Exposure apparatus, exposure apparatus adjustment method, and article manufacturing method

Abstract

To provide a technique advantageous for reducing haze of an optical element in a projection optical system while suppressing a flow rate consumption of supplied gas.SOLUTION: An exposure apparatus that exposes a substrate has: a holding part holding the substrate; a projection optical system which projects an image of a pattern on the original plate onto the substrate held by the holding part; a supply part which supplies gas into a space between the projection optical system and the substrate held by the holding part; and a control part which controls supply of gas by the supply part on the basis of information on haze of an optical element in the projection optical system opposing to the substrate held by the holding part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] One type of equipment used in the manufacturing process (lithography process) of liquid crystal panels, semiconductor devices, and the like is an exposure apparatus, which projects the pattern of an original illuminated by an illumination optical system onto a substrate to expose the substrate. In an exposure apparatus, contaminants can be generated from the resist (photosensitive material) applied to the substrate by exposing it to light. The contaminants react with impurities such as acids, bases, and organic substances in the surrounding atmosphere or on the surface of the optical elements, causing the optical elements located around the substrate to become cloudy. Optical elements located at the bottom of the projection optical system and exposed in the space between the projection optical system and the substrate so as to face the substrate are particularly susceptible to clouding.

[0003] Furthermore, the contaminants that cloud the optical elements located at the bottom of the projection optical system do not only come from the resist. The projection optical system is surrounded by drive systems and structures that use grease and adhesives that are prone to generating contaminants, and the components themselves are made of resins and rubbers that are prone to generating contaminants. Contaminants from these sources are carried by air conditioning to the area around the substrate, reaching the optical elements located at the bottom of the projection optical system and clouding them.

[0004] Fogging of optical elements can cause deterioration of pattern transfer performance due to insufficient exposure, uneven illuminance, flare, etc. For this reason, some exposure apparatuses are equipped with air nozzles located near the optical elements to blow away contaminants. When blowing away contaminants with an air nozzle, it is generally advantageous to flow gas at high speed throughout the entire space between the substrate and the optical elements, and it is desirable to use a large flow rate of clean gas, such as clean dry air or nitrogen gas.

[0005] Patent Document 1 discloses a configuration in which a gas is flowed into the space between the substrate and the optical element at a flow rate substantially greater than the supply flow rate. In Patent Document 1, a gas supply port is provided on the outside of the projection optical system, and a wind guide plate is arranged to guide the gas blown out from the gas supply port into the space between the substrate and the optical element. The effect of this wind guide plate is to generate the Coanda effect, which guides the gas into the space between the substrate and the optical element while drawing in ambient gas, thereby increasing the flow rate. Patent Document 2 discloses a configuration in which a rectifying mechanism is provided that narrows the flow path after the gas supply port to increase the flow rate on the substrate side, and gas containing contaminants generated from the resist is blown away. In Patent Document 2, contaminants are blown away in a localized area rather than the entire space between the substrate and the optical element, thereby suppressing gas flow consumption and preventing contaminants from reaching the optical element. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-333152 [Patent Document 2] Japanese Patent Application Publication No. 2018-045167 Summary of the Invention [Problem to be solved by the invention]

[0007] However, simply flowing clean gas at a high speed to protect optical elements from contaminants can result in the gas around the projection optical system being entrained by the clean gas, carrying contaminants to the area around the substrate. These contaminants can then reach the lowest optical elements in the projection optical system, fogging them. In particular, if the gas flow is concentrated on the lens surface or the substrate surface while maintaining a high flow rate to prevent contaminants from reaching the optical elements, the surrounding gas and even contaminants can be entrained in those areas, potentially exacerbating the fogging of the optical elements. Conversely, flowing clean gas at a low speed can prevent the entrainment of contaminants around the projection optical system, but it becomes difficult to prevent contaminants from the resist from reaching the optical elements. However, if clean gas is flowed throughout the entire space in an attempt to simultaneously prevent fogging caused by contaminants around the substrate and contaminants from the resist, the flow rate becomes too high, making it difficult to flow the gas at a high speed.

[0008] SUMMARY OF THE INVENTION In view of the above problems, the present invention provides an advantageous technique for reducing fogging of optical elements in a projection optical system while suppressing consumption of the flow rate of the supply gas. [Means for solving the problem]

[0009] According to one aspect of the present invention, there is provided an exposure apparatus for exposing a substrate, the exposure apparatus comprising: a holder for holding the substrate; a projection optical system for projecting an image of a pattern of an original onto the substrate held by the holder; a supply unit for supplying gas to a space between the projection optical system and the substrate held by the holder; and a projection optical system facing the substrate held by the holder. of Optical elements On the surface Cloudy position and a control unit that controls the supply of gas by the supply unit based on the information. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide an advantageous technique for reducing fogging of optical elements in a projection optical system while suppressing consumption of the flow rate of the supply gas. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing the configuration of a main part of an exposure apparatus according to a first embodiment. [Figure 2] FIG. 1 is a diagram showing the configuration of a main part of an exposure apparatus according to a first embodiment. [Figure 3] FIG. 3 is a bottom view of the projection optical system and the first supply unit. [Figure 4] 10A and 10B are diagrams showing an example of how an optical element becomes cloudy. [Figure 5] 10A and 10B are diagrams showing examples of cloudy patterns. [Figure 6] 10A and 10B are diagrams showing examples of cloudy patterns. [Figure 7] 10A and 10B are diagrams showing examples of cloudy patterns. [Figure 8] FIG. 10 is a diagram showing the configuration of an exposure apparatus in a second embodiment. [Figure 9] 10A and 10B are diagrams showing examples of cloudy patterns. [Figure 10] 10A and 10B are diagrams showing examples of cloudy patterns. [Figure 11] 10A and 10B are diagrams showing examples of cloudy patterns. [Figure 12] 10A and 10B are diagrams showing examples of cloudy patterns. [Figure 13] FIG. 10 is a diagram showing the configuration of the main parts of an exposure apparatus according to a third embodiment. [Figure 14] FIG. 10 is a diagram showing the configuration of the main parts of an exposure apparatus according to a fourth embodiment. [Figure 15] FIG. 1 is a diagram showing the overall configuration of an exposure apparatus. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0013] First Embodiment FIG. 1 is a diagram showing the main configuration of an exposure apparatus 100 in a first embodiment. In this specification and drawings, directions are indicated in an XYZ coordinate system in which the horizontal plane is the XY plane. A substrate stage 4, which will be described later, holds a substrate W on its holding surface so that the surface of the substrate W is parallel to the horizontal plane (XY plane). Therefore, in the following, the directions that are orthogonal to each other in a plane along the holding surface of the substrate stage 4 are referred to as the X-axis and Y-axis, and the direction perpendicular to the X-axis and Y-axis is referred to as the Z-axis. Furthermore, in the following, the directions that are parallel to the X-axis, Y-axis, and Z-axis in the XYZ coordinate system are referred to as the X-direction, Y-direction, and Z-direction, respectively.

[0014] The exposure apparatus 100 is an exposure apparatus that exposes a substrate W, and includes a substrate stage 4 as a holder that holds the substrate W, and a projection optical system 2 that projects an image of a pattern on an original (not shown) onto the substrate W held by the substrate stage 4. The exposure apparatus 100 may also include a mechanism for holding the original, an illumination optical system that illuminates the original, etc., but these are not shown here. The exposure apparatus 100 also includes a controller 23 that controls each part of the exposure apparatus 100. The controller 23 is configured by, for example, a computer including a CPU (processor) and memory, and is electrically connected to each part in the apparatus to comprehensively control each part. The controller 23 may be installed in a location separate from the room (e.g., a clean room) in which the exposure apparatus 100 is installed, and may be realized as a server device connected to the exposure apparatus 100 via a wired or wireless network.

[0015] The projection optical system 2 may include multiple optical elements such as lenses, glass plates, etc., and in particular includes an optical element 3 arranged at the lowest end, as shown in Fig. 1. During exposure, the optical element 3 is exposed in the space between the projection optical system 2 and the substrate W so as to face the substrate W held by the substrate stage 4.

[0016] The exposure apparatus 100 includes a first supply unit 10 that supplies a first gas 40 to a space S between a substrate W placed on a substrate stage 4 and an optical element 3 of a projection optical system 2. The first supply unit 10 includes a gas supply port 11 that blows the first gas 40 toward the space S and a flow rate adjuster 20 that adjusts the flow rate of the gas blown out from the gas supply port 11. The gas supply port 11 may also be called a blowout port and may be formed as an opening or a nozzle. The first supply unit 10 may also include a rectifying mechanism 12. The rectifying mechanism 12 includes a first opening 12a located far from the exposure center and a second opening 12b located close to the exposure center. The rectifying mechanism 12 is installed to at least one of align the flow of air around the first supply unit 10 in a certain direction, prevent the surrounding air from being drawn in, and align the direction of the surrounding air. However, the rectifying mechanism 12 is not essential to the first supply unit 10.

[0017] Figure 2 shows a modified example of the configuration of the exposure apparatus 100 shown in Figure 1. As shown in Figure 2, the gas supply port 11 of the first supply unit 10 may be larger than that shown in Figure 1. Note that in Figure 1, the second opening 12b is located directly below the optical element 3, and in Figure 2, the gas supply port 11 is located directly below the optical element 3. However, these may be located outside the projection optical system 2, and gas may be supplied from that location into the space S between the optical element 3 and the substrate stage 4.

[0018] 3 shows a view of the projection optical system 2 and the first supply unit 10 viewed from below. As shown in Fig. 3, the size of the gas supply port 11 in the direction (X direction) perpendicular to the blowing direction of the first gas 40 is preferably larger than an irradiation range 61 of the laser light (exposure light). More preferably, it is larger than an area 62 through which the laser light passes on the first surface 31 of the optical element 3 facing the substrate W.

[0019] The first gas 40 is preferably a clean gas so as not to cloud the optical element 3. A clean gas means a gas with few impurities such as acids, bases, and organic compounds. More preferably, the clean gas is air from which impurities such as acids, bases, and organic compounds have been removed, called clean air, a gas obtained by drying clean air, called clean dry air, or an inert gas such as nitrogen gas.

[0020] In the space where the first supply unit 10 is arranged, a second supply unit 5 that supplies a second gas 41 is also arranged. As shown in FIGS. 1 and 2, a gas supply port 11 is arranged between the second supply unit 5 and the projection optical system 2. The second supply unit 5 may be understood as equipment that performs air conditioning within a chamber or clean room (not shown) that houses the substrate stage 4 and the projection optical system 2. The second supply unit 5 may be, but does not have to be, included in the exposure apparatus 100. A portion of the second gas 41 supplied from the second supply unit 5 passes through the space between the optical element 3 and the substrate stage 4 (substrate W).

[0021] The second supply unit 5 is equipped with a chemical filter 6, which keeps the second gas 41 clean. A clean state for the second gas 41 means that the chemical filter 6 keeps the second gas 41 clean by keeping it free of impurities such as acids, bases, and organic impurities. However, the chemical filter 6 deteriorates over time, and therefore the second gas 41 cannot be kept clean semi-permanently. Furthermore, if the source of the second gas 41 in the second supply unit 5 is the air in a clean room in which the exposure apparatus 100 is located, the cleanliness of the second gas 41 may depend on the cleanliness of the clean room, even if the second gas 41 passes through the chemical filter 6. In addition, poor cleanliness in the clean room may accelerate the rate of deterioration of the chemical filter 6.

[0022] Furthermore, impurities may be mixed into the second gas 41 as it passes through the space S between the optical element 3 and the substrate stage 4 (substrate W). These impurities may include acids, bases, organic impurities, and other substances generated from adhesives and greases used in actuators, guides, bearings, and other components that drive the substrate stage 4. These impurities may also include acids, bases, organic impurities, and other substances generated from resins, rubbers, and other components of structures and mounted components. This makes it difficult to maintain the second gas 41 in a clean state. Furthermore, when the gas in the space where the first supply unit 10 is disposed is circulated and passed through the chemical filter 6 to become the second gas 41, the second gas 41 is also affected by contaminants 50 generated from the resist of the substrate W (described later), further accelerating the deterioration rate of the chemical filter 6. Therefore, in such cases, it is also difficult to maintain the second gas 41 in a clean state.

[0023] As described above, the second gas 41 loses its clean state over time. Therefore, one of the roles of the first supply unit 10 is to prevent the second gas 41 that is no longer clean from reaching the optical element 3.

[0024] Next, we will explain the fogging that occurs on the optical element 3 when the exposure apparatus irradiates the substrate W with laser light via the projection optical system 2 (i.e., when the substrate W is exposed). When the substrate W is irradiated with laser light, contaminants 50 are generated from the substrate W. This is because the substrate W is coated with resist, and the contaminants 50 are generated from the resist during exposure. The contaminants 50 are impurities such as acids, bases, and organic substances. The contaminants 50 include components that are generated with a vertically upward velocity, and reach the optical element 3 via the second gas 41 or the first gas 40, causing the optical element 3 to fogging up. Therefore, one of the roles of the first supply unit 10 is to prevent the contaminants 50 from reaching the optical element 3.

[0025] As described above, there are two main factors that cause the optical element 3 to become cloudy. The first factor is the contaminant 50 that comes from directly below the optical element 3. The second factor is contaminants (impurities) other than the contaminant 50. These mainly come into contact with gas from outside the space S. For example, the hot spring substance is carried in by being mixed with the second gas 41 that comes from around the optical element 3.

[0026] Typically, the progression of fogging due to the first factor is faster than the progression of fogging due to the second factor. Therefore, the flow rate of the first gas 40 supplied from the first supply unit 10 in the first embodiment is set to be faster than that of the second gas 41 so as to blow away the contaminants 50. However, the components of the resist applied to the substrate W vary depending on the usage conditions of the exposure apparatus, and more contaminants 50 than expected may be generated and unable to be blown away. Furthermore, for example, the cleanliness of the clean room may be poor, causing contamination of the second gas 41 or early deterioration of the chemical filter 6. In such cases, even if the contaminants 50 are blown away by the first gas 40, the second gas 41 may reach the optical element 3 via the path 41a, 42b, or 43c shown in FIGS. 1 to 3, thereby fogging the optical element 3. Thus, when setting the flow rate of the first supply unit 10, it may be difficult to predict the progression of fogging, making it difficult to set an appropriate flow rate to counteract the fogging.

[0027] To address this problem, in one embodiment, the control unit 23 can be configured to control the supply of gas by the first supply unit 10 based on information about the fogging of the optical element 3 of the projection optical system 2 that faces the substrate W held by the substrate stage 4. Alternatively, in one embodiment, an adjustment method for the exposure apparatus 100 is executed. The adjustment method may include steps that are executed by the control unit 23, and may also include steps that are executed by a user (operator). In one example, the adjustment method may include a step of identifying a fogging pattern of the optical element 3 that is arranged to face the substrate W, and a step of adjusting the flow rate or flow velocity of the first gas 40 that is supplied to the space S between the substrate W and the optical element 3 in accordance with the identified fogging pattern. Such an adjustment method will be described in detail below.

[0028] First, the fogging pattern will be described in detail. In this embodiment, the fogging information includes position information of the fogging on the surface of the optical element 3, and the position information is expressed as a fogging pattern as shown below.

[0029] FIG. 4 shows representative examples of a cloudy position 42 caused by the second gas 41 and a cloudy position 51 caused by the contaminant 50. FIG. 4 is a view of the first surface 31 of the optical element 3 viewed from below the projection optical system 2. As shown in FIG. 4, the cloudy position 42 caused by the second gas 41 is located around the first surface 31 of the optical element 3. The cloudy position 51 caused by the contaminant 50 is located in the center of the first surface 31 or downstream in the flow direction of the first gas 40. This is because the second gas 41 tends to reach the optical element 3 by being drawn in, diffusing, or mixing from all directions toward the first gas 40 from the interface with the first gas 40 blown out from the first supply unit 10. In the case of the contaminant 50, the direction of travel of the generated contaminant 50 tends to be vertically upward, and it continues to travel vertically upward until it reaches the optical element 3. That is, by checking whether the fogging on the first surface 31 of the optical element 3 is at the fogging position 42 or the fogging position 51, it is possible to determine whether the fogging is caused by the second gas 41 or the contaminant 50. Based on the result of the determination, the flow rate adjuster 20 is adjusted according to the following procedure, thereby reducing the fogging.

[0030] First, in the first step, a first initial flow rate of the first supply unit 10 is set. If the first supply unit 10 has been used up to now, the flow rate set at that time may be set as the first initial flow rate. Furthermore, if it is possible to predict from past experience whether the current fogging of the optical element 3 is fogging caused by the second gas 41 or the contaminant 50, the first initial flow rate may be set as follows. For example, if it is predicted that the fogging is caused by the second gas 41, the first initial flow rate of the first supply unit 10 may be set so that the ratio of the flow rate of the first gas 40 to the flow rate of the second gas 41 is 1.5 to 2. If it is predicted that the fogging is caused by the contaminant 50, the first initial flow rate of the first supply unit 10 may be set so that the flow rate of the first gas 40 is faster than the flow rate of the second gas 41. For example, the first initial flow rate may be determined so that the flow rate of the first gas 40 is at least twice as fast as the flow rate of the second gas 41. If it is empirically known that a faster flow rate of the first gas 40 is preferable, the first initial flow rate may be determined so that the flow rate of the first gas 40 is at least three times as fast as the flow rate of the second gas 41. Alternatively, the first initial flow rate may be determined so that the flow rate of the first gas 40 is at least ten times as fast as the flow rate of the second gas 41. Generally, fogging caused by the contaminants 50 can have a more serious impact on exposure performance. Therefore, the following description will be given assuming that the first initial flow rate of the first supply unit 10 is set so that the flow rate of the first gas 40 is at least twice as fast as the flow rate of the second gas 41.

[0031] Next, in the second step, the pattern of cloudiness on the first surface 31 is confirmed. The frequency of cloudiness checks can be, for example, every few months. A detailed example of the frequency will be described later. Examples of methods for checking the location of cloudiness will be described below. The first method is for the user to visually check the first surface 31 of the optical element 3. This can be done inside the exposure apparatus, or by removing the optical element 3. The second method is to check using a measuring device. The optical element 3 is removed, and the reflectance and transmittance are measured using the measuring device. The third method may be to check from information related to the measurement results of flare and illuminance using a laser beam in the exposure apparatus, or information related to exposure accuracy, such as variations in exposure line width. Other methods may also be used as long as they can confirm the location of cloudiness or information that can estimate the location of cloudiness.

[0032] Next, the third procedure will be described. As an example of the third procedure, a case where the fogging position 42 is fogging will be described. That is, the fogging is caused by the second gas 41. To reduce the fogging caused by the second gas 41, it is necessary to adjust the flow rate of the first gas 40 so that the difference in flow velocity between the first gas 40 and the second gas 41 is reduced so that the second gas 41 is less likely to be entrained in or mixed with the first gas 40. If the difference in flow velocity between the first gas 40 and the second gas 41 is reduced, the air flow becomes closer to laminar flow, and the second gas is less likely to be entrained in or mixed with the first gas 40. Specifically, in the first embodiment, when the fogging of the optical element 3 is at the fogging position 42, the flow rate adjuster 20 is adjusted so that the first initial flow rate of the first supply unit 10 is reduced so that the flow rate (flow velocity) of the first gas 40 is reduced. This reduces fogging caused by the second gas 41. The flow rate of the first supply unit 10 after this flow rate adjustment is set as a second initial flow rate.

[0033] Here, the amount of change by which the first initial flow rate is reduced will be described. The amount of change here may be a fixed value (e.g., −10%). Preferably, the amount of second gas 41 that is entrained and reaches the first surface 31 is calculated based on the distance between the substrate W and the first surface 31, the cloudy position 42, the flow velocity of the first gas 40, the difference in flow velocity between the first gas 40 and the second gas 41, and the effective range of the laser light on the first surface 31. Then, based on the calculation result, the amount of change by which the first initial flow rate is reduced is determined depending on how much the degree of clouding on the first surface 31 is desired to be reduced over a period of time. For example, if the degree of clouding is desired to be reduced by half, it is preferable to adjust the flow velocity of the first gas 40 so that the entrainment of the second gas 41 is reduced by half. However, it is not preferable to adjust the initial flow rate from the beginning so that the difference in flow velocity between the first gas 40 and the second gas 41 becomes zero. This is because, in the initial stage, the flow rate of the first gas 40 suitable for fogging caused by the pollutant 50 is unknown, and therefore, if the flow rate of the first gas 40 is reduced too much, there is a possibility that fogging caused by the pollutant 50 will progress rapidly. Also, although there is a way to determine a preferable amount of change in the initial stage, the flow rate will naturally approach the optimum value in the subsequent steps, so there is no need to worry too much about it.

[0034] Next, as a fourth step, after a predetermined period of time has elapsed, the user checks the fogging pattern. At this time, it is assumed that the fogging at the fogging position 42 has worsened.

[0035] In this case, in the fifth step, similar to the third step described above, the second initial flow rate is adjusted to be smaller by the flow rate adjuster 20. The flow rate after this adjustment is set as the third initial flow rate. In this case, the adjustment amount of the flow rate adjuster 20 may be determined by calculating an adjustment ratio from the relationship between the amount of progress of fogging from the previous time to the current time and the amount adjusted by the flow rate adjuster 20 the previous time.

[0036] Next, after a predetermined period of time has passed, as in the above-described second and fourth procedures, the fogging pattern is checked in the sixth procedure, and the flow rate is adjusted in the seventh procedure, as in the third and fifth procedures. The above series of steps is repeated.

[0037] On the other hand, a case where the cloudy position 51 is found to be cloudy when the cloudy pattern is checked, which may be at any stage, will be described. That is, this is a response to cloudiness caused by the contaminant 50. Here, this will be described as another example of the third procedure described above.

[0038] In order to reduce fogging caused by the contaminants 50, the first gas 40 blown out from the first supply unit 10 must blow away the contaminants 50 so as to overcome their movement in the vertically upward direction. Therefore, the contaminants 50 can be blown away by increasing the flow rate and flow velocity of the first gas. In the example shown in FIG. 4 , the fogging position 51a is located in the center of the first surface 31, and the contaminants 50 are hardly pushed away. However, if the flow rate (flow velocity) of the first gas 40 can push away some of the contaminants, the contaminants may move downstream of the first gas 40, as shown at the fogging position 51b. When the fogging is located at the fogging position 51 in this manner, in the first embodiment, the flow rate (flow velocity) of the first gas 40 is increased by the flow rate adjuster 20, i.e., the first initial flow rate is increased, thereby reducing fogging caused by the contaminants 50. The flow rate of the first supply unit 10 after this flow rate adjustment is referred to as the second initial flow rate.

[0039] Here, the amount of change by which the first initial flow rate is increased will be described. The amount of change here may be a fixed value (for example, +50%). Preferably, the amount of change in the first initial flow rate is determined by calculating the position change of the cloudy position 51 when the flow rate of the first gas 40 is increased from the distance between the substrate W and the first surface 31, the cloudy position 51, and the flow rate of the first gas 40. For example, in this case, if the particle size, initial velocity, and flow rate of the contaminants 50 ejected vertically can be predicted, the amount of change in the position of the cloudy position 51 can be calculated. Then, the amount of change by which the first initial flow rate is increased can be determined so that the cloudy position 51 is outside the effective range of the laser light on the first surface 31. However, when such physical quantities are difficult to predict, the amount of change may be determined by assuming that fogging position 51 changes in proportion to the flow velocity of first gas 40 or the square of the flow velocity, based on the relationship between the flow velocity of first gas 40 and the distance from fogging position 51 to the center of first surface 31. Also, although there is a preferable way to determine the amount of change in the initial stage, it is not necessary to worry too much about it, as the flow rate will naturally approach an optimal value in the subsequent steps.

[0040] Next, as a fourth step, after a predetermined period of time has elapsed, the user checks the fogging pattern. At this time, it is assumed that the fogging at the fogging position 51 has worsened.

[0041] In this case, in the fifth step, similar to the third step described above, the flow rate adjuster 20 adjusts the second initial flow rate to be larger. The flow rate after this adjustment is set as the third initial flow rate. In this case, the adjustment amount of the flow rate adjuster 20 may be determined by calculating an adjustment ratio from the relationship between the amount of fogging progressed from the previous time to the current time and the amount adjusted by the flow rate adjuster 20 the previous time.

[0042] Next, as in the procedure described above, after a predetermined period of time has passed, the fogging pattern is confirmed (identified) in a sixth procedure, and the flow rate or flow velocity of the gas supplied to the space S is adjusted in a seventh procedure. The above series of steps is repeatedly executed.

[0043] The above-described series of steps describes the progression of one type of fogging, but the flow rate of the first gas 40 may be adjusted by a combination of steps depending on the progression of the fogging caused by the second gas 41 and the fogging caused by the pollutant 50.

[0044] Here, the cloudy position 42 and the cloudy position 51 will be described in detail. Cloudiness on the optical element 3 does not occur as a single point, but rather occurs over a certain range. For example, when determining that cloudiness occurs at the cloudy position 42 on the first surface 31, the cloudy position 42 may be the most cloudy part on the first surface 31, i.e., the part with the most contaminants. For example, the control unit 23 may calculate the center of gravity of the convex part on a curve (criteria value profile) showing the relationship between the first surface 31 and the cloudiness (criteria value) as shown in FIG. 4, and identify this center of gravity as the cloudy position 42, which is the most cloudy part. The cloudy position 51 can also be determined in a similar manner. Furthermore, while the main cause can be determined from the cloudy position 42 and the cloudy position 51, in reality, the wind flow may be complex, and the cloudiness may not be 100% determined to be due to either of the two factors. However, countermeasures are determined depending on the cloudy position.

[0045] Examples of methods for checking the cloudy position will be described below. The first method is to visually check the first surface 31 of the optical element 3. This can be done inside the exposure device or by removing the optical element 3. The second method is to check using a measuring device. The optical element 3 is removed and the reflectance and transmittance are measured for confirmation. The third method may be to check from information related to the measurement results of flare and illuminance using a laser beam in the exposure device, or information related to exposure accuracy, such as variations in exposure line width. Any other method may also be used as long as it is possible to check the cloudy position or information that can be used to estimate the cloudy position.

[0046] The timing for checking the fogging position and adjusting the flow rate will be explained below. The slightest fogging of the optical element 3 does not necessarily mean that the exposure apparatus will become unusable. It is possible to determine the threshold level of fogging that makes it difficult to use the exposure apparatus. To give an example of the period until the fogging threshold is exceeded, it could be as short as 12 months or as long as 36 months or more. However, these are just examples and will vary depending on the usage conditions of the exposure apparatus.

[0047] Furthermore, as the fogging progresses, it may begin to progress rapidly. From this perspective, if the resist on the substrate W is changed to an unknown one at the start of operation of the exposure apparatus, or if the amount of contaminants is unknown or there is a possibility that the amount of contaminants may change, the rate at which the fogging progresses becomes unknown. In such cases, it is better to check the location of the fogging after, for example, two weeks to one month has passed and adjust the flow rate. By doing so, it is possible to address the cause of the fogging in the early stages of its progression. As a result, it is possible to stop or slow the progression of the fogging in the early stages.

[0048] On the other hand, if the progression of fogging is stable, it is sufficient to check the location of the fogging every one to two months and adjust the flow rate. However, if the exposure tool is used in an environment with strict restrictions on the progression of fogging, it is preferable to check the fogging and adjust the flow rate in a shorter period than the above.

[0049] As described above, the flow rate of the first gas 40 can be adjusted depending on the fogging position. The control unit 23 controls the flow rate adjustment unit 20 based on the fogging information, thereby controlling the flow rate of the air from the first supply unit 10 relative to the flow rate of the gas from the second supply unit 5. Below, examples of adjusting the flow rate (flow velocity) of the first gas 40 for various fogging pattern examples shown in Fig. 5 will be described. Note that, as explained with respect to the series of procedures above, it is assumed that the flow rate (flow velocity) of the first gas 40 is greater than the flow rate (flow velocity) of the second gas 41 in the initial state.

[0050] When the fogging pattern is one of the patterns shown in FIGS. 5(A), (B), (C), and (D) or 6(A), (B), (C), and (D), it is determined that the main cause of the fogging is the second gas 41 passing through paths 41a, 41b, and 41c shown in FIGS. 1 to 3. In particular, in the case of FIG. 5(D), it is determined that the entrainment of the second gas 41 passing through path 41a has a significant effect. In these cases, the difference in flow velocity between the first gas 40 and the second gas 41 should be reduced so that the second gas 41 is not entrained in the first gas 40 or is less likely to mix with the first gas 40. Therefore, in this case, the flow rate adjuster 20 is adjusted to reduce the flow rate (flow rate) of the first gas 40. However, it should be noted that the effect of the contaminant 50 on fogging is not zero.

[0051] 7(A), (B), (C), or (D), it is determined that the main cause of the fogging is pollutants 50. Therefore, in this case, the flow rate adjuster 20 is adjusted to increase the flow rate (flow velocity) of the first gas 40.

[0052] If no fogging has occurred, the flow rate (flow velocity) of the first gas 40 at the timing of checking the fogging pattern is adjusted using the flow rate adjusting unit 20 so as to be reduced, or the flow rate (flow velocity) is maintained.

[0053] Although the above describes methods for adjusting the flow rate for various fogging patterns, for more complex fogging patterns that cannot be fully expressed, the flow rate can be adjusted by combining them. Furthermore, by adjusting the flow rate in the above manner, it is possible to prevent excessive consumption of flow rate for fogging factors, thereby reducing flow rate consumption.

[0054] As described above, according to this embodiment, it is possible to deal with both fogging caused by contaminants from the periphery of the projection optical system and fogging caused by contaminants from the resist on the substrate, while suppressing consumption of the flow rate of the supply gas.

[0055] Second Embodiment An exposure apparatus according to a second embodiment will be described with reference to FIG. 8. Similar to FIG. 3, FIG. 8 is a view of the projection optical system 2 and the first supply unit 10 viewed from below. Note that the following description is similar to that of the first embodiment. As shown in FIG. 8, the first supply unit 10 in the second embodiment has a plurality of gas supply ports 11, whereas the first supply unit 10 has a single gas supply port 11 in FIG. 8. As shown in FIG. 8, the first supply unit 10 has a plurality of gas supply ports 11a, 11b, and 11c, and a plurality of flow rate adjusters 20a, 20b, and 20c connected to the plurality of gas supply ports 11a, 11b, and 11c, respectively. The plurality of flow rate adjusters 20a, 20b, and 20c can individually adjust the flow rates of the first gases 40a, 40b, and 40c blown out from the plurality of gas supply ports 11a, 11b, and 11c. The control unit 23 controls each of the plurality of flow rate adjusters 20a, 20b, and 20c in accordance with fogging information. This makes it possible to control the flow rates of the first gases 40a, 40b, 40c blown out from the plurality of gas supply ports 11a, 11b, 11c of the first supply unit relative to the flow rate of the second gas 41 from the second supply unit 5.

[0056] In one example, the control unit 23 can control each of the flow rate adjusters 20a, 20b, and 20c depending on which of the fogging patterns shown in Figures 9 to 13 the fogging pattern corresponds to. Below, examples of adjusting the flow rate (flow velocity) of the first gas 40 for the various fogging pattern examples shown in Figures 9 to 13 will be described. Note that, as described with respect to the series of procedures in the first embodiment above, in the initial state, the flow rate (flow velocity) of the first gas 40 is assumed to be greater than the flow rate (flow velocity) of the second gas 41.

[0057] 9 to 13, the multiple gas supply ports 11a, 11b, and 11c are arranged along a first direction (X direction) within the surface of the optical element 3. Therefore, each of the multiple gas supply ports 11a, 11b, and 11c is arranged to allow gas to flow in a second direction (-Y direction, i.e., airflow direction) perpendicular to the X direction.

[0058] A case will be described in which the fogging pattern, which is the acquired fogging position information, is one of the fogging patterns shown in either FIG. 9(A) or (B). The fogging pattern in FIG. 9(A) shows that the fogging is greater on the upstream side of the airflow in the second direction than in the center on the surface of the optical element 3, and that the fogging is present throughout the entire surface in the first direction. The fogging pattern in FIG. 9(B) shows a pattern in which the fogging in FIG. 9(A) extends to the downstream side, causing the entire surface to become fogging. In these cases, it is determined that the main cause of the fogging is the second gas 41 passing through the paths 41a, 41b, and 41c shown in FIGS. 1, 2, and 6. Therefore, in these cases, the difference in flow velocity between the first gases 40a, 40b, and 40c and the second gas 41 should be reduced so that the second gas 41 is less likely to be entrained in or mixed with the first gases 40a, 40b, and 40c. Therefore, in these cases, the control unit 23 adjusts the flow rate adjustment units 20a, 20b, and 20c so as to reduce the flow rates (flow velocities) of the first gases 40a, 40b, and 40c.

[0059] Next, we will explain the case where the acquired fogging pattern is one of the fogging patterns shown in Figures 10(A), (B), (C), and (D). The fogging patterns in Figures 10(A) and (B) show that the fogging is greater upstream of the airflow in the second direction than in the center on the surface of the optical element 3, and that the fogging is present in part of the first direction. The fogging patterns in Figures 10(C) and (D) show that the fogging in Figures 10(A) and 10(B), respectively, extends to the downstream side. In these cases, it is determined that the main cause of the fogging is the second gas 41 passing through paths 41a and 41b shown in Figures 1 and 2. Therefore, in these cases, the difference in flow velocity between the first gas 40a and the second gas 41 should be reduced so that the second gas 41 is less likely to be entrained in or mix with the first gas 40a. Therefore, in these cases, the control unit 23 adjusts the flow rate adjustment unit 20a so as to decrease the flow rate (flow velocity) of the first gas 40a corresponding to the position of the fogging in the first direction.

[0060] Next, a case where the acquired fogging pattern is one of those shown in FIGS. 11A, 11B, 11C, and 11D will be described. The fogging patterns in FIGS. 11A, 11B, 11C, and 11D indicate that the fogging is greater at the edges of the surface of the optical element 3 in the first direction than at the center. In this case, it is determined that the main cause of the fogging is the second gas 41 passing through the path 41c shown in FIG. 6. Therefore, in this case, the difference in flow velocity between the first gases 40b and 40c and the second gas 41 should be reduced so that the second gas 41 is less likely to be entrained or mixed with the first gases 40b and 40c. Therefore, in this case, the control unit 23 adjusts the flow rate adjustment units 20b and 20c to reduce the flow rate (flow velocity) of the first gases 40b and 40c blown out from the gas supply ports on the edges in the first direction.

[0061] Next, we will explain the case where the acquired fogging pattern is one of the fogging patterns shown in Figures 12(A), (B), (C), (D), (E), and (F). The fogging patterns in Figures 12(A), (B), (C), (D), (E), and (F) indicate that the fogging is greater in the center or downstream of the center in the second direction on the surface of the optical element 3. In this case, it is determined that the main cause of the fogging is contaminants 50. Therefore, in this case, the control unit 23 adjusts the flow rate adjusters to increase the flow rate (flow velocity) of the gas blown out from the gas supply port corresponding to the position of the fogging in the first direction. Specifically, when the fogging pattern is the pattern shown in Figure 12(A) or (D), the control unit 23 adjusts the flow rate adjusters 20a, 20b, and 30c to increase the flow rate (flow velocity) of the first gas 40a, 40b, and 40c. 12(B) or (E), the control unit 23 adjusts the flow rate adjuster 20a to increase the flow rate (flow velocity) of the first gas 40a. If the fogging pattern is the pattern shown in FIG. 12(C) or (F), the control unit 23 adjusts the flow rate adjuster 20b, 20c to increase the flow rates (flow velocity) of the first gases 40b, 40c.

[0062] Furthermore, if the acquired fogging position information indicates that there is no fogging on the surface of the optical element 3, the control unit 23 adjusts the flow rate (flow velocity) of the first gas 40 using the flow rate adjustment unit 20 to reduce the flow rate (flow velocity), or maintains the flow rate (flow velocity).

[0063] As described above, the flow rate adjustment method for the fogging pattern has been shown, but for more complicated fogging patterns that cannot be fully expressed, the flow rate may be adjusted by combining them.

[0064] In the second embodiment, since there are a plurality of gas supply ports 11, it is possible to adjust the flow velocity distribution of the first gas 40 in the X direction. Therefore, it is possible to effectively deal with localized fogging distribution while suppressing flow consumption.

[0065] <Third embodiment> An exposure apparatus of the third embodiment will be described with reference to Figure 13. Note that parts not specifically mentioned in the following description are the same as those of the first and second embodiments. The difference between Figure 13 and Figure 1 is that the exposure apparatus 100 of Figure 13 is provided with an exhaust unit 70 that exhausts gas from the space between the optical element 3 and the substrate W. In Figure 13, the gas inlet 71 of the exhaust unit 70 is directed toward the substrate W, but it may also be directed horizontally so as to face the gas supply port 11. The exhaust unit 70 is particularly effective against fogging caused by the contaminants 50, and simply providing the exhaust unit 70 can improve the effects of the first and second embodiments.

[0066] 3, the size of the gas inlet 71 in the X direction is preferably larger than the irradiation range 61 of the substrate W that is irradiated onto the substrate W via the projection optical system 2 shown in FIG. 3. More preferably, it is larger than the range 62 through which the laser light passes on the first surface 31 of the optical element 3 that faces the substrate W. Also, the size of the gas inlet 71 is preferably the same as or larger than the size of the gas supply port 11.

[0067] The exhaust flow rate by the exhaust unit 70 is effective as long as it is greater than 0 (zero), but is preferably equal to or greater than the supply flow rate of the first gas 40 by the first supply unit 10. By doing so, the flows of the first gas 40 and the second gas 41 in the space S between the optical element 3 and the substrate W are rectified, and not only is a flow formed that sucks in the contaminants 50, but entrainment and mixing of the first gas 40 and the second gas 41 is reduced.

[0068] The number of gas inlets 71 in the exhaust unit 70 may be one, or may be multiple like the gas supply ports 11 of the first supply unit 10 in the second embodiment. When there are multiple gas inlets 71, the gas intake amount of each may be controlled so that the distribution of the gas intake amounts of the gas inlets 71 can be adjusted.

[0069] With a configuration including the exhaust section 70 as described above, the effect of reducing fogging on the first surface 31 of the optical element 3 by adjusting the flow rate (flow velocity) of the first gas 40 as described in the first and second embodiments can be more effectively achieved.

[0070] <Fourth embodiment> An exposure apparatus of the fourth embodiment will be described with reference to Figure 14. Note that parts not specifically mentioned in the following description are the same as those of the first, second, and third embodiments. Figure 14 differs from Figure 13 in that an exhaust adjustment unit 81 is provided to adjust the amount of exhaust by the exhaust unit 70.

[0071] As in the first to third embodiments, the flow rate of the first gas 40 from the first supply unit 10 is adjusted by the flow rate adjuster 20 depending on the fogging pattern. In the fourth embodiment, the control unit 23 controls the exhaust adjuster 81 so that the exhaust rate by the exhaust unit 70 is adjusted depending on the gas supply rate by the first supply unit 10. As a result, the exhaust flow rate of the exhaust unit 70 is increased or decreased by the exhaust adjuster 81 depending on the increase or decrease in the adjustment amount of the flow rate of the first gas 40. When there are multiple gas supply ports 11 and gas inlets 71, it is preferable to increase or decrease the exhaust flow rate of the gas inlet 71 depending on the increase or decrease in the flow rate of the first gas 40 for each gas supply port 11.

[0072] The flow of the first gas 40 supplied from the first supply unit 10 can be supported by the exhaust unit 70, making it possible to suppress increases or decreases in the flow rate depending on the fogging pattern. Furthermore, in the fourth embodiment, the flow of the first gas 40 and the second gas 41 in the space S between the optical element 3 and the substrate W can be rectified by adjusting the flow rate of the exhaust from the exhaust unit 70 using the exhaust adjustment unit 81. Therefore, an even greater fogging reduction effect can be obtained than in the first to third embodiments.

[0073] <Embodiments Related to Exposure Apparatus> FIG. 15 shows the overall configuration of an exposure apparatus 100. The exposure apparatus 100 includes an illumination optical system 21, an original stage 22, a projection optical system 2, a substrate stage 4, and a controller 23 that controls them. The illumination optical system 21 uses light from a light source 24, such as a laser, to illuminate an original M held on the original stage 22. The projection optical system 2 projects and transfers a pattern image from the original M onto a substrate W held on the substrate stage 4. The controller 23 controls scanning of the substrate stage 4 and the original stage 22. The air conditioning unit 26 includes piping components for supplying a first gas 40 to the first supply unit 10 via a flow rate regulator 20. For example, the air conditioning unit 26 supplies clean air or nitrogen gas to the first supply unit 10. A second gas 41 is supplied from a second supply unit 5 to the space in which the first supply unit 10 is located. The second gas 41 may originate from the air in a clean room, making it difficult to maintain a completely clean state. Furthermore, the space in which the first supply unit 10 is located is difficult to maintain in a completely clean state because the drive system and structures of the substrate stage 4, as well as the components themselves, use grease, adhesives, resins, rubber, etc., which are prone to generating contaminants.

[0074] The first supply unit 10 described in the first to fourth embodiments is disposed between or near the projection optical system 2 and the substrate stage 4, and supplies the first gas 40 between the substrate stage 4 and the lowest optical element 3 of the projection optical system 2. The control unit 23 controls the flow rate adjustment unit 20 to adjust the flow rate (flow speed) of the first gas 40 according to the fogging pattern so as to protect the optical element 3 from contaminants 50 generated from the substrate W and the contaminated second gas 41, thereby reducing fogging of the optical element 3.

[0075] <Embodiment of an article manufacturing method> The article manufacturing method according to an embodiment of the present invention is suitable for manufacturing articles such as microdevices, such as semiconductor devices, and elements having microstructures. The article manufacturing method according to this embodiment includes a step of forming a latent image pattern on a photosensitive agent applied to a substrate using the above-described exposure apparatus (a step of exposing the substrate), and a step of developing the substrate on which the latent image pattern has been formed. Furthermore, this manufacturing method includes other well-known steps (oxidation, film formation, vapor deposition, doping, planarization, etching, resist stripping, dicing, bonding, packaging, etc.). The article manufacturing method according to this embodiment is advantageous over conventional methods in at least one of article performance, quality, productivity, and production cost.

[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] 2: projection optical system, 3: optical element, 4: substrate stage, 5: second supply unit, 10: first supply unit, 11: gas supply port, 20: flow rate adjustment unit, 23: control unit, 100: exposure apparatus

Claims

1. An exposure apparatus for exposing a substrate, a holder for holding the substrate; a projection optical system that projects an image of a pattern of an original onto the substrate held by the holding unit; a supply unit that supplies a gas to a space between the projection optical system and the substrate held by the holder; a control unit that controls the supply of gas by the supply unit based on positional information of cloudiness on a surface of an optical element of the projection optical system that faces the substrate held by the holding unit; An exposure apparatus comprising:

2. The supply unit includes: a gas supply port for blowing out gas to be supplied to the space; a flow rate adjusting unit that adjusts the flow rate of the gas blown out from the gas supply port; and The control unit controls the flow rate adjustment unit based on the position information.

2. An exposure apparatus according to claim 1.

3. The control unit determining a cause of fogging of the optical element based on the position information; If it is determined that the cause of the fogging is contaminants generated from the resist on the substrate, controlling the flow rate adjustment unit so that the flow rate of the gas supplied to the space is increased; When it is determined that the cause of the fogging is a contaminant mixed in the gas from outside the space, the flow rate adjusting unit is controlled so as to reduce the flow rate of the gas supplied to the space.

3. The exposure apparatus according to claim 2.

4. The supply unit includes: a plurality of gas supply ports for blowing out gas to be supplied to the space; a plurality of flow rate adjusting units that individually adjust the flow rates of the gases blown out from the plurality of gas supply ports; and the plurality of gas supply ports are arranged along a first direction in the surface of the optical element, and are each arranged to cause a gas to flow in a second direction perpendicular to the first direction; the control unit controls each of the plurality of flow rate adjustment units based on the position information.

2. An exposure apparatus according to claim 1.

5. The exposure apparatus described in Claim 4, characterized in that when the position information indicates that the fogging is greater at the ends than at the center in the first direction within the surface of the optical element, the control unit controls the multiple flow rate adjustment units to reduce the flow rate of gas blown out from the gas supply port on the end side of the first direction among the multiple gas supply ports.

6. The exposure apparatus described in Claim 4, characterized in that when the position information indicates that the fogging is greater upstream of the air flow than at the center in the second direction on the surface of the optical element, the control unit controls the multiple flow rate adjustment units to reduce the flow rate of gas blown out from the gas supply port among the multiple gas supply ports that corresponds to the position of the fogging in the first direction.

7. The exposure apparatus described in Claim 4, characterized in that when the position information indicates that the fogging is greater in the center or downstream of the center in the second direction within the surface of the optical element, the control unit controls the multiple flow rate adjustment units to increase the flow rate of gas blown out from the gas supply port among the multiple gas supply ports that corresponds to the position of the fogging in the first direction.

8. An exposure apparatus as described in Claim 4, characterized in that when the position information indicates that there is no fogging on the surface of the optical element, the control unit controls the multiple flow rate adjustment units to reduce or maintain the flow rate of gas blown out from each of the multiple gas supply ports.

9. 9. The exposure apparatus according to claim 5, wherein the control unit acquires the position information based on a judgment value profile of haze on the surface of the optical element.

10. 10. An exposure apparatus according to claim 1, further comprising an exhaust unit that exhausts gas from the space.

11. 11. An exposure apparatus according to claim 10, further comprising an exhaust adjustment unit that adjusts the amount of exhaust by the exhaust unit.

12. 12. The exposure apparatus according to claim 11, wherein the control unit controls the exhaust adjustment unit so that the amount of exhaust by the exhaust unit is adjusted according to the amount of gas supplied by the supply unit.

13. An exposure apparatus for exposing a substrate, comprising: a holder for holding the substrate; a projection optical system that projects an image of a pattern of an original onto the substrate held by the holding unit; a supply unit that supplies a gas to a space between the projection optical system and the substrate held by the holder; a control unit that controls the supply of gas by the supply unit based on positional information of cloudiness on a surface of an optical element of the projection optical system that faces the substrate held by the holding unit, The supply unit includes: a gas supply port for blowing out gas to be supplied to the space; a flow rate adjusting unit that adjusts the flow rate of the gas blown out from the gas supply port, The control unit determines a cause of fogging of the optical element based on the position information, If it is determined that the cause of the fogging is contaminants generated from the resist on the substrate, controlling the flow rate adjustment unit so that the flow rate of the gas supplied to the space is increased; When it is determined that the cause of the fogging is a contaminant mixed in the gas from outside the space, the flow rate adjusting unit is controlled so as to reduce the flow rate of the gas supplied to the space. An exposure apparatus characterized by:

14. An exposure apparatus for exposing a substrate, comprising: a holder for holding the substrate; a projection optical system that projects an image of a pattern of an original onto the substrate held by the holding unit; a supply unit that supplies a gas to a space between the projection optical system and the substrate held by the holder; a control unit that controls the supply of gas by the supply unit based on information about fogging of an optical element of the projection optical system that faces the substrate held by the holding unit, The supply unit includes: a plurality of gas supply ports for blowing out gas to be supplied to the space; a plurality of flow rate adjusting units that individually adjust the flow rates of the gases blown out from the plurality of gas supply ports, the plurality of gas supply ports are arranged along a first direction in the surface of the optical element, and are each arranged to cause a gas to flow in a second direction perpendicular to the first direction; The control unit controls each of the plurality of flow rate adjustment units based on the information. An exposure apparatus characterized by:

15. An exposure apparatus for exposing a substrate, comprising: a holder for holding the substrate; a projection optical system that projects an image of a pattern of an original onto the substrate held by the holding unit; a supply unit that supplies a gas to a space between the projection optical system and the substrate held by the holder; a control unit that controls the supply of gas by the supply unit based on information about fogging of an optical element of the projection optical system that faces the substrate held by the holding unit; an exhaust section that exhausts gas from the space; an exhaust adjustment unit that adjusts the amount of exhaust by the exhaust unit; An exposure apparatus comprising:

16. A method for adjusting an exposure apparatus that exposes a substrate, comprising: acquiring positional information of cloudiness on a surface of an optical element of a projection optical system arranged to face the substrate; adjusting the flow rate or flow velocity of the gas supplied to the space between the substrate and the optical element in accordance with the acquired position information; An adjusting method comprising the steps of:

17. 1. A method for adjusting an exposure apparatus that exposes a substrate, comprising: identifying a haze pattern representing the location of haze on an optical element of a projection optical system positioned facing the substrate; adjusting the flow rate or flow velocity of the gas supplied to the space between the substrate and the optical element in response to the identified haze pattern; An adjusting method comprising the steps of:

18. exposing a substrate using an exposure apparatus adjusted according to the adjustment method of claim 16 or 17; developing the exposed substrate; and manufacturing an article from the developed substrate.

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