JP2002258487A - Method and device for aligner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for aligner which can expose a photosensitive substrate to patterns while easily and precisely correcting shape errors among the patterns when the photosensitive substrate is exposed to the patterns in a connection state by positioning them at patterns formed on the photosensitive substrate. SOLUTION: The aligner device EX is equipped with a measuring instrument S which measures the orthogonality of arrays of matrix-shaped patterns formed on the photosensitive substrate P and an orthogonality correcting member B which corrects the orthogonality of pattern images so that the difference between the measured orthogonality and the orthogonality of a pattern image of next exposure becomes smaller, so the photosensitive substrate P can be exposed to the patterns while the orthogonality errors of the respective patterns are easily and precisely corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an exposure method and an exposure apparatus for exposing a pattern on a photosensitive substrate.

[0002]

2. Description of the Related Art When manufacturing a liquid crystal display, which has been widely used as a display element of a personal computer, a television receiver, or the like, a mask and a glass substrate coated with a photosensitive agent are fixed on a mask in a stationary state. By irradiating exposure light, an image of a pattern formed on the mask is transferred onto a glass substrate (photosensitive substrate) via a projection optical system, and the photosensitive substrate is sequentially moved stepwise to join the patterns. A step-and-repeat type exposure apparatus for forming a screen is used.

[0003] As a management parameter when a pattern is formed on a photosensitive substrate using such an exposure apparatus, a shift, enlargement or reduction error, which is a position error in the horizontal direction (X direction or Y direction) of a pattern image, is used. Scaling, rotation as a rotation error (error in the direction around the Z axis), and deviation from the right angle of the row and column of the array (the amount of tilt of the pattern image in the Y direction with respect to the X axis). There is orthogonality.

[0004]

By the way, a liquid crystal display is formed by superposing a plurality of layers while joining a plurality of patterns on the same layer. And the accuracy of detection of alignment systems, errors between devices when different layers are formed by multiple exposure devices, or damage to alignment marks due to the processing of the photosensitive substrate or deformation of the photosensitive substrate itself. Patterns that can be superimposed on layers
Alternatively, a difference in orthogonality (orthogonality error) may occur between patterns joined in the same layer.

For example, in the photosensitive substrate P shown in FIG.
A second layer (second layer pattern) SD is formed so as to be superimposed on the first layer (first layer pattern) G. The first layer pattern G originally has a shape indicated by a broken line. Have to do it. However, when an actual first layer pattern G as shown by a solid line is formed as shown by a solid line so as to fall in the Y direction with respect to the X axis with respect to the target shape of the first layer pattern G shown by a broken line, The difference in orthogonality (orthogonality error) between the first layer pattern G formed first on P and the second layer pattern SD formed later so as to overlap the first layer pattern G is shown in FIG. Will happen. When an orthogonality error occurs between the first layer pattern G and the second layer pattern SD, the first layer pattern G and the second
The overlapping amount m with the layer pattern SD is different at each position on the photosensitive substrate P, the transistor performance at each position on the photosensitive substrate P is different, and the liquid crystal display has a luminance distribution.

In addition, the first layer joined in the same layer
Between the layer patterns G and G (or the second layer pattern SD
Also, when an orthogonality error occurs between (a) and (SD), the joining accuracy is reduced, for example, a portion that overlaps or does not overlap at the joining portion is mixed. As described above, a liquid crystal display with low performance is manufactured due to the difference in the orthogonality of each pattern.

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and when a plurality of patterns are jointed and exposed by first aligning with a pattern formed on a photosensitive substrate, a pattern between the patterns is formed. It is an object of the present invention to provide an exposure method and an exposure apparatus that can expose a pattern on a photosensitive substrate while easily and accurately correcting an error.

[0008]

In order to solve the above-mentioned problems, the present invention employs the following structure corresponding to FIGS. 1 to 7 shown in the embodiment. According to the exposure method of the present invention, a matrix-shaped pattern is formed on a photosensitive substrate (P) on which a pattern (G) is formed in a matrix by performing first and second exposures while aligning the pattern (G). In the exposure method of joining and exposing the images of (SD), the orthogonality of the array of the pattern (G) formed on the photosensitive substrate (P) is measured, and the orthogonality of the array of the pattern (G) and the first orthogonality are measured. Pattern images (S
The orthogonality of the pattern image (SD) is corrected so that the difference from the orthogonality of D) becomes small.

An exposure apparatus according to the present invention comprises a photosensitive substrate (P) on which a pattern (G) is formed in a matrix form, the first exposure and the second exposure being performed so as to overlap the pattern (G). An exposure apparatus for joining and exposing the images of the pattern (SD), the measuring apparatus (S) for measuring the orthogonality of the array of the patterns (G) formed on the photosensitive substrate (P), and the measured pattern ( G), and the pattern images (S) in the first exposure and the second exposure.
And a orthogonality correction member (B) for correcting the orthogonality of the pattern image (SD) so that the difference between the orthogonality of D) and the orthogonality of D) is reduced.

According to the present invention, with respect to the matrix pattern (G) previously formed on the photosensitive substrate (P), the first and second patterns are aligned with this pattern (G).
Matrix-like patterns (S
When joining D), the orthogonality of the array of the matrix-like patterns (G) formed on the photosensitive substrate (P) is measured first, and this measurement result is compared with the first and second patterns to be formed next. Each pattern (S
The pattern (SD) formed to be superimposed next so that the difference (orthogonality error) from the orthogonality of D) becomes small.
Is corrected, it is possible to prevent a shift (overlap difference) between patterns between different layers. That is, the exposure is performed by correcting the orthogonality of the pattern (SD) to be superimposed next according to the orthogonality of the pattern (G) previously formed on the photosensitive substrate (P), and thereby exposing the first layer pattern and the first layer pattern. Since the orthogonality error between the two-layer patterns is reduced, the shape and performance of the pattern at each position on the photosensitive substrate (P) can be made uniform with high accuracy, and a high-performance device can be manufactured.

According to the exposure method of the present invention, a first exposure is performed on a predetermined area of the photosensitive substrate (P), and a second exposure is performed so that at least a part of the predetermined area overlaps the predetermined area. In the exposure method for forming a matrix-like pattern (G, SD), the orthogonality of the arrangement of the pattern (G, SD) by the first exposure corresponding to a part of which is partially overlapped and the pattern (G, SD) by the second exposure The orthogonality of the first and second pattern images (G, SD) is corrected so that the difference between the orthogonality of the array of (SD) and the orthogonality of the array of (SD) becomes small.

According to the present invention, a predetermined area of the photosensitive substrate (P) is subjected to a first exposure, a second exposure is performed so as to at least partially overlap the predetermined area, and a continuous matrix is formed. When forming the pattern (G, SD), the orthogonality of the arrangement of the pattern (G, SD) by the first exposure corresponding to a part where a part overlaps and the pattern (G, SD) by the second exposure Since the orthogonality of the first and second pattern images (G, SD) is corrected so as to reduce the difference between the orthogonality of the array and the adjacent pattern images (G, SD) by the first and second exposures. (G, SD), it is possible to reduce the orthogonality error between patterns (G, SD) to be joined in the same layer, and to join the patterns with high accuracy. Therefore,
High performance devices can be manufactured.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an exposure method and an exposure apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration diagram showing an exposure apparatus of the present invention.

As shown in FIG. 1, an exposure apparatus EX includes an illumination optical system IL for illuminating a light beam from a light source 1 onto a mask M held on a mask stage MST, and an illumination optical system IL.
A blind portion 4 that adjusts the area of an opening that is arranged in the inside and allows the exposure light EL to pass therethrough to define an illumination range of the mask M by the exposure light EL, and a substrate image of the mask M illuminated by the exposure light EL. A projection optical system PL that projects onto the photosensitive substrate P on the stage PST, and a measuring device S that measures information about the orthogonality of the arrangement of the patterns formed on the photosensitive substrate P.
And an optical member (orthogonality correction member) B capable of deforming the image of the pattern projected on the photosensitive substrate P. The operation of the entire exposure apparatus EX is performed based on an instruction from the control unit CONT.

The pattern formed on the mask M is a matrix-like pattern, for example, a pattern for forming an X electrode, a Y electrode and an active element in a liquid crystal display element, which has an array in the XY directions. Pattern.

As the light source 1, a mercury lamp is used.
As the exposure light EL, a g-line (436 nm) and an h-line (40
5 nm), i-line (365 nm) and the like.

The exposure light EL emitted from the light source 1 is condensed by the elliptical mirror 2, reflected by the return mirror 3a of the illumination optical system IL, and incident on the optical unit IU constituting the illumination optical system IL. The optical unit IU includes a relay lens,
A plurality of optical integrators for equalizing the exposure light EL, an input lens for inputting the exposure light EL to the optical integrator, a relay lens for condensing the exposure light EL emitted from the optical integrator on the mask M, and a plurality of condenser lenses Lens (optical element).

As shown in FIG. 1, masks M each having a matrix pattern are mounted on a mask changer 7. The mask changer 7 is disposed movably above the mask stage MST, and can load and unload each of the masks M with respect to the mask stage MST.

The mask M to be mounted on the mask changer 7 is stored in a mask library (not shown).
To mount the mask M in the mask library on the mask changer 7, the mask M is loaded onto the mask stage MST by a loader (not shown) from the mask library, and the mask changer 7 receives the mask M on the mask stage MST. Mask M is mask changer 7
Mounted on On the other hand, in order to return the mask M mounted on the mask changer 7 into the mask library, the mask M is loaded from the mask changer 7 onto the mask stage MST, and the mask M on the mask stage MST is masked by the loader (not shown). Return to library.

Exposure light E emitted from the optical unit IU
L is reflected by the return mirror 3b and is reflected in the two-dimensional direction (XY
Direction) mask M on movable mask stage MST
Incident on. Further, the exposure light EL transmitted through the mask M is incident on the projection optical system PL, is transmitted through a plurality of lenses (optical elements) constituting the projection optical system PL and is incident on the substrate P, and the image of the pattern of the mask M is formed. Is formed on the surface of the photosensitive substrate P.

The photosensitive substrate P has a surface coated with a photosensitive agent, and is held by a substrate holder PH. The substrate holder PH that holds the photosensitive substrate P is set on the substrate stage PST. The substrate stage PST is provided so as to be movable in the XYZ directions, and is provided so as to be rotatable around the Z axis. Furthermore, a leveling adjustment of the photosensitive substrate P may be performed when the photosensitive substrate P is supported by providing a mechanism that can also move in the tilt direction with respect to the optical axis AX of the exposure light EL.

The position of the substrate stage PST in the XY plane is detected by the laser interferometer 5. On the other hand, the position of the substrate stage PST in the Z direction (the optical axis direction of the projection optical system PL) is detected by a focus position detection system 6 including a light projection system 6a and a light receiving system 6b. The detection results of the laser interferometer 5 and the focus position detection system 6 are output to the control device CONT, and the substrate stage PST is moved via the drive mechanism PSTD based on an instruction from the control device CONT. The focus position detection system 6 is a projection optical system PL for the surface (exposure processing surface) of the photosensitive substrate P held by the substrate holder PH.
Detects the position (focus position) in the optical axis direction of
Information on this position is output to the control unit CONT. When performing the exposure process, the control device CONT controls the drive mechanism PSTD via the drive mechanism PSTD so that the surface position of the photosensitive substrate P matches the image formation position of the projection optical system PL based on the detection result of the focus position detection system 6. The substrate stage PST is moved.

A fiducial mark FM whose height is set to the same height as the photosensitive substrate P is fixed on the substrate stage PST. An off-axis type substrate alignment microscope 11 is provided at a position outside the projection optical system PL. The position of the substrate stage PST when the fiducial mark FM is aligned with the reference point of the projection area of the projection optical system PL by a TTL alignment system (not shown), and the measurement area of the substrate alignment microscope 11 by the substrate alignment microscope 11 The distance (base line) from the position of the substrate stage PST when the fiducial mark FM is aligned with the reference point is measured by the laser interferometer 5. Then, the alignment marks formed on the photosensitive substrate P are aligned with the substrate alignment microscope 1.
After the detection and alignment in step 1, the photosensitive substrate P is moved by the amount of the base line and sent immediately below the projection optical system PL to expose the pattern of the mask M to an arbitrary position on the photosensitive substrate P.

The exposure apparatus EX according to the present embodiment
Means that the mask M and the photosensitive substrate P are stationary and the mask M
And a step-and-repeat type exposure apparatus that sequentially moves the photosensitive substrate P stepwise, and exposes each of a plurality of patterns on one photosensitive substrate P. Each pattern is formed on each of the plurality of masks M, and the exposure apparatus E
X exposes patterns to different regions of the photosensitive substrate P while exchanging the masks M.

The measuring device (LSA alignment system) S
By measuring the marks formed on the photosensitive substrate P, information on the orthogonality of the arrangement of the patterns formed on the photosensitive substrate P is measured. This measuring device S
Has a laser light source 12, and a laser beam LB from the laser light source 12 irradiates a mark formed on the photosensitive substrate P via a projection optical system PL. Then, optical information of the reflected light (diffraction light) of the light applied to the mark is detected by a detector (not shown) via the projection optical system PL, and the mark formed on the photosensitive substrate P based on the detection signal. To detect the position information.

Here, the marks are formed at predetermined positions in association with each of several typical (3 to 9) patterns (shot areas) provided on the photosensitive substrate P.
The measuring device S measures the position information of these marks, performs a statistical operation (EGA process) on the obtained position information, and determines the positions of all the patterns (shot areas) set on the photosensitive substrate P. Ask. Then, the orthogonality of the pattern arrangement is calculated based on the obtained position information and the ideal position (ideal grid). At this time, various parameters (shift, scaling, rotation) other than the orthogonality can also be obtained.

The optical member (orthogonality correction member) B corrects the orthogonality of the image of the pattern formed on the mask M, and is provided between the mask M and the photosensitive substrate P on the optical path of the exposure light EL. Are located in In the present embodiment,
The optical member B is provided between the mask M and the projection optical system PL. The optical member B is made of, for example, parallel flat glass made of quartz glass or the like, has a transmittance that does not affect the exposure processing, and has a thickness that can be bent.

As shown in FIG. 2, an optical member B formed in a rectangular shape in a plan view is supported by a driving device BK capable of deforming the optical member B into a predetermined shape. Drive unit BK
Is a frame-like member 20 attached to the edge of the optical member B.
And a plurality of minute moving mechanisms (piezo elements) 2 having upper ends (one ends) connected to a plurality of predetermined positions of the optical member B via the frame-shaped member 20 and lower ends (other ends) connected to the support 21.
2 is provided. The support base 21 has an opening at the center so as not to block the exposure light EL transmitted through the optical member B. Each of the piezo elements 22 is driven based on an instruction from the control device CONT. And
The optical member B is deformed into an arbitrary shape by driving an arbitrary piezo element 22 of the plurality of piezo elements 22 by a predetermined amount to displace the edge of the optical member B. The shape of the shot area (projection area) is set according to the shape of the optical member B.

For example, when the pattern formed on the mask M is a matrix having an array perpendicular to the X and Y directions as shown in FIG. 3A, the exposure light EL as shown in FIG. When the optical member B disposed on the optical path is not deformed, the projected image of the pattern becomes a matrix having an array perpendicular to the XY directions. on the other hand,
As shown in FIG. 3C, by deforming the optical member B so as to be twisted around the X axis by the driving device BK, the projected image of the exposure light EL transmitted through the optical member B becomes a parallelogram (diamond). Deform to deform into a shape. On this occasion,
Of the two sides parallel to the Y direction of the optical member B, the side H on the + X side
When 1 is rotated in the -θx direction and the side H2 on the -X side is twisted in the + θx direction, two sides of the pattern parallel to the Y direction are distorted in the projected image so as to fall in the -X direction, and Two sides parallel to the X direction are also X in the projected image.
Parallel to the direction. Similarly, although not shown, of the two sides of the optical member B parallel to the Y direction, the side H1 on the + X side is set to +
When the side H2 on the −X side is rotated in the θx direction so as to twist in the −θx direction, two sides of the pattern parallel to the X direction are also parallel to the X direction in the projected image and parallel to the Y direction in the pattern. These two sides are distorted in the projected image so as to fall in the + X direction.

Further, as shown in FIG. 3D, of the two sides of the optical member B parallel to the Y direction, the sides H1 and -1 on the + X side.
The projection image of the exposure light EL transmitted through the optical member B is reduced in the X direction by holding the side H2 on the X side and curving the central portion upward. Conversely, as shown in FIG. 3E, by projecting the central portion of the optical member B in a downwardly convex shape, the projected image of the exposure light EL transmitted through the optical member B is enlarged in the X direction. Similarly, although illustration is omitted, of the two sides parallel to the X direction of the optical member B, the side on the + Y side and the side on the −Y side are held, and the central portion is curved upwardly in a convex shape. The projected image of the exposure light EL transmitted through the optical member B is reduced in the Y direction, and the projected image of the exposure light EL transmitted through the optical member B is enlarged in the Y direction by curving the central portion downward and convex. .

A method for exposing the image of the pattern formed on the mask M onto the photosensitive substrate P by the exposure apparatus EX having the above-described configuration will be described. Here, the first layer pattern G previously formed on the photosensitive substrate P
Next, a process of exposing the respective divided patterns SD1 to SD6 of the second layer pattern SD while aligning the divided patterns will be described. 4 to 6, small sections in the six divided patterns are elements arranged in a matrix, and are shown as corresponding to pixels of a display element in a liquid crystal display.

First, as shown in FIG. 4, a first layer pattern G is formed on a photosensitive substrate P. The first layer pattern G is formed by joining a plurality of divided patterns G1 to G6. Divided pattern G of first layer pattern G
A mark (not shown) is formed on each of the divided patterns G1 to G6 in a predetermined positional relationship with each of the divided patterns G1 to G6.

Next, the mark of the first layer pattern G (G1 to G6) formed earlier on the photosensitive substrate P is measured by the measuring device S. The measurement result of the measurement device S is output to the control device CONT, and the control device CONT outputs the ideal lattice (FIG. 4) of the first layer pattern G (divided patterns G1 to G6).
The orthogonality of the array is determined. That is,
The degree of orthogonality of the first layer pattern G is obtained by EGA processing by the measuring device S.

Next, the second layer pattern SD is exposed so as to overlap the first layer pattern G. At this time, as shown in FIG. 5, the difference between the orthogonality of the first layer pattern G and the orthogonality of the second layer pattern SD (orthogonality error) is reduced so that the image of the second layer pattern SD is reduced. Exposure is performed with the orthogonality corrected. At this time, the divided pattern G1 of the first layer pattern G
G6 and each of the divided patterns SD1 to SD6 of the second layer pattern SD are adjusted such that the overlap amount m is the same at any position on the photosensitive substrate P.

The second pattern SD (divided patterns SD1 to SD1)
The correction of the orthogonality of the image in SD6) is controlled by distorting the image of the pattern. At this time, the shape of the image of the second layer pattern SD is controlled so as to match the orthogonality of the first layer pattern G, that is, to reduce the difference from the orthogonality of the first layer pattern G. That is, based on the measurement result (orthogonality) of the measurement device S, the control device CONT determines the orthogonality of the pattern G previously formed on the photosensitive substrate P and the orthogonality of the image of the pattern SD to be exposed next. So that the difference between
The shape of the image of the pattern SD is adjusted using the optical member B.

The controller CONT is an optical member (orthogonality correction member) arranged on the optical path of the exposure light EL, as described with reference to FIG. 3C, according to the orthogonality of the first layer pattern G. B is deformed to be twisted by the driving device BK. The projected image of the second layer pattern SD is deformed so as to fall in the X direction according to the amount of deformation of the optical member B, and generates an orthogonality according to the orthogonality of the first layer pattern G.

As described above, the orthogonality of the arrangement of the first layer pattern G is measured, and the shape of the optical member B is set according to the measurement result. The difference from the orthogonality of the layer pattern SD is reduced.

Here, the amount of twist (shape) of the optical member B
And the shape of the pattern image (orthogonality) at that time are obtained in advance by experiments, calculations (simulations), and the like, and are input to the control unit CONT.
The control device CONT determines the first relationship between the relationship and the measuring device S.
Based on the measurement result regarding the orthogonality of the layer pattern G,
The torsion amount of the optical member B is determined, and the drive unit BK is instructed to generate the determined torsion amount.

In forming a pattern on the same layer,
By joining a plurality of divided patterns G1 to G6 (SD1 to SD6), a pattern G (S
D) is formed, but due to various causes such as apparatus accuracy (stage movement accuracy, etc.) and processing process accuracy (deformation of the photosensitive substrate P due to the processing process, damage to marks, etc.), adjacent divided patterns to be joined together. There may be a difference in orthogonality between G1 to G6 (SD1 to SD6). In this case, at each position of the photosensitive substrate P, an overlapping amount of a joint portion between adjacent patterns is different, or a portion which overlaps or does not overlap appears at each joint portion, and a uniform pattern may not be formed. There is. However, by making the orthogonality correction different each time each of the divided patterns is exposed, adjacent patterns can be joined together with high accuracy. For example, as shown in FIG. 6, the orthogonality is set to θ1 at the time of exposure of the division pattern SD3 (first exposure), and the orthogonality is set to θ2 at the time of exposure of the division pattern SD5 (second exposure). As described above, by performing different orthogonality corrections for each of the divided patterns G1 to G6 (SD1 to SD6), it is possible to accurately join adjacent patterns in the same layer. In addition, it is possible to improve the overlay accuracy between patterns that are overlaid on different layers.

When it is desired to perform not only the orthogonality correction but also the scaling correction in the X direction, the two sides in the ± X direction of the optical member B are held as described with reference to FIGS. The lever optical member B is curved. Similarly, when it is desired to perform scaling correction in the Y direction, the optical member B is curved while holding two sides of the optical member B in the ± Y direction.

As described above, the orthogonality of the arrangement of the first layer patterns G previously formed on the photosensitive substrate P is measured, and the orthogonality of the first layer patterns G and the exposure The orthogonality of the second layer pattern SD (divided patterns SD1 to SD6) to be formed next is corrected so that the difference between the orthogonality of the divided patterns SD1 to SD6 of the second layer pattern SD to be joined is reduced. As a result, it is possible to reduce a pattern shift (overlap difference) between adjacent shot areas or between different layers. That is, according to the orthogonality of the first layer pattern G, the orthogonality of the second layer pattern SD to be superimposed next is corrected and exposed, so that the first layer pattern G and the second layer pattern SD are exposed. Are superimposed at each position on the photosensitive substrate P without causing an orthogonality error, so that the shape and performance of the pattern at each position on the photosensitive substrate P can be made uniform with high accuracy.

The orthogonality is corrected by disposing an optical member B made of parallel flat glass between the mask M and the photosensitive substrate P, and distorting the pattern image by changing the shape of the optical member B. Done. Thus, the projection image can be easily controlled to an arbitrary shape only by changing the shape of the optical member B by twisting or bending.

The orthogonality is corrected differently in each of the divided patterns G1 to G6 (SD1 to SD6) to be joined in the same layer. Therefore, when exposing adjacent patterns while joining them together, each of the divided patterns G1 to G6 (SD1 to SD6) is different. No difference occurs at the seam. In other words, there is no difference in the overlapping state at each position of the photosensitive substrate P where adjacent patterns overlap or do not overlap in the joint portion, and the pattern accuracy of the joint portion can be improved.

Using the optical member B, not only orthogonality correction and scaling correction but also shift correction can be performed. To perform shift correction, the optical member B is tilted (tilted) by a predetermined angle with respect to the optical axis AX of the projection optical system PL. When performing scaling correction in one of the X and Y directions, the optical member B is bent in one direction as shown in FIGS. 3D and 3E. Let it. X direction and Y direction 2
To perform scaling correction in the direction, the optical member B
May be provided in the optical axis direction of the projection optical system PL, one of the optical members B may be curved in the X direction, and the other optical member B may be curved in the Y direction. Further, a plurality of optical members B are provided along the optical axis direction of the projection optical system PL, and the orthogonality correction is performed by one optical member B, the scaling correction is performed by another optical member B, and another optical member B is corrected. Can be used to perform shift correction. When performing rotation correction, the substrate stage PST is rotated around the Z axis.

In the present embodiment, the amount of deformation (torsion) of the optical member B is determined by the amount of torsion of the optical member B determined in advance by experiments or simulations and the shape of the pattern image (orthogonality) at that time. The shape is set based on the relationship, but without using the relationship, the shape (mark position) of the projected image at that time is measured by a measuring device while deforming the optical member B, and the projected image is determined based on the measurement result. Can be performed by feedback control such that the amount of deformation of the optical member B is adjusted so as to obtain a desired shape.

In order to deform the optical member B with high accuracy, the number of places where the piezo elements 22 of the driving device BK are installed may be increased. Then, by driving an arbitrary piezo element 22 of the plurality of piezo elements 22, only the corners of the optical member B are curved or the bending directions of the respective corners are made different (for example, one corner is formed). Part B is curved upward and the other corners are curved downward).
Can be transformed into a curved shape (non-linear shape). By doing so, it is possible to form a projection image having a desired shape, such as making the side of the projection image by the exposure light EL transmitted through the optical member B into a curved shape.

In the present embodiment, the optical member B is disposed between the mask M (mask stage MST) and the projection optical system PL. However, the optical member B is located between the mask M and the photosensitive substrate P on the optical path of the exposure light EL. It may be placed at any position as long as it is between. For example, it can be arranged at a predetermined position between the optical elements constituting the projection optical system PL or between the projection optical system PL and the photosensitive substrate P (substrate stage PST).

In the present embodiment, the piezo element 22 is used as a minute moving mechanism for deforming the optical member B in the driving device BK, but any moving mechanism having a predetermined resolution and a stroke may be used. In addition, the piezo elements 22 are finely arranged at approximately equal intervals around the optical member B, and the other elements are non-linearly displaced with respect to two opposing piezo elements. Can be corrected.

In this embodiment, when correcting the orthogonality of the projected image, the projected image is distorted by twisting the optical member B made of a parallel plate glass disposed on the optical path of the exposure light EL. A plurality of optical members (glasses) each having a predetermined shape are provided on the turret, and a desired orthogonality correction among a plurality of prepared optical members is performed based on the measurement result of the orthogonality of the pattern image by the measuring device S. It is also possible to select an optical member capable of realizing the above, and drive the turret so that this optical member is arranged on the optical path of the exposure light EL.

The projected image on the photosensitive substrate P can be deformed by inclining the photosensitive substrate P with respect to the optical axis.

In the present embodiment, the first layer pattern G is formed by joining a plurality of divided patterns G1 to G6. However, the first layer pattern G is formed by batch exposure or scan exposure in which the divided patterns G1 to G6 are exposed once. Also in this case, the deformation of the photosensitive substrate P is predicted, and the overlapping and splicing can be performed accurately even when the second layer pattern SD is dividedly exposed to the first layer pattern G.

The exposure apparatus EX according to the present embodiment has a configuration in which a desired pattern is formed by joining a plurality of divided patterns by a step-and-repeat method.
The substrate stage PST holding the photosensitive substrate P can be synchronously moved while irradiating the mask M with the exposure light EL. Further, the present invention can be applied to a multi-scan type exposure apparatus having a plurality of projection optical systems PL and performing scanning while splicing shot areas of each projection optical system PL. In the case of the multi-scan type exposure apparatus, the shape of the projected image by one projection optical system PL is often trapezoidal, but the optical member B is deformed so that each of the trapezoidal shapes is overlapped with the joining portion by a predetermined amount. .

The application of the exposure apparatus EX is not limited to an exposure apparatus for a liquid crystal for exposing a liquid crystal display element pattern to a square glass plate, but an exposure apparatus for manufacturing a semiconductor and a thin film magnetic head are manufactured. Exposure equipment, etc.
It can be widely used for manufacturing devices having a matrix-like pattern.

The light source 1 of the exposure apparatus EX of the present embodiment has g
Line (436 nm), h line (405 nm), i line (365
nm) as well as a KrF excimer laser (248n
m), an ArF excimer laser (193 nm) and an F ₂ laser (157 nm) can be used.

The magnification of the projection optical system PL may be not only a reduction system but also any one of an equal magnification and an enlargement system.

As the projection optical system PL, when far ultraviolet rays such as an excimer laser are used, a material that transmits far ultraviolet rays such as quartz or fluorite is used as a glass material, and when an F ₂ laser or X-ray is used, a catadioptric system is used. Alternatively, a refraction optical system (a reflection type mask is used as the mask M) may be used.

Substrate stage PST and mask stage MS
When a linear motor is used for T, either an air levitation type using an air bearing or a magnetic levitation type using Lorentz force or reactance force may be used. Also,
The stage may be a type that moves along a guide or a guideless type that does not have a guide.

When a plane motor is used as the stage driving device, one of the magnet unit (permanent magnet) and the armature unit is connected to the stage, and the other of the magnet unit and the armature unit is connected to the moving surface of the stage. (Base).

The reaction force generated by the movement of the substrate stage PST may be mechanically released to the floor (ground) using a frame member as described in Japanese Patent Application Laid-Open No. 8-166475. The present invention is also applicable to an exposure apparatus having such a structure.

As described in JP-A-8-330224, a reaction force generated by the movement of the mask stage MST is mechanically moved to the floor (ground) using a frame member.
You may escape to The present invention is also applicable to an exposure apparatus having such a structure.

As described above, the exposure apparatus according to the embodiment of the present invention converts various subsystems including the components described in the claims of the present application into predetermined mechanical accuracy, electrical accuracy,
It is manufactured by assembling to maintain optical accuracy. Before and after this assembly, adjustments to achieve optical accuracy for various optical systems, adjustments to achieve mechanical accuracy for various mechanical systems, and various electric systems to ensure these various accuracy Are adjusted to achieve electrical accuracy. The process of assembling the exposure apparatus from various subsystems includes mechanical connections, wiring connections of electric circuits, and piping connections of pneumatic circuits among the various subsystems. It goes without saying that there is an assembling process for each subsystem before the assembling process from these various subsystems to the exposure apparatus. When the process of assembling the various subsystems into the exposure apparatus is completed, comprehensive adjustment is performed, and various precisions of the entire exposure apparatus are secured. It is desirable that the manufacture of the exposure apparatus be performed in a clean room in which the temperature, cleanliness, and the like are controlled.

As shown in FIG. 7, in the semiconductor device, a step 201 for designing the function and performance of the device, a step 202 for manufacturing a mask (reticle) based on the design step, and a substrate as a substrate of the device are manufactured. Step 203, a substrate processing step 20 of exposing a mask pattern to a substrate by the exposure apparatus of the above-described embodiment.
4. The device is manufactured through a device assembling step (including a dicing step, a bonding step, and a package step) 205, an inspection step 206, and the like.

[0063]

The exposure method and the exposure apparatus according to the present invention have the following effects. According to the exposure method according to the first aspect and the exposure apparatus according to the seventh aspect, the first and second patterns are aligned with respect to the matrix-like pattern previously formed on the photosensitive substrate. When joining the respective matrix-like patterns by the exposure, the orthogonality of the arrangement of the matrix-like patterns formed on the photosensitive substrate is first measured, and this measurement result is compared with the first pattern which is the next pattern to be formed. And the orthogonality of the patterns formed so as to be superimposed next is corrected so that the difference (orthogonality error) between the orthogonality of each pattern and the second exposure due to the second exposure is reduced. (Overlap difference) between the patterns can be prevented. Therefore, the shape and performance of the pattern at each position on the photosensitive substrate can be made uniform with high accuracy, and a high-performance device can be manufactured.

According to the exposure method of the second aspect and the exposure apparatus of the eighth aspect, the orthogonality is corrected by using the orthogonality correction member disposed between the mask and the photosensitive substrate. This is performed by distorting the image, and the pattern image can be easily controlled to an arbitrary shape.

Since the correction of the orthogonality is performed differently for the first exposure and the second exposure, there is a difference between the joints when exposing adjacent patterns while joining them. In other words, there is no difference in the overlapping state at each joint on the photosensitive substrate, and the pattern accuracy of the joint can be improved.

According to the exposure method of the fourth aspect, the first method
Since the orthogonality between the pattern image in the first exposure and the pattern image in the second exposure is obtained by measuring a plurality of predetermined pattern images provided in each pattern image, the orthogonality can be measured with high accuracy.

According to the exposure method of the fifth aspect, the first method
The pattern image in the exposure and the pattern image in the second exposure are adjusted on at least one of shift, scaling, and rotation to expose the pattern formed on the photosensitive substrate. When exposure is performed by overlapping, accurate pattern formation can be performed.

According to the exposure method of the sixth aspect, the first exposure is performed on a predetermined area of the photosensitive substrate, and the second exposure is performed so that at least a part of the predetermined area overlaps the predetermined area. When forming a continuous matrix pattern, the difference between the orthogonality of the pattern arrangement by the first exposure and the orthogonality of the pattern arrangement by the second exposure corresponding to a part where a part overlaps is reduced. , First and second
Since the orthogonality of the pattern image is corrected, the first
When joining adjacent pattern images by the second exposure, the orthogonality error between the patterns joined in the same layer can be reduced, and the patterns can be joined with high accuracy. Therefore, a high-performance device can be manufactured.

[Brief description of the drawings]

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

FIG. 2 is a view for explaining an orthogonality correction member in the exposure apparatus of the present invention.

FIG. 3 is a diagram for explaining how the orthogonality of a pattern image is changed by an orthogonality correction member.

FIG. 4 is a diagram illustrating an embodiment of the exposure method of the present invention.

FIG. 5 is a diagram illustrating an embodiment of the exposure method of the present invention.

FIG. 6 is a diagram illustrating an embodiment of the exposure method of the present invention.

FIG. 7 is a flowchart illustrating an example of a semiconductor device manufacturing process.

FIG. 8 is a diagram illustrating a problem of a conventional exposure method.

[Explanation of symbols]

 Reference Signs List 1 light source 4 blind part B optical member (orthogonality correction member) BK driving device EL exposure light EX exposure device IL illumination optical system M mask P photosensitive substrate PL projection optical system S measuring device (alignment system) G first layer pattern (matrix) Pattern) G1 to G6 division pattern SD Second layer pattern (matrix pattern) SD1 to SD6 division pattern

Claims (8)

[Claims] 1. An exposure method for exposing a photosensitive substrate on which a pattern is formed in a matrix pattern, by aligning the pattern and aligning the pattern image of the matrix pattern by a first exposure and a second exposure. Measuring the orthogonality of the pattern array formed on the photosensitive substrate so that the difference between the orthogonality of the pattern array and the orthogonality of the pattern image in the first exposure and the second exposure is reduced. An exposure method, wherein the orthogonality of the pattern image is corrected. 2. The exposure method according to claim 1, wherein the correction of the orthogonality is controlled by distorting a pattern image formed by the first exposure and the second exposure. 3. The exposure method according to claim 1, wherein the orthogonality is corrected differently between the first exposure and the second exposure. 4. The exposure method according to claim 1, wherein an orthogonality between the pattern image in the first exposure and the pattern image in the second exposure is provided in each of the pattern images. An exposure method characterized by measuring and obtaining a plurality of predetermined pattern images. 5. The exposure method according to claim 1, wherein the pattern image in the first exposure and the pattern image in the second exposure adjust at least one of shift, scaling, and rotation. And exposing the pattern on the photosensitive substrate. 6. Exposure to form a continuous matrix pattern by performing a first exposure on a predetermined area of the photosensitive substrate and a second exposure to at least partially overlap the predetermined area. The method according to claim 1, wherein the difference between the orthogonality of the pattern arrangement by the first exposure corresponding to the overlapping part and the orthogonality of the pattern arrangement by the second exposure is reduced.
And correcting the orthogonality of the second pattern image. 7. An exposure apparatus for exposing a matrix pattern image formed by a first exposure and a second exposure on a photosensitive substrate having a matrix pattern formed thereon so as to overlap the pattern. A measuring device for measuring the orthogonality of the array of the patterns formed on the photosensitive substrate; and the orthogonality of the measured array of the patterns and the orthogonality of the pattern images in the first exposure and the second exposure. An exposure apparatus comprising: an orthogonality correction member that corrects the orthogonality of the pattern image so as to reduce the difference. 8. The exposure apparatus according to claim 7, wherein the pattern images exposed by the first exposure and the second exposure project a pattern provided on the same or a different mask onto the photosensitive substrate. An exposure apparatus, wherein the orthogonality correction member is disposed between the mask and the photosensitive substrate.