JPH11121365A - Aligner and exposing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable enlarging of the substrate to be exposed without extending the stroke of the substrate stage to be exposed, and to permit conducting positional control in a highly precise manner, by a method wherein a substrate is mounted and a substrate stage, which can be rotated at the number of rotation for each specific angle, is provided. SOLUTION: Four apertures 5a, 56,... are provided on a reticle table 5, and annular reticle turntables 6a, 6b,... are provided on the apertures 5a, 5b,... formed on the upper surface of the reticle table 5. Reticles 20a, 20b,... are placed on the reticle turntables 6a, 6b,... in such a manner that the center of rotation of the reticle turntables 6a, 6b,... and the center of the reticles 10a, 20b,... coincide with each other, and the reticles 20a, 20b,... are rotated at every 180 deg. in association with the rotation of the reticle turntables 6a, 6b,.... Also, the angle of rotation of the substrate 9 to be exposed and a reticle 4 may be set at 90 deg. step.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an exposure apparatus and an exposure method used for manufacturing a liquid crystal display, a semiconductor integrated circuit, and the like.

[0002]

2. Description of the Related Art In the manufacture of liquid crystal displays, semiconductor integrated circuits, and the like, a circuit pattern formed on a projection original (such as a reticle in this specification) such as a reticle or a mask is illuminated by an illumination optical system. It is performed by image-transferring a pattern onto a photosensitive substrate (collectively referred to as a substrate to be exposed in this specification) such as a glass plate or a wafer coated with a photosensitive agent such as a resist by a projection optical system. With the increase in size of liquid crystal displays and the like, there is an increasing demand for projecting and exposing a circuit pattern on a large-sized substrate to be exposed. As a method of projecting and exposing a circuit pattern on a large substrate to be exposed, the substrate to be exposed is divided into four front, rear, left and right exposure regions, and a substrate stage on which the substrate to be exposed is mounted is moved back and forth, left and right, A method of sequentially exposing four exposure regions is known. That is, first, for example, the first left exposure area is placed at the image forming position of the projection optical system to perform the first exposure, and further, the substrate stage to be exposed is moved in the left and right direction to project the front right exposure area to the projection optical system. The second exposure is performed at the imaging position of the system. Next, the substrate stage to be exposed is moved in parallel in the front-rear direction, and the third exposure is performed with the exposure area in the rear right portion positioned at the image forming position of the projection optical system. Then, a fourth exposure is performed with the rear left portion at the image forming position of the projection optical system.

[0003]

However, when the substrate stage to be exposed is configured to move in parallel with the enlargement of the substrate to be exposed, it is necessary to extend the stroke of the substrate stage to be exposed by the amount of the parallel movement. is there. For this reason, there has been a disadvantage that the exposure target substrate stage itself becomes large and the weight increases. In addition, for example, when controlling the position of a large substrate stage to be exposed using a laser interferometer, a long moving mirror is required, but there are certain restrictions on the length of the moving mirror for manufacturing reasons. There is also a problem that the accuracy of the surface is deteriorated at the end face of the long movable mirror, and the accuracy is reduced when a movable mirror having a length longer than a certain length is used for position control. Therefore, an object of the present invention is to provide an exposure apparatus that can cope with an increase in the size of a substrate to be exposed without extending the stroke of the substrate stage to be exposed and that can perform high-precision position control.

[0004]

Means for Solving the Problems To solve the above problems, the invention according to claim 1 will be described with reference to FIG. 1 showing an embodiment. The pattern of a reticle (20a) is formed on a substrate (9). An exposure apparatus, comprising: a substrate stage (10) on which a substrate (9) is mounted and which can be rotated by any one of rotation amounts of 90 ° and 180 °. Device. According to a second aspect of the present invention, in the exposure apparatus of the first aspect, a reticle stage (4) is provided, the reticle (20a) being mounted thereon and being rotatable by the same rotation amount as the substrate stage (10). This is a feature of the exposure apparatus. According to a third aspect of the present invention, there is provided the exposure apparatus of the first aspect, further comprising a projection optical system of an erect image system for projecting a pattern of the reticle (20a) onto the substrate (9). It is. A fourth aspect of the present invention is the exposure apparatus according to the second aspect, further comprising a control device (18) for controlling the substrate stage (10) and the reticle stage (4).
According to a fifth aspect of the present invention, in the exposure apparatus according to the fourth aspect, the control device (18) controls at least the substrate stage (10) by at least 90 after exposing the pattern of the reticle (20a).
The exposure apparatus is characterized in that the exposure apparatus is rotated by any one of the rotation amounts of every ° and every 180 °. According to a sixth aspect of the present invention, in the exposure apparatus of the fourth aspect, the reticle stage (4) holds a plurality of reticles (20a) to (20d), and the control device (18) controls the plurality of reticles (20). The substrate stage (1) is formed so that a combined pattern obtained by combining the patterns of 20a) to (20d) is formed on the substrate (9).
0) and a reticle stage (4).

[0005] A reticle (20)
a) exposing the pattern of the reticle (20a) to the substrate (9); and exposing the substrate (9) to the substrate (9) at every 90 ° or at every 180 °. And a step of rotating by an amount of rotation. According to an eighth aspect of the present invention, in the exposure method of the seventh aspect, the reticle (20
An exposure method comprising the step of rotating a) by the same amount of rotation as the substrate (9). A ninth aspect of the present invention is the exposure method according to the eighth aspect, wherein the direction in which the reticle (20a) rotates is the same as the direction in which the substrate (9) rotates.

[0006]

FIG. 1 is a sectional view of an exposure apparatus according to an embodiment of the present invention. The illumination light beam 2 from the light source 1 enters the illumination optical system 3 and passes through the illumination optical system 3.
Illuminates the reticle 20a placed on the reticle table 5. A circuit pattern is drawn on the reticle 20a, and the circuit pattern on the reticle 20a is exposed by the projection optical system 8 of the same size and the erect image system.
Exposure is performed on the substrate 9 to be exposed placed on the substrate 9. In the present embodiment, the substrate 9 to be exposed is a square glass plate having a size of about 500 mm × 600 mm and a thickness of about 1.
1 mm. The reticle table 5 has an outer edge fixed to the reticle stage 4 and the reticle stage 4 is configured to be movable in the XY directions. The reticle table 5 of this embodiment has four openings 5a to 5d.
Are provided, and ring-shaped reticle turntables 6a to 6d are provided at openings 5a to 5d on the upper surface of reticle table 5, respectively. Reticle turntables 6a to 6d have inner diameters larger than openings 5a to 5d, and are configured to surround openings 5a to 5d, respectively. Racks are respectively formed on the outer edges of the reticle turntables 6a to 6d, and are configured to be independently rotatable by motors 7a to 7d via pinion gears.

Reticles 20a to 20d are mounted on reticle turntables 6a to 6d.
6d rotation center and center Ca of reticles 20a to 20d
ＣCd coincide with each other, and with rotation of reticle turntables 6a〜6d, reticles 20a〜2
0d can be rotated every 180 °. The circuit pattern drawn on the reticles 20a to 20d has an overlap portion so that a part of the pattern is overlapped on the substrate 9 to be exposed and the screen is synthesized.

A movable mirror 17 is provided on the reticle stage 4. The laser interferometer 16 irradiates the movable mirror 17 with a laser beam to detect the position of the reticle stage 4 in the Y direction. Although not shown in FIG. 1, a laser interferometer for detecting the position of the reticle stage 4 in the X direction is also provided. The reticle alignment microscope 14 detects reticle alignment marks formed on the reticles 20a to 20d, respectively, and determines the positions of the reticles 20a to 20d.

On the other hand, the exposed substrate stage 10 comprises an XYZ stage 10a movable in the X, Y, and Z directions in FIG. 1 and an exposed substrate turntable 10b arranged on the XYZ stage 10a. The exposure substrate turntable 10b is configured to be rotatable by a motor 11. The substrate to be exposed 9 is a turntable 10 for the substrate to be exposed.
b, the center Cs of the substrate 9 to be exposed is aligned with the rotation center of the substrate turntable 10b, and the substrate 9 is rotated by 180 ° with the rotation of the substrate turntable 10b. Can be rotated.

A moving mirror 13 is provided on the XYZ stage 10a. The laser interferometer 12 irradiates the movable mirror 13 with a laser beam to detect the position of the XYZ stage 10a in the Y direction. Although not shown in FIG. 1, the laser interferometer 1 detects the position of the XYZ stage 10a in the X direction.
Two are also provided. Exposed substrate alignment microscope 1
Reference numeral 5 denotes a so-called off-axis alignment microscope which is disposed at a predetermined distance from the optical axis of the projection optical system 8 and detects a substrate alignment mark formed on the substrate 9 to be exposed. The controller 18 controls the entire exposure apparatus. In this embodiment, the controller 18 particularly controls the reticle stage 4, the reticle turntables 6a to 6d, the XYZ stage 10a, and the substrate to be exposed turntable 10b.

Next, the control of the controller 18 for exposing a liquid crystal circuit pattern on a glass substrate using the exposure apparatus according to the present invention will be described. In the present embodiment, the substrate 9 to be exposed is divided into four front, rear, left and right exposure regions, and the controller 18 first exposes the left half of the exposure region. Prior to exposure,
The reticle 20a-20d on which the liquid crystal circuit pattern is drawn is connected to the reticle turntables 6a-6d as shown in FIG.
Place it on top with the direction aligned. In the first step,
The control device 18 detects the position of the alignment mark on the substrate 9 to be exposed by the substrate alignment optical system 15, moves the XYZ stage 10 a based on the detected position value and the output of the laser interferometer 12, Exposure substrate 9
Is moved to the projection area of the projection optical system 8. The control device 18 detects the position of the alignment mark on the reticle 20 a by the reticle alignment microscope 14, and detects the position detection value and the laser interferometer 1.
6, the reticle stage 4 is moved based on the output of
Control is performed so that the center of the reticle 20a coincides with the optical axis L. The control device 18 exposes the circuit pattern on the reticle 20a to the circuit pattern image 21a on the left rear first area A1 on the substrate 9 to be exposed. Further, the control device 18 sets the XYZ stage 10a to X based on the output of the laser interferometer 12.
The first region A2 on the left front side of the substrate 9 to be exposed is moved to the projection region of the projection optical system 8 by parallel movement in the direction, and the circuit pattern image 22a is exposed.

In the second step, the controller 18
Controls the reticle stage 4 in parallel in the X direction based on the output of the laser interferometer 16 so that the center of the reticle 20b coincides with the optical axis L. Control device 18
Rotates the reticle turntable 6a in synchronization with the movement of the reticle 20b on the optical axis L, and rotates the reticle 20a by 180 °. On the other hand, the control device 18 moves the XYZ stage 10 a in the X direction based on the output of the laser interferometer 12, and places the left front second area B 2 in the projection area of the projection optical system 8. The control device 18 overlaps and exposes the overlap portion of the circuit pattern image 22a and the overlap portion of the circuit pattern image 22b to synthesize the images. Further, similarly, the XYZ stage 10a is moved in parallel in the -X direction, the left rear second area B1 is placed in the projection area of the projection optical system 8, the circuit pattern image 21b is exposed, and the image is synthesized with the circuit pattern image 21a.

In the third and fourth steps, the control device 1
8, the same operation is repeated, and the circuit pattern image 21c,
22c, 22d, and 21d are sequentially formed, and two sets of circuit pattern images 21, 2 in which four circuit pattern images are synthesized on a screen.
2 is formed in the left half exposure area on the substrate 9 to be exposed. 2
When the set of circuit pattern images 21 and 22 are formed, all the reticle turntables 6a to 6d complete the 180 ° rotation operation, and the reticles 20a to 20d are arranged as shown in FIG.

Next, the right half exposure area on the substrate 9 to be exposed is exposed. In the fifth step, the controller 18
Is rotated by 180 ° about the center Cs of the substrate 9 to be exposed by the motor 14.
By rotating, the remaining right half exposure area is moved to the projection area side of the projection optical system 8. Thereafter, the same operation as described above is repeated to expose the circuit pattern images 23 and 24 to the right half exposure area as shown in FIG.

As described above, when exposing four stages of exposure to the front, rear, left and right of the substrate 9 to be exposed, the substrate stage 10 to be exposed is moved in parallel between the respective exposure regions. A stroke is required to move the stage 10 in parallel in both the X and Y directions, and the installation area of the substrate stage 10 to be exposed is much larger than the area of the substrate stage 10 itself.
On the other hand, in the present embodiment, since the exposure target substrate stage 10 is configured to be rotated every 180 ° about the center Cs of the exposure target substrate 9 as a rotation center, the stroke in the X direction is the same as that in the related art, but in the Y direction. Can be greatly reduced. Thereby, the installation area of the substrate stage 10 to be exposed can be significantly reduced,
The device can be reduced in size and weight. In particular, when manufacturing a liquid crystal device, the direction of the liquid crystal is aligned in one direction by a rubbing process. Therefore, it is important to align the direction of the device on the substrate 9 to be exposed according to the direction of the liquid crystal. In the present invention, the reticles 20a to 20
By rotating d, it becomes possible to form the device on the substrate 9 to be exposed with the orientation of the device aligned with the orientation of the liquid crystal.

Next, a description will be given of a second embodiment in which a circuit pattern is exposed on a wafer by using the exposure apparatus of the present embodiment. In the second embodiment, a wafer is used as the substrate 9 to be exposed. The substrate 9 to be exposed is divided into two left and right image areas. As shown in FIGS. 4 and 5, the control device 18 first repeatedly exposes the left half of the exposure area on the substrate 9 using the reticle 20 on which the circuit pattern is drawn. After exposing the left half of the exposure area on the substrate 9 to be exposed, the controller 18 controls the reticle turntable 6.
And the substrate to be exposed turntable 10b, respectively, so that the substrate to be exposed 9 is rotated around the center Cs of the substrate to be exposed 9 as shown in FIG.
The rotation is made 180 ° with the center Ce of 0 as the rotation center. Thereafter, similarly, the right half exposure region on the substrate 7 is exposed. When the circuit pattern of the reticle 20 is, for example, for a semiconductor element, it is not always necessary to align the device orientation on the substrate 9 to be exposed. Therefore, as a third embodiment, as shown in FIG. 6, after exposing the left half of the substrate 9 to be exposed, the control device 18 rotates the reticle 20 by 180 ° without rotating the reticle 20. Let me.

Next, a fourth embodiment will be described. Book 4
In this embodiment, a square glass substrate is used as the substrate 9 to be exposed. In the first embodiment described above, the rotation angles of the substrate 9 to be exposed and the reticle 4 are set in 180 ° steps, but in the present embodiment, the rotation angles are set in 90 ° steps. For example, as shown in FIG. 7, the substrate 9 to be exposed is divided into four equal regions of front, rear, left and right. Control device 18
After exposing the circuit pattern image 21, the substrate 9 to be exposed and the reticle 20 are each rotated by 90 ° in the same direction to expose the circuit pattern image 22. Further, the control device 18
The circuit pattern image 23 is exposed by rotating the substrate 9 and the reticle 20 by 90 °. Although FIG. 7 shows up to the third exposure, the exposure is performed by further rotating the substrate 9 and the reticle 20 by 90 ° to complete four circuit pattern images on the substrate 9. As described above, in the present embodiment, by setting the rotation angle to 90 ° steps, not only the stroke in the Y direction can be halved, but also the stroke in the X direction can be halved. It is possible to further reduce the installation area.

In the exposure apparatus of the above-described embodiment, when the reticles 20a to 20d are rotated, the reticles 20a to 20d are rotated.
Although reticle turntables 6a to 6d on which 0d is mounted are rotated by motors 7a to 7d, a configuration without a motor is also possible. That is, the reticle table 5 on which the reticles 20a to 20d and the reticle turntables 6a to 6d are placed is once taken out of the reticle stage 4, and the reticle stage 4 is changed again by changing the installation angle of the reticle 20.
May be placed on Also, reticle turntable 6a ~
In addition to the configuration for rotating each of the reticle tables 5d, the entire reticle table 5 can be configured to rotate about the center Cr of the reticle table 5 as a rotation center.
Incidentally, the exposure apparatus of the present invention is a proximity exposure apparatus,
Either the scanning type exposure system or the stationary type exposure system can be applied, and both the reduction optical system and the equal magnification optical system can be used. Further, both the erecting optical system and the inverted optical system are applicable. Further, as a light source of the exposure apparatus, a light source such as an I-ray, a g-ray, a laser light source, an X-ray, and an electron beam may be used.

[0019]

As described above, according to the present invention, the substrate is 9
The exposure apparatus can be configured without extending the movement stroke of the substrate stage by rotating the substrate at a rotation amount of either 0 ° or 180 °. Even if the stage is enlarged, the apparatus can be configured with a minimum required installation area and weight. Thereby, a commonly used moving mirror can be used. Further, by rotating the reticle in the same rotation step as the rotation step of the substrate, it is possible to expose even a directional pattern.

[Brief description of the drawings]

FIG. 1 is a sectional view of an exposure apparatus according to an embodiment of the present invention.

FIG. 2 is a view for explaining exposure to a left half exposure area in the first embodiment.

FIG. 3 is a view for explaining exposure to an exposure area on the right half of the first embodiment.

FIG. 4 is a view for explaining exposure to the left half exposure area in the second embodiment.

FIG. 5 is a view for explaining exposure to an exposure area on the right half of the second embodiment.

FIG. 6 is a diagram illustrating a third embodiment.

FIG. 7 is a diagram illustrating a fourth embodiment.

[Explanation of symbols]

REFERENCE SIGNS LIST 1 light source 2 illuminating light beam 3 illuminating optical system 4 reticle stage 5 reticle table 5 a to 5 d reticle table opening 6 a to 6 d reticle turntable 7 a to 7 d motor 8 projection optical system 9 substrate to be exposed 10 ... Substrate to be exposed 10a ... XYZ stage 10b ... Turntable to be exposed substrate 11 ... Motor 12, 16 ... Laser interferometer 13,17 ... Movable mirror 14 ... Reticle alignment microscope 15 ... Substrate to be exposed alignment microscope 18 ... Control device 20, 20a-20
d: reticle 21, 22, 23, 24, 21a, 21b, 22a, 2
2b, 21c, 22c, 21d, 22d: Circuit pattern image Ca to Ce: Center of reticle Cs: Center of substrate to be exposed Cr: Center of reticle table L: Optical axis

Claims (9)

[Claims] 1. An exposure apparatus for exposing a pattern of a reticle onto a substrate, comprising: a substrate stage on which the substrate is placed and which can be rotated by any one of rotation amounts of 90 ° and 180 °. Exposure apparatus characterized by the above-mentioned. 2. An exposure apparatus according to claim 1, further comprising a reticle stage on which said reticle is mounted and which can rotate by the same amount of rotation as said substrate stage. 3. The exposure apparatus according to claim 1, further comprising an erecting image system projection optical system for projecting the reticle pattern onto the substrate. 4. An exposure apparatus according to claim 2, further comprising a control device for controlling said substrate stage and said reticle stage. 5. The exposure apparatus according to claim 4, wherein the control device is configured to: after exposing the pattern of the reticle,
An exposure apparatus wherein at least the substrate stage is rotated by the rotation amount. 6. The exposure apparatus according to claim 4, wherein the reticle stage holds a plurality of reticles, and the control device forms a combined pattern obtained by combining the patterns of the plurality of reticles on the substrate. An exposure apparatus for controlling the substrate stage and the reticle stage. 7. An exposure method for exposing a reticle pattern onto a substrate, comprising: exposing the reticle pattern onto the substrate; and rotating the substrate by any one of rotations of 90 ° and 180 °. An exposure method. 8. The exposure method according to claim 7, further comprising the step of rotating said reticle by the same amount of rotation as said substrate. 9. The exposure method according to claim 8, wherein the direction in which the reticle rotates and the direction in which the substrate rotates are the same.