JP4235584B2 - 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.

To achieve the above object, an exposure apparatus according to the present invention, while conveying the object to be exposed in a predetermined direction, by scanning the light beam in the direction substantially perpendicular to the conveyance direction of the object to be exposed by the exposure optical system,該被An exposure apparatus that directly exposes a functional pattern on an exposure body, the exposure position formed in advance on the object to be exposed, with the front side of the scanning position of the light beam being an imaging position in the transport direction of the object to be exposed An imaging means for imaging a functional pattern serving as a reference, an illuminating means for illuminating the functional pattern serving as a reference and enabling imaging by the imaging means, and a scanning direction of the light beam on a scanning start side of the light beam orthogonally provided on a line sensor that detects the scanning start time of the light beam, the start and end of the reference position of the preset exposure function pattern to be imaged the reference by said image pickup means to detect Calculating a time at which the light beam passes through the respective reference positions with respect to the scanning start time, wherein the light beam passes through the line sensor, the irradiation start and irradiation stop of the light beam on the basis of the calculated time Optical system control means for performing control.

With such a configuration, while the object to be exposed is transported in a predetermined direction, the illumination unit illuminates a reference function pattern formed in advance on the object to be exposed, and the imaging unit emits a light beam in the transport direction of the object to be exposed. The functional pattern serving as the reference is imaged with the near side of the scanning position as the imaging position, and the exposure optical system scans the light beam in a direction substantially perpendicular to the conveying direction of the object to be exposed, and the light beam is scanned on the scanning start side. The light sensor scanning start time is detected by a line sensor provided orthogonal to the beam scanning direction, and the exposure start preset to the reference function pattern imaged by the imaging means by the optical system control means and detecting a reference position of the end, with respect to the scanning start time the light beam passes through the line sensor calculates the time the light beam passes through the respective reference position, the light Bee based on the calculated time Controlling the start and irradiation stop of irradiation. 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.

  In addition, the detection of the reference position by the optical system control unit is performed by binarizing the image of the reference function pattern acquired by the imaging unit and comparing it with image data corresponding to the preset reference position. Thus, it is performed by detecting a portion where both data coincide with each other. As a result, the image of the function pattern serving as a reference acquired by the imaging unit is binarized by the optical system control unit, and compared with image data corresponding to a preset reference position. Detect as position.

  Further, the image pickup means has light receiving elements arranged in a line. As a result, the one-dimensional image data of the functional pattern serving as a reference is acquired by the imaging means in which the light receiving elements are arranged in a line.

  Further, the illumination means is provided on the back side of the object to be exposed. Thereby, it illuminates from the back side of a to-be-exposed body with an illumination means.

Further, the exposure optical system includes two polarization elements arranged with their polarization axes orthogonal to each other and separated from each other, and electro-optic modulation arranged between the two polarization elements to change the polarization plane of polarized light by applying a voltage an optical switch having a vessel, in which provided on the optical axis of the light beam. As a result, the applied voltage of the electro-optic modulator disposed between two polarizing elements disposed with the polarization axes orthogonal to each other is controlled to start or stop irradiation of the light beam.

Then, the object to be exposed is inclined with respect to the moving direction so that the scanning locus of the light beam that is scanned relative to the object to be exposed is parallel to the arrangement direction of the reference function pattern. in which arranged. Accordingly, the object to be exposed is arranged to be inclined with respect to the moving direction so that the scanning trajectory of the light beam is parallel to the reference direction of the functional pattern.

The pattern forming method according to the invention, while conveying the object to be exposed in a predetermined direction, by scanning the light beam in the direction substantially perpendicular to the conveyance direction of the object to be exposed by the exposure optical system, the exposure on該被exposure member A pattern forming method for directly forming a pattern, wherein a functional pattern serving as a reference of an exposure position previously formed on the object to be exposed is illuminated by an illuminating unit, and the light beam is scanned in the transport direction of the object to be exposed The reference functional pattern is imaged by an imaging means at a position on the near side of the position, and scanning of the light beam is started by a line sensor provided on the light beam scanning start side orthogonal to the scanning direction of the light beam. time is detected and the detected start and end of the reference position of the preset exposure function pattern to be imaged the reference by the imaging means by an optical system control means, wherein the light beam is the Calculating a time at which the light beam passes through the respective reference positions with respect to the scanning start time passing in the sensor, and the control of irradiation start and irradiation stop of the light beam based on the calculated time, predetermined A predetermined exposure pattern is formed at the position .

With such a method, while the object to be exposed is transported in a predetermined direction, the imaging unit captures an image of the reference function pattern at the position in front of the scanning position of the light beam in the transport direction of the object to be exposed, and exposure. The optical system scans the light beam in a direction substantially perpendicular to the conveying direction of the object to be exposed, and the light beam scanning start time is set by a line sensor provided on the light beam scanning start side perpendicular to the light beam scanning direction. Detecting and detecting a reference position for the start and end of exposure set in advance in the functional pattern image picked up by the image pickup means by the optical system control means , and light based on the scan start time when the light beam passes through the line sensor. calculating a time at which the beam passes through the reference position, and the control of irradiation start and irradiation stop of the light beam based on the calculated time, other functions putter at positions corresponding to the functional patterns Performing the exposure of.

  In addition, the detection of the reference position by the optical system control unit is performed by binarizing the image of the reference function pattern acquired by the imaging unit and comparing it with image data corresponding to the preset reference position. Thus, it is performed by detecting a portion where both data coincide with each other. As a result, the image of the function pattern serving as a reference acquired by the imaging unit is binarized by the optical system control unit, and compared with image data corresponding to a preset reference position. Detect as position.

  Further, the image pickup means has light receiving elements arranged in a line. As a result, the one-dimensional image data of the functional pattern serving as a reference is acquired by the imaging means in which the light receiving elements are arranged in a line.

  Further, the illumination means is provided on the back side of the object to be exposed. Thereby, it illuminates from the back side of a to-be-exposed body with an illumination means.

Further, the exposure optical system includes two polarization elements arranged with their polarization axes orthogonal to each other and separated from each other, and electro-optic modulation arranged between the two polarization elements to change the polarization plane of polarized light by applying a voltage an optical switch having a vessel, in which provided on the optical axis of the light beam. As a result, the applied voltage of the electro-optic modulator disposed between two polarizing elements disposed with the polarization axes orthogonal to each other is controlled to start or stop irradiation of the light beam.

Then, the object to be exposed is inclined with respect to the moving direction so that the scanning locus of the light beam that is scanned relative to the object to be exposed is parallel to the arrangement direction of the reference function pattern. in which arranged. Accordingly, the object to be exposed is arranged to be inclined with respect to the moving direction so that the scanning trajectory of the light beam is parallel to the reference direction of the functional pattern.

According to the first and seventh aspects of the invention, while the object to be exposed is transported in a predetermined direction, the imaging unit captures a reference function pattern that is formed in advance on the object to be exposed, and this image is used as the reference. The exposure start and end reference positions set in advance in the functional pattern image are detected, and the exposure optical system scans the light beam in a direction substantially perpendicular to the conveying direction of the object to be exposed, and the light beam is scanned on the scanning start side. The scanning start time of the light beam is detected by a line sensor provided perpendicular to the scanning direction of the beam, and the time at which the light beam passes each reference position with reference to the scanning start time at which the light beam passes through the line sensor. calculated, based on the computed time can control the irradiation start and irradiation stop of the light beam, high-precision exposure of a predetermined function pattern in a predetermined position relative to the feature pattern to be the reference It can be carried out. 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 and eighth aspects of the invention, the image of the reference function pattern acquired by the imaging unit is binarized and compared with image data corresponding to a preset reference position. By detecting the coincident part as the reference position, the reference position can be detected at high speed in real time.

  Further, according to the inventions according to claims 3 and 9, the cost of the imaging means is obtained by acquiring the one-dimensional image data of the functional pattern serving as a reference by the imaging means in which the light receiving elements are arranged in a line. In addition to suppressing the increase, the data processing speed can be improved.

  According to the fourth and tenth aspects of the present invention, since the illumination unit is disposed on the back side of the object to be exposed, the contrast of the image acquired by the imaging unit is improved and the acquisition accuracy of the image data is improved. . Therefore, highly accurate exposure can be realized.

  Further, according to the inventions according to claims 5 and 11, the irradiation of the light beam is started by controlling the applied voltage of the electro-optic modulator disposed between the two polarizing elements arranged with the polarization axes orthogonal to each other. Alternatively, by stopping the irradiation, the switching operation of the irradiation and the stop of the light beam can be performed at high speed. Therefore, the exposure pattern formation accuracy can be improved.

  According to the inventions according to claims 6 and 12, the exposure object is moved in the moving direction so that the scanning locus of the light beam with respect to the exposure object moving at a constant speed is parallel to the arrangement direction of the reference function pattern. With this arrangement, the exposure pattern can be accurately formed without any deviation between the exposure start position and the exposure end position in the reference functional pattern arrangement direction.

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 conveying unit 4, an imaging unit 5, and a back light irradiating unit 6 as an illuminating unit. And an optical system control means 7. 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 images of pixels of a black matrix as a function pattern serving as a reference of an exposure position 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 imaging unit 5, a plurality of imaging units 5 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. The optical system control unit 7 detects a reference position for the start and end of exposure set in advance in the pattern image of the pixel 22 imaged by the imaging unit 5, and the scanning start time when the laser beam passes through the line sensor 17. The time when the laser beam passes through each of the reference positions is calculated with reference to the above, and the start and stop of the irradiation of the laser beam in the laser light source 2 are controlled based on the calculated time, and the output of the line sensor 17 Based on the above, the voltage applied to the light deflecting means 10 is controlled to deflect the laser beam emission direction, and the rotation speed of the polygon mirror 12 is controlled to maintain the scanning speed of the laser beam at a predetermined speed. The conveyance speed of the glass substrate 8 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. 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 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 and pattern forming method of the first embodiment configured as described above 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.

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 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 arrangement 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 is adjusted while scanning the laser beam. Specifically, as shown in FIG. 13, 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.

If the exposure pixel column number shown in FIG. 5 is designated as “L ₁ , L ₄ ...”, For example, the first pixel column L _{1 is} exposed as shown in FIG. After the execution, the exposure can be executed on the _fourth pixel column L ₄ by skipping the second column and the third column. Thereby, it is possible to perform exposure only for a region corresponding to red or blue or green. Note that the number of jumps may be specified instead of the pixel column number.

  As described above, according to the exposure apparatus and pattern formation method of the first embodiment, the pixels 22 of the black matrix 21 formed in advance on the glass substrate 8 imaged by the imaging unit 5 are imaged, and Since the exposure position is formed by detecting the reference position set in advance in the image and controlling the start or stop of the laser beam irradiation based on the reference position, the exposure accuracy for the pixel 22 is improved. To do.

  In addition, 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 accuracy of superimposing the functional 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.

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

  The CAD data of the exposure pattern only needs to include minimum exposure pattern data that is exposed based on the reference position set in the pixel 22, and the capacity of the storage unit that stores the CAD data is reduced. Can do. Therefore, an increase in the cost of the apparatus can be suppressed and the data processing speed can be improved.

  FIG. 15 is a conceptual view showing the main part of the second embodiment of the exposure apparatus according to the present invention. The exposure apparatus according to the second embodiment includes a guide light source 42 that emits guide light having a wavelength of, for example, 550 nm or more, in addition to the laser light source 2, and guides the guide light emitted from the guide light source 42 forward in the traveling direction. A mirror 43 that bends the path of light to the optical path side of the laser beam is disposed, and a half mirror 44 is disposed between the optical switch 9 and the light deflecting means 10 on the optical path of the laser beam so that the guide light is converted into the laser beam. The light is superimposed and emitted on the same optical axis. As a result, the laser beam and the guide light are scanned so as to overlap each other. In this case, the laser beam is on / off controlled by the optical switch 9, but the guide light is always on (irradiation state) when the apparatus is in operation.

  In the exposure operation in the second embodiment configured as described above, first, the time when the guide light passes through the line sensor 17 is detected as the scanning start time. Next, after the elapse of a predetermined time with reference to the scanning start time, the optical switch controller 24 turns on the optical switch 9 to emit a laser beam, and the glass substrate 8 is irradiated to start exposure. Next, after a predetermined time has elapsed from the scanning start time, the optical switch 9 is turned off to stop the laser beam emission, and the exposure ends. In this case, the guide light is always in an irradiated state, but as described above, the guide light is, for example, red or infrared light having a long wavelength, and thus, for example, a resist or the like applied on the glass substrate 8 is not exposed.

  According to the second embodiment, the same effects as those of the first embodiment can be obtained, and unnecessary exposure for detecting the scan start time in the first embodiment can be eliminated and only a predetermined position can be obtained. Can be exposed.

As shown in FIG. 16, exposure start times t ₃ , t ₅ ... And exposure end times t ₄ ... Are controlled with reference to a predetermined reference position for the pixel 22 and the conveyance speed of the glass substrate 8 is controlled. For example, it is possible to expose a pattern having a complicated shape as shown in FIG.
Moreover, in the said embodiment, although the illumination means was back lighting, 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.

1 is a conceptual diagram showing a first embodiment of an exposure apparatus according to the present 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. It is explanatory drawing which shows the method of jumping and exposing the pixel row | line | column of a black matrix. It is a conceptual diagram which shows the principal part of 2nd Embodiment of the exposure apparatus by this invention. It is explanatory drawing which shows the method of forming the exposure pattern of a complicated shape on the basis of the reference position preset to the pixel of a black matrix.

Explanation of symbols

1 ... Exposure apparatus
DESCRIPTION OF SYMBOLS 3 ... Exposure optical system 5 ... Imaging means 6 ... Back light irradiation means 7 ... Optical system control means 8 ... Glass substrate (to-be-exposed body)
9 ... Optical switch 15A, 15B ... Polarizing element 16 ... Electro-optic modulator
17 ... Line sensor 21 ... Black matrix 22 ... Pixel (functional pattern)
p: Polarization axis

Claims (12)

While conveying the object to be exposed in a predetermined direction, the light beam by the exposure optical system by scanning in a direction substantially perpendicular to the conveyance direction of the object to be exposed, an exposure apparatus that exposes functionality directly pattern on該被exposure member ,
An imaging means for imaging a functional pattern serving as a reference for an exposure position formed in advance on the object to be exposed, with the near side of the scanning position of the light beam in the transport direction of the object to be exposed as an imaging position;
Illuminating means for illuminating the reference functional pattern and enabling imaging by the imaging means;
A line sensor provided on the scanning start side of the light beam perpendicular to the scanning direction of the light beam and detecting a scanning start time of the light beam;
A reference position of exposure start and end preset in the reference function pattern imaged by the imaging means is detected, and the light beam is detected with reference to the scanning start time when the light beam passes through the line sensor. Optical system control means for calculating the time of passing each reference position, and controlling the start and stop of irradiation of the light beam based on the calculated time ;
An exposure apparatus comprising:   The detection of the reference position by the optical system control means is performed by binarizing the image of the reference function pattern acquired by the imaging means and comparing it with image data corresponding to the preset reference position. 2. An exposure apparatus according to claim 1, wherein the exposure is performed by detecting a portion where both data coincide with each other.   The exposure apparatus according to claim 1, wherein the image pickup unit is a device in which light receiving elements are arranged in a line.   The exposure apparatus according to claim 1, wherein the illumination unit is provided on a back side of the object to be exposed. The exposure optical system includes two polarizing elements disposed with their polarization axes orthogonal to each other and separated from each other, and an electro-optic modulator disposed between the two polarizing elements to change the polarization plane of polarized light by applying a voltage. The exposure apparatus according to claim 1 , further comprising: an optical switch having an optical axis on the optical axis of the light beam. The object to be exposed is arranged to be inclined with respect to the moving direction so that a scanning locus of the light beam that is scanned relative to the object to be exposed is parallel to the arrangement direction of the reference function pattern. an apparatus according to claim 1, characterized in that the. While conveying the object to be exposed in a predetermined direction, the exposure optical system by scanning a light beam in the direction substantially perpendicular to the conveyance direction of the object to be exposed, there a pattern forming method of directly forming an exposure pattern on該被exposure member And
Illuminating a functional pattern serving as a reference for an exposure position formed in advance on the object to be exposed by an illumination means;
The functional pattern serving as the reference is imaged by an imaging unit at a position on the near side of the scanning position of the light beam in the transport direction of the object to be exposed;
A scanning start time of the light beam is detected by a line sensor provided on the scanning start side of the light beam perpendicular to the scanning direction of the light beam;
An optical system control unit detects a reference position of exposure start and end preset in the reference function pattern imaged by the imaging unit, and uses the scanning start time when the light beam passes through the line sensor as a reference Calculating the time when the light beam passes through each reference position , controlling the start and stop of irradiation of the light beam based on the calculated time, and forming a predetermined exposure pattern at a predetermined position. A pattern forming method characterized by the above.   The detection of the reference position by the optical system control means is performed by binarizing the image of the reference function pattern acquired by the imaging means and comparing it with image data corresponding to the preset reference position. 8. The pattern forming method according to claim 7, wherein the pattern forming method is performed by detecting a portion where both data coincide with each other.   9. The pattern forming method according to claim 7, wherein the image pickup means includes light receiving elements arranged in a line.   The pattern forming method according to claim 7, wherein the illumination unit is provided on a back side of the object to be exposed. The exposure optical system includes two polarizing elements disposed with their polarization axes orthogonal to each other and separated from each other, and an electro-optic modulator disposed between the two polarizing elements to change the polarization plane of polarized light by applying a voltage. The pattern forming method according to claim 7 , further comprising: an optical switch including : on an optical axis of the light beam. The object to be exposed is arranged to be inclined with respect to the moving direction so that a scanning locus of the light beam that is scanned relative to the object to be exposed is parallel to the arrangement direction of the reference function pattern. the pattern forming method according to any one of claims 7 to 11, characterized in that the.

Images