Exposure device and exposure method

By using inclined reflective surfaces and an optical displacement meter that projects laser light from a perpendicular direction, the exposure device addresses the issue of increased work distance in laser interferometers, achieving accurate and cost-effective stage displacement measurement.

JP2025044041APending Publication Date: 2025-04-01SCREEN HOLDINGS CO LTD
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Patent Information

Application Number
JP2023151720
Authority / Receiving Office
JP · JP
Patent Type
Applications
Current Assignee / Owner
Filing Date
2023-09-19
Publication Date
2025-04-01

AI Technical Summary

Technical Problem

Existing exposure devices face challenges in maintaining measurement accuracy due to increased work distance (WD) of laser interferometers, which makes them susceptible to air fluctuations and temperature changes, and also results in higher equipment costs.

Method used

The exposure device incorporates one or more reflective surfaces that are inclined and movable with the stage, and an optical displacement meter that projects laser light from a position distant from the reflective surface in a direction intersecting the main scanning direction, allowing for accurate detection of stage displacement with reduced WD.

Benefits of technology

This configuration reduces the work distance of the laser beam, enhancing measurement accuracy and reducing costs by minimizing the impact of environmental fluctuations and the need for high-power lasers or complex optical systems.

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Abstract

To provide a technique capable of reducing WD of a laser displacement meter for detecting a displacement amount of a stage.SOLUTION: An exposure device includes a stage 2, a stage moving mechanism 3, an exposure head 51, a first reflection surface 710, and a first displacement meter 61. The stage 2 has an upper surface 2S for supporting a substrate W. The stage moving mechanism 3 moves the stage 2 in a Y direction. The exposure head 51 can emit light toward the substrate W supported on the upper surface 2S of the stage 2. The first reflection surface 710 is movable together with the stage 2, and is inclined in a +Z direction toward a -Y direction. The first displacement meter 61 can detect a displacement amount in the Y direction of the first reflection surface 710. The first displacement meter 61 has a laser light source 611 which can project a laser beam to the first reflection surface 710 from a position separated in the +Z direction, and a detector 614 capable of detecting reflection light of the laser beam reflected on the first reflection surface 710.SELECTED DRAWING: Figure 1
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Description

[Technical field]

[0001] The subject matter disclosed herein relates to an exposure apparatus and method. [Background technology]

[0002] For example, exposure apparatuses that perform direct writing by light irradiation are known as a method for forming a pattern on a substrate such as a semiconductor wafer or a glass substrate. In this type of exposure apparatus, a substrate on which a photosensitive layer such as a resist is formed is held on a stage, and the stage is moved in the main scanning direction. Then, a pattern light is emitted from an exposure head according to the position of the stage in the main scanning direction, and a predetermined pattern is written on the photosensitive layer.

[0003] In such an exposure apparatus, when the stage is moved, the stage may be displaced in an unexpected direction, for example, by meandering. When such a displacement occurs, the pattern may not be formed as specified, and distortion of the pattern may occur. Therefore, techniques for correcting the unexpected displacement of the stage have been proposed.

[0004] For example, Patent Document 1 discloses a mask stage that controls the coordinates of a mask with high precision. Specifically, a bar mirror is fixed on a mask table on which the mask is placed, and the position of the bar mirror is measured by a laser interferometer fixed to a base plate, thereby detecting the position of the mask table. A sensor is attached to the bar mirror to measure the distance or displacement to the mask. When the mask table on which the mask is placed is moved, the position information measured by the laser interferometer is corrected using the distance information or displacement information detected by a sensor means. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2016-100541 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in Patent Document 1, the laser interferometer is arranged to project laser light along a direction in which the displacement of the mask table is to be measured. Therefore, when the measurement range of the laser interferometer becomes large, the WD (work distance) of the laser light becomes long. When the WD becomes long, the laser light becomes susceptible to the effects of air fluctuations and temperature unevenness, and there is a risk of the measurement accuracy decreasing. In addition, a laser interferometer with a long WD may require a high-output laser and a complex optical system, and is generally expensive. Therefore, there is also a problem that the cost of the device increases significantly.

[0007] An object of the present invention is to provide a technique capable of reducing the WD of a laser displacement meter that detects the amount of displacement of a stage. [Means for solving the problem]

[0008] In order to solve the above problem, a first aspect is an exposure apparatus comprising: a stage having a support surface for supporting a substrate; a stage moving mechanism for moving the stage in a predetermined moving direction; an exposure head capable of irradiating light toward the substrate supported on the support surface of the stage; one or more reflective surfaces movable together with the stage and inclined toward a first direction toward a second direction intersecting the first direction; and an optical displacement meter capable of detecting an amount of displacement of the one or more reflective surfaces in the first direction, wherein the optical displacement meter has a laser light source capable of projecting laser light onto the reflective surface from a position away in the second direction, and a detector capable of detecting reflected light of the laser light reflected by the reflective surface.

[0009] A second aspect is the exposure apparatus of the first aspect, wherein the one or more reflecting surfaces are fixed on the supporting surface, and the optical displacement meter projects the laser light onto the reflecting surface from above the supporting surface.

[0010] A third aspect is an exposure apparatus of the first or second aspect, wherein the one or more reflective surfaces include a plurality of first reflective surfaces arranged in the movement direction, and the optical displacement meter includes a first displacement meter capable of detecting the amount of displacement of each of the first reflective surfaces in the first direction.

[0011] A fourth aspect is the exposure apparatus of the third aspect, wherein the one or more reflective surfaces further include a plurality of second reflective surfaces arranged in the movement direction, each of the second reflective surfaces is positioned away from each of the first reflective surfaces in a third direction that intersects the movement direction, each of the second reflective surfaces is positioned between two of the first reflective surfaces adjacent to each other in the movement direction, and the optical displacement meter includes a second displacement meter capable of detecting the amount of displacement of each of the second reflective surfaces in the first direction.

[0012] A fifth aspect is the exposure apparatus of the fourth aspect, wherein the first direction is parallel to the movement direction.

[0013] A sixth aspect is the exposure apparatus of the fourth aspect, wherein the first direction is a direction intersecting the movement direction.

[0014] A seventh aspect is an exposure apparatus of the first or second aspect, further comprising a determination unit that determines whether there is an abnormality in the measurement data by comparing the measurement data measured by the optical displacement meter with normal data.

[0015] An eighth aspect is an exposure method including the steps of: a) supporting a substrate on a support surface of a stage; b) moving the stage in a predetermined movement direction; c) irradiating light onto the substrate supported on the support surface of the stage moved by step b); and d) detecting the amount of displacement of one or more reflective surfaces moving together with the stage using an optical displacement meter, wherein the reflective surfaces are inclined toward a first direction in a second direction intersecting the first direction, and the optical displacement meter includes a laser light source that projects laser light from a position away from the reflective surface in the second direction, and a detector of the optical displacement meter that detects the reflected light of the laser light reflected by the reflective surface. Effect of the Invention

[0016] According to the exposure apparatus of the first to seventh aspects and the exposure method of the eighth aspect, by irradiating the laser light from the second direction intersecting with the first direction in which the displacement amount is measured, the WD of the laser light can be made shorter than when the displacement amount is detected by projecting the laser light along the first direction. This makes it possible to detect the displacement amount of the stage with high accuracy and at low cost.

[0017] According to the exposure apparatus of the second aspect, the optical displacement gauge can be brought close to the stage without interfering with it, thereby shortening the WD of the laser light.

[0018] According to the exposure apparatus of the third aspect, the length of the first reflecting surface in the first direction can be shortened, thereby reducing deformation of the first reflecting surface and improving the detection accuracy of the amount of displacement.

[0019] According to the exposure apparatus of the fourth aspect, in a period in which the first displacement meter 61 cannot detect the amount of displacement between the two first reflecting surfaces, the second displacement meter 62 can detect the amount of displacement of the second reflecting surface 720. This makes it possible to avoid a period in which the amount of displacement of the stage 2 cannot be measured.

[0020] According to the exposure apparatus of the fifth aspect, the amount of displacement in the moving direction of the stage can be measured by detecting the amount of displacement of the first reflecting surface in the first direction.

[0021] According to the exposure apparatus of the sixth aspect, it is possible to detect the amount of displacement of the stage in a direction intersecting the direction of movement of the stage.

[0022] According to the exposure apparatus of the seventh aspect, unexpected displacement of the stage can be detected, and therefore it becomes possible to deal with the abnormality appropriately. [Brief description of the drawings]

[0023] [Figure 1] 1 is a perspective view of an exposure apparatus according to a first embodiment. [Diagram 2] 2 is a diagram showing a schematic configuration of a first displacement meter shown in FIG. 1. [Diagram 3] 2 is a side view of the stage shown in FIG. 1 as viewed from the -X side. [Figure 4] 2 is a top view of the stage shown in FIG. 1 as seen from the +Z side. [Diagram 5] 11 is a side view showing how a displacement amount ΔY of the stage is measured by the first displacement meter. FIG. [Figure 6] 6 is a diagram showing the relationship between a displacement amount ΔY of the stage and the displacement amounts detected by a first displacement meter and a second displacement meter. FIG. [Figure 7] 2 is a block diagram showing a configuration of a control unit shown in FIG. 1. [Figure 8] FIG. 2 is a diagram showing a flow of exposure processing in the exposure apparatus. [Figure 9] FIG. 11 is a top view of the stage of the exposure apparatus related to the second embodiment, as viewed from the +Z side. [Figure 10] FIG. 10 is a side view of the stage shown in FIG. 9 as viewed from the -Y side. [Figure 11] FIG. 13 is a top view of the -X side portion of the stage according to the modified example, as viewed from the +Z side. [Figure 12] FIG. 12 is a side view of the stage shown in FIG. 11 as viewed from the -X side. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Note that the components described in the embodiment are merely examples, and are not intended to limit the scope of the present invention. In the drawings, the dimensions and numbers of each part may be exaggerated or simplified as necessary for ease of understanding.

[0025] In each drawing, an XYZ Cartesian coordinate system is appropriately provided in which the X-axis direction and the Y-axis direction are horizontal and the Z-axis direction is vertical, in order to facilitate understanding of the positional relationship of each element in the exposure apparatus 100. The direction toward the +Z side is the upward direction, and the direction toward the -Z side is the downward direction.

[0026] <1. First embodiment> 1 is a perspective view of an exposure apparatus 100 according to the first embodiment. The exposure apparatus 100 is an apparatus that draws a pattern by irradiating light onto the upper surface of a substrate W on which a layer of a photosensitive material (photosensitive layer) such as a resist is formed. The substrate W is, for example, a semiconductor substrate, a printed circuit board, a substrate for a color filter, a glass substrate for a flat panel display used in a weather display device or a plasma display device, or a substrate for an optical disk. The exposure apparatus 100 includes a base 1, a stage 2, a stage moving mechanism 3, a gantry 4, an exposure unit 5, a measurement section 6, a plurality of first mirrors 71, a plurality of second mirrors 72, and a control section 9.

[0027] The base 1 has a rectangular shape when viewed from above. The base 1 supports a stage 2, a stage moving mechanism 3, a gantry 4, an exposure unit 5, and a measurement part 6 from below.

[0028] The stage 2 has an upper surface 2S that holds the substrate W. The upper surface 2S is a horizontal surface parallel to the X and Y directions. The substrate W is placed on the upper surface 2S in a horizontal position. The upper surface 2S has a plurality of suction holes formed therein. The stage 2 can fix the substrate W to the upper surface 2S by applying a negative pressure (suction pressure) to the suction holes. Note that a chuck that grips the periphery of the substrate W may be provided on the upper surface 2S, and the substrate W may be fixed to the upper surface 2S by the chuck. The upper surface 2S is an example of a support surface.

[0029] The stage moving mechanism 3 moves the stage 2 in the main scanning direction (Y direction), the sub-scanning direction (X-axis direction), and a rotation direction (rotation direction around the Z axis (θ-axis direction)). The stage moving mechanism 3 has a support plate 31, a sub-scanning mechanism 32, a base plate 33, a main scanning mechanism, and a rotation mechanism 35.

[0030] The support plate 31 is disposed below the stage 2 and rotatably supports the stage 2. The base plate 33 is disposed below the support plate 31 and supports the support plate 31 and the sub-scanning mechanism 32. The sub-scanning mechanism 32 moves the support plate 31 relative to the base plate 33 in the sub-scanning direction, that is, the X direction. The main scanning mechanism 34 moves the base plate 33 relative to the base 1 in the main scanning direction, that is, the Y direction. The stage 2 moves in the Y direction as the base plate 33 moves in the Y direction. The sub-scanning mechanism 32 and the main scanning mechanism 34 are, for example, a linear motor mechanism including a linear motor and a guide, or a ball screw mechanism including a rotary motor, a ball screw, and a guide. The rotation mechanism 35 is provided on the support plate 31 and rotates the stage 2 about a rotation axis A extending in the Z direction. The sub-scanning mechanism 32, the main scanning mechanism 34, and the rotation mechanism 35 operate based on a control command from the control unit 9.

[0031] The gantry 4 is fixed to the base 1. The gantry 4 has two support columns 41 and a beam 43. The lower part of the support column 41 is fixed to the base 1 and extends in the Z direction. The two support columns 41 are arranged at an interval in the X direction. The beam 43 connects the upper parts of the two support columns 41 and extends in the X direction. In this example, the stage 2 and the base plate 33 of the stage moving mechanism 3 are arranged between the two support columns 41 in the X direction, and the beam 43 is arranged above the stage 2.

[0032] The gantry 4 is a member that supports the exposure unit 5 and the measurement unit 6. Each exposure head 51 of the exposure unit 5 and the measurement unit 6, which will be described later, are fixed to the −Y side surface of a beam portion 43 in the gantry 4.

[0033] The exposure unit 5 has one or more exposure heads 51. In this example, five exposure heads 51 are arranged along the X-axis direction. Each exposure head 51 has a spatial light modulator 510. The spatial light modulator 510 modulates laser light based on strip data corresponding to a drawing pattern.

[0034] The exposure unit 5 has a light irradiation section 53. The light irradiation section 53 irradiates the exposure head 51 with laser light. The light irradiation section 53 is housed, for example, inside the gantry 4. The light irradiation section 53 has a laser driving section 531, a laser oscillator 533, and an illumination optical system 535. By operation of the laser driving section 531, the laser oscillator 533 emits laser light to the illumination optical system 535. The illumination optical system 535 changes the magnification of the laser light incident from the laser oscillator 533, and uniformizes the light amount distribution. The laser light emitted from the illumination optical system 535 is irradiated onto the spatial light modulator 510 of each exposure head 51.

[0035] The spatial light modulator 510 spatially modulates the laser light irradiated from the light irradiation unit 53 on a channel-by-channel basis, and reflects necessary light that contributes to drawing a pattern and unnecessary light that does not contribute to drawing a pattern in different directions. Note that spatially modulating light means changing the spatial distribution (amplitude, phase, polarization, etc.) of light. The exposure head 51 irradiates the modulated laser light onto the substrate W moving directly below the exposure head 51. As a result, the drawing pattern is exposed onto the unprocessed substrate W.

[0036] The spatial light modulator 510 may be, for example, a grating type optical element such as a GLV (Grating Light Valve, a registered trademark of Silicon Light Machines, Inc.) or a DMD (Digital Mirror Device).

[0037] The measuring unit 6 is a device for measuring the position of the stage 2. The measuring unit 6 includes a first displacement meter 61, a second displacement meter 62, a connecting member 63, and a displacement meter moving mechanism 65. The first displacement meter 61 and the second displacement meter 62 detect the amount of displacement of the stage 2 in the Y direction, as described below. The first displacement meter 61 and the second displacement meter 62 are optical displacement meter. The first displacement meter 61 and the second displacement meter 62 are disposed above the upper surface 2S of the stage 2. The first displacement meter 61 and the second displacement meter 62 are disposed at the same position in the Y direction.

[0038] The connecting member 63 is a member that connects the first displacement gauge 61 or the second displacement gauge 62 to the gantry 4. The displacement gauge moving mechanism 65 is a mechanism that moves the first displacement gauge 61 and the second displacement gauge 62 integrally along the X direction. In this embodiment, the connecting member 63 is fixed to the displacement gauge moving mechanism 65. The displacement gauge moving mechanism 65 moves the connecting member 63 in the X direction, whereby the first displacement gauge 61 and the second displacement gauge 62 move in the X direction. The displacement gauge moving mechanism 65 is configured, for example, by a ball twisting mechanism. The displacement gauge moving mechanism 65 is electrically connected to the control unit 9 and operates based on a control command from the control unit 9.

[0039] When the sub-scanning mechanism 32 moves the stage 2 in the X direction, the first mirrors 71 and the second mirrors 72 move in the X direction. For this reason, the control unit 9 controls the displacement meter moving mechanism 65 to move the first displacement meter 61 and the second displacement meter 62 in the X direction.

[0040] Each of the first mirrors 71 and each of the second mirrors 72 is fixed to the upper surface 2S of the stage 2. Each of the first mirrors 71 has a first reflecting surface 710, and each of the second mirrors 72 has a second reflecting surface 720. They are fixed to the upper surface 2S of the stage 2. Therefore, each of the first reflecting surfaces 710 and each of the second reflecting surfaces 720 move together with the stage 2. The first displacement meter 61 detects the amount of displacement of the first reflecting surface 710 in the Y direction. In addition, the second displacement meter 62 detects the displacement of each of the second reflecting surfaces 720.

[0041] 1, each of the first mirrors 71 and each of the second mirrors 72 is disposed on the -X side with respect to the substrate W. However, one of the first mirrors 71 and each of the second mirrors 72 may be disposed on the +X side with respect to the substrate W, and the other may be disposed on the -X side with respect to the substrate W. However, by disposing each of the first mirrors 71 and the second mirrors 72 on the same side with respect to the substrate W, the first displacement gauge 61 and the second displacement gauge 62 can be brought close to each other. This makes it easy to move the first displacement gauge 61 and the second displacement gauge 62 integrally by the displacement gauge moving mechanism 65.

[0042] FIG. 2 is a diagram showing a schematic configuration of the first displacement meter 61. As shown in FIG. 2, the first displacement meter 61 has a laser light source 611, a light projecting lens 612, a light receiving lens 613, and a detector 614. The laser light source 611 outputs a laser light. The laser light source 611 is, for example, an LED (Light Emitting Diode). The light output from the laser light source 611 is collected by the light projecting lens 612 and irradiated onto a first mirror 71, which is a measurement target. As shown in FIG. 1, the first mirror 71 is fixed to the upper surface 2S of the stage 2, and has a first reflecting surface 710 capable of reflecting the laser light. The first displacement meter 61 projects a laser light in a direction inclined toward the -Z side toward the -Y direction.

[0043] The light reflected by the first reflecting surface 710 of the first mirror 71 is imaged on the detector 614 by the light receiving lens 613. The detector 614 is composed of a PSD (Position Sensitive Detector) or a CMOS (Complementary Metal Oxide Semiconductor), etc. When the distance from the first displacement meter 61 to the first reflecting surface 710 of the first mirror 71 changes, the image position on the detector 614 changes. The first displacement meter 61 measures the change (amount of displacement) of the distance to the first reflecting surface 710 based on the change in the image position detected by the detector 614, and transmits the measured amount of displacement to the control unit 9.

[0044] Although not shown in the figure, the second displacement meter 62 has a configuration similar to that of the first displacement meter 61. The second displacement meter 62 measures the change in the distance from the second displacement meter 62 to the second reflecting surface 720 of the second mirror 72, and outputs the measurement result to the control unit 9.

[0045] FIG. 3 is a side view of the stage 2 shown in FIG. 1 as viewed from the -X side. FIG. 4 is a top view of the stage 2 shown in FIG. 1 as viewed from the +Z side. As shown in FIG. 3 and FIG. 4, a plurality of first reflecting surfaces 710 formed by a plurality of first mirrors 71 are arranged in a line at regular intervals along the Y direction. A plurality of second reflecting surfaces 720 formed by a plurality of second mirrors 72 are also arranged in a line at regular intervals along the Y direction. Each second reflecting surface 720 is located away from each first reflecting surface 710 in the X direction (specifically, on the +X side). Each second reflecting surface 720 is located between two first reflecting surfaces 710, 710 adjacent to each other in the Y direction. The first reflecting surface 710 and the second reflecting surface 720 are rectangular and have the same size. The second reflecting surface 720 may have a size or shape different from that of the first reflecting surface 710. The first reflecting surface 710 and the second reflecting surface 720 extend in the Y direction and are inclined toward the +Z side from the +Y side to the -Y side. The first reflecting surface 710 and the second reflecting surface 720 are inclined with respect to the upper surface 2S of the stage 2.

[0046] 5 is a side view showing how the first displacement gauge 61 measures the displacement amount ΔY of the stage 2. Here, as shown in FIG. 5, the inclination angle of the first reflecting surface 710 with respect to the upper surface 2S is set to α. Assume that the stage 2 moves by ΔY from the position indicated by the solid line to the position indicated by the two-dot chain line in the +Y direction. Then, the first reflecting surface 710 also moves together with the stage 2, causing the distance from the first displacement gauge 61 to the first reflecting surface 710 to vary. The relationship between the displacement amount ΔY of the stage 2 and the displacement amount d of the distance from the first displacement gauge 61 to the first reflecting surface 710 is expressed by the following equation using the inclination angle α.

[0047] (Formula) ΔY=d / sin α

[0048] In this way, the displacement amount ΔY of the stage 2 can be calculated by detecting the displacement amount d with the first displacement meter 61. Also, as shown in Fig. 5, the displacement amount d measured with the laser light is detected as a value smaller than the displacement amount ΔY. That is, the WD of the laser can be made smaller than when the laser light is projected along the Y direction.

[0049] Fig. 6 is a diagram showing the relationship between the displacement amount ΔY of the stage 2 and the displacement amount detected by the first displacement meter 61 and the second displacement meter 62. The displacement amount detected by the first displacement meter 61 is referred to as the "first displacement amount," and the displacement amount detected by the second displacement meter 62 is referred to as the "second displacement amount." Fig. 6(A) is a graph showing the change over time in the displacement amount (movement amount) of the stage 2 in the Y direction, Fig. 6(B) is a graph showing the change over time in the first displacement amount, and Fig. 6(C) is a graph showing the change over time in the second displacement amount.

[0050] As described above, the first reflecting surfaces 710 are disposed at regular intervals along the Y direction. Therefore, the first displacement amount detected by the first displacement meter 61 periodically changes as shown in Fig. 6(B) by alternating periods during which the displacement amount increases linearly and periods during which the displacement amount is not detected. In addition, as shown in Fig. 6(C), the second displacement amount detected by the second displacement meter 62 also periodically changes.

[0051] 6(B) and (C), in the exposure apparatus 100, the first displacement meter 61 and the second displacement meter 62 are configured to detect the first displacement amount and the second displacement amount alternately in time. That is, in a period in which one of the first displacement meter 61 and the second displacement meter 62 does not detect the displacement amount, the other detects the displacement amount. For example, at time t 1 From time t 2 During this period, the first displacement meter 61 does not detect the first displacement amount, but the second displacement meter 62 detects the second displacement amount. 3 From time t 4During the period up to , the second displacement meter 62 does not detect the second displacement amount, but the first displacement meter 61 detects the first displacement amount. In this manner, since at least one of the first displacement meter 61 and the second displacement meter 62 is configured to measure the displacement amount, it is possible to constantly measure the displacement amount of the stage 2. Note that the displacement amount of the stage 7 can be calculated by accumulating the first displacement amount and the second displacement amount detected by the first displacement meter 61 and the second displacement meter 62.

[0052] In general, the end of the first reflecting surface 710 is easily distorted due to the influence of the processing accuracy of the first mirror 71 or the mounting accuracy of the first mirror 71. Furthermore, the tip (-Y side end) of the first reflecting surface 710 is easily displaced due to vibration of the first reflecting surface 710, etc. For this reason, it may be difficult to accurately detect the amount of displacement near the end of the first reflecting surface 710 in the Y direction. Similarly, it may be difficult to accurately detect the amount of displacement at the end of the second reflecting surface 720. Therefore, as shown in Figures 6(B) and 6(C), the second displacement meter 62 detects the time (t 1 ) 10 ) at which the second displacement meter 62 is no longer able to detect the displacement. 3 ) a little before the time (t 2 ) detection of the first displacement amount is started. The first displacement meter 61, the second displacement meter 62, the first reflecting surface 710 and the second reflecting surface 720 are appropriately positioned so that such a measurement is possible. This makes it possible to obtain the displacement amount detected at a location inside the ends of the first reflecting surface 710 and the second reflecting surface 720, and therefore makes it possible to measure the movement amount (displacement amount) of the stage with high accuracy.

[0053] 6 is a displacement amount detected at the end (-Y side end) of the second reflecting surface 720, and therefore the detection accuracy is low. 10 later than (and at time t 1 Preferably, the second displacement obtained from a time (before time t 2The first displacement amount obtained at time t 2 It is preferable that a first displacement amount obtained from a time later than time t1 (and earlier than time t3) is used.

[0054] FIG. 7 is a block diagram showing the configuration of the control unit 9 shown in FIG. 1. The control unit 9 includes a processor such as a CPU (Central Processing Unit) and a storage unit 99. The storage unit 99 is electrically connected to the processor, and specifically includes a main storage device such as a RAM (Random Access Memory) and an auxiliary storage device such as a hard disk. The storage unit 99 stores a program P. The processor executes the program P to function as an irradiation control unit 91, a stage control unit 93, a drawing control unit 95, and a determination unit 97. Some of the functions of the control unit 9 may be realized in hardware by a dedicated circuit.

[0055] The irradiation control unit 91 controls the light irradiation unit 53 of the exposure unit 5 to cause the light irradiation unit 53 to emit a line beam of light toward the exposure head 51. The stage control unit 93 controls the stage moving mechanism 3 to move the stage 2 in the Y direction, which is the main scanning direction, and the X direction, which is the sub-scanning direction, relative to the exposure head 51. The drawing control unit 95 controls the spatial light modulator 510 of the exposure head 51 based on the drawing recipe stored in the storage unit 99 and position information of the stage 2. More specifically, the drawing control unit 95 controls the drive voltage applied to each channel of the spatial light modulator 510 to cause the spatial light modulator 510 to modulate the line beam of light so as to correspond to the drawing pattern.

[0056] In the drawing recipe, for example, pattern data indicating a drawing pattern to be formed on the substrate W and various conditions for drawing (such as the amount of light emitted from the exposure unit 5 and the moving speed of the stage 2) are described in a predetermined data format. The pattern data is, for example, data obtained by rasterizing CAD data generated using CAD (computer aided design), and position information on the substrate W to be irradiated with light is recorded in pixel units. In addition, the position information of the stage 2 is data measured by a length measuring device (not shown). The length measuring device is, for example, a linear encoder provided in the main scanning mechanism 34. It should be noted that a laser interferometer may be used as the length measuring device.

[0057] The drawing control unit 95 controls the displacement gauge moving mechanism 65 to move the first displacement gauge 61 and the second displacement gauge 62 in the X direction. As described later, the exposure device 100 exposes the photosensitive layer of the substrate W by alternately repeating a main scanning movement in which the stage 2 is moved in the Y direction (main scanning direction) and a sub-scanning movement in which the stage 2 is moved in the X direction (sub-scanning direction) while irradiating light from the exposure head 51. When the stage 2 is moved in the X direction, the positional relationship between the first displacement gauge 61 and the second displacement gauge 62 and each of the first mirrors 71 and the second mirrors 72 is shifted. Therefore, the drawing control unit 95 moves the first displacement gauge 61 and the second displacement gauge 62 in the X direction in accordance with the sub-scanning movement of the stage 2. As a result, the positional relationship between the first displacement gauge 61 and each of the first mirrors 71 and the positional relationship between the second displacement gauge 62 and each of the second mirrors 72 are maintained in the X direction.

[0058] The determination unit 97 determines whether or not there is an abnormality in stage 2. In detail, the determination unit 97 acquires measurement data measured by the first displacement meter 61 and the second displacement meter. Then, the determination unit 97 compares the acquired measurement data with normal data D1 previously stored in the storage unit 99 to determine whether or not there is an abnormality in the measurement data. The determination unit 97 displays the determination result regarding the abnormality on the display DP1 connected to the control unit 9. This notifies the user that there is an abnormality in the measurement data. Note that, instead of displaying on the display DP1, the determination unit 97 notifies the user by turning on a warning lamp or outputting a warning sound from a speaker.

[0059] 8 is a diagram showing the flow of exposure processing in exposure apparatus 100. First, a transfer device such as a robot places a substrate W on the upper surface 2S of stage 2. This brings the substrate W into a state where it is supported by stage 2 (step S1). With substrate W supported on its upper surface 2S, stage 2 adsorbs and fixes it.

[0060] Next, the control unit 9 aligns the substrate W (step S2). That is, the stage control unit 93 controls the stage moving mechanism 3 to adjust the position of the substrate W in the X direction and Y direction, and the angle of the substrate W in the θ-axis direction. For example, a notch or alignment mark provided on the substrate W is captured by a camera, and the position and angle of the substrate W are identified using the obtained image.

[0061] When the alignment process is completed, exposure of the substrate W is started. That is, the stage control unit 93 controls the stage moving mechanism 3 to move the stage 2 in the main scanning direction (Y direction) (step S3). The drawing control unit 95 controls the spatial light modulator 510 according to the position of the stage 2 in the Y direction to emit a spatially modulated line beam light from the spatial light modulator 510. As a result, a strip-shaped area extending in the Y direction is exposed on the upper surface 2S of the substrate W. Also, in step S3, the first displacement meter 61 and the second displacement meter 62 detect the amount of displacement. Measurement data of the amount of displacement detected by the first displacement meter 61 and the second displacement meter 62 is transmitted to the determination unit 97 of the control unit 9.

[0062] After step S3, the determination unit 97 compares the measurement data with the normal data D1 to determine whether the measurement data is abnormal (step S4). In step S4, the determination unit 97 determines whether there is a difference between the measurement data and the normal data D1 that exceeds a predetermined threshold.

[0063] If there is an abnormality in the measurement data (Yes in step S4), the determination unit 97 causes the display DP1 to display an image informing the user of the abnormality (step S5). Then, the exposure process ends. Note that even if there is an abnormality in the measurement data, the control unit 9 may proceed to the next step S6 and continue the exposure process.

[0064] If it is determined that there is no abnormality in the measurement data (No in step S4), the writing control unit 95 determines whether or not an unexposed area exists on the substrate W (step S6). If an unexposed area exists (Yes in step S6), the stage control unit 93 moves the stage 2 in the sub-scanning direction (X direction) by the width of the strip-like area (step S7). Also, in step S7, the writing control unit 95 moves the first displacement meter 61 and the second displacement meter 62 in the same direction (X direction) as the movement direction of the stage 2 and by the same distance as the movement amount of the stage 2. Then, step S3 is executed again.

[0065] Moreover, if it is determined that there is no unexposed area (No in step S6), exposure apparatus 100 ends the exposure process.

[0066] <Effects> As described above, the exposure apparatus 100 includes the stage 2, the stage moving mechanism 3, the exposure head 51, one or more first reflecting surfaces 710, and an optical displacement meter (first displacement meter 61). The stage 2 has an upper surface 2S that supports the substrate W. The stage moving mechanism 3 moves the stage 2 in a predetermined moving direction (Y direction). The exposure head 51 can irradiate light toward the substrate W supported on the supporting surface (upper surface 2S) of the stage 2. The one or more reflecting surfaces (first reflecting surfaces 710) can move together with the stage 2, and are inclined toward the first direction (Y direction) and in the second direction (Z direction) that intersects with the first direction. The optical displacement meter (first displacement meter 61) can detect the amount of displacement of the one or more reflecting surfaces (first reflecting surfaces 710) in the first direction (Y direction). The optical displacement meter (first displacement meter 61) includes a laser light source 611 and a detector 614. The laser light source 611 can project laser light onto the reflecting surface (first reflecting surface 710) from a position away in the second direction (Z direction). The detector 614 can detect the reflected light of the laser light reflected by the reflecting surface (first reflecting surface 710).

[0067] The exposure method of this embodiment includes a) a step (step S1) of supporting the substrate W on the support surface (upper surface 2S) of the stage 2, b) a step (step S3) of moving the stage 2 in a predetermined moving direction (Y direction), c) a step (step S3) of irradiating light onto the substrate W supported by the stage 2 moved by step b), and d) a step (step S3) of detecting the displacement amount of one or more reflecting surfaces (first reflecting surfaces 710) moving together with the stage 2 by an optical displacement meter (first displacement meter 61). The reflecting surface (first reflecting surface 710) is inclined toward the first direction (Y direction) in a second direction (Z direction) intersecting the first direction. The first displacement meter 61 has a laser light source 611 and a detector 614. The laser light source 611 can project laser light onto the reflecting surface (first reflecting surface 710) from a position away in the second direction (Z direction). The detector 614 is capable of detecting the reflected light of the laser light reflected by the reflecting surface (first reflecting surface 710).

[0068] According to these configurations, when detecting the amount of displacement of the stage 2 in the first direction (Y direction), the optical displacement meter (first displacement meter 61) detects the amount of displacement of the stage 2 in the first direction (Y direction) by projecting laser light from a position away in the second direction (Z direction). Therefore, the WD of the laser light can be made shorter than when the laser light is projected along the Y direction. Therefore, the amount of displacement of the stage 2 can be detected with high accuracy and at low cost.

[0069] In addition, because the laser light is projected from a second direction (Z direction) that intersects with the first direction (Y direction), it is possible to free up space in the Y direction for measuring the amount of displacement. This allows for effective use of the device space, making it possible to reduce the device size.

[0070] Furthermore, one or more reflecting surfaces (first reflecting surface 710) are fixed to the support surface (upper surface 2S), and the optical displacement meter (first displacement meter 61) can project laser light onto the reflecting surface (first reflecting surface 710) from above the support surface (upper surface 2S). With this configuration, the optical displacement meter (first displacement meter 61) can be brought close to the stage 2 without interfering with it. This makes it possible to shorten the WD of the laser light.

[0071] Furthermore, a plurality of first reflecting surfaces 710 are arranged in the moving direction (Y direction) of the stage 2. The optical displacement meter (first displacement meter 61) is capable of detecting the amount of displacement of each of the first reflecting surfaces 710. With this configuration, the length of the first reflecting surfaces 710 in the Y direction can be shortened. This can reduce deformation of the first reflecting surfaces 710, thereby improving the detection accuracy of the amount of displacement.

[0072] Further, a plurality of second reflecting surfaces 720 are arranged in the moving direction (Y direction) of the stage 2. Each second reflecting surface 720 is located away from each first reflecting surface 710 in a third direction (X direction) intersecting the moving direction (Y direction). Each second reflecting surface 720 is located between two adjacent first reflecting surfaces 710 in the moving direction (Y direction). The second displacement meter 62 can detect the amount of displacement of each second reflecting surface 720 in the first direction (Y direction). According to this configuration, the second displacement meter 62 can detect the amount of displacement of the second reflecting surface 720 during a period in which the first displacement meter 61 cannot detect the amount of displacement between the first reflecting surface 710 and the first reflecting surface 710. Therefore, it is possible to avoid the occurrence of a period in which the amount of displacement of the stage 2 cannot be measured.

[0073] The first direction (Y direction) is a direction parallel to the movement direction (Y direction) of the stage 2. With this configuration, the amount of displacement of the stage 2 in the movement direction (Y direction) can be measured by detecting the amount of displacement of the reflecting surface (first reflecting surface 710) in the first direction (Y direction).

[0074] The exposure apparatus 100 further includes a determination unit 97. The determination unit 97 determines whether there is an abnormality in the measurement data by comparing the measurement data measured by the optical displacement meter (first displacement meter 61) with normal data D1. With this configuration, it is possible to detect unexpected displacement of the stage 2, and therefore it is possible to appropriately deal with the abnormality.

[0075] <2. Second embodiment> Next, a second embodiment will be described. In the following description, elements having the same functions as elements already described will be given the same reference numerals or reference numerals with an additional alphabetical character, and detailed description thereof may be omitted.

[0076] FIG. 9 is a top view of the stage 2 of the exposure apparatus 100 according to the second embodiment, seen from the +Z side. FIG. 10 is a side view of the stage 2 shown in FIG. 9, seen from the -Y side. As shown in FIGS. 9 and 10, the measurement unit 6 of this embodiment further includes a third displacement meter 66, a fourth displacement meter 67, and a displacement meter moving mechanism 68. The exposure apparatus 100 further includes a plurality of third mirrors 73 and a plurality of fourth mirrors 74. In the exposure apparatus 100 of this embodiment, the third displacement meter 66 and the fourth displacement meter 67 detect the amount of displacement of each of the third mirrors 73 and each of the fourth mirrors 74. This makes it possible to measure the amount of displacement of the stage 2 in the X direction. The third displacement meter 66 and the fourth displacement meter 67 are disposed above the upper surface 2S of the stage 2.

[0077] The third mirrors 73 and the fourth mirrors 74 are fixed to the upper surface 2S of the stage 2. Each of the third mirrors 73 has a third reflecting surface 730, and each of the fourth mirrors 74 has a fourth reflecting surface 740. The third reflecting surfaces 730 formed by the third mirrors 73 are arranged at regular intervals along the Y direction. The fourth reflecting surfaces 740 formed by the fourth mirrors 74 are also arranged at regular intervals along the Y direction. The third reflecting surface 730 and the fourth reflecting surface 740 are rectangular extending in the Y direction and inclined toward the +Z side from the +X side to the -X side. The third reflecting surface 730 and the fourth reflecting surface 740 are inclined with respect to the upper surface 2S of the stage 2.

[0078] The third displacement gauge 66 and the fourth displacement gauge 67 are optical displacement gauges and have the same configuration as the first displacement gauge 61 and the second displacement gauge 62. The displacement gauge moving mechanism 68 is fixed to the gantry 4 like the displacement gauge moving mechanism 65, and moves the third displacement gauge 66 and the fourth displacement gauge 67 in the X direction relative to the gantry 4. That is, the third displacement gauge 66 and the fourth displacement gauge 67 are supported so as to be movable in the X direction relative to the gantry 4.

[0079] 9, the third displacement meter 66 and the fourth displacement meter 67 project laser light in a direction inclined toward the -Z side toward the -X direction. Then, the third displacement meter 66 detects the reflected light reflected by the third reflecting surface 730, and the fourth displacement meter 67 detects the reflected light reflected by each of the fourth reflecting surfaces 740. The third displacement meter 66 and the fourth displacement meter 67 can detect the displacement of the third reflecting surface 730 and the fourth reflecting surface 740 in the X direction.

[0080] As described above, in this embodiment, the first direction (X direction) in which the third displacement meter 66 detects the displacement of the third reflecting surface 730 intersects with the movement direction (Y direction) of the stage 2. This makes it possible to detect the amount of displacement of the stage 2 in the direction (X direction) intersecting with the movement direction (Y direction) of the stage 2.

[0081] <3. Modification> Although the embodiment has been described above, the present invention is not limited to the above, and various modifications are possible.

[0082] For example, it is not essential that the first displacement gauge 61 and the second displacement gauge 62 are supported by the gantry 4 , and they may be supported by a member provided separately from the gantry 4 .

[0083] In the above embodiment, the first displacement gauge 61 and the second displacement gauge 62 are arranged at the same position in the Y direction, but they may be arranged with a shift in the Y direction. In this case, it is preferable to adjust the shift of each second reflection surface 720 with respect to each first reflection surface 710 in accordance with the shift of the second displacement gauge 62 with respect to the first displacement amount 61.

[0084] In the above embodiment, the first mirror 71 is fixed to the upper surface 2S of the stage 2. However, for example, the first mirror 71 may be fixed to the side surface on the +X side or the -X side of the stage 2. This modification will be described with reference to FIGS. 11 and 12.

[0085] FIG. 11 is a top view of the -X side portion of the stage 2 according to the modified example, viewed from the +Z side. FIG. 12 is a side view of the stage 2 shown in FIG. 11, viewed from the -X side. As shown in FIG. 11 and FIG. 12, each first reflecting surface 710 and each second reflecting surface 720 may be fixed to the side surface on the -X side of the stage 2. In this case, each first reflecting surface 710 is arranged, for example, so as to be inclined toward the -X direction, which is one of the X directions, toward the -Y direction, which is one of the Y directions. Also, the first displacement meter 61 and the second displacement meter 62 are arranged so as to project laser light in a direction inclined toward the +X direction toward the -Y direction from a position away from the first reflecting surface 710 in the -X direction.

[0086] Although the present invention has been described in detail, the above description is merely illustrative in all respects, and the present invention is not limited thereto. It is understood that countless variations not illustrated can be envisioned without departing from the scope of the present invention. The configurations described in the above embodiments and variations can be appropriately combined or omitted as long as they are not mutually contradictory. [Explanation of symbols]

[0087] 2: Stage 2S:Top surface (support surface) 3: Stage movement mechanism 7: Stage 9: Control section 51: Exposure head 61: First displacement meter 62: Second displacement gauge 97: Judgment section 100: Exposure device 510: Spatial light modulator 611: Laser light source 614: Detector 710: 1st reflective surface 720: 2nd reflective surface W: Substrate

Claims

1. An exposure apparatus comprising: a stage having a support surface for supporting a substrate; a stage moving mechanism that moves the stage in a predetermined moving direction; an exposure head capable of irradiating light toward the substrate supported on the support surface of the stage; one or more reflecting surfaces movable with the stage and tilted toward a first direction and a second direction intersecting the first direction; an optical displacement meter capable of detecting a displacement amount of the one or more reflecting surfaces in the first direction; Equipped with The optical displacement meter includes: a laser light source capable of projecting laser light from a position away from the reflection surface in the second direction; a detector capable of detecting reflected light of the laser light reflected on the reflecting surface; An exposure apparatus comprising:

2. 2. The exposure apparatus according to claim 1, the one or more reflective surfaces are fixed on the support surface; The optical displacement meter is an exposure device that projects the laser light onto the reflecting surface from above a supporting surface.

3. 3. The exposure apparatus according to claim 1, The one or more reflecting surfaces include a plurality of first reflecting surfaces arranged in the moving direction, The optical displacement meter includes: a first displacement meter capable of detecting an amount of displacement of each of the first reflecting surfaces in the first direction; An exposure apparatus comprising:

4. 4. The exposure apparatus according to claim 3, The one or more reflective surfaces include: A plurality of second reflecting surfaces arranged in the moving direction; Further comprising: Each of the second reflecting surfaces is located apart from each of the first reflecting surfaces in a third direction intersecting the moving direction, Each of the second reflecting surfaces is located between two of the first reflecting surfaces adjacent to each other in the moving direction, The optical displacement meter includes: a second displacement meter capable of detecting an amount of displacement of each of the second reflecting surfaces in the first direction; An exposure apparatus comprising:

5. 5. The exposure apparatus according to claim 4, An exposure apparatus, wherein the first direction is parallel to the movement direction.

6. 5. The exposure apparatus according to claim 4, An exposure apparatus, wherein the first direction is a direction intersecting the movement direction.

7. 3. The exposure apparatus according to claim 1, a determination unit that determines whether or not there is an abnormality in the measurement data measured by the optical displacement meter by comparing the measurement data with normal data; The exposure apparatus further comprises:

8. An exposure method comprising the steps of: a) supporting a substrate on a support surface of a stage; b) moving the stage in a predetermined direction of movement; c) irradiating the substrate supported on the support surface of the stage moved by step b) with light; d) detecting the amount of displacement of one or more reflecting surfaces that move together with the stage by an optical displacement meter; Including, the reflecting surface is inclined toward a first direction in a second direction intersecting the first direction, The optical displacement meter includes: a laser light source that projects laser light from a position away from the reflecting surface in the second direction; a detector of the optical displacement meter that detects the reflected light of the laser light reflected on the reflecting surface; The exposure method includes the steps of:

Citation Information

Patent Citations

  • Mask stage and stage device

    JP2016100541A