JP2007041244A - Stage position variation information acquisition method and apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To acquire position fluctuation information with higher accuracy in a stage position fluctuation information acquisition method for transferring a stage and acquiring stage position fluctuation information for each position.
[MEANS FOR SOLVING PROBLEMS] Four reference position correction marks 81a are provided at a position on a moving stage 14 which is a vertex of a preset quadrangle S, and four reference position correction marks 81a are moved by an image pickup means as the moving stage 14 is moved. The reference position correction mark detection position information indicating the position of the reference position correction mark is acquired based on the position of the reference position correction mark image in the captured field-of-view image and the preset reference position. A stage based on the relationship between the square shape formed by the acquired reference position correction mark position information and the square shape formed by the reference position correction mark, and the reference position and the image position of the mark. The relative position variation information of is acquired.
[Selection] Figure 17

Description

  In the present invention, the mark provided on the stage is imaged by the imaging means, the position of the mark is measured based on the position of the image of the mark in the captured field image, and the position of the stage is determined based on the measured position of the mark. The present invention relates to a stage position change information acquisition method and apparatus for acquiring position change information.

  Conventionally, various exposure apparatuses using a photolithographic technique have been proposed as apparatuses for recording a predetermined pattern on a substrate of a flat panel display such as a printed wiring board or a liquid crystal display.

  As an exposure apparatus as described above, for example, a light beam is scanned in a main scanning direction and a sub scanning direction on a substrate coated with a photoresist, and the light beam is modulated based on exposure image data representing an exposure pattern. An exposure apparatus for forming an exposure pattern by doing so has been proposed.

  Further, as the above exposure apparatus, for example, a spatial light modulation element such as a digital micromirror device (hereinafter referred to as DMD) is used, and a light beam is modulated by the spatial light modulation element according to exposure image data. Various exposure apparatuses that perform exposure are proposed.

  As an exposure apparatus as described above, for example, a stage on which a substrate is placed is transferred in a predetermined transfer direction, and a desired exposure pattern is formed on the substrate by irradiating the substrate with a modulated light beam. An exposure apparatus has been proposed (see, for example, Patent Document 1).

  When exposure is performed as the stage is moved as in the above exposure apparatus, the stage meanders, yaws or pitches due to the influence of the mechanical control accuracy of a predetermined transfer mechanism for transferring the stage. And the exposure pattern may be distorted.

  Therefore, for example, in Patent Document 2, a plurality of mark rows in which a number of marks are arranged at predetermined intervals in the stage transfer direction are provided on the stage in a direction perpendicular to the transfer direction. The mark is imaged by a camera provided for each mark row together with the stage transfer, and the position fluctuation amount of the stage at each position in the transfer direction is obtained by detecting the position of the mark image, and the position fluctuation quantity An exposure apparatus that exposes an appropriate exposure pattern by performing exposure in consideration of the above has been proposed.

  Here, when images of marks in a plurality of rows are picked up by a plurality of cameras as described above and the positions of the images are detected, it is necessary to provide a reference position in the field of view of each camera. Must be set to the same position in the camera's field of view.

  Therefore, for example, a reference position acquisition scale in which a large number of reference position acquisition marks are arranged in a direction perpendicular to the transfer direction is provided at the tip of the stage, and the reference position acquisition mark is located at a predetermined position in the field of view of each camera. A method has been considered in which the stage is moved to image the reference position acquisition mark, and the position of the reference position acquisition mark image in the captured field-of-view image is acquired as the reference position.

Japanese Patent Laid-Open No. 2004-233718 JP 2000-321025 A

  However, when the reference position is acquired as described above, the reference position is determined depending on, for example, the installation accuracy of the reference position acquisition scale on the stage or the installation accuracy of the reference position acquisition mark on the reference position acquisition scale. The direction in which the acquisition marks are arranged may be inclined with respect to the direction orthogonal to the transfer direction. When such an inclination occurs, the reference positions for the respective cameras are set to different positions, and thus the stage. Therefore, it is impossible to accurately measure the position of the mark for obtaining the position variation amount, and it is not possible to obtain a highly accurate position variation amount of the stage.

  In view of the above circumstances, the present invention is a stage position variation information acquisition method and apparatus for acquiring a stage position variation amount as described above, and is more effective without being affected by a reference position shift as described above. It is an object of the present invention to provide a stage position variation information acquisition method and apparatus capable of acquiring highly accurate stage position variation information.

In the stage position variation information acquisition method of the present invention, the stage is moved relative to the imaging means for imaging on the stage, the mark provided on the stage is imaged by the imaging means, and the captured field-of-view image In the stage position variation information acquisition method for measuring the position of the mark based on the position of the image of the mark and acquiring the relative position variation information of the stage based on the measured position of the mark, Four reference position correction marks are provided at positions on the stage, and the four reference position correction marks are sequentially picked up by the image pickup means as the stage is moved, and the position of the reference position correction mark image in the captured field image And a reference position correction mark detection position indicating the position of the reference position correction mark based on a preset reference position Information, and the relationship between the shape of the quadrangle formed by the acquired reference position correction mark detection position information and the shape of the quadrangle formed by the reference position correction mark, the reference position, and the position of the mark image In the stage position variation information acquisition method of the present invention, a reference position correction mark is provided on a long glass member, and the long glass is obtained. The member can be placed on the stage so as to be on a rectangular diagonal line formed by the reference position correction marks, and the reference position correction marks can be imaged.

  Moreover, a long member can be formed with a low thermal expansion material.

  Further, the reference position correction mark can be imaged a plurality of times.

  The stage position variation information acquisition apparatus according to the present invention moves the stage relative to the imaging means for imaging the stage, images the marks provided on the stage by the imaging means, and in the captured field-of-view image In the stage position variation information acquisition device that measures the position of the mark based on the position of the image of the mark and acquires the relative position variation information of the stage based on the measured position of the mark, Four reference position correction marks are provided at the position on the stage, and the position of the reference position correction mark image in the field-of-view image obtained by sequentially imaging the four reference position correction marks by the image pickup means as the stage is moved. And reference position correction mark detection that indicates the position of the reference position correction mark based on a preset reference position A reference position correction mark detection position information acquisition unit for acquiring position information, and a rectangular shape formed by the reference position correction mark detection position information acquisition unit acquired by the reference position correction mark detection position information acquisition unit and the reference position correction And a stage position variation information acquisition unit that acquires relative position variation information of the stage based on the relationship with the rectangular shape formed by the mark for use, the reference position, and the position of the image of the mark. .

  In the stage position variation information acquisition apparatus of the present invention, the reference position correction mark is provided on a long glass member, and the long glass member can be attached to and detached from the stage. Thus, it can be installed so as to be on the diagonal of the quadrangle formed by the reference position correction mark.

  Moreover, a long member can be formed with a low thermal expansion material.

  Further, the image pickup means can pick up the reference position correction mark a plurality of times.

  Here, “providing on the stage” includes not only providing directly on the stage but also providing via a member installed on the stage.

  Further, based on the relationship between the square shape formed by the reference position correction mark detection position information and the square shape formed by the reference position correction mark, the reference position and the position of the image of the mark. “Acquisition of relative position variation information” means, for example, that the reference is based on a deviation between a square shape formed by the reference position correction mark detection position information and a square shape formed by the reference position correction mark. The position may be corrected, the position of the mark image may be acquired using the corrected reference position, and the relative position variation information of the stage may be acquired based on the acquired position of the mark image. The position of the mark image is acquired using the reference position, and the position of the acquired mark image is formed by the reference position correction mark detection position information. Correction is performed based on the deviation between the square shape and the square shape formed by the reference position correction mark, and the relative position variation information of the stage is acquired based on the position of the image of the corrected mark. Alternatively, the position of the image of the mark is acquired using the reference position, the relative position variation information of the stage is acquired using the position of the acquired image of the mark, and the acquired relative position variation information is obtained. The correction is performed based on the deviation between the square shape formed by the reference position correction mark detection position information and the square shape formed by the reference position correction mark, and the corrected relative position variation information is acquired. It may be.

  According to the stage position variation information acquisition method and apparatus of the present invention, four reference position correction marks are provided at positions on the stage that are the vertices of a preset square, and the four reference position correction marks are transferred along with the stage transfer. The reference position correction mark detection position indicating the position of the reference position correction mark based on the position of the reference position correction mark image in the captured field image and the preset reference position Information is acquired, based on the relationship between the rectangular shape formed by the acquired reference position correction mark position information and the rectangular shape formed by the reference position correction mark, the reference position, and the position of the mark image The relative position variation information of the stage is acquired, so that it is not affected by the deviation of the reference position as described above. Ri can be acquired with high precision stage position variation information

  Hereinafter, an exposure apparatus using an embodiment of an apparatus and method for acquiring stage position variation information according to the present invention will be described in detail with reference to the drawings. The present exposure apparatus is an exposure apparatus that transfers a stage on which a substrate is installed in a predetermined transfer direction and exposes a predetermined exposure pattern to the substrate on the stage along with the transfer. It is an exposure apparatus that acquires stage position fluctuation information for each position in the transfer direction and exposes an exposure pattern corrected based on the stage position information. First, a schematic configuration of the present exposure apparatus will be described. FIG. 1 is a perspective view showing a schematic configuration of the exposure apparatus.

  As shown in FIG. 1A, the exposure apparatus 10 includes a flat moving stage 14 that holds the substrate 12 by adsorbing the substrate 12 to the surface. Two guides 20 extending along the stage transfer direction (Y direction) are installed on the upper surface of the thick plate-shaped installation table 18 supported by the four legs 16, and the moving stage 14 is a guide. 20 is supported so as to be able to reciprocate. And not only the board | substrate 12 but the glass chart 80 is installed in the movement stage 14. FIG.

  As shown in FIG. 1B, the glass chart 80 is provided with a reference mark 80a on the upper surface of a long member made of glass, and is configured to be detachable on the moving stage 14. ing. The reference mark 80a is provided on the upper surface of the glass member with a predetermined interval (for example, 10.0 mm interval). As shown in FIG. 1A, the glass chart 80 is placed on the moving stage 14 so that the direction in which the rows of the reference marks 80a extend coincides with the stage transfer direction. In addition, the installation method of a glass chart and its use are explained in full detail later.

  A U-shaped gate 22 is provided at the center of the installation table 18 so as to straddle the moving path of the moving stage 14. Each end of the U-shaped gate 22 is fixed to both side surfaces of the installation base 18. A scanner 24 to be described later is provided on one side of the gate 22, and a plurality of cameras 26 for imaging the front and rear ends of the substrate 12 and the reference mark of the glass chart 80 are provided on the other side. Is provided.

  The scanner 24 and the camera 26 are respectively attached to the gate 22 and fixedly arranged above the moving path of the moving stage 14. The scanner 24 and the camera 26 are connected to a controller (described later) that controls them.

  As shown in FIGS. 2 and 3B, the scanner 24 includes ten exposure heads 30 (30A to 30J) arranged in a substantially matrix of 2 rows and 5 columns.

  As shown in FIG. 4, a digital micromirror device (DMD) 36 that is a spatial light modulation element (SLM) that spatially modulates an incident light beam is provided inside each exposure head 30. In the DMD 36, a large number of micromirrors 38 are two-dimensionally arranged in a direction orthogonal to each other, and the micromirrors 38 are attached so that the column direction of the micromirrors 38 forms a predetermined set inclination angle θ with the scanning direction. Therefore, the exposure areas 32A to 32J by each exposure head 30 are rectangular areas inclined with respect to the scanning direction, as shown in FIG. Along with the movement of the stage 14, a strip-shaped exposed region 34 is formed on the substrate 12 for each exposure head 30. Although a light source that makes a light beam incident on each exposure head 30 is not shown, for example, a laser light source or the like can be used.

  The DMD 36 provided in each of the exposure heads 30 is on / off controlled in units of micromirrors 38, and the substrate 12 is exposed to a dot pattern (black / white) corresponding to the micromirrors 38 of the DMD 36. The aforementioned strip-shaped exposed region 34 is formed by two-dimensionally arranged dots corresponding to the micromirrors 38 shown in FIG. The two-dimensional array dot pattern is inclined with respect to the scanning direction, so that dots arranged in the scanning direction pass between dots arranged in the direction intersecting the scanning direction. The interval pitch can be narrowed, and high resolution can be achieved.

  Further, as shown in FIGS. 3A and 3B, the exposure heads of the respective rows arranged in a line so that each of the strip-shaped exposed areas 34 partially overlaps the adjacent exposed areas 34. Each of 30 is arranged at a predetermined interval in the arrangement direction. For this reason, for example, the portion that cannot be exposed between the exposure area 32A located on the leftmost side of the first row and the exposure area 32C located on the right side of the exposure area 32A is the exposure area located on the leftmost side of the second row. It is exposed by 32B. Similarly, the portion that cannot be exposed between the exposure area 32B and the exposure area 32D located on the right side of the exposure area 32B is exposed by the exposure area 32C.

  Next, the electrical configuration of the exposure apparatus 10 will be described.

  As shown in FIG. 5, the exposure apparatus 10 receives vector data representing an exposure pattern to be exposed, output from a data creation apparatus 40 having a CAM (Computer Aided Manufacturing) station, and performs raster conversion on the vector data. Acquired by the conversion unit 50, the detection position information acquisition unit 52 that acquires the detection position information of the reference mark 80 a based on the captured image of the reference mark 80 a of the glass chart 80 captured by the camera 26, and the detection position information acquisition unit 52. Based on the detected position information, a stage position fluctuation information acquisition unit 54 that acquires position fluctuation information of the movement stage 14 at a predetermined position, and the position fluctuation information of the movement stage 14 acquired by the stage position fluctuation information acquisition unit 54 Based on the exposure image data representing the exposure pattern to be exposed. Based on the image data correction unit 56 to be corrected and the exposure image data corrected by the image data correction unit 56, a control signal to be supplied to each DMD 36 of each exposure head 30 is generated, and the control signal is output to each exposure head 30. Controls the exposure head controller 58 that outputs to the stage, a transfer mechanism 60 that transfers the moving stage 14 in the stage transfer direction, a linear encoder 62 that acquires transfer distance information of the moving stage 14 by the transfer mechanism 60, and the entire exposure apparatus. And a controller 70. The moving mechanism 60 may adopt any known configuration as long as it moves the moving stage 14 back and forth along the guide 20. The operation of each component will be described in detail later.

  Next, the operation of the exposure apparatus 10 will be described with reference to the drawings.

  As described above, the exposure apparatus 10 moves the moving stage 14 on which the substrate 12 is placed in the stage transfer direction, and sequentially outputs a control signal from the exposure head controller 58 to the exposure head 30 along with the transfer. A desired exposure pattern is exposed on the substrate 12 by forming exposure points in time series on the substrate 12 on the moving stage 14 by the DMD 36 of the exposure head 30.

  Here, when performing exposure while transferring the moving stage 14 as described above, the moving stage 14 meanders due to the mechanical control accuracy of the transfer mechanism 60 and the like, and the substrate 12 on the moving stage 14 is exposed. In some cases, the exposure pattern is distorted.

  Further, when the moving stage 14 is transferred, not only the meandering as described above but also yawing and pitching vibration are generated. Therefore, it is necessary to detect and correct these.

  Therefore, in the present exposure apparatus 10, position fluctuation information of the moving stage 14 due to the meandering or the like is acquired in advance, exposure image data is corrected according to the position fluctuation information, and exposure is performed based on the corrected exposure image data. By doing so, distortion of the exposure pattern as described above is suppressed.

  First, a method for acquiring position variation information of the moving stage 14 will be described.

[How to obtain information on the movement of the moving stage]
First, as shown in FIGS. 1 (A) and 6 (A), a glass chart 80 is installed on the upper surface in the vicinity of one end of the moving stage 14 in the X direction. Note that the substrate 12 may or may not be installed when acquiring the position variation information of the moving stage 14. The moving stage 14 is once transferred from the position shown in FIG. 1A to the upstream end, and then transferred to the downstream side at a desired speed. The upstream side is the right side in FIG. 1A, that is, the side where the scanner 24 is installed with respect to the gate 22, and the downstream side is the left side in FIG. This is the side where the camera 26 is installed with respect to the gate 22.

  As the moving stage 14 is transferred to the downstream side, the pulse signal is counted by the linear encoder 62, and the transfer distance information of the moving stage 14 by the transfer mechanism 60 is acquired as the count number of the pulse signal. Is output to the controller 70.

  Then, the controller 70 outputs an imaging control signal to the camera 26 for each preset count number, and the camera 26 sequentially images the reference marks 80a on the glass chart 80 in accordance with the imaging control signal. The count indicating the timing at which the imaging control signal is output is set to a count corresponding to the interval between the reference marks 80a provided on the glass chart 80. For example, when the linear encoder 62 counts one pulse every transfer distance of 0.1 μm and the reference marks 80a are provided on the glass chart 80 at intervals of 10.0 mm, 100,000 pulses (10.0 mm /0.1 μm) An imaging control signal is output from the controller 70 every time it is counted. By controlling as described above, it is possible to perform imaging according to the interval between the reference marks 80a.

  Then, as shown in FIG. 7, a visual field image 80 c including the reference mark image 80 b of the reference mark 80 a is sequentially captured for each reference mark 80, and the visual field image data is output to the detection position information acquisition unit 52.

  When the imaging of all the reference marks 80a is completed with the glass chart 80 installed as shown in FIG. 6A, the moving stage 14 is returned to the upstream end again. Next, as shown in FIG. 6B, a glass chart 80 is installed on the upper surface in the vicinity of the other end in the X direction of the moving stage 14, and imaging of the reference mark 80a is performed in the same manner as described above. The visual field image data is output to the detected position information acquisition unit 52. The camera 26 is installed so that the fiducial mark 80a of the glass chart 80 is located within the field of view. However, the camera 26 is supported so as to be movable in the X direction, and the camera 26 is disposed within the field of view. You may make it move so that 80a may be located.

  Here, as shown in FIG. 7, the reference position 80d in the visual field image 80c is preset in the detection position information acquisition unit 52. Then, the detected position information acquisition unit 52 acquires the positional deviation amount (x1, y1) between the reference position 80d and the actually captured reference mark image 80b for each visual field image 80c at each position of the moving stage 14. To do. The reference position 80d is set in advance before imaging the reference mark 80a as described above. The setting method will be described in detail later.

  When the reference mark 80a is imaged as described above to obtain the positional deviation amount (x1, y1), the reference mark 80a in the glass chart 80 is set to a preset position (for example, on the glass chart 80 (for example, (10.0 mm interval) is measured in advance by a known measuring device, and when the position of the reference mark 80a is deviated from a preset position, the amount of deviation is also determined. In consideration of the above, it is desirable to calculate and obtain the positional deviation amount (x1, y1).

  Then, the displacement amount of the reference mark image 80b for each visual field image 80c acquired by the detection position information acquisition unit 52 as described above is transferred to the stage position variation information acquisition unit 54 as detection position information of each reference mark 80a. Is output.

  Then, as shown in FIG. 8, the stage position variation information acquisition unit 54 receives the reference mark 80a when the moving stage 14 does not meander, that is, when the moving stage 14 is transferred in an ideal state. The coordinate value of the position information 80e (hereinafter referred to as “reference mark position information”) is set in advance. Based on the coordinate value of the reference mark position information 80e and the positional deviation information, the actual captured reference mark is captured. The coordinate position information 80f of 80a is acquired. Note that the vertical axis in FIG. 8 indicates the position in the X direction on the moving stage 14, and the horizontal axis indicates the transfer distance position in the Y direction of the moving stage 14.

  Then, based on the coordinate value of the coordinate position information 80f acquired as described above, the position variation information of the moving stage 14 located at the predetermined transfer distance position is acquired. Hereinafter, for example, a method of calculating the position variation information when the moving stage 14 is located at the transfer distance position P shown in FIG. 8 will be specifically described.

  The position fluctuation information of the moving stage 14 at the transfer distance position P includes the position fluctuation amount of the moving stage 14 in the X direction (hereinafter referred to as “X direction position fluctuation amount”) and the position fluctuation amount of the moving stage 14 in the Y direction ( Hereinafter referred to as “Y-direction position fluctuation amount”), and the position fluctuation amount of the moving stage 14 in the rotation direction (θ direction) (hereinafter referred to as “θ-direction position fluctuation amount”).

  Specifically, when obtaining the Y-direction position variation amount, first, a straight line L connecting the coordinate position information A and the coordinate position information B is obtained, and a straight line connecting the coordinate position information C and the coordinate position information D. M is required. Then, the distance dY between the midpoint C1 of the coordinate position information A and the coordinate position information B and the midpoint C2 of the coordinate position information C and the coordinate position information D is obtained. The value of dY is the Y-direction position variation amount. When the point defining the position of the stage is assumed to be an equidistant position from a straight line passing through the coordinate position information A and the coordinate position information D and a straight line passing through the coordinate position information B and the coordinate position information C. DY can be calculated by the following equation, for example.

dY = (D1 + D2) / 2
However, D1: Value obtained by subtracting the y coordinate value of the coordinate position information B from the y coordinate value of the coordinate position information C
D2: A value obtained by subtracting the y-coordinate value of the coordinate position information A from the y-coordinate value of the coordinate position information D. Generally, the position of the reference mark on the stage is affected by the position variation amount in the θ direction of the stage, but the stage is moved. By calculating the average position of the mark positions arranged equidistant from the definition point, the mark position fluctuation caused by the θ-direction position fluctuation amount is canceled out, and the pure position fluctuation amount in the Y direction can be calculated.

  And when calculating | requiring (theta) direction position variation | change_quantity, while passing the coordinate position information B, the straight line N which has the same inclination as the straight line M is calculated | required. Then, an angle dθ formed by the straight line N and the straight line L is obtained. For dθ, for example, an approximate value can be calculated by the following equation. The value of dθ is the θ-direction position fluctuation amount.

dθ = (D2-D1) / E
However, D1: Value obtained by subtracting the y coordinate value of the coordinate position information B from the y coordinate value of the coordinate position information C
D2: Value obtained by subtracting the y coordinate value of the coordinate position information A from the y coordinate value of the coordinate position information D
E: Value obtained by subtracting the x-coordinate value of the coordinate position information C from the x-coordinate value of the coordinate position information D. Further, when obtaining the X-direction position fluctuation amount, first, the x coordinate of the midpoint C1 is determined from the x coordinate of the midpoint C2. A value dX ′ obtained by subtracting the coordinates is obtained. Then, dX is calculated by the following equation. This dX becomes the X direction position fluctuation amount.

dX = dX ′ − (Dy−Y0) · sin (dθ)
However, Dy: y-coordinate value of the coordinate position information D Y0: y-coordinate value of the point R defining the position of the stage Note that (Dy−Y0) · sin (dθ) is subtracted from dX ′ This is because the amount of position variation in the X direction due to the rotation of the stage 14 is subtracted.

  As described above, the position variation information of the moving stage 14 at the transfer distance position P is acquired as dY, dθ, dX.

  In the same manner as described above, the position fluctuation amount of the moving stage 14 at each transfer distance position of each reference mark position information 80e is calculated.

  Here, since the reference marks 80a are arranged at a predetermined interval (for example, 10.0 mm), the amount of position variation is acquired discretely in the Y direction and cannot be acquired continuously. Therefore, the stage position variation information acquisition unit 54 performs interpolation processing on the position variation information acquired for each transfer distance position, and calculates position variation information at the transfer distance position between the reference marks 80a. Specifically, as shown in FIG. 9, the stage position variation information acquisition unit 54 acquires each transfer distance position for each of the X-direction position variation amount dX, the Y-direction position variation amount dY, and the θ-direction position variation amount. A meandering curve passing through the position fluctuation information (x mark) is obtained, and position fluctuation information at the transfer distance position between the reference marks 80a is calculated based on the meandering curve. In the present embodiment, the meandering curve is obtained as described above, but any other interpolation processing may be used.

  The position variation information acquired by the stage position variation information acquisition unit 54 as described above is output to the image data correction unit 56.

  In the above embodiment, when the position variation information of the moving stage 14 is acquired, the glass chart 80 is installed so as to be within the range of the moving stage 14 as shown in FIGS. 6 and 10A. Since the fiducial mark 80a is imaged, for example, when the exposure head 39 is installed on the upstream side and the camera 26 is installed on the downstream side as in the exposure apparatus of the above embodiment, exposure is performed. Even if the head 30 reaches the exposure start position of the substrate 12 on the moving stage 14, the reference mark 80a of the glass chart 80 does not reach the field of view of the camera, so that the moving stage at the interval D shown in FIG. 14 position fluctuation information cannot be acquired, and exposure according to the position fluctuation information of the moving stage 14 cannot be performed.

  Therefore, for example, as shown in FIG. 10B and FIG. 11, the glass chart 80 is located downstream of the exposure start position of the substrate 12 on the moving stage 14 by at least a distance D between the exposure head 30 and the camera 26 in the Y direction. The reference mark 80a may be imaged from the time when the exposure position by the exposure head 30 passes the exposure start position. Also in this case, as described above, after the glass chart 80 is set as shown in FIG. 11A and the reference mark 80a is imaged, the glass chart 80 is replaced as shown in FIG. 11B. Therefore, it is necessary to image the reference mark 80a.

  In addition, as described above, the glass chart 80 is not projected from the tip of the moving stage 14 and the reference mark 80a is imaged. As shown in FIG. You may make it arrange | position adjacent.

  In the above-described embodiment, one glass chart 80 is replaced at two places on the moving stage 14 to capture the reference mark 80a. However, the two glass charts 80 are used to move these. The fiducial marks 80a may be imaged by installing them at the two locations on the stage 14. In addition, since the direction which replaced and used one glass chart 80 like the said embodiment can absorb the dispersion | variation in arrangement | positioning of the reference | standard mark 80a for every glass chart, more highly accurate acquisition of position variation information is possible. Is possible.

  Alternatively, the glass chart 80 may be configured by providing a plurality of rows of reference marks 80a on a single glass plate having a width equivalent to the width of the moving stage 14 in the X direction. As described above, it is more convenient to carry the glass chart 80 with a long member.

  Moreover, in the said embodiment, although the length was used as the glass chart 80 whose length is equivalent to the length of the moving stage 14 in the Y direction, the glass chart is shorter than the transfer distance of the moving stage 14 in the Y direction. The glass chart is installed with a shift in the Y direction, the reference mark 80a is imaged at each installation location, and the positions of the reference mark images acquired by the imaging at each installation are connected. Good. As described above, shortening the glass chart 80 is convenient for carrying.

  Further, in the above-described embodiment, one glass chart 80 is installed on each of the upper surfaces in the vicinity of both ends in the X direction of the moving stage 14 to capture the reference mark 80a. , (B), a plurality of glass charts 80 may be installed on the moving stage 14 to image the reference mark 80a. When installing a plurality of glass charts 80 as described above, for example, the first position variation information of the moving stage 14 is acquired based on the reference mark 80a of the glass chart 80 located on the outside, and on the inside. Based on the reference mark 80 of the glass chart 80 that is positioned, the second position variation information of the moving stage 14 is acquired, and a statistic such as an average of the first position variation information and the second position variation information is taken. You can do it. As described above, more accurate position variation information can be acquired by acquiring statistics of a plurality of position variation information.

  After the position variation information of the moving stage 14 is acquired as described above, the image data correction unit 56 performs a correction process on the exposure image data based on the input position variation information, and the corrected exposure is performed. Although exposure is performed by the exposure head 30 based on the image data, a method for obtaining the reference position 80d used when calculating the positional deviation amount (x1, y1) of the reference mark image 80 before the description of the exposure processing. Will be described.

[Reference position acquisition method]
First, as shown in FIG. 14A, a reference position acquisition scale 90 is installed at the tip of the moving stage 14 on the downstream side in the Y direction. The reference position acquisition scale 90 is provided with the reference position acquisition marks 90a arranged in a line along the length direction on the upper surface of the long member, and the reference position acquisition marks 90a are arranged in the Y direction. It is installed on the moving stage 14 so as to be aligned in the orthogonal direction. The reference position acquisition scale 90 may be fixed to the moving stage 14 or may be detachably installed.

  Then, the moving stage 14 provided with the reference position acquisition scale 90 as shown in FIG. 14A is transferred from the upstream side in the Y direction toward the downstream side at a desired speed. The reference position acquisition mark 90a is positioned at the position where the reference position acquisition mark 90a is in the field of view of the camera 26 and the moving stage 14 is transferred to a preset transfer distance position. Imaged.

  The visual field image 81c (see FIG. 7) including the reference position acquisition mark image of the reference position acquisition mark 90a imaged as described above is output to the detection position information acquisition unit 52, and the detection position information acquisition unit 52 The position of the reference position acquisition mark image in the visual field image 81c is acquired as a temporary reference position.

  If there are a plurality of reference position acquisition mark images in the field-of-view image 81c, one of the reference position acquisition mark images may be selected based on a predetermined setting rule. For example, the position of the reference position acquisition mark image closest to the gravity center position of the visual field image 81c may be acquired as the temporary reference position. Further, the reference position acquisition marks 90 a may be provided at intervals such that only one reference position acquisition mark 90 a exists in the field of view of the camera 26.

  Further, the temporary reference position is shown in FIG. 6A as a reference mark row (hereinafter referred to as “first reference mark row”) when the glass chart 80 is installed as shown in FIG. 6A. As described above, the reference mark row (hereinafter referred to as “second reference mark row”) when the glass chart 80 is installed is set respectively. In the present embodiment, since the first reference mark row and the second reference mark row are imaged by separate cameras 26, a temporary reference position is set for each camera 26. Hereinafter, the temporary reference position set corresponding to the first reference mark row is referred to as “first temporary reference position”, and the temporary reference position set corresponding to the second reference mark row is referred to as “first reference mark row”. This is referred to as “2 temporary reference position”.

  Here, when the reference position acquisition marks 90a on the reference position acquisition scale 90 are arranged in a direction orthogonal to the Y direction, that is, along the X direction, the temporary reference position acquired as described above. Can be used as the reference position 80d as it is, for example, installation accuracy when the reference position acquisition mark 90a is provided on the reference position acquisition scale 90 or installation accuracy when the reference position acquisition scale 90 is installed on the moving stage 14. For example, as shown in FIG. 14B, the reference position acquisition mark 90a may be installed at an angle α with respect to the X direction. The line C shown in FIG. 14B is the central axis of the reference position acquisition mark 90a row.

  As described above, if the extending direction of the reference position acquisition marks 90a is inclined with respect to the X direction, accurate position information of the reference marks arranged on the moving stage 14 cannot be acquired.

  More specifically, when the extending direction of the reference position acquisition mark 90a row is inclined with respect to the X direction as described above, the reference mark 80a originally present at the same position in the Y direction as shown in FIG. The coordinate position information 80f (for example, p1 and p2, p3 and p4) are shifted from each other in the Y direction, and accurate position information of the reference mark disposed on the moving stage 14 cannot be acquired.

  Therefore, an angular deviation amount α with respect to the X direction in the extending direction of the reference position acquisition mark 90a row as described above is acquired, the temporary reference position is corrected based on the angular deviation amount α, and the corrected temporary reference position is corrected. Is a reference position 80d.

  As a method for obtaining the angle deviation amount α, first, as shown in FIG. 16A, a reference position correcting glass chart 81 is arranged to be inclined at a predetermined angle with respect to the Y direction (X direction), and a moving stage. 14 is transferred from the upstream side in the Y direction toward the downstream side at a desired speed. Then, two predetermined reference position correction marks 81 a on the reference position correction glass chart 81 are imaged by the camera 26. The reference position correction mark 81a to be imaged is desirably located in the vicinity of the end of the reference position correction glass chart 81 in the length direction.

  Then, as shown in FIG. 16B, a reference position correcting glass chart 81 is installed so as to be symmetric with respect to the axis Y1 extending in the Y direction with respect to the position shown in FIG. Similarly, two reference position correction marks 81a corresponding to the two predetermined points in the reference position correction glass chart 81 are imaged by the camera 26. The axis Y1 is a central axis in the X direction. Also, the two reference position correction marks 81a imaged in the state shown in FIG. 16A and the two reference position correction marks 81a imaged in the state shown in FIG. 16B are the same. is there. Further, the positions of the four reference position correction marks 81a to be imaged in the X direction and the Y direction are set in advance in a reference position deviation amount acquisition unit 52b described later as reference position correction mark position information.

  As described above, the reference position correction mark 80a that is the apex of the rectangle S set in advance is imaged.

  Then, the visual field image including the four reference position correction marks 81a imaged as described above is output to the detection position information acquisition unit 52, and the detection position information acquisition unit 52 performs the reference position correction in the visual field image. A positional deviation amount between the position of the mark image and the temporary reference position set as described above in the reference position setting unit 52a is calculated. At this time, with respect to the reference position correction marks 81a at both ends of the side s1 along the first reference mark row, a positional deviation amount is calculated based on the first temporary reference position, and the second For the reference position correction marks 81a at both ends of the side s2 along the reference mark row, the amount of displacement is calculated based on the second temporary reference position.

  The positional deviation amount acquired as described above is output to the reference positional deviation amount acquisition unit 52b. In the reference positional deviation amount acquisition unit 52b, the input positional deviation amount and a preset reference position correction are performed. Based on the mark position information for reference, reference position correction mark detection position information 81b for each reference position correction mark 81a as shown in FIG. 17 is acquired.

  In the reference position deviation amount acquisition unit 52b, the angle deviation amount α is acquired based on the following expression.

α = Arctan (D / DX) ≈D / DX = {(L2 ² −L1 ² ) / (4 × DY)} / DX
However, L1: reference position correction mark detection position information r1 and
Distance to reference position correction mark detection position information r4
L2: Reference position correction mark detection position information r2 and
Distance to reference position correction mark detection position information r3
DY: For reference position correction from the y coordinate value of the reference position correction mark detection position information r3
A value obtained by subtracting the y-coordinate value of the mark detection position information r1
DX: For reference position correction from the x-coordinate value of the reference position correction mark detection position information r3
A value obtained by subtracting the x-coordinate value of the mark detection position information r4. Based on the angle deviation amount α acquired as described above, the first and first values set in the reference position setting unit 52a in the detection position information acquisition unit 2 is corrected and set as the correct reference position 80d.

  In the above-described embodiment, the amount of shift in the Y direction between the first temporary reference position and the second temporary reference position is acquired by acquiring the angle shift amount α as described above, and based on this shift amount. The first and second temporary reference positions are corrected to obtain the correct reference position 80d. For example, the first and second temporary reference positions are used in the same manner as described above. 14 position fluctuation information may be acquired, and the position fluctuation information may be corrected based on the angle shift amount α. Further, the detected position information or the coordinate position information 80f of the reference mark 80a may be corrected based on the angle deviation amount α.

  Moreover, in the said embodiment, although the glass chart 81 for reference | standard position correction | amendment was comprised from the elongate member as mentioned above, it is not restricted to this, For example, it is for 4 reference | standard position correction | amendment on one glass plate. The mark 81a may be provided, and the glass plate may be installed on the moving stage 14. In addition, carrying around etc. is more convenient when it is constructed from a long member as in the above embodiment.

  Further, in the above embodiment, one reference position correction glass chart 81 is replaced on the moving stay 14 and the four reference position correction marks 81a are imaged. These separate reference position correction glass charts 81 may be used, and each of them may be replaced on the moving stage 14 to image the four reference position correction marks 81a. In this case, the two reference position correction glass charts 81 are not necessarily the same as long as the positions of the reference position correction marks 81a to be imaged are known in the X direction and the Y direction. Note that the use of one reference position correction glass chart 81 as in the above embodiment can absorb variations in the distance between the two reference position correction marks 81a on the diagonal.

  Further, the glass chart 80 used when acquiring the position variation information of the moving stage 14 is used as a reference position correcting glass chart 81, and a part of the reference marks 81a of the glass chart 80 is used as a reference position correcting mark 81a. You may do it. If it carries out as mentioned above, carrying around is convenient and can also aim at reduction of cost.

  The reference position correcting glass chart 81 is not necessarily formed of glass, but is preferably formed of a low thermal expansion material.

  Next, a method of exposing an exposure pattern on the substrate 12 using the position variation information of the moving stage 14 acquired based on the reference position 80d corrected as described above will be described.

[Exposure processing]
First, in the data creation device 40, vector data representing an exposure pattern to be exposed on the substrate 12 is created. The vector data is output to the raster conversion unit 50, raster-converted by the raster conversion unit 50, and exposed in a bitmap format. After being converted to image data, it is output to the image data correction unit 56 and temporarily stored.

  Then, the image data correction unit 56 performs correction processing on the temporarily stored exposure image data based on the input position variation information of the moving stage 14, and sends the corrected exposure image data to the exposure head control unit 58. Output.

  Specifically, for example, with respect to the X-direction position fluctuation amount dX and the Y-direction position fluctuation amount dY, the correction process is performed by changing the exposure image data in the X direction and the Y direction by an amount corresponding to the dX and dY. A shift process may be performed. In addition, the θ-direction position variation amount dθ may be rotated by an angle corresponding to the dθ. Instead of performing rotation processing, the component of dθ may be decomposed into components in the X direction and Y direction, and the shift processing may be further performed in the X direction and Y direction only by that component. In addition, as long as the correction process cancels out the X-direction position fluctuation amount dX, the Y-direction position fluctuation amount dY, and the θ-direction position fluctuation amount dθ, any known calculation is not limited to the shift process and the rotation process as described above. Processing may be performed.

  Then, the corrected exposure image data subjected to the correction process as described above is output to the exposure head controller 58.

  In this embodiment, correction processing is performed after raster conversion of vector data. Alternatively, raster conversion may be performed after correction processing is performed on exposure image data in vector format.

  Then, after the position variation information of the moving stage 14 is acquired, the moving stage 14 is again transferred to the upstream end. Then, it is transferred toward the downstream side at a desired speed, and exposure is started when the tip of the substrate 12 is detected by the camera 26.

  Specifically, a control signal based on the exposure image data is output from the exposure head controller 58 to the DMD 36 of each exposure head 30, and the exposure head 30 turns on / off the micromirror of the DMD 36 based on the input control signal. The substrate 12 is exposed by turning it off. When a control signal is output from the exposure head controller 58 to each exposure head 30, a control signal corresponding to each position of each exposure head 30 with respect to the substrate 12 is sequentially exposed as the moving stage 14 is transferred. Output from the head controller 58 to each exposure head 30.

  In the above embodiment, the exposure image data is corrected based on the position variation information of the moving stage 14, but the exposure image data is not corrected, but based on the position variation information. The exposure head 30 and the moving stage may be relatively moved so as to cancel the direction position fluctuation amount dX, the Y direction position fluctuation amount dY, and the θ direction position fluctuation amount dθ.

  Further, as shown in FIGS. 18A and 18B, a transparent glass plate 85, a glass frame 86 that supports the glass plate 85, and one end of the glass frame 86 are supported so as to be rotatable around the Y-direction axis. A rotating shaft 87 extending in the Y direction, an eccentric cam 88 for moving the other end of the glass frame 86 in a direction (Z direction) perpendicular to the XY plane, and rotating with the eccentric cam 88 pivotally supported. An electric motor 89 for rotating the glass frame 86 around the Y direction axis by controlling the electric motor 89 to rotate the eccentric cam 88, and the position of the exposure beam Le emitted from the exposure head 30 is set to X. The X direction position variation amount dX may be corrected by moving in the direction.

  Further, by rotating the glass frame 86 around the X direction axis using the same mechanism as described above, the position of the exposure beam Le is moved in the Y direction to correct the Y direction position variation dY. Also good.

  In the above-described embodiment, when the reference mark 80a, the reference position acquisition mark 90a, and the reference position correction mark 81a in the glass chart 80 are imaged, a plurality of times of imaging are performed for one mark, and the positions of the plurality of mark images are determined. Statistics such as an average may be acquired. By averaging as described above, an imaging error by the camera 26 can be further reduced.

  In the above-described embodiment, the exposure apparatus including the DMD as the spatial light modulation element has been described. However, in addition to the reflective spatial light modulation element, a transmissive spatial light modulation element can also be used.

  In the above embodiment, the method and apparatus for acquiring position variation information of the moving stage 14 when the moving stage 14 is transferred to the exposure head 30 and the camera 26 have been described. However, the stage is fixed and the stage is fixed. In contrast, when the exposure head 30 and the camera 26 are transferred, information on the relative position variation of the stage with respect to the exposure head 30 and the camera 26 can be acquired in the same manner as described above.

  The stage position variation information acquisition method and apparatus according to the present invention is not limited to the exposure apparatus as described above, and is a drawing apparatus that performs drawing by moving a stage on which a drawing target is installed relative to the drawing head. Is also applicable.

(A) The perspective view which shows schematic structure of the exposure apparatus using one Embodiment of the stage position variation information acquisition method and apparatus of this invention, (B) The glass chart used in the stage position variation information acquisition method and apparatus of this invention Perspective view 1 is a perspective view showing the configuration of a scanner of the exposure apparatus in FIG. (A) is a plan view showing an exposed region formed on the exposure surface of the substrate, and (B) is a plan view showing an array of exposure areas by each exposure head. The figure which shows DMD in the exposure head of the exposure apparatus of FIG. 1 is a block diagram showing an electrical configuration of an exposure apparatus using an embodiment of the present invention. The figure for demonstrating the method to acquire the positional variation information of a movement stage in the exposure apparatus using one Embodiment of this invention. The figure which shows the visual field image imaged with the camera The figure for demonstrating the method to acquire the positional variation information of a movement stage based on the detection position information of a reference mark Diagram showing position variation information of moving stage The figure for demonstrating other embodiment of the position variation information acquisition method of a moving stage. The figure for demonstrating other embodiment of the position variation information acquisition method of a moving stage. The figure for demonstrating other embodiment of the position variation information acquisition method of a moving stage. The figure for demonstrating other embodiment of the position variation information acquisition method of a moving stage. The figure for demonstrating the acquisition method of the reference position used when acquiring the detection position information of a reference mark The figure which shows the coordinate position information of the reference mark acquired when the reference position acquisition mark row | line | column for acquiring a reference position is inclined by angle (alpha) with respect to the X direction. Diagram for explaining the reference position acquisition method Diagram for explaining the reference position acquisition method The figure for demonstrating an example of the method of correct | amending an exposure pattern mechanically based on the positional variation information of a moving stage

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Exposure apparatus 12 Substrate 14 Moving stage 18 Installation stand 20 Guide 22 Gate 24 Scanner 26 Camera 30 Exposure head 32 Exposure area 36 DMD
52 Detection position information acquisition unit (reference position correction mark detection position information acquisition unit)
52a Reference position setting unit 52b Reference position deviation amount acquisition unit 54 Stage position variation information acquisition unit 80 Glass chart 80a Reference mark 80a
80b Reference mark image 80c Field of view image 80d Reference position 80e Reference mark position information 80f Reference mark coordinate position information 81 Reference position correction glass chart 81a Reference position correction mark 81b Reference position correction mark detection position information 85 Glass plate 86 Glass frame 87 Rotating shaft 88 Eccentric cam 89 Electric motor 90 Reference position acquisition scale 90a Reference position acquisition mark

Claims (8)

The stage is moved relative to the imaging means for imaging on the stage, and a mark provided in advance on the stage is imaged by the imaging means, and the image of the mark in the captured field image is located at the position of the image. In the stage position variation information acquisition method for measuring the position of the mark based on the position and acquiring the relative position variation information of the stage based on the measured position of the mark,
Four reference position correction marks are provided at positions on the stage that are the vertices of a preset rectangle,
The four reference position correction marks are sequentially imaged by the imaging means along with the transfer of the stage,
Obtaining reference position correction mark detection position information indicating the position of the reference position correction mark based on a position of the image of the reference position correction mark in the captured field image and a preset reference position;
Based on the relationship between the square shape formed by the acquired reference position correction mark detection position information and the square shape formed by the reference position correction mark, the reference position, and the position of the image of the mark. A stage position variation information acquisition method comprising acquiring relative position variation information of the stage. The reference position correction mark is provided on a long glass member,
The long glass member is replaced on the stage so as to be on a diagonal of a quadrangle formed by the reference position correction mark, and the reference position correction mark is imaged. Item 1. The stage position variation information acquisition method according to Item 1.   3. The stage position variation information acquisition method according to claim 2, wherein the long member is formed of a low thermal expansion material.   4. The stage position variation information acquisition method according to claim 1, wherein the reference position correction mark is imaged a plurality of times. The stage is moved relative to the imaging means for imaging the stage, the mark provided on the stage is imaged by the imaging means, and based on the position of the image of the mark in the captured field image In the stage position variation information acquisition device that measures the position of the mark and acquires the relative position variation information of the stage based on the measured position of the mark,
Four reference position correction marks are provided at positions on the stage that are the vertices of a preset square,
Based on the position of the image of the reference position correction mark and the preset reference position in the field-of-view image obtained by sequentially capturing the four reference position correction marks by the imaging means along with the transfer of the stage, the reference position correction A reference position correction mark detection position information acquisition unit for acquiring reference position correction mark detection position information indicating the position of the mark;
The relationship between the rectangular shape formed by the reference position correction mark detection position information acquired by the reference position correction mark detection position information acquisition unit and the rectangular shape formed by the reference position correction mark, the reference A stage position variation information acquisition apparatus comprising: a stage position variation information acquisition unit configured to acquire relative position variation information of the stage based on the position and the position of the mark image. The reference position correction mark is provided on a long glass member,
The long glass member is detachable with respect to the stage, and is installed so as to be on a rectangular diagonal formed by the reference position correction mark on the stage. 6. The stage position variation information acquisition apparatus according to claim 5, wherein the stage position variation information acquisition apparatus is provided.   The stage position variation information acquisition apparatus according to claim 6, wherein the long member is formed of a low thermal expansion material.   8. The stage position variation information acquisition apparatus according to claim 5, wherein the imaging unit images the reference position correction mark a plurality of times.

Images