Exposure method, exposure apparatus, and method for manufacturing article

Abstract

The exposure method includes: predicting changes in the optical properties of the projection optics system during exposure of multiple substrates via the projection optics system; adjusting the optical properties based on the prediction results before exposure; and performing exposure after the adjustment, wherein, in the adjustment, the optical properties at the start of exposure are adjusted in a direction different from the direction of the optical property change based on the predicted changes in the optical properties.

Description

Exposure method, exposure device, and method for manufacturing article The present disclosure relates generally to exposure, and more particularly to exposure methods, exposure apparatus, and methods for making articles. The manufacturing process of semiconductor devices or liquid crystal display devices uses an exposure device that illuminates a master through an illumination optical system and projects the pattern of the master onto a substrate via a projection optical system to expose the substrate. If the projection optical system absorbs the exposure light and generates heat, aberrations occur. Aberrations affect the results of the exposure process. Japanese Patent Application Laid-Open No. 2014-103343 discusses a method for predicting aberrations caused by an exposure process and determining whether to perform the next exposure process based on the predicted results. Considering productivity, when aberrations occur, the aberrations are corrected to quickly perform the next exposure process. Moreover, even when performing exposure processing on a batch, the aberrations will change. If the aberrations increase in the middle of the batch, the resolution performance will decrease and the desired quality cannot be met. The present disclosure generally provides an exposure method capable of performing an exposure process with reduced influence of aberrations, as well as an exposure apparatus and a method for manufacturing an article. According to some embodiments, an exposure method includes predicting changes in optical characteristics of a projection optical system during exposure of multiple substrates via the projection optical system, adjusting the optical characteristics before the exposure based on a prediction result of the prediction, and performing the exposure after the adjustment. In the adjustment, the optical characteristics at the start of the exposure are adjusted in a direction different from the direction of the change in the optical characteristics based on the change in the optical characteristics predicted in the prediction. Further features of the present disclosure will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings. The following exemplary embodiments of the present disclosure will be described with reference to the drawings. The following exemplary embodiments are not intended to limit the disclosure set forth in the scope of the claims. Although the exemplary embodiments describe multiple features, not all features are essential to the present disclosure, and these features may be combined in any given manner. In the drawings, identical or similar components are represented by the same reference numerals. Redundant descriptions thereof will be omitted. In this specification and the drawings, directions are generally expressed using an XYZ coordinate system having mutually orthogonal axes, where the vertical direction is the Z axis and the horizontal plane perpendicular to the vertical direction is the XY plane. If an XYZ coordinate system is illustrated in the drawings, that coordinate system takes precedence. The specific configuration of each exemplary embodiment will be described below. FIG1 is a schematic diagram illustrating the configuration of an exposure apparatus 100 according to a first exemplary embodiment. Light emitted from a light source 101 is incident on an illumination optical system 102. A diffractive optical element 103 forms a light intensity distribution (hereinafter also referred to as an effective light source distribution) on a pupil plane of the illumination optical system 102, and illuminates a reticle 104 with the resulting light. Reticle 104 is a master sheet formed of, for example, quartz glass, on whose surface a pattern to be transferred (e.g., a circuit pattern) is formed using chromium. Light incident on the pattern drawn on reticle 104 is diffracted by reticle 104 and enters projection optical system 107. The light is adjusted in intensity by aperture stop 108 disposed in projection optical system 107 and reaches substrate 110, thereby projecting the pattern on reticle 104 in a reduced size. Here, substrate 110 is formed, for example, of single crystal silicon having a surface coated with a photosensitive material (resist). Control unit 120 includes a processor, a circuit system, or a combination thereof, and can be configured as a controller to control one or more units or components in exposure apparatus 100. Storage unit 130 stores information obtained from control unit 120. Reticle 104 is held on reticle stage 106. Reticle stage 106 is driven to scan in the +Y direction. Substrate stage 111, which holds substrate 110, is driven to scan in the -Y direction. After the exposure of a shooting (shot) area is finished, these stages are driven in a step-by-step manner to expose the next shooting area. A reticle reference plate 105 different from reticle 104 is disposed on reticle stage 106. Reticle reference plate 105 is provided with reticle side marks for measuring aerial images. Reticle side marks are line and space patterns arranged in a cycle. Detection plate 112 is further disposed on substrate stage 111. Detection plate 112 is provided with substrate side marks (not shown) for measuring aerial images. Substrate side marks are line and space patterns arranged in a cycle identical to that of the reticle side marks. Photodetector 115 is located below detection plate 112. The light blocking portion of the line and space pattern on the reticle side and substrate side marks is, for example, formed by chrome. Its light-transmitting portion is formed by glass.Reticle stage 106 is driven in the Y direction so that light emitted from light source 101 illuminates the reticle side marks on reticle reference plate 105 via illumination optical system 102. The light that passes through the reticle side marks on reticle reference plate 105 reaches the substrate side marks on detection plate 112 via projection optical system 107. The light that reaches the reticle side marks passes through the substrate side marks on detection plate 112 and reaches photodetector 115. Next, aerial image measurement, a measurement method for measuring astigmatism (optical characteristics), will be described. Light emitted from light source 101 illuminates reticle reference plate 105 via illumination optical system 102, whereby the reticle side marks are projected onto the substrate side marks in a reduced size via projection optical system 107. If substrate stage 111 is moved in the Z direction, which is the optical axis direction, while projecting in the reduced size state, the image of the reticle side marks projected in a reduced size at the optimal focus position of projection optical system 107 coincides with the substrate side marks. Here, the amount of light received by photodetector 115 is maximized. When substrate stage 111 moves away from the optimal focus position, the image of the reticle-side mark projected onto the substrate-side mark on detection plate 112 at a reduced size loses contrast and blurs, and the amount of light received by photodetector 115 decreases. Figure 2 is a diagram illustrating the relationship between focus and light intensity when substrate stage 111 is driven in the Z direction. Figure 2 illustrates an example of a situation where substrate stage 111 is driven beyond the optimal focus position in the Z direction, with the reticle-side mark projected onto the substrate-side mark at a reduced size. The horizontal axis indicates focus, and the vertical axis indicates the amount of light detected by photodetector 115. The illustrated relationship between focus and light intensity has an upwardly convex curved shape. The peak position of the curved shape represents the optimal focus position. While this exemplary embodiment describes an example of determining the optimal focus position based on the detection results of light passing through the reticle-side mark and substrate-side mark by photodetector 115, the method for determining the optimal focus position is not limited to this example. Figure 3 is a schematic diagram illustrating the line and space pattern of reticle-side mark 113. The substrate-side mark has a similar configuration. The reticle side mark 113 and the substrate side mark each include X and Y direction lines and spatial patterns for astigmatism measurement. As the X and Y direction lines and spatial patterns of the reticle side mark 113 are projected onto the substrate side mark in a reduced size, the substrate carrier 111 is driven in the Z direction over an area spanning (including) the optimal focus position in both the X and Y directions. As a result, the relationship between the focus and the amount of light shown in Figure 2 can be obtained for both the X and Y direction lines and spatial patterns. Based on the obtained relationship between the focus and the amount of light of the X and Y direction lines and spatial patterns, the optimal focus position in the X and Y directions is determined according to the corresponding position (peak position) where the amount of light is maximized. Astigmatism can be determined by determining the difference between the optimal focus position in the X direction and the optimal focus position in the Y direction.FIG4 is a flowchart for storing the aberration saturation amount P (first coefficient) used in a prediction equation (model) for predicting astigmatism according to this exemplary embodiment. In this exemplary embodiment, first information, or information including the aberration saturation amount P (first coefficient) for predicting changes in optical characteristics during the exposure process, is obtained in advance. In step S110, astigmatism is measured based on the effective light source distribution used for the exposure process. In step S120, exposure processing is performed on the Nth substrate among the substrates to be measured in advance that has not yet been exposed. The substrate to be measured in advance refers to a substrate used to determine the aberration saturation amount P. For example, the substrate to be measured in advance is a substrate included in a batch. The aberration saturation amount P is a value specific to the exposure process conditions. In step S130, the control unit 120 determines whether the exposure process has been performed on all the substrates to be measured in advance. If the exposure process has not yet been performed on all the substrates to be measured in advance ("No" in step S130), the process returns to step S110. If the exposure process has been performed on all the substrates to be measured in advance ("Yes" in step S130), the processing proceeds to step S140. In step S140, the astigmatism is measured based on the effective light source distribution used for the exposure process. In step S150, the control unit 120 determines the aberration saturation amount P to be used in the prediction equation. In step S160, the storage unit 130 stores the exposure process conditions and the aberration saturation amount P in association with each other, and then the processing ends. In the present exemplary embodiment, an example has been described in which all the substrates to be measured in advance (for example, 25 substrates included in a batch) are measured for optical characteristics (astigmatism). However, if the amount of information obtained is sufficient, it is not necessary to measure all the substrates to be measured in advance for optical characteristics (astigmatism). For example, if it is determined in step S130 that the exposure process has been performed on all the substrates to be measured in advance, the processing can skip step S140 and proceed to step S150. The aberration saturation amount P determined in step S150 and used in the prediction equation for predicting astigmatism is obtained by fitting the measured value of astigmatism to the prediction equation expressed by equations (1), (2), and (3). The amount of astigmatism that will occur in the actual exposure process can be predicted based on the determined aberration saturation amount P, the prediction equations (1), (2), and (3), and the measurement results of the aberrations before the exposure process (second information). , Equation (1) , equation (2), and . Equation (3) Here, Φ indicates the predicted occurrence amount of modeled astigmatism, and the suffix N indicates the timing of measurement of astigmatism. In this exemplary embodiment, three time constants (K) are used. The suffix m indicates the model number, where m=1 refers to a long-term time constant model, m=2 refers to a medium-term time constant model, and m=3 refers to a short-term time constant model. Although three time constant models are used in this exemplary embodiment to determine three aberration saturation amounts P, the number of time constant models can be two or more. α indicates the exposure load, whose value changes according to the exposure conditions. As expressed in equation (3), the exposure load α can be determined based on the reticle transmittance R, the exposure amount D, the shooting size A, the number of shots Num between one astigmatism measurement and another astigmatism measurement, and the time T between one astigmatism measurement and another astigmatism measurement. Other parameters such as the resist reflectivity can be used to calculate the exposure load α. Figure 5 illustrates the results of aberration prediction according to this exemplary embodiment. The horizontal axis indicates time and the vertical axis indicates the amount of astigmatism. The white dots represent the measured values ​​of astigmatism obtained in steps S110 and S140, and the solid line represents the predicted aberrations that occur using the prediction equation. The control unit 120 measures the astigmatism in steps S110 and S140 in advance under feasible exposure processing conditions, and determines the aberration saturation amount P based on the measured values ​​and equations (1), (2), and (3). Then, the storage unit 130 stores the aberration saturation amount P determined by the control unit 120 and the exposure processing conditions in association with each other. When the control unit 120 performs exposure processing under the same exposure processing conditions as those stored in the storage unit 130, the control unit 120 predicts the amount of aberration that occurs during the exposure processing based on the information stored in the storage unit 130. Specifically, the control unit 120 predicts the amount of aberration that occurs based on the aberration saturation amount P stored in the storage unit 130 in association with the exposure processing conditions, equations (1), (2), and (3), and the result of the astigmatism measurement measured before the exposure processing. Next, virtual irradiation for correcting astigmatism will be described. Figures 6A and 6B illustrate an example of a light intensity distribution (effective light source distribution) on the pupil plane of illumination optical system 102 for virtual illumination according to this exemplary embodiment. Light emitted from light source 101 is shaped by diffractive optical element 103 in illumination optical system 102 into the effective light source distribution shown in Figures 6A or 6B. The dotted line in Figures 6A and 6B indicates σ = 1. The white area has a light intensity. Light with the shaped effective light source distribution enters projection optical system 107 via illumination optical system 102 without passing through reticle 104. Here, aperture stop 108 located near the pupil of projection optical system 107 is closed, so that light entering projection optical system 107 illuminates aperture stop 108 and does not reach substrate 110.When light that has entered projection optical system 107 is incident on a set of lenses that constitute projection optical system 107, absorption by the lens glass material and by the antireflection coating causes the lenses to heat up, and the refractive index of the lenses changes, causing wavefront aberration. For example, if the effective light source distribution shown in FIG6A is formed by diffractive optical element 103 and then enters projection optical system 107, projection optical system 107 generates a wavefront aberration with a distribution corresponding to the effective light source distribution. In other words, the sign of astigmatism can be controlled by switching diffractive optical element 103 to select an effective light source distribution so that astigmatism has a desired sign and then performing virtual illumination. Furthermore, the desired amount of astigmatism can be obtained by adjusting the duration of virtual illumination. While this exemplary embodiment describes an example of performing virtual illumination using the 2θ component of the wavefront aberration, the 3θ or 4θ components can also be used without any particular limitation. A method for determining the duration of virtual illumination will now be described. First, information regarding the relationship between the duration of virtual illumination on projection optical system 107 and the amount of change in astigmatism in projection optical system 107 is obtained in advance. Next, a proportionality coefficient (Coef) indicating the amount of change in astigmatism of the projection optical system 107 per unit time is determined based on the obtained information. The proportionality coefficient (Coef) is a second coefficient. The duration of virtual irradiation (irradiation time) is then determined based on equation (4): . , Equation (4) Wherein T is the duration of virtual irradiation, and AS is the amount of astigmatism to be changed when adjusting the astigmatism of the projection optical system 107 to a desired value (desired value of astigmatism). Although the amount of astigmatism to be changed is adjusted by adjusting the duration of virtual irradiation in the present exemplary embodiment, the amount of virtual irradiation may be used instead of the duration of virtual irradiation. FIG7 is a flowchart of performing virtual irradiation to correct astigmatism according to the present exemplary embodiment. First, in step S210, the control unit 120 determines whether to perform astigmatism measurement. Here, the timing of performing astigmatism measurement can be freely set by the user. Astigmatism measurement can be set to be performed at the beginning of a batch or before exposing a specific reticle. If astigmatism measurement is not performed ("No" in step S210), the process proceeds to step S270. In step S270, exposure processing is performed, and the process ends. If astigmatism measurement is performed ("Yes" in step S210), then in step S220, astigmatism is measured based on the effective light source distribution used for exposure processing. Then, in step S230, based on the astigmatism measurement result and the aberration saturation amount P stored in association with the exposure process conditions stored in the storage unit 130, the control unit 120 determines whether the astigmatism exceeds the allowable range (predetermined range) during the processing of the target substrate (prediction process). In step S230, the astigmatism is predicted using equations (1), (2), and (3). The storage unit 130 stores a plurality of exposure process conditions, each of which is associated with first information including the aberration saturation amount P (first coefficient). The control unit 120 selects an exposure process condition that is the same as the exposure process condition when the astigmatism was measured from the exposure process conditions stored in the storage unit 130, and predicts the change in astigmatism using the aberration saturation amount P associated with the selected exposure process condition. The target substrate refers to a substrate to be processed before the next astigmatism measurement, for example, when the user sets the astigmatism measurement to be performed at the beginning of a batch, it refers to all substrates in the batch. The user sets the allowable range (predetermined range) for each exposure process condition in advance based on the influence of aberration and the desired accuracy of the exposure process. If the astigmatism does not exceed the allowable range during the processing of the target substrate ("No" in step S230), the adjustment process is not performed, and the process proceeds to step S270. In step S270, the control unit 120 performs an exposure process (exposure process), and the process ends. If the astigmatism exceeds the allowable range during the processing of the target substrate ("Yes" in step S230), the process proceeds to step S240. In step S240, the control unit 120 determines whether the astigmatism changes in the positive direction during the processing of the target substrate based on the prediction equation expressed by equations (1), (2), and (3).If the astigmatism changes in the positive direction ("Yes" in step S240), then in step S250, the control unit 120 retracts the reticle 104 and performs virtual irradiation so that the astigmatism at the start of the exposure process has a value on the negative side within the allowable range (adjustment process). If the astigmatism changes in the negative direction ("No" in step S240), then in step S260, the control unit 120 retracts the reticle 104 and performs virtual irradiation so that the astigmatism at the start of the exposure process has a value on the positive side within the allowable range (adjustment process). The effective light source distribution used for the virtual irradiation in steps S250 and S260 is switched so that the astigmatism has a desired sign by the virtual irradiation. The amount of change in the astigmatism (optical characteristic) to be changed by the virtual irradiation in steps S250 and S260 is determined so that the astigmatism does not exceed the allowable range during the processing of the target substrate (e.g., one batch). Then, based on the determined amount of change in the optical characteristic, the optical characteristic at the start of the exposure process is adjusted. In other words, during the exposure process of the target substrate, the astigmatism is adjusted so that the astigmatism is within the allowable range (predetermined range) without performing astigmatism adjustment. Specifically, based on the predicted change in the optical characteristics, the optical characteristics at the start of the exposure process are adjusted in a direction different from the direction in which the optical characteristics change. For example, the optical characteristics (astigmatism) at the start of the exposure process are adjusted to a positive value or a negative value. This is synonymous with adjusting the optical characteristics to a value that deviates from the optimal optical characteristics. Alternatively, instead of adjusting the optical characteristics, the following configuration may be adopted: the condition under which the optical characteristics are optimal (for example, the position of the substrate carrier 111 under which the optical characteristics are optimal) is adjusted to a condition under which the optical characteristics are not optimal. Furthermore, desirably, the astigmatism is adjusted so that the value of the astigmatism of the target substrate (for example, one batch) during exposure is close to zero (0) on average, while the astigmatism does not exceed the allowable range during the processing of the target substrate. After the adjustment process in steps S250 and S260, in step S270, the retracted reticle 104 is moved to a position where exposure processing can be performed, and exposure processing is performed while the diffractive optical element 103 is switched to the effective light source distribution for the exposure process (exposure process). The process then ends. In this exemplary embodiment, whether to perform virtual irradiation is determined by determining whether astigmatism exceeds the allowable range during processing of the target substrate. However, a threshold value can be set instead of the allowable range (predetermined range), and whether to perform virtual irradiation can be determined by comparing the astigmatism measurement results with the threshold value. FIG8 illustrates an example of astigmatism adjustment according to this exemplary embodiment. In the example of FIG8 , 25 substrates included in a batch are target substrates. Since the upper and lower limit values ​​are indicated by a dotted chain line, the allowable range of astigmatism in nanometers (nm) is -30 (nm) to +40 (nm). The dotted line indicates the change in astigmatism when no astigmatism adjustment is performed. Without performing astigmatism adjustment, the astigmatism exceeds the allowable range when processing the thirteenth substrate.In this case, the exposure processing results of the thirteenth and subsequent substrates are greatly affected by astigmatism. In this exemplary embodiment, based on the measurement results of astigmatism, the previously obtained aberration saturation amount P, and equations (1), (2), and (3), the change in astigmatism (optical characteristics) during the processing of the target substrate is obtained, and the astigmatism amount to be adjusted is obtained. Specifically, the time change direction (tilt direction) of astigmatism and the amount of change (maximum change amount) of astigmatism during the processing of the target substrate (e.g., a batch) are obtained, and then the astigmatism amount to be adjusted is obtained. Here, the change in astigmatism (optical characteristics) according to this exemplary embodiment is synonymous with the amount of change (slope) of astigmatism per unit time, and includes the elements of the maximum change amount of astigmatism expected to change during the processing of the target substrate (substrates included in a batch) and the tilt direction of astigmatism. In this exemplary embodiment, an example of adjusting astigmatism based on the time change direction (tilt direction) of astigmatism and the amount of change (maximum change amount) of astigmatism during the processing of the target substrate (e.g., a batch) has been described. However, astigmatism can be adjusted based only on the maximum change amount of astigmatism. More specifically, according to this exemplary embodiment, the factors indicating changes in astigmatism (optical characteristics) include one or both of the amount of change in the optical characteristics per unit time and / or the maximum amount of change in the optical characteristics during the exposure process. For example, in FIG8 , based on the astigmatism measurement results, the previously obtained aberration saturation amount P, and equations (1), (2), and (3), it is predicted that the slope direction of the change in astigmatism is the positive direction, and the amount of change in aberration (maximum amount of change) during the processing of the target substrate (e.g., a batch) is +60 (nm). Therefore, the control unit 120 adjusts the astigmatism through virtual irradiation so that even if the astigmatism changes by +60 (nm), the astigmatism does not exceed the allowable range. In the example of FIG8 , the astigmatism is adjusted in a direction (the negative direction) different from the tilt direction of the astigmatism (the positive direction), and the adjustment amount is adjusted so that the astigmatism at the start of exposure is -30 (nm), so that even if the astigmatism adjustment is not performed during the exposure, the astigmatism is within the allowable range. In other words, during the adjustment process, the optical characteristics (astigmatism) at the start of the exposure process are adjusted toward a sign different from the sign of the slope of the change in the optical characteristics predicted in the prediction process. Through this adjustment, the astigmatism during the processing of the target substrate falls within the allowable range, and the influence of the aberration on the result of the exposure process can be reduced. In this exemplary embodiment, an example of adjusting the astigmatism to -30 (nm) based on the lower limit of the allowable range has been described. However, in the example of Figure 8, the astigmatism can be adjusted to -20 (nm) because the astigmatism can be adjusted so that the astigmatism falls within the allowable range during the exposure process. Desirably, the astigmatism during the exposure process (exposure process) changes to a value close to 0 within the allowable range. Therefore, desirably, the adjustment of the astigmatism is performed so that the average value of the astigmatism value during the exposure process is close to 0.For example, in this exemplary embodiment, the astigmatism is adjusted to -25 (nm) so that the average value of the astigmatism in the exposure process is a value close to 0. In this exemplary embodiment, an example of adjusting the astigmatism is described. However, the optical property to be adjusted can be any optical property that changes due to irradiating the projection optical system with light, and is not limited to astigmatism. Examples of optical properties to be adjusted according to this exemplary embodiment include spherical aberration, coma, field curvature, and distortion aberration (distortion). In this exemplary embodiment, by applying the pre-acquired aberration saturation amount P and the measurement results of the astigmatism to the prediction equation, the amount of aberration generated during the exposure process can be predicted, and the astigmatism can be adjusted by performing virtual irradiation based on the prediction result. As a result, during the exposure process of the target substrate (e.g., a batch), the exposure process can be performed in a state where the astigmatism is within the allowable range set by the user without adjusting the astigmatism, and the influence of the astigmatism on the exposure process results can be reduced. The second exemplary embodiment is characterized in that an article is manufactured using the exposure device (exposure method) according to the first exemplary embodiment. Figure 9 is a flowchart of the method for manufacturing an article according to this exemplary embodiment. In step S310, an exposure process is performed in which optical characteristics (astigmatism) are adjusted using an exposure device (exposure method) according to the first exemplary embodiment and exposure of the substrate is performed. In step S320, a development process is performed in which the photosensitive material patterned on the substrate by exposure in the exposure process is developed. In step S330, a manufacturing process is performed in which an article is manufactured using the substrate developed in the development process. Examples of articles to be manufactured by this manufacturing method include semiconductor integrated circuit (IC) elements, liquid crystal display elements, color filters, and microelectromechanical systems (MEMS). In the exposure process, for example, a substrate coated with a photosensitive material (such as a silicon substrate and a glass substrate) is exposed to light using an exposure device (lithography equipment) to pattern the substrate. The manufacturing process includes, for example, etching, resist removal, cutting, bonding, and packaging of the substrate developed in the development process. According to this manufacturing method, articles of higher quality than ever before can be manufactured. The disclosure of this specification includes various exemplary embodiments and the following exposure methods, exposure devices, and methods for manufacturing articles: [Item 1] According to some embodiments, an exposure method may include: predicting changes in optical properties of a projection optical system in exposure in which an exposure process is performed on a substrate via the projection optical system; before the exposure, adjusting the optical properties by irradiating the projection optical system with light based on a prediction result in the prediction; and performing exposure after the adjustment, wherein, in the adjustment, the optical properties at the start of the exposure are adjusted to a positive value or a negative value based on the change in the optical properties predicted in the prediction, so that the optical properties fall within a predetermined range during the exposure without adjusting the optical properties.[Item 2] The exposure method according to some embodiments may include item 1, wherein a change in optical characteristics is predicted based on first information and second information, the first information being information for predicting a change in optical characteristics during exposure, and the second information being information obtained by measuring the optical characteristics before exposure. [Item 3] The exposure method according to some embodiments may include any of items 1 and 2, wherein the element indicating a change in optical characteristics includes one or both of an amount of change in the optical characteristics per unit time and a maximum amount of change in the optical characteristics during the exposure process. [Item 4] The exposure method according to some embodiments may include any of items 1 to 3, wherein, in the adjustment, the optical characteristics are adjusted so that an average value of the optical characteristics during the exposure process is small. [Item 5] The exposure method according to some embodiments may include any of items 1 to 4, wherein a predetermined range is set for each exposure process condition. [Item 6] The exposure method according to some embodiments may include any of items 1 to 5, wherein, in the adjustment, the optical characteristics at the start of exposure are adjusted to have a sign different from the sign of the slope of the change in the optical characteristics predicted in the prediction. [Item 7] The exposure method according to some embodiments may include any of items 1 to 6, wherein the optical characteristic is astigmatism of the projection optical system. [Item 8] The exposure method according to some embodiments may include any of items 2 to 7, wherein the first information used to predict a change in optical characteristics during exposure includes information related to a first coefficient included in a prediction equation used in the prediction. [Item 9] The exposure method according to some embodiments may include item 8, wherein the first coefficient is a value indicating an amount of aberration saturation. [Item 10] The exposure method according to some embodiments may include any of items 1 to 9, wherein the optical characteristics are adjusted in the adjustment by irradiating with light for a period of time, the period being determined based on a second coefficient indicating an amount of change in the optical characteristics per unit time. [Item 11] The exposure method according to some embodiments may include any of items 1 to 10, wherein the irradiation with light in the adjustment illuminates a projection optical system rather than the substrate. [Item 12] The exposure method according to some embodiments may include any of items 1 to 11, wherein the adjustment is performed when the patterned master is located in a position not to be illuminated by light. [Item 13] The exposure method according to some embodiments may include any of items 1 to 12, wherein the adjustment is not performed when a prediction result of the prediction indicates that the optical characteristics fall within a predetermined range. [Item 14] The exposure method according to some embodiments may include any one of items 2 to 13, wherein first information as information for predicting changes in optical characteristics during exposure is stored in association with exposure processing conditions, and the first information is used to predict optical characteristics when exposure processing is performed under the same conditions as the exposure processing conditions.[Item 15] An exposure method according to some embodiments may include any of items 1 to 14, wherein the light intensity distribution on a pupil plane of an illumination optical system during irradiation with light is switched based on a prediction result. [Item 16] According to some embodiments, an exposure apparatus may include: a projection optical system configured to project light; and a control unit configured to control the adjustment of optical characteristics when an exposure process is performed on a substrate via the projection optical system by irradiating the projection optical system with light; wherein the control unit predicts a change in the optical characteristics of the projection optical system and, based on the prediction result, controls the adjustment of the optical characteristics at the start of the exposure process to a positive or negative value so that the optical characteristics fall within a predetermined range during the exposure process without adjusting the optical characteristics. [Item 17] According to some embodiments, a method for manufacturing an article may include: performing exposure using the exposure method according to any of items 1 to 15, wherein the optical characteristics are adjusted and exposure of the substrate is performed; developing a photosensitive material patterned on the substrate by the exposure; and manufacturing an article from the substrate developed during the development. The present disclosure is not limited to the aforementioned exemplary embodiments, and various changes and modifications may be made without departing from the spirit and scope of the present disclosure. The claims are hereby appended to disclose the scope of the present disclosure. According to some embodiments of the present disclosure, exposure processing can be performed with reduced aberration effects. Although the present disclosure has been described with reference to exemplary embodiments, it should be understood that the present disclosure is not limited to the disclosed exemplary embodiments. The scope of the appended claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions. 100: Exposure device 101: Light source 102: Illumination optical system 103: Diffraction optical element 104: Reticle 105: Reticle reference plate 106: Reticle stage 107: Projection optical system 108: Aperture stop 110: Substrate 111: Substrate carrier 112: Detection plate 113: Reticle side mark 115: Photodetector 120: Control unit 130: Storage unit A: Shooting size AS: Astigmatism amount D: Exposure amount K: Time constant m: Model number Num: Number of shots P: Aberration saturation amount R: Reticle transmittance S110: Step S120: Step S130: Step S140: Step S150: Step S160: Step S210: Step S220: Step S230: Step S240: Step S250: Step S260: Step S270: Step T: Time α: Exposure load Φ: Predicted occurrence amount [Figure 1] is a schematic diagram illustrating the structure of an exposure apparatus according to the first exemplary embodiment. [Figure 2] is a graph illustrating the relationship between focus and light intensity when the substrate stage is driven in the Z direction. [Figure 3] is a schematic diagram illustrating the line and space pattern of a reticle side mark. [Figure 4] is a flowchart for storing aberration saturation amounts, which are used in a prediction equation for predicting astigmatism, according to the first exemplary embodiment. [Figure 5] illustrates the results of aberration prediction according to the first exemplary embodiment. [Figures 6A and 6B] illustrate an example of light intensity distribution on a pupil plane of an illumination optical system for dummy irradiation according to the first exemplary embodiment. [Figure 7] is a flowchart for performing dummy irradiation to correct astigmatism according to the first exemplary embodiment. [Figure 8] illustrates an example of astigmatism adjustment according to the first exemplary embodiment. [Figure 9] is a flowchart for a method for manufacturing an article according to the second exemplary embodiment.

Claims

1. An exposure method, comprising: Predicting changes in the optical properties of the projection optics system during exposure processing of multiple substrates via the projection optics system; Before the exposure, the optical properties are adjusted based on the predicted results; and after the adjustment, the exposure is performed, wherein, in the adjustment, the optical properties at the start of the exposure are adjusted in a direction different from the direction of the change in the optical properties, based on the predicted change in the optical properties; and wherein, in the adjustment, the optical properties are adjusted by illuminating the projection optical system with light.

2. The exposure method according to claim 1, wherein the optical properties are adjusted in the adjustment by irradiating with light for a period of time, the time being determined based on a second coefficient indicating the amount of change of the optical properties per unit time.

3. The exposure method according to claim 1, wherein the projection optics system is illuminated by light rather than the substrate during the adjustment.

4. The exposure method according to claim 1, wherein the adjustment is performed when the patterned master film is located in a position where it will not be illuminated.

5. The exposure method according to claim 1, wherein the light intensity distribution on the pupil plane of the illumination optics during illumination is switched based on the prediction result.

6. The exposure method according to claim 1, wherein the change in the optical property is predicted based on first information and second information, the first information being information used to predict the change in the optical property during the exposure, and the second information being information obtained by measuring the optical property prior to the exposure.

7. The exposure method according to claim 6, wherein the first information is stored in association with exposure processing conditions, and the first information is used to predict the optical properties when the exposure processing is performed under the same conditions as the exposure processing conditions.

8. The exposure method according to claim 6, wherein the first information includes information relating to a first coefficient included in the prediction equation used in the prediction.

9. The exposure method according to claim 8, wherein the first coefficient is a value indicating the amount of aberration saturation.

10. The exposure method according to claim 1, wherein the element indicating the change of the optical property includes one or both of the change of the optical property per unit time and the maximum change of the optical property during the exposure process.

11. The exposure method according to claim 1, wherein, In the adjustment, the optical properties are adjusted such that the average value of the optical properties during the exposure process is close to zero (0).

12. The exposure method according to claim 1, wherein, In the adjustment, the optical characteristics at the start of the exposure are adjusted to a sign different from the sign of the slope of the change in the optical characteristics predicted in the prediction.

13. The exposure method according to claim 1, wherein the optical characteristic is astigmatism of the projection optical system.

14. The exposure method according to claim 1, wherein the adjustment of the optical characteristic in the adjustment is to make the value of the optical characteristic positive or negative.

15. An exposure method, comprising: Predicting changes in the optical properties of the projection optics system during exposure processing of multiple substrates via the projection optics system; Before the exposure, the optical properties are adjusted based on the predicted results; and after the adjustment, the exposure is performed, wherein, in the adjustment, the optical properties at the start of the exposure are adjusted based on the predicted changes in the optical properties in the prediction, such that the optical properties fall within a predetermined range even if the optical properties are not adjusted during the exposure; and wherein, in the adjustment, the optical properties are adjusted by illuminating the projection optical system with light.

16. The exposure method according to claim 15, wherein the predetermined range is set for each exposure processing condition.

17. The exposure method according to claim 15, wherein the adjustment is not performed if the predicted result indicates that the optical characteristics fall within the predetermined range.

18. An exposure apparatus, comprising: The projection optics system is configured to project light; And a control unit, configured to perform control to adjust the optical characteristics of the projection optical system before performing exposure processing on a plurality of substrates via the projection optical system, wherein the control unit predicts changes in the optical characteristics and, based on the prediction, performs control to adjust the optical characteristics at the start of the exposure processing in a direction different from the direction of the change in the optical characteristics; and wherein, in the adjustment, the optical characteristics are adjusted by illuminating the projection optical system with light.

19. A method for manufacturing an article, the method comprising: Exposure is performed using the exposure method described in claim 1, wherein optical properties are adjusted and exposure of the substrate is performed; Developing a photosensitive material patterned on a substrate by the exposure during the exposure; and manufacturing an article from the substrate developed during the exposure.

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