JP2000214597A - Aligner and liquid crystal display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aligner capable of exposing a substrate having a large area with high throughput and high resolution and being inexpensively constituted with a simple structure. SOLUTION: In a state where a stage 8 on which the substrate 1 is placed and an array unit 10 on which plural laser modules 601 respectively having a semiconductor laser chip are mounted in rows are opposed in parallel with each other, the substrate 1 is scanned while radiating laser beams emitted by the semiconductor laser chips of plural laser modules 601 perpendicularly to a substrate surface in this aligner 100. The laser module 601 is provided to be movable in a row direction on the array unit 10. It is equipped with a positioning means 4 setting the position of the laser module 601 in the row direction on the array unit 10 based on data expressing a pattern to expose the substrate 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus suitable for exposing a large area substrate. The invention also relates to a liquid crystal display formed using such an exposure device.

[0002]

2. Description of the Related Art Heretofore, as this type of exposure apparatus, there has been known an exposure apparatus which employs a projection exposure method in which a predetermined mask pattern is projected on a substrate to form an exposure pattern. I have. In the case of this projection exposure method, the substrate surface is divided into a plurality of blocks from the trade-off between the resolution of the optical system and the exposure area per time,
A stepper system is used in which the entire substrate is exposed by repeating irradiation for each block.

However, the stepper type exposure apparatus has a problem that the exposure time increases as the substrate has a larger area because the number of times of irradiation increases in proportion to the square of the diagonal size of the substrate. For example, a single exposure time of a stepper type exposure apparatus, which is currently the mainstream in an exposure apparatus for manufacturing an A4 size liquid crystal display, is about 5 minutes, but a 40-inch (1 m square) where market expansion is expected in the future. Considering the exposure of a large display described above, the exposure time increases in proportion to the square of the area.
The exposure time for each time is as long as 50 minutes or more, which greatly deviates from the practical exposure time. Furthermore, as the size of the substrate increases, the inertial force acting on the stage increases, and it becomes more difficult to move the stage with high accuracy in a short time in a method that repeatedly moves and stops, such as a stepper method. Furthermore, when the substrate surface is divided into a plurality of blocks and exposed by the stepper method, a difference in contrast (so-called block separation) occurs at the joint between the blocks due to the lack of superposition accuracy between the blocks, and the mass production time is increased. This causes a drop in the non-defective rate. In order to increase the area that can be exposed at one time, there is a method using a large-diameter exposure lens. However, in addition to the fundamental limitation of resolution and exposure area, it is very difficult to manufacture a lens, and the exposure apparatus is extremely difficult. There is a problem that it becomes expensive.
Further, in the LSI manufacturing process using a substrate having a diameter of several inches, resolution up to submicron is realized. However, when exposing a large glass substrate as in the manufacturing process of a liquid crystal display, a certain depth of focus is secured. It is very difficult to realize a line width down to the submicron unit from a trade-off with the above.

On the other hand, as another type of exposure apparatus, a CAD such as a wiring pattern without a mask is used.
There is known a direct-drawing system that irradiates a substrate with a converged energy beam such as a laser beam or an electron beam based on data and performs exposure in a one-stroke manner. In this direct drawing method, the stage movement is not repeated for each block unlike the stepper method, so that the stage movement becomes easy. Further, since the substrate surface is not exposed while being divided into a plurality of blocks, so-called block separation does not occur. Further, it is easy to realize a line width up to a submicron unit.

As an example of an exposure apparatus using this direct drawing method,
An apparatus has been proposed in which an argon laser beam as a light source is split into eight beams, and each split laser beam is turned on / off by one ultrasonic modulation element to form a pattern (particularly). JP-A-62-26819). As a similar exposure apparatus using a direct drawing method, there is an example in which a semiconductor laser is used as a light source (Japanese Patent Laid-Open No. 2-740).
No. 22). Further, when exposing a large-area substrate in a liquid crystal display manufacturing process, a plurality of semiconductor laser light sources are arranged in an array in order to avoid a decrease in throughput and an increase in the cost of an optical system. An apparatus configured by combining optical systems has been proposed (Japanese Unexamined Patent Application Publication No.
Japanese Patent Application Laid-Open No. 8-334803 discloses an arrangement in which laser light sources are similarly arranged in an array, and wavelength conversion using a non-linear crystal is applied to the laser light sources to produce an ultraviolet laser light source. Gazette).

However, in the conventional exposure apparatus of the direct writing type, the light source is fixed on the array, and in order to perform exposure at a desired pitch, the entire array must be replaced or the array must be replaced by an amount necessary for the apparatus. There is a problem that it must be provided in large quantities. In the case of using an ultraviolet laser light source, since the conversion efficiency when performing wavelength conversion using a nonlinear crystal is low, a sufficient light output cannot be obtained and the exposure time becomes long. Furthermore, the cost of making the light source module is also
It is inevitable that the cost will be higher than in the case where the light emitted from the semiconductor laser is directly used.

SUMMARY OF THE INVENTION An object of the present invention is to provide an exposure apparatus which can expose a large-area substrate with high throughput and high resolution and can be constructed at a low cost with a simple structure. Another object of the present invention is to provide a liquid crystal display formed using such an exposure apparatus.

[0008]

According to a first aspect of the present invention, there is provided an exposure apparatus comprising: a stage on which a substrate to be exposed is mounted; and a plurality of laser modules each having a semiconductor laser chip. The stage and the array unit are radiated perpendicularly to the substrate surface with the laser light emitted from the semiconductor laser chips of the plurality of laser modules in a state where the array units mounted in parallel with each other face each other in parallel. In the exposure apparatus for scanning the substrate by relatively moving the laser module, each of the laser modules is provided movably in the column direction on the array unit, based on data representing a pattern to expose the substrate. Positioning means for setting the position of each of the laser modules in the column direction on the array unit. To.

In the exposure apparatus according to the first aspect, the positioning means sets the position in the column direction of each of the laser modules arranged in a row on the array unit based on the data representing the pattern to be exposed on the substrate. Then, while controlling the on / off of the semiconductor laser chip of each of the laser modules, the stage on which the substrate is mounted and the array unit are maintained in a parallel state and are relatively positioned in a direction perpendicular to the column direction. Moved to Thus, a single scan forms a linear exposure pattern on the substrate at a position corresponding to each of the laser modules. Therefore, by changing the position of each laser module in the column direction, exposure patterns of various pitches are formed on the substrate with a relatively small number of scans without replacing the array unit. As a result, a large area substrate can be exposed at a high throughput. Further, since this exposure apparatus belongs to the direct drawing system, it can perform exposure with high resolution. In addition, since a semiconductor laser is used as a light source, there is no need to employ a complicated optical system, and a simple structure can be used at a low cost.

According to a second aspect of the present invention, in the exposure apparatus of the first aspect, the semiconductor laser chip of each of the laser modules emits blue laser light.

In the exposure apparatus according to the present invention, since the semiconductor laser chip of each laser module emits blue laser light, the beam diameter of the laser light, that is, the line width of the exposure line is reduced to the submicron order (diffraction of blue light). (0.5 μm, which is the limit), and the resolution can be further improved. In addition, since the beam diameter of the laser beam can be reduced to the order of submicrons, the energy density of the laser beam irradiated on the substrate increases, so that high-speed scanning can be performed, and the throughput further increases.

According to a third aspect of the present invention, in the exposure apparatus according to the first or second aspect, the array unit is configured by combining an X array unit extending in the X direction and a Y array unit extending in the Y direction. The plurality of laser modules are arranged symmetrically with respect to the center in the longitudinal direction of the X array unit and the Y array unit so as to have a predetermined pitch along the longitudinal direction of the X array unit and the Y array unit, respectively. It is characterized by that.

In the exposure apparatus according to the third aspect, the positioning means sets the position in the column direction of each laser module arranged in a line on the array unit based on the data representing the pattern to be exposed on the substrate. At this time, the plurality of laser modules are arranged at a predetermined pitch (this is referred to as a “module pitch”) along the longitudinal direction of the X array unit and the Y array unit.
The array units and the Y array units are arranged symmetrically with respect to the longitudinal center. For example, when exposing a substrate having a relatively small area at a small pitch, the plurality of laser modules may be densely arranged at the center in the longitudinal direction of the X array unit and the Y array unit so that the number of scans may be relatively small. Placed in On the other hand, when exposing a substrate having a relatively large area, the plurality of laser modules are arranged so as to be distributed over the entire length of the X array unit and the Y array unit. Then, when scanning in the X direction, while controlling on / off of the semiconductor laser chip of each laser module on the Y array unit,
The stage on which the substrate is mounted and the array unit are X
Moved relative to the direction. As a result, a plurality of exposure lines extending linearly in the X direction and having a pitch corresponding to the module pitch on the Y array unit in the Y direction are formed by one scan. When scanning in the Y direction, the stage on which the substrate is mounted and the array unit are relatively moved in the X direction while controlling the on / off of the semiconductor laser chip of each laser module of the X array unit. Is done. With this, a single scan extends linearly in the Y direction,
A plurality of exposure lines having a pitch corresponding to the module pitch on the X array unit in the X direction are formed. Therefore, by changing the module pitch on the X array unit and the Y array unit, an exposure pattern having various pitches in the X direction and the Y direction can be relatively formed on the substrate without replacing the array unit. It is formed with a small number of scans. As a result,
A large area substrate can be exposed with high throughput.

A pitch (a target pitch) extending linearly in the X direction and smaller than the minimum pitch that the laser module on the Y array unit can take in the Y direction.
When it is desired to form an exposure line having the following, the module pitch on the Y array unit is set to an integral multiple of the target pitch, and scanning in the X direction is repeated while shifting the array unit by the target pitch in the Y direction. good. Similarly, if it is desired to form an exposure line extending linearly in the Y direction and having a pitch (target pitch) smaller than the minimum pitch that the laser module on the Y array unit can take in the X direction, the X array unit The upper module pitch may be set to an integral multiple of the target pitch, and scanning in the Y direction may be repeated while shifting the array unit by the target pitch in the X direction.

According to a fourth aspect of the present invention, in the exposure apparatus according to any one of the first to third aspects, each of the laser modules includes a semiconductor laser chip and a photodetector for detecting an output of the semiconductor laser chip. And two sets of laser systems including at least two laser systems, and control means for switching and operating the two sets of laser systems based on the output of the photodetector.

In the exposure apparatus according to the fourth aspect, usually, only one of the two laser systems (this is called an "original laser system") is used, and the original laser system emits light. The irradiated laser light is applied to the substrate surface. If an abnormality occurs in the original laser system, the control means recognizes the abnormality based on the output of the photodetector of the original laser system and instantaneously recognizes the other laser system (this is referred to as a “backup laser system”). Calling). Then, the laser light emitted from the spare laser system is irradiated on the substrate surface. In this case, even if an abnormality occurs in the original laser system of a certain laser module during exposure of a certain substrate, the exposure is continued by the spare laser system of the laser module without interrupting the scanning. be able to.

A warning to the effect that an abnormality has occurred in the original laser system can be issued to the outside.

According to a fifth aspect of the present invention, in the exposure apparatus of the fourth aspect, the control means controls a certain laser module based on an output of the photodetector while exposing a certain substrate. When recognizing that an abnormality has occurred, another laser module is selected, and a portion of the substrate surface to be irradiated by the laser module having the abnormality is irradiated with the laser light emitted by the another laser module. It is characterized in that control for adding an exposure sequence is performed.

According to the fifth aspect of the present invention, when an abnormality occurs in a certain laser module while exposing a certain substrate, the laser module on the substrate surface where the abnormality has occurred should irradiate. A portion is irradiated with laser light emitted from another laser module. Therefore, the exposure of the substrate is performed reliably.

A liquid crystal display according to a sixth aspect is characterized in that at least the picture element electrodes are patterned by exposure using the exposure apparatus according to any one of the first to fifth aspects.

The liquid crystal display according to the sixth aspect is produced at high throughput because at least the picture element electrodes are patterned by exposure using the exposure apparatus according to any one of the first to fifth aspects. You. Further, since this exposure apparatus belongs to the direct drawing system, it can perform exposure with high resolution.
That is, by narrowing the beam system of the laser light emitted from the laser module, the gap (line width) between the pixel electrodes is reduced.
Are finished to the submicron order, and a high aperture ratio is realized. In addition, since exposure is not performed by dividing the substrate surface into a plurality of blocks as in the stepper method, so-called block separation does not occur.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 1 shows an exposure apparatus 100 according to an embodiment as viewed obliquely from above.

The glass substrate 1 is placed on an XYZ stage 8, and a cross-shaped array unit 10 is arranged above them. The array unit 10 is configured by combining an X array unit 6 having a total length of 2 m extending in the X direction and a Y array unit 7 having a total length of 2 m extending in the Y direction in a cross shape. The X array unit 6 includes three elongated sub arrays 61, 62, and 63, and the Y array unit 7 includes three elongated sub arrays 71, 72, and 73. Each sub-array 61, 62, 63, 71, 72,
Reference numeral 73 denotes 201 laser modules 601 each.
Is the longitudinal direction of the sub-array (hereinafter simply referred to as “longitudinal direction”).
That. ) Are mounted in a line. One set of subarrays intersecting in the X and Y directions has one laser module 601 located at the origin (center in the longitudinal direction) overlapped, and as a result, is constituted by a total of 401 laser modules. Therefore, the array unit 10 has a total of 12
It includes 03 laser modules 601. The size in the X and Y directions of each laser module 601 is 5 mm × 5
mm. The irradiation pattern of the blue laser light emitted from each laser module 601 to the substrate 1 is a circle having a diameter of 0.5 μm, which is the diffraction limit of the blue light.

As shown in FIG. 2, on the sub-array 61 extending in the X direction, each laser module 601 can move along the longitudinal direction. The pitch of the laser modules 601 arranged in the longitudinal direction (hereinafter referred to as “module pitch”) is adjusted in the range of 5 to 10 mm. When the module pitch is set to 10 mm, the laser modules 601, 601,. (Approximately 2 m), and when the module pitch is set to 5 mm, the laser modules 601, 601,... Are densely arranged at the center in the longitudinal direction (range of about 1 m) with the origin at the center. Is done. In each of the other sub-arrays 62, 63, 71, 72, and 73, the laser module 601 can be similarly moved along the longitudinal direction.

The laser modules 601 included in the array unit 10 are connected in parallel to the module controller 3 shown in FIG. Therefore, the module controller 3 transmits a plurality of laser modules 601, 60 based on a control signal from the main controller 2.
Can be controlled on / off independently of each other.

The positioning controller 4 includes a plurality of laser modules 601, 601,... On the sub-arrays 61, 62, 63, 71, 72, 73 based on the module positioning data output by the main controller 2.
Position.

The stage controller 5 moves the XYZ stage 8 based on a control signal from the main controller 2. The XYZ stage 8 is moved so as to scan the substrate 1 from end to end in the X and Y directions, but is used in the Z direction to correct a slight displacement such as a focus adjustment at the time of beam irradiation. .

The main controller 2 controls the exposure apparatus 1
00 overall control. That is, while controlling the alignment unit 9, the stage controller 5 and the module controller 3 are controlled based on the exposure pattern data.
Generate a control signal for Then, according to the exposure pattern data, each laser module 601 included in the array unit 10 is synchronized with the movement of the XYZ stage 8.
Is turned on / off by the module controller 3.
Thereby, exposure of a desired pattern can be performed.

FIGS. 3A and 3B show the structure of the laser module 601. FIG. As shown in FIG. 3A, this laser module 601
2, a collimating lens 613 for converting the light L1 emitted from the laser chip 611 into a plane wave L2, and the collimating lens 613
A beam splitter 614 for splitting the emitted light L2 into a light L3 for irradiating the substrate and a light L4 for monitoring the operation state of the laser chip 611, and a beam splitter 6
A photodetector 615 for monitoring the operating state of the laser chip 611 in response to the light L4 from the light source 14; a control signal transmitter 616 for converting a light intensity monitor voltage generated by the photodetector 615 into an electric signal required for signal processing; A condenser lens 617 for condensing the light L3 emitted from the splitter 614 and irradiating the substrate 1 and a condenser lens drive unit 618 for adjusting the diameter of the output beam L by moving the position of the condenser lens 617 up and down. Have. The semiconductor laser chip 611 used here has a wavelength of 420 n.
m (blue) and an output of 10 mW. The laser chip 611, the control signal transmitter 616, and the condenser lens drive unit 618 are connected to the above-mentioned module controller 3 via connection terminals 619a, 619b, 619c provided on the side surfaces of the module, respectively. The module controller 3 performs feedback control by a known method based on a signal from the control signal transmitter 616 so that the output of the laser chip 611 becomes a predetermined level.

As shown in FIG. 3B, in the laser module 601, the original laser systems 611, 613,
614, 615, 617, and 618 (these are collectively denoted by reference numeral 610), and a spare laser system 611 ',
613 ', 614', 615 ', and 617' (collectively denoted by reference numeral 610 ') are incorporated. When an abnormal operation of the laser chip 611 or the photodetector 615 is detected while using the original laser system 610,
The module controller 3 issues a command so that the spare laser system 610 'operates instantaneously. At this time, since a slight difference occurs in the exposure position, the main controller 2 controls the movement of the module controller 3 and the stage controller 5 so that the difference in the exposure position is corrected. Also,
In order to prevent waste in the exposure sequence, two laser systems 610 and 61 in one laser module are used.
The position of 0 'is arranged parallel to the beam scanning direction.

The exposure apparatus 100 operates as follows according to the exposure sequence shown in FIG.

In this example, in order to form the picture element electrodes on the glass substrate 1 of 1 m × 1 m, in the X direction and the Y direction, the minimum pitch that the laser module 601 can take on each subarray is smaller than 5 mm. A grid-like exposure pattern having a pitch of 50 μm in the X direction and a pitch of 100 μm in the Y direction is formed.

First, the main controller 2 reads the exposure pattern data, and generates control data for the stage controller 5 and the module controller 3 and module positioning data to be transmitted to the positioning controller 4 based on the exposure pattern data. Then, those data are accumulated (S1 in FIG. 7). On the basis of the module positioning data, the positioning controller 4 controls the sub-arrays 61, 62, 63, 71, 72,
The laser modules 601, 601,.
Position. In this example, as shown in FIG. 4A, the module pitch in the Y direction is
Each of the sub-arrays 71, 72, 73 has a laser module 60 mm.
1 is displaced by 2 mm. Similarly, as shown in FIG. 5E, the module pitch in the X direction is 6 mm in each of the sub-arrays 61, 62, and 63, and the position of the laser module 601 is set to 2 mm between adjacent sub-arrays 61, 62, and 63. It is shifted. By arranging the laser modules 601, the individual laser modules 6
A pattern with a pitch smaller than the size of 01 (5 mm per side) can be formed.

Next, height adjustment and alignment of the substrate 1 are performed using the XYZ stage 8 and the alignment unit 9 shown in FIG. At this time, height adjustment is performed so that the diameter of the laser beam L to be irradiated becomes a desired value (here, 0.5 μm).
The condensing lens drive unit 618 also operates within 1 and is adjusted to the optimum position (S2).

A light source for exposure has a wavelength of 420 nm.
Since the blue semiconductor laser chip 611 is used, an ultraviolet-sensitive resist used in a stepper is used as a photosensitive agent on the substrate 1 (because the wavelength is close,
The spectral sensitivity is considered to be sufficient. ).

Next, exposure is started (S 3). That is, i) as shown in FIG. 4A, the stage 8 on which the substrate 1 is placed is once moved to the start position (the left position of the Y array unit 7), and then the stage 8 is accelerated in the + X direction. First, the substrate 1 is moved at a constant speed of 1 m / s from when the left end of the substrate 1 reaches the irradiation position of the Y array unit 7. During this stage movement, on / off of each laser module 601 of the Y array unit 7 is controlled according to the exposure pattern data. In this manner, the first scanning in the X direction is performed, and as shown in FIG. 4B, a plurality of exposures extending linearly in the X direction with a line width of 0.5 μm and having a pitch in the Y direction of 2 mm. A line 1x is formed. The reason that the speed of the stage 8 in the X and Y directions during exposure can be set to a relatively high speed of 1 m / s is that the diameter of the output beam L is narrowed to 0.5 μm by the condenser lens 617 to the order of submicron. (It is considered that the light energy is sufficient.)

Subsequently, the stage 8 is connected to the Y array unit 7
Stage 8 with 100 μm Y
Move in the direction. Then, a second scan in the X direction is performed by moving in the −X direction in a direction opposite to the first scan. As a result, as shown in FIG. 5C, a new exposure line having a line width of 0.5 μm is provided at a position shifted by 100 μm in the Y direction with respect to each exposure line 1x formed first. Form 1x. In this manner, the stage movement is repeated while controlling the on / off of each laser module 601 of the Y array unit 7 to make 10 reciprocations in the X direction, thereby making the laser module 601 reciprocate 0.5 times as shown in FIG.
Exposure patterns 1x, 1 extending linearly in the X direction with a line width of μm, and having a pitch of 100 μm in the Y direction.
x,...

Ii) Thereafter, the on / off of each laser module 601 of the X array unit 6 is controlled by moving the stage 8 in the + Y direction at a speed of 1 m / s in the same procedure as the scanning in the X direction. In this way, the first scanning in the Y direction is performed, and as shown in FIG.
Extends linearly in the Y direction with a line width of
m are formed (see FIG. 5).
In FIG. 6E and FIG. 6F, the already formed exposure line in the X direction is omitted for easy understanding. ). Subsequently, the stage 8 is moved in the X direction by 50 μm to perform a second scan in the Y direction, and as shown in FIG.
0.5 μm each at a position shifted by 50 μm in the X direction with respect to each exposure line 1y formed at the first time.
A new exposure line 1y having a line width of m is formed. Thus, each laser module 6 of the X array unit 6
By controlling the ON / OFF of 01 and repeating the stage movement to make 20 reciprocations in the Y direction, the exposure extends linearly in the X direction with a line width of 0.5 μm, and the pitch in the Y direction is 50 μm. The patterns 1y, 1y,... Are formed.

As a result of the above i) and ii), FIG.
As shown in FIG.
A plurality of lines 1x and 1y having a line width of 50 μm are formed in a grid pattern having a pitch of 50 μm in the X direction and 100 μm in the Y direction.

The time required for one round trip of the stage 8 is 2
If it is set to seconds, the processing time per substrate in this exposure step is expected to be 3 minutes in consideration of alignment, substrate replacement, and the like. Since the processing time when the conventional stepper method is used is 50 minutes, it can be seen that the processing time can be significantly reduced by this exposure step, and a large liquid crystal display substrate can be exposed with a practical throughput.

During the above-described exposure, the module controller 3 controls each laser module 601
Of each laser module 601 based on the signal from the control signal transmitter 616 of FIG.
In addition to controlling the injection current to the laser module, it is monitored whether or not the operation of each laser module 601 is normal (S4 in FIG. 7). If the scanning is completed without any abnormality, the exposure process is completed (S5).

On the other hand, any of the laser modules 601
If an abnormality such as output drop that cannot be controlled
The main controller 2 and the module controller 3 act as control means to stop the current supply to the semiconductor laser 611 of the laser module 601 to issue a warning to the operator and immediately to the spare semiconductor laser 611 in the laser module 601. Is operated (S6), and exposure is continued by the spare laser system 610 '(S7). Note that, even when the photodetector 615 is used instead of the semiconductor laser 611 to cause the abnormality, the exposure is continued by switching to the spare laser system 610 'in the same manner. Subsequently, the module controller 3 monitors whether there is any abnormality in the operation of each of the laser modules 601 (S8). If the scanning is completed without any abnormality, the exposure process is completed (S5).

If the spare laser system 610 'becomes abnormal in the laser module 601 operated by the spare laser system 610' or some other abnormality occurs (S8), the laser module immediately The operation of 601 is stopped, a warning is issued to the operator, and the irradiation position of the substrate 1 at that time is stored (S
9). After once terminating the exposure based on the normal data (S10), the correction pattern data is generated and read (S11, S12), and only the area in the substrate 1 where the exposure has not been performed is performed (S3 to S5). ).

In this case, even if the laser module 601 suddenly becomes abnormal during the exposure, the exposure of the substrate 1 in progress can be executed to the end, and the yield of exposure can be improved. Further, when an abnormality occurs in any one of the laser modules 601, a warning is immediately issued to the operator, so that the laser module can be replaced after the exposure is completed based on the warning.

Further, in this embodiment, since the resist applied to the substrate 1 is for ultraviolet light, exposure in combination with a stepper becomes possible. For example, if a 0.5 μm pattern in a pixel is exposed by the exposure apparatus 100 and a pattern with a large line width such as a driver section is exposed by a stepper, optimal exposure can be performed in consideration of the throughput and characteristics of each exposure apparatus. Becomes Of course, even when the driver unit requires a line width on the order of submicron,
In 00, the sub-arrays 61, 62, 63, 71, 72, 7
Since the module pitch is variable on 3, the exposure can be continuously performed by one exposure process without changing the array.

In the present exposure apparatus 100, the number and length of the sub-arrays included in the X-array unit 6 and the Y-array unit 7 can be variably set, thereby easily adapting to the required production scale and equipment cost. Can be done.

When a pixel electrode having a size of 50 μm × 100 μm is manufactured by a stepper capable of forming a cutout pattern having a line width of 2 μm, which is widely used in the production of liquid crystal displays at present, an aperture ratio of 94.times. 08%
Becomes On the other hand, if a pattern having a line width of 0.5 μm is formed by the exposure apparatus 100, the aperture ratio becomes 9
8.505%, and the aperture ratio can be increased by 4.425 points as compared with the conventional case. In addition, considering the overlay accuracy between the picture element electrode and the source bus line in the liquid crystal display, it is difficult to realize a 94% aperture ratio with a stepper. It can be expected that the aperture ratio can be increased by more than the point. Furthermore, in the stepper method, a picture element portion is divided into a plurality of blocks on a substrate and exposed. Therefore, if overlay accuracy is low, block separation (difference in contrast between blocks) may occur. According to the method, since exposure is performed by continuously scanning the substrate, there is no such concern at all. Therefore, the non-defective rate of the liquid crystal display can be improved.

[0049]

As is apparent from the above description, in the exposure apparatus according to the first aspect, the positioning means is provided for each of the laser modules arranged in a row on the array unit based on the data representing the pattern to be exposed on the substrate. Since the position in the column direction is set, exposure patterns with various pitches can be formed on the substrate with a relatively small number of scans without replacing the array unit. As a result, a large area substrate can be exposed at a high throughput. Further, since this exposure apparatus belongs to the direct drawing system, it can perform exposure with high resolution. In addition, since a semiconductor laser is used as a light source, there is no need to employ a complicated optical system, and a simple structure can be used at a low cost.

In the exposure apparatus according to the second aspect, since the semiconductor laser chip of each laser module emits blue laser light, the beam diameter of the laser light, that is, the line width of the exposure line is set to a submicron order (blue light). It can be stopped down to the diffraction limit of 0.5 μm), and the resolution can be further improved. In addition, since the beam diameter of the laser light can be reduced to the order of submicrons, the energy density of the laser light irradiated onto the substrate is increased, so that high-speed scanning can be performed and the throughput can be further increased.

According to a third aspect of the present invention, in the exposure apparatus according to the first or second aspect, the array unit is configured by combining an X array unit extending in the X direction and a Y array unit extending in the Y direction. The plurality of laser modules are arranged symmetrically with respect to the center in the longitudinal direction of the X array unit and the Y array unit so as to have a predetermined pitch along the longitudinal direction of the X array unit and the Y array unit, respectively. Therefore, without replacing the array unit, the X
Exposure patterns having various pitches in the Y and Y directions can be formed with a relatively small number of scans. As a result, a large area substrate can be exposed at a high throughput.

In the exposure apparatus according to the present invention, each of the laser modules includes two sets of laser systems each including at least a semiconductor laser chip and a photodetector for detecting the output of the semiconductor laser chip, and outputs the output of the photodetector. Control means for switching and operating the two laser systems based on the above, so that even if an abnormality occurs in the original laser system of a certain laser module during the exposure of a certain substrate, the scanning can be performed without interruption. Exposure can be continued by the spare laser system of the laser module.

In the exposure apparatus according to the fifth aspect, when the control unit recognizes that an abnormality has occurred in a certain laser module based on the output of the photodetector while exposing a certain substrate, Since another laser module is selected, control is performed to add an exposure sequence for irradiating a laser beam emitted by the another laser module to a portion of the substrate surface to be irradiated by the abnormal laser module, Exposure of the substrate can be reliably completed.

A liquid crystal display according to a sixth aspect is characterized in that at least the picture element electrodes are patterned by exposure using the exposure apparatus according to any one of the first to fifth aspects.

The liquid crystal display according to the sixth aspect is the first aspect.
Since at least the picture element electrodes are patterned by the exposure using the exposure apparatus described in any one of the above items 1 to 5, high-throughput production is possible. Further, since this exposure apparatus belongs to the direct drawing system, it can perform exposure with high resolution. In other words, by narrowing the beam system of the laser light emitted from the laser module, the size of the gap (line width) between the picture element electrodes can be finished to the order of submicron, and a high aperture ratio can be realized. In addition, since exposure is not performed by dividing the substrate surface into a plurality of blocks as in the stepper method, so-called block separation does not occur.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a state in which an exposure apparatus according to an embodiment of the present invention is operating.

FIG. 2 is a diagram illustrating movement of a laser module in a subarray of the exposure apparatus.

FIG. 3 is a diagram showing a structure of the laser module.

FIG. 4 is a view for explaining an exposure process by the exposure apparatus.

FIG. 5 is a view for explaining an exposure process by the exposure apparatus.

FIG. 6 is a view for explaining an exposure step by the exposure apparatus.

FIG. 7 is a flowchart showing an exposure sequence for the exposure apparatus.

[Explanation of symbols]

 Reference Signs List 1 board 2 main controller 3 module controller 4 positioning controller 5 stage controller 6 X array 7 Y array 8 XYZ stage 9 alignment unit 61, 62, 63, 71, 72, 73 sub array 601 laser module

Claims (6)

[Claims] 1. A method according to claim 1, wherein a stage on which a substrate to be exposed is mounted and an array unit on which a plurality of laser modules each having a semiconductor laser chip are mounted in a row are opposed in parallel to each other. An exposure apparatus for scanning the substrate by relatively moving the stage and the array unit while irradiating the laser light emitted by the semiconductor laser chip of the laser module perpendicularly to the substrate surface, and scanning the substrate. A positioning means for setting the position of each of the laser modules on the array unit in the column direction on the array unit based on data representing a pattern to be exposed on the substrate; An exposure apparatus comprising: 2. The exposure apparatus according to claim 1, wherein the semiconductor laser chip of each laser module emits blue laser light. 3. The exposure apparatus according to claim 1, wherein the array unit is configured by combining an X array unit extending in an X direction and a Y array unit extending in a Y direction. An exposure apparatus symmetrically arranged with respect to the center in the longitudinal direction of the X array unit and the Y array unit so as to have a predetermined pitch along the longitudinal direction of the X array unit and the Y array unit, respectively. . 4. The exposure apparatus according to claim 1, wherein each of the laser modules includes a laser system including at least a semiconductor laser chip and a photodetector for detecting an output of the semiconductor laser chip. An exposure apparatus, comprising: a control unit that is mounted as a set and switches and operates the two sets of laser systems based on an output of the photodetector. 5. The exposure apparatus according to claim 4, wherein the control unit recognizes that an abnormality has occurred in a certain laser module based on an output of the photodetector while exposing a certain substrate. At this time, control is performed to select another laser module and add an exposure sequence for irradiating a laser beam emitted by the another laser module to a portion of the substrate surface to be irradiated by the laser module in which the abnormality has occurred. An exposure apparatus comprising: 6. A liquid crystal display wherein at least picture element electrodes are patterned by exposure using the exposure apparatus according to claim 1. Description: