TWI654662B - Exposure device and article manufacturing method - Google Patents

Abstract

Even when the illuminance of the exposed light is high, a plurality of astigmatisms with mutually different directions in the projection optical system are converged within an allowable range. The exposure device has a projection optical system that projects a pattern of a mask onto a substrate. The exposure device includes a first optical element that can change a position or shape for adjusting the astigmatism of the projection optical system, and a second optical element that is disposed on a pupil of the projection optical system. Near the surface or the pupil surface; the control unit controls the position or shape of the first optical element; the supply unit supplies gas to the second optical element in order to adjust the temperature distribution of the second optical element, and the supply unit supplies gas to the second optical element, The astigmatism in the first direction generated by the temperature distribution of the second optical element and the astigmatic increase and decrease directions in the second direction different from the first direction are opposite to each other, so that the astigmatism in the first direction is converged within an allowable range , Controlling the position or shape of the first optical element so that the astigmatism in the second direction converges within an allowable range.

Description

Exposure device and article manufacturing method

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

[0002] An exposure device is used in a lithography process in a process of manufacturing a semiconductor device, a liquid crystal display device, or the like. The exposure device uses an illumination optical system to illuminate a mask (reduction mask), and is applied to a projection optical system. The development of a mask pattern by projecting a mask on a photosensitive resist layer. [0003] The optical element of the projection optical system absorbs the exposed light and generates a temperature distribution in the optical element, so that the refractive index distribution and the surface shape of the optical element change. From the viewpoint of imaging characteristics, it is desirable to reduce aberrations such as focus difference or astigmatism that may occur due to changes in the refractive index distribution and surface shape of the optical element. [0004] Therefore, there is known an exposure device in which the entire temperature inside the projection optical system rises due to the absorption of the exposed light by the components in the projection optical system, and enters the lens barrel housing the projection optical system. The temperature-adjusted gas is supplied to reduce a change in temperature distribution in the projection optical system. [0005] Japanese Patent Application Laid-Open No. 2016-95412 discloses that when supplying gas between a meniscus lens and a convex lens provided near a pupil of a projection optical system, information based on a mask pattern used for exposure is disclosed. The temperature distribution of the meniscus lens and the direction of the gas flow are controlled in such a manner. [0006] In Japanese Patent Application Laid-Open No. 2016-95412, a lens is locally cooled by allowing a gas to flow through a region where the temperature of the lens rises. Therefore, when light with high illuminance is incident on the projection optical system, it is estimated that The temperature distribution is not sufficiently uniform. In this case, it is particularly difficult to converge both the astigmatism in the vertical and horizontal directions of the projection optical system within the allowable range.

[0007] As an aspect of the present invention, an exposure apparatus that solves the above-mentioned problems includes a projection optical system that projects a pattern of a mask onto a substrate. The projection optical system includes a first optical element. Astigmatism changes the position or shape; and the second optical element is disposed near the pupil surface or the pupil surface of the projection optical system, and the exposure device includes a control unit that controls the position or shape of the first optical element; And the supply unit supplies gas to the second optical element in order to adjust the temperature distribution of the second optical element, and the supply unit supplies gas to the second optical element so that the temperature distribution of the second optical element due to exposure The astigmatism in the first direction and the astigmatism in the second direction which is different from the first direction are opposite to each other, so that the astigmatism in the first direction is converged within an allowable range, and the first optical element is controlled. The position or shape of the element is such that the astigmatism in the second direction during exposure is converged within an allowable range.

Other features of the present invention will become apparent from the following description of the embodiments (refer to the accompanying drawings).

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

(First Embodiment)

An exposure apparatus according to this embodiment will be described with reference to FIG. 1. FIG. 1 is a schematic diagram of an exposure apparatus according to the first embodiment. The exposure device can be used, for example, in a photolithography process in a process of manufacturing a flat panel such as a liquid crystal display device or an organic EL device. use. In particular, in this embodiment, the exposure apparatus is a scanning projection exposure apparatus that transfers (exposes) an image of a pattern formed on a mask to a flat plate (on a substrate) by a step-and-scan method. In FIG. 1, the scanning direction of the original plate 9 and the substrate 19 during exposure in a plane perpendicular to the Z axis that is the vertical direction is taken as the Y axis, and the non-scanning direction orthogonal to the Y axis is taken as the X axis. The substrate 19 is, for example, a substrate to be processed that is made of a glass material and has a surface coated with a photosensitizer (resist layer).

The exposure apparatus of this embodiment includes an illumination system IL, a projection optical system PO, an original plate driving mechanism that scans a mask (original plate) 9 disposed on the object surface OP disposed on the projection optical system PO, and an image disposed on the projection optical system PO A substrate driving mechanism and a control unit C that scan the substrate 19 with the IP surface.

The illumination system IL may include, for example, a light source LS, a first focusing lens 3, a fly-eye lens 4, a second focusing lens 5, a slit defining member 6, an imaging optical system 7, and a plane mirror 8. The light source LS may include, for example, a mercury lamp 1 and an elliptical mirror 2. The slit-defining member 6 defines the illumination range of the original plate 9 (that is, the cross-sectional shape of the slit-shaped light that illuminates the original plate 9). The imaging optical system 7 is configured to image a slit defined by the slit defining member 6 on an object plane. The plane mirror 8 bends a light path in the lighting system IL. The projection optical system PO projects the pattern of the original plate 9 arranged on the object plane OP onto the substrate 19 arranged on the image plane IP, and the substrate 19 is exposed. The projection optical system PO may be constituted as any optical system among the equal-magnification imaging optical system, the magnification imaging optical system, and the reduction imaging optical system. Among them, the projection optical system PO is preferably configured as an equal-magnification imaging optical system, and the principal rays are parallel on the object plane side and the image plane side, that is, the object plane and the image plane have bi-telecentricity.

[0013] The projection optical system PO has a first plane mirror 13, a first concave mirror 14, a convex mirror 15, and a second concave mirror 16 as reflecting mirrors that are sequentially arranged from the object plane side in the light path from the object plane OP to the image plane IP. And second plane mirror 17. The light path between the object OP and the first plane mirror 13 and the light path between the second plane mirror 17 and the image plane IP are parallel. The plane including the mirror surface of the first plane mirror 13 and the plane including the mirror surface of the second plane mirror 17 are at an angle of 90 degrees to each other. The first plane mirror 13 and the second plane mirror 17 may be integrally formed. The first concave mirror 14 and the second concave mirror 16 may be integrally formed. The projection optical system PO includes cylindrical lenses 21 and 22, and a plano-concave lens (or plano-convex lens) 12 'arranged in the light path between the object plane OP and the first plane mirror 13. The projection optical system PO includes cylindrical lenses 23 and 24 arranged in the light path between the second plane mirror 17 and the image plane. In the projection optical system PO, a meniscus lens (aspherical lens) 15 'is disposed in front of the convex mirror 15 in order to correct color aberrations on the axis caused by these lenses. The reflecting surface of the convex mirror 15 corresponds to the pupil surface of the projection optical system. The convex mirror 15 is disposed on the pupil surface of the projection optical system, and the meniscus lens 15 'is disposed near the pupil surface of the projection optical system. These optical elements produce an uneven temperature distribution during exposure. [0014] The cylindrical lenses 23 and 24 constitute a projection optical system that adjusts a second direction (y direction) orthogonal to a first direction (z direction) along the light path between the object plane OP and the first plane mirror 13. The first optical system of the projection magnification. The cylindrical lenses 21 and 22 constitute a second optical system that adjusts the projection magnification of the projection optical system in a third direction (x direction) orthogonal to the first direction and the second direction. The plano-concave lens 12 'constitutes a third optical system that adjusts the projection magnification of the projection optical system in the first direction and the second direction. [0015] The cylindrical lens 21 is a concave cylindrical surface having a flat upper surface and a lower cylindrical surface having a curvature in the x direction, and has an air gap of about 5 mm to 20 mm to the upper surface of the cylindrical lens 22. The upper surface of the cylindrical lens 22 is a convex cylindrical surface having a curvature in the x direction, the lower surface is a convex spherical surface, and the upper surface of the plano-concave lens 12 'having a concave spherical surface on the upper surface and a flat surface on the lower surface has 5 to 20 mm Left and right air gap. The cylindrical lens 21 or the cylindrical lens 22 is configured to be movable (drivable) in the z-direction by an actuator 31 (driving section). The cylindrical lens 21 is driven in the z direction through the opposing cylindrical lens 22 to correct the magnification in the x direction. In addition, by driving the plano-concave lens 12 'in the z direction by the actuator 31, the magnification is corrected isotropically in the x direction and the y direction. [0016] The control unit C is composed of, for example, a computer, and is connected to each component of the exposure device via a line, and can control the operation and adjustment of each component according to a program or the like. The control unit C can control an actuator (drive unit) that drives a cylindrical lens and a plano-concave lens to control the position, shape, or both of the lenses. [0017] The cylindrical lens 23 has a flat surface on the upper surface and a concave cylindrical surface having a curvature in the scanning direction on the lower surface, and has an air gap of about 5 mm to 20 mm to the upper surface of the cylindrical lens 24. The cylindrical lens 24 has a convex cylindrical surface having a curvature in the scanning direction on the upper surface and a flat surface on the lower surface. The cylindrical lens 23 or the cylindrical lens 24 is configured to be capable of changing (moving) the position in the z direction by the actuator 32. By moving the cylindrical lens 23 in the z direction by the actuator 32, the magnification in the y direction can be corrected. The ranges of the thicknesses and intervals of the cylindrical lenses 21, 22, 23, and 24 that do not cause self-weight deformation when held in space are arbitrary, and the ranges that the space holding mechanism and the up-and-down driving mechanism can form are arbitrary. When the cylindrical surface is synthetic quartz with a refractive index of about 1.475, when the radius of curvature is about 47,000 mm, the magnification is changed by about 1 ppm through a movement of 1 mm. However, it is necessary to change the cylindrical surface and the spherical surface minutely so that the size of the image passing through the three lenses provided at the reference height position is exactly the same as when there is no three lenses. In addition, the concave and convex surfaces of the cylindrical surface and the concave and convex surfaces of the spherical surface may be opposite to each other. In addition, the magnification correction unit is not limited to a cylindrical lens, and a mechanism that can change the position, shape, or both of the parallel flat plates and bend the parallel flat plates, or a mechanism that adjusts the rotation position of the lens may be used.

In addition, when the cylindrical lens is moved as described above, the projection magnification can be adjusted, but astigmatism can also be adjusted. For example, when adjusting the projection magnification in the y direction, when the cylindrical lens 23 having a flat surface on the upper surface and a concave cylindrical surface having curvature in the scanning direction on the lower surface is moved in the z direction, it is positive to the scanning direction. The refractive power in the direction of intersection does not change, but a negative refractive power is generated in the scanning direction. Therefore, the line image (V line) in the scanning direction is imaged at a position (lower side) farther from the projection optical system than the line image (H line) in a direction perpendicular to the scanning direction. That is, the first optical system has sensitivity to a projection magnification in the y direction, and has sensitivity to astigmatism occurring in the vertical and horizontal directions (x, y directions). The second optical system has sensitivity to a projection magnification in the x direction and sensitivity to astigmatism occurring in the vertical and horizontal directions. The third optical system has sensitivity to projection magnifications in the x-direction and y-direction, and has no sensitivity to astigmatism occurring in the vertical and horizontal directions. Therefore, by driving these lenses, astigmatism in the vertical and horizontal directions can be generated without changing the projection magnification in two directions orthogonal to each other. As an example, when the cylindrical lens 21 is driven by +1 mm in the Z direction, the cylindrical lens 23 is driven by +2 mm in the Z direction, and the plano-concave lens 12 'is driven by +1 mm in the Z direction. Astigmatism in the vertical and horizontal directions of 3 μm occurs with a change in the projection magnification. According to the aforementioned mechanism, the amount of correction of astigmatism is proportional to the amount of driving of the lens. Therefore, if a space is provided between the lenses to avoid interference during driving, the amount of lens driving can be increased, and the amount of astigmatism correction can be increased.

Therefore, the position of any lens (first optical element) among the cylindrical lenses 21, 22, 23, and 24 and the plano-concave lens 12 'is controlled by the control unit C. Thereby, the projection magnification in the x and y directions can be set as a predetermined target value, and the astigmatism in the vertical and horizontal directions can be within an allowable range. In addition, when a parallel flat plate is used instead of a cylindrical lens, the projection magnification and astigmatism can be adjusted by controlling the shape of the parallel flat plate.

Next, the temperature distribution of the meniscus lens 15 'will be described. FIG. 2 shows the temperature distribution of the meniscus lens 15 'when a certain mask pattern is exposed on the substrate. The temperature distribution of the convex mirror 15 is also substantially the same as that of the meniscus lens 15 '. A high-temperature portion is located on both sides of the B-axis direction through the center of the lenticular lens 15 ', and a low-temperature portion is located on both sides of the C-axis direction through the center of the lenticular lens 15'. Fig. 3 shows the Z5 term and the Z6 term when the temperature distribution of the meniscus lens 15 'is decomposed by the Booknick function.

The left diagram of FIG. 3 is the temperature distribution of the Z5 term shape of the Book Nick coefficient, and the right diagram of FIG. 3 is the temperature distribution of the Z6 term shape of the Book Nick coefficient. in In the temperature distribution of the Z5 term shape of the book coefficient, there are high-temperature portions near both ends in the X-axis direction through the center of the meniscus lens 15 ', and near both ends in the Z-axis direction through the center of the meniscus lens 15'. There is a low temperature section. In the temperature distribution of the Z6 term shape of the book coefficient, there are high-temperature portions near both ends in the B-axis direction through the center of the lenticular lens 15 ', and at both ends in the C-axis direction through the center of the lenticular lens 15' There is a low temperature section nearby. The B-axis and C-axis are axes inclined at an angle of 45 degrees from the X-axis or the Z-axis, and the axes are perpendicular to each other.

When the meniscus lens 15 'generates a temperature distribution of the Z5 term, it becomes a refractive index distribution of the Z5 term, and a wavefront aberration of the Z5 term is generated. When the wavefront aberration of the Z5 term is generated, the focal position of the horizontal line (H line) and the vertical position (V line) of the mask pattern are staggered. As a result, astigmatism in the vertical and horizontal directions is generated as the difference between the focal position of the H line and the focal position of the V line. In addition, when the meniscus lens 15 'generates a temperature distribution of the Z6 term, it becomes a refractive index distribution of the Z6 term, and a wavefront aberration of the Z6 term is generated. When the wavefront aberration of the Z6 term is generated, the focus position of the upper right oblique line (S line) inclined by 45 degrees with respect to the H line of the mask pattern and the focus position of the upper left oblique line (T line) inclined by 135 degrees (degrees) with respect to the H line are staggered. . Therefore, astigmatism in the oblique direction occurs as a difference between the focal position of the S line and the focal position of the T line. Here, the astigmatism in the oblique direction is referred to as the astigmatism in the first direction, and the astigmatism in the vertical and horizontal directions is referred to as the aberration in the second direction. In addition, the above-mentioned vertical and horizontal directions differ by 45 degrees, but the angular difference between the first direction and the second direction is not limited to 45 degrees, as long as they are mutually different directions. In addition, the astigmatism in the oblique direction is not limited to the Z6 term, and may also include the Z13 term. The astigmatism in the vertical and horizontal directions is not limited to the Z5 term, and may also include the Z12 term. Wait.

Next, the temperature adjustment of the convex mirror 15 or the meniscus lens 15 '(second optical element) will be described. FIG. 4 shows the peripheral structures of the convex mirror 15 and the meniscus lens 15 '. The figure on the right side of Fig. 4 is a view seen from the Y direction, and the figure on the left side of Fig. 4 shows a cross-sectional view at DD '. The one-dot chain line in the Y-axis direction indicates the optical axis. The convex mirror 15 and the meniscus lens 15 'are held by a lens barrel 100 (holding portion). As shown in FIG. 4, a closed space 102 is formed between the convex mirror 15 and the meniscus lens 15 '. The lens barrel 100 is provided with a plurality of holes 103 and 104 extending in the Z direction. The hole 103 is a gas supply port, and the hole 104 is a gas exhaust port. Fig. 5 shows a sectional view of the lens barrel 100 passing through AA '. The lens barrel 100 is provided with a plurality of air supply ports 103A to G as through holes. Each of the plurality of air supply ports 103A to G extends in the same Z direction. In addition, in the lens barrel 100, exhaust ports 104A to G are provided as through holes on the side opposite to the air supply ports 103A to G with respect to the optical axis of the meniscus lens 15 'at the intersection of the one-dot chain line. . In addition, in a direction (Z direction) from the air supply port to the exhaust port, the air supply port and the exhaust port extend inside the lens barrel 100. For example, the air supply port 103A extends in a direction (Z direction) parallel to a line passing through the air supply port 103D and the optical axis of the meniscus lens 15 '. On the lower side of the lens barrel 100, a plurality of air supply ports 103A to G are provided at substantially equal intervals in the X-axis direction. A plurality of exhaust ports 104A to G are provided on the upper side of the lens barrel 100 at substantially equal intervals in the X-axis direction. The plurality of air supply ports 103A to G and the air discharge ports 104A to G are provided so as to cover the entire diameter in the X direction of the convex mirror 15 and the meniscus lens 15 '. A gas supply path 36 for supplying gas is connected to the plurality of gas supply ports 103A to G, and a gas discharge path 37 for discharging gas is connected to the plurality of exhaust ports 104A to G. As a gas By selecting air, nitrogen, etc., air does not need to replace the gas inside the closed space, and there is no waiting time until the replacement is completed. Therefore, the exposure device can be used immediately, which is excellent in this respect. Since nitrogen is an inert gas, it is excellent in that mirrors and lenses are not blurred.

The gas supply path 36 and the exhaust path 37 are connected to a gas supply unit 35 that adjusts the flow rate and temperature of the gas, and the supply and exhaust of the gas is adjusted through the gas supply unit 35. The gas supply unit 35 adjusts the temperature of the gas to a fixed temperature. In addition, the air supply path 36 and the exhaust path 37 may be one system or a plurality of systems. One system may be provided in one hole, or one system may be branched and connected to each hole. If there are multiple systems, the gas flow rate and temperature can be adjusted independently in each system. The operation of the gas supply unit 35 is controlled by the control unit C.

An arrow 107 indicates the flow of the gas before flowing into the gas supply ports 103A to G. The plurality of arrows correspond to each of the plurality of air supply ports 103A to G. The gas whose temperature has been adjusted by the gas supply unit 35 is supplied from a plurality of gas supply ports 103A to G. The arrow 108 indicates the flow of the gas flowing from the exhaust ports 104A to G, and the gas is discharged from the exhaust ports 104A to G. Thereby, a gas flow 109 is formed in the closed space 102 between the convex mirror 15 and the meniscus lens 15 ', and the temperature in the closed space 102 is adjusted. The plurality of air supply ports 103A to G and the air discharge ports 104A to G are provided so as to cover the entire diameter in the X direction of the convex mirror 15 and the meniscus lens 15 '. That is, the air supply ports 103A and 103G and the exhaust ports 104A and 104G are arranged near the outer periphery of the convex mirror 15 and the meniscus lens 15 '. Therefore, the temperature-adjusted gas can be sprayed on the entire area of the surface of the convex mirror 15 and the meniscus lens 15 '. In addition, a plurality of air supply ports 103A to G and exhaust air ports 104A to G are in the Z direction. It extends upwards, so the orientation is consistent. Furthermore, the flow rate of the supplied air matches the flow rate of the discharged air. Thereby, the flow paths of the gas are consistent in the Z direction (one direction), and the flow of the gas does not stagnate in the closed space 102, so the gas flows through the laminar flow 109. That is, the gas is caused to flow from each of the plurality of air supply ports through the surfaces of the convex mirror 15 and the meniscus lens 15 'in the same direction.

In this way, the temperature distribution of the convex mirror 15 and the meniscus lens 15 'can be adjusted by supplying the temperature-adjusted gas to the closed space 102 between the convex mirror 15 and the meniscus lens 15', so that the gas flows through the surfaces of the convex mirror 15 and the meniscus lens 15 ' . After the temperature-controlled gas is continuously supplied to the closed space 102 between the convex mirror 15 and the meniscus lens 15 ', the temperature distribution of the convex mirror 15 and the meniscus lens 15' connected to the closed space 102 becomes relative Z as shown in FIG. Axis-symmetric temperature distribution. FIG. 6 is a diagram showing a schematic temperature distribution of the convex mirror 15 and the meniscus lens 15 '. Region 1 is the region with the lowest temperature, region 2 is the region with higher temperature than region 1, and region 3 is the region with the highest temperature. The convex mirror 15 and the meniscus lens 15 'are heated by exposure, and the temperature becomes higher as they move away from the gas supply port. It can be seen that in the area close to the air supply port, the temperature is lowered due to the low-temperature gas. When the temperature distribution is symmetrical to the left and right with respect to the Z axis, the wavefront aberration of the Z5 term becomes larger, and the wavefront aberration of the Z6 term becomes smaller. That is, compared with the case where no gas is supplied, the astigmatism in the vertical and horizontal directions becomes larger and the astigmatism in the oblique direction becomes smaller. When the substrate is exposed at a high illuminance, temperature unevenness of the lens of the projection optical system becomes large, and aberration becomes large. However, even when the substrate is exposed at a high illuminance, astigmatism in the oblique direction can be made by controlling the supply of gas by the gas supply unit 35 as described above. Converge within the allowable range. As a specific example, the temperature-adjusted gas is continuously supplied to the space 102 between the convex mirror 15 and the meniscus lens 15 'through the gas supply unit 35. As a result, the amount of reduction in astigmatism in the oblique direction is 2.5 m.

In this way, instead of uniformizing the temperature distribution of the convex mirror 15 and the meniscus lens 15 ′ as a whole, the flow of gas is formed so that the astigmatism in the oblique direction becomes smaller and the astigmatism in the vertical and horizontal directions becomes larger to adjust the temperature distribution . Therefore, the astigmatism in the vertical and horizontal directions may not be within the allowable range, but may be larger than before the gas is supplied.

Next, a method for correcting astigmatism in the vertical and horizontal directions will be described. FIG. 7 shows a flowchart of the correction method. First, the control unit C controls the gas supply unit 35. As described above, the temperature-adjusted gas is supplied to the closed space 102 between the convex mirror 15 and the meniscus lens 15 ', and the temperature distribution of the convex mirror 15 and the meniscus lens 15' is adjusted (S301 ). While the gas is continuously supplied, the control unit C controls each part of the exposure device so that the projection optical system PO projects the pattern of the original plate 9 on the substrate 19 and exposes the substrate 19. For example, when the substrate is exposed at a high illuminance, the temperature of a lens or the like of the projection optical system becomes high, and the aberration may not converge within an allowable range. When the gas is supplied in S301, the astigmatism in the oblique direction of the projection optical system converges within the allowable range, but the astigmatism in the vertical and horizontal directions does not converge within the allowable range. Therefore, the astigmatism in the vertical and horizontal directions is measured every time the substrate 19 whose exposure is completed is replaced, or the astigmatism in the horizontal and vertical directions is measured in batches (S302). For example, astigmatism can be measured using a focus sensor 40 (measurement unit) arranged on a substrate stage that moves a substrate. Then, based on the measurement results, The amount of occurrence of astigmatism in the vertical and horizontal directions is measured, and the amount of movement of any of the cylindrical lenses 21, 22, 23, 24 and the plano-concave lens 12 'for reducing the astigmatism in the vertical and horizontal directions is allowed (S303 ). Then, the lens is driven based on the calculated amount of lens movement (S304). Thus, both the astigmatism in the vertical and horizontal directions and the astigmatism in the oblique direction can converge within the allowable range. Then, the next substrate is exposed using the projection optical system whose astigmatism is within the allowable range (S305).

In this way, the gas supply unit adjusts the temperature of the second optical element by flowing gas over the surface of the second optical element so that the astigmatism in the first direction and the The astigmatism in the second direction, which is different in direction, increases and decreases in opposite directions. Furthermore, the gas supply unit adjusts the temperature of the second optical element by flowing a gas through the surface of the second optical element so that the astigmatism in the first direction converges within an allowable range. Furthermore, the position or shape of the first optical element is controlled so that the astigmatism in the second direction at the time of exposure converges within an allowable range. As a result, even when the illuminance is high, the astigmatism in the first direction and the astigmatism in the second direction of the projection optical system can be converged within an allowable range.

(Second Embodiment)

Next, an exposure apparatus according to a second embodiment will be described. The gas supply port and the exhaust port of the gas from the gas supply unit 35 are not limited to the holes opened in the lens barrel 100. In the present embodiment, a structure in which a punching plate provided with a plurality of holes is attached to a side surface of the lens barrel 100 is used. If it is a hole made in the lens barrel 100, manufacturing of the lens barrel 100 is easy. On the other hand, in the case of a punching plate, it is possible to effectively reduce the cooling unevenness of the temperature adjustment. FIG. 8 is a cross-sectional view of the lens barrel 100 to which a punching plate is mounted. A large opening having the same length as the diameter of the convex mirror 15 and the concave-convex lens 15 ′ is provided on the lower side in the z-axis direction of the lens barrel 100, and a punch provided with a plurality of holes 204 is installed so as to cover the opening.孔板 201。 Orifice 201. In addition, a large opening is also provided on the upper side in the z-axis direction of the lens barrel 100, and a punching plate 200 provided with a plurality of holes 203 is installed so as to cover the opening. Gas is supplied to the closed space 102 between the convex mirror 15 and the meniscus lens 15 'through the holes of the punching plate 201, and gas is discharged from the closed space 102 through the holes of the punching plate 200. In this way, the gas is supplied through the opening having the same length as the diameter of the convex mirror 15 and the meniscus lens 15 'and the gas is discharged, so that the gas can flow through the entire surface of the convex mirror 15 and the meniscus lens 15'. Therefore, the convex mirror 15 and the concave-convex lens 15 'have a temperature distribution as shown in FIG. Therefore, even when the substrate is exposed at a high illuminance, the astigmatism in the oblique direction can be converged within the allowable range. [0031] (Third Embodiment) Next, an exposure apparatus according to a third embodiment will be described. In the first embodiment, the astigmatism in the vertical and horizontal directions is measured. In this embodiment, the amount of change in astigmatism in the vertical and horizontal directions is calculated based on the information of the mask pattern and the accumulated exposure amount. [0032] First, through experiments, a coefficient (exposure history coefficient) of the change in astigmatism in the vertical and horizontal directions with respect to the cumulative exposure of the substrate is obtained. Specifically, a cumulative exposure meter that detects light branched from the light path of the illumination optical system IL is used. The correspondence between the illuminance of light branched from the light path of the illumination optical system IL and the illuminance of light on the substrate is obtained in advance. During the continuous exposure period, the illuminance measured by the cumulative exposure amount is accumulated, and the cumulative exposure amount on the substrate is indirectly obtained based on the correspondence relationship. In the case of continuous exposure, while measuring the cumulative exposure, the focus sensor 40 measures the change in astigmatism in the vertical and horizontal directions. Then, the control unit C uses these measurement data to obtain a coefficient of a change in the astigmatism in the vertical and horizontal directions with respect to the cumulative exposure amount of the substrate. The exposure history coefficient is stored in the memory of the control unit C. Then, when actually exposing the substrate, instead of the measurement of S302 in FIG. 7, the control unit C uses the obtained exposure history coefficient, the information of the mask pattern, and the cumulative exposure amount when actually exposing the substrate to calculate the vertical and horizontal directions. The amount of change in astigmatism. Then, the control unit C calculates a driving amount of a cylindrical lens or the like required to correct the astigmatism in the vertical and horizontal directions. Then, the control section C controls the driving section that drives the lens based on the calculated driving amount. [0033] According to the method of this embodiment, it is possible to predict changes in astigmatism in the vertical and horizontal directions during periods when aberration cannot be measured with a focus sensor, such as during a period when the substrate is moved to expose the substrate, and the lens can be driven to correct the aberration. . Therefore, changes in the astigmatism in the vertical and horizontal directions during one substrate process or one shot exposure can also be corrected. [0034] (Manufacturing Method of Article) Next, a method of manufacturing an article (semiconductor IC element, liquid crystal display element, color filter, MEMS, etc.) using the above exposure device will be described. A program for exposing a photosensitive-coated substrate (wafer, glass substrate, etc.), a program for developing the substrate (photosensitive agent), and a program for processing the developed substrate by other known processing programs by using the above-mentioned exposure device To make items. Other well-known procedures include etching, resist stripping, dicing, bonding, packaging, and the like. According to this manufacturing method, articles of higher quality than in the past can be manufactured. [0035] The preferred embodiments of the present invention have been described above, but the present invention is not limited to these embodiments, and various modifications and changes can be made within the scope of the gist thereof. In addition, the description has been made on the premise that the control unit C in the exposure apparatus performs calculation and control, but a control unit outside the exposure apparatus may be used as the control unit. Although an example in which one meniscus lens 15 'is arranged near the convex mirror 15 has been described, a plurality of lenses may be arranged. In this case, a gas is supplied to the space between the plurality of lenses, and the temperature distribution of the lenses is adjusted as described above. In addition, when the required exposure accuracy is low, a meniscus lens may not be arranged. In this case, the gas supply unit adjusts the temperature distribution of the convex mirror by flowing a gas through the surface of the convex mirror. In addition, the reflective projection optical system has been described, but it can also be applied to a refractive projection optical system. In the case of a refractive-type projection optical system, the temperature-adjusted gas is caused to flow through a lens arranged near the pupil surface, so that astigmatism in one direction occurs, and astigmatism in other directions is corrected by other optical elements. The scope of the attached patent application should be given the broadest interpretation to encompass all such modifications and equivalent structures and functions.

[0036]

IL‧‧‧Lighting System

1‧‧‧ Mercury lamp

2‧‧‧ oval mirror

3‧‧‧ the first focusing lens

4‧‧‧ fly eye lens

5‧‧‧Second focusing lens

6‧‧‧ Slit delimiting structure

7‧‧‧ imaging optical system

8‧‧‧ flat mirror

9‧‧‧Mask

13‧‧‧The first plane mirror

14‧‧‧The first concave mirror

15‧‧‧ convex mirror

16‧‧‧Second concave mirror

17‧‧‧Second Plane Mirror

19‧‧‧ substrate

21‧‧‧ cylindrical lens

22‧‧‧ cylindrical lens

23‧‧‧ cylindrical lens

24‧‧‧ cylindrical lens

31‧‧‧Actuator

32‧‧‧Actuator

35‧‧‧Gas Supply Department

36‧‧‧Gas supply path

37‧‧‧Exhaust path

40‧‧‧Focus Sensor

100‧‧‧ lens barrel

102‧‧‧ closed space

103‧‧‧hole

104‧‧‧hole

107‧‧‧ gas flow

108‧‧‧ gas flow

109‧‧‧Gas flow

200‧‧‧ punching plate

201‧‧‧ punching plate

203‧‧‧hole

204‧‧‧hole

103A ～ G‧‧‧Air supply port

104A ～ G‧‧‧ exhaust port

12’‧‧‧ Plano-Concave Lenses

15’‧‧‧ Convex lens

C‧‧‧Control Department

IP‧‧‧Image surface

LS‧‧‧Light source

OP‧‧‧ Surface

PO‧‧‧ Projection Optical System

FIG. 1 is a configuration diagram of an exposure apparatus.

FIG. 2 is a diagram showing the temperature distribution of the meniscus lens 15 'after exposure.

FIG. 3 is a graph showing temperature distributions of terms Nickel coefficients Z5 and Z6.

FIG. 4 is a diagram showing peripheral structures of the convex mirror 15 and the meniscus lens 15 '.

FIG. 5 is a sectional view of the lens barrel 100.

FIG. 6 is a diagram showing a temperature distribution after gas supply.

FIG. 7 is a flowchart showing a method of correcting astigmatism.

FIG. 8 is a diagram showing a lens barrel, an air supply port, and an exhaust port according to the second embodiment.

Claims (14)

An exposure device having a projection optical system for projecting a pattern of a mask onto a substrate, the projection optical system includes: a first optical element that can change a position or a shape in order to adjust the astigmatism of the projection optical system; and a second optical element And arranged near the pupil surface or the pupil surface of the projection optical system, the exposure device includes: a control unit that controls the position or shape of the first optical element; and a supply unit for adjusting the temperature of the second optical element To supply gas to the second optical element, and the supply unit supplies gas to the second optical element such that the astigmatism in the first direction and the first direction are different from the first direction due to the temperature distribution of the second optical element The direction of increase and decrease of the astigmatism in the second direction is opposite to each other, so that the astigmatism in the first direction converges within an allowable range. The control unit controls the position or shape of the first optical element so that the The astigmatism converges within the allowable range. The exposure apparatus according to claim 1, wherein the projection optical system has a holding portion that holds the second optical element, and the supply portion is the same along each other from each of a plurality of air supply ports provided in the holding portion. The direction of gas flows through the surface of the aforementioned second optical element. The exposure apparatus according to claim 2, wherein, in the holding portion, each of the plurality of air supply ports extends in the same direction. The exposure apparatus according to claim 2, wherein in the holding portion, a plurality of exhaust ports are provided on a side opposite to the air supply port with respect to the optical axis of the second optical element, and the plurality of air supply And the aforementioned plurality of exhaust ports extend in the same direction. According to the exposure apparatus of claim 1, wherein the position or shape of the first optical element is controlled by the control unit, the projection magnification of the projection optical system in a direction perpendicular to each other can be adjusted, and the second direction can be performed. Of astigmatism. The exposure apparatus according to claim 1, wherein the exposure apparatus includes a measurement unit that measures the astigmatism in the second direction of the projection optical system, and controls the first measurement unit based on a measurement result obtained by the measurement unit. The position or shape of an optical element, so that the astigmatism in the second direction converges within an allowable range. The exposure device according to claim 1, wherein the control unit calculates the first optical element required to converge the astigmatism in the second direction within an allowable range based on an exposure history of the substrate by the projection optical system. The driving amount of the first optical element is controlled based on the calculated driving amount. The exposure apparatus according to claim 1, wherein the second direction is a direction that is 45 degrees different from the first direction. The exposure apparatus according to claim 1, wherein the projection optical system includes a concave mirror, a convex mirror, and a lens, and the lens is disposed between the concave mirror and the convex mirror, and is held to form a space between the convex mirror and the second optical element. It is a convex mirror or lens. The exposure device according to claim 9, wherein the supply unit supplies gas to a space between the convex mirror and the lens. An exposure device having a projection optical system for projecting a pattern of a mask onto a substrate, the projection optical system includes: a first optical element that can change a position or a shape in order to adjust the astigmatism of the projection optical system; and a second optical element And arranged near the pupil surface or the pupil surface of the projection optical system, the exposure device includes: a control unit that controls the position or shape of the first optical element; and a supply unit for adjusting the temperature of the second optical element Distribution to supply gas to the second optical element, and the supply unit supplies gas to the second optical element so that the astigmatism in the first direction due to the temperature distribution of the second optical element is converged within an allowable range, so that The astigmatism in the second direction crossing the first direction becomes larger, and the control unit controls the position or shape of the first optical element so that the astigmatism in the second direction converges within an allowable range. An exposure device includes a projection optical system for projecting a pattern of a mask onto a substrate. The projection optical system includes: a first optical element that can be driven to adjust the astigmatism of the projection optical system; and a second optical element that performs exposure during exposure. The exposure device includes a driving unit that drives the first optical element, and a supply unit that supplies gas to the second optical element in order to adjust the temperature distribution of the second optical element. The supply unit Supplying gas to the second optical element such that the astigmatism in the first direction and the astigmatism in the second direction different from the first direction increase and decrease due to the temperature distribution of the second optical element. The astigmatism in the first direction is converged within an allowable range, and the driving unit drives the first optical element so that the astigmatism in the second direction is converged within an allowable range. An exposure device includes a projection optical system that projects a pattern of a mask onto a substrate. The projection optical system includes: a first optical element that can be driven to adjust the astigmatism of the projection optical system; and a second optical element that exposes The exposure device includes a driving unit that drives the first optical element, and a supply unit that supplies gas to the second optical element in order to adjust the temperature distribution of the second optical element. The supply unit A gas is supplied to the second optical element so that the astigmatism in the first direction due to the temperature distribution of the second optical element is within an allowable range, and the astigmatism in the second direction that intersects the first direction is changed. The driving unit drives the first optical element so that the astigmatism in the second direction converges within an allowable range. A manufacturing method for manufacturing an article, comprising the steps of: exposing a substrate using an exposure apparatus according to any one of claims 1 to 13; developing the substrate after exposure; and manufacturing the aforementioned article by processing the substrate after development. .