Detection device, exposure device, and detection method

Abstract

The invention provides a technology capable of detecting the position of an alignment mark in the horizontal direction with high precision even when the position of the alignment mark in the vertical direction is shifted. The detection device includes an X-ray irradiation unit, an image sensor, and a calculation unit. The X-ray irradiation unit irradiates X-rays toward the substrate from above or below the substrate on the stage. The image sensor receives the X-ray transmitted through the substrate and acquires a detection image. The calculation unit calculates, on the basis of the design information and the detection image, a correction amount in the horizontal direction corresponding to the offset amount of the distance from the X-ray irradiation unit to the alignment mark in the vertical direction, and corrects the position of the alignment mark in the horizontal direction in the detection image. As a result, even when the distance from the X-ray irradiation unit to the alignment mark in the vertical direction varies, the position of the alignment mark in the horizontal direction can be calculated with high accuracy on the basis of the detection image of the image sensor.

Description

Technical Field

[0001] The present invention relates to a technology for detecting the position of an alignment mark formed on a substrate. Background Art

[0002] Conventionally, there is known an exposure device for exposing a pattern on the upper surface of a printed substrate. In the exposure device, an alignment mark formed on the printed substrate is detected, and an exposure position on the printed substrate is determined based on the position of the alignment mark.

[0003] The alignment mark is sometimes formed on the lower layer of the printed circuit board, that is, the copper foil layer. In this case, when the printed circuit board is placed on a workbench, the alignment mark is not exposed to the outside. Therefore, the alignment mark is detected by irradiating the printed circuit board with X-rays and receiving the X-rays that have passed through the printed circuit board.

[0004] For example, Patent Document 1 describes a related art for detecting an alignment mark using X-rays.

[0005] Prior art literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2014-184492 Summary of the invention

[0007] Problems to be solved by the invention

[0008] However, when the flatness of the worktable is low or the printed circuit board has a dimensional error or warpage, the position of the alignment mark of the printed circuit board placed on the worktable may be shifted in the vertical direction from the designed position. In this case, due to the vertical position shift of the alignment mark, the position of the alignment mark detected by X-ray may be shifted in the horizontal direction.

[0009] If the detection position of the alignment mark is offset, the exposure position will also be offset relative to the printed circuit board. In particular, in recent years, as the pattern of the printed circuit board has become finer, it has been required to control the exposure position with higher precision.

[0010] The present invention has been made in view of such circumstances, and an object of the present invention is to provide a technique capable of detecting the position of an alignment mark in the horizontal direction with high accuracy even when the position of the alignment mark in the vertical direction is misaligned.

[0011] Means for solving problems

[0012] In order to solve the above-mentioned problems, the first invention of the present application is a detection device, which detects the position of an alignment mark formed on a substrate, wherein the detection device comprises: a workbench, which supports the substrate in a substantially horizontal posture; an X-ray irradiation unit, which irradiates X-rays toward the substrate from above or below the substrate on the workbench; an image sensor, which receives the X-rays that have passed through the substrate to obtain a detection image; a storage unit, which stores design information of the alignment mark; and a calculation unit, which calculates the position of the alignment mark based on the design information and the detection image, the calculation unit calculates a horizontal correction amount corresponding to an offset amount of the distance in the vertical direction from the X-ray irradiation unit to the alignment mark based on the design information and the detection image, and uses the correction amount to correct the horizontal position of the alignment mark in the detection image.

[0013] A second invention of the present application is the detection device of the first invention, wherein the calculation unit calculates the correction amount based on the size of the alignment mark in the design information and the size of the alignment mark in the detection image.

[0014] The third invention of the present application is based on the detection device of the second invention, wherein the alignment mark is a circle, and the calculation unit performs an elliptical approximation on the alignment mark in the detection image, or calculates the maximum inner circle of the alignment mark, and uses the short diameter of the ellipse or the diameter of the maximum inner circle as the size of the alignment mark in the detection image.

[0015] The fourth invention of the present application is based on the detection device of the first invention, wherein the alignment mark includes a plurality of sub-marks, and the calculation unit calculates the correction amount based on the positional relationship between the plurality of sub-marks in the design information and the positional relationship between the plurality of sub-marks in the detection image.

[0016] The fifth invention of the present application comprises: any one of the detection devices of the first to fourth inventions; an exposure unit, which irradiates light to a specified position of the substrate supported on the workbench; a moving mechanism, which moves the workbench and the exposure unit relative to each other; and an exposure control unit, which controls the exposure unit and the moving mechanism, and the exposure control unit determines the irradiation position of the light of the exposure unit according to the position of the alignment mark calculated by the calculation unit.

[0017] The sixth invention of the present application is a detection method for detecting the position of an alignment mark formed on a substrate, wherein the detection method includes the following steps: step (a): supporting the substrate in a substantially horizontal posture, and irradiating X-rays toward the substrate from an X-ray irradiation unit located above or below the substrate, receiving the X-rays that have passed through the substrate to obtain a detection image; and step (b): calculating the position of the alignment mark based on design information of the alignment mark and the detection image, in which step (b) a horizontal correction amount corresponding to an offset amount of the distance from the X-ray irradiation unit to the alignment mark in the up and down directions is calculated based on the design information and the detection image, and the horizontal position of the alignment mark in the detection image is corrected using the correction amount.

[0018] Effects of the Invention

[0019] According to the first to sixth inventions, even when the distance from the X-ray irradiation unit to the alignment mark in the vertical direction varies, the horizontal position of the alignment mark can be calculated with high accuracy based on the detection image of the image sensor.

[0020] In particular, according to the second invention, the correction amount can be calculated based on a single marker.

[0021] In particular, according to the third invention, the size of the alignment mark in the detection image can be measured with higher accuracy in consideration of the thickness of the alignment mark.

[0022] In particular, according to the fourth invention, even when the dimensional accuracy of a single mark is low, the correction amount can be calculated with high accuracy by utilizing the positional relationship of a plurality of marks.

[0023] In particular, according to the fifth invention, by detecting the position of the alignment mark with high accuracy, the exposure position on the substrate can be determined with high accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a side view of the exposure device.

[0025] Figure 2 It is a partial cross-sectional view of the substrate.

[0026] Figure 3 This is a control block diagram of an exposure device.

[0027] Figure 4 This is a diagram conceptually showing functions implemented in a computer.

[0028] Figure 5 This is a flowchart showing the operation flow of the exposure device.

[0029] Figure 6It is a diagram schematically showing the positional relationship among the X-ray irradiation unit, the substrate, and the image sensor.

[0030] Figure 7 It is a diagram showing a state of position correction of an alignment mark.

[0031] Figure 8 A diagram showing a method of determining the origin position in a detection image.

[0032] Fig. 9 This is a diagram schematically showing the positional relationship among the X-ray irradiation unit, the substrate, and the image sensor when the alignment mark is composed of two sub-marks. DETAILED DESCRIPTION

[0033] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0034] <1. Structure of exposure device>

[0035] Figure 1 1 is a side view of an exposure device 1 including a detection device according to an embodiment of the present invention. The exposure device 1 is a device for irradiating light onto the upper surface of a substrate 9 coated with a photosensitive material to expose a pattern on the upper surface of the substrate 9. The substrate 9 is, for example, a printed substrate. Figure 1 As shown, the exposure apparatus 1 includes a base 10 , a stage 20 , a moving mechanism 30 , an exposure unit 40 , an X-ray irradiation unit 50 , an image sensor 60 , and a computer 70 .

[0036] The base 10 is a support platform for supporting the workbench 20, the moving mechanism 30, the exposure unit 40, the X-ray irradiation unit 50, and the image sensor 60. The base 10 has a flat plate-like shape extending along a horizontal plane. The base 10 is fixed to the floor of the factory. The base 10 is formed of a material such as carbon, which can transmit X-rays irradiated from the X-ray irradiation unit 50 described later.

[0037] The workbench 20 is a plate that supports the substrate 9. The workbench 20 has a flat upper surface. The substrate 9 is supported on the upper surface of the workbench 20 in a substantially horizontal posture. The workbench 20 may have a chuck pin for fixing the substrate 9 and a plurality of adsorption holes for adsorbing the substrate 9. The workbench 20 is formed of a material such as carbon that can transmit X-rays irradiated from the X-ray irradiation unit 50 described later.

[0038] The moving mechanism 30 is a mechanism for moving the workbench 20 relative to the base 10. The moving mechanism 30 includes a main scanning mechanism and a sub-scanning mechanism. The main scanning mechanism moves the workbench 20 in a main scanning direction along a horizontal plane. The sub-scanning mechanism moves the workbench 20 in a sub-scanning direction which is a direction along a horizontal plane and orthogonal to the main scanning direction. When the workbench 20 moves in the main scanning direction and the sub-scanning direction, the substrate 9 is also transported along the main scanning direction and the sub-scanning direction together with the workbench 20.

[0039] The main scanning mechanism and the sub-scanning mechanism use, for example, a mechanism that converts the rotational motion of the motor into a linear motion via a ball screw, or a mechanism that uses a linear motor. In addition, the moving mechanism 30 may include a lifting mechanism that moves the workbench 20 in the up-down direction, and a rotating mechanism that rotates the workbench 20 around an axis extending in the up-down direction.

[0040] The exposure unit 40 is a unit for exposing the substrate 9 supported by the workbench 20. Figure 1 As shown, the exposure unit 40 includes a head 41, an illumination optical system 42, and a laser oscillator 43. The head 41 is fixed to a frame (not shown) extending from the base 10. Therefore, in the present embodiment, the position of the head 41 relative to the base 10 is fixed.

[0041] The laser oscillator 43 emits pulse light according to the driving signal supplied from the computer 70. The pulse light emitted from the laser oscillator 43 is introduced to the head 41 via the illumination optical system 42. A spatial modulator is provided inside the head 41. The spatial modulator uses, for example, a GLV (Grating Light Valve) (registered trademark) which is a diffraction grating type spatial light modulator. The pulse light introduced into the head 41 is modulated into a predetermined pattern by the spatial modulator and irradiated onto the upper surface of the substrate 9. Thus, the photosensitive material on the upper surface of the substrate 9 is exposed.

[0042] When the exposure device 1 is operated, the substrate 9 is transported in the main scanning direction and the sub-scanning direction by the moving mechanism 30 and pulse light is irradiated from the head 41. Thus, a pattern is exposed on the upper surface of the substrate 9.

[0043] Figure 2 : is a partial cross-sectional view of the substrate 9. The substrate 9 of the present embodiment is opaque, and an alignment mark 90 is formed on its lower surface. The alignment mark 90 is, for example, a hole formed in the copper foil layer as the lower layer of the substrate 9. Therefore, when the substrate 9 is placed on the upper surface of the workbench 20, the alignment mark 90 is not exposed to the outside. The shape of the alignment mark 90 in the bottom view is, for example, circular. However, the alignment mark 90 may also be other shapes such as a rectangle or a cross.

[0044] The X-ray irradiation unit 50 is a unit that irradiates the substrate 9 with radiation, i.e., X-rays, in order to detect the above-mentioned alignment mark 90. ​​The X-ray irradiation unit 50 is arranged below the base 10. In the present embodiment, the position of the X-ray irradiation unit 50 relative to the base 10 is fixed. The X-ray irradiation unit 50 emits X-rays upward. That is, the X-ray irradiation unit 50 irradiates X-rays toward the substrate 9 from below the substrate 9. The X-rays emitted from the X-ray irradiation unit 50 spread radially, and pass through the base 10, the workbench 20, and the substrate 9 to irradiate the image sensor 60.

[0045] The image sensor 60 is a sensor that receives X-rays and obtains a detection image I. The image sensor 60 is arranged above the substrate 9 supported by the workbench 20. The X-ray irradiation unit 50 is fixed to a frame (not shown) extending from the base 10. Therefore, in the present embodiment, the position of the image sensor 60 relative to the base 10 is fixed. That is, the positional relationship between the X-ray irradiation unit 50 and the image sensor 60 is fixed.

[0046] The X-rays emitted from the X-ray irradiation unit 50 and transmitted through the base 10, the workbench 20, and the substrate 9 are received by the image sensor 60. The image sensor 60 detects the intensity of the X-rays through a plurality of light receiving elements arranged in the main scanning direction and the sub-scanning direction. Thus, the image sensor 60 obtains a detection image I. The detection image I is a two-dimensional image composed of a plurality of pixels arranged in the main scanning direction and the sub-scanning direction. The image sensor 60 outputs the obtained detection image I to the computer 70.

[0047] The computer 70 is a unit for controlling the operation of each unit of the exposure apparatus 1 . Figure 3 1 is a control block diagram of the exposure device 1. Figure 3 As shown in FIG. 1 , the computer 70 includes a processor 71 such as a CPU, a memory 72 such as a RAM, and a storage unit 73 such as a hard disk drive. The storage unit 73 stores a detection program P1 for detecting the alignment mark 90, an exposure program P2 for performing exposure processing, and design information D of the alignment mark 90. Figure 3 As shown, the computer 70 is electrically connected to the moving mechanism 30 , the exposure unit 40 , the X-ray irradiation unit 50 , and the image sensor 60 .

[0048] Figure 4 FIG. 7 is a diagram conceptually showing functions implemented in the computer 70. Figure 4 As shown, the computer 70 includes a calculation unit 74 and an exposure control unit 75. The calculation unit 74 includes a correction amount calculation unit 741 and a correction unit 742.

[0049] The function of the calculation unit 74 is realized by the computer 70 operating according to the above-mentioned detection program P1. The exposure device 1 operates as a detection device that detects the position of the alignment mark 90 formed on the substrate 9 through the calculation unit 74. The function of the exposure control unit 75 is realized by the computer 70 operating according to the above-mentioned exposure program P2. The exposure device 1 controls the operation of the moving mechanism 30 and the exposure unit 40 through the exposure control unit 75, thereby performing exposure processing on the substrate 9.

[0050] <2. Regarding the operation of the exposure device>

[0051] Next, a series of processes in which the exposure apparatus 1 described above detects the position of the alignment mark 90 formed on the substrate 9 and exposes the substrate 9 based on the detection result will be described. Figure 5 It is a flowchart showing the operation flow of the exposure device 1 .

[0052] The exposure device 1 first moves the stage 20 by the moving mechanism 30 , thereby moving the substrate 9 to a detection position for detecting the alignment mark 90 (step S1 ). Specifically, the substrate 9 is moved so that the alignment mark 90 is disposed between the X-ray irradiation unit 50 and the image sensor 60 .

[0053] Next, X-rays are emitted from the X-ray irradiation unit 50. The X-rays are emitted upward from the X-ray irradiation unit 50, pass through the base 10, the table 20, and the substrate 9, and enter the image sensor 60. The image sensor 60 generates a detection image I by receiving the X-rays (step S2). In addition, the image sensor 60 outputs the obtained detection image I to the computer 70.

[0054] Figure 6 Schematically shows the positional relationship among the X-ray irradiation unit 50, the substrate 9, and the image sensor 60. Figure 6 In the example, the position of the alignment mark 90 is shifted upward from the originally designed position due to positioning error of the substrate 9, warping of the substrate 9, etc. The calculation unit 74 of the computer 70 calculates the horizontal position of the alignment mark 90 in consideration of the positional shift of the alignment mark 90 in the vertical direction.

[0055] Figure 6 Where Z0, Z1, ΔZ, D0, D2, d2, and Δd represent the following values, respectively.

[0056] Z0: The vertical distance from the X-ray irradiation unit 50 to the image sensor 60 (design information)

[0057] Z1: The vertical distance from the X-ray irradiation unit 50 to the original alignment mark 90 (design information)

[0058] ΔZ: Positional deviation of the alignment mark 90 in the vertical direction

[0059] D0: Size of alignment mark 90 (design information)

[0060] D2: Detection of the size of the alignment mark 90 in the image I (measured value)

[0061] d2: The position of the alignment mark 90 with the X-ray irradiation unit 50 as the origin in the detection image I (measured value)

[0062] Δd: The amount of displacement of the alignment mark 90 from its original position with the X-ray irradiation unit 50 as the origin in the detection image I

[0063] Z0, Z1, and D0 are design information D stored in advance in the storage unit 73 as fixed values. D2 and d2 are measurement values ​​measured based on the detection image I acquired by the image sensor 60.

[0064] exist Figure 6 According to the geometric proportional relationship, the following equation (1) holds.

[0065] D2 / D0=Z0 / (Z1+ΔZ) (1)

[0066] If the formula (1) is transformed, the following formula (2) is obtained.

[0067] ΔZ=D0·Z0 / D2-Z1 (2)

[0068] D0, Z0, and Z1 in the formula (2) are the design information D read from the storage unit 73. In addition, D2 in the formula (2) is a measurement value measured based on the detection image I. The correction amount calculation unit 741 measures D2 based on the detection image I. Then, the correction amount calculation unit 741 calculates the positional deviation ΔZ in the vertical direction of the alignment mark 90 according to the measured D2 and D0, Z0, and Z1 read from the storage unit 73 by the formula (2) (step S3).

[0069] In addition, Figure 6 According to the geometric proportional relationship, the following formula (3) holds.

[0070] Δd / d2=ΔZ / Z1 (3)

[0071] If equation (3) is transformed, the following equation (4) is obtained.

[0072] Δd=d2·ΔZ / Z1 (4)

[0073] Z1 in the formula (4) is the design information D read from the storage unit 73. In addition, d2 in the formula (4) is a measurement value measured based on the detection image I. In addition, ΔZ in the formula (4) is a value calculated by the above-mentioned formula (2). The correction amount calculation unit 741 measures d2 based on the detection image I. Then, the correction amount calculation unit 741 calculates the horizontal position deviation Δd of the alignment mark 90 in the detection image I by formula (4) based on the measured d2, ΔZ calculated by the above-mentioned formula (2), and Z1 read from the storage unit 73 (step S4).

[0074] The horizontal position shift amount Δd is caused by the vertical position shift amount ΔZ of the alignment mark 90. ​​Therefore, the correction amount calculation unit 741 uses the inverse of the position shift amount Δd -Δd as the correction amount of the position of the alignment mark 90 in the detection image I. In this way, the correction amount calculation unit 741 calculates the horizontal correction amount -Δd corresponding to the vertical shift amount ΔZ of the distance from the X-ray irradiation unit 50 to the alignment mark 90 based on the design information D and the detection image I (step S5).

[0075] When the correction amount -Δd is calculated, the correction unit 742 corrects the position d2 of the horizontal direction of the registration mark 90 in the detection image I by using the correction amount -Δd (step S6 ).

[0076] Figure 7 : is a diagram showing the position correction of the alignment mark 90 after the correction amount -Δd is calculated. Figure 7 In the horizontal plane, the x-axis and y-axis are defined to be orthogonal to each other. Figure 7 Where (x, y), (x', y'), and θ represent the following items respectively.

[0077] (x, y): coordinates of the alignment mark 90 measured in the detection image I

[0078] (x', y'): coordinates of the alignment mark 90 after correction in the detection image I

[0079] θ: The vector angle of the alignment mark 90 centered at the origin O in the detection image I

[0080] The correction unit 742 decomposes the correction amount -Δd into a component Δx in the x direction and a component Δy in the y direction using the following equations (5) and (6).

[0081] Δx=-Δd·cosθ (5)

[0082] Δy=-Δd·sinθ (6)

[0083] Then, the correction unit 742 corrects the coordinates (x, y) of the alignment mark 90 using the following equation (7) to calculate the original coordinates (x′, y′) of the alignment mark 90 .

[0084] (x', y')=(x+Δx, y+Δy) (7)

[0085] Thus, the influence of the vertical position deviation of the alignment mark 90 is eliminated, and the original horizontal position of the alignment mark 90 is obtained. Thus, even when the vertical distance from the X-ray irradiation unit 50 to the alignment mark 90 changes, the horizontal position of the alignment mark 90 can be detected with high accuracy based on the detection image I of the image sensor 60.

[0086] When the position of the alignment mark 90 after correction is determined, the exposure control unit 75 operates the moving mechanism 30 and the exposure unit 40 according to the position of the alignment mark 90. ​​Thus, the pattern is exposed at a predetermined position on the upper surface of the substrate 9 (step S7). The exposure position of the pattern on the upper surface of the substrate 9 is determined based on the position of the alignment mark 90. ​​Therefore, by the processing of the above-mentioned steps S3 to S6, the position of the alignment mark 90 is detected with high accuracy, thereby also being able to determine the exposure position on the substrate 9 with high accuracy.

[0087] In particular, in this embodiment, the positional deviation amount ΔZ of the alignment mark 90 in the vertical direction is calculated based on the size D0 of the alignment mark 90 in the design information D and the size D2 of the alignment mark 90 in the detection image I, and the positional deviation amount Δd of the alignment mark 90 on the detection image I corresponding to ΔZ is calculated. Thus, the correction amount -Δd can be calculated based on the individual mark.

[0088] <3. Determination of the origin of the detection image>

[0089] In the above example, the position of the alignment mark 90 is measured with the position of the X-ray irradiation unit 50 as the origin O in the detection image I. The position of the origin O may be physically aligned with the center of the detection image I, for example. However, in order to determine the position of the origin O with higher accuracy, the calculation unit 74 may determine the position of the origin O in the detection image I by the following method.

[0090] Figure 8 is a diagram showing a method for determining the position of the origin O in the detection image I. When determining the origin O, first Figure 8 As shown, the substrate 9 is configured so that the first reference point M1 and the second reference point M2 of the substrate 9 are projected within the effective range of the image sensor 60. The first reference point M1 and the second reference point M2 may be alignment marks 90 or patterns other than alignment marks 90 formed on the substrate 9.

[0091] In this state, the vertical position of the substrate 9 is changed by the lifting mechanism of the moving mechanism 30, and the X-ray irradiation unit 50 and the image sensor 60 are photographed. Thus, two detection images I with different magnifications are obtained. In addition, the intersection of the first straight line L1 obtained by connecting the first reference point M1 of the two detection images I and the second straight line L2 obtained by connecting the second reference point M2 of the two detection images I is set as the origin O of the detection image I. Thus, the origin O of the detection image I can be determined with high accuracy.

[0092] <4. Measurement of the position and size of the alignment mark>

[0093] In the above example, the calculation unit 74 measures the position d2 and size D2 of the alignment mark 90 in the detection image I obtained by the image sensor 60. When the alignment mark 90 is circular, the position d2 of the alignment mark 90 may be, for example, the center position of the alignment mark 90. ​​When the alignment mark 90 is circular, the size of the alignment mark 90 may be, for example, the diameter of the alignment mark 90.

[0094] However, when the thickness of the alignment mark 90 in the vertical direction is large, the alignment mark 90 may appear in the detection image I as a shape extending in radial directions with the origin O as the center.

[0095] At this time, the calculation unit 74 performs an ellipse approximation on the alignment mark 90 in the detection image I, and uses the short diameter of the ellipse as the diameter of the alignment mark 90. ​​In addition, the calculation unit 74 may also obtain the maximum inner circle of the alignment mark 90 in the detection image I, and use the diameter of the maximum inner circle as the diameter of the alignment mark 90. ​​In addition, the calculation unit 74 may set the position after shifting the center of the ellipse to the opposite side of the origin O by a distance equivalent to the difference between the long diameter and the short diameter as the center position of the alignment mark 90.

[0096] This makes it possible to more accurately measure the position d2 and the size D2 of the alignment mark 90 in the detection image I. Therefore, the position of the alignment mark 90 after correction can also be calculated more accurately.

[0097] <5. Case where an alignment mark has two sub-marks>

[0098] In the above example, the alignment mark 90 is composed of one mark. However, the dimensional accuracy of the alignment mark 90 composed of one mark is prone to variation. Therefore, the alignment mark 90 may be composed of a plurality of sub-marks 91 .

[0099] Fig. 9This is a diagram schematically showing the positional relationship among the X-ray irradiation unit 50, the substrate 9, and the image sensor 60 when the alignment mark 90 is composed of two sub-marks 91. In this case, the position of the alignment mark 90 in the detection image I is the midpoint of the two sub-marks 91 in the detection image I. In addition, the definitions of D0 and D2 described above are replaced as follows.

[0100] D0: Interval between two sub-marks 91 (design information)

[0101] D2: Detection of the interval between two sub-markers 91 in image I (measured value)

[0102] Then, as in the first embodiment described above, the calculation unit 74 calculates the correction amount -Δd of the alignment mark 90 by performing the calculations of equations (1) to (7). That is, the calculation unit 74 calculates the correction amount -Δd based on the positional relationship between the two sub-marks 91 in the design information D and the positional relationship between the two sub-marks 91 in the detection image I. In this way, by using the positional relationship of a plurality of marks instead of the size of a single mark, the correction amount -Δd of the alignment mark 90 can be calculated with high accuracy even when the dimensional accuracy of the single mark is low.

[0103] exist Fig. 9 In the example, the alignment mark 90 is composed of two sub-marks 91. However, the number of sub-marks 91 constituting the alignment mark 90 may be three or more. In this case, for example, two sub-marks 91 out of the three or more sub-marks 91 may be focused on, and the process of calculating the correction amount -Δd using equations (1) to (7) may be performed multiple times while changing the combination of the two sub-marks 91 being focused on, and the average value of the multiple correction amounts -Δd obtained may be calculated.

[0104] <6. Modifications>

[0105] As mentioned above, although one embodiment of the present invention has been described, the present invention is not limited to the above-mentioned embodiment.

[0106] In the above embodiment, the X-ray irradiation unit 50 is arranged below the substrate 9, and the image sensor 60 is arranged above the substrate 9. However, the X-ray irradiation unit 50 may be arranged above the substrate 9, and the image sensor 60 may be arranged below the substrate 9. That is, the X-ray irradiation unit 50 only needs to irradiate X-rays toward the substrate 9 from above or below the substrate 9 on the workbench 20, and the image sensor 60 only needs to receive the X-rays that have passed through the substrate 9.

[0107] In addition, in the above-mentioned embodiment, the positions of the X-ray irradiation unit 50 and the image sensor 60 are fixed. However, the X-ray irradiation unit 50 and the image sensor 60 can also be moved in the main scanning direction or the sub-scanning direction.

[0108] In addition, in the above-mentioned embodiment, the image sensor 60 directly detects X-rays. However, the image sensor 60 may be composed of a scintillator that converts X-rays into visible light and a camera that receives the converted visible light.

[0109] In the above embodiment, the moving mechanism 30 moves the worktable 20 relative to the stationary exposure unit 40. However, the moving mechanism 30 may move the exposure unit 40 relative to the stationary worktable 20. Furthermore, the moving mechanism 30 may move both the worktable 20 and the exposure unit 40. That is, the moving mechanism 30 only needs to move the worktable 20 and the exposure unit 40 relative to each other.

[0110] In the above embodiment, a printed circuit board is cited as an example of the substrate 9. However, the substrate 9 may be another type of substrate such as a semiconductor wafer or a substrate for a flat panel display.

[0111] In the above embodiment, the exposure apparatus 1 is described as being equipped with the detection device of the alignment mark 90. ​​However, the detection device of the present invention may be installed in a device other than the exposure apparatus 1 such as a coating device, a developing device, a cleaning device, or an inspection device.

[0112] Furthermore, each element in the above-described embodiment and modified examples may be appropriately selected and excluded within a range where no contradiction occurs.

[0113] Explanation of symbols

[0114] 1 Exposure device

[0115] 9 substrate

[0116] 10 Base

[0117] 20 Workbench

[0118] 30 Mobile mechanism

[0119] 40 Exposure Department

[0120] 41 Head

[0121] 42 Illumination optical system

[0122] 43 Laser Oscillator

[0123] 50 X-ray irradiation unit

[0124] 60 Image Sensor

[0125] 70 Computer

[0126] 74 Computing Department

[0127] 75 Exposure Control Unit

[0128] 90 Alignment mark

[0129] 91 subtags

[0130] 741 Correction amount calculation unit

[0131] 742 Correction Department

[0132] D. Design Information

[0133] I Detection Image

[0134] O origin

[0135] P1 Test Procedure

[0136] P2 exposure program.

Claims

1. A detection device for detecting the position of an alignment mark formed on a substrate, characterized in that: The detection device comprises: a worktable supporting the substrate in a substantially horizontal posture; An X-ray irradiation unit irradiates X-rays toward the substrate from above or below the substrate on the workbench; An image sensor receives X-rays transmitted through the substrate to obtain a detection image; a storage unit storing design information of the alignment mark; as well as a calculation unit that calculates the position of the alignment mark based on the design information and the detection image, The calculation unit calculates a horizontal correction amount corresponding to an offset of a distance in a vertical direction from the X-ray irradiation unit to the alignment mark based on the design information and the detection image, and uses the correction amount to correct the horizontal position of the alignment mark in the detection image.

2. The detection device according to claim 1, characterized in that: The calculation unit calculates the correction amount based on the size of the alignment mark in the design information and the size of the alignment mark in the detection image.

3. The detection device according to claim 2, characterized in that: The alignment mark is circular, The calculation unit performs elliptical approximation on the alignment mark in the detection image, or obtains a maximum inner circle of the alignment mark, and uses the short diameter of the ellipse or the diameter of the maximum inner circle as the size of the alignment mark in the detection image.

4. The detection device according to claim 1, characterized in that: The alignment mark includes a plurality of sub-marks. The calculation unit calculates the correction amount based on the positional relationship between the plurality of sub-marks in the design information and the positional relationship between the plurality of sub-marks in the detection image.

5. An exposure device, characterized in that: have: The detection device according to any one of claims 1 to 4; an exposure unit that irradiates light to a predetermined position of the substrate supported by the stage; A moving mechanism that enables the workbench and the exposure unit to move relative to each other; as well as an exposure control unit that controls the exposure unit and the moving mechanism, The exposure control section determines a position at which the light of the exposure section is irradiated based on the position of the alignment mark calculated by the calculation section.

6. A detection method for detecting the position of an alignment mark formed on a substrate, characterized in that: The detection method comprises the following steps: Step (a): supporting the substrate in a substantially horizontal posture, irradiating the substrate with X-rays from an X-ray irradiation unit located above or below the substrate, and receiving the X-rays that have passed through the substrate to obtain a detection image; and Step (b): calculating the position of the alignment mark based on the design information of the alignment mark and the detection image, In the step (b), the horizontal correction amount corresponding to the offset of the distance from the X-ray irradiation part to the alignment mark in the up and down directions is calculated based on the design information and the detection image, and the horizontal position of the alignment mark in the detection image is corrected using the correction amount.

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