more second alignment marks are calculated based on an image obtained by imaging the three or more first alignment marks and the three or more second alignment marks in a state in which the first substrate and the second substrate are separated from each other by a first imaging unit arranged on the opposite side to the side on which the first substrate is supported in a first substrate holding unit that holds the first substrate, and an image obtained by imaging the three or more first alignment marks and the three or more second alignment marks of the first substrate and the second substrate that are joined to each other by the first imaging unit, and the horizontal offset amount is calculated based on the calculated positional deviation amount and positional deviation direction.

18. The method for bonding substrates according to claim 16 or 17.

25. In the step of calculating the horizontal offset amount, a horizontal offset vector reflecting the horizontal offset amount is calculated.

18. The method for bonding substrates according to claim 16 or 17.

26. A substrate bonding method for bonding a first substrate and a second substrate, comprising the steps of: the first substrate is provided with three or more first alignment marks; the second substrate is provided with three or more second alignment marks, the number of which is equal to the three or more first alignment marks; capturing images of the three or more first alignment marks and the three or more second alignment marks of each of the first substrate and the second substrate bonded to each other by a first imaging unit; and separating axial components and rotational components along two intersecting axial directions of a misalignment vector determined by the misalignment amounts and misalignment directions of the three or more first alignment marks and the three or more second alignment marks, and performing alignment of the second substrate with respect to the first substrate using representative positions of the three or more second alignment marks shifted by a horizontal offset vector that reflects an axial offset amount that is an offset amount in the two axial directions of the second substrate with respect to the first substrate when bonding the first substrate and the second substrate based on the separated axial components and rotational components. Board bonding method.

27. A substrate bonding method for bonding a first substrate and a second substrate, comprising the steps of: the first substrate is provided with three or more first alignment marks; the second substrate is provided with three or more second alignment marks, the number of which is equal to the three or more first alignment marks; a step of capturing images of the three or more first alignment marks, the three or more second alignment marks, at least one third alignment mark different from the three or more first alignment marks, and at least one fourth alignment mark different from the three or more second alignment marks, the number of which is the same as that of the at least one third alignment mark, on each of the first substrate and the second substrate bonded to each other, by a first imaging unit; calculating a positional shift amount and a positional shift direction of each of the three or more first alignment marks and the three or more second alignment marks and a positional shift amount and a positional shift direction of each of the at least one third alignment mark and the at least one fourth alignment mark based on an image obtained by imaging the three or more first alignment marks, the three or more second alignment marks, the at least one third alignment mark, and the at least one fourth alignment mark with the first imaging unit, separating a warp component of a positional shift vector determined by the calculated positional shift amount and positional shift direction, and calculating a protrusion offset amount, which is an offset amount of a protrusion amount of a central portion of the first substrate toward the second substrate relative to a peripheral portion of the first substrate when the first substrate and the second substrate are bonded together, based on the separated warp component; and bringing a central portion of a bonding surface of the first substrate into contact with a central portion of a bonding surface of the second substrate in a state in which the central portion of the first substrate is protruded toward the second substrate by the protrusion offset amount relative to the peripheral portion of the first substrate. Board bonding method.

28. In the step of calculating the protrusion offset amount, the protrusion offset amount is calculated so that the warpage amounts of the first substrate and the second substrate bonded to each other become zero.

28. The method of claim 27.

29. In the step of calculating the protrusion offset amount, the protrusion offset amount is calculated based on statistics of the positional deviation amount and the positional deviation direction calculated for a preset number of the first substrate and the second substrate bonded to each other.

29. The method for bonding substrates according to claim 27 or 28.

Images