JP4195413B2 - Exposure apparatus and pattern forming method - Google Patents

Description

  The present invention relates to an exposure apparatus and a pattern forming method for directly exposing a functional pattern on an object to be exposed, and more particularly, to image a reference position set in a reference function pattern previously formed on the object to be exposed by an imaging unit. The exposure apparatus and pattern that improve detection accuracy of the functional pattern and suppress the rise of the exposure apparatus by controlling the start or stop of irradiation of the light beam with reference to the reference position. It relates to a forming method.

  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 and a pattern forming method that address such problems and improve the overlay accuracy of functional patterns and suppress the rise of the exposure apparatus.

In order to achieve the above object, an exposure apparatus of the present invention scans a light beam emitted from an exposure optical system relatively in a direction orthogonal to the moving direction of the object to be exposed, and forms a functional pattern on the object to be exposed. A light deflector provided in the exposure optical system for deflecting the light beam in a moving direction of the object to be exposed, and a scanning position of the light beam irradiated to the object to be exposed. And an optical system control means for controlling the deflection angle of the light deflection means and processing the image acquired by the imaging means. The system control means changes the deflection angle of the light deflection means during the scanning of the light beam, swings the light beam on the exposure object to the imaging position side of the imaging means, and the deflection start time of the light deflection means And the waved light beam Based on the time detected by the imaging means, the relative distance between the scanning position of the light beam and the imaging position of the imaging means is calculated, and the deflection angle of the light deflection means is set so that the relative distance becomes a predetermined value. It is something to control.

  With such a configuration, the optical system control means changes the deflection angle of the light deflection means provided in the exposure optical system during scanning of the light beam, and swings the light beam to the imaging position side of the imaging means on the object to be exposed. Based on the deflection start time of the light deflection means and the time when the shaked light beam is detected by the imaging means for imaging the position on the near side with respect to the scanning position of the light beam in the moving direction of the object to be exposed. The relative distance between the scanning position of the light beam and the imaging position of the imaging means is calculated, and the deflection angle of the light deflecting means is controlled so that the relative distance becomes a predetermined value based on the calculation result. Thereby, the overlay accuracy of the predetermined function pattern with respect to the reference function pattern formed in advance on the object to be exposed is improved.

  The optical system control means controls the deflection angle of the light deflection means before exposing the predetermined functional pattern on the object to be exposed. Thereby, before the functional pattern is exposed on the object to be exposed, the deflection angle of the light deflecting unit is controlled to adjust the scanning position of the light beam.

  The optical system control unit detects a reference position that is acquired by the imaging unit and preset in a function pattern that is a reference formed on the object to be exposed, and the light beam is irradiated with the reference position as a reference. Controls start or stop of irradiation. Thereby, the reference position preset in the reference function pattern acquired by the imaging means is detected by the optical system control means, and the light beam irradiation start or irradiation stop is controlled based on the reference position.

The pattern forming method of the present invention is a pattern forming method in which a light beam irradiated from an exposure optical system is scanned relatively in a direction orthogonal to the moving direction of the object to be exposed, and the functional pattern is exposed on the object to be exposed. A method is provided in which a deflection angle of a light deflecting unit provided in the exposure optical system for deflecting the light beam in a moving direction of the object to be exposed is changed during scanning of the light beam. A step of swinging the exposure object in the moving direction, a deflection start time of the light deflecting unit, and the shaken light beam before the moving direction of the exposure object with respect to the scanning position of the light beam on the exposure object. Calculating the relative distance between the scanning position of the light beam and the imaging position of the imaging means based on the time detected by the imaging means for imaging the position on the side, so that the relative distance becomes a predetermined value The deflection angle of the light deflection means A method Gosuru, previously comprising the steps of acquiring an image in relation to the standard function patterns provided, previously set in function pattern to be obtained the reference by the imaging means by Ri before Symbol exposed object on the imaging device Performing a step of detecting a predetermined reference position and a step of exposing a predetermined functional pattern to a predetermined position with respect to the reference position by controlling irradiation start or irradiation stop of the light beam with reference to the reference position. To do.

  By such a method, during scanning of the light beam, the light deflection means swings the light beam toward the front side in the moving direction of the object to be exposed, the light beam is detected by the imaging means, and the deflection is started and then detected by the imaging means. The relative distance between the scanning position of the light beam and the imaging position of the imaging means is calculated based on the time until the adjustment is performed, and the relative distance is adjusted to a predetermined value based on the calculation result. A predetermined functional pattern is exposed at a predetermined position with respect to the formed reference functional pattern.

  The light deflection means changes the deflection angle during scanning of the light beam before the predetermined functional pattern is exposed on the object to be exposed. Thus, the deflection angle is changed by controlling the light deflecting means before forming the functional pattern on the object to be exposed.

  According to the first and fourth aspects of the present invention, during scanning of the light beam, the light deflection unit swings the light beam on the object to be exposed to the imaging position side of the imaging unit, and the light beam is detected by the imaging unit. The relative distance between the scanning position of the light beam and the imaging position of the imaging means is calculated based on the time from the start of deflection until detection by the imaging means, and the relative distance becomes a predetermined value based on the calculation result. By adjusting as described above, it is possible to easily correct the scanning position deviation of the light beam without adding a special correction system. Further, as described above, by correcting the deviation of the scanning position of the light beam, exposure of a predetermined exposure pattern at a predetermined position can be performed with high accuracy.

  According to the second and fifth aspects of the present invention, the control for changing the deflection angle by the light deflecting means is executed before the predetermined functional pattern is exposed on the object to be exposed. In addition, the scanning position correction of the light beam can always be executed. Therefore, it is possible to perform exposure with respect to the reference function pattern with higher accuracy.

  Furthermore, according to the invention according to claim 3, by controlling the start or stop of irradiation of the light beam with reference to a reference position preset in the reference function pattern acquired by the imaging means. Thus, exposure to the reference function pattern can be performed with high accuracy. 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.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a conceptual view showing a first embodiment of an exposure apparatus according to the present invention. The exposure apparatus 1 directly 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, an illumination unit 6, and an optical system control unit. 7. The functional pattern is a pattern of components necessary for the product to perform its intended operation. For example, in a color filter, a black matrix pixel pattern and red, blue, and green color filters are used. A pattern, which is a wiring pattern or various electrode patterns in a semiconductor component. 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. In addition, a line sensor 17 is provided at the 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 time 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 on the front side of the scanning position of the laser beam in the conveyance direction indicated by an arrow A above the conveyance unit 4. The image pickup means 5 picks up images of black matrix pixels as a reference functional pattern formed in advance on the glass substrate 8, 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 5 may be installed accordingly.

  An illumination unit 6 is provided below the transport unit 4. The illuminating unit 6 illuminates the pixel 22 and enables the imaging unit 5 to capture an image.

  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. The optical system control unit 7 detects a reference position set in advance in the pattern image of the pixel 22 imaged by the imaging unit 5, and starts or stops irradiation of the laser beam in the laser light source 2 with reference to the reference position. And 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 control the scanning speed of the laser beam. 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 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. The polygon drive unit 25B that controls the driving of the polygon mirror 12, the transport controller 26 that controls the transport speed of the transport unit 4, the illumination light controller 27 that turns on and off the illumination unit 6, and the imaging unit 5 An A / D converter 28 for A / D converting the image, an image processor 29 for determining the irradiation start position and the irradiation stop position of the laser beam based on the A / D converted image data, and the image processor 29 Data of the laser beam irradiation start position (hereinafter referred to as exposure start position) and the irradiation stop position (hereinafter referred to as exposure end position) obtained by the above processing. And a storage unit 30 for storing 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 creation processing unit 31 that creates modulation data to be turned on / off and a control unit 32 that appropriately controls the entire apparatus to perform a predetermined target operation are provided.

  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 38B 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. Furthermore, for each of these data, for example, 3 × 3 CCD pixel images 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 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.

Based on the determination result, the number of matches is counted in the counting circuit 38A shown in FIG. 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. 11A, the exposure end position LUT is used. (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, for example, “1900” and “4900” in the line CCD of the imaging means 5 corresponding to the reference position 2 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. 12, 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 (scanning position) is adjusted while scanning the laser beam. Specifically, as shown in FIG. 13, the adjustment of the scanning position is performed by driving the light deflection unit driving unit 25 </ b> A of the optical system control unit 7 outside the functional pattern formation region of the color filter on the glass substrate 8. The deflection angle θ of the light deflecting means 10 is changed until the light beam passes through the imaging position of the imaging means 5 at the rear of the moving direction of the glass substrate 8 at a predetermined deflection speed v as shown in FIG. Shake a lot. As a result, the light beam crosses the imaging position on the glass substrate 8 of the imaging means 5 twice. Therefore, as shown in FIG. 5B, the output of the imaging means 5 is detected as two peak outputs when the light beam crosses the imaging position for the first time and when it crosses for the second time. In this case, in the control unit 32, the time τ ₁ between the deflection start time obtained from the light deflection unit driving unit 25A and the first detection time of the light beam obtained from the imaging unit 5, and the deflection speed v of the light beam. And a relative distance D ₁ from the imaging position to the scanning position of the light beam is obtained by calculating D ₁ = τ ₁ × v. The deflection angle θ of the light deflection means 10 corresponding to the relative distance D ₁ is θ ₁ as shown in FIG. Here, when the distance D ₁ obtained by the calculation is deviated from the predetermined distance D, the control unit 32 determines it and calculates τ ₂ = D / v and is detected by the imaging means 5. After τ ₂ hours have elapsed from the detection time of the second light beam, the deflection operation of the light deflection means 10 is stopped and the deflection angle is maintained at θ ₂ . As a result, the light beam is scanned while maintaining a predetermined distance D with respect to the imaging position of the imaging means 5. Thus, when the adjustment of the scanning position of the light beam is completed, the process proceeds to step S5.

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 immediately after the line sensor 17 detects the scanning start time of the laser beam, 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 exposure apparatus and pattern forming method of the present invention, the light deflecting means 10 swings the light beam backward in the moving direction of the glass substrate 8 during scanning of the light beam, and the light beam is picked up by the imaging means 5. The relative distance D ₁ between the scanning position of the light beam and the imaging position of the imaging means 5 is calculated based on the time from detection and deflection until detection by the imaging means 5, and the above based on the calculation result By adjusting the relative distance D ₁ to be the predetermined value D, it is possible to easily correct the scanning position deviation of the light beam without adding a special correction system. Therefore, exposure of a predetermined exposure pattern at a predetermined position can be performed with high accuracy.

  Further, the pixel 22 of the black matrix 21 formed in advance on the glass substrate 8 imaged by the imaging means 5 is photographed, a reference position preset in the image of the photographed pixel 22 is detected, and the reference position is used as a reference. Since the exposure pattern is formed by controlling the start or stop of the irradiation of the laser beam, the exposure accuracy for the pixel 22 is improved.

  Since the exposure pattern is formed on the pixel 22 based on a predetermined reference position, it is possible to eliminate the problem of deterioration in the overlay accuracy of the function patterns due to the difference in accuracy between the exposure apparatuses. . 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, the cost increase of the exposure apparatus 1 can be suppressed.

  The exposure apparatus of the present invention is not limited to those applied to large substrates such as color filters of liquid crystal displays, and can also be applied to exposure apparatuses such as semiconductors.

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 by this invention. 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 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.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Exposure apparatus 3 ... Exposure optical system 5 ... Imaging means 6 ... Illumination means 7 ... Optical system control means 8 ... Glass substrate (exposed body)
DESCRIPTION OF SYMBOLS 10 ... Light deflection means 21 ... Black matrix 22 ... Pixel (functional pattern)

Claims (5)

An exposure apparatus that exposes a functional pattern to the object to be exposed by relatively scanning a light beam emitted from the exposure optical system in a direction orthogonal to the moving direction of the object to be exposed,
A light deflector provided in the exposure optical system for deflecting the light beam in a moving direction of the object to be exposed;
Imaging means for imaging a position on the near side in the moving direction of the object to be exposed with respect to a scanning position of a light beam applied to the object to be exposed;
An optical system control means for controlling a deflection angle of the light deflection means and processing an image acquired by the imaging means;
The optical system control means changes the deflection angle of the light deflection means during the scanning of the light beam, swings the light beam on the object to be imaged to the imaging position side, and deflects the light deflection means. The relative distance between the scanning position of the light beam and the imaging position of the imaging means is calculated based on the start time and the time when the shaken light beam is detected by the imaging means, and the relative distance is a predetermined value. An exposure apparatus for controlling the deflection angle of the light deflecting means so that 2. An exposure apparatus according to claim 1, wherein said optical system control means executes control of a deflection angle of said light deflection means before exposing said functional pattern on said object to be exposed. The optical system control unit detects a reference position that is acquired by the imaging unit and preset in a function pattern that is a reference formed on the object to be exposed, and the light beam is irradiated with the reference position as a reference. 2. The exposure apparatus according to claim 1, wherein start or irradiation stop is controlled. A pattern forming method in which a light beam emitted from an exposure optical system is relatively scanned in a direction orthogonal to a moving direction of an object to be exposed, and a functional pattern is exposed on the object to be exposed,
A deflection angle of a light deflecting means provided in the exposure optical system for deflecting the light beam in the moving direction of the object to be exposed is changed during the scanning of the light beam, so that the light beam is moved in the moving direction of the object to be exposed. Swinging to the near side,
The deflection start time of the light deflection means and the time when the shaken light beam is detected by an imaging means for imaging the position of the exposure object in the moving direction relative to the scanning position of the light beam on the exposure object. Calculating a relative distance between the scanning position of the light beam and the imaging position of the imaging means based on
Controlling the deflection angle of the light deflection means so that the relative distance is a predetermined value;
A step of acquiring an image of the feature pattern to be provided in advance based on the I Ri before Symbol exposed object on the imaging unit,
Detecting a reference position preset in the function pattern serving as the reference acquired by the imaging means;
Controlling the start or stop of irradiation of the light beam with reference to the reference position to expose a predetermined functional pattern at a predetermined position with respect to the reference position;
The pattern formation method characterized by performing. 5. The pattern forming method according to claim 4, wherein the light deflection means changes the deflection angle during the scanning of the light beam before exposing the functional pattern on the object to be exposed.

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