JP5853343B2 - Scan exposure equipment using microlens array - Google Patents

Description

  The present invention relates to a scanning exposure apparatus that exposes a mask pattern onto a substrate by a microlens array in which microlenses are two-dimensionally arranged.

  A thin film transistor liquid crystal substrate, a color filter substrate, and the like form a predetermined pattern by overlaying and exposing a resist film or the like formed on a glass substrate several times. These exposed substrates may expand and contract during the film formation process, and the lower layer pattern for overlay exposure may differ from the designed pitch depending on manufacturing conditions (exposure apparatus characteristics and temperature conditions). is there. In such overlay exposure, if a change in the pitch of the exposure position occurs, the change in the pitch has to be absorbed by correcting the magnification on the exposure apparatus side. That is, when the dimensional variation of the substrate to be exposed occurs, it is necessary to arrange the image at the center of a predetermined position on the substrate of the pitch after the variation by adjusting the magnification of the image for the deviation of the pitch. .

  On the other hand, recently, a scan exposure apparatus using a microlens array in which microlenses are two-dimensionally arranged has been proposed (Patent Document 1). In this scan exposure apparatus, a plurality of microlens arrays are arranged in one direction, and a substrate and a mask are moved relative to the microlens array and the exposure light source in a direction perpendicular to the arrangement direction. The exposure light scans the mask and forms an exposure pattern formed on the mask on the substrate.

JP2007-3829A

  However, this conventional scanning exposure apparatus has the following problems. In an exposure apparatus using a projection optical system using a combination of ordinary lenses, it is easy to adjust the magnification by adjusting the distance between the lenses. However, in the case of a microlens, for example, an erecting equal-magnification image is formed on a substrate by arranging eight lenses in the optical axis direction within a thickness of 4 mm, for example. The magnification cannot be adjusted. That is, in the case of using a conventional microlens array, only an erect life-size image can be exposed. Therefore, the conventional scan exposure apparatus using the microlens array has a problem that it cannot cope with a change in the pitch of the substrate to be exposed.

  In particular, in the manufacturing process of the liquid crystal display panel, heat treatment is performed on a plurality of layers. For this reason, the glass substrate shrinks after the heat treatment of each layer. In particular, the shrinkage of the glass substrate often shrinks toward the center of the glass substrate as shown in FIG. FIG. 20A is a diagram showing 16 ideal lattice patterns formed on one glass substrate, and FIG. 20B is a diagram showing the distortion of the lattice pattern due to shrinkage after heat treatment. It is a pattern which shows the state which generate | occur | produced. Thus, the glass substrate often shrinks toward the center due to heat treatment in a plurality of layers, and it is necessary to correct this distortion during the next patterning exposure. However, an exposure apparatus combined with a normal lens can correct pattern deformation while changing the magnification. However, a scanning exposure apparatus using a microlens array has a drawback that the magnification cannot be changed.

  The present invention has been made in view of such problems, and in an exposure apparatus using a microlens array, heat treatment is performed on a plurality of layers during overlay exposure, and the glass substrate is deformed to be distorted into a conventional pattern. An object of the present invention is to provide a scan exposure apparatus using a microlens array capable of performing overexposure with high accuracy even if the above occurs.

A scan exposure apparatus using a microlens array according to the present invention is arranged above a substrate to be exposed, and a microlens array in which a plurality of microlenses are two-dimensionally arranged,
A holder for holding the microlens array at its periphery,
A mask disposed above the microlens array and having a predetermined exposure pattern formed thereon;
An exposure light source for irradiating the mask with exposure light;
A moving device that relatively moves the microlens array, the substrate, and the mask in a first direction;
A first drive member that tilts the microlens array in a plane orthogonal to the first direction with respect to the holder;
A second driving member that rotates the mask around the optical axis of the exposure light or moves the mask in a direction perpendicular to the optical axis;
A control device that controls tilting of the microlens array by the first driving member and rotation or movement of the mask by the second driving member according to a position of relative movement of the microlens array by the moving device. When,
It is characterized by having.

In the scanning exposure apparatus using this microlens array, for example, the microlens array is configured by laminating a plurality of unit microlens arrays in which a plurality of microlenses are two-dimensionally arranged,
A polygonal (hexagonal) field stop having a polygonal aperture such as a hexagon is disposed at the reverse imaging position between the unit microlens arrays,
An aperture stop having a circular opening is disposed at least at a part of the maximum enlarged portion of the exposure light between the unit microlens arrays,
The polygonal (hexagonal) field stop and the aperture stop are arranged between the unit microlens arrays in a row along a virtual line in a direction inclined in the first direction or in a direction perpendicular to the first direction.

The scan exposure apparatus using the microlens array further includes an alignment pattern detection unit that detects a reference alignment pattern on the substrate.
The second driving member rotates the mask around the optical axis of the exposure light so that a mask alignment pattern provided on the mask matches the reference alignment pattern, or a direction perpendicular to the optical axis. Can be configured to be moved.

In this case, the reference alignment pattern is a linear pattern extending in a direction perpendicular to a relative scanning direction (first direction) between the microlens array, the substrate, and the mask,
The mask alignment pattern is also a linear pattern extending in a direction perpendicular to the first direction,
The second driving member rotates the mask around the optical axis of the exposure light so that the reference alignment pattern and the mask alignment pattern are parallel, or moves in a direction perpendicular to the optical axis. It is preferable to make it.

Furthermore, a plurality of the microlens arrays are arranged in a direction perpendicular to the first direction, and the first driving member has a correlation between the plurality of microlens arrays at different angles. It can be configured to be inclined.

Further, instead of the first drive member, a third drive member is provided that moves at least a part of the unit microlens array with respect to the other unit microlens array so that the optical axis of the constituent microlens is deviated,
It is also possible to adjust the exposure position on the substrate by the microlens array by biasing the optical axis of the microlens at the reversal imaging position between the unit microlens arrays.

  According to the present invention, in the exposure apparatus using the microlens array, when distortion deformation occurs in the substrate due to heat treatment of the lower layer film, it is detected during or before exposure, The microlens array is tilted in a plane orthogonal to the first direction by the first driving member to adjust the magnification of the microlens array in the direction orthogonal to the first direction, and the mask is exposed to the optical axis of the exposure light by the second driving member. The exposure position of the mask pattern in the plane perpendicular to the optical axis is adjusted by rotating around or moving in the direction perpendicular to the optical axis. The exposure position can be adjusted according to the distortion. As described above, since the exposure misalignment is detected and eliminated in real time online, the dimensional accuracy of the exposure position in the overlay exposure can be improved efficiently.

It is a schematic diagram which shows the exposure apparatus which concerns on embodiment of this invention. It is a longitudinal cross-sectional view which shows the part of one micro lens array of the exposure apparatus which concerns on embodiment of this invention. It is a perspective view which shows the state in which this micro lens array is arranged in multiple numbers. It is a figure which shows a micro lens. It is a figure which shows the hexagonal field stop. It is a top view which shows arrangement | positioning of the hexagonal field stop of a micro lens. It is a perspective view which shows the arrangement | positioning relationship between a mask and a micro lens array. It is sectional drawing which shows the state by which the micro lens array is arrange | positioned at the holder. It is sectional drawing which shows the operation | movement which tilts a micro lens array with the piezoelectric element which is an actuator. (A), (b) is a figure which shows the relationship between the mask 3 of embodiment of this invention, and the pattern of the lower layer on a board | substrate. It is a figure which similarly shows the operation | movement. It is a figure which similarly shows the operation | movement. It is a figure which similarly shows the operation | movement. It is a figure which shows the operation | movement which tilts a micro lens array. It is a figure which shows the magnification correction by the inclination of a some micro lens array. It is sectional drawing which similarly shows the microlens array of a state without an optical axis deviation. It is sectional drawing which similarly shows the microlens array of the state which deflected the optical axis. It is a perspective view which similarly shows the microlens array of a state without an optical axis deviation. FIG. 5 is a perspective view showing a microlens array when the exposure position is similarly deviated by the optical axis deviation and the exposure area is enlarged. (A), (b) is a figure explaining the conventional problem.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings. FIG. 1 is a schematic view showing an exposure apparatus according to an embodiment of the present invention, FIG. 2 is a longitudinal sectional view showing a part of the same microlens array, and FIG. 3 is a diagram in which a plurality of microlens arrays are arranged. 4 is a diagram showing a microlens, FIG. 5 is a diagram showing its hexagonal field stop, FIG. 6 is a plan view showing the arrangement of the hexagonal field stop of the microlens, and FIG. 7 is the present invention. FIG. 8 and FIG. 9 are views showing a magnification correction method by tilting a microlens array.

  As shown in FIG. 1, the exposure light emitted from the exposure light source 4 is guided to the mask 3 through an optical system 21 including a plane mirror, and the exposure light transmitted through the mask 3 is applied to the microlens array 2. Then, the pattern formed on the mask 3 is imaged on the substrate 1 by the microlens array 2. A dichroic mirror 22 is disposed on the optical path of the optical system 21, and observation light from the camera 23 is reflected by the dichroic mirror 22 and travels coaxially with the exposure light from the exposure light source 4 toward the mask 3. The observation light converges on the substrate 1 by the microlens array 2 and reflects the reference pattern already formed on the substrate 1, and the reflected light of the reference pattern is reflected by the microlens array 2, the mask 3 and the dichroic. The light enters the camera 23 via the mirror 22. The camera 23 detects the reflected light of the reference pattern and outputs this detection signal to the image processing unit 24. The image processing unit 24 performs image processing on the reference pattern detection signal to obtain a reference pattern detection image. The image signal of the reference pattern obtained by the image processing unit 24 is input to the control unit 25, and the control unit 25 calculates a deviation between the mask position and the reference pattern based on the detected reference pattern, The tilt angle of the microlens array 2 and the rotation angle or movement amount of the mask 3 for eliminating this shift amount are calculated. Then, the control unit 25 outputs a signal corresponding to the inclination angle of the microlens array 2 to the actuator 20 (first driving member of the microlens array) including the piezoelectric elements 14 and 15 that drive the inclination of the microlens array 2. ) And the actuator 20 (piezoelectric elements 14 and 15) drives the microlens array 2 to tilt based on this signal. Further, the control unit 25 outputs a signal corresponding to a rotation angle for rotating the mask 3 around the optical axis or a movement amount in a direction perpendicular to the optical axis to a second driving member (not shown) of the mask. A moving device (not shown) integrates the substrate 1 and the mask 3, and the microlens array 2, the exposure light source 4, and the optical system 21, and relatively moves them in the scan direction 5 (first direction). The exposure light that has been moved and transmitted through the mask pattern is scanned on the substrate 1.

  Next, the exposure mode by the microlens array will be described in more detail. As shown in FIG. 2, a microlens array 2 configured by two-dimensionally arranging microlenses 2 a is disposed above a substrate 1 to be exposed such as a glass substrate. A mask 3 is disposed on the mask 3 and an exposure light source 4 is disposed above the mask 3. The mask 3 is formed with a light shielding film made of a Cr film 3b on the lower surface of the transparent substrate 3a, and the exposure light passes through the holes formed in the Cr film 3b and is converged on the substrate by the microlens array 2. In the present embodiment, for example, the substrate 1 and the mask 3 are fixed, and the microlens array 2 and the exposure light source 4 are moved in the direction of the arrow 5 in synchronization, whereby the exposure light from the exposure light source 4 is masked. And the substrate 1 is scanned in the direction of arrow 5. The movement of the microlens array 2 and the exposure light source 4 is driven by a driving source of an appropriate moving device. The microlens array 2 and the exposure light source 4 may be fixed and the substrate 1 and the mask 3 may be moved.

  As shown in FIG. 3, the microlens array 2 is arranged on a support substrate 6 as a holder in, for example, four rows in a direction perpendicular to the scanning direction 5 in two rows. As viewed in the direction 5, three of the four microlens arrays 2 in the rear stage are respectively arranged between the four microlens arrays 2 in the front stage so that the two rows of microlens arrays 2 are staggered. Is arranged. Thereby, the entire region of the exposure region in the direction perpendicular to the scanning direction 5 on the substrate 1 is exposed by the two rows of microlens arrays 2.

  As shown in FIG. 4, each microlens 2a of each microlens array 2 has, for example, a four-lens eight-lens configuration, and four unit microlens arrays 2-1, 2-2, 2-3, 2- 4 has a laminated structure. Each unit microlens array 2-1 or the like is composed of two lenses. As a result, the exposure light once converges between the unit microlens array 2-2 and the unit microlens array 2-3, and further forms an image on the substrate below the unit microlens array 2-4. 5 is arranged between the unit microlens array 2-2 and the unit microlens array 2-3, and the unit microlens array 2-3 and the unit microlens array 2-4 are arranged. Between these, a circular aperture stop 10 is arranged.

  FIG. 6 is a diagram showing the arrangement of the microlenses 2a as the position of the hexagonal field stop 12 of the microlenses 2a in order to show the arrangement of the microlenses 2a in each microlens array 2. FIG. 6 shows a state in which the optical axis of the micro lens 2a described later is not shifted (shifted). As shown in FIG. 6, the microlenses 2a are arranged on a straight line in a direction perpendicular to the scanning direction 5, and the microlens rows adjacent to the scanning direction 5 are slightly in the lateral direction (perpendicular to the scanning direction). In the direction). The opening of the hexagonal field stop 12 is divided into a central rectangular portion 12a and triangular portions 12b and 12c on both sides when viewed in the scanning direction 5. In FIG. 6, a broken line is a line segment that connects each corner of the hexagon of the hexagonal field stop 12 in the scanning direction 5. In FIG. 6, regarding each microlens array extending in the direction perpendicular to the scanning direction 5, when viewing the three hexagonal field stops 12 in the scanning direction 5, a certain first hexagonal field stop 12 is displayed. The right triangular portion 12c of the second row overlaps with the triangular portion 12b on the left side of the hexagonal field stop 12 in the second row adjacent to the rear in the scanning direction, and the triangular portion 12b on the left side of the hexagonal field stop 12 in the first row has 3 These microlenses 2a are arranged so as to overlap the triangular portion 12c on the right side of the hexagonal field stop 12 in the row. In this manner, three rows of microlenses 2a are arranged as one set with respect to the scanning direction 5. In other words, the microlenses 2a in the fourth row are arranged at the same position as the microlenses 2a in the first row in the direction perpendicular to the scanning direction 5. At this time, in the three rows of hexagonal field stops 12, adding the area of the triangular portion 12 b and the area of the triangular portion 12 c of the two rows of hexagonal field stops 12 adjacent to each other in the scanning direction 5 overlaps the scanning direction 5. The linear density of the total area of the two triangular portions 12b and 12c is the same as the linear density of the area of the central rectangular portion 12a. The linear density is the opening area of the hexagonal field stop 12 per unit length in the direction perpendicular to the scanning direction 5. That is, the total area of the triangular portions 12b and 12c is an area of an assumed rectangular portion in which the base of the triangular portions 12b and 12c is the length and the height of the triangular portions 12b and 12c is the width. Since the assumed rectangular portion has the same length as the rectangular portion 12a, the linear density of the triangular portions 12b and 12c is compared with the opening area (linear density) per unit length in the direction perpendicular to the scanning direction 5. And the linear density of the rectangular portion 12a is the same. For this reason, when the substrate 1 is scanned by the three rows of microlenses 2a, it is exposed to a uniform amount of light in the entire area in the direction perpendicular to the scanning direction 5. Therefore, in each microlens array 2, microlenses 2 a of integer multiples of 3 are arranged in the scanning direction 5, so that the substrate is uniform over the entire scan area by one scan. You will receive a light exposure.

  In the microlens array 2 configured as described above, the exposure light and the microlens array 2 are moved relative to the substrate 1 while the exposure light is irradiated from the exposure light source 4, thereby exposing the exposure light. The substrate 1 is exposed to a uniform amount of light over the entire exposure target area of the substrate 1 by scanning the substrate. That is, the substrate 1 is not subjected to spot-like exposure according to the position of the microlens 2a, but the region between the microlenses 2a in one row is exposed by the microlenses 2a in the other row, and the substrate 1 is As in the case of receiving planar exposure, uniform exposure is performed over the entire area to be exposed. The pattern projected on the substrate 1 is not the shape of the hexagonal field stop 12 and the aperture stop 10 of the microlens 2a, but the mask pattern (exposure) formed in the hole of the Cr film (light-shielding film) 3b of the mask 3. Pattern). The stop provided at the reversal imaging position is not limited to a hexagonal field stop having a hexagonal opening, but may be a polygon.

  FIG. 7 shows a modification of the arrangement mode of the plurality of microlens arrays 2 shown in FIG. As shown in FIG. 7, the microlens array 2 is arranged on the support plate 6 in two rows of the microlens array 2 b and the microlens array 2 c so as to form a row in a direction perpendicular to the scanning direction 5. In addition, the microlens array 2b and the microlens array 2c are arranged so as to be shifted from each other in the scanning direction 5. As shown in FIGS. 8 and 9, the microlens array 2 is disposed in a hole 6 a provided in the support plate 6, and each hole 6 a has a size corresponding to the outer shape of each microlens array 2. have. The microlens array 2 is arranged so that adjacent microlens arrays 2 (the microlens array 2b and the microlens array 2c) are close to each other in the direction orthogonal to the scanning direction 5. The portion of the support plate 6 between the microlens arrays 2 adjacent to each other in the direction orthogonal to the scan direction 5 is extremely thin, and the end of the microlens array 2 in the direction orthogonal to the scan direction 5 is this end. The distance between the microlenses 2a and the edge is shorter than 1/2 of the arrangement pitch of the microlenses 2a. For this reason, as shown in FIG. 7, each microlens array 2 is connected between the microlenses 2 a of all the microlens arrays 2 in the direction orthogonal to the scan direction 5 even if it is continuous in the direction orthogonal to the scan direction 5. Can be made the same interval. That is, the pitch in the direction orthogonal to the scanning direction 5 of the microlenses 2 a is constant for all the microlens arrays 2. In the scanning direction 5, one microlens array 2 is arranged, and the pitch of the microlenses 2a in the microlens array 2 is constant.

  In addition, the microlens array 2 can also be arrange | positioned with respect to the support plate 6 so that it may mutually space apart in both the scanning direction 5 and the direction orthogonal to the scanning direction 5, as shown in FIG. In this case, when viewed in the scanning direction 5, the microlens array 2 can be provided so that the ends overlap each other, and therefore, the end of each microlens array 2 in the direction orthogonal to the scanning direction 5. It is not necessary to shorten the distance between the microlens 2a and the edge of the microlens 2a so that it is less than ½ of the pitch of the microlens 2a, and the width of the end of each microlens array 2 can be made sufficiently large. Further, the holes 6a of the support plate 6 do not need to have a short interval as shown in FIG. 7 in the direction orthogonal to the scanning direction 5, and can be made sufficiently wide. 7 and 3, the microlens arrays 2 are arranged in a staggered manner in the direction orthogonal to the scanning direction 5, but the microlens arrays 2 are close to each other as shown in FIG. In this case, the microlens array 2 can be arranged in a straight line in the scanning direction 5.

  In the embodiment shown in FIG. 7, each microlens array 2b has, for example, two sides facing in the scanning direction 5, one supported by two piezoelectric elements 14a and 14b, and the other by one piezoelectric element 15a. The microlens array 2c is supported by, for example, two sides facing the scanning direction 5, one supported by one piezoelectric element 14c and the other supported by two piezoelectric elements 15b and 15c. . In the embodiment shown in FIG. 3, each microlens array 2 has two sides facing each other in the direction perpendicular to the scanning direction 5. As in FIG. 7, one is composed of two piezoelectric elements and the other is one piezoelectric element. Supported by the element.

  As shown in FIGS. 8 and 9, holes 6a having a shape corresponding to the shape of the microlens array 2 are formed at the arrangement position of the microlens array 2 on the support plate 6 as described above. 2 is fitted in the hole 6a. In addition, the upper surface of the support plate 6 is notched around the hole 6a to form a step 6b. A piezoelectric element 14 (14a, 14a, 14b, 14c), 15 (15a, 15b, 15c) are arranged. The microlens array 2 is formed with a flange portion 9 extending in the horizontal direction at an upper portion thereof, and the flange portion 9 is positioned at a step 6b around the hole 6a of the support plate 6.

  The piezoelectric elements 14 and 15 have their base portions 141 and 151 fixed to the lower portion of the step 6 b of the support plate 6, and their tips 142 and 152 fixed to the lower surface of the flange portion 9 of the microlens array 2. Yes. The piezoelectric elements 14 and 15 are connected to the control device 25 by a lead wire 7, and the piezoelectric elements 14 and 15 are supplied with a drive voltage from the control device through the lead wire 7 as shown in FIG. To deform. That is, in FIG. 8, since the piezoelectric elements 14 and 15 are not deformed, the optical axis of the microlens array 2 is oriented in the vertical direction (perpendicular to the surface of the support plate 6), but in FIG. The left piezoelectric element 14 is deformed so that the tip 142 thereof faces upward, whereby the microlens array 2 is oriented in the direction in which the optical axis is inclined with respect to the vertical direction. In this way, the direction of the optical axis of the microlens array 2 can be adjusted by adjusting the voltage applied to the piezoelectric element. Therefore, if the reference pattern on the substrate is misaligned, the misalignment is detected during exposure. In addition, this positional shift can be eliminated by adjusting the inclination angle of one or a plurality of microlens arrays. Needless to say, the support points by the piezoelectric elements 14 and 15 are not limited to the above-described three points, and four or more points may be provided. In this case, it is necessary to regulate the deformation amounts of four or more piezoelectric elements.

  In the support mechanism of the microlens array 2 configured as described above, the deformation amount of the piezoelectric elements 14 and 15 can be controlled by controlling the voltage applied to the piezoelectric elements 14 and 15, and the support is made at three points. By adjusting the combination of deformation amounts of the piezoelectric elements 14 and 15 of the microlens array 2, the microlens array 2 can be tilted in an arbitrary direction.

  That is, the control unit 25 outputs a signal corresponding to the inclination angle of the microlens array 2 to the actuator 20 including the piezoelectric elements 14 and 15 that drive the inclination of the microlens array 2. 14 and 15) drive the microlens array by tilting based on this signal. That is, the actuator 20 (piezoelectric elements 14 and 15) adjusts the voltage applied to the piezoelectric elements 14 and 15 based on the inclination angle of the microlens array 2 so that the microlens array 2 has a predetermined inclination angle. To drive.

  In this case, in the case of the arrangement mode of the microlens array 2 shown in FIG. 3, the piezoelectric elements 14 and 15 are disposed on the two sides facing the direction perpendicular to the scanning direction 5 in the microlens array 2. By making the relative deformation amount between the piezoelectric element 15 and the piezoelectric element 15 different, the microlens array 2 can be tilted in the direction perpendicular to the scanning direction 5 as shown in FIG. In FIG. 15, the scanning direction is a direction perpendicular to the paper surface. On the other hand, in the case of the arrangement mode of the microlens array 2b shown in FIG. 7, the microlens array 2b is not driven by driving the piezoelectric element 15a, but by varying the amount of drive deformation between the piezoelectric element 14a and the piezoelectric element 14b. It can be tilted in a direction perpendicular to the scanning direction 5. Also in the case of the arrangement of the microlens array 2c shown in FIG. 7, the piezoelectric element 14c is not driven, and the microlens array 2c is made different by changing the amount of driving deformation between the piezoelectric element 15b and the piezoelectric element 15c. It can be tilted in a direction perpendicular to the scanning direction 5. Therefore, in any of the arrangement modes shown in FIGS. 3 and 7, as shown in FIG. 15, the microlens array can be tilted in the direction perpendicular to the scanning direction.

  FIG. 10 shows the relationship between the mask in the scan exposure apparatus according to the embodiment of the present invention and the exposure patterns 50a to 50p of the lower layer whose substrate has been deformed by exposure in the previous process. 10A shows the entire substrate 1, and FIG. 10B shows an enlarged view of the region indicated by the two-dot chain line in FIG. 10A. The mask 3 has a mask pattern 31 formed inside the frame 30. For example, the substrate 1 is divided into 16 parts, and an exposure pattern is formed in each region, whereby 16 liquid crystal display substrates can be collected. That is, the 16 exposure patterns 50a to 50p correspond to 16 liquid crystal display substrates to be manufactured. The scan exposure apparatus according to the present embodiment exposes the 16 divided areas of the substrate 1 with, for example, a mask 3 having a four-head configuration. Therefore, the four divided areas on the substrate 1 are 1 for each area. An exposure pattern corresponding to one region is formed on one mask 3 by exposure with one mask 3.

  Specifically, for example, the substrate 1 is divided into four by a line segment passing through the center, and four liquid crystal display substrates are collected from each divided region. Then, one mask head is arranged in each divided area, and the one mask head is sequentially moved to each of the four exposure pattern areas in each divided area. Expose the area. That is, one mask head is moved to the positions of the exposure patterns 50a, 50b, 50f, and 50e in FIG. 10A in this order, and the microlens array is scanned relative to the mask 3 at each position. The pattern of the mask 3 is transferred to the substrate, and this operation is sequentially repeated in four areas. Further, the exposure patterns 50c, 50d, 50h, and 50g are also sequentially exposed in this order by another second head mask (not shown). Further, the exposure patterns 50i, 50j, 50n, and 50m are sequentially exposed by a third head mask (not shown). Further, the exposure patterns 50k, 50l, 50p, and 50o are sequentially exposed by a fourth head mask (not shown). Thus, in the first step, the exposure patterns 50a, 50c, 40i, and 50k are simultaneously exposed by four heads in the first step, and in the second step, the exposure patterns 50b and 50d by the four heads. , 50j, and 50l are simultaneously exposed so that the respective heads are moved in conjunction with each other, and 16 areas are sequentially exposed in 4 steps using 4 heads. In each process, for example, the substrate 1 and the mask 3 are fixed, the microlens array 2 supported by the support substrate 6, and the light source 4 that irradiates the entire transmission region of the microlens array 2 with exposure light. , Moved in the scanning direction 5. At this time, as shown in FIG. 15, a plurality of microlens arrays 2 are arranged for one mask 3 (four in the illustrated example of FIG. 15).

  Thus, exposure patterns 50a to 50p are formed on the film on the substrate 1 by conventional exposure. As shown in FIG. 20A, the film on the substrate 1 is initially formed into, for example, a linear pattern extending horizontally in 16 divided regions on the substrate 1 (when obtaining 16 products). Is formed. And by exposing several layers, as shown in FIG.20 (b) and FIG.10 (a), the glass substrate 1 is distorted by a thermal stress, and the conventional exposure patterns 50a-50p expand at four corner parts. , It is deformed to shrink at the center. Then, as shown in FIG. 10B, for example, when the mask 3 is intended to be overlaid with the mask pattern in the region of the exposure pattern 50f on the substrate 1, for example, the support substrate with respect to the substrate 1 and the mask 3 is used. The microlens array 2 supported by 6 and the light source 4 that irradiates exposure light to the entire transmission region of the microlens array 2 are moved in the scanning direction 5. Alternatively, the substrate 1 and the mask 3 may be moved in the direction opposite to the scanning direction 5 with respect to the microlens array 2 and the light source 4. In either case, the exposure light transmitted through the mask 3 is converged on the film on the substrate 1 by the microlens array 2, the exposure light is scanned in the scanning direction 5, and the mask pattern is transferred to the film.

  At this time, the mask 3 has a pattern 31 to be exposed (in the illustrated example, a linear pattern extending in the horizontal direction) formed in the frame 30 thereof. The mask 3 can be rotated around the optical axis of the exposure light (perpendicular to the paper surface of FIG. 10) or moved in a direction perpendicular to the optical axis, depending on the degree of distortion of the previous layer. Thus, the rotation angle or movement amount of the mask 3 is set. Further, the rotation of the mask 3 around the optical axis of the exposure light may rotate the entire mask of four heads, or rotate each mask 3 out of the four heads individually, It can also be adjusted to an appropriate angle for each mask.

  As shown in FIG. 11, marks A are formed on the substrate 1 at two points separated in the longitudinal direction of the microlens array 2 (direction perpendicular to the scanning direction 5) at the exposure start point of the exposure pattern 50f. Yes. When the substrate 1 is distorted, the line connecting the two marks A departs from the direction of the line when the substrate is not distorted as shown in FIG. ing. Therefore, the control device (not shown) moves the mask 3 on the optical axis of the exposure light so that the reference pattern AA formed on the lower layer by the previous exposure and the exposure pattern 31 of the mask 3 are parallel to each other. Rotate around.

  Such adjustment of the mask position with respect to the lower layer is not limited to rotating the mask 3 around the optical axis of the exposure light, and the mask 3 is perpendicular to the optical axis in a plane perpendicular to the optical axis of the exposure light. It may be performed by moving (shifting) in the direction (XY direction).

  In addition to the reference line (the line connecting the marks AA), the substrate 1 has marks BB at a position in the middle of scanning by the microlens array 2 in the exposure region 50f as shown in FIG. As shown in FIG. 13, a mark CC is provided at the final position of scanning by the microlens array 2.

  FIG. 14 shows that the magnification in the direction perpendicular to the scanning direction 5 is adjusted by inclining the microlens array 2 with respect to the support substrate 6 (holder) as shown in FIGS. FIG. That is, as shown in FIG. 14A, in the exposure pattern 50a, the portion near the corner portion of the substrate has the conventional exposure pattern spread more widely in the direction perpendicular to the scanning direction 5, and is close to the center portion of the substrate. The portion has a smaller spread of this conventional exposure pattern. For this reason, when the exposure is performed on the exposure pattern of the lower layer near the center of the substrate, as shown in FIG. 14B, the inclination angle of the microlens array 2 is small, and FIG. 14C and FIG. As shown in FIG. 4D, when the exposure is performed on the exposure pattern of the lower layer near the substrate corner, the inclination angle of the microlens array 2 is increased toward the substrate corner. As a result, the magnification of the microlens array 2 in the direction perpendicular to the scanning direction 5 is adjusted, and a pattern corresponding to the distortion of the substrate 1 can be overlaid and exposed on the lower layer.

  Next, the operation of the scan exposure apparatus of the present embodiment configured as described above will be described. First, as shown in FIGS. 1 and 2, the exposure light transmitted through the holes of the mask 3 by moving the microlens array 2 and the light source 4 relative to the substrate 1 and the mask 3 in the scanning direction 5. Thus, the substrate 1 is scanned. The microlens array 2 basically transfers an erecting equal-magnification image of the exposure pattern formed on the mask 3 to a film on the substrate. By this one scan, for example, an exposure pattern 50f shown in FIG. 10A is formed on the film on the substrate. Other exposure patterns 50a and the like are similarly formed by a single scan of exposure light. That is, for example, in a state where the mask 3 and the substrate 1 are fixed, the microlens array 2 and the light source are moved from one end side of the mask 3 toward the other end side in the scanning direction 5. As a result, one layer is exposed.

  Then, after the exposure of the lower layer is completed in this way, the exposure pattern of the lower layer is distorted due to the thermal strain on the substrate as shown in FIG. If the pattern is overexposed, the pattern of the lower layer and the pattern of the upper layer do not match, and the target pattern cannot be formed on the film on the substrate. Therefore, in the present invention, as shown in FIG. 11, the camera 23 detects two marks A formed on the surface of the substrate 1, and obtains a line segment connecting the two marks A-A. This AA line is used as an index for recognizing the degree of substrate distortion. That is, in the present invention, the control device moves the mask 3 to the optical axis of the exposure light so that the AA line as the reference alignment pattern and the mask alignment pattern extending in the lateral direction of the mask 3 are parallel to each other. Rotate around. Thereby, even if the pattern of the lower layer is distorted due to the thermal distortion of the substrate, the direction of the mask pattern of the mask 3 can be aligned with the distortion.

  As described above, the microlens array 2 and the light source scan and move with respect to the mask 3 in a state where the rotation angle around the optical axis of the mask 3 is set based on the reference alignment pattern AA. The camera that has detected the reference alignment pattern AA at 11 also moves together with the microlens array 2, and this camera is formed on the substrate 1 at a position corresponding to the intermediate position of the mask 3 shown in FIG. When detecting -B, the control device uses the BB line as an index for recognizing the degree of substrate distortion, and the control device uses a BB line as a reference alignment pattern and a mask alignment pattern extending in the horizontal direction in the mask 3 The mask 3 is further rotated around the optical axis of the exposure light so that. That is, the rotation angle of the mask 3 set based on the reference alignment pattern AA is readjusted based on the reference alignment pattern BB. Of course, before exposure, the reference alignment patterns AA, BB, and CC may be confirmed in advance by an alignment camera, and based on this, the rotation of the mask and the movement of the microlens array may be linked.

  Then, when the microlens array 2 and the light source are further scanned and moved with respect to the mask 3, this time, the camera is a reference alignment pattern formed on the substrate 1 at a position corresponding to the position on the other end side of the mask 3. Two marks C are detected. Then, using the CC line as an index for recognizing the degree of substrate distortion, the control device causes the CC line as the reference alignment pattern and the mask alignment pattern extending in the lateral direction in the mask 3 to be parallel. The mask 3 is rotated around the optical axis of the exposure light. That is, the rotation angle of the mask 3 set based on the reference alignment pattern BB is readjusted based on the reference alignment pattern CC. The reference alignment patterns AA, BB, and CC are detected so as to move integrally with the microlens array 2 regardless of the camera 23 that observes the substrate coaxially with the light source 4. A line sensor may be provided ahead of the optical axis of the light in the scanning direction, and the reference alignment patterns AA, BB, and CC may be detected by the line sensor.

  In this way, during the scanning movement of the microlens array 2 and the light source, the line sensor provided in front of the camera 23 or the microlens array 2 in the scanning direction moves in the scanning direction in the exposure region by the microlens array 2. The reference alignment patterns AA, BB, and CC formed on the substrate 1 are pre-detected and sequentially detected at the front end or at a position preceding the microlens array 2, and based on the detection result. Thus, the rotation angle around the optical axis of the mask 3 is adjusted so that the reference alignment pattern on the substrate 1 and the mask alignment pattern extending in the lateral direction of the mask 3 are parallel to each other. As a result, even if the substrate 1 is thermally distorted, the pattern of the lower layer is distorted, and the degree of distortion of the substrate varies depending on the position of the substrate, the pattern of the upper layer can be accurately reproduced on the lower layer. Can be overexposed. In this way, when the lower layer pattern is deformed due to thermal distortion of the substrate, the upper layer pattern can be over-exposed at a position corresponding to the deformation in the scan direction 5. Exposure failure can be eliminated by substrate distortion.

  On the other hand, since the distortion of the exposure pattern due to the thermal distortion of the substrate also occurs in the direction perpendicular to the scanning direction 5 as shown in FIG. 20B, the microlens array 2 is formed as shown in FIG. The support substrate 6 is tilted in a plane perpendicular to the scanning direction 5 to eliminate pattern distortion in the direction perpendicular to the scanning direction 5. As shown in FIG. 14A, in the vicinity of the corner portion of the substrate 1, the pattern of the lower layer is located farther from the line segment that penetrates the center of the substrate in the scanning direction 5. The lens array 2 is inclined at a larger angle with respect to the support substrate 6, and the exposure pattern of the mask 3 is overlaid on the lower layer with high accuracy. On the other hand, at the position closer to the center of the substrate 1, the distance between the pattern of the lower layer and the line segment passing through the substrate center in the scanning direction 5 is smaller, so the tilt angle of the microlens array 2 is smaller. To do. Therefore, the tilt angle of the microlens array 2 is changed according to the position where the microlens array 2 is exposed, and the exposure of the upper layer is adjusted with high accuracy to the position of the exposure pattern of the lower layer where distortion occurs. Overlapping patterns. Thereby, when the lower layer pattern is deformed due to thermal distortion of the substrate, the exposure pattern of the upper layer can be superimposed and exposed at a position corresponding to the deformation in the direction perpendicular to the scanning direction 5. The upper layer can be exposed with precision according to the substrate distortion. In FIGS. 14B, 14C, and 14D, only one microlens array is shown for one exposure region for simplification of illustration. As shown in FIG. 15, a plurality of microlens arrays 2 work together to expose one exposure area.

  The upper layer is exposed while simultaneously controlling the adjustment of the exposure position of the upper layer with respect to the scan direction 5 (mask rotation) and the adjustment of the exposure position of the upper layer with respect to the direction perpendicular to the scan direction 5 (tilting of the microlens array). As a result, even if two-dimensional thermal distortion occurs in the substrate 1, it is possible to carry out repeated exposure with high accuracy.

  FIG. 15 shows the exposure light and the substrate 1 when a plurality of microlens arrays 2 arranged in a direction perpendicular to the scanning direction 5 are gradually increased in inclination angle with respect to the adjacent microlens array 2. It is a figure which shows the relationship. As shown in FIG. 15, as the inclination angle of the microlens array 2 increases, the incident angle of the exposure light with respect to the substrate 1 gradually decreases from 90 ° (becomes an acute angle). As a result, the distances b1, b2, b3 of the exposure regions between the adjacent microlens arrays 2 are gradually increased, and the inclination angle is the largest with respect to the pattern of the end portion (reference point) of the horizontally arranged microlens array 2. The pattern at the position farthest from the reference point of the large microlens array 2 is farther from the reference point than the exposure position when all the microlens arrays 2 are horizontal. In this way, the exposure position on the substrate can be adjusted and the exposure area on the substrate can be enlarged simply by gradually increasing the inclination angle of the microlens array 2 arranged in a row. Conversely, when the exposure area is reduced, the microlens array 2 may be inclined in the reverse direction.

  In the above embodiment, as shown in FIG. 15, by adjusting the microlens array, by adjusting the magnification or adjusting the exposure position in the microlens array that can originally only expose an erecting equal-magnification image. However, the present invention is not limited to this, and as shown in FIGS. 16 to 19 (another embodiment), adjustment of the magnification of the microlens array and exposure can also be performed by biasing the optical axis of the microlens. The position can be adjusted.

  Next, another embodiment of the present invention will be described. In this embodiment, the magnification in the direction perpendicular to the scanning direction 5 is not adjusted by tilting the microlens array, but the magnification in the direction perpendicular to the scanning direction 5 is adjusted by deviation of the optical axis of the microlens. is there. FIG. 16 is a schematic diagram showing a stacked state of the unit microlens arrays 2-1, 2-2, 2-3 and 2-4. The configuration of each microlens 2a such as the four unit microlens arrays 2-1 is composed of two convex lenses for each unit microlens array 2-1. In the normal state, as shown in FIG. 16, the optical axes of the microlenses 2a of the unit microlens arrays 2-1, 2-2, 2-3, 2-4 are all coincident. Therefore, the exposure light is perpendicularly incident on the substrate as shown in FIG.

  Thus, in the present embodiment, as shown in FIG. 17, the optical axes of the microlenses 2a of the unit microlens array 2-1 in the first layer and the unit microlens array 2-2 in the second layer are The optical axes of the microlenses 2a of the unit microlens array 2-3 in the third layer and the unit microlens array 2-4 in the fourth layer can be shifted (shifted) by the size of d. It has become. This deviation d is, for example, 0.3 μm. As described above, as the optical axes of the microlenses of the unit microlens arrays 2-3 and 2-4 are deviated, the exposure light is converted into the unit microlens array 2-2 and the unit microlens array 2 as shown in FIG. -3, the exposure light is incident on the substrate at a position slightly deviated from that in FIG. The optical axis of the exposure light emitted from the lowermost fourth unit microlens array 2-4 is about twice the amount d of the optical axis of the microlens of the third unit microlens array 2-3. The amount of deviation of the exposure light on the substrate is about 2d. That is, when the optical axis of the microlens is deviated by the deviation amount d, the projection pattern is deviated by about 2d on the substrate. When d = 0.3 μm described above, the projection pattern on the substrate is only 0.6 μm. Be biased.

  In this way, the exposure position on the substrate by the microlens array can be adjusted by shifting the optical axis of the microlens 2a such as the unit microlens array 2-1.

  The deviation of the optical axis of the microlens may be achieved by moving some unit microlens arrays in a direction perpendicular to the optical axis with respect to other unit microlens arrays. The unit microlens array may be moved by, for example, applying a voltage to the piezoelectric element so as to push the unit microlens array in a direction perpendicular to the optical axis by an amount of distortion of the piezoelectric element due to the voltage change. . In this case, the piezoelectric element serves as the driving member, but the driving member is not limited to the piezoelectric element, and various devices or members can be used.

  Note that when the magnification is reduced, the exposure position can be similarly adjusted. In the above embodiment, between the first and second layer unit microlens arrays 2-1 and 2-2 and the third and fourth layer unit microlens arrays 2-3 and 2-4, The exposure position was adjusted by deviating the optical axis of the microlens 2a. This is to shift the optical axis of the microlens of the unit microlens array at the inverted imaging position of the microlens array. For this reason, the number of unit microlens arrays in the microlens array 2 is not limited to four as in the above embodiment, but in this case as well, the deviation of the optical axis of the microlens of the unit microlens array is not limited. Needs to be performed at the reverse imaging position of the microlens array.

  Also in this embodiment, even if the substrate dimension fluctuates in the overlay exposure, this can be detected in real time and the exposure position can be adjusted to the exposure pattern in the lower layer with high accuracy. That is, in the present embodiment, in the exposure apparatus, the positional deviation between the lower layer pattern and the exposure pattern during the exposure is corrected by adjusting the position of the optical axis of the microlens by moving the unit microlens array in the microlens array. It is possible to correct misalignment in real time and perform highly accurate overlay exposure.

  In addition, in this embodiment, the exposure position on the substrate is adjusted by shifting the optical axis of the micro lens 2a, and hence the magnification of the exposure pattern is adjusted. Does not vary for microlens arrays. That is, the surface to be exposed on the substrate can be positioned within the range of the focal depth of all the microlenses. Normally, the focal depth of the microlens array is 50 μm, but there is an advantage that the exposure surface on the substrate can be positioned within this focal depth.

1: Substrate 2: Microlens array 2a: Microlens 2-1 to 2-4: Unit microlens array 3: Mask 3a: Transparent substrate 3b: Cr film 4: Exposure light source 5: Scanning direction 6: Support substrate 10: Lens Field region 12: Hexagon field stop 12a: Rectangular portion 12b, 12c: Triangular portion 14 (14a, 14b, 14c), 15 (15a, 15b, 15c): Piezoelectric element 20: Actuator 21: Optical system 22: Dichroic mirror 23 : Line CCD camera 24: Image processing unit 25: Control units 50 a to 50 p: Exposure pattern

Claims (6)

A microlens array disposed above the substrate to be exposed and having a plurality of microlenses arranged two-dimensionally;
A holder for holding the microlens array at its periphery,
A mask disposed above the microlens array and having a predetermined exposure pattern formed thereon;
An exposure light source for irradiating the mask with exposure light;
A moving device that relatively moves the microlens array, the substrate, and the mask in a first direction;
A first drive member that tilts the microlens array in a plane orthogonal to the first direction with respect to the holder;
A second driving member that rotates the mask around the optical axis of the exposure light or moves the mask in a direction perpendicular to the optical axis;
A control device that controls tilting of the microlens array by the first driving member and rotation or movement of the mask by the second driving member according to a position of relative movement of the microlens array by the moving device. When,
A scanning exposure apparatus using a microlens array characterized by comprising: The microlens array is formed by laminating a plurality of unit microlens arrays in which a plurality of microlenses are two-dimensionally arranged,
A polygonal field stop having a polygonal aperture is disposed at the reverse imaging position between the unit microlens arrays,
An aperture stop having a circular opening is disposed at least at a part of the maximum enlarged portion of the exposure light between the unit microlens arrays,
The polygonal field stop and the aperture stop are arranged between the unit microlens arrays in a row along a virtual line in a direction inclined in the first direction or in a direction perpendicular to the first direction. A scan exposure apparatus using the microlens array according to Item 1. An alignment pattern detection unit for detecting a reference alignment pattern on the substrate;
The second driving member rotates the mask around the optical axis of the exposure light so that a mask alignment pattern provided on the mask matches the reference alignment pattern, or a direction perpendicular to the optical axis. The scanning exposure apparatus using the microlens array according to claim 1 or 2, wherein The reference alignment pattern is a linear pattern extending in a direction perpendicular to the first direction, which is a relative scanning direction of the microlens array, the substrate, and the mask;
The mask alignment pattern is also a linear pattern extending in a direction perpendicular to the first direction,
The second driving member rotates the mask around the optical axis of the exposure light so that the reference alignment pattern and the mask alignment pattern are parallel, or moves in a direction perpendicular to the optical axis. A scan exposure apparatus using the microlens array according to claim 3. A plurality of the microlens arrays are arranged in a direction perpendicular to the first direction, and the first driving member tilts the plurality of microlens arrays at different angles with a correlation with each other. A scan exposure apparatus using the microlens array according to any one of claims 1 to 4. A microlens array disposed above the substrate to be exposed and having a plurality of microlenses arranged two-dimensionally;
A holder for holding the microlens array at its periphery,
A mask disposed above the microlens array and having a predetermined exposure pattern formed thereon;
An exposure light source for irradiating the mask with exposure light;
A moving device that relatively moves the microlens array, the substrate, and the mask in a first direction;
Have
The microlens array is formed by laminating a plurality of unit microlens arrays in which a plurality of microlenses are two-dimensionally arranged,
A polygonal field stop having a polygonal aperture is disposed at the reverse imaging position between the unit microlens arrays,
An aperture stop having a circular opening is disposed at least at a part of the maximum enlarged portion of the exposure light between the unit microlens arrays,
The polygonal field stop and the aperture stop are arranged between the unit microlens arrays in a row on a line in a direction inclined in the first direction or in a direction perpendicular to the first direction,
Furthermore,
A second driving member that rotates the mask around the optical axis of the exposure light or moves the mask in a direction perpendicular to the optical axis;
The exposure position on the substrate by the microlens array is adjusted by moving at least a part of the unit microlens array with respect to the other unit microlens array so that the optical axis of the constituent microlens is deviated. A drive member;
Control for controlling the rotation or movement of the mask by the second driving member and the deviation of the optical axis of the microlens by the third driving member according to the relative movement position of the microlens array by the moving device. Equipment,
A scanning exposure apparatus using a microlens array characterized by comprising:

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