JP5344766B2 - Photomask, laser annealing apparatus using the same, and exposure apparatus - Google Patents

Abstract

Disclosed is a photomask provided with a plurality of mask patterns (2) which are formed at a given arrangement pitch in a direction crossing a substrate transfer direction and through which light is passed, and a plurality of alignment marks (4) which each have a structure provided with a pair of thin lines (4a, 4b) formed with an interval equal to the integral multiple of the arrangement pitch in the direction crossing the substrate transfer direction of the plurality of patterns provided on a substrate and parallel to the substrate transfer direction, and are disposed at a given distance from each other in the substrate transfer direction at a position on the side opposite to the substrate transfer direction with respect to the plurality of mask patterns (2), reference positions which are preset between the pairs of thin lines (4a, 4b) being formed to be shifted from each other by a predetermined distance in the direction crossing the substrate transfer direction. Consequently, even when light is applied to a position offset in a direction crossing the substrate transfer direction of a substrate of the same kind, the property of following the substrate that is moving is favorable.

Description

  The present invention relates to a photomask for selectively irradiating light on a plurality of positions on a substrate by following the substrate being conveyed in a certain direction, and more specifically, a position offset in the direction intersecting the substrate conveyance direction of the same type of substrate. The present invention also relates to a photomask for improving the followability to a moving substrate, a laser annealing apparatus using the same, and an exposure apparatus even when irradiating light.

  A conventional photomask of this type is formed at a constant arrangement pitch in a direction intersecting the substrate transport direction, and a plurality of mask patterns that allow light to pass through, and a substrate transport direction of a plurality of patterns provided on the substrate, It has a structure with a pair of fine lines formed in parallel to the substrate transport direction with an interval equal to an integral multiple of the array pitch in the cross direction, and a fixed distance in the direction opposite to the substrate transport direction with respect to multiple mask patterns And one alignment mark formed at a distant position (see, for example, Patent Document 1).

JP 2008-216593 A

  However, in such a conventional photomask, the interval between the pair of fine lines parallel to the substrate conveyance direction of the alignment mark is a dimension that is an integral multiple of the arrangement pitch of the plurality of patterns provided on the substrate in the direction intersecting the substrate conveyance direction. Therefore, when irradiating light to a position offset in the direction crossing the substrate transport direction of the same type of substrate, the pair of fine lines of the alignment mark interferes with the edge of the pattern on the substrate parallel to the substrate transport direction. In some cases, it is difficult to detect the reference position of the alignment mark. For this reason, the follow-up performance of the photomask with respect to the substrate is lowered, and there is a possibility that the target position on the substrate cannot be accurately irradiated with light.

  In view of this, the present invention addresses such problems and attempts to improve the followability to a moving substrate even when light is irradiated to a position that is offset in the direction intersecting the substrate transport direction of the same type of substrate. An object of the present invention is to provide a photomask to be used, a laser annealing apparatus using the same, and an exposure apparatus.

  In order to achieve the above object, the photomask according to the first aspect of the present invention selectively emits light at a plurality of positions on a substrate in which a plurality of patterns are provided in a matrix with a constant arrangement pitch on the surface and conveyed in a fixed direction. A plurality of mask patterns formed at a constant arrangement pitch in a direction intersecting with the substrate transport direction, and a plurality of patterns provided on the substrate. A structure having a pair of fine lines formed in parallel to the substrate transport direction with an interval equal to an integer multiple of the arrangement pitch in the direction intersecting the direction, and the substrate transport direction with respect to the plurality of mask patterns A predetermined distance between the pair of thin wires is arranged in advance in a direction intersecting the substrate transport direction at a position opposite to the substrate transport direction at a certain distance from each other. A plurality of alignment marks formed in a state displaced from each other by a distance is because, those having a.

  With such a configuration, when irradiating light at a position offset in the direction crossing the substrate transport direction of the same type of substrate, an appropriate one of a plurality of alignment marks arranged at a certain distance from each other in the substrate transport direction is used. One alignment mark is selected, and interference between a pair of fine lines parallel to the substrate conveyance direction of the alignment mark and both edges of the pattern provided on the substrate parallel to the substrate conveyance direction is reduced.

  Further, in a state where the reference position of one alignment mark selected from the plurality of alignment marks and the reference position set on the substrate are aligned, the pair of fine lines of the selected alignment mark is The pixels provided on the substrate are arranged so as to substantially coincide with a center line parallel to the substrate transport direction of the pixels. Thereby, in the state where the reference position of one selected alignment mark and the reference position set on the substrate are aligned with each other, the pair of fine lines of the selected alignment mark is provided on the substrate. The pixel is arranged so as to substantially match the center line parallel to the substrate transport direction of the pixel, and interference between the pair of fine lines and both edges of the pattern provided on the substrate parallel to the substrate transport direction is further reduced. .

  Furthermore, a plurality of microlenses were formed on the substrate side corresponding to the mask patterns. Thereby, light is condensed on the substrate by a plurality of microlenses formed on the substrate side corresponding to each mask pattern.

  The plurality of mask patterns are formed in a matrix at a constant arrangement pitch in the substrate transport direction and the intersecting direction. Thereby, light is irradiated to a plurality of positions on the substrate through a plurality of mask patterns formed in a matrix at a constant arrangement pitch in the substrate transport direction and the intersecting direction.

  The laser annealing apparatus according to the second aspect of the present invention is the position of a substrate on which a plurality of patterns are provided in a matrix with a constant arrangement pitch and conveyed in a fixed direction, and a photomask disposed opposite to the substrate. A laser annealing apparatus that selectively irradiates a plurality of positions on the substrate with laser light and anneals the thin film formed on the substrate, and is constant in a direction intersecting the transport direction of the substrate The substrate transport direction having a plurality of mask patterns formed at an array pitch and allowing laser light to pass through, and an interval equal to an integer multiple of the array pitch in the direction intersecting the substrate transport direction of the plurality of patterns provided on the substrate A structure having a pair of thin lines formed in parallel with each other, and fixed to each other in the substrate transport direction at a position opposite to the substrate transport direction with respect to the plurality of mask patterns. A plurality of alignment marks which are arranged apart from each other, and are formed so that reference positions preset between the pair of thin wires are shifted from each other by a predetermined distance in a direction intersecting the substrate transport direction; , A mask stage that moves the photomask in the substrate transport direction so that one alignment mark can be selected from the plurality of alignment marks, and a plurality of alignments of the photomask A line camera arranged so that the longitudinal center axis of the thin light-receiving portion coincides with the center line of the alignment mark selected from the marks in the direction crossing the substrate transport direction, and the reference position of the selected alignment mark And the reference position preset on the substrate so that the positional relationship is a predetermined relationship. And alignment means for relatively moving said photomask in the cross direction and the substrate transfer direction is obtained with a.

  With this configuration, when annealing is performed by irradiating a laser beam at a position that is offset in the direction crossing the substrate transport direction of the same type of substrate, the mask stage is moved in the substrate transport direction and is mutually constant in the substrate transport direction. An appropriate alignment mark is selected from a plurality of alignment marks arranged at a distance, and a pair of fine lines parallel to the substrate transport direction of the alignment mark and a reference position on the substrate are imaged with a line camera. The alignment means moves the substrate and the photomask relative to each other in the direction intersecting the substrate transport direction so that the positional relationship between the reference position of the alignment mark and the reference position of the substrate becomes a predetermined relationship based on the captured image. To do.

  Further, the selected alignment in a state in which the reference position of one selected alignment mark among the plurality of alignment marks provided on the photomask is aligned with the reference position set on the substrate. The pair of fine lines of the mark is arranged so as to substantially match a center line parallel to the substrate transport direction of the pixels provided on the substrate. Thereby, in the state where the reference position of one selected alignment mark and the reference position set on the substrate are aligned with each other, the pair of fine lines of the selected alignment mark is provided on the substrate. The pixel is arranged so as to substantially match the center line parallel to the substrate transport direction of the pixel, and interference between the pair of fine lines and both edges of the pattern provided on the substrate parallel to the substrate transport direction is further reduced. .

  The photomask has a plurality of microlenses formed on the substrate side corresponding to the mask patterns. Thereby, the laser beam is condensed on the substrate by the plurality of microlenses formed on the substrate side corresponding to each mask pattern.

  In addition, according to the exposure apparatus of the third invention, a substrate on which a plurality of patterns are provided in a matrix with a constant arrangement pitch and is transported in a fixed direction, and a photomask disposed opposite to the substrate, Is an exposure apparatus that selectively irradiates a plurality of positions on the substrate with ultraviolet rays and exposes a photosensitive material applied on the substrate, and is constant in a direction intersecting the transport direction of the substrate. A plurality of mask patterns which are formed at an arrangement pitch of the plurality of mask patterns, and the substrate conveyance direction has an interval equal to an integer multiple of the arrangement pitch in the direction intersecting the substrate conveyance direction of the plurality of patterns provided on the substrate. And a pair of fine lines formed in parallel to each other, arranged at a position opposite to the substrate transport direction with respect to the plurality of mask patterns and spaced apart from each other in the substrate transport direction. And a plurality of alignment marks formed in such a manner that a predetermined reference position between the pair of fine lines is shifted from each other by a predetermined distance in a direction intersecting the substrate transport direction. And a mask stage that allows the photomask to move in the substrate transport direction to select one alignment mark from the plurality of alignment marks, and is selected from the plurality of alignment marks of the photomask. A line camera arranged so that the longitudinal center axis of the thin light-receiving part coincides with the center line in the direction intersecting the substrate transport direction of the alignment mark, and the reference position of the selected alignment mark and the substrate are preset. The substrate and the photomask so that the positional relationship with the determined reference position is a predetermined relationship The is obtained and a alignment means for relatively moving in the cross direction and the direction of substrate conveyance.

  With such a configuration, when exposure is performed by irradiating ultraviolet rays to a position offset in the direction crossing the substrate transport direction of the same type of substrate, the mask stage is moved in the substrate transport direction so that a certain distance can be kept in the substrate transport direction. An appropriate alignment mark is selected from the plurality of alignment marks arranged in a row, and a pair of fine lines parallel to the substrate transport direction of the alignment mark and a reference position on the substrate are imaged with a line camera, and the captured image Based on the above, the alignment means moves the substrate and the photomask relative to each other in the direction intersecting the substrate transport direction so that the positional relationship between the reference position of the alignment mark and the reference position of the substrate becomes a predetermined relationship.

  Further, the selected alignment in a state in which the reference position of one selected alignment mark among the plurality of alignment marks provided on the photomask is aligned with the reference position set on the substrate. The pair of fine lines of the mark is arranged so as to substantially match a center line parallel to the substrate transport direction of the pixels provided on the substrate. Thereby, in the state where the reference position of one selected alignment mark and the reference position set on the substrate are aligned with each other, the pair of fine lines of the selected alignment mark is provided on the substrate. The pixel is arranged so as to substantially match the center line parallel to the substrate transport direction of the pixel, and interference between the pair of fine lines and both edges of the pattern provided on the substrate parallel to the substrate transport direction is further reduced. .

  The photomask has a plurality of microlenses formed on the substrate side corresponding to the mask patterns. Thereby, ultraviolet rays are condensed on the substrate by a plurality of microlenses formed on the substrate side corresponding to each mask pattern.

  According to the invention according to claim 1, even when irradiating light at a position offset in the direction crossing the substrate transport direction of the same type of substrate, by selecting an appropriate alignment mark from a plurality of alignment marks, It is possible to reduce interference between the pair of fine lines of the selected alignment mark and both edges of the pattern provided on the substrate parallel to the substrate transport direction. Therefore, detection of a pair of fine lines of the selected alignment mark is facilitated, and calculation of the reference position of the alignment mark is facilitated. Therefore, the photomask can be made to follow the moving substrate satisfactorily using one alignment mark selected from the plurality of alignment marks.

  According to the invention of claim 2, the pair of fine lines of the alignment mark selected from among the plurality of alignment marks are furthest away from both edges parallel to the substrate transport direction of the pattern provided on the substrate. Since the pattern is located at a substantially central position, the pair of fine lines can be detected more easily by avoiding interference between the pair of fine lines and both edges of the pattern.

  Furthermore, according to the invention which concerns on Claim 3, light can be condensed on a board | substrate with a microlens, and the utilization efficiency of light can be improved.

  According to the fourth aspect of the invention, the light irradiation area can be enlarged, and for example, the tact time of the laser annealing process or the exposure process can be shortened.

  According to the fifth aspect of the present invention, even when annealing is performed by irradiating a laser beam at a position offset in the direction crossing the substrate transport direction of the same type of substrate, an appropriate alignment from a plurality of alignment marks. By selecting the mark, it is possible to reduce interference between the pair of fine lines of the selected alignment mark and both edges of the pattern provided on the substrate parallel to the substrate transport direction. Therefore, detection of a pair of fine lines of the selected alignment mark is facilitated, and calculation of the reference position of the alignment mark is facilitated. Therefore, the photomask can be made to follow the moving substrate satisfactorily using one alignment mark selected from the plurality of alignment marks.

  Furthermore, according to the invention of claim 6, the pair of fine lines of the alignment mark selected from the plurality of alignment marks provided on the photomask are both parallel to the substrate transport direction of the pattern provided on the substrate. Since it is located at the substantially center position of the pattern farthest from the edge portion, it is possible to avoid the interference between the pair of fine lines and both edges of the pattern, and to detect the pair of fine lines more easily. Therefore, the calculation of the reference position of the photomask becomes easier, the alignment between the photomask and the substrate can be performed reliably, and the target position set on the substrate can be accurately irradiated. .

  And according to the invention concerning Claim 7, a laser beam can be condensed on a board | substrate with a micro lens, and the power of a laser light source can be reduced. Therefore, the burden on the laser light source can be reduced and the life of the light source can be extended.

  Further, according to the invention according to claim 8, even when exposure is performed by irradiating ultraviolet rays at a position offset in the direction crossing the substrate transport direction of the same type of substrate, one appropriate alignment mark is selected from a plurality of alignment marks. By selecting, interference between the pair of fine lines of the selected alignment mark and both edges of the pattern provided on the substrate parallel to the substrate transport direction can be reduced. Therefore, detection of a pair of fine lines of the selected alignment mark is facilitated, and calculation of the reference position of the alignment mark is facilitated. Therefore, the photomask can be made to follow the moving substrate satisfactorily using one alignment mark selected from the plurality of alignment marks.

  According to the ninth aspect of the present invention, the pair of fine lines of the alignment mark selected from the plurality of alignment marks provided on the photomask are both parallel to the substrate transport direction of the pattern provided on the substrate. Since it is located at the substantially center position of the pattern farthest from the edge portion, it is possible to avoid the interference between the pair of fine lines and both edges of the pattern, and to detect the pair of fine lines more easily. Therefore, the calculation of the reference position of the photomask becomes easier, the alignment between the photomask and the substrate can be reliably performed, and the target position set on the substrate can be accurately irradiated.

  Furthermore, according to the invention which concerns on Claim 10, an ultraviolet-ray can be condensed on a board | substrate with a micro lens, and the power of the light source for exposure can be reduced. Therefore, the burden on the exposure light source can be reduced and the life of the light source can be extended.

It is a figure which shows embodiment of the photomask by this invention, (a) is a top view, (b) is XX sectional drawing of (a). It is a top view which shows schematic structure of a TFT substrate. It is a partial section front view showing a schematic structure of a laser annealing apparatus of the present invention. It is a block diagram which shows the structure of the control means of the said laser annealing apparatus. It is a top view explaining the prior alignment of a TFT substrate and a photomask using the drawing mark provided in the said TFT substrate. It is a top view explaining tracking of a photomask with respect to a TFT substrate under movement. It is explanatory drawing which shows the positional relationship of the annealing target position of a TFT substrate, and the 1st alignment mark of a photomask. It is explanatory drawing which shows the positional relationship of another annealing target position of a TFT substrate, and the 2nd alignment mark of a photomask.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. 1A and 1B are views showing an embodiment of a photomask according to the present invention, in which FIG. 1A is a plan view and FIG. 1B is a sectional view taken along line XX of FIG. The photomask 1 selectively irradiates light on a plurality of positions on a substrate on a surface where a plurality of patterns are provided in a matrix at a constant arrangement pitch and are conveyed in a fixed direction. And a plurality of microlenses 3 and a plurality of alignment marks 4.

Here, the substrate to be used in a plurality of patterns (hereinafter referred to as "pixels 5"), arranged at the arrangement pitch P ₁ in the substrate transfer direction indicated by the arrow A as shown in FIG. 2, the cross-direction board conveying direction the sequence is obtained by arranged at a pitch P _2, along the edges to form a data line 6, for example along the parallel edges of the substrate conveying direction of each pixel 5 and intersects the substrate transfer direction of each pixel 5 For example, a TFT substrate 8 on which a gate line 7 is formed. Further, in the outside the display area of the substrate conveying direction leading side, the center position with respect to the gate line 7 of the substrate conveying direction leading side is separated by a distance L _1, is provided substantially cross-shaped retraction mark 9, Photo The mask 1 and the TFT substrate 8 can be aligned in advance. Here, when the pull-in mark 9 is not present, for example, a predetermined specific data line 6 serving as a reference for alignment on the TFT substrate 8 side cannot be detected, and another data line 6 is erroneously detected. possibility of Te become aligned shifted by several pitch of the arrangement pitch P ₂ of the substrate conveying direction and in the cross direction same direction of pixels 5 has. Therefore, the pull-in mark 9 is provided on the TFT substrate 8 so that the photomask 1 and the TFT substrate 8 can be aligned in advance, thereby facilitating detection of the specific data line 6.

As shown in FIG. 1, the plurality of mask patterns 2 are for selectively irradiating light to a plurality of preset positions (hereinafter referred to as “light irradiation target positions”) on the TFT substrate 8. Arrangement pitch equal to the arrangement pitches P ₁ and P ₂ of the plurality of pixels 5 provided on the TFT substrate 8, which is an opening having a fixed shape through which light is formed in the light shielding film 11 provided on the surface of the substrate 10. Thus, it is formed in a matrix in the substrate transport direction and the crossing direction. In the present embodiment, the plurality of mask patterns 2 are shown as two mask pattern rows 2A and 2B intersecting the substrate transport direction.

  On the back surface (TFT substrate 8 side) of the transparent substrate 10, a plurality of microlenses 3 are provided as shown in FIG. The plurality of microlenses 3 are convex lenses for condensing light on the TFT substrate 8, and are arranged with the optical axes aligned with the centers of the mask patterns 2.

In the first to third viewing windows 12A, 12B, and 12C formed at positions opposite to the substrate conveyance direction indicated by the arrow A with respect to the plurality of mask patterns 2, the first, second, and second are respectively provided. 3 alignment marks 4A, 4B, and 4C are provided. The first to third alignment marks 4A to 4C are moved by following the moving TFT substrate 8 while meandering the photomask 1, and the light irradiation target positions on the plurality of mask patterns 2 and the TFT substrate 8 are moved. is intended to align the, while being spaced apart from each other by a distance L ₂ in the substrate transfer direction, the central axis and the substrate conveying direction leading side that intersects the substrate transfer direction of the first alignment mark 4A a longitudinal central axis of the mask pattern column 2A is formed so as to form a distance L _3.

Further, each of the first to third alignment marks 4A to 4C has an interval nP ₂ (n is an integer of 1 or more) equal to an integral multiple of the array pitch P _{2 in} the direction intersecting the substrate transport direction of the plurality of pixels 5. And having a structure in which a single thin wire 4c that obliquely intersects the substrate transport direction is provided between a pair of thin wires 4a and 4b formed in parallel with the substrate transport direction, and the second and third alignment marks 4B, The alignment reference position of 4C (for example, the midpoint position between the pair of thin wires 4a and 4b) is shifted by distances D ₁ and D ₂ in the direction intersecting the substrate transport direction with reference to the reference position of the first alignment mark 4A. It is formed in the state.

  In this case, the single thin line 4c that obliquely intersects the substrate transport direction indicates the reference position of the photomask 1 and the TFT substrate when the photomask 1 of the present invention is used in a laser annealing apparatus or exposure apparatus described later. A center line intersecting the substrate transport direction of the alignment mark 4 of the photomask 1 is formed on the longitudinal central axis of the elongated light receiving portion 24 of the line camera 17 (see FIG. 5) provided for detecting the reference position 8. Used for accurate alignment. Specifically, the positions of the pair of fine wires 4a and 4b and the oblique fine wires 4c of the alignment mark 4 are detected based on the one-dimensional image captured by the line camera 17, and the distance between the fine wires 4a and 4c and the fine wires 4c, The distance between 4b is calculated, and the photomask 1 is moved with respect to the line camera 17 by moving the photomask 1 in the substrate transport direction so that both distances are equal.

  Further, the oblique thin line 4c can be used for detecting the gate line 7 provided on the TFT substrate 8 in the same manner as described above. For example, the gate line 7 is imaged by the line camera 17, and the dimension of the portion of the gate line 7 divided by the three thin lines 4 a to 4 c of the alignment mark 4 is calculated. If it is detected that the dimension between the fine lines 4a and 4c of the gate line 7 is equal to the dimension between the fine lines 4c and 4b, the gate line 7 matches the center line of the alignment mark 4 in the direction crossing the substrate transport direction. Can be detected. Therefore, the movement distance or movement time of the TFT substrate 8 is measured with reference to the moment when the gate line 7 matches the center line of the alignment mark 4, and the movement distance or movement time becomes a predetermined constant value. If laser light or ultraviolet light is sometimes irradiated, the laser light or ultraviolet light can be accurately irradiated to the light irradiation target position on the TFT substrate 8.

Further, the reference positions of the first to third alignment marks 4A to 4C are formed so as to have a certain positional relationship with the mask pattern 2. For example, in the present embodiment, as shown in FIG. 1, the first alignment mark 4A has a center line parallel to the substrate transport direction of two mask patterns 2 adjacent to one of the mask pattern rows 2A and 2B. The second alignment mark 4B is formed so as to match the midpoint position. The second alignment mark 4B has a distance D ₁ = P ₂ / in the direction in which the center position intersects the substrate conveyance direction with respect to the center position of the first alignment mark 4A. It is formed in a state shifted by two. Therefore, the center line of the second alignment mark 4B parallel to the substrate transport direction matches the center of one of the mask patterns 2. The third alignment mark 4C, the center position _{(the m} odd) Distance D _{2 =} mP _2/4 in a direction intersecting the substrate transport direction with respect to the center position of the first alignment mark 4A deviated by It is formed in a state. Thus, the third alignment mark 4C a center line parallel to the substrate transport direction would match the position shifted by P _2/4 to either the substrate conveying direction from the center of the mask pattern 2 cross direction.

  Furthermore, among the first to third alignment marks 4A to 4C, the selected position is selected in a state where the reference position of the selected alignment mark 4 and the reference position set on the TFT substrate 8 are aligned. The pair of thin lines 4a and 4b of the alignment mark 4 are arranged so as to substantially coincide with the center line parallel to the substrate transport direction of the pixel 5 respectively. Therefore, in the state in which the alignment between the photomask 1 and the TFT substrate 8 is performed using the alignment marks 4A to 4C, the pair of thin lines 4a and 4b of the alignment marks 4A to 4C are respectively the pixels 5. Therefore, the data line 6 is not interfered with the data line 6 provided along the edge of the pixel 5, and is not interfered with the data line 6 provided along the edge of the pixel 5. Detection of the thin wires 4a and 4b is facilitated. Therefore, it becomes easy to calculate the reference positions of the alignment marks 4A to 4C.

  The reference position of each of the alignment marks 4A to 4C is not limited to the midpoint position between the pair of thin wires 4a and 4b, but may be set to a position that internally divides the pair of thin wires 4a and 4b at a certain ratio. Alternatively, either one of the pair of thin wires 4a and 4b may be defined as the reference position.

  In the above embodiment, the case where the micro lens 3 is provided on the TFT substrate 8 side corresponding to the mask pattern 2 has been described. However, the present invention is not limited to this, and the micro lens 3 may be omitted. When the photomask 1 of the present invention is used for laser annealing, it is more effective to provide the microlens 3 because the laser energy can be condensed. Further, the microlens 3 is not necessarily required when used for exposure. However, when the microlens 3 is provided, the mask pattern 2 can be projected and reduced on the substrate, and the resolution of the exposure pattern can be improved.

  Furthermore, although the case where the two mask pattern rows 2A and 2B are provided has been described in the above embodiment, the present invention is not limited to this, and even if there is one mask pattern row, three or more rows are provided. Also good.

  Next, a laser annealing apparatus using the photomask 1 according to the present invention will be described. FIG. 3 is a partial sectional front view showing a schematic configuration of the laser annealing apparatus of the present invention. This laser annealing apparatus includes, for example, a TFT substrate 8 in which a plurality of pixels 5 are provided in a matrix at a constant arrangement pitch on the surface and are conveyed in the direction of arrow A, and a photomask 1 disposed opposite to the TFT substrate 8. And the laser beam 21 is selectively irradiated to a plurality of positions on the TFT substrate 8, and the amorphous silicon thin film formed on the TFT substrate 8 is annealed to form polysilicon. , A laser light source 14, a coupling optical system 15, a mask stage 16, a line camera 17, an alignment means 18, and a control means 19.

  The transfer means 13 has the TFT substrate 8 placed on the upper surface and transfers it at a constant speed, for example, in the direction of arrow A shown in FIG. 3, and sucks the gas into a large number of ejection holes for ejecting gas to the upper surface. An air stage 20 having a plurality of suction holes is provided, and the TFT substrate 8 is floated on the air stage 20 by a certain amount due to the balance between gas ejection and suction, and the TFT substrate 8 is moved by a transport roller (not shown). It grips and conveys both edge portions, and is provided with a position sensor and a speed sensor not shown.

    A laser light source 14 is provided above the conveying means 13. The laser light source 14 is an excimer laser that emits laser light 21 having a wavelength of, for example, 308 nm or 353 nm at a repetition period of, for example, 50 Hz.

  A coupling optical system 15 is provided on the optical path of the laser light 21 emitted from the laser light source 14. The coupling optical system 15 expands the beam diameter of the laser light 21 and irradiates the photomask 1 with a uniform intensity distribution in the transverse section of the beam. For example, a plurality of fly-eye lenses and a plurality of fly-eye lenses It is configured with a condenser lens.

  A mask stage 16 is provided on the downstream side of the coupling optical system 15 in the traveling direction of the laser light 21. The mask stage 16 holds the photomask 1 in close proximity to the TFT substrate 8, forms an opening 22 in the center, and grips the peripheral edge of the photomask 1. . And it can be moved in the directions of arrows B and C shown in FIG. 3 by a driving means 23 such as a motor.

Of the first to third viewing windows 12A to 12C of the photomask 1 held on the mask stage 16, the conveying means 13 faces one viewing window (the second viewing window 12B in FIG. 3). On the side, a line camera 17 is provided. This line camera 17 images the surface of the TFT substrate 8 and the alignment mark 4 of the photomask 1 through the bottom, and outputs a one-dimensional image thereof. A plurality of light receiving elements are arranged in a straight line. The long and narrow light receiving portion 24 (see FIG. 5), and the alignment mark 4 (in FIG. 3), the longitudinal center axis of the light receiving portion 24 is selected from the first to third alignment marks 4A to 4C. The second alignment mark 4B is shown in the case where the second alignment mark 4B is selected).
An illumination light source 25 is provided above the mask stage 16 so as to face the line camera 17 so that the imaging position of the line camera 17 can be illuminated.

  An alignment means 18 is provided so that the mask stage 16 can be moved in the direction crossing the substrate transport direction. This alignment means 18 is for aligning the TFT substrate 8 and the photomask 1 and is composed of, for example, a linear motor, an electromagnetic actuator, a rail and a motor, or the like.

  A control unit 19 is connected to the transport unit 13, the laser light source 14, the mask stage 16, the line camera 17, and the alignment unit 18. The control means 19 moves the photomask 1 in the substrate transport direction in accordance with a plurality of preset annealing target positions on the TFT substrate 8, and selects one of the first to third alignment marks 4A to 4C. After selecting the alignment mark 4 and aligning the one alignment mark 4 with the reference position set in advance on the TFT substrate 8, the photomask 1 is irradiated with the laser light 21 and a plurality of the alignment marks 4 on the substrate are irradiated. The annealing target position is annealed, and as shown in FIG. 4, an image processing unit 26, a memory 27, a calculation unit 28, a transport unit drive controller 29, a mask stage drive controller 30, and an alignment unit drive controller. 31, a laser light source drive controller 32, and a control unit 33.

  Here, the image processing unit 26 performs real-time processing on the one-dimensional image captured by the line camera 17 to detect a luminance change in the longitudinal direction of the elongated light receiving unit 24 of the line camera 17, and data on the TFT substrate 8. The reference position set on the line 6 and the position of the pair of thin lines 4a and 4b of the alignment mark 4 of the photomask 1 are detected, and the pull-in mark 9 on the TFT substrate 8 is detected from the luminance change in the substrate transport direction at the output of the line camera 17. The thin line 9a (see FIG. 2) intersecting the substrate transport direction is detected.

Further, the memory 27 includes dimensions L ₂ and L ₃ (see FIG. 1) set on the photomask 1, dimensions L ₁ and P ₁ (see FIG. 2) set on the TFT substrate 8, and first to third dimensions. The TFT substrate until the laser light source 14 is turned on after the alignment target values Ds ₁ and Ds ₂ corresponding to the alignment marks 4A to 4C and the thin line 9a intersecting the substrate transfer direction of the pull-in mark 9 of the TFT substrate 8 are detected. In addition to storing a target value Ls of the distance traveled by 8, a calculation result in a calculation unit 28 described later is temporarily stored. The alignment target value Ds ₁ is a target value of the distance between the reference position of the alignment mark 4 and the center position of the pull-in mark 9 on the substrate, and the target value Ds ₂ is equal to the reference position of the alignment mark 4. The target value of the distance between the reference position set on the substrate, for example, the right edge in the substrate transfer direction of the specific data line 6.

  Further, the calculation unit 28 calculates the distance D between the reference position of the TFT substrate 8 detected by the image processing unit 26 and the reference position of the selected alignment mark 4 on the photomask 1, and The moving distance L of the TFT substrate 8 is calculated based on the output of the position sensor.

  The transfer means drive controller 29 controls the drive of the transfer means 13 with a pulse having a constant period so that the TFT substrate 8 is transferred at a predetermined speed.

  Further, the mask stage drive controller 30 moves one of the first to third alignment marks 4A to 4C formed on the photomask 1 by moving the mask stage 16 in the directions of arrows B and C in FIG. 4 is selected, and driving means 23 provided on the mask stage 16 is driven.

Further, the alignment means drive controller 31 calculates the distance D between the reference position of the TFT substrate 8 calculated by the calculation unit 28 and the reference position of the selected alignment mark 4 on the photomask 1 and the alignment read from the memory 27. Compared with the target values Ds ₁ and Ds ₂ , the alignment means 18 is driven so that the two coincide with each other, and the photomask 1 is moved in a direction intersecting the substrate transport direction.

  Further, the laser light source drive controller 32 controls turning on and off of the laser light source 14. And the control part 33 integrates and controls the whole so that each said component may operate | move appropriately.

Next, the operation of the laser annealing apparatus configured as described above will be described.
First, necessary information is stored in the memory 27 of the control means 19 and an initial setting is made. The drive means 23 of the mask stage 16 is driven by the mask stage drive controller 30 of the control unit 19, the mask stage 16 is moved by a distance L ₂ in the arrow B direction shown in FIG. As a result, the first viewing window 12A is positioned above the line camera 17, and the first alignment mark 4A is selected.

  At this time, based on the one-dimensional image picked up by the line camera 17, a pair of fine lines 4a of the first alignment mark 4A is obtained from the luminance change in the longitudinal direction of the elongated light receiving part 24 of the line camera 17 by the image processing unit 26. The positions of the thin lines 4b and the oblique thin lines 4c are detected, the distance between the thin lines 4a and 4c and the distance between the thin lines 4c and 4b are calculated by the calculation unit 28, and the mask stage 16 is controlled by the mask stage drive controller 30 so that both distances are equal. Is finely adjusted to move the substrate in the substrate conveyance direction, and the longitudinal center axis of the light receiving unit 24 of the line camera 17 and the substrate alignment direction of the first alignment mark 4A of the photomask 1 are accurately aligned with the center line in the intersecting direction. I do.

  Next, the conveying means 13 is arranged so that the TFT substrate 8 having an amorphous silicon thin film formed on the surface thereof has an upper surface of the air stage 20 so that the pull-in mark 9 shown in FIG. In this state, the conveyance is started at a constant speed in the direction of arrow A.

  When the TFT substrate 8 is transported and the pull-in mark 9 reaches the lower side of the first viewing window 12A formed on the photomask 1, shooting by the line camera 17 is started, and the line camera 17 starts shooting at regular time intervals. A captured image is output. This captured image is input to the image processing unit 26 of the control means 19 and subjected to image processing. From the luminance change in the longitudinal direction of the elongated light receiving unit 24 of the line camera 17, in the substrate transport direction of the pull-in mark 9 of the TFT substrate 8. The position of the parallel fine line 9b (see FIG. 2) and the position of the pair of fine lines 4a and 4b of the first alignment mark 4A are detected.

In the calculation unit 28, the pull-in mark 9 is based on the position data of the thin line 9 b of the pull-in mark 9 detected by the image processing unit 26 and the position data of the pair of thin lines 4 a and 4 b of the first alignment mark 4 A. The distance D between the center line parallel to the substrate transport direction of the thin wire 9b and the reference position (for example, the center position) of the first alignment mark 4A is calculated, and the alignment target value Ds ₁ stored in the memory 27 is calculated. Compare with

Next, the alignment means drive controller 31 drives and controls the alignment means 18 so that the distance D matches the alignment target value Ds _1, and moves the photomask 1 in the directions of arrows E and F in FIG. The TFT substrate 8 and the photomask 1 are aligned in advance.

The image processing unit 26 processes a one-dimensional image captured by the line camera 17 and detects a thin line 9a that intersects the substrate transport direction of the pull-in mark 9 from a luminance change along the substrate transport direction. Further, the calculation unit 28 calculates the distance L by which the TFT substrate 8 moves after detecting the fine wire 9 a based on the output of the position sensor provided in the transport means 13, and stores the distance L and the memory 27. Compared with the target value Ls of the movement distance of the TFT substrate 8 (in this embodiment, Ls = L ₁ + L ₃ ), the two match and a plurality of data lines 6 on the TFT substrate 8 as shown in FIG. When the intersection of the plurality of gate lines 7 coincides with the center of the plurality of mask patterns 2 of the photomask 1, a lighting command for the laser light source 14 is output to the laser light source drive controller 32.

  Upon receiving the lighting command, the laser light source drive controller 32 turns on the laser light source 14 for a certain period of time. As a result, as shown in FIG. 7, the laser light 21 is condensed at the intersection of the data line 6 and the gate line 7 of the TFT substrate 8 by the microlens 3 of the photomask 1, and the amorphous silicon film at the intersection is annealed. Processed and polysiliconized.

Thereafter, based on the captured image captured by the line camera 17 in the same manner as described above, for example, the data line 6 of the TFT substrate 8 close to a predetermined reference position in the light receiving unit 24 of the line camera 17 is a specific data line. 6, the position of the specific data line 6 and the position of the pair of thin lines 4a and 4b of the first alignment mark 4A are detected. Then, a distance D between the center line of the specific data line 6 and the reference position (for example, the center position) of the first alignment mark 4A is calculated, and the distance D is the alignment target value stored in the memory 27. The alignment means 18 is driven so as to match Ds ₂ and the photomask 1 is moved in the directions of arrows E and F shown in FIG. 6 to align the TFT substrate 8 with the photomask 1. Thereby, the photomask 1 can be made to follow the moving TFT substrate 8.

  In this case, as shown in FIG. 7, the pair of thin wires 4a and 4b of the first alignment mark 4A is farthest from both edges parallel to the substrate transport direction (arrow A direction) of the pixel 5 of the TFT substrate 8. Located on the center line parallel to the arrow A direction. Therefore, the pair of thin lines 4 a and 4 b can be easily detected without interfering with the data line 6 provided along the edge of the pixel 5. Therefore, the calculation of the reference position of the first alignment mark 4 is facilitated, and the photomask 1 can be made to accurately follow the moving TFT substrate 8.

In this way, each time the TFT substrate 8 moves by 2P ₁ (P ₁ is the arrangement pitch of the pixels 5 in the substrate transport direction) while the photomask 1 follows the moving TFT substrate 8, the laser light source drive controller 32. Thus, the laser light source 14 is turned on for a certain time. As a result, the amorphous silicon film at all the annealing target positions 34 on the TFT substrate 8 can be annealed to form polysilicon.

Next, a case where laser annealing processing is performed on another TFT substrate 8 having a different annealing target position 34 using the same photomask 1 will be described.
In this case, when the annealing target position 34 of the pixel 5 is a position on the gate line 7 that coincides with the center line parallel to the substrate transport direction (arrow A direction) as shown in FIG. transport direction may do it moved by (arrow a direction) and the arrangement pitch P ₂ of the half pitch of the pixels 5 in the transverse direction in the same direction (P _2/2).

  However, in this case, as shown in FIG. 8, the pair of fine lines 4a and 4b of the first alignment mark 4A interferes with the data line 6 of the TFT substrate 8. It cannot be detected separately from the data line 6. Therefore, the reference position of the first alignment mark 4A cannot be calculated, and the photomask 1 cannot follow the moving TFT substrate 8.

Therefore, in such a case, in the present invention, the mask stage 16 moves in the arrow C direction shown in FIG. 3 by a distance L ₂ by driving the driving unit 23 by the mask stage drive controller 30, is detected by a line camera 17 The alignment mark 4 is switched from the first alignment mark 4A to the second alignment mark 4B. Here, the second alignment mark. 4B, since the first alignment mark 4A are those provided shifted by D _{1 =} P _2/2 and in the cross direction the substrate transporting direction (arrow A direction), the second As shown in FIG. 8, the pair of thin lines 4a and 4b of the alignment mark 4B are positioned on a center line parallel to the substrate transport direction (arrow A direction) of the pixel 5, and the detection of the second alignment mark 4B is performed. It becomes easy. Therefore, the photomask 1 can be made to follow the moving TFT substrate 8 by using the second alignment mark 4B, and the TFT substrate 8 having a different annealing target position 34 can be used by using the same photomask 1. Can be annealed with high positional accuracy.

  Further, when annealing a target position different from any of the above annealing target positions 34, the third alignment mark 4C formed on the photomask 1 may be selected corresponding to the target position. Also in this case, in a state where the TFT substrate 8 and the photomask 1 are aligned, the pair of fine wires 4a and 4b of the third alignment mark 4C are separated from both edge portions parallel to the substrate transport direction of the pixels 5. Since it is located in the middle of the pixel 5, the pair of thin lines 4a and 4b and the data line 6 do not interfere with each other, the detection of the third alignment mark 4C is facilitated, and the photomask 1 is moved to the moving TFT substrate 8. Can be followed.

  In the above embodiment, the case where the substrate is the TFT substrate 8 has been described. However, the present invention is not limited to this, and the substrate is applied to the surface by irradiating a plurality of positions on the substrate with the laser light 21. Any thin film can be used as long as it is intended to anneal the thin film.

  In the above-described embodiment, the case where the photomask 1 of the present invention is applied to a laser annealing apparatus has been described. However, the present invention is not limited to a laser annealing apparatus, and is also applied to an exposure apparatus that exposes a photosensitive material applied on a substrate. can do. In this case, the laser light source 14 of the laser annealing apparatus may be replaced with an exposure light source composed of a xenon lamp that emits ultraviolet light, an ultrahigh pressure mercury lamp, or a laser light source that emits ultraviolet light. Accordingly, the photomask 1 is moved in the substrate transport direction in accordance with a plurality of exposure target positions set in advance on the substrate, and one alignment mark 4 is selected from the plurality of alignment marks 4, and the one alignment is performed. After aligning the reference position of the mark 4 with a reference position set in advance on the substrate, the photomask 1 can be irradiated with ultraviolet rays to expose a plurality of exposure target positions on the substrate.

In this case, a plurality of mask pattern rows of the photomask 1 are provided, and each mask pattern of the mask pattern row on the front side in the substrate transport direction among the plurality of mask pattern rows of the photomask 1 whose exposure target position on the front side in the substrate transport direction is provided 2 is irradiated for a certain period of time, and thereafter, each time the substrate is moved by a distance equal to the arrangement pitch P ₁ of the mask pattern 2 in the substrate conveyance direction, the ultraviolet light is irradiated for a certain period of time. The exposure target position can be subjected to multiple exposure. Therefore, the power of the exposure light source can be reduced to reduce the burden on the light source, and the life of the light source can be extended.

  And in the above description, when aligning the photomask 1 and the substrate, the case where the photomask 1 side is moved in the direction intersecting the substrate transport direction has been described, but the present invention is not limited to this, The substrate side may be moved, and both the photomask 1 and the substrate may be moved.

DESCRIPTION OF SYMBOLS 1 ... Photomask 2 ... Mask pattern 3 ... Micro lens 4 ... Alignment mark 4A ... 1st alignment mark 4B ... 2nd alignment mark 4C ... 3rd alignment mark 4a, 4b, 4c ... Fine line of alignment mark 5 ... Pixel (Pattern provided on the substrate)
8 ... TFT substrate (substrate)
16 ... Mask stage 17 ... Line camera 18 ... Alignment means

Claims (10)

A photomask for selectively irradiating light on a plurality of positions on a substrate, wherein a plurality of patterns are provided in a matrix at a constant arrangement pitch on the surface and conveyed in a fixed direction,
A plurality of mask patterns that are formed at a constant array pitch in a direction intersecting the transport direction of the substrate, and allow light to pass through;
A structure comprising a pair of fine lines formed in parallel to the substrate transport direction with an interval equal to an integer multiple of the array pitch in the cross direction and the substrate transport direction of the plurality of patterns provided on the substrate, The plurality of mask patterns are disposed at positions opposite to the substrate transport direction at a certain distance from each other in the substrate transport direction, and a reference position set in advance between the pair of fine lines is the substrate transport direction. A plurality of alignment marks formed in a state shifted from each other by a predetermined distance in a direction intersecting with
A photomask characterized by comprising:   Among the plurality of alignment marks, in a state in which a reference position of one selected alignment mark and a reference position set on the substrate are aligned, the pair of fine lines of the selected alignment mark is the substrate 2. The photomask according to claim 1, wherein the photomask is arranged so as to substantially coincide with a center line parallel to a substrate conveyance direction of the pixels provided in the substrate.   The photomask according to claim 1 or 2, wherein a plurality of microlenses are formed on the substrate side corresponding to each of the mask patterns.   The photomask according to any one of claims 1 to 3, wherein the plurality of mask patterns are formed in a matrix at a constant arrangement pitch in a substrate transport direction and a crossing direction thereof. A plurality of patterns on the surface are provided in a matrix at a constant arrangement pitch and aligned with a photomask placed opposite to the substrate and a laser is applied to a plurality of positions on the substrate. A laser annealing apparatus for selectively irradiating light and annealing a thin film formed on the substrate,
A plurality of mask patterns formed at a constant arrangement pitch in a direction intersecting with the substrate conveyance direction and allowing laser light to pass through, and an integer of arrangement pitches in the direction intersecting with the substrate conveyance direction of the plurality of patterns provided on the substrate A structure having a pair of thin lines formed in parallel to the substrate transport direction with a spacing equal to twice, and in the substrate transport direction at a position opposite to the substrate transport direction with respect to the plurality of mask patterns A plurality of the reference positions preset between the pair of thin wires are shifted from each other by a predetermined distance in a direction intersecting the substrate transport direction. An alignment mark and a photomask provided with the alignment mark are held, and the photomask is moved in the substrate transport direction, and one alignment mark is selected from the plurality of alignment marks. And the mask stage which was the instrument mark can be selected,
A line camera arranged by aligning the longitudinal center axis of the thin light receiving portion with the center line in the direction intersecting with the substrate transport direction of the alignment mark selected from the plurality of alignment marks of the photomask;
The substrate and the photomask are relative to each other in a direction crossing the substrate transport direction so that a positional relationship between a reference position of the selected alignment mark and a reference position preset on the substrate is a predetermined relationship. Moving alignment means,
A laser annealing apparatus comprising:   Among the plurality of alignment marks provided on the photomask, the reference position of the selected alignment mark is aligned with the reference position of the selected alignment mark and the reference position set on the substrate. 6. The laser annealing apparatus according to claim 5, wherein the pair of thin wires are arranged so as to substantially coincide with a center line parallel to a substrate transport direction of the pixels provided on the substrate.   7. The laser annealing apparatus according to claim 5, wherein the photomask has a plurality of microlenses formed on the substrate side corresponding to the mask patterns. A plurality of patterns are provided in a matrix at a constant arrangement pitch on the surface, and a substrate that is transported in a certain direction is aligned with a photomask that is disposed opposite to the substrate, and is positioned at a plurality of positions on the substrate. An exposure apparatus that selectively irradiates ultraviolet rays and exposes a photosensitive material coated on the substrate,
A plurality of mask patterns formed at a constant arrangement pitch in a direction crossing the substrate transport direction and allowing ultraviolet light to pass through, and an integer multiple of the array pitch of the plurality of patterns provided on the substrate in the direction intersecting the substrate transport direction And having a pair of fine lines formed in parallel to the substrate transport direction at equal intervals to each other in the substrate transport direction at positions opposite to the substrate transport direction with respect to the plurality of mask patterns. And a plurality of alignments formed such that a reference position preset between the pair of thin wires is shifted from each other by a predetermined distance in a direction intersecting the substrate transport direction. And a photomask provided with a mark, and the photomask is moved in the substrate transport direction to align one of the plurality of alignment marks. And the mask stage you can be selected mark put,
A line camera arranged by aligning the longitudinal center axis of the thin light receiving portion with the center line in the direction intersecting with the substrate transport direction of the alignment mark selected from the plurality of alignment marks of the photomask;
The substrate and the photomask are relative to each other in a direction crossing the substrate transport direction so that a positional relationship between a reference position of the selected alignment mark and a reference position preset on the substrate is a predetermined relationship. Moving alignment means,
An exposure apparatus comprising:   Among the plurality of alignment marks provided on the photomask, the reference position of the selected alignment mark is aligned with the reference position of the selected alignment mark and the reference position set on the substrate. 9. The exposure apparatus according to claim 8, wherein the pair of thin lines are arranged so as to substantially coincide with a center line parallel to a substrate transport direction of pixels provided on the substrate.   10. The exposure apparatus according to claim 8, wherein the photomask has a plurality of microlenses formed on the substrate side corresponding to the mask patterns.

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