Substrate bonding device and substrate bonding method

Abstract

To provide a substrate bonding device and a substrate bonding method capable of bonding a first substrate and a second substrate with high accuracy.SOLUTION: A first chuck 10 holds a first substrate W1. A second chuck 20 holds a second substrate W2. A first mark M10 is arranged on the first chuck 10. A second mark M20 is arranged on the second chuck 20. An imaging unit 50 captures images of the first mark M10 and the second mark M20 separately. A control unit 91 predicts a first mark position at which the first mark M10 is located based on a first image of the first mark M10 captured by the image unit 50. The control unit 91 predicts a second mark position at which the second mark M20 is located based on a second image of the second mark M20 captured by the image unit 50. The control unit 91 controls at least a second actuator 520 based on the predicted first and second mark positions to bond the first substrate W1 and the second substrate W2.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] Conventionally, a device has been known that includes a first member that holds a first substrate, a second member that is disposed opposite the first member and 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. After aligning the first member and the second member, the first substrate and the second substrate are bonded together. As such a device, for example, Patent Document 1 describes a device including a first holding means that holds a first plate-like body on which a first alignment mark is formed, a second holding means that holds a second plate-like body having light transmissivity on which a second alignment mark is formed, and an imaging means that is disposed on the side opposite the first plate-like body with respect to the second plate-like body and images the first plate-like body and the second plate-like body.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, for example, in a substrate bonding apparatus for bonding two substrates, since the two substrates are electrically connected to each other, it is required to align the two substrates with high precision.

[0005] However, in a substrate bonding apparatus, for example, due to vibration or thermal drift, etc. (hereinafter sometimes referred to as vibration, etc.), relative positional fluctuations may occur between the first member and the second member, so there is a risk that the alignment accuracy will decrease. Specifically, for example, even if it is determined whether the relative position of the alignment mark of the second substrate with respect to the alignment mark of the first substrate is within the target range, and the second substrate is moved in a direction approaching 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 will decrease due to vibration, etc. That is, it is difficult to bond the first substrate and the second substrate with high accuracy.

[0006] The present invention has been made in view of the above problems, and an object thereof is to provide a substrate bonding apparatus and a substrate bonding method capable of accurately bonding a first substrate and a second substrate.

Means for Solving the Problems

[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 control unit. The first chuck holds a first substrate. The second chuck is disposed opposite to 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 with 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 control unit controls the first actuator and the second actuator. The imaging unit images the first mark and the second mark separately. The control unit predicts a first mark position where the first mark is located based on a first image obtained by the imaging unit imaging the first mark. The control unit predicts a second mark position where the second mark is located based on a second image obtained by the imaging unit imaging the second mark. The control unit 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.

[0008] In an embodiment, there is one imaging unit. The one imaging unit images the first mark and the second mark at different timings.

[0009] In an embodiment, there are a plurality of imaging units. The plurality of imaging units image the first mark and the second mark simultaneously.

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

[0011] In one embodiment, the first chuck has a transparent plate having translucency on which the first mark is provided, and / or the second chuck has a transparent plate having translucency on which the second mark is provided. 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 is within a target range based on the predicted first mark position and the second mark position, and bonds the first substrate and the second substrate 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. 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.

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

Advantages of the Invention

[0016] According to the present invention, a substrate bonding apparatus and a substrate bonding method capable of accurately bonding a first substrate and a second substrate can be provided.

Brief Description of the Drawings

[0017]

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Modes for Carrying Out the Invention

[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, the same or corresponding parts are denoted by the same reference numerals and the description thereof will not be repeated. In the present specification, for the sake of easy understanding of the invention, the X-axis, Y-axis, and Z-axis that are orthogonal to each other may be described. In the present embodiment, the X-axis and Y-axis are parallel to the horizontal direction, and the Z-axis is parallel to the vertical direction. Also, for convenience, one side Z1 in the Z-axis direction indicates the upward direction, and the other side Z2 in the Z-axis direction indicates the downward direction. However, the upward and downward directions are defined for the sake of explanation and do not necessarily coincide with the vertical direction.

[0019] (First Embodiment) With reference to FIGS. 1 to 3, the substrate bonding apparatus 1 according to the first embodiment of the present invention will be described. FIG. 1 is a side view schematically showing the overall configuration of the substrate bonding apparatus 1 of the first embodiment.

[0020] First, with reference to FIG. 1, the schematic configuration of the substrate bonding apparatus 1 will be described. 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 the 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 the present embodiment, four first frames SF1 are provided, and four second frames SF2 are provided. The four first frames SF1 have two sets of first frame SF1 sets (not shown) each composed of two first frames SF1 arranged at a predetermined interval in the X direction. These two sets of 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 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 the first frames SF1 adjacent in the X direction and two second frames SF2 connecting the upper ends of the first frames SF1 adjacent in the Y direction. That is, the four second frames SF2 are arranged at positions corresponding to the four sides of a rectangle in plan view. Note that the support frame SF may be fixed to the wall or ceiling of the room in which the substrate bonding apparatus 1 is installed.

[0022] The first chuck 10 holds the first substrate W1. In the present embodiment, the first chuck 10 sucks 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 arranged to face the first chuck 10. The first chuck 10 and the second chuck 20 are separated by a predetermined distance. The direction in which the first chuck 10 and the second chuck 20 are separated is not particularly limited, but is, for example, the vertical direction (Z direction). In the present embodiment, the second chuck 20 is arranged 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 particularly necessary, the first substrate W1 and the second substrate W2 may be described 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 shape or a rectangular shape in plan view. In this embodiment, the substrate W has a substantially circular shape in plan view.

[0028] Also, in this embodiment, the substrate W has a front surface Wa and a back surface Wb located on the side opposite to the front surface Wa. The front surface Wa is a device formation surface on which elements are formed. The back surface Wb is a non-device formation surface on which no elements are 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, unless otherwise particularly described for ease of understanding, each substrate W is not turned upside down.

[0029] The first chuck 10 and the second chuck 20 are configured to be relatively movable in directions (X direction and Y direction) intersecting 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 direction and the Y direction.

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

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

[0032] Also, the first chuck 10 and the second chuck 20 are configured to be relatively movable in the 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 the present embodiment, the second actuator 520 moves the first chuck 10 in the Z direction.

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

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

[0035] The substrate bonding device 1 aligns the first chuck 10 and the second chuck 20. Specifically, the substrate bonding device 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 device 1 aligns the first chuck 10 and the second chuck 20 by the first actuator 510 so that a second point P2 at a predetermined position (for example, the center) on the surface Wa (here, the upper surface) of the second substrate W2 is directly below a first point P1 at a predetermined position (for example, 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. Also, the second point P2 does not have to be located at the center of the surface Wa of the second substrate W2.

[0036] Further, the substrate bonding apparatus 1 bonds the first substrate W1 and the second substrate W2. Specifically, the first substrate W1 is moved downward by the second actuator 520 to bond the first substrate W1 and the second substrate W2.

[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, for example, on the first chuck 10 or 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 surface or the lower surface of a transparent plate 30 having translucency such as glass fixed in the through hole 10a. The first mark M10 is formed in a predetermined shape on the upper surface or the 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, for example, on the second chuck 20 or on a member attached to the second chuck 20. In the present 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, when the member 35 is a transparent plate having translucency, the second mark M20 may be formed on the lower surface of the member 35.

[0040] In the present embodiment, for ease of understanding, it is assumed that the horizontal positional relationship between the center of the first substrate W1 with respect to the center of the first mark M10 and the horizontal positional relationship between the center of the second substrate W2 with respect to the center of the second mark M20 are the same. That is, if the second mark M20 is aligned horizontally with respect to the first mark M10, it is assumed that the second substrate W2 can be aligned horizontally with respect to the first substrate W1.

[0041] The imaging unit 50 captures the first mark M10 and the second mark M20. The imaging unit 50 is disposed at a position where the first mark M10 and the second mark M20 can be imaged. In the present 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 the present embodiment, the imaging unit 50 captures 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 image sensor. For example, the image sensor is a CCD (Charge Coupled Device) image sensor or a CMOS (Complementary Metal Oxide Semiconductor) image sensor. The imaging unit 50 transmits the captured imaging data to the control device 90 (see FIG. 2). The imaging data includes image data.

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

[0044] As shown in FIG. 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. By the control device 90, the substrate bonding apparatus 1 aligns 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 the image data captured by the imaging unit 50, and bonds the first substrate W1 and the second substrate W2.

[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 arithmetic unit. Note that the control unit 91 may have a Graphics Processing Unit (GPU) and a Field Programmable Gate Array (FPGA).

[0047] The storage unit 93 stores data and computer programs. The data defines, for example, processing contents and processing procedures for alignment and bonding.

[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 a removable medium. The control unit 91 executes the computer program stored in the storage unit 93 to execute an alignment operation and a bonding operation.

[0049] In addition, the control unit 91 controls the first actuator 510 based on the captured image captured by the imaging unit 50 to horizontally align the first chuck 10 and the second chuck 20. This will be specifically described below.

[0050] The control unit 91 controls the imaging unit 50. The control unit 91 controls the imaging unit 50 to separately image the first mark M10 and the second mark M20. In the present embodiment, the control unit 91 controls the imaging unit 50 to image the first mark M10 and the second mark M20 at different timings. Thereby, the imaging unit 50 separately images the first mark M10 and the second mark M20. In the present embodiment, the imaging unit 50 images the first mark M10 and the second mark M20 at different timings. Also, in the present embodiment, the imaging unit 50 adjusts the focal length to focus on the first mark M10 and image the first mark M10, and focuses on the second mark M20 and images the second mark M20. Note that the imaging unit 50 images a predetermined number or more of first images and a predetermined number or more of second images.

[0051] Based on the first image captured by the imaging unit 50 of the first mark M10, the control unit 91 predicts the first mark position where the first mark M10 is located. Specifically, the control unit 91 calculates the position of the center of the first mark M10 with respect 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 with respect to the center of the first image. Then, the control unit 91 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 several seconds to several tens of seconds ahead. In the present embodiment, the control unit 91 generates first mark position data associating the 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 is located based on the second image captured by the imaging unit 50. Specifically, the control unit 91 calculates the position of the center of the second mark M20 with respect 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 with respect 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 several seconds to several tens of seconds ahead. In the present embodiment, the control unit 91 generates second mark position data associating the future time with the predicted second mark position, and stores the second mark position data in the storage unit 93.

[0053] Note that, as a method for the control unit 91 to predict the first mark position and the second mark position, it may be calculated using a predetermined function or mathematical formula, or it may be calculated using a learned model generated by machine learning. When generating a learned model, the control unit 91 may generate a learned model using, for example, a plurality of calculated first mark positions and second mark positions and the imaging time.

[0054] The machine learning algorithm is not particularly limited as long as it is supervised learning. For example, it is a multi-layer perceptron, support vector machine, linear regression, Kalman filter, decision tree, nearest neighbor method, naive Bayes classifier, support vector machine, or neural network. Therefore, the learned model includes, for example, a multi-layer perceptron, support vector machine, linear regression, Kalman filter, decision tree, nearest neighbor method, naive Bayes classifier, support vector machine, or neural network.

[0055] For example, a neural network includes an input layer, one or more intermediate 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, a plurality of intermediate layers, and an output layer.

[0056] Note that in this embodiment, the learned model includes a multi-layer perceptron or a support vector machine.

[0057] Based on the predicted first mark position and second mark position, the control unit 91 controls at least the second actuator 520 to bond the first substrate W1 and the second substrate W2 together. Specifically, the control unit 91 calculates the timing at which the relative horizontal position of the second substrate W2 with respect to the first substrate W1 is within the target range. Thereafter, the control unit 91 controls the second actuator 520 to bond the first substrate W1 and the second substrate together at the calculated timing.

[0058] Next, with reference to FIG. 3, the substrate bonding method of the substrate bonding apparatus 1 of the present 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 the present 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. Note that step S11 is an example of the "step of holding the first substrate" of the present invention. Step S12 is an example of the "step of holding the second substrate" of the present invention. Step S13 is an example of the "imaging step" of the present invention. Step S14 is an example of the "step of predicting the position of the first mark" of the present invention. Step S15 is an example of the "imaging step" of the present invention. Step S16 is an example of the "step of predicting the position of the second mark" of the present invention. Step S17 is an example of the "calculating step" of the present invention. Step S18 is an example of the "bonding step" of the present invention.

[0059] Here, for the sake of simplicity of explanation, it is assumed that the first mark M10 and the second mark M20 are arranged in advance within a predetermined range in the horizontal direction. The predetermined range is larger than the target range and includes the target range. The method of arranging the first mark M10 and the second mark M20 within a predetermined range in the horizontal direction is not particularly limited. For example, the second chuck 20 may be moved by the first actuator 510 based on the imaging result of the imaging unit 50, so that the first mark M10 and the second mark M20 are arranged within a predetermined range in the horizontal direction. Also, for example, when a transfer robot (not shown) that transfers the substrate W delivers the first substrate W1 and the second substrate W2 to the first chuck 10 and the second chuck 20, respectively, the first mark M10 and the second mark M20 may be arranged within a predetermined range in the horizontal direction.

[0060] As shown in FIG. 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 to hold 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 to hold 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 to image the first mark M10. Thereby, the imaging unit 50 focuses on the first mark M10 and images the first mark M10. At this time, the imaging unit 50 images several tens to several hundreds or more. The image data imaged by the imaging unit 50 is transmitted to the control unit 91. The image data includes information in which the captured image captured by the imaging unit 50 and the imaging time are associated.

[0063] Next, in step S14, the control unit 91 predicts the first mark position where the first mark M10 is located. Specifically, the control unit 91 calculates the position of the center of the first mark M10 with respect to the center of the first image (the first mark position) based on the first image. Then, the control unit 91 predicts the future first mark position based on the plurality of first mark positions calculated from the plurality of first images. Note that the control unit 91 predicts the first mark position several seconds to several tens of seconds ahead.

[0064] Next, in step S15, the imaging unit 50 images the second mark M20. Specifically, the control unit 91 controls the imaging unit 50 to image the second mark M20. Thereby, the imaging unit 50 focuses on the second mark M20 and images the second mark M20. At this time, the imaging unit 50 images several tens to several hundreds or more. The image data imaged by the imaging unit 50 is transmitted to the control unit 91. The image data includes information in which the captured image captured by the imaging unit 50 and the imaging time are associated.

[0065] Next, in step S16, the control unit 91 predicts the position of the second mark M20 where the second mark M20 is located. Specifically, the control unit 91 calculates the position of the center of the second mark M20 with respect to the center of the second image (the second mark position) based on the second image. Then, the control unit 91 predicts the future second mark position based on the plurality of second mark positions calculated from the plurality of second images. Note that the control unit 91 predicts the second mark position several seconds to several tens of seconds ahead.

[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 falls within the 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 falls within the target range. The target range is, for example, a range of several nm to several tens of nm 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 at the timing when the relative position of the second substrate W2 with respect to the first substrate W1 falls within the target range. Specifically, the control unit 91 lowers the first chuck 10 by the second actuator 520 so that the first substrate W1 and the second substrate come into contact with each other at the timing when the first mark position and the second mark position fall within the target range.

[0068] In the above 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 captured by the imaging unit 50 of the first mark M10. The control unit 91 predicts the position of the second mark based on the second image captured by the imaging unit 50 of the second mark M20. Then, the control unit 91 controls at least the second actuator 520 based on the predicted positions of the first mark and the second mark, and bonds the first substrate W1 and the second substrate W2 together. Therefore, even when a relative position variation occurs between the first substrate W1 and the second substrate W2 due to vibration or the like, the relative position variation 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. Thus, the first substrate W1 and the second substrate W2 can be accurately bonded together.

[0070] Also, as described above, the first mark M10 and the second mark M20 are imaged separately. Specifically, in this embodiment, the imaging unit 50 images the first mark M10 and the second mark M20 at different timings. Therefore, for example, even when the first mark M10 and the second mark M20 cannot be imaged simultaneously by one imaging unit 50, the first mark M10 and the second mark M20 can be easily imaged by one imaging unit 50. When aligning on the order of several hundred nm to several tens of nm or less, since it is necessary to make the imaging magnification of the imaging unit 50 very large, it is difficult to image the first mark M10 and the second mark M20 having different heights simultaneously by one imaging unit 50.

[0071] Also, as described above, the imaging unit 50 images the second mark M20 through the transparent plate 30. Therefore, two alignment marks (the first mark M10 and the second mark M20) can be easily imaged by one imaging unit 50.

[0072] Further, 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 falls within the target range based on the predicted first mark position and second mark position, and bonds the first substrate W1 and the second substrate W2 at the calculated timing. Therefore, the amount of misalignment of the second substrate W2 with respect to the first substrate W1 can be easily kept within the target range.

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

[0074] As shown in FIG. 4, the substrate bonding apparatus 1 laminates and bonds the first substrate W1 and the second substrate W2. In the present 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 (for example, several tens to several hundreds) of semiconductor chips (not shown). Each semiconductor chip constitutes an integrated circuit such as a CPU and / or a DRAM, for example. 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 formed of a metal material such as copper, gold, or aluminum. In the present embodiment, the electrodes are formed of copper, for example.

[0076] The electrodes of the first substrate W1 and the electrodes of the second substrate W2 are joined and electrically connected. The electrodes of the second substrate W2 are arranged at positions overlapping 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 surface Wa of the first substrate W1. The electrodes of the second substrate W2 are exposed on the surface Wa of the second substrate W2. Note that 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 conveyance 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 conveyance unit TU, a bonding unit JU, a center robot CR, a transfer robot TR, and a control device 90.

[0079] The conveyance path CP conveys the first substrate W1 and the second substrate W2. The conveyance 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 conveyance unit TU, and the bonding unit JU are arranged so as to face the conveyance path CP.

[0080] The center robot CR holds and conveys the first substrate W1 and the second substrate W2. The center robot CR moves within the conveyance path CP. The center robot CR conveys 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 conveyance unit TU.

[0081] The first load port LP1 accommodates a plurality (for example, 25 sheets) of the first substrates W1. Specifically, the plurality of first substrates W1 are accommodated in a hoop (also referred to as a carriage) (not shown) in a stacked state. The hoop that accommodates the first substrate W1 is arranged in the first load port LP1.

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

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

[0084] The stacked substrate WL is a substrate in which the first substrate W1 and the second substrate W2 are stacked and bonded together. In the present embodiment, the stacked substrate WL is configured by stacking and joining 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 treatment on the first substrate W1 and the second substrate W2. The type of gas used for the plasma treatment is not particularly limited, but for example, it is oxygen or nitrogen.

[0086] The activation unit AU has, for example, a high-frequency power source 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 turned into plasma. For example, when oxygen gas is used as the processing gas, the oxygen gas is turned 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. That is, 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 discharges the cleaning liquid. The cleaning liquid includes, for example, deionized water (DIW), carbonated water, electrolyzed ion water, ozone water, ammonia water, hydrochloric acid water with a dilution concentration (e.g., about 10 ppm to 100 ppm), or reduced water (hydrogen water). In this embodiment, the cleaning liquid is pure water such as DIW.

[0088] By cleaning the first substrate W1 and the second substrate W2 with the cleaning unit CU, the electrodes of the first substrate W1 and the second substrate W2 are cleaned. At this time, hydroxyl groups are formed on the surface of the electrodes.

[0089] The transfer unit TU is arranged so as to face the transfer path CP, the pre-alignment unit PU, and the bonding unit JU. A transfer robot TR is accommodated in the transfer unit TU.

[0090] The transfer robot TR holds and transfers the first substrate W1 and the second substrate W2. The transfer 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 transfer robot TR is fixed to the floor of the transfer unit TU and does not move within the transfer unit TU. Therefore, the transfer accuracy of the transfer robot TR is higher than that of the center robot CR that moves within the transfer 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 bonding unit JU. Note that the alignment by the pre-alignment unit PU may be referred to as pre-alignment.

[0092] FIG. 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, in addition to the first chuck 10 and the second chuck 20 described in the first embodiment, a base 2, a first actuator 200, and a second actuator 100.

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

[0094] In the present embodiment, the first chuck 10 holds the first substrate W1. In the present 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 portion 12 fixed to the first stage 11. The first stage 11 has one surface 11a to which the first holding portion 12 is attached. The first stage 11 has, for example, a rectangular parallelepiped shape. The first stage 11 is formed of, for example, a ceramic or metal having a small coefficient of linear expansion.

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

[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 horizontally along the upper surface of the base 2. Further, as will be described later, the second chuck 20 rotates the second substrate W2 in the circumferential direction.

[0098] The second chuck 20 includes 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 formed of, for example, a ceramic or metal having a small coefficient of linear expansion.

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

[0100] Further, the second holding portion 22 is configured to be rotatable in the circumferential direction. Specifically, the second holding portion 22 is configured to be rotatable about the center of the second holding portion 22. In other words, the second holding portion 22 rotates the second substrate W2 in the circumferential direction. Further, the second holding portion 22 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 up and down. As a result, the first substrate W1 is turned upside down or moved up and down.

[0102] Specifically, the second actuator 100 includes an inversion portion 110, a lifting portion 120, and a first gantry 130. In FIG. 5, the first gantry 130 is drawn with a two-dot chain line.

[0103] The reversing unit 110 reverses the first chuck 10 upside down. The reversing unit 110 has a rotating shaft portion 111 fixed to the first chuck 10 and a first rotating portion (not shown) that rotates the rotating shaft portion 111. The rotating shaft portion 111 may be constituted by one shaft portion passing through the first chuck 10, or may be constituted by a pair of shaft portions arranged with the first chuck 10 interposed therebetween. The first rotating portion has, for example, a stepping motor. When the first rotating portion rotates the rotating shaft portion 111 by 180°, the first chuck 10 is reversed 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 with respect to the second chuck 20. The angle detection unit includes, for example, three or more distance measurement sensors. The distance measurement sensors are attached to, for example, one surface 11a of the first chuck 10 and measure the distance to the second chuck 20. By rotating the rotating shaft portion 111 based on the detection results of the distance measurement sensors, the first chuck 10 can be arranged parallel to the second chuck 20.

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

[0106] The elevating 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, coils. The movers 122a also have encoders that detect the distance traveled along the rails (not shown).

[0107] The 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 plurality of magnets are arranged such that the N poles and the S poles are alternately arranged along the vertical direction. By passing an electric current 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 the present embodiment, the first actuator 200 moves the second chuck 20 horizontally along the upper surface of the base 2. Further, in the present 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 in the horizontal plane.

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

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

[0111] The pair of linear motors 2111 are disposed outside the second stage 21 of the second chuck 20 in the Y direction. The pair of linear motors 2111 are arranged 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 the side surface of the second stage 21. The mover 2111a moves along the rail 2111b. The mover 2111a has, for example, a coil. Also, the mover 2111a 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 such that the N poles and the S poles are alternately arranged along the X direction. By energizing 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] A pair of linear guides 2112 are arranged between the second stage 21 of the second chuck 20 and the support base 213. The pair of linear guides 2112 are arranged at a predetermined distance apart in the Y direction. The pair of linear guides 2112 are respectively arranged along the pair of linear motors 2111.

[0115] Each linear guide 2112 has a mover 2112a and a rail 2112b. The mover 2112a is fixed to the lower surface (the surface on the support base 213 side) of the second stage 21. The mover 2112a moves along the rail 2112b. The mover 2112a has, for example, a 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] FIG. 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 the present 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 base 213 and the base 2. The pair of linear motors 2121 are arranged 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 on the base 2 side) of the support base 213. The mover 2121a moves along the rail 2121b. The mover 2121a has, for example, a coil. The mover 2121a also has an encoder for detecting 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 plurality of magnets are arranged such that the N poles and the S poles are alternately arranged along the Y direction. By passing an electric current through 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 arranged at a predetermined distance from each other in the X direction. The pair of linear guides 2122 are respectively arranged along the pair of linear motors 2121.

[0121] Each linear guide 2122 has a mover 2122a and a rail 2122b. The mover 2122a is fixed to the lower surface (the surface on the base 2 side) of the support base 213. The mover 2122a moves along the rail 2122b. The mover 2122a has, for example, a 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 base 213 and the second chuck 20 linearly with high precision.

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

[0123] FIG. 8 is a schematic view showing the structure around the support base 213 from below. As shown in FIGS. 6 and 8, the bonding unit JU includes a detection mechanism 300. The detection mechanism 300 detects the movement of one of the first chuck 10 and the second chuck 20 in the XY plane. In the present embodiment, the detection mechanism 300 detects the movement of the second chuck 20 in the XY plane.

[0124] Specifically, the detection mechanism 300 has, for example, a two-dimensional scale 301 (hereinafter referred to as a 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 that extends in the XY directions. The 2D scale 301 is, for example, a reflective diffraction grating scale. The 2D scale 301 is configured such that the grating pitch changes along the X direction and the Y direction.

[0125] The support base 213 is provided with an opening 213a. The opening 213a is disposed below the 2D scale 301. Also, the opening 213a has an opening larger than that of 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 the opening 213a of the support base 213. Note that 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 the light reflected by the 2D scale 301. As the second chuck 20 moves, the light reception signal of the detection sensor 302 changes. Thereby, the moving amounts of the second chuck 20 in the X direction and the Y direction are detected.

[0127] As shown in FIG. 5, the bonding unit JU includes a first substrate detection unit 310 and a first reference mask 410. The first substrate detection unit 310 detects the first substrate W1. Specifically, the first substrate W1 has one or more alignment marks. The first substrate detection unit 310 detects the alignment marks of the first substrate W1.

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

[0129] Further, 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 where 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 includes a mark member 411 on which an alignment mark as a first mark is formed, and a pair of support columns 412 that support the mark member 411. Hereinafter, the alignment mark of the mark member 411 may be referred to as the first mark. Note that the mark member 411 is an example of the "transparent plate" of the present invention.

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

[0132] Here, by detecting the alignment mark of the first substrate W1 and the first mark of the first reference mask 410 by the first substrate detection unit 310, the relative position of the alignment mark of the first substrate W1 with respect to the first mark of the first reference mask 410 can be detected. Specifically, with one surface 11a of the first stage 11 facing downward, the first substrate detection unit 310 is moved in the horizontal direction to detect the alignment mark of the first substrate W1 and the first mark of the first reference mask 410. At this time, after the alignment mark of the first substrate W1 is detected by the first substrate detection unit 310, until the first mark of the first reference mask 410 is detected, the direction and distance in which the first substrate detection unit 310 and the second chuck 20 have moved are detected by the detection mechanism 300. Thereby, the relative position of the alignment mark of the first substrate W1 with respect to the first mark of the first reference mask 410 can be detected.

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

[0134] The bonding unit JU includes a second gantry 350, and the second substrate detector 320 is fixed to the second gantry 350. In FIG. 5, a part of the second gantry 350 is drawn with a two-dot chain line. The second substrate detector 320 includes, for example, a camera. The second substrate detector 320 includes an imaging element. For example, the imaging element is a CCD image sensor or a CMOS image sensor. The second substrate detector 320 transmits the captured imaging data to the control device 90. The imaging data includes image data.

[0135] In this embodiment, the second substrate detector 320 has cameras 321 and 322 with different magnifications. The camera 321 is a relatively low-magnification camera. The camera 322 is a relatively high-magnification camera. The magnification of the camera 322 is larger than that of the camera 321. Since the camera 321 has a relatively large angle of view, it is easy to detect the alignment marks of the second substrate W2. On the other hand, since the camera 322 has a relatively small angle of view and a high magnification, the detection accuracy of the alignment marks is high.

[0136] When the second substrate detector 320 detects the alignment marks of the second substrate W2, after detecting the alignment marks with the camera 321, the alignment marks are detected with the camera 322. Therefore, an operation of moving the second substrate detector 320 (the cameras 321 and 322) is required between the detection by the camera 321 and the detection by the camera 322. However, for the sake of simplicity of explanation, hereinafter, both the detection by the camera 321 and the detection by the camera 322 are described as the detection by the second substrate detector 320. Also, the operation of moving the second substrate detector 320 between the detection by the camera 321 and the detection by the camera 322 is omitted from the description.

[0137] Further, the second substrate detection unit 320 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 includes a mark member 421 having alignment marks as second marks, and a support column 422 that supports the mark member 421. Hereinafter, the alignment marks of the mark member 421 may be referred to as second marks. Note that the mark member 421 is an example of the "transparent plate" of the present invention.

[0139] The mark member 421 has second marks formed with high precision. For example, the second marks are formed by performing etching or the like on the mark member 421. The mark member 421 is formed of, for example, a member having a small coefficient of linear expansion. Further, the mark member 421 may be formed of, for example, a member having translucency. In the present embodiment, the mark member 421 is formed of, for example, glass that transmits visible light. Note that the mark member 421 may be formed of a member that does not transmit visible light.

[0140] Here, the second substrate detection unit 320 detects the alignment mark of the second substrate W2 and the second mark of the second reference mask 420, so that the relative position of the alignment mark of the second substrate W2 with respect to the second mark of the second reference mask 420 can be detected. Specifically, by moving the second chuck 20 and the second substrate W2 in the horizontal direction, the alignment mark of the second substrate W2 and the second mark of the second reference mask 420 are detected. At this time, after the alignment mark of the second substrate W2 is detected by the second substrate detection unit 320, until the second mark of the second reference mask 420 is detected, the direction and distance in which the first substrate detection unit 310 and the second chuck 20 have moved are detected by the detection mechanism 300. Thereby, the relative position of the alignment mark of the second substrate W2 with respect to the second mark of the second reference mask 420 can be detected.

[0141] FIG. 9 is a perspective view schematically showing the structure of the bonding unit JU from below. As shown in FIG. 9, the bonding unit JU includes an imaging unit 50. In the present embodiment, the imaging unit 50 transmits the captured imaging 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 facing the mark member 411 of the first chuck 10. Further, in the present embodiment, the imaging unit 50 images the mark member 411 and the mark member 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 timings. 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 one screen.

[0143] In this embodiment, the imaging unit 50 is attached to the first stage 11. The imaging unit 50 may be attached to, for example, one surface 11a (see FIG. 5) of the first stage 11. Further, the imaging unit 50 may be attached to the first stage 11 so as to penetrate the first stage 11, for example. 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 bonding the first substrate W1 held by the first chuck 10 and the second substrate W2 held by the second chuck 20, the first reference mask 410 and the second reference mask 420 are arranged to face each other in the vertical direction. At this time, the first mark of the first reference mask 410 and the second mark of the second reference mask 420 are arranged to face each other in the vertical direction. However, in the XY plane, the position of the first mark of the first reference mask 410 and the position of the second mark of the second reference mask 420 may or may not completely coincide. The first mark of the first reference mask 410 and the second mark of the second reference mask 420 only need to be arranged at positions that can be imaged by the imaging unit 50.

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

[0146] As shown in FIG. 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 transfer robot TR, the pre-alignment unit PU, and the bonding unit JU. Specifically, the control unit 91 of the control device 90 controls the center robot CR, the activation unit AU, the cleaning unit CU, the transfer 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 transfer robot TR, the pre-alignment unit PU, and the bonding unit JU.

[0147] The control unit 91 calculates, for example, the relative position of the alignment mark of the first substrate W1 with respect to the first mark of the first reference mask 410 based on the detection results of the detection mechanism 300 and the first substrate detection unit 310. Further, the control unit 91 calculates, for example, the relative position of the alignment mark of the second substrate W2 with respect to the second mark of the second reference mask 420 based on the detection results of the detection mechanism 300 and the second substrate detection unit 320. Further, the control unit 91 calculates, for example, the relative positional relationship between the first mark of the first reference mask 410 and the second mark of the second reference mask 420 based on the detection result of the imaging unit 50. Therefore, the control unit 91 can calculate, for example, the relative positional relationship between the alignment mark of the first substrate W1 and the alignment mark of the second substrate W2 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] Note that, 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 are substantially the same as calculating the relative position between the first substrate W1 and the second substrate W2.

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

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

[0151] As shown in FIG. 11, in step S101, the first substrate W1 is held by the first chuck 10. Specifically, the control unit 91 loads the first substrate W1 passed from the pre-alignment unit PU to the transfer robot TR into the bonding unit JU. The control unit 91 controls the transfer robot TR to load the first substrate W1 into the bonding unit JU. At this time, with the surface to be bonded to the second substrate W2 of the first substrate W1 (hereinafter sometimes referred to as the bonding surface) facing upward, the transfer robot TR transports the first substrate W1. Then, the transfer robot TR passes the first substrate W1 to the first chuck 10. Thereby, the first substrate W1 is held by the first chuck 10.

[0152] Next, in step S102, the second substrate W2 is held by the second chuck 20. Specifically, the control unit 91 loads the second substrate W2 passed from the pre-alignment unit PU to the transfer robot TR into the bonding unit JU. The control unit 91 controls the transfer robot TR to load the second substrate W2 into the bonding unit JU. At this time, the transfer robot TR transfers the second substrate W2 with the surface to be bonded to the first substrate W1 (hereinafter sometimes referred to as the bonding surface) facing upward. Then, the transfer robot TR passes the second substrate W2 to the second chuck 20. Thereby, the second substrate W2 is 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. As a result, 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 the 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 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 elevating portion 120 of the second actuator 100 to lower the first chuck 10 by a predetermined amount of descent. 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, several μm or more and ten-odd μm or less.

[0156] Next, steps S106 to S111 are executed in the same manner as steps S13 to S18 shown in FIG. 3.

[0157] Specifically, in step S106, the control unit 91 controls the imaging unit 50 to image the first mark M10. Specifically, the control unit 91 controls the imaging unit 50 to focus on the first mark M10 and image the first mark M10. At this time, the imaging unit 50 images dozens to hundreds or more 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 position of the first mark, i.e., the first mark position. Specifically, the control unit 91 calculates the position of the center of the first mark with respect to the center of the first image (the first mark position) based on the first image. Then, the control unit 91 predicts the future first mark position based on the multiple first mark positions calculated from the multiple first images.

[0159] Next, in step S108, the control unit 91 controls the imaging unit 50 to image the second mark. Specifically, the control unit 91 controls the imaging unit 50 to focus on the second mark and image the second mark. At this time, the imaging unit 50 images dozens to hundreds or more 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 position of the second mark, i.e., the second mark position. Specifically, the control unit 91 calculates the position of the center of the second mark M20 with respect to the center of the second image (the second mark position) based on the second image. Then, the control unit 91 predicts the future second mark position based on the multiple second mark positions calculated from the multiple second images.

[0161] Next, in step S110, the control unit 91 calculates the timing when the relative position of the second substrate W2 with respect to the first substrate W1 is within the target range. Specifically, the control unit 91 calculates the timing when the relative position of the second mark position with respect to the first mark position is within the target range. The target range is, for example, a range of several nm to dozens of nm 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 at the timing when the relative position of the second substrate W2 with respect to the first substrate W1 is within the target range. Specifically, the control unit 91 lowers the first chuck 10 by the second actuator 100 so that the first substrate W1 and the second substrate come into contact with each other at the timing when the first mark position and the second mark position are within the target range.

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

[0164] Other substrate bonding methods 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, it is not necessary to separately provide a member for fixing the imaging unit 50. Further, between either the first mark of the first reference mask 410 and the second mark of the second reference mask 420 and the imaging unit 50, it is possible to suppress a relative position variation caused by vibration or the like, so that it is possible to further suppress a decrease in alignment accuracy. Also, compared to the case where the imaging unit 50 is attached to a member other than the first chuck 10 and the second chuck 20, it becomes easier to arrange the imaging unit 50 near the first mark and the second mark. Thus, it is possible to suppress a decrease in the detection accuracy of the first mark and the second mark by the imaging unit 50.

[0166] Other effects of the second embodiment are the same as those of the first embodiment.

[0167] (Third Embodiment) With reference to FIGS. 12 and 13, the substrate bonding apparatus 1 according to the third embodiment of the present invention will be described. FIG. 12 is a perspective view schematically showing the structure of the bonding unit JU of the substrate bonding apparatus 1 of the third embodiment from below. In the third embodiment, different from the second embodiment, an example in which the substrate bonding apparatus 1 includes two imaging units 50 and 51 will be described.

[0168] As shown in FIG. 12, the imaging unit 50 is attached to the first chuck 10, for example, in the same manner as in the second embodiment. Different from 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 the present embodiment, the bonding unit JU of the substrate bonding apparatus 1 further includes an imaging unit 51. In the present embodiment, the imaging unit 51 transmits the captured imaging data to the control device 90.

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

[0171] Similar to the imaging unit 50, the imaging unit 51 is attached to the first chuck 10. 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 the present embodiment, while the imaging unit 50 images the first mark of the mark member 411, the imaging unit 51 images the second mark of the mark member 421.

[0173] In the present embodiment, the second mark of the mark member 421 is disposed at a position spaced apart from the first mark of the mark member 411 in the X direction. 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 the same as those of the second embodiment.

[0175] Next, with reference to FIG. 13, the method of bonding substrates by the bonding unit JU of the present embodiment will be described. FIG. 13 is a flowchart showing the method of bonding substrates by the bonding unit JU. In the present embodiment, the method of bonding substrates by the bonding unit JU includes steps S101 to S105, S201, S202, S110, and S111. Note that step S201 is an example of the "imaging step" of the present invention. Step S202 is an example of the "step of predicting the first mark position" and the "step of predicting the second mark position" 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 images the first mark of the mark member 411, and at the same time, the imaging unit 51 images the second mark of the mark member 421. Note that the other methods 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 of the second embodiment.

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

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

[0181] The other substrate bonding methods of the third embodiment are the same as those of the second embodiment.

[0182] In this embodiment, as described above, the first mark of the mark member 411 and the second mark of the mark member 421 are imaged separately. Specifically, in this embodiment, while the imaging unit 50 images the first mark of the mark member 411, the imaging unit 51 images the second mark of the mark member 421. Therefore, compared with the case where two alignment marks (the first mark and the second mark) are imaged by one imaging unit 50, the imaging time of the alignment marks can be shortened.

[0183] Also, by providing the two imaging units 50 and 51, it is possible to improve the degree of freedom in the positions where the first mark and the second mark are arranged.

[0184] In this embodiment, an example in which the mark member 421 is arranged at a position facing the mark member 411 in the vertical direction has been described, but the present invention is not limited to this. That is, the mark member 421 may be arranged 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 where the first mark and the second mark are arranged.

[0185] Other effects of the third embodiment are the same as 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 implemented in various aspects without departing from the gist thereof. Also, by appropriately combining a plurality of components disclosed in the above embodiments, various inventions can be formed. For example, some components may be deleted from all the components shown in the embodiments. Furthermore, components from different embodiments may be appropriately combined. The drawings are schematically shown mainly for each component to facilitate understanding, and the thickness, length, number, interval, etc. of each illustrated component may be different from the actual ones for convenience in drawing preparation. Also, the materials, shapes, dimensions, etc. of each component shown in the above embodiments are examples and are not particularly limited, and various changes can be made without substantially departing from the effects of the present invention.

[0187] For example, in the above embodiment, an example in which the first chuck 10 is moved in the vertical direction and the second chuck 20 is moved in the horizontal direction has been described. However, 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. Further, one of the first chuck 10 and the second chuck 20 may be moved in both the vertical direction and the horizontal direction.

[0188] Also, for example, in the second embodiment, an example in which both the imaging unit 50 and the imaging unit 51 are attached to the first chuck 10 has been described. However, 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. Further, 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. Also, 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] Also, for example, in the first embodiment, an example has been described in which even when a relative position variation occurs between the first substrate W1 and the second substrate W2 due to vibration or the like, the first substrate W1 and the second substrate W2 can be accurately bonded by adjusting the focal length of the imaging unit 50 and separately imaging the first mark M10 and the second mark M20. However, the present invention is not limited to this. For example, even when the position 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 does not enter the field of view of the imaging unit 50, it is possible to accurately bond the first substrate W1 and the second substrate W2. Specifically, for example, when the position accuracy of the second mark M20 is low, after the imaging unit 50 images the first mark M10, the imaging unit 50 may be moved in the horizontal direction or the orientation of the imaging unit 50 may be changed, so that the imaging unit 50 images the second mark M20.

[0190] In the above-described embodiment, an example has been described in which the control unit 91 predicts the first mark position based on the first image and predicts the second mark position based on the second image. However, 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 predict the second mark position based on a partial region of the second image. With such a configuration, compared to the case where the first mark position is predicted based on all regions of the first image and the second mark position is predicted based on all regions of the second image, the data size of the image used for prediction can be reduced, so the calculation time can be shortened.

[0191] Also, in the above-described embodiment, in the bonding step, an example has been described in which one of the first substrate W1 and the second substrate W2 is moved in the vertical direction by the second actuator to bond the first substrate W1 and the second substrate W2. That is, in the bonding step, an example has been described in which the first substrate W1 and the second substrate W2 are not aligned horizontally by the first actuator. However, the present invention is not limited to this. In the bonding step, the first substrate W1 and the second substrate W2 may be bonded while being aligned. Specifically, in the bonding step, the first substrate W1 and the second substrate W2 may be bonded by the second actuator while the first substrate W1 and the second substrate W2 are aligned horizontally by the first actuator. In other words, the control unit 91 may control the first actuator to align the first substrate W1 and the second substrate W2 and then control the second actuator to bond the first substrate W1 and the second substrate W2. With such a configuration, it is possible to easily bring the relative position of the second substrate W2 with respect to the first substrate W1 within the target range.

Industrial Applicability

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

Explanation of Reference Numerals

[0193] 1: Substrate bonding apparatus 10: First chuck 20: Second chuck 30: Transparent plate 50, 51: Imaging unit 91: Control unit 100: Second actuator 200: First actuator 411: Mark member (transparent plate) 421: Mark member (transparent plate) 510: First actuator 520: Second actuator M10: First mark M20: Second mark S11, S101: Step (process of holding the first substrate) S12, S102: Step (process of holding the second substrate) S13, S15, S106, S108, S201: Step (imaging process) S14, S107, S202: Step (process of predicting the position of the first mark) S16, S109, S202: Step (process of predicting the position of the second mark) S17, S110: Step (calculation process) S18, S111: Step (bonding process) W1: First substrate W2: Second substrate

Claims

1. a first chuck for holding a first substrate; a second chuck disposed opposite to the first chuck for holding a second substrate; a first actuator for moving one of the first chuck and the second chuck in a direction intersecting with the 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 the 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 imaging the first mark and the second mark; a control unit for controlling the first actuator and the second actuator ; and 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 obtained by the imaging unit imaging the first mark, predicts a second mark position where the second mark is located based on a second image obtained by the imaging unit imaging the second mark, and controls at least the second actuator based on the predicted first mark position and second mark position to bond the first substrate and the second substrate together, a substrate bonding device.

2. the imaging unit is one, and the one imaging unit images the first mark and the second mark at different timings, the substrate bonding device according to Claim 1.

3. there are a plurality of the imaging units, and the plurality of imaging units simultaneously image the first mark and the second mark, the substrate bonding device according to Claim 1.

4. the imaging unit is attached to either one of the first chuck and the second chuck, the substrate bonding device according to any one of Claims 1 to 3.

5. the first chuck has a transparent plate having translucency provided with the first mark, and / or the second chuck has a transparent plate having translucency provided with the second mark, and the imaging unit images at least one of the first mark and the second mark through the transparent plate, the substrate bonding device according to any one of Claims 1 to 3.

6. the control unit Based on the predicted first mark position and the second mark position, calculate the timing at which the relative position of the second substrate with respect to the first substrate falls within the target range. The substrate bonding apparatus according to any one of claims 1 to 3, wherein the first substrate and the second substrate are bonded together at the calculated timing.

7. The control unit predicts the first mark position based on a partial region of the first image, The substrate bonding apparatus according to any one of claims 1 to 3, wherein the second mark position is predicted based on a partial region of the second image.

8. 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 while aligning them. The substrate bonding apparatus according to any one of claims 1 to 3.

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

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