Exposure apparatus, exposure method, and method for manufacturing articles

Abstract

This technology offers advantages in achieving both anti-fogging performance of the optical elements of a projection optical system and measurement accuracy of the substrate position. [Solution] The exposure apparatus comprises a projection optical system, a supply unit that supplies gas to the space between the projection optical system and the substrate, a measurement unit that measures the position of the substrate, a detection unit that detects the height of the substrate, and a control unit that controls the supply of gas by the supply unit. The control unit controls the supply of gas by the supply unit during a first preparation period in which the detection unit detects the height of the substrate before exposure begins, so that the flow velocity of the gas passing between the measurement unit and the substrate is the same as the flow velocity during the exposure period. After the first preparation period and before exposure begins, during a second preparation period in which the measurement unit measures the position of the substrate, the control unit controls the supply of gas by the supply unit so that the flow velocity of the gas passing between the measurement unit and the substrate is smaller than the flow velocity during the exposure period.

Description

Technical Field

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

Background Art

[0002] As one of the apparatuses used in the lithography process in the manufacturing process of liquid crystal panels and semiconductor devices, there is an exposure apparatus that projects the pattern of a reticle illuminated by an illumination optical system onto a substrate to expose the substrate. A resist is applied to the substrate (wafer) used in the exposure apparatus, and contaminants can be generated from the resist by exposure. Such contaminants react with impurities such as acids, bases, and organics in the surrounding atmosphere or impurities such as acids, bases, and organics in the film of optical elements around the wafer, clouding the optical elements. In particular, the optical element disposed at the lowermost end of the projection optical system is disposed directly above the wafer, so clouding is likely to occur.

[0003] Moreover, the contaminants that cloud the optical element disposed at the lowermost end of the projection optical system do not come only from the resist. Around the projection optical system, there are drive systems and structures using grease and adhesives that are likely to generate contaminants, or resins and rubbers that are likely to generate contaminants in the components themselves. The contaminants generated therefrom are carried by the air conditioning to the vicinity of the wafer and reach the optical element disposed at the lowermost end of the projection optical system, clouding the optical element.

[0004] Clouding of the optical element can cause insufficient exposure amount, uneven illuminance, flare, etc., and can reduce the transfer accuracy of the reticle pattern onto the wafer. Therefore, an air nozzle for blowing off contaminants may be disposed near the optical element of the exposure apparatus. When blowing off contaminants with an air nozzle, generally, it is advantageous to flow a gas at a high flow rate and a large flow rate throughout the space between the wafer and the optical element. For such a gas, for example, clean air, clean dry air, nitrogen gas, etc. are used.

[0005] Patent Document 1 describes a method for flowing a substantially larger flow rate between a wafer and an optical element than the supply flow rate. Specifically, Patent Document 1 describes providing a gas supply port near the projection optical system and arranging a guide plate to guide the gas blown out from the gas supply port between the wafer and the optical element. This guide plate draws in gas from a clean area, straightens the flow, and guides the gas between the wafer and the optical element, allowing the gas to flow at a high velocity and large flow rate.

[0006] Patent Document 2 describes a technique for adjusting the gas flow rate based on the distribution of clouding on the optical element, thereby flowing the maximum possible amount of gas, because simply flowing a high-velocity, high-flow gas between the wafer and the optical element can actually cause contaminants to be drawn in. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2022-011815 [Patent Document 2] Japanese Patent Publication No. 2023-148841 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] However, simply flowing gas at high velocity and high flow rate to protect optical elements from contaminants will also flow gas at high velocity and high flow rate into the measurement system downstream of the optical elements. As a result, air fluctuations may occur in the optical path of the measurement system, potentially reducing measurement accuracy. Furthermore, the high-velocity gas may hit the structure of the measurement system, causing the structure itself to vibrate slightly, which may also reduce measurement accuracy. In addition, supplying gas can create a difference in conditions between exposure and measurement, which may also lead to a decrease in measurement accuracy.

[0009] This invention provides a technology that is advantageous in achieving both anti-fogging performance of the optical elements of a projection optical system and measurement accuracy of the substrate position. [Means for solving the problem]

[0010] According to one aspect of the present invention, an exposure apparatus for exposing a substrate is provided, comprising: a projection optical system for projecting an image of a pattern of a master plate onto the substrate; a supply unit for supplying gas to the space between the projection optical system and the substrate; a measurement unit for measuring the position of the substrate; a detection unit for obliquely incidenting light onto the substrate and detecting the height of the substrate using the light reflected by the substrate; and a control unit for controlling the supply of gas by the supply unit, wherein the control unit controls the supply of gas by the supply unit so that the flow velocity of the gas passing between the measurement unit and the substrate is the same as the flow velocity during the exposure period during a first preparation period in which the detection unit detects the height of the substrate before exposure is started; and after the first preparation period and before exposure is started, during a second preparation period in which the measurement unit performs measurements, the supply of gas by the supply unit so that the flow velocity of the gas passing between the measurement unit and the substrate is smaller than the flow velocity during the exposure period. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a technology that is advantageous in achieving both anti-fogging performance of the optical elements of a projection optical system and measurement accuracy of the substrate position. [Brief explanation of the drawing]

[0012] [Figure 1] A diagram showing the configuration of an exposure apparatus. [Figure 2] A diagram showing the configuration of the detection unit. [Figure 3] A diagram illustrating the size of the gas supply unit. [Figure 4] A diagram illustrating the control of the substrate stage in the exposure sequence. [Figure 5] Timing chart for adjusting the flow rate of the first gas. [Figure 6] A diagram showing the configuration of an exposure apparatus equipped with a temperature sensor. [Figure 7] A diagram showing the configuration of an exposure apparatus equipped with a temperature sensor and multiple flow rate adjustment units. [Figure 8A] A diagram for explaining the flow rate adjustment of gas using a plurality of flow rate adjustment units. [Figure 8B] A diagram for explaining the flow rate adjustment of gas using a plurality of flow rate adjustment units. [Figure 8C] A diagram for explaining the flow rate adjustment of gas using a plurality of flow rate adjustment units. [Figure 9] A diagram showing the overall configuration of the exposure apparatus.

Embodiments for Carrying Out the Invention

[0013] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the invention according to the claims. Although a plurality of features are described in the embodiments, not all of these plurality of features are essential for the invention, and the plurality of features may be arbitrarily combined. Further, in the accompanying drawings, the same or similar configurations are given the same reference numerals, and duplicate explanations are omitted.

[0014] FIG. 1 is a schematic diagram of an exposure apparatus 100 in an embodiment. In this specification and the drawings, directions are indicated in an XYZ coordinate system with the horizontal plane as the XY plane. Generally, a substrate W to be exposed is placed on a substrate stage 4 such that its surface is parallel to the horizontal plane (XY plane). Therefore, hereinafter, in the plane along the surface of the substrate W, the directions orthogonal to each other are defined as the X-axis and the Y-axis, and the direction perpendicular to the X-axis and the Y-axis is defined as the Z-axis. Further, hereinafter, the directions 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.

[0015] <First Embodiment> In FIG. 1, the exposure apparatus 100 may include a projection optical system 2, a substrate stage 4, a measurement unit 7, a detection unit 90, and a control unit 23. The projection optical system 2 may include an optical element 3 located at its lowermost end. The exposure apparatus 100 may further include a gas supply unit 10 (supply unit). The gas supply unit 10 supplies a first gas 40 into the space between the projection optical system 2 (optical element 3 thereof) and the substrate W (wafer) held by the substrate stage 4. The gas supply unit 10 may include a gas supply port 11 and a flow rate adjustment unit 20 that adjusts the supply flow rate of the first gas 40 from the gas supply port 11. The gas supply unit 10 may be fixed to the projection optical system 2 or may be fixed to a base (not shown) in its vicinity.

[0016] The measurement unit 7 is configured to emit measurement light toward the substrate stage 4 and measure the XY-direction position of the substrate stage 4 or the substrate W. The measurement unit 7 may be, for example, an OAS (Off-axis Alignment Scope) for measuring marks on the substrate. In order to improve the measurement accuracy by the measurement unit 7, it is required to keep the temperature, pressure, and humidity of the atmosphere through which the measurement light passes constant. The measurement unit 7 is disposed at any position where the first gas 40 flows. In FIG. 1, the measurement unit 7 is disposed on the downstream side of the projection optical system 2 with respect to the gas flow of the first gas 40, but may be disposed upstream of the projection optical system 7.

[0017] The detection unit 90 is configured to obliquely incident light on the substrate W and detect the height (Z-direction position) of the substrate W using the light reflected by the substrate W. Specifically, as shown in FIG. 2, the detection unit 90 may include a light projecting unit 90a and a light receiving unit 90b. By obliquely incident the measurement light 91 from the light projecting unit 90a on the substrate W and receiving the light reflected by the substrate W by the light receiving unit 90b, the height of the substrate W can be measured.

[0018] The gas supply unit 10 may further include a rectifier plate 12. A first opening 13a is formed at a position far from the exposure center by the partition wall of the gas supply port 11 and the rectifier plate 12, and a second opening 13b is formed at a position closer to the exposure center by the projection optical system 2 and the rectifier plate 12. The rectifier plate 12 is intended to straighten the airflow around the gas supply unit 10 in a certain direction, prevent the entrainment of surrounding gas, and straighten the direction of entrainment of surrounding gas, but it is not essential. For example, in an example without the rectifier plate 12, the lower wall of the gas supply port 11 of the gas supply unit 10 may be extended between the optical element 3 and the substrate stage 4 to serve as a rectifier plate. Also, in Figures 1 and 2, the gas supply port 11 is positioned below the projection optical system 2, but the gas supply port 11 may be positioned outside the projection optical system 2 and configured to supply the first gas 40 between the optical element 3 and the substrate stage 4 from that location.

[0019] The control unit 23 is composed of a computer including, for example, a CPU (processor) and memory, and is electrically connected to each part of the device, and controls each part comprehensively. The control unit 23 may be installed in a separate location from the room where the exposure apparatus 100 is installed (for example, a clean room), and may be implemented as a server device connected to the exposure apparatus 100 via a wired or wireless network.

[0020] Figure 3 shows the gas supply unit 10 as viewed from below the projection optical system 2 (the rectifier plate 12 is not shown). As shown in Figure 3, it is preferable that the size of the gas supply port 11 in the direction perpendicular to the blowing direction of the first gas 40 (X direction) is larger than the irradiation range 61, which is the range in which the laser light is irradiated onto the substrate W via the projection optical system 2. It is even more preferable that this size is larger than the range 62 in which the laser light passes over the first surface 31 of the optical element 3 on the substrate W side.

[0021] The first gas 40 is preferably a clean gas so as not to adversely affect the clouding of the optical element 3. A clean gas means a gas with few impurities such as acids, bases, and organic substances. It is even more preferable that the gas is clean air, which is air from which impurities such as acids, bases, and organic substances have been removed; clean dry air, which is clean air that has been dried; or an inert gas such as nitrogen gas.

[0022] The first gas 40 can be supplied from an air conditioning unit 26, as shown in Figure 9, which will be described later. The air conditioning unit 26 may be located inside or outside the exposure apparatus. The air conditioning unit 26 is equipped with a temperature control unit that can adjust the temperature of the first gas 40, and the temperature of the first gas 40 is set to match the ambient (air) temperature between the projection optical system 2 and the substrate stage 4. Alternatively, considering that heat is lost in the piping before reaching the area between the projection optical system 2 and the substrate stage 4, the temperature of the first gas 40 may be set to a temperature slightly higher than the ambient (air) temperature between the projection optical system 2 and the substrate stage 4. An air conditioning unit 5 is located in the space where the gas supply unit 10 is located, and in addition to the first gas 40, a second gas 41 is supplied. At least a portion of the second gas 41 flows between the optical element 3 and the substrate stage 4.

[0023] The room housing the exposure apparatus 100 is also equipped with an air conditioning system 5. The second gas 41 blown out from the air conditioning system 5 is kept clean by a chemical filter 6 located inside the air conditioning system 5. A clean state for the second gas 41 means that it is kept in a state with few impurities such as acids, bases, and organic matter by the chemical filter 6. However, the chemical filter 6 deteriorates with long-term use, so it cannot keep the second gas 41 clean semi-permanently. Furthermore, if the source of the second gas 41 in the air conditioning system 5 is the air from the cleanroom housing the exposure apparatus 100, the cleanliness of the second gas 41 may depend on the cleanliness of the cleanroom, even after passing through the chemical filter 6. In addition, if the cleanliness of the cleanroom is poor, the deterioration rate of the chemical filter 6 may be accelerated.

[0024] By the time the second gas 41 passes between the optical element 3 and the substrate stage 4, impurities may be mixed into the second gas 41. These impurities could be acids, bases, or organic substances generated from adhesives or greases used in actuators, guides, bearings, etc., for driving the substrate stage 4. Alternatively, the impurities could be acids, bases, or organic substances generated from resins, rubbers, etc., of structures, mounted components, etc. For this reason, it may be difficult to maintain a clean state of the second gas 41. Furthermore, in a configuration where the gas in the space where the gas supply unit 10 is located is circulated and the gas that passes through the chemical filter 6 becomes the second gas 41, the deterioration rate of the chemical filter 6 may be further accelerated due to the influence of contaminants 50 generated from the resist of the substrate W.

[0025] Thus, since the second gas 41 ceases to be clean, one of the roles of the gas supply unit 10 is to prevent the second gas 41 from reaching the optical element 3.

[0026] Next, we will explain the case when the exposure apparatus 100 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 on which the resist is coated. Contaminants 50 are impurities such as acids, bases, and organic matter. The contaminants 50 have components that are generated with a vertically upward velocity, and these reach the optical element 3 via the second gas 41, causing the optical element 3 to become cloudy. Another role of the gas supply unit 10 is to prevent this, and for this purpose, the first gas 40 is blown out to prevent the contaminants 50 from reaching the optical element 3.

[0027] As described above, the factors that cause the optical element 3 to become cloudy can be broadly divided into two categories. One is caused by contaminants 50, which come from directly below the optical element 3. The other is caused by contaminants other than contaminants 50 (impurities), which are carried by the second gas 41 and come from the surrounding area of ​​the optical element 3.

[0028] In this situation, the flow rate of the first gas 40 supplied from the gas supply unit 10 is usually set to a higher flow rate than that of the second gas 41 so that the contaminants 50 can be blown away. This is because the fogging of the optical element 3 tends to progress faster when caused by contaminants 50 than when caused by the second gas 41. When the flow rate adjustment unit 20 adjusts the first gas 40 to a high flow rate, the airflow directly below the measurement unit 7, which is downstream in the direction of the airflow, that is, in the region through which the measurement light from the measurement unit 7 passes, also becomes high speed.

[0029] However, if the airflow in the region through which the measurement light from the measurement unit 7 passes becomes high speed, turbulence is more likely to occur, making it easier to entrain surrounding air and potentially making it difficult to maintain constant temperature, pressure, and humidity. In other words, it may become difficult to maintain high accuracy in the measurement of the measurement unit 7. Furthermore, if the airflow in this region becomes high speed, it may affect the structure of the measurement unit 7 itself with vibrations. For example, the structure of the measurement unit 7 itself may vibrate in the following cases: (a) When the measuring unit 7 itself is vulnerable to external forces and prone to vibration. (b) When a thin cover is provided on the lower surface of the measuring unit 7, and the thin cover vibrates due to the airflow. (c) When there is a protrusion in the structure of the measurement unit 7, and the high-velocity first gas 40 directly hits it, causing it to vibrate.

[0030] In this way, when the structure of the measurement unit 7 itself vibrates, the measurement light also vibrates. As a result, high-precision measurement may become difficult with the measurement unit 7.

[0031] As shown in Figure 1, the exposure apparatus 100 may further include an exhaust unit 70 and an exhaust flow rate adjustment unit 81. The exhaust unit 70 has an exhaust port 71 that exhausts gas from the space between the optical element 3 and the measuring unit 7. The flow rate of the first gas 40 is adjusted by the flow rate adjustment unit 20, and accordingly, the exhaust flow rate adjustment unit 81 also adjusts the exhaust flow rate.

[0032] The exhaust section 70 not only sucks in the pollutants 50 blown away by the first gas 40 from the gas supply section 10, but also functions to rectify the high-speed flow of the first gas 40. For this reason, the exhaust section 70 is positioned downstream of the gas supply section 10, as shown in Figure 1. Furthermore, it is preferable to position the exhaust section 70 between the optical element 3 and the measurement section 7. The reasons for this are as follows:

[0033] The first reason is to reduce the amount of pollutants 50 that reach the measurement unit 70. As shown in Figure 4(a), if the exhaust unit 70 is located between the optical element 3 and the measurement unit 7, the pollutants 50 blown away by the first gas 40 will be partially sucked in through the exhaust port 71, thus reducing the amount that reaches the measurement unit 7.

[0034] The second reason is to improve the anti-fogging performance for the optical element 3. When the substrate stage 4 moves below the measurement unit 7, the flow rate of the first gas 40 is set to the second flow rate by the flow rate adjustment unit 20, which reduces the flow velocity and the force that blows away the contaminants 50. However, as shown in Figure 4(b), because the exhaust unit 70 is positioned, even if there are contaminants 50 remaining on the substrate W, those contaminants 50 are sucked in by the exhaust port 70, so the amount of contaminants 50 that reach the optical element 3 is reduced.

[0035] Thirdly, by drawing in the first gas 40 before it reaches below the measuring unit 7, the flow of the first gas 40 can be more easily slowed down. This makes it easier to reduce the flow rate adjustment range of the first gas 40 compared to the first embodiment.

[0036] Thus, providing the exhaust section 70 and the exhaust flow rate adjustment section 81 is preferable because it assists in effective airflow control using the gas supply section 10. However, providing the exhaust section 70 and the exhaust flow rate adjustment section 81 is not essential.

[0037] In this embodiment, in order to maintain high-precision measurement by the measurement unit 7, the flow rate of the first gas 40 is adjusted based on the position of the substrate stage 4 and the exposure sequence. The exposure sequence (exposure method) in this embodiment may include the following steps. (First step) A step in which, before exposure begins, during a first preparation period in which the height of the substrate is detected using the detection unit 90, the gas supply by the gas supply unit 10 is controlled so that the gas flow velocity passing between the measurement unit 7 and the substrate is the same as the flow velocity during the exposure period. (Second step) After the first preparation period and before exposure begins, during the second preparation period in which measurements are taken using the measurement unit 7, the gas supply by the gas supply unit 10 is controlled so that the gas flow velocity between the measurement unit 7 and the substrate is smaller than the flow velocity during the exposure period.

[0038] The specific flow of the exposure sequence in this embodiment is shown below. (a) Wafer loading: The substrate W is loaded from the substrate storage section and mounted on the substrate stage 4. (b) Focus adjustment: Focus adjustment is performed by controlling the Z position of the substrate stage 4 below the projection optical system 2 (at this time, the positional relationship is as shown in Figure 4(c)). Focus adjustment includes focus measurement using the detection unit 90. (c) Reference position adjustment: A correction value is determined for the reference value (baseline) representing the distance between the projection optical system 2 and the measurement unit 7 (at this time, the substrate stage 4 moves back and forth between the position shown in Figure 4(a) and the position shown in Figure 4(b)). (d) Measurement: Measurement light 9 is emitted from the measurement unit 7, and the substrate stage 4 is moved below the measurement unit 7 to measure the reference position of the substrate stage 4 and each reference position of the substrate W (at this time, the positional relationship is as shown in Figure 4(b)). (e) Exposure: Exposure light is emitted from the projection optical system 2, and the substrate stage 4 is scanned and moved below the projection optical system 2 to expose the substrate W (at this time, the positional relationship is as shown in Figure 4(a)). (f) Wafer unloading: Remove the substrate W from the substrate stage 4 and return the substrate W to the substrate storage unit. Once (f) is completed, the process may be repeated from (a). The sequence from (a) to (f) may also be performed individually. For example, only the measurement in (d) may be performed.

[0039] The flow rate adjustment by the flow rate adjustment unit 20 to improve the measurement accuracy of the measurement unit 7 will be described below. Figure 5(a) shows a timing chart of the flow rate adjustment of the first gas 40 by the flow rate adjustment unit 20. The horizontal axis is time and the exposure sequence number described above is indicated. The vertical axis shows the supply flow rate adjusted by the flow rate adjustment unit 20 or the exhaust flow rate adjusted by the exhaust flow rate adjustment unit 81. As shown in Figure 5(a), the flow rate is adjusted to the first flow rate during the period from (a) wafer loading to (b) focus adjustment (first preparation period). During the period from (c) reference position adjustment to (d) measurement (second preparation period), the flow rate is adjusted to the second flow rate, which is smaller than the first flow rate. Also, during the period of (e) exposure operation (exposure period) and (f) wafer unload operation, the flow rate is adjusted to the first flow rate.

[0040] To improve the measurement accuracy of the measurement unit 7, the flow rate adjustment unit 20 adjusts the gas flow rate to satisfy, for example, the following two conditions. (1)(e) The flow rate of the first gas 40 supplied from the gas supply unit 10 during exposure (first flow rate) is equal to or greater than the flow rate in other sequences. (2)(e) The flow rate of the first gas 40 supplied from the gas supply unit 10 during exposure (first flow rate) is greater than (d) the flow rate of the first gas 40 supplied from the gas supply unit 10 during measurement (second flow rate).

[0041] Furthermore, (e) it is advantageous to make the flow rate (first flow rate) of the first gas 40 supplied from the gas supply unit 10 during exposure faster than the flow velocity of the second gas 41. Therefore, the control unit 23 controls the supply of gas by the gas supply unit 10 so that the flow velocity of the first gas 40 is greater than the flow velocity of the second gas 41 supplied from the air conditioning unit 5.

[0042] In addition, (e) it is preferable that the flow rate of the first gas 40 supplied from the gas supply unit 10 during exposure (first flow rate) be equal to or greater than the moving speed of the substrate stage 4 as it scans during exposure. Therefore, the control unit 23 controls the supply of gas by the gas supply unit 10 so that the flow velocity of the first gas 40 is greater than the scanning speed of the substrate stage 4. The reason for this is that it is necessary to blow away contaminants 50 during the scanning movement of the substrate stage 4, and this blowing away process is not affected.

[0043] (d) The flow rate of the first gas 40 during measurement is preferably set to be smaller than the flow rate of the first gas 40 during exposure (e), and to have a flow velocity similar to that of the second gas 41. A similar flow velocity means a flow velocity difference that creates a flow that is close to laminar flow, rather than a flow that is disturbed by the difference in flow velocities between the first gas 40 and the second gas 41, and does not necessarily have to be perfect laminar flow. For example, if the flow velocity of the second gas 41 is 1 to 2 m / s, it is preferable to set the flow velocity of the first gas 40 in the region below the measurement unit 7 to be about 0 to 3 m / s. If the flow is close to laminar flow, it becomes less likely for air from the surrounding atmosphere to be entrained or mixed, resulting in less air fluctuation, that is, an atmosphere with stable temperature, pressure, and humidity. Therefore, high measurement accuracy can be obtained by the measurement unit 7. Furthermore, in the case of a weak flow close to laminar flow, only a stable, weak force is applied to the structure of the measurement unit 7, and the strong forces, shocks, and unexpected vectors caused by turbulence are reduced. This is advantageous for the measurement unit 7 in terms of vibration.

[0044] (b) Focus adjustment includes focus measurement performed at the same position as during (e) exposure using the detection unit 90. Therefore, it is preferable that the flow rate of the first gas 40 be set to the first flow rate so that the conditions are the same as during (e) exposure. Focus measurement is also performed using the detection unit 90 during (e) exposure, and the measured value is used. Therefore, it is preferable that the flow rate of the first gas 40 be set to the first flow rate so that the conditions are the same as during exposure when adjusting focus using the detection unit 90. Due to the structure of the gas supply unit 10, the influence of the first gas 40 on the detection unit 90 or the measurement light 91 is small, so no problems arise even if the flow rate of the first gas 40 is set to the first flow rate.

[0045] (c) During the reference position adjustment, the substrate stage 4 moves back and forth between the position shown in Figure 4(a) and the position shown in Figure 4(b). At this time, it is possible to switch the flow rate of the first gas 40 between the first flow rate and the second flow rate, but it is preferable to fix it to the second flow rate. Since the influence of the first gas 40 is greater on the measurement unit 7 than on the detection unit 90, it is better to set it to the second flow rate considering the influence on the measurement unit 7.

[0046] During periods other than the exposure period and the period during which measurements are taken by the measurement unit 7, i.e., during the periods of sequences (a) and (f), the flow rate should be adjusted within the range between the first and second flow rates, but it is preferable that it be adjusted in advance for subsequent sequences. For example, in a sequence performed in the order of (a) to (f), it is preferable to set the flow rate to the first flow rate in advance for sequences (a) and (f), as shown in Figure 5(a). Also, if (b) focus adjustment is performed independently, the flow rate setting value by the flow rate adjustment unit 20 in that section should be the first flow rate. If (d) measurement is performed independently, the flow rate setting value by the flow rate adjustment unit 20 in that section should be the second flow rate.

[0047] Next, it will be explained how the flow rate adjustment unit 20 preferably adjusts the first gas 40 during the transition between each sequence. When the substrate stage 4 transitions from (c) measurement to (d) exposure, it is preferable that the adjustment by the flow rate adjustment unit 20 is completely completed and the flow rate switches within the movement time of the substrate stage 4. In this transition, it is preferable that the flow rate is changed smoothly. That is, the control unit 23 controls the flow rate adjustment unit 20 so that, for example, the transition between the first flow rate and the second flow rate is continuous or stepwise. However, the flow rate may be changed abruptly in this transition. A preferred transition is that the flow rate is adjusted to the first flow rate before reaching the exposure start position, and switched to the second flow rate before reaching the measurement start position. However, even if the flow rate switching is delayed, the effect of maintaining measurement accuracy and the effect of preventing contaminants 50 from reaching the optical element 3 remain.

[0048] Even when the substrate stage 4 moves from (c) reference position adjustment to (d) measurement, it is preferable that the adjustment by the flow rate adjustment unit 20 is completed and the flow rate is switched within the movement time of the substrate stage 4.

[0049] The temperature control of the first gas 40 will now be explained. For example, temperature control of the first gas 40 may become important when the flow rate of the first gas 40 is changed significantly, or when the first flow rate is high and the temperature of the first gas blown out from the gas supply port 11 decreases (for example, due to adiabatic expansion or the Joule-Thomson effect). If the temperature of the first gas 40 changes when the flow rate of the first gas 40 is changed significantly, it is advisable to set the temperature adjustment value of the air conditioning unit 26 to change according to the flow rate change. Specifically, the temperature should be adjusted so that the temperature of the first gas 40 when it reaches below the projection optical system 2 is constant for both the first flow rate and the second flow rate. If it is difficult to predict temperature changes, a temperature sensor 27 may be placed in the gas supply unit 10 as shown in Figure 6, and the air conditioning unit 26 may control the temperature according to the measurement results from the temperature sensor 27. In this manner, the air conditioning unit 26 (temperature control unit) controls the temperature so that the temperature of the gas blown out from the gas supply port 11 remains constant before and after the flow rate adjustment unit 20 adjusts the flow rate.

[0050] Alternatively, a configuration as shown in Figure 7 may be adopted. In Figure 7, the gas supply unit 10 includes a plurality of flow rate adjustment units that adjust the flow rate of the gas blown out from the gas supply port 11, and the control unit 23 changes the flow velocity of the gas passing between the measurement unit 7 and the substrate W by individually controlling the plurality of flow rate adjustment units. Here, during the first preparation period (the period from (a) wafer loading to (b) focus adjustment operations described above) and the exposure period, the control unit 23 controls the plurality of flow rate adjustment units so that the flow rate of the gas blown out from the gas supply port 11 becomes a first flow rate. Furthermore, during the second preparation period (the period from (c) reference position adjustment to (d) measurement operations described above), the control unit 23 controls the plurality of flow rate adjustment units so that the flow rate of the gas blown out from the gas supply port 11 becomes a second flow rate which is smaller than the first flow rate.

[0051] In Figure 7, the air conditioning unit 26 (temperature control unit) is configured to supply gases with different temperatures to multiple flow rate adjustment units. From the air conditioning unit 26, a first gas 40H set to a higher temperature and a first gas 40L set to a lower temperature than the first gas 40H are supplied via separate systems. The flow rate adjustment unit 20 may include a first flow rate adjustment unit 20a that adjusts the flow rate of the first gas 40H and a second flow rate adjustment unit 20b that adjusts the flow rate of the first gas 40L. The temperature of the first gas 40 may also be adjusted by adjusting the mixing ratio of the first gas 40H and the first gas 40L based on the temperature measured by the temperature sensor 27 to generate a gas at a first or second flow rate. If the temperature of the first gas blown out from the gas supply port 11 decreases due to the Joule-Thomson effect described above, when setting the first flow rate, the mixing ratio of the first gas 40H is increased to generate a gas at the first flow rate, thereby raising the temperature upstream of the gas supply port 11. When setting the second flow rate, the mixing ratio of the first gas 40L is increased to generate the gas at the second flow rate, thereby lowering the temperature upstream of the gas supply port 11. Therefore, the control unit 23 adjusts the mixing ratio of the gases from each of the multiple flow rate adjustment units before and after the flow rate adjustment is performed by each of the multiple flow rate adjustment units, thereby keeping the temperature of the mixed gas constant.

[0052] With this configuration, flow rate adjustment can be performed at any temperature in each sequence from (a) to (f). Since the optimal flow rate and temperature can be achieved in each sequence, more accurate measurements can be realized. Although Figure 7 shows an example of two flow rate adjustment systems, three or more flow rate adjustment systems may be provided.

[0053] Next, a preferred exhaust flow rate adjustment value for the exhaust section 70 will be described. Figure 5(b) shows an example of a preferred exhaust flow rate adjustment value with a dashed line. The exhaust flow rate adjustment value is preferably 50% or more of the flow rate adjustment value of the first gas 40, and more preferably greater than or equal to the flow rate adjustment value of the first gas 40. This is to rectify the high-speed flow of the first gas 40 as described above. If the flow rate adjustment value of the first gas 40 becomes large, the flow may become blocked because the space between the optical element 3 and the substrate W is narrow. To reduce this flow blockage, the exhaust flow rate adjustment value may be set to a magnitude related to the flow rate adjustment value of the first gas 40. Also, to reduce this flow blockage, when the first gas 40 is adjusted to a first flow rate, it is preferable that the exhaust flow rate adjustment is completed before the adjustment to the first flow rate is completed. However, this is not essential. Conversely, when the first gas 40 is adjusted to a second flow rate, it is preferable that the exhaust flow rate adjustment value is adjusted with a delay. However, this is also not essential.

[0054] <Second Embodiment> Referring to Figure 8, an exposure apparatus according to the second embodiment will be described. In the second embodiment, the same reference numerals are used for components that are the same as those in the first embodiment described above, and their descriptions are omitted. Matters not specifically mentioned in the following description will follow the description of the first embodiment described above.

[0055] In the second embodiment, the control unit 23 individually controls a plurality of flow rate adjustment units so that a flow rate distribution corresponding to the distance between the measurement unit (for example, the X measurement unit 101X described later) and the substrate stage 4 is formed. Figure 8A is a view of the substrate stage 4 from above. The flow rate adjustment unit 20 may include a plurality of flow rate adjustment units 20a, 20b, and 20c. By controlling the adjustment of each of the plurality of flow rate adjustment units 20a, 20b, and 20c, it is possible to give the first gas from the gas supply unit 10 a flow rate distribution in the X direction. The exposure apparatus 100 further includes an X measurement unit 101X that measures the position of the substrate stage 4 in the X direction and a Y measurement unit 101Y that measures the position of the substrate stage 4 in the Y direction. The X measurement unit 101X and the Y measurement unit 101Y emit measurement light 102X and 102Y, respectively, to measure the position of the substrate stage 4.

[0056] Figure 8B shows a state in which the substrate stage 4 has moved away from the X measurement unit 101X compared to the state in Figure 8A. Figure 8C shows a state in which the substrate stage 4 has moved closer to the X measurement unit 101X compared to the state in Figure 8A. In the second embodiment, the flow rate distribution of the first gas in the X direction is formed by a plurality of flow rate adjustment units 20a, 20b, and 20c, thereby performing flow rate adjustment according to the position of the substrate stage 4 in the X direction, in addition to the flow rate adjustment in the first embodiment. Specifically, in the states shown in Figures 8A and 8C, the flow rate distribution of the first gas 40 is formed by the plurality of flow rate adjustment units 20a, 20b, and 20c such that the flow rate is equal at each position in the X direction. The sum of the flow rates of the first gases 40a, 40b, and 40c (total flow rate) is the first flow rate. As shown in Figure 8B, when the position of the substrate stage 4 moves away from the X measurement unit 101X, the flow rate adjustment unit 20c adjusts the flow rate of the first gas 40c accordingly so that the flow rate of the gas on the X measurement unit 101X side decreases. At this time, when the substrate stage 4 is furthest from the X measurement unit 101X, the flow rate adjustment unit 20c adjusts the flow velocity of the first gas 40c to be equal to the flow velocity of the second gas 41. Alternatively, when the distance between the substrate stage 4 and the X measurement unit 101X is 50% or more of the maximum, the flow velocity of the first gas 40c should be adjusted to be equal to the flow velocity of the second gas 41. As a result, the gas flowing on the X measurement unit 101X side becomes close to laminar flow with less turbulence and less difference in flow velocity, thereby achieving high accuracy in the measurement of the X measurement unit 101X.

[0057] <Embodiment of an exposure apparatus> Figure 9 shows the overall configuration of the exposure apparatus 100. The exposure apparatus 100 may include an illumination optical system 21, a master plate stage 22, a projection optical system 2, a substrate stage 4, and a control unit 23. The illumination optical system 21 uses light from a light source 24 (e.g., a laser light source) to illuminate the master plate M held by the master plate stage 22. The projection optical system 2 projects a pattern image from the master plate M onto the substrate W held by the substrate stage 4. This transfers the pattern to the resist coated on the substrate W. The substrate stage 4 and the master plate stage 5 move by scanning in response to commands from the control unit 23.

[0058] The air conditioning unit 26 is equipped with piping components for supplying the first gas 40 to the gas supply unit 10 through the flow rate adjustment unit 20, supplying, for example, clean air or nitrogen gas to the gas supply unit 10. The space in which the gas supply unit 10 is located is supplied with the second gas 41 from the air conditioning device 5. The source of the second gas 41 may be cleanroom air, making it difficult to maintain a completely clean state. Furthermore, the space in which the gas supply unit 10 is located is difficult to maintain completely clean because the drive system and structure of the substrate stage 4, or the parts themselves, use grease, adhesives, resins, rubber, etc., which are prone to generating contaminants. The exhaust unit 70 is configured not only to discharge contaminants 50 but also to contribute to the rectification of the high-speed flow of the first gas 40. The measurement unit 7 measures the position of the substrate stage 4 or the substrate W, and the detection unit 90 is configured to measure the position of the substrate stage 4 or the substrate W in the Z direction.

[0059] As described in the first and second embodiments, the gas supply unit 10 is positioned in or near the projection optical system 2 and supplies the first gas 40 between the lowest optical element 3 of the projection optical system 2 and the substrate stage 4. The gas supply unit 10 supplies the first gas 40 to protect the optical element 3 from contaminants 50 and contaminated second gas 41 generated from the substrate W while the substrate W is held by the substrate stage 4. This prevents or slows down fogging of the optical element 3.

[0060] Here, the flow rate adjustment unit 20 adjusts the flow rate of the first gas 40 according to the exposure sequence and the position of the substrate stage 4. This makes it possible to obtain an exposure environment and a measurement environment that have little impact on exposure and also have little impact on the measurement accuracy of the measurement unit 7 and the detection unit 90. Similarly, the exhaust flow rate adjustment unit 81 adjusts the exhaust flow rate according to the exposure sequence and the position of the substrate stage 4. This makes it possible to support the airflow control of the first gas 40 in such a way that it has little impact on exposure and also has little impact on the measurement accuracy of the measurement unit 7 and the detection unit 90.

[0061] <Embodiment of Article Manufacturing Method> The article manufacturing method according to an embodiment of the present invention is suitable for manufacturing articles such as microdevices, semiconductor devices, and elements having a microstructure. The article manufacturing method of this embodiment includes the steps of forming a latent image pattern on a photosensitive agent coated on a substrate using the above-described exposure apparatus (a step of exposing the substrate) and developing the substrate on which the latent image pattern was formed in the above step. 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 of this embodiment is advantageous over conventional methods in at least one of the performance, quality, productivity, and production cost of the article.

[0062] The disclosures herein include at least the following technologies: (Item 1) An exposure apparatus for exposing a substrate, A projection optical system that projects an image of the pattern of the original plate onto the substrate, A supply unit that supplies gas to the space between the projection optical system and the substrate, A measuring unit for measuring the position of the substrate, A detection unit that obliquely incidents light onto the substrate and detects the height of the substrate using the light reflected by the substrate, The system includes a control unit that controls the supply of gas by the supply unit, The control unit, In the first preparation period before exposure begins, during which the detection unit detects the height of the substrate, the supply unit controls the gas supply so that the gas flow velocity between the measurement unit and the substrate is the same as the flow velocity during the exposure period. After the first preparation period and before exposure begins, during the second preparation period in which the measurement unit performs measurements, the supply of gas by the supply unit is controlled so that the gas flow velocity between the measurement unit and the substrate is smaller than the flow velocity during the exposure period. An exposure apparatus characterized by the following features. (Item 2) The exposure apparatus according to item 1, characterized in that the first preparation period includes a period of time for mounting the delivered substrate onto the stage and a period of time for the detection unit to detect the height of the substrate and adjust the focus of the projection optical system based on the result of the detection. (Item 3) The exposure apparatus according to item 1 or 2, characterized in that the second preparation period includes the period for operations to perform measurements by the measuring unit. (Item 4) The exposure apparatus according to item 3, wherein the second preparation period further includes a period of operation for determining a baseline correction value representing the distance between the projection optical system and the measuring unit. (Item 5) The aforementioned supply unit is A gas supply port for blowing out the gas supplied to the aforementioned space, It includes a flow rate adjustment unit that adjusts the flow rate of gas blown out from the gas supply port, The control unit controls the flow rate adjustment unit to change the flow velocity of the gas passing between the measurement unit and the substrate. An exposure apparatus according to any one of items 1 to 4, characterized by the features described above. (Item 6) The control unit, During the first preparation period and the exposure period, the flow rate adjustment unit is controlled so that the flow rate of the gas blown out from the gas supply port becomes a first flow rate. During the second preparation period, the flow rate adjustment unit is controlled so that the flow rate of the gas blown out from the gas supply port becomes a second flow rate that is smaller than the first flow rate. The exposure apparatus according to item 5, characterized by the features described herein. (Item 7) The supply unit includes a plurality of flow rate adjustment units that adjust the flow rate of the gas blown out from the gas supply port. The control unit changes the flow velocity of the gas passing between the measuring unit and the substrate by individually controlling the plurality of flow rate adjustment units. An exposure apparatus according to any one of items 1 to 4, characterized by the features described above. (Item 8) The control unit, During the first preparation period and the exposure period, the plurality of flow rate adjustment units are controlled so that the flow rate of the gas blown out from the gas supply port becomes a first flow rate. During the second preparation period, the plurality of flow rate adjustment units are controlled so that the flow rate of the gas blown out from the gas supply port becomes a second flow rate that is smaller than the first flow rate. The exposure apparatus according to item 7, characterized by the features described herein. (Item 9) The exposure apparatus according to item 6, further comprising an exhaust unit for exhausting gas from the aforementioned space. (Item 10) The aforementioned exhaust section is With respect to the airflow of the gas supplied by the supply unit, an exhaust port is provided at a position downstream of the projection optical system and upstream of the measurement unit to exhaust gas from the space, It includes an exhaust flow rate adjustment unit that adjusts the exhaust flow rate from the exhaust port, The control unit controls the exhaust flow rate adjustment unit according to the gas supply flow rate from the supply unit. The exposure apparatus according to item 9, characterized by the features described herein. (Item 11) The exposure apparatus according to item 10, characterized in that the control unit controls the exhaust flow rate adjustment unit so that the exhaust flow rate from the exhaust port is greater than the flow rate of gas blown out from the gas supply port. (Item 12) The exposure apparatus according to item 10 or 11, characterized in that the exhaust flow rate adjustment by the exhaust flow rate adjustment unit is completed before the adjustment to the first flow rate by the flow rate adjustment unit is completed. (Item 13) The exposure apparatus according to item 6, characterized in that the control unit controls the flow rate adjustment unit so that the flow rate of the gas blown out from the gas supply port is within the range between the first flow rate and the second flow rate during periods other than the exposure period and the period during which the measurement unit performs measurements. (Item 14) The exposure apparatus according to item 6, characterized in that the control unit controls the flow rate adjustment unit so that the transition between the first flow rate and the second flow rate is continuous or stepwise. (Item 15) The exposure apparatus according to any one of items 1 to 14, characterized in that the measuring unit is located downstream of the projection optical system with respect to the gas flow supplied by the supply unit. (Item 16) The exposure apparatus according to any one of items 1 to 14, characterized in that the measuring unit is positioned upstream of the projection optical system with respect to the airflow of the gas supplied by the supply unit. (Item 17) The exposure apparatus according to any one of items 1 to 16, characterized in that the control unit controls the supply of gas by the supply unit so that the flow velocity of the gas supplied from the supply unit and passing through the space is greater than the flow velocity of the gas supplied from the air conditioning unit that provides air conditioning for the room in which the exposure apparatus is housed and passing through the space. (Item 18) The stage has a stage that holds and moves the substrate, The exposure apparatus according to any one of items 1 to 17, characterized in that the control unit controls the supply of gas by the supply unit so that the flow velocity of the gas supplied from the supply unit and passing through the space is greater than the scanning speed of the stage. (Item 19) The exposure apparatus according to item 6, further comprising a temperature control unit that controls the temperature so that the temperature of the gas blown out from the gas supply port remains constant before and after the flow rate is adjusted by the flow rate adjustment unit. (Item 20) The system further includes a temperature control unit that supplies gases with different temperatures to the plurality of flow rate adjustment units, The control unit adjusts the mixing ratio of the gases from each of the multiple flow rate adjustment units before and after the flow rate is adjusted by each of the multiple flow rate adjustment units, thereby keeping the temperature of the gas mixture constant. The exposure apparatus according to item 7, characterized by the features described herein. (Item 21) The stage has a stage that holds and moves the substrate, The control unit individually controls the plurality of flow rate adjustment units so that a flow rate distribution corresponding to the distance between the measurement unit and the stage is formed. The exposure apparatus according to item 7, characterized by the features described herein. (Item 22) An exposure method for exposing a substrate using an exposure apparatus comprising: a projection optical system for projecting an image of the pattern of a master plate onto the substrate; a supply unit for supplying gas to the space between the projection optical system and the substrate; a measurement unit for measuring the position of the substrate; and a detection unit for irradiating light onto the substrate and detecting the height of the substrate using the light reflected by the substrate, wherein the exposure apparatus comprises: Before exposure begins, during a first preparation period in which the height of the substrate is detected using the detection unit, a first step is taken to control the supply of gas by the supply unit so that the gas flow velocity passing between the measurement unit and the substrate is the same as the flow velocity during the exposure period. After the first preparation period and before exposure begins, in a second preparation period during which measurements are taken using the measurement unit, a second step is taken to control the supply of gas by the supply unit so that the gas flow velocity between the measurement unit and the substrate is smaller than the flow velocity during the exposure period. An exposure method characterized by having the following: (Item 23) A step of exposing a substrate using an exposure apparatus described in any one of items 1 to 21, The process of developing the exposed substrate, A method for manufacturing an article, characterized by including a developed substrate and manufacturing an article from the developed substrate.

[0063] The invention is not limited to the embodiments described above, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, claims are attached to disclose the scope of the invention. [Explanation of Symbols]

[0064] 100: Exposure device, 2: Projection optical system, 4: Substrate stage, 7: Measurement unit, 10: Gas supply unit, 11: Gas supply port, 20: Flow rate adjustment unit, 90: Detection unit

Claims

1. An exposure apparatus for exposing a substrate, A projection optical system that projects an image of the pattern of the original plate onto the substrate, A supply unit that supplies gas to the space between the projection optical system and the substrate, A measuring unit for measuring the position of the substrate, A detection unit that obliquely incidents light onto the substrate and detects the height of the substrate using the light reflected by the substrate, The system includes a control unit that controls the supply of gas by the supply unit, The control unit, During the first preparation period in which the detection unit detects the height of the substrate before exposure begins, the supply of gas by the supply unit is controlled so that the gas flow velocity between the measurement unit and the substrate is the same as the flow velocity during the exposure period. After the first preparation period and before exposure begins, during the second preparation period in which the measurement unit performs measurements, the supply of gas by the supply unit is controlled so that the gas flow velocity between the measurement unit and the substrate is smaller than the flow velocity during the exposure period. An exposure apparatus characterized by the following features.

2. The exposure apparatus according to claim 1, characterized in that the first preparation period includes a period of time for mounting the delivered substrate onto the stage and a period of time for the detection unit to detect the height of the substrate and adjust the focus of the projection optical system based on the result of the detection.

3. The exposure apparatus according to claim 1, characterized in that the second preparation period includes the period for operations to perform measurements by the measuring unit.

4. The exposure apparatus according to claim 3, wherein the second preparation period further includes a period of operation for determining a baseline correction value representing the distance between the projection optical system and the measuring unit.

5. The aforementioned supply unit is A gas supply port for blowing out the gas supplied to the aforementioned space, It includes a flow rate adjustment unit that adjusts the flow rate of gas blown out from the gas supply port, The control unit controls the flow rate adjustment unit to change the flow velocity of the gas passing between the measurement unit and the substrate. The exposure apparatus according to feature 1.

6. The control unit, During the first preparation period and the exposure period, the flow rate adjustment unit is controlled so that the flow rate of the gas blown out from the gas supply port becomes a first flow rate. During the second preparation period, the flow rate adjustment unit is controlled so that the flow rate of the gas blown out from the gas supply port becomes a second flow rate that is smaller than the first flow rate. The exposure apparatus according to feature 5.

7. The supply unit includes a plurality of flow rate adjustment units that adjust the flow rate of the gas blown out from the gas supply port. The control unit changes the flow velocity of the gas passing between the measuring unit and the substrate by individually controlling the plurality of flow rate adjustment units. The exposure apparatus according to feature 1.

8. The control unit, During the first preparation period and the exposure period, the plurality of flow rate adjustment units are controlled so that the flow rate of the gas blown out from the gas supply port becomes a first flow rate. During the second preparation period, the plurality of flow rate adjustment units are controlled so that the flow rate of the gas blown out from the gas supply port becomes a second flow rate that is smaller than the first flow rate. The exposure apparatus according to claim 7.

9. The exposure apparatus according to claim 6, further comprising an exhaust unit for exhausting gas from the aforementioned space.

10. The aforementioned exhaust section is With respect to the airflow of the gas supplied by the supply unit, an exhaust port is provided at a position downstream of the projection optical system and upstream of the measurement unit to exhaust gas from the space, It includes an exhaust flow rate adjustment unit that adjusts the exhaust flow rate from the exhaust port, The control unit controls the exhaust flow rate adjustment unit according to the gas supply flow rate from the supply unit. The exposure apparatus according to feature 9.

11. The exposure apparatus according to claim 10, characterized in that the control unit controls the exhaust flow rate adjustment unit so that the exhaust flow rate from the exhaust port is greater than the flow rate of gas blown out from the gas supply port.

12. The exposure apparatus according to claim 10, characterized in that the exhaust flow rate adjustment by the exhaust flow rate adjustment unit is completed before the adjustment to the first flow rate by the flow rate adjustment unit is completed.

13. The exposure apparatus according to claim 6, characterized in that the control unit controls the flow rate adjustment unit so that the flow rate of the gas blown out from the gas supply port is within the range between the first flow rate and the second flow rate during periods other than the exposure period and the period during which the measurement unit performs measurements.

14. The exposure apparatus according to claim 6, characterized in that the control unit controls the flow rate adjustment unit so that the transition between the first flow rate and the second flow rate is continuous or stepwise.

15. The exposure apparatus according to claim 1, characterized in that the measuring unit is located downstream of the projection optical system with respect to the gas flow supplied by the supply unit.

16. The exposure apparatus according to claim 1, characterized in that the measuring unit is positioned upstream of the projection optical system with respect to the gas flow supplied by the supply unit.

17. The exposure apparatus according to claim 1, characterized in that the control unit controls the supply of gas by the supply unit so that the flow velocity of the gas supplied from the supply unit and passing through the space is greater than the flow velocity of the gas supplied from the air conditioning unit that provides air conditioning for the room in which the exposure apparatus is housed and passing through the space.

18. The stage has a stage that holds and moves the substrate, The exposure apparatus according to claim 1, characterized in that the control unit controls the supply of gas by the supply unit so that the flow velocity of the gas supplied from the supply unit and passing through the space is greater than the scanning speed of the stage.

19. The exposure apparatus according to claim 6, further comprising a temperature control unit that controls the temperature so that the temperature of the gas blown out from the gas supply port remains constant before and after the flow rate is adjusted by the flow rate adjustment unit.

20. The system further includes a temperature control unit that supplies gases with different temperatures to the plurality of flow rate adjustment units, The control unit adjusts the mixing ratio of the gases from each of the multiple flow rate adjustment units before and after the flow rate is adjusted by each of the multiple flow rate adjustment units, thereby keeping the temperature of the gas mixture constant. The exposure apparatus according to claim 7.

21. The stage has a stage that holds and moves the substrate, The control unit individually controls the plurality of flow rate adjustment units so that a flow rate distribution corresponding to the distance between the measurement unit and the stage is formed. The exposure apparatus according to claim 7.

22. An exposure method for exposing a substrate using an exposure apparatus comprising: a projection optical system for projecting an image of the pattern of a master plate onto the substrate; a supply unit for supplying gas to the space between the projection optical system and the substrate; a measurement unit for measuring the position of the substrate; and a detection unit for irradiating light onto the substrate and detecting the height of the substrate using the light reflected by the substrate, wherein the exposure apparatus comprises: Before exposure begins, during a first preparation period in which the height of the substrate is detected using the detection unit, a first step is taken to control the supply of gas by the supply unit so that the gas flow velocity passing between the measurement unit and the substrate is the same as the flow velocity during the exposure period. After the first preparation period and before exposure begins, in a second preparation period during which measurements are taken using the measurement unit, a second step is taken to control the supply of gas by the supply unit so that the gas flow velocity between the measurement unit and the substrate is smaller than the flow velocity during the exposure period. An exposure method characterized by having the following:

23. A step of exposing a substrate using an exposure apparatus according to any one of claims 1 to 21, The process of developing the exposed substrate, A method for manufacturing an article, characterized by including a developed substrate and manufacturing an article from the developed substrate.

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