Exposure apparatus, exposure method, and article manufacturing method

Abstract

A technique is provided that is advantageous for correcting fluctuations in the imaging performance of a projection optical system. [Solution] An exposure apparatus that exposes a substrate via an original, comprising: a projection optical system that projects a pattern of the original onto the substrate; a drive unit that drives at least one optical element of the projection optical system by locally applying a force to the optical element; and a correction unit that corrects fluctuations in the imaging performance of the projection optical system, wherein the correction unit corrects fluctuations in the imaging performance in accordance with the driving of the optical element by the drive unit based on information indicating the relationship between fluctuation information regarding fluctuations in the imaging performance caused by deformation of the optical element that occurs when the drive unit drives the optical element and drive information regarding the driving of the optical element by the drive unit.

Description

[Technical Field]

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

[0002] Known exposure apparatus technologies include those that correct aberrations and fluctuations in the imaging position caused by manufacturing errors and the effects of exposure heat by driving optical elements such as lenses that constitute a projection optical system. In such technologies, if the desired driving is not achieved due to the driving accuracy of the optical elements (or the driving mechanism that drives them), the optical elements themselves that are the targets of driving may end up causing other aberrations or fluctuations in the imaging position.

[0003] Therefore, techniques have been proposed for correcting aberrations and fluctuations in imaging position that occur when the optical element to be driven cannot be driven as desired (see Patent Documents 1 and 2). Patent Document 1 discloses a technique for correcting driving errors (imperfections in the driving mechanism) of an optical element (lens) and deviations in imaging position that occur in principle when the optical element is tilted. Patent Document 2 discloses a technique for correcting aberrations that occur due to driving errors of an optical element. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 10-12515 [Patent Document 2] Patent No. 5006762 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, the demands on the performance of exposure apparatuses have become increasingly high, and it has become difficult to meet the performance requirements of exposure apparatuses by simply correcting the driving errors of optical elements and the deviations in the imaging position and aberrations that occur in principle when tilting optical elements. For example, driving an optical element causes minute deformations of the optical element, which deforms the optical surface (lens surface) of the optical element, thereby causing fluctuations in aberrations and imaging position. However, conventional techniques are unable to correct the effects of deformations of the optical surface caused by driving such optical elements.

[0006] The present invention has been made in view of the above problems of the conventional technology, and has an exemplary object to provide a technique that is advantageous for correcting fluctuations in the imaging performance of a projection optical system. [Means for solving the problem]

[0007] One aspect of the present invention relates to an exposure apparatus that exposes a substrate, the exposure apparatus having: a projection optical system that projects a pattern of an original onto the substrate; a first drive unit that applies a local force to a first optical element included in the projection optical system to move the first optical element in a first direction perpendicular to an optical axis of the projection optical system; and a correction unit that corrects fluctuations in imaging performance of the projection optical system, the correction unit including a second optical element different from the first optical element and a second drive unit that drives the second optical element, based on information indicating a relationship between the movement of the first optical element by the first drive unit and fluctuations in imaging performance resulting from deformation of the first optical element caused by the application of the force, the second drive unit performs at least one of driving the second optical element in a direction parallel to the optical axis of the projection optical system and driving the second optical element to tilt with respect to a plane perpendicular to the optical axis of the projection optical system, and the deformation of the second optical element caused by driving the second drive unit is smaller than the deformation of the first optical element caused by driving the first drive unit.

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

[0009] According to the present invention, for example, it is possible to provide a technique that is advantageous for correcting fluctuations in the imaging performance of a projection optical system. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram schematically showing the configuration of an exposure apparatus in a first embodiment of the present invention. [Figure 2] 1A and 1B are diagrams illustrating an example of deformation of an optical surface of an optical element. [Figure 3] FIG. 10 is a diagram showing an example of information indicating the relationship between variation information and drive information. [Figure 4] 10 is a flowchart for explaining an operation process in the exposure apparatus. [Figure 5] FIG. 2 is a diagram for explaining a specific configuration of a correction mechanism. [Figure 6]FIG. 10 is a diagram for explaining the configuration of an exposure apparatus in a second embodiment of the present invention. 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 invention according to the claims. 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 FIG. 1 is a diagram schematically showing the configuration of an exposure apparatus 100 in a first embodiment of the present invention. Exposure apparatus 100 is a lithography apparatus used in a lithography process, which is a manufacturing process for articles (devices) such as semiconductor elements, liquid crystal display elements, and thin-film magnetic heads, and forms a pattern on a substrate. Exposure apparatus 100 exposes a substrate (each shot area on the substrate) via an original (reticle or mask) and a projection optical system, and transfers the pattern of the original onto the substrate. Exposure apparatus 100 may be configured, for example, as an exposure apparatus (stepper) that exposes the original and substrate while they are stationary, or as an exposure apparatus (scanner) that exposes the original and substrate while scanning them.

[0013] In this specification and the accompanying drawings, directions are indicated in an XYZ coordinate system, with the direction parallel to the surface on which the substrate is placed being the XY plane. The directions parallel to the X-axis, Y-axis, and Z-axis in the XYZ coordinate system are the X-direction, Y-direction, and Z-direction, respectively, and rotation around the X-axis, Y-axis, and Z-axis are respectively designated as θX, θY, and θZ.

[0014] The exposure apparatus 100 has an illumination optical system (not shown) that illuminates the original 101 with light (exposure light) from a light source (not shown), an original stage (not shown) that holds and drives the original 101, and a projection optical system 102 that projects the pattern of the original 101 onto a substrate 109. The exposure apparatus 100 also has a substrate stage (not shown) that holds and drives the substrate 109, a control unit 106, and a memory unit SU.

[0015] The control unit 106 is configured as an information processing device (computer) including a CPU, memory, etc. The control unit 106 comprehensively controls each unit of the exposure apparatus 100 to operate the exposure apparatus 100 in accordance with the programs stored in the storage unit SU. The control unit 106 controls the exposure process that exposes the substrate 109 (each shot area on the substrate). The storage unit SU includes storage devices such as RAM, ROM, and a hard disk. The storage unit SU stores (stores) the programs executed by the control unit 106, i.e., the programs for operating the exposure apparatus 100, as well as various information and data.

[0016] In the exposure apparatus 100, light from a light source illuminates an original 101 via an illumination optical system, and the light that passes through the original 101 (light that reflects the pattern of the original 101) is projected onto a substrate 109 via a projection optical system 102. In this way, the pattern of the original 101 is transferred onto the substrate 109. The light source includes, for example, an excimer laser that emits light with a wavelength of 248 nm or light with a wavelength of 193 nm.

[0017] The exposure apparatus 100 may not be able to achieve the desired imaging performance due to manufacturing errors and other factors. Furthermore, during the exposure process, a portion of the exposure light is absorbed by the projection optical system 102 and generates heat (exposure heat). This may cause deformation or a refractive index distribution in the optical elements that make up the projection optical system 102, resulting in fluctuations in imaging performance. The imaging performance primarily refers to the imaging performance of the projection optical system 102, and includes, for example, aberrations of the projection optical system 102 and fluctuations in the imaging position when transferring the pattern of the original 101 onto the substrate 109. The fluctuations in the imaging position include fluctuations in the lateral shift of the pattern transferred onto the substrate 109 (lateral shift of the imaging position), fluctuations in the imaging magnification of the pattern transferred onto the substrate 109, and fluctuations in the distortion of the pattern transferred onto the substrate 109. Furthermore, if the exposure apparatus 100 is a scanner, the fluctuations in the imaging position may include fluctuations in the imaging magnification only in the direction perpendicular to the scanning direction of the original 101 and the substrate 109. Thus, the fluctuation in the imaging performance includes at least one of the fluctuation in the aberration of the projection optical system 102, the fluctuation in the lateral shift of the imaging position, the fluctuation in the imaging magnification, and the fluctuation in distortion.

[0018] In order to deal with such variations in imaging performance, the exposure apparatus 100 has a driving unit 105 that drives at least one optical element 104 of the projection optical system 102, such as a lens or a plate. The driving unit 105 includes an actuator (driving element) and drives the optical element 104 by locally applying a force to the optical element 104. In this embodiment, the driving unit 105 locally applies at least one of a compressive force and a tensile force to the optical element 104, thereby driving the optical element 104 in a direction perpendicular to the optical axis 103 of the projection optical system 102, thereby correcting the above-mentioned variations in imaging performance.

[0019] Here, the inventors have found that when optical element 104 is driven by drive unit 105, optical element 104 undergoes minute deformation, resulting in deformation of the optical surface, which is the surface of optical element 104. Note that the optical surface means a surface that is set for the purpose of transmitting or reflecting light, that is, for the purpose of exerting an optical effect on light.

[0020] 2(a), 2(b), and 2(c) are schematic diagrams illustrating an example of deformation of the optical surface of the optical element 104 that occurs when the driver 105 drives the optical element 104. For example, as shown in FIG. 2(a), saddle-shaped deformation occurs on the optical surface of the optical element 104 when the driver 105 drives the optical element 104. Furthermore, if the lens barrel (not shown) of the projection optical system 102 supports the optical element 104 at three support portions, as shown in FIG. 2(b), deformation occurs on the optical surface of the optical element 104 due to friction at the three support portions when the driver 105 drives the optical element 104. FIG. 2(c) illustrates the simultaneous occurrence of the deformation shown in FIG. 2(a) and the deformation shown in FIG. 2(b). Note that the deformations shown in Figures 2(a), 2(b), and 2(c) are just examples, and various deformations occur on the optical surface of the optical element 104 depending on the support method for the optical element 104 and the drive method for the drive unit 105.

[0021] If the optical surface of the optical element 104 is deformed as a result of the drive unit 105 driving the optical element 104, this will cause aberrations and fluctuations in the imaging position of the projection optical system 102, resulting in fluctuations in imaging performance. Such fluctuations in imaging performance, i.e., fluctuations in imaging performance caused by deformation of the optical element 104 that occurs when the drive unit 105 drives the optical element 104, will be referred to below as "driving imaging fluctuations."

[0022] Therefore, in this embodiment, the exposure apparatus 100 has a correction unit 107 for correcting fluctuations in the imaging performance of the projection optical system 102, in particular, drive imaging fluctuations. The correction unit 107 may be configured integrally with the control unit 106. In other words, the control unit 106 may have the functions of the correction unit 107. Furthermore, in this embodiment, information indicating the relationship between fluctuation information regarding drive imaging fluctuations and drive information regarding the drive of the optical element 104 by the drive unit 105 is acquired in advance and stored in the storage unit SU. Here, the fluctuation information includes information on at least one of fluctuations in aberration of the projection optical system 102, fluctuations in lateral shift of the imaging position, fluctuations in imaging magnification, and fluctuations in distortion, as described above.

[0023] Fig. 3 is a diagram showing an example of information 302 indicating the relationship between variation information and drive information. In Fig. 3, the horizontal axis indicates the drive position of the optical element 104, which is drive information related to the drive of the optical element 104 by the drive unit 105, and the horizontal axis indicates the aberration of the projection optical system 102, which is information related to drive image formation variation. Referring to Fig. 3, the information 302 can be obtained as a function by performing function fitting on multiple pieces of data 301 indicating the correlation between the drive position of the optical element 104 and the aberration of the projection optical system 102. The function obtained in this manner and its coefficient values ​​are stored as information 302 in the storage unit SU.

[0024] The correction unit 107 obtains the drive imaging variation based on information 302 stored in the storage unit SU and the drive position of the optical element 104 obtained from the drive unit 105, and corrects the drive imaging variation via the correction mechanism 108 provided in the exposure apparatus 100. In this way, the correction unit 107 corrects the drive imaging variation in accordance with the drive of the optical element 104 by the drive unit 105, based on information 302 indicating the relationship between the variation information and the drive information. As a result, even if deformation occurs in (the optical surface of) the optical element 104 when the drive unit 105 drives the optical element 104, it is possible to correct the variation in imaging performance caused by the deformation of the optical element 104.

[0025] In the present embodiment, the drive information regarding the drive of the optical element 104 by the drive unit 105 has been described as the drive position of the optical element 104, but is not limited thereto. For example, when the drive unit 105 drives the optical element 104 by (expansion / contraction by) voltage, the drive information may be a voltage value or a current value provided to the drive unit 105 to drive the optical element 104. Furthermore, when the drive unit 105 drives the optical element 104 by (expansion / contraction by) air pressure, the drive information may be a pressure value (air pressure value) provided to the drive unit 105 to drive the optical element 104. In this way, the drive information may be information regarding the drive of the optical element 104 by the drive unit 105. Furthermore, the information that the correction unit 107 obtains from the drive unit 105 when calculating the drive imaging variation is changed depending on the type of drive information.

[0026] The information indicating the relationship between the variation information and the drive information may be obtained from an external generation device that generates such information, or exposure apparatus 100 may have a generation unit that generates such information. If exposure apparatus 100 has a generation unit, the information indicating the relationship between the variation information and the drive information is generated in control unit 106 or correction unit 107. In other words, in exposure apparatus 100, control unit 106 or correction unit 107 is made to function as a generation unit that generates information indicating the relationship between the variation information and the drive information.

[0027] There are three methods for generating information indicating the relationship between the variation information and the drive information, for example: However, the method for generating information indicating the relationship between the variation information and the drive information is not limited to these methods.

[0028] In the first method, a surface shape measuring device is used to measure the deformation of the optical element 104 that occurs when the driving unit 105 drives the optical element 104, and a measurement value (amount of deformation) is obtained. Then, an optical simulation is performed based on the measurement value obtained by the surface shape measuring device to determine the driving image formation fluctuation, thereby generating information indicating the relationship between the fluctuation information and the driving information.

[0029] In the second method, a structural analysis simulation is performed to find the deformation of the optical element 104 that occurs when the driving unit 105 drives the optical element 104. Then, an optical simulation is performed based on the deformation of the optical element 104 found by the structural analysis simulation to find the driving imaging fluctuation, thereby generating information that indicates the relationship between the fluctuation information and the driving information.

[0030] In the third method, a measurement device that measures imaging performance such as wavefront aberration and imaging position is used to measure fluctuations in imaging performance caused by deformation of the optical element 104 and acquire measurement values ​​while driving the optical element 104 with the driving unit 105. Then, information indicating the relationship between fluctuation information and drive information is generated based on the measurement values ​​acquired by the measurement device and information related to the driving of the optical element 104 by the driving unit 105 when the measurement values ​​were acquired.

[0031] Referring to FIGS. 4(a) and 4(b), the operation process (exposure method) in exposure apparatus 100, including driving of optical element 104 by drive unit 105 and correction of drive imaging fluctuation by correction unit 107, will be described.

[0032] 4A is a flowchart showing an example of operational processing in the exposure apparatus 100. In S401, the control unit 106 instructs the drive unit 105 to drive the optical element 104 in order to correct variations in imaging performance due to the effects of manufacturing errors, exposure heat, and the like (drive instruction). In S402, the drive unit 105 drives the optical element 104 based on the drive instruction from the control unit 106 (drive execution). In S403, the correction unit 107 calculates a drive imaging variation based on information indicating the relationship between variation information and drive information stored in the storage unit SU and information related to driving the optical element 104 in S402 (drive execution) obtained from the drive unit 105 (calculation execution). In S404, the correction unit 107 corrects the drive imaging variation calculated in S403 via the correction mechanism 108 (correction execution). According to the operation process shown in FIG. 4(a), even if deformation occurs in the optical element 104 (the optical surface thereof) when the optical element 104 is driven by the driving unit 105, the fluctuation in imaging performance caused by the deformation of the optical element 104 can be corrected.

[0033] FIG. 4B is a flowchart showing another example of the operation processing in the exposure apparatus 100. In S401, the control unit 106 instructs the drive unit 105 to drive the optical element 104 to correct fluctuations in imaging performance due to the effects of manufacturing errors, exposure heat, and the like (drive instruction). In S403, the correction unit 107 calculates the drive imaging fluctuation based on information indicating the relationship between fluctuation information and drive information stored in the storage unit SU and information related to driving the optical element 104 in S401 (drive instruction) (calculation execution). Unlike the operation processing shown in FIG. 4A, S403 is performed before S402 (drive execution). In S402, the drive unit 105 drives the optical element 104 based on the drive instruction from the control unit 106 (drive execution). In S404, the correction unit 107 corrects the drive imaging fluctuation calculated in S403 via the correction mechanism 108 (correction execution). 4(b), S402 (driving execution) and S404 (correction execution) are performed simultaneously, which makes it possible to correct in real time the fluctuation in imaging performance caused by the deformation of the optical element 104 that occurs when the driving unit 105 drives the optical element 104.

[0034] A specific configuration of the correction mechanism 108 will be described with reference to FIGS. 5(a) and 5(b).

[0035] 5A, the correction mechanism 108 includes an optical element 501 that constitutes the projection optical system 102, and a drive element 502 (correction drive unit) that drives the optical element 501 in a direction parallel to the optical axis 103 of the projection optical system 102. When the drive element 502 drives an optical element 501 other than the optical element 104 of the projection optical system 102, fluctuations in imaging performance occur in the exposure apparatus 100 (projection optical system 102). Therefore, by having the drive element 502 drive the optical element 501 in a direction parallel to the optical axis 103 so as to cancel out fluctuations in imaging performance caused by deformation of the optical element 104 that occurs when the drive unit 105 drives the optical element 104, it is possible to correct the drive imaging fluctuations. Note that the deformation of the optical element 501 that occurs when the drive element 502 drives the optical element 501 is smaller than the deformation of the optical element 104 that occurs when the drive unit 105 drives the optical element 104, and can be ignored. This is because the drive unit 105 drives the optical element 104 in a direction perpendicular to the optical axis 103 of the projection optical system 102, while the drive element 502 drives the optical element 501 in a direction parallel to the optical axis 103 of the projection optical system 102.

[0036] The correction mechanism 108 also includes an optical element 506 that constitutes the projection optical system 102, and a drive element 507 (correction drive unit) that drives the optical element 506 in a direction that tilts it with respect to a plane perpendicular to the optical axis 103 of the projection optical system 102. When the drive element 507 drives an optical element 506 that is different from the optical element 104 of the projection optical system 102 (the optical element 506 tilts), a fluctuation in imaging performance occurs in the exposure apparatus 100 (projection optical system 102). Therefore, by driving the optical element 506 by the drive element 507 in a direction that tilts it with respect to a plane perpendicular to the optical axis 103 so as to cancel out the fluctuation in imaging performance caused by the deformation of the optical element 104 that occurs when the drive unit 105 drives the optical element 104, it becomes possible to correct the drive imaging fluctuation. The deformation of the optical element 506 that occurs when the driving element 507 drives the optical element 506 is smaller than the deformation of the optical element 104 that occurs when the driving unit 105 drives the optical element 104, and can be ignored. This is because the driving unit 105 drives the optical element 104 in a direction perpendicular to the optical axis 103 of the projection optical system 102, while the driving element 507 drives the optical element 506 in a direction that tilts it with respect to a plane perpendicular to the optical axis 103 of the projection optical system 102.

[0037] The correction mechanism 108 also includes an original driver 503 that drives the original 101 in a direction parallel to the optical axis 103 of the projection optical system 102. The original driver 503 is embodied, for example, as an original stage that holds and drives the original 101. When the original driver 503 drives the original 101, the distance between the original 101 and the projection optical system 102 fluctuates, causing fluctuations in imaging performance in the exposure apparatus 100 (projection optical system 102). Therefore, the original driver 503 drives the original 101 in a direction parallel to the optical axis 103 so as to cancel out fluctuations in imaging performance caused by deformation of the optical element 104 that occurs when the driver 105 drives the optical element 104, thereby making it possible to correct the driving imaging fluctuations.

[0038] The correction mechanism 108 also includes a substrate driver 504 that drives the substrate 109 in a plane perpendicular to the optical axis 103 of the projection optical system 102. The substrate driver 504 is embodied, for example, as a substrate stage that holds and drives the substrate 109. When the substrate driver 504 drives the substrate 109, the positional relationship between the substrate 109 and the projection optical system 102 fluctuates, causing a lateral shift in the imaging position in the exposure apparatus 100 (projection optical system 102). Therefore, by having the substrate driver 504 drive the substrate 109 in a plane perpendicular to the optical axis 103 so as to cancel out the lateral shift in the imaging position caused by deformation of the optical element 104 that occurs when the driver 105 drives the optical element 104, it is possible to correct the lateral shift in the imaging position.

[0039] The correction mechanism 108 also includes a light source 505 and a wavelength changer 515 that changes the wavelength of the light emitted from the light source 505 and illuminating the original 101. When the wavelength changer 515 changes the wavelength of the light illuminating the original 101, the wavelength of the light incident on the projection optical system 102 is changed, causing fluctuations in imaging performance in the exposure apparatus 100 (projection optical system 102). Therefore, by changing the wavelength of the light illuminating the original 101 with the wavelength changer 515 so as to cancel out fluctuations in imaging performance caused by deformation of the optical element 104 that occurs when the driver 105 drives the optical element 104, it becomes possible to correct the driving imaging fluctuations.

[0040] 5(b), the correction mechanism 108 includes an optical element 508 that constitutes the projection optical system 102, and a drive element 509 that drives one end of the optical element 508 in a direction that bends the optical element 508. When the drive element 509 drives an optical element 508 other than the optical element 104 of the projection optical system 102, the optical element 508 is deformed, causing a fluctuation in imaging performance in the exposure apparatus 100 (projection optical system 102). Therefore, by driving one end of the optical element 508 by the drive element 509 in a direction that bends the optical element 508, the fluctuation in imaging performance caused by the deformation of the optical element 104 that occurs when the drive unit 105 drives the optical element 104 can be compensated for, thereby making it possible to correct the drive imaging fluctuation.

[0041] For example, as shown in FIGS. 2(b) and 2(c), if the deformation of the optical surface of the optical element 104 includes a three-fold rotationally symmetric component, three-fold rotationally symmetric wavefront aberration occurs, causing fluctuations in imaging performance. In this case, the driving element 509 is disposed so as to be three-fold rotationally symmetric with respect to the optical element 508, and the driving element 509 is driven in a direction that bends three ends of the optical element 508. This enables the correcting unit 107 to generate three-fold rotationally symmetric wavefront aberration. Therefore, by driving the driving element 509 in a direction that bends three ends of the optical element 508, the correcting unit 107 can correct the three-fold rotationally symmetric wavefront aberration caused by the deformation of the optical element 104 that occurs when the driving unit 105 drives the optical element 104.

[0042] In the present embodiment, steady deformation has been described as the deformation of the optical element 104 that occurs when the driving unit 105 drives the optical element 104, but this is not limiting. For example, the deformation of the optical element 104 that occurs when the driving unit 105 drives the optical element 104 may be unsteady deformation.

[0043] As the exposure process speed in exposure apparatus 100 increases, temporal fluctuations in imaging performance due to exposure heat become more pronounced, and it is therefore required that drive unit 105 also drive optical element 104 at high speed. When drive unit 105 drives optical element 104 at high speed, the optical surface of optical element 104 deforms in accordance with the acceleration of optical element 104 driven by drive unit 105. In this case, by using the acceleration of optical element 104 as drive information related to the drive of optical element 104 by drive unit 105, it is possible to correct fluctuations in imaging performance due to non-steady deformation such as deformation due to acceleration of optical element 104 driven by drive unit 105.

[0044] Specifically, the acceleration of the optical element 104 is used as drive information, and the drive imaging variation with respect to the acceleration of the optical element 104 is used as variation information, and information indicating the relationship between the drive information and the variation information is acquired in advance and stored in the storage unit SU. The correction unit 107 calculates the drive imaging variation based on the information stored in the storage unit SU and the acceleration of the optical element 104 obtained from the drive unit 105, and corrects the drive imaging variation via the correction mechanism 108 provided in the exposure apparatus 100. As a result, even if deformation occurs in (the optical surface of) the optical element 104 due to the acceleration of the optical element 104 when the drive unit 105 drives the optical element 104, it is possible to correct the variation in imaging performance caused by the deformation of the optical element 104.

[0045] Second Embodiment In the first embodiment, the optical element 104 is assumed to be an optical element such as a lens or plate that transmits exposure light, and the driver 105 drives the optical element 104 in a direction parallel to the optical axis 103 of the projection optical system 102. In the second embodiment, with reference to Figures 6(a), 6(b), and 6(c), a case will be described in which the projection optical system 102 is configured as an optical system that includes a reflecting mirror with refractive power.

[0046] 6(a), in this embodiment, the projection optical system 102 includes imaging units 601 and 604 and at least one reflecting mirror, specifically, concave mirrors 602 and 603. In the projection optical system 102, light passing through the original 101 forms an image by the imaging unit 601, and the light formed by the imaging unit 601 forms an image again via the concave mirrors 602 and 603, and then forms an image on the substrate 109 via the imaging unit 604.

[0047] 6(b) shows an example of the relative positioning of the concave mirror 602 and the driver 105. FIG. 6(c) shows an example of the relative positioning of the concave mirror 603 and the driver 105. As shown in FIG. 6(b), the concave mirror 602 includes a reflecting surface 612 for reflecting light from the original 101 and a through-hole 605 for passing light (light from the original 101) that is reflected by the concave mirror 603 and enters the imaging unit 604. As shown in FIG. 6(c), the concave mirror 603 includes a reflecting surface 613 for reflecting light from the original 101 and a through-hole 606 for passing light emitted from the imaging unit 601 (light from the original 101 passing through the concave mirror 602).

[0048] The driver 105 disposed relative to the concave mirror 602 drives the concave mirror 602 in at least one of a direction parallel to the optical axis 103 of the projection optical system 102, a direction perpendicular to the optical axis 103, and a direction tilted relative to a plane perpendicular to the optical axis 103. Similarly, the driver 105 disposed relative to the concave mirror 603 drives the concave mirror 603 in at least one of a direction parallel to the optical axis 103 of the projection optical system 102, a direction perpendicular to the optical axis 103, and a direction tilted relative to a plane perpendicular to the optical axis 103.

[0049] Because the concave mirror 602 includes the through-hole 605, its rigidity against external forces is low, and when the driver 105 drives the concave mirror 602, the force applied by the driver 105 causes deformation in the reflecting surface 612 of the concave mirror 602. Similarly, because the concave mirror 603 includes the through-hole 606, its rigidity against external forces is low, and when the driver 105 drives the concave mirror 603, the force applied by the driver 105 causes deformation in the reflecting surface 613 of the concave mirror 603. If deformation occurs in the reflecting surfaces (optical surfaces) of the concave mirrors 602 and 603 as a result of the driver 105 driving these mirrors, this will cause aberrations in the projection optical system 102 and fluctuations in the imaging position, resulting in fluctuations in imaging performance.

[0050] Therefore, in this embodiment as well, the exposure apparatus 100 has a correction unit 107 for correcting fluctuations in the imaging performance of the projection optical system 102, in particular, drive imaging fluctuations. Furthermore, in this embodiment, information indicating the relationship between fluctuation information regarding the drive imaging fluctuations and drive information regarding the drive of the concave mirrors 602 and 603 by the drive unit 105 is acquired in advance and stored in a storage unit SU. The correction unit 107 determines the drive imaging fluctuations based on the information stored in the storage unit SU and the drive positions of the concave mirrors 602 and 603 obtained from the drive unit 105, and corrects the drive imaging fluctuations via a correction mechanism 108 provided in the exposure apparatus 100. Note that the correction mechanism 108 includes, for example, optical elements other than the concave mirrors 602 and 603 of the projection optical system 102, and a drive element (correction drive unit) that drives the other optical elements. In this way, based on information indicating the relationship between the variation information and the drive information, correction unit 107 corrects the drive imaging variation in response to the drive of concave mirror 602 and concave mirror 603 by drive unit 105. As a result, even if deformation occurs in (the reflecting surface of) concave mirror 602 and concave mirror 603 when drive unit 105 drives concave mirror 602 and concave mirror 603, it is possible to correct the variation in imaging performance caused by such deformation.

[0051] <Third embodiment> The method for manufacturing an article according to an embodiment of the present invention is suitable for manufacturing articles such as semiconductor devices, flat panel displays, liquid crystal display devices, and MEMS. This manufacturing method includes the steps of exposing a substrate coated with a photosensitive agent using the exposure apparatus 100 (exposure method) described above and developing the exposed photosensitive agent. The developed photosensitive agent pattern is then used as a mask to perform etching and ion implantation processes on the substrate, forming a circuit pattern on the substrate. These exposure, development, etching, and other processes are repeated to form a circuit pattern consisting of multiple layers on the substrate. In subsequent processes, the substrate on which the circuit pattern has been formed is diced (processed), followed by chip mounting, bonding, and inspection. This manufacturing method may also include other well-known processes (e.g., oxidation, film formation, vapor deposition, doping, planarization, resist stripping, 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.

[0052] The disclosure of the present specification includes the following exposure apparatus, exposure method, and method for manufacturing an article.

[0053] (Item 1) An exposure apparatus that exposes a substrate through an original, a projection optical system that projects the pattern of the original onto the substrate; a driving unit that drives at least one optical element of the projection optical system by locally applying a force to the optical element; a correction unit that corrects fluctuations in the imaging performance of the projection optical system; and the correction unit corrects the fluctuation in the imaging performance in response to the driving of the optical element by the driving unit, based on information indicating a relationship between fluctuation information on the fluctuation in the imaging performance caused by deformation of the optical element when the driving unit drives the optical element and drive information on the driving of the optical element by the driving unit. An exposure apparatus characterized by:

[0054] (Item 2) 2. The exposure apparatus according to item 1, wherein the driving section drives the optical element by applying at least one of a compressive force and a tensile force to the optical element as the force.

[0055] (Item 3) 3. The exposure apparatus according to item 1 or 2, wherein the drive unit drives the optical element in a direction perpendicular to the optical axis of the projection optical system.

[0056] (Item 4) 4. The exposure apparatus according to any one of items 1 to 3, further comprising a generating unit that generates the information indicating the relationship between the variation information and the drive information.

[0057] (Item 5) 5. The exposure apparatus according to item 4, wherein the generation unit acquires measurement values ​​obtained by measuring deformation of the optical element that occurs when the drive unit drives the optical element, and generates the information indicating the relationship between the variation information and the drive information by performing an optical simulation based on the acquired measurement values ​​to determine fluctuations in the imaging performance.

[0058] (Item 6) 5. The exposure apparatus according to item 4, wherein the generation unit performs a structural analysis simulation to determine the deformation of the optical element that occurs when the drive unit drives the optical element, and performs an optical simulation based on the determined deformation of the optical element to determine the fluctuation in the imaging performance, thereby generating the information indicating the relationship between the fluctuation information and the drive information.

[0059] (Item 7) 5. The exposure apparatus according to item 4, wherein the generation unit generates the information indicating the relationship between the variation information and the drive information by acquiring measurement values ​​obtained by measuring the variation in the imaging performance caused by deformation of the optical element while driving the optical element with the drive unit.

[0060] (Item 8) 8. The exposure apparatus according to any one of items 1 to 7, further comprising a storage unit that stores the information indicating the relationship between the variation information and the drive information.

[0061] (Item 9) 9. An exposure apparatus according to any one of items 1 to 8, characterized in that the fluctuation information includes at least one of information on fluctuations in aberration of the projection optical system, fluctuations in lateral shift of the imaging position, fluctuations in imaging magnification, and fluctuations in distortion.

[0062] (Item 10) 10. An exposure apparatus according to any one of items 1 to 9, characterized in that the drive information includes at least one of information on the drive position of the optical element driven by the drive unit, a voltage value or current value to be given to the drive unit to drive the optical element by voltage, a pressure value to be given to the drive unit to drive the optical element by air pressure, and an acceleration of the optical element driven by the drive unit.

[0063] (Item 11) 11. The exposure apparatus according to any one of items 1 to 10, wherein the correction unit includes a correction drive unit that drives an optical element other than the optical element of the projection optical system in at least one of a direction parallel to the optical axis of the projection optical system and a direction tilted relative to a plane perpendicular to the optical axis of the projection optical system.

[0064] (Item 12) Item 12. The exposure apparatus according to item 11, wherein the deformation of the other optical element that occurs when the correction drive unit drives the optical element is smaller than the deformation of the optical element that occurs when the drive unit drives the optical element.

[0065] (Item 13) 13. The exposure apparatus according to any one of items 1 to 12, wherein the correction unit includes an original drive unit that drives the original in a direction parallel to the optical axis of the projection optical system.

[0066] (Item 14) 14. The exposure apparatus according to any one of items 1 to 13, wherein the correction unit includes a substrate drive unit that drives the substrate in a plane perpendicular to the optical axis of the projection optical system.

[0067] (Item 15) 15. The exposure apparatus according to any one of items 1 to 14, wherein the correction unit includes a wavelength change unit that changes the wavelength of the light that illuminates the original.

[0068] (Item 16) 16. The exposure apparatus according to any one of items 1 to 15, wherein the correction unit corrects fluctuations in three-fold rotationally symmetric wavefront aberration as fluctuations in the imaging performance of the projection optical system.

[0069] (Item 17) 17. The exposure apparatus according to any one of items 1 to 16, wherein the deformation of the optical element includes deformation of an optical surface of the optical element.

[0070] (Item 18) An exposure apparatus that exposes a substrate through an original, a projection optical system that projects the pattern of the original onto the substrate; a driving unit that drives at least one reflecting mirror of the projection optical system; a correction unit that corrects fluctuations in the imaging performance of the projection optical system; and the correction unit corrects the fluctuation in the imaging performance in response to the driving of the reflecting mirror by the driving unit, based on information indicating a relationship between fluctuation information on the fluctuation in the imaging performance caused by deformation of the reflecting mirror when the driving unit drives the reflecting mirror, and drive information on the driving of the reflecting mirror by the driving unit. An exposure apparatus characterized by:

[0071] (Item 19) Item 19. An exposure apparatus according to item 18, wherein the reflecting mirror is a concave mirror including a reflecting surface for reflecting light from the original and a through hole for passing the light.

[0072] (Item 20) 20. The exposure apparatus described in item 18 or 19, characterized in that the drive unit drives the reflecting mirror in at least one of a direction parallel to the optical axis of the projection optical system, a direction perpendicular to the optical axis of the projection optical system, and a direction tilted relative to a plane perpendicular to the optical axis of the projection optical system.

[0073] (Item 21) 21. The exposure apparatus according to any one of items 18 to 20, wherein the correction unit includes a correction drive unit that drives an optical element other than the reflecting mirror of the projection optical system.

[0074] (Item 22) 1. An exposure method for exposing a substrate using an exposure apparatus having a projection optical system that projects a pattern of an original onto the substrate, comprising: a first step of driving at least one optical element of the projection optical system by locally applying a force to the optical element; a second step of correcting fluctuations in the imaging performance of the projection optical system; and In the second step, the fluctuation in the imaging performance is corrected in accordance with the driving of the optical element in the first step, based on information indicating a relationship between fluctuation information on the fluctuation in the imaging performance caused by deformation of the optical element when the optical element is driven and drive information on the driving of the optical element. An exposure method characterized by:

[0075] (Item 23) Item 23. Exposing a substrate using the exposure method according to Item 22; developing the exposed substrate; manufacturing an article from the developed substrate; A method for manufacturing an article, comprising:

[0076] 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]

[0077] 100: exposure device 101: original 102: projection optical system 104: optical element 105: driving unit 106: control unit 107: correction unit 108: correction mechanism

Claims

1. An exposure apparatus for exposing a substrate, a projection optical system that projects a pattern of an original onto the substrate; a first driving unit that applies a force locally to a first optical element included in the projection optical system to move the first optical element in a first direction perpendicular to an optical axis of the projection optical system; a correction unit that corrects fluctuations in the imaging performance of the projection optical system; and The correction unit a second optical element different from the first optical element; a second driving unit that drives the second optical element, the second driving unit performs at least one of driving the second optical element to move in a direction parallel to the optical axis of the projection optical system and driving the second optical element to tilt with respect to a plane perpendicular to the optical axis of the projection optical system, based on information indicating a relationship between the movement of the first optical element by the first driving unit and a variation in the imaging performance caused by deformation of the first optical element due to the application of the force; a deformation of the second optical element caused by driving the second driving unit is smaller than a deformation of the first optical element caused by driving the first driving unit; An exposure apparatus characterized by:

2. 2. The exposure apparatus according to claim 1, wherein the first driving unit applies at least one of a compressive force and a tensile force to the first optical element to move the first optical element.

3. 2. The exposure apparatus according to claim 1, further comprising a generating unit that generates the information.

4. The exposure apparatus of claim 3, wherein the generation unit acquires measurement values ​​obtained by measuring deformation of the first optical element due to driving of the first optical element, and generates the information by performing an optical simulation based on the acquired measurement values ​​to determine fluctuations in the imaging performance.

5. The exposure apparatus of claim 3, wherein the generation unit generates the information by performing a structural analysis simulation to determine the deformation of the first optical element due to driving of the first optical element, and performing an optical simulation based on the determined deformation of the first optical element to determine the fluctuation in the imaging performance.

6. 4. The exposure apparatus according to claim 3, wherein the generation unit generates the information by acquiring measurement values ​​obtained by measuring fluctuations in the imaging performance caused by deformation of the first optical element while driving the first optical element with the first drive unit.

7. 2. The exposure apparatus according to claim 1, further comprising a storage unit that stores the information.

8. 2. The exposure apparatus according to claim 1, wherein the information relating to the fluctuation in the imaging performance caused by the deformation of the first optical element includes at least one of information relating to the fluctuation in aberration of the projection optical system, the fluctuation in lateral shift of the imaging position, the fluctuation in imaging magnification, and the fluctuation in distortion.

9. 2. The exposure apparatus of claim 1, wherein the information regarding the driving of the first optical element by the first driving unit includes at least one of information regarding the driving position of the first optical element driven by the first driving unit, a voltage value or current value to be given to the first driving unit to drive the first optical element by voltage, a pressure value to be given to the first driving unit to drive the first optical element by air pressure, and an acceleration of the first optical element driven by the first driving unit.

10. 2. The exposure apparatus according to claim 1, wherein the correction unit includes an original drive unit that drives the original in a direction parallel to the optical axis of the projection optical system.

11. 2. The exposure apparatus according to claim 1, wherein the correction unit includes a substrate drive unit that drives the substrate within a plane perpendicular to the optical axis of the projection optical system.

12. 2. The exposure apparatus according to claim 1, wherein the correction unit includes a wavelength change unit that changes the wavelength of the light that illuminates the original.

13. 2. The exposure apparatus according to claim 1, wherein the correction unit corrects wavefront aberration with three-fold rotational symmetry.

14. 2. The exposure apparatus according to claim 1, wherein the deformation of the first optical element includes deformation of an optical surface of the first optical element.

15. 2. The exposure apparatus according to claim 1, wherein the first optical element is a mirror.

16. 16. The exposure apparatus according to claim 15, wherein the mirror is a concave mirror including a reflective surface for reflecting the light from the original and a through-hole for passing the light.

17. 1. An exposure method for exposing a substrate using an exposure apparatus having a projection optical system that projects a pattern of an original onto the substrate, comprising: a first step of locally applying a force to a first optical element included in the projection optical system to move the first optical element in a first direction perpendicular to an optical axis of the projection optical system; a second step of correcting fluctuations in the imaging performance of the projection optical system; and in the second step, a drive unit that drives a second optical element different from the first optical element performs at least one of driving to move the second optical element in a direction parallel to the optical axis of the projection optical system and driving to tilt the second optical element with respect to a plane perpendicular to the optical axis of the projection optical system, based on information indicating a relationship between movement of the first optical element and a variation in the imaging performance caused by deformation of the first optical element due to application of the force; a deformation of the second optical element caused by the driving unit being smaller than a deformation of the first optical element caused by the force; An exposure method characterized by:

18. exposing a substrate using the exposure method according to claim 17; developing the exposed substrate; manufacturing an article from the developed substrate; A method for manufacturing an article, comprising:

Images