Illumination optical system, exposure apparatus, adjustment method, and article manufacturing method

Abstract

To provide a technique which is advantageous for reducing occurrence of an excessive load on a block plate for regulating a light radiation region of a surface to be illuminated.SOLUTION: An illumination optical system for illuminating a surface to be illuminated by light from a light source, comprises: a block plate for regulating a shape of a light radiation region on a surface to be illuminated; a deforming part for driving the block plate to deform it; a detecting part for detecting a displacement on each of a plurality of parts on the block plate: and a control part for adjusting a shape of the light radiation region by controlling the deforming part. The control part restricts the deformation of the block plate by the deforming part so that a displacement difference between adjacent parts on the plurality of parts does not become greater than a threshold value, on the basis of a detection result output by the detecting part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an illumination optical system, an exposure apparatus, an adjustment method, and a method for manufacturing an article. [Background technology]

[0002] An exposure apparatus is provided with an illumination optical system that illuminates a mask (original) as an illumination surface, and a projection optical system that projects an image of the mask pattern illuminated by the illumination optical system onto a substrate. The illumination optical system forms a secondary light source, which is essentially a surface light source consisting of multiple light sources, through a fly's eye lens (e.g., a micro fly's eye lens) that functions as an optical integrator, by collecting light beams emitted from a light source. The light beams from the secondary light source are then collected by a condenser lens to superimpose and illuminate a mask on which a predetermined pattern is formed. The projection optical system also forms an image on the substrate using light that has passed through the mask pattern. In this way, the exposure apparatus can transfer the image of the mask pattern onto the substrate.

[0003] In an exposure apparatus, it is essential to obtain a uniform exposure dose (cumulative exposure dose) on the substrate in order to accurately transfer a fine pattern formed on a mask onto the substrate. Therefore, in the exposure apparatus, a light-shielding plate (variable blade) that defines the shape of the light irradiation area on the mask is provided at a position optically conjugate with the mask in the illumination optical system (see, for example, Patent Document 1). Patent Document 1 discloses a technology for correcting the exposure dose distribution on the substrate by individually driving each of multiple locations (positions) on the light-shielding plate to deform the plate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-66956 Summary of the Invention [Problem to be solved by the invention]

[0005] As disclosed in Patent Document 1, when each of multiple locations on the light-shielding plate is driven individually to deform the variable blade, depending on the amount of drive between adjacent locations, excessive load may be placed on the light-shielding plate, causing it to break or undergo plastic deformation.

[0006] Therefore, an object of the present invention is to provide an advantageous technique for reducing excessive load on a light-shielding plate that defines the light-irradiated area of ​​the illuminated surface. [Means for solving the problem]

[0007] In order to achieve the above object, an illumination optical system according to one aspect of the present invention is an illumination optical system that illuminates an illumination target surface with light from a light source, and includes a light blocking plate that defines the shape of a light irradiation area on the illumination target surface, a deformation unit that drives and deforms the light blocking plate, and a displacement unit that determines the displacement of each of a plurality of points on the light blocking plate. acquisition and a control unit that adjusts the shape of the light irradiation area by controlling the deformation unit, and the control unit controls the deformation unit based on the detection result of the detection unit during adjustment of the shape of the light irradiation area so that a displacement difference between adjacent points in the plurality of points does not exceed a threshold. Control It is characterized by:

[0008] Further objects and other aspects of the present invention will become apparent from the following description of preferred embodiments with reference to the accompanying drawings. [Effects of the Invention]

[0009] According to the present invention, for example, it is possible to provide an advantageous technique for reducing excessive load on a light shielding plate that defines a light irradiation area on an illumination surface. [Brief explanation of the drawings]

[0010] [Figure 1] Schematic diagram showing an example of the configuration of an exposure apparatus [Figure 2] FIG. 1 is a plan view showing an example of the configuration of a slit beam forming unit according to a first embodiment; [Figure 3] FIG. 10 is a diagram for explaining shape control of the variable blade in the slit light forming unit. [Figure 4] A diagram showing the relationship between the load on the variable blade and the safety factor for the variable blade's strength. [Figure 5] Flowchart showing control of exposure apparatus [Figure 6] Flowchart showing the determination process of the first embodiment [Figure 7] 1 is a flowchart showing an adjustment process according to a first embodiment; [Figure 8] FIG. 10 is a plan view showing a configuration example of a slit beam forming unit according to a second embodiment; [Figure 9] Flowchart showing the determination process of the second embodiment [Figure 10] 10 is a flowchart showing an adjustment process according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0012] First Embodiment A first embodiment of the present invention will be described. FIG. 1 is a schematic diagram showing an example configuration of an exposure apparatus 100 of this embodiment. The exposure apparatus 100 is an exposure apparatus that performs scanning exposure of a substrate 15 using slit light, and can include an illumination optical system 1, an alignment scope 2, a projection optical system 4, a substrate stage 16, and a controller 17. Scanning exposure is performed on each of a plurality of shot areas on the substrate 15. A mask 3 serving as an original is disposed between the alignment scope 2 and the projection optical system 4, and is held by an original stage (not shown) so as to be movable in the scanning direction (the Y-axis direction in FIG. 1). The substrate 15 is also held by the substrate stage 16 so as to be movable in the scanning direction.

[0013] The illumination optical system 1 is an optical system that illuminates a mask 3 (illuminated surface) with light from a light source 5. The illumination optical system 1 includes, for example, a light source 5, a first condenser lens 6, a fly's eye lens 7, a plane mirror 10, a second condenser lens 8, a slit light forming unit 200, and an imaging optical system 9. The light source 5 may include, for example, a high-pressure mercury lamp and an elliptical mirror. Note that, although the light source 5 is a component of the illumination optical system 1 in the configuration example of FIG. 1, this is not limiting, and the light source 5 does not have to be a component of the illumination optical system 1 (exposure apparatus 100).

[0014] Light emitted by the light source 5 passes through the first condenser lens 6 and the fly's eye lens 7, and then its optical path is bent by the plane mirror 10 before entering the slit beam forming unit 200. The slit beam forming unit 200 is a mechanism that uses a light shielding plate (hereinafter sometimes referred to as a blade) to shape the light from the light source 5, thereby forming a slit beam to be irradiated onto the mask 3 as the illuminated surface. In this embodiment, the slit beam forming unit 200 is configured as a field stop that defines the shape of the light irradiation region R on the mask 3 (i.e., the cross-sectional shape of the slit beam illuminating the mask 3) to, for example, an arc shape that is long in the X direction. This field stop (blade) is the Fourier transform plane of the fly's eye lens 7 and is positioned optically conjugate with the mask 3. The imaging optical system 9 is positioned so that the slit beam formed (defined) by the slit beam forming unit 200 illuminates the object plane (mask 3) of the projection optical system 4. The alignment scope 2 simultaneously detects the alignment marks on the mask 3 and the substrate 15 via the projection optical system 4.

[0015] Here, the illumination optical system 1 may be provided with a changer that changes the illumination shape that illuminates the mask 3. The illumination shape includes optical characteristics such as the incident angle distribution and illuminance distribution of the light that illuminates the mask 3. The changer can be, for example, an aperture 18 disposed on the exit surface of the fly-eye lens 7. Changing the aperture 18 makes it possible to switch between illumination shapes such as annular illumination, large σ illumination, and small σ illumination. However, changing the aperture 18 disposed on the exit surface of the fly-eye lens 7 changes the illuminance distribution of the light incident on the slit beam forming unit 200, which in turn changes the unevenness of the illumination light amount (illumination light amount distribution) on the mask 3, i.e., the unevenness of the exposure amount (exposure amount distribution) on the substrate. Therefore, when switching the illumination shape, it is necessary to optimize (reduce) the unevenness of the exposure amount on the substrate for each illumination shape by changing the aperture 18 disposed on the exit surface of the fly-eye lens 7 and controlling the slit beam forming unit 200. Note that the changer that changes the illumination shape is not limited to the configuration described above. Furthermore, the diaphragm 18 disposed on the exit surface of the fly-eye lens 7 may be disposed on the entrance surface side of the fly-eye lens 7.

[0016] The projection optical system 4 includes, for example, a first plane-parallel plate 12a, a plane mirror 13, a concave mirror 11, a convex mirror 14, and a second plane-parallel plate 12b, and projects an image of the pattern of the mask 3 illuminated by the illumination optical system 1 onto a substrate 15. The mask 3 is located at the object plane of the projection optical system 4, and the substrate 15 is located at the image plane of the projection optical system 4. The projection optical system 4 can be configured as an 1x magnification imaging optical system, a magnification imaging optical system, or a reduction imaging optical system, but in this embodiment it is configured as an 1x magnification optical system. The slit light passing through the mask 3 passes through the first plane-parallel plate 12a, the first surface 13a of the plane mirror 13, the first surface 11a of the concave mirror 11, the convex mirror 14, the second surface 11b of the concave mirror 11, the second surface 13b of the plane mirror 13, and the second plane-parallel plate 12b, and is incident on the substrate 15. As a result, an image of the pattern of the mask 3 illuminated by the illumination optical system 1 is formed on the substrate.

[0017] The control unit 17 is configured by a computer including a calculation unit 17a (e.g., a CPU) and a storage unit 17b (e.g., a memory), and controls the entire exposure apparatus 100. Furthermore, as described below, the control unit 17 can function as a setting unit (determination unit) that sets (determines) the position coordinates to which the slit beam forming unit 200 (blade) should be controlled in accordance with the target exposure dose of the substrate 15 (i.e., the target illumination light dose of the mask 3). The calculation unit 17a performs processing related to the control of the slit beam forming unit 200, such as calculating command values ​​for controlling the slit beam forming unit 200. The storage unit 17b stores parameters related to the control of the slit beam forming unit 200, such as condition thresholds for drive constraints, which will be described later. Here, the exposure dose of the substrate 15 is sometimes referred to as the integrated exposure dose, and is a value determined by the time integral of the intensity of light irradiated onto the substrate 15. Similarly, the illumination light dose of the mask 3 is a value determined by the time integral of the intensity of light irradiated onto the mask 3.

[0018] [Configuration of the slit beam forming unit] The slit beam forming unit 200 of this embodiment will be described below. Fig. 2 is a plan view showing an example of the configuration of the slit beam forming unit 200. The slit beam forming unit 200 is a mechanism that adjusts the shape of the opening OP (slit) that passes light from the light source 5, thereby adjusting the shape of the light irradiation region R on the mask 3 and correcting unevenness in the amount of exposure on the substrate 15 that occurs when scanning exposure of the substrate 15 is performed. The light irradiation region R on the mask 3 is the region of the mask 3 that is irradiated (illuminated) with slit beams by the illumination optical system 1 (illumination region), and may also be understood as the region that is projected (irradiated) onto the substrate 15 via the projection optical system 4 (exposure region).

[0019] The slit beam forming unit 200 of this embodiment includes, for example, a variable blade 201 (light shielding plate) that can be made of a flexible metal member, and a fixed blade 202 that can be made of a highly tough member. The slit beam forming unit 200 defines (adjusts) the shape of an opening OP formed between the variable blade 201 and the fixed blade 202 by driving and deforming the variable blade 201. A slit beam is formed by light from the light source 5 passing through the opening OP, and the shape of the light irradiation region R on the mask 3 is defined. In other words, the variable blade 201 of the slit beam forming unit 200 may be understood as a member that defines the shape of the light irradiation region R on the mask 3.

[0020] The opening width of the light irradiation region R (aperture OP) in the scanning direction (Y-axis direction) corresponds to the light irradiation time at each position on the mask 3 (i.e., the exposure time at each position on the substrate 15). Therefore, by adjusting the shape (opening width) of the aperture OP, it is possible to adjust the amount of illumination light at each position on the mask 3 (i.e., the amount of exposure at each position on the substrate 15). Here, the variable blade 201 and the fixed blade 202 in this embodiment are configured so that the shape of the aperture OP (i.e., the shape of the light irradiation region R) is arc-shaped, but this is not limiting, and the shape of the aperture OP may be rectangular.

[0021] The slit beam forming unit 200 also includes a deformation unit 210 that deforms the variable blade 201 (light shielding plate) by driving and displacing each of a plurality of drive target locations on the variable blade 201. In this embodiment, the deformation unit 210 includes a plurality of drive units 211-217 that are provided at the plurality of drive target locations on the variable blade 201. The plurality of drive units 211-217 can be arranged along the extension direction of the aperture OP. Under the control of the control unit 17, each of the plurality of drive units 211-217 drives (pushes and pulls) the variable blade 201 to displace it, thereby locally changing the opening width of the aperture OP in the Y-axis direction. In this way, the slit beam forming unit 200 also functions as an adjustment unit that adjusts the shape of the aperture OP (i.e., the shape of the light irradiation region R of the mask 3) using the plurality of drive units 211-217 under the control of the control unit 17.

[0022] Each of the multiple drivers 211-217 includes, for example, a rotational direction relief mechanism 210a, an X-axis direction relief mechanism 210b, a Z-axis direction relief mechanism 210c, an adjustment member 210d, and an actuator 210e. The adjustment member 210d is guided to be movable in the direction of the arrow and is driven (pushed and pulled) in the direction of the arrow by the actuator 210e. This transmits the force of the actuator 210e to the variable blade 201 via the rotational direction relief mechanism 210a, the X-axis direction relief mechanism 210b, and the Z-axis direction relief mechanism 210c. In other words, the variable blade 201 can be locally displaced to locally change the opening width of the aperture OP in the Y-axis direction. In this way, by deforming the variable blade 201 using the multiple drivers 211-217, the shape of the light irradiation region R of the mask 3 can be adjusted, and unevenness in the illumination light intensity on the mask 3, i.e., unevenness in the exposure amount on the substrate, can be controlled (corrected).

[0023] The slit light forming unit 200 may also include a first detecting unit 220 (displacement sensors 221-227) that detects the displacement of each of a plurality of locations (detection target locations) on the variable blade 201. Each of the displacement sensors 221-227 of the first detecting unit 220 detects the amount of drive of each drive target location on the variable blade 201 by each of the driving units 211-217, thereby detecting the displacement of each location on the variable blade 201. That is, each of the displacement sensors 221-227 of the first detecting unit 220 detects, as its detection target location, each of the drive target locations driven by each of the driving units 211-217 of the deformation unit 210. In the example of FIG. 2, each of the displacement sensors 221-227 is configured to detect the amount of drive of the adjustment member 210d by the actuator 210e, as the amount of drive of each location on the variable blade 201.

[0024] With this configuration, the control unit 17 can monitor, based on the detection results of the first detection unit 220 (displacement sensors 221-227), the displacement difference between adjacent detection target locations among the plurality of detection target locations of the variable blade 201. As described above, the first detection unit 220 (displacement sensors 221-227) of this embodiment is configured to detect the amount of drive of the variable blade 201 by each of the drive units 211-217 of the deformation unit 210. Therefore, it can also be said that the control unit 17 monitors, based on the detection results of the first detection unit 220, the displacement difference (difference in drive amount) between adjacent drive target locations among the plurality of drive target locations.

[0025] Here, the control unit 17 may employ a closed-loop control method in which the control unit 17 measures the drive amount of each of the drive units 211-217 based on the detection result of the first detection unit 220, and drives each of the drive units 211-217 until a predetermined drive amount or drive position is reached. Each of the displacement sensors 221-227 may be configured as an optical position detection device having a light-emitting unit 220a and a light-receiving unit 220b.

[0026] [Control of the slit beam forming part] The control of the slit beam forming unit 200 will be described below. The slit beam forming unit 200 is controlled based on the detection result of the first detection unit 220 (displacement sensors 221-227) so that the illumination light amount on the mask of the slit beam that has passed through the aperture OP becomes the target illumination light amount, that is, so that the exposure amount on the substrate becomes the target exposure amount. Here, the slit beam forming unit 200 can be controlled by the control unit 17. The control unit 17 can be configured to control each unit of the exposure apparatus 100, but in controlling the slit beam forming unit 200, it may also be understood as a component of the illumination optical system 1.

[0027] 3 excerpts the variable blade 201 and the drivers 213-215 of the slit beam forming unit 200 shown in FIG. 2, and illustrates the shape control of the variable blade 201 (i.e., the aperture OP) in the slit beam forming unit 200. FIG. 3(a) shows a state in which the drivers 213-215 drive the variable blade 201 so that the shape of the variable blade 201 (i.e., the aperture OP) becomes a reference shape (e.g., a circular arc shape). FIG. 3(b) shows a state in which the drivers 213-215 drive the variable blade 201 to deform it from its reference shape so that the illumination light amount of the mask 3 becomes the target illumination light amount (i.e., so that the exposure amount of the substrate 15 becomes the target exposure amount). 3, only the drivers 213-215 are shown, but the same control as that of the drivers 213-215 is performed on the multiple drivers 211-217 shown in FIG. 2, and the variable blade 201 can be deformed as a whole so that the amount of illumination light on the mask 3 becomes the target amount of illumination light. This makes it possible to correct unevenness in the amount of illumination light on the mask 3, i.e., unevenness in the amount of exposure on the substrate 15.

[0028] The closer the distance between adjacent drivers among multiple drivers 211-217, the more precisely variable blade 201 can be deformed, improving the accuracy of correction for uneven illumination light intensity. In the example of FIG. 3, the distance between drivers refers to distance 301 between driver 213 and driver 214, and distance 302 between driver 214 and driver 215. On the other hand, the narrower the distance between drivers, the greater the load applied to variable blade 201 between adjacent drivers. FIG. 4 shows the relationship between the load applied to variable blade 201 and the safety factor for the yield strength of variable blade 201. The safety factor is expressed as the ratio between the reference strength, which represents the limit stress at which the material constituting variable blade 201 breaks, and the allowable stress actually applied to the material, and is generally expressed by the following formula: Safety factor SF = Reference strength [N] / Allowable stress [N] (1)

[0029] The allowable stress in equation (1) corresponds to the load in FIG. 4 and affects the spacing and displacement difference between adjacent drive target locations in variable blade 201. The displacement difference may be understood as the difference in spacing and drive amount between adjacent drive units in multiple drive units 211-217. In the example of FIG. 3, the displacement difference can be defined as the amount of change in position difference 303 between the drive target location of drive unit 213 and the drive target location of drive unit 214, and the amount of change in position difference 304 between the drive target location of drive unit 214 and the drive target location of drive unit 215. The reference strength (limit stress) is determined by the characteristics of the material of variable blade 201. Generally, a safety factor below 1 indicates that the load exceeds the reference strength of the material, which may cause fracture or plastic deformation in the case of variable blade 201.

[0030] Therefore, the control unit 17 of this embodiment monitors the displacement difference between adjacent drive target locations (detection target locations) of the variable blade 201 while adjusting the shape of the light irradiation region R (aperture OP) by controlling the deformation unit 210. Then, while monitoring the displacement difference while adjusting the shape of the light irradiation region R, the control unit 17 limits the deformation of the variable blade 201 by the deformation unit 210 (the multiple drive units 211 to 217) so that the displacement difference does not exceed a threshold. In other words, the control unit 17 is provided with a function to impose a drive constraint for limiting the deformation of the variable blade 201 by the deformation unit 210 so that the displacement difference does not exceed a threshold. Note that in this embodiment, the displacement difference between adjacent drive target locations (detection target locations) of the variable blade 201 may be simply referred to as a "displacement difference."

[0031] [Exposure equipment operation flow] The control flow of exposure apparatus 100 will be described below. Figure 5 is a flowchart showing the control of exposure apparatus 100 of this embodiment. Each step in the flowchart of Figure 5 is executed by control unit 17. Note that steps S12 to S15 in the flowchart of Figure 5 may be understood to represent a method of adjusting illumination optical system 1 (adjustment step).

[0032] In step S11, the control unit 17 sets exposure parameters. The exposure parameters are parameters that determine the operating conditions of each unit of the exposure apparatus 100, and can be obtained from the exposure conditions (illumination conditions) set in the exposure apparatus 100 by the user. For example, one exposure condition is the exposure dose (target exposure dose) of the substrate 15. Exposure parameters related to the exposure dose include the scanning speed of the mask 3 and the substrate 15, and the intensity of light incident on the mask 3 and / or the substrate 15. In this embodiment, the exposure conditions are set by the user, but are not limited to this. For example, a system may be constructed in which the exposure apparatus 100 used in device manufacturing and an inspection apparatus that inspects the exposure line width are connected via a network, and exposure conditions such as exposure line width correction parameters are automatically fed back.

[0033] In step S12, the control unit 17 determines the X-axis range of the exposure area on the substrate 15, i.e., the X-axis range of the light irradiation area R on the mask 3. In the exposure apparatus 100, the maximum exposure area is determined according to the size of the variable blade 201, i.e., the light irradiation area R determined by the illumination optical system 1. However, the maximum exposure area is not necessarily used in device manufacturing. The exposure area required in device manufacturing can be determined by the pattern range of the mask 3. However, the pattern of the mask 3 is basically designed to maximize device productivity. Therefore, the optimal size of the exposure area varies depending on the device manufacturing process. In this embodiment, the X-axis range of the exposure area on the substrate 15, i.e., the X-axis range of the light irradiation area R on the mask 3, is determined according to a setting value set by the user. The X-axis range of the light irradiation area R can be adjusted by driving a blade (not shown) that defines the width of the slit light in the X-axis direction in the X-axis direction.

[0034] In step S13, the control unit 17 determines the target shape (width in the Y-axis direction) of the exposure area according to the light intensity distribution of the slit light so that the exposure amount at each position on the substrate 15 (shot area) becomes the target exposure amount. That is, the control unit 17 determines the target shape (width in the Y-axis direction) of the light irradiation area R (aperture OP) according to the light intensity distribution of the slit light so that the illumination light amount at each position on the mask 3 becomes the target illumination light amount. For example, the light intensity distribution of the slit light can be measured in advance using a light intensity sensor (not shown) provided on the substrate stage 16. Furthermore, the width of the aperture OP in the scanning direction (Y-axis direction) corresponds to the exposure time at each position on the substrate 15. Therefore, the control unit 17 determines the width in the Y-axis direction of the aperture OP for each position in the X-axis direction based on the light intensity distribution of the slit light measured in advance so that the target exposure amount is obtained at each position on the substrate 15.

[0035] In step S14, control unit 17 performs a determination process to determine a target deformation amount of variable blade 201 by deformation unit 210 (i.e., a target drive amount for each of drive units 211-217). In this determination process, the target deformation amount (target drive amount) is determined so as to satisfy the constraint that the displacement difference does not exceed threshold value dm. FIG. 6 is a flowchart showing the determination process of this embodiment, and the determination process of this embodiment will be described below with reference to the flowchart shown in FIG.

[0036] In step S21, control unit 17 calculates the deformation amount of variable blade 201 by deformation unit 210 (i.e., the drive amount of each of drive units 211-217) based on the shape of opening OP (width in the Y-axis direction) determined in step S13. For example, control unit 17 calculates a target shape of variable blade 201 for realizing the shape of opening OP determined in step S13, and can thereby calculate the drive amount of each of drive units 211-217 so that the shape of variable blade 201 becomes the target shape. Here, by calculating the drive amount of each of drive units 211-217 in step S21, it becomes possible to estimate the load applied to variable blade 201 due to the difference in drive amount between adjacent drive units.

[0037] In step S22, control unit 17 estimates a displacement difference between adjacent drive target locations among the plurality of drive target locations of variable blade 201, based on the drive amounts of each of drive units 211 to 217 calculated in step S21. The displacement difference may be understood as the amount of change in the positional difference between adjacent drive target locations on variable blade 201. Explaining this using the example of FIG. 3, control unit 17 estimates, as the displacement difference, the amount of change in positional difference 303 between the drive target location of drive unit 213 and the drive target location of drive unit 214, and the amount of change in positional difference 304 between the drive target location of drive unit 214 and the drive target location of drive unit 215.

[0038] In step S23, the control unit 17 compares the displacement difference estimated in step S22 with a threshold value dm previously set in the storage unit 17b, and determines whether the displacement difference estimated in step S22 satisfies the constraint that the displacement difference does not exceed the threshold value dm. Here, the threshold value dm is a value indicating the upper limit of the load on the variable blade 201, and can be set based on the allowable stress (pressure resistance) of the variable blade 201. However, it may also be determined based on parameters such as the characteristics of the material constituting the variable blade 201 and the safety factor. In this embodiment, the threshold value dm may be set based on the displacement difference that applies a load to the variable blade 201 so that adjacent drive target locations satisfy a predetermined safety factor, as calculated using equation (1), or may be set by any method based on the load on the variable blade 201. Furthermore, the threshold value dm may be set to a different value for each of adjacent drive target locations.

[0039] If it is determined in step S23 that the constraints are satisfied, that is, if it is determined that there is no portion of variable blade 201 where the displacement difference estimated in step S22 exceeds threshold dm (upper load limit), the process proceeds to step S24. In step S24, control unit 17 determines the deformation amount of variable blade 201 (the drive amount of each of drive units 211-217) calculated in step S21 as the target deformation amount of variable blade 201 (the target drive amount of each of drive units 211-217).

[0040] On the other hand, if it is determined in step S23 that the constraint condition is not satisfied, i.e., if it is determined that there is a portion of the variable blade 201 where the displacement difference estimated in step S22 exceeds the threshold dm (upper load limit), the process proceeds to step S25. In step S25, the control unit 17 determines the target drive amount of the drive unit that drives the portion of the variable blade 201 where the displacement difference exceeds the threshold dm so that the constraint condition is satisfied (so that the displacement difference does not exceed the threshold dm). For example, the control unit 17 determines the target drive amount of the drive unit that drives the portion of the variable blade 201 where the displacement difference exceeds the threshold dm to be a constrained drive amount that imposes a drive constraint so that the displacement difference is less than the threshold dm. The constrained drive amount may be defined, for example, as the maximum drive amount that can keep the displacement difference less than the threshold dm. At this time, the control unit 17 may notify the operator as an error that the displacement difference estimated in step S22 exceeded the threshold dm. For the remaining drive units that drive the portions of the variable blade 201 where the displacement difference does not exceed the threshold dm, the drive amount calculated in step S21 is determined as the target drive amount.

[0041] Here, the drive constraint in step S23 is a constraint that allows variable blade 201 to be driven only in a direction that reduces the displacement difference so that the displacement difference does not exceed threshold dm while variable blade 201 is being driven by driver 211-217. A constraint release threshold dm' for releasing the drive constraint may be set as necessary. Constraint release threshold dm' is set to a value smaller than threshold dm, and the drive constraint can be released when the displacement difference falls below constraint release threshold dm'.

[0042] In addition, in step S25 of this embodiment, the target drive amount of the driver for driving the portion of variable blade 201 whose displacement difference exceeds threshold dm is determined to be a constrained drive amount that imposes a drive constraint so that the displacement difference is less than threshold dm, but this is not limited to this. For example, control unit 17 may change the illumination conditions of mask 3 by illumination optical system 1 and then return to step S13 of Fig. 5 in order to re-determine the target deformation amount of variable blade 201 by deformation unit 210 (target drive amount of each driver 211-217) so as to satisfy the constraint. The illumination conditions may include, for example, at least one of the intensity of light from light source 5, the illumination shape by aperture 18, and the scanning speed of mask 3 and substrate 15.

[0043] After the determination process of step S14 (steps S21 to S25 in FIG. 6) described above is completed, the process proceeds to step S15 in FIG. 5. In step S15, the control unit 17 performs an adjustment process to adjust the shape of the light irradiation region R (opening OP) by controlling the deformation unit 210 (each of the drive units 211 to 217) based on the target deformation amount (target drive amount) determined in step S14. In the adjustment process, even if the deformation unit 210 (each of the drive units 211 to 217) is controlled based on the target deformation amount determined in step S14, an excessive load may be unintentionally applied to the variable blade 201 due to abnormal operation of the deformation unit 210 (drive units 211 to 217). Therefore, in the adjustment process of this embodiment, while the shape of the light irradiation region R is being adjusted, the deformation of the variable blade 201 by the deformation unit 210 is limited so that the displacement difference does not exceed the threshold value dn while monitoring the displacement difference based on the detection result of the first detection unit 220 (displacement sensors 221 to 227). FIG. 7 is a flowchart showing the adjustment process of this embodiment, and the adjustment process of this embodiment will be described below with reference to the flowchart shown in FIG.

[0044] In step S31, the control unit 17 starts the deformation (driving) of the variable blade 201 by the deformation unit 210 (each of the driving units 211 to 217) so that the variable blade 201 reaches the target deformation amount (target driving amount) determined in step S14. That is, the control unit 17 starts the deformation (driving) of the variable blade 201 by the deformation unit 210 (each of the driving units 211 to 217) so that the shape of the light irradiation region R (opening OP) becomes the target shape determined in step S13.

[0045] In step S32, the control unit 17 calculates a displacement difference between adjacent drive target locations among the plurality of drive target locations of the variable blade 201 based on the detection result of the first detection unit 220 (displacement sensors 221 to 227). Next, in step S33, the control unit 17 compares the displacement difference calculated in step S32 with a threshold value dn previously set in the storage unit 17b, and determines whether the displacement difference calculated in step S32 exceeds the threshold value dn. Here, the threshold value dn is a value indicating the upper load limit of the variable blade 201, similar to the threshold value dm used in the determination process described above. The threshold value dn can be set based on the allowable stress (pressure resistance) of the variable blade 201, but may also be determined based on parameters such as the properties of the material constituting the variable blade 201 and a safety factor. Furthermore, the threshold value dn may be the same value as the threshold value dm, or may be set to a different value for each of the adjacent drive target locations.

[0046] If it is determined in step S33 that the displacement difference does not exceed the threshold value dn, i.e., if it is determined that there is no portion of the entire variable blade 201 where the displacement difference exceeds the threshold value dn (upper load limit), the process proceeds to step S34. In step S34, the control unit 17 determines whether the deformation (driving) of the variable blade 201 by the deformation unit 210 (each of the drive units 211-217) has been completed. For example, the control unit 17 can determine that the deformation of the variable blade 201 has been completed when the deformation amount (drive amount) of the variable blade 201 by the deformation unit 210 (each of the drive units 211-217) has reached the target deformation amount (target drive amount) determined in step S14. If the deformation of the variable blade 201 has not been completed, the process returns to step S32 and continues to monitor the displacement difference. Then, if the deformation of the variable blade 201 has been completed, the process proceeds to step S35. In step S35, control unit 17 determines the current deformation amount (drive amount) of variable blade 201 caused by deformation unit 210 (each drive unit 211-217) based on the detection result of first detection unit 220 (displacement sensors 221-227), and stores the determined amount in memory unit 17b. The current deformation amount (drive amount) determined in step S35 can be used in the next determination process and / or adjustment process.

[0047] On the other hand, if it is determined in step S33 that the displacement difference has reached (exceeded) the threshold value dn, that is, if it is determined that there is a portion of variable blade 201 where the displacement difference has reached (exceeded) the threshold value dn, the process proceeds to step S36. Then, in step S36, control unit 17 imposes a drive constraint on the deformation of variable blade 201 on the drive unit that drives the portion of variable blade 201 where the displacement difference has reached the threshold value dn, and stops the deformation (drive) of variable blade 201. At this time, control unit 17 may notify the operator that the displacement difference has exceeded the threshold value dn as an error.

[0048] Here, the drive constraint in step S33 is a constraint that allows the variable blade 201 to be driven only in a direction that reduces the displacement difference so that the displacement difference does not exceed the threshold value dn. If necessary, a constraint release threshold value dn' for releasing the drive constraint may be set. The constraint release threshold value dn' is set to a value smaller than the threshold value dn, and the drive constraint can be released when the displacement difference falls below the constraint release threshold value dn'.

[0049] In addition, in this embodiment, the process proceeds to step S35 after stopping the deformation (driving) of variable blade 201 in step S36, but this is not limited to this. For example, control unit 17 may change the illumination conditions of mask 3 by illumination optical system 1 and then return to step S13 in Fig. 5 in order to re-determine the target deformation amount of variable blade 201 by deformation unit 210 (target drive amount of each drive unit 211-217) so as to satisfy the constraints. The illumination conditions may include, for example, at least one of the intensity of light from light source 5, the illumination shape by diaphragm 18, and the scanning speed of mask 3 and substrate 15.

[0050] When the adjustment process of step S15 described above (steps S31 to S36 in FIG. 7) is completed, the process proceeds to step S16 in FIG. 5. In step S16, the control unit 17 exposes the substrate 15 (scanning exposure) while scanning the mask 3 and the substrate 15 relative to each other, in a state in which the shape of the light irradiation region R (opening OP) has been adjusted through steps S11 to S15 described above. In step S16, scanning exposure may be performed on each of a plurality of shot regions on the substrate 15, or on one or several shot regions. In this case, steps S11 to S16 may be repeatedly performed on other shot regions on the substrate 15.

[0051] In this embodiment, the control of the slit beam forming unit 200, particularly the driving of the deformation unit 210 (drive units 211 to 217) provided on the variable blade 201, has been described in detail, but in reality, there are also advance preparations such as moving the substrate stage 16 to an exposure start position. By starting the scanning exposure of the substrate 15 at the timing when these advance preparations are completed, the pattern of the mask 3 is transferred to the substrate 15. Furthermore, in this embodiment, an example has been described in which the scanning exposure of the substrate 15 is performed after driving the deformation unit 210 (drive units 211 to 217) provided on the variable blade 201, but the deformation unit 210 (drive units 211 to 217) may be driven during the scanning exposure of the substrate 15.

[0052] Furthermore, exposure apparatus 100 of the present embodiment achieves both an arrangement of drive units 211-217 at closer intervals in slit beam forming unit 200 and a reduction in excessive load on variable blade 201. In other words, exposure apparatus 100 can accurately transfer the pattern of mask 3 onto substrate 15, that is, can perform exposure with a uniform illuminance distribution.

[0053] As described above, exposure apparatus 100 of the present embodiment monitors the displacement difference between adjacent drive target locations on variable blade 201 while adjusting the shape of light irradiation region R, and limits the deformation of variable blade 201 so that the displacement difference does not exceed a threshold. This makes it possible to reduce the occurrence of excessive load on variable blade 201, which defines light irradiation region R on mask 3 (illumination surface).

[0054] Second Embodiment A second embodiment of the present invention will be described. This embodiment differs from the first embodiment in the configuration of the slit beam forming unit 200. Note that this embodiment basically inherits the first embodiment, and matters not mentioned in this embodiment may follow the first embodiment.

[0055] In the first embodiment described above, an example is described in which a first detection unit 220 is used to detect the drive amount of each of the drive units 211 to 217 in the deformation unit 210. On the other hand, in the present embodiment, an example is described in which a second detection unit 230 is used to directly detect the shape of the variable blade 201 instead of the first detection unit 220. Note that in the present embodiment, an example is described in which the second detection unit 230 is used instead of the first detection unit 220, but the second detection unit 230 may be used in addition to the first detection unit 220.

[0056] FIG. 8 is a plan view showing an example of the configuration of the slit beam forming unit 200 of the second embodiment. As described above, the slit beam forming unit 200 of this embodiment includes a second detection unit 230 that directly detects the shape of the variable blade 201. The second detection unit 230 includes multiple displacement sensors 231-237 that detect the displacement of multiple detection target locations P1-P7 on the variable blade 201, respectively. The multiple detection target locations P1-P7 can be set arbitrarily, but in this embodiment, at least one detection target location can be set to a different position from the multiple drive target locations. For example, the multiple displacement sensors 231-237 can be arranged so that at least one detection target location among the multiple detection target locations P1-P7 is located between multiple drive target locations. In the example of FIG. 8, one detection target location is provided between the drive target locations, but two or more detection target locations may also be provided between the drive target locations.

[0057] Here, the second detection unit 230 is not limited to the above configuration, and may be configured to detect displacements by the displacement sensors 231-237, with drive target locations driven by the drive units 211-217 of the deformation unit 210 as detection target locations. That is, the drive target locations driven by the drive units 211-217 of the deformation unit 210 may be the same as the detection target locations whose displacements are detected by the displacement sensors 231-237 of the second detection unit 230. Furthermore, the displacement sensors 231-237 of the second detection unit 230 may be configured as optical position detection devices having a light projecting unit and a light receiving unit, similar to the displacement sensors 221-227 of the first detection unit 220.

[0058] With this configuration, based on the detection results of the second detection unit 230 (displacement sensors 231-237), the control unit 17 can monitor the displacement difference between adjacent detection target locations among the plurality of detection target locations P1-P7 of the variable blade 201. Note that in this embodiment, the displacement difference between adjacent detection target locations among the plurality of detection target locations P1-P7 of the variable blade 201 may be simply referred to as the "displacement difference."

[0059] The control flow of exposure apparatus 100 equipped with slit beam formation unit 200 of this embodiment will be described below. The control flow of exposure apparatus 100 in this embodiment can be executed by control unit 17 according to the flowchart of Fig. 5 described in the first embodiment, but steps S14 to S15 differ from those in the first embodiment. Therefore, steps S14 to S15 of this embodiment will be described below with reference to Figs. 9 and 10.

[0060] Fig. 9 is a flowchart showing the determination process (step S14) of this embodiment. Note that steps S41 to S45 in Fig. 9 are similar to steps S21 to S25 in Fig. 6 described in the first embodiment, and therefore, the following will only describe the differences from steps S21 to S25 in Fig. 6, and detailed description will be omitted.

[0061] In step S41, control unit 17 calculates the amount of deformation of variable blade 201 by deformation unit 210 (i.e., the drive amount of each of drive units 211-217) based on the shape of opening OP (width in the Y-axis direction) determined in step S13. Next, in step S42, control unit 17 estimates a displacement difference between adjacent detection target locations among the multiple detection target locations P1-P7 of variable blade 201, based on the drive amount of each of drive units 211-217 calculated in step S41. The displacement difference may be understood as the amount of change in the positional difference between adjacent detection target locations among the multiple detection target locations P1-P7 of variable blade 201.

[0062] In step S43, the control unit 17 compares the displacement difference estimated in step S42 with a threshold value lm previously set in the storage unit 17b, and determines whether the displacement difference estimated in step S42 satisfies the constraint that the displacement difference does not exceed the threshold value lm. Here, the threshold value lm is a value indicating the upper load limit of the variable blade 201, and can be set based on the allowable stress (pressure resistance) of the variable blade 201. However, it may also be determined based on parameters such as the characteristics of the material constituting the variable blade 201 and the safety factor. In this embodiment, the threshold value lm may be set based on the displacement difference that applies a load to the variable blade 201 so that adjacent detection target locations satisfy a predetermined safety factor, as calculated using equation (1), or it may be set by any method based on the load on the variable blade 201. Furthermore, the threshold value lm may be set to a different value for each of adjacent detection target locations.

[0063] If it is determined in step S43 that the constraints are satisfied, that is, if it is determined that there is no portion of variable blade 201 where the displacement difference estimated in step S42 exceeds threshold lm (upper load limit), the process proceeds to step S44. In step S44, control unit 17 determines the deformation amount of variable blade 201 (the drive amount of each of drive units 211-217) calculated in step S41 as the target deformation amount of variable blade 201 (the target drive amount of each of drive units 211-217).

[0064] On the other hand, if it is determined in step S43 that the constraint condition is not satisfied, i.e., if it is determined that there is a portion of the variable blade 201 where the displacement difference estimated in step S42 exceeds the threshold lm (upper load limit), the process proceeds to step S45. In step S45, the control unit 17 determines the target drive amount of the drive unit that drives the portion where the displacement difference exceeds the threshold lm so that the constraint condition is satisfied (so that the displacement difference does not exceed the threshold lm). For example, the control unit 17 determines the target drive amount of the drive unit that drives the portion where the displacement difference exceeds the threshold lm to be a constrained drive amount that imposes a drive constraint so that the displacement difference is less than the threshold lm. The constrained drive amount may be defined, for example, as the maximum drive amount that can keep the displacement difference less than the threshold lm. At this time, the control unit 17 may notify the operator as an error that the displacement difference estimated in step S42 exceeded the threshold lm. For the remaining drive units that drive the portions of the variable blade 201 where the displacement difference does not exceed the threshold lm, the drive amount calculated in step S41 is determined as the target drive amount.

[0065] Here, the drive constraint in step S43 is a constraint that allows the variable blade 201 to be driven only in a direction that reduces the displacement difference so that the displacement difference does not exceed the threshold lm while the drive units 211 to 217 are driving the variable blade 201. If necessary, a constraint release threshold lm' for releasing the drive constraint may be set. The constraint release threshold lm' is set to a value smaller than the threshold lm, and the drive constraint may be released when the displacement difference falls below the constraint release threshold lm'. Furthermore, in order to re-determine the target deformation amount (target drive amount) of the variable blade 201 by the deformation unit 210 so as to satisfy the constraint condition, the illumination condition of the mask 3 by the illumination optical system 1 may be changed without executing step S45, and then the process may return to step S13 in FIG. 5.

[0066] Fig. 10 is a flowchart showing the adjustment process (step S15) of this embodiment. Note that steps S51 to S56 in Fig. 10 are similar to steps S31 to S36 in Fig. 7 described in the first embodiment, and therefore, the following will focus on the differences from steps S31 to S36 in Fig. 7, and detailed description will be omitted.

[0067] In step S51, control unit 17 starts deformation (driving) of variable blade 201 by deformation unit 210 (each drive unit 211-217) so as to reach the target deformation amount (target drive amount) determined in step S14 of Fig. 5 (steps S41-S45 of Fig. 9). Next, in step S52, control unit 17 calculates the displacement difference between adjacent detection target locations among the plurality of detection target locations P1-P7 of variable blade 201 based on the detection results of second detection unit 230 (displacement sensors 231-237).

[0068] In step S53, the control unit 17 compares the displacement difference calculated in step S52 with a threshold value ln previously set in the storage unit 17b, and determines whether the displacement difference calculated in step S52 exceeds the threshold value ln. Here, the threshold value ln is a value indicating the upper load limit of the variable blade 201, similar to the threshold value lm used in the determination process described above (step S43 in FIG. 9). The threshold value ln can be set based on the allowable stress (pressure resistance) of the variable blade 201, but may also be determined based on parameters such as the characteristics of the material constituting the variable blade 201 and a safety factor. Furthermore, the threshold value ln may be the same value as the threshold value lm, or may be set to different values ​​for adjacent detection target locations.

[0069] If it is determined in step S53 that the displacement difference does not exceed the threshold ln, i.e., if it is determined that there is no portion of the entire variable blade 201 where the displacement difference exceeds the threshold ln (upper load limit), the process proceeds to step S54. In step S54, the control unit 17 determines whether the deformation (driving) of the variable blade 201 by the deformation unit 210 (each of the drive units 211-217) has been completed. If the deformation (driving) of the variable blade 201 has been completed, the process proceeds to step S55. In step S55, the control unit 17 determines the current deformation amount (drive amount) of the variable blade 201 by the deformation unit 210 (each of the drive units 211-217) based on the detection result of the second detection unit 230 (displacement sensors 231-237), and stores the current deformation amount (drive amount) in the memory unit 17b. The current deformation amount (drive amount) determined in step S55 can be used in the next determination process and / or adjustment process.

[0070] On the other hand, if it is determined in step S53 that the displacement difference has reached (exceeded) the threshold value ln, i.e., if it is determined that there is a portion of variable blade 201 where the displacement difference has reached (exceeded the threshold value ln), the process proceeds to step S56. Then, in step S56, control unit 17 imposes a drive constraint on the deformation of variable blade 201 on the drive unit that drives the portion of variable blade 201 where the displacement difference has reached the threshold value ln, and stops the deformation (drive) of variable blade 201.

[0071] Here, the drive constraint in step S53 is a constraint that allows the variable blade 201 to be driven only in a direction that reduces the displacement difference so that the displacement difference does not exceed a threshold ln. If necessary, a constraint release threshold ln' may be set to release the drive constraint. The constraint release threshold ln' is set to a value smaller than the threshold ln, and the drive constraint may be released when the displacement difference falls below the constraint release threshold ln'. Furthermore, when the deformation of the variable blade 201 is stopped, the illumination conditions of the mask 3 by the illumination optical system 1 may be changed before returning to step S13 in FIG. 5 in order to re-determine the target deformation amount of the variable blade 201 by the deformation unit 210 so as to satisfy the constraint condition.

[0072] As described above, the exposure apparatus 100 of the present embodiment monitors the displacement difference between adjacent detection target locations on the variable blade 201 while adjusting the shape of the light irradiation region R, and limits the deformation of the variable blade 201 so that the displacement difference does not exceed a threshold. This makes it possible to reduce excessive load on the variable blade 201, which defines the light irradiation region R on the mask 3 (illumination surface). That is, in this embodiment, the load on the variable blade 201 is calculated from the displacement of a small section of the variable blade 201, and is monitored. This prevents wear on the variable blade 201 due to excessive load, while realizing a shape deformation that can uniform the illuminance distribution. Note that in this embodiment, the second detection unit 230 is used to monitor the deformation of the variable blade 201. However, the first detection unit 220 may also be used to monitor the deformation of the variable blade 201, as in the first embodiment.

[0073] <Embodiments of manufacturing methods of articles> The method for manufacturing an article according to an embodiment of the present invention is suitable for manufacturing articles such as microdevices, such as semiconductor devices, and elements having a microstructure. The method for manufacturing an article according to this embodiment includes the steps of forming a latent image pattern on a photosensitive agent applied to a substrate using the above-described exposure apparatus (exposing the substrate), developing (processing) the substrate on which the latent image pattern has been formed, and manufacturing an article from the processed substrate. Furthermore, this manufacturing method includes other well-known processes (oxidation, film formation, vapor deposition, doping, planarization, etching, resist stripping, dicing, bonding, packaging, etc.). The method for manufacturing an article according to this embodiment is advantageous over conventional methods in at least one of the performance, quality, productivity, and production cost of the article.

[0074] <Summary of the embodiment> The disclosure of the present specification includes the following illumination optical system, exposure apparatus, adjustment method, and article manufacturing method.

[0075] (Item 1) An illumination optical system that illuminates an illumination target surface with light from a light source, a light blocking plate that defines the shape of a light irradiation area on the illumination surface; a deformation unit that drives and deforms the light blocking plate; a detection unit that detects displacement of each of a plurality of locations on the light blocking plate; a control unit that adjusts the shape of the light irradiation area by controlling the deformation unit; Equipped with The control unit, during adjustment of the shape of the light irradiation area, limits the deformation of the light shielding plate by the deformation unit based on the detection results of the detection unit so that the difference in displacement between adjacent locations among the multiple locations does not exceed a threshold value.

[0076] (Item 2) the deformation unit deforms the light blocking plate by driving and displacing each of the plurality of locations on the light blocking plate; 2. The illumination optical system according to item 1, wherein the detection unit detects the displacement of each of the plurality of locations by detecting the amount of drive of each of the plurality of locations by the deformation unit.

[0077] (Item 3) 3. The illumination optical system according to item 1 or 2, wherein the detection unit detects the displacement of each of the plurality of locations by detecting the shape of the light blocking plate.

[0078] (Item 4) the deformation unit includes a plurality of drive units that respectively drive and displace a plurality of drive target locations on the light blocking plate, 4. The illumination optical system described in any one of items 1 to 3, characterized in that, in the light-shielding plate, at least one of the multiple locations at which displacement is detected by the detection unit is located at a position different from each of the multiple drive target locations.

[0079] (Item 5) 5. The illumination optical system according to any one of items 1 to 4, wherein the threshold value is set based on an allowable stress of the light blocking plate.

[0080] (Item 6) The illumination optical system described in any one of items 1 to 5, characterized in that the control unit stops the deformation of the light shielding plate by the deformation unit when the displacement difference reaches the threshold value during adjustment of the shape of the light irradiation area.

[0081] (Item 7) the control unit sets a driving constraint on the deformation of the light blocking plate by the deformation unit when the displacement difference reaches the threshold value during adjustment of the shape of the light irradiation area; 7. The illumination optical system according to item 6, wherein the drive constraint is a constraint that allows the light blocking plate to be driven only in a direction that reduces the displacement difference.

[0082] (Item 8) The illumination optical system described in any one of items 1 to 7, characterized in that the control unit determines a target deformation amount of the light shielding plate by the deformation unit based on a target illumination light amount of the illuminated surface so as to satisfy the constraint that the displacement difference does not exceed the threshold value, and adjusts the shape of the light irradiation area by controlling the deformation unit based on the target deformation amount.

[0083] (Item 9) An illumination optical system that illuminates an illumination target surface with light from a light source, a light blocking plate that defines the shape of a light irradiation area on the illumination surface; a deformation unit that deforms the light blocking plate by driving and displacing each of a plurality of locations on the light blocking plate; a control unit that adjusts the shape of the light irradiation area by controlling the deformation unit; Including, The control unit determines a target deformation amount of the light shielding plate by the deformation unit based on a target illumination light intensity of the illuminated surface so as to satisfy a constraint that the displacement difference between adjacent locations among the plurality of locations does not exceed a threshold value, and adjusts the shape of the light irradiation area by controlling the deformation unit based on the target deformation amount.

[0084] (Item 10) An exposure apparatus that performs scanning exposure of a substrate, an illumination optical system according to any one of items 1 to 9, which illuminates an original having an illumination surface; and a projection optical system which projects an image of the pattern of the original onto the substrate. An exposure apparatus comprising:

[0085] (Item 11) 1. A method for adjusting an illumination optical system that illuminates an illumination target surface with light from a light source, comprising: The illumination optical system includes: a light blocking plate that defines the shape of a light irradiation area on the illumination surface; a deformation unit that drives and deforms the light blocking plate; a detection unit that detects displacement of each of a plurality of locations on the light blocking plate; Equipped with An adjustment method characterized in that, during adjustment of the shape of the light irradiation area, the deformation of the light shielding plate by the deformation unit is limited based on the detection results of the detection unit so that the displacement difference between adjacent locations in the multiple locations does not exceed a threshold value.

[0086] (Item 12) 1. A method for adjusting an illumination optical system that illuminates an illumination target surface with light from a light source, comprising: The illumination optical system includes: a light blocking plate that defines the shape of a light irradiation area on the illumination surface; a deformation unit that deforms the light blocking plate by driving and displacing each of a plurality of locations on the light blocking plate; Equipped with An adjustment method characterized by determining a target deformation amount of the light-blocking plate by the deformation unit based on a target illumination light intensity of the illuminated surface so as to satisfy the constraint that the displacement difference between adjacent locations among the multiple locations does not exceed a threshold value, and adjusting the shape of the light-irradiated area by controlling the deformation unit based on the target deformation amount.

[0087] (Item 13) an adjusting step of adjusting the illumination optical system of the exposure apparatus by the adjusting method according to item 11 or 12; an exposure step of exposing a substrate using the exposure apparatus in which the illumination optical system has been adjusted in the adjustment step; a processing step of processing the substrate exposed in the exposure step; a manufacturing process for manufacturing an article from the substrate processed in the processing process; A method for manufacturing an article, comprising:

[0088] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0089] 1: illumination optical system, 3: mask (original), 4: projection optical system, 15: substrate, 16: substrate stage, 17: control unit, 100: exposure device, 200: slit light forming unit, 210: deformation unit, 220: first detection unit, 230: second detection unit

Claims

1. An illumination optical system that illuminates an illumination target surface with light from a light source, a light blocking plate that defines the shape of a light irradiation area on the illumination surface; a deformation unit that drives and deforms the light blocking plate; a detection unit that acquires displacements of each of a plurality of locations on the light blocking plate; a control unit that adjusts the shape of the light irradiation area by controlling the deformation unit; Equipped with The control unit controls the deformation unit based on the detection results of the detection unit during adjustment of the shape of the light irradiation area so that the displacement difference between adjacent locations among the multiple locations does not exceed a threshold.

2. the deformation unit deforms the light blocking plate by driving and displacing each of the plurality of locations on the light blocking plate; 2. The illumination optical system according to claim 1, wherein the detection section detects the displacement of each of the plurality of locations by detecting the amount of drive of each of the plurality of locations by the deformation section.

3. 2. The illumination optical system according to claim 1, wherein the detector detects the displacement of each of the plurality of locations by detecting the shape of the light blocking plate.

4. the deformation unit includes a plurality of drive units that respectively drive and displace a plurality of drive target locations on the light blocking plate, The illumination optical system according to claim 1, wherein at least one of the plurality of locations on the light-shielding plate where displacement is detected by the detection unit is located at a position different from each of the plurality of drive target locations.

5. 2. The illumination optical system according to claim 1, wherein the threshold value is set based on an allowable stress of the light-shielding plate.

6. The illumination optical system according to claim 1 , wherein the control unit stops the deformation of the light blocking plate by the deformation unit when the displacement difference reaches the threshold value during adjustment of the shape of the light irradiation area.

7. the control unit sets a driving constraint on the deformation of the light blocking plate by the deformation unit when the displacement difference reaches the threshold value during adjustment of the shape of the light irradiation area; 7. The illumination optical system according to claim 6, wherein the drive constraint is a constraint that allows the light blocking plate to be driven only in a direction that reduces the displacement difference.

8. The illumination optical system according to claim 1, wherein the control unit determines a target deformation amount of the light shielding plate by the deformation unit based on a target illumination light amount of the illuminated surface so as to satisfy a constraint that the displacement difference does not exceed the threshold value, and adjusts the shape of the light irradiation area by controlling the deformation unit based on the target deformation amount.

9. An illumination optical system that illuminates an illumination target surface with light from a light source, a light blocking plate that defines the shape of a light irradiation area on the illumination surface; a deformation unit that drives each of a plurality of locations on the light blocking plate to deform the light blocking plate; a control unit that adjusts the shape of the light irradiation area by controlling the deformation unit; Equipped with The control unit controls the deformation unit so that a difference in displacement between adjacent locations among the plurality of locations does not exceed a threshold value.

10. An exposure apparatus that performs scanning exposure of a substrate, an illumination optical system according to any one of claims 1 to 9, which illuminates an original having an illumination surface; a projection optical system that projects an image of the pattern of the original onto the substrate; An exposure apparatus comprising:

11. 1. A method for adjusting an illumination optical system that illuminates an illumination target surface with light from a light source, comprising: The illumination optical system includes: a light blocking plate that defines the shape of a light irradiation area on the illumination surface; a deformation unit that drives and deforms the light blocking plate; a detection unit that acquires displacements of each of a plurality of locations on the light blocking plate; Equipped with An adjustment method characterized by controlling the deformation unit based on the detection results of the detection unit during adjustment of the shape of the light irradiation area so that the displacement difference between adjacent locations in the multiple locations does not exceed a threshold value.

12. 1. A method for adjusting an illumination optical system that illuminates an illumination target surface with light from a light source, comprising: The illumination optical system includes: a light blocking plate that defines the shape of a light irradiation area on the illumination surface; a deformation unit that drives each of a plurality of locations on the light blocking plate to deform the light blocking plate; Equipped with An adjustment method comprising controlling the deformation unit so that a difference in displacement between adjacent locations among the plurality of locations does not exceed a threshold value.

13. an adjusting step of adjusting an illumination optical system of an exposure apparatus by the adjusting method according to claim 11 or 12; an exposure step of exposing a substrate using the exposure apparatus in which the illumination optical system has been adjusted in the adjustment step; a processing step of processing the substrate exposed in the exposure step; a manufacturing process for manufacturing an article from the substrate processed in the processing process; A method for manufacturing an article, comprising:

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