JPH11251219A - Aligner, exposure method, and manufacture of display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aligner, exposure method, and a method for manufacturing a display device wherein, in relation to an aligner for screen compositing, unevenness in partitions on a sensitized substrate caused by exposure amount is reduced. SOLUTION: A pattern on a reticle 9 is exposed and developed on a sensitized substrate 11 so that parts of a plurality of partitions overlap each other, brightness of a resist image in each region and overlapped regions is detected, and the position of a reticle blind 6 and driving during exposure are controlled (16) according to the difference in brightness for controlling the exposure amount, thus unevenness in partitions is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exposure apparatus used for manufacturing a semiconductor element, a liquid crystal display substrate, and the like. In particular, the present invention relates to an exposure apparatus having a large area by overlapping a part of unit area patterns on a photosensitive substrate. And an exposure apparatus for performing so-called screen synthesis for forming a pattern.

[0002]

2. Description of the Related Art Conventionally, in this type of exposure apparatus, in order to cope with an increase in the size of a photosensitive substrate to be exposed, the exposure region of the photosensitive substrate is divided into a plurality of unit regions and exposure corresponding to each unit region is performed. A method of screen synthesis for repeatedly synthesizing a desired pattern is finally used. When performing this screen synthesis, the drawing error of the reticle, which is a mask for pattern projection, the aberration of the lens of the projection optical system, the positioning error of the stage for positioning the photosensitive substrate, etc. In order to prevent the occurrence of a break in the pattern, the exposure is performed by overlapping the boundaries of the respective exposure regions by a small amount. However, when the exposure areas are overlapped, the exposure amount in this area is 2
As a result, the line width at the joint of the pattern changes depending on the characteristics of the photosensitive agent. Further, when screen synthesis is performed, a step may occur at a joint portion of a pattern due to a shift in the position between adjacent exposure regions, and the characteristics of the device may be impaired. Furthermore, if the process of superimposing the single-layer pattern synthesized on the screen into multiple layers is assigned to different exposure apparatuses for each layer, the overlay error of the exposure area of each layer is reduced due to the difference in lens aberration and the positioning accuracy of each exposure apparatus. The contrast changes discontinuously at the seams of the pattern, and particularly in the case of an active matrix liquid crystal device, the contrast changes discontinuously at the seams of the pattern, and the quality of the device deteriorates.

As means for eliminating such inconveniences in screen synthesis, Japanese Patent Application Laid-Open No. Hei 7-235466 discloses a dimming unit for reducing the amount of transmitted light at a position corresponding to a pattern joint of a reticle blind. A technique is disclosed in which the exposure amount of a portion where a pattern is superimposed substantially matches the exposure amount of another portion. The method of adjusting the reticle blind at this time is an exposure control which is a control purpose in order to quantitatively adjust the position of the reticle blind so as to minimize the variation of the exposure amount under the same conditions as when actually performing the exposure operation. The positioning offset of the reticle blind is adjusted using a light amount sensor capable of monitoring the amount.

[0004]

By the way, when an exposure apparatus actually exposes a photosensitive substrate, a brightness difference is generated,
One of the factors that cause unevenness is the exposure amount. If the exposure amount is uneven, the line width unevenness and color unevenness of the film may occur. However, it is necessary for the light amount sensor to adjust the unevenness due to the exposure amount while detecting the light amount sensor so as not to generate a lightness difference of one gradation when the light / dark difference is divided into 256 gradations. There is considerable difficulty in performance. In addition, if the detection itself is possible, a large amount of time is required to adjust the exposure amount so as not to generate a lightness difference of one gradation, and the labor required for maintenance management cannot be ignored. SUMMARY OF THE INVENTION In view of the above problems, the present invention can easily and more accurately adjust the exposure amount of each divided area of an exposure apparatus that performs screen composition, and can reduce unevenness on a photosensitive substrate due to the exposure amount. An object of the present invention is to provide an exposure apparatus, an exposure method, and a method for manufacturing a display apparatus.

[0005]

Means for Solving the Problems To solve the above-mentioned problems, the exposure apparatus according to the present invention will be described with reference to FIG. 1 showing an embodiment of the present invention. An exposure detecting means for transferring the pattern to a plurality of divided areas on the photosensitive substrate (11), wherein the exposure detecting means detects an exposure result of at least a part of each of at least two of the plurality of divided areas. Things. The exposure apparatus according to claim 2, wherein the plurality of partitioned areas are configured such that a part of adjacent areas overlap with each other, and the exposure detection unit detects at least an exposure result of the overlapped area. Splicing can be smoothed.

According to a third aspect of the present invention, since the exposure detecting means detects the brightness of the divided area after exposure, the exposure result can be easily detected. The exposure apparatus according to claim 4, further comprising an exposure control unit (16) for controlling an exposure amount of the photosensitive substrate (11) based on an output of the exposure detection unit, so that unevenness caused by exposure of the photosensitive substrate is provided. Can be reduced. The exposure method according to claim 5, wherein the pattern on the mask (9) is transferred to a plurality of partitioned areas on the photosensitive substrate (11),
Exposing at least two of the plurality of divided areas on the photosensitive substrate (11); and detecting an exposure result of at least a part of each of the at least two divided areas. A method of controlling the exposure amount of the photosensitive substrate (11) at the time of the transfer on the basis of the transfer.

According to a sixth aspect of the present invention, there is provided an exposure method for transferring a plurality of patterns onto a photosensitive substrate (11) such that a part of the patterns overlaps each other.
Exposing the partitioned area and a second partitioned area that partially overlaps the first partitioned area to detect a brightness difference between the double-exposed area and the other areas, and This is a method of adjusting the exposure amount of the photosensitive substrate (11) at the time of the transfer using the difference.

The exposure method according to claim 7, wherein the photosensitive substrate (11) is developed after the exposure, and the light generated from the patterns respectively formed in the double-exposed area and the other areas by the development. To detect the lightness difference, the lightness difference can be detected in a wider dynamic range than the lightness difference before development. According to a eighth aspect of the present invention, there is provided a method of manufacturing a display device, comprising:
1) A method for manufacturing a display device on which a display device is formed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a diagram showing a schematic configuration of an exposure apparatus 23 according to one embodiment of the present invention. Illumination light from the ultra-high pressure mercury lamp 1 as an exposure light source is condensed by the elliptical mirror 2,
The light enters the wavelength selection filter 4 via the reflecting mirror 3a. The wavelength selection filter 4 allows only the wavelength necessary for exposure (generally, the wavelength of g-line or i-line) to pass, and the illumination light that has passed through the wavelength selection filter 4 is a fly-eye integrator 5
The light flux is converted into a light flux having a uniform illuminance distribution and reaches the reticle blind 6.

The reticle blind 6 is driven by a driving mechanism 7 to change the size of the opening to adjust the illumination range on the reticle 9 by the illumination light, and has two openings as shown in FIG. The blinds 6a and 6b are configured with the chrome surfaces facing each other. In addition, each of the blinds 6a and 6b has a light shielding portion 6d formed by evaporating chromium on a transparent glass substrate 6c and attenuating the transmittance of illumination light, and a light reducing portion 6e and chromium. No opening 6f is provided. Further, the chromium film in the darkening portion 6e is formed in a dot shape having a size equal to or smaller than the resolution limit of the exposure device 23 and is vapor-deposited on the glass substrate 6c. The dimming rate of the dimming unit 6e is changed by increasing the dimming rate toward the light shielding unit 6d. FIG. 3 shows the exposure characteristics of one of the reticle blinds 6 by the blind 6a or 6b. 3 (d) is obtained for the reticle blind 6 shown in FIG. 3 (b), and the exposure characteristic shown in FIG. 3 (e) is obtained for the reticle blind 6 shown in FIG. 3 (c). By combining the screens as shown in FIG. 3A so that the light reducing portions 6e of the reticle blind 6 overlap, a flat exposure characteristic can be obtained after the combining of the screens.

A part of the light beam emitted from the fly-eye integrator 5 is reflected by the beam splitter 18 and enters the integrated exposure meter 19, and the opening / closing time of the shutter 17 is controlled based on this information. That is, the exposure amount is controlled. The illumination light that has passed through the opening of the reticle blind 6 is reflected by the reflecting mirror 3b and enters the lens system 8, which forms an image of the opening of the reticle blind 6 on the reticle 9, and The area is illuminated. There is no particular need to prepare a reticle 9 for testing, and a reticle 9 having a normal circuit pattern is used. The image of the pattern existing in the illumination range of the reticle 9 is formed on the photosensitive substrate 11 such as a wafer or a glass plate by the projection optical system 10, whereby the pattern image of the reticle 9 is exposed on a specific region of the photosensitive substrate 11. You.

The photosensitive substrate 11 is fixed on a stage 12. The stage 12 is a well-known one in which a pair of blocks movable in directions orthogonal to each other are superimposed, and the position of the stage 12 is determined by a moving mirror 14 on the stage 12 of a laser beam 15 from a laser interferometer system (not shown). Is detected based on the reflected light from the photosensitive substrate 1
1 is adjusted in the horizontal plane. When performing screen synthesis, after one exposure for a certain reticle (pattern area) is completed, the reticle 9 is replaced and the stage 12 is driven to move another area of the photosensitive substrate 11 to the projection optical system 10. Position and expose. Thereafter, the same procedure is repeated every time the exposure is completed, and the entire area of the photosensitive substrate 11 is exposed. A plurality of types of patterns are formed on one reticle, and the reticle blind 6 changes the irradiation area in the reticle (changes to a different pattern area) in conjunction with the change of the exposure area on the photosensitive substrate 11. Synthesis may be performed.

The shutter 17, the integrated exposure meter 19, and the driving mechanism 7 are all controlled by the control device 16. That is, after the reticle blind 6 is set by the drive mechanism 7 with respect to the pattern area of the reticle 9 to be exposed, the shutter 17 is controlled by a command from the control device 16.
Opens to start exposure of the photosensitive substrate 11, and the integrated exposure meter 19 measures the integrated exposure. Then, when the information from the integrated exposure meter 19 reaches the predetermined exposure amount, the shutter 17 is closed to end the exposure.

When the exposure of the entire area of the photosensitive substrate 11 is completed, the photosensitive substrate 11 is developed by a developer (not shown) to form a resist image, and is set in the macro inspection apparatus 24 shown in FIG. The macro inspection device 24 can quantitatively detect the brightness of each position on the substrate. The macro inspection apparatus 24 and the exposure apparatus main body 23 are connected by an online cable 25 to obtain a value for controlling the reticle blind 6 based on the brightness value of the resist image calculated from the macro inspection apparatus 24, and automatically obtain the value. The position of the reticle blind 6 is set.

At this time, as shown in FIG. 4 (a), if the adjacent partitioned areas have a predetermined positional relationship, the exposure is performed with a uniform exposure amount, whereas as shown in FIG. 4 (b). When the adjacent partitioned areas are close to each other, the amount of exposure is excessive in the overlapping area. As shown in FIG. 4C, when the adjacent partitioned areas are far from each other, the amount of exposure is insufficient in the overlapping area. Since light and dark appear in the exposure result according to the excess or deficiency of the exposure amount, the reticle blind 6 is controlled to optimize the exposure amount of the photosensitive substrate 11 as described above according to the light and darkness appearing in the exposure result. .

Therefore, as shown in FIG. 3 (a), the position at which the brightness is detected by the macro inspection device 24 may be a straight line such as the straight line m of the arrow extending over the overlapping area and over the adjacent partitioned area. Good, point B in the overlapping area
And points A and C in each of the divided areas. From the viewpoint of reducing unevenness, for example, it is sufficient to detect only the lightness of two points A and B, for example.

The operation flow of this embodiment will be described below with reference to FIG. First, a predetermined reticle 9 corresponding to the exposure position on the photosensitive substrate 11 is loaded on a reticle stage (not shown) (S1), and the reticle 9 and the photosensitive substrate 11 are loaded.
Are aligned with the projection optical system 10 by the stage 12 and the reticle stage (S2), and the predetermined reticle blind 6 corresponding to the exposure position on the photosensitive substrate 11 is formed.
Is arranged at a predetermined position (S3), and is exposed (S4). That is, the shutter 17 is opened, and the shutter 17 is closed when the integrated value of the exposure amount by the integrated exposure meter 19 reaches the predetermined exposure amount. Here, it is determined whether or not the exposure has been completed for the entire area of the photosensitive substrate 11 (S5).
1 is moved (S6) so that a part of the adjacent partitioned area is overlapped, and the process returns to step S1 to load a predetermined reticle 9 corresponding to a new exposure area.
In step S5, if the exposure for all the regions is completed with YES, the process proceeds to step S7, and the brightness of the region corresponding to the opening of each exposed divided region and the region corresponding to the overlapping portion is detected. The opening time of the shutter 17 is set based on the detected difference in brightness, and the exposure amount is controlled by controlling the position of the reticle blind 6 and the set value such as the moving position or moving speed of the reticle blind 6 during exposure. Is controlled (S8).

A feature of this embodiment is that the exposure amount is controlled according to the exposure result. In particular, in a display device, if the unevenness is visually recognized, the commercial value is lost. Therefore, the most important issue is not whether the exposure amount is uneven but whether the exposure result is uneven. In this regard, in this embodiment, in which the exposure amount is controlled according to the exposure result, it is possible to improve the quality of the display device as a final product.

The present invention is not limited to the above embodiment. That is, (1). The detection of the exposure result may be performed at any time before the development after the exposure, before the etching after the development, or after the etching. (2) The detection of the exposure result can be performed visually or by an optical device. Examples of the optical device include a lightness meter that measures lightness, a line width measuring device that measures the line width of a pattern, and an electron microscope or a still image camera that looks at the structure of a resist image after development or the structure of a substrate after etching. is there. The structure at this time includes a line width or a film thickness of the pattern. Further, a lightness meter and a line width measuring device can be built in the exposure device 23.

(3) The exposure amount is controlled by changing the position of the reticle blind 6, controlling the moving position or moving speed of the reticle blind 6 during exposure, controlling the opening time of the shutter 17, and controlling the reticle blind 6. Defocusing can be performed at a position, illumination unevenness can be eliminated by adjusting the lens system 8 and the projection optical system 10, and the integrated exposure meter 19 can be adjusted. (4) There may be no problem that the overlapping areas between the divided areas are eliminated and the adjacent divided areas are in a straight line.

(5) Even if the reticle 9 is eliminated and there is no pattern, there is no problem in measuring the brightness. (6) The reticle 9 and the photosensitive substrate 11 are also brought into close contact with a scanning type exposure apparatus which has a plurality of projection optical systems 10 and performs exposure by synchronously moving the reticle 9 and the photosensitive substrate 11. The present invention can also be applied to a proximity type exposure apparatus that performs exposure by exposure. In addition, as an exposure apparatus, it can be widely applied not only to a liquid crystal device but also to an exposure apparatus for exposing a semiconductor element.

(7) As the exposure light, besides the g, h, and i lines, a KrF excimer laser (248 nm), an ArF excimer laser (193 nm), and an F ₂ laser (157 nm)
In addition, charged particle beams such as X-rays and electron beams can be used. For example, when an electron beam is used, a thermionic emission type lanthanum hexaborite (La) is used as an electron gun.
B ₆ ) and tantalum (Ta) can be used. (8) The magnification of the projection optical system 10 may be any of a reduction system, an equal magnification, and an enlargement system. Further, as the projection optical system 10, when using an excimer laser, quartz or fluorite is used as a glass material, and when using X-rays, a catadioptric optical system is used (a reflective type mask is used as a mask). When an electron beam is used, an electro-optical system including an electron lens and a deflector may be used as the optical system. The optical path through which the electron beam passes is evacuated.

[0023]

As described above, according to the present invention, in adjusting a portion related to the exposure amount of an exposure apparatus, visual unevenness at the time of product completion can be reduced without being affected by the performance of a light amount sensor. Therefore, the quality as a final product can be improved. Also, for adjustment work,
In most cases, only the actual exposure takes time, so that the time can be reduced. Furthermore, particularly for a display device, visual unevenness at the time of product completion can be reduced, so that extremely high quality can be realized.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of an exposure apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a specific example of a reticle blind according to one embodiment of the present invention.

FIG. 3 is a diagram illustrating a reticle blind of FIG. 2 and an exposure amount thereof.

FIG. 4 is a view for explaining a positional relationship of a reticle blind of FIG. 2 and an exposure amount thereof;

FIG. 5 is a diagram showing a connection example between an exposure apparatus and a macro inspection apparatus according to an embodiment of the present invention.

FIG. 6 is a diagram showing an operation flow of an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ultra-high pressure mercury lamp 2 Elliptic mirror 4 Wavelength selection filter 5 Fly-eye integrator 6 Reticle blind 6a, 6b Each reticle blind 6c Glass substrate 6d Light-shielding part 6e Light-reducing part 6f Opening 7 Driving mechanism 8 Lens system 9 Reticle 10 Projection lens system 11 Photosensitive substrate 12 Stage 14 Moving mirror 15 Laser beam 16 Control device 17 Shutter 19 Integrated exposure meter 23 Exposure device 24 Macro inspection device 25 Online cable

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01L 21/30 516D

Claims (8)

[Claims] 1. An exposure apparatus for transferring a pattern on a mask to a plurality of divided areas on a photosensitive substrate, wherein the exposure apparatus detects at least a part of the exposure result of at least two of the plurality of divided areas. An exposure apparatus comprising a detection unit. 2. The apparatus according to claim 1, wherein the plurality of divided areas partially overlap each other, and the exposure detecting means detects an exposure result of at least the overlapped areas. Exposure equipment. 3. An exposure apparatus according to claim 1, wherein said exposure detecting means detects the lightness of said divided area after exposure. 4. The exposure apparatus according to claim 1, further comprising an exposure control unit that controls an exposure amount of the photosensitive substrate based on an output of the exposure detection unit. 5. An exposure method for transferring a pattern on a mask to a plurality of partitioned areas on a photosensitive substrate, comprising: exposing at least two of the plurality of partitioned areas on the photosensitive substrate; Detecting an exposure result of at least a part of each of the regions, and controlling an exposure amount of the photosensitive substrate at the time of the transfer based on the exposure result. 6. An exposure method for transferring a plurality of patterns onto a photosensitive substrate so that a part of the patterns overlaps with each other, wherein: a first partition region on the photosensitive substrate; and a second partition partially overlapping the first partition region. Each area is exposed, and the brightness difference between the double-exposed area and the other areas is detected,
An exposure method, comprising: adjusting an exposure amount of the photosensitive substrate during the transfer using the detected brightness difference. 7. The photosensitive substrate is developed after the exposure,
7. The exposure method according to claim 6, wherein the lightness difference is detected by receiving light generated from a pattern formed in each of the double-exposed area and the other area by the development. 8. A method for manufacturing a display device, comprising: forming a display device on a glass plate by using the exposure method according to claim 6. Description: