JP2019105675A - Exposure apparatus and exposure method - Google Patents

Abstract

To provide an exposure apparatus in which misalignment between a substrate to be exposed and a photomask due to the influence of yawing can be prevented.SOLUTION: In the exposure method: by comparing reference pattern data obtained by imaging an existing reference pattern formed on a substrate to be exposed and reference position part data of a photomask to detect a deviation amount of the photomask in a width direction and a provisional travel amount of the photomask is calculated; apparatus-intrinsic yawing characteristic data in which a yawing state of the substrate to be exposed or the photomask changes is stored in advance; and a control is performed to correct the photomask travel amount on the basis of the yawing characteristic data.SELECTED DRAWING: Figure 11

Description

  The present invention relates to an exposure apparatus and an exposure method.

  Exposure apparatuses are used in a wide range of technical fields such as light alignment processing for performing alignment processing on an alignment film of a liquid crystal panel and exposure of a photoresist used in a photolithography process. In recent years, flat panel displays (FPDs) such as liquid crystal panels and organic EL (Electro-Luminescence) panels have been increased in size and in high definition. In FPD, the larger the photomask used for exposure, the higher the production cost. In addition, in the case of a large photomask, there is a problem that the probability of occurrence of bending or distortion becomes high. As this measure, for example, an alignment processing apparatus disclosed in Patent Document 1 is known. In this orientation processing apparatus, a set of a plurality of small photomasks is used for a substrate transported at a constant speed in a fixed direction.

  In the above-described alignment processing apparatus, the displacement amount of the photomask with respect to the substrate is detected from the positional relationship between the existing linear pattern formed on the substrate and the reference pattern formed on the photomask. The position at which this shift amount is detected is on the upstream side in the transport direction with respect to the position at which the exposure processing is performed thereafter. After that, the substrate portion at the position where the above-mentioned deviation amount is detected is moved to the position where the exposure processing is performed by the substrate being transported to the downstream side. At this time, the photomask is corrected and moved in the width direction (the direction perpendicular to the transport direction) based on the above displacement amount to prevent the photomask from being displaced with respect to the exposure expected position. Such a method of correcting and controlling the position in the width direction of the photomask is referred to as so-called follow-up control.

  The photomask is provided with an exposure light transmitting portion for performing exposure and an imaging light transmitting portion for detecting the linear pattern and the reference pattern. The light transmission unit for exposure is disposed on the downstream side in the transport direction, and the light transmission unit for imaging is disposed on the upstream side in the transport direction. The reason for arranging the light transmission unit for exposure and the light transmission unit for imaging at different positions in the transport direction is because the position and design of the imaging unit and the substrate part whose displacement amount has been detected reach the exposure position. This is because it takes time to follow the photomask to correct the position of the photomask. The distance between the light transmitting portion for exposure and the light transmitting portion for imaging may require a length of about 100 mm.

JP, 2011-164639, A

  When the above-described conventional techniques are applied to the manufacture of liquid crystal panels and the like in which high definition is promoted, the following problems occur. That is, due to the mechanical state of the substrate transfer guide (substrate transfer axis) for transferring the substrate, the substrate is transferred with yawing. As described above, there is a distance between the position at which the amount of displacement of the photomask with respect to the substrate is detected and the position at which exposure processing is actually performed. Therefore, if the substrate yaws until the substrate portion where the above displacement amount of the photomask is detected reaches the position where the exposure processing is performed, the correction of the displacement amount in the follow-up control is actually performed. An exposure position error occurs.

  By the way, in recent years, the number of pixels of the full high-definition liquid crystal television that has been widespread is 2,073,600 in total (horizontal pixel) 1920 × vertical (vertical pixel) 1080, and the total length and width in total. In 2160, the total is 8,294,400 pixels, that is, four times as many pixels as full high-definition television. In addition, development of 8K television has also started. With the progress of such high definition, the line and space of the source line, the gate line, the black matrix and the like formed on the substrate are narrowed. If the substrate to be transported is affected by yawing, it is expected that even a slight deviation of the photomask with respect to the substrate will have a large effect. As a result, in the exposure process, it is more important to prevent the shift of the photomask with respect to the substrate. The effect of the yawing of the transfer substrate is the same as in the processing of performing various light irradiations on the substrate such as exposure processing of various materials, light annealing processing, and laser processing in addition to the light alignment processing of the alignment film.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an exposure apparatus and an exposure method capable of preventing misalignment of a photomask due to the influence of yawing of a substrate or the like.

  In order to solve the problems described above and to achieve the object, according to an aspect of the present invention, the reference position portion and the light transmitting portion for exposure are formed apart in the mask surface, and the existing reference pattern is formed along the scanning direction. An imaging unit that is disposed integrally with the photomask and the photomask that moves relatively along the scanning direction with respect to the substrate on which the exposure pattern is formed, and that images the reference pattern and the reference position portion And comparing the reference pattern data and the reference position portion data captured by the imaging unit with the reference pattern of the partial exposure planned region of the substrate and the reference position portion data, and the scan of the substrate to be exposed The amount of displacement of the photomask in the width direction perpendicular to the direction is detected to calculate the amount of temporary movement of the photomask, and the exposure light transmitting portion of the region for partial exposure is exposed to light. And a control unit that performs control to move the photomask in the width direction based on the temporary movement amount along with movement to the position, and a partial exposure planned area along the scanning direction on the substrate to be exposed An exposure apparatus for exposing continuously or intermittently, wherein the control unit is configured to move the substrate to be exposed or the photomask along with relative movement of the substrate to be exposed and the photomask in the scanning direction. The device-specific yawing characteristic in which the yawing state changes is stored in advance as yawing characteristic data, and the provisional movement amount is corrected based on the yawing characteristic data to move the photomask in the width direction. .

  In the aspect, a difference between positions in the scanning direction of both end portions in the width direction in the existing width direction pattern extending in the width direction of the substrate to be exposed taken by the imaging unit is detected, and the yawing is performed. It is preferable to detect a temporal change in characteristics and update the yawing characteristic data when the difference between the positions in the scanning direction of the both end portions of the width direction pattern is larger than an allowable value.

  In the aspect described above, the substrate to be exposed is transported in the scan direction along the substrate transport guide, and the photomask is movable in the width direction perpendicular to the scan direction to a fixed position in the scan direction. Is preferably provided.

  In the aspect described above, preferably, the reference pattern and the width direction pattern are selected from a black matrix, a gate line, a source line, a row of pixel electrodes, a row of color filters, and the like formed on a substrate to be exposed.

  Another aspect of the present invention is a substrate on which an existing reference pattern is formed along the scanning direction on a photomask in which a reference position portion and an exposure light transmitting portion are formed apart from each other in a mask surface. A step of relatively moving in the scanning direction, a step of imaging the reference pattern and the reference position portion formed at a position corresponding to the partial exposure planned region of the substrate to be exposed; By comparing the reference pattern position data and the reference position portion data, the amount of displacement of the photomask with respect to the substrate to be exposed in the width direction perpendicular to the scanning direction is detected, and the provisional movement amount of the photomask is determined. The partial exposure scheduled area corresponds to the light transmitting portion for exposure in accordance with the step of calculating and the relative movement of the substrate to be exposed and the photomask in the scanning direction. Before the exposure is performed, the yawing state of the substrate to be exposed or the photomask generated due to the relative movement of the substrate to be exposed or the photomask changes, based on preset device-specific yawing characteristic data, The provisional movement amount of the photomask is corrected to calculate the correction movement amount, and the photomask is moved along the width direction based on the correction movement amount, and the partial exposure is performed through the light transmission portion for exposure. And b. Exposing light into the planned area.

  In the above aspect, the change with time of the yawing characteristic is detected by detecting the difference in the position in the scanning direction of both end portions of the existing widthwise pattern extending in the width direction of the substrate to be exposed imaged by the imaging unit. It is preferable that the yawing characteristic data be updated when the difference between the positions in the scanning direction at both ends of the widthwise pattern is larger than an allowable value.

  In the aspect described above, the substrate to be exposed is transported in the scan direction along the substrate transport guide, and the photomask is provided movably in the width direction perpendicular to the scan direction at a fixed position in the scan direction. Is preferred.

  In the aspect described above, preferably, the reference pattern and the width direction pattern are selected from a black matrix, a gate line, a source line, a row of pixel electrodes, a row of color filters, and the like formed on the substrate to be exposed.

  According to the exposure apparatus and the exposure method according to the present invention, misalignment between the substrate to be exposed and the photomask due to the influence of yawing of the substrate to be exposed or the photomask can be prevented.

FIG. 1 is a partial perspective view of an exposure apparatus according to an embodiment of the present invention. FIG. 2 is a block diagram of an exposure apparatus according to the embodiment of the present invention. FIG. 3 is a plan view showing a state where the color filter substrate is mounted on the exposure apparatus according to the embodiment of the present invention. FIG. 4 is an explanatory view showing a correspondence between a photomask and an imaging unit in the exposure apparatus according to the embodiment of the present invention. FIG. 5 is an explanatory view showing a double focus structure of an imaging element constituting an imaging unit in the exposure apparatus according to the embodiment of the present invention. FIG. 6 is a plan view showing a state in which the color filter substrate is mounted on the exposure apparatus according to the embodiment of the present invention and traveled to the vicinity of the exposure unit. FIG. 7 is an explanatory plan view showing a relationship between an imaging light transmission portion for imaging a reference pattern of a color filter substrate and a reference position portion and an exposure light transmission portion in the exposure apparatus according to the embodiment of the present invention. is there. FIG. 8 is an explanatory plan view showing the position of the light transmitting portion 17 for exposure when performing control in which correction based on yawing characteristic data is added to the amount of mask movement in the exposure apparatus according to the embodiment of the present invention . FIG. 9 is an explanatory plan view showing a result of performing a light alignment process on a color filter substrate using the exposure apparatus according to the embodiment of the present invention. FIG. 10 is an explanatory plan view showing a result of a comparative example in which the correction of the mask movement amount based on the yawing characteristic data is not performed. FIG. 11 is a flowchart showing an exposure method according to an embodiment of the present invention. FIG. 12 is a diagram illustrating the exposure method according to the embodiment of the present invention, in which when the color filter substrate is mounted on the substrate stage, the color filter substrate travels and extends in the width direction when there is no shift in alignment position. It is explanatory drawing which shows the example which measures the rotation angle of yawing from the position of the both ends of the formed black matrix. FIG. 13 is a view showing the measurement results of the substrate rotation angle at the imaging position in the imaging light transmission part in the exposure apparatus and the position of the substrate passing through the exposure light transmission part in the example shown in FIG. 12; is there. In the exposure method according to the embodiment of the present invention, FIG. 14 extends in the width direction when the color filter substrate is caused to travel with the color filter substrate being mounted on the substrate stage in a state where the alignment position is shifted. It is explanatory drawing which shows the example which measures the rotation angle of yawing from the position of the both ends of the black matrix formed in this way. FIG. 15 is a view showing the measurement results of the substrate rotation angle at the imaging position in the imaging light transmission part in the exposure apparatus and the position of the substrate passing through the exposure light transmission part in the example shown in FIG. is there.

  The present invention can be applied to an apparatus and method for performing light irradiation such as exposure processing of an alignment film of a liquid crystal panel, light annealing processing, laser processing, and exposure processing of various materials. Hereinafter, an embodiment in which the present invention is applied to an exposure apparatus and an exposure method for performing a light alignment process on a color filter substrate of a liquid crystal panel and a color filter substrate (counter substrate) on which a counter electrode is formed is based on the drawings. Explain.

  However, it should be noted that the drawings are schematic, and that dimensions, ratios of dimensions, numbers, shapes, etc. of respective members are different from actual ones. In addition, the drawings also include portions in which dimensional relationships, ratios, quantities, shapes, etc. are different among the drawings.

[Arrangement of exposure apparatus]
1 to 3 show an exposure apparatus 1 according to the present embodiment. As shown in FIGS. 1 and 2, the exposure apparatus 1 includes an apparatus body 2, a substrate transfer unit 3, three exposure units 4L, 4R, and 4C (see FIG. 3), an imaging unit 5, and photomask driving. A unit 6 and a control unit 7 are provided. As shown in FIG. 3, in exposure apparatus 1 according to the present embodiment, an alignment film (not shown) in which each of three exposure units 4L, 4R, 4C is provided on the surface of color filter substrate 9 as a substrate to be exposed. The photo-alignment process of As shown in FIG. 3, the exposure units 4L and 4R are disposed on both sides in the width direction W at the position Pm1 in the substrate transfer unit 3, and the exposure unit 4C is in the center in the width direction W at the position Pm2 in the substrate transfer unit 3. It is arranged.

  The apparatus main body 2 includes a plate-like substrate stage 8 on a base portion (not shown). As shown in FIG. 1 and FIG. 3, this substrate stage 8 has a width dimension and a length dimension capable of mounting the color filter substrate 9 as a counter substrate of the liquid crystal panel and moving it in the scanning direction S.

  As shown in FIG. 1, the substrate stage 8 selectively opens the opening 8A so as not to block the illumination light from the position detection illumination 21 applied to the imaging light transmission portion 18 formed on the photomask 16 described later. Is formed. The substrate stage 8 is formed of a plate-like porous body, and compressed air is jetted out from the upper surface to make the color filter substrate 9 float, so that the color filter substrate 9 runs smoothly on the substrate stage 8. It is possible.

  The substrate transport unit 3 includes a pair of parallel linear guides 10 and 11 extending along the scanning direction S on both sides of the substrate stage 8 in the width direction W (direction perpendicular to the scanning direction S). In the present embodiment, a linear block portion 12 which is driven to move in the scanning direction S along the linear guide 10 is provided. As shown in FIG. 1, the linear block portion 12 connects and fixes the end portion in the width direction of the color filter substrate 9. The linear block unit 12 can be advanced and retracted along the scanning direction S by a linear drive unit (not shown).

  The exposure units 4L, 4R, and 4C include an exposure light source 13, a mirror 15 that reflects the exposure light 14 emitted from the exposure light source 13 toward the lower substrate stage 8, and a photomask 16 on which the exposure light 14 is irradiated. And. The beam of exposure light 14 emitted toward the photomask 16 is set to have an irradiation area such that the entire area of the exposure light transmitting portion 17 described later of the photomask 16 can be irradiated.

  As shown in FIG. 1, the photomask 16 is driven by a photomask driving unit 6 provided on the apparatus body 2 side. The photomask 16 moves only in the width direction W perpendicular to the scanning direction S at the time of exposure.

  As shown in FIG. 4, in the photomask 16, a set of a plurality of exposing light transmitting portions 17 and an imaging light transmitting portion 18 are formed in the mask surface. The photomask 16 has a light shielding film 19 formed on the surface of a transparent glass substrate. The light shielding film 19 is not formed in the regions of the plurality of exposure light transmitting portions 17 and the imaging light transmitting portion 18 in the photomask, so that light can be transmitted.

  The exposure light transmitting portion 17 has a rectangular slit shape elongated along the scanning direction S, and is formed parallel to each other at a predetermined pitch along a width direction W perpendicular to the scanning direction S. The imaging light transmitting portion 18 has a slit shape elongated in the width direction W. At the central portion in the width direction W of the imaging light transmitting portion 18, a reference position portion 19A is formed of a light shielding film 19 so as to cross the slit. As shown in FIG. 4, in the photomask 16, the imaging light transmitting portion 18 including the reference position portion 19A and the exposure light transmitting portion 17 are arranged to be separated by a distance D along the scanning direction S. There is.

  Specifically, the imaging unit 5 is configured by a linear CCD camera. The imaging unit 5 is configured by a row of a plurality of imaging elements 5C1 to 5Cn along a width direction W perpendicular to the scanning direction S. As shown in FIG. 4, the imaging unit 5 is set to have a length that enables imaging in the width direction W of the imaging light transmitting unit 18. The imaging unit 5 is fixed in position with respect to the photomask 16 so as to follow the movement of the photomask 16 so as to maintain the positional relationship as shown in FIG. 4. The imaging unit 5 may be fixed to the photomask 16. Further, as shown in FIG. 1, in the present embodiment, the imaging unit 5 is disposed above the substrate stage 8 and the position detection illumination 21 is disposed below the substrate stage 8. However, the illumination for position detection is 21 may be disposed above the substrate stage 8 and the imaging unit 5 may be disposed below the substrate stage 8.

  As shown in FIG. 5, the imaging device 5C is configured to be able to simultaneously image the reference position portion 19A of the photomask 16 and the black matrix 20 as the existing reference pattern in the color filter substrate 9. As shown in FIG. 1, a position detection illumination 21 is disposed below the photomask 16 and the substrate stage 8. The position detection illumination 21 may be set to follow in synchronization with the photomask 16.

  As shown in FIG. 2, the control unit 7 includes a main control unit 22, a light source power supply unit 23, an image processing unit 24, a mask drive unit controller 25, a substrate transport unit controller 26, a storage unit 27, and computations. And a unit 28. As shown in FIG. 3, control corresponding to the exposure units 4L, 4R, 4C is controlled by one control unit 7.

  Hereinafter, the control unit 7 will be described focusing on the control system corresponding to the exposure unit 4L. The light source power supply unit 23 turns on the power of the exposure light source 13 of the exposure unit 4L when the operation of the exposure apparatus 1 starts, and causes the exposure light source 13 to emit the exposure light 14. The image processing unit 24 obtains reference pattern data of a predetermined black matrix 20 (reference pattern data) along the scanning direction S of the color filter substrate 9 obtained by the linear CCD camera of the imaging unit 5 and reference of the photomask 16. The data (reference position portion data) of the reference position portion of the position portion 19A is detected.

  The mask drive controller 25 operates the photomask drive unit 6 based on the control signal from the main control unit 22 to adjust the photomask 16 to a position in the width direction W perpendicular to the scanning direction S. Accordingly, the mask drive controller 25 brings the light transmitting portion 17 for the exposure portion of the photomask 16 and the planned exposure position on the color filter substrate 9 into a mask-aligned state.

  The substrate transport controller 26 controls the traveling speed and the like of the linear block 12 and the color filter substrate 9 which move in the scanning direction S with respect to the linear guide 10 based on a control signal from the main controller 22.

  The storage unit 27 stores position data of the black matrix 20 serving as a reference pattern on the color filter substrate 9, an operation program of the entire apparatus, and an alignment control program of the photomask 16.

  The storage unit 27 includes a yawing characteristic data storage unit 27A. The yawing characteristic data storage unit 27A stores yawing characteristic data unique to the apparatus. The device-specific yawing characteristic data is, for example, a characteristic determined by mechanical adjustment caused by the substrate stage 8, the linear guides 10 and 11, the linear block portion 12 and the like. The color filter substrate 9 changes its yawing state under the influence of the yawing characteristic corresponding to the position with respect to the substrate stage 8 according to such a yawing characteristic.

  The yawing is a state in which the color filter substrate 9 rotates around the vertical axis while maintaining the horizontal surface on the substrate stage 8. Therefore, in the exposure light transmission part 17 (exposure position), the amount of deviation of the photomask 16 obtained from the reference pattern of the color filter substrate 9 observed through the imaging light transmission part 18 and the imaging data of the reference position 19A. Thus, the amount of deviation due to the yawing characteristic is combined.

  The device-specific yawing characteristics can be obtained by the following method. First, the color filter substrate 9 (test substrate) accurately positioned on the substrate stage 8 is run as usual. At this time, as shown in FIG. 8, the length of the black matrix 20A orthogonal to the black matrix 20 in the scanning direction S through the imaging light transmitting portion 18 for each partial exposure scheduled region of the color filter substrate 9 passing the photomask 16. It is sufficient to detect the difference d in the scanning direction S between the two direction end portions 20x and 20y.

  In this manner, yawing characteristic data for each planned exposure position can be obtained as the color filter substrate 9 travels. The yawing characteristic data is detected at the position of the imaging light transmitting portion 18 at the predetermined transport position of the color filter substrate 9, but at this time, the partial exposure is scheduled to be opposed to the exposure light transmitting portion 17. It is stored as yawing characteristic data in the area. Such a difference d can be detected only by imaging the imaging light transmitting portion 18 of the photomask 16 and the black matrix 20 A of the color filter substrate 9 with the existing imaging portion 5, thus increasing the device cost Absent.

  The yawing characteristic data storage unit 27A stores in advance the yawing characteristic data obtained in this manner. The controller 7 can correct the photomask movement amount by applying an offset based on the yawing characteristic data.

  The arithmetic unit 28 compares the reference pattern data with the reference position data, and calculates the amount of deviation of the photomask 16 with respect to the planned exposure position of the color filter substrate 9. Further, the arithmetic unit 28 performs arithmetic operation for correcting the photomask movement amount based on the yawing characteristic data stored in the yawing characteristic data storage unit 27A.

  The main control unit 22 is connected to the light source power supply unit 23, the image processing unit 24, the mask drive unit controller 25, the substrate conveyance unit controller 26, the storage unit 27, and the calculation unit 28. The main control unit 22 outputs control signals to the light source power supply unit 23, the image processing unit 24, the mask drive unit controller 25, the substrate transport unit controller 26, the storage unit 27, and the calculation unit 28 according to the control program. Integrate and control the operation.

[Operation of exposure apparatus]
Hereinafter, the operation of the exposure apparatus 1 will be described. First, as shown in FIG. 3, the color filter substrate 9 is disposed on the substrate stage 8. The color filter substrate 9 is positioned with respect to the substrate stage 8 using alignment marks 29 formed at the four corners of the color filter substrate 9, and the color filter substrate 9 is fixed by suction or the like in the linear block portion 12.

  Next, compressed air is jetted from the surface of the porous body of the substrate stage 8 to float the color filter substrate 9. After that, the linear block unit 12 is driven by the control signal from the substrate conveyance unit controller 26 of the control unit 7 to start conveyance of the color filter substrate 9 in the scan direction S at a constant speed.

  As shown in FIG. 6, when the color filter substrate 9 approaches the exposure units 4L, 4R, 4C, the imaging light transmission unit 18 of the photomask 16 and the reference position unit 19A pass through the imaging unit 5 on the color filter substrate 9. The imaging of the reference pattern of the specific black matrix 20 and the reference position portion 19A is started.

  As shown in FIG. 7, the color filter substrate 9 approaches the exposure units 4L, 4R, 4C, and the partial exposure scheduled region to be exposed first on the color filter substrate 9 reaches the position Ps observed by the imaging light transmission unit 18. When the image is taken, the imaging unit 5 takes an image. In the main control unit 22, the width direction W of the color filter substrate 9 and the photomask 16 is determined based on reference pattern data and reference position portion data of the predetermined black matrix 20 in the color filter substrate 9 detected by the image processing unit 24. The shift amount of the photomask 16 is calculated, and the movement amount (provisional movement amount) of the photomask 16 is stored in the storage unit 27.

(When equipment-specific yawing characteristics have not changed over time)
Next, when the color filter substrate 9 at the position P0 shown in FIG. 7 advances to the position P1 shown in FIG. 8, the yawing characteristic inherent to the device (rotational element shown by arrow R1 in the drawing: inclination of .theta. The case of existence will be described.

  In this case, the control unit 7 adds the correction based on the yawing characteristic data in addition to the above-described provisional movement amount in consideration of the yawing characteristic data stored in the yawing characteristic data storage unit 27A of the storage unit 27 ) To control the movement of the photomask 16 by determining the final mask movement amount. As a result, as shown in FIG. 8, the hatched area exposed by the exposure light transmitting portion 17 is on the area (color filter formation area) between two adjacent black matrices 20 extending in the scanning direction S. The alignment film (not shown) can be subjected to light alignment processing.

(When equipment-specific yawing characteristics change over time)
Next, as shown in FIG. 8, the yawing characteristic data corresponding to the difference d in the scanning direction S between the end portions 20x and 20y of the black matrix 20A at the position of the imaging light transmitting portion 18 is the yawing characteristic data. When the yawing characteristic data stored in the storage unit 27A changes, the yawing characteristic data is updated. As a guide for updating the yawing characteristic data, it may be determined whether or not the value of the position difference d is less than or equal to a predetermined allowable value.

(effect)
In the exposure apparatus 1 according to the present embodiment, an appropriate mask movement amount is set by setting an offset so as to cancel the exposure position error according to the deviation amount of the photomask 16 due to the yawing characteristic which is a fixed value unique to the apparatus. Can be determined. FIG. 9 shows the result of processing in which light alignment processing is performed between the black matrices 20 on the high-definition color filter substrate 9 using the exposure apparatus 1 according to the present embodiment. As shown in FIG. 9, the light alignment processing unit 30 indicated by hatching is processed without shifting with the region between the black matrices 20. FIG. 10 shows the result of the light alignment process (comparative example) in the case where the process of correcting the mask movement amount is not performed in consideration of the yawing characteristic data. In the comparative example shown in FIG. 10, the light alignment processing unit 30 is largely deviated from the region between the black matrices 20.

  As described above, according to the present embodiment, misalignment between the color filter substrate 9 and the photomask 16 due to the yawing characteristic unique to the device can be prevented. In the present embodiment, there is an effect that enables higher definition and larger size of FPD.

[Exposure method]
FIG. 11 is a flowchart of the exposure method according to the present embodiment. Hereinafter, the exposure method of the present embodiment will be described. This exposure method is applied to the case where the light alignment process is performed on the color filter substrate 9 using the exposure apparatus 1 shown in FIGS. 1 and 2.

  First, as shown in FIG. 3, the color filter substrate 9 is aligned and disposed on the substrate stage 8 of the exposure apparatus 1. Then, the substrate transport unit 3 is started, and transport of the color filter substrate 9 at a constant speed along the scanning direction S is started (step S1).

  The black matrix 20 as a reference pattern extending in the scanning direction S in the first exposure planned area (partial exposure planned area) of the color filter substrate 9 using the imaging unit 5 and the photomask 16 shown in FIG. The formed reference position portion 19A is imaged (step S2).

  By comparing the reference pattern data captured by the imaging unit 5 with the reference position data, the deviation amount of the photomask 16 with respect to the color filter substrate 9 in the width direction W perpendicular to the scanning direction S of the color filter substrate 9 is determined. The temporary movement amount of the photomask 16 is calculated and detected. Then, in accordance with the offset amount set to cancel the exposure position error in accordance with the displacement amount of the photomask 16 due to the device-specific yawing characteristic of the color filter substrate 9 set in advance, the photomask 16 is added with the provisional displacement amount. The corrected movement amount is calculated, and the photomask 16 is moved based on the corrected movement amount (step S3).

  At this time, as shown in FIG. 8, the scanning direction S of both ends 20 x and 20 y of the existing black matrix 20 A (width direction pattern) extending in the width direction W of the color filter substrate 9 imaged by the imaging unit 5 The difference in position d is detected. Then, it is determined whether the amount of change in the yawing characteristic is larger than the allowable value (step S4). Here, as the amount of change in the yawing characteristic, specifically, it may be determined whether or not the difference d in the position in the scanning direction S of both ends of the black matrix 20A is larger than an allowable value (length). However, it may be determined using other parameters.

  In the step S4, when the change amount of the yawing characteristic is smaller than the allowable value, the exposure process is performed (step S5). In step S4, when the change amount of the yawing characteristic is larger than the allowable value, the offset based on the new yawing characteristic is set and the yawing characteristic data is updated (step S6).

  When the exposure process of step S5 is completed, it is determined whether there is a next exposure scheduled area (partial exposure scheduled area) on the color filter substrate 9 (step S7). If there is no next exposure scheduled area, the light alignment processing is completed up to the end of the color filter substrate 9, so the control is ended. If the next exposure scheduled area is present in step S7, the process returns to step S2, and the imaging unit 5 captures the reference pattern and the reference position in the next exposure scheduled area to acquire an image.

  In the above-described exposure method, the reference pattern and the existing width direction pattern are formed using gate lines, source lines, pixel electrode rows, color filter rows, etc. in addition to the black matrices 20 and 20A formed on the color filter substrate 9. It is also good.

(Method to prevent false detection of yawing characteristic change)
FIG. 12 shows a state in which the alignment position does not shift when the color filter substrate 9 is mounted on the substrate stage 8. As described above, when substrate transfer is performed in the state where there is no positional shift, from two positions of both ends 20x1 and 20y1 of the black matrix 20A formed to extend in the width direction W of the color filter substrate 9 The process of measuring the rotation angle of yawing is shown.

  The relationship between the position of the substrate and the rotation angle θ as shown in FIG. 13 by repeating the measurement of two points (20x1, 20y1) at each position Ps to be observed by the imaging light transmitting portion 18 as described above. Can be detected.

  Next, FIG. 14 shows a state where there is a shift in alignment position when the color filter substrate 9 is mounted on the substrate stage 8. When carrying the substrate in such a state where there is a positional deviation, first, the positions of the two ends 20 x 1 and 20 y 1 of the black matrix 20 A formed to extend in the width direction W of the color filter substrate 9 From the point of view to the step of measuring the turning angle of the yawing.

  By repeating measurement of two points (20x1, 20y1) at each position Ps to be observed by the imaging light transmitting portion 18 as described above, the relationship between the position of the substrate and the rotation angle θ as shown in FIG. Can be detected. Here, as shown in FIG. 14, for example, the result of FIG. 13 is obtained only by obtaining the result of FIG. 15 focusing on only two points of both ends 20 x 1 and 20 y 1 indicated by (1) in the figure. Whether the yawing characteristic in (1) has changed can not be grasped.

  Therefore, in addition to the ends 20x1 and 20y1 of the black matrix 20 from which the angle data in (1) in FIG. 15 is obtained, for example, if focusing also on two points of both ends 20x2 and 20y2 shown in (2) It can be determined that the initial arrangement position of the color filter substrate 9 is shifted. That is, in the example shown in FIG. 15, it can be determined that, for example, an angle of 3 degrees has been added at each position of the substrate.

  As a result, it can be determined that the yawing characteristic has not changed. Further, from this result, it is possible to determine whether the alignment adjustment of the color filter substrate 9 is completed. Thus, by observing the positions of at least four points at the positions (1) and (2) in FIG. 14, it can be determined whether or not a change in the yawing characteristic has occurred. In addition, by observing at least four points of (1) and (2) in this manner, it is possible to detect that there has been a positional deviation of the initial arrangement of the color filter substrate 9, and thus notify the exposure apparatus 1 of a defect in alignment adjustment. It is also possible to set an alert such as a warning display.

(Other embodiments)
Although the embodiments of the present invention have been described above, it should not be understood that the statements and drawings that form a part of the disclosure of the embodiments limit the present invention. Various alternative embodiments, examples and operation techniques will be apparent to those skilled in the art from this disclosure.

  For example, although the present invention has been described by applying the present invention to the exposure apparatus 1 that performs the light alignment process on the color filter substrate 9 in each of the above embodiments, the light alignment process may be performed on the alignment film on the TFT substrate side . Further, it is needless to say that the present invention can be applied to light annealing processing, laser processing, exposure processing to various materials based on lithography technology, and the like as another embodiment of the present invention.

  In the above embodiment, the color filter substrate 9 is caused to travel in the scanning direction S with respect to the exposure units 4L, 4R, 4C, but the color filter substrate 9 is fixed to the substrate stage 8 and the exposure units 4L, 4R, 4C are fixed. It may be configured to travel in the scan direction S. The scanning direction S in the case of causing the exposure units 4L, 4R, and 4C to travel relative to the color filter substrate 9 is opposite to the scanning direction S in which the color filter substrate 9 travels.

D distance S scan direction W width direction 1 exposure device 4L, 4R, 4C exposure unit 5 imaging unit 7 control unit 8 substrate stage 9 color filter substrate (exposure substrate)
DESCRIPTION OF SYMBOLS 10 and 11 linear guide 12 linear block part 16 photomask 17 light transmission part for exposure 18 light transmission part for imaging 19A reference position part 20 black matrix 27 storage part 27A yawing characteristic data storage part

Claims (8)

The reference position portion and the light transmitting portion for exposure are formed apart from each other in the mask surface, and relative to the substrate to be exposed on which the existing reference pattern is formed along the scanning direction, along the scanning direction. With a moving photomask
An imaging unit disposed integrally with the photomask and imaging the reference pattern and the reference position unit;
The reference pattern of the partial exposure scheduled region of the substrate to be exposed and the reference position portion compare the reference pattern data and the reference position portion data imaged by the imaging unit, and the scanning direction of the substrate to be exposed The amount of displacement of the photomask in the width direction forming a right angle is detected to calculate the amount of provisional movement of the photomask, and the partial exposure scheduled region is moved to the position where exposure is performed in the exposure light transmitting portion. A control unit that performs control of moving the photomask in the width direction based on the temporary movement amount;
Equipped with
An exposure apparatus which continuously or intermittently exposes the partial exposure scheduled area along the scan direction on the substrate to be exposed,
The control unit
A device-specific yawing characteristic that changes the yawing state of the substrate to be exposed or the photomask generated as the relative movement of the substrate to be exposed and the photomask in the scanning direction is made beforehand as yawing characteristic data An exposure apparatus which stores the temporary movement amount based on the yawing characteristic data and moves the photomask in the width direction.   The difference between the positions in the scanning direction of both end portions in the width direction in the existing width direction pattern extending in the width direction of the substrate to be exposed imaged by the imaging unit is detected, and the change with time of the yawing characteristic is The exposure apparatus according to claim 1, wherein the yawing characteristic data is detected and detected when the difference between the positions in the scanning direction of the both end portions of the width direction pattern is larger than an allowable value.   The substrate to be exposed is transported in the scan direction along a substrate transport guide, and the photomask is provided at a fixed position in the scan direction so as to be movable in the width direction perpendicular to the scan direction. An exposure apparatus according to claim 1 or 2.   The exposure apparatus according to claim 2, wherein the reference pattern and the width direction pattern are selected from a black matrix, a gate line, a source line, a row of pixel electrodes, a row of color filters, and the like formed on the substrate to be exposed. The photomask in which the reference position portion and the light transmitting portion for exposure are formed apart from each other in the mask plane is relative to the substrate to be exposed on which the existing reference pattern is formed in the scanning direction. The process of moving
Imaging the reference pattern and the reference position portion formed at a position corresponding to the partial exposure planned region of the substrate to be exposed;
The provisional movement of the photomask is detected by comparing the imaged reference pattern position data with the reference position portion data, detecting the amount of displacement of the photomask with respect to the substrate in the width direction perpendicular to the scanning direction. Calculating the quantity;
Before the exposure is carried out before the partial exposure planned region reaches the position corresponding to the light transmitting portion for exposure with the relative movement of the substrate to be exposed and the photomask in the scanning direction, the object to be exposed is exposed. The provisional movement amount of the photomask is corrected based on preset device-specific yawing characteristic data in which the yawing state of the substrate to be exposed or the photomask changes due to the relative movement of the exposure substrate or the photomask. Calculating a correction movement amount, and moving the photomask along the width direction based on the correction movement amount;
Exposing the partial exposure scheduled area through the exposure light transmitting portion;
Exposure method.   A change in yawing characteristics over time is detected by detecting a difference in position in the scanning direction of both end portions of the existing widthwise pattern extending in the width direction of the substrate to be exposed imaged by the imaging unit, and the width direction is detected. 6. The exposure method according to claim 5, wherein the yawing characteristic data is updated when a difference in position in the scanning direction between both ends of the pattern is larger than an allowable value.   The substrate to be exposed is transported in the scan direction along a substrate transport guide, and the photomask is provided so as to be movable in the width direction perpendicular to the scan direction at a fixed position in the scan direction. The exposure method of Claim 5 or Claim 6.   The exposure method according to claim 6, wherein the reference pattern and the width direction pattern are selected from a black matrix, a gate line, a source line, a row of pixel electrodes, a row of color filters, etc. formed on the substrate to be exposed.

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