JPH07302754A - Scanning type aligner - Google Patents

Abstract

PURPOSE:To increase the throughput more than conventional one when the relative positional relation between a mask and a sensing substrate is corrected before exposure. CONSTITUTION:The relative positional relation between a mask 3 and a sensing substrate 4 in transit is previously detected as exposure starting position. In case of exposure, previously detected positional data are read out of a memory 11 so as to correct the relative positional relation. Through these procedures, even if the mask 3 and the sensing substrate 4 including the rapid fluctuation in the flatness unable to be predicted by conventional method wherein relative positional relation of the mask 3 and the sensing substrate 4 in the exposure scanning has been measured and corrected are included, the throughput will not be decreased, thereby enabling the exposure to be performed causing no defective image-formation at all.

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,
For example, it is suitable for application to an exposure apparatus used for manufacturing a liquid crystal display device.

[0002]

2. Description of the Related Art Conventionally, in this type of exposure apparatus, the relative position of the mask and the photosensitive substrate in the in-plane direction and the position of the projection optical system in the optical axis direction are detected and the relative position is determined during scanning exposure. (Alignment operation) and positioning in the optical axis direction (focus operation) are simultaneously (ie, in real time) corrected. That is, a method is adopted in which the pattern formed on the mask is exposed on the photosensitive substrate side while correcting the relative positional relationship between the mask and the photosensitive substrate during scanning exposure.

[0003]

However, in this method, the factors caused by the apparatus itself (mechanical response, accuracy of control system, etc.) and the factors caused by materials (the steep flatness of the mask and the photosensitive substrate itself) are used. However, the correction operation for the input result and the detection result may be delayed due to the change of (1) and the like, and the correction operation may not follow the scanning speed. In such a case, the positional relationship between the mask and the photosensitive substrate cannot always be maintained within a favorable accuracy range, and there is a possibility that the device may malfunction due to a partial reduction in resolution.

For example, the flatness of the mask or the photosensitive substrate varies in thickness, and particularly in the photosensitive substrate, a steep change is likely to occur partially due to deformation due to heat treatment or foreign substances mixed in with the supporting surface. . Therefore, when such a change occurs, the time from the detection of the change amount to the position correction by the drive system may not be in time for the scanning speed, and the resolution may be deteriorated. If the measurement point used to detect the correction amount can be provided in the exposure area, the correction amount can be obtained directly from the measurement value, but if the measurement point must be provided outside the exposure area, Since the correction amount is only predicted from the measured value, there is a possibility that the correction amount may not be able to cope with a sharp change. Therefore, in order to avoid such a problem, it is conceivable to reduce the scanning speed to perform exposure, but throughput (that is, processing capacity)
It was a good idea to avoid the decline of.

The present invention has been made in consideration of the above points. Even when an unpredictable change in flatness occurs, the relative positional relationship between the mask and the photosensitive substrate is maintained at a proper position while maintaining a high throughput. The present invention intends to propose a scanning type exposure apparatus that can perform exposure by correcting the relationship.

[0006]

In order to solve such a problem, in the present invention, the mask (3) is illuminated and the image of the mask (3) is exposed through the projection optical systems (2A) and (2B). By projecting onto the substrate (4) and scanning the mask (3) and the photosensitive substrate (4) with respect to the projection optical systems (2A) and (2B), the entire surface of the mask (3) is exposed to the photosensitive substrate (2). 4) Position detection means (7), (8), (9), (10) for detecting the relative positional relationship between the mask (3) and the photosensitive substrate (4) in a scanning type exposure apparatus that exposes light onto the surface. When,
A storage means (11) for storing the position information obtained by the position detection means (7), (8), (9), (10), and a mask based on the position information read from the storage means (11). The position correction means (13), (14) and (15) for correcting the relative positional relationship between (3) and the photosensitive substrate (4), the mask (3) and the photosensitive substrate (4) are used as the projection optical system ( 2A),
Position detection means (7), (8), (9), (10) when being conveyed to the exposure start position through the projection area of (2B).
To detect the relative positional relationship between the mask (3) and the photosensitive substrate (4), and when the mask (3) and the photosensitive substrate (4) are stopped at the exposure start position and / or during exposure, The relative positional relationship between the mask (3) and the photosensitive substrate (4) is corrected based on the position information read from the storage means (11) by the position correction means (13), (14) and (15). A control means (12) is provided.

In the present invention, the position information is the first position information regarding the direction perpendicular to the optical axes of the projection optical systems (2A) and (2B), and the projection optical systems (2A) and (2).
This is the second position information regarding the optical axis direction of B). Further, in the present invention, the first position information is the relative position of the mask (3) and the photosensitive substrate (4), and the second position information is the optical axis of the mask (3) and the photosensitive substrate (4). The relative position in the direction and the relative tilt amount between the mask (3) and the photosensitive substrate (4).

Further, in the present invention, the control means (12)
Is a position correction means (13) based on the relative position of the mask (3) and the photosensitive substrate (4) when the mask (3) and the photosensitive substrate (4) are stopped at the exposure start position. (1
4) and 15) to control the projection optical systems (2A) and (2) in the positional relationship between the mask (3) and the photosensitive substrate (4).
The positional relationship in the direction perpendicular to the optical axis of B) is corrected, and during exposure, the relative position of the mask (3) and the photosensitive substrate (4) in the optical axis direction and / or the mask (3) and the photosensitive substrate (4). Position correction means (1
3), (14), and (15) are controlled, and the projection optical system (2A), among the positional relationships between the mask (3) and the photosensitive substrate (4),
The positional relationship of (2B) in the optical axis direction is corrected.

Further, in the present invention, the storage means (11)
Holds the data map obtained based on the position information for the arbitrary position in the scanning direction detected by the position detecting means (7), (8), (9), (10).

In the present invention, the position correction means (1
3), (14) and (15) are the average surface of the photosensitive substrate (4) or the photosensitive substrate (4) which should be present with respect to the surface of the mask (3) obtained based on the position information read from the data map. ) Is corrected in advance when the photosensitive substrate (4) or the mask (3) is stopped at the exposure start position so as to coincide with the average surface of the mask (3) that should exist. To do so.

In the present invention, the position correction means (1
3), 14) and 15) create a correction map representing a correction value at an arbitrary position based on the position information read from the data map, and according to the correction map, the mask (3) and / or the photosensitive substrate ( The positional relationship of 4) is sequentially corrected during exposure.

[0012]

The relative positional relationship between the mask (3) and the photosensitive substrate (4) is previously detected during the transportation to the exposure start position, and the previously detected position information is stored in the storage means (11) at the time of exposure. )
And the relative positional relationship between the mask (3) and the photosensitive substrate (4) is corrected to read the relative positional relationship between the mask (3) and the photosensitive substrate (4) during exposure scanning. Even when the mask (3) and the photosensitive substrate (4) that include abrupt changes that cannot be predicted by the conventional method of executing the correction at the same time are used, the throughput is not reduced, and there is no risk of defective imaging. It can be exposed.

At this time, the position detecting means (7),
The position information detected by (8), (9), and (10) is the first position information regarding the plane direction perpendicular to the optical axes of the projection optical systems (2A) and (2B), and the projection optical system ( 2A), (2
By using the second position information in the optical axis direction of B), the positioning accuracy is excellent, and the risk of defective imaging can be further reduced. Further, the first position information is a relative position between the mask (3) and the photosensitive substrate (4), and the second position information is a relative position in the optical axis direction between the mask (3) and the photosensitive substrate (4). By setting the relative tilt amount between the mask (3) and the photosensitive substrate (4), the relative positional relationship can be efficiently corrected.

When the mask (3) and the photosensitive substrate (4) are stopped at the exposure start position, the projection optical system (based on the relative position between the mask (3) and the photosensitive substrate (4) is used. Two
After the positional relationship in the directions perpendicular to the optical axes of (A) and (2B) is corrected and scanning of the mask (3) and the photosensitive substrate (4) is started, the mask (3) and the photosensitive substrate ( The projection optical system (2) based on the relative position of the optical axis direction of (4) and / or the relative tilt amount of the mask (3) and the photosensitive substrate (4).
By correcting the positional relationship between A) and (2B) in the optical axis direction, scanning exposure can be performed in a state where there is no defective imaging without reducing the throughput.

Further, by holding a data map created on the basis of the relative positional relationship at an arbitrary position in the scanning direction in the storage means (11), the mask (3) and the photosensitive substrate (4) are again exposed at the time of exposure. Since it is not necessary to measure the relative positional relationship with, it is possible to improve the scanning speed during exposure.

Further, the average surface of the photosensitive substrate (4) or the photosensitive substrate (4) which should be present on the surface of the mask (3) obtained based on the position information read from the data map.
By correcting the positional relationship of the photosensitive substrate (4) or the mask (3) in advance so as to match the average surface of the mask (3) that should be present with respect to the surface of (1), the exposure at the time of exposure is performed. The scanning speed can be further improved, and the throughput can be improved.

A correction map representing a correction value at an arbitrary position is created based on the position information read from the data map, and the positional relationship between the mask (3) and / or the photosensitive substrate (4) is being exposed according to the correction map. The positional relationship between the mask (3) and the photosensitive substrate (4) can always be corrected to an optimum state by sequentially performing the correction, and the resolution can be further improved.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, reference numeral 1 generally shows a schematic structure of a scanning type exposure apparatus. This scanning type exposure apparatus 1
Are two imaging optical systems (or projection optical systems) 2A, 2
The mask 3 and the photosensitive substrate 4, which are arranged so as to face each other with the imaging optical system 2 constituted by B in between, are placed in the left-right direction (X
In this method, the original image pattern formed (or drawn) on the mask 3 is projected and exposed on the photosensitive substrate 4 by performing synchronous scanning in the direction).

Here, each of the two imaging optical systems 2A and 2B has a plurality of imaging optical systems arranged in the Y direction in the drawing,
The projected images of the plurality of imaging optical systems on the photosensitive substrate 4 are arranged in a zigzag manner, and the ends of adjacent images in other columns are arranged to overlap in the Y direction. That is, of the regions projected by the two imaging optical systems 2A and 2B, the end regions are overlapped and exposed with a fixed time difference, and as a result, a large area in the Y direction can be exposed by one scan. Has been done.

In the case of this scanning type exposure apparatus 1, the transport system (not shown) for transporting the mask 3 and the photosensitive substrate 4 to the holders 3A and 4A is arranged not on both sides of the imaging optical system 2 but on one side. There is. That is, after the mask and the photosensitive substrate are placed on the holder and the exposure is completed, it is necessary to move the photosensitive substrate and the like again to the position of the transport system in order to replace the photosensitive substrate. Therefore, the scanning type exposure apparatus 1 passes through the position (projection area) of the imaging optical system 2 from the conveyance system provided at a position deviated from the imaging optical system 2 and is scanned to the exposure start position ( That is, during the forward scan period), the mask 3 and the photosensitive substrate 4 are
While the relative positional relationship of the mask 3 is measured, the mask 3 and the photosensitive substrate 4 are scanned in the opposite direction (that is, backward scanning) while the relative positional relationship is corrected based on the measurement result. The pattern formed on the photosensitive substrate 4 is projected and exposed.

As described above, the scanning type exposure apparatus 1 described in this embodiment is provided with a detection period of a relative positional relationship at the time of the forward scan which is an essential scanning period, and the mask 3 and the photosensitive substrate 4 are relatively moved during this period. By detecting the physical positional relationship in advance, it is possible to follow a sharp change in the flatness of the mask 3 and the photosensitive substrate 4 without lowering the throughput.

Each part of the scanning type exposure apparatus 1 capable of realizing such exposure will be described. First, regarding the mask 3 and the photosensitive substrate 4, the mask 3 and the photosensitive substrate 4 are attached to the scanning stage 5 having a U-shaped cross section through the holders 3A and 4A, respectively. The scanning stage 5 is attached to the main body 6 so as to be movable along the rail 6A, and the movement of the scanning stage 5 realizes the synchronous scanning of the mask 3 and the photosensitive substrate 4. Has been done. An illumination optical system 6B is held in the main body 6, and the original pattern formed (or drawn) on the mask 3 is illuminated by the illumination light emitted from the illumination optical system 6B. .

Further, the scanning type exposure apparatus 1 is provided with two detection optical systems for accurately aligning the mask 3 and the photosensitive substrate 4. One is an alignment sensor 7 used for measuring the relative position between the mask 3 and the photosensitive substrate 4, and one is a relative distance between the mask 3 and the photosensitive substrate 4 (or a high distance not through the imaging optical system 2). Is a focus sensor 8 used for measurement. The relative distance between the mask 3 and the photosensitive substrate 4 is the distance in the optical axis direction of the imaging optical system 2.

Here, the alignment sensor 7 is fixed to the main body 6 together with the imaging optical system 2, and the relative position measuring mark (() is arranged at an arbitrary position in the scanning direction (X direction) of the mask 3 and the photosensitive substrate 4. Hereinafter, it will be referred to as an alignment mark). Incidentally, in the embodiment, the alignment sensor 7 mainly comprises a CCD camera, and the mask 3 and the photosensitive substrate 4 are processed by the signal processing of the image pickup screen.
It is designed to measure the positional deviation of the alignment mark formed above.

On the other hand, the focus sensor 8 is a light emitting element 8A.
And two light receiving elements 8B. In the case of this embodiment, a plurality of focus sensors 8 are prepared along the Y-axis direction. The plurality of focus sensors 8 are arranged so that the straight line connecting the detection points of the focus sensor 8 is sandwiched by the two straight lines connecting the projection regions of the respective imaging optical systems 2A and 2B. The focus sensor 8 irradiates the surface of the mask 3 and the photosensitive substrate 4 with illumination light in the shape of a slit emitted from the light emitting element 8A, and forms a slit image on each surface on the light receiving element 8B. By re-imaging and measuring the relative distance between the images, the relative distance between the mask 3 and the photosensitive substrate 4 is measured.

These two detection optical systems (alignment sensor 7 and focus sensor 8) detect the measurement results S1 and S.
2 is sent to the storage device 11 via the detection systems 9 and 10 corresponding to each detection optical system. Incidentally, the storage device 11 is provided with a storage medium such as a fixed disk and stores the position information of the measurement point by the alignment sensor 7 and the focus sensor 8.

Here, the storage device 11 stores the detection results S1 and S2 obtained at each measurement point. In particular, a flatness map representing the flatness of the surfaces of the mask 3 and the photosensitive substrate 4 is created based on the detection result S2 in the optical axis direction, and the storage device 11 stores the flatness map.

A control system 12 is prepared as a control means for finely adjusting the holders 3A and 4A and the scanning stage 5 based on the position information stored in the storage device 11. The control system 12 controls the drive systems 13, 14 and 15 based on the position information read from the storage device 11, respectively, and corrects the positions of the holders 3A, 4A and the scanning stage 5. That is, the alignment can be corrected by moving the holders 3A and 4A in the XY directions, and by moving in the Z direction, the focus (the position in the optical axis direction of the imaging optical system 2) and the leveling (of the imaging optical system 2). The inclination with respect to the optical axis) can be corrected.

An example of a series of scanning exposure operations by the scanning type exposure apparatus 1 having the above-mentioned structure will be described with reference to FIGS. 2 and 3. First, in the initial setting, the scanning stage 5 is shown in FIG.
As shown in (A), it is stopped at a position outside the imaging optical system 2. The scanning type exposure apparatus 1 attaches the mask 3 and the photosensitive substrate 4 to the holders 3A and 4A of the scanning stage 5 stopped at this position from the carrying system, and starts carrying to the exposure start position.

The carrying direction at this time is the direction indicated by the arrow in FIGS. 2 (B) and 2 (C). By the movement of the scanning stage 5, the mask 3 and the photosensitive substrate 4 are synchronously scanned. During this forward scan, the control system 12 measures the distance between the mask 3 and the photosensitive substrate 4 in the optical axis direction for each fixed measurement interval or position in the scanning direction set in advance from the storage device 11. Similarly, the scanning stage 5 is temporarily stopped at the position of an arbitrary number of alignment marks preset in the storage medium, and the relative displacement between the mask 3 and the photosensitive substrate 4 is measured at each position.

When the measurement of the distance between the alignment mark position and the optical axis direction is completed, the mask pattern is exposed on the photosensitive substrate 4 side by scanning in the reverse direction (that is, backward scanning), so that FIG. As shown, the scanning stage 5 is stopped at a position where the mask 3 and the photosensitive substrate 4 are completely separated from the imaging optical system 2. At this time, the control system 12 shifts, rotates, scales, orthogonally (from the relative displacement between the mask 3 and the photosensitive substrate 4 obtained by measuring a plurality of alignment marks, by a method using a least square method or the like. Each element such as (the inclination of the axis perpendicular to the scanning direction) is derived, and a control signal is applied to the drive system 13 based on these elements to correct the installation position of the holder 3A and to shift the position of the mask 3 with respect to the photosensitive substrate 4. to correct.

At this time, the control system 12 controls the imaging optical system 2
A magnification adjustment mechanism (not shown) and an image shifter mechanism (not shown) that adjusts the transfer position of the transferred image correct the magnification and the orthogonality. Further, at this time, the control system 12 respectively creates the flatness map of the mask 3 and the flatness map of the photosensitive substrate 4 based on the measurement results of the plurality of focus sensors 8.

Incidentally, each of the image forming systems forming the image forming optical system 2 has a focus height and a range (depth of focus) at which an optimum resolving power can be obtained, and the control system 12 takes these into consideration and the mask 3 And the photosensitive substrate 4 are both set within the depth of focus to create an approximate surface with the mask 3 as a reference surface.
At this time, the approximate surface is derived by the least-squares method or the like, with respect to the focus height of the photosensitive substrate 4 (or the mask 3) and the inclination of the surface of the area including all the projection areas of the plurality of imaging systems. At this stage, the control system 12 controls the drive system 14 so that the inclination of the photosensitive substrate 4 matches the approximate surface, and corrects the mounting position of the mask 3 and the photosensitive substrate 4.

When the correction of the mounting position of the mask 3 and the control of the interval and the inclination in the optical axis direction based on the flatness map are completed in this way, the control system 12 uses an arrow as shown in FIG. 3 (E). The scanning of the scanning stage 5 in the direction shown is started, and the image of the pattern formed on the mask 3 is transferred to the photosensitive substrate 4.
The projection exposure is performed in order. By the way, in the case of this embodiment,
Since the relative positional relationship between the mask 3 and the photosensitive substrate 4 is corrected to the optimum condition by the correction process described above, there is no risk of image formation failure due to this exposure scanning.

Further, in this case, since a complicated calculation process is not required during the scanning period, the scanning speed at the time of exposure can be increased, and the exposure operation can be completed in a much shorter time than the conventional case. it can. When the scanning stage 5 finishes scanning to the position of the transport system, the control system 12 stops the scanning stage 5 and exposes the mask 3 and the photosensitive substrate 4 which are currently attached to the holders 3A and 4A. Replace with the photosensitive substrate 4. The above operation is one cycle of the exposure operation.

According to the above construction, the photosensitive substrate 4 received from the transport system is passed through the position of the imaging optical system 2 and is transported to the exposure start position provided on the opposite side of the transport system during the forward scan. , The relative position between the mask 3 and the photosensitive substrate 4 is measured by the alignment sensor 7, and the distance between the mask 3 and the photosensitive substrate 4 in the optical axis direction is also measured by the focus sensor 8. By correcting the relative positional relationship between the mask 3 and the photosensitive substrate 4 before the scanning exposure based on the information of 1., it is possible to increase the scanning speed at the time of the backward scanning, and to further improve the throughput. Can be improved.

Particularly in the case of the conventional method of measuring and correcting the relative positional relationship at the time of exposure, it is necessary to subject the acquired measurement data to complicated statistical processing represented by the least square method or the like. Because of this, it was necessary to use a CPU with high processing capacity, but in the case of this embodiment, such a C
Economical without the need to use PU.

Further, since the various elements necessary for correcting the relative positional relationship between the mask 3 and the photosensitive substrate 4 are acquired before the exposure operation, the steepness is difficult to predict by the method of measuring and correcting at the same time as the exposure. Even when exposure is performed using the mask 3 and the photosensitive substrate 4 that include various changes, it is possible to effectively prevent the occurrence of imaging defects and the like.

In the above-described embodiment, the case has been described in which the photosensitive substrate 4 is preliminarily corrected so as to match the approximate surface obtained by using the mask 3 as the reference surface at the exposure start position which is the end point of the forward scanning. The invention is not limited to this, and the position of the photosensitive substrate 4 may be sequentially corrected during the backward scan. In this case, a control map for correction (representing a correction value at an arbitrary position of the photosensitive substrate) based on the flatness map is prepared in advance while the scanning stage 5 is stopped at the exposure start position. After scanning is started, the interval in the optical axis direction and / or the inclination angle with respect to the optical axis may be sequentially corrected based on this control map. By the way, the inclination angle may be in the direction along the skiyan direction,
Further, it may be in a direction orthogonal to the scanning direction.
In addition, by using the measured value of the focus sensor 8 obtained during the exposure, the control according to these control maps can be performed more reliably.

As described above, even when the position of the photosensitive substrate 4 is corrected during the scanning exposure, the positional information regarding the exposure area is known in advance and the control amount for the correction has already been calculated. Can be controlled so as to always be in an appropriate position with respect to the mask 3. As a result, it is possible to perform exposure without defective imaging. At this time, scanning is performed when the response of the drive system for controlling the position or inclination of the photosensitive substrate 4 in the optical axis direction is not good, or when the drive system cannot follow the change in the flatness of the mask or the photosensitive substrate. A mechanism for controlling the illuminance of the illumination light flux at a slightly reduced speed may be added, and the illuminance may be reduced by utilizing this mechanism. Even in this case, the throughput can be improved as compared with the conventional case, and the exposure can be performed without fear of deterioration of resolution.

Further, in the correction during the scanning exposure, the case where the position of the mask 3 is fixed and the height of the photosensitive substrate 4 is sequentially corrected has been described, but the photosensitive substrate 4 side is fixed and the mask 3 side is fixed. The present invention can be widely applied to the case where the correction is performed and the case where the mask 3 and the photosensitive substrate 4 are simultaneously corrected. Even in this case, it is possible to perform exposure without fear of deterioration of resolution.

Further, in the above-mentioned embodiment, the case where the present invention is applied to the scanning type exposure apparatus using two image forming optical systems has been described, but the present invention is not limited to this, and one to one column of image forming optical systems. The present invention can be widely applied to a scanning type exposure apparatus using only that and a scanning type exposure apparatus using three or more columns. In either case, it is possible to realize scanning exposure with higher throughput and less resolution degradation than in the past.

Further, in the above embodiment, the case where the alignment sensor 7 is constituted by a CCD camera and the scanning stage 5 is temporarily stopped at the time of alignment for picking up an image of the alignment mark by the CCD camera has been described. The invention is not limited to this, and if a laser interference type alignment method is adopted, the scanning stage 5 does not have to be stopped every time alignment measurement is performed. This makes it possible to further improve the throughput.

In the above-mentioned embodiment, the position for measuring the position information in the optical axis direction is not particularly limited, but the present invention is not limited to this, and the position where the alignment mark is measured by the alignment sensor 7 is used. You may measure simultaneously. By doing so, the throughput can be further increased.

Further, in the above-mentioned embodiment, the case where the position information in the optical axis direction is measured without passing through the imaging optical systems 2A and 2B, that is, the case where the measurement position is provided in the vicinity of the exposure area, is described. The invention is not limited to this, and can be applied to the case where the position in the optical axis direction is measured via the imaging optical systems 2A and 2B, that is, when the measurement position is provided in the exposure area. In this case, since the position information within the exposure amount area can be obtained as a measured value, the correction accuracy can be further improved.

In the above-mentioned embodiment, the mutual relationship between the attachment position of the focus sensor 8 and the attachment position of the alignment sensor 7 has not been described.
By disposing the focus sensor 8 on the upstream side (front side) in the forward scanning direction with respect to the alignment sensor 7, accurate focus can be applied at the alignment mark position without lowering the throughput and alignment accuracy is further enhanced. Can be increased.

[0048]

As described above, according to the present invention, the relative positional relationship between the mask and the photosensitive substrate is detected in advance during conveyance to the exposure start position, and the position detected in advance during exposure is detected. By reading the information from the storage means and correcting the relative positional relationship between the mask and the photosensitive substrate, the conventional method for simultaneously measuring and correcting the relative positional relationship between the mask and the photosensitive substrate during exposure scanning. With the method, even when using a mask and a photosensitive substrate that include a sharp change that cannot be predicted in terms of flatness change, it is possible to easily realize a scanning type exposure apparatus that can perform exposure without defective imaging without lowering the throughput. can do.

Further, by previously detecting the first position information regarding the direction perpendicular to the optical axis of the projection optical system and the second position information regarding the optical axis direction of the projection optical system,
It is possible to easily realize a scanning exposure apparatus that has excellent positioning accuracy and can further reduce the risk of defective imaging. At this time, the first position information is masked (3)
Relative to the photosensitive substrate (4), and the second position information is the relative position of the mask (3) and the photosensitive substrate (4) with respect to the optical axis direction and the mask (3) and the photosensitive substrate (4). If the relative amount of inclination is used, it is possible to limit the inspection items that are excellent in positioning accuracy and that can eliminate the risk of defective imaging to a minimum.

When the exposure stop position is stopped, the optical axis of the projection optical system is determined based on the relative position between the mask (3) and the photosensitive substrate (4) before scanning the mask and the photosensitive substrate. After the positional relationship in the direction perpendicular to the is corrected and the scanning of the mask and the photosensitive substrate is started, the relative position of the mask (3) and the photosensitive substrate (4) in the optical axis direction and / or the mask (3). By correcting the positional relationship in the optical axis direction of the projection optical system on the basis of the relative tilt amount of the photosensitive substrate (4) and the photosensitive substrate (4), it is possible to realize scanning exposure without a possibility of image defect within a range where the throughput is not lowered. It is possible to easily realize a scanning type exposure apparatus capable of performing the above.

By storing a data map created on the basis of the relative positional relationship at an arbitrary position in the scanning direction in the storage means, the relative positional relationship between the mask and the photosensitive substrate is measured again during scanning exposure. Therefore, it is possible to realize the scanning type exposure apparatus that can realize the improvement of the scanning speed during the exposure.

Further, it should match the average photosensitive substrate surface to be present with respect to the mask surface or the mask surface to be present with respect to the photosensitive substrate surface, which is determined based on the position information read from the data map. By preliminarily correcting the positional relationship between the photosensitive substrate or the mask before the start of scanning, it is possible to realize a scanning exposure apparatus capable of further improving the scanning speed during exposure.

Further, a correction map representing a correction at an arbitrary position is created based on the position information read from the data map, and the positional relationship of the mask and / or the photosensitive substrate is sequentially corrected according to the correction map during the exposure, It is possible to realize a scanning type exposure apparatus that can always correct the positional relationship between the mask and the photosensitive substrate to an optimum state, and can realize exposure under the condition of higher resolution.

[Brief description of drawings]

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

FIG. 2 is a schematic optical path diagram for explaining scanning exposure.

FIG. 3 is a schematic optical path diagram used for explaining scanning exposure.

[Explanation of symbols]

1 ... Scanning exposure apparatus, 2A, 2B ... Imaging optical system,
3 ... Mask, 4 ... Photosensitive substrate, 5 ... Scanning stage,
7 ... Alignment sensor, 8 ... Focus sensor,
8A ... Light emitting element, 8B ... Light receiving element, 9, 10 ... Detection system, 11 ... Storage device, 12 ... Control system.

Front page continuation (72) Inventor Tomohide Hamada 3 2-3 Marunouchi, Chiyoda-ku, Tokyo Nikon Corporation

Claims (7)

[Claims] 1. A mask is illuminated, an image of the mask is projected onto a photosensitive substrate via a projection optical system, and the mask and the photosensitive substrate are scanned with respect to the projection optical system. In a scanning type exposure apparatus that exposes the entire surface of a mask onto the photosensitive substrate, position detecting means for detecting a relative positional relationship between the mask and the photosensitive substrate, and position information obtained by the position detecting means. And a position correction unit that corrects a relative positional relationship between the mask and the photosensitive substrate based on the position information read from the storage unit, and the mask and the photosensitive substrate are the projection optical units. When it is conveyed to the exposure start position through the projection area of the system, the relative position relationship between the mask and the photosensitive substrate is detected by the position detecting means, and the mask and the photosensitive substrate are detected. When the plate is stopped at the exposure start position and / or during the exposure, the relative position of the mask and the photosensitive substrate based on the position information read from the storage unit by the position correction unit. A scanning exposure apparatus comprising: a control unit that corrects the relationship. 2. The position information is a first information regarding a direction perpendicular to an optical axis of the projection optical system.
Second position information and the second optical axis direction of the projection optical system.
2. The scanning exposure apparatus according to claim 1, characterized in that 3. The first position information is a relative position between the mask and the photosensitive substrate, and the second position information is a relative position of the mask and the photosensitive substrate in the optical axis direction and the relative position. The scanning type exposure apparatus according to claim 2, wherein the relative amount of inclination between the mask and the photosensitive substrate is used. 4. The control means controls the position correcting means based on a relative position between the mask and the photosensitive substrate when the mask and the photosensitive substrate are stopped at the exposure start position. Then, the positional relationship between the mask and the photosensitive substrate in the direction perpendicular to the optical axis of the projection optical system is corrected, and during the exposure, the optical axis direction of the mask and the photosensitive substrate is corrected. Of the positional relationship between the mask and the photosensitive substrate, and the position in the optical axis direction of the projection optical system is controlled based on the relative position of the mask and the photosensitive substrate. The scanning exposure apparatus according to claim 3, wherein the relationship is corrected. 5. The storage means holds a data map obtained on the basis of the position information for an arbitrary position in the scanning direction detected by the position detecting means.
The scanning type exposure apparatus according to claim 2, claim 3, or claim 4. 6. The position correction means, with respect to an average surface of the photosensitive substrate or an average surface of the photosensitive substrate which should be present with respect to the surface of the mask obtained based on the position information read from the data map. 6. The positional relationship of the photosensitive substrate or the mask is corrected in advance while being stopped at the exposure start position so as to coincide with an average surface of the mask that should exist. Scanning exposure equipment. 7. The position correction means creates a correction map representing a correction value at the arbitrary position based on the position information read from the data map, and according to the correction map, the mask and / or the photosensitive substrate. 6. The scanning type exposure apparatus according to claim 5, wherein the positional relationship of [1] is sequentially corrected during the exposure.