JP4488685B2 - Exposure equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an exposure apparatus that exposes a mask pattern onto a substrate such as a color filter.
[0002]
[Prior art]
As an exposure apparatus that exposes a substrate, a so-called proximity type exposure apparatus is known. In this exposure apparatus, after the stage on which the substrate is placed enters under the photomask, the stage is raised to bring the substrate and the photomask close to each other, and the substrate and the photomask are opposed to each other through the proximity gap. . Then, the substrate is exposed by irradiating the photomask with a light beam.
[0003]
[Problems to be solved by the invention]
However, the proximity gap is relatively small, and various inconveniences occur when there is an abnormality in the height of the substrate surface. For example, if a foreign substance adheres to the substrate and a projection occurs on the substrate surface, or the substrate surface rises due to uneven thickness of the substrate itself, etc. When they are close to each other, the stage and the photomask locally bite high portions, and the photomask may be damaged.
[0004]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an exposure apparatus that can prevent contact between a substrate and a photomask in a proximity type exposure apparatus.
[0005]
[Means for Solving the Problems]
The present invention will be described below. In order to facilitate understanding of the present invention, reference numerals in the accompanying drawings are appended in parentheses, but the present invention is not limited to the illustrated embodiment.
[0006]
An exposure apparatus (1) according to the present invention is an exposure apparatus that performs exposure with a substrate (100) and a photomask (4) on a stage (2) facing each other through a proximity gap. Drive means (3) for driving between the placement position on which the substrate is placed and the exposure position at which the substrate is exposed, and the progress of the substrate in the movement path of the substrate from the placement position to the exposure position Extending across the entire width of the substrate in a direction crossing the direction, and so that the interval between the photomask and the stage is smaller than the interval between the photomask and the stage when the substrate is exposed. A gate (7) arranged, a specifying means (8... 8) for specifying the height of the surface of the substrate on the upstream side in the traveling direction of the substrate from the gate, and the substrate specified by the specifying means. Execution means (9) for executing a predetermined process for preventing contact between the substrate and the photomask based on the height of the surface, and the specifying means includes a height of the surface of the substrate. A plurality of measuring devices (8..., 8) measuring each of the plurality of measuring devices, each measuring point crossing the traveling direction of the substrate in the movement path of the substrate from the placement position to the exposure position. The plurality of measuring devices and the gate are arranged so as to be arranged over the entire width of the substrate with a gap in the direction in which the plurality of measuring devices are arranged, and the gate extends The problems described above are solved by being positioned so that the directions are parallel to each other .
[0007]
According to the exposure apparatus of the present invention, since the distance between the stage and the gate is smaller than the distance between the stage and the photomask at the time of exposure, a locally high portion of the substrate surface led to the gate becomes a photomask at the time of exposure. If the size is in contact, the locally high portion contacts the gate. Therefore, the substrate cannot pass through the gate as it is, and the substrate passes through the gate after a locally high portion is removed by the gate, or the substrate is damaged. In any case, the substrate is not guided under the photomask while the locally high portion remains. Accordingly, contact between the substrate and the photomask is prevented, and the photomask is protected.
[0008]
In addition, when a locally high portion that may come into contact with the photomask is present on the substrate surface, the locally high portion is detected by the specifying unit, and the execution unit prevents contact between the substrate and the photomask. Furthermore, even if there is a locally high portion in a region other than the measurement point of the specifying means, the locally high portion is removed by the gate or the substrate is destroyed by the gate, so that the photomask is reliably protected. . Note that the height from the appropriate reference position to the substrate surface can be used as the height of the substrate surface. The reference position may be a position where the relative position with respect to the photomask can be specified. The position of the photomask may be used as the reference position, and the position of the gate or stage may be used as the reference position if the relative position between the photomask and the gate or stage is specified. For example, when the stage position is used as the reference position, specifying the thickness of the substrate is nothing but specifying the height of the substrate surface, so the specifying means specifies the thickness of the substrate. Something to do is also included.
[0009]
Furthermore, since the height of the substrate surface is specified over the entire width of the substrate by the plurality of measuring devices, an abnormality in the height of the substrate surface is accurately detected. Further, since the height of the substrate surface is measured while the substrate is moved to the exposure position, the production efficiency of the exposure apparatus is not lowered.
[0010]
In the exposure apparatus of the present invention, as the predetermined processing, the execution unit is further upstream in the traveling direction of the substrate than the gate when the height of the surface of the substrate specified by the specifying unit exceeds an allowable value. On the side, a process for removing the substrate from the movement path of the substrate may be executed. In this case, if there is a possibility that the locally high portion of the substrate is in contact with the photomask, the execution means removes the substrate from the movement path, and thus the photomask is protected. Further, even if a locally high portion exists in a region other than the measurement point, the locally high portion is removed by the gate or the substrate is destroyed by the gate, so that the photomask is reliably protected. In addition, as a process for removing the substrate from the movement path, for example, a process of stopping the operation of the driving unit may be executed. Further, the allowable value may be set as appropriate. For example, when the substrate is passed through the gate, the substrate surface may not be in contact with the gate, or may be a value that allows for a predetermined margin.
[0011]
In the exposure apparatus of the present invention, the exposure apparatus includes a proximity / separation unit (6) for relatively moving the stage and the photomask so as to approach or separate from each other, and the execution unit specifies the specification unit as the predetermined process. Based on the height of the surface of the substrate, the driving means and the drive means to move the substrate to the exposure position while maintaining an interval between the stage and the photomask within an appropriate range of the proximity gap You may perform the process which controls operation | movement of the said proximity separation means. In this case, since the substrate is moved to the exposure position while maintaining the proximity gap, the exposure apparatus is produced in comparison with the conventional exposure apparatus in which the substrate and the photomask are brought close to each other after the substrate is moved to the exposure position. Efficiency is improved. Also, since the distance between the substrate and the photomask is controlled based on the height of the substrate surface specified by the specifying means, even if the substrate and the photomask are relatively moved at a relatively narrow distance called a proximity gap, There is no risk of contact with the photomask. Further, even if a locally high portion exists in a region other than the measurement point, the locally high portion is removed by the gate or the substrate is destroyed by the gate, so that the photomask is reliably protected. The appropriate range of the proximity gap may be set as appropriate according to various circumstances when performing exposure. For example, the amount of allowance for the amount of deflection of the photomask may be set as the appropriate range of the proximity gap.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1A and 1B are a side view and a plan view, respectively, showing an exposure apparatus 1 of the present invention. The exposure apparatus 1 is configured as an apparatus that performs proximity-type exposure on the color filter substrate 100.
[0015]
The substrate 100 is made of, for example, a glass substrate, and a photosensitive resin or a resist in which a pigment is dispersed is formed in a thin film on the surface of the glass substrate. The substrate 100 is formed with a thickness of 1 mm and an area of 4 m ² , for example. A plurality of color filters are taken out from one substrate 100. For this reason, the exposure apparatus 1 sequentially exposes the plurality of exposure regions 100a... 100a on the substrate 100.
[0016]
The exposure apparatus 1 includes a stage 2 on which the substrate 100 is placed, a driving device 3 that drives the stage 2 in the horizontal direction, a photomask 4 disposed above the stage 2, and a mask holder 5 that holds the photomask 4. A driving device 6 for driving the mask holder 5 in the vertical direction, a gate 7 disposed above the stage 2, measuring devices 8... 8 for measuring the height of the surface of the substrate 100, and a control device 9. I have. In addition, the exposure apparatus 1 further includes various apparatuses such as an illumination apparatus that irradiates a light beam from above the photomask 4 toward the substrate 100 and a laser length measuring instrument that measures the horizontal position of the stage 2. However, since it is not the gist of the present invention, explanation is omitted.
[0017]
The stage 2 is driven by the driving device 3 between a placement position indicated by a two-dot chain line in FIG. 1B and an exposure position where the photomask 4 is positioned on the exposure region 100a. At the mounting position, the substrate 100 on which a thin film is formed by a coater (not shown) is mounted on the stage 2. The drive device 3 is configured as an electric motor, for example.
[0018]
The mask holder 5 is formed in a frame shape and holds the outer peripheral side of the photomask 4 by suction. The driving device 6 holds the mask holder 5 at three points by holders 6a... 6a. The driving device 6 can independently drive the holders 6a... 6a up and down, and can adjust the vertical position and inclination of the mask holder 5. The drive device 6 is configured as an electric motor, for example. The control device 10 is configured as a computer including, for example, a CPU, a ROM, a RAM, and an external storage device, and controls operations of the drive device 3, the drive device 6 and the like according to a program recorded in the external storage device.
[0019]
The gate 7 is formed as a long member extending over the entire width B <b> 1 of the substrate 100, and is provided adjacent to the photomask 4. As shown in FIG. 2, the lower end 7a of the gate 7 has a distance s1 between the surface of the stage 2 and the distance s2 between the photomask 4 and the stage 2 during exposure over the entire width B1 of the substrate 100. It is set to be. For example, when the proximity gap P when the substrate 100 having a certain thickness is placed on the stage 2 is 100 μm, the distance s3 between the substrate 100 and the lower end portion 7a is set to 80 μm. The gate 7 is made of, for example, a metal having high hardness.
[0020]
The measuring devices 8... 8 are arranged over the entire width B 1 of the substrate 100. The measuring devices 8... 8 are arranged so that the distance between the measuring points p1 of each measuring device 8 is 10 cm, for example. For example, as shown in FIG. 3, the measurement device 8 is configured as a measurement device that uses a laser confocal method. The measuring device 8 includes a laser light source 71, a confocal optical system 80, and a light receiving element 78. The confocal optical system 80 includes, for example, a collimating lens 72, a beam splitter 73, an objective lens 74, an imaging lens 75, and a light blocking member 77 provided with a pinhole 76. The light beam of the laser light source 71 reaches the substrate 100 through the collimator lens 72, the beam splitter 73, and the objective lens 74, and the light reflected by the substrate 100 passes through the beam splitter 73, the imaging lens 75, and the pinhole 76. And reaches the light receiving element 78. When the focal point of the objective lens 74 coincides with the surface of the substrate 100, the light reflected from the substrate 100 is condensed at the position of the pinhole 76 by the imaging lens 75 and received by the light receiving element 78. On the other hand, when the focus of the objective lens 74 is deviated from the surface of the substrate 100, the light reflected from the substrate 100 is not condensed at the position of the pinhole 76, and a part of the light is blocked by the light shielding member 77. Accordingly, the height of the substrate 100 is detected based on the position where the light amount detected by the light receiving element 78 becomes maximum when the objective lens 74 is vibrated up and down.
[0021]
The operation of the exposure apparatus 1 having the above configuration will be described.
[0022]
FIG. 4 is a flowchart showing a procedure of gap monitoring processing executed by the control device 9. As shown in FIG. 5A, this process is started when the stage 2 on which the substrate 100 is placed moves to a position immediately before the measuring devices 8... 8, and the stage 2 is moved under the photomask 4. During execution, it is repeatedly executed at a predetermined cycle (for example, 0.1 second).
[0023]
In step S1, the control device 9 measures the height of the surface of the substrate 100 based on signals from the measuring devices 8. Next, it is determined whether or not the maximum height among the substrate heights measured at the plurality of measurement points by the measuring devices 8 ... 8 exceeds a predetermined allowable value (step S2). The allowable value is, for example, a value that allows for a margin in the height at which the surface of the substrate 100 contacts the lower end portion 7a. If it is determined that the allowable value is not exceeded, the gap amount between the photomask 4 and the substrate 100 is maintained in the proximity gap based on the substrate height measured by the measuring devices 8. Then, the operation of the driving device 7 is controlled to move the photomask 5 up and down (step S3). For example, the feedforward control is executed in consideration of the measured substrate height, the distance between the measuring devices 8... 8 and the photomask 4, and the amount of movement of the stage 2. As a result, as shown in FIG. 5B, even if the surface of the substrate 100 has a relatively small convex portion 100b, the gap amount between the photomask 4 and the substrate 100 becomes a proximity gap. Kept. If it is determined that the allowable value is exceeded, an instruction signal is output to the driving device 3 so as to stop the movement of the stage 2 (step S3). Accordingly, as shown in FIG. 5C, when there is a risk of contact between the convex portion (foreign matter) 100c of the substrate 100 and the photomask 4, the intrusion of the convex portion 100c under the photomask 4 is avoided. The When the stage 2 is stopped, the substrate 100 is removed from the stage 2 by, for example, an operator's manual work. Note that steps S2 and S4 may be omitted and only the operation for maintaining the proximity gap may be performed, or step S3 may be omitted and only the operation for stopping stage 2 may be performed.
[0024]
Since there are gaps between the measurement points p1... P1 of the measuring devices 8... 8, the protrusions 100 c of the substrate 100 pass through the gaps, and the protrusions 100 c that may come into contact with the photomask 4 are detected. May not be. However, as is apparent from FIG. 5C, the convex portion 100c contacts the gate 7 before entering under the photomask 4, and the convex portion 100c is scraped off by the lower end portion 7a or the substrate 100 is cracked. By detecting the abnormality, the photomask 4 is prevented from being damaged.
[0025]
The present invention is not limited to the above embodiment, and may be implemented in various forms as long as it is substantially the same as the technical idea of the present invention.
[0026]
The material of the gate 7 may be appropriately selected. For example, it may be selected from the viewpoint of reducing the deflection due to the dead weight of the gate 7 and reducing the variation in the distance s1 in the entire width B1 of the substrate 100, or selecting from the viewpoint of giving the substrate 100 sufficient strength to break. Also good. Similarly, the cross-sectional shape of the gate 7 may be set as appropriate. For example, it may be formed thick in the height direction from the viewpoint of reducing the deflection due to its own weight, or an acute angle may be given to the portion in contact with the substrate 100 so that the convex portion of the substrate 100 can be easily scraped off.
[0027]
The position of the gate 7 may be provided at any position on the movement path of the substrate 100 from the placement position to the exposure position. For example, the distance between the photomask 4 and the gate 7 may be increased so that the substrate 100 starts to enter under the photomask after the entire substrate 100 passes through the gate 7. The movement path from the mounting position to the exposure position may not be a straight line, and the direction in which the substrate 100 passes through the gate 7 and the direction in which the substrate 100 enters under the photomask 4 may not be the same.
[0028]
The measuring devices 8... 8 may be provided at any position from a coater that forms a thin film on the substrate 100 to a position where the substrate 100 enters under the photomask. Before the substrate 100 is placed on the stage 2, the thickness of the substrate 100 may be measured. For example, the thickness of the substrate 100 may be measured by providing a pair of opposing displacement sensors and passing the substrate 100 between the displacement sensors.
[0029]
The operation of maintaining the proximity gap between the substrate 100 and the photomask 4 in the proximity gap may be performed by moving the stage 2 up and down. In this case, for example, when the gate 7 is provided adjacent to the photomask 4, the distance s1 between the gate 7 and the stage 2 varies due to the vertical movement of the stage 2 for maintaining the proximity gap. Therefore, the substrate 100 passes through the gate 7 even when the convex portion on the surface of the substrate 100 is large as compared with the case where the distance s1 is fixed as in the embodiment, and the substrate 100, the photomask 4 and The gap amount is maintained at the proximity gap, and the substrate 100 is exposed. The convex portion contacts the gate 7 only when the convex portion passes through the gap between the measurement points and there is a possibility that the gap between the substrate 100 and the photomask 4 cannot be maintained in the proximity gap.
[0030]
A gate 7 and a measuring device 8... 8 are placed in an exposure apparatus that allows the substrate 100 to enter under the photomask 4 with the gap between the photomask 4 and the substrate 100 relatively large, and then brings the substrate 100 close to the photomask 4. May be provided.
[0031]
【The invention's effect】
As described above, according to the present invention, since the distance between the stage and the gate is smaller than the distance between the stage and the photomask at the time of exposure, a locally high portion of the substrate surface led to the gate is exposed. If it is sometimes sized to contact the photomask, its locally high portion contacts the gate. Therefore, the substrate cannot pass through the gate as it is, and the substrate passes through the gate after a locally high portion is removed by the gate, or the substrate is damaged. In any case, the substrate is not guided under the photomask while the locally high portion remains. Accordingly, contact between the substrate and the photomask is prevented, and the photomask is protected.
[Brief description of the drawings]
FIG. 1 is a side view and a plan view showing the configuration of an exposure apparatus of the present invention.
FIG. 2 is a view of the exposure apparatus of FIG. 1 as viewed from the direction of travel of the substrate.
FIG. 3 is a view showing the arrangement of a measurement apparatus of the exposure apparatus shown in FIG.
4 is a flowchart showing a procedure of gap monitoring processing executed by the control device of the exposure apparatus shown in FIG.
FIG. 5 is a view showing a state of the exposure apparatus when the gap monitoring process of FIG. 4 is executed.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Exposure apparatus 2 Stage 3 Drive apparatus 4 Photomask 6 Drive apparatus 7 Gate 8 Measuring apparatus 9 Control apparatus 100 Substrate

Claims (3)

In an exposure apparatus that performs exposure with a substrate on a stage and a photomask facing each other through a proximity gap,
Driving means for driving the stage between a placement position where the substrate is placed and an exposure position where the substrate is exposed;
In the movement path of the substrate from the mounting position to the exposure position, the substrate extends so as to extend over the entire width of the substrate in a direction crossing the traveling direction of the substrate, and the substrate is exposed to light. A gate disposed so that a distance between the stage and a photomask and the stage is narrower than a distance between the stage,
Specifying means for specifying the height of the surface of the substrate on the upstream side of the gate in the traveling direction of the substrate;
Execution means for executing a predetermined process for preventing contact between the substrate and the photomask based on the height of the surface of the substrate specified by the specifying means;
The specifying means includes a plurality of measuring devices that measure the height of the surface of the substrate,
The plurality of measuring devices spans the entire width of the substrate in a state where each measurement point has a gap with respect to a direction crossing the traveling direction of the substrate in the movement path of the substrate from the mounting position to the exposure position. Arranged to be arranged,
The exposure apparatus , wherein the plurality of measurement devices and the gate are positioned such that a direction in which the plurality of measurement devices are arranged and a direction in which the gate extends are parallel to each other .   The execution means, as the predetermined processing, when the height of the surface of the substrate specified by the specifying means exceeds an allowable value, the substrate is moved upstream of the gate in the traveling direction of the substrate. The exposure apparatus according to claim 1, wherein a process for removing the substrate from the movement path is executed. Proximity separation means for moving the stage and the photomask relative to each other so as to approach or separate from each other,
The execution means, as the predetermined processing, based on the height of the surface of the substrate specified by the specification means, while maintaining the interval between the stage and the photomask within an appropriate range of the proximity gap, The exposure apparatus according to claim 1, wherein a process for controlling operations of the driving unit and the approaching / separating unit is performed so as to move the substrate to the exposure position.

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