Substrate separation device

Abstract

Provided is a substrate separation device capable of accurately separating a bonded substrate. The substrate separation device 1 according to an embodiment includes: a holding part 10 that holds a bonded substrate S obtained by bonding a pair of substrates; a rotation drive part 122 that causes the holding part 10 to rotate; a nozzle 30 that causes the bonded substrate S to separate by discharging fluid toward the outer periphery of the rotating bonded substrate S; a nozzle moving part 40 that causes the nozzle 30 to move; an image capturing part that captures an image of an outer peripheral surface CS of the bonded substrate S held by the holding part 10; and a control device 100 that controls the nozzle moving part 40. The control device 100 controls a height adjustment mechanism 43 of the nozzle moving part 40 so as to cause the height position of the nozzle 30 to match the position of a separation surface RS of the bonded substrate S detected from the image captured by a camera 431.

Description

Substrate separation device

[0001] The present invention relates to a substrate separation device.

[0002] In the manufacturing process of three-dimensional semiconductor devices, a technique for separating a bonded substrate formed by bonding two substrates is used to transfer a layer formed on one substrate to the other substrate, thereby forming a uniform thin film.

[0003] As a technique for separating such substrates, a technique has been proposed in which the front and back surfaces of the bonded substrate are held by suction between a pair of holding parts (holders), and while rotating, high-pressure water (water jet) is supplied from a nozzle toward the separation surface exposed on the outer periphery of the bonded substrate, thereby utilizing the wedge effect of the fluid to separate the bonded substrate.

[0004] Japanese Patent Application Publication No. 11-005064

[0005] To ensure uniform separation of bonded substrates, the fluid must always be applied accurately to the separation surface. If the fluid deviates from the separation surface, the separation process will not proceed due to the wedge effect, resulting in uneven progress in the separation process within the bonded substrate surface, which can lead to defects such as cracks and chips. Therefore, there was a need for accurate detection of the separation surface in the direction perpendicular to the surface of the bonded substrate.

[0006] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a substrate separating device that can accurately separate bonded substrates.

[0007] A substrate separation device according to an embodiment of the present invention includes a holding unit that holds a bonded substrate formed by bonding a pair of substrates together, a rotation drive unit that rotates the holding unit, a nozzle that separates the bonded substrates by ejecting a fluid toward the outer periphery of the rotating bonded substrates, a nozzle moving unit that moves the nozzle, an imaging unit that captures an image of the outer periphery of the bonded substrate held by the holding unit, and a control device that controls the nozzle moving unit, wherein the control device controls the nozzle moving unit to align the height position of the nozzle with the position of the separation surface of the bonded substrates detected from the image captured by the imaging unit.

[0008] According to the embodiment of the present invention, the bonded substrates can be separated accurately.

[0009] 1 is a side view showing a substrate separating apparatus of an embodiment; FIG. 2 is a plan view showing bonded substrates and a positioning unit when the bonded substrates are carried in; FIG. 3 is a plan view showing bonded substrates and a positioning unit when the bonded substrates are positioned before a separation process; FIG. 4 is a plan view showing displacement of a nozzle to a standby position, a separation start position, and a central separation position; FIG. 5 is a plan view showing a bonded substrate, a positioning unit, and a nozzle when the bonded substrates are centrally separated; FIG. 6 is a block diagram showing the configuration of a control device; FIG. 7 is a flowchart showing a procedure for separating bonded substrates of an embodiment; FIG. 8 is an explanatory diagram showing a process from carrying in of a bonded substrate to a separation process of an embodiment; FIG. 9 is a flowchart showing a procedure for detecting the tilt of a nozzle; FIG. 10 is a plan view showing the positional relationship between a nozzle and a camera when detecting the tilt of a nozzle; FIG. 11 is an explanatory diagram (a) showing the state of reflected light from a discharged fluid, and FIG. 12 is an example of an image captured by a camera; FIG. 13 is a graph showing changes in the height of a detected separation surface; FIG. 14 is a flowchart showing a procedure for determining the height of a nozzle; FIG. 15 is an explanatory diagram (a) showing the outer circumferential surface and separation surface as viewed from the side of a bonded substrate; FIG. 16 is an explanatory diagram (b) showing the state of reflected light from the bonded substrate; and FIG. 17 is an example of an image captured by a camera. 10 is a schematic diagram showing the positional relationship between bonded substrates, a nozzle, and a camera in a modified example. FIG.

[0010] A substrate separating apparatus according to an embodiment will be described with reference to the drawings. The drawings are schematic diagrams, and the size, proportions, and the like of each part are exaggerated for ease of understanding. As shown in FIG. 1 , the substrate separating apparatus 1 separates bonded substrates S by discharging a fluid from a nozzle 30. The gripping unit 210 and the placement unit 220, which are located in the foreground, are omitted from FIG. 1 . In the following description, the direction along the rotation axis of the bonded substrate S is the Z direction, the direction in which the nozzle 30 discharges the fluid in a plane perpendicular to the Z direction is the Y direction, and the direction perpendicular to the Y direction is the X direction. The rotation plane of the bonded substrate S is parallel to the XY plane. In this embodiment, the Z direction is the vertical direction, and the XY direction is the horizontal direction, but the installation direction of the substrate separating apparatus 1 is not limited to this.

[0011] [Laminated Substrate] The laminated substrate S is a circular substrate formed by bonding a first substrate Sa and a second substrate Sb together. The first substrate Sa has a bonding surface Sa1, a surface Sa2 opposite the bonding surface Sa1, and an outer peripheral surface Sa3 connecting the bonding surfaces Sa1 and Sa2. The second substrate Sb has a bonding surface Sb1, a surface Sb2 opposite the bonding surface Sb1, and an outer peripheral surface Sb3 connecting the bonding surfaces Sa1 and Sa2. That is, the laminated substrate S is a pair of circular surfaces, and has a first surface Sa2 and a second surface Sb2 opposite the first substrate Sa and the second substrate Sb. Hereinafter, surface Sa2 will be referred to as the first surface of the laminated substrate S, and surface Sb2 will be referred to as the second surface of the laminated substrate S. 14(a), the recess formed by bonding the first substrate Sa and the second substrate Sb is referred to as a separation surface RS when viewed from the outer peripheral surface CS of the bonded substrate S. The outer peripheral surface CS of the bonded substrate S is composed of the outer peripheral surface Sa3 of the first substrate Sa, the separation surface RS, and the outer peripheral surface Sb3 of the second substrate Sb. The first substrate Sa is, for example, a substrate having a porous layer formed on the surface of a semiconductor wafer and a single-crystal Si layer further formed thereon.

[0012] The second substrate Sb is, for example, a substrate in which a single-crystal Si layer is formed on the surface of a semiconductor wafer. Such a first substrate Sa and a second substrate Sb are bonded together via an insulating layer formed on the first substrate Sa or the second substrate Sb, thereby forming a bonded substrate S. In the following description, even if the first substrate Sa and the second substrate Sb are separated from each other, the bonded substrate S will be referred to as a bonded substrate S as long as the bonding surfaces Sa1 and Sb1 are overlapping each other.

[0013] [Substrate Separation Apparatus] The substrate separation apparatus 1 separates the first substrate Sa of the bonded substrate S from the porous layer and forms multiple single-crystal Si layers on the second substrate Sb. As shown in FIG. 1 , the substrate separation apparatus 1 has a holding unit 10, a positioning unit 20, a nozzle 30, a nozzle moving unit 40, and a control device 100.

[0014] [Holding Unit] The holding unit 10 holds and rotates both surfaces (Sa2 and Sb2) of the bonded substrate S. The holding unit 10 has a first holder 110 and a second holder 120.

[0015] (First Holding Unit) The first holder 110 has a first holding unit 111 and a support mechanism 112. The first holding unit 111 is a circular plate having a diameter smaller than the diameter of the surface of the bonded substrate S. The support mechanism 112 is connected to the center of the surface of the first holding unit 111 via a support shaft in the Z direction, and supports the first holding unit 111 rotatably so that its center becomes the rotation center Ct. In this embodiment, the support shaft is connected to a drive source that rotates a second holding unit 121 (described later) via a pulley and a timing belt, and rotates in synchronization with the second holding unit 121.

[0016] In this embodiment, the surface of the first holding unit 111 fixed to the support mechanism 112 faces up, and the opposite surface faces down. Although not shown, the first holding unit 111 has a suction hole formed on the surface that contacts the bonded substrate S, and by connecting an exhaust device to this suction hole, one surface of the bonded substrate S (surface Sa2 of the first substrate Sa) can be suction-held by negative pressure.

[0017] (Second Holder) The second holder 120 has a second holding unit 121, a rotation drive unit 122, and an attachment / detachment drive unit 123. The second holding unit 121 is a circular plate having the same diameter as the first holding unit 111. The rotation drive unit 122 rotates the bonded substrate S. The rotation drive unit 122 has a Z-direction drive shaft connected to the center of the second holding unit 121, and rotatably supports the second holding unit 121. The rotation drive unit 122 has a motor as a drive source that rotates the second holding unit 121. The drive shaft is the shaft of the motor, and when the motor is operated, the second holding unit 121 rotates around a rotation center Ct.

[0018] In this embodiment, the surface of the second holding unit 121 attached to the rotation drive unit 122 faces downward, and the opposite surface faces upward and faces the first holding unit 111. In other words, the first holding unit 111 and the second holding unit 121 are disposed facing each other at a distance so that their centers of rotation Ct coincide. Although not shown, the second holding unit 121 has a suction hole that opens on the surface that contacts the bonded substrate S, and by connecting an exhaust device to this suction hole, the other surface of the bonded substrate S (surface Sb2 of the second substrate Sb) can be suction-held by negative pressure.

[0019] The attachment / detachment driving unit 123 causes the holding unit 10 to hold the bonded substrate S. The attachment / detachment driving unit 123 moves the second holding unit 121 in a direction toward or away from the first holding unit 111. The attachment / detachment driving unit 123 has a cylinder as a driving source. The bonded substrate S is inserted between the first holding unit 111 and the second holding unit 121, which are spaced apart, and the attachment / detachment driving unit 123 moves the second holding unit 121 toward the first holding unit 111, so that the bonded substrate S can be sandwiched and held between the first holding unit 111 and the second holding unit 121.

[0020] [Positioning Unit] The positioning unit 20 positions the central axis Cs of the bonded substrate S to the central axis Ct determined by the holding unit 10 (see FIGS. 2 and 3). That is, the positioning unit 20 aligns the central axis Cs of the bonded substrate S disposed between the first holder 110 and the second holder 120 with the central axis Ct of the first holder 110 and the second holder 120. The positioning unit 20 has a gripping unit 210, a placing unit 220, an axial direction driving unit 230, and an opening / closing driving unit 240 (see FIG. 1).

[0021] (Gripping section) The gripping section 210 grips the outer periphery of the bonded substrate S. The outer periphery of the bonded substrate S is the side surface along the outer edge of the circumference. A plurality of gripping sections 210 are arranged at equal intervals at positions surrounding the holding section 10, that is, at positions along the outer periphery of the bonded substrate S held by the holding section 10. The gripping sections 210 in this embodiment are four upright pins.

[0022] (Placement Section) The placement section 220 places the bonded substrate S. The placement section 220 has a placement surface that supports the bonded substrate S, and has each of the gripping sections 210 attached thereto. Four placement sections 220 are provided in one-to-one correspondence with the gripping sections 210. In this embodiment, the surface of the bonded substrate S that is held by the second holder 120, i.e., the surface Sb2 of the second substrate Sb, is placed on the placement section 220.

[0023] (Axial Driving Unit) The axial driving unit 230 moves the gripping unit 210 and the placing unit 220 in an axial direction parallel to the rotation axis of the holding unit 10. The axial driving unit 230 has a support unit 231, a biasing unit 232, and an absorbing unit 233. The support unit 231 is an upright member that supports the gripping unit 210 and the placing unit 220 at its tip. The biasing unit 232 is provided so as to be movable in the axial direction by a driving mechanism such as a cam rotated by a cylinder. The absorbing unit 233 is interposed between the biasing unit 232 and the support unit 231, and transmits the movement of the biasing unit 232 to the support unit 231 and absorbs vibrations generated when the bonded substrate S is separated. The absorbing unit 233 may be, for example, a compression spring, a leaf spring, an elastic body made of rubber or resin, a cylinder, or the like, as long as it can absorb vibrations generated when the bonded substrate S is separated.

[0024] (Opening / Closing Drive Unit) The opening / closing drive unit 240 moves the gripping unit 210 and the placing unit 220 between a closed position where the gripping unit 210 contacts the outer periphery of the bonded substrate S, and an open position where the gripping unit 210 is separated from the outer periphery of the bonded substrate S. The position of the gripping unit 210 is set so that the center Cs of the bonded substrate S is positioned at the rotation center Ct when the gripping unit 210 is in the closed position. The opening / closing drive unit 240 has an arm 241 that moves in the radial direction of the bonded substrate S (centripetal direction and centrifugal direction relative to the rotation center Ct) by a drive mechanism such as a cam that rotates by a cylinder (not shown). A support unit 231 is connected to the arm 241 so as to be axially movable.

[0025] (Nozzle) The nozzle 30 separates the bonded substrate S into the substrate Sa and the substrate Sb by ejecting a fluid toward the outer periphery of the rotating bonded substrate S. The nozzle 30 of this embodiment ejects a fluid toward the outer periphery of the bonded substrate S that is held by the holding unit 10 and rotates.

[0026] The nozzle 30 of this embodiment is a jetting device that sprays high-pressure fluid onto an object. The nozzle 30 is connected via piping, valves, and the like to a supply device 31 that includes a pump and the like that supplies the high-pressure fluid. The nozzle 30 is configured to be able to jet water (e.g., a water jet), which is a high-pressure fluid, and has a very small hole diameter (0.1 to 1 mm), and the thickness of the tip of the nozzle 30 is thick enough to withstand high-pressure water (1 to 5 cm). Furthermore, depending on the inclination of the axis of the hole provided in the nozzle 30 through which the fluid is jetted, or the inclination of the nozzle 30 itself, the fluid may be jetted from the nozzle 30 at a predetermined inclination. In other words, the fluid may be jetted from the nozzle 30 at an angle θ° with respect to the horizontal.

[0027] 3, the axis of the nozzle 30 is provided on an extension of the radius of the positioned bonded substrate S, and the outlet at the tip of the nozzle 30 is directed toward the outer periphery of the bonded substrate S. Therefore, the nozzle 30 ejects the fluid in a direction parallel to the rotation plane of the bonded substrate S and toward the center Cs. However, the gripping part 210 is provided at a position that does not overlap with the extension of the axis of the nozzle 30.

[0028] (Nozzle Moving Unit) As shown in Figures 4 and 5, the nozzle moving unit 40 changes the fluid ejection direction of the nozzle 30 between a first direction that is a direction along the tangent to the outer periphery of the bonded substrate S and a second direction that is a direction toward the central axis Cs of the bonded substrate S. The first and second directions are parallel to each other. In other words, the nozzle 30 ejects fluid in two directions by changing its position from the separation start position [a] to the central separation position [b] in Figure 4 without changing the fluid ejection direction. The nozzle moving unit 40 of this embodiment can move the nozzle 30 in a direction along the outer periphery of the bonded substrate S. The nozzle moving unit 40 has a contact / separation mechanism 41, a position adjustment mechanism 42, and a height adjustment mechanism 43.

[0029] (Contact / Separate Mechanism) The contact / separate mechanism 41 moves the nozzle 30 between a standby position where the discharge port is separated from the outer periphery of the bonded substrate S and a discharge position where the nozzle 30 approaches the outer periphery and can separate the bonded substrate S by discharging fluid. In other words, the contact / separate mechanism 41 moves the nozzle 30 along the Y direction. The contact / separate mechanism 41 can be, for example, a ball screw mechanism driven by a servo motor.

[0030] (Position Adjustment Mechanism) The position adjustment mechanism 42 moves the nozzle 30 between a separation start position [a] along a tangent to the outer periphery of the bonded substrate S held and rotated by the holding unit 10, and a central separation position [b] toward the central axis Cs of the bonded substrate S. In other words, the nozzle 30 moves along the X direction by the position adjustment mechanism 42. The position adjustment mechanism 42 can be, for example, a ball screw mechanism driven by a servo motor.

[0031] As shown in FIG. 4 , the nozzle 30 can move along an arc trajectory from the separation start position [a] to the central separation position [b] by the contact / separation mechanism 41 and the position adjustment mechanism 42. As a result, the fluid ejected from the nozzle 30 is sprayed toward a partial region of the outer periphery of the bonded substrate S, indicated by Ra in FIG. 4 . This partial region is a region including an arc with a central angle of 90 degrees on the outer periphery of the bonded substrate S. Since the bonded substrate S rotates at least during separation of the outer periphery, even if the fluid is ejected to a partial region of the outer periphery, the ejected fluid can reach the entire periphery. Furthermore, as the separation portion of the bonded substrate S, indicated by the hatched portion in FIG. 4 , expands, the fluid also reaches the central portion of the bonded substrate S through the gap between the first substrate Sa and the second substrate Sb. When the center of the bonded substrate S is separated, the nozzle 30 is positioned at the central separation position [b], as shown in FIG. 5 . Before the start of separation of the bonded substrate S and after the completion of separation, the nozzle 30 is moved to a standby position [c] separated from the outer periphery of the bonded substrate S by the contact / separation mechanism 41 and the position adjustment mechanism 42 .

[0032] The distance d between the discharge port of the nozzle 30 positioned in the first direction and the outer periphery of the bonded substrate S is the same as the distance d between the discharge port of the nozzle 30 positioned in the second direction and the outer periphery of the bonded substrate S. This allows the discharge port of the nozzle 30 in the first direction and the discharge port of the nozzle 30 in the second direction to be as close to the outer periphery of the bonded substrate S as possible.

[0033] (Height Adjustment Mechanism) The height adjustment mechanism 43 moves the nozzle 30 in the height direction (Z-axis direction). The height adjustment mechanism 43 can be, for example, a cylinder. That is, the height adjustment mechanism 43 moves the nozzle 30 along the Z-direction. The separation surface RS of the rotating bonded substrate S moves slightly up and down in height depending on how the bonded substrate S is held and deflected. Furthermore, if the fluid is ejected from the nozzle 30 at a predetermined inclination, when moving the nozzle 30 in the Z-axis direction, it is necessary to adjust the height of the nozzle 30 in the vertical direction, taking into account the inclination of the fluid ejected from the nozzle 30, in order to accurately hit the fluid (hereinafter referred to as ejected fluid) on the separation surface RS. The height adjustment mechanism 43 includes a camera 431 as an imaging unit, and moves the nozzle 30 in the height direction based on the detection results of the camera 431.

[0034] The camera 431 may have a depth of field of 35 μm to 50 μm. As shown in FIG. 4, the camera 431 is positioned at a 90° angle with respect to the axis of the nozzle 30 and on an extension of the diameter of the bonded substrate S. In the XY plane, the axis of the nozzle 30 coincides with the ejection direction of the ejected fluid ejected from the nozzle 30. The camera 431 may be installed on a fixed stand, or may be installed on a lift-up table or the like so that it can be adjusted to match the height of the bonded substrate S held by the holder 10.

[0035] It is desirable that the camera 431 be placed at a certain distance from the discharged fluid in order to reduce the influence of water droplets when capturing an image.

[0036] A light 433, which is an irradiation unit, is provided near the camera 431 and is parallel to the optical axis of the camera 431, and the irradiation light from the light 433 is irradiated in a direction perpendicular to the discharged fluid. The camera 431 detects the position of the discharged fluid by detecting the reflected light (specularly reflected light) of the irradiated irradiation light that is specularly reflected from the surface of the discharged fluid. The camera 431 is also installed in a position where it can capture an image of the outer circumferential surface CS including the separation surface RS of the loaded bonded substrate S. When the bonded substrate S is loaded and held by the holding unit 10, the focal position of the camera 431 is located on the separation surface RS of the bonded substrate S.

[0037] The camera 431 may be one that photographs only one point on the outer peripheral surface CS of the stationary bonded substrate S, but is preferably one that can photograph the entire circumference of the outer peripheral surface CS of the bonded substrate S rotating at a predetermined angular interval or continuously. That is, the outer peripheral surface CS of the bonded substrate S held by the holding unit 10 is not necessarily held at the same height due to reasons such as the dimensional accuracy of the holding unit 10 and the bonded substrate S, and it is expected that slight deviations will occur in the circumferential direction. Therefore, when the separation operation is performed while the bonded substrate S is being rotated, the height of the nozzle 30 can be adjusted according to the rotation angle and height of the bonded substrate S, thereby making it possible to reliably discharge the fluid onto the separation surface RS.

[0038] [Control Device] The control device 100 is a device that controls the substrate separating device 1, and controls the operations of the holding unit 10, the positioning unit 20, the nozzle 30, and the nozzle moving unit 40. The control device 100 can be realized, for example, by a dedicated electronic circuit or a computer that operates according to a predetermined program.

[0039] More specifically, the control device 100 controls the rotation and movement of the second holding unit 121 by controlling the rotation drive unit 122 and the attachment / detachment drive unit 123. The control device 100 also controls the movement of the gripper 210 and the placement unit 220 by controlling the axial drive unit 230 and the opening / closing drive unit 240. Furthermore, the control device 100 controls the ejection of fluid from the nozzle 30 by controlling the supply device 31, and controls the movement of the nozzle 30 by controlling the contact / separation mechanism 41 and the position adjustment mechanism 42 provided in the nozzle movement unit 40.

[0040] Next, alignment of the position of the nozzle 30 with the separation surface RS of the bonded substrate S will be described.

[0041] (1) Calculation of the movement amount of the nozzle 30 based on the inclination of the discharged fluid The control device 100 detects the inclination of the fluid discharged from the nozzle 30 based on the image captured by the camera 431. Based on the detected inclination of the discharged fluid and the distance from the discharge port of the nozzle 30 to an arbitrary processing position on the separation surface RS to which the discharged fluid is supplied, the control device 100 controls the nozzle movement unit 40 to align the height position of the nozzle 30 with the height position of the separation surface RS.

[0042] Therefore, as shown in FIG. 6, the control device 100 has an image capturing processing unit 101 that controls the image capturing timing of the camera 431, the rotation of the bonded substrate S, the movement of the nozzle 30, and the like.

[0043] Before the bonded substrate S is carried in, the imaging processing unit 101 moves the nozzle 30 to a position where the camera 431 can capture an image of the discharged fluid, and captures an image of the discharged fluid. The captured image is stored in the image storage unit 102a in the storage unit 102. The tilt detection unit 103 detects the tilt of the discharged fluid based on the captured image and stores the detected tilt in the tilt storage unit 102b. The calculation unit 104 calculates the amount of movement of the nozzle 30 so as to align the height position of the nozzle 30 with the height of the separation surface RS, based on the detected tilt of the discharged fluid and the distance from the discharge port of the nozzle 30 to an arbitrary processing position on the separation surface RS. In other words, the calculation unit 104 calculates the amount of movement of the nozzle 30 in the height direction so that the nozzle 30 is positioned at a position where the discharged fluid discharged from the nozzle 30 hits the separation surface RS.

[0044] (2) Height correction control based on change in height of separation surface The control device 100 corrects the calculated movement amount of the nozzle 30 with a correction amount based on the height of the separation surface RS, which moves up and down in accordance with the rotation of the bonded substrate S, and controls the movement of the nozzle 30 in the vertical direction.

[0045] To calculate the correction amount based on the height of the separation surface RS, which moves up and down in accordance with the rotation of the bonded substrate S, the imaging processing unit 101 captures images of the outer peripheral surface CS of the bonded substrate S, which is held by the holding unit 10 and rotates, for at least one revolution before the discharge of the discharged fluid. The storage unit 102 has a separation surface height storage unit 102c that stores the rotation angle of the bonded substrate S at the time of image capture and the position of the separation surface RS of the bonded substrate S detected from the image captured by the camera 431, in association with each other. The separation surface height detection unit 105 detects changes in the position of the separation surface RS of the bonded substrate S using a specific position of the bonded substrate S as a reference. For example, if the bonded substrate S is a semiconductor wafer, the position of the notch is used as a reference. Using the position of the notch as a reference, the amount of change in the height of the separation surface RS of the bonded substrate S is detected in association with the angle of separation from the notch position. In order to detect the amount of change in the height of the separation surface RS of the bonded substrate S, it is necessary to detect the height position of the separation surface RS for at least one circumference, but by using the position of the notch as a reference, it is possible to easily determine one circumference of the rotating bonded substrate S.

[0046] The control device 100 has a calculation unit 104 that refers to the values ​​stored in the separation surface height memory unit 102c and calculates the movement amount of the nozzle 30 based on the height of the separation surface RS and the rotation angle of the bonded substrate S. The calculation unit 104 refers to the inclination of the discharged fluid stored in the inclination memory unit 102b and calculates the movement amount of the nozzle 30 based on the inclination of the discharged fluid and the distance from the discharge port of the nozzle 30 to an arbitrary processing position on the separation surface RS. The nozzle height correction unit 106 calculates the correction amount for the height of the nozzle 30 based on a change in the height of the separation surface RS. The nozzle height correction unit 106 outputs a control signal to the nozzle movement unit 40 based on the movement amount of the nozzle 30 calculated by the calculation unit 104 and the calculated correction amount for the height of the nozzle 30.

[0047] The control device 100 includes a separation status determination unit 107 that determines the separation status from images captured by the camera 431. The separation status determination unit 107 determines the progress of the separation process by comparing the images captured by the camera 431 with reference images of the separation status at each stage, which are pre-stored in the memory unit 102. More specifically, as the separation process progresses, fluid infiltrates the bonding surfaces Sa1 and Sb2 of the first substrate Sa and the second substrate Sb, increasing the recess between the first substrate Sa and the second substrate Sb, i.e., increasing the separation surface RS. Therefore, by comparing the reference image at the separation stage of the outer periphery of the bonded substrate S with the image captured by the camera 431, it can be determined that the outer periphery has separated if the images match. Alternatively, a method can be employed in which the distance between the two substrates in the bonded substrate S is calculated from the captured image, and the degree of separation or completion of separation can be determined if the distance exceeds a preset threshold. Based on the result of this determination, the control device 100 can control the movement of the nozzle 30 and the ejection time and intensity of the fluid ejected from the nozzle 30 .

[0048] [Operation] The operation of the substrate separating apparatus 1 as described above will be described with reference to the flowchart in Fig. 7 and the explanatory diagram in Fig. 8 in addition to Figs. 1 to 6 above. Note that Ph1 in Fig. 8 is a fixed reference position of the lower surface of the first holder 110, and Ph2 is a transfer position which is the position of the lower surface of the mounting unit 220 when the mounting unit 220 transfers the bonded substrate S between it and the robot arm M. Ps1 is a separation position which is the height position of the lower surface of the second substrate Sb when the bonded substrate S is sandwiched between the first holder 110 and the second holder 120 and separated by ejecting fluid from the nozzle 30 while rotating the bonded substrate S. Ps2 is a receiving position which is the position of the upper surface of the mounting unit 220 when the positioning unit 20 receives the bonded substrate S from the holding unit 10.

[0049] First, the substrate separating apparatus 1 detects the inclination of the discharged fluid before the bonded substrate S is carried in (S101). Fig. 9 is a flowchart showing the procedure for detecting the inclination of the discharged fluid in S101.

[0050] To detect the inclination of the discharged fluid, the photographing processing unit 101 moves the nozzle 30 to an imaging position (S201). As shown in Fig. 10, the imaging position is a position where the discharged fluid overlaps with the focal position of the camera 431. After moving the nozzle 30, the photographing processing unit 101 causes the camera 431 to capture an image of the fluid discharged from the nozzle 30 (S202, S203).

[0051] FIG. 11( a) is an explanatory diagram showing the state of light reflected from the surface of the ejected fluid. As shown in FIG. 11( a), the light emitted from the light 433 is specularly reflected at the center of the ejected fluid, indicated by the black arrow, but is diffused at the peripheral portion. For example, in the case of an ejected fluid with a diameter of 100 μm, the light is specularly reflected at approximately 20 μm from the center. Therefore, when the ejected fluid illuminated by the light 433 is imaged with the camera 431, the central portion appears bright (high brightness) and linear, while the peripheral portion appears dark (low brightness), as shown in the image of FIG. 11( b). In other words, by irradiating the ejected fluid with light from the light 433, an image with clear contrast between the central and peripheral portions can be captured. The captured image is stored in the image storage unit 102a (S204).

[0052] Next, the tilt detection unit 103 detects the tilt from the captured image (S205). The tilt detection unit 103 detects the tilt of the ejected fluid from the captured image stored in the image storage unit 102a, and stores the detected tilt in the tilt storage unit 102b (S206). As shown in FIG. 11, the central part of the ejected fluid appears as a straight line, so the tilt of the ejected fluid can be detected by detecting the tilt angle of this line. As described above, the ejected fluid in the captured image has a clear contrast between the central part and the peripheral part, so it is possible to accurately detect the tilt. By going through the above S201 to S206, the process of detecting the tilt of the ejected fluid (S101) is completed.

[0053] At this time, the second holder 120 is located at a position separated from the first holder 110 ( FIG. 8(A) ). The gripping unit 210 and the mounting unit 220 are located at the delivery position Ph2 and also at the open position. The robot arm M of the transport device carries in the bonded substrate S and mounts the bonded substrate S on the mounting unit 220 ( FIG. 8(B) , step S102). The gripping unit 210 rises to raise the bonded substrate S ( FIG. 8(C) ). Furthermore, the second holder 120 rises to contact the lower surface of the second substrate Sb, and raises the bonded substrate S, thereby slightly separating it from the mounting unit 220 ( FIG. 8(D) , step S103).

[0054] As shown in Fig. 3, the gripping unit 210 moves to the closed position to grip the outer periphery of the bonded substrate S and position the central axis Cs of the bonded substrate S to the central axis Ct (Fig. 8(E), step S104). Thereafter, the gripping unit 210 moves to the open position (Fig. 8(F)) and retreats to the delivery position Ph2 together with the placement unit 220 (Fig. 8(G), step S105). Then, the second holder 120 rises to hold the bonded substrate S by contacting it with the first holder 110 and sandwiching it, positioning the bonded substrate S at the separation position Ps1 and holding it by suction using the negative pressure of the suction holes (Fig. 8(H), step S106).

[0055] In this state, the second holder 120 rotates, thereby rotating the bonded substrate S together with the first holder 110 (rotation process: step S107). When the bonded substrate S is held and rotated by the holder 10, the height of the separation surface RS on the side surface of the bonded substrate S may fluctuate slightly depending on how well the bonded substrate S is held and flexed. FIG. 12 is a graph showing the height of the separation surface RS versus the rotation angle. In FIG. 12, the rotation angles at which a straight line extending in the vertical axis direction appears between 200 and 400 degrees, 600 and 800 degrees, 800 and 1000 degrees, and 1200 and 1400 degrees are the rotation angles at which a notch appears in the bonded substrate S that rotates one or more times. In other words, the height displacement between the notch at a certain rotation angle and the next notch that appears (between the above-mentioned lines) can be determined as the height displacement for one rotation. 12, with the reference height being 0, the height of the separation surface RS varies within ±150 μm with each rotation of the bonded substrate S. The control device 100 corrects the position of the nozzle 30 in accordance with the variation in the height of the separation surface RS, and controls the discharged fluid so that it does not deviate from the separation surface RS.

[0056] 13 is a flowchart showing the procedure for determining the height of the nozzle 30 in accordance with changes in the height of the separation surface. When the bonded substrate S is held by the first holder 110 and the second holder 120, the imaging processing unit 101 rotates the bonded substrate S while capturing an image of the outer peripheral surface CS for one revolution using the camera 431 (S301). The rotation of the bonded substrate S causes the height of the separation surface RS to rise and fall. By adjusting the focal length and position of the camera 431, the separation surface RS is prevented from falling outside the angle of view of the camera 431 even if the separation surface RS rises and falls.

[0057] 14(b) is an explanatory diagram showing the state of light reflected from the bonded substrate S. As shown in FIG. 14(b), the light irradiated from the light 433 is specularly reflected at the portion of the outer peripheral surface CS of the bonded substrate S indicated by the black arrow where the illumination light is perpendicularly incident, but the light is diffused at the curved portion where the outer peripheral surface CS of the bonded substrate S and the surface Sa2 are connected. Therefore, when the bonded substrate S illuminated by the light 433 is imaged, as in the image shown in FIG. 14(c), the central portion of the outer peripheral surface Sa3 of the first substrate Sa and the central portion of the outer peripheral surface Sb3 of the second substrate Sb of the outer peripheral surface CS of the bonded substrate S become specularly reflective surfaces that specularly reflect the irradiated light, and the specularly reflected light is detected, resulting in a bright (high brightness) image. In contrast, the central portion including the separation surface RS between the first substrate Sa and the second substrate Sb is a dark (low brightness) image. That is, by irradiating the outer peripheral surface CS of the bonded substrate S with the light 433, it is possible to capture an image with clear contrast between the outer peripheral surface Sa3 of the first substrate Sa and the outer peripheral surface Sb3 of the second substrate Sb, as well as the central portion sandwiched between them. The captured image is stored in the image storage unit 102a (S302).

[0058] Next, the separation surface height detection unit 105 detects a change in the height of the separation surface RS from the captured image (S303). The separation surface height detection unit 105 detects the area between the two specular reflection surfaces as the separation surface RS. Specifically, the separation surface height detection unit 105 detects an area several μm wide from the center between the two linear areas where specular reflection light is detected as the separation surface RS. The separation surface height detection unit 105 can accurately detect the height of the separation surface RS by using a captured image with high contrast. The separation surface height detection unit 105 transmits information about the detected height of the separation surface RS to the separation surface height storage unit 102c. The separation surface height storage unit 102c stores the height of the separation surface RS detected from the captured image in association with the rotation angle of the bonded substrate S (S304).

[0059] The calculation unit 104 calculates the movement amount of the nozzle 30 based on the relationship between the inclination of the discharged fluid and the distance from the discharge port of the nozzle 30 to an arbitrary processing position on the separation surface RS (S305). Thereafter, the nozzle height correction unit 106 calculates the height correction amount of the nozzle 30 (S306). A control signal is output to the nozzle movement unit 40 based on the movement amount of the nozzle 30 calculated by the calculation unit 104 and the calculated correction amount of the height of the nozzle 30 (S307).

[0060] The height position of the nozzle 30 is determined by going through the above steps S301 to S307. Next, the nozzle 30 moves from the standby position [c] shown in FIG. 4 and is positioned at the separation start position [a] (step S108). Based on the height position determined in S307, the height position of the nozzle 30 is also adjusted. Then, the nozzle 30 ejects the fluid toward the outer periphery of the bonded substrate S (separation step: step S109). This starts separation of the bonded substrate S (step S110).

[0061] The nozzle 30 moves so as to follow the separation surface RS of the bonded substrate S (displacement step: step S111). Here, as described above, the distance of the nozzle 30 from the separation surface RS and the height of the separation surface RS change with the rotation of the bonded substrate S and the transition of the separation portion on the separation surface RS. By changing the height of the nozzle 30 based on these changes, the discharged fluid discharged from the nozzle 30 hits the separation surface RS accurately, and the separation step progresses.

[0062] Then, as the separation progresses and the bonding surface Sa1 and the bonding surface Sb1 are separated at the location corresponding to the central axis Cs (YES in step S112), the ejection of the fluid from the nozzle 30 stops (step S113).The rotation of the first holder 110 and the second holder 120 stops, and the rotation of the bonded substrate S stops (step S114).

[0063] Thereafter, the negative pressure in the first holder 110 and the second holder 120 is released, the second holder 120 descends and hands over the bonded substrate S to the mounting section 220, and the robot arm M of the transport device lifts up the bonded substrate S from the underside of the bonded substrate S, and the robot arm M carries the bonded substrate S out (see Figures 8(B) and (A), step S115).

[0064] [Effects] (1) The substrate separating device 1 of this embodiment includes a holding unit 10 that holds a bonded substrate S in which a pair of substrates are bonded together, a rotation drive unit 122 that rotates the holding unit 10, a nozzle 30 that separates the bonded substrate S by ejecting a fluid toward the outer periphery of the rotating bonded substrate S, a nozzle moving unit 40 that moves the nozzle 30, an imaging unit that captures an image of the outer periphery CS of the bonded substrate S held by the holding unit 10, and a control device 100 that controls the nozzle moving unit 40. The control device 100 controls a height adjustment mechanism 43 of the nozzle moving unit 40 to align the height position of the nozzle 30 with the position of the separation surface RS of the bonded substrate S detected from the image captured by the camera 431.

[0065] This makes it possible to accurately detect the separation surface RS of the bonded substrate S in the height direction and always accurately apply the fluid to the separation surface RS, ensuring reliable separation processing using the wedge effect. As a result, separation can proceed uniformly within the surface of the bonded substrate S, and defects such as cracks or chips in the substrates can be prevented, making it possible to form a uniform thin film on the substrates by copying a layer formed on one substrate to the other.

[0066] (2) The camera 431 captures images of the outer peripheral surface CS of the bonded substrate S, which is held and rotated by the holder 10, for one or more revolutions. The control device 100 associates and stores the rotation angle of the bonded substrate S with the position of the separation surface RS of the bonded substrate S detected from the image captured by the camera 431, and controls the height adjustment mechanism 43 of the nozzle moving unit 40 to align the height position of the nozzle 30 with the position of the separation surface RS.

[0067] Therefore, even if the height of the bonded substrate S varies slightly depending on the rotation angle, it is possible to accurately grasp the position of the separation surface RS of the bonded substrate S detected from the image captured by the camera 431, and it is possible to accurately align the ejected fluid with the separation surface RS around the entire outer periphery of the bonded substrate S.

[0068] (3) The camera 431 captures an image of the discharged fluid discharged from the nozzle 30, and the control device 100 detects the inclination of the discharged fluid discharged from the nozzle 30 based on the image captured by the camera 431, and controls the height adjustment mechanism 43 of the nozzle movement unit 40 to align the height position of the nozzle 30 with the height of the separation surface RS based on the detected inclination of the discharged fluid and the distance from the discharge port of the nozzle 30 to the separation surface RS. In other words, the heightwise movement of the nozzle 30 is controlled so that the nozzle 30 is positioned at a position where the discharged fluid discharged from the nozzle 30 hits the separation surface RS.

[0069] Therefore, even if the fluid discharged from the nozzle 30 is inclined, the height adjustment mechanism 43 can be controlled to align the height position of the nozzle 30 with the separation surface RS, taking into account the amount of inclination, so that the fluid is accurately sprayed onto the separation surface RS. As a result, not only is the fluid not able to move away from the separation surface RS and prevent the separation of the bonded substrate S from progressing, but the risk of the discharged fluid colliding with other parts of the bonded substrate S and damaging the substrate is eliminated. In particular, since the discharged fluid turns into a mist at a location far from the discharge position from the nozzle 30, it is necessary to bring the nozzle 30 closer to the separation surface RS. However, the distance between the fluid and the processing point by the nozzle 30 varies depending on the location, and the inclination angle of the discharged fluid also changes accordingly. Therefore, detecting the inclination of the discharged fluid and setting the appropriate height of the nozzle 30 accordingly is extremely effective for performing appropriate separation work.

[0070] (4) The camera 431 includes a light 433 that irradiates the outer peripheral surface CS of the bonded substrate S or the fluid discharged from the nozzle 30 with illumination light in the coaxial direction with the camera 431. Therefore, the camera 431 can directly capture the coaxial reflected light that is generated when the illumination light from the light irradiating unit strikes the vicinity of the separation surface RS or the fluid discharged from the nozzle 30 and is reflected. This allows for a clearer image of the separation surface RS to be obtained compared to when an image is captured using scattered light such as natural light or indoor light, thereby improving the alignment accuracy of the nozzle 30. Furthermore, the light 433 provides a large amount of irradiated light or reflected light, which improves the accuracy and contrast of the captured image and facilitates image analysis when detecting the position of the separation surface RS or the position of the fluid discharged from the nozzle 30.

[0071] (5) The camera 431 captures an image of the outer peripheral surface CS of the bonded substrate S after separation has started and before separation is completed, and the control device 100 determines the separation status from the image captured by the imaging unit. Therefore, the camera 431 can determine the separation status of the bonded substrate S in addition to aligning the nozzle 30, and the control device 100 can control the fluid ejection time, intensity, position, etc. based on the determination result, thereby more accurately performing the separation process of the bonded substrate S.

[0072] [Modifications] The following modifications can also be applied to this embodiment. (1) As shown in FIG. 15 , a plate 432 for preventing water droplets from adhering to the camera 431 can be provided in front of the lens of the camera 431, between the camera 431 and the bonded substrate S, and closer to the camera 431 than the discharge port of the nozzle 30. This plate 432 is preferably made of transparent glass or plastic. By providing such a water droplet adhesion prevention plate 432, it is possible to prevent water droplets from adhering to the imaging unit (camera 431). In particular, when determining the separation status from an image captured by the imaging unit as described above, even if the imaging unit captures an image of the discharged fluid to align the nozzle 30 while the bonded substrate S is held by the holding unit 10, it is possible to prevent water droplets from adhering to the imaging unit and not interfere with the subsequent imaging of the separation surface RS of the bonded substrate S. The plate 432 may be provided integrally with the camera 431 or as a separate member.

[0073] (2) When the inclination that occurs when the discharged fluid reaches the separation surface RS from the tip of the nozzle 30 due to factors such as the shape of the nozzle 30 can be almost ignored in the separation operation, there is no need to detect the inclination angle of the discharged fluid by image analysis, as described in the embodiment. Also, when the inclination angle is determined in advance by simulation or calculation, it is possible to reflect that value in the correction amount in the height direction of the separation surface RS and the nozzle 30 acquired by the camera 431. In this case, there is also no need to detect the inclination angle of the discharged fluid by image analysis, as described in the embodiment.

[0074] (3) When the amount of displacement in the rotation angle of the bonded substrate S can be almost ignored in the separation operation due to factors such as the thickness, material, and diameter of the bonded substrate S, it is also possible to determine the amount of movement of the nozzle 30 by photographing only one point on the bonded substrate S without photographing the outer peripheral surface CS for more than one revolution.

[0075] (4) Depending on the brightness around the separation surface RS, the light 433 that irradiates the outer periphery of the bonded substrate S with illumination light or the fluid discharged from the nozzle 30 may not be necessary. Furthermore, if the position of the separation surface RS and the inclination angle of the discharged fluid can be determined from the captured image without making the illumination light coaxial with the optical axis of the camera 431, the installation position of the light 433 can also be changed as appropriate.

[0076] (5) As the camera 431, in addition to a normal camera that captures visible light, a camera that captures images of the separation surface RS or the fluid using infrared light, radiation, etc. can also be used, and in addition to a camera that captures still images, a camera that captures moving images such as a video camera can also be used. Furthermore, there is no limit to the number of cameras 431, and in the case of detecting positions at multiple locations on the outer periphery of the bonded substrate S, multiple cameras 431 may be installed according to the detection positions.

[0077] (6) Instead of determining the separation status from the image captured by the camera 431, or in parallel with that, the progress of separation of the bonded substrate S may be determined based on a time previously determined by experiment or simulation, and the nozzle 30 may be moved accordingly.

[0078] (7) When determining the separation status, it is preferable that the timing of image capture by the camera 431 is at least one or more points after the start of separation and before the completion of separation, and it is also possible to capture an image after the completion of separation. In addition, the start and completion of separation of the bonded substrate S can be determined based on the movement position of the nozzle 30, and the success or failure of the separation work can be determined from the captured images before and after that.

[0079] (8) In the illustrated embodiment, the bonded substrate S is rotated horizontally. However, it is also possible to rotate the bonded substrate S vertically by holding the bonded substrate S from the left and right sides with the holding unit 10. In this case, the nozzle moving unit 40 moves the nozzle 30 horizontally, i.e., in a direction parallel to the central axis of rotation of the bonded substrate S, instead of adjusting the nozzle 30 in the height direction as described in the embodiment.

[0080] [Other Embodiments] The present invention is not limited to the above-described embodiments, and includes other embodiments shown above. The present invention also includes combinations of all or any of the above-described embodiments and other embodiments. Furthermore, various omissions, substitutions, and modifications can be made to these embodiments without departing from the scope of the invention, and such modifications are also included in the present invention.

[0081] REFERENCE SIGNS LIST 1 Substrate separation device 10 Holding unit 20 Positioning unit 30 Nozzle 31 Supply device 40 Nozzle moving unit 41 Contact / separation mechanism 42 Position adjustment mechanism 43 Height adjustment mechanism 100 Control unit 101 Photography processing unit 102 Memory unit 102a Image memory unit 102b Inclination memory unit 102c Separation surface height memory unit 103 Inclination detection unit 104 Separation surface height detection unit 105 Calculation unit 106 Nozzle height correction unit 107 Separation status determination unit 110 First holder 111 First holding unit 112 Support mechanism 112a Support shaft 120 Second holder 121 Second holding unit 122 Rotation drive unit 122a Drive shaft 123 Attachment / detachment drive unit 210 Grip unit 220 Placement unit 230 Axial direction driving part 231 Support part 232 Urging part 233 Absorbing part 240 Opening / closing driving part 241 Arm 431 Camera 432 Plate 433 Light

Claims

1. A substrate separation device comprising: a holding unit that holds both sides of a bonded substrate formed by bonding a pair of substrates together; a rotation drive unit that rotates the holding unit; a nozzle that separates the bonded substrate by ejecting a fluid toward the outer periphery of the rotating bonded substrate; a nozzle movement unit that moves the nozzle; an imaging unit that captures an image of the outer periphery of the bonded substrate held by the holding unit; and a control device that controls the nozzle movement unit, wherein the control device controls the nozzle movement unit to align a position of the nozzle with the position of the separation surface of the bonded substrate detected from the image captured by the imaging unit.

2. The substrate separation device according to claim 1, wherein the imaging unit images one or more revolutions of the outer circumferential surface of the bonded substrate held by the holding unit and rotating, and the control device associates and stores the rotation angle of the bonded substrate with the position of the separation surface of the bonded substrate detected from the image captured by the imaging unit, and controls the nozzle moving unit to align the height position of the nozzle with the position of the separation surface.

3. A substrate separation device as described in claim 1, wherein the imaging unit images the fluid ejected from the nozzle, and the control device detects an inclination of the fluid ejected from the nozzle from the image captured by the imaging unit, and controls the nozzle moving unit to align the height position of the nozzle with the height of the separation surface based on the detected inclination of the fluid and the distance from the nozzle outlet to the separation surface.

4. A substrate separation apparatus according to claim 1, further comprising a light irradiation section which irradiates the outer periphery of said bonded substrate or the fluid discharged from said nozzle with illumination light in a direction coaxial with said imaging section.

5. The substrate separation device according to claim 1, wherein the imaging section images an outer peripheral surface of the bonded substrate after separation has started and before separation is completed, and the control device determines a separation status from the image captured by the imaging section.

6. The substrate separation device according to claim 3, wherein the imaging unit images the fluid discharged between the imaging unit and the bonded substrate while the bonded substrate is held by the holding unit, and a plate for preventing water droplets from adhering to the imaging unit is provided between the imaging unit and the bonded substrate and on the bonded substrate side of the nozzle discharge port.

Images