JPH1064782A - Scanning aligner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aligner which uses a small projection optical system and can perform its aligning operation efficiently over a large area of light sensitive substrate. SOLUTION: In the scanning aligner for performing scanning alignment exposure in synchronism with a mask 10 and a light sensitive substrate 14, moving means 16Y and 18Y are provided for moving the light sensitive substrate and mask in a Y direction substantially perpendicular to a scanning direction (X direction) for scanning exposure. By moving the light sensitive substrate 14 and mask 10 in the Y direction for scanning exposure, even when a large area of pattern 10a formed on the mask 10 is divided in the Y direction to join it to an adjacent region on the substrate 14, exposure can be realized and thus even when a small-size projection optical system is employed, a large pattern can be light-exposed. The movement of the substrate 14 alone in the Y direction as well as the repetition of the scanning exposure enables the single mask pattern to be exposed on a plurality of regions on a large area of the substrate, thus improving a throughput of the scanning aligner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scanning type exposure apparatus, and more particularly to a scanning type exposure apparatus suitable for performing pattern exposure on a large photosensitive substrate such as a glass substrate for a liquid crystal display panel.

[0002]

2. Description of the Related Art In recent years, liquid crystal display panels have been widely used in place of CRTs as image display devices because their display quality has been remarkably improved and they are thin and lightweight. In particular, the screen size of an active matrix type direct-view type liquid crystal panel is increasing, and the size of a glass substrate used for manufacturing the same is also increasing.

As an exposure apparatus for exposing an element pattern of a display panel to such a large glass substrate, a photomask or reticle (hereinafter, referred to as a mask) on which a pattern is formed and a photosensitive agent such as a photoresist are applied. A so-called proximity type exposure apparatus that performs batch exposure by bringing a glass substrate (hereinafter, referred to as a photosensitive substrate) in close proximity, and a step-and-repeat type exposure using a refraction optical system having a large transfer area and a unit size as a projection optical system. The apparatus and the projection optical system are equal-magnification reflection optical systems, the mask is illuminated with an arc-shaped illumination light to form an image of the mask on the photosensitive substrate in an arc shape, and the mask and the photosensitive substrate are projected optically. There is a mirror projection type exposure apparatus that scans the system.

[0004]

When a large-sized photosensitive substrate is exposed by a proximity type exposure apparatus, a large-sized mask corresponding to the size of the substrate and the photosensitive substrate need to be brought close to several tens μm. . For this reason, the flatness of the mask and the photosensitive substrate becomes a problem, and the mask and the photosensitive substrate come into contact with each other due to the surface shape (irregularity) of the resist applied to the substrate or dust attached to the surface, or conversely, the interval is too large. Therefore, it is very difficult to transfer the pattern of the mask over the entire surface of the photosensitive substrate without any defect. In addition, since the distance between the mask and the photosensitive substrate greatly affects the resolution, line width, and line shape of the transferred image, if the distance is not uniformly maintained at the design value, an active matrix type liquid crystal panel or high-definition The STN mode liquid crystal panel cannot be manufactured.

The step-and-repeat type exposure apparatus uses a mask having a size of about 6 inches, which is relatively small as compared with the photosensitive substrate, and performs pattern transfer to a large-sized photosensitive substrate by step-and-repeat. In this step-and-repeat method, since a mask used for manufacturing a semiconductor element can be used, techniques cultivated in semiconductor element manufacturing, such as drawing accuracy, pattern dimension management, and dust management, can be applied. However,
In order to expose a large photosensitive substrate with a device pattern having an area exceeding the effective projection area (image circle) of the projection optical system, the area to be transferred of the photosensitive substrate is divided into small areas and each is exposed. Exposure is required.

In a display section of an active matrix liquid crystal panel, when a small shift occurs at a boundary portion of a pattern formed by divided exposure, the performance of the element changes at this portion, and luminance is displayed on a completed liquid crystal panel. Appears unevenly. The line based on the uneven brightness is easily recognized by human eyes, and becomes a defect in display quality of the liquid crystal panel. Also, when the number of divisions increases, the number of exposures increases,
In some cases, the mask needs to be replaced many times during the exposure of one photosensitive substrate, which causes a reduction in the processing capability of the apparatus.

Further, in the mirror projection system, the entire surface of the mask is transferred onto the photosensitive substrate by relatively scanning an arc-shaped slit extending in a direction perpendicular to the scanning direction of the mask and the photosensitive substrate with respect to the mask and the photosensitive substrate. Therefore, in order to expose a large photosensitive substrate efficiently, it is necessary to make the slit length as long as the dimension of the photosensitive substrate. For this reason, it is necessary to increase the size of the optical system, and there is a problem in that the size of the apparatus must be increased to be expensive.

As for the size of the mask, the size of the mask on which a pattern to be transferred to the entire area of the photosensitive substrate is drawn is usually larger than that of the photosensitive substrate. When quartz or the like is used as the material of the mask in order to improve the patterning accuracy of the mask or to suppress the influence of the heat of the illumination light for transfer, there is a problem that the manufacturing cost of the mask is significantly increased. The present invention has been made in view of the above problems, and has as its object to provide an exposure apparatus that can efficiently perform exposure on a large-area photosensitive substrate using a small projection optical system.

[0009]

According to the present invention, there is provided a scanning exposure apparatus for scanning and exposing a mask and a photosensitive substrate in synchronization with each other. The object is achieved by providing moving means for moving in a direction substantially perpendicular to the scanning direction.

By having means for moving both the photosensitive substrate and the mask in a direction substantially perpendicular to the scanning direction, a large-area pattern formed on the mask is divided in the direction perpendicular to the scanning direction and divided on the photosensitive substrate. Exposure can be performed by connecting adjacent regions. Therefore, a very large pattern can be exposed even if a small projection optical system is used.

Further, by repeating scanning exposure while moving only the photosensitive substrate in a direction substantially perpendicular to the scanning direction, 1
One mask pattern can be exposed to a plurality of regions on a large-area photosensitive substrate, and the throughput of a scanning exposure apparatus can be improved.

That is, the scanning exposure apparatus according to the present invention includes illumination optical systems (L1 to L5) for illuminating the pattern of the mask (10, 50) in predetermined illumination areas (11a to 11e, 11a 'to 11e'). A projection optical system (12a to 12e) for projecting a light beam transmitted through the mask pattern onto the photosensitive substrate in a substantially equal size and an erect image, and an illumination area (11).
a to 11e, 11a 'to 11e') in the first direction (X direction) with the mask (10, 50) and the photosensitive substrate (14).
Scanning means (16X, 18X, 3
2) and at least the length of the photosensitive substrate (14) in the second direction (Y direction) substantially perpendicular to the first direction, and at least the length of the illumination regions (11a to 11e) in the second direction (Y direction). Moving means (16Y, 18) for moving by a corresponding distance
Y).

The moving means (16Y, 18Y) moves the photosensitive substrate (14) and the mask (10) in the second direction (Y).
Direction), the mask and the photosensitive substrate may be moved in synchronization or may be moved out of synchronization. The amount of movement of the mask and the photosensitive substrate in the second direction may be set to be equal depending on how one pattern to be exposed on the photosensitive substrate is arranged on the mask, or the amount of movement of the mask may be set. May be set larger than the moving amount of the photosensitive substrate.

When a large pattern is synthesized by exposing a partial pattern exposed on a photosensitive substrate by one scanning exposure in a direction perpendicular to the scanning direction and exposing, a control means for controlling a moving means ( 50), it is preferable to control the moving means so that the plurality of partial patterns partially overlap in the second direction. In this manner, by exposing a plurality of partial patterns so as to partially overlap with each other, it is possible to suppress pattern breakage and uneven exposure at a joint portion of the partial patterns.

An alignment mark (2) used for alignment between the mask and the photosensitive substrate is provided on the mask and the photosensitive substrate.
3a to 23n and 24a to 24n) are formed, and the scanning exposure apparatus uses a mask and a photosensitive substrate based on the detection result of detecting the alignment mark by the alignment detecting means (20a, 20b) provided in the apparatus. Is performed, and then scanning exposure is performed. At this time, the accuracy required for positioning the mask and the photosensitive substrate is as follows:
It depends on the definition and line width of the mask pattern. Also,
Attempts to perform scanning exposure with increased alignment accuracy increase the number of alignment mark measurements and reduce the throughput of the apparatus. Therefore, means for selecting the alignment accuracy and the like according to the required overlay accuracy and the like, for example, the first mode in which the alignment is performed only once on one photosensitive substrate, and the scanning mode, The provision of the selection means (50) for selecting the second mode in which the alignment is performed every movement in the second direction can improve the throughput while securing the alignment accuracy.

The mask and the photosensitive substrate are arranged, for example, on upper and lower stages (20, 15) of a U-shaped scanning frame (30) sandwiching the projection optical system (12) therebetween, and the scanning frame is connected to the projection optical system. By moving them, they can be moved synchronously. The moving means (16Y) for moving in the direction (Y direction) orthogonal to the scanning direction (X direction)
It may be provided only for the photosensitive substrate (14). Also in this case, the moving distance of the photosensitive substrate by the moving means needs to be at least a distance corresponding to the length of the illumination area in a direction orthogonal to the scanning direction.

Further, a plurality of projection optical systems (12a to 12e) for forming an erect image at the same magnification are provided along a direction (Y direction) orthogonal to the scanning direction of the mask (10, 50) and the photosensitive substrate (14). By arranging and scanning the mask and the photosensitive substrate in synchronization with the plurality of projection optical systems, long projections in the direction orthogonal to the scanning direction can be performed without increasing the image circle of each projection optical system. Area (13a to 13e)
Can be formed. Therefore, a conventional small projection optical system can be used as it is. Since the scanning direction (X direction) is constant, by selecting the number of projection optical systems and the scanning distance, it is possible to realize an exposure apparatus smaller than the conventional one according to the size of the photosensitive substrate.

Also, since means (16Y, 18Y) for moving in a direction substantially perpendicular to the scanning direction are provided, the number of scans can be increased a plurality of times, and a large area can be obtained without increasing the size of the projection optical system. An exposure apparatus capable of exposing a pattern can be realized.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a schematic configuration of an example of a scanning exposure apparatus according to the present invention. A light beam emitted from a light source 1 such as an ultra-high pressure mercury lamp is reflected by an elliptical mirror 2 and then enters a dichroic mirror 3. The dichroic mirror 3 reflects a light beam having a wavelength required for exposure and transmits a light beam having another wavelength. The light beam reflected by the dichroic mirror 3 is selectively restricted from being irradiated on the projection optical system side by a shutter 4 arranged to be able to advance and retreat with respect to the optical axis AX1. When the shutter 4 is opened, the light beam enters the wavelength selection filter 5,
The projection optical system 11a becomes a light beam having a wavelength (usually, at least one band among g, h, and i lines) suitable for performing transfer. Further, since the intensity distribution of the light flux is highest in the vicinity of the optical axis and becomes Gaussian distribution decreasing in the periphery, it is necessary to make the intensity uniform at least in the projection area 12a of the projection optical system 11a. Therefore, the fly-eye lens 6
And the condenser lens 8 to make the intensity of the light beam uniform. Note that the mirror 7 is a bending mirror on the array.

The luminous flux having uniform intensity is applied to the pattern surface of the mask 10 via the field stop 9. The field stop 9 has an opening for limiting the projection area 13a on the photosensitive substrate 14. A lens system may be provided between the field stop 9 and the mask 10 so that the pattern surface of the field stop 9 and the mask 10 and the projection surface of the photosensitive substrate 14 are conjugate to each other.

The configuration from the light source 1 to the field stop 9 is an illumination optical system L1 for the projection optical system 12a. In this example, the illumination optical systems L2 to L2 have the same configuration as the illumination optical system L1.
5 is provided to supply the light beams from the illumination optical systems L2 to L5 to the projection optical systems 12b to 12e, respectively. The luminous flux emitted from each of the plurality of illumination optical systems L1 to L5 is
Different partial areas (illumination areas) 11a to 1 on the mask 10
1e are each illuminated. The plurality of luminous fluxes transmitted through the mask 10 are transferred to different projection areas 13a to 13e on the photosensitive substrate 14 via the projection optical systems 12a to 12e corresponding to the illumination optical systems L1 to L5.
The pattern image of e is formed. Projection optical systems 12a to 12e
Are erecting equal-magnification real imaging (erect erect image) optical systems.
In FIG. 1, the optical axis direction of the projection optical systems 12a to 12e is the Z direction, the scanning direction of the mask 10 and the photosensitive substrate 14 is the X direction in the direction perpendicular to the Z direction, and the directions perpendicular to the Z direction and the X direction are the directions. Let it be the Y direction.

The photosensitive substrate 14 is mounted on a substrate stage 15. The substrate stage 15 has an X-direction driving device 16X having a long stroke in the scanning direction (X direction) to perform one-dimensional scanning exposure. I have. Further, it has a high-resolution and high-accuracy X-direction position measuring device (for example, a laser interferometer) 17X in the scanning direction. Further, the mask 10 is supported by a mask stage 20, and, like the substrate stage 15, the mask stage 20 has an X-direction driving device 18X having a long stroke in the scanning direction (X direction) and the position of the mask stage 20 in the scanning direction. X-direction position measuring device 19X for detecting

Further, the substrate stage 15 and the mask stage 20 have a function of moving in the Y direction substantially orthogonal to the X direction which is the scanning direction. That is, the substrate stage 1
5 is provided with a Y direction driving device 16Y and a Y direction position measuring device 17Y for driving the substrate stage 15 in the Y direction. Similarly, the mask stage 20 is provided with a Y-direction driving device 18Y for driving the mask stage 20 in the Y direction and a Y-direction position measuring device 19Y for detecting the position of the mask stage 20 in the Y direction. Y direction drive device 16
The amount of movement of the substrate stage 15 in the Y direction by Y, and Y
The moving amount of the mask stage 20 in the Y direction by the direction driving device 18Y is at least the Y amount of the illumination regions 11a to 11e.
The distance is equivalent to the length in the direction.

The photosensitive substrate 14 and the mask 10 are fixed on, for example, a U-shaped scanning frame as shown in FIG. 8, and the photosensitive substrate 14 and the mask 10 are integrally driven in the scanning direction (X direction). It can also be configured to do so. In that case, if a driving device for driving the scanning frame on which the photosensitive substrate 14 and the mask 10 are mounted in the X direction is provided, an X-direction driving device 16 for driving the substrate stage 15 in the X direction is provided.
It is not necessary to separately provide X and an X-direction driving device 18X for driving the mask stage 20 in the X-direction. Similarly, by driving the scanning frame in the Y direction, the photosensitive substrate 1
4 and the mask 10 may be configured to be driven integrally in the Y direction. In that case, by providing a driving means for driving the scanning frame in the Y direction, a Y direction driving device 16 for driving the substrate stage 15 in the Y direction is provided.
It is not necessary to separately provide Y and the Y-direction driving device 18Y for driving the mask stage 20 in the Y-direction.

FIG. 2 is a top view of the photosensitive substrate 14 held on the substrate stage 15. As shown in FIG. 2, the projection regions 13a to 13e on the photosensitive substrate 14 are adjacent to each other in the Y direction (for example, 13a and 13b, 13b and 13e).
c) is displaced by a predetermined amount in the X direction in the figure, and the ends of adjacent regions are arranged so as to overlap in the Y direction as shown by the broken lines. Therefore, the plurality of projection optical systems 12
a to 12e are also displaced by a predetermined amount in the X direction corresponding to the arrangement of the projection areas 13a to 13e, and are arranged so as to overlap in the Y direction. The shapes of the projection regions 13a to 13e are parallelograms in the drawing, but may be hexagons, rhombuses, trapezoids, or the like. Further, a plurality of illumination optical systems L1 to L
5 is arranged such that the illumination areas 11a to 11e on the mask 10 have the same arrangement as the projection areas 13a to 13e. On the photosensitive substrate 14, alignment marks (substrate marks) 24a to 24n are provided outside the exposure region 14a.

FIG. 3 is a top view of the mask 10, in which a pattern area 10a in which a pattern to be transferred to the photosensitive substrate 14 is formed. The mask 10 includes substrate marks 24a to 24c on the photosensitive substrate 14 outside the pattern region 10a.
Alignment mark (mask mark) corresponding to 24n
23a to 23n are provided. In the case of this example, as is apparent from the drawing, the dimension in the Y direction of the pattern region 10a formed on the mask 10 is the same as that of the illumination regions 11a to 11e.
Larger than the direction dimension.

As shown in FIGS. 1 and 3, alignment systems 20a and 20b are disposed above the mask 10.
The mask 10 is controlled by the alignment systems 20a and 20b.
And the substrate marks 24a to 24n formed on the photosensitive substrate 14 via the projection optical systems 12a and 12e. That is, the illumination light emitted from the alignment systems 20a and 20b is applied to the mask 1 via the reflecting mirrors 25a and 25b.
In addition to irradiating the mask marks 23a to 23n formed on the substrate mark 0, the substrate marks 24a to 24n on the photosensitive substrate 14 are illuminated via the optical systems 12a and 12e at both ends of the plurality of projection optical systems 12a to 12e. Irradiate.

The substrate mark 2 formed on the photosensitive substrate 14
The reflected lights from 4a to 24f are projected optical systems 12a and 12e.
Light reflected from the mask marks 23a to 23f formed on the mask 10 enters the alignment systems 20a and 20b via the reflectors 25a and 25b. Alignment system 20
a and 20b detect the position of each alignment mark based on the reflected light from the mask 10 and the photosensitive substrate 14.

FIG. 4 is an explanatory view showing an image of the mask mark 23 when the alignment systems 20a and 20b are of a type that includes a CCD camera as a detector and determines the position of the mark by image processing. 27 is an observation field of view of the alignment system, 28 is an alignment system 20
a, an index mark provided in 20b. After moving the mask stage 20 or the substrate stage 15 by a predetermined distance in the X direction, the substrate marks 22a,
22b and the mask marks 23a to 23n on the mask 10 are simultaneously detected by the alignment systems 20a and 20b, whereby the position coordinates of the substrate stage 15 and the mask
Can be clearly associated with the position coordinates. If necessary, the position of the mask 10 is controlled by finely moving the mask stage 20 by the X-direction driving device 19X and the Y-direction driving device 18Y.

FIG. 5 shows the mask mark 23 and the substrate mark 2
FIG. 4 is a diagram showing an image obtained by simultaneously capturing images No. 4 and No. 4 by alignment systems 20a and 20b. Alignment detection system 20
By managing the position of the index mark 28 with respect to the substrate mark 22 provided on the substrate stage 15, a and 20 b can be calibrated with respect to the position reference of the substrate stage 15. Also, while moving the mask stage 20 and the substrate stage 15 in the X direction,
Substrate marks 24a to 24n on photosensitive substrate 14 and mask 1
By simultaneously detecting the mask marks 23a to 23n on 0 by the alignment systems 20a and 20b, the relative position between the photosensitive substrate 14 and the mask 10 can be detected.

This scanning type exposure apparatus includes a mask stage 2
0 and the substrate stage 15 in at least the illumination regions 11a to 11e in the Y direction substantially orthogonal to the X direction which is the scanning direction.
In the Y direction. Therefore, after scanning exposure is performed by driving the mask stage 20 and the substrate stage 15 in synchronization with each other in the X direction, the mask stage 20 and the substrate stage 15 are stepwise moved in the Y direction by a distance corresponding to the width of the illumination regions 11a to 11e. By repeating the scanning exposure in the X direction performed once or several times, it is possible to connect a plurality of partial patterns and transfer the large mask pattern 10a onto the large photosensitive substrate 14.

Returning to FIG. 1, the control device 50 controls the entire scanning type exposure apparatus, and
The measurement results of X, 17Y, 19X, and 19Y and the alignment outputs of the alignment systems 20a and 20b are input. Further, the control device 50 has a storage device 51.

Next, using the flowchart of FIG.
An example of a scanning exposure sequence performed by the control device 50 will be described. Active matrix type liquid crystal panels require a plurality of pattern layers to be exposed in a manufacturing process in order to form the active elements. For this reason, a plurality of masks 10 serving as an original plate are prepared, and the pattern layers are superposed and exposed while exchanging the masks.

In FIG. 10, when the mask 10 placed on the mask stage 20 is replaced by a mask loader (not shown), that is, when the determination in step 10 is “Y”
In the case of “ES”, the process proceeds to step 11 and the projection optical system 1
The new mask 10 is positioned with respect to the exposure apparatus by the alignment systems 20a and 20b held by the holding members holding 2a to 12e. This positioning is performed by the alignment system 20 as described with reference to FIG.
The mask marks 23a and 23m are detected by a and 20b, and the position of the mask placed on the mask stage 20 is adjusted by driving means (not shown) so that the position of the mask mark with respect to the index mark 28 has a predetermined relationship. This is done by: If the mask has not been replaced, step 11 is omitted.

Next, proceeding to step 12, the photosensitive substrate 14 to be exposed is loaded on the substrate stage 15 by a substrate loader (not shown), and the loaded photosensitive substrate 14 is positioned with respect to the exposure apparatus. Specifically, step 11
In the same manner as the alignment of the mask 10 in the above, the substrate marks 24a, 24b are
m is detected, and the substrate mark 24 corresponding to the index mark 28 is detected.
This is performed by controlling a driving unit (not shown) provided on the substrate stage 15 so that the positions of a and 24m have a predetermined relationship.

At step 13, the projection optical system 12a is driven by driving the mask stage 20 and the substrate stage 15 in, for example, the -X direction by the X-direction driving device 18X of the mask stage 20 and the X-direction driving device 16X of the substrate stage 15. Mask 12 and photosensitive substrate 1 for ~ 12e
4 is scanned in the forward direction. At this time, the relative positions of the mask marks 23a to 23e and the substrate marks 24a to 24e are detected by one alignment system 20a. The other alignment system 20b includes mask marks 23m and 23m.
g and the relative positions of the substrate marks 24m and 24g are detected. The mask marks 23a to 23e thus detected,
23g, 23m and substrate marks 24a to 24e, 24g,
The position relative to 24 m is stored in the storage device 51.

When the forward scanning of the mask 10 and the photosensitive substrate 14 is completed, the mask 10 completely deviates from the illumination areas 11a to 11e, and at the scanning start position where the photosensitive substrate 14 completely deviates from the projection areas 13a to 13e, the mask 10 And the photosensitive substrate 14 are aligned. This alignment in step 14 is performed during the forward scan in step 13 and the mask mark 2 stored in the storage device 51 is detected.
3a to 23e, 23g, and 23m and the amount of movement of the mask 10 in the X direction, the Y direction, and the rotation direction such that the relative position error between the substrate marks 24a to 24e, 24g, and 24m, which are paired with 3a to 23e, 23g, and 23m, are minimized. And the position of the mask 10 on the mask stage 20 is adjusted by driving means (not shown) in accordance with the above.

Then, the process proceeds to a step 15, wherein the mask 10
The first scanning exposure is performed by synchronously scanning (backward scanning) the photosensitive substrate 14 in the + X direction with respect to the projection optical systems 12a to 12e.

At this time, as shown in FIG.
Since the dimension in the Y direction of the whole of 1a to 11e is smaller than the dimension in the Y direction of the pattern region 10a of the mask 10, the dimension in the X direction is 1%.
A part of the pattern area 10 a formed on the mask 10, that is, a partial pattern area having a width PA1 in the Y direction shown in FIG. This one
The area on the photosensitive substrate 14 exposed in the second scanning exposure is:
This is a region having a width PB1 in the Y direction shown in FIG. Since the projection optical systems 12a to 12e are erecting equal-magnification real imaging optical systems, the width PA1 on the mask 10 is equal to the width PB on the photosensitive substrate 14.
Equal to one.

When the first scanning exposure is completed, the process proceeds to step 16, where the mask 10 and the photosensitive substrate 14 are step-moved in the Y direction by driving the Y-direction driving devices 16Y and 18Y. The distance of the step movement is PA1 (= PB
1). In the alignment operation, the mask 10
If the entirety of the mask and the photosensitive substrate 14 are positioned, the movement in the Y direction is performed by synchronizing the mask 10 and the photosensitive substrate 14. As in the example shown in the flowchart of FIG. 10, when aligning the mask 10 with the photosensitive substrate 14 immediately before performing exposure on the photosensitive substrate 14, or when aligning the mask 10 with a previously measured position, the mask 10 It is not necessary to synchronously move the photosensitive substrate 14 in the Y direction.

Subsequently, in step 17, the mask 10 and the photosensitive substrate 14 are again moved to the projection optical systems 12a to 12e by -X by the X-direction driving device 18X of the mask stage 20 and the X-direction driving device 16X of the substrate stage 15.
The forward scan is performed in synchronization with the direction. At this time, the relative positions of the mask marks 23f, 23n and the substrate marks 24f, 24n are detected by the alignment system 20a. Further, the mask marks 23h to 23h are controlled by the alignment system 20b.
1 and the relative positions of the substrate marks 24h to 24l are detected. The mask marks 23f, 23h,
23l, 23n and corresponding substrate marks 24f, 2
The relative positions with respect to 4h to 24l and 24n are stored in the storage device 51.

When the forward scan of the mask 10 and the photosensitive substrate 14 is completed, in step 18, the scanning is started, in which the mask 10 is completely removed from the illumination areas 11a to 11e and the photosensitive substrate 14 is completely removed from the projection areas 13a to 13e. At the position, alignment between the mask 10 and the photosensitive substrate 14 is performed. This alignment is performed by the mask marks 23f, 23f detected in step 17 and stored in the storage device 51.
h to 23l, 23n and corresponding substrate mark 24
f, 24h to 24l, 24n, the amount of movement of the mask 10 in the X, Y, and rotational directions that minimizes the relative position error of the pair is determined by the least square method or the like, and the mask on the mask stage 20 is accordingly determined. This is performed by adjusting the position of 10 by a driving unit (not shown).

Thereafter, the process proceeds to step 19, where the mask 10 and the photosensitive substrate 14 are synchronously scanned (backward scanning) in the + X direction with respect to the projection optical systems 12a to 12e, so that the second scanning exposure is performed. In the second scanning exposure, FIG.
Are illuminated by the illumination areas 11a 'to 11e' and scanned in the X direction. As a result, as shown in FIG. 2, a region having a width PB2 in the Y direction on the photosensitive substrate 14 is scanned and exposed in the X direction in the projection regions 13a 'to 13e'. Since the projection optical systems 12a to 12e are erecting equal-magnification real imaging optical systems, the width PA2 on the mask 10 is
Equal to the upper width PB2.

The width PA1 in the Y direction set on the mask 10
And the area having the width PA2 correspond to Y in the pattern area 10a.
A portion having a width d1 in the Y direction located substantially at the center in the direction overlaps. Therefore, the pattern region 10a of the mask 10
Among them, a region elongated in the X direction and having a width d1 in the Y direction shown in FIG.
The exposure is overlapped with the second scanning exposure (width d in the Y direction).
2 area). This area is exposed at the end of the projection area 13e at the time of the first scanning exposure, and is scanned at the end of the projection area 13a 'at the time of the second scanning exposure,
An appropriate exposure amount is obtained by two overlapping exposures.

Next, an example in which a large area continuous pattern is exposed on the photosensitive substrate 14 using a mask having a pattern arrangement different from the pattern arrangement of the mask 10 shown in FIG. 3, as in the case of FIG. explain. FIG. 6 is a top view of the mask 50 used in this method. In the mask 50, for example, as shown in FIG. 6, a pattern region 10b and a pattern region 10c are divided and arranged. The pattern areas 10a and 10b are obtained by dividing and drawing the pattern drawn on the pattern area 10a formed on the mask 10 shown in FIG. The width PA1 in the Y direction of the mask 10 of FIG.
Are drawn on the pattern area 10c, and the partial pattern of the area having the width PA2 is drawn on the pattern area 10c in the Y direction. Patterns of a region having a width d1 in the Y direction of the mask 10 are drawn on both the region 10d elongated in the X direction of the pattern region 10b of the mask 50 and the region 10e elongated in the X direction of the pattern region 10c. . That is, the pattern formed in the pattern region 10b of the mask 50 used here and the pattern region 10c
The pattern partially overlaps with the pattern formed in.

Scanning exposure of a pattern using the mask 50 is performed according to a flow substantially the same as the flow chart shown in FIG. What is different from the flowchart of FIG. 10 is the step moving distance in the Y direction between the mask 50 and the photosensitive substrate 14 in Step 16 of FIG. In the example using the mask 10 of FIG. 3 described above, the moving distance of the mask in the Y direction in Step 16 is equal to the moving distance of the photosensitive substrate 14 in the Y direction. However, the mask 5 shown in FIG.
In the scanning exposure in which the pattern exposure area 14a shown in FIG. 2 is formed on the photosensitive substrate 14 using 0, the moving distance of the mask 50 and the photosensitive substrate 14 in the Y direction is different.

That is, in the case of this example, the moving distance of the photosensitive substrate 14 in the Y direction is PB1 (FIG. 2).
Is the Y-direction moving distance Sy (FIG. 6). By setting the moving distance in the Y direction between the mask 50 and the photosensitive substrate 14 in this manner, the overlapping pattern portions 10d and 10e of the pattern region 10b and the pattern region 10c of the mask 50.
However, it overlaps in a region elongated in the X-direction with a width d2 in the Y-direction shown in FIG. 2, so that one continuous large pattern can be exposed evenly.

Next, another example of the scanning exposure apparatus according to the present invention will be described with reference to FIGS. FIG. 7 is a diagram showing a schematic configuration of a scanning exposure apparatus, and FIG. 8 is an explanatory diagram showing an example of a scanning mechanism. 7, the same functional portions as those in FIG. 1 are denoted by the same reference numerals as those in FIG. 1, and detailed description will be omitted. FIG.
The scanning exposure apparatus shown in FIG. 1 is provided with a Y-direction driving device 16Y only on the photosensitive substrate 14 side, and is not provided with a Y-direction driving device 18Y on the mask side 10. It is different from the device. This scanning type exposure apparatus uses a mask 10 which is small and inexpensive compared to the size of the photosensitive substrate 14 and is capable of transferring a pattern drawn on the mask 10 to the photosensitive substrate 14 a plurality of times.

FIG. 8 shows a scanning exposure apparatus for synchronously scanning the mask 10 and the photosensitive substrate 14 with a U-shaped scanning frame. The U-shaped scanning frame 30 is placed on a base 31 and scanned in the X direction by an X-direction driving device 32. The mask stage 20 is located above the scanning frame 30.
Are provided, and the mask 10 is held on the mask stage 20. The mask stage 20 includes driving devices 43 and 4
The positions in the X direction, the Y direction, and the rotation direction can be adjusted by driving the 4, 45. A substrate stage 15 is provided below the scanning frame 30, and the substrate 14 is held on the substrate stage 15. The substrate stage 15 can be moved in the Y direction on the scanning frame 30 by the Y direction driving device 16Y.

The mask 10 and the photosensitive substrate 14 are provided with a mask mark 23 and a substrate mark 24 for aligning the mask 10 and the photosensitive substrate 14. As an alignment mode using the mask mark 23 and the substrate mark 24, here, a first mode in which an alignment operation is first performed only once for exposure of one photosensitive substrate 14, and And a second mode for performing an alignment operation at each scanning exposure is set in the exposure apparatus.
The operator may be able to select a mode in accordance with the pattern overlay accuracy or the like.
When 0 is a pattern that does not require much accuracy, the first mode is selected and executed according to the pattern (type) of the mask, and when the pattern is strict in accuracy, the second mode is selected and executed. I just need.

In the first mode, measurement using the mask mark 23 and the substrate mark 24 is performed before starting the scanning exposure, and the driving devices 43, 44, 45 are performed based on the measurement result.
Is controlled to adjust the position of the mask 10, so that the alignment operation between the mask 10 and the photosensitive substrate 14 is performed only once before the start of the scanning exposure. In the subsequent scanning exposure, the mask 10 and the photosensitive substrate 14 are aligned according to the mechanical accuracy of the Y-direction driving device 16Y without performing measurement using the mask mark 23 and the substrate mark 24. Also, the second
In the mode, the mask mark 23 and the substrate mark 24 are measured each time the scanning frame 30 performs the forward scan before each scanning exposure, and the driving devices 43 and 4 are measured based on the measurement results.
The position of the mask 10 is controlled by the masks 4 and 45.

Next, an example of a scanning exposure sequence by the control device 50 will be described with reference to the flowchart of FIG. As described above, the pattern exposure on the photosensitive substrate 14 is performed by overlapping a plurality of pattern layers while exchanging the mask 10.

When the mask 10 placed on the mask stage 20 has been replaced, that is, when the determination in step 20 of the flowchart shown in FIG. 11 is "YES", the process proceeds to step 21 and the alignment system 20a, 20
By detecting the mask mark 23 by b, the alignment of the mask 10 with respect to the exposure apparatus is performed. If the mask has not been replaced, step 21 is omitted. Next, proceeding to step 22, the photosensitive substrate 14 is loaded onto the substrate stage 15 by a substrate loader (not shown), and the substrate marks 24 are detected by the alignment systems 20a and 20b. Position.

When the alignment mode set in the exposure apparatus is the first mode, the process proceeds from step 23 to step 2
Proceed to 4. In step 24, the scanning frame 30 is driven in, for example, the −X direction by the X-direction driving device 32, so that the mask 10 and the photosensitive substrate 14 perform forward scanning in synchronization. At this time, the relative positions of the mask mark 23 and the substrate mark 24 are detected by the alignment systems 20a and 20b. The detected relative position between the mask mark 23 and the substrate mark 24 is stored in the storage device 51.

When the forward scan between the mask 10 and the photosensitive substrate 14 is completed, at a scanning start position where the mask 10 and the photosensitive substrate 14 completely deviate from the projection optical system 12, at step 25, the mask 10 and the photosensitive substrate 14 Perform alignment. This alignment is performed by the mask mark 23 and the substrate mark 24 detected in step 24 and stored in the storage device 51.
The amounts of movement of the mask 10 in the X direction, the Y direction, and the rotation direction such that the relative position error of the mask 10 is minimized are determined by the least square method or the like, and the mask 1
It is performed by adjusting the position of 0 by the driving devices 43, 44, 45.

Then, the process proceeds to a step 26, wherein the mask 10
The first scanning exposure is performed by performing synchronous scanning (backward scanning) of the photosensitive substrate 14 in the + X direction. By this first scanning exposure, pattern exposure is performed on the area 14a on the photosensitive substrate 14.

When the first scanning exposure is completed, the process proceeds to step 27, in which the photosensitive substrate 14 is step-moved in the Y direction by driving the Y-direction driving device 16Y. The distance of the step movement is Ly. Subsequently, in step 28, the scanning frame 30 is moved in the −X direction by the X-direction driving device 32 to scan the mask 10 and the photosensitive substrate 14 in the forward direction with respect to the projection optical system 12, and scan and expose during the forward scanning. Thus, pattern exposure is performed on the region 14b on the photosensitive substrate 14. In the case of this example, the region 1 on the photosensitive substrate 14
The pattern exposed to 4a and the pattern exposed to region 14b are the same pattern.

When the first mode is selected as the alignment mode, the scanning exposure is executed in both the forward scan and the backward scan of the scanning frame 30 which reciprocates in the X direction, so that the exposure efficiency can be increased. In the example shown in the figure, the pattern exposure areas 14a and 14b on the photosensitive substrate 14 are shown.
Is two, but as the number of pattern exposure regions 14a, 14b,... Set on the photosensitive substrate 14 increases, the throughput can be improved as compared with the second mode.

Next, a sequence when the alignment mode set in the exposure apparatus is the second mode will be described. At this time, the process proceeds from step 23 to step 29.
In step 29, the scanning frame 30 is driven in, for example, the −X direction by the X-direction driving device 32,
The mask 10 and the photosensitive substrate 14 are scanned in the forward direction in synchronization.
At this time, the relative positions of the mask mark 23 and the substrate mark 24 are detected by the alignment systems 20a and 20b. The detected relative position between the mask mark 23 and the substrate mark 24 is stored in the storage device 51.

When the forward scan between the mask 10 and the photosensitive substrate 14 is completed, at a scanning start position where the mask 10 and the photosensitive substrate 14 completely deviate from the projection optical system 12, in Perform alignment. This alignment is performed by the mask mark 23 and the substrate mark 2 detected in step 29 and stored in the storage device 51.
X of the mask 10 that minimizes the relative position error with respect to
The amount of movement in the direction, the Y direction, and the rotation direction is obtained by the least square method or the like, and the mask position on the mask stage 20 is adjusted by the driving devices 43, 44, and 45 according to the calculated values.

Then, the process proceeds to a step 31, wherein the mask 10
The first scanning exposure is performed by performing synchronous scanning (backward scanning) of the photosensitive substrate 14 in the + X direction. By this first scanning exposure, pattern exposure is performed on the area 14a on the photosensitive substrate 14.

When the first scanning exposure is completed, the process proceeds to step 32, where the photosensitive substrate 14 is step-moved in the Y direction by driving the Y-direction driving device 16Y. The distance of the step movement is Ly. Subsequently, steps 33 and 3
In step 4, the same operation as steps 29 and 30 is repeated,
After performing the alignment mark detection and the alignment operation based on the detection result, scanning exposure is performed in step 35. In the case of the second mode, alignment detection is performed during forward scanning, so that scanning exposure is always performed only during backward scanning, that is, when the scanning frame 30 is moved in the + X direction.

The scanning exposure apparatus described so far is
Mask 1 only in the Y direction orthogonal to the scanning direction (X direction)
A mechanism for stepwise moving the photosensitive substrate 14 is provided. However, by providing a function of stepping not only in the Y direction but also in the X direction, as shown in FIG. 9, a plurality of regions 14c to 14f of the photosensitive substrate 14 arranged not only in the Y direction but also in the X direction. Pattern exposure can be performed, and the pattern can be transferred to a larger photosensitive substrate 14.

[0064]

According to the present invention, there is provided a function of relatively moving one or both of the mask and the photosensitive substrate in a direction substantially orthogonal to the scanning direction, thereby enabling a plurality of scanning exposures. With this configuration, a large projection area can be obtained while using a small projection optical system. Therefore, a compact and low-cost scanning exposure apparatus can be realized.

[Brief description of the drawings]

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

FIG. 2 is a top view of a photosensitive substrate held on a substrate stage.

FIG. 3 is a top view of a mask.

FIG. 4 is a view of a mask mark imaged by an alignment system.

FIG. 5 is a diagram of a mask mark and a substrate mark captured by an alignment system.

FIG. 6 is a top view showing another example of the mask.

FIG. 7 is a diagram showing a schematic configuration of another example of the scanning exposure apparatus according to the present invention.

FIG. 8 is an explanatory diagram illustrating an example of a scanning mechanism.

FIG. 9 is a diagram showing an example of an arrangement of patterns exposed on a photosensitive substrate.

FIG. 10 is a flowchart illustrating an example of a scanning exposure sequence.

FIG. 11 is a flowchart for explaining another example of the sequence of the scanning exposure.

[Explanation of symbols]

L1 to L5: illumination optical system, 9: field stop, 10: mask, 10a: pattern area, 11a to 11e: illumination area, 12a to 12e: projection optical system, 13a to 13e: projection area, 14: photosensitive substrate, 14a , 14b: pattern exposure area, 15: substrate stage, 16Y: Y direction driving device, 17X, 17Y: position measuring device, 18Y: Y direction driving device, 19X, 19Y: position measuring device, 20a, 20
b: alignment system, 22a, 22b: substrate mark, 2
3a to 23n: mask mark, 24a to 24n: substrate mark, 27: observation field, 28: index mark, 30: scanning frame, 31: base, 32: X-direction drive device, 4
3, 44, 45 ... drive device

Claims (5)

[Claims] An illumination optical system for illuminating a mask pattern in a predetermined illumination area, and a projection optics for projecting a light beam transmitted through the mask pattern onto a photosensitive substrate in substantially the same size and forming an erect real image. A scanning unit for synchronizing and scanning the mask and the photosensitive substrate in a first direction with respect to the illumination region; and at least a photosensitive substrate in a second direction substantially orthogonal to the first direction. Moving means for moving at least a distance corresponding to a length of the illumination area in the second direction. 2. The scanning exposure apparatus according to claim 1, wherein said moving means moves the mask and the photosensitive substrate in the second direction in synchronization with each other. 3. The scanning exposure apparatus according to claim 1, wherein a plurality of partial patterns formed on the photosensitive substrate by the scanning unit performing a plurality of scans in the first direction are formed on the photosensitive substrate. A scanning exposure apparatus comprising: a control unit that controls the moving unit so that the moving unit partially overlaps in the direction. 4. The scanning exposure apparatus according to claim 1, wherein the mask and the photosensitive substrate are respectively formed with alignment marks used for positioning the mask and the photosensitive substrate. Detecting means for detecting the alignment mark; positioning means for performing positioning between the mask and the photosensitive substrate based on a detection result by the detecting means; and a first mode for performing the positioning only once. , The second
A scanning mode exposure apparatus comprising a selection unit for selecting a second mode for performing the alignment each time the image pickup device moves in the direction of. 5. An illumination optical system for illuminating a mask pattern in a predetermined illumination area, and a projection optical system for projecting a light beam transmitted through the mask pattern on a photosensitive substrate in substantially the same size and an erect image. Scanning means for integrally holding the mask and the photosensitive substrate and scanning the illumination area in a first direction; and a second direction substantially orthogonal to the first direction for the photosensitive substrate. A stage for moving at least a distance corresponding to a length of the illumination area in the second direction.