Substrate bonding device, substrate processing device, and substrate bonding method

Abstract

A substrate bonding device (1) comprises: a control unit (80) that controls a movement mechanism (62) that moves a stage (61); and a processing unit (81) that acquires the movement speed of a moving feature portion (MA2) on the basis of multiple images of the feature portion (MA2) captured by an imaging unit (72) at multiple different times, and acquires low-movement-speed coordinates of the feature portion (MA2) where the acquired movement speed of the feature portion (MA2) is lower than a predetermined threshold value. The control unit (80) is configured to cause the movement mechanism (62) to move the stage (61) and execute processing for aligning a pair of substrates (W) such that the low-movement-speed coordinates of the feature portion (MA2) match target coordinates.

Description

Substrate bonding apparatus, substrate processing apparatus, and substrate bonding method

[0001] The present invention relates to a substrate bonding apparatus, a substrate processing apparatus, and a substrate bonding method, and more particularly to a substrate bonding apparatus, a substrate processing apparatus, and a substrate bonding method that include an imaging unit that images a characteristic portion provided on at least one of a stage and a substrate.

[0002] A substrate bonding apparatus including an imaging unit that captures an image of an alignment mark (feature portion) provided on a substrate has been known. Such a substrate bonding apparatus is disclosed, for example, in Japanese Patent Application Laid-Open No. 2020-202398.

[0003] The substrate bonding device disclosed in JP 2020-202398 A includes an upper chuck that holds an upper substrate, a lower chuck that holds a lower substrate, an upper imaging unit (imaging unit), a lower imaging unit (imaging unit), and a movement mechanism that moves the lower chuck in a horizontal direction. In this substrate bonding device, the upper imaging unit captures an image of a lower alignment mark provided on the lower substrate, and the lower imaging unit captures an image of an upper alignment mark provided on the upper substrate. The movement mechanism then moves the lower chuck so that the captured lower alignment mark and the upper alignment mark overlap. This adjusts (aligns) the horizontal positions of the upper chuck (upper substrate) and the lower chuck (lower substrate).

[0004] Japanese Patent Application Laid-Open No. 2020-202398

[0005] In conventional substrate bonding apparatuses such as those described in JP 2020-202398 A, at least one of the upper and lower chucks may vibrate due to vibrations from devices surrounding the substrate bonding apparatus or vibrations from the substrate bonding apparatus itself. In this case, even if the horizontal positions of the upper and lower chucks are aligned (aligned) so that the captured lower alignment mark and the upper alignment mark overlap, as in JP 2020-202398 A, the post-adjustment positions cannot be determined due to vibrations from at least one of the upper and lower chucks. Even if the post-adjustment positions are not determined, bonding the upper and lower substrates (a pair of substrates) results in inadequate bonding. Therefore, it is desirable to suppress alignment errors caused by vibrations even when the chuck (stage) vibrates.

[0006] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide a substrate bonding apparatus, a substrate processing apparatus, and a substrate bonding method that are capable of suppressing alignment errors caused by vibrations.

[0007] In order to achieve the above object, a substrate bonding apparatus according to a first aspect of the present invention comprises a pair of stages each holding a pair of substrates to be bonded to each other, an imaging unit that images a characteristic portion provided on at least one of the stages or the substrates, a control unit that controls a movement mechanism that moves at least one of the pair of stages, and a processing unit that acquires the movement speed of the characteristic portion based on a plurality of images of the moving characteristic portion imaged by the imaging unit at a plurality of different times, and acquires a low-movement-speed coordinate of the characteristic portion at which the acquired movement speed of the characteristic portion is lower than a predetermined threshold, and the control unit is configured to perform an alignment process for the pair of substrates by moving at least one of the pair of stages using the movement mechanism so that the low-movement-speed coordinate of the characteristic portion matches a target coordinate.

[0008] In the substrate bonding apparatus according to the first aspect, the control unit is preferably configured to, after performing the alignment process, start the process of bonding the substrates at a first timing when the characteristic portion approaches the target coordinates by a distance smaller than a predetermined distance.

[0009] In this case, the processing unit is preferably configured to acquire a first timing at which the characteristic portion approaches the target coordinates by a distance smaller than a predetermined distance, based on images of the characteristic portion continuously captured by the imaging unit.

[0010] In the substrate bonding apparatus according to the first aspect, the processing unit is preferably configured to acquire a movement trajectory of the characteristic part based on a plurality of images of the characteristic part captured by the imaging unit, and to acquire coordinates of the characteristic part at a low movement speed based on the acquired movement trajectory of the characteristic part.

[0011] In this case, it is preferable to further include a movement trajectory noise cut filter that cuts noise from the data of the movement trajectory of the characteristic part, and the processing unit is configured to acquire the coordinates of the characteristic part at low movement speed based on the movement trajectory of the characteristic part in a state in which noise has been cut by the movement trajectory noise cut filter.

[0012] In the substrate bonding apparatus according to the first aspect, the processing unit is preferably configured to acquire the low-movement-speed coordinates of the acquired characteristic part at a minimum movement speed, and the control unit is configured to perform alignment processing so that the low-movement-speed coordinates of the characteristic part at a minimum movement speed coincide with the target coordinates.

[0013] In the substrate bonding apparatus according to the first aspect, the processing unit is preferably configured to acquire time series data of the movement speed of the characteristic portion based on the plurality of images, predict a second timing at which the movement speed of the characteristic portion will be slower than a predetermined threshold based on the acquired time series data, and predict the coordinates of the characteristic portion at the second timing as coordinates at the low movement speed, and the control unit is configured to start the process of bonding the substrates at the second timing.

[0014] In this case, the processing unit is preferably configured to perform a fitting process to obtain an approximation line that approximates the acquired time series data, predict the second timing based on the approximation line obtained by the fitting process, and predict the coordinates of the characteristic part at the second timing as coordinates at a low moving speed.

[0015] The substrate bonding apparatus for predicting the second timing preferably further includes a time series data noise cut filter for cutting noise in the time series data of the moving speed of the characteristic portion, and the processing unit is configured to perform a fitting process based on the time series data from which noise has been cut by the time series data noise cut filter, and predict the coordinate at the time of the low moving speed.

[0016] In the substrate bonding apparatus according to the first aspect, the characteristic portion preferably includes at least one of a reference mark provided on the stage, an alignment mark provided on the substrate, an edge of the substrate, and a notch or an orientation flat formed on the substrate.

[0017] In the substrate bonding apparatus according to the first aspect, preferably, the pair of stages includes an upper stage that holds one of the pair of substrates, an upper substrate, and a lower stage that holds the other of the pair of substrates, the imaging unit is attached to the upper stage and configured to capture an image of a characteristic portion provided on at least one of the lower stage and the lower substrate, and the control unit is configured to perform alignment processing by moving the lower stage relative to the upper stage using the movement mechanism so that the coordinates of the characteristic portion at a low movement speed coincide with target coordinates.

[0018] In the substrate bonding apparatus according to the first aspect, preferably, the pair of stages includes an upper stage that holds one of the pair of substrates, an upper substrate, and a lower stage that holds the other of the pair of substrates, the imaging unit is arranged so as not to move in synchronization with the upper stage and the lower stage, and is configured to image a characteristic portion provided on at least one of the upper stage and the upper substrate, and the control unit is configured to perform alignment processing by changing the target coordinates by moving the lower stage relative to the upper stage using the movement mechanism so that the coordinates of the characteristic portion at a low movement speed become new target coordinates.

[0019] A substrate processing apparatus according to a second aspect of the present invention includes a stage for holding an object to be processed, an imaging unit for imaging a characteristic part provided on at least one of the object to be processed or the stage, a control unit for controlling a moving mechanism for moving the stage, and a processing unit for acquiring the moving speed of the characteristic part based on a plurality of images of the moving characteristic part imaged by the imaging unit at a plurality of different times, and acquiring a low-moving-speed coordinate of the characteristic part at which the acquired moving speed of the characteristic part is lower than a predetermined threshold, and the control unit is configured to perform an alignment process in which the moving mechanism moves the stage so that the acquired low-moving-speed coordinate of the characteristic part matches a target coordinate.

[0020] A substrate bonding method according to a third aspect of the present invention is a substrate bonding method for bonding a pair of substrates held on a pair of stages, and includes the steps of: capturing images of a characteristic portion provided on at least one of the stage and the substrate at a plurality of different times; acquiring a movement speed of the characteristic portion based on a plurality of images of the characteristic portion captured at the plurality of different times; acquiring a low-movement-speed coordinate of the characteristic portion at which the acquired movement speed of the characteristic portion is lower than a predetermined threshold; and moving the stage to perform an alignment process for the pair of substrates so that the acquired low-movement-speed coordinate of the characteristic portion matches a target coordinate.

[0021] According to the present invention, the movement speed (movement amount per unit time) of the stage at the target coordinates that serve as the reference for alignment is relatively small, so that alignment errors caused by vibrations can be suppressed.

[0022] FIG. 1 is a schematic diagram showing the configuration of a substrate bonding apparatus according to a first embodiment of the present invention. FIG. 2 is a block diagram showing the configuration of the substrate bonding apparatus according to the first embodiment. FIG. 3 is a perspective view of a bonding unit according to the first embodiment. FIG. 4 is a side view of an upper stage of a bonding unit according to the first embodiment. FIG. 5 is a side view of an upper stage and a lower stage of a bonding unit according to the first embodiment. FIG. 6 is a top view of an upper stage and a first substrate of a bonding unit according to the first embodiment. FIG. 7 is a view showing an upper reference mark according to the first embodiment. FIG. 8 is a top view of a lower stage and a second substrate of a bonding unit according to the first embodiment. FIG. 9 is a view showing a lower reference mark according to the first embodiment. FIG. 10 is a view showing an upper alignment mark arranged on an upper substrate. FIG. 11 is a view showing a lower alignment mark arranged on a lower substrate. FIG. 12 is a flowchart showing a process flow of the substrate bonding apparatus according to the first embodiment. FIG. 13 is a view for explaining an alignment mark / reference mark detection step (a step of detecting a lower alignment mark and a lower reference mark) of the process flow of the substrate bonding apparatus according to the first embodiment. FIG. 14 is a view for explaining an alignment mark / reference mark detection step (a step of detecting an upper alignment mark and an upper reference mark) of the process flow of the substrate bonding apparatus according to the first embodiment. FIG. 10 is a diagram for explaining a first alignment step and a second alignment step in the process flow of the substrate bonding apparatus according to the first embodiment. FIG. 11 is a flowchart for explaining a second alignment step in the process flow of the substrate bonding apparatus according to the first embodiment. FIG. 12 is a diagram showing a state in which the lower reference mark is moving due to vibration of the upper stage. FIG. 13 is a diagram showing a state in which coordinates at a low moving speed (movement trajectory of the lower reference mark) and target coordinates match. FIG. 14 is a diagram showing the positional relationship between the lower reference mark and target coordinates when starting a process of bonding substrates. FIG. 15 is a block diagram showing the configuration of a substrate bonding apparatus according to a second embodiment. FIG. 16 is a side view of the upper stage and the lower stage of the bonding unit according to the second embodiment. FIG. 17 is a flowchart for explaining a second alignment step in the process flow of the substrate bonding apparatus according to the second embodiment. FIG. 18 is a diagram showing a state in which the upper reference mark is moving due to vibration of the upper stage. FIG. 19 is a diagram showing a state in which the target coordinates have been changed to match coordinates at a low moving speed (movement trajectory of the lower reference mark). FIG. 19 is a block diagram showing the configuration of a substrate bonding apparatus according to a third embodiment.Fig. 10 is a flowchart showing a process flow of the substrate bonding apparatus according to the third embodiment; Fig. 11 is a flowchart for explaining a second alignment step of the process flow of the substrate bonding apparatus according to the third embodiment; Fig. 12 is a diagram showing time-series data of the moving speed of the lower reference mark; Fig. 13 is a diagram showing an edge of a substrate and an orientation flat; Fig. 14 is a diagram showing the configuration of a substrate processing apparatus according to a modified example;

[0023] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The present invention will now be described in detail with reference to the accompanying drawings, in which:

[0024] Unless otherwise specified, the substrate bonding apparatus described in this specification bonds substrates under atmospheric pressure.

[0024] 1 and 2, the configuration of a substrate bonding apparatus 1 according to a first embodiment will be described. In the following description, the up-down direction is referred to as the Z direction. The upward direction is referred to as the Z1 direction, and the downward direction is referred to as the Z2 direction. The direction perpendicular to the Z direction is referred to as the X direction. One side of the X direction is referred to as the X1 direction, and the other side is referred to as the X2 direction. The direction perpendicular to the Z direction and the X direction is referred to as the Y direction. One side of the Y direction is referred to as the Y1 direction, and the other side is referred to as the Y2 direction.

[0025] The substrate bonding apparatus 1 is an apparatus for bonding an upper substrate W1 and a lower substrate W2. Hereinafter, the upper substrate W1 and the lower substrate W2 are collectively referred to as substrates W. The substrate W may be made of a silicon wafer, a compound semiconductor wafer, a glass substrate, or the like, and may have elements formed thereon. As shown in FIGS. 1 and 2 , the substrate bonding apparatus 1 includes a load port 2, a plasma processing unit 3, a cleaning unit 4, and a bonding unit 5. Also, as shown in FIG. 1 , the substrate bonding apparatus 1 includes a first transfer chamber 11, a second transfer chamber 12, a third transfer chamber 13, and a fourth transfer chamber 14. The substrate bonding apparatus 1 also includes a pre-activation aligner 21, a load lock chamber 22, an unload lock chamber 23, a post-cleaning staging table 24, a pre-bonding aligner 25, and a post-bonding staging table 26. The substrate bonding apparatus 1 also includes a control device 30 and a display unit 31. The substrate W is an example of the "object to be processed" in the claims.

[0026] 1, as an example, six load ports 2 are arranged. The six load ports 2 include a first load port 2a on which a carrier CA accommodating an upper substrate W1 is placed, a second load port 2b on which a carrier CA accommodating a lower substrate W2 is placed, and a third load port 2c on which a carrier CA accommodating the bonded upper substrate W1 and lower substrate W2 is placed.

[0027] In Fig. 1, as an example, two plasma processing units 3 are arranged. In Fig. 1, as an example, two cleaning units 4 (two stages) are arranged. In Fig. 1, as an example, two bonding units 5 are arranged.

[0028] A first transfer robot RB1 is disposed in the first transfer chamber 11. A second transfer robot RB2 is disposed in the second transfer chamber 12. A third transfer robot RB3 is disposed in the third transfer chamber 13. A fourth transfer robot RB4 is disposed in the fourth transfer chamber 14.

[0029] The pre-activation aligner 21 positions the substrate W using a notch N (see FIGS. 6 and 8) or an orientation flat O (see FIG. 29) formed on the substrate W as a reference before the substrate W is activated by the plasma processing unit 3. The notch N is a V-shaped groove formed on the outer peripheral surface of the substrate W to indicate the crystal orientation of the substrate W. The orientation flat O is a flat surface portion formed on the outer peripheral surface of the substrate W to indicate the crystal orientation of the substrate W.

[0030] The load lock chamber 22 accommodates the substrate W unloaded from the pre-activation aligner 21 by the second transport robot RB2. In Fig. 1, the load lock chamber 22 is disposed below the pre-activation aligner 21. The unload lock chamber 23 accommodates the substrate W unloaded from the plasma processing unit 3 by the second transport robot RB2.

[0031] The post-cleaning staging table 24 holds the substrate W cleaned by the cleaning unit 4. The substrate W is transported from the cleaning unit 4 to the post-cleaning staging table 24 by the third transport robot RB3. The pre-bonding aligner 25 positions the substrate W based on a notch N or an orientation flat O formed on the substrate W before the substrates W are bonded together by the bonding unit 5. The post-bonding staging table 26 holds the pair of substrates W bonded by the bonding unit 5. The substrate W is transported from the bonding unit 5 to the post-bonding staging table 26 by the third transport robot RB3.

[0032] The control device 30 includes a processor such as a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The control device 30 controls the overall operation of the substrate bonding apparatus 1. The control device 30 includes a storage unit 30a. The storage unit 30a is, for example, a flash memory, a solid state drive, or a hard disk. The storage unit 30a stores programs to be executed by the control device 30.

[0033] The display unit 31 is, for example, a liquid crystal display, an organic EL display, a micro LED display, etc. The display unit 31 includes a display unit 31 a attached to the substrate bonding apparatus 1 itself and a display unit 31 b such as a portable tablet terminal.

[0034] (Joining Unit) Next, the structure of the joining unit 5 will be described in detail with reference to FIGS.

[0035] As shown in FIG. 3 , the bonding unit 5 includes an upper stage 51, a lower stage 61, an XY stage 62, and a base 70. The bonding unit 5 also includes an alignment mark imaging unit 71, a reference mark imaging unit 72, and an inspection imaging unit 73. As shown in FIG. 2 , the bonding unit 5 also includes a bonding unit control unit 80, a processing unit 81, and a movement trajectory noise cut filter 82. The bonding unit 5 is housed, for example, in a chamber. The upper stage 51 and the lower stage 61 are examples of "stages" in the claims. The XY stage 62 is an example of a "moving mechanism" in the claims. The reference mark imaging unit 72 is an example of an "imaging unit" in the claims. The bonding unit control unit 80 is an example of a "control unit" in the claims.

[0036] The pedestal 70 supports the upper stage 51 and the lower stage 61. The pedestal 70 is disposed, for example, on the floor of a clean room in which the substrate bonding apparatus 1 is disposed. As shown in FIG. 4 , a gate-shaped frame 64 is provided on the pedestal 70. A Z-direction linear motor 64a is attached to each of two pillars of the frame 64, and a shaft 65b is attached to the Z-direction linear motor 64a. The upper stage 51 is supported by the shaft 65b. The Z-direction linear motor 64a attached to the frame 64 moves the shaft 65b in the Z direction, thereby raising and lowering the upper stage 51 in the Z direction. In addition, a rotation motor 65a is provided on the shaft 65b, and the upper stage 51 can be turned upside down by driving the rotation motor 65a.

[0037] As shown in FIG. 5, the upper stage 51 includes an upper chuck 51a, an upper rotation motor 51b, and an upper reference mark MA1.

[0038] The upper chuck 51a is, for example, a vacuum chuck or an electrostatic chuck. As shown in Fig. 6, the upper chuck 51a has, for example, a disk shape. As shown in Fig. 5, the upper rotation motor 51b is an electric motor that rotates the disk-shaped upper chuck 51a about a central axis L1. The upper stage 51 can be inverted by rotating about an axis L2 by being driven by a rotation motor 65a (see Fig. 4).

[0039] As shown in Fig. 6, the upper reference mark MA1 is disposed on the upper stage 51. The upper reference mark MA1 is disposed on the surface of the upper stage 51. Fig. 6 shows an example in which four upper reference marks MA1 are disposed. As shown in Fig. 7, the upper reference mark MA1 is formed on a transparent plate member 51e made of quartz. The upper reference mark MA1 is composed of, for example, two rectangular portions ma1. The two rectangular portions ma1 are diagonally spaced apart from each other.

[0040] 5, the lower stage 61 includes a lower chuck 61a, a lower rotation motor 61b, and a lower reference mark MA2. The lower reference mark MA2 is an example of the "characteristic portion" and "reference mark" in the claims.

[0041] The lower chuck 61a is, for example, a vacuum chuck or an electrostatic chuck. The lower chuck 61a has, for example, a disk shape (see FIG. 8). As shown in FIG. 5, the lower rotation motor 61b is an electric motor that rotates the disk-shaped lower chuck 61a around a central axis L3. As shown in FIG. 3, the XY stage 62 includes an X-direction linear slider 62a and a Y-direction linear slider 62b. The X-direction linear slider 62a moves the lower stage 61 along the X direction, and the Y-direction linear slider 62b moves the lower stage 61 along the Y direction.

[0042] As shown in Fig. 8, the lower reference mark MA2 is disposed on the lower stage 61. The lower reference mark MA2 is disposed on the surface of the lower stage 61. Fig. 8 shows an example in which four lower reference marks MA2 are disposed. As shown in Fig. 9, the lower reference mark MA2 is formed on a transparent plate member 61e made of quartz. Furthermore, the lower reference mark MA2 is formed, for example, by a cross-shaped portion ma2.

[0043] 3, the alignment mark imaging unit 71 is configured to capture images of alignment marks (upper alignment mark AM1 and lower alignment mark AM2, which will be described later) placed on the substrate W. The alignment mark imaging unit 71 is, for example, a microscope camera that captures images using visible light. The alignment mark imaging unit 71 also includes an upper alignment mark imaging unit 71a and a lower alignment mark imaging unit 71b.

[0044] The upper alignment mark imaging unit 71a is attached to the gate-shaped frame 63. The upper alignment mark imaging unit 71a is positioned so that its imaging direction faces the Z2 direction (downward). The upper alignment mark imaging unit 71a images the lower alignment mark AM2 (see FIG. 8) that is arranged on the lower substrate W2 held on the lower stage 61. The upper alignment mark imaging unit 71a also includes an upper wide-field alignment mark imaging unit 711a and an upper narrow-field alignment mark imaging unit 712a. While the upper narrow-field alignment mark imaging unit 712a has a narrower imaging range than the upper wide-field alignment mark imaging unit 711a, it is able to image the lower alignment mark AM2 with higher accuracy.

[0045] The lower alignment mark imaging unit 71b is attached to the Y-direction linear slider 62b of the XY stage 62. This allows the lower alignment mark imaging unit 71b to move in the Y direction together with the Y-direction linear slider 62b. The lower alignment mark imaging unit 71b is positioned so that its imaging direction faces the Z1 direction (upward). The lower alignment mark imaging unit 71b images the upper alignment mark AM1 (see FIG. 6) located on the upper substrate W1 held on the upper stage 51. The lower alignment mark imaging unit 71b also includes a lower wide-field alignment mark imaging unit 711b and a lower narrow-field alignment mark imaging unit 712b. While the lower narrow-field alignment mark imaging unit 712b has a narrower imaging range than the lower wide-field alignment mark imaging unit 711b, it can image the upper alignment mark AM1 with higher accuracy.

[0046] The fiducial mark imaging unit 72 captures images of the upper and lower reference marks MA1 and MA2 from the vertical direction when the upper stage 51 and the lower stage 61 are positioned so that the upper and lower reference marks MA1 and MA2 overlap when viewed from the Z direction (vertical direction) (see FIG. 15 ). The fiducial mark imaging unit 72 is, for example, a visible light camera. The imaging data (image) captured by the fiducial mark imaging unit 72 is transmitted to the processing unit 81 (see FIG. 2 ).

[0047] 5, the reference mark imaging unit 72 is disposed, for example, on the back surface side of the upper stage 51. The back surface side of the upper stage 51 means the side opposite to the side on which the upper substrate W1 is held. The reference mark imaging unit 72 is disposed so as to penetrate the upper stage 51. An upper reference mark MA1 is disposed at the end of the reference mark imaging unit 72 penetrating the upper stage 51.

[0048] In the first embodiment, the reference mark imaging unit 72 images a feature provided on at least one of the lower stage 61 and the lower substrate W2. The following description will be given assuming that the feature is a lower reference mark MA2 provided on the lower stage 61.

[0049] 3, the inspection imaging unit 73 images the upper substrate W1 and the lower substrate W2 in a bonded state. The inspection imaging unit 73 is, for example, an infrared camera. The inspection imaging unit 73 is attached to the gate-shaped frame 63.

[0050] As shown in FIG. 2 , the bonding unit control unit 80 includes a processor such as a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The bonding unit control unit 80 controls the operation of the bonding unit 5. For example, the bonding unit control unit 80 controls the XY stage 62 that moves the lower stage 61. The bonding unit control unit 80 also includes a storage unit 801. The storage unit 801 is, for example, a flash memory, a solid state drive, or a hard disk. The storage unit 801 stores programs to be executed by the bonding unit control unit 80.

[0051] The processing unit 81 includes a processor such as a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). As described above, the imaging data (image) captured by the reference mark imaging unit 72 is transmitted to the processing unit 81. The processing unit 81 analyzes the captured image through image processing.

[0052] The movement trajectory noise cut filter 82 is configured to cut noise in the movement trajectory data of the characteristic portion (lower reference mark MA2). The movement trajectory noise cut filter 82 is, for example, a low-pass filter. The movement trajectory noise cut filter 82 cuts high-frequency noise in the movement trajectory data.

[0053] (Substrate) The structure of the substrate W (W1, W2) will be described.

[0054] As shown in Fig. 6, the upper substrate W1 has a disk shape. A V-shaped notch N is formed in the upper substrate W1. Note that an orientation flat O may be formed instead of the notch N. The notch N and the orientation flat O are intended to indicate the crystal orientation of the upper substrate W1. An upper alignment mark AM1 is also arranged on the upper substrate W1. For example, a plurality of upper alignment marks AM1 are arranged. Fig. 6 shows an example in which four upper alignment marks AM1 are arranged. As shown in Fig. 10, the upper alignment mark AM1 is formed, for example, by a cross-shaped portion am1.

[0055] As shown in Figure 8, the lower substrate W2 has the same configuration as the upper substrate W1. That is, the lower substrate W2 has a disk shape. A V-shaped notch N is formed on the lower substrate W2. Note that an orientation flat O may be formed instead of the notch N. Also, a lower alignment mark AM2 is arranged on the lower substrate W2. For example, a plurality of lower alignment marks AM2 are arranged. Figure 8 shows an example in which four lower alignment marks AM2 are arranged. Also, as shown in Figure 11, the lower alignment mark AM2 is composed of, for example, four L-shaped portions am2.

[0056] (Processing Flow of Substrate Bonding Apparatus) A processing flow of the substrate bonding apparatus 1 will be described with reference to FIG.

[0057] 12, the first transport robot RB1 removes the upper substrate W1 from the first load port 2a and removes the lower substrate W2 from the second load port 2b. The substrates W (upper substrate W1 and lower substrate W2) are then transported to the pre-activation aligner 21 by the first transport robot RB1. The substrates W transported to the pre-activation aligner 21 are aligned by the pre-activation aligner 21. The substrates W are then transported to the load lock chamber 22 by the first transport robot RB1.

[0058] 12 , the second transport robot RB2 transports the substrate W placed in the load lock chamber 22 to the plasma processing unit 3. Then, a surface modification step (surface modification treatment) is performed on the substrate W transported to the plasma processing unit 3. In the surface modification step, plasma is applied to the surface of the substrate W to remove fine organic matter adhering to the substrate W and to perform a surface modification treatment that changes the composition of the surface of the substrate W. The substrate W whose surface has been modified in the plasma processing unit 3 is transported to the unload lock chamber 23 by the second transport robot RB2.

[0059] 12 , the substrate W transported to the unload lock chamber 23 is transported to the cleaning unit 4 by the second transport robot RB2. In the cleaning unit 4, a cleaning liquid is discharged onto the substrate W to clean the substrate W. The cleaning liquid is, for example, pure water. After cleaning, the substrate W is transported to the post-cleaning staging table 24 by the third transport robot RB3.

[0060] 12 , the substrate W transported to the staging table 24 after cleaning is transported to the pre-bonding aligner 25 by the fourth transport robot RB4. The substrate W transported to the pre-bonding aligner 25 is aligned by the pre-bonding aligner 25. The substrate W is then transported to the bonding unit 5 by the fourth transport robot RB4. Here, the upper substrate W1 is held by the upper chuck 51 a of the upper stage 51 facing upward. The lower substrate W2 is held by the lower chuck 61 a of the lower stage 61 facing upward. The upper stage 51 is then rotated and inverted so that the upper stage 51 faces downward.

[0061] 12, as shown in FIG. 13, the lower alignment mark AM2 of the lower substrate W2 held by the lower chuck 61a of the lower stage 61 is imaged by the upper alignment mark imaging unit 71a fixed to the frame 63. For example, the lower alignment mark AM2 is imaged by the upper wide-field alignment mark imaging unit 711a of the upper alignment mark imaging unit 71a to roughly detect the position of the lower alignment mark AM2, and then the lower alignment mark AM2 is imaged by the upper narrow-field alignment mark imaging unit 712a to detect the position of the lower alignment mark AM2 with high accuracy. Similarly, the lower reference mark MA2 arranged on the lower stage 61 is imaged by the upper alignment mark imaging unit 71a. As a result, the positions (coordinates) of the lower alignment mark AM2 and the lower reference mark MA2 are detected.

[0062] 14, the upper alignment mark AM1 of the upper substrate W1 held by the upper chuck 51a of the upper stage 51 is imaged by the lower alignment mark imaging unit 71b fixed to the XY stage 62. A plurality of upper alignment marks AM1 are arranged on the upper substrate W1, and the lower alignment mark imaging unit 71b images the plurality of upper alignment marks AM1. Similarly, the upper reference mark MA1 arranged on the upper stage 51 is imaged by the lower alignment mark imaging unit 71b. This allows the positions (coordinates) of the upper alignment mark AM1 and the upper reference mark MA1 to be detected.

[0063] 12, the upper substrate W1 and the lower substrate W2 are aligned so as to be positioned at a horizontal joining position based on the detected positions (coordinates) of the lower alignment mark AM2, the lower reference mark MA2, the upper alignment mark AM1, and the upper reference mark MA1, as shown in Fig. 15. Specifically, by operating the XY stage 62, the upper rotation motor 51b of the upper stage 51, and the lower rotation motor 61b of the lower stage 61, the upper substrate W1 and the lower substrate W2 are aligned so as to minimize positional deviation between the upper substrate W1 and the lower substrate W2 at the horizontal joining position.

[0064] (Second Alignment Step) In step S7 shown in FIG. 12 , the second alignment step is performed. After the first alignment step in step S6, the upper stage 51 may vibrate relative to the lower stage 61 due to vibrations of devices surrounding the substrate bonding apparatus 1 or vibrations of the substrate bonding apparatus 1 itself. The second alignment step is a step for suppressing errors in the alignment between the upper substrate W1 and the lower substrate W2 caused by vibrations. As a detailed processing flow of step S7, as shown in FIG. 16 , in step S11, the fiducial mark imaging unit 72 images the lower fiducial mark MA2 as a characteristic portion that moves due to vibrations at multiple different times. While FIG. 17 shows the lower fiducial mark MA2 imaged at three times from time t0 to time t2, in reality, the lower fiducial mark MA2 is imaged at many more times. For example, due to vibrations, the fiducial mark imaging unit 72 vibrates along an ellipse together with the upper stage 51.

[0065] In step S12 shown in Fig. 16, in the first embodiment, the processing unit 81 is configured to acquire a movement trajectory of the lower reference mark MA2 (see Fig. 17) based on multiple images of the lower reference mark MA2 captured by the reference mark imaging unit 72. The movement trajectory r(t) of the lower reference mark MA2 is expressed, for example, by the following equation (1). Note that the movement trajectory is, for example, a collection of actually acquired coordinate data itself.

[0066] 16, in the first embodiment, the processing unit 81 is configured to acquire the movement speed of the lower reference mark MA2 based on the acquired movement trajectory of the lower reference mark MA2. For example, the processing unit 81 acquires the movement speed of the lower reference mark MA2 by performing differentiation (difference) processing on the acquired movement trajectory of the lower reference mark MA2 (the above formula (1)).

[0067] In step S14 shown in FIG. 16 , in the first embodiment, the processing unit 81 is configured to acquire, based on the acquired movement trajectory (movement speed), the low-movement-speed coordinates of the lower reference mark MA2 at which the acquired movement speed of the lower reference mark MA2 is lower than a predetermined threshold. The processing unit 81 is also configured to acquire, based on the movement trajectory of the lower reference mark MA2 in a state in which noise has been cut by the movement trajectory noise cut filter 82, the low-movement-speed coordinates of the lower reference mark MA2 at which the acquired movement speed of the lower reference mark MA2 is minimum. For example, in the example shown in FIG. 17 , the movement speed of the lower reference mark MA2 is minimum at point P1 on the elliptical movement trajectory. The processing unit 81 acquires the coordinates of point P1 as the low-movement-speed coordinates. The time tm at which the movement speed of the lower reference mark MA2 is minimum is expressed, for example, by the following equation (2): The coordinates at the time of low moving speed are expressed by the following equation (3).

[0068] In step S15 shown in Fig. 16 , in the first embodiment, the bonding unit control unit 80 is configured to perform alignment processing for the pair of substrates W (upper substrate W1, lower substrate W2) by moving the lower stage 61 relative to the upper stage 51 using the XY stage 62 so that the coordinates (point P1) of the lower reference mark MA2 at the low movement speed coincide with the target coordinates, as shown in Fig. 18 . The target coordinates are the coordinates of the position where the lower reference mark MA2 should be located if there is no vibration. If the target coordinates are (X, Y), the XY stage 62 moves the lower stage 61 by the coordinates (a, b) shown in the following equation (4): The movement locus r1(t) of the lower reference mark MA2 after the lower stage 61 is moved is expressed by the following equation (5). The target coordinates (X, Y) are expressed by the following equation (6).

[0069] (Substrate Bonding Process) In step S8 shown in FIG. 12 , in the first embodiment, as shown in FIG. 19 , the bonding unit control unit 80 is configured to, after performing the alignment process, start the process of bonding the substrates W (W1, W2) at a first timing when the lower reference mark MA2 approaches the target coordinates by a distance smaller than a predetermined distance. Specifically, the processing unit 81 is configured to acquire the first timing when the lower reference mark MA2 approaches the target coordinates by a distance smaller than the predetermined distance, based on images of the lower reference mark MA2 continuously captured by the reference mark imaging unit 72. The predetermined distance is a distance sufficiently close to the predetermined target coordinates (including a case where the distance is zero), and is stored in a memory unit (not shown) of the processing unit 81. The processing unit 81 transmits the acquired first timing to the bonding unit control unit 80. The bonding unit control unit 80 is configured to start the process of bonding the substrates W (W1, W2) based on the first timing transmitted from the processing unit 81. 19 shows an example in which the center (center of gravity) of the lower reference mark MA2 coincides with the target coordinates (distance smaller than the predetermined distance = 0) at the first timing. Then, at the first timing, the upper stage 51 is lowered to the Z2 side. This bonds the upper substrate W1 and the lower substrate W2.

[0070] 12 , the overlapping upper alignment mark AM1 and lower alignment mark AM2 are imaged by the reference mark imaging unit 72. The processing unit 81 acquires the bonding accuracy of the upper substrate W1 and the lower substrate W2 based on the image acquired by the reference mark imaging unit 72. Then, based on the currently acquired bonding accuracy, the processing unit 81 corrects the amount of movement when the upper substrate W1 and the lower substrate W2 are moved relative to each other in the next first alignment step of the upper substrate W1 and the lower substrate W2.

[0071] [Effects of the First Embodiment] In the first embodiment, the following effects can be obtained.

[0072] In the first embodiment, as described above, the bonding unit control unit 80 is configured to perform the alignment process for the pair of substrates W by moving the lower stage 61 using the XY stage 62 so that the coordinates of the lower reference mark MA2 at the low movement speed coincide with the target coordinates. As a result, the movement speed of the upper stage 51 is slow at the target coordinates. In other words, since the movement amount (positional deviation amount) of the upper stage 51 per time caused by vibration is relatively small at the target coordinates, alignment based on the target position can suppress alignment errors caused by vibration.

[0073] In the first embodiment, as described above, the bonding unit control unit 80 is configured to perform the alignment process and then start the process of bonding the substrates W at a first timing when the lower reference mark MA2 approaches the target coordinates by less than a predetermined distance. Even after the alignment process is performed so that the coordinates of the lower reference mark MA2 at the low moving speed coincide with the target coordinates, the upper stage 51 vibrates, and the distance between the lower reference mark MA2 and the target coordinates also changes due to the vibration. Therefore, by starting the process of bonding the substrates W at the first timing when the lower reference mark MA2 approaches the target coordinates by less than a predetermined distance, bonding of the substrates W can be started at a timing when the lower reference mark MA2 is relatively close to the target coordinates. As a result, misalignment between the bonded substrates W can be suppressed.

[0074] In the first embodiment, as described above, the processing unit 81 is configured to acquire the first timing at which the lower reference mark MA2 approaches the target coordinates to a distance smaller than a predetermined distance, based on images of the lower reference mark MA2 continuously captured by the reference mark imaging unit 72. This allows the processing unit 81 to acquire the coordinates of the lower reference mark MA2 that moves due to vibration in real time (at relatively short time intervals), and therefore can appropriately acquire the first timing at which the distance between the lower reference mark MA2 that moves due to vibration and the target coordinates becomes relatively small.

[0075] In the first embodiment, as described above, the processing unit 81 is configured to acquire the movement trajectory of the lower reference mark MA2 based on multiple images of the lower reference mark MA2 captured by the reference mark imaging unit 72, and to acquire the coordinates of the lower reference mark MA2 at the low movement speed based on the acquired movement trajectory of the lower reference mark MA2. This allows the processing unit 81 to easily calculate the movement speed of the lower reference mark MA2 simply by performing differentiation (difference) processing on the movement trajectory (position coordinates), and therefore, to easily acquire the coordinates of the lower reference mark MA2 at the low movement speed.

[0076] In the first embodiment, as described above, the substrate bonding apparatus 1 further includes a movement trajectory noise cut filter 82 that cuts out noise in the movement trajectory data of the lower reference mark MA2. The processing unit 81 is configured to acquire the coordinates of the lower reference mark MA2 at a low movement speed based on the movement trajectory of the lower reference mark MA2 in a state in which noise has been cut out by the movement trajectory noise cut filter 82. As a result, noise in the movement trajectory of the lower reference mark MA2 is cut out, and the movement trajectory after noise cut out is a smooth movement trajectory. Therefore, the processing unit 81 can easily perform differentiation processing on the movement trajectory of the lower reference mark MA2 after noise cut out.

[0077] In the first embodiment, as described above, the processing unit 81 acquires the low-speed coordinates of the lower reference mark MA2 at which the acquired movement speed of the lower reference mark MA2 is minimum, and the joining unit control unit 80 is configured to perform alignment processing so that the low-speed coordinates of the lower reference mark MA2 at which the movement speed is minimum coincide with the target coordinates. As a result, the movement speed of the upper stage 51 is minimum at the target coordinates, and therefore the movement amount (positional deviation amount) of the upper stage 51 per time at the target coordinates is also minimum. As a result, alignment errors caused by vibration can be more effectively suppressed.

[0078] In the first embodiment, as described above, the lower reference mark MA2 is provided on the lower stage 61. As a result, the lower reference mark MA2 provided on the lower stage 61 is originally provided on the lower stage 61, so it is possible to save the effort (process) of providing a new characteristic part on the lower stage 61 that is different from the lower reference mark MA2, and it is also possible to prevent the structure of the substrate bonding apparatus 1 from becoming complicated.

[0079] In the first embodiment, as described above, the pair of stages includes the upper stage 51 that holds the upper substrate W1 and the lower stage 61 that holds the lower substrate W2, and the fiducial mark imaging unit 72 is attached to the upper stage 51 and configured to image the lower fiducial mark MA2 provided on the lower stage 61. The bonding unit control unit 80 is configured to perform the alignment process by moving the lower stage 61 relative to the upper stage 51 using the XY stage 62 so that the coordinates of the lower fiducial mark MA2 at the low movement speed coincide with the target coordinates. As a result, the lower stage 61 is moved relative to the upper stage 51 by the XY stage 62 so that the coordinates of the lower fiducial mark MA2 at the low movement speed, imaged by the fiducial mark imaging unit 72, coincide with the target coordinates, thereby positioning the target coordinates on the movement trajectory of the lower fiducial mark MA2. As a result, the bonding process of the pair of substrates W after the alignment process can be easily started at a timing when the distance between the lower fiducial mark MA2 and the target coordinates is sufficiently small.

[0080] 20 and 21 , the configuration of a substrate bonding apparatus 1a according to a second embodiment will be described. In a bonding unit 5a of the substrate bonding apparatus 1a according to the second embodiment, a reference mark imaging unit 72a is provided so as not to move in synchronization with the upper stage 51 and the lower stage 61. The reference mark imaging unit 72a is an example of the "imaging unit" in the claims.

[0081] As shown in FIG. 21 , the reference mark imaging unit 72a is provided so as not to move in synchronization with the upper stage 51 and the lower stage 61. For example, the reference mark imaging unit 72a is provided at a distance from the upper stage 51 and the lower stage 61. The reference mark imaging unit 72a is configured to image an upper reference mark MA1 provided on the upper stage 51. Note that the reference mark imaging unit 72a is provided integrally with the base 70 on which the upper stage 51 and the lower stage 61 are provided, and the influence of vibration on the reference mark imaging unit 72a can be considered to be substantially the same as the influence of vibration on the upper stage 51. The reference mark imaging unit 72a is, for example, a visible light camera. Note that the upper reference mark MA1 is an example of a "characteristic portion" and a "reference mark" in the claims.

[0082] (Processing flow of substrate bonding apparatus) The processing flow of the substrate bonding apparatus 1a of the second embodiment is similar to the processing flow of the substrate bonding apparatus 1 of the first embodiment shown in Fig. 12, but differs in the second alignment step of step S7. The second alignment step of the second embodiment will be described with reference to Fig. 22.

[0083] In step S21 shown in Fig. 22, the reference mark imaging unit 72a images the upper reference mark MA1 as a characteristic part that moves due to vibration at a plurality of different times, as shown in Fig. 23. For example, due to vibration, the upper reference mark MA1 vibrates together with the upper stage 51 so as to describe an ellipse.

[0084] 22, the processing unit 81a acquires the movement trajectory of the upper reference mark MA1 based on multiple images of the upper reference mark MA1 captured by the reference mark imaging unit 72a. The movement trajectory r(t) of the upper reference mark MA1 is expressed, for example, by the following equation (1):

[0085] 22, the processing unit 81a is configured to acquire the movement speed of the upper reference mark MA1 based on the acquired movement trajectory of the upper reference mark MA1. For example, the processing unit 81a is configured to acquire the movement speed of the upper reference mark MA1 by performing differentiation (difference) processing on the acquired movement trajectory of the upper reference mark MA1 (the above formula (1)).

[0086] In step S24 shown in FIG. 22 , the processing unit 81a acquires, based on the acquired movement trajectory (movement speed), the low-movement-speed coordinates of the upper reference mark MA1 at which the acquired movement speed of the upper reference mark MA1 is lower than a predetermined threshold. The processing unit 81a also acquires, based on the movement trajectory of the upper reference mark MA1 in a state in which noise has been cut by the movement trajectory noise cut filter 82, the low-movement-speed coordinates of the upper reference mark MA1. Specifically, the processing unit 81a acquires the low-movement-speed coordinates of the upper reference mark MA1 at which the acquired movement speed of the lower reference mark MA2 is minimum. For example, in the example shown in FIG. 23 , the movement speed of the upper reference mark MA1 is minimum at point P2 on the elliptical movement trajectory. The processing unit 81a acquires the coordinates of point P2 as the low-movement-speed coordinates. The low-movement-speed coordinates of the upper reference mark MA1 are expressed by the following equation (3), as in the case of the lower reference mark MA2 in the first embodiment.

[0087] In step S25 shown in FIG. 22 , in the second embodiment, as shown in FIG. 24 , the bonding unit control unit 80 a is configured to change the target coordinates by moving the lower stage 61 relative to the upper stage 51 using the XY stage 62 so that the coordinates (point P2) of the lower reference mark MA2 at the low movement speed become new target coordinates, thereby performing the alignment process for the pair of substrates W (upper substrate W1, lower substrate W2). The target coordinates are the coordinates of the position where the upper reference mark MA1 should be located if there is no vibration. If the target coordinates are (X, Y), the XY stage 62 moves the lower stage 61 by the coordinates (a, b) shown in the following equation (4). The bonding unit control unit 80 a is an example of the "controller" in the claims. As a result, the target coordinates (X1, Y1) after the movement of the lower stage 61 are changed as shown in the following equation (7). Thereafter, the substrate bonding step of step S8 (see FIG. 12) is carried out in the same manner as in the first embodiment.

[0088] [Effects of the Second Embodiment] In the second embodiment, the following effects can be obtained.

[0089] In the second embodiment, as described above, the fiducial mark imaging unit 72a is provided so as not to move synchronously with the upper stage 51 and the lower stage 61 and is configured to image the upper fiducial mark MA1 provided on the upper stage 51. The bonding unit control unit 80a is configured to perform the alignment process by changing the target coordinates by moving the lower stage 61 relative to the upper stage 51 using the XY stage 62 so that the coordinates of the upper fiducial mark MA1 at the low movement speed become new target coordinates. As a result, the target coordinates are changed so that the coordinates of the upper fiducial mark MA1 at the low movement speed become the new target coordinates, and the new target coordinates can be positioned on the movement trajectory of the upper fiducial mark MA1. As a result, the bonding process of the pair of substrates W after the alignment process can be easily started at a timing when the distance between the upper fiducial mark MA1 and the target coordinates is sufficiently small.

[0090] [Third Embodiment] The configuration of a substrate bonding apparatus 1b according to a third embodiment will be described with reference to Fig. 25. Unlike the first and second embodiments in which the coordinates of the characteristic portions at the time of low movement speed are acquired based on the movement trajectory, in the substrate bonding apparatus 1b according to the third embodiment, a processing unit 81b acquires the coordinates at the time of low movement speed based on time-series data of the movement speed of the lower reference mark MA2.

[0091] 25 , the configuration of the substrate bonding apparatus 1b of the third embodiment is the same as the configuration of the substrate bonding apparatus 1 of the first embodiment, except that it includes a time-series data noise cut filter 83 that cuts noise in the time-series data of the movement speed of the lower reference mark MA2, instead of the movement trajectory noise cut filter 82. The time-series data noise cut filter 83 has the same configuration as the movement trajectory noise cut filter 82.

[0092] (Processing flow of substrate bonding apparatus) As shown in Figure 26, the processing flow of the substrate bonding apparatus 1b of the third embodiment differs from the processing flow of the substrate bonding apparatus 1 of the first embodiment in the second alignment process of step S7a and the bonding process of step S8a.

[0093] 26, in the second alignment step (step S7a) of the third embodiment, as shown in Fig. 27, in step S31, the lower reference mark MA2, which is a characteristic part that moves due to vibration, is imaged at a plurality of different times by the reference mark image-capturing unit 72. For example, due to vibration, the lower reference mark MA2 vibrates elliptally together with the lower stage 61.

[0094] In step S32 shown in Fig. 27, the processing unit 81b acquires time-series data on the movement speed of the lower reference mark MA2 based on multiple images of the lower reference mark MA2 captured by the reference mark imaging unit 72. For example, as shown in Fig. 28, time-series data on the movement speed of the lower reference mark MA2 is acquired, with the horizontal axis representing time and the vertical axis representing movement speed. In Fig. 28, the movement speed data of the lower reference mark MA2 is indicated by black circles. Furthermore, the processing unit 81b acquires multiple position coordinates of the lower reference mark MA2, which change from moment to moment, and calculates the movement speed, which changes from moment to moment, by performing differential (difference) processing on the multiple position coordinates.

[0095] In step S33 shown in FIG. 27 , the processing unit 81b is configured to predict, based on the acquired time-series data, a second timing at which the movement speed of the lower reference mark MA2 will be lower than a predetermined threshold. Specifically, the processing unit 81b performs a fitting process to obtain an approximation line that approximates the acquired time-series data, and predicts the second timing based on the approximation line obtained by the fitting process. Furthermore, the movement speed changes periodically, and the second timing is a point in the cycle of the periodically changing movement speed. Furthermore, in the third embodiment, the processing unit 81b performs the fitting process based on time-series data in which noise has been removed by the time-series data noise-cut filter 83. In FIG. 28 , the approximation line is indicated by a solid line.

[0096] 27, the processing unit 81b is configured to predict the coordinates of the lower reference mark MA2 at the second timing as low-movement-speed coordinates at which the movement speed of the lower reference mark MA2 is minimum (see FIG. 28). In FIG. 28, as an example, the point at which the movement speed first becomes 0 is set as the minimum (low-movement-speed coordinates), but the second or subsequent points at which the movement speed becomes 0 may also be set as the minimum (low-movement-speed coordinates). The predicted low-movement-speed coordinates are transmitted to the joining unit control unit 80b.

[0097] 27, the bonding unit control unit 80b is configured to perform alignment processing for the pair of substrates W (upper substrate W1, lower substrate W2) by moving the lower stage 61 relative to the upper stage 51 using the XY stage 62 so that the coordinates of the lower reference mark MA2 at the time of low movement speed coincide with the target coordinates. The bonding unit control unit 80b is an example of the "control unit" in the claims.

[0098] In the bonding process (step S8a) of the third embodiment shown in Figure 26, the bonding unit control unit 80b is configured to start the process of bonding the substrates W (W1, W2) at the second timing predicted in step S33 shown in Figure 27.

[0099] [Effects of the Third Embodiment] In the third embodiment, the following effects can be obtained.

[0100] In the third embodiment, as described above, the processing unit 81b acquires time-series data of the movement speed of the lower fiducial mark MA2 based on multiple images, and predicts the second timing at which the movement speed of the lower fiducial mark MA2 will be lower than a predetermined threshold based on the acquired time-series data. The processing unit 81b also predicts the coordinates of the lower fiducial mark MA2 at the second timing as coordinates at the low movement speed. The bonding unit control unit 80b is configured to start the process of bonding the substrate W at the second timing. Because the second timing is predicted based on the time-series data of the movement speed of the lower fiducial mark MA2, the second timing can be predicted even for a time point when there is no data on the movement speed of the lower fiducial mark MA2. This allows the second timing to be more appropriately acquired, thereby more appropriately suppressing alignment errors caused by vibration. Furthermore, because the periodicity of the movement speed is understood based on the time-series data of the movement speed of the lower fiducial mark MA2, the second timing can be appropriately predicted, even when the movement speed changes in a relatively complex manner, and the process of bonding the substrate W can be started at the appropriate second timing.

[0101] In the third embodiment, as described above, the processing unit 81b is configured to execute a fitting process to find an approximation line that approximates the acquired time-series data, predict the second timing based on the approximation line found by the fitting process, and predict the coordinates of the lower reference mark MA2 at the second timing as the coordinates at the time of low movement speed. As a result, even if the acquired time-series data of the movement speed of the lower reference mark MA2 is not smooth (varies), the time-series data is fitted by the approximation line, making it possible to easily predict the second timing based on the approximation line found by the fitting process.

[0102] In the third embodiment, as described above, the substrate bonding apparatus 1b further includes a time-series data noise cut filter 83 that cuts out noise in the time-series data of the movement speed of the lower reference mark MA2. The processing unit 81b is configured to perform a fitting process based on the time-series data from which noise has been cut out by the time-series data noise cut filter 83, and to predict coordinates at low movement speeds. Since noise has been cut out from the time-series data of the movement speed of the lower reference mark MA2, the time-series data after noise cutout is smooth. Therefore, the processing unit 81b can appropriately perform a fitting process on the movement trajectory of the time-series data after noise cutout.

[0103] [Modifications] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the description of the above-mentioned embodiments, and further includes all modifications (modifications) within the meaning and scope of the claims.

[0104] In the first and second embodiments, the bonding unit control unit 80 performs an alignment process so that the coordinates at the low moving speed coincide with the target coordinates, and then starts the process of bonding the substrates W at the first timing when the characteristic portions (the upper reference mark MA1 and the lower reference mark MA2) approach the target coordinates by less than a predetermined distance. However, the present invention is not limited to this. For example, the bonding unit control unit 80 may acquire the first timing once and then start the process of bonding the substrates W at a time earlier than the first timing. In this way, even if there is a time lag between the time when the bonding unit control unit 80 starts the process of bonding the substrates W and the time when the substrates W are brought closer to each other and bonded (contacted) to each other, the bonding process of the substrates W can be started at a time earlier than the first timing in anticipation of the time lag, thereby further suppressing misalignment between the bonded substrates W.

[0105] In the above first and second embodiments, an example is shown in which the process of bonding the substrates W is started at the first timing when the distance between the characteristic portions (upper reference mark MA1 and lower reference mark MA2) and the target coordinates is smaller than a predetermined distance, that is, when the distance is 0. However, the present invention is not limited to this. For example, the process of bonding the substrates W may be started at the first timing when the predetermined distance is slightly larger than 0.

[0106] In the first and second embodiments, the movement trajectory acquired by the processing unit (81, 81 a) is composed of the coordinate data itself that has actually been acquired, but the present invention is not limited to this. For example, the movement trajectory acquired by the processing unit (81, 81 a) may be a function of the movement trajectory acquired by fitting the acquired coordinate data.

[0107] In the first and second embodiments, an example was shown in which the trajectory noise cut filter 82 that cuts noise in the trajectory data of the characteristic portions (MA1, MA2) is provided, but the present invention is not limited to this. For example, if the trajectory data contains relatively little noise, the trajectory noise cut filter 82 may not be provided.

[0108] In the first to third embodiments, the processing units (81, 81a, 81b) acquire the low-movement-speed coordinates of the acquired feature portions (MA1, MA2) at the lowest moving speed, but the present invention is not limited to this. For example, the low-movement-speed coordinates may be coordinates that are smaller than a predetermined threshold and larger than the minimum, rather than the coordinates at the lowest moving speed.

[0109] In the third embodiment, the processing unit 81b performs a fitting process to obtain an approximation line that approximates the acquired time-series data and predicts the second timing based on the approximation line obtained by the fitting process. However, the present invention is not limited to this. For example, if the acquired time-series data is smooth, the fitting process may not be necessary.

[0110] In the third embodiment, the processing unit 81b executes the fitting process based on the time-series data from which noise has been cut by the time-series data noise cut filter 83. However, the present invention is not limited to this. For example, if the time-series data contains relatively little noise, the time-series data noise cut filter 83 may not be provided.

[0111] In the first to third embodiments described above, the characteristic part is an upper reference mark MA1 provided on the upper stage 51 or a lower reference mark MA2 provided on the lower stage 61, but the present invention is not limited to this. For example, the characteristic part may be an alignment mark (AM1 shown in FIG. 6 or AM2 shown in FIG. 8) provided on the substrate W, the edge E of the substrate W, a notch N or orientation flat O formed on the substrate W, or the like, as shown in FIG. 29 . The characteristic part may also be a circuit or the like provided on the substrate W. Because the alignment marks (AM1, AM2) provided on the substrate W, the edge E of the substrate W, and the notch N or orientation flat O formed on the substrate W are originally provided on the substrate W, it is possible to save the effort (step) of providing new characteristic parts on the substrate W and to prevent the structure of the substrate bonding apparatus from becoming complicated.

[0112] While the first to third embodiments described above illustrate examples in which the present invention is applied to a substrate bonding apparatus (1, 1a, 1b), the present invention is not limited thereto. The present invention may also be applied to a substrate processing apparatus 100 according to a modified example shown in FIG. 30 . The substrate processing apparatus 100 according to this modified example is, for example, an exposure apparatus. The substrate processing apparatus 100 includes a first member 101 and a second member 102 spaced apart from the first member 101. The substrate processing apparatus 100 also includes an imaging unit 103 disposed on the first member 101. A substrate W is disposed on the second member 102, and a characteristic portion 104 is formed on the second member 102. The imaging unit 103 images the characteristic portion 104. In the substrate processing apparatus 100, for example, as in the first and second embodiments described above, the moving speed of the characteristic portion 104 is acquired based on multiple images of the moving characteristic portion 104 captured by the imaging unit 103. Then, the low-moving-speed coordinate of the characteristic portion 104, at which the acquired moving speed of the characteristic portion 104 is minimum, is acquired. Then, the first member 101 and the second member 102 are moved relatively by a moving mechanism (not shown) so that the coordinates of the characteristic portion 104 at the low moving speed coincide with the target coordinates, and a process of aligning the first member 101 and the second member 102 is performed. The second member 102 is an example of a "stage" in the claims.

[0113] DESCRIPTION OF SYMBOLS 1, 1a, 1b Substrate bonding apparatus 51 Upper stage (stage) 61 Lower stage (stage) 62 XY stage (moving mechanism) 72, 72a Reference mark imaging section (imaging section) 80, 80a, 80b Bonding unit control section (control section) 81, 81a, 81b Processing section 82 Movement trajectory noise cut filter 83 Time series data noise cut filter 100 Substrate processing apparatus 102 Second member (stage) 103 Imaging section 104 Characteristic portion AM1 Upper alignment mark (characteristic portion, alignment mark) AM2 Lower alignment mark (characteristic portion, alignment mark) E Edge (characteristic portion) MA1 Upper reference mark (characteristic portion, reference mark) MA2 Lower reference mark (characteristic portion, reference mark) N Notch (characteristic portion) O Orientation flat (characteristic portion) W Substrate (processing object) W1 Upper board W2 Lower board

Claims

a pair of stages each holding a pair of substrates to be bonded together; an imaging unit that images a characteristic portion provided on at least one of the stage and the substrate; a control unit that controls a movement mechanism that moves at least one of the pair of stages; a processing unit that acquires a moving speed of the characteristic part based on a plurality of images of the moving characteristic part captured by the imaging unit at a plurality of different times, and acquires a low-moving-speed coordinate of the characteristic part at which the acquired moving speed of the characteristic part is lower than a predetermined threshold, the control unit is configured to perform alignment processing of the pair of substrates by moving at least one of the pair of stages using the movement mechanism so that the coordinates of the characteristic portion at a low movement speed coincide with target coordinates.

2. The substrate bonding apparatus according to claim 1, wherein the control unit is configured to, after performing the alignment process, start a process of bonding the substrates at a first timing when the characteristic portion approaches the target coordinates by a distance smaller than a predetermined distance.

3. The substrate bonding apparatus according to claim 2, wherein the processing unit is configured to acquire the first timing at which the characteristic portion approaches the target coordinates at a distance smaller than the predetermined distance based on images of the characteristic portion continuously captured by the imaging unit. 　 The processing unit acquiring a movement trajectory of the characteristic part based on a plurality of images of the characteristic part captured by the imaging unit; The substrate bonding apparatus according to claim 1 , further comprising: a step of acquiring coordinates of the characteristic portion at a low moving speed based on the acquired movement trajectory of the characteristic portion. 　 further comprising a movement trajectory noise cut filter that cuts noise in the movement trajectory data of the characteristic portion; 5. The substrate bonding apparatus according to claim 4, wherein the processing unit is configured to acquire the coordinates of the characteristic portion at a low movement speed based on the movement trajectory of the characteristic portion in a state in which noise has been cut by the movement trajectory noise cut filter. 　 the processing unit acquires a low-movement-speed coordinate of the characteristic part at which the movement speed of the acquired characteristic part is minimum; The substrate bonding apparatus according to claim 1 , wherein the control unit is configured to perform the alignment process so that the target coordinates coincide with the low-movement-speed coordinates of the characteristic portion where the movement speed is minimum. 　 the processing unit acquires time-series data of the movement speed of the characteristic part based on the plurality of images, predicts a second timing at which the movement speed of the characteristic part will be slower than the predetermined threshold based on the acquired time-series data, and predicts coordinates of the characteristic part at the second timing as the low-movement-speed coordinates; The substrate bonding apparatus according to claim 1 , wherein the control unit is configured to start the process of bonding the substrates at the second timing.

8. The substrate bonding apparatus according to claim 7, wherein the processing unit is configured to perform a fitting process to obtain an approximation line that approximates the acquired time series data, predict the second timing based on the approximation line obtained by the fitting process, and predict coordinates of the characteristic part at the second timing as the coordinates at the low moving speed. 　 further comprising a time-series data noise cut filter that cuts noise from the time-series data of the moving speed of the characteristic part; 9. The substrate bonding apparatus according to claim 8, wherein the processing unit is configured to perform the fitting process based on the time series data from which noise has been cut by the time series data noise cut filter, and to predict the coordinate at the time of the low moving speed.

2. The substrate bonding apparatus of claim 1, wherein the feature portion includes at least one of a reference mark provided on the stage, an alignment mark provided on the substrate, an edge of the substrate, and a notch or orientation flat formed on the substrate. 　 the pair of stages includes an upper stage that holds one upper substrate of the pair of substrates and a lower stage that holds the other lower substrate of the pair of substrates, the imaging unit is attached to the upper stage and configured to image the characteristic portion provided on at least one of the lower stage and the lower substrate; 2. The substrate bonding apparatus according to claim 1, wherein the control unit is configured to perform the alignment process by moving the lower stage relative to the upper stage using the movement mechanism so that the coordinates of the characteristic portion at a low movement speed coincide with the target coordinates. 　 the pair of stages includes an upper stage that holds one upper substrate of the pair of substrates and a lower stage that holds the other lower substrate of the pair of substrates, the imaging unit is provided so as not to move in synchronization with the upper stage and the lower stage, and is configured to image the characteristic portion provided on at least one of the upper stage and the upper substrate, 2. The substrate bonding apparatus according to claim 1, wherein the control unit is configured to perform the alignment process by moving the lower stage relative to the upper stage using the movement mechanism so that the coordinates of the characteristic portion at a low movement speed become the new target coordinates, thereby changing the target coordinates. 　 a stage for holding the object to be processed; an imaging unit that images a characteristic portion provided on at least one of the processing object and the stage; a control unit that controls a movement mechanism that moves the stage; a processing unit that acquires a moving speed of the characteristic part based on a plurality of images of the moving characteristic part captured by the imaging unit at a plurality of different times, and acquires a low-moving-speed coordinate of the characteristic part at which the acquired moving speed of the characteristic part is lower than a predetermined threshold, The control unit is configured to perform an alignment process in which the movement mechanism moves the stage so that the acquired coordinates of the characteristic portion at a low movement speed coincide with target coordinates. 　 A substrate bonding method for bonding a pair of substrates held by a pair of stages, comprising the steps of: capturing images of a feature provided on at least one of the stage and the substrate at a plurality of different times; acquiring a moving speed of the characteristic portion based on a plurality of images of the characteristic portion captured at a plurality of different times; acquiring coordinates of the characteristic portion at a low moving speed, where the moving speed of the characteristic portion acquired is lower than a predetermined threshold; and performing a process of aligning the pair of substrates by moving the stage so that the acquired coordinates of the characteristic portion at the low moving speed coincide with target coordinates.

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