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

Abstract

To provide a substrate bonding apparatus capable of suppressing alignment errors caused by vibration. [Solution] This substrate bonding apparatus 1 includes a reference mark imaging unit 72 that images a lower reference mark MA2 provided on the lower stage 61, a bonding unit control unit 80 that controls the XY stage 62 that moves the lower stage 61, and a processing unit 81 that acquires the moving speed of the lower reference mark MA2 based on multiple images of the moving lower reference mark MA2 captured by the reference mark imaging unit 72 at multiple different times, and acquires the coordinates of the lower reference mark MA2 at a low moving speed when the acquired moving speed of the lower reference mark MA2 is less than a predetermined threshold. The bonding unit control unit 80 is configured to move the lower stage 61 with the XY stage 62 so that the coordinates of the lower reference mark MA2 at a low moving speed and the target coordinates coincide and perform alignment processing of a pair of substrates W.

Description

Technical Field

[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 including an imaging unit that images a characteristic portion provided on at least one of a stage and a substrate.

Background Art

[0002] Conventionally, a substrate bonding apparatus including an imaging unit that images an alignment mark (characteristic portion) provided on a substrate has been known (see, for example, Patent Document 1).

[0003] The substrate bonding apparatus described in Patent Document 1 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 moving mechanism that moves the lower chuck in a horizontal direction. In this substrate bonding apparatus, a lower alignment mark provided on the lower substrate is imaged by the upper imaging unit, and an upper alignment mark provided on the upper substrate is imaged by the lower imaging unit. Then, the lower chuck is moved by the moving mechanism so that the imaged lower alignment mark and upper alignment mark overlap. Thereby, the horizontal positions of the upper chuck (upper substrate) and the lower chuck (lower substrate) are adjusted (aligned).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In conventional substrate bonding apparatuses, such as the one described in Patent Document 1, vibrations of surrounding equipment or vibrations of the substrate bonding apparatus itself can cause at least one of the upper and lower chucks to vibrate. In this case, even if the horizontal positions of the upper and lower chucks are aligned so that the imaged lower alignment mark and upper alignment mark overlap, as described in Patent Document 1, the adjusted position may not be fixed due to vibrations of at least one of the upper or lower chucks. If the upper and lower substrates (a pair of substrates) are bonded while the adjusted position is not fixed, the joint cannot be properly formed. Therefore, it is desirable to suppress alignment errors caused by vibrations, even when the chuck (stage) vibrates.

[0006] This invention was made to solve the above-mentioned problems, and one of its objectives is to provide a substrate bonding apparatus, a substrate bonding apparatus, and a substrate bonding method that can suppress alignment errors caused by vibration. [Means for solving the problem]

[0007] To achieve the above objective, a substrate bonding apparatus according to the first aspect of this invention comprises: a pair of stages each holding a pair of substrates to be bonded to each other; an imaging unit for imaging a feature portion provided on at least one of the stages and the substrates; a control unit for controlling a moving mechanism that moves at least one of the pair of stages; and a processing unit that acquires the moving speed of the feature portion based on a plurality of images of the moving feature portion captured by the imaging unit at a plurality of different time points, and acquires the coordinates of the feature portion at a low moving speed when the acquired moving speed of the feature portion is less than a predetermined threshold. The control unit is configured to perform a positioning process of the pair of substrates by moving at least one of the pair of stages with the moving mechanism so that the coordinates of the feature portion at a low moving speed coincide with the target coordinates.

[0008] In the substrate bonding apparatus according to the first aspect described above, preferably, the control unit is configured to start the process of bonding the substrate at a first timing when the feature portion approaches the target coordinates to a distance smaller than a predetermined distance after the alignment process has been performed.

[0009] In this case, preferably, the processing unit is configured to acquire a first timing in which a feature portion approaches a target coordinate to a distance less than a predetermined distance, based on an image of the feature portion continuously captured by the imaging unit.

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

[0011] In this case, preferably, the system further includes a movement trajectory noise cut filter that cuts out noise from the movement trajectory data of the feature portion, and the processing unit is configured to obtain the coordinates of the feature portion at low movement speed based on the movement trajectory of the feature portion in a state where noise has been cut out by the movement trajectory noise cut filter.

[0012] In the substrate bonding apparatus according to the first aspect described above, preferably, the processing unit is configured to acquire the coordinates of the feature portion at the lowest movement speed when the acquired feature portion has the minimum movement speed, and the control unit is configured to perform alignment processing so that the coordinates of the feature portion at the lowest movement speed when the movement speed is minimum coincide with the target coordinates.

[0013] In the substrate bonding apparatus according to the first aspect described above, preferably, the processing unit acquires time-series data of the movement speed of feature portions based on a plurality of images, predicts a second timing in which the movement speed of the feature portions becomes less than a predetermined threshold based on the acquired time-series data, and predicts the coordinates of the feature portions at the second timing as low-movement-speed coordinates, and the control unit is configured to start the process of bonding the substrates at the second timing.

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

[0015] In the substrate bonding apparatus for predicting the second timing described above, preferably, a time-series data noise cut filter is further provided to cut noise from the time-series data of the moving speed of the feature 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 to predict the coordinates at low moving speed.

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

[0017] In the substrate bonding apparatus according to the first aspect described above, preferably, the pair of stages includes an upper stage that holds one of the pair of substrates' upper substrates and a lower stage that holds the other of the pair of substrates' lower substrates, and the imaging unit is attached to the upper stage and configured to image feature portions 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 a moving mechanism so that the coordinates of the feature portion at low moving speed coincide with the target coordinates.

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

[0019] A substrate processing apparatus according to a second aspect of this invention comprises a stage for holding an object to be processed, an imaging unit for imaging a feature portion provided on at least one of the object to be processed and the stage, a control unit for controlling a moving mechanism for moving the stage, and a processing unit that acquires the moving speed of a feature portion based on a plurality of images of the moving feature portion captured by the imaging unit at a plurality of different time points, and acquires the coordinates of the feature portion at a low moving speed when the acquired moving speed of the feature portion is less than a predetermined threshold, wherein the control unit is configured to perform a positioning process in which the moving mechanism moves the stage so that the acquired coordinates of the feature portion at a low moving speed coincide with the target coordinates.

[0020] A third aspect of this invention is a substrate bonding method for bonding a pair of substrates held on a pair of stages, comprising the steps of: imaging a feature portion provided on at least one of the stages and the substrates at a plurality of different times; acquiring the movement speed of the feature portion based on a plurality of images of the feature portion imaged at a plurality of different times; acquiring the coordinates of the feature portion at a low movement speed when the acquired movement speed of the feature portion is less than a predetermined threshold; and moving the stages to perform alignment processing of the pair of substrates so that the acquired coordinates of the feature portion at a low movement speed coincide with the target coordinates. [Effects of the Invention]

[0021] According to the present invention, since the moving speed (the amount of movement per unit time) of the stage at the target coordinates serving as the alignment reference is relatively small, it is possible to suppress the alignment error caused by vibration.

Brief Description of the Drawings

[0022] [Figure 1] It is a schematic diagram showing the configuration of a substrate bonding apparatus according to the first embodiment of the present invention. [Figure 2] It is a block diagram showing the configuration of a substrate bonding apparatus according to the first embodiment. [Figure 3] It is a perspective view of a bonding unit according to the first embodiment. [Figure 4] It is a side view of the upper stage of the bonding unit according to the first embodiment. [Figure 5] It is a side view of the upper stage and the lower stage of the bonding unit according to the first embodiment. [Figure 6] It is a top view of the upper stage of the bonding unit and the first substrate according to the first embodiment. [Figure 7] It is a diagram showing the upper reference mark according to the first embodiment. [Figure 8] It is a top view of the lower stage of the bonding unit and the second substrate according to the first embodiment. [Figure 9] It is a diagram showing the lower reference mark according to the first embodiment. [Figure 10] It is a diagram showing the upper alignment mark arranged on the upper substrate. [Figure 11] It is a diagram showing the lower alignment mark arranged on the lower substrate. [Figure 12] It is a flowchart showing the processing flow of the substrate bonding apparatus according to the first embodiment. [Figure 13] It is a diagram for explaining the alignment mark and reference mark detection step (step of detecting the lower alignment mark and the lower reference mark) of the processing flow of the substrate bonding apparatus according to the first embodiment. [Figure 14]This diagram illustrates the alignment mark and reference mark detection step (the step of detecting the upper alignment mark and the upper reference mark) of the processing flow of the substrate bonding apparatus according to the first embodiment. [Figure 15] This diagram illustrates the first alignment step and the second alignment step of the processing flow of the substrate bonding apparatus according to the first embodiment. [Figure 16] This is a flowchart illustrating the second alignment step of the processing flow of the substrate bonding apparatus according to the first embodiment. [Figure 17] This diagram shows the lower reference mark moving due to vibrations in the upper stage. [Figure 18] This diagram shows the state where the coordinates at low movement speed (the movement trajectory of the lower reference mark) coincide with the target coordinates. [Figure 19] This diagram shows the positional relationship between the lower reference mark and the target coordinates when starting the process of joining the circuit boards. [Figure 20] This is a block diagram showing the configuration of a substrate bonding apparatus according to the second embodiment. [Figure 21] This is a side view of the upper and lower stages of the joining unit according to the second embodiment. [Figure 22] This is a flowchart illustrating the second alignment step of the processing flow of the substrate bonding apparatus according to the second embodiment. [Figure 23] This diagram shows the upper reference mark moving due to vibrations on the upper stage. [Figure 24] This figure shows the state after changing the target coordinates to match the coordinates at low movement speed (the movement trajectory of the lower reference mark). [Figure 25] This is a block diagram showing the configuration of a substrate bonding apparatus according to the third embodiment. [Figure 26] This flowchart shows the processing flow of the substrate bonding apparatus according to the third embodiment. [Figure 27] This is a flowchart illustrating the second alignment step of the processing flow of the substrate bonding apparatus according to the third embodiment. [Figure 28]This figure shows the time-series data of the movement speed of the lower reference mark. [Figure 29] This diagram shows the edges and orientation flats of the circuit board. [Figure 30] This figure shows the configuration of a substrate processing apparatus with modifications. [Modes for carrying out the invention]

[0023] Embodiments of the present invention will be described below with reference to the drawings. Unless otherwise specified, the substrate bonding apparatus described herein shall perform substrate bonding under atmospheric pressure.

[0024] [First Embodiment] Referring to Figures 1 and 2, the configuration of the substrate bonding apparatus 1 according to the first embodiment will be described. In the following description, the vertical direction is referred to as the Z direction. The upward direction is referred to as the Z1 direction, and the downward direction 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 as the X2 direction. The direction perpendicular to both the Z and X directions is referred to as the Y direction. One side of the Y direction is referred to as the Y1 direction, and the other side as the Y2 direction.

[0025] The substrate bonding apparatus 1 is a device for bonding an upper substrate W1 and a lower substrate W2. Hereafter, the upper substrate W1 and the lower substrate W2 will be collectively referred to as substrate W. The substrate W is made of a silicon wafer, a compound semiconductor wafer, a glass substrate, etc., and may have elements formed on it. As shown in Figures 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 Figure 1, the substrate bonding apparatus 1 includes a first transport chamber 11, a second transport chamber 12, a third transport chamber 13, and a fourth transport 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 transfer table 24, a pre-bonding aligner 25, and a post-bonding transfer table 26. The substrate bonding apparatus 1 also includes a control device 30 and a display unit 31. Note that substrate W is an example of the "object to be processed" in the claims.

[0026] In Figure 1, as an example, six load ports 2 are arranged. The six load ports 2 include a first load port 2a where a carrier CA for accommodating the upper substrate W1 is arranged, a second load port 2b where a carrier CA for accommodating the lower substrate W2 is arranged, and a third load port 2c where a carrier CA for accommodating the joined upper substrate W1 and lower substrate W2 is arranged.

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

[0028] The first transport robot RB1 is located in the first transport room 11. The second transport robot RB2 is located in the second transport room 12. The third transport robot RB3 is located in the third transport room 13. The fourth transport robot RB4 is located in the fourth transport room 14.

[0029] Before activation, the pre-activation aligner 21 positions the substrate W based on notches N (see Figures 6 and 8) or orientation flats O (see Figure 29) formed on the substrate W, before the substrate W is activated by the plasma processing unit 3. A notch N is a V-shaped groove formed on the outer circumferential surface of the substrate W to indicate the crystal orientation of the substrate W. An orientation flat O is a flat surface formed on the outer circumferential surface of the substrate W to indicate the crystal orientation of the substrate W.

[0030] The load lock chamber 22 contains the substrates W that have been unloaded from the pre-activation aligner 21 by the second transport robot RB2. In Figure 1, the load lock chamber 22 is located below the pre-activation aligner 21. The unload lock chamber 23 contains the substrates W that have been unloaded from the plasma processing unit 3 by the second transport robot RB2.

[0031] The post-cleaning transfer table 24 holds the substrates W that have been cleaned by the cleaning unit 4. The transport of the substrates W from the cleaning unit 4 to the post-cleaning transfer table 24 is performed by the third transport robot RB3. The pre-bonding aligner 25 positions the substrates W based on the notches N or orientation flats O formed on the substrates W before they are bonded together by the bonding unit 5. The post-bonding transfer table 26 holds the pair of substrates W that have been bonded together by the bonding unit 5. The transport of the substrates W from the bonding unit 5 to the post-bonding transfer table 26 is performed by the third transport robot RB3.

[0032] The control device 30 includes a CPU (Central Processing Unit) as a processor, ROM (Read Only Memory), and 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, flash memory, a solid-state drive, or a hard disk. The storage unit 30a stores programs that the control device 30 executes.

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

[0034] (Joining unit) Next, the structure of the joint unit 5 will be described in detail with reference to Figures 2 to 9.

[0035] As shown in Figure 3, the bonding unit 5 comprises an upper stage 51, a lower stage 61, an XY stage 62, and a base 70. The bonding unit 5 also comprises an alignment mark imaging unit 71, a reference mark imaging unit 72, and an inspection imaging unit 73. Furthermore, as shown in Figure 2, the bonding unit 5 comprises 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. Note that the upper stage 51 and lower stage 61 are examples of "stages" in the claims. The XY stage 62 is an example of a "movement 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 base 70 supports the upper stage 51 and the lower stage 61. The base 70 is placed, for example, on the floor of the cleanroom where the substrate bonding apparatus 1 is located. As shown in Figure 4, a gate-shaped frame 64 is provided on the base 70. Z-direction linear motors 64a are attached to each of the two column sections of the frame 64, and a shaft 65b is attached to the Z-direction linear motors 64a. The upper stage 51 is supported by the shaft 65b. The upper stage 51 moves up and down in the Z direction as the shaft 65b is moved in the Z direction by the Z-direction linear motors 64a attached to the frame 64.

[0037] As shown in Figure 5, the upper stage 51 includes an upper chuck 51a, an upper rotating 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 Figure 6, the upper chuck 51a has, for example, a disc shape. As shown in Figure 5, the upper rotation motor 51b is an electric motor that rotates the disc-shaped upper chuck 51a around the central axis L1. The upper stage 51 is reversible by rotating around the axis L2 driven by the rotation motor 65a (see Figure 4).

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

[0040] As shown in Figure 5, the lower stage 61 includes a lower chuck 61a, a lower rotating 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 disc shape (see Figure 8). The lower rotation motor 61b is an electric motor that rotates the disc-shaped lower chuck 61a around the central axis L3, as shown in Figure 5. Also, as shown in Figure 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 Figure 8, the lower reference mark MA2 is positioned on the lower stage 61. The lower reference mark MA2 is positioned on the surface of the lower stage 61. Figure 8 shows an example in which four lower reference marks MA2 are positioned. As shown in Figure 9, the lower reference mark MA2 is formed on a transparent quartz plate member 61e. The lower reference mark MA2 is also composed of, for example, a cross-shaped portion ma2.

[0043] As shown in Figure 3, the alignment mark imaging unit 71 is configured to image alignment marks (upper alignment mark AM1 and lower alignment mark AM2, described later) placed on the substrate W. The alignment mark imaging unit 71 is, for example, a microscope camera that images 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 mounted on a 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 Figure 8) located on the lower substrate W2 held by 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. The upper narrow-field alignment mark imaging unit 712a has a narrower imaging range than the upper wide-field alignment mark imaging unit 711a, but can image the lower alignment mark AM2 with higher precision.

[0045] The lower alignment mark imaging unit 71b is attached to the Y-direction linear slider 62b of the XY stage 62. As a result, the lower alignment mark imaging unit 71b moves along 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 Figure 6) located on the upper substrate W1 held by 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. The lower narrow-field alignment mark imaging unit 712b has a narrower imaging range than the lower wide-field alignment mark imaging unit 711b, but can image the upper alignment mark AM1 with higher precision.

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

[0047] As shown in Figure 5, the reference mark imaging unit 72 is positioned, for example, on the back side of the upper stage 51. The back 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 also positioned to penetrate the upper stage 51. The upper reference mark MA1 is positioned beyond where the reference mark imaging unit 72 penetrates the upper stage 51.

[0048] Furthermore, in the first embodiment, the reference mark imaging unit 72 images a characteristic portion provided on at least one of the lower stage 61 and the lower substrate W2. The characteristic portion is described below as the lower reference mark MA2 provided on the lower stage 61.

[0049] As shown in Figure 3, the inspection imaging unit 73 images the upper substrate W1 and lower substrate W2 in their bonded state. The inspection imaging unit 73 is, for example, an infrared camera. The inspection imaging unit 73 is mounted on a gantry-type frame 63.

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

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

[0052] The movement trajectory noise cut filter 82 is configured to cut noise from the movement trajectory data of the feature 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 from the movement trajectory data.

[0053] (substrate) The configuration of circuit board W (W1, W2) will be explained.

[0054] As shown in Figure 6, the upper substrate W1 has a disc shape. A V-shaped notch N is formed on the upper substrate W1. Alternatively, an orientation flat O may be formed instead of the notch N. The notch N and orientation flat O are for indicating the crystal orientation of the upper substrate W1. An upper alignment mark AM1 is also placed on the upper substrate W1. For example, multiple upper alignment marks AM1 are placed. Figure 6 shows an example in which four upper alignment marks AM1 are placed. As shown in Figure 10, the upper alignment mark AM1 is composed of, for example, 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 disc shape. A V-shaped notch N is formed on the lower substrate W2. Alternatively, an orientation flat O may be formed instead of the notch N. In addition, a lower alignment mark AM2 is placed on the lower substrate W2. For example, multiple lower alignment marks AM2 are placed. Figure 8 shows an example in which four lower alignment marks AM2 are placed. Also, as shown in Figure 11, the lower alignment mark AM2 is composed of, for example, four L-shaped parts am2.

[0056] (Processing flow of substrate bonding equipment) The processing flow of the substrate bonding apparatus 1 will be explained with reference to Figure 12.

[0057] (Substrate transport process) In step S1 of Figure 12, the first transport robot RB1 removes the upper substrate W1 from the first load port 2a and the lower substrate W2 from the second load port 2b. Subsequently, the substrates W (upper substrate W1 and lower substrate W2) are transported by the first transport robot RB1 to the pre-activation aligner 21. The substrates W transported to the pre-activation aligner 21 are aligned by the pre-activation aligner 21. After that, the substrates W are transported by the first transport robot RB1 to the load lock chamber 22.

[0058] (Surface modification process) In step S2 shown in Figure 12, the substrate W located in the load lock chamber 22 is transported to the plasma processing unit 3 by the second transport robot RB2. Then, a surface modification process (surface modification treatment) is performed on the substrate W transported to the plasma processing unit 3. In the surface modification process, 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 surface composition 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] (Washing process) In step S3 shown in Figure 12, the substrate W, which has been 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 solution is discharged onto the substrate W, and the substrate W is cleaned. The cleaning solution is, for example, pure water. After cleaning, the substrate W is transported to the post-cleaning transfer table 24 by the third transport robot RB3.

[0060] (Reversal process) In step S4 shown in Figure 12, the substrate W, which has been transported to the transfer 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. After that, the substrate W is transported to the bonding unit 5 by the fourth transport robot RB4. Here, the upper substrate W1 is held in the upper chuck 51a of the upper stage 51, which is facing upwards. The lower substrate W2 is held in the lower chuck 61a of the lower stage 61, which is also facing upwards. After that, the upper stage 51 is rotated and inverted so that the upper stage 51 faces downwards.

[0061] (Alignment mark / reference mark detection process) In step S5 shown in Figure 12, as shown in Figure 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, and after the approximate position of the lower alignment mark AM2 is detected, the lower alignment mark AM2 is imaged by the upper narrow-field alignment mark imaging unit 712a, and the position of the lower alignment mark AM2 is detected with high precision. Similarly, the lower reference mark MA2 placed on the lower stage 61 is imaged by the upper alignment mark imaging unit 71a. This allows the positions (coordinates) of the lower alignment mark AM2 and the lower reference mark MA2 to be detected.

[0062] Furthermore, as shown in Figure 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, which is fixed to the XY stage 62. Multiple upper alignment marks AM1 are arranged on the upper substrate W1, and the lower alignment mark imaging unit 71b images these multiple upper alignment marks AM1. Similarly, the upper reference mark MA1, located on the upper stage 51, is imaged by the lower alignment mark imaging unit 71b. This allows the positions (coordinates) of the upper alignment marks AM1 and the upper reference mark MA1 to be detected.

[0063] (First alignment process) In step S6 shown in Figure 12, as shown in Figure 15, the upper substrate W1 and the lower substrate W2 are aligned to the horizontal joint position based on the detected positions (coordinates) of the lower alignment mark AM2, lower reference mark MA2, upper alignment mark AM1, and upper reference mark MA1. 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 that the misalignment at the horizontal joint position between the upper substrate W1 and the lower substrate W2 is minimized.

[0064] (Second alignment process) In step S7 shown in Figure 12, a second alignment process is performed. After the first alignment process in step S6, the upper stage 51 may vibrate relative to the lower stage 61 due to vibrations of surrounding equipment or vibrations of the substrate bonding apparatus 1 itself. The second alignment process is a process to suppress the alignment error between the upper substrate W1 and the lower substrate W2 caused by vibration. As shown in Figure 16, in step S11, the lower reference mark MA2, which is a feature portion that moves due to vibration, is imaged by the reference mark imaging unit 72 at multiple different time points. In Figure 17, the lower reference mark MA2 is shown imaged at three time points from time t0 to time t2, but in reality, the lower reference mark MA2 is imaged at many more time points. For example, due to vibration, the reference mark imaging unit 72 vibrates along with the upper stage 51 in an elliptical manner.

[0065] In step S12 shown in Figure 16, in the first embodiment, the processing unit 81 is configured to acquire the movement trajectory of the lower reference mark MA2 (see Figure 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 by, for example, the following equation (1). Note that the movement trajectory is, for example, a set of coordinate data that was actually acquired.

number

[0066] In step S13 shown in Figure 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 differential (difference) processing on the acquired movement trajectory of the lower reference mark MA2 (equation (1) above).

[0067] In step S14 shown in Figure 16, in the first embodiment, the processing unit 81 is configured to acquire the coordinates of the lower reference mark MA2 at low movement speed, where the acquired movement speed of the lower reference mark MA2 is less than a predetermined threshold, based on the acquired movement trajectory (movement speed). Furthermore, the processing unit 81 is configured to acquire the coordinates of the lower reference mark MA2 at low movement speed, based on the movement trajectory of the lower reference mark MA2 after noise has been cut off by the movement trajectory noise cut filter 82. Specifically, the processing unit 81 acquires the coordinates of the lower reference mark MA2 at low movement speed, where the acquired movement speed of the lower reference mark MA2 is minimized. For example, in the example shown in Figure 17, the movement speed of the lower reference mark MA2 is minimized at point P1 on the elliptical movement trajectory. The processing unit 81 acquires the coordinates of point P1 as the coordinates at low movement speed. The time t where the movement speed of the lower reference mark MA2 is minimized... m This can be expressed, for example, by the following equation (2).

number

number

[0068] In step S15 shown in Figure 16, in the first embodiment, the bonding unit control unit 80 is configured to perform alignment processing of 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 low movement speed coincide with the target coordinates, as shown in Figure 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 amount of coordinates (a, b) shown in equation (4) below.

number

number

number

[0069] (Substrate bonding process) In step S8 shown in Figure 12, in the first embodiment, as shown in Figure 19, the bonding unit control unit 80 is configured to start the process of bonding the substrates W(W1, W2) at a first timing when the lower reference mark MA2 approaches the target coordinates to a distance smaller than a predetermined distance after performing the alignment process. Specifically, the processing unit 81 is configured to acquire the first timing when the lower reference mark MA2 approaches the target coordinates to a distance smaller than a predetermined distance, based on the image of the lower reference mark MA2 continuously captured by the reference mark imaging unit 72. The predetermined distance is a distance that is sufficiently close to the predetermined target coordinates (including the case where the distance is 0), and is stored in the storage 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. Figure 19 shows an example where, at the first timing, the center (centroid) of the lower reference mark MA2 coincides with the target coordinates (distance smaller than the predetermined distance = 0). Then, at the first timing, the upper stage 51 is lowered towards Z2. As a result, the upper substrate W1 and the lower substrate W2 are joined together.

[0070] (Inspection process) In step S9 shown in Figure 12, the reference mark imaging unit 72 captures images of the upper alignment mark AM1 and the lower alignment mark AM2, which overlap each other. The processing unit 81 acquires the bonding accuracy of the upper substrate W1 and the lower substrate W2 based on the images captured by the reference mark imaging unit 72. Then, based on the bonding accuracy acquired this time, 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 process between 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 alignment processing of a pair of substrates W by moving the lower stage 61 with the XY stage 62 so that the coordinates of the lower reference mark MA2 at low movement speed coincide with the target coordinates. As a result, the movement speed of the upper stage 51 is small at the target coordinates. That is, at the target coordinates, the amount of movement (positional displacement) of the upper stage 51 per unit time due to vibration is relatively small, so by aligning with the target position as a reference, alignment errors due to vibration can be suppressed.

[0073] In the first embodiment, as described above, the bonding unit control unit 80 is configured to start the bonding process of the substrates W at a first timing when the lower reference mark MA2 approaches the target coordinates to a distance smaller than a predetermined distance after the alignment process has been performed. However, even after the alignment process has been performed so that the coordinates of the lower reference mark MA2 at low movement speed coincide with the target coordinates, the upper stage 51 is still vibrating, and the distance between the lower reference mark MA2 and the target coordinates is also changing due to the vibration. Therefore, as described above, by starting the bonding process of the substrates W at a first timing when the lower reference mark MA2 approaches the target coordinates to a distance smaller than a predetermined distance, the 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 a first timing in which the lower reference mark MA2 approaches the target coordinates to a distance smaller than a predetermined distance, based on the image of the lower reference mark MA2 continuously captured by the reference mark imaging unit 72. As a result, the processing unit 81 can acquire the coordinates of the lower reference mark MA2 moving due to vibration in real time (at relatively short time intervals), and can appropriately acquire the first timing in which the distance between the lower reference mark MA2 moving 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 low movement speed based on the acquired movement trajectory of the lower reference mark MA2. As a result, the processing unit 81 can easily calculate the movement speed of the lower reference mark MA2 simply by performing differential (difference) processing on the movement trajectory (position coordinates), and thus can easily acquire the coordinates of the lower reference mark MA2 at 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 noise from the data of the movement trajectory of the lower reference mark MA2. The processing unit 81 is configured to acquire the coordinates of the lower reference mark MA2 at low movement speeds based on the movement trajectory of the lower reference mark MA2 after the noise has been cut by the movement trajectory noise cut filter 82. As a result, the noise in the movement trajectory of the lower reference mark MA2 is cut, and the movement trajectory after noise cut is a smooth movement trajectory. Therefore, the processing unit 81 can easily perform differential processing on the movement trajectory of the lower reference mark MA2 after noise cut.

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

[0078] In the first embodiment, as described above, the lower reference mark MA2 is provided on the lower stage 61. As a result, since the lower reference mark MA2 provided on the lower stage 61 is already provided on the lower stage 61, it is possible to eliminate the effort (process) of newly providing a feature part on the lower stage 61 that is different from the lower reference mark MA2, and it is also possible to suppress the complexity of the structure of the substrate bonding apparatus 1.

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

[0080] [Second Embodiment] The configuration of the substrate bonding apparatus 1a of the second embodiment will be described with reference to Figures 20 and 21. In the bonding unit 5a of the substrate bonding apparatus 1a of the second embodiment, 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. Note that the reference mark imaging unit 72a is an example of the "imaging unit" in the claims.

[0081] As shown in Figure 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 spaced apart from the upper stage 51 and the lower stage 61. The reference mark imaging unit 72a is configured to image the upper reference mark MA1 provided on the upper stage 51. 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 effect of vibration on the reference mark imaging unit 72a and the effect of vibration on the upper stage 51 can be considered to be substantially the same. The reference mark imaging unit 72a is, for example, a visible light camera. The upper reference mark MA1 is an example of the "characteristic portion" and "reference mark" in the claims.

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

[0083] In step S21 shown in Figure 22, as shown in Figure 23, the upper reference mark MA1, which is a feature portion that moves due to vibration, is captured by the reference mark imaging unit 72a at multiple different time points. For example, due to vibration, the upper reference mark MA1 vibrates together with the upper stage 51 in an elliptical manner.

[0084] In step S22 shown in Figure 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).

number

[0085] In step S23 shown in Figure 22, the processing unit 81a is configured to obtain the movement speed of the upper reference mark MA1 based on the movement trajectory of the acquired upper reference mark MA1. For example, the processing unit 81a is configured to obtain the movement speed of the upper reference mark MA1 by performing a differential (difference) operation on the acquired movement trajectory of the upper reference mark MA1 (equation (1) above).

[0086] In step S24 shown in Figure 22, the processing unit 81a obtains the coordinates of the upper reference mark MA1 at low movement speed, based on the acquired movement trajectory (movement speed), where the acquired movement speed of the upper reference mark MA1 is less than a predetermined threshold. The processing unit 81a also obtains the coordinates of the upper reference mark MA1 at low movement speed, based on the movement trajectory of the upper reference mark MA1 after noise has been cut by the movement trajectory noise cut filter 82. In detail, the processing unit 81a obtains the coordinates of the upper reference mark MA1 at low movement speed where the acquired movement speed of the lower reference mark MA2 is minimized. For example, in the example shown in Figure 23, the movement speed of the upper reference mark MA1 is minimized at point P2 on the elliptical movement trajectory. The processing unit 81a obtains the coordinates of point P2 as the coordinates at low movement speed. The coordinates of the upper reference mark MA1 at low movement speed are expressed by the following equation (3), similar to the case of the lower reference mark MA2 in the first embodiment described above.

number

[0087] In step S25 shown in Figure 22, in the second embodiment, as shown in Figure 24, the bonding unit control unit 80a 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 low movement speed become the new target coordinates, thereby performing alignment processing of 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 originally 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 amount of coordinates (a, b) shown in equation (4) below. Note that the bonding unit control unit 80a is an example of a "control unit" in the claims.

number

number

[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 reference mark imaging unit 72a is provided so as not to move in synchronization with the upper stage 51 and the lower stage 61, and is configured to image the upper reference mark MA1 provided on the upper stage 51. The bonding unit control unit 80a 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 of the upper reference mark MA1 at low movement speed become the new target coordinates, and to perform the alignment process. As a result, the target coordinates are changed so that the coordinates of the upper reference mark MA1 at low movement speed become the new target coordinates, so that the new target coordinates can be positioned on the movement trajectory of the upper reference 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 reference mark MA1 and the target coordinates is sufficiently small.

[0090] [Third Embodiment] Referring to Figure 25, the configuration of the substrate bonding apparatus 1b of the third embodiment will be described. Unlike the first and second embodiments described above, in the substrate bonding apparatus 1b of the third embodiment, the low-speed coordinates of the feature portion are acquired based on the movement trajectory. In this third embodiment, the processing unit 81b acquires the low-speed coordinates based on the time-series data of the movement speed of the lower reference mark MA2.

[0091] As shown in Figure 25, the configuration of the substrate bonding apparatus 1b of the third embodiment is the same as that 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 from the time-series data of the movement speed of the lower reference mark MA2, instead of the movement trajectory noise cut filter 82. The configuration of the time-series data noise cut filter 83 is the same as that of the movement trajectory noise cut filter 82.

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

[0093] In the second alignment step (step S7a) of the third embodiment shown in Figure 26, as shown in Figure 27, in step S31, the lower reference mark MA2, which is a feature portion that moves due to vibration, is imaged by the reference mark imaging unit 72 at multiple different time points. For example, due to vibration, the lower reference mark MA2 vibrates in an elliptical shape together with the lower stage 61.

[0094] In step S32 shown in Figure 27, the processing unit 81b acquires time-series data of 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 Figure 28, time-series data of the movement speed of the lower reference mark MA2 is acquired with time on the horizontal axis and movement speed on the vertical axis. In Figure 28, the data of the movement speed of the lower reference mark MA2 is shown by black circles. The processing unit 81b also acquires multiple position coordinates of the lower reference mark MA2 that change moment by moment, and calculates the movement speed that changes moment by moment by performing differential (difference) processing on the multiple position coordinates.

[0095] In step S33 shown in Figure 27, the processing unit 81b is configured to predict a second timing at which the movement speed of the lower reference mark MA2 is less than a predetermined threshold, based on the acquired time series data. Specifically, the processing unit 81b performs a fitting process to find 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. The movement speed changes periodically, and the second timing is a point in time where the periodic change in the movement speed occurs. In the third embodiment, the processing unit 81b performs the fitting process based on time series data from which noise has been cut by the time series data noise cut filter 83. In Figure 28, the approximation line is shown as a solid line.

[0096] In step S34 shown in Figure 27, the processing unit 81b is configured to predict the coordinates of the lower reference mark MA2 at the second timing as the coordinates at the lowest movement speed when the movement speed of the lower reference mark MA2 is at its minimum (see Figure 28). In Figure 28, as an example, the point where the movement speed first becomes 0 is used as the minimum (low movement speed coordinate), but the point where the movement speed becomes 0 second or later may also be used as the minimum (low movement speed coordinate). The predicted low movement speed coordinates are transmitted to the joining unit control unit 80b.

[0097] In step S35 shown in Figure 27, the bonding unit control unit 80b is configured to perform alignment processing of 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 low movement speed coincide with the target coordinates. Note that 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 reference mark MA2 based on a plurality of images, predicts a second timing in which the movement speed of the lower reference mark MA2 is less than a predetermined threshold based on the acquired time-series data, and predicts the coordinates of the lower reference mark MA2 at the second timing as low movement speed coordinates. The bonding unit control unit 80b is configured to start the process of bonding the substrate W at the second timing. As a result, since the second timing is predicted based on the time-series data of the movement speed of the lower reference mark MA2, it is possible to predict the second timing even for times when there is no data on the movement speed of the lower reference mark MA2. Therefore, the second timing can be acquired more appropriately, and alignment errors caused by vibration can be suppressed more appropriately. In addition, since the periodicity of the movement speed is grasped based on the time-series data of the movement speed of the lower reference 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 an appropriate second timing.

[0101] In the third embodiment, as described above, the processing unit 81b is configured to perform a fitting process to find 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 lower reference mark MA2 at the second timing as the coordinates at 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 (variable), the time series data is fitted by the approximation line, so the second timing can be easily predicted based on the approximation line obtained 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 noise from the time-series data of the movement speed of the lower reference mark MA2. The processing unit 81b is configured to perform fitting processing based on the time-series data from which noise has been cut by the time-series data noise cut filter 83, and to predict the coordinates at low movement speeds. As a result, since the noise from the time-series data of the movement speed of the lower reference mark MA2 is cut, the time-series data after noise cut is smooth time-series data. Therefore, the processing unit 81b can appropriately fit the movement trajectory of the time-series data after noise cut.

[0103] [Differentiation] It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims rather than by the description of the embodiments above, and further includes all modifications (exceptions) within the meaning and scope equivalent to the claims.

[0104] In the first and second embodiments described above, the bonding unit control unit 80 is configured to perform alignment processing so that the low-speed coordinates and the target coordinates coincide, and then to start the process of bonding the substrates W at a first timing when the feature portion (upper reference mark MA1, lower reference mark MA2) approaches the target coordinates to a distance smaller than a predetermined distance. However, the present invention is not limited to this. For example, the bonding unit control unit 80 may first acquire the first timing and then start the process of bonding the substrates W at a time earlier than the time when the next first timing occurs. This allows for a time lag between the time the bonding unit control unit 80 starts the process of bonding the substrates W and the time when the substrates W are brought close to each other and bonded (contact) together. By anticipating this time lag and starting the process of bonding the substrates W at a time earlier than the time when the first timing occurs, the misalignment between the bonded substrates W can be further suppressed.

[0105] In the first and second embodiments described above, examples were shown in which the process of joining the substrate W is started at a first timing of distance = 0, where the feature portion (upper reference mark MA1, lower reference mark MA2) is at a distance less than a predetermined distance from the target coordinates. However, the present invention is not limited thereto. For example, the process of joining the substrate W may be started with a first timing where the predetermined distance is slightly greater than 0.

[0106] In the first and second embodiments described above, examples were shown in which the movement trajectory acquired by the processing unit (81, 81a) is composed of the actual acquired coordinate data itself, but the present invention is not limited thereto. For example, the movement trajectory acquired by the processing unit (81, 81a) may be a function of the movement trajectory acquired by fitting the acquired coordinate data.

[0107] In the first and second embodiments described above, examples were shown in which a movement trajectory noise cut filter 82 is provided to cut noise from the movement trajectory data of the feature portion (MA1, MA2), but the present invention is not limited thereto. For example, if the noise in the movement trajectory data is relatively low, the movement trajectory noise cut filter 82 may not be provided.

[0108] In the first to third embodiments described above, the processing units (81, 81a, 81b) were shown to acquire the coordinates of the feature portion at which the movement speed of the acquired feature portion (MA1, MA2) is minimized. However, the present invention is not limited to this. For example, the coordinates at which the movement speed is minimized may not be the coordinates at which the movement speed is minimized, but rather coordinates that are smaller than a predetermined threshold and larger than the minimum.

[0109] In the third embodiment described above, the processing unit 81b performs a fitting process to approximate 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 described above, the processing unit 81b is shown to perform fitting processing based on time-series data from which noise has been removed by the time-series data noise cut filter 83. However, the present invention is not limited to this. For example, in cases where the noise in the time-series data is relatively low, the time-series data noise cut filter 83 may not be provided.

[0111] In the first to third embodiments described above, examples were shown in which the feature portion 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 thereto. For example, the feature portion may be an alignment mark (AM1 shown in Figure 6, AM2 shown in Figure 8) provided on the substrate W, the edge E of the substrate W as shown in Figure 29, a notch N or orientation flat O formed on the substrate W, etc. Alternatively, the feature portion may be a circuit provided on the substrate W. Since 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, the effort (process) of newly providing the feature portion on the substrate W can be saved, and the complexity of the structure of the substrate bonding apparatus can be suppressed.

[0112] In the first to third embodiments described above, examples of applying the present invention to a substrate bonding apparatus (1, 1a, 1b) were shown, but 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 Figure 30. This modified substrate processing apparatus 100 is, for example, an exposure apparatus. The substrate processing apparatus 100 comprises a first member 101 and a second member 102 arranged spaced apart from the first member 101. The substrate processing apparatus 100 also comprises an imaging unit 103 arranged on the first member 101. A substrate W is arranged on the second member 102, and a feature portion 104 is formed thereon, and the imaging unit 103 images the feature portion 104. In the substrate processing apparatus 100, for example, similar to the first and second embodiments described above, the moving speed of the feature portion 104 is obtained based on a plurality of images of the moving feature portion 104 captured by the imaging unit 103. Then, the coordinates of the feature portion 104 at the lowest moving speed, where the acquired moving speed of the feature portion 104 is minimized, are obtained. Then, the first member 101 and the second member 102 are moved relative to each other by a moving mechanism (not shown) so that the coordinates of the feature portion 104 at low moving speed coincide with the target coordinates, and an alignment process is performed between the first member 101 and the second member 102. The second member 102 is an example of the "stage" in the claims. [Explanation of symbols]

[0113] 1, 1a, 1b substrate bonding equipment 51 Upper Stage (Stage) 61 Lower Stage (Stage) 62 XY Stage (Movement Mechanism) 72, 72a Reference mark imaging unit (imaging unit) 80, 80a, 80b Joint Unit Control Unit (Control Unit) 81, 81a, 81b Processing Unit 82. Movement Trajectory Noise Cut Filter 83 Time-series data noise reduction filter 100 Substrate Processing Equipment 102 Second component (stage) 103 Imaging Unit 104 Feature section AM1 Upper alignment mark (characteristic part, alignment mark) AM2 Lower alignment mark (characteristic part, alignment mark) E-edge (feature part) MA1 Upper reference mark (characteristic part, reference mark) MA2 Lower reference mark (characteristic part, reference mark) N-notch (characteristic part) O Orientation Flat (Feature Section) W Substrate (object to be processed) W1 Upper Circuit Board W2 Lower Circuit Board

Claims

1. A pair of stages each holding a pair of substrates that are joined together, An imaging unit for imaging a characteristic portion provided on at least one of the stage and the substrate, A control unit that controls a moving mechanism that moves at least one of the pair of stages, The system includes a processing unit that acquires the movement speed of the feature portion based on multiple images of the moving feature portion captured by the imaging unit at multiple different time points, and acquires the coordinates of the feature portion at low movement speed when the acquired movement speed of the feature portion is less than a predetermined threshold, A substrate bonding apparatus, wherein the control unit is configured to perform a positioning process of the pair of substrates by moving at least one of the pair of stages using the moving mechanism so that the coordinates of the feature portion at low moving speed coincide with the target coordinates.

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

3. The substrate bonding apparatus according to claim 2, wherein the processing unit is configured to acquire a first timing in which the feature portion approaches the target coordinates to a distance smaller than the predetermined distance, based on an image of the feature portion continuously captured by the imaging unit.

4. The aforementioned processing unit, Based on the multiple images of the feature portion captured by the imaging unit, the movement trajectory of the feature portion is obtained. The substrate bonding apparatus according to claim 1, configured to acquire the coordinates of the feature portion at a low movement speed based on the movement trajectory of the acquired feature portion.

5. The system further includes a movement trajectory noise cut filter that cuts out noise in the movement trajectory data of the aforementioned feature portion. The substrate bonding apparatus according to claim 4, wherein the processing unit is configured to acquire the coordinates of the feature portion at a low moving speed based on the moving trajectory of the feature portion in a state where noise has been cut off by the moving trajectory noise cut filter.

6. The processing unit obtains the coordinates of the feature portion at the lowest movement speed when the movement speed of the acquired feature portion is minimized. The substrate bonding apparatus according to claim 1, wherein the control unit is configured to perform the alignment process so that the coordinates of the feature portion at the lowest moving speed, where the moving speed is minimized, coincide with the target coordinates.

7. The processing unit acquires time-series data of the movement speed of the feature portion based on the plurality of images, predicts a second timing in which the movement speed of the feature portion becomes less than a predetermined threshold based on the acquired time-series data, and predicts the coordinates of the feature portion 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 find 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 feature portion at the second timing as the coordinates at the low moving speed.

9. The system further includes a time-series data noise reduction filter that cuts out noise in the time-series data of the movement speed of the aforementioned feature portion. The substrate bonding apparatus according to claim 8, wherein the processing unit is configured to perform the fitting process based on time-series data from which noise has been removed by the time-series data noise cut filter, and to predict the coordinates at low moving speed.

10. The substrate bonding apparatus according to 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, the edge of the substrate, and a notch or orientation flat formed on the substrate.

11. The pair of stages includes an upper stage that holds the upper substrate of one of the pair of substrates, and a lower stage that holds the lower substrate of the other of the pair of substrates. The imaging unit is attached to the upper stage and is configured to image the characteristic portion provided on at least one of the lower stage and the lower substrate. 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 moving mechanism so that the coordinates of the feature portion at low moving speed coincide with the target coordinates.

12. The pair of stages includes an upper stage that holds the upper substrate of one of the pair of substrates, and a lower stage that holds the lower substrate of the other 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. The substrate bonding apparatus according to claim 1, wherein the control unit is configured to change the target coordinates by moving the lower stage relative to the upper stage using the moving mechanism so that the coordinates of the feature portion at low moving speed become the new target coordinates, and then execute the alignment process.

13. A stage for holding the object to be processed, An imaging unit that images a characteristic portion provided on at least one of the object to be processed and the stage, A control unit that controls the movement mechanism that moves the aforementioned stage, The system includes a processing unit that acquires the movement speed of the feature portion based on multiple images of the moving feature portion captured by the imaging unit at multiple different time points, and acquires the coordinates of the feature portion at low movement speed when the acquired movement speed of the feature portion is less than a predetermined threshold, A substrate processing apparatus, wherein the control unit is configured to perform an alignment process in which the stage is moved by the moving mechanism so that the coordinates of the acquired feature portion at low moving speed coincide with the target coordinates.

14. A substrate bonding method for bonding a pair of substrates held on a pair of stages, A step of imaging a characteristic portion provided on at least one of the stage and the substrate at multiple different times, A step of obtaining the movement speed of the feature portion based on multiple images of the feature portion captured at multiple different time points, A step of obtaining the coordinates of the feature portion at a low movement speed, where the movement speed of the acquired feature portion is less than a predetermined threshold, A substrate bonding method comprising the step of moving the stage to perform alignment processing of the pair of substrates so that the coordinates of the acquired feature portion at low movement speed coincide with the target coordinates.

Images