JP4253708B2 - Exposure equipment - Google Patents

Description

  The present invention relates to an exposure apparatus that exposes a functional pattern on an object to be exposed, and more specifically, detects and detects a reference position set in a reference function pattern formed in advance on the object to be exposed by an imaging unit, The present invention relates to an exposure apparatus that improves the overlay accuracy of functional patterns and suppresses the rise of the exposure apparatus by controlling the start or stop of irradiation of a light beam with reference to the reference position.

  A conventional exposure apparatus uses a mask in which a mask pattern corresponding to a functional pattern is formed in advance on a glass substrate, and transfers and exposes the mask pattern on an object to be exposed. For example, a stepper or a micromirror projection (Mirror) There are Projection and Proximity devices. However, in these conventional exposure apparatuses, when a plurality of layers of functional patterns are formed in layers, the overlay accuracy of the functional patterns between the layers becomes a problem. In particular, in the case of a large mask used for forming a TFT or a color filter for a large liquid crystal display, high absolute dimensional accuracy is required for the arrangement of the mask pattern, and the cost of the mask is increased. In addition, in order to obtain the overlay accuracy, alignment of the functional pattern of the underlayer and the mask pattern is necessary, and this alignment is difficult particularly in a large mask.

On the other hand, there is an exposure apparatus that directly draws a CAD data pattern on an object to be exposed using an electron beam or a laser beam without using a mask. This type of exposure apparatus includes a laser light source, an exposure optical system that reciprocally scans a laser beam emitted from the laser light source, and a transport unit that transports the object to be exposed, based on CAD data. The laser beam is reciprocated while controlling the emission state of the laser light source, and the object to be exposed is conveyed in a direction orthogonal to the scanning direction of the laser beam, and a CAD data pattern corresponding to the functional pattern is formed on the object to be exposed. It is formed two-dimensionally (see, for example, Patent Document 1).
JP 2001-144415 A

  However, in such a direct drawing type conventional exposure apparatus, the point that high absolute dimensional accuracy is required for the pattern arrangement of CAD data is the same as the exposure apparatus using a mask, and a plurality of exposure apparatuses are used. In the manufacturing process for forming a functional pattern, there is a problem that the accuracy of superimposing the functional patterns is deteriorated when there is a variation in accuracy between exposure apparatuses. Therefore, in order to cope with such a problem, a high-precision exposure apparatus is necessary, and the cost of the exposure apparatus is increased.

  Further, the point that the alignment of the functional pattern of the underlayer and the CAD data pattern has to be taken in advance is the same as in other exposure apparatuses using a mask, and there is the same problem as described above.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an exposure apparatus that addresses such problems and improves the overlay accuracy of function patterns and suppresses the rise of the exposure apparatus.

In order to achieve the above object, an exposure apparatus according to a first aspect of the present invention scans a light beam emitted from an exposure optical system in a direction perpendicular to the moving direction of an object to be exposed, An exposure apparatus that exposes a functional pattern at a predetermined pitch, an imaging unit that images a reference functional pattern serving as a reference of an exposure position formed in advance on the object to be exposed, and the two references acquired by the imaging unit By taking the logical sum of each image data using the image data of the functional pattern, to generate a defect-free reference function pattern image by removing defects in the reference function pattern image corresponding to one scanning region of the light beam, An optical system control means for detecting a reference position of exposure start or end in the defect-free reference function pattern image, and controlling the start or stop of irradiation of the light beam with reference to the reference position; It includes those were.

With this configuration, the image data of the two reference function patterns acquired by the image pickup means by the optical system control means is used to calculate the logical sum of the image data, and the reference function pattern image corresponding to one scanning region of the light beam. A defect-free reference function pattern image is generated by removing a defect in the step, an exposure start or end reference position is detected in the defect-free reference function pattern image, and irradiation of the light beam is started based on the reference position. Or the irradiation stop is controlled. Thereby, even when the reference function pattern previously formed on the object to be exposed has a defect, the predetermined function pattern is formed with high accuracy at the predetermined position.

  Further, the optical system control means uses the image data of the previous reference function pattern acquired by the imaging means and the image data of the newly acquired reference function pattern before and after the moving direction of the object to be exposed. In this case, a defect-free reference function pattern image is generated by calculating the logical sum of the image data at the same position. Thus, using the image data of the previous reference function pattern acquired by the image pickup means and the image data of the newly acquired reference function pattern, the optical system control means can mutually perform before and after the moving direction of the object to be exposed. A logical sum of the image data at the same position is taken to generate a defect-free reference function pattern image.

Furthermore, the optical system control means, defect-free by the at image data of the reference feature pattern acquired by the imaging unit using the image data of the reference feature pattern next to each other, the logical sum of the image data The reference function pattern image is generated. As a result, the image data of the reference function pattern acquired by the imaging unit is used to obtain the logical sum of the image data by the optical system control unit using the image data of the adjacent reference function pattern, and the defect-free reference function pattern Generate an image.

  The second invention scans the light beam emitted from the exposure optical system in a direction perpendicular to the moving direction of the object to be exposed, and exposes the functional pattern on the object to be exposed at a predetermined pitch. An exposure apparatus, an imaging unit that images a reference function pattern that is a reference of an exposure position formed in advance on the object to be exposed, and image data of the reference function pattern of a predetermined area acquired by the imaging unit, A reference function pattern image that cannot be obtained by the imaging means is copied to an area subsequent to a predetermined area, and an exposure start or end reference position is detected from the complemented reference function pattern image, and the reference position is used as a reference. And optical system control means for controlling the start or stop of irradiation of the light beam.

  With such a configuration, the image data of the reference function pattern of the predetermined area acquired by the image pickup means by the optical system control means is copied to the area following the predetermined area, and the image of the reference function pattern that cannot be acquired by the image pickup means is complemented. Then, the exposure start or end reference position is detected in the complemented reference function pattern image, and the light beam irradiation start or irradiation control is controlled based on the reference position. Thereby, even when all of the reference function patterns formed on the object to be exposed in the scanning direction of the light beam cannot be acquired by the imaging unit, the predetermined function pattern is formed at a predetermined position with high accuracy.

According to the first aspect of the present invention, the logical sum of each image data is obtained using the image data of the two reference function patterns acquired by the imaging means, and the reference function pattern image corresponding to one scanning region of the light beam is obtained. Since the defect-free reference function pattern image is generated by removing the defect, even when the reference function pattern formed in advance on the object to be exposed has a defect, the predetermined function pattern is highly accurate at a predetermined position. Can be exposed. Therefore, even when a plurality of layers of functional patterns are stacked, the accuracy of overlaying the functional patterns of each layer is increased. As a result, even when a multilayer pattern is formed using a plurality of exposure apparatuses, it is possible to eliminate the problem of deterioration in the accuracy of superimposing functional patterns due to the difference in accuracy between the exposure apparatuses. Up can be suppressed.

According to the second aspect of the present invention, the moving direction of the object to be exposed is determined using the image data of the previous reference function pattern acquired by the imaging unit and the image data of the newly acquired reference function pattern . By taking the logical sum of the image data at the same position before and after and generating a defect-free reference function pattern image, defects such as foreign matter adhering to the stage on which the object is placed are removed. In some cases, the defect can be removed. Accordingly, it is possible to prevent the defect from being erroneously recognized as a reference position and to perform exposure, and it is possible to improve the exposure accuracy of a predetermined function pattern.

Furthermore, according to the third aspect of the present invention, in the image data of the reference function pattern acquired simultaneously in the scanning direction of the light beam by the imaging means, the logic of each image data is used using the image data of the adjacent reference function pattern. By taking the sum and generating a defect-free reference function pattern image, even when there is a defect in the scanning region of the light beam in the last row, the adjacent function pattern is compared and the defect is removed. be able to.

According to the fourth aspect of the invention, the image data of the reference function pattern of the predetermined area acquired by the imaging unit is copied to the area subsequent to the predetermined area, and the image of the reference function pattern that cannot be acquired by the imaging unit is complemented. By doing so, for example, even when the imaging area of the imaging means is narrower than the scanning area of the light beam, the image data in the entire scanning area of the light beam is completely converted based on the image data acquired by the imaging means. Can be generated into shape. Therefore, the number of imaging means can be reduced, and the cost of the apparatus can be reduced.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a conceptual view showing an embodiment of an exposure apparatus according to the present invention. The exposure apparatus 1 exposes a functional pattern on an object to be exposed, and includes a laser light source 2, an exposure optical system 3, a transport unit 4, an imaging unit 5, and a back light irradiation unit 6 as an illumination unit. The optical system control means 7 is provided. The functional pattern is a pattern of components necessary for the original operation of the product. For example, in a color filter, a black matrix pixel pattern and red, blue, and green color filters are used. In a semiconductor component, it is a wiring pattern, various electrode patterns, or the like. In the following description, an example in which a glass substrate for a color filter is used as an object to be exposed will be described.

  The laser light source 2 emits a light beam. For example, the laser light source 2 is a high-power all-solid mode-locked laser light source having an output of 4 W or more for generating 355 nm ultraviolet rays.

  An exposure optical system 3 is provided in front of the laser light source 2 in the light beam emission direction. The exposure optical system 3 reciprocates and scans a laser beam as a light beam on the glass substrate 8. The optical switch 9, the light deflecting means 10, the first mirror 11, , A polygon mirror 12, an fθ lens 13, and a second mirror 14.

  The optical switch 9 switches between irradiation of the laser beam and irradiation stop state. For example, as shown in FIG. 2, the first and second polarizing elements 15A and 15B are switched to the polarization of the polarizing elements 15A and 15B. The axes p are arranged so as to be orthogonal to each other (in the figure, the polarization axis p of the polarization element 15A is set in the vertical direction, and the polarization axis p of the polarization element 15B is set in the horizontal direction), The electro-optic modulator 16 is disposed between the first and second polarizing elements 15A and 15B. The electro-optic modulator 16 operates to rotate the polarization plane of polarized light (linearly polarized light) at a high speed of several nsec when a voltage is applied. For example, when the applied voltage is zero, linearly polarized light having, for example, a vertical polarization plane selectively transmitted by the first polarizing element 15A in FIG. The second polarizing element 15B is reached. Since the second polarizing element 15B is disposed so as to selectively transmit linearly polarized light having a horizontal polarization plane, the linearly polarized light having a vertical polarization plane cannot be transmitted. The laser beam is stopped from irradiation. On the other hand, when a voltage is applied to the electro-optic modulator 16 and the polarization plane of the linearly polarized light incident on the electro-optic modulator 16 is rotated by 90 degrees as shown in FIG. The linearly polarized light having a horizontal polarization plane when emitted from the electro-optic modulator 16 passes through the second polarizing element 15B. As a result, the laser beam enters an irradiation state.

  The light deflecting means 10 is adjusted so as to scan the correct position by shifting the scanning position of the laser beam in a direction orthogonal to the scanning direction (coinciding with the direction of arrow A shown in FIG. 1 in the moving direction of the glass substrate 8). For example, an acousto-optic element (AO element) is used.

  The first mirror 11 is a plane mirror for bending the traveling direction of the laser beam that has passed through the light deflecting means 10 in the installation direction of a polygon mirror 12 described later. Further, the polygon mirror 12 performs reciprocal scanning with a laser beam, and for example, eight mirrors are formed on the side surface of a regular octagonal columnar rotator. In this case, the laser beam reflected by one of the mirrors is scanned in a one-dimensional forward direction as the polygon mirror 12 rotates, and returns at the moment when the irradiation position of the laser beam moves to the next mirror surface. Returning to step S1, the one-dimensional forward scanning is started again with the rotation of the polygon mirror 12.

  Further, the fθ lens 13 is configured so that the scanning speed of the laser beam becomes constant on the glass substrate 8, and is arranged with the focal point position substantially coincident with the position of the mirror surface of the polygon mirror 12. The second mirror 14 reflects the laser beam that has passed through the fθ lens 13 and makes it incident in a direction substantially perpendicular to the surface of the glass substrate 8 and is a flat mirror. Further, a line sensor 17 is provided at a scanning start side portion of the laser beam that performs reciprocating scanning in the vicinity of the exit side surface of the fθ lens 13 so as to be orthogonal to the scanning direction. The amount of deviation between the position and the actual scanning position is detected, and the scanning start time of the laser beam is detected. The line sensor 17 may be provided not on the fθ lens 13 side but on the glass substrate transport stage 18 (to be described later) side as long as it can detect the scanning start point of the laser beam.

  A conveying means 4 is provided below the second mirror 14. The transport means 4 places the glass substrate 8 on the stage 18 and transports the glass substrate 8 at a predetermined speed in a direction orthogonal to the scanning direction of the laser beam. For example, the transport roller 19 moves the stage 18. And a conveyance drive unit 20 such as a motor for rotating the conveyance roller 19.

An imaging unit 5 is provided above the transport unit 4 and on the front side of the scanning position of the laser beam in the transport direction indicated by the arrow A. The image pickup means 5 picks up pixels of a black matrix as a reference function pattern that is formed in advance on the glass substrate 8 and serves as a reference for exposure, and is, for example, a line CCD in which light receiving elements are arranged in a line. Here, as shown in FIG. 3, the distance D between the imaging position E of the imaging means 5 and the scanning position F of the laser beam is an integral multiple (n times) of the transport direction arrangement pitch P of the pixels 22 of the black matrix 21. ). Thereby, the scanning timing can be adjusted so that the laser beam starts scanning when the glass substrate 8 is conveyed and the center of the pixel 22 coincides with the scanning position of the laser beam. The distance D is preferably as small as possible. Thereby, the movement error of the glass substrate 8 can be reduced, and the scanning position of the laser beam can be more accurately positioned with respect to the pixel 22. Although FIG. 1 shows an example in which three imaging means 5 are installed, when the scanning range of the laser beam is narrower than the image processing area of one imaging means 5, one imaging means 5 may be used. When the scanning range is wider than the image processing area of one image pickup means 5, a plurality of image pickup means may be installed accordingly.

  A back light irradiating means 6 is provided below the conveying means 4. The back light irradiating means 6 illuminates the pixels 22 and enables the imaging means 5 to take an image, and is, for example, a surface light source.

An optical system control means 7 is provided in connection with the laser light source 2, the optical switch 9, the light deflection means 10, the polygon mirror 12, the line sensor 17, the transport means 4 and the imaging means 5. This optical system control means 7 uses the image data of the two pixels 22 acquired by the imaging means 5 to perform a logical sum of the respective image data, thereby eliminating defects in the pixel 22 image corresponding to one scanning region of the laser beam. A defect-free pixel 22 image is generated by removal, a reference position of exposure start or end is detected in the defect-free pixel 22 image , and irradiation start or irradiation of the laser beam in the laser light source 2 is performed based on the reference position. In addition to controlling the stop, the voltage applied to the light deflecting means 10 is controlled based on the output of the line sensor 17 to deflect the laser beam emission direction, and the rotational speed of the polygon mirror 12 is controlled to scan the laser beam. The speed is maintained at a predetermined speed, and the transport speed of the glass substrate 8 by the transport means 4 is controlled to a predetermined speed. The light source driving unit 23 that turns on the laser light source 2, the optical switch controller 24 that controls the start and stop of the irradiation of the laser beam, and the optical deflection unit driving unit 25 A that controls the deflection amount of the laser beam in the optical deflection unit 10. A polygon drive unit 25B that controls the driving of the polygon mirror 12, a transport controller 26 that controls the transport speed of the transport unit 4, a back light controller 27 that turns on and off the back light irradiating unit 6, and an imaging unit 5 An A / D conversion unit 28 that performs A / D conversion on the image captured in step A, an image processing unit 29 that determines an irradiation start position and an irradiation stop position based on the A / D converted image data, and image processing Laser beam irradiation start position (hereinafter referred to as exposure start position) and irradiation stop position (hereinafter referred to as exposure end position) obtained by processing by the unit 29 A storage unit 30 that stores data and stores a look-up table for an exposure start position and an exposure end position, which will be described later, and the optical switch 9 based on the exposure start position and exposure end position data read from the storage unit 30. A modulation data generation processing unit 31 that generates modulation data for turning on / off the signal, and a control unit 32 that appropriately controls the entire apparatus to perform a predetermined target operation.

  4 and 5 are block diagrams illustrating an example of the configuration of the image processing unit 29. As shown in FIG. 4, the image processing unit 29 includes, for example, three ring buffer memories 33A, 33B, 33C connected in parallel, and, for example, three lines connected in parallel for each of the ring buffer memories 33A, 33B, 33C. A buffer circuit 34A, 34B, 34C; a comparator 35 connected to the line buffer memories 34A, 34B, 34C; The output data 34A, 34B, and 34C are compared with the look-up table (exposure start position LUT) of image data corresponding to the first reference position that defines the exposure start position obtained from the storage unit 30 shown in FIG. An exposure start position determination circuit 36 that outputs an exposure start position determination result when the two data match, A look-up table (for the exposure end position) corresponding to the output data of the nine line buffer memories 34A, 34B, 34C and the second reference position for determining the exposure end position obtained from the storage unit 30 shown in FIG. And an exposure end position determination circuit 37 that outputs an exposure end position determination result when the two data coincide with each other.

  As shown in FIG. 5, the image processing unit 29 inputs the exposure start position determination result and counts the number of coincidence of image data corresponding to the first reference position, and the counting circuit 38A. A comparison circuit 39A that outputs an exposure start signal to the modulation data creation processing unit 31 shown in FIG. 1 when both numerical values coincide with each other by comparing the output of the above and the exposure start pixel number obtained from the storage unit 30 shown in FIG. A counting circuit 38B for inputting the above-described exposure end position determination result and counting the number of coincidence of the image data corresponding to the second reference position, the output of the counting circuit 38B, and the exposure obtained from the storage unit 30 shown in FIG. A comparison circuit 39B that outputs an exposure end signal to the modulation data generation processing unit 31 shown in FIG. 1 when both numerical values match with the end pixel number and the output of the counting circuit 38A. A leading pixel counting circuit 40 that counts the number of cells, and an output pixel when both numerical values match by comparing the output of the leading pixel counting circuit 40 with the exposure pixel column number obtained from the storage unit 30 shown in FIG. A comparison circuit 41 that outputs a column designation signal to the modulation data creation processing unit 31 shown in FIG. 1 is provided. The counting circuits 38A and 37B are reset by the reading start signal when the reading operation by the imaging means 5 is started. The head pixel counting circuit 40 is reset by an exposure pattern end signal when the formation of a predetermined exposure pattern designated in advance is completed.

Next, the operation of the exposure apparatus 1 configured as described above and the pattern forming method will be described.
First, when the exposure apparatus 1 is turned on, the optical system control means 7 is driven. As a result, the laser light source 2 is activated and a laser beam is emitted. At the same time, the polygon mirror 12 starts rotating, and the laser beam can be scanned. However, at this time, the laser beam is not irradiated because the optical switch 9 is still off.

  Next, the glass substrate 8 is placed on the stage 18 of the conveying means 4. Since the transport means 4 transports the glass substrate 8 at a constant speed, the scanning trajectory (arrow B) of the laser beam is relatively relative to the moving direction (arrow A) of the stage 18 as shown in FIG. It becomes diagonal. Therefore, when the glass substrate 8 is installed in parallel with the moving direction (arrow A), the exposure position is the scanning start pixel 22a and scanning end pixel 22b of the black matrix 21, as shown in FIG. The case where it shifts by occurs. In this case, as shown in FIG. 4B, the glass substrate 8 is installed inclined with respect to the transport direction (arrow A direction), and the arrangement direction of the pixels 22 and the scanning locus of the laser beam (arrow B). Should match. However, in reality, the amount of deviation is small because the scanning speed of the laser beam is much faster than the conveying speed of the glass substrate 8. Accordingly, the glass substrate 8 is installed in parallel to the moving direction, the deviation amount is measured based on the data imaged by the imaging means 5, and the deviation amount is controlled by controlling the light deflection means 10 of the exposure optical system 3. It may be corrected. In the following description, it is assumed that the amount of deviation is negligible.

  Next, the conveyance drive unit 20 is driven to move the stage 18 in the direction of arrow A in FIG. At this time, the transport driving unit 20 is controlled by the transport controller 26 of the optical system control means 7 so as to have a constant speed.

  Next, when the black matrix 21 formed on the glass substrate 8 reaches the imaging position of the imaging means 5, the imaging means 5 starts imaging, and the exposure start position and the exposure end based on the image data of the captured black matrix 21. Perform position detection. Hereinafter, the pattern forming method will be described with reference to the flowchart shown in FIG.

  First, in step S <b> 1, the image of the pixel 22 of the black matrix 21 is acquired by the imaging unit 5. The acquired image data is captured and processed in the three ring buffer memories 33A, 33B, and 33C of the image processing unit 29 shown in FIG. Then, the latest three data are output from the ring buffer memories 33A, 33B, and 33C. In this case, for example, the previous data is output from the ring buffer memory 33A, the previous data is output from the ring buffer memory 33B, and the latest data is output from the ring buffer memory 33C. Further, for each of these data, for example, images of 3 × 3 CCD pixels are arranged on the same clock (time axis) by three line buffer memories 34A, 34B, 34C. The result is obtained as an image as shown in FIG. When this image is digitized, it corresponds to a numerical value of 3 × 3 as shown in FIG. Since these digitized images are arranged on the same clock, they are compared with a threshold value by the comparison circuit 35 and binarized. For example, if the threshold value is “45”, the image in FIG. 10A is binarized as shown in FIG.

  Next, in step S2, a reference position for exposure start and exposure end is detected. Specifically, the reference position is detected by comparing the binarized data with the exposure start position LUT data obtained from the storage unit 30 shown in FIG.

  For example, when the first reference position for designating the exposure start position is set at the upper left corner of the pixel 22 of the black matrix 21 as shown in FIG. 9A, the exposure start LUT is In this case, the exposure start LUT data is “000011011”. Therefore, the binarized data is compared with the data “000011011” of the exposure start LUT, and when the two data match, it is determined that the image data acquired by the imaging means 5 is the first reference position. Then, a start position determination result is output from the exposure start position determination circuit 36. As shown in FIG. 10, when six pixels 22 are arranged, the upper left corner of each pixel 22 corresponds to the first reference position.

As shown in FIG. 11, when a foreign matter or a flaw exists on the stage 18 or the glass substrate 8 and an image of the defect 42 due to the foreign matter or the like is acquired in the pixel 22 by the imaging unit 5, the defect 42. May be mistaken for the reference position. Therefore, in the first embodiment, the image data of the pixel row L ₁ acquired by the imaging unit 5 is stored in the storage unit 20. When the image data of the next pixel row L ₂ is acquired, the image data of the pixel row L ₁ is read from the storage unit 20, and the moving direction of the glass substrate 8 in the image processing unit 29 as shown in FIG. The logical sum of the image data of the pixels 22 at the same position before and after the arrow A direction) is calculated. At this time, it is rare that the defect 42 exists at the same position of the two pixels 22. Therefore, the defect 42 can be removed from the image data by calculating the logical sum of the image data of each pixel 22. Thereby, the reference position as described above is detected using the image data of the defect-free pixel column.

Further, since the image of a new pixel row cannot be acquired for the last pixel row, the defect 42 cannot be removed by the above-described method. In this case, the image of the defect 42 is removed by calculating the logical sum of the image data of the adjacent pixels 22. Specifically, and FIG. 11 (b) and the last column of the pixel columns L _n images obtained as shown in, the moving direction of the glass substrate 8 on the image shifted by one pitch the pixel columns L _n images in a column direction ( The logical sum of the image data of the pixels 22 at the same position before and after the arrow A direction) is calculated. In this case, it is rare that the defect 42 is present at the same time at the same position in adjacent to each other pixels 22, therefore, by taking the logical sum of image data of each pixel 22, with respect to the last column pixel column L _n The defect 42 can also be removed from the image. Thereby, a defect-free pixel column can be generated.

Next, the number of coincidences is counted in the counting circuit 38A shown in FIG. 5 based on the determination result. Then, the count number is compared in the comparison circuit 39A with the exposure start pixel number obtained from the storage unit 30 shown in FIG. 1, and when the two values match, the exposure start signal is sent to the modulation data creation processing unit 31 shown in FIG. Output. In this case, as shown in FIG. 10, for example, when determined in the scanning direction of the laser beam first pixel 22 ₁ and the fourth upper-left corner corner pixels 22 ₄ and the first reference position, said first The element addresses, for example, “1000” and “4000” in the line CCD of the imaging means 5 corresponding to the reference position are stored in the optical switch controller 24.

  On the other hand, the binarized data is compared with the exposure end position LUT data obtained from the storage unit 30 shown in FIG. For example, when the second reference position for designating the exposure end position is set at the upper right corner of the pixel 22 of the black matrix 21 as shown in FIG. (B) in this figure, and the data of the exposure end position LUT at this time is “110110000”. Therefore, the binarized data is compared with the data “110110000” of the exposure end position LUT, and when the two data match, it is determined that the image data acquired by the imaging means 5 is the reference position for the end of exposure. Then, the end position determination result is output from the exposure end position determination circuit 37. As described above, when six pixels 22 are arranged, for example, as shown in FIG. 10, the upper right corner of each pixel 22 corresponds to the second reference position.

Based on the determination result, the number of matches is counted in the counting circuit 38B shown in FIG. Then, the count number is compared with the exposure end pixel number obtained from the storage unit 30 shown in FIG. 1 in the comparison circuit 39B, and when the two values match, the exposure end signal is sent to the modulation data creation processing unit 31 shown in FIG. Output. In this case, as shown in FIG. 10, for example, when defined as a right upper corner portion of the laser beam first pixel in the scanning direction of 22 ₁ and the fourth pixel 22 ₄ second reference position, said The element addresses in the line CCD of the imaging means 5 corresponding to the reference position 2, for example “1900”, “4900”, are stored in the optical switch controller 24. When the reference position of the exposure start position and the exposure end position is detected as described above, the process proceeds to step S3.

In step S3, the exposure position in the moving direction of the glass substrate 8 is detected. Here, as shown in FIG. 3, the distance D between the scanning position F of the laser beam and the imaging position E of the imaging means 5 is set to an integral multiple (n times) of the array pitch P in the moving direction of the pixels 22. Therefore, the exposure position can be determined by counting the scanning period of the laser beam. For example, as shown in FIG. 13, when the distance D between the scanning position of the laser beam and the imaging position of the imaging means 5 is set to, for example, three times the arrangement pitch P of the pixels 22, the pixel in step S2 After the first and second reference positions are detected at the end of 22 (see (a) in the figure), when the glass substrate 8 moves and the pixel column center line reaches the imaging position of the imaging means 5 (same as above) The timing coincides with the scanning start timing of the laser beam. Here, when the laser beam is scanning with the period T, the conveyance speed of the glass substrate 8 is controlled to move by one pitch of the pixels 22 in synchronization with the period T of the laser beam. Accordingly, during the next 1T, the pixel 22 moves to the position shown in FIG. Further, after 2T, the pixel 22 moves to the position shown in FIG. After 3T, the column center line of the pixels 22 reaches the scanning position of the laser beam as shown in FIG. Thus, the exposure position is detected.

  Next, in step S4, the exposure position is adjusted while scanning the laser beam. Specifically, as shown in FIG. 14, the exposure position is adjusted by changing the current laser beam scanning position (element address) detected by the line sensor 17 provided on the fθ lens 13 and a predetermined reference element address. The amount of deviation is detected by comparison, and the optical deflection means 10 is controlled so that the scanning position of the laser beam matches the reference element address (reference scanning position).

Next, in step S5, exposure is started. The exposure is started by controlling the ON timing of the optical switch 9 with the optical switch controller 24. In this case, first, the optical switch 9 is turned on to scan the laser beam, and as soon as the scanning start time of the laser beam is detected by the line sensor 17, the optical switch 9 is turned off. At this time, for example, the element address “1000” of the imaging means 5 corresponding to the exposure start position in FIG. 10 is read from the modulation data creation processing unit 31, and the time t ₁ from the laser beam scanning start time to the exposure start position is calculated. Calculated by the control unit 32. In this case, the scanning time t ₀ from the scanning start time of the laser beam to the element address “1” of the imaging means 5 is measured in advance, and the scanning speed of the laser beam is synchronized with the clock CLK of the line CCD of the imaging means 5. If this is done, the scan start time t ₁ can be easily obtained as t ₁ = t ₀ +1000 CLK by counting the number of clocks up to the element address “1000”. Thus, the exposure is started by turning on the optical switch 9 after t ₁ from the scanning start time of the laser beam.

Next, in step S6, the exposure end position is detected. The exposure end position is obtained in the same manner as described above, for example, the exposure end time t ₂ at the element address “1900” is t ₂ = t ₀ +1900 CLK. As a result, the optical switch 9 is turned off after t ₂ from the scanning start time of the laser beam to complete the exposure.

  Next, in step S7, it is determined whether one scanning of the laser beam is completed. If "NO" determination is made here, the process returns to step S2 and the above-described operation is repeated. Then, in step S2, as shown in FIG. 10, for example, when the second exposure start position “4000” and the second exposure end position “4900” are detected, the process proceeds to step S5 through step S4, and the above-mentioned. In the same manner as described above, the exposure starts from the element address “4000”, and the exposure ends at the element address “4900”.

  If “YES” determination is made in step S7, the process returns to step S1 to move to an operation for detecting a new exposure position. Then, by repeatedly executing the above operation, an exposure pattern is formed on a desired area.

  As described above, according to the above-described embodiment, the image data of the first pixel column acquired by the imaging unit 5 and stored in the storage unit 20 is read out, and ORed with the newly acquired image data of the next pixel column. By removing the image, an image different from the original pixel row image due to the defect 42 such as a foreign matter or scratch attached to the stage 18 or the glass substrate 8 is removed, and image data of a defect-free pixel row is generated. be able to. Accordingly, it is possible to prevent the defect 42 from being erroneously recognized as a reference position and to expose the same, and it is possible to improve the exposure accuracy of a predetermined function pattern.

  In addition, since a reference position predetermined for the pixel 22 is detected using the image data of the defect-free pixel row, and an exposure pattern is formed based on the reference position, the overlapping of functional patterns on the pixel 22 is performed. The alignment accuracy is improved. Therefore, high overlay accuracy can be ensured even when applied to a step of forming a laminated pattern using a plurality of exposure apparatuses 1. Thereby, it is not necessary to equalize the mechanical accuracy between the exposure apparatuses, and the cost of the exposure apparatus 1 can be suppressed.

  Then, the reference position predetermined for the pixel 22 is read by the image pickup means 5, and exposure and exposure stop are performed with reference to the reference position. Therefore, it is necessary to align the pixel 22 and the exposure pattern in advance. The exposure work becomes easy.

FIG. 15 is a conceptual view showing an embodiment of an exposure apparatus according to the second invention. Here, parts different from the exposure apparatus shown in FIG. 1 will be described. The second invention comprises only one image pickup means 5 having an image processing area narrower than the scanning range of the laser beam.

In this case, for the detection of the reference position set for the pixel 22 of the black matrix 21, as shown in FIG. 16, for example, image data of the pixel row L1 is acquired by _one image pickup means 5, and the acquired image data and This is performed in comparison with the exposure start position LUT and the exposure end position LUT shown in FIG. Thereby, for example, when the exposure start position is set at the upper left corner of the _first pixel 22 ₁ and the exposure end position is set at the upper right corner of the _fourth pixel 22 ₄ , the imaging means 5 corresponding thereto is set. The line CCD element addresses, for example, “1000” and “4900” are stored in the storage unit 20.

  On the other hand, when the pixels 22 are arranged at a predetermined pitch in the column direction, the pixel column image acquired by the imaging unit 5 is copied to an area subsequent to the image processing area 43A of the imaging unit 5 and the imaging unit The pixel row image that cannot be acquired in step 5 is complemented, and exposure is performed based on the complemented pixel row image. That is, when the arrangement pitch of the pixels 22 in the column direction is W (for example, 1000 CLK), the pixel column image following the image processing region 43A of the imaging unit 5 is, for example, as shown in FIG. It starts after 4W (= 4000CLK) from "1000". Therefore, after performing exposure for “3900CLK” time between the exposure start position “1000” and the exposure end position “4900” read from the storage unit 20, the same exposure control (for example, exposure time “3900CLK”) is exposed. If applied to the area 4W after the start position “1000” (the copied pixel row image area 43B), the pixel row following the image processing area 43A of the imaging means 5 as shown in FIG. However, the same exposure pattern 44 can be formed. Furthermore, if the same operation is repeatedly executed, the entire area of the pixel row can be exposed.

  As described above, according to the second aspect of the present invention, the pixel column image acquired by the imaging unit 5 is copied to the missing region of the subsequent image to generate a pixel column image, and based on the generated pixel column image Thus, a predetermined functional pattern can be exposed with high accuracy even for a pixel column in a region that cannot be obtained by the imaging means 5.

  In addition, since it is not necessary to acquire all the images of the pixel row, the number of installed image pickup means 5 can be reduced, and the cost of the exposure apparatus can be reduced. In this case, since the image processing area 43A may be narrow, the high-resolution imaging means 5 can be applied, and the detection accuracy of the reference position is improved. Therefore, the exposure accuracy of the exposure pattern can be further improved.

  Although FIG. 15 shows an example in which the imaging unit 5 is disposed above the conveying unit 4, the imaging unit 5 may be disposed below the conveying unit 4. In this case, due to the presence of a suction groove, a mounting bolt, or the like that sucks the glass substrate 8 formed on the stage 18, an image acquired by the imaging means of the pixel rows of the black matrix 21 formed in advance on the glass substrate 8 is lost. There is. At this time, in the same manner as described above, if a pixel row image that cannot be acquired by the imaging unit 5 is complemented, a predetermined functional pattern can be enhanced even for a pixel row hidden behind the suction groove or the mounting bolt. The exposure can be performed with high accuracy.

Moreover, in the said 1st and 2nd embodiment, although the illumination means was made into back illumination, it is good also as epi-illumination.
And the exposure apparatus of this invention is not limited to what is applied to large sized substrates, such as a color filter of a liquid crystal display, It can apply also to exposure apparatuses, such as a semiconductor.

It is a conceptual diagram which shows embodiment of the exposure apparatus by this invention. It is a perspective view explaining the structure and operation | movement of an optical switch. It is explanatory drawing which shows the relationship between the scanning position of a laser beam, and the imaging position of an imaging means. It is a block diagram which shows the first half part of a processing system in the internal structure of an image processing part. It is a block diagram which shows the latter half part of a processing system in the internal structure of an image processing part. It is explanatory drawing which shows the relationship between the black matrix which moves to the direction orthogonal to the scanning direction of a laser beam, and the scanning locus | trajectory of a laser beam. It is a flowchart explaining the procedure of the pattern formation method using the said exposure apparatus. It is explanatory drawing which shows the method of binarizing the output of a ring buffer memory. It is explanatory drawing which shows the image of the exposure start position preset to the pixel of the black matrix, and its lookup table. It is explanatory drawing which shows the relationship between the reference position preset to the pixel of a black matrix, and the element of an imaging means. It is explanatory drawing which shows the method of removing the image of the defect which exists in the pixel of a black matrix. It is explanatory drawing which shows the image of the exposure end position preset to the pixel of a black matrix, and its lookup table. It is explanatory drawing which shows the method of detecting the exposure position with respect to the said pixel of the conveyance direction of a glass substrate. It is explanatory drawing which shows the method of correct | amending the scanning position of a laser beam. It is a conceptual diagram which shows embodiment of the exposure apparatus by 2nd invention. It is explanatory drawing which shows the method of producing | generating and exposing the pixel row | line | column image of the missing black matrix.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Exposure apparatus 5 ... Imaging means 7 ... Optical system control means 8 ... Glass substrate (exposed body)
21 ... Black matrix 22 ... Pixel (reference function pattern)
42 ... Defect 43 ... Image processing area (predetermined area)

Claims (4)

An exposure apparatus that relatively scans a light beam emitted from an exposure optical system in a direction orthogonal to a moving direction of an object to be exposed, and exposes a functional pattern on the object to be exposed at a predetermined pitch,
An imaging means for imaging a reference function pattern serving as a reference of an exposure position formed in advance on the object to be exposed;
By taking the logical sum of the image data using the image data of the two reference function patterns acquired by the imaging means, the defects in the reference function pattern image corresponding to one scanning area of the light beam are removed. A defect reference function pattern image is generated, an exposure start or end reference position is detected in the defect-free reference function pattern image, and the light beam irradiation start or irradiation stop is controlled based on the reference position. Optical system control means;
An exposure apparatus comprising: The optical system control means uses the image data of the previous reference function pattern acquired by the imaging means and the image data of the newly acquired reference function pattern before and after the moving direction of the object to be exposed. 2. An exposure apparatus according to claim 1 , wherein a defect-free reference function pattern image is generated by calculating a logical sum of image data at the same position. The optical system control means uses the image data of the reference function patterns adjacent to each other in the image data of the reference function patterns acquired simultaneously in the scanning direction of the light beam by the image pickup means, and performs a logical sum of the image data. 2. An exposure apparatus according to claim 1 , wherein a defect-free reference function pattern image is generated. An exposure apparatus that relatively scans a light beam emitted from an exposure optical system in a direction orthogonal to a moving direction of an object to be exposed, and exposes a functional pattern on the object to be exposed at a predetermined pitch,
An imaging means for imaging a reference function pattern serving as a reference of an exposure position formed in advance on the object to be exposed;
The image data of the reference function pattern of the predetermined area acquired by the imaging unit is copied to an area subsequent to the predetermined area to complement the image of the reference function pattern that cannot be acquired by the imaging unit, and the supplemented reference function An optical system control unit that detects a reference position of exposure start or end in the pattern image and controls the start or stop of irradiation of the light beam with reference to the reference position;
An exposure apparatus comprising:

Images