Exposure apparatus, method for producing article, and exposure method

Abstract

To provide an exposure apparatus that can improve the through-put corresponding to the accuracy required for positioning an original plate and a substrate.SOLUTION: An exposure apparatus that projects an image of a pattern on an original plate onto a substrate to expose the substrate comprises: an imaging part which acquires a first image of a substrate mark formed on the substrate; and a control part which controls the position of the substrate on the basis of the first image acquired by the imaging part, where first resolutions when the imaging part acquires the first image in order to expose each of at least two layers of a plurality of layers of the substrate are different from each other.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to an exposure apparatus, a method for manufacturing an article, and an exposure method.

Background Art

[0002] Conventionally, in an exposure apparatus, improvement in the accuracy of alignment between a reticle and a substrate has been demanded. For this reason, for example, improvement in the accuracy of measuring the position of a substrate mark formed on the substrate has been carried out. At this time, the accuracy of the position measurement can be improved by increasing the resolution of an image sensor that images the substrate mark.

[0003] On the other hand, when using an image sensor having such a high resolution, the amount of data of an image acquired by the imaging increases. Therefore, the accumulation time for acquiring the data, the transfer time and the processing time of the acquired data increase, and the throughput decreases. Patent Document 1 discloses an exposure apparatus that suppresses a decrease in throughput by reducing the amount of data of an image of a substrate mark acquired by narrowing an imaging range so as to image only the substrate mark when aligning the reticle and the substrate.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] On the other hand, in an exposure apparatus that exposes each of a plurality of layers overlapped with each other on a substrate, high accuracy may not be required in alignment between a reticle and the substrate when exposing a predetermined layer. That is, in that case, it is not necessary to image the substrate mark formed on the substrate with high resolution. In other words, if the substrate mark is imaged at an unnecessarily high resolution in such a case, the accumulation time for acquiring the image data of the substrate mark at that time, and the transfer time and processing time of the acquired data will increase, resulting in a decrease in throughput.

[0006] Therefore, an object of the present invention is to provide an exposure apparatus capable of improving throughput according to the accuracy required for alignment between a reticle and a substrate.

Means for Solving the Problems

[0007] An exposure apparatus according to the present invention is an exposure apparatus that projects an image of a pattern of a reticle onto a substrate and exposes the substrate, and includes an imaging unit that acquires a first image of a substrate mark formed on the substrate, and a control unit that controls the position of the substrate based on the first image acquired by the imaging unit. The first resolution when the imaging unit acquires the first image in order to expose at least two of a plurality of layers on the substrate is different from each other.

Effects of the Invention

[0008] According to the present invention, it is possible to provide an exposure apparatus capable of improving throughput according to the accuracy required for alignment between a reticle and a substrate.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, the exposure apparatus according to the present embodiment will be described in detail with reference to the accompanying drawings. Note that the drawings shown below may be drawn at scales different from the actual ones for easy understanding of the present embodiment. Also, hereinafter, in the direction perpendicular to the substrate mounting surface on which the substrate 6a is mounted on the substrate stage 6b (the direction parallel to the optical axis of the projection optical system 5) is defined as the Z direction. Also, in the plane perpendicular to the Z direction, the direction in which the substrate 6a moves by scanning is defined as the Y direction (the second direction), and the direction perpendicular to the Y direction in which the substrate 6a moves stepwise is defined as the X direction (the first direction).

[0011] Conventionally, in an exposure apparatus, higher precision and higher functionality have been demanded. In particular, improvement in the alignment accuracy between the reticle and the substrate greatly contributes to the higher precision of the exposure apparatus. That is, the measurement accuracy of the positions of the reticle mark formed on the reticle and the substrate mark formed on the substrate for performing the alignment directly affects the performance of the exposure apparatus. Also, in an exposure apparatus, an increase in throughput, that is, the number of substrates that can be processed per unit time, is also demanded from the viewpoint of productivity.

[0012] In an exposure apparatus, generally, the position is measured by imaging a reticle mark and a substrate mark respectively. Therefore, by increasing the resolution of the imaging device that performs the imaging, the accuracy of the measurement can be improved, and thus the high-precision of the exposure apparatus can be achieved. However, since the amount of data of the image acquired by an imaging device having a high resolution becomes large, the accumulation time, transfer time, and processing time of the data increase, resulting in a decrease in throughput.

[0013] Therefore, conventionally, an exposure apparatus has been proposed that suppresses a decrease in throughput by reducing the amount of data of the image of each mark acquired by narrowing the imaging range so as to image only the reticle mark and the substrate mark respectively when aligning the reticle and the substrate. On the other hand, in an exposure apparatus, there are cases where high accuracy is not required in the alignment between the original plate and the substrate. In that case, it is not necessary to image the reticle mark and the substrate mark respectively with high resolution.

[0014] That is, if the reticle mark and the substrate mark are imaged with unnecessarily high resolution in such a case, the accumulation time of the data at that time, and the transfer time and processing time of the acquired data increase, causing a decrease in throughput. Therefore, an object of the present embodiment is to provide an exposure apparatus capable of improving throughput according to the accuracy required for alignment between the reticle and the substrate.

[0015] FIG. 1 shows a schematic cross-sectional view of an exposure apparatus 100 according to the present embodiment. The exposure apparatus 100 according to the present embodiment projects an image of a pattern of a reticle 3a onto a substrate 6a and exposes the substrate 6a, for example, when forming patterns on each of a plurality of layers superposed on the substrate 6a.

[0016] The exposure apparatus 100 according to this embodiment includes an illumination optical system 1, an alignment measurement unit 2a (imaging unit, first imaging unit), off-axis measurement units 2b and 2c (imaging units, second imaging units), a reticle stage 3b, and a light-shielding unit 4. The exposure apparatus 100 according to this embodiment further includes a projection optical system 5, a substrate stage 6b, an alignment control unit 8 (control unit), a drive unit 9, and a main control unit 10 (control unit).

[0017] The illumination optical system 1 has at least one optical element that defines an illumination region on the reticle surface of the reticle 3a, and illuminates the illumination region on the reticle surface of the reticle 3a by guiding the exposure light emitted from a light source (not shown) to the reticle 3a. The reticle stage 3b is configured to be movable while holding the reticle 3a such that the reticle surface of the reticle 3a is disposed at the object plane position of the projection optical system 5.

[0018] The light-shielding unit 4 can adjust the exposure region on the substrate surface of the substrate 6a by driving in the X and Y directions. Thereby, the pattern formed on the reticle surface of the reticle 3a can be transferred to a predetermined pattern region (shot region) on the substrate surface of the substrate 6a in an optimal panel layout.

[0019] The projection optical system 5 adopts, for example, a mirror projection method formed by a plurality of mirrors. The projection optical system 5 projects an image of the pattern formed on the reticle 3a onto the substrate surface of the substrate 6a at a predetermined projection magnification (for example, 1:1, 1 / 2, 2 times, etc.) by guiding the exposure light that has passed through the reticle 3a to the substrate 6a. The substrate stage 6b is configured to be movable while holding the substrate 6a, which is, for example, a glass substrate, such that the substrate surface of the substrate 6a is disposed at the image plane position of the projection optical system 5.

[0020] The drive unit 9 is configured to drive the reticle stage 3b and the substrate stage 6b at least in the X and Y directions. The main control unit 10 is configured to control each operation in the exposure apparatus 100 according to this embodiment.

[0021] In the exposure apparatus 100 according to this embodiment, for example, strip-shaped or arc-shaped exposure light is irradiated from the illumination optical system 1 onto the reticle 3a. Then, the exposure light that has passed through the reticle 3a is guided to the substrate 6a by the projection optical system 5, and the reticle stage 3b and the substrate stage 6b scan and move at a speed ratio corresponding to the projection magnification of the projection optical system 5 while being synchronized with each other in the Y direction.

[0022] Thereby, the pattern formed on the reticle surface of the reticle 3a is transferred to a predetermined pattern region on the substrate surface of the substrate 6a. Then, by sequentially repeating the above transfer to each of the plurality of pattern regions on the substrate surface of the substrate 6a while stepwise moving the substrate stage 6b in the X direction, the exposure process for one substrate 6a can be completed.

[0023] In the exposure apparatus 100 according to this embodiment, when transferring the pattern formed on the reticle 3a to each pattern region on the substrate surface of the substrate 6a, alignment between each pattern region and the reticle 3a is performed. Specifically, in the exposure apparatus 100 according to this embodiment, an alignment measurement unit 2a including two alignment scopes that are separated from each other by a predetermined distance in the X direction and are each movable in the XY plane is provided between the illumination optical system 1 and the reticle stage 3b.

[0024] The alignment measurement unit 2a provided in the exposure apparatus 100 according to this embodiment can observe (detect) each of the plurality of substrate marks SXY formed in each pattern region on the substrate surface of the substrate 6a through the projection optical system 5. Further, the alignment measurement unit 2a can observe (detect) each of the plurality of reticle marks MXY formed on the reticle surface of the reticle 3a without passing through the projection optical system 5. That is, the alignment measurement unit 2a can acquire an image (second image) by imaging each of the plurality of substrate marks SXY through the projection optical system 5 and imaging each of the plurality of reticle marks MXY without passing through the projection optical system 5.

[0025] In addition, in the exposure apparatus 100 according to the present embodiment, off-axis measurement units 2b and 2c each including two off-axis scopes spaced apart from each other by a predetermined distance in the X direction are provided between the projection optical system 5 and the substrate stage 6b. Each off-axis scope provided in the off-axis measurement units 2b and 2c is movable in the XY plane.

[0026] The off-axis measurement units 2b and 2c provided in the exposure apparatus 100 according to the present embodiment can observe (detect) each of the plurality of substrate marks SXY formed in each pattern region on the substrate surface of the substrate 6a without passing through the projection optical system 5. That is, the off-axis measurement units 2b and 2c can acquire an image (first image) by imaging each of the plurality of substrate marks SXY without passing through the projection optical system 5.

[0027] FIG. 2 shows an example of an image of the alignment mark FXY acquired by the alignment measurement unit 2a in the exposure apparatus 100 according to the present embodiment. Specifically, in the image of the alignment mark FXY acquired by the alignment measurement unit 2a, an image of the substrate mark SXY formed in a predetermined pattern region on the substrate surface of the substrate 6a and an image of the reticle mark MXY formed on the reticle surface of the reticle 3a are formed. On the other hand, in the image of the alignment mark FXY acquired by the off-axis measurement units 2b and 2c, an image of the substrate mark SXY formed in a predetermined pattern region on the substrate surface of the substrate 6a is formed.

[0028] That is, in the exposure apparatus 100 according to the present embodiment, the positions of a predetermined substrate mark SXY and a reticle mark MXY adjacent to sandwich the predetermined substrate mark SXY are measured by one of the two alignment scopes included in the alignment measurement unit 2a. Further, the positions of another substrate mark SXY and a reticle mark MXY adjacent to sandwich the another substrate mark SXY are measured by the other of the two alignment scopes included in the alignment measurement unit 2a.

[0029] Also, in the exposure apparatus 100 according to the present embodiment, the positions of still another four substrate marks SXY are measured by each of the four off-axis scopes included in the off-axis measurement units 2b and 2c. In this way, the alignment measurement unit 2a and the off-axis measurement units 2b and 2c can simultaneously measure the positions of six substrate marks SXY and the positions of the reticle marks MXY adjacent to two of the six substrate marks SXY respectively.

[0030] Specifically, the positions of each substrate mark SXY and each reticle mark MXY are measured based on the image information of each substrate mark SXY and each reticle mark MXY obtained by photoelectrically converting the light reception amounts in the alignment measurement unit 2a and the off-axis measurement units 2b and 2c. Then, alignment between the reticle 3a and the substrate 6a is performed based on the measured positions of each substrate mark and each reticle mark.

[0031] FIG. 3 shows a partial schematic cross-sectional view of the off-axis measurement unit 2b provided in the exposure apparatus 100 according to the present embodiment. Here, the off-axis measurement unit 2b is shown, but the alignment measurement unit 2a and the off-axis measurement unit 2c also have the same configuration as the off-axis measurement unit 2b.

[0032] As shown in FIG. 3, the illumination light (measurement light) emitted from the alignment light source (illumination light source) 11 such as an optical fiber is guided by the illumination optical system 13 to the polarization beam splitter 14. Next, the illumination light having S polarization perpendicular to the paper surface, which is reflected by the polarization beam splitter 14, passes through the relay lens 15 and the λ / 4 plate (quarter-wave plate) 16, and is converted into illumination light having circular polarization. Then, the converted illumination light is guided by the objective lens 17 to the substrate mark SXY formed in a predetermined pattern region on the substrate surface of the substrate 6a, and the substrate mark SXY is Köhler illuminated.

[0033] Next, the reflected light (or diffracted light or scattered light) from the substrate mark SXY passes through the objective lens 17 and the λ / 4 plate 16 again so as to return the optical path, and is converted into reflected light having P polarization parallel to the paper surface. Then, the converted reflected light passes through the relay lens 15, the polarization beam splitter 14, and the imaging optical system 18, and is guided to the imaging element 19, so that an image of the substrate mark SXY is formed on the imaging surface of the imaging element 19.

[0034] The imaging element 19 provided in the off-axis measurement unit 2b is a two-dimensional photoelectric conversion element having a binning function capable of setting various resolutions by virtually combining a plurality of pixels as will be described in detail later, and the resolution can be changed. The alignment control unit 8 has a setting unit that sets the resolution and integration time in the imaging element 19 and the light amount of the alignment light source 11 based on the process data regarding the alignment accuracy output from the main control unit 10.

[0035] The alignment control unit 8 also has an arithmetic unit that acquires an image captured by the imaging element 19 and calculates the position information of the substrate mark SXY and the master mark MXY based on the acquired image. Then, the calculated position information is output to the main control unit 10, and the main control unit 10 controls the position of the substrate stage 6b based on the input position information, thereby performing alignment between the reticle 3a and the substrate 6a.

[0036] Next, a process of appropriately specifying the resolution for the image sensor 19 by the alignment control unit 8 in the exposure apparatus 100 according to the present embodiment will be described in detail. As described above, in the alignment measurement unit 2a, off-axis measurement units 2b and 2c provided in the exposure apparatus 100 according to the present embodiment, an image sensor 19 with a variable readout resolution is used.

[0037] FIG. 4(a) shows a part of an image obtained by imaging the alignment mark FXY when a high resolution is specified for the image sensor 19, specifically, an enlarged view of the region AR in FIG. 2. FIG. 4(b) shows a part of an image obtained by imaging the alignment mark FXY when a predetermined low resolution is specified for the image sensor 19, specifically, an enlarged view of the region AR in FIG. 2.

[0038] Specifically, the high resolution in FIG. 4(a) is the resolution when binning is not performed on the pixels in the image sensor 19. The predetermined low resolution in FIG. 4(b) is the resolution when 2×2 binning is performed on the pixels in the image sensor 19.

[0039] In the exposure apparatus 100 according to the present embodiment, in a process that requires high alignment accuracy in the alignment between the reticle 3a and the substrate 6a, as shown in FIG. 4(a), a high resolution is specified for the image sensor 19, and the alignment mark FXY is imaged.

[0040] On the other hand, in a process where the requirement for alignment accuracy in the alignment between the reticle 3a and the substrate 6a is low, for example, as shown in FIG. 4(b), a predetermined low resolution is specified for the image sensor 19, and the alignment mark FXY is imaged. That is, in the exposure apparatus 100 according to the present embodiment, the resolution of the imaging device 19 is determined from the alignment accuracy between the reticle 3a and the substrate 6a. In other words, in the exposure apparatus 100 according to the present embodiment, the imaging device 19 changes the resolution by performing binning based on the alignment accuracy between the reticle 3a and the substrate 6a.

[0041] Here, each process means a process of forming each pattern layer that is superposed on the substrate surface of the substrate 6a, for example. In the exposure apparatus 100 according to the present embodiment, in a process where the requirement for alignment accuracy is low as described above, the resolution of the imaging device 19 is specified to be low, thereby reducing the amount of data of the image acquired by the imaging device 19. Thereby, the accumulation time required for imaging the alignment mark FXY, and the transfer time and processing time of the image acquired by the imaging can be reduced.

[0042] The resolution specified for the imaging device 19 by the alignment control unit 8 is determined from a table showing the relationship between the required alignment accuracy set by the main control unit 10 and the measurement accuracy of the positions of the substrate mark SXY and the reticle mark MXY. And the measurement accuracy improves as the resolution specified for the imaging device 19 increases, while it decreases as the resolution specified for the imaging device 19 decreases.

[0043] The table may be determined in advance as described later, and can be determined as shown in FIG. 5, for example. Specifically, the table shown in FIG. 5 plots the resolution that can ensure the measurement accuracy of the positions of the substrate mark SXY and the reticle mark MXY determined based on the required alignment accuracy.

[0044] More specifically, in the table shown in FIG. 5, the binning size is shown as the resolution. That is, when the binning size is n (n = 1, 2, 3, ···), it means that n pixels are virtually combined with each other along a predetermined direction. For example, when the binning size is 1, it means that each pixel is not combined with each other. When the binning size is 3, it means that three pixels are virtually combined with each other along a predetermined direction.

[0045] As shown in FIG. 5, in the table, the binning size 1 is set when the required alignment accuracy is 400 nm or more and less than 420 nm. That is, a high resolution without binning for the imaging device 19 is specified, and the alignment mark FXY is imaged. On the other hand, the binning size 2 is set when the required alignment accuracy is 420 nm or more and less than 450 nm, and the binning size 3 is set when the required alignment accuracy is 450 nm or more and less than 490 nm.

[0046] Also, the binning size 4 is set when the required alignment accuracy is 490 nm or more and less than 550 nm, and the binning size 5 is set when the required alignment accuracy is 550 nm or more. As described above, when the required alignment accuracy is relatively low, a relatively low resolution with binning for the imaging device 19 is specified, and the alignment mark FXY is imaged, thereby ensuring the alignment accuracy between the original plate 3a and the substrate 6a.

[0047] Also, in the exposure apparatus 100 according to the present embodiment, the accumulation time at each pixel in the imaging device 19 and the light amount of the alignment light source 11 are determined. Specifically, the accumulation time and the light amount are determined based on the resolution determined as described above in the imaging device 19.

[0048] For example, the accumulation time and the light amount can be obtained in advance such that the measurement accuracy of the positions of the substrate mark SXY and the original plate mark MXY becomes high according to each resolution specified for the imaging device 19. Also, the accumulation time and the amount of light may be changed, that is, reset based on the luminance measured in an image captured at a predetermined accumulation time and light amount in the past, for example, in the previous time.

[0049] FIG. 6 is a flowchart showing a process of calculating the positions of the respective substrate marks SXY and the respective reticle marks MXY in the exposure apparatus 100 according to the present embodiment. First, before the process is performed, for example, the alignment accuracies (first accuracy, second accuracy) in the X direction and the Y direction respectively required for the alignment between the reticle 3a and the substrate 6a when exposing a predetermined layer on the substrate 6a are manually input to the main control unit 10.

[0050] When the process starts, the alignment control unit 8 acquires information on the alignment accuracy required in each of the X direction and the Y direction from the main control unit 10 (step S101, first acquisition step). Next, the alignment control unit 8 determines whether it is possible to perform binning in the X direction based on the input alignment accuracy required in the X direction (step S102, first determination step).

[0051] Specifically, in step S102, the alignment control unit 8 refers to a table showing the relationship (first relationship) between the alignment accuracy in the X direction and the binning size (first binning size) of the image sensor 19. Then, from the reference, the binning size (first resolution, second resolution) corresponding to the input alignment accuracy required in the X direction is determined. If it is determined that the determined binning size in the X direction is 2 or more, that is, binning can be performed (Yes in step S102), the determined binning size is set in the X direction (step S103, first determination step). Then, the process proceeds to step S104.

[0052] On the other hand, if it is determined that binning is not performed because the binning size in the X direction is 1, that is, it is difficult to ensure the required alignment accuracy for binning (No in step S102), the process proceeds to step S104. That is, in this case, without performing step S103, high resolution is set in the X direction for the imaging device 19.

[0053] Next, in step S104, the alignment control unit 8 determines whether binning can be performed in the Y direction based on the required alignment accuracy in the input Y direction (first determination step). Specifically, in step S104, the alignment control unit 8 refers to a table showing the relationship (second relationship) between the alignment accuracy in the Y direction and the binning size (second binning size) of the imaging device 19. Then, from this reference, the binning size (first resolution, second resolution) corresponding to the required alignment accuracy in the input Y direction is determined. If it is determined that the determined binning size in the Y direction is 2 or more, that is, binning can be performed (Yes in step S104), the determined binning size is set in the Y direction (steps S105, first determination step). Then, the process proceeds to step S106.

[0054] On the other hand, if it is determined that binning is not performed because the binning size in the Y direction is 1, that is, it is difficult to ensure the required alignment accuracy for binning (No in step S104), the process proceeds to step S106. That is, in this case, without performing step S105, high resolution is set in the Y direction for the imaging device 19.

[0055] Next, in step S106, the alignment control unit 8 sets the accumulation time for each pixel in the imaging device 19 provided in each of the alignment measurement unit 2a, the off-axis measurement units 2b and 2c, and the light amount of the alignment light source 11. Specifically, in step S106, a table (not shown) indicating the relationship (the third relationship) between the binning sizes in the X and Y directions, the accumulation time, and the amount of light is referred to. Then, based on the determined binning sizes in the X and Y directions from the reference, the accumulation time and the amount of light are set. Then, under the set conditions, the alignment control unit 8 causes the alignment measurement unit 2a, the off-axis measurement units 2b and 2c to image the alignment mark FXY respectively (step S107, the first imaging step).

[0056] Next, the alignment control unit 8 determines whether the maximum value of the luminance in the image captured in step S107 is within a predetermined range (step S108). For example, when the captured image (image information) is 8-bit output, it is desirable that the maximum value of the luminance is 200 bits or more and less than 250 bits. If the maximum value of the luminance is not within the predetermined range (No in step S108), at least one of the accumulation time for each pixel in the imaging device 19 and the amount of light of the alignment light source 11 is reset (changed) (step S109), and the process returns to step S107.

[0057] Specifically, in step S109, if the maximum value of the luminance is lower than the predetermined range, that is, if the required luminance cannot be ensured, the accumulation time is reset to increase it and / or the amount of light is reset to increase it. On the other hand, if the maximum value of the luminance is higher than the predetermined range, the accumulation time is reset to reduce it and / or the amount of light is reset to reduce it.

[0058] If the maximum value of the luminance in the image captured in step S107 is within the predetermined range (Yes in step S108), the alignment control unit 8 calculates the positions of the substrate mark SXY and the reticle mark MXY from the captured image (step S110). That is, in step S110, the alignment control unit 8 calculates the amount of misalignment (first misalignment amount) of the substrate mark SXY with respect to the original plate mark MXY in the XY plane (first plane) from the captured image (first calculation step). Then, the process ends.

[0059] After the process ends, the main control unit 10 moves at least one of the original plate stage 3b, the projection optical system 5, and the substrate stage 6b based on the calculated amount of misalignment (first driving step, alignment step). Then, the main control unit 10 controls an exposure process of projecting an image of the pattern of the original plate 3a onto the substrate 6a and exposing the substrate 6a.

[0060] FIG. 7 is a flowchart showing a process (second determination step) of creating a table showing the relationship between the alignment accuracy required for alignment between the original plate 3a and the substrate 6a in the exposure apparatus 100 and the resolution in the image sensor 19, specifically the binning size. As will be described in detail later, in the exposure apparatus 100, after performing the alignment while changing the resolution with respect to the image sensor 19, the alignment control unit 8 measures the misalignment of each substrate mark SXY with respect to the original plate mark MXY or the reference position. Thereby, an appropriate resolution is determined for the alignment accuracy required for the alignment.

[0061] That is, in this process, the relationship between the alignment accuracy required for alignment between the original plate 3a and the substrate 6a in each of the X direction and the Y direction and the resolution in the image sensor 19, specifically the binning size, is determined (third determination step). Note that this process may be performed using an exposure substrate before actual exposure, or may be performed in advance using an adjustment substrate on which the substrate mark SXY for alignment is exposed.

[0062] First, before this process is performed, information on a plurality of alignment accuracies is manually input to the main control unit 10. When the process starts, information on the plurality of alignment accuracies is input from the main control unit 10 to the alignment control unit 8 (step S201).

[0063] Next, the alignment control unit 8 selects (acquires) a predetermined alignment accuracy from among the input plurality of alignment accuracies (step S202, second acquisition step). Then, the binning size is set in each of the X direction and the Y direction so that the initial value of the resolution in the image pickup device 19 becomes the lowest resolution for the image pickup device 19 (step S203, first setting step).

[0064] For example, in step S203, a 5×5 binning size is set as the lowest resolution for the image pickup device 19. In step S203, for example, when the binning size for an alignment accuracy lower (worse) than the predetermined alignment accuracy has already been determined, the binning size may be set as the initial value of the resolution for the predetermined alignment accuracy.

[0065] Next, the alignment control unit 8 causes the alignment measurement unit 2a, the off-axis measurement units 2b and 2c, in which 5×5 binning is performed respectively, to image the alignment mark FXY. Thereby, the positions of the respective original plate marks MXY and the respective substrate marks SXY are measured (step S204, second imaging step). Then, the amount of positional deviation (second amount of positional deviation) in the X direction and the amount of positional deviation (third amount of positional deviation) in the Y direction of each substrate mark SXY are calculated from the measured positions of the respective original plate marks MXY and the respective substrate marks SXY (step S205, second calculation step).

[0066] Specifically, in step S205, the amount of positional deviation in each of the X direction and the Y direction of each substrate mark SXY with respect to each original plate mark MXY is calculated from the image acquired by the alignment measurement unit 2a. In step S205, the amounts of positional deviation in the X direction and the Y direction of each substrate mark SXY with respect to the reference position are calculated from the images acquired by the off-axis measurement units 2b and 2c. Here, the reference position is a position determined based on the relative positions of the off-axis measurement units 2b and 2c with respect to the alignment measurement unit 2a. In other words, it is a reference position in the coordinate systems of the off-axis measurement units 2b and 2c.

[0067] Next, the alignment control unit 8 inputs the calculated amount of positional deviation to the main control unit 10. By controlling the driving of the original plate stage 3b, the projection optical system 5, and the substrate stage 6b, the main control unit 10 performs correction driving (step S206, the second driving step). Specifically, in step S206, for example, by driving a predetermined correction glass included in the projection optical system 5, the magnification component included in the amount of positional deviation is corrected.

[0068] Also in step S206, for example, by offset driving the position in the XY plane of the original plate stage 3b, the shift component included in the amount of positional deviation is corrected. Also in step S206, for example, by rotating the substrate stage 6b in the XY plane, the rotation component included in the amount of positional deviation is corrected.

[0069] Next, the alignment control unit 8 causes the alignment measurement unit 2a and the off-axis measurement units 2b and 2c to image the alignment mark FXY (the third imaging step). Then, from the image of the alignment mark FXY acquired by the alignment measurement unit 2a, the amount of positional deviation in the X direction (the fourth amount of positional deviation) and the amount of positional deviation in the Y direction (the fifth amount of positional deviation) of each substrate mark SXY with respect to each original plate mark MXY are calculated.

[0070] Also, the amount of deviation of each substrate mark SXY from the reference position in each of the X direction and the Y direction is calculated from the images of the alignment mark FXY acquired by the off-axis measurement units 2b and 2c, respectively (step S207, third calculation step). In step S207, in order to improve the accuracy of the measurement in each of the X direction and the Y direction, it is preferable to specify a high resolution for the imaging device 19, that is, to set the binning size to a smaller value (second setting step).

[0071] Next, it is determined whether or not the amount of deviation measured in step S207 is equal to or less than an allowable value determined based on the predetermined alignment accuracy set in step S202 (step S208). That is, in step S208, it is determined whether or not the amount of deviation in the X direction calculated in step S207 is equal to or less than an allowable value (first allowable value) determined based on the set predetermined alignment accuracy (first determination step). Also, in step S208, it is determined whether or not the amount of deviation in the Y direction calculated in step S207 is equal to or less than an allowable value (second allowable value) determined based on the set predetermined alignment accuracy (second determination step).

[0072] Consider the case where the amounts of deviation in both the X direction and the Y direction measured in the images of the alignment mark FXY acquired by the alignment measurement unit 2a and the off-axis measurement units 2b and 2c, respectively, are both equal to or less than the allowable value (Yes in step S208). In this case, in each of the alignment measurement unit 2a and the off-axis measurement units 2b and 2c, the binning size in the measurement in step S204 is determined as the resolution corresponding to the predetermined alignment accuracy set in step S202 (step S210). Then, the process proceeds to step S211.

[0073] Consider the case where at least one of the amounts of positional deviation in the X and Y directions calculated in step S207 is greater than the allowable value (No in step S208). In this case, set the binning size in the predetermined measurement unit where the amount of positional deviation greater than the allowable value is measured in a predetermined direction to be smaller by a predetermined size (step S209). Then, return to step S204.

[0074] Specifically, in step S210, for example, reset the binning size to be smaller by 1. By repeating steps S204 to S208 in this way, the resolution of the imaging element 19 in each of the alignment measurement unit 2a, the off-axis measurement units 2b and 2c that is appropriate for the predetermined alignment accuracy set in step S202 can be determined.

[0075] In step S211, it is determined whether the resolution determination in step S210 has been performed for all of the plurality of alignment accuracies input in step S201. If the determination has not been made for at least one of the plurality of alignment accuracies (No in step S211), return to step S202 and continue the process. On the other hand, if the determination has been made for all of the plurality of alignment accuracies, end the process.

[0076] As described above, in the exposure apparatus 100 according to the present embodiment, an imaging element 19 with variable resolution by performing binning and an alignment control unit 8 for changing the binning size in the imaging element 19 are provided. Then, the binning size in the imaging element 19 provided in each of the alignment measurement unit 2a, the off-axis measurement units 2b and 2c is changed according to the alignment accuracy required for the alignment between the reticle 3a and the substrate 6a.

[0077] That is, the measurement accuracy of the positions of the original mark MXY formed on the original plate 3a and the substrate mark SXY formed on the substrate 6a is changed according to the alignment accuracy required for the alignment between the original plate 3a and the substrate 6a. For example, in the exposure apparatus 100 according to the present embodiment, the resolution when the imaging device 19 acquires an image of each mark is different for at least two of the plurality of layers that are superposed on each other on the substrate 6a.

[0078] When the alignment accuracy required for the alignment is low, the data amount of the image acquired by the imaging device 19 can be reduced by increasing the binning size in the imaging device 19 to set a low resolution. Thereby, the throughput can be improved by reducing the accumulation time, transfer time, and processing time of the data of the image.

[0079] Therefore, even if the imaging device 19 having a high resolution is provided, the positions of the original mark MXY and the substrate mark SXY can be measured while improving the throughput according to the required alignment accuracy. That is, in the exposure apparatus 100 according to the present embodiment, the throughput can be easily improved without using a difficult configuration of replacing the imaging device 19 or changing the optical system that guides the measurement light to the imaging device 19 according to the required alignment accuracy. Further, in the exposure apparatus 100 according to the present embodiment, the resolution of the imaging device 19 corresponding to each alignment accuracy, that is, the binning size, can be determined based on the measurement results of the positions of the original mark MXY and the substrate mark SXY.

[0080] Note that in the exposure apparatus 100 according to the present embodiment, both the alignment measurement unit 2a and the off-axis measurement units 2b and 2c are configured to be binnable, but it is not limited thereto. That is, if one of the alignment measurement unit 2a and the off-axis measurement units 2b and 2c, for example, the off-axis measurement units 2b and 2c, can be binned, the above-described effects can be achieved.

[0081] [Method for manufacturing an article] The method for manufacturing a semiconductor device as an article according to this embodiment includes a pre-process of forming an integrated circuit chip on a wafer and a post-process of completing the integrated circuit chip on the wafer formed by the pre-process as a product. The pre-process includes a step of exposing a wafer coated with a photosensitive agent using the exposure apparatus 100 according to this embodiment and a step of developing the wafer. The post-process also includes an assembly process (dicing and bonding) and a packaging (encapsulation) process.

[0082] The method for manufacturing a liquid crystal display device as an article according to this embodiment includes a step of forming a transparent electrode. The step of forming the transparent electrode includes a step of applying a photosensitive agent to a glass substrate on which a transparent conductive film is vapor-deposited, a step of exposing the glass substrate coated with the photosensitive agent using the exposure apparatus 100 according to this embodiment, and a step of developing the glass substrate.

[0083] According to the method for manufacturing an article according to this embodiment, an article of higher quality than the conventional manufacturing method can be manufactured. Although the preferred embodiments have been described above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist thereof.

[0084] The disclosure of this embodiment includes the following configurations and methods. Exposure apparatus (Configuration 1) that projects an image of an original pattern onto a substrate and exposes the substrate, comprising: an imaging unit that acquires a first image of a substrate mark formed on the substrate; and a control unit that controls the position of the substrate based on the first image acquired by the imaging unit, wherein a first resolution at which the imaging unit acquires the first image in order to expose at least two of a plurality of layers on the substrate is different from each other. Exposure apparatus according to Configuration 1, characterized in that the first resolution is determined based on a first accuracy of alignment of the position of the substrate. Exposure apparatus according to Configuration 1 or 2, characterized in that the imaging unit changes the first resolution by performing binning. Exposure apparatus according to any one of Configurations 1 to 3, characterized in that the control unit performs: a first acquisition step of acquiring a first accuracy of alignment of the position of the substrate when exposing a predetermined layer among the plurality of layers; a first determination step of determining the first resolution according to the first accuracy acquired by the first acquisition step; and a first imaging step of causing the imaging unit, in which the first resolution determined by the first determination step is set, to acquire the first image. Exposure apparatus according to Configuration 4, further comprising a projection optical system that projects an image onto the substrate by guiding exposure light that has passed through the original onto the substrate, wherein the first determination step includes a step of determining a first binning size corresponding to the first accuracy acquired by the first acquisition step from a first relationship between a first binning size in a first direction in a first plane perpendicular to the optical axis of the projection optical system and the first accuracy. Exposure apparatus according to Configuration 5, characterized in that the first determination step includes a step of determining a second binning size corresponding to the first accuracy acquired by the first acquisition step from a second relationship between a second binning size in a second direction perpendicular to the first direction in the first plane and the first accuracy. (Configuration 7) The imaging unit includes a light source that emits measurement light toward the substrate mark. The first imaging step includes determining an accumulation time and a light amount corresponding to a first binning size and a second binning size determined from a third relationship between the first binning size and the second binning size, the accumulation time in the imaging element of the imaging unit when acquiring the first image, and the light amount of the measurement light emitted from the light source. The exposure apparatus according to Configuration 6 is characterized by this. (Configuration 8) The first imaging step includes a step of acquiring a first image with the determined first binning size, second binning size, accumulation time, and light amount, and a step of determining whether the maximum value of the luminance in the acquired first image is within a predetermined range. The exposure apparatus according to Configuration 7 is characterized by this. (Configuration 9) The first imaging step includes a step of changing at least one of the accumulation time and the light amount when the maximum value is not within the predetermined range. The exposure apparatus according to Configuration 8 is characterized by this. (Configuration 10) An original stage movable while holding the original, a projection optical system that projects an image onto the substrate by guiding the exposure light that has passed through the original to the substrate, and a substrate stage movable while holding the substrate are provided. The control unit calculates a first position deviation amount of the substrate mark with respect to the original mark formed on the original in a first plane perpendicular to the optical axis of the projection optical system from the first image acquired in the first imaging step, a first driving step of moving at least one of the original stage, the projection optical system, and the substrate stage based on the first position deviation amount calculated in the first calculating step, and an exposure step of projecting the image onto a predetermined layer and exposing the predetermined layer. The exposure apparatus according to any one of Configurations 4 to 9 is characterized by this. (Configuration 11) The control unit performs a second determination step of determining the relationship between the first accuracy and the first resolution. The exposure apparatus according to any one of Configurations 4 to 10 is characterized by this. (Configuration 12) An exposure apparatus comprising a projection optical system that projects an image onto a substrate by guiding exposure light that has passed through a reticle to the substrate, wherein the second determination step includes a third determination step of determining a first relationship between a first binning size and a first accuracy in a first direction in a first plane perpendicular to the optical axis of the projection optical system, and a second relationship between a second binning size and the first accuracy in a second direction perpendicular to the first direction in the first plane, the exposure apparatus according to Configuration 11. (Configuration 13) The third determination step includes a second acquisition step of acquiring a predetermined accuracy of alignment of the position of the substrate, a first setting step of setting each of the first binning size and the second binning size to a predetermined value, and a second imaging step of acquiring a first image at the first binning size and the second binning size set by the first setting step, the exposure apparatus according to Configuration 12. (Configuration 14) The exposure apparatus includes a reticle stage movable while holding the reticle and a substrate stage movable while holding the substrate, and the third determination step includes a second calculation step of calculating a second displacement amount in the first direction and a third displacement amount in the second direction of a substrate mark with respect to a reticle mark formed on the reticle from the first image acquired by the second imaging step, and a second driving step of moving at least one of the reticle stage, the projection optical system, and the substrate stage based on the second displacement amount and the third displacement amount calculated by the second calculation step, the exposure apparatus according to Configuration 13. (Configuration 15) The third determination step includes a second setting step of setting each of the first binning size and the second binning size to a value smaller than a predetermined value, and a third imaging step of acquiring the first image after performing the second driving step and the second setting step, the exposure apparatus according to Configuration 14. (Configuration 16) The third determination step includes a third calculation step of calculating a fourth position deviation amount in a first direction and a fifth position deviation amount in a second direction of the substrate mark with respect to the original mark from a first image acquired by the third imaging step, a first determination step of determining whether the fourth position deviation amount calculated by the third calculation step is less than or equal to a first allowable value determined from a predetermined accuracy, and a second determination step of determining whether the fifth position deviation amount calculated by the third calculation step is less than or equal to a second allowable value determined from a predetermined accuracy. The exposure apparatus according to Configuration 15, characterized in that it comprises the above. (Configuration 17) The third determination step includes a step of determining the first binning size and the second binning size set by the first setting step as the first binning size and the second binning size corresponding to a predetermined accuracy when it is determined in the first determination step that the fourth position deviation amount is less than or equal to the first allowable value and it is determined in the second determination step that the fifth position deviation amount is less than or equal to the second allowable value. The exposure apparatus according to Configuration 16, characterized in that it comprises the above. (Configuration 18) The imaging unit is configured to acquire a second image of the original mark formed on the original, the control unit is configured to control the position of the original based on the second image acquired by the imaging unit, the first acquisition step includes a step of acquiring a second accuracy of alignment of the position of the original when exposing a predetermined layer, the first determination step includes a step of determining a second resolution according to the second accuracy acquired by the first acquisition step, and the first imaging step includes a step of causing the imaging unit set with the second resolution determined by the first determination step to acquire a second image. The exposure apparatus according to any one of Configurations 4 to 17, characterized in that it comprises the above. (Configuration 19) It is provided with a projection optical system that projects an image onto the substrate by guiding the exposure light that has passed through the original to the substrate. The imaging unit includes a first imaging unit that images the original mark formed on the original and images the substrate mark through the projection optical system, and a second imaging unit that images the substrate mark without passing through the projection optical system. The exposure apparatus according to any one of Configurations 1 to 18, characterized in that it comprises the above. A method for manufacturing an article, comprising: exposing a substrate by the exposure apparatus according to any one of Configurations 1 to 19; developing the exposed substrate; and manufacturing an article from the developed substrate. A lithography method of projecting an image of a reticle pattern onto a substrate using an exposure apparatus including an imaging unit capable of imaging a substrate mark formed on the substrate, and exposing the substrate, the method including: a first imaging step of obtaining an image of the substrate mark by the imaging unit; and an alignment step of aligning the substrate based on the image obtained in the first imaging step, wherein resolutions in the first imaging step for exposing at least two of a plurality of layers in the substrate are different from each other.

Description of Reference Numerals

[0085] 2b, 2c off-axis measurement unit (imaging unit) 3a reticle 6a substrate 8 alignment control unit (control unit) 10 main control unit (control unit) 100 exposure apparatus SXY substrate mark

Claims

1. An exposure apparatus that projects an image of an original pattern onto a substrate and exposes the substrate, comprising: an imaging unit that acquires a first image of a substrate mark formed on the substrate; a control unit that controls the position of the substrate based on the first image acquired by the imaging unit; and comprising: wherein, when the imaging unit acquires the first image in order to expose at least two of a plurality of layers on the substrate, a first resolution at this time is different for each layer, and the exposure apparatus is characterized in this.

2. The exposure apparatus according to claim 1, wherein the first resolution is determined based on a first accuracy of alignment of the position of the substrate.

3. The exposure apparatus according to claim 1, wherein the imaging unit changes the first resolution by performing binning.

4. The control unit: a first acquisition step of acquiring a first accuracy of alignment of the position of the substrate when exposing a predetermined layer among the plurality of layers; a first determination step of determining the first resolution according to the first accuracy acquired by the first acquisition step; and a first imaging step of causing the imaging unit, in which the first resolution determined by the first determination step is set, to acquire the first image, and the exposure apparatus according to claim 1 is characterized by performing these steps.

5. comprising a projection optical system that projects the image onto the substrate by guiding exposure light that has passed through the original onto the substrate, wherein the first determination step includes a step of determining a first binning size corresponding to the first accuracy acquired by the first acquisition step from a first relationship between a first binning size in a first direction in a first plane perpendicular to the optical axis of the projection optical system and the first accuracy, and the exposure apparatus according to claim 4 is characterized in this.

6. The exposure apparatus according to claim 5, wherein the first determination step includes a step of determining a second binning size corresponding to the first accuracy acquired by the first acquisition step from a second relationship between a second binning size in a second direction perpendicular to the first direction in the first plane and the first accuracy.

7. The imaging unit includes a light source that emits measurement light toward the substrate mark. The first imaging step includes determining the accumulation time and the light quantity of the measurement light emitted from the light source corresponding to the first binning size and the second binning size determined from a third relationship between the first binning size and the second binning size and the accumulation time in the imaging element of the imaging unit when acquiring the first image. The exposure apparatus according to claim 6 is characterized by this.

8. The first imaging step includes the step of acquiring the first image with the determined first binning size, second binning size, accumulation time, and light quantity, and the step of determining whether the maximum value of the luminance in the acquired first image is within a predetermined range. The exposure apparatus according to claim 7 is characterized by including these.

9. The first imaging step includes the step of changing at least one of the accumulation time and the light quantity when the maximum value is not within the predetermined range. The exposure apparatus according to claim 8 is characterized by this.

10. a reticle stage movable while holding the reticle, a projection optical system that projects the image onto the substrate by guiding the exposure light that has passed through the reticle to the substrate, a substrate stage movable while holding the substrate, and includes the control unit performs a first calculation step of calculating a first position deviation amount of the substrate mark with respect to the reticle mark formed on the reticle in a first plane perpendicular to the optical axis of the projection optical system from the first image acquired by the first imaging step, a first driving step of moving at least one of the reticle stage, the projection optical system, and the substrate stage based on the first position deviation amount calculated by the first calculation step, and an exposure step of projecting the image onto the predetermined layer and exposing the predetermined layer. The exposure apparatus according to claim 4 is characterized by performing these.

11. The control unit performs a second determination step of determining the relationship between the first accuracy and the first resolution. The exposure apparatus according to claim 4 is characterized by this.

12. includes a projection optical system that projects the image onto the substrate by guiding the exposure light that has passed through the reticle to the substrate The second determination step includes a third determination step of determining a first relationship between a first binning size in a first direction in a first plane perpendicular to the optical axis of the projection optical system and the first accuracy, and a second relationship between a second binning size in a second direction perpendicular to the first direction in the first plane and the first accuracy. The exposure apparatus according to claim 11, wherein:

13. The third determination step includes: a second acquisition step of acquiring a predetermined accuracy of alignment of the position of the substrate; a first setting step of setting each of the first binning size and the second binning size to a predetermined value; a second imaging step of acquiring the first image at the first binning size and the second binning size set by the first setting step; The exposure apparatus according to claim 12, wherein:

14. a reticle stage movable while holding the reticle; a substrate stage movable while holding the substrate; comprising: The third determination step includes: a second calculation step of calculating a second position deviation amount in the first direction and a third position deviation amount in the second direction of the substrate mark with respect to the reticle mark formed on the reticle from the first image acquired by the second imaging step; a second driving step of moving at least one of the reticle stage, the projection optical system, and the substrate stage based on the second position deviation amount and the third position deviation amount calculated by the second calculation step; The exposure apparatus according to claim 13, wherein:

15. The third determination step includes: a second setting step of setting each of the first binning size and the second binning size to a value smaller than the predetermined value; a third imaging step of acquiring the first image after performing the second driving step and the second setting step; The exposure apparatus according to claim 14, wherein:

16. The third determination step includes: a third calculation step of calculating a fourth position deviation amount in the first direction and a fifth position deviation amount in the second direction of the substrate mark with respect to the reticle mark from the first image acquired by the third imaging step; a first determination step of determining whether the fourth position deviation amount calculated by the third calculation step is less than or equal to a first allowable value determined from the predetermined accuracy; A second determination step of determining whether the fifth amount of positional deviation calculated by the third calculation step is equal to or less than a second allowable value determined from the predetermined accuracy; The exposure apparatus according to claim 15, comprising the above.

17. The third determination step includes, when it is determined in the first determination step that the fourth amount of positional deviation is equal to or less than the first allowable value and it is determined in the second determination step that the fifth amount of positional deviation is equal to or less than the second allowable value, determining the first binning size and the second binning size set by the first setting step as the first binning size and the second binning size corresponding to the predetermined accuracy. The exposure apparatus according to claim 16, characterized by including the above.

18. The imaging unit is configured to acquire a second image of a reticle mark formed on the reticle, The control unit is configured to control the position of the reticle based on the second image acquired by the imaging unit, The first acquisition step includes a step of acquiring a second accuracy of alignment of the position of the reticle when exposing the predetermined layer, The first determination step includes a step of determining a second resolution according to the second accuracy acquired by the first acquisition step, The first imaging step includes a step of causing the imaging unit, in which the second resolution determined by the first determination step is set, to acquire the second image. The exposure apparatus according to claim 4, characterized by including the above.

19. A projection optical system that projects the image onto the substrate by guiding the exposure light that has passed through the reticle to the substrate, The imaging unit includes a first imaging unit that images a reticle mark formed on the reticle and images the substrate mark through the projection optical system, and a second imaging unit that images the substrate mark without passing through the projection optical system. The exposure apparatus according to claim 1, characterized by including the above.

20. A step of exposing a substrate with the exposure apparatus according to any one of claims 1 to 19; A step of developing the exposed substrate; Including, A method for manufacturing an article, characterized by manufacturing an article from the developed substrate.

21. An exposure method of projecting an image of a pattern of a reticle onto a substrate and exposing the substrate using an exposure apparatus including an imaging unit capable of imaging a substrate mark formed on the substrate, A first imaging step of causing the imaging unit to acquire an image of the substrate mark; An alignment step of aligning the substrate based on the image acquired in the first imaging step; comprising; An exposure method, wherein resolutions in the first imaging step for exposing at least two of a plurality of layers in the substrate are different from each other.

Images