Detection device, exposure device and detection method

Abstract

To provide a technique capable of accurately detecting a position of an alignment mark in a horizontal direction even when a position of the alignment mark in a vertical direction is deviated.SOLUTION: A detection device includes an X-ray irradiation section 50, an image sensor 60 and a calculation section. The X-ray irradiation section 50 irradiates a base plate 9 on a stage with X ray from an upper part or a lower part of the base plate 9. The image sensor 60 acquires a detection image by receiving X ray transmitted through the base plate 9. The calculation section calculates a correction amount -Δd in a horizontal direction according to a deviation amount ΔZ of a distance in a vertical direction from the X-ray irradiation section 50 to an alignment mark 90 based on design information and the detection image, and corrects a position of the alignment mark 90 in the horizontal direction in the detection image. With this, a position of the alignment mark 90 in the horizontal direction can be accurately calculated based on the detection image of the image sensor 60 even when a distance in the vertical direction from the X-ray irradiation section 50 to the alignment mark 90 is varied.SELECTED DRAWING: Figure 6

Description

[Technical field]

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

[0002] Conventionally, there is known an exposure apparatus that exposes a pattern onto the upper surface of a printed circuit board. In the exposure apparatus, an alignment mark formed on the printed circuit board is detected, and an exposure position on the printed circuit board is determined based on the position of the alignment mark.

[0003] Alignment marks are sometimes formed on the copper foil layer, which is the lower layer of the printed circuit board. In this case, the alignment marks are not exposed to the outside when the printed circuit board is placed on the stage. For this reason, the alignment marks are detected by irradiating the printed circuit board with X-rays and receiving the X-rays that have passed through the printed circuit board.

[0004] A conventional technique for detecting alignment marks using X-rays is described in, for example, Patent Document 1. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2014-184492 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, if the flatness of the stage is low or if the printed circuit board has dimensional errors or warping, the position of the alignment mark on the printed circuit board placed on the stage may shift vertically from the designed position. In this case, the vertical shift of the alignment mark may cause the position of the alignment mark detected by X-rays to shift horizontally.

[0007] If the detected position of the alignment mark is shifted, the exposure position on the printed circuit board will also be shifted. In particular, in recent years, as patterns on printed circuit boards have become finer, there has been a demand for more accurate control of the exposure position.

[0008] The present invention has been made in consideration of the above circumstances, and has an object to provide a technique that can accurately detect the horizontal position of an alignment mark even if the vertical position of the alignment mark is misaligned. [Means for solving the problem]

[0009] In order to solve the above problems, a first invention of the present application is a detection device for detecting a position of an alignment mark formed on a substrate, comprising: a stage for supporting the substrate in an approximately horizontal position; an X-ray irradiation unit for irradiating X-rays toward the substrate from above or below the substrate on the stage; an image sensor for receiving the X-rays that have passed through the substrate to obtain a detection image; a memory unit for storing design information of the alignment mark; and a calculation unit for calculating the position of the alignment mark based on the design information and the detection image, wherein the calculation unit calculates a horizontal correction amount corresponding to the amount of deviation in the vertical distance from the X-ray irradiation unit to the alignment mark based on the design information and the detection image, and corrects the horizontal position of the alignment mark in the detection image by the correction amount.

[0010] A second invention of the present application is a 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.

[0011] The third invention of the present application is a detection device of the second invention, wherein the alignment mark is circular, and the calculation unit approximates the alignment mark to an ellipse in the detection image, or determines the maximum enclosed circle of the alignment mark, and sets the minor axis of the ellipse or the diameter of the maximum enclosed circle as the size of the alignment mark in the detection image.

[0012] A fourth invention of the present application is a detection device as described in claim 1, wherein the alignment mark includes a plurality of sub-marks, and the calculation unit calculates the correction amount based on a positional relationship of the plurality of sub-marks in the design information and a positional relationship of the plurality of sub-marks in the detection image.

[0013] The fifth invention of the present application comprises a detection device according to any one of the first to fourth inventions, an exposure unit which irradiates light to a predetermined position on the substrate supported by the stage, a movement mechanism which moves the stage and the exposure unit relatively, and an exposure control unit which controls the exposure unit and the movement mechanism, wherein the exposure control unit determines the position at which light is irradiated by the exposure unit based on the position of the alignment mark calculated by the calculation unit.

[0014] A sixth invention of the present application is a detection method for detecting the position of an alignment mark formed on a substrate, comprising the steps of: a) supporting the substrate in an approximately horizontal position, irradiating X-rays toward the substrate 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 b) calculating the position of the alignment mark based on design information of the alignment mark and the detection image, wherein in step b), a horizontal correction amount corresponding to the deviation in the vertical distance from the X-ray irradiation unit to the alignment mark 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 by the correction amount. Effect of the Invention

[0015] According to the first to sixth aspects of the invention, even if the vertical distance from the X-ray irradiation unit to the alignment mark varies, the horizontal position of the alignment mark can be calculated with high accuracy based on the image detected by the image sensor.

[0016] In particular, according to the second aspect of the present invention, the correction amount can be calculated based on a single mark.

[0017] In particular, according to the third aspect of the present invention, the size of the alignment mark in the detection image can be measured with higher accuracy by taking into account the thickness of the alignment mark.

[0018] In particular, according to the fourth aspect of the invention, even if the dimensional accuracy of a single mark is low, the amount of correction can be calculated with high accuracy by utilizing the positional relationship between a plurality of marks.

[0019] In particular, according to the fifth aspect of the invention, by detecting the positions of the alignment marks with high accuracy, the exposure position on the substrate can also be determined with high accuracy. [Brief description of the drawings]

[0020] [Figure 1] FIG. [Diagram 2] FIG. [Diagram 3] FIG. 2 is a control block diagram of the exposure apparatus. [Figure 4] FIG. 2 is a diagram conceptually illustrating functions realized in a computer. [Diagram 5] 4 is a flowchart showing the flow of operations of the exposure apparatus. [Figure 6] 2 is a diagram showing a schematic diagram of the positional relationship between an X-ray irradiation unit, a substrate, and an image sensor. [Figure 7] 11A and 11B are diagrams showing how the position of an alignment mark is corrected; [Figure 8] FIG. 13 is a diagram showing a method for identifying the position of the origin in a detected image. [Figure 9]13 is a diagram showing a schematic diagram of the positional relationship between an X-ray irradiation unit, a substrate, and an image sensor when an alignment mark is composed of two sub-marks. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0022] <1. Configuration of exposure equipment> 1 is a side view of an exposure apparatus 1 including a detection apparatus according to one embodiment of the present invention. This exposure apparatus 1 is an apparatus that irradiates light onto the upper surface of a substrate 9 on which a photosensitive material is applied, to expose a pattern on the upper surface of the substrate 9. The substrate 9 is, for example, a printed circuit board. As shown in FIG. 1, 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.

[0023] The base 10 is a support base that supports the stage 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 outer shape that spreads along a horizontal plane. The base 10 is fixed to the floor of a factory. The base 10 is made of a material such as carbon that is transmissive to X-rays irradiated from the X-ray irradiation unit 50 described later.

[0024] The stage 20 is a plate that supports the substrate 9. The stage 20 has a flat upper surface. The substrate 9 is supported on the upper surface of the stage 20 in a substantially horizontal position. The stage 20 may have a chuck pin for fixing the substrate 9 and a plurality of suction holes for suctioning the substrate 9. The stage 20 is made of a material such as carbon that is transmissive to X-rays irradiated from the X-ray irradiation unit 50 described later.

[0025] The moving mechanism 30 is a mechanism that moves the stage 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 stage 20 in a main scanning direction along a horizontal surface. The sub-scanning mechanism moves the stage 20 in a sub-scanning direction that is a direction along the horizontal surface and perpendicular to the main scanning direction. When the stage 20 moves in the main scanning direction and the sub-scanning direction, the substrate 9 is also transported in the main scanning direction and the sub-scanning direction together with the stage 20.

[0026] The main scanning mechanism and the sub-scanning mechanism may be, for example, a mechanism that converts the rotational motion of a motor into linear motion via a ball screw, or a mechanism that uses a linear motor. The movement mechanism 30 may also include a lifting mechanism that moves the stage 20 in the vertical direction, or a rotation mechanism that rotates the stage 20 around an axis that extends in the vertical direction.

[0027] The exposure section 40 is a unit that exposes the substrate 9 supported by the stage 20. As shown in Fig. 1, the exposure section 40 has 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 this embodiment, the position of the head 41 with respect to the base 10 is fixed.

[0028] The laser oscillator 43 emits pulsed light in accordance with a drive signal supplied from the computer 70. The pulsed light emitted from the laser oscillator 43 is introduced into the head 41 via the illumination optical system 42. A spatial modulator is provided inside the head 41. For example, a GLV (Grating Light Valve) (registered trademark), which is a diffraction grating type spatial light modulator, is used as the spatial modulator. The pulsed 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. As a result, the photosensitive material on the upper surface of the substrate 9 is exposed.

[0029] When the exposure apparatus 1 is in operation, the substrate 9 is transported in the main scanning direction and the sub-scanning direction by the movement mechanism 30 while being irradiated with pulsed light from the head 41. As a result, a pattern is exposed onto the upper surface of the substrate 9.

[0030] 2 is a partial cross-sectional view of the substrate 9. The substrate 9 in this embodiment is opaque, and has an alignment mark 90 formed on its lower surface. The alignment mark 90 is, for example, a hole formed in a copper foil layer that is a lower layer of the substrate 9. Therefore, when the substrate 9 is placed on the upper surface of the stage 20, the alignment mark 90 is not exposed to the outside. The shape of the alignment mark 90 when viewed from below is, for example, a circle. However, the alignment mark 90 may have other shapes, such as a rectangle or a cross.

[0031] The X-ray irradiation unit 50 is a unit that irradiates the substrate 9 with X-rays, which are radiation, in order to detect the above-mentioned alignment mark 90. ​​The X-ray irradiation unit 50 is disposed below the base 10. In this 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, pass through the base 10, the stage 20, and the substrate 9, and are irradiated to the image sensor 60.

[0032] The image sensor 60 is a sensor that receives X-rays and obtains a detection image I. The image sensor 60 is disposed above a substrate 9 supported by a stage 20. The X-ray irradiation unit 50 is fixed to a frame (not shown) extending from the base 10. Therefore, in this embodiment, the position of the image sensor 60 with respect to the base 10 is fixed. In other words, the positional relationship between the X-ray irradiation unit 50 and the image sensor 60 is fixed.

[0033] The X-rays emitted from the X-ray irradiation unit 50 and transmitted through the base 10, the stage 20, and the substrate 9 are received by the image sensor 60. The image sensor 60 detects the intensity of the X-rays using a large number of light receiving elements arranged in the main scanning direction and the sub-scanning direction. In this way, the image sensor 60 obtains a detection image I. The detection image I is a two-dimensional image composed of a large number 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.

[0034] The computer 70 is a unit for controlling the operation of each part of the exposure apparatus 1. FIG. 3 is a control block diagram of the exposure apparatus 1. As shown in FIG. 3, the computer 70 has 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 an exposure process, and design information D for the alignment mark 90. ​​As shown in FIG. 3, 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.

[0035] Fig. 4 is a diagram conceptually showing functions realized in the computer 70. As shown in Fig. 4, the computer 70 has a calculation unit 74 and an exposure control unit 75. The calculation unit 74 also has a correction amount calculation unit 741 and a correction unit 742.

[0036] The function of the calculation unit 74 is realized by the computer 70 operating in accordance with the detection program P1 described above. The exposure apparatus 1 operates as a detection apparatus that detects the position of the alignment mark 90 formed on the substrate 9 by the calculation unit 74. The function of the exposure control unit 75 is realized by the computer 70 operating in accordance with the exposure program P2 described above. The exposure apparatus 1 performs an exposure process on the substrate 9 by controlling the operation of the movement mechanism 30 and the exposure unit 40 by the exposure control unit 75.

[0037] <2. Operation of the exposure device> Next, a series of processes in which the exposure apparatus 1 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 is a flowchart showing the flow of the operation of the exposure apparatus 1.

[0038] The exposure apparatus 1 first moves the stage 20 by the movement mechanism 30. This moves the substrate 9 to a detection position where the alignment mark 90 is detected (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.

[0039] 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 stage 20, and the substrate 9, and are incident on the image sensor 60. The image sensor 60 receives the X-rays to generate a detection image I (step S2). Then, the image sensor 60 outputs the acquired detection image I to the computer 70.

[0040] Fig. 6 is a diagram showing a schematic diagram of the positional relationship between the X-ray irradiation unit 50, the substrate 9, and the image sensor 60. In the example of Fig. 6, the position of the alignment mark 90 is shifted upward from the original design position due to an error in positioning the substrate 9 or warpage of the substrate 9. The calculation unit 74 of the computer 70 calculates the horizontal position of the alignment mark 90 by taking into account the vertical positional shift of the alignment mark 90.

[0041] Z0, Z1, ΔZ, D0, D2, d2, and Δd in FIG. 6 respectively indicate the following values. Z0: The vertical distance from the X-ray irradiation unit 50 to the image sensor 60 (design information) Z1: The vertical distance from the X-ray irradiation unit 50 to the original alignment mark 90 (design information) ΔZ: Vertical positional deviation of the alignment mark 90 D0: Size of alignment mark 90 (design information) D2: Size (measurement value) of alignment mark 90 in detected image I d2: Position (measurement value) of the alignment mark 90 in the detected image I with the X-ray irradiation unit 50 as the origin Δd: deviation amount of the position of the alignment mark 90 from the original position with the X-ray irradiation unit 50 as the origin in the detection image I

[0042] Z0, Z1, and D0 are design information D that is stored in advance as fixed values ​​in the storage unit 73. D2 and d2 are measurement values ​​measured based on the detection image I acquired by the image sensor 60.

[0043] In FIG. 6, the following equation (1) holds due to the geometric proportional relationship. D2 / D0=Z0 / (Z1+ΔZ) (1)

[0044] By transforming equation (1), we obtain the following equation (2). ΔZ=D0·Z0 / D2-Z1 (2)

[0045] D0, Z0, and Z1 in formula (2) are design information D read out from memory unit 73. Furthermore, D2 in formula (2) is a measurement value measured based on detected image I. Correction amount calculation unit 741 measures D2 based on detected image I. Then, correction amount calculation unit 741 calculates vertical positional deviation amount ΔZ of alignment mark 90 using formula (2) based on measured D2 and D0, Z0, and Z1 read out from memory unit 73 (step S3).

[0046] Furthermore, in FIG. 6, due to the geometric proportional relationship, the following formula (3) is established. Δd / d2=ΔZ / Z1 (3)

[0047] By transforming equation (3), we obtain the following equation (4). Δd=d2 ΔZ / Z1 (4)

[0048] In equation (4), Z1 is the design information D read out from the memory unit 73. In addition, d2 in equation (4) is a measurement value measured based on the detected image I. In addition, ΔZ in equation (4) is a value calculated by the above-mentioned equation (2). The correction amount calculation unit 741 measures d2 based on the detected image I. Then, the correction amount calculation unit 741 calculates the horizontal positional deviation amount Δd of the alignment mark 90 in the detected image I by equation (4) based on the measured d2, ΔZ calculated by the above-mentioned equation (2), and Z1 read out from the memory unit 73 (step S4).

[0049] This horizontal positional deviation Δd is caused by the vertical positional deviation ΔZ of the alignment mark 90. ​​Therefore, the correction amount calculation unit 741 sets the inverse of the positional deviation Δd, −Δd, as the correction amount of the position of the alignment mark 90 in the detection image I. In this manner, the correction amount calculation unit 741 calculates the horizontal correction amount -Δd according to the deviation ΔZ of the vertical 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).

[0050] When the correction amount -Δd is calculated, the correction unit 742 corrects the horizontal position d2 of the alignment mark 90 in the detected image I by the above-mentioned correction amount -Δd (step S6).

[0051] Fig. 7 is a diagram showing the state of position correction of the alignment mark 90 after the correction amount -Δd is calculated. In Fig. 7, an x-axis and a y-axis that are perpendicular to each other are defined in a horizontal plane. In Fig. 7, (x, y), (x', y'), and θ respectively indicate the following items. (x, y): Coordinates of the alignment mark 90 measured in the detected image I (x', y'): coordinates of the alignment mark 90 after correction in the detected image I θ: vector angle of alignment mark 90 centered on origin O in detected image I

[0052] The correction unit 742 breaks down the correction amount −Δd into an x-direction component Δx and a y-direction component Δy using the following equations (5) and (6). Δx=-Δd·cosθ (5) Δy=-Δd·sinθ (6)

[0053] Then, the correction unit 742 corrects the coordinates (x, y) of the alignment mark 90 according to the following equation (7) to calculate the original coordinates (x', y') of the alignment mark 90. (x',y')=(x+Δx,y+Δy) (7)

[0054] This cancels the effect of the vertical positional deviation of the alignment mark 90, and determines the original horizontal position of the alignment mark 90. ​​In this way, even if the vertical distance from the X-ray irradiation unit 50 to the alignment mark 90 varies, the horizontal position of the alignment mark 90 can be detected with high accuracy based on the detected image I of the image sensor 60.

[0055] Once the corrected position of alignment mark 90 has been determined, exposure control unit 75 operates movement mechanism 30 and exposure unit 40 based on the position of alignment mark 90. ​​As a result, a pattern is exposed at a predetermined position on the top surface of substrate 9 (step S7). The exposure position of the pattern on the top surface of substrate 9 is determined based on the position of alignment mark 90. ​​Therefore, by accurately detecting the position of alignment mark 90 through the processes of steps S3 to S6 described above, the exposure position on substrate 9 can also be accurately determined.

[0056] In particular, in this embodiment, the vertical positional deviation amount ΔZ of the alignment mark 90 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 further, the positional deviation amount Δd of the alignment mark 90 on the detection image I corresponding to ΔZ is calculated. This makes it possible to calculate the correction amount -Δd based on a single mark.

[0057] <3. Identifying the origin of the detected image> In the above example, the position of the alignment mark 90 is measured in the detection image I with the position of the X-ray irradiation unit 50 set as the origin O. The position of this origin O may be physically aligned with the center of the detection image I, for example. However, in order to specify 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.

[0058] 8 is a diagram showing a method for identifying the position of the origin O in the detected image I. When identifying the origin O, first, as shown in FIG. 8, the substrate 9 is positioned 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 an alignment mark 90, or may be a pattern other than the alignment mark 90 formed on the substrate 9.

[0059] In this state, the X-ray irradiation unit 50 and the image sensor 60 capture images while changing the vertical position of the substrate 9 by the lifting mechanism of the moving mechanism 30. As a result, two detection images I with different magnifications are obtained. The intersection of a first straight line L1 obtained by connecting the first reference points M1 of the two detection images I and a second straight line L2 obtained by connecting the second reference points M2 of the two detection images I is set as the origin O of the detection image I. As a result, the origin O of the detection image I can be identified with high accuracy.

[0060] <4. Measuring the position and size of alignment marks> 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 acquired by the image sensor 60. If 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. ​​Also, if the alignment mark 90 is circular, the size of the alignment mark 90 may be, for example, the diameter of the alignment mark 90.

[0061] However, if the alignment mark 90 has a large thickness in the vertical direction, the alignment mark 90 may appear in the detection image I as having a shape extending in radial directions with the origin O as the center.

[0062] In this case, the calculation unit 74 may approximate the alignment mark 90 to an ellipse in the detection image I, and use the minor axis of the ellipse as the diameter of the alignment mark 90. ​​The calculation unit 74 may also obtain a maximum enclosed circle of the alignment mark 90 in the detection image I, and use the diameter of the maximum enclosed circle as the diameter of the alignment mark 90. ​​The calculation unit 74 may also shift the center of the above ellipse to the opposite side from the origin O by a distance equivalent to the difference between the major axis and the minor axis, and use the position as the center position of the alignment mark 90.

[0063] This makes it possible to more accurately measure the position d2 and size D2 of the alignment mark 90 in the detection image I. Therefore, the corrected position of the alignment mark 90 can also be calculated with higher accuracy.

[0064] <5. When the alignment mark has two sub-marks> In the above example, the alignment mark 90 is composed of one mark. However, the alignment mark 90 composed of one mark is prone to variation in dimensional accuracy. Therefore, the alignment mark 90 may be composed of multiple sub-marks 91.

[0065] 9 is a diagram showing a schematic diagram of 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 above-mentioned definitions of D0 and D2 are replaced as follows. D0: Distance between two submarks 91 (design information) D2: Distance between two sub-marks 91 in the detected image I (measured value)

[0066] Then, similarly to the above-described first embodiment, the calculation unit 74 calculates the correction amount -Δd of the alignment mark 90 by performing calculations of the formulas (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 between multiple 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 if the dimensional accuracy of a single mark is low.

[0067] 9, the alignment mark 90 is composed of two submarks 91. However, the number of submarks 91 constituting the alignment mark 90 may be three or more. In that case, for example, by focusing on two submarks 91 out of the three or more submarks 91, the process of calculating the correction amount -Δd using equations (1) to (7) may be executed multiple times while changing the combination of the two submarks 91 of interest, and an average value of the multiple obtained correction amounts -Δd may be calculated.

[0068] <6. Variations> Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment.

[0069] In the above embodiment, the X-ray irradiation unit 50 is disposed below the substrate 9, and the image sensor 60 is disposed above the substrate 9. However, the X-ray irradiation unit 50 may be disposed above the substrate 9, and the image sensor 60 may be disposed below the substrate 9. That is, the X-ray irradiation unit 50 may be configured to irradiate X-rays from above or below the substrate 9 on the stage 20 toward the substrate 9, and the image sensor 60 may be configured to receive X-rays that have passed through the substrate 9.

[0070] In the above 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 may be movable in the main scanning direction or the sub-scanning direction.

[0071] In the above embodiment, the image sensor 60 directly detects X-rays. However, the image sensor 60 may be configured with a scintillator that converts X-rays into visible light and a camera that receives the converted visible light.

[0072] In the above embodiment, the moving mechanism 30 moves the stage 20 relative to the stationary exposure unit 40. However, the moving mechanism 30 may move the exposure unit 40 relative to the stationary stage 20. The moving mechanism 30 may move both the stage 20 and the exposure unit 40. In other words, the moving mechanism 30 may be any mechanism that moves the stage 20 and the exposure unit 40 relatively.

[0073] In the above embodiment, a printed circuit board is given as an example of the substrate 9. However, the substrate 9 may be other types of substrates, such as a semiconductor wafer or a substrate for a flat panel display.

[0074] Also, in the above embodiment, a description has been given of the exposure apparatus 1 equipped with a detection apparatus for detecting the alignment mark 90. ​​However, the detection apparatus of the present invention may be installed in an apparatus other than the exposure apparatus 1, such as a coating apparatus, a developing apparatus, a cleaning apparatus, or an inspection apparatus.

[0075] Furthermore, the elements appearing in the above-described embodiment and modified examples may be appropriately selected to the extent that no contradiction occurs. [Explanation of symbols]

[0076] 1 Exposure equipment 9 Substrate 10 Base 20 Stages 30 Moving mechanism 40 Exposure section 41 Head 42 Illumination optical system 43 Laser Oscillator 50 X-ray irradiation section 60 Image Sensor 70 Computer 74 Calculation section 75 Exposure control section 90 Alignment Mark 91 Submark 741 Correction amount calculation unit 742 Correction Section D Design information I Detected image O Origin P1 Detection Program P2 Exposure Program

Claims

1. A detection device for detecting a position of an alignment mark formed on a substrate, comprising: a stage that supports the substrate in a substantially horizontal position; an X-ray irradiation unit that irradiates X-rays toward the substrate from above or below the substrate on the stage; an image sensor that receives X-rays transmitted through the substrate and obtains a detection image; a storage unit that stores design information of the alignment mark; a calculation unit that calculates a position of the alignment mark based on the design information and the detected image; Equipped with The calculation unit is calculating a horizontal correction amount corresponding to a vertical deviation amount of a distance from the X-ray irradiation unit to the alignment mark based on the design information and the detection image; The detection device corrects the horizontal position of the alignment mark in the detected image by the correction amount.

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

3. 3. The detection device according to claim 2, the alignment mark is circular; A detection device in which the calculation unit approximates the alignment mark in the detection image as an ellipse or determines the maximum enclosed circle of the alignment mark, and sets the minor axis of the ellipse or the diameter of the maximum enclosed circle as the size of the alignment mark in the detection image.

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

5. A detection device according to any one of claims 1 to 4, an exposure unit that irradiates light onto a predetermined position of the substrate supported by the stage; a moving mechanism that moves the stage and the exposure unit relatively; an exposure control unit that controls the exposure unit and the movement mechanism; Equipped with The exposure control unit determines a position to be irradiated with light by the exposure unit based on the position of the alignment mark calculated by the calculation unit.

6. A detection method for detecting a position of an alignment mark formed on a substrate, comprising the steps of: a) supporting the substrate in a substantially horizontal position, 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; b) calculating a position of the alignment mark based on design information of the alignment mark and the detected image; Equipped with In the step b), calculating a horizontal correction amount corresponding to a vertical deviation amount of a distance from the X-ray irradiation unit to the alignment mark based on the design information and the detection image; correcting a horizontal position of the alignment mark in the detected image by the correction amount.

Images