JP2008304834A - Pattern-drawing device and distortion-correcting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology which can prevent the deviations of a plurality of imaging positions from their ideal imaging positions (theoretical imaging positions) in a prescribed permissible range, the deviations being caused by the distortion of lenses or the like. <P>SOLUTION: Imaging positions on a substrate, at which the images of sample patters S(1), S(2) to S(m) are formed, are measured to calculate every shift amount Px(1), Px(2) to Px(m) of the imaging positions of the sample patterns based on their ideal imaging positions, respectively. Then, on the basis of the quantities Px(1), Px(2) to Px(m) of the deviations, offset correction quantities at aperture positions are determined. Then, the imaging positions of a plurality of regular patterns are evenly shifted in a prescribed direction by moving the positions of apertures AP by the offset correction quantities. By this, a maximum deviation quantity is decreased. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technique for drawing a plurality of regular patterns on a substrate on which a photosensitive material is formed.

  Conventionally, in the manufacturing process of substrates for color filters, liquid crystal display devices, flat panel display (FPD) glass substrates such as liquid crystal display devices and plasma display devices, semiconductor substrates, printed circuit boards and the like, photosensitive materials have been used. 2. Description of the Related Art A pattern drawing apparatus that draws a regular pattern on the surface of a substrate by irradiating the substrate with the light is used.

  Such a pattern drawing apparatus includes, for example, a light shielding plate having a plurality of openings (slits) and a projection optical system including lenses. The light from the light source is partially shielded by the light shielding plate, becomes a plurality of light beams, enters the projection optical system, and is further scaled by the projection optical system to form an image on the substrate. As a result, a plurality of regular patterns are drawn on the substrate.

  In recent years, with the progress of miniaturization of patterns due to high integration of semiconductor integrated circuits, high precision is also required for pattern drawing positions. One of the causes that hinders high-precision drawing is, for example, dimensional variations that tend to occur in the photomask plane. Patent Document 1 proposes a technique for correcting this dimensional variation by changing an offset value added to an electron beam in accordance with each position in the photomask surface.

JP 2007-34143 A

  One of the causes that the drawing position (that is, the imaging position of the light beam on the substrate) deviates from the drawing position (ideal imaging position) that should theoretically form an image in pattern drawing is that the projection optical system is used. A distortion aberration (distortion) of the constituting lens can be considered.

  For example, it is assumed that slits are formed in the light shielding plate at regular intervals in a predetermined direction. The imaging positions of the two light beams that have passed through the slits located at both ends of this slit row can be made to coincide with the ideal imaging positions by adjusting the lens magnification of the projection optical system (determining the magnification by holding both ends) ). However, since an actual lens has distortion, even if the positions of both ends coincide with the ideal imaging position, the imaging position between them (that is, the imaging position of the light beam that has passed through the slits other than both ends) is ideal. It will be displaced from the imaging position. Further, distortion of the light shielding plate and deviation of the irradiation position of the light source also cause the imaging position to deviate from the ideal imaging position. As a result, the patterns to be formed at regular intervals in the predetermined direction become unequal intervals.

  The present invention has been made in view of the above problems, and suppresses the deviation of the imaging position from the ideal imaging position (the position where the image should be theoretically formed) due to lens distortion or the like within a predetermined allowable range. The purpose is to provide technology that can be used.

  The invention according to claim 1 is a pattern drawing apparatus for drawing a plurality of regular patterns on a substrate on which a photosensitive material is formed, wherein the light from the light source is partially shielded by a light shielding plate having a plurality of openings. A mask means for forming a plurality of light fluxes; an imaging means for forming a plurality of regular patterns on a substrate by scaling the plurality of light fluxes by a lens; and An imaging position measuring means for measuring each imaging position of the sample pattern, at least one of which is a sample pattern, and the imaging position and a position to be theoretically imaged for each of the sample patterns A deviation amount calculating means for calculating a deviation amount from the ideal imaging position, and an offset correction of the mask means based on the deviation amount calculated for each of the sample patterns. Comprises an offset correction amount determining means for determining, and a mask position adjustment means for adjusting the position of said mask means based on the offset correction amount.

  A second aspect of the present invention is the pattern drawing apparatus according to the first aspect, wherein the plurality of openings are formed at equal intervals in a predetermined direction, and the sample pattern is the plurality of regular patterns. Of the patterns, there are at least three patterns including patterns formed at both ends in a predetermined direction, and light fluxes respectively passing through the openings located at both ends of the opening row formed in the predetermined direction. Lens magnification determining means for determining the magnification of the lens so that the interval between the imaging positions coincides with the interval between both ends at the ideal imaging position.

  A third aspect of the present invention is the pattern drawing apparatus according to the first or second aspect, wherein the shift amount is a value indicating how much the image forming position is shifted from the ideal image forming position in a predetermined direction. And the offset correction amount determination means extracts the maximum value and the minimum value of the deviation amounts calculated for each of the sample patterns, and based on the average value of the maximum value and the minimum value, The offset correction amount for a predetermined direction is determined.

  A fourth aspect of the present invention is the pattern drawing apparatus according to the first or second aspect, wherein the shift amount is a value indicating how much the image forming position is shifted from the ideal image forming position in a predetermined direction. And the offset correction amount determining means determines the offset correction amount for the predetermined direction based on an average value of the deviation amounts calculated for each of the sample patterns.

  A fifth aspect of the present invention is the pattern drawing apparatus according to any one of the first to fourth aspects, wherein the amount of deviation is determined by how much the imaging position deviates in a predetermined direction from the ideal imaging position. Approximate linear calculation means for obtaining a linear function obtained by approximating the deviation amount calculated for each of the sample patterns by a least square method, and approximating by a least square method based on the linear function An appropriate magnification calculating unit that calculates a magnification of the lens that gives a deviation amount such that the slope of the linear function becomes 0, and obtains the appropriate magnification, and a lens magnification adjusting unit that adjusts the magnification of the lens to the appropriate magnification And comprising.

  According to a sixth aspect of the present invention, there is provided a photosensitive material in which light from a light source is partially shielded by a light shielding plate having a plurality of openings to form a plurality of light fluxes, and the plurality of light fluxes are scaled by a lens. A correction method for correcting a drawing position in a pattern drawing apparatus for drawing a plurality of regular patterns on the substrate by forming an image on the formed substrate, wherein at least one of the plurality of regular patterns A sample pattern, measuring the imaging position in each predetermined direction of the sample pattern, and for each of the sample patterns, how much the imaging position is in the predetermined direction from the ideal imaging position A step of calculating a deviation amount indicating whether or not there is a deviation, and the light shielding plate based on the deviation amount calculated for each of the sample patterns And a step of determining an offset correction amount for the predetermined direction, based on the offset correction amount, and adjusting the position of the predetermined direction of the light shielding plate, the.

  In the invention of claim 7, the light from the light source is partially shielded by the light shielding plate having a plurality of openings to form a plurality of light fluxes, and the plurality of light fluxes are scaled by a lens to obtain a photosensitive material. A correction method for correcting a drawing position in a pattern drawing apparatus for drawing a plurality of regular patterns on the substrate by forming an image on the formed substrate, wherein at least one of the plurality of regular patterns is Measuring the imaging position in each predetermined direction of the sample pattern as a sample pattern, and how much the imaging position is deviated from the ideal imaging position in the predetermined direction for each of the sample patterns And calculating a deviation amount indicating whether or not the sample pattern and approximating the deviation amount calculated for each of the sample patterns by a least square method. A step of obtaining a linear function, and a magnification of the lens that gives a deviation amount such that the slope of the linear function approximated by the least square method is zero based on the linear function is obtained as an appropriate magnification. A step of adjusting the magnification of the lens to the appropriate magnification, a step of calculating a shift amount under the appropriate magnification for each of the sample patterns, and the calculated for each of the sample patterns A step of determining an offset correction amount for the predetermined direction of the light shielding plate based on a deviation amount under an appropriate magnification, and a position of the light shielding plate in the predetermined direction is adjusted based on the offset correction amount. And a step of performing.

  The invention of claim 8 is the distortion correction method according to claim 6 or 7, wherein the plurality of openings are formed at equal intervals in a predetermined direction, and the sample pattern is the plurality of the plurality of openings. Among the regular patterns, at least three patterns including patterns formed at both ends in a predetermined direction, and both ends of the opening row formed in the predetermined direction before calculating the shift amount Determining the magnification of the lens so that the interval between the imaging positions of the light beams respectively passing through the aperture located at the same position matches the interval between both ends at the ideal imaging position.

  The invention according to claim 9 is the distortion correction method according to any one of claims 6 to 8, wherein the shift amount indicates how much the image forming position is shifted from the ideal image forming position in a predetermined direction. In the step of determining the offset correction amount, a maximum value and a minimum value of the deviation amounts calculated for each of the sample patterns are extracted, and an average value of the maximum value and the minimum value is determined. Based on the above, the offset correction amount for the predetermined direction is determined.

  A tenth aspect of the present invention is the distortion correction method according to any one of the sixth to ninth aspects, wherein the plurality of openings are in a first direction and a second direction orthogonal to the first direction. Each is formed at equal intervals, and after adjusting the position of the light shielding plate in the first direction, the position in the second direction is adjusted.

  According to the first to tenth aspects of the present invention, at least one of the plurality of regular patterns is used as a sample pattern, and the offset correction amount is based on the amount of deviation between each imaging position of the sample pattern and the ideal imaging position. Is calculated. Then, the position of the mask means is adjusted based on the obtained offset correction amount. Therefore, the imaging position of each pattern can be shifted uniformly. As a result, the deviation of the imaging position from the ideal imaging position can be kept within a predetermined allowable range.

  In particular, according to the second and eighth aspects of the present invention, the interval between the imaging positions of the two light beams that have passed through the apertures located at both ends of the aperture row coincides with the interval between the both ends at the ideal imaging position. Thus, since the magnification of the lens is determined, it is possible to efficiently specify an offset correction amount capable of keeping the deviation of the imaging position from the ideal imaging position within a predetermined allowable range.

  In particular, according to the third and ninth aspects of the invention, the offset correction amount is determined based on the average value of the maximum value and the minimum value of the deviation amount. That is, the offset correction amount is determined based on the maximum shift amount in the predetermined direction and the maximum shift amount in the direction opposite to the predetermined direction. Thus, by extracting the peak value of the deviation amount and calculating the offset correction amount using the peak value, it is possible to easily and efficiently calculate the offset correction amount that can reduce the maximum deviation amount. Can do.

  In particular, according to the invention of claim 4, the offset correction amount is determined based on the average value of the deviation amounts. According to this configuration, it is possible to easily obtain an offset correction amount that takes into account the shift amount for each of the plurality of regular patterns.

  In particular, according to the invention of claim 5, the magnification of the lens is corrected to a lens magnification (appropriate magnification) that gives a deviation amount such that the slope of the linear function approximated by the least square method becomes zero. Thereby, the deviation of the deviation amount can be eliminated.

  In particular, according to the seventh aspect of the invention, the offset correction amount is calculated and the position of the light shielding plate is adjusted after eliminating the deviation of the shift amount by adjusting the magnification of the lens. Accordingly, it is possible to effectively reduce the deviation of the imaging positions of the plurality of regular patterns from the ideal imaging position.

  In particular, according to the invention of claim 10, the position of the light shielding plate is adjusted for each of the first direction and the second direction orthogonal to the first direction. It is possible to effectively reduce the deviation of the imaging positions of the regular patterns from the ideal imaging positions.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. In addition, in each figure referred in the following description, in order to clarify the positional relationship and operation direction of each member, the common XYZ orthogonal coordinate system is attached | subjected.

<1. Overall Configuration of Pattern Drawing Device>
1 and 2 are a side view and a top view showing a configuration of a pattern drawing apparatus 1 according to an embodiment of the present invention. The pattern drawing device 1 is a device for drawing a predetermined pattern on the upper surface of a glass substrate (hereinafter simply referred to as “substrate”) 9 for a color filter in a process of manufacturing a color filter of a liquid crystal display device. As shown in FIGS. 1 and 2, the pattern drawing apparatus 1 includes a stage 10 for holding a substrate 9, a stage drive unit 20 connected to the stage 10, and a head unit 30 having a plurality of optical heads 32. And an irradiation light photographing unit 40 for photographing irradiation light from each optical head 32 and a control unit 50 for controlling the operation of each part of the apparatus.

  The stage 10 has a flat outer shape, and is a holding unit for placing and holding the substrate 9 on the upper surface thereof in a horizontal posture. A plurality of suction holes (not shown) are formed on the upper surface of the stage 10. For this reason, when the substrate 9 is placed on the stage 10, the substrate 9 is fixedly held on the upper surface of the stage 10 by the suction pressure of the suction holes. A layer of a photosensitive material such as a color resist is formed on the surface of the substrate 9 held on the stage 10.

  The stage drive unit 20 is a mechanism for moving the stage 10 in the main scanning direction (Y-axis direction), the sub-scanning direction (X-axis direction), and the rotation direction (rotation direction around the Z-axis). The stage drive unit 20 includes a rotation mechanism 21 that rotates the stage 10, a support plate 22 that rotatably supports the stage 10, a sub-scanning mechanism 23 that moves the support plate 22 in the sub-scanning direction, and a sub-scanning mechanism 23. And a main plate 24 that supports the support plate 22 and a main scanning mechanism 25 that moves the base plate 24 in the main scanning direction.

  The rotation mechanism 21 includes a linear motor 21 a that includes a mover attached to the end portion on the −Y side of the stage 10 and a stator laid on the upper surface of the support plate 22. A rotation shaft 21 b is provided between the lower surface side of the center portion of the stage 10 and the support plate 22. For this reason, when the linear motor 21a is operated, the mover moves in the X-axis direction along the stator, and the stage 10 rotates within a predetermined angle range around the rotation shaft 21b on the support plate 22.

  The sub-scanning mechanism 23 includes a linear motor 23 a configured by a mover attached to the lower surface of the support plate 22 and a stator laid on the upper surface of the base plate 24. In addition, a pair of guide portions 23 b extending in the sub-scanning direction is provided between the support plate 22 and the base plate 24. For this reason, when the linear motor 23a is operated, the support plate 22 moves in the sub-scanning direction along the guide portion 23b on the base plate 24.

  The main scanning mechanism 25 has a linear motor 25 a composed of a mover attached to the lower surface of the base plate 24 and a stator laid on the base 60 of the apparatus 1. A pair of guide portions 25 b extending in the main scanning direction is provided between the base plate 24 and the base 60. For this reason, when the linear motor 25a is operated, the base plate 24 moves in the main scanning direction along the guide portion 25b on the base 60.

  The head unit 30 is a mechanism for irradiating a predetermined pattern of pulsed light onto the upper surface of the substrate 9 held on the stage 10. The head unit 30 includes a frame 31 installed on the base 60 so as to straddle the stage 10 and the stage driving unit 20, and seven optical heads 32 attached to the frame 31 at equal intervals along the sub-scanning direction. have. One laser oscillator 34 is connected to each optical head 32 via an illumination optical system 33. In addition, a laser driving unit 35 is connected to the laser oscillator 34. Therefore, when the laser driving unit 35 is operated, pulse light is oscillated from the laser oscillator 34, and the oscillated pulse light is introduced into each optical head 32 via the illumination optical system 33.

  In each optical head 32, an emission part 36 for emitting the pulsed light introduced from the illumination optical system 33 downward and a part of the pulsed light to partially shield the pulsed light to form a light beam having a predetermined shape. Aperture unit 37 and a projection optical system 38 for imaging the pulsed light on the upper surface of the substrate 9 are provided. In the aperture unit 37, an aperture AP which is a glass plate on which a predetermined light shielding pattern is formed by a plurality of slits is set. In general, a plurality of slits are formed in the aperture AP at equal intervals in the X direction (sub-scanning direction) and the Y direction (main scanning direction). The pulsed light emitted from the emission unit 36 is partially shielded when passing through the aperture AP set in the aperture unit 37, and enters the projection optical system 38 as a light beam having a predetermined pattern. The incident light beam is scaled by a lens included in the projection optical system 38 and imaged on the upper surface of the substrate 9. As a result, a plurality of regular patterns are drawn on the photosensitive material formed on the upper surface of the substrate 9.

  FIG. 3 is a diagram illustrating an example of the aperture AP. The aperture AP is composed of a glass plate, a metal plate, or the like that has been processed to block light. As illustrated in FIG. 3, the aperture AP has a large number of slits SL, which are openings through which light passes, at equal intervals along each of the main scanning direction (Y direction) and the sub-scanning direction (X direction). It is formed in an array. Although simplified in FIG. 3, for example, about 170 slits SL are formed in each aperture AP at intervals of about 300 μm in the sub-scanning direction, for example. Further, in FIG. 3, each slit SL is shown as having a rectangular shape with the main scanning direction as the longitudinal direction, but the shape of the slit SL is not limited to this. By irradiating the substrate 9 with the pulsed light that has passed through the slits SL, a large number of regular patterns are drawn on the substrate 9.

  Further, as conceptually shown in FIG. 1, each optical head 32 is provided with an aperture driving unit 39 for adjusting the position of the aperture AP set in the aperture unit 37. The aperture drive unit 39 can adjust the projection position of the pattern on the substrate 9 by adjusting the horizontal position (including the inclination in the horizontal plane) of the aperture AP. The aperture drive unit 39 can be configured by combining a plurality of linear motors, for example.

  The irradiation light photographing unit 40 is a mechanism for photographing the pulsed light emitted from each optical head 32. The irradiation light photographing unit 40 includes a CCD camera 41, a guide rail 42, and a camera driving mechanism 43 configured by a linear motor or the like. The CCD camera 41 is arranged with the shooting direction facing upward. When the camera drive mechanism 43 is operated, the CCD camera 41 moves in the sub-scanning direction along the guide rail 42 attached to the side on the + Y side of the base plate 24.

  When the CCD camera 41 is used, first, the main scanning mechanism 25 is operated, and the base plate 24 is positioned so that the CCD camera 41 is positioned below the head unit 30 (the state shown in FIGS. 1 and 2). Then, by operating the camera driving mechanism 43, the CCD camera 41 is moved in the sub-scanning direction, and the pulsed light emitted from each optical head 32 is photographed by the CCD camera 41. Image data acquired by photographing is transferred from the CCD camera 41 to the control unit 50.

  The control unit 50 is a processing unit for controlling the operation of each unit in the pattern drawing apparatus 1. FIG. 4 is a block diagram illustrating a connection configuration between the above-described units of the pattern drawing apparatus 1 and the control unit 50. As shown in FIG. 4, the control unit 50 includes the rotation mechanism 21, the sub-scanning mechanism 23, the main scanning mechanism 25, the laser driving unit 35, the illumination optical system 33, the projection optical system 38, the aperture driving unit 39, and the CCD. It is electrically connected to the camera 41 and the camera drive mechanism 43, and controls these operations. In addition, the control part 50 is comprised by the computer which has CPU and memory, for example, and performs said control when a computer operate | moves according to the program installed in the computer.

  When performing a drawing process in such a pattern drawing apparatus 1, pulse light is emitted from each optical head 32 while moving the stage 10 in the main scanning direction and the sub-scanning direction according to the inputted drawing data, and the substrate 9. Draw a pattern on top. Specifically, first, pulse light is emitted from each optical head 32 while moving the stage 10 in the main scanning direction. Thus, a plurality of patterns are drawn on the upper surface of the substrate 9 in the main scanning direction with a predetermined exposure width (for example, 50 mm width). When one drawing in the main scanning direction is completed, the pattern drawing apparatus 1 moves the stage 10 by the exposure width in the sub-scanning direction and moves the stage 10 in the main scanning direction again from each optical head 32. Irradiate pulsed light. As described above, the pattern drawing apparatus 1 repeats the drawing in the main scanning direction a predetermined number of times (for example, four times) while shifting the substrate 9 in the sub-scanning direction by the exposure width of the optical head 32, so that the color is formed on the substrate 9. Draw a filter pattern.

<2. Image distortion correction function>
As described above, pattern drawing on the photosensitive material on the substrate is performed by forming an image of the pulsed light that has passed through the slit SL formed in the aperture AP on the upper surface of the substrate 9 by the projection optical system 38. Here, the projection optical system 38 is composed of a plurality of lenses. Due to distortion (distortion) of these lenses, the image formation position (pattern drawing position) of the light beam on the upper surface of the substrate 9 is theoretically formed. It shifts from the position (ideal image forming position) to be made (image distortion). That is, theoretically, the intervals between patterns to be drawn by being arranged at equal intervals in the X direction and Y direction are unequal intervals (see, for example, FIG. 9B). The pattern drawing apparatus 1 has a function (image distortion correction function) for reducing the influence of the image distortion. There are two modes of the image distortion correction function that can be realized by the pattern drawing apparatus 1. Below, each aspect is demonstrated concretely.

<A. Image Distortion Correction Function According to First Mode>
<A-1. Principle of correction>
In the first aspect, image distortion is corrected by adjusting the horizontal position of the aperture AP. The principle of this correction will be described. Due to lens distortion of the projection optical system 38, deviations from the ideal imaging position (deviation amounts Px (1), Px (2),... Px (m)) occur at the imaging positions of a plurality of regular patterns. (For example, refer to the upper part of FIG. 9B.) In pattern drawing, the deviation from the ideal image formation position for each of a plurality of patterns is required to be within a predetermined allowable error range. Then, it is required that the deviation amount (maximum deviation amount PxM (see FIG. 9A)) for the pattern that is most greatly deviated from the ideal image formation position is equal to or less than a predetermined allowable error. By moving the position of the AP in an appropriate direction by an appropriate distance, the imaging positions of a plurality of regular patterns are uniformly shifted in a predetermined direction (the lower part of FIG. 9B). To achieve a reduction of the large shift amount (Fig. 9 (c)).

<A-2. Functional configuration>
The image distortion correction function according to the first aspect will be specifically described with reference to FIG. FIG. 5 is a diagram schematically showing only the part related to the image distortion correction function according to the first aspect in the configuration of the pattern drawing apparatus 1.

  The pattern drawing apparatus 1 uses the irradiation light photographing unit 40, the aperture driving unit 39, and the control unit 50 to realize an image distortion correction function. Inside the control unit 50, an A / D conversion unit 51 for converting the image data received from the irradiation light photographing unit 40 from analog data to digital data, image data, and data such as a deviation amount described later are temporarily stored. A memory 52 for holding the data, a CPU 53 for performing various data processing while accessing the memory 52, and a driver 54 for operating the aperture drive unit 39 based on a command from the CPU 53. Are electrically connected to each other. The A / D converter 51 is electrically connected to the CCD camera 41 of the irradiation light photographing unit 40, and the driver 54 is electrically connected to the aperture driver 39.

  Further, the CPU 53 implements a deviation amount calculation unit 531 and an offset correction amount determination unit 532. The deviation amount calculation unit 531 calculates a deviation amount between each imaging position of the plurality of regular patterns on the upper surface of the substrate and the ideal imaging position. The offset correction amount determination unit 532 determines an offset correction amount that can reduce the maximum shift amount based on the shift amount calculated by the shift amount calculation unit 531. However, the “offset correction amount” is a value that defines the direction and distance of movement of the aperture AP, as will be described later. Each of these functional units may be realized by the CPU 53 executing a program, or may be realized in a circuit (hardware) manner.

<A-3. Processing behavior>
<Overall flow>
An image distortion correction processing operation according to the first aspect will be described. The correction process described below may be performed every time the drawing data is changed, or may be performed every time the magnification setting of the projection optical system 38 is changed. Further, it may be performed periodically at predetermined intervals. Alternatively, it may be performed at the time of initial setting of the apparatus.

  In this correction processing, as shown in FIG. 6, first, image distortion in the X direction is corrected (step S1), and then image distortion in the Y direction is corrected (step S2). That is, the image distortion in each direction is corrected by adjusting the horizontal position of the aperture AP independently in each of the X direction and the Y direction.

<Flow of image distortion correction processing in the X direction>
Processing for correcting image distortion in the X direction will be described with reference to FIGS. FIG. 7 is a diagram showing a flow of image distortion correction processing in the X direction. FIG. 8 is a diagram illustrating a flow of the imaging position acquisition process. FIG. 9 is a diagram for explaining a change in the amount of deviation before and after the adjustment of the aperture position. FIG. 9B shows a state in which a plurality of regular patterns (ideal imaging positions) that should be imaged at equal intervals in the X direction are imaged at unequal intervals due to lens distortion. Show. FIGS. 9 (a) and 9 (c) are diagrams for easily showing the deviation amounts of the plurality of regular patterns from the ideal image formation position. The horizontal axis represents the ideal image formation position of each pattern. The amount of deviation in the + X direction from the ideal imaging position is shown on the vertical axis (the same applies to FIG. 11 referred later). In particular, FIG. 9A shows the amount of deviation before adjustment of the aperture position. FIG. 9C shows the amount of deviation after adjustment of the aperture position.

  In the following description, the aperture AP is provided with one or more slit rows formed of n slits SL formed at equal intervals in the X direction, and n pieces in the X direction are irradiated by one irradiation. The pattern is drawn on the substrate (n is about 170, for example). Hereinafter, among these n patterns, the i-th pattern in the X direction is referred to as a pattern T (i) (i is a natural number of 1 to n).

  Please refer to FIG. First, in the initial state (more specifically, the lens magnification in the initial state and the aperture AP position in the initial state), each pattern T (1), T (2),... T (n) imaged on the substrate. The image forming position information indicating the image forming position in the X direction (that is, the X coordinate value of the image forming position) is acquired (step S11). However, it is not necessary to acquire all the imaging position information of the n patterns T (1), T (2),... T (n), and in this embodiment, at least the slit row (in the X direction) Three or more patterns (for example, patterns every predetermined number (for example, two)) T (1), T (4) including patterns T (1), T (n) formed at both ends of the slit row) , T (7),... T (n) are sample patterns, and these sample patterns (hereinafter referred to as sample patterns S (1), S (2), S (3),... S (m)) The imaging position information x (1), x (2), x (3),... X (m) may be acquired (see FIG. 9B). This situation is the same in the process of step S14 described later. If the number of sample patterns is increased, the accuracy of the correction process can be increased. Conversely, if the number of sample patterns is reduced, the processing speed can be increased.

  Here, the acquisition processing of the imaging position information will be described with reference to FIG. FIG. 8 is a diagram illustrating a flow of the imaging position information acquisition process. First, the control unit 50 operates the main scanning mechanism 25 to move the base plate 24 so that the CCD camera 41 is positioned below the head unit 30 (the state shown in FIGS. 1 and 2). Then, the CCD camera 41 is moved in the sub-scanning direction while irradiating pulse light from each optical head 32, and the pulse light irradiated from each optical head 32 and passing through the aperture AP and the projection optical system 38 is detected by the CCD camera 41. A picture is taken (step S121). Here, the image data acquired by photographing is transmitted from the CCD camera 41 to the A / D conversion unit 51 in the control unit 50.

  Subsequently, the A / D converter 51 converts the image data received from the CCD camera 41 in step S121 from analog data to digital data, and stores the converted image data in the memory 52 (step S122).

  Subsequently, the CPU 53 reads the image data stored in the memory 52 in step S122, and analyzes the read image data, whereby each of the sample patterns S (1), S (2),... S (m). Image position information x (1), x (2),... X (m) are acquired (step S123). Thus, the imaging position information is acquired.

  Refer to FIG. 7 again. When the processing at step S11 is executed and the imaging position information in the initial state is acquired, subsequently, the imaging position information x (1), x (2),... X (m) acquired at step S11. Based on the above, the magnification and focus of the lens of the projection optical system 38 are adjusted (step S12). More specifically, the control unit 50 determines the interval d between the imaging positions of the pattern T (1) and the pattern T (n) (that is, the light fluxes that have passed through the slits SL positioned at both ends of each slit row). The separation distance between the imaging positions) is the interval do between the ideal imaging positions of the patterns T (1) and T (n) (that is, the ideal imaging position of the pattern T (1) and the ideal of the pattern T (n). The lens magnification of the projection optical system 38 is adjusted so as to coincide with the separation distance from the imaging position (see FIG. 9B).

  Subsequently, the position of the aperture AP is adjusted so that the imaging positions of the pattern T (1) and the pattern T (n) coincide with the ideal imaging position (step S13). In addition, the process of step S13 is not necessarily essential. This is because the position of the aperture AP is adjusted more accurately in later processing (step S17). For example, this processing may be executed only when it is determined that the imaging positions of the patterns T (1) and T (2) are significantly deviated from the ideal imaging position by a predetermined value. .

  Subsequently, a result indicating the imaging position in the X direction of each pattern T (1), T (2),... T (n) imaged on the substrate under the lens magnification adjusted in step S12. Image position information (that is, the X coordinate value of the imaging position) is acquired (step S14). However, here, as described above, it is not necessary to acquire all the imaging position information of the n patterns T (1), T (2),... T (n), and the sample patterns S (1), The imaging position information x (1), x (2),... X (m) for S (2),. The process of step S14 may be performed in the same manner as the process of step S11 (that is, the imaging position information may be acquired based on image data acquired by photographing pulsed light with the CCD camera 41). ). In addition, when the center position of zooming is accurately known (that is, when the lens of the projection optical system 38 is zoomed, a plurality of patterns formed on the upper surface of the substrate are uniformly changed around which position). If it is known whether the image is to be doubled), the imaging position information after zooming is calculated by calculation based on the imaging position information acquired in step S11 without having to capture the pulsed light again. Also good.

  Subsequently, the deviation amount calculation unit 531 performs sample patterns S (1), S (2) based on the imaging position information x (1), x (2),... X (m) acquired in step S14. ,... S (m) are calculated for displacements Px (1), Px (2),. However, this shift amount is a value indicating how much the image forming position of each pattern is shifted from the ideal image forming position in the + X direction, as shown in FIG. 9B. That is, when the imaging position of the sample pattern S (i) is shifted in the + X direction from the ideal imaging position, the shift amount Px (i) takes a positive value. On the other hand, when there is a deviation in the −X direction from the ideal imaging position, the deviation Px (i) takes a negative value. In step S12, the imaging positions (patterns T (1) and T (n) (that is, sample patterns S (1) and S (m)) of the light beams that have passed through the slits SL located at both ends of the slit row. Since the lens magnification of the projection optical system 38 is adjusted so that the interval d of (imaging imaging position) coincides with the interval do of each ideal imaging position, the deviation amount among the deviation amounts calculated in step S13. The values of Px (1) and deviation Px (m) are the same value. In particular, when the process of step S13 is executed and the position of the aperture AP is adjusted so that the imaging positions of the pattern T (1) and the pattern T (n) coincide with the ideal imaging position, the amount of deviation The values of Px (1) and deviation Px (m) are both “0”.

  Subsequently, the offset correction amount determination unit 532 includes the deviation amounts Px (1), Px (2),... For the sample patterns S (1), S (2),. Based on Px (m), the offset capable of reducing the maximum deviation PxM (the maximum value among the deviations Px (1), Px (2),... Px (m) (see FIG. 9A)). A correction amount Qx is determined (step S16). Details of the process of determining the offset correction amount Qx will be specifically described later.

  Subsequently, the CPU 53 operates the aperture drive unit 39 via the driver 54, and adjusts the position of the aperture AP based on the offset correction amount Qx calculated in step S16 (step S17). However, the value of the offset correction amount Qx determined in step S16 defines the distance by which the aperture AP should be moved in the + X direction. That is, when the offset correction amount Qx is a positive value “+ t”, the CPU 53 moves the aperture AP in the + X direction by “t / m (where“ m ”is the lens magnification of the projection optical system 38). On the other hand, when the offset correction amount Qx is a negative value “−t”, the aperture AP is moved by “t / m” in the −X direction. When the position of the aperture AP is moved based on the offset correction amount Qx, as shown in FIG. 9B, the imaging positions of a plurality of regular patterns T (1), T (2),... T (n) Shifts uniformly. Here, as the offset correction amount Qx, a value capable of reducing the maximum deviation amount PxM is obtained. Therefore, by moving the aperture AP based on the offset correction amount Qx, as shown in FIG. The maximum shift amount PxM of a plurality of regular patterns formed on the substrate can be reduced.

  Through the above processing, the image distortion in the X direction is corrected. As described above, when the correction process for the X direction is completed, the correction process for the Y direction is subsequently executed (FIG. 6). The correction process for the Y direction is performed by executing the same process as described above for the Y direction.

<Determination method of offset correction amount>
As described above, the offset correction amount determination unit 532 includes the deviation amounts Px (1), Px (2),... Px (m) for the sample patterns S (1), S (2),. Based on the above, an offset correction amount Qx that can reduce the maximum shift amount PxM is determined (step S16 in FIG. 7). There are two modes for determining the offset correction amount Qx. In the first aspect, the offset correction amount is calculated using the maximum value and the minimum value among the deviation amounts Px (1), Px (2),... Px (m). In the second mode, the offset correction amount is calculated using an average value of the shift amounts Px (1), Px (2),... Px (m). The offset correction amount determination unit 532 may calculate the offset correction amount in any manner. Below, each aspect is demonstrated concretely.

<Calculation processing of offset correction amount according to first aspect>
The offset correction amount calculation process according to the first aspect will be described with reference to FIG. FIG. 10 is a diagram showing the flow of the offset correction amount calculation process.

  First, the maximum value K1 and the minimum value K2 among the deviation amounts Px (1), Px (2),... Px (m) for the sample patterns S (1), S (2),. Is extracted (step S101). That is, the maximum value K1 is a value indicating the maximum shift amount in the + X direction, and the minimum value K2 is a value indicating the maximum shift amount in the -X direction. In other words, the maximum value K1 and the minimum value K2 are values indicating the peak of the deviation amount in the X direction.

  Subsequently, an average value Kav of the maximum value K1 and the minimum value K2 extracted in step S101 is calculated and acquired as an offset amount (step S102).

  Subsequently, a value obtained by reversing the sign of the offset amount (that is, the average value Kav) calculated in step S22 is acquired as the offset correction amount Qx (step S23).

  That is, the offset correction amount Qx is obtained by executing the calculation shown in (Equation 1).

  Qx = (K1 + K2) / (-2) (Equation 1)

  For example, as shown in FIG. 9A, the imaging positions of the sample patterns S (1), S (2),... S (m) are biased in the + X direction, and the shift amount Px (1) at this time ), Px (2),..., Px (m), where the maximum value K1 and the minimum value K2 are “4” and “0”, respectively, the offset correction amount Qx is “−2” from (Equation 1). Become.

  In this case, the aperture AP is moved by “2” in the −X direction by executing the process of step S17 (FIG. 7). As a result, as shown in FIG. 9B, the imaging positions of the plurality of regular patterns T (1), T (2),... T (n) are uniformly shifted by “2” in the −X direction. To do. As a result, as shown in FIG. 9C, the maximum value of the deviation amount after the adjustment of the aperture position is “2”, and the minimum value is “−2”. That is, the maximum deviation PxM is reduced from “4” to “2” by adjusting the aperture position.

  For example, as shown by the phantom lines in FIG. 11A, the imaging positions of the sample patterns S (1), S (2),... S (m) are biased in the −X direction. Assuming that the maximum value K1 and the minimum value K2 of the deviation amounts Px (1), Px (2),... Px (m) are “0” and “−3”, respectively, ) Is +1.5.

  In this case, the aperture AP is moved by “1.5” in the + X direction by executing the process of step S17 (FIG. 7). As a result, the imaging positions of the plurality of regular patterns T (1), T (2),... T (n) are uniformly shifted by “1, 5” in the + X direction. As a result, as shown by the solid line in FIG. 11A, the maximum value of the deviation after adjustment of the aperture position is “+1.5”, and the minimum value is “−1.5”. That is, the maximum deviation PxM is reduced from “3” to “1.5” by adjusting the aperture position.

  Further, for example, as shown by the phantom lines in FIG. 11B, the imaging positions of the sample patterns S (1), S (2),... S (m) are S-shaped in the −X direction and the −X direction. When the maximum value K1 and the minimum value K2 of the shift amounts Px (1), Px (2),... Px (m) are “5” and “−2”, respectively, The offset correction amount Qx is “−1.5” from (Equation 1).

  In this case, the aperture AP is moved by “1.5” in the −X direction by executing the process of step S17 (FIG. 7). Thus, the imaging positions of the plurality of regular patterns T (1), T (2),... T (n) are uniformly shifted by “1, 5” in the −X direction. As a result, as shown by the solid line in FIG. 11B, the maximum value of the deviation after adjustment of the aperture position is “−3.5”, and the minimum value is “−3.5”. That is, the maximum deviation PxM is reduced from “5” to “3.5” by adjusting the aperture position. The above is the offset correction amount calculation processing according to the first aspect.

<Calculation processing of offset correction amount according to second aspect>
The offset amount calculation processing according to the second aspect will be described with reference to FIG. FIG. 12 is a diagram illustrating the flow of the offset correction amount calculation process.

  First, an average value Pav of deviation amounts Px (1), Px (2),... Px (m) for each of the sample patterns S (1), S (2),. (Step S201).

  Subsequently, a value obtained by inverting the sign of the offset amount (that is, the average value Pav) acquired in step S201 is acquired as the offset correction amount Qx (step S32).

  That is, the offset correction amount Qx is acquired by executing the calculation shown in (Expression 2) (where “m” is the number of sample patterns (ie, measurement points)).

  Qx = (Px (1) + Px (2) +... + Px (m)) / (− m) (Equation 2)

  For example, the deviation amounts Px (1), Px (2),... Px (m) of the sample patterns S (1), S (2),... S (m) are “0”, “1”, “2”, respectively. ”,“ 3 ”,“ 4 ”,“ 3 ”,“ 2 ”,“ 1 ”, and“ 0 ”, the offset correction amount Qx is“ −2 ”from (Equation 2).

  In this case, the aperture AP is moved by “2” in the −X direction by executing the process of step S17 (FIG. 7). As a result, the imaging positions of the plurality of regular patterns T (1), T (2),... T (n) are uniformly shifted by “2” in the −X direction (see FIG. 9B). As a result, the maximum value of the deviation amount after adjustment of the aperture position is “2”, and the minimum value is “−2”. That is, the maximum shift amount PxM is reduced from “4” to “2” by adjusting the aperture position. The above is the offset correction amount calculation processing according to the second aspect.

<A-4. effect>
According to the image distortion correction function according to the first aspect, the offset correction amount Qx is calculated based on the shift amounts Px (1), Px (2),... Px (m), and based on the obtained offset correction amount Qx. Since the position of the aperture AP is adjusted, the imaging positions of the plurality of regular patterns T (1), T (2),... T (n) can be shifted uniformly. As a result, the maximum deviation PxM can be reduced and kept within a predetermined allowable range.

  Further, since the position of the aperture AP is adjusted in each of the X direction and the Y direction, the maximum deviation amount can be kept within a predetermined allowable range in both directions.

  In addition, the lens magnification of the projection optical system 38 is adjusted so that the imaging positions of the light beams that have passed through the slits SL located at both ends of the slit row formed in the direction related to the adjustment coincide with the ideal imaging positions. In addition, since the offset correction amount Qx is calculated, the appropriate offset correction amount Qx can be calculated efficiently.

  In particular, in the offset correction amount calculation processing according to the first aspect, based on the average value Kav of the maximum value K1 and the minimum value K2 of the shift amounts Px (1), Px (2),... Px (m). To determine the offset correction amount Qx. That is, by extracting the peak value of the deviation amount in the direction related to the adjustment and calculating the offset correction amount Qx using the peak value, the offset correction amount Qx that can reduce the maximum deviation amount PxM can be simply and It can be calculated efficiently.

  In particular, in the offset correction amount calculation processing according to the second aspect, the offset correction amount Qx is determined based on the average value Pav of the shift amounts Px (1), Px (2),... Px (m). The offset correction amount Qx that can reduce the maximum shift amount PxM can be easily obtained by taking into account the shift amount for each of the sample patterns S (1), S (2),... S (m).

<B. Image Distortion Correction Function According to Second Mode>
<B-1. Principle of correction>
In the second mode, image distortion is corrected by adjusting both the horizontal position of the aperture AP and the lens magnification of the projection optical system 38. The principle of this correction will be described. As described above, due to the lens distortion of the projection optical system 38, the imaging positions of a plurality of regular patterns are shifted from the ideal imaging position (deviation amounts Px (1), Px (2),... Px (M)) occurs (for example, see the upper part of FIG. 15B). In the second mode, first, the deviation of the deviation is eliminated by adjusting the lens magnification of the projection optical system 38 to an appropriate value (FIG. 15 (b) lower stage). Then, by moving the aperture AP, the imaging positions of a plurality of regular patterns are uniformly shifted in a predetermined direction (FIG. 16B). Thereby, reduction of the maximum deviation amount is realized (FIG. 16C).

<B-2. Functional configuration>
The image distortion correction function according to the second aspect will be described with reference to FIG. FIG. 13 is a diagram schematically showing only the part related to the image distortion correction function according to the second aspect of the configuration of the pattern drawing apparatus 1. In the following, only differences from the first image distortion correction function will be described. In FIG. 13, the same functional parts as those in FIG. 5 are denoted by the same reference numerals.

  The pattern drawing apparatus 1 implements an image distortion correction function using the irradiation light photographing unit 40, the aperture driving unit 39, the projection optical system 38, and the control unit 50. Inside the control unit 50, an A / D conversion unit 51, a memory 52, a CPU 53, and a driver 54 are provided, and these are electrically connected to each other. The A / D converter 51 is electrically connected to the CCD camera 41 of the irradiation light photographing unit 40, and the driver 54 is electrically connected to the aperture driver 39. The CPU 53 is electrically connected to the projection optical system 38 and adjusts the lens position of the projection optical system 38 to adjust the lens magnification to a predetermined value.

  Further, the CPU 53 implements a deviation amount calculation unit 531, an offset correction amount determination unit 532, an approximate straight line calculation unit 533, and a lens magnification calculation unit 534. The approximate straight line calculation unit 533 calculates a linear function (approximate straight line) obtained by approximating the deviation amount by the least square method. The lens magnification calculator 534 calculates the lens magnification of the projection optical system 38 that can make the deviation of the deviation amount uniform based on the approximate line acquired by the approximate line calculator 533. Each of these functional units may be realized by the CPU 53 executing a program, or may be realized in a circuit (hardware) manner.

<B-3. Processing action>
<Overall flow>
The image distortion correction processing operation according to the second aspect will be described. In the second image distortion correction process, as in the first image distortion correction process, first, the image distortion in the X direction is corrected, and then the image distortion in the Y direction is corrected (FIG. 6). reference).

<Flow of image distortion correction processing in the X direction>
The flow of processing for correcting image distortion in the X direction will be described with reference to FIGS. FIG. 14 is a diagram showing a flow of image distortion correction processing in the X direction. FIG. 15 is a diagram for explaining a change in the deviation amount before and after the adjustment of the lens magnification, and FIG. 16 is a diagram for explaining a change in the deviation amount before and after the adjustment of the aperture position.

  Refer to FIG. First, the control unit 50 forms imaging position information x (1), x (2), X (X) of each sample pattern S (1), S (2),... S (m) formed on the substrate. ... X (m) is acquired (step S21), and based on the acquired imaging position information x (1), x (2),. (Step S22), and if necessary, the position of the aperture AP is further adjusted (step S23). Subsequently, the sample patterns S (1), S (2),... S (m) formed on the substrate under the lens magnification (initial magnification Mo) adjusted in step S22 in the X direction. The imaging position information x (1), x (2),... X (m) is acquired (step S24). Subsequently, based on the imaging position information x (1), x (2),... X (m) acquired in step S24, the deviation amount calculation unit 531 performs sample patterns S (1), S (2). ,... S (m) are calculated for deviations Px (1), Px (2),... Px (m) (step S25). Since the processes in steps S21 to S25 are the same as those in steps S11 to S15 related to the first image distortion correction process (FIG. 7), detailed description thereof is omitted.

  When the deviation amounts Px (1), Px (2),... Px (m) are calculated for each of the sample patterns S (1), S (2),... S (m), then the CPU 53 Based on the respective deviation amounts Px (1), Px (2),... Px (m), the lens magnification M of the projection optical system 38 capable of making the deviation of the deviation amount uniform is calculated (step S26). Details of the processing for calculating the lens magnification M will be specifically described later.

  Subsequently, the CPU 53 changes the lens magnification of the projection optical system 38 to the lens magnification M calculated in step S26 (step S27).

  Subsequently, the control unit 50 forms imaging position information x ′ (1) of each sample pattern S (1), S (2),... S (m) under the lens magnification M adjusted in step S27. , X ′ (2),... X ′ (m) are acquired (step S28). This process may be performed similarly to the process of step S21 (that is, the imaging position information may be acquired based on image data acquired by photographing pulsed light with the CCD camera 41). Further, when the center position of zooming is accurately known, imaging position information x ′ (1), x ′ (2),. x ′ (m) may be calculated.

  Subsequently, the deviation amount calculation unit 531 determines the sample patterns S (1), S based on the imaging position information x ′ (1), x ′ (2),... X ′ (m) acquired in step S28. (2),... S (m) The shift amounts Px ′ (1), Px ′ (2),... Px ′ (m) are calculated (step S29). This process is the same as step S25. Here, since the lens magnification of the projection optical system 38 is changed from the initial magnification Mo to the new lens magnification M in the previous step S27, the sample patterns S (1), S (2),... S (m). The deviation amounts Px ′ (1), Px ′ (2),... Px ′ (m) are approximated by a straight line having a slope of “0” as shown in FIG. . That is, the deviation of each pattern is uniform.

  Subsequently, the offset correction amount determination unit 532 determines the maximum shift amount PxM (each shift amount Px based on the shift amounts Px ′ (1), Px ′ (2),... Px ′ (m) acquired in step S29. An offset correction amount Qx that can reduce '(1), Px' (2), ... Px '(m)) is determined (step S30). This process is the same as the process of step S16 (FIG. 7). In the determination process of the offset correction amount Qx here, either of the two determination processing modes described above may be employed.

  Subsequently, the CPU 53 operates the aperture drive unit 39 via the driver 54, and adjusts the position of the aperture AP based on the offset correction amount Qx calculated in step S30 (step S31). This process is the same as step S17 (FIG. 7). When the position of the aperture AP is moved based on the offset correction amount Qx, as shown in FIG. 16B, the imaging positions of a plurality of regular patterns T (1), T (2),... T (n) Shifts uniformly. Here, the deviation of the amount of deviation is made uniform by adjusting the lens magnification first (FIG. 16A). In this state, by adjusting the aperture position and uniformly shifting the imaging positions of the patterns T (1), T (2),... T (n), as shown in FIG. It is possible to effectively reduce the amount of deviation. Therefore, the maximum deviation amount PxM can be greatly reduced.

  Through the above processing, the image distortion in the X direction is corrected. As described above, when the correction process for the X direction is completed, the correction process for the Y direction is subsequently executed. The correction process for the Y direction is performed by executing the same process as described above for the Y direction.

<Lens magnification calculation method>
As described above, the CPU 53 shifts based on the shift amounts Px (1), Px (2),... Px (m) for the sample patterns S (1), S (2),. The lens magnification M of the projection optical system 38 capable of making the quantity deviation uniform is calculated (step S26 in FIG. 14). The calculation process of the lens magnification M will be described with reference to FIG. FIG. 17 is a diagram showing a flow of processing for calculating the lens magnification M. In the following, FIG. 15 will be referred to as appropriate.

  First, the approximate straight line calculation unit 533 acquires a linear function (approximate straight line L) that approximates the shift amounts Px (1), Px (2),... Px (m) (step S301). More specifically, as shown in FIG. 15A, a straight line that approximates the relationship between the ideal image formation position (horizontal axis in FIG. 15) and the shift amount (vertical axis in FIG. 15) of each pattern is minimized. Calculated by the square method and obtained as an approximate straight line L.

  Subsequently, the lens magnification calculator 534 calculates the lens magnification M based on the approximate straight line L acquired in step S301. More specifically, this process is performed as follows. First, the ideal imaging positions (patterns T (1), T (n) (that is, sample patterns S (1), S (m)) of the light beams that have passed through the slits SL located at both ends of each slit row are ideal. At the imaging position), displacement amounts PLx (1) and PLx (m) obtained from the approximate straight line L are acquired (FIG. 15A) (step S302).

  Subsequently, a new lens magnification M is calculated based on the deviations PLx (1) and PLx (m) calculated in step S302 (step S303). More specifically, the slope of the linear function obtained by approximating the shift amounts Px ′ (1), Px ′ (2),... Px ′ (m) acquired under the new lens magnification M by the least square method is obtained. The lens magnification M so as to be “0” is calculated. Such a lens magnification M indicates the separation distance between the ideal image formation positions (ideal image formation positions of the patterns S (1) and S (m)) of the light beams that have passed through the slits SL located at both ends of each slit row. If “Dx”, it is obtained by executing the calculation shown in (Expression 3).

  M = Mo * (Dx−PLx (1) −PLx (m)) / Dx (Equation 3)

  The initial magnification Mo is set so that the imaging positions of the sample patterns S (1) and S (m) coincide with the ideal imaging position. Therefore, under the initial magnification Mo, as shown in the upper part of FIG. 15B, the separation distance between the imaging position of the sample pattern S (1) and the imaging position of the sample pattern S (m) is “Dx”. It has become. On the other hand, at the lens magnification M after adjustment, as shown in the lower part of FIG. 15B, the separation distance between the imaging position of the sample pattern S (1) and the imaging position of the sample pattern S (m) is “ “Dx” is changed to “Dx ′” (where Dx ′ = Dx−PLx (1) −PLx (m)). As a result, as shown in FIG. 15C, the inclination of the approximate straight line L relating to the shift amounts Px ′ (1), Px ′ (2),... Px ′ (m) obtained under the new lens magnification M. Becomes “0”. The fact that the slope of the approximate straight line L is “0” means that the deviation of the deviation amount in the X direction is eliminated uniformly in the deviation amounts Px ′ (1), Px ′ (2),... Px ′ (m). It means that The above is the lens magnification M calculation process.

<B-4. effect>
According to the image distortion correction function according to the second aspect, the offset correction amount Qx is calculated after eliminating the deviation of the shift amount by adjusting the magnification of the lens, and the aperture is calculated based on the obtained offset correction amount Qx. Since the position of the AP is adjusted, the deviation of each of the plurality of regular patterns T (1), T (2),... T (n) from the ideal imaging position can be effectively reduced. .

<3. Modification>
The embodiment of the present invention has been described above, but the present invention is not limited to the above example. For example, the pattern drawing apparatus 1 has seven optical heads 32, but the number of optical heads is not limited to seven. The pattern drawing apparatus 1 uses the pulsed light of the laser oscillator 34, but the light source and the irradiation method are not limited to the above examples. For example, a configuration using not only single-wavelength light but also light or ultraviolet light in which a plurality of wavelengths are mixed may be used, and a configuration may be used that irradiates continuous light instead of pulsed light.

  Further, the pattern drawing apparatus 1 is configured to adjust the lens magnification using the interval between the image forming positions of the patterns on both ends before obtaining the shift amount used for calculating the offset amount (see FIG. In step S12) of FIG. 7, this lens magnification adjustment process is not always essential. For example, this processing may be omitted when it is guaranteed that the lens magnification has been adjusted to an appropriate value. When the lens magnification adjustment process is not performed, the pattern formed at both ends of the slit row formed in the direction to be adjusted is not necessarily included in the sample pattern. At least one pattern may be used as the sample pattern.

  In addition, the pattern drawing apparatus 1 is intended for processing the glass substrate 9 for the color filter, but other substrates such as a semiconductor substrate, a printed board, and a glass substrate for a plasma display device are intended for processing. Also good.

It is a side view of the pattern drawing apparatus which concerns on embodiment of this invention. It is a top view of the pattern drawing apparatus which concerns on embodiment of this invention. It is a figure which shows an example of an aperture. It is the block diagram which showed the connection structure between a control part and each part. It is the figure which showed typically only the part in connection with the image distortion correction function which concerns on a 1st aspect among the structures of a pattern drawing apparatus. It is a figure which shows the flow of the whole correction process. It is a figure which shows the flow of the correction process of the image distortion about a X direction. It is a figure which shows the flow of an acquisition process of imaging position information. It is a figure for demonstrating the change of the deviation | shift amount before and behind a correction process. It is a figure which shows the flow of the calculation process of the offset correction amount which concerns on a 1st aspect. It is a figure for demonstrating the change of the deviation | shift amount before and behind a correction process. It is a figure which shows the flow of the calculation process of the offset correction amount which concerns on a 2nd aspect. It is the figure which showed typically only the part in connection with the image distortion correction function which concerns on a 2nd aspect among the structures of a pattern drawing apparatus. It is a figure which shows the flow of the correction process of the image distortion about a X direction. It is a figure for demonstrating the change of the deviation | shift amount before and behind a correction process. It is a figure for demonstrating the change of the deviation | shift amount before and behind a correction process. It is a figure which shows the flow of a process which calculates the lens magnification M.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Pattern drawing apparatus 9 Board | substrate 10 Stage 20 Stage drive part 30 Head part 32 Optical head 38 Projection optical system 39 Aperture drive part 40 Irradiation light imaging | photography part 41 Camera 50 Control part 531 Deviation amount calculation part 532 Offset correction amount determination part 533 Approximate straight line Calculation unit 534 Lens magnification calculation unit AP aperture

Claims (10)

A pattern drawing apparatus for drawing a plurality of regular patterns on a substrate on which a photosensitive material is formed,
Mask means for partially shielding light from the light source by a light shielding plate having a plurality of openings to form a plurality of light fluxes;
An image forming means for forming a plurality of regular patterns on a substrate by scaling the plurality of light beams by a lens,
An imaging position measuring means for measuring at least one of the plurality of regular patterns as a sample pattern and measuring an imaging position of each of the sample patterns;
For each of the sample patterns, a deviation amount calculating means for calculating a deviation amount between the imaging position and an ideal imaging position, which is a position that should theoretically be imaged,
An offset correction amount determining means for determining an offset correction amount of the mask means based on the deviation amount calculated for each of the sample patterns;
Mask position adjusting means for adjusting the position of the mask means based on the offset correction amount;
A pattern drawing apparatus comprising: The pattern drawing apparatus according to claim 1,
The plurality of openings are formed at equal intervals in a predetermined direction,
The sample pattern is at least three patterns including patterns formed at both ends in a predetermined direction among the plurality of regular patterns;
The distance between the imaging positions of the light beams that have passed through the openings located at both ends of the opening row formed in the predetermined direction is the same as the distance between both ends at the ideal imaging position. Lens magnification determining means for determining the magnification,
A pattern drawing apparatus comprising: The pattern drawing apparatus according to claim 1, wherein:
The amount of deviation is a value indicating how much the imaging position deviates from the ideal imaging position in a predetermined direction,
The offset correction amount determining means is
The maximum value and the minimum value of the deviation amounts calculated for each of the sample patterns are extracted, and the offset correction amount for the predetermined direction is calculated based on the average value of the maximum value and the minimum value. A pattern drawing apparatus characterized by determining. The pattern drawing apparatus according to claim 1, wherein:
The amount of deviation is a value indicating how much the imaging position deviates from the ideal imaging position in a predetermined direction,
The offset correction amount determining means is
The pattern drawing apparatus, wherein the offset correction amount for the predetermined direction is determined based on an average value of the deviation amounts calculated for each of the sample patterns. The pattern drawing apparatus according to any one of claims 1 to 4,
The amount of deviation is a value indicating how much the imaging position deviates from the ideal imaging position in a predetermined direction,
Approximate line calculation means for obtaining a linear function approximating the deviation amount calculated for each of the sample patterns by a least square method;
Based on the linear function, calculating the magnification of the lens that gives a deviation amount such that the slope of the linear function approximated by the least square method is 0, and obtaining an appropriate magnification,
Lens magnification adjusting means for adjusting the magnification of the lens to the appropriate magnification;
A pattern drawing apparatus comprising: The light from the light source is partially blocked by the light-shielding plate having a plurality of openings to form a plurality of light beams, and the plurality of light beams are scaled by a lens and connected to a substrate on which a photosensitive material is formed. A correction method for correcting a drawing position in a pattern drawing apparatus that draws a plurality of regular patterns on the substrate by imaging,
Measuring at least one of the plurality of regular patterns as a sample pattern, and measuring an imaging position in each predetermined direction of the sample pattern;
For each of the sample patterns, calculating a deviation amount indicating how much the imaging position is displaced in the predetermined direction from the ideal imaging position;
Determining an offset correction amount for the predetermined direction of the light shielding plate based on the shift amount calculated for each of the sample patterns;
Adjusting the position of the light shielding plate in the predetermined direction based on the offset correction amount;
A distortion correction method comprising: The light from the light source is partially blocked by the light-shielding plate having a plurality of openings to form a plurality of light beams, and the plurality of light beams are scaled by a lens and connected to a substrate on which a photosensitive material is formed. A correction method for correcting a drawing position in a pattern drawing apparatus that draws a plurality of regular patterns on the substrate by imaging,
Measuring at least one of the plurality of regular patterns as a sample pattern and measuring an imaging position in a predetermined direction of each of the sample patterns;
For each of the sample patterns, calculating a deviation amount indicating how much the imaging position is displaced in the predetermined direction from the ideal imaging position;
Obtaining a linear function approximating the deviation amount calculated for each of the sample patterns by a least square method;
Calculating a magnification of the lens that gives a deviation amount such that the slope of the linear function approximated by the least squares method is 0 based on the linear function, and obtaining the appropriate magnification;
Adjusting the magnification of the lens to the appropriate magnification;
For each of the sample patterns, calculating a deviation amount under the appropriate magnification;
Determining an offset correction amount for the predetermined direction of the light shielding plate based on a shift amount under the appropriate magnification calculated for each of the sample patterns;
Adjusting the position of the light shielding plate in the predetermined direction based on the offset correction amount;
A distortion correction method comprising: The distortion correction method according to claim 6 or 7,
The plurality of openings are formed at equal intervals in a predetermined direction,
The sample pattern is at least three patterns including patterns formed at both ends in a predetermined direction among the plurality of regular patterns;
Before calculating the deviation amount,
The distance between the imaging positions of the light beams that have passed through the openings located at both ends of the opening row formed in the predetermined direction is the same as the distance between both ends at the ideal imaging position. Determining the magnification,
A distortion correction method comprising: The distortion correction method according to any one of claims 6 to 8,
The amount of deviation is a value indicating how much the imaging position deviates from the ideal imaging position in a predetermined direction,
In the step of determining the offset correction amount,
The maximum value and the minimum value of the deviation amounts calculated for each of the sample patterns are extracted, and the offset correction amount for the predetermined direction is calculated based on the average value of the maximum value and the minimum value. A distortion correction method characterized by determining. The distortion correction method according to any one of claims 6 to 9,
The plurality of openings are formed at equal intervals in a first direction and a second direction orthogonal to the first direction, respectively.
A distortion correction method comprising adjusting the position of the light shielding plate in the second direction after adjusting the position of the light shielding plate in the first direction.

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