Exposure apparatus and method of manufacturing an article

Abstract

The present disclosure relates to an exposure apparatus and a method of manufacturing an article. The exposure apparatus exposes a substrate while moving a reticle and the substrate in a scanning direction, and has an illumination optical system that illuminates an illuminated surface of the reticle with light from a light source. The illumination optical system includes a first light-blocking portion disposed at a position that departs from a conjugate surface of the illuminated surface toward the light source side, a second light-blocking portion disposed at a position that departs from the conjugate surface toward the illuminated surface side, and a shield portion disposed between the first light-blocking portion and the second light-blocking portion, which defines an illumination range of the illuminated surface. A sum of a first distance between the conjugate surface and the first light-blocking portion in a direction of an optical axis of the illumination optical system and a second distance between the conjugate surface and the second light-blocking portion in the direction of the optical axis is 5 mm or more and 20 mm or less, and the first light-blocking portion and the second light-blocking portion are disposed so that the first distance and the second distance are different.

Description

[0001] This divisional application is a divisional application of Chinese patent application No. 202080060934.8, filed on July 21, 2020, entitled "Exposure apparatus and method of manufacturing article". Technical Field

[0002] This invention relates to an exposure apparatus and a method for manufacturing an article. Background Technology

[0003] Conventional exposure apparatuses utilize an illumination optics system to illuminate a master image (intermediate mask or mask) and project the pattern of the master image onto a substrate (wafer) via a projection optics system. In these exposure apparatuses, the miniaturization of semiconductor devices necessitates high resolution. To achieve high resolution, shortening the wavelength of the exposure light, increasing the numerical aperture (NA) of the projection optics system (high NA), and employing distorted illumination (ring illumination, bipolar illumination, quadrupole illumination, etc.) are effective methods.

[0004] On the other hand, with the increasing multi-layering of equipment structures in recent years, there is a growing demand for improved overlap accuracy in exposure apparatuses. Patent Document 1 discloses an exposure apparatus having a light-shielding portion positioned after defocusing from the conjugate surface of the illuminated surface towards the light source, and another light-shielding portion positioned after defocusing from the conjugate surface of the illuminated surface towards the illuminated surface. The exposure apparatus disclosed in Patent Document 1 is effective in improving overlap accuracy.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2010-73835 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] However, in the exposure apparatus disclosed in Patent Document 1, a decrease in illuminance occurs due to the light-shielding portion, and an asymmetry (XY asymmetry) in the cumulative effective light source occurs. When a large asymmetry occurs in the cumulative effective light source, for example, when transferring line and space patterns with the same line width in both the longitudinal and transverse directions to the substrate, a line width difference arises between the longitudinal and transverse patterns.

[0010] The present invention provides an exposure device that is advantageous in suppressing the reduction of illuminance in the illuminated surface and the occurrence of asymmetry in the cumulative effective light source.

[0011] Solution to the problem

[0012] To achieve the above objective, an exposure apparatus, as one aspect of the present invention, exposes the substrate while moving the original and the substrate in a scanning direction. It is characterized by having an illumination optical system that illuminates the illuminated surface of the original using light from a light source. The illumination optical system includes: a first light-shielding portion disposed at a position away from the light source from the conjugate surface of the illuminated surface; a second light-shielding portion disposed at a position away from the conjugate surface from the illuminated surface; and a shielding portion disposed between the first and second light-shielding portions, defining the illumination range of the illuminated surface. The sum of a first distance between the conjugate surface and the first light-shielding portion along the optical axis of the illumination optical system and a second distance between the conjugate surface and the second light-shielding portion along the optical axis is 5 mm or more and 20 mm or less. The first and second light-shielding portions are configured such that the first and second distances are different.

[0013] The effects of the invention

[0014] According to the present invention, for example, an exposure apparatus can be provided that is advantageous in suppressing the reduction of illuminance in the illuminated surface and the occurrence of asymmetry in the cumulative effective light source.

[0015] Other features and advantages of the invention will become clear from the following description with reference to the accompanying drawings. Furthermore, in the drawings, the same or identical structures are given the same reference numerals. Attached Figure Description

[0016] The accompanying drawings are included in and form a part of the specification, illustrating embodiments of the invention, and together with the description thereof serve to explain the principles of the invention.

[0017] Figure 1 This is a schematic cross-sectional view showing the structure of the exposure apparatus as one aspect of the present invention.

[0018] Figure 2 This is a diagram used to illustrate the details of the first light-shielding part, the shielding unit, and the second light-shielding part.

[0019] Figure 3 This is a diagram used to illustrate the cumulative effective light source.

[0020] Figure 4 This diagram illustrates the functions of the first and second light-shielding parts.

[0021] Figure 5 This is a diagram used to illustrate the structure for reducing the XY asymmetry of the cumulative effective light source.

[0022] Figure 6 This is a diagram used to illustrate specific numerical examples related to the first and second light-shielding parts.

[0023] Figure 7 This is a diagram used to illustrate specific numerical examples related to the first and second light-shielding parts. Detailed Implementation

[0024] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Furthermore, the following embodiments do not limit the invention as defined in the claims. Several features are described in the embodiments, but not all of these features are necessarily essential to the invention; moreover, the features can be arbitrarily combined. Moreover, in the drawings, the same or identical structures are given the same reference numerals, and repeated descriptions are omitted.

[0025] Figure 1 This is a schematic cross-sectional view showing the structure of the exposure apparatus 100 as one aspect of the present invention. The exposure apparatus 100 is a step-scan exposure apparatus (scanner) that transfers the pattern of the original 25 onto the substrate by exposing the substrate 27 while moving the original 25 and the substrate 27 in the scanning direction (scanning exposure). The exposure apparatus 100 includes: an illumination optical system 110 that illuminates the original 25 (intermediate mask or mask) using light from the light source 1; and a projection optical system 26 that projects the pattern of the original 25 onto the substrate 27 (wafer, glass plate, etc.).

[0026] Light source 1 includes a mercury lamp with a wavelength of approximately 365 nm, a KrF excimer laser with a wavelength of approximately 248 nm, an ArF excimer laser with a wavelength of approximately 193 nm, and other excimer lasers, which emit a beam of light (exposure light) to illuminate the original 25.

[0027] The illumination optical system 110 includes a routing optical system 2, an emission angle preservation optical element 5, a diffraction optical element 6, a condenser lens 7, a light-shielding component 8, a prism unit 10, and a zoom lens unit 11. Additionally, the illumination optical system 110 includes an optical integrator 12, an aperture 13, a condenser lens 14, a first light-shielding part 18, a second light-shielding part 20, a shielding unit 19, a condenser lens 21, and a collimator lens 23.

[0028] The routing optical system 2 is positioned between the light source 1 and the emission angle preservation optical element 5, guiding the light beam from the light source 1 to the emission angle preservation optical element 5. The emission angle preservation optical element 5 is positioned on the light source side of the diffractive optical element 6, guiding the light beam from the light source 1 to the diffractive optical element 6 while maintaining its divergence angle constant. The emission angle preservation optical element 5 includes optical integrators such as compound eye lenses, microlens arrays, and fiber bundles. The emission angle preservation optical element 5 reduces the impact of output variations from the light source 1 on the light intensity distribution (pattern distribution) formed by the diffractive optical element 6.

[0029] The diffractive optical element 6 is disposed on a surface that is in a Fourier transform relationship with the pupil surface of the illumination optical system 110. The diffractive optical element 6, on a surface conjugate to the pupil surface of the projection optical system 26 (i.e., the pupil surface of the illumination optical system 110 and the surface conjugate to the pupil surface of the illumination optical system 110), transforms the light intensity distribution of the light beam from the light source 1 through diffraction, forming a desired light intensity distribution. The diffractive optical element 6 can also be constructed from a computer-generated hologram (CGH) designed by a computer to obtain a desired diffraction pattern on the diffraction pattern surface. In this embodiment, the shape of the light source formed on the pupil surface of the projection optical system 26 is referred to as the effective light source shape. Furthermore, "effective light source" refers to the light angle distribution in the illuminated surface and the conjugate surface of the illuminated surface. The diffractive optical element 6 is disposed between the emission angle preservation optical element 5 and the condenser lens 7.

[0030] In the illumination optical system 110, multiple diffractive optical elements 6 may also be provided. For example, each of the multiple diffractive optical elements 6 may be mounted (mounted) in one of the multiple slots corresponding to the turntable (not shown). The multiple diffractive optical elements 6 each form a different effective light source shape. These effective light source shapes include small circular shapes, large circular shapes, annular shapes, bipolar shapes, quadrupole shapes, and other shapes. The method of illuminating the illuminated surface with an effective light source shape of annular shape, bipolar shape, or quadrupole shape is called deformable illumination.

[0031] The light beam from the emission angle preservation optical element 5 is diffracted by the diffractive optical element 6 and guided to the condenser lens 7. The condenser lens 7 is disposed between the diffractive optical element 6 and the prism unit 10, so that the light beam diffracted by the diffractive optical element 6 is focused to form a diffraction pattern (light intensity distribution) on the Fourier transform surface 9.

[0032] The Fourier transform surface 9 is located between the optical integrator 12 and the diffractive optical element 6, and is optically related to the diffractive optical element 6 in a Fourier transform relationship. By replacing the diffractive optical element 6 arranged in the optical path of the illumination optical system 110, the shape of the diffraction pattern formed on the Fourier transform surface 9 can be changed.

[0033] The light-shielding member 8 is configured to move in a direction perpendicular to the optical axis 1b of the illumination optical system 110 and is positioned upstream of the Fourier transform surface 9 (light source side). The light-shielding member 8 is positioned slightly away from the Fourier transform surface 9 (defocused).

[0034] The prism unit 10 and the zoom lens unit 11 are disposed between the Fourier transform surface 9 and the optical integrator 12, functioning as a zoom optical system to amplify the light intensity distribution formed on the Fourier transform surface 9. The prism unit 10 adjusts the annularity and other parameters of the light intensity distribution formed on the Fourier transform surface 9 and guides it to the zoom lens unit 11. The zoom lens unit 11 is disposed between the prism unit 10 and the optical integrator 12. The zoom lens unit 11, for example, includes multiple zoom lenses, adjusts the light intensity distribution formed on the Fourier transform surface 9 by a value σ based on the ratio of the NA of the illumination optical system 110 to the NA of the projection optical system 26, and guides it to the optical integrator 12.

[0035] An optical integrator 12 is disposed between the zoom lens unit 11 and the condenser lens 14. The optical integrator 12 includes a fly-eye lens that forms a large number of secondary light sources and guides them to the condenser lens 14 based on the light intensity distribution after adjusting the ring ratio, aperture angle, and σ value. However, the optical integrator 12 may also include other optical elements such as a light pipe, diffractive optical elements, or a microlens array instead of the fly-eye lens. The optical integrator 12 uses the light beam after passing through the diffractive optical element 6 to uniformly illuminate the original plate 25 disposed on the illuminated surface 24. An aperture 13 is disposed between the optical integrator 12 and the condenser lens 14.

[0036] A condenser lens 14 is disposed between the optical integrator 12 and the original plate 25. This allows a large beam of light guided from the optical integrator 12 to be focused and illuminate the original plate 25 in an overlapping manner. When light is incident on the optical integrator 12 and focused by the condenser lens 14, the conjugate surface 19, which serves as the focal plane of the condenser lens 14, is illuminated in a generally rectangular shape.

[0037] A semi-reflective mirror 15 is disposed at the rear end of the condenser lens 14. A portion of the exposure light reflected by the semi-reflective mirror 15 is incident on the light intensity measuring optical system 16. A light intensity measuring sensor 17 is disposed at the rear end of the light intensity measuring optical system 16. The exposure amount during exposure is appropriately controlled based on the light intensity measured by the sensor 17.

[0038] Between the first light-shielding part 18 and the second light-shielding part 20, specifically near the conjugate surface 19a (conjugate surface 19a) of the illuminated surface 24, a shielding unit (shielding part) 19 including an X-blade and a Y-blade is arranged to provide illumination with a generally rectangular light intensity distribution. Furthermore, "near the conjugate surface 19a" refers to the distance from the conjugate surface 19a required to prevent interference between the X-blade and Y-blade of the shielding unit 19, for example, approximately 0.2 mm away from the conjugate surface 19a in the optical axis direction. The shielding unit 19 is arranged to define the illumination range of the original plate 25 (illuminated surface 24) and is scanned synchronously with the original plate stage 29 and the substrate stage 28. The original plate stage 29 is a stage that moves while holding the original plate 25, and the substrate stage 28 is a stage that moves while holding the substrate 27.

[0039] Two light-shielding portions are provided at a position away from (defocused) the shielding unit 19 (the conjugate surface 19a of the illuminated surface 24). In this embodiment, these are a first light-shielding portion 18 and a second light-shielding portion 20. The first light-shielding portion 18 is positioned away from the conjugate surface 19a of the illuminated surface 24 toward the light source side. The second light-shielding portion 20 is positioned away from the conjugate surface 19a of the illuminated surface 24 toward the illuminated surface side.

[0040] The light reflected by the mirror 22, which has a predetermined tilt relative to the beam from the condenser lens 21, illuminates the original 25 via the collimator lens 23.

[0041] The projection optics system 26 projects the pattern of the original 25 onto the substrate 27. The resolution of the pattern of the original 25 depends on the shape of the effective light source. Therefore, by forming an appropriate distribution of the effective light source in the illumination optics system 110, the resolution of the pattern of the original 25 can be improved.

[0042] Reference Figure 2 Details of the first light-shielding part 18, the shielding unit 19, and the second light-shielding part 20 are explained. Figure 2 In the diagram, the y-direction represents the scanning direction. The masking unit 19 includes scanning masking blades 19d and 19e that move during scanning exposure.

[0043] First light-shielding section 18 Figure 2The diagram shows a first light-shielding member 18a and a second light-shielding member 18b. The second light-shielding member side end 18aA of the first light-shielding member 18a and the first light-shielding member side end 18bA of the second light-shielding member 18b are located within the effective light-emitting area. By blocking a portion of the light, the intensity of the light reaching the illuminated surface 24 is adjusted. For example, the first light-shielding member 18a is connected to an actuator (not shown). By using the actuator to move the first light-shielding member 18a along the scanning direction (y-direction), the opening width defined by the end 18aA of the first light-shielding member 18a and the end 18bA of the second light-shielding member 18b can be changed. Thus, the first light-shielding portion 18 constitutes a variable slit. Furthermore, in this embodiment, a first moving part FMU is provided for the first light-shielding portion 18, which moves the first light-shielding member 18a and the second light-shielding member 18b in the direction along the optical axis 1b of the illumination optical system 110.

[0044] Second light-shielding section 20 Figure 2 The diagram shows a third light-shielding member 20a and a fourth light-shielding member 20b. The ends 20aA of the third light-shielding member 20a on the fourth light-shielding member side and the end 20bA of the fourth light-shielding member 20b on the third light-shielding member side are located within the effective light-emitting area. By blocking a portion of the light, the intensity of the light reaching the illuminated surface 24 is adjusted. The third light-shielding member 20a is connected to an actuator (not shown). By moving the third light-shielding member 20a along the scanning direction (y-direction) using the actuator, the opening width defined by the ends 20aA of the third light-shielding member 20a and the end 20bA of the fourth light-shielding member 20b can be changed. Thus, the second light-shielding section 20 constitutes a variable slit. Furthermore, in this embodiment, a second moving part SMU is provided for the second light-shielding section 20, which moves the third light-shielding member 20a and the fourth light-shielding member 20b in the direction along the optical axis 1b of the illumination optical system 110.

[0045] like Figure 2 As shown, in a plane including the optical axis 1b and parallel to the scanning direction, a first distance d1 is defined between the conjugate surface 19a along the optical axis 1b and the end portion 18aA of the first light-shielding member 18a. Furthermore, in a plane including the optical axis 1b and parallel to the scanning direction, a second distance d2 is defined between the conjugate surface 19a along the optical axis 1b and the end portion 20aA of the third light-shielding member 20a. In this case, the first distance d1 and the second distance d2 are different values. Additionally, the distance between the conjugate surface 19a and the end portion 18bA of the second light-shielding member 18b is equal to the first distance d1, and the distance between the conjugate surface 19a and the end portion 20bA of the fourth light-shielding member 20b is equal to the second distance d2. Thus, the first light-shielding portion 18 and the second light-shielding portion 20 are configured such that the first distance d1 and the second distance d2 are different.

[0046] In addition, such as Figure 2 As shown, in a plane including the optical axis 1b and parallel to the scanning direction, the midpoint between the end points 18aA of the first light-shielding member 18a and 18bA of the second light-shielding member 18b is defined as 18c. Similarly, the midpoint between the end points 20aA of the third light-shielding member 20a and 20bA of the fourth light-shielding member 20b is defined as 20c. The distance from the midpoint 18c to the end points 18aA of the first light-shielding member 18a and 18bA of the second light-shielding member 18b is defined as S1, and the distance from the midpoint 20c to the end points 20aA of the third light-shielding member 20a and 20bA of the fourth light-shielding member 20b is defined as S2. In this case, distances S1 and S2 are different values. Furthermore, the straight line connecting the midpoints 18c and 20c is parallel to the optical axis 1b.

[0047] Reference Figure 3 a and Figure 3 b indicates the cumulative effective light source. In Figure 3 a and Figure 3 In b, the y-direction represents the scanning direction. Figure 3 a shows the illuminated area 24e of the illuminated surface 24. Figure 3 b shows the illumination area 19b of the conjugate surface 19a (masking unit 19) that is conjugate to the illuminated surface 24.

[0048] During exposure, the illumination area 24e is scanned. The incident angle distribution illuminating a point on the exposure surface is obtained by accumulating the incident angle distribution of illumination on points along the line 24f parallel to the scanning direction (y-direction) within the illumination area 24e; this is called the accumulated effective light source. The line 19c is the set of points in the conjugate surface 19a that are conjugate to points along the line 24e. Therefore, the accumulated effective light source is equivalent to the result of accumulating the incident angle distribution of illumination on the illuminated surface 24 using beams passing through points along the line 19c.

[0049] Reference Figure 4 a, Figure 4 b and Figure 4 c explains the functions of the first light-shielding part 18 and the second light-shielding part 20. Figure 4 a, Figure 4 b and Figure 4 In c, the y-direction represents the scanning direction. Figure 4 a is an enlarged view of the vicinity of the optical integrator 12, the condenser lens 14, the first light-shielding part 18, and the second light-shielding part 20. Figure 4 In diagram a, light rays emitted from optical integrator 12 and passing through condenser lens 14 and conjugate surface 19a at points A, B, and C are shown. Here, points A, B, and C are... Figure 3The point on line 19 shown in b. Figure 4 Figure b is a diagram showing the effective light sources 24a, 24b, and 24c at points A', B', and C' of the illuminated surface 24. Each of points A', B', and C' is conjugate to points A, B, and C of the conjugate surface 19a of the illuminated surface 24. Figure 4 c is a diagram showing the cumulative effective light source 24d obtained by accumulating all light rays passing through the straight lines including points A', B', and C' of the illuminated surface 24.

[0050] Furthermore, in this embodiment, to facilitate understanding of the invention, an example is given of an effective light source that is circular in shape, commonly referred to as conventional lighting. However, through the combination of the prism unit 10 and the diffractive optical element 6, it can become a ring, multipole, or other shapes. The present invention is not limited to the shape of the effective light source formed by the diffractive optical element 6, prism unit 10, etc.

[0051] Reference Figure 4 a. The light ray 12a emitted parallel to the optical axis 1b from the optical integrator 12 and directed towards point A on the conjugate surface 19a via the condenser lens 14 will not be blocked by the first light-shielding part 18 and the second light-shielding part 20. Therefore, the effective light source 24a at point A' of the illuminated surface 24 is as follows: Figure 4 As shown in b, it is roughly circular and approximately symmetrical in the scanning direction.

[0052] On the other hand, regarding the light ray 12b that is emitted obliquely from the optical integrator 12 on the side closer to the first light-shielding member than the optical axis 1b and passes through the condenser lens 14 toward point B of the conjugate surface 19a, a portion of it is blocked by the first light-shielding member 18a and the third light-shielding member 20a. Therefore, the effective light source 24b at point B' of the illuminated surface 24 becomes a shape with both ends missing in the scanning direction relative to the circle, and has an asymmetry (XY asymmetry) between the distribution in the x-direction (the direction orthogonal to the y-direction) and the distribution in the y-direction.

[0053] Furthermore, regarding the light ray 12c that is emitted obliquely from the optical integrator 12 on the side closer to the second light-shielding member than the optical axis 1b and passes through the condenser lens 14 toward point C of the conjugate surface 19a, a portion of it is blocked by the second light-shielding member 18b and the fourth light-shielding member 20b. Therefore, the effective light source 24c at point C' of the illuminated surface 24 becomes a shape missing at both ends of the scanning direction relative to the circle, exhibiting an asymmetry (XY asymmetry) between the distribution in the x-direction (the direction orthogonal to the y-direction) and the distribution in the y-direction.

[0054] Thus, when considering the cumulative effective light source 24d obtained by accumulating all light beams passing through the straight line including points A, B, and C, the cumulative effective light source 24d is as follows: Figure 4 As shown in c, it exhibits XY asymmetry.

[0055] Reference Figure 5 a and Figure 5 b describes the structure used to reduce the XY asymmetry of the cumulative effective light source 24d. Figure 5 Figure a shows the illumination distribution 24ee (illumination area 24e) of the illuminated surface 24 formed by a beam of light illuminating the conjugate surface 19a at a maximum angle θ0. The distribution of the conjugate surface 19a is imaged on the illuminated surface 24 at an imaging magnification β by the condenser lens 21 and the collimator lens 23.

[0056] The maximum incident angle of the light beam illuminating the conjugate surface 19a is set as θ0. The first distance S1 and the second distance S2 are determined such that the light ray passing through the end 18aA of the first light-shielding member 18a at angle θ0 and the light ray passing through the end 20aA of the third light-shielding member 20a at angle -θ0 intersect at point 19aa on the conjugate surface 19a. Furthermore, as described above, the first distance S1 is the distance from the midpoint 18c to the end 18aA of the first light-shielding member 18a, and the second distance S2 is the distance from the midpoint 20c to the end 20aA of the third light-shielding member 20a. The point where the straight line connecting the end 18aA of the first light-shielding member 18a and the end 20aA of the third light-shielding member 20a intersects the conjugate surface 19a is set as 19bb, and the distance between point 19bb and point 19cc is set as S. The points on the illuminated surface 24 corresponding to each of the points 19aa, 19bb, and 19cc on the conjugate surface 19a are designated as 24g, 24h, and 24i.

[0057] In the illuminated surface 24, the light illuminating the area further inside the contrast point 24g is not blocked by the first light-shielding member 18a and the third light-shielding member 20a, so its intensity is constant. Conversely, in the illuminated surface 24, the light illuminating the area further outside the contrast point 24h is blocked by the first light-shielding member 18a and the third light-shielding member 20a, so its intensity is zero. The other end of the illumination distribution 24ee is blocked by the second light-shielding member 18b and the fourth light-shielding member 20b, forming the same shape. Therefore, the illumination distribution 24ee has a shape close to a trapezoid. Let the lower base and upper base of the trapezoid be w0 and w100, respectively.

[0058] The effective light source for illuminating the points between the point 24i and the point 24g on the illuminated surface 24 is substantially circular, just like the effective light source at the above-mentioned point A'. The effective light source for illuminating the points between the point 24g and the point 24h on the illuminated surface 24 has a large XY asymmetry, just like the effective light source at the above-mentioned point B'. In addition, at the points between the point 24g and the point 24h on the illuminated surface 24, since they are blocked by both the first light shielding portion 18 and the second light shielding portion 20, the illuminance decreases. Therefore, by increasing the ratio of w100 to w0 and decreasing the distance between the point 24g and the point 24h, the decrease in illuminance and the occurrence of the XY asymmetry of the cumulative effective light source 24d can be suppressed.

[0059] The lower base w0 of the illumination distribution 24ee is expressed as w0 = 2βS. On the other hand, the upper base w100 of the illumination distribution 24ee is expressed as w100 = 2β(S1 - d1×tanθ0) = 2β(S2 - d2×tanθ0). Therefore, the ratio w100 / w0 of the upper base w100 to the lower base w0 is expressed as w100 / w0 = (S1 - d1×tanθ0) / S = (S2 - d2×tanθ0) / S.

[0060] The points 19aa and 19bb on the conjugate surface 19a are represented by the points where the straight line passing through the end portion 18aA of the first light shielding member 18a intersects the conjugate surface 19a. Therefore, in the case of d1 < d2, regarding w100 / w0, the smaller d1 is, the closer it is to 1, and it becomes 1 when d1 = 0. In addition, in the case of d1 > d2, regarding w100 / w0, the smaller d2 is, the closer it is to 1, and it becomes 1 when d2 = 0.

[0061] As described above, between the first light shielding portion 18 and the second light shielding portion 20, the scanning shielding blades 19d and 19e are arranged. Since the scanning shielding blades 19d and 19e move during the scanning exposure, a certain amount of space is required. Therefore, the distance between the first light shielding portion 18 and the second light shielding portion 20 in the direction along the optical axis 1b cannot be less than a predetermined value D. Using the first distance d1 between the first light shielding portion 18 and the conjugate surface 19a and the second distance d2 between the second light shielding portion 20 and the conjugate surface 19a, the predetermined value D is expressed as D = d1 + d2. Generally, the predetermined value D is 5 mm or more and 20 mm or less.

[0062] Figure 5 b is a diagram showing the illumination distribution 24ee for illuminating the illuminated surface 24 formed by the light beam illuminating the conjugate surface 19a at the maximum angle θ0 in the case where the first distance d1 and the second distance d2 are equal. Due to the condition D = d1 + d2, compared with Figure 5 the first distance d1 shown in a, Figure 5The first distance d1 shown in b is larger. Therefore, w100 / w0 is as follows: Figure 5 It becomes smaller as shown in b.

[0063] The following are specific numerical examples related to the first light-shielding part 18 and the second light-shielding part 20. Let D = 8 [mm], S = 5 [mm], and θ0 = 0.4 [rad]. Figure 6 This illustrates the relationship between w100 / w0 and d1 / d2. Figure 6 In the diagram, the vertical axis represents w100 / w0, and the horizontal axis represents d1 / d2. For example... Figure 6 As shown, the relationship between w100 / w0 and d1 / d2 is expressed by a quadratic expression, which becomes the minimum when d1 = d2.

[0064] When the cumulative effective light source has XY asymmetry over 24 days, the illuminance decreases due to the correction of this XY asymmetry. To reduce this illuminance decrease, if it is necessary to reduce the XY asymmetry to below 15%, it is preferable to make w100 / w0 0.7 or higher. (Refer to...) Figure 6 It can be seen that in order for w100 / w0 to be greater than 0.7, d2 / d1 needs to be greater than 2 or d2 / d1 needs to be less than 1 / 2.

[0065] Next, refer to Figure 7 Explain the conditions for the maximum and minimum values ​​of d2 / d1. This corresponds to the inclined portion of the lighting distribution 24ee. Figure 4 Points C' and B' shown in b have a shift in the center of gravity of the light rays in the scanning direction (a shift in the center of gravity of the light rays). This shift in the center of gravity affects the overlap accuracy, so it is not preferred. However, the shift in the center of gravity of the light rays can be controlled by using the ratio of d1 to d2.

[0066] Figure 7 This diagram illustrates the light center shift in this embodiment, assuming conventional lighting and a structure where a light-shielding portion is placed only upstream of the conjugate surface of the illuminated surface. Figure 7 In the diagram, the vertical axis represents the shift of the ray's center of gravity, and the horizontal axis represents d1 / d2. (See reference...) Figure 7 The shift in the center of gravity of the light rays reaches its minimum, specifically zero, when d1 / d2 = 1. This means that no shift in the center of gravity of the light rays is caused. To improve overlap accuracy, the shift in the center of gravity of the light rays is preferably less than half that of conventional structures where a light-shielding portion is located only upstream of the conjugate surface of the illuminated surface. (Refer to...) Figure 7 It can be seen that in order to shift the center of gravity of the light rays to less than half the size of the previous structure, 1 / 4 is required. <d2 / d1<4。

[0067] Therefore, the condition that the first distance d1 from the conjugate surface 19a to the first light shielding portion 18 and the second distance d2 from the conjugate surface 19a to the second light shielding portion 20 should satisfy is d1≠d2, and more preferably 1 / 4 < d2 / d1 < 1 / 2 or 2 < d2 / d1 < 4. In this way, it is preferable that the distance of one of the first distance d1 and the second distance d2 is greater than twice and less than four times the distance of the other.

[0068] In addition, in the present embodiment, as described above, an actuator for moving the first light shielding member 18a in the scanning direction and a first moving unit FMU for moving the first light shielding portion 18 (the first light shielding member 18a and the second light shielding member 18b) in the direction along the optical axis 1b are provided. Similarly, an actuator for moving the third light shielding member 20a in the scanning direction and a second moving unit SMU for moving the second light shielding portion 20 (the third light shielding member 20a and the fourth light shielding member 20b) in the direction along the optical axis 1b are provided. By having such a drive mechanism, it is possible to set the optimal d1, d1, S1, and S2 according to the illumination mode, and it is possible to further reduce (suppress) the shift of the light center of gravity, the reduction of illuminance, and the XY asymmetry in the effective light source.

[0069] The method for manufacturing an article in the embodiment of the present invention is applicable to manufacturing articles such as flat panel displays, liquid crystal display elements, semiconductor elements, and MEMS. The above manufacturing method includes: a step of exposing a substrate coated with a photosensitive agent using the above exposure apparatus 100; and a step of developing the exposed photosensitive agent. In addition, using the pattern of the developed photosensitive agent as a mask, an etching step, an ion implantation step, etc. are performed on the substrate to form a circuit pattern on the substrate. These exposure, development, etching, etc. steps are repeated to form a circuit pattern composed of multiple layers on the substrate. In the post-process, the substrate on which the circuit pattern is formed is cut (processed), and chip mounting, bonding, and inspection steps are performed. In addition, the above manufacturing method may include other known steps (oxidation, film formation, evaporation, doping, planarization, resist stripping, etc.). The method for manufacturing an article in the present embodiment is more advantageous in at least one aspect of the performance, quality, productivity, and production cost of the article compared with the prior art.

[0070] The invention is not limited to the above embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, claims are appended to disclose the scope of the invention.

[0071] This application claims priority based on Japanese Patent Application No. 2019-160666 filed on September 3, 2019, and the entire content thereof is incorporated herein by reference.

Claims

1. An exposure apparatus for exposing a substrate while moving a master and a substrate in a scanning direction, characterized in that, An illumination optical system that uses light from a light source to illuminate the illuminated surface of the original plate. The illumination optical system includes: The first light-shielding part is disposed at a position away from the light source side from the conjugate surface of the illuminated surface; The second light-shielding portion is positioned away from the conjugate surface on the illuminated surface side; and A shielding portion, disposed between the first light-shielding portion and the second light-shielding portion, defines the illumination range of the illuminated surface. In the first distance between the conjugate surface and the first light-shielding part along the direction of the optical axis of the illumination optical system and the second distance between the conjugate surface and the second light-shielding part along the direction of the optical axis, the distance of one is greater than twice and less than four times the distance of the other.

2. The exposure apparatus according to claim 1, characterized in that, The sum of the first distance and the second distance is greater than 5 mm and less than 20 mm.

3. The exposure apparatus according to claim 1, characterized in that, It also has: The first moving part moves the first light-shielding part in a direction along the optical axis; and The second moving part moves the second light-shielding part in a direction along the optical axis.

4. The exposure apparatus according to claim 3, characterized in that, It also includes a modification unit that modifies the angular distribution of light formed by the illumination optical system on the illuminated surface. The first light-shielding part and the second light-shielding part move together.

5. The exposure apparatus according to claim 1, characterized in that, The shielding portion is disposed on or near the conjugate surface.

6. The exposure apparatus according to claim 1, characterized in that, Each of the first and second light-shielding portions includes a variable slit.

7. A method for manufacturing an article, characterized in that, have: The process of exposing a substrate using the exposure apparatus described in claim 1; The process of developing the exposed substrate; and The process of manufacturing articles from the developed substrate.

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