Substrate bonding device and substrate bonding method

Abstract

In the present invention, a first chuck holds a first substrate. A second chuck holds a second substrate. A first mark is provided to the first chuck. A second mark is provided to the second chuck. An imaging unit images the first mark and the second mark M separately. On the basis of a first image obtained as a result of the imaging unit imaging the first mark, the control unit predicts a first mark location at which the first mark is located. On the basis of a second image obtained as a result of the imaging unit imaging the second mark M, the control unit predicts a second mark location at which the second mark M is located. On the basis of the predicted first mark location and second mark location, the control unit controls at least a second actuator and thereby bonds the first substrate and the second substrate.

Description

Substrate bonding apparatus and substrate bonding method

[0001] The present invention relates to a substrate bonding apparatus and a substrate bonding method.

[0002]

[0003] Conventionally, there has been known an apparatus that includes a first member that holds a first substrate, a second member that is disposed opposite the first member and that holds a second substrate, an actuator that moves the second member, and an imaging unit that images a first alignment mark provided on the first member and a second alignment mark provided on the second member, and that bonds the first substrate and the second substrate together after aligning the first member and the second member. For example, Patent Document 1 describes an apparatus that includes a first holding means that holds a first plate-like body on which the first alignment mark is formed, a second holding means that holds a second optically transparent plate-like body on which the second alignment mark is formed, and an imaging means that is disposed on the opposite side of the second plate-like body from the first plate-like body and that images the first plate-like body and the second plate-like body.

[0003] JP 2014-165331 A

[0004] Incidentally, for example, in a substrate bonding apparatus that bonds two substrates together, the two substrates are electrically connected to each other, so it is required to align the two substrates with high precision.

[0005] However, in a substrate bonding apparatus, for example, fluctuations in the relative position between the first member and the second member occur due to vibrations or thermal drift (hereinafter sometimes referred to as vibrations, etc.), which can result in a decrease in alignment accuracy. Specifically, for example, even if a determination is made as to whether the relative position of the alignment mark of the second substrate with respect to the alignment mark of the first substrate is within a target range, and the second substrate is moved toward the first substrate and bonded after determining that it is within the target range, the alignment accuracy between the first substrate and the second substrate decreases due to vibrations, etc. In other words, it is difficult to bond the first substrate and the second substrate with high accuracy.

[0006] At least one aspect of the present invention provides a substrate bonding apparatus and a substrate bonding method that are capable of bonding a first substrate and a second substrate together with high precision.

[0007] According to one aspect of the present invention, a substrate bonding apparatus includes a first chuck, a second chuck, a first actuator, a second actuator, a first mark, a second mark, one or more imaging units, and a controller. The first chuck holds a first substrate. The second chuck is disposed opposite the first chuck and holds a second substrate. The first actuator moves one of the first chuck and the second chuck in a direction intersecting the direction in which the first chuck and the second chuck face each other. The second actuator moves the first chuck or the second chuck in the direction in which the first chuck and the second chuck face each other. The first mark is disposed on the first chuck. The second mark is disposed on the second chuck. The one or more imaging units image the first mark and the second mark. The controller controls the first actuator and the second actuator. The imaging unit separately images the first mark and the second mark. The control unit predicts a first mark position where the first mark is located based on a first image of the first mark captured by the imaging unit. The control unit predicts a second mark position where the second mark is located based on a second image of the second mark captured by the imaging unit. The control unit controls at least the second actuator based on the predicted first mark position and the predicted second mark position to bond the first substrate and the second substrate together.

[0008] In one embodiment, the number of the imaging units is one, and the one imaging unit captures images of the first mark and the second mark at different times.

[0009] In one embodiment, there are a plurality of imaging units, and the plurality of imaging units simultaneously capture images of the first mark and the second mark.

[0010] In one embodiment, the imaging unit is attached to either the first chuck or the second chuck.

[0011] In one embodiment, the first chuck has a light-transmitting transparent plate on which the first mark is provided, and / or the second chuck has a light-transmitting transparent plate on which the second mark is provided, and the imaging unit images at least one of the first mark and the second mark through the transparent plate.

[0012] In one embodiment, the control unit calculates the timing at which the relative position of the second substrate with respect to the first substrate will be within a target range based on the predicted first mark position and second mark position, and bonds the first substrate and the second substrate together at the calculated timing.

[0013] In one embodiment, the control unit predicts the first mark position based on a partial region of the first image, and the control unit predicts the second mark position based on a partial region of the second image.

[0014] In one embodiment, the control unit controls the first actuator to align the first substrate and the second substrate, and controls the second actuator to bond the first substrate and the second substrate together.

[0015] According to another aspect of the present invention, a substrate bonding method includes the steps of holding a first substrate with a first chuck, holding a second substrate with a second chuck disposed opposite the first chuck, separately capturing images of a first mark disposed on the first chuck and a second mark disposed on the second chuck with one or more imaging units, predicting a first mark position where the first mark is located based on a first image of the first mark captured by the imaging unit, predicting a second mark position where the second mark is located based on a second image of the second mark captured by the imaging unit, and bonding the first substrate and the second substrate together based on the predicted first mark position and second mark position.

[0016] According to the present invention, it is possible to provide a substrate bonding apparatus and a substrate bonding method that are capable of bonding a first substrate and a second substrate together with high precision.

[0017] FIG. 1 is a side view schematically showing the overall configuration of the substrate bonding apparatus of the first embodiment. FIG. 2 is a block diagram showing the configuration of the substrate bonding apparatus of the first embodiment. FIG. 3 is a flowchart showing a substrate bonding method of the substrate bonding apparatus of the first embodiment. FIG. 4 is a plan view showing a schematic configuration of the substrate bonding apparatus of the second embodiment. FIG. 5 is a perspective view schematically showing the structure of the bonding unit of the second embodiment. FIG. 6 is a schematic view showing the structure around the second chuck of the bonding unit from the X direction. FIG. 7 is a schematic view showing the structure around the second chuck of the bonding unit from the Y direction. FIG. 8 is a schematic view showing the structure around the support table from below. FIG. 9 is a perspective view schematically showing the structure of the bonding unit from below. FIG. 10 is a block diagram of the substrate bonding apparatus of the second embodiment. FIG. 11 is a flowchart showing a substrate bonding method using the bonding unit. FIG. 12 is a perspective view schematically showing the structure of the bonding unit of the substrate bonding apparatus of the third embodiment from below.

[0018] Hereinafter, an embodiment of a substrate bonding apparatus according to the present invention will be described with reference to the drawings. In the drawings, identical or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated. In this specification, to facilitate understanding of the invention, mutually orthogonal X-, Y-, and Z-axes may be described. In this embodiment, the X- and Y-axes are parallel to the horizontal direction, and the Z-axis is parallel to the vertical direction. For convenience, one side Z1 of the Z-axis direction indicates the upward direction, and the other side Z2 of the Z-axis direction indicates the downward direction. However, the upward and downward directions are defined for convenience of explanation and do not necessarily correspond to the vertical direction.

[0019] First Embodiment A substrate bonding apparatus 1 according to a first embodiment of the present invention will be described with reference to Figures 1 to 3. Figure 1 is a side view schematically showing the overall configuration of the substrate bonding apparatus 1 of the first embodiment.

[0020] First, a schematic configuration of a substrate bonding apparatus 1 will be described with reference to Fig. 1. As shown in Fig. 1, the substrate bonding apparatus 1 includes a support frame SF, a first chuck 10, a second chuck 20, a first actuator 510, and a second actuator 520.

[0021] The support frame SF is fixed to a floor (not shown) on which the substrate bonding apparatus 1 is installed. The support frame SF is made of, for example, metal. The support frame SF has, for example, a plurality of first frames SF1 extending in the vertical direction and a plurality of second frames SF2 extending in the horizontal direction. In this embodiment, four first frames SF1 are provided, and four second frames SF2 are provided. The four first frames SF1 include two first frame SF1 sets (not shown), each consisting of two first frames SF1 arranged at a predetermined interval in the X direction. These two first frame SF1 sets overlap each other in the X direction and are arranged at a predetermined interval in the Y direction. The four first frames SF1 are arranged at positions corresponding to the four corners of a rectangle in a plan view. The lower end of each first frame SF1 is fixed to the floor. The four second frames SF2 include two second frames SF2 connecting the upper ends of adjacent first frames SF1 in the X direction and two second frames SF2 connecting the upper ends of adjacent first frames SF1 in the Y direction. That is, the four second frames SF2 are arranged at positions corresponding to the four sides of a rectangle in a plan view. The support frame SF may be fixed to a wall or ceiling of a room in which the substrate bonding apparatus 1 is installed.

[0022] The first chuck 10 holds the first substrate W1. In this embodiment, the first chuck 10 adsorbs and holds the first substrate W1. The first chuck 10 holds the first substrate W1 substantially horizontally. The first chuck 10 is, for example, a vacuum chuck or an electrostatic chuck.

[0023] The second chuck 20 is disposed opposite the first chuck 10. The first chuck 10 and the second chuck 20 are spaced apart by a predetermined distance. The direction in which the first chuck 10 and the second chuck 20 are spaced apart is not particularly limited, but may be, for example, the vertical direction (Z direction). In this embodiment, the second chuck 20 is disposed below the first chuck 10.

[0024] The second chuck 20 holds the second substrate W2. In this embodiment, the second chuck 20 adsorbs and holds the second substrate W2. The second chuck 20 holds the second substrate W2 substantially horizontally. The second chuck 20 is, for example, a vacuum chuck or an electrostatic chuck.

[0025] Hereinafter, unless otherwise required, the first substrate W1 and the second substrate W2 may be referred to as the substrate W.

[0026] The substrate W is, for example, a semiconductor wafer, a substrate for a liquid crystal display device, a substrate for a plasma display, a substrate for a field emission display (FED), a substrate for an optical disk, a substrate for a magnetic disk, a substrate for a magneto-optical disk, a substrate for a photomask, a ceramic substrate, or a substrate for a solar cell. In this embodiment, the substrate W is a semiconductor wafer.

[0027] The substrate W has, for example, a circular or rectangular shape in a plan view. In this embodiment, the substrate W has a substantially circular shape in a plan view.

[0028] In this embodiment, the substrate W has a front surface Wa and a back surface Wb located opposite the front surface Wa. The front surface Wa is a device-forming surface on which elements are formed. The back surface Wb is a non-device-forming surface on which elements are not formed. The first substrate W1 is held on the lower surface of the first chuck 10 with the front surface Wa facing downward. The second substrate W2 is held on the upper surface of the second chuck 20 with the front surface Wa facing upward. In this embodiment, for ease of understanding, the substrates W are not turned upside down unless otherwise specified.

[0029] The first chuck 10 and the second chuck 20 are configured to be relatively movable in directions (X and Y directions) that intersect with the direction (Z direction) in which the first chuck 10 and the second chuck 20 face each other. In this embodiment, the first actuator 510 moves the second chuck 20 in the X and Y directions.

[0030] The first actuator 510 is fixed to the floor (not shown) on which the substrate bonding apparatus 1 is placed.

[0031] The first actuator 510 is not particularly limited, but includes, for example, a drive source such as a motor or a pump, and a transmission member such as a gear that transmits the drive force of the drive source to the second chuck 20 .

[0032] The first chuck 10 and the second chuck 20 are configured to be relatively movable in a direction (Z direction) in which the first chuck 10 and the second chuck 20 face each other. Specifically, the second actuator 520 moves the first chuck 10 or the second chuck 20 in the Z direction. In this embodiment, the second actuator 520 moves the first chuck 10 in the Z direction.

[0033] The second actuator 520 is fixed to the first frame SF1, for example.

[0034] The second actuator 520 is not particularly limited, but includes, for example, a drive source such as a motor or a pump, and a transmission member such as a gear that transmits the drive force of the drive source to the second chuck 20 .

[0035] The substrate bonding apparatus 1 aligns the first chuck 10 and the second chuck 20. Specifically, the substrate bonding apparatus 1 aligns the first substrate W1 and the second substrate W2 in the horizontal direction by aligning the first chuck 10 and the second chuck 20 in the horizontal direction. For example, the substrate bonding apparatus 1 aligns the first chuck 10 and the second chuck 20 using the first actuator 510 so that a second point P2 at a predetermined position (e.g., the center) on the surface Wa (here, the upper surface) of the second substrate W2 is positioned directly below a first point P1 at a predetermined position (e.g., the center) on the surface Wa (here, the lower surface) of the first substrate W1. Note that the first point P1 does not have to be located at the center of the surface Wa of the first substrate W1. Furthermore, the second point P2 does not have to be located at the center of the surface Wa of the second substrate W2.

[0036] The substrate bonding apparatus 1 also bonds the first substrate W1 and the second substrate W2 together. Specifically, the first substrate W1 and the second substrate W2 are bonded together by moving the first substrate W1 downward using the second actuator 520.

[0037] The substrate bonding apparatus 1 includes a first mark M10, a second mark M20, an imaging unit 50, and a control device 90 (see FIG. 2).

[0038] The first mark M10 is disposed on the first chuck 10. The first mark M10 may be formed on the first chuck 10, or may be formed on a member attached to the first chuck 10. In the present embodiment, the first chuck 10 has a through-hole 10a, and the first mark M10 is disposed in the through-hole 10a. The first mark M10 includes, for example, a recess formed on the upper or lower surface of a light-transmitting transparent plate 30 such as glass that is fixed in the through-hole 10a. The first mark M10 is formed in a predetermined shape on the upper or lower surface of the transparent plate 30 by etching or the like.

[0039] The second mark M20 is disposed on the second chuck 20. The second mark M20 may be formed on the second chuck 20, for example, or may be formed on a member attached to the second chuck 20. In this embodiment, the second mark M20 includes, for example, a recess formed in a predetermined shape by etching or the like on the upper surface of a member 35 fixed to the second chuck 20. Note that, for example, if the member 35 is a transparent plate having light-transmitting properties, the second mark M20 may be formed on the lower surface of the member 35.

[0040] In this embodiment, for ease of understanding, it is assumed that the horizontal positional relationship of the center of the first substrate W1 relative to the center of the first mark M10 is the same as the horizontal positional relationship of the center of the second substrate W2 relative to the center of the second mark M20. In other words, if the second mark M20 is aligned with the first mark M10 in the horizontal direction, the second substrate W2 can be aligned with the first substrate W1 in the horizontal direction.

[0041] The imaging unit 50 captures images of the first mark M10 and the second mark M20. The imaging unit 50 is disposed in a position where it can capture images of the first mark M10 and the second mark M20. In this embodiment, the imaging unit 50 is disposed above the first chuck 10. The imaging unit 50 is fixed to, for example, the second frame SF2 of the support frame SF. In this embodiment, the imaging unit 50 captures an image of the second mark M20 through the transparent plate 30.

[0042] The imaging unit 50 includes, for example, a camera. The imaging unit 50 includes an imaging element. For example, the imaging element is a charge coupled device (CCD) image sensor or a complementary metal oxide semiconductor (CMOS) image sensor. The imaging unit 50 transmits captured imaging data to the control device 90 (see FIG. 2 ). The imaging data includes image data.

[0043] Next, the substrate bonding apparatus 1 will be further described with reference to Fig. 2. Fig. 2 is a block diagram showing the configuration of the substrate bonding apparatus 1 of the first embodiment.

[0044] 2, the control device 90 controls the substrate bonding apparatus 1. The control device 90 controls the first actuator 510, the second actuator 520, and the imaging unit 50.

[0045] The control device 90 controls various operations of the substrate bonding apparatus 1. The control device 90 causes the substrate bonding apparatus 1 to align the first chuck 10 and the second chuck 20. The control device 90 aligns the first chuck 10 and the second chuck 20 based on image data captured by the imaging unit 50, and bonds the first substrate W1 and the second substrate W2 together.

[0046] The control device 90 includes a control unit 91 and a storage unit 93. The control unit 91 has a processor. The control unit 91 has, for example, a central processing unit (CPU). Alternatively, the control unit 91 may have a general-purpose computer. The control unit 91 may also have a graphics processing unit (GPU) and a field programmable gate array (FPGA).

[0047] The storage unit 93 stores data and computer programs, for example, data that defines the processing content and processing procedures for alignment and joining.

[0048] The storage unit 93 includes a main storage device and an auxiliary storage device. The main storage device is, for example, a semiconductor memory. The auxiliary storage device is, for example, a semiconductor memory and / or a hard disk drive. The storage unit 93 may include removable media. The control unit 91 executes a computer program stored in the storage unit 93 to perform the alignment operation and the joining operation.

[0049] Furthermore, the control unit 91 controls the first actuator 510 based on the image captured by the imaging unit 50 to align the first chuck 10 and the second chuck 20 in the horizontal direction. This will be described in detail below.

[0050] The control unit 91 controls the imaging unit 50. The control unit 91 controls the imaging unit 50 to capture images of the first mark M10 and the second mark M20 separately. In this embodiment, the control unit 91 controls the imaging unit 50 to capture images of the first mark M10 and the second mark M20 at different timings. As a result, the imaging unit 50 captures images of the first mark M10 and the second mark M20 separately. In this embodiment, the imaging unit 50 captures images of the first mark M10 and the second mark M20 at different timings. Furthermore, in this embodiment, the imaging unit 50 adjusts the focal length to focus on the first mark M10 to capture the first mark M10, and to focus on the second mark M20 to capture the second mark M20. Note that the imaging unit 50 captures a predetermined number of first images or more and captures a predetermined number of second images or more.

[0051] The control unit 91 predicts the first mark position where the first mark M10 will be located, based on a first image of the first mark M10 captured by the imaging unit 50. Specifically, the control unit 91 calculates the position of the center of the first mark M10 relative to the center of the first image based on the first image. Note that the first mark position is, for example, the position of the center of the first mark M10 relative to the center of the first image. The control unit 91 then predicts the future first mark position based on a predetermined number or more of first mark positions calculated from a predetermined number or more of first images. For example, the control unit 91 predicts the first mark position from several seconds to several tens of seconds into the future. In this embodiment, the control unit 91 generates first mark position data that associates a future time with the predicted first mark position, and stores the first mark position data in the storage unit 93.

[0052] Similarly, the control unit 91 predicts the second mark position where the second mark M20 will be located, based on a second image in which the imaging unit 50 captures the second mark M20. Specifically, the control unit 91 calculates the position of the center of the second mark M20 relative to the center of the second image based on the second image. Note that the second mark position is, for example, the position of the center of the second mark M20 relative to the center of the second image. Then, the control unit 91 predicts the future second mark position based on a predetermined number or more of second mark positions calculated from a predetermined number or more of second images. For example, the control unit 91 predicts the second mark position from several seconds to several tens of seconds into the future. In this embodiment, the control unit 91 generates second mark position data that associates a future time with the predicted second mark position, and stores the second mark position data in the storage unit 93.

[0053] The control unit 91 may predict the first mark position and the second mark position by using a predetermined function or formula, or by using a trained model generated by machine learning. When generating the trained model, the control unit 91 may generate the trained model by using, for example, the calculated first mark positions and second mark positions and the time of image capture.

[0054] The machine learning algorithm is not particularly limited as long as it is supervised learning, and may be, for example, a multilayer perceptron, a support vector machine, a linear multiple regression, a Kalman filter, a decision tree, a nearest neighbor method, a naive Bayes classifier, a support vector machine, or a neural network. Therefore, the trained model includes, for example, a multilayer perceptron, a support vector machine, a linear multiple regression, a Kalman filter, a decision tree, a nearest neighbor method, a naive Bayes classifier, a support vector machine, or a neural network.

[0055] For example, a neural network includes an input layer, one or more hidden layers, and an output layer. Specifically, the neural network is a deep neural network (DNN), a recurrent neural network (RNN), or a convolutional neural network (CNN), and performs deep learning. For example, a deep neural network includes an input layer, multiple hidden layers, and an output layer.

[0056] In this embodiment, the trained model includes a multi-layer perceptron or a support vector machine.

[0057] The control unit 91 controls at least the second actuator 520 based on the predicted first and second mark positions to bond the first substrate W1 and the second substrate W2 together. Specifically, the control unit 91 calculates the timing at which the horizontal position of the second substrate W2 relative to the first substrate W1 will fall within a target range. Thereafter, the control unit 91 controls the second actuator 520 to bond the first substrate W1 and the second substrate W2 together at the calculated timing.

[0058] Next, with reference to FIG. 3, a substrate bonding method of the substrate bonding apparatus 1 of this embodiment will be described. FIG. 3 is a flowchart showing the substrate bonding method of the substrate bonding apparatus 1 of the first embodiment. In this embodiment, the substrate bonding method of the substrate bonding apparatus 1 includes steps S11 to S18. Steps S11 to S18 are executed by the control unit 91. Step S11 is an example of the "step of holding a first substrate" of the present invention. Step S12 is an example of the "step of holding a second substrate" of the present invention. Step S13 is an example of the "step of taking an image" of the present invention. Step S14 is an example of the "step of predicting a first mark position" of the present invention. Step S15 is an example of the "step of taking an image" of the present invention. Step S16 is an example of the "step of predicting a second mark position" of the present invention. Step S17 is an example of the "step of calculating" of the present invention. Step S18 is an example of the "step of bonding" of the present invention.

[0059] For ease of explanation, it is assumed here that the first mark M10 and the second mark M20 are preliminarily arranged within a predetermined range in the horizontal direction. The predetermined range is larger than the target range and encompasses the target range. The method for arranging the first mark M10 and the second mark M20 within the predetermined range in the horizontal direction is not particularly limited. For example, the first mark M10 and the second mark M20 may be arranged within the predetermined range in the horizontal direction by moving the second chuck 20 using the first actuator 510 based on the imaging results of the imaging unit 50. Furthermore, for example, the first mark M10 and the second mark M20 may be arranged within the predetermined range in the horizontal direction when a transport robot (not shown) that transports the substrate W transfers the first substrate W1 and the second substrate W2 to the first chuck 10 and the second chuck 20, respectively.

[0060] 3, in step S11, the first chuck 10 holds the first substrate W1. At this time, the control unit 91 may control the first chuck 10 so that the first chuck 10 holds the first substrate W1.

[0061] Next, in step S12, the second chuck 20 holds the second substrate W2. At this time, the control unit 91 may control the second chuck 20 so that the second chuck 20 holds the second substrate W2.

[0062] Next, in step S13, the imaging unit 50 images the first mark M10. Specifically, the control unit 91 controls the imaging unit 50 so that the imaging unit 50 images the first mark M10. As a result, the imaging unit 50 focuses on the first mark M10 and images the first mark M10. At this time, the imaging unit 50 captures several tens to several hundreds of images. The image data captured by the imaging unit 50 is transmitted to the control unit 91. The image data includes information that associates the captured image captured by the imaging unit 50 with the capture time.

[0063] Next, in step S14, the control unit 91 predicts the first mark position where the first mark M10 will be located. Specifically, the control unit 91 calculates the position of the center of the first mark M10 relative to the center of the first image (first mark position) based on the first image. Then, the control unit 91 predicts the future first mark position based on multiple first mark positions calculated from multiple first images. Note that the control unit 91 predicts the first mark position up to several seconds to several tens of seconds into the future.

[0064] Next, in step S15, the imaging unit 50 images the second mark M20. Specifically, the control unit 91 controls the imaging unit 50 so that the imaging unit 50 images the second mark M20. As a result, the imaging unit 50 focuses on the second mark M20 and images the second mark M20. At this time, the imaging unit 50 captures tens to hundreds of images or more. The image data captured by the imaging unit 50 is transmitted to the control unit 91. The image data includes information that associates the captured image captured by the imaging unit 50 with the capture time.

[0065] Next, in step S16, the control unit 91 predicts the second mark position where the second mark M20 will be located. Specifically, the control unit 91 calculates the position of the center of the second mark M20 relative to the center of the second image (second mark position) based on the second image. Then, the control unit 91 predicts the future second mark position based on multiple second mark positions calculated from multiple second images. Note that the control unit 91 predicts the second mark position up to several seconds to several tens of seconds into the future.

[0066] Next, in step S17, the control unit 91 calculates the timing at which the relative position of the second substrate W2 with respect to the first substrate W1 will fall within a target range. Specifically, the control unit 91 calculates the timing at which the relative position of the second mark position with respect to the first mark position will fall within the target range. The target range is, for example, a range of several nanometers to several tens of nanometers centered on the first mark position.

[0067] Next, in step S18, the control unit 91 bonds the first substrate W1 and the second substrate W2 together when the relative position of the second substrate W2 with respect to the first substrate W1 falls within a target range. Specifically, the control unit 91 controls the second actuator 520 to lower the first chuck 10 so that the first substrate W1 and the second substrate W2 come into contact with each other when the first mark position and the second mark position fall within the target range.

[0068] In this manner, the first substrate W1 and the second substrate W2 are bonded together.

[0069] In this embodiment, as described above, the control unit 91 predicts the position of the first mark based on the first image of the first mark M10 captured by the imaging unit 50. The control unit 91 predicts the position of the second mark based on the second image of the second mark M20 captured by the imaging unit 50. The control unit 91 then controls at least the second actuator 520 based on the predicted first and second mark positions to bond the first substrate W1 and the second substrate W2 together. Therefore, even if a relative positional change occurs between the first substrate W1 and the second substrate W2 due to vibration or the like, the relative positional change between the first substrate W1 and the second substrate W2 can be predicted and the first substrate W1 and the second substrate W2 can be bonded together with high accuracy.

[0070] Furthermore, as described above, the first mark M10 and the second mark M20 are separately imaged. Specifically, in this embodiment, the imaging unit 50 images the first mark M10 and the second mark M20 at different times. Therefore, for example, even if it is not possible to simultaneously image the first mark M10 and the second mark M20 using a single imaging unit 50, the first mark M10 and the second mark M20 can be easily imaged using a single imaging unit 50. Note that when aligning marks M10 and M20 to within an order of several hundred nanometers to several tens of nanometers, it is necessary to set the imaging magnification of the imaging unit 50 to be very large, making it difficult to simultaneously image the first mark M10 and the second mark M20, which are at different heights, using a single imaging unit 50.

[0071] Furthermore, as described above, the imaging unit 50 captures an image of the second mark M20 through the transparent plate 30. Therefore, one imaging unit 50 can easily capture images of two alignment marks (the first mark M10 and the second mark M20).

[0072] Furthermore, as described above, the control unit 91 calculates the timing at which the relative position of the second substrate W2 with respect to the first substrate W1 will be within the target range based on the predicted first and second mark positions, and bonds the first substrate W1 and the second substrate W2 together at the calculated timing. Therefore, the amount of positional misalignment of the second substrate W2 with respect to the first substrate W1 can be easily kept within the target range.

[0073] Second Embodiment A substrate bonding apparatus 1 according to a second embodiment of the present invention will be described with reference to Figures 4 to 11. Figure 4 is a plan view showing a schematic configuration of the substrate bonding apparatus 1 of the second embodiment. In the second embodiment, an example will be described in which, unlike the first embodiment, the imaging unit 50 is fixed to the first chuck 10.

[0074] 4, the substrate bonding apparatus 1 stacks and bonds a first substrate W1 and a second substrate W2 together. In this embodiment, the substrate bonding apparatus 1 performs, for example, an activation process, a cleaning process, and a bonding process on the first substrate W1 and the second substrate W2.

[0075] The substrate W has a plurality of (e.g., tens to hundreds) semiconductor chips (not shown). Each semiconductor chip constitutes an integrated circuit such as a CPU and / or a DRAM. Each semiconductor chip has, for example, a semiconductor element layer (not shown) in which a plurality of semiconductor elements such as transistors are formed, and a plurality of electrodes (not shown). The electrodes are made of a metal material such as copper, gold, or aluminum. In this embodiment, the electrodes are made of, for example, copper.

[0076] The electrodes of the first substrate W1 and the electrodes of the second substrate W2 are bonded and electrically connected, and the electrodes of the second substrate W2 are positioned so as to overlap with the electrodes of the first substrate W1 when the first substrate W1 is turned upside down.

[0077] The electrodes of the first substrate W1 are exposed on the front surface Wa of the first substrate W1. The electrodes of the second substrate W2 are exposed on the front surface Wa of the second substrate W2. The electrodes of the first substrate W1 and the second substrate W2 may be formed as, for example, bumps and / or electrode pads.

[0078] The substrate bonding apparatus 1 includes a transport path CP, a first load port LP1, a second load port LP2, a third load port LP3, an activation unit AU, a cleaning unit CU, a pre-alignment unit PU, a transport unit TU, a bonding unit JU, a center robot CR, a transport robot TR, and a control device 90.

[0079] The transport path CP transports the first substrate W1 and the second substrate W2. The transport path CP has, for example, a linear shape. The center robot CR, the first load port LP1, the second load port LP2, the third load port LP3, the activation unit AU, the cleaning unit CU, the pre-alignment unit PU, the transport unit TU, and the bonding unit JU are arranged to face the transport path CP.

[0080] The center robot CR holds and transports the first substrate W1 and the second substrate W2. The center robot CR moves within the transport path CP. The center robot CR transports the first substrate W1 and the second substrate W2 between the first load port LP1, the second load port LP2, the third load port LP3, the activation unit AU, the cleaning unit CU, and the transport unit TU.

[0081] The first load port LP1 accommodates a plurality of (e.g., 25) first substrates W1. Specifically, the plurality of first substrates W1 are accommodated in a stacked state in a FOUP (also called a carriage) (not shown). The FOUP accommodating the first substrates W1 is disposed on the first load port LP1.

[0082] The second load port LP2 accommodates a plurality of (e.g., 25) second substrates W2. Specifically, the plurality of second substrates W2 are accommodated in a stacked state in a FOUP (not shown). The FOUP accommodating the second substrates W2 is disposed on the second load port LP2.

[0083] The third load port LP3 accommodates a plurality of (e.g., 25) laminated substrates WL. Specifically, the plurality of laminated substrates WL are accommodated in a stacked state in a hoop (not shown). The hoop accommodating the laminated substrates WL is disposed on the third load port LP3.

[0084] The laminated substrate WL is a substrate in which a first substrate W1 and a second substrate W2 are stacked and bonded together. In this embodiment, the laminated substrate WL is formed by stacking and bonding the first substrate W1 and the second substrate W2.

[0085] The activation unit AU activates the surfaces of the first substrate W1 and the second substrate W2. The activation unit AU activates at least the surfaces of the electrodes of the first substrate W1 and the second substrate W2. Specifically, the activation unit AU performs plasma processing on the first substrate W1 and the second substrate W2. The type of gas used in the plasma processing is not particularly limited, but may be, for example, oxygen or nitrogen.

[0086] The activation unit AU includes, for example, a high-frequency power supply and a pair of electrodes to which a high-frequency voltage is applied. By applying a high-frequency voltage between the pair of electrodes, the processing gas is converted into plasma. For example, when oxygen gas is used as the processing gas, the oxygen gas is converted into plasma and becomes oxygen ions. When the oxygen ions are irradiated onto the surface of the first substrate W1 or the second substrate W2, dangling bonds (unbonded hands) are generated on the surface of the electrode. In other words, the surface of the electrode is activated.

[0087] The cleaning unit CU cleans the first substrate W1 and the second substrate W2. The cleaning unit CU supplies a cleaning liquid to the first substrate W1 and the second substrate W2. Specifically, the cleaning unit CU has a cleaning nozzle (not shown) that ejects the cleaning liquid. Examples of the cleaning liquid include deionized water (DIW), carbonated water, electrolytic ionized water, ozone water, ammonia water, hydrochloric acid water with a diluted concentration (for example, about 10 ppm to 100 ppm), and reduced water (hydrogen water). In this embodiment, the cleaning liquid is pure water such as DIW.

[0088] The electrodes of the first substrate W1 and the second substrate W2 are cleaned by the cleaning unit CU, and hydroxyl groups are formed on the surfaces of the electrodes.

[0089] The transport unit TU is disposed so as to face the transport path CP, the pre-alignment unit PU, and the joining unit JU. The transport unit TU accommodates a transport robot TR.

[0090] The transport robot TR holds and transports the first substrate W1 and the second substrate W2. The transport robot TR delivers the first substrate W1 and the second substrate W2 between the center robot CR, the pre-alignment unit PU, and the bonding unit JU. The transport robot TR is fixed to the floor of the transport unit TU and does not move within the transport unit TU. For this reason, the transport accuracy of the transport robot TR is higher than that of the center robot CR, which moves within the transport path CP.

[0091] The pre-alignment unit PU aligns the first substrate W1 and the second substrate W2 one by one. In this embodiment, the pre-alignment unit PU aligns the first substrate W1 and the second substrate W2 one by one before alignment in the joining unit JU. Note that alignment by the pre-alignment unit PU may be referred to as pre-alignment.

[0092] 5 is a perspective view schematically showing the structure of the bonding unit JU of the second embodiment. The bonding unit JU bonds the first substrate W1 and the second substrate W2 under atmospheric pressure. As shown in FIG. 5, the bonding unit JU includes a base 2, a first actuator 200, and a second actuator 100 in addition to the first chuck 10 and second chuck 20 described in the first embodiment.

[0093] The base 2 supports the first chuck 10, the second chuck 20, the first actuator 200, the second actuator 100, etc. The base 2 is made of a material that is not easily deformed by the weight and heat of the first actuator 200, the second actuator 100, etc. The base 2 is made of, for example, stone.

[0094] In this embodiment, the first chuck 10 holds the first substrate W1. In this embodiment, the first chuck 10 turns the first substrate W1 upside down and moves the first substrate W1 up and down, as will be described later.

[0095] The first chuck 10 has a first stage 11 and a first holding part 12 fixed to the first stage 11. The first stage 11 has one surface 11a to which the first holding part 12 is attached. The first stage 11 has, for example, a rectangular parallelepiped shape. The first stage 11 is made of, for example, ceramic, metal, or the like having a small linear expansion coefficient.

[0096] The first holding unit 12 holds the first substrate W1. The holding method by the first holding unit 12 is not particularly limited, but may be, for example, a vacuum method. That is, the first holding unit 12 adsorbs the back surface Wb of the first substrate W1 (the surface opposite to the surface to be bonded to the second substrate W2). The first holding unit 12 has, for example, a cylindrical or disc shape. The first holding unit 12 is formed, for example, from ceramic or metal with a low linear expansion coefficient.

[0097] In this embodiment, the second chuck 20 holds the second substrate W2. In this embodiment, as will be described later, the second chuck 20 moves the second substrate W2 in the horizontal direction along the upper surface of the base 2. In addition, as will be described later, the second chuck 20 rotates the second substrate W2 in the circumferential direction.

[0098] The second chuck 20 has a second stage 21 and a second holding portion 22 fixed to the second stage 21. The second stage 21 holds the second holding portion 22. The second stage 21 has, for example, a rectangular parallelepiped shape. The second stage 21 is made of, for example, ceramic, metal, or the like having a small linear expansion coefficient.

[0099] The second holding unit 22 holds the second substrate W2. The holding method by the second holding unit 22 is not particularly limited, but may be, for example, a vacuum method. That is, the second holding unit 22 adsorbs the back surface Wb of the second substrate W2 (the surface opposite to the surface to be bonded to the first substrate W1). The second holding unit 22 has, for example, a cylindrical or disc shape. The second holding unit 22 is formed, for example, from ceramic or metal with a low linear expansion coefficient.

[0100] The second holding unit 22 is configured to be rotatable in the circumferential direction. Specifically, the second holding unit 22 is configured to be rotatable around its center. In other words, the second holding unit 22 rotates the second substrate W2 in the circumferential direction. The second holding unit 22 also rotates the second substrate W2 within a horizontal plane.

[0101] The second actuator 100 moves the first chuck 10. In this embodiment, the second actuator 100 turns the first chuck 10 upside down or moves the first chuck 10 upside down. As a result, the first substrate W1 is turned upside down or moved upside down.

[0102] Specifically, the second actuator 100 has an inverting section 110, an elevating section 120, and a first gantry 130. In Fig. 5, the first gantry 130 is depicted by a two-dot chain line.

[0103] The inversion unit 110 inverts the first chuck 10 upside down. The inversion unit 110 has a rotating shaft unit 111 fixed to the first chuck 10 and a first rotating unit (not shown) that rotates the rotating shaft unit 111. The rotating shaft unit 111 may be composed of a single shaft unit that penetrates the first chuck 10, or may be composed of a pair of shaft units that are arranged on either side of the first chuck 10. The first rotating unit has, for example, a stepping motor. The first rotating unit rotates the rotating shaft unit 111 by 180 degrees, thereby inverting the first chuck 10 upside down.

[0104] In this embodiment, the joining unit JU includes an angle detection unit (not shown). The angle detection unit detects the angle of the first chuck 10 relative to the second chuck 20. The angle detection unit includes, for example, three or more distance measurement sensors. The distance measurement sensors are attached, for example, to one surface 11 a of the first chuck 10 and measure the distance to the second chuck 20. By rotating the rotation shaft portion 111 based on the detection results of the distance measurement sensors, the first chuck 10 can be positioned parallel to the second chuck 20.

[0105] The lifting unit 120 moves the first chuck 10 up and down. The lifting unit 120 has a pair of support members 121 and a pair of lifting mechanisms 122. The support members 121 support the reversing unit 110. The support members 121 rotatably support the rotation shaft portion 111 of the reversing unit 110.

[0106] The lifting mechanism 122 has a plurality of movers 122a and a plurality of rails (not shown). The movers 122a are fixed to the support member 121. Two movers 122a are fixed to one support member 121. The movers 122a move along the rails. The movers 122a have, for example, a coil. The movers 122a also have an encoder that detects the distance moved along the rails (not shown).

[0107] A rail (not shown) is fixed to the first gantry 130 so as to extend in the vertical direction. The rail has a plurality of magnets. The magnets are arranged so that their north and south poles are alternately aligned in the vertical direction. When a current is passed through the coil of the mover 122a, the mover 122a moves along the rail. When the mover 122a moves up and down along the rail, the first chuck 10 moves up and down.

[0108] The first actuator 200 moves the second chuck 20. In this embodiment, the first actuator 200 moves the second chuck 20 in the horizontal direction along the upper surface of the base 2. In addition, in this embodiment, the first actuator 200 rotates the second holding portion 22 of the second chuck 20 in the circumferential direction. In other words, the first actuator 200 rotates the second holding portion 22 of the second chuck 20 within a horizontal plane.

[0109] Specifically, the first actuator 200 has a parallel movement unit 210 and a second rotation unit 230 (see FIG. 6 ). The parallel movement unit 210 moves the second chuck 20 parallel to the upper surface of the base 2. The parallel movement unit 210 has a movement unit 211 that moves the second chuck 20 in the X direction, a movement unit 212 that moves the second chuck 20 in the Y direction, and a support base 213 that is disposed between the movement unit 211 and the movement unit 212.

[0110] 6 is a schematic view showing the structure around the second chuck 20 of the joining unit JU from the X direction. As shown in FIGS. 5 and 6 , the moving part 211 is disposed on a support table 213. The moving part 211 has a linear motor 2111 and a linear guide 2112. In this embodiment, the moving part 211 has a pair of linear motors 2111 and a pair of linear guides 2112.

[0111] The pair of linear motors 2111 are disposed outward in the Y direction from the second stage 21 of the second chuck 20. The pair of linear motors 2111 are disposed at a predetermined distance from each other in the Y direction.

[0112] Each linear motor 2111 has a mover 2111a and a rail 2111b. The mover 2111a is fixed to a side surface of the second stage 21. The mover 2111a moves along the rail 2111b. The mover 2111a has, for example, a coil. The mover 2111a also has an encoder that detects the distance moved along the rail 2111b.

[0113] The rail 2111b is fixed to the support base 213 so as to extend in the X direction. The rail 2111b has a plurality of magnets. The plurality of magnets are arranged so that their north and south poles are alternately aligned along the X direction. When a current is applied to the coil of the mover 2111a, the mover 2111a moves along the rail 2111b. When the mover 2111a moves along the rail 2111b, the second chuck 20 moves in the X direction.

[0114] The pair of linear guides 2112 are disposed between the second stage 21 of the second chuck 20 and the support base 213. The pair of linear guides 2112 are disposed at a predetermined distance in the Y direction. The pair of linear guides 2112 are disposed along the pair of linear motors 2111, respectively.

[0115] Each linear guide 2112 has a mover 2112a and a rail 2112b. The mover 2112a is fixed to the lower surface of the second stage 21 (the surface on the support base 213 side). The mover 2112a moves along the rail 2112b. The mover 2112a has, for example, an inverted U-shaped cross section and sandwiches the rail 2112b from both sides in the Y direction. The rail 2112b is fixed to the support base 213 so as to extend in the X direction. The linear guide 2112 moves the second chuck 20 linearly with high precision.

[0116] 7 is a schematic view showing the structure around the second chuck 20 of the joining unit JU from the Y direction. As shown in FIGS. 5 and 7, the moving part 212 is disposed on the base 2. The moving part 212 has a linear motor 2121 and a linear guide 2122. In this embodiment, the moving part 212 has a pair of linear motors 2121 and a pair of linear guides 2122.

[0117] The pair of linear motors 2121 are disposed between the support table 213 and the base 2. The pair of linear motors 2121 are disposed at a predetermined distance from each other in the X direction.

[0118] Each linear motor 2121 has a mover 2121a and a rail 2121b. The mover 2121a is fixed to the lower surface (the surface facing the base 2) of the support stand 213. The mover 2121a moves along the rail 2121b. The mover 2121a has, for example, a coil. The mover 2121a also has an encoder that detects the distance moved along the rail 2121b.

[0119] The rail 2121b is fixed to the base 2 so as to extend in the Y direction. The rail 2121b has a plurality of magnets. The magnets are arranged so that their north and south poles are alternately aligned along the Y direction. When a current is applied to the coil of the mover 2121a, the mover 2121a moves along the rail 2121b. When the mover 2121a moves along the rail 2121b, the support base 213 and the second chuck 20 move in the Y direction.

[0120] The pair of linear guides 2122 are disposed between the support base 213 and the base 2. The pair of linear guides 2122 are disposed at a predetermined distance in the X direction. The pair of linear guides 2122 are disposed along the pair of linear motors 2121, respectively.

[0121] Each linear guide 2122 has a mover 2122a and a rail 2122b. The mover 2122a is fixed to the lower surface (the surface facing the base 2) of the support table 213. The mover 2122a moves along the rail 2122b. The mover 2122a has, for example, an inverted U-shaped cross section and sandwiches the rail 2122b from both sides in the X direction. The rail 2122b is fixed to the base 2 so as to extend in the Y direction. The linear guide 2122 moves the support table 213 and the second chuck 20 linearly with high precision.

[0122] The second rotating unit 230 is attached to a lower part of the second holding unit 22 of the second chuck 20. The second rotating unit 230 rotates the second holding unit 22 in the circumferential direction. The second rotating unit 230 includes, for example, a motor. In the present embodiment, the second rotating unit 230 includes a direct drive motor. This makes it possible to control the rotation angle of the second substrate W2 with high precision.

[0123] Fig. 8 is a schematic diagram showing the structure around the support table 213 from below. As shown in Fig. 6 and Fig. 8, the joining unit JU includes a detection mechanism 300. The detection mechanism 300 detects movement of one of the first chuck 10 and the second chuck 20 within the XY plane. In this embodiment, the detection mechanism 300 detects movement of the second chuck 20 within the XY plane.

[0124] Specifically, the detection mechanism 300 includes, for example, a two-dimensional scale 301 (hereinafter referred to as the 2D scale 301) and a detection sensor 302. The 2D scale 301 is attached to the lower surface of the second stage 21 of the second chuck 20. The 2D scale 301 has a rectangular shape extending in the X and Y directions. The 2D scale 301 is, for example, a reflective diffraction grating scale. The 2D scale 301 is configured so that the grating spacing changes along the X and Y directions.

[0125] An opening 213a is provided in the support base 213. The opening 213a is disposed below the 2D scale 301. The opening 213a has an opening larger than the 2D scale 301.

[0126] The detection sensor 302 is disposed on the base 2. The detection sensor 302 protrudes upward (toward the second chuck 20) ​​from an opening 213a of the support base 213. The detection sensor 302 may be disposed below the support base 213. The detection sensor 302 emits laser light toward the 2D scale 301 and receives light reflected by the 2D scale 301. As the second chuck 20 moves, the light reception signal of the detection sensor 302 changes. As a result, the amount of movement of the second chuck 20 in the X and Y directions is detected.

[0127] 5, the joining unit JU includes a first substrate detector 310 and a first reference mask 410. The first substrate detector 310 detects the first substrate W1. Specifically, the first substrate W1 has one or more alignment marks. The first substrate detector 310 detects the alignment marks of the first substrate W1.

[0128] The first board detection unit 310 is fixed to the second stage 21. The first board detection unit 310 includes, for example, a camera. The first board detection unit 310 includes an imaging element. For example, the imaging element is a CCD image sensor or a CMOS image sensor. The first board detection unit 310 transmits the captured imaging data to the control device 90. The imaging data includes image data. In this embodiment, the first board detection unit 310 has a camera 311. Note that the first board detection unit 310 may have multiple cameras with different magnifications, similar to the second board detection unit 320 described below.

[0129] Furthermore, the first substrate detection unit 310 detects the first reference mask 410. Specifically, the first reference mask 410 has alignment marks. The first substrate detection unit 310 detects the alignment marks of the first reference mask 410. Note that the first substrate detection unit 310 detects the first reference mask 410 in a state in which one surface 11a of the first stage 11 faces downward.

[0130] The first reference mask 410 is fixed to the first stage 11. The first reference mask 410 has a mark member 411 on which an alignment mark serving as a first mark is formed, and a pair of supports 412 that support the mark member 411. Hereinafter, the alignment mark of the mark member 411 may be referred to as the first mark. The mark member 411 is an example of the "transparent plate" in the present invention.

[0131] The mark member 411 has a first mark formed with high precision. For example, the first mark is formed by etching the mark member 411. The mark member 411 is formed of, for example, a material with a small linear expansion coefficient. The mark member 411 may also be formed of, for example, a material having translucency. In this embodiment, the mark member 411 is formed of, for example, glass that transmits visible light.

[0132] Here, the first substrate detection unit 310 detects the alignment marks of the first substrate W1 and the first marks of the first reference mask 410, thereby detecting the relative positions of the alignment marks of the first substrate W1 with respect to the first marks of the first reference mask 410. Specifically, the alignment marks of the first substrate W1 and the first marks of the first reference mask 410 are detected by moving the first substrate detection unit 310 horizontally with one surface 11a of the first stage 11 facing downward. At this time, the detection mechanism 300 detects the direction and distance moved by the first substrate detection unit 310 and the second chuck 20 from when the first substrate detection unit 310 detects the alignment marks of the first substrate W1 until when the first marks of the first reference mask 410 are detected. This makes it possible to detect the relative positions of the alignment marks of the first substrate W1 with respect to the first marks of the first reference mask 410.

[0133] The joining unit JU includes a second substrate detection unit 320 and a second reference mask 420. The second substrate detection unit 320 detects the second substrate W2. Specifically, the second substrate W2 has one or more alignment marks. The second substrate detection unit 320 detects the alignment marks of the second substrate W2.

[0134] The joining unit JU includes a second gantry 350, and the second board detection unit 320 is fixed to the second gantry 350. Note that in FIG. 5 , a portion of the second gantry 350 is depicted by a two-dot chain line. The second board detection unit 320 includes, for example, a camera. The second board detection unit 320 includes an imaging element. For example, the imaging element is a CCD image sensor or a CMOS image sensor. The second board detection unit 320 transmits the captured imaging data to the control device 90. The imaging data includes image data.

[0135] In this embodiment, the second substrate detection unit 320 has a camera 321 and a camera 322 with different magnifications. The camera 321 is a camera with a relatively low magnification. The camera 322 is a camera with a relatively high magnification. The camera 322 has a higher magnification than the camera 321. The camera 321 has a relatively large angle of view, making it easy to detect the alignment marks on the second substrate W2. On the other hand, the camera 322 has a relatively small angle of view and a high magnification, making it possible to detect the alignment marks with high accuracy.

[0136] When detecting the alignment marks of the second substrate W2 using the second substrate detection unit 320, the alignment marks are detected by the camera 321 and then by the camera 322. For this reason, it is necessary to move the second substrate detection unit 320 (cameras 321 and 322) between the detection by the camera 321 and the detection by the camera 322. However, to simplify the explanation, hereinafter, both the detection by the camera 321 and the detection by the camera 322 will be described as detection by the second substrate detection unit 320. Furthermore, the operation of moving the second substrate detection unit 320 between the detection by the camera 321 and the detection by the camera 322 will be omitted.

[0137] The second substrate detection unit 320 also detects the second reference mask 420. Specifically, the second reference mask 420 has alignment marks. The second substrate detection unit 320 detects the alignment marks of the second reference mask 420.

[0138] The second reference mask 420 is fixed to the second stage 21. The second reference mask 420 has a mark member 421 on which an alignment mark serving as a second mark is formed, and supports 422 that support the mark member 421. Hereinafter, the alignment mark of the mark member 421 may be referred to as the second mark. The mark member 421 is an example of the "transparent plate" in the present invention.

[0139] The mark member 421 has a second mark formed with high precision. For example, the second mark is formed by etching the mark member 421. The mark member 421 is formed of, for example, a material with a small linear expansion coefficient. The mark member 421 may also be formed of, for example, a material having translucency. In this embodiment, the mark member 421 is formed of, for example, glass that transmits visible light. Note that the mark member 421 may also be formed of a material that does not transmit visible light.

[0140] Here, the second substrate detection unit 320 detects the alignment marks of the second substrate W2 and the second marks of the second reference mask 420, thereby detecting the relative positions of the alignment marks of the second substrate W2 with respect to the second marks of the second reference mask 420. Specifically, the second chuck 20 and the second substrate W2 are moved in the horizontal direction to detect the alignment marks of the second substrate W2 and the second marks of the second reference mask 420. At this time, the detection mechanism 300 detects the direction and distance moved by the first substrate detection unit 310 and the second chuck 20 after the second substrate detection unit 320 detects the alignment marks of the second substrate W2 and before detecting the second marks of the second reference mask 420. This makes it possible to detect the relative positions of the alignment marks of the second substrate W2 with respect to the second marks of the second reference mask 420.

[0141] 9 is a perspective view showing the structure of the joining unit JU from below. As shown in FIG. 9, the joining unit JU includes an imaging unit 50. In this embodiment, the imaging unit 50 transmits captured image data to the control device 90.

[0142] The imaging unit 50 is attached to either the first chuck 10 or the second chuck 20. In the present embodiment, the imaging unit 50 is attached to the first chuck 10. The imaging unit 50 is disposed at a position on the first chuck 10 facing the mark member 411. In addition, in the present embodiment, the imaging unit 50 images the mark members 411 and 421. The imaging unit 50 images the alignment mark (first mark) formed on the mark member 411 and the alignment mark (second mark) formed on the mark member 421 via the mark member 411. In the present embodiment, the imaging unit 50 images the first mark and the second mark at different times. That is, the imaging unit 50 images the alignment mark of the mark member 411 and the alignment mark of the mark member 421 within a single screen.

[0143] In this embodiment, the imaging unit 50 is attached to the first stage 11. The imaging unit 50 may be attached, for example, to one surface 11a of the first stage 11 (see FIG. 5 ). The imaging unit 50 may also be attached to the first stage 11 so as to penetrate the first stage 11. In this embodiment, the imaging unit 50 is attached to the first stage 11 so as to penetrate the first stage 11 in the thickness direction.

[0144] When the first substrate W1 held by the first chuck 10 and the second substrate W2 held by the second chuck 20 are bonded together, the first reference mask 410 and the second reference mask 420 are arranged facing each other in the vertical direction. At this time, the first marks of the first reference mask 410 and the second marks of the second reference mask 420 are arranged facing each other in the vertical direction. However, in the XY plane, the positions of the first marks of the first reference mask 410 and the positions of the second marks of the second reference mask 420 may or may not completely coincide with each other. It is sufficient that the first marks of the first reference mask 410 and the second marks of the second reference mask 420 are arranged in positions that can be imaged by the imaging unit 50.

[0145] Next, the substrate bonding apparatus 1 will be described with reference to Fig. 10. Fig. 10 is a block diagram of the substrate bonding apparatus 1 according to the second embodiment.

[0146] 10 , the control device 90 controls various operations of the substrate bonding apparatus 1. The control device 90 controls the center robot CR, the activation unit AU, the cleaning unit CU, the transport robot TR, the pre-alignment unit PU, and the bonding unit JU. Specifically, a control unit 91 of the control device 90 controls the center robot CR, the activation unit AU, the cleaning unit CU, the transport robot TR, the pre-alignment unit PU, and the bonding unit JU by transmitting control signals to the center robot CR, the activation unit AU, the cleaning unit CU, the transport robot TR, the pre-alignment unit PU, and the bonding unit JU.

[0147] The control unit 91 calculates the relative positions of the alignment marks of the first substrate W1 with respect to the first marks of the first reference mask 410, for example, based on the detection results of the detection mechanism 300 and the first substrate detection unit 310. The control unit 91 also calculates the relative positions of the alignment marks of the second substrate W2 with respect to the second marks of the second reference mask 420, for example, based on the detection results of the detection mechanism 300 and the second substrate detection unit 320. The control unit 91 also calculates the relative positional relationship between the first marks of the first reference mask 410 and the second marks of the second reference mask 420, for example, based on the detection results of the imaging unit 50. Therefore, the control unit 91 can calculate the relative positional relationship between the alignment marks of the first substrate W1 and the alignment marks of the second substrate W2, for example, based on the detection results of the detection mechanism 300, the first substrate detection unit 310, the second substrate detection unit 320, and the imaging unit 50.

[0148] For example, calculating the relative position between the first reference mask 410 and the second reference mask 420, and calculating the relative position between the first chuck 10 and the second chuck 20 is substantially the same as calculating the relative position between the first substrate W1 and the second substrate W2.

[0149] The other configurations of the control unit 91 of the second embodiment are the same as those of the first embodiment.

[0150] Next, with reference to FIG. 11 , a substrate bonding method using the bonding unit JU of this embodiment will be described. FIG. 11 is a flowchart showing the substrate bonding method using the bonding unit JU. In this embodiment, the substrate bonding method using the bonding unit JU includes steps S101 to S111. Step S101 is an example of the "step of holding a first substrate" of the present invention. Step S102 is an example of the "step of holding a second substrate" of the present invention. Step S106 is an example of the "step of taking an image" of the present invention. Step S107 is an example of the "step of predicting a first mark position" of the present invention. Step S108 is an example of the "step of taking an image" of the present invention. Step S109 is an example of the "step of predicting a second mark position" of the present invention. Step S110 is an example of the "step of calculating" of the present invention. Step S111 is an example of the "step of bonding" of the present invention. The operations of steps S101 to S111 are performed by the control unit 91 of the control device 90 by controlling the center robot CR, activation unit AU, cleaning unit CU, transport robot TR, pre-alignment unit PU, and bonding unit JU.

[0151] 11 , in step S101, the first substrate W1 is held by the first chuck 10. Specifically, the controller 91 loads the first substrate W1, which has been transferred from the pre-alignment unit PU to the transport robot TR, into the joining unit JU. The controller 91 controls the transport robot TR to load the first substrate W1 into the joining unit JU. At this time, the transport robot TR transports the first substrate W1 with the surface of the first substrate W1 to be bonded to the second substrate W2 (hereinafter, sometimes referred to as the bonding surface) facing upward. The transport robot TR then transfers the first substrate W1 to the first chuck 10. This causes the first substrate W1 to be held by the first chuck 10.

[0152] Next, in step S102, the second substrate W2 is held by the second chuck 20. Specifically, the controller 91 loads the second substrate W2, which has been transferred from the pre-alignment unit PU to the transport robot TR, into the joining unit JU. The controller 91 controls the transport robot TR to load the second substrate W2 into the joining unit JU. At this time, the transport robot TR transports the second substrate W2 with the surface of the second substrate W2 to be bonded to the first substrate W1 (hereinafter, sometimes referred to as the bonding surface) facing upward. The transport robot TR then transfers the second substrate W2 to the second chuck 20. This causes the second substrate W2 to be held by the second chuck 20.

[0153] Next, in step S103, the control unit 91 controls the second actuator 100 to turn the first chuck 10 upside down, so that the bonding surface of the first substrate W1 faces downward.

[0154] Next, in step S104, the control unit 91 controls the first actuator 200 to move the second chuck 20 to a reference position. The reference position is, for example, the position of the second chuck 20 when the center of the second holding portion 22 of the second chuck 20 is located directly below the center of the first holding portion 12 of the first chuck 10. In this state, the distance between the first substrate W1 and the second substrate W2 is, for example, several mm to several tens of mm or more.

[0155] Next, in step S105, the control unit 91 lowers the first substrate W1. Specifically, the control unit 91 controls the lifting unit 120 of the second actuator 100 to lower the first chuck 10 by a predetermined amount. As a result, the distance between the first substrate W1 and the second substrate W2 falls within a predetermined range. The predetermined range is, for example, from several μm to several tens of μm.

[0156] Next, steps S106 to S111 are executed in the same manner as steps S13 to S18 shown in FIG.

[0157] Specifically, in step S106, the control unit 91 controls the imaging unit 50 to capture an image of the first mark M10. Specifically, the control unit 91 controls the imaging unit 50 to focus on the first mark M10 and capture an image of the first mark M10. At this time, the imaging unit 50 captures several tens to several hundreds of images. The image data captured by the imaging unit 50 is transmitted to the control unit 91.

[0158] Next, in step S107, the control unit 91 predicts the first mark position where the first mark will be located. Specifically, the control unit 91 calculates the position of the center of the first mark relative to the center of the first image (first mark position) based on the first image. Then, the control unit 91 predicts the future first mark position based on multiple first mark positions calculated from multiple first images.

[0159] Next, in step S108, the control unit 91 controls the imaging unit 50 to capture an image of the second mark. Specifically, the control unit 91 controls the imaging unit 50 to focus on the second mark and capture an image of the second mark. At this time, the imaging unit 50 captures several tens to several hundreds of images. The image data captured by the imaging unit 50 is transmitted to the control unit 91.

[0160] Next, in step S109, the control unit 91 predicts the second mark position where the second mark will be located. Specifically, the control unit 91 calculates the position of the center of the second mark M20 relative to the center of the second image (second mark position) based on the second image. Then, the control unit 91 predicts the future second mark position based on multiple second mark positions calculated from multiple second images.

[0161] Next, in step S110, the control unit 91 calculates the timing at which the relative position of the second substrate W2 with respect to the first substrate W1 will fall within a target range. Specifically, the control unit 91 calculates the timing at which the relative position of the second mark position with respect to the first mark position will fall within the target range. The target range is, for example, a range of several nanometers to several tens of nanometers centered on the first mark position.

[0162] Next, in step S111, the control unit 91 bonds the first substrate W1 and the second substrate W2 together when the relative position of the second substrate W2 with respect to the first substrate W1 falls within a target range. Specifically, the control unit 91 controls the second actuator 100 to lower the first chuck 10 so that the first substrate W1 and the second substrate W2 come into contact with each other when the first mark position and the second mark position fall within the target range.

[0163] In this manner, the first substrate W1 and the second substrate W2 are bonded together.

[0164] Other aspects of the substrate bonding method of the second embodiment are the same as those of the first embodiment.

[0165] In this embodiment, as described above, the imaging unit 50 is attached to either the first chuck 10 or the second chuck 20. Therefore, there is no need to provide a separate member for fixing the imaging unit 50. Furthermore, fluctuations in the relative position between the imaging unit 50 and either the first mark of the first reference mask 410 or the second mark of the second reference mask 420 due to vibration or the like can be suppressed, thereby further suppressing a decrease in alignment accuracy. Furthermore, compared to when the imaging unit 50 is attached to a member other than the first chuck 10 or the second chuck 20, the imaging unit 50 can be more easily positioned near the first mark and the second mark. Therefore, a decrease in the detection accuracy of the first mark and the second mark by the imaging unit 50 can be suppressed.

[0166] Other effects of the second embodiment are similar to those of the first embodiment.

[0167] Third Embodiment A substrate bonding apparatus 1 according to a third embodiment of the present invention will be described with reference to Figures 12 and 13. Figure 12 is a perspective view showing a schematic view from below of the structure of a joining unit JU of the substrate bonding apparatus 1 of the third embodiment. In the third embodiment, an example will be described in which the substrate bonding apparatus 1 is equipped with two imaging units 50 and 51, unlike the second embodiment.

[0168] 12 , similarly to the second embodiment, the imaging unit 50 is attached to, for example, the first chuck 10. Unlike the second embodiment, the imaging unit 50 images only one of the first mark of the mark member 411 and the second mark of the mark member 421. Here, the imaging unit 50 images the mark member 411.

[0169] In this embodiment, the joining unit JU of the substrate bonding apparatus 1 further includes an imaging section 51. Note that in this embodiment, the imaging section 51 transmits captured image data to the control device 90.

[0170] The imaging unit 51 is disposed at a position spaced apart in the X direction from the imaging unit 50. The imaging unit 51 is also disposed at a position facing the mark member 411 of the first chuck 10.

[0171] The imaging unit 51 is attached to the first chuck 10, similar to the imaging unit 50. The imaging unit 51 images only the other of the first mark of the mark member 411 and the second mark of the mark member 421. Here, the imaging unit 51 images the second mark of the mark member 421. Specifically, the imaging unit 51 images the second mark of the mark member 421 through the mark member 411. In other words, the imaging unit 51 images the second mark of the mark member 421 through the mark member 411.

[0172] In this embodiment, the imaging unit 50 captures an image of the first mark of the mark member 411 , and at the same time, the imaging unit 51 captures an image of the second mark of the mark member 421 .

[0173] In this embodiment, the second mark of the mark member 421 is disposed at a position spaced apart in the X direction from the first mark of the mark member 411. The imaging unit 50 is disposed at a position facing the first mark of the mark member 411, and the imaging unit 51 is disposed at a position facing the second mark of the mark member 421.

[0174] The other configurations of the third embodiment are similar to those of the second embodiment.

[0175] Next, a substrate bonding method using the bonding unit JU of this embodiment will be described with reference to FIG. 13. FIG. 13 is a flowchart showing the substrate bonding method using the bonding unit JU. In this embodiment, the substrate bonding method using the bonding unit JU includes steps S101 to S105, S201, S202, S110, and S111. Step S201 is an example of the "imaging step" of the present invention. Step S202 is an example of the "first mark position predicting step" and the "second mark position predicting step" of the present invention.

[0176] As shown in FIG. 13, steps S101 to S105 are executed in the same manner as in the second embodiment.

[0177] Next, in step S201, the imaging unit 50 captures an image of the first mark of the mark member 411, and simultaneously the imaging unit 51 captures an image of the second mark of the mark member 421. Other aspects of step S201 are the same as steps S106 and S108 of the second embodiment.

[0178] Next, in step S202, the control unit 91 predicts the first mark position where the first mark is located and predicts the second mark position where the second mark is located. Note that the other methods of step S202 are the same as steps S107 and S109 in the second embodiment.

[0179] Next, steps S110 and S111 are executed in the same manner as in the second embodiment.

[0180] In this manner, the first substrate W1 and the second substrate W2 are bonded together.

[0181] Other aspects of the substrate bonding method of the third embodiment are the same as those of the second embodiment.

[0182] In this embodiment, as described above, the first mark of mark member 411 and the second mark of mark member 421 are separately imaged. Specifically, in this embodiment, the imaging unit 50 images the first mark of mark member 411, and at the same time, the imaging unit 51 images the second mark of mark member 421. Therefore, the time required to image the alignment marks can be shortened compared to when two alignment marks (the first mark and the second mark) are imaged using one imaging unit 50.

[0183] Furthermore, by providing two image capturing units 50 and 51, it is possible to improve the degree of freedom in the positions at which the first mark and the second mark are arranged.

[0184] In this embodiment, an example has been described in which the mark member 421 is disposed at a position that faces the mark member 411 in the vertical direction, but the present invention is not limited to this. That is, the mark member 421 may be disposed at a position that does not face the mark member 411 in the vertical direction. In this case, it is possible to further improve the degree of freedom in the positions at which the first mark and the second mark are disposed.

[0185] Other effects of the third embodiment are similar to those of the second embodiment.

[0186] The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the above embodiments and can be embodied in various forms without departing from the spirit and scope of the present invention. Furthermore, various inventions can be formed by appropriately combining multiple components disclosed in the above embodiments. For example, some components may be omitted from all components shown in the embodiments. Furthermore, components from different embodiments may be appropriately combined. The drawings mainly show each component in a schematic manner to facilitate understanding. The thickness, length, number, spacing, etc. of each component shown may differ from the actual thickness, length, number, spacing, etc. of each component shown in the above embodiments due to the convenience of drawing. Furthermore, the materials, shapes, dimensions, etc. of each component shown in the above embodiments are merely examples and are not particularly limited. Various modifications are possible within a scope that does not substantially deviate from the effects of the present invention.

[0187] For example, in the above embodiment, an example has been described in which the first chuck 10 is moved in the vertical direction and the second chuck 20 is moved in the horizontal direction, but the present invention is not limited to this. For example, the second chuck 20 may be moved in the vertical direction and the first chuck 10 may be moved in the horizontal direction. Furthermore, one of the first chuck 10 and the second chuck 20 may be moved in both the vertical direction and the horizontal direction.

[0188] Furthermore, for example, in the third embodiment, an example has been described in which both the imaging unit 50 and the imaging unit 51 are attached to the first chuck 10, but the present invention is not limited to this. For example, both the imaging unit 50 and the imaging unit 51 may be attached to the second chuck 20. Alternatively, one of the imaging unit 50 and the imaging unit 51 may be attached to the first chuck 10, and the other of the imaging unit 50 and the imaging unit 51 may be attached to the second chuck 20. Alternatively, at least one of the imaging unit 50 and the imaging unit 51 may be attached to a member other than the first chuck 10 and the second chuck 20, such as the first gantry 130.

[0189] Furthermore, for example, in the first embodiment, an example has been described in which the first substrate W1 and the second substrate W2 can be bonded together with high precision by adjusting the focal length of the imaging unit 50 to separately capture images of the first mark M10 and the second mark M20, even when the relative position between the first substrate W1 and the second substrate W2 fluctuates due to vibration or the like. However, the present invention is not limited to this. For example, even when the positional accuracy of at least one of the first mark M10 and the second mark M20 is low and at least one of the first mark M10 and the second mark M20 is not within the field of view of the imaging unit 50, the first substrate W1 and the second substrate W2 can be bonded together with high precision. Specifically, for example, if the positional accuracy of the second mark M20 is low, the imaging unit 50 may image the first mark M10, and then the imaging unit 50 may image the second mark M20 by moving the imaging unit 50 horizontally or changing the orientation of the imaging unit 50.

[0190] In the above embodiment, the control unit 91 predicts the first mark position based on the first image and the second mark position based on the second image, but the present invention is not limited to this. For example, the control unit 91 may predict the first mark position based on a partial region of the first image and the second mark position based on a partial region of the second image. This configuration can reduce the data size of the images used for prediction compared to predicting the first mark position based on the entire region of the first image and predicting the second mark position based on the entire region of the second image, thereby shortening the calculation time.

[0191] In the above embodiment, the bonding step has been described as an example in which the first substrate W1 and the second substrate W2 are bonded together by vertically moving one of the first substrate W1 and the second substrate W2 using the second actuator. That is, the bonding step has been described as an example in which the first substrate W1 and the second substrate W2 are not aligned horizontally using the first actuator. However, the present invention is not limited to this. The first substrate W1 and the second substrate W2 may be bonded together while being aligned with each other in the bonding step. Specifically, the first substrate W1 and the second substrate W2 may be bonded together by the second actuator while being aligned with each other in the horizontal direction using the first actuator. In other words, the control unit 91 may bond the first substrate W1 and the second substrate W2 together by controlling the second actuator while controlling the first actuator to align the first substrate W1 and the second substrate W2. With this configuration, the relative position of the second substrate W2 with respect to the first substrate W1 can be easily set within the target range.

[0192] The present invention is suitably used in a substrate bonding apparatus and a substrate bonding method.

[0193] This application claims priority to Japanese Patent Application No. 2023-212163 filed on December 15, 2023, the entire contents of which are incorporated herein by reference.

Claims

a first chuck for holding a first substrate; a second chuck for holding a second substrate, the second chuck being disposed opposite the first chuck; a first actuator for moving one of the first chuck and the second chuck in a direction intersecting a direction in which the first chuck and the second chuck face each other; a second actuator for moving the first chuck or the second chuck in a direction in which the first chuck and the second chuck face each other; a first mark disposed on the first chuck; a second mark disposed on the second chuck; one or more imaging units for capturing images of the first mark and the second mark; and a control unit for controlling the first actuator and the second actuator, the imaging unit separately capturing images of the first mark and the second mark, the control unit predicting a first mark position where the first mark will be located based on a first image obtained by the imaging unit capturing the first mark, and predicting a second mark position where the second mark will be located based on a second image obtained by the imaging unit capturing the second mark, a substrate bonding apparatus that controls at least the second actuator based on the predicted first mark position and the second mark position to bond the first substrate and the second substrate together.

2. The substrate bonding apparatus according to claim 1, wherein there is one imaging section, and the one imaging section images the first mark and the second mark at different times.

3. The substrate bonding apparatus according to claim 1, wherein the imaging section is provided in plurality, and the plurality of imaging sections simultaneously capture images of the first mark and the second mark.

4. A substrate bonding apparatus according to any one of claims 1 to 3, wherein the imaging unit is attached to either the first chuck or the second chuck.

5. A substrate bonding apparatus as described in any one of claims 1 to 3, wherein the first chuck has a light-transmitting transparent plate on which the first mark is provided, and / or the second chuck has a light-transmitting transparent plate on which the second mark is provided, and the imaging unit images at least one of the first mark and the second mark through the transparent plate.

6. A substrate bonding apparatus as described in any one of claims 1 to 3, wherein the control unit calculates the timing at which the relative position of the second substrate with respect to the first substrate will be within a target range based on the predicted first mark position and second mark position, and bonds the first substrate and the second substrate together at the calculated timing.

7. A substrate bonding apparatus as described in any one of claims 1 to 3, wherein the control unit predicts the first mark position based on a partial area of ​​the first image, and predicts the second mark position based on a partial area of ​​the second image.

8. A substrate bonding apparatus as described in any one of claims 1 to 3, wherein the control unit controls the first actuator to align the first substrate and the second substrate, while controlling the second actuator to bond the first substrate and the second substrate together.

9. A substrate bonding method comprising: a step of holding a first substrate with a first chuck; a step of holding a second substrate with a second chuck disposed opposite the first chuck; a step of separately capturing images of a first mark disposed on the first chuck and a second mark disposed on the second chuck with one or more imaging units; a step of predicting a first mark position where the first mark is located based on a first image of the first mark captured by the imaging unit; a step of predicting a second mark position where the second mark is located based on a second image of the second mark captured by the imaging unit; and a step of bonding the first substrate and the second substrate together based on the predicted first mark position and second mark position.

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