JP2006272861A - Method for measuring position gap, exposure method and test pattern - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a position gap measuring method for measuring position gap between positions being written, respectively, with a different writing unit exactly. <P>SOLUTION: When each image Ga, Gb being written by a writing head 10a, 10b, respectively, is written on a recording medium 1 such that the position of the edge Fa, Fb matches each other, pixels Qa(n-5) and Qb(1) adjacent to a blank are written contiguously to the opposite sides of a blank pixel group J5 without writing the blank pixel group J5 consisting of a predetermined number of pixels including at least any one of pixels Qa(n) and Qb(1) in respective images Ga and Gb being written contiguously to each other while holding the edges Fa and Fb between and arranged in a direction intersecting the extending direction of the edge Fa, Fb. Position gap between the images Ga and Gb is measured based on the difference between the interval of the pixels adjacent to a blank written on the recording medium 1 and the length of the predetermined number of pixels. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a misregistration measurement method, an exposure method, and a test pattern, and more specifically, a misregistration measurement method for measuring a misregistration amount between images drawn on a recording medium in different drawing units, and the misregistration described above. The present invention relates to an exposure method in which exposure is performed by applying a measurement method, and a test pattern used in the positional deviation measurement method.

  2. Description of the Related Art Conventionally, as an example of a drawing apparatus that draws an image on a recording medium, a drawing apparatus having a plurality of exposure drawing heads equipped with a DMD (digital micromirror device) is known (Patent Literature). 1). Also, such a drawing apparatus is known that draws an image on the photosensitive material by conveying a drawing table on which a photosensitive material as a recording medium is placed in one direction under a drawing head. Yes. In the drawing apparatus, each drawing area by each drawing head is a rectangular (stripe) area extending in the direction in which the drawing table is conveyed.

Since the drawing apparatus draws an image on the same photosensitive material using drawing heads which are different drawing units, it is necessary to adjust the positional deviation between the drawing positions drawn by the drawing heads. In such a case, by drawing an image of a test pattern over each drawing position drawn by each drawing head on the photosensitive material, developing the photosensitive material on which the test pattern is drawn, and observing with a microscope, A positional deviation amount between the drawing positions is obtained, and a positional deviation between the drawing positions is corrected based on the positional deviation amount.
JP 2004-001244 A

  However, the method of drawing the image of the test pattern over each drawing position on the photosensitive material and obtaining the amount of positional deviation between the drawing positions is shifted in the direction in which a gap is generated between the images drawn at each drawing position. In this case, the distance between the edges of each image only needs to be measured, which is easy to measure, but when the images drawn at the respective drawing positions deviate in the overlapping direction, the position of the edge of each image is determined. There is a problem that it is difficult to determine and it is difficult to accurately measure the amount of misalignment between the drawing positions.

  The present invention has been made in view of the above circumstances, and provides a misregistration measuring method, an exposure method, and a test pattern that can more accurately measure the misregistration amount between the rendering positions of different rendering units. It is for the purpose.

  The misregistration measurement method of the present invention is a misregistration measurement method for measuring the misregistration amount between the rendering positions of different rendering units, and is adjacent to each other with the rendering position edges of the rendering units in between. Drawing a blank pixel group composed of a predetermined number of pixels arranged in a crossing direction that includes at least one of the respective pixels in each image to be drawn on and intersects the direction in which the edge extends. Rather, a blank adjacent pixel drawn so as to be adjacent to both sides of the blank pixel group is drawn, and the interval between each blank adjacent pixel drawn on the recording medium and the pixel length of the number of pixels of the blank pixel group are drawn. The positional deviation amount between each drawing position is measured based on the difference between the drawing positions.

  The recording medium is drawn with one or more types of reference areas in which a predetermined number of pixels are arranged for measuring the interval between blank adjacent pixels drawn on the recording medium. Can do.

  The misregistration measuring method includes at least one type of reference region in which a predetermined number of pixels are arranged to measure an interval between the blank adjacent pixels when performing drawing in the drawing unit. It can be drawn on the recording medium.

  The misregistration measurement method is a misregistration measurement method for measuring the misregistration amount between the rendering positions rendered on the recording medium in different rendering units, for example. When drawing each image on the recording medium for each drawing unit so that the positions of the edges of each image coincide with each other, the images should be drawn so as to be adjacent to each other with the edge where the positions coincide with each other. The blank pixel without drawing a blank pixel group including a predetermined number of pixels arranged in a crossing direction that includes at least one of the respective pixels in each image and intersects the extending direction of the edge. Drawing blank adjacent pixels drawn so as to be adjacent to both sides of the group, based on the difference between the spacing between each blank adjacent pixel drawn on the recording medium and the pixel length of the number of pixels of the blank pixel group It can be made to measure the positional deviation amount between the writing position.

  The exposure method of the present invention spatially modulates light emitted from a light source by each of a plurality of exposure heads each having a spatial light modulator in which a large number of modulation elements that modulate incident light are two-dimensionally arranged. Each of the obtained images is imaged on the same photosensitive material and exposed to the photosensitive material, and the positional deviation measuring method is the same as that when exposing the photosensitive material with the plurality of exposure heads. Measuring the amount of misalignment between the images formed by each of the exposure heads by applying to the measurement of the amount of misalignment between them, and forming each image on the photosensitive material by each exposure head based on the amount of misalignment It is characterized in that exposure of the photosensitive material by the exposure head is executed by correcting the positional deviation between the images.

  The test pattern of the present invention is a test pattern used for measuring a positional deviation amount of drawing positions of different drawing units, and is drawn adjacent to each other with an edge of each drawing position of the drawing unit in between. A blank pixel group consisting of a predetermined number of pixels arranged in a crossing direction that intersects the direction in which the edge extends and includes at least one of the respective pixels in each power image; and on both sides of the blank pixel group It is characterized in that it is provided with blank adjacent pixels that are drawn in adjacent drawing units.

  The test pattern may further include one or more types of reference regions in which a predetermined number of pixels are arranged.

  It is desirable that the predetermined number of pixels is determined according to an expected amount of positional deviation between the images.

  The length of pixels corresponding to the number of pixels in the blank pixel group means the length of a predetermined number of pixels arranged in the intersecting direction.

  According to the misregistration measuring method of the present invention, a misregistration measuring method for measuring the misregistration amount of the rendering position of different rendering units, which is adjacent to each other with an edge of the rendering position of each rendering unit in between. A blank pixel group consisting of a predetermined number of pixels arranged in a crossing direction that intersects with the extending direction of the edge and includes at least one of the respective pixels in each image to be drawn is drawn. Without drawing blank adjacent pixels drawn so as to be adjacent to both sides of the blank pixel group, and the interval between the blank adjacent pixels drawn on the recording medium and the number of pixels of the blank pixel group. Since the amount of positional deviation between the drawing positions is measured based on the difference from the length, the amount of positional deviation between the drawing positions of different drawing units can be measured more accurately.

  That is, even when the images drawn in the different drawing units are shifted in the overlapping direction, each blank adjacent pixel can be set as a non-drawing area in which no pixel is drawn. The boundary with the non-drawing area can be accurately determined. As a result, it is possible to accurately measure the interval between the blank adjacent pixels, so that the difference between the length between the blank adjacent pixels and the length of the blank pixel group composed of a predetermined number of pixels can be accurately obtained. The amount of positional deviation between the drawing positions of each drawing unit can be measured more accurately.

  In addition, the recording medium is drawn with one or more types of reference areas in which a predetermined number of pixels are arranged for measuring the interval between blank adjacent pixels drawn on the recording medium. By doing so, the interval between the blank adjacent pixels can be measured more easily.

  In addition, when drawing is performed in a drawing unit, one or more types of reference areas in which a predetermined number of pixels are arranged for measuring the interval between blank adjacent pixels are also drawn on the recording medium. If so, the interval between the blank adjacent pixels can be measured more easily.

  According to the test pattern of the present invention, the test pattern is used to measure the drawing position deviation amount of different drawing units, and is drawn so as to be adjacent to each other with an edge of each drawing position of the drawing unit in between. A blank pixel group including a predetermined number of pixels arranged in a crossing direction including at least one of the respective pixels in each image to be crossed and intersecting the extending direction of the edge, and both sides of the blank pixel group Since a blank adjacent pixel drawn in each drawing unit is provided so as to be adjacent to each other, it is possible to more accurately measure the amount of displacement between the drawing positions of different drawing units.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a conceptual diagram showing an embodiment of a positional deviation measuring method of the present invention, FIG. 2 is a diagram showing a reference area, FIG. 3 is a diagram showing a state of measuring a positional deviation amount between images, and FIG. ) Is a diagram showing a state in which there is no displacement between images, FIG. 3B is a diagram showing a state in which images overlap each other, and FIG. 3C is a diagram in which there is a gap between images. FIG. FIG. 4 is a diagram showing an example of an aspect in which an image is drawn on a recording medium by a drawing head.

  The misregistration measuring method according to the above-described embodiment is to obtain the misregistration amount between the rendering positions of the rendering heads 10a, 10b,. The amount of positional deviation between the drawing positions can be obtained by measuring the amount of positional deviation between the images Ga, Gb,... Drawn on the recording medium 1 by the drawing heads 10a, 10b,. . That is, the images Ga, Gb,... Are drawn at the drawing positions of the drawing heads 10a, 10b,.

  The method of measuring the amount of positional deviation between the drawing positions, that is, the amount of positional deviation between the images Ga, Gb... Is the same between any images (between the drawing positions). The measurement of the amount of misalignment will be described.

  In the above-described misalignment measuring method, the images Ga and Gb are recorded by the drawing heads 10a and 10b so that the edges Fa and Fb of the images Ga and Gb drawn by the drawing heads 10a and 10b different from each other coincide with each other. When drawing on the medium 1, the crossing direction includes the pixel Qa (n) in the image Ga that should be drawn so as to be adjacent to each other with the edges Fa and Fb interposed therebetween, and intersects the edges Fa and Fb. A blank pixel group J5 composed of a predetermined number of pixels arranged in the X direction in the figure, for example, the blank pixels without drawing five pixels from Qa (n-4) to Qa (n). Qa (n−5) and Qb (1) which are blank adjacent pixels which should be drawn so as to be adjacent to both sides of the group J5 are drawn, and Qa (b) which is a blank adjacent pixel drawn on the recording medium 1 is drawn. n-5) and Qb (1) And spacing between, based on a comparison of the length corresponding to the number of the predetermined pixels, each image Ga, measures the positional deviation amount between the Gb. The length corresponding to the predetermined number of pixels is the length of the predetermined number of pixels which is the number of pixels of the blank pixel group J5. The blank adjacent pixels that should be drawn so as to be adjacent to both sides of the blank pixel group may be one pixel in the image Ga and one pixel in the image Gb, or each of the images Ga and Gb. May be a plurality of pixels.

  The X direction and the Y direction are orthogonal to each other, and here, the amount of positional deviation in the X direction between the images Ga and Gb is measured. Note that the present invention can also be used for the measurement of the positional deviation amount in the X direction.

  Further, in the image Ga on the recording medium 1, a reference area indicating the length in the X direction for drawing the interval between each blank adjacent pixel is drawn. Here, the reference area has a length corresponding to each of the 5 pixels, 5 pixels ± 1 pixel, 5 pixels ± 2 pixels, and 5 pixels ± 3 pixels, which are the predetermined number of pixels. Adopt an area. That is, a reference region having a length corresponding to 2 pixels, 3 pixels, 4 pixels, 5 pixels, 6 pixels, 7 pixels, and 8 pixels is employed. It should be noted that when the images Ga and Gb are drawn without positional deviation, the interval between each blank adjacent pixel is an interval of 5 pixels.

  In FIG. 2, a reference region L (2) having a length of 2 pixels, a reference region L (3) having a length of 3 pixels, and a reference region L (4) having a length of 4 pixels, 5 Reference area L (5) having a length of pixels, reference area L (6) having a length of 6 pixels, reference area L (7) having a length of 7 pixels, and a length of 8 pixels Each of the reference regions L (8) having

  Note that the pixels NL adjacent to both sides of each reference area are drawn on the recording medium 1 so that the reference area is a non-drawing area, that is, a non-drawing area.

  Here, a blank space that is an interval between the pixel Qa (e-5) adjacent to the edge Fa of the image Ga drawn on the recording medium 1 and the pixel Qb (1) adjacent to the edge Fb of the image Gb. The case where the space | interval between adjacent pixels is calculated | required is demonstrated. Here, the interval between the blank adjacent pixels is obtained by comparing the interval between the blank adjacent pixels with the length of the reference regions L (2) to L (8).

  For example, as shown in FIG. 3A, when the interval between the blank adjacent pixels drawn on the recording medium 1 is equal to the length of the reference region L (5), the position between the images Ga and Gb is set. It can be seen that there is no deviation. That is, the edge Fa on the image Gb side in the image Ga and the position of the edge Fb on the image Ga side in the image Gb coincide with each other.

  Further, as shown in FIG. 3B, when the interval between the blank adjacent pixels is equal to the length of the reference region L (2), the image Ga and the image Gb are misaligned in the overlapping direction. It can be seen that the amount of displacement is 3 pixels. That is, the above three pixels are obtained by subtracting two pixels, which are intervals between blank adjacent pixels, from a predetermined five pixels, the edge Fa of the image Ga is located in the image Gb, and the image Gb It can be seen that the edge Fb is located in the image Ga.

  Further, as shown in FIG. 3C, when the length between the blank adjacent pixels is equal to the length of the reference region L (7), the image Ga and the image Gb are displaced in the direction in which the gap is generated. It can be seen that the amount of displacement is two pixels. That is, the above two pixels are obtained by subtracting a predetermined 5 pixels from 7 pixels that are intervals between blank adjacent pixels, and between the edge Fa of the image Ga and the edge Fb of the image Gb. It can be seen that there is a gap.

  As described above, according to the present invention, the non-drawing area can be left between the blank adjacent pixels even when the images are shifted in the overlapping direction. Can be measured. As a result, the amount of positional deviation between the images, that is, the amount of positional deviation between the drawing positions can be measured more accurately.

  As shown in FIG. 4, the drawing heads 10a and 10b draw a region R1 extending in the arrow X direction in the drawing on the recording medium 1, and the conveyance direction orthogonal to the X direction (the arrow Y direction in the drawing). ) And the images Ga and Gb may be drawn on the recording medium 1 arranged in parallel to the XY plane formed by the X direction and the Y direction.

  The test pattern of the present invention includes the blank pixel group and the blank adjacent pixel, and the test pattern may further include the reference region.

  Each of the drawing heads 10a and 10b may have a number of drawing elements arranged in a matrix. The following description also includes a description of the case where the positional deviation between the drawing positions of each drawing unit is measured using one drawing element as one drawing unit.

  Hereinafter, measurement of the amount of misalignment between the images Ga and Gb when the images Ga and Gb are drawn on the recording medium 1 by the drawing heads 10a and 10b having a large number of drawing elements arranged in the matrix form, etc. That is, measurement of the amount of positional deviation between the drawing positions of the drawing heads 10a and 10b will be described.

  FIG. 5 is a diagram showing the drawing elements arranged in a matrix provided in the drawing head, FIG. 6 is a diagram showing the relationship between the positions of the drawing elements and the positions of the pixels drawn by these drawing elements, and FIG. FIG. 8 is a diagram showing the relationship between each drawing element provided in the exposure head and the position of a pixel drawn by each drawing element, and FIG. 8 is between images drawn by a drawing head provided with drawing elements arranged in a matrix It is a figure which shows a mode that a positional deviation amount is measured, and Fig.8 (a) is a figure which shows the state which the clearance gap has produced between images. FIG. 8B is a diagram illustrating a state in which images overlap each other, and FIG. 8C is a diagram illustrating a state in which no positional deviation occurs between the images. FIG. 9 is a diagram showing a pixel row drawn by setting a blank pixel group, FIG. 10 is a diagram showing a pixel row drawn by setting a blank pixel group between the images, and FIG. 11 is a drawable area of the drawing head. 2 is a diagram showing a positional relationship between an image drawn by a drawing head in order to measure a positional deviation amount.

  As shown in FIG. 5, each of the drawing element A provided in the drawing head 10a and the drawing element B provided in the drawing head 10b are parallel to the XY plane with the drawing elements arranged in the X direction and the Y direction in the drawing. In a flat plane, the angle θ is inclined. When the drawing heads 10a and 10b are stopped without being conveyed and an image is drawn on the recording medium 1 by the drawing heads 10a and 10b, the drawing elements A (y, x: y = 1 to m, x = 1). To n) and pixels drawn on the recording medium 1 corresponding to the drawing element B (y, x: y = 1 to m, x = 1 to n) are as follows.

  That is, as shown in FIG. 6, for example, the drawing elements in the column (x) including m drawing elements ranging from the drawing element A (1, x) to the drawing element A (m, x) in the drawing head 10a are The drawing elements arranged obliquely with respect to the X direction and the Y direction and extending from the drawing element A (1, x + 1) to the drawing element A (m, x + 1) in the column (x + 1) adjacent to this column are the columns ( x) is arranged in parallel with the drawing element. By arranging the drawing elements obliquely, the interval in the X direction between the drawing elements adjacent to each other in the column (x) and the column (x + 1) can be made smaller than the interval between the drawing elements. Since the drawing head 10a is conveyed in the Y direction, the pixels Sa (y, x: y = 1 to m) drawn on the recording medium 1 by the drawing elements constituting the row (x) and the row ( The spacing in the X direction between adjacent pixels of pixels Sa (y, x + 1: y = 1 to m) drawn on the recording medium 1 by the drawing elements constituting x + 1) can be made precise.

  Here, in the drawing element A (y, x: y = 1 to m, x = 1 to n) and the drawing element B (y, x: y = 1 to m, x = 1 to n), 1 ≦ y ≦ Drawing elements in the range of 20 are used, and drawing elements in the range of 21 <y are not used. As a result, the drawing element A (20, x) and the drawing element A (1, x + 1) become drawing elements for drawing adjacent pixels on the recording medium 1, and the Y in the recording medium 1 is drawn by different drawing elements. It is possible to avoid drawing pixels aligned in the direction (conveying direction).

  Here, an interval in the X direction between the pixel Sa (20, x) drawn by the drawing element A (20, x) and the pixel Sa (1, x + 1) drawn by the drawing element A (1, x + 1) is determined. It is set to be equal to the interval in the X direction between other adjacent pixels. For example, the interval Vo between the pixel Sa (20, x) and the pixel Sa (1, x + 1) in the X direction is equal to the interval V1 between the pixel Sa (1, x) and the pixel Sa (2, x) in the X direction, or the pixel Sb. The interval V2 in the X direction between (19, x + 1) and the pixel Sa (20, x + 1) is set to be equal.

  Also, as shown in FIG. 7, the n-th drawing element A (y, n), which is the last column of the drawing element A, and the first drawing element B (y, 1) of the drawing element B are In the columns adjacent to each other, the drawing element A (20, n) and the drawing element B (1, 1) are drawing elements that draw pixels adjacent to each other in the X direction. Then, each of the drawing element A (20, n) and the drawing element B (1, 1) is adjacent to the pixel Sa (20, n) and the element Sa (1, 1) in the X direction on the recording medium 1. Draw.

  Since the drawing head 10a and the drawing head 10b are individually installed, it is necessary to adjust the position for each of the drawing heads 10a and 10b. The above adjustment is performed based on the measurement of the amount of displacement between the images Ga and Gb drawn by the drawing element A and the drawing element B, respectively.

  Here, as in the prior art, for example, all of the pixels Sa (y, n: y = 1 to 20) on the recording medium 1 are drawn in black with the drawing element A (y, n: y = 1 to 20). In addition, when all of the drawing elements B (y, 1: y = 1 to 20) are drawn in black, gaps are generated between the images Ga and Gb drawn by the drawing elements A and B, respectively. Measurement of the amount of misalignment can be accurately performed, but the amount of misalignment cannot be accurately measured when no gap is generated between the images Ga and Gb.

  Hereinafter, the case where the measurement of the positional deviation amount can be accurately performed and the case where the measurement cannot be performed will be described with reference to FIG. 8A, 8 </ b> B, and 8 </ b> C, and FIGS. 9 and 10 described later, the pixel Sa (y, x: y = 21 to m) and the drawing element B (y, x : Y = 21 to m) is not drawn and is not shown.

  Also, the drawing heads 10a and 10b are stopped without conveying the drawing heads 10a and 10b, and the pixels drawn on the recording medium 1 by the drawing elements A and B are shown above the drawing. A line extending in the X direction drawn on the recording medium 1 by the drawing elements A and B while conveying the drawing heads 10a and 10b in the Y direction is shown below.

  An error occurs in the placement of the drawing heads 10a and 10b, and as shown in FIG. 8A, the pixels Sa (20, n) and Sb (which should be adjacent to each other in the X direction drawn on the recording medium 1). 1, 1), all of the pixel Sa (y, n: y = 1 to 20) and the drawing element B (y, 1: y = 1 to 20) are drawn in black. It is easy to measure the length of the gap by observing an image showing a line extending in the X direction in the figure. That is, it is easy to accurately determine the position of the edge Fa of the pixel Sa (20, n) and the position of the edge Fa of the pixel Sb (1, 1).

  However, an error occurs in the placement of the drawing heads 10a and 10b, and as shown in FIG. 8B, the pixel Sa (20, n) and the pixel which are drawn on the recording medium 1 and should be adjacent to each other in the X direction. When the position of Sb (1, 1) is switched in the X direction, all of the pixel Sa (y, n: y = 1 to 20) and the drawing element B (y, 1: y = 1 to 20) It is difficult to measure the overlapping length of the images Ga and Gb by observing an image showing a line extending in the X direction in the drawing obtained by drawing in black. That is, it is difficult to accurately determine the position of the edge Fa of the pixel Sa (20, n) and the position of the edge Fb of the pixel Sb (1, 1).

  Further, as shown in FIG. 8C, there is also a gap between the pixel Sa (20, n) drawn on the recording medium 1 and supposed to be adjacent to each other in the X direction and the element Sa (1, 1). A state where no overlap occurs, that is, a state where no positional deviation occurs between the images Ga and Gb is difficult to distinguish from the state where the images Ga and Gb shown in FIG. 8B overlap. That is, it is difficult to accurately determine the position of the edge Fa of the pixel Sa (20, n) and the position of the edge Fb of the pixel Sb (1, 1).

  On the other hand, by applying the positional deviation measuring method, even when the images Ga and Gb overlap each other, the positional deviation amount between the images Ga and Gb can be measured more accurately.

  That is, as shown in FIG. 9, for example, the number of pixels constituting the blank pixel group is 10 pixels, and the drawing element A (10, n) and the drawing element B (1, 1) are connected to the blank pixel group. Are set to blank adjacent pixels adjacent to both sides. Each of the drawing heads 10a and 10b draws the pixel Sa (y, n: y =) on the recording medium 1 without drawing the pixel Sa (y, n: y = 11 to 20) corresponding to the blank pixel group. 1 to 10) and the drawing element B (y, 1: y = 1 to 20) are all drawn in black. As a result, a gap can be created between the pixel Sa (10, n) and the pixel Sb (1, 1), the position of the edge Fa ′ of the pixel Sa (10, n), and the pixel Sb (1, The position of the edge Fb in 1) can be accurately determined. Thereby, the space | interval between blank adjacent pixels and the space | interval between pixel Sa (10, n) and pixel Sb (1, 1) can be measured correctly.

  Then, similarly to the above, based on the difference between the interval between each blank adjacent pixel and the length of the blank pixel group composed of a predetermined number of pixels, the positional deviation amount between the images Ga and Gb is accurately calculated. Can be measured.

  Note that the number of pixels constituting the blank pixel group is set according to the expected amount of positional deviation.

  The blank pixel group may be set over the image Ga and the image Gb. That is, as shown in FIG. 10, for example, when the number of blank pixels is set to 10, the pixel Sa (20, n) adjacent to the edge of the image Ga and the pixel Sa (1, 1, adjacent to the edge of the image Gb are set. ) Including the pixel Sa (16, n) to the pixel Sb (5, 1), and the blank adjacent pixels adjacent to the blank pixel group are the pixels Sa (15, n) in the image Ga and the image Gb. The pixel Sb (6, 1) can also be set. In such a case, the interval between the blank adjacent pixels is obtained by measuring the interval between the position of the edge Fa ″ of the pixel Sa (15, n) and the position of the edge Fb ″ of the pixel Sb (6, 1). Similarly to the above, even when the images Ga and Gb overlap each other, the positional deviation amount between the images Ga and Gb can be accurately measured.

  Note that, as shown in FIG. 11, even when the drawable ranges Ra and Rb of the images drawn by the drawing heads 10a and 10b are set to overlap, all the drawable ranges Ra and Rb are set. Without using the area for drawing. By setting the positions of the edges Fa and Fb of the images Ga and Gb drawn by the drawing heads 10a and 10b so as to coincide with each other when drawn correctly on the recording medium 1, the image is similar to the above. The amount of misalignment can be measured. The present invention can also be applied to the connection of pixel arrangements in one DMD as shown in FIG. For example, since the value of the interval V0 varies depending on how the unused pixels are set, the unused pixel is determined so that the interval V0 becomes an optimum interval by obtaining the interval V0 by the method of the present embodiment. Can be set.

  Next, a description will be given of an exposure apparatus that performs an exposure method for performing exposure by applying the above-described positional deviation measurement method.

  FIG. 12 is a diagram showing a schematic configuration of the optical system of the exposure apparatus, FIG. 13 is a perspective view showing the schematic configuration of the entire exposure apparatus, and FIG. 14 is a perspective view showing how the exposure head accommodated in the exposure unit exposes the photosensitive material. 15 is an enlarged perspective view showing the configuration of the DMD described later, FIG. 16 is a perspective view showing the operation of the micromirror, and FIG. 16A shows the locus of the pixel light beam when the DMD is turned off. FIG. 16B is a plan view showing the trajectory of the pixel light beam when the DMD is turned on. FIG. 17A is a diagram showing a locus on the photosensitive material of a pixel light beam formed by reflecting each micromirror when the DMD is not tilted, and FIG. 17B is a pixel when the DMD is tilted. It is a figure which shows the locus | trajectory on the photosensitive material of a light beam.

  An exposure apparatus that performs an exposure method that performs exposure by applying the above-described positional deviation measurement method includes a plurality of DMDs that are spatial light modulators in which a large number of modulation elements that modulate incident light are two-dimensionally arranged. Each of the exposure heads is an exposure method in which light emitted from a light source is subjected to spatial light modulation, and an image pattern obtained by spatial light modulation is imaged on the photosensitive material to expose the photosensitive material. Applying the displacement measurement method to the measurement of the drawing displacement when exposing a photosensitive material with multiple exposure heads, measuring the amount of drawing displacement between each image pattern imaged by each of the exposure heads, and the drawing displacement Based on the amount, the exposure deviation between the image patterns formed on the photosensitive material by each exposure head is corrected, and the exposure of the photosensitive material by the exposure head is executed.

  The drawing heads 10a, 10b,... Correspond to exposure heads 230A, 230B,. The recording medium 1 corresponds to an optical material 201 described later. Further, the drawing areas on the recording medium 1 on which the images Ga, Gb,... Are drawn by the drawing heads 10a, 10b,... Correspond to the strip-shaped exposed areas 234A, 234B,. is there.

  As shown in the figure, the exposure apparatus 200 is a spatial light modulator formed by arranging a plurality of micromirrors M, which are microscopic light modulation elements, two-dimensionally, the light emitted from the light source 238 and emitted through the optical fiber 240. Spatial light modulation is performed by a certain DMD (digital micromirror device) 236, and a pixel light beam L corresponding to each micromirror M formed according to the light modulation state of each micromirror M is coupled onto the photosensitive material 201. An image, for example, a wiring pattern is exposed on the photosensitive material 201.

  The exposure apparatus 200 is configured in a so-called flatbed type, and includes a flat stage 214 that holds a photosensitive material 201 that is an exposure target to be exposed to the surface. Two guides 220 extending along the stage moving direction are installed on the upper surface of the thick plate-shaped installation base 218 supported by the four legs 216. The stage 214 is arranged so that the longitudinal direction thereof faces the stage moving direction, and is supported by the guide 220 so as to be reciprocally movable. The exposure apparatus 200 is provided with a driving device (not shown) for driving the stage 214 along the guide 220.

  A U-shaped gate 222 is provided at the center of the installation table 218 so as to straddle the moving path of the stage 214. Each of the end portions of the gate 222 is fixed to both side surfaces of the installation table 218. An exposure unit 224 is provided on one side of the gate 222, and a plurality of (for example, two) detection sensors 226 for detecting the front and rear ends of the photosensitive material 201 are provided on the other side. . The exposure unit 224 and the detection sensor 226 are respectively attached to the gate 222 and fixedly arranged above the moving path of the stage 214. The exposure unit 224 and the detection sensor 226 are connected to an exposure apparatus controller 228 that controls the synchronization and timing of each part of the exposure apparatus 200.

  Inside the exposure unit 224, as shown in FIG. 13, a plurality of (for example, eight) exposure heads 230A, 230B,... Arranged in a substantially matrix of i rows and j columns (for example, 2 rows and 4 columns). (Hereinafter, these are collectively referred to as exposure head 230).

  As shown in FIG. 14, each exposure area 232 by the exposure heads 230A, 230B,... Is configured in a rectangular shape having a long side in the transport direction (arrow Y direction in the figure), for example. In this case, in the photosensitive material 201, strip-shaped exposed regions 234A, 234B (hereinafter collectively referred to as exposed regions 234) are formed for each exposure head 230 in accordance with the exposure operation. .

  In addition, each of the exposure heads 230 in each row arranged so that the strip-shaped exposed regions 234 are arranged without a gap in an orthogonal direction (the arrow X direction in the drawing) orthogonal to the transport direction is set at a predetermined interval ( The exposure area is shifted by a natural number times the long side). That is, for example, a portion that cannot be exposed between the exposure area 232A by the exposure head 230A and the exposure area 232B by the exposure head 230B can be an exposure area 232F by the exposure head 230F.

  As shown in FIG. 12, each exposure head 230 uses a digital micromirror device (DMD) as a spatial light modulator that spatially modulates a light beam emitted from a light source 238 and emitted through an optical fiber 240. 236. The DMD 236 is connected to the exposure apparatus controller 228 provided with an image data processing unit, a mirror drive control unit, and the like.

  The image data processing unit of the exposure apparatus controller 228 generates a control signal for driving and controlling the micromirrors to be controlled by the DMD 236 for each exposure head 230 based on the input image data. Further, the mirror drive control unit as the DMD controller controls the angle of the reflection surface of each micromirror in the DMD 236 for each exposure head 230 based on the control signal generated by the image data processing unit.

  As shown in FIG. 13, bundle-shaped optical fibers 240 respectively drawn from the light sources 238 are arranged on the light incident side of the DMD 236 arranged in each exposure head 230. The light source 238 may be constituted by an ultraviolet lamp (UV lamp), a xenon lamp, or the like that can be used as a general light source.

  Although not shown, the light source 238 is provided with a plurality of multiplexing modules that multiplex laser beams emitted from a plurality of semiconductor laser chips and input them to the optical fiber. The optical fiber extending from each multiplexing module is a multiplexing optical fiber that propagates the combined laser beam, and a plurality of optical fibers are bundled into one to form a bundle-shaped optical fiber 240.

  Further, as shown in FIG. 12, a mirror 242 that reflects the light emitted from the bundle optical fiber 240 toward the DMD 236 is arranged on the light incident side of the DMD 236 of each exposure head 230.

  As shown in FIG. 15, the DMD 236 has a rectangular shape in which a large number of micromirrors M arranged in a two-dimensional manner are supported on a SRAM cell (memory cell) 244 and supported by pillars (not shown). The mirror device is configured by arranging a large number (for example, 600 × 800) of micromirrors M constituting a pixel (pixel) in a grid pattern. A micromirror M supported by a support column is provided at the top of each pixel, and a material having high reflectance such as aluminum is deposited on the surface of the micromirror M.

  Directly below the micromirror M is a silicon gate CMOS SRAM cell 244 manufactured on a normal semiconductor memory manufacturing line via a post including a hinge and a yoke (not shown), and the whole is monolithic. (Integrated type).

  When a digital signal is written to the SRAM cell 244 of the DMD 236, the micromirror M supported by the support is tilted within a range of ± α degrees (for example, ± 10 degrees) with respect to the substrate side on which the DMD 236 is disposed with the diagonal line as the center. It is done. FIG. 16A shows a state where the micromirror M is tilted to + α degrees when the micromirror M is in the on state, and FIG. 16B shows a state where the micromirror M is tilted to −α degrees when the micromirror M is in the off state. Therefore, by controlling the inclination of the micromirror M in each pixel of the DMD 236 as described above according to the image signal, the light incident on the DMD 236 is reflected in a direction corresponding to the inclination of the micromirror M. It is done.

  FIG. 15 shows an example of a state in which a part of the DMD 236 is enlarged and the micromirror M is controlled to + α degrees or −α degrees. The on / off control of each micromirror M is performed by the exposure apparatus controller 228 connected to the DMD 236. For example, the light reflected by the micromirror M in the on state is the light emission side of the DMD 236. The photosensitive material 201 is exposed by being imaged through an imaging optical system 259 (see FIG. 12), which will be described later. Further, the light reflected by the off-state micromirror M enters a light absorber (not shown) and is absorbed and does not expose the photosensitive material 201.

  Further, the DMD 236 is arranged slightly inclined so that the long side direction of the rectangular shape forms a predetermined angle θ (for example, 0.1 ° to 0.5 °) with the transport direction (the arrow Y direction in the figure). It is preferable to do this. FIG. 17A shows a trajectory (hereinafter referred to as a transport trajectory) on the photosensitive material 201 by the above-described transport of the pixel light beam L formed by being reflected by each micromirror when the DMD 236 is not tilted. B) shows the transport locus of the pixel light beam L when the DMD 236 is tilted.

  As described above, by tilting the DMD 236, the transport line pitch P2 indicated by the transport trajectory of the pixel light beam L that has passed through each micromirror M (see FIG. 17B) is transported when the DMD 236 is not tilted. It can be made narrower than the line pitch Pl (see FIG. 17A), and the resolution of the image exposed on the photosensitive material 201 can be greatly improved. On the other hand, since the tilt angle of the DMD 236 is very small, the transport width W2 when the DMD 236 is tilted and the transport radiation W1 when the DMD 236 is not tilted are substantially the same.

  Moreover, it can also arrange | position so that the substantially same position (dot) on the same conveyance line may be accumulated and exposed (multiple exposure) by a different micro mirror row | line | column. In such a case, the same region on the photosensitive material is subjected to multiple exposure, exposure can be controlled with higher resolution, and high-definition exposure can be realized. In addition, such high-resolution exposure can make the connection between the exposure heads inconspicuous.

  Next, the imaging optical system 259 provided on the light emission side of the DMD 236 of the exposure head 230 will be described. As shown in FIG. 12, the imaging optical system 259 sequentially forms a lens system 250 along the optical path from the DMD 236 side to the photosensitive material 201 side in order to form an image of the light source on the photosensitive material 201. 252, microlens array 254, and objective lens systems 256 and 258 are arranged.

  Here, the lens systems 250 and 252 are configured as an enlargement optical system, and the area of the exposure area 232 on the photosensitive material 201 exposed by the pixel light beam reflected by the DMD 236 is enlarged to a required size. Yes.

  As shown in FIG. 12, the microlens array 254 is formed by integrally forming a plurality of microlenses 260 corresponding to the micromirrors M of the DMD 236 on a one-to-one basis. The pixel light beams that have passed through 250 and 252 are arranged to pass through.

  The entire microlens array 254 is formed in a rectangular flat plate shape, and apertures 262 (shown in FIG. 12) are integrally disposed in the portions where the microlenses 260 are formed. The aperture 262 forms an aperture stop that is arranged in one-to-one correspondence with each microlens 260.

  The objective lens systems 256 and 258 are configured as, for example, an equal magnification optical system. The photosensitive material 201 is disposed at a position where the pixel light beam L is imaged through the objective lens systems 256 and 258. The lens systems 250 and 252 and the objective lens systems 256 and 258 in the imaging optical system 259 are shown as one lens in FIG. 12, but a plurality of lenses (for example, a convex lens and a concave lens) are used. It may be a combination.

  With the exposure head 230 configured as described above, the light emitted from the light source 238 can be imaged on the surface of the photosensitive material 201 to form an image.

  Next, an operation for exposing an image on the photosensitive material 201 by the exposure apparatus 200 will be described.

  First, the above-described positional deviation measurement method is applied to each of the exposure heads 230A, 230B,... To form an image on the photosensitive material 201 by the exposure heads 230A, 230B,. The amount of positional deviation between each image is measured. Then, based on the measured displacement amount, the displacement between the images formed on the photosensitive material is corrected by the exposure heads 230A, 230B,.

  Although not shown, the light source 238 collimates a laser beam such as ultraviolet light emitted from each of the laser light emitting elements in a divergent light state with a collimator lens and condenses it with a condenser lens. The light is incident on the incident end face, is combined in the optical fiber, and is incident on the optical fiber 240 coupled to the output end of the optical fiber.

  Image data corresponding to an image to be exposed is input to an exposure apparatus controller 228 connected to the DMD 236 and temporarily stored in a memory in the exposure apparatus controller 228. This image data is data representing the density of each pixel constituting the image by binary values (whether or not dots are recorded).

  The stage 214 having the photosensitive material 201 adsorbed on the surface thereof is transferred at a constant speed from the upstream side to the downstream side in the transport direction along the guide 220 by a driving device (not shown). When the leading end of the photosensitive material 201 is detected by the detection sensor 226 attached to the gate 222 when the stage 214 passes under the gate 222, the image data stored in the memory is sequentially read out for each of a plurality of lines. A control signal for controlling the micromirror M is generated for each exposure head 230 based on the image data read by the image data processing unit.

  Then, the mirror drive control unit of the exposure apparatus controller 228 performs on / off control of each micro mirror of the DMD 236 for each exposure head 230 based on a control signal in which the shading adjustment for uniformizing the light amount distribution and the adjustment of the exposure amount are performed. The

  When the light beam emitted from the optical fiber 240 and reflected by the mirror 242 is irradiated to the DMD 236, the laser light reflected when the micromirror of the DMD 236 is in the on state is reflected by the corresponding microlens 260 of the microlens array 254. An image is formed on the exposure surface of the photosensitive material 201 through a lens system including In this manner, the pixel light beam L emitted from the DMD 236 is turned on / off for each micromirror, and the photosensitive material 201 is exposed in pixel units (exposure areas) of approximately the same number as the number of used pixels of the DMD 236.

  Further, by moving the photosensitive material 201 together with the stage 214 at a constant speed, the photosensitive material 201 is relatively moved in the direction opposite to the stage moving direction by the exposure unit 224, and a strip-shaped exposure is completed for each exposure head 230. A region 234 is formed, and an image is exposed on the photosensitive material 201.

  That is, the image is formed on the photosensitive material 201 by irradiating the photosensitive material 201 with the pixel light beam L generated by performing the modulation corresponding to the image to be exposed and formed by the DMD 236.

  When exposure of the photosensitive material 201 by the exposure unit 224 is completed and the rear end of the photosensitive material 201 is detected by the detection sensor 226, the stage 214 is moved to the most upstream side in the transport direction along the guide 220 by a driving device (not shown). It is returned to a certain origin, and again moved along the guide 220 from the upstream side in the transport direction to the downstream side at a constant speed.

  In the exposure apparatus 200 according to the present embodiment, a DMD is used as a spatial light modulator used in the exposure head 230. For example, a MEMS (Micro E1ectro Mechanica1Systems) type spatial light modulator (SLM) is used. Reflective diffraction grating type grating light valve element (GLV element, manufactured by Silicon Light Machine Co., Ltd., for details of the GLV element, see US Pat. No. 5,311,360). Spaces other than MEMS types, such as optical elements (PLZT elements) that modulate transmitted light by the electro-optic effect, or transmissive spatial light modulators such as liquid crystal light shutters (FLC), etc. An optical modulator can be used in place of the DMD.

  Note that MEMS is a general term for a micro system that integrates micro-sized sensors, actuators, and control circuits based on a micro-machining technology based on an IC manufacturing process. A MEMS-type spatial light modulator is an electrostatic force. It means a spatial light modulator driven by electromechanical operation using

  The present invention is also applicable to measurement of drawing position deviation in an ink jet drawing apparatus.

The conceptual diagram which shows embodiment of the position shift measuring method of this invention Diagram showing reference area The figure which shows a mode that the amount of position shift between images is measured It is a figure which shows an example of the aspect which draws an image on a recording medium with a drawing head. The figure which shows the drawing element arranged in the matrix form with which a drawing head is equipped. The figure which shows the relationship between the position of each drawing element and the position of the pixel drawn with these drawing elements The figure which shows the relationship between each drawing element with which each exposure head is equipped, and the position of the pixel drawn by each drawing element The figure which shows a mode that the amount of position shift between the images drawn with the drawing head provided with the drawing element arranged in the matrix form is measured. The figure which shows the pixel row which set the blank pixel group and is drawn The figure which shows the pixel row | line drawn by setting the blank pixel group over between each image FIG. 6 is a diagram showing a positional relationship between a drawable area of the drawing head and an image drawn by the drawing head in order to measure a positional deviation amount. The figure which shows schematic structure of the optical system of exposure apparatus The perspective view which shows schematic structure of the whole exposure apparatus The perspective view which shows a mode that the exposure head accommodated in the exposure unit exposes a photosensitive material The perspective view which expands and shows the structure of DMD Perspective view showing operation of micromirror (A) is a plan view showing the transport locus of the pixel light beam when the DMD is not tilted, and (B) is a plan view showing the transport locus of the pixel light beam when the DMD is tilted.

Explanation of symbols

1 Recording medium 1
10a Drawing head 10b Drawing head Ga image Gb image Fa edge Fb edge J5 Blank pixel group Qa (n-5) Blank adjacent pixel Qb (1) Blank adjacent pixel

Claims (6)

A displacement measurement method for measuring a displacement amount of drawing positions of different drawing units,
In a crossing direction that includes at least one of the respective pixels in each image to be drawn so as to be adjacent to each other with an edge of the drawing position of each of the drawing units in between, and intersects the direction in which the edge extends Draw blank adjacent pixels that are drawn adjacent to both sides of the blank pixel group without drawing a blank pixel group consisting of a predetermined number of pixels lined up,
A positional shift amount between each drawing position is measured based on a difference between an interval between each blank adjacent pixel drawn on the recording medium and a pixel length of the number of pixels of the blank pixel group. Misalignment measurement method.   The recording medium is drawn with one or more types of reference areas in which a predetermined number of pixels are arranged to measure the interval between the blank adjacent pixels drawn on the recording medium. The positional deviation measuring method according to claim 1, wherein:   When drawing in the drawing unit, one or more types of reference areas in which a predetermined number of pixels are arranged for measuring the interval between the blank adjacent pixels are also drawn on the recording medium. The positional deviation measuring method according to claim 1 or 2. Each of the images obtained by spatially modulating the light emitted from the light source by each of a plurality of exposure heads having a spatial light modulator in which a large number of modulation elements that modulate incident light are arranged in a two-dimensional manner. An exposure method for forming an image on the same photosensitive material and exposing the photosensitive material,
The positional deviation measuring method according to any one of claims 1 to 3 is applied to measurement of an amount of positional deviation between images when the photosensitive material is exposed by the plurality of exposure heads, and each of the exposure heads is connected. The amount of misalignment between the images to be imaged is measured, and based on the amount of misalignment, the misalignment between the images to be imaged on the photosensitive material by each exposure head is corrected to correct the position of the photosensitive material by the exposure head. An exposure method comprising performing exposure. A test pattern used for measuring a drawing position deviation amount of different drawing units,
A crossing direction that includes at least one of the pixels in each image to be drawn so as to be adjacent to each other with an edge of each drawing position of the drawing unit in between and intersects with the extending direction of the edge A blank pixel group consisting of a predetermined number of pixels lined up to
A test pattern comprising: blank adjacent pixels drawn in each drawing unit so as to be adjacent to both sides of the blank pixel group.   6. The test pattern according to claim 5, further comprising at least one type of reference area in which a predetermined number of pixels are arranged.

Images