METHOD FOR MANUFACTURING TRANSMISSION OPTICAL ELEMENT, EXPOSURE APPARATUS, METHOD FOR MANUFACTURING ARTICLE, AND TRANSMISSION OPTICAL ELEMENT

Abstract

To provide a technique related to a transmissive optical element, which has an advantage in equalizing illuminance distribution on an illuminated surface.SOLUTION: A manufacturing method of a light transmissive optical element includes: a first step of forming an optical thin film on a surface of the optical element; and a second step of removing the optical thin film formed in the first step in its thickness direction. In the second step, the optical thin film is removed in its thickness direction in such a manner that at least a part of the optical thin film remains even in a region in which the optical thin film is to be removed.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] In a lithography process for manufacturing an article such as a semiconductor device, an exposure apparatus is used that has an illumination optical system that illuminates an original and a projection optical system that projects the pattern of the original illuminated by the illumination optical system onto a substrate. The pattern of the original is projected onto the substrate, and the pattern is transferred to a resist (photosensitive agent) arranged (coated) on the surface of the substrate. In an exposure apparatus, if the illumination of the original is non-uniform, the pattern may not be transferred well to the resist on the substrate. Therefore, in order to illuminate the original with uniform illuminance, a rod-type optical integrator or an optical integrator including multiple wavefront division elements arranged two-dimensionally is used in the illumination optical system.

[0003] On the other hand, in an illumination optical system, non-uniformity in the illuminance distribution on the illuminated surface may be observed due to dirt or decentering of the optical system, unevenness in the anti-reflection coating, etc. Therefore, a technology has been disclosed in which a filter with a dot pattern (light shielding object) on a quartz substrate is placed at a position that is optically conjugate with the illuminated surface, and the dot density (transmittance distribution) is changed to uniform the illuminance distribution on the illuminated surface (see Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2006-210554 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, with the technology disclosed in Patent Document 1, it is difficult to uniformize the illuminance distribution on the illuminated surface with sufficient precision. For example, when it is necessary to slightly change the transmittance using a filter, the number of dots is reduced, so that the error in the transmittance due to the error in the dot size becomes large, and the illuminance distribution on the illuminated surface cannot be corrected with high precision.

[0006] The present invention has been made in consideration of the problems with the conventional techniques, and has an exemplary object to provide a technique relating to a transmissive optical element that is advantageous in making the illuminance distribution on the illuminated surface uniform. [Means for solving the problem]

[0007] In order to achieve the above object, a manufacturing method according to one aspect of the present invention includes the steps of: It is incorporated into an illumination optical system that illuminates an illuminated surface. A method for manufacturing a light-transmitting optical element, comprising the steps of: forming an optical thin film on a surface of the optical element by superposing a plurality of thin films having different refractive indices on each other; Work With a step of acquiring an illuminance distribution formed on the illuminated surface, a step of designing a light transmittance distribution of the optical thin film based on the acquired illuminance distribution, and a step of determining a portion of the surface of the optical element where the optical thin film should be removed and an amount of the optical thin film to be removed in the portion, according to the light transmittance distribution; The above On the surface of the optical element The formed optical thin film Against , The amount of removal is such that a part of the optical thin film remains in the portion to be removed. The optical thin film is removed in the thickness direction. Work The process and Yes It is characterized by the above.

[0008] Further objects or other aspects of the present invention will become apparent from the following description of the embodiments with reference to the accompanying drawings. Effect of the Invention

[0009] According to the present invention, for example, it is possible to provide a technique relating to a transmissive optical element that is advantageous in making the illuminance distribution on the illuminated surface uniform. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic diagram showing a configuration of an exposure apparatus according to one aspect of the present invention. [Diagram 2] FIG. 1 is a schematic diagram showing a configuration of a light-transmitting optical element. [Diagram 3] 1 is a flowchart illustrating a method for manufacturing an optical element according to one aspect of the present invention. [Figure 4] 4 is a flowchart for explaining in detail the step S02 shown in FIG. 3. [Diagram 5] FIG. 4 is a diagram for explaining step S02 shown in FIG. 3 in detail. [Figure 6] FIG. 4 is a diagram for explaining step S02 shown in FIG. 3 in detail. [Figure 7] FIG. 5 is a diagram for explaining a specific method of removal processing of S24 shown in FIG. [Figure 8] FIG. 5 is a diagram for explaining a specific method of removal processing of S24 shown in FIG. [Figure 9] FIG. 5 is a diagram for explaining a specific method of removal processing of S24 shown in FIG. [Figure 10] FIG. 5 is a diagram for explaining a specific method of removal processing of S24 shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, the embodiments will be described in detail with reference to the attached drawings. Note that the following embodiments do not limit the invention according to the claims. Although the embodiments describe a number of features, not all of these features are essential to the invention, and the features may be combined in any manner. Furthermore, in the attached drawings, the same reference numbers are used for the same or similar configurations, and duplicated descriptions are omitted.

[0012] 1 is a schematic diagram showing the configuration of an exposure apparatus 100 according to one aspect of the present invention. The exposure apparatus 100 is a lithography apparatus used in, for example, a manufacturing process (lithography process) of a semiconductor device or the like, and forms a pattern on a substrate. The exposure apparatus 100 exposes a substrate W via an original R, and in this embodiment, is a step-and-scan exposure apparatus (scanner) that exposes the substrate W (scanning exposure) while moving the original R and the substrate W in a scanning direction, thereby transferring the pattern of the original R onto the substrate. However, the exposure apparatus 100 can also employ a step-and-repeat method or other exposure methods.

[0013] 1, the exposure apparatus 100 has an illumination optical system 101, an original driving unit 102, a projection optical system 103, a substrate driving unit 104, and a measurement unit 105. In this embodiment, a coordinate system is defined in which an axis along the normal direction of the substrate W is defined as the Z axis, and axes along directions perpendicular to each other in a plane parallel to the substrate W are defined as the X axis and the Y axis.

[0014] The illumination optical system 101 uses light (light beam) from a light source 1 to illuminate an original R placed on an illuminated surface (object surface of the projection optical system 103). The light source 1 includes, for example, an extra-high pressure mercury lamp that emits light such as i-line (wavelength 365 nm). However, the light source 1 is not limited to this, and may be a KrF excimer laser that emits light with a wavelength of 248 nm, an ArF excimer laser that emits light with a wavelength of 193 nm, or an F excimer laser that emits light with a wavelength of 157 nm. 2 The light source 1 may be a laser. Alternatively, the light source 1 may be an EUV light source that emits light with an extreme ultraviolet wavelength (EUV light) of about 11 nm to 14 nm.

[0015] A pattern (e.g., a circuit pattern) to be transferred to the substrate W is formed on the original R. The original R is made of a material that transmits light from the light source 1 (illumination optical system 101), such as quartz glass as a base material. The original driving unit 102 includes, for example, a movable original stage that holds the original R, and an original driving mechanism that drives the original stage about the X-axis and Z-axis.

[0016] The projection optical system 103 projects the pattern of the original R illuminated by the illumination optical system 101 onto the substrate W. The projection optical system 103 includes an imaging optical system, the front focal point of which is located on the surface (position) on which the original R is disposed, and the rear focal point of which is located on the surface on which the substrate W is disposed. In other words, the projection optical system 103 makes the position of the original R and the position of the substrate W conjugate with each other.

[0017] The substrate W is a substrate onto which the pattern of the original R is transferred, and has a resist (photosensitive material) on its surface. The substrate driving unit 104 includes a movable substrate stage that holds the substrate W, and a substrate driving mechanism that drives the substrate stage about the X-axis, Y-axis, and Z-axis (and their rotational directions ωx, ωy, and ωz).

[0018] The measurement unit 105 includes, for example, a light quantity sensor, and measures the illuminance distribution formed on the illuminated surface. In this embodiment, the measurement unit 105 is disposed on the object surface of the projection optical system 103, specifically, on the original stage constituting the original driving unit 102.

[0019] The illumination optical system 101 will be described in detail below. The illumination optical system 101 includes a first relay lens 3, a bending mirror M1, an optical integrator 4, a second relay lens 5, and a bending mirror M2. The first relay lens 3 and the bending mirror M1 constitute a first illumination optical system 10, and the second relay lens 5 and the bending mirror M2 constitute a second illumination optical system 12. Light from the first illumination optical system 10 enters the second illumination optical system 12 via the optical integrator 4.

[0020] The elliptical mirror 2 has a first focal point and a second focal point, and collects light from the light source 1 arranged at the first focal point at the second focal point. The first relay lens 3 includes an imaging optical system, the front focal point of which is arranged at the second focal point of the elliptical mirror 2, and the rear focal point of which is arranged at the incident surface of the optical integrator 4. In other words, the first relay lens 3 makes the second focal point of the elliptical mirror 2 and the incident surface of the optical integrator 4 in a conjugate relationship. Thus, in this embodiment, the illumination optical system 101 includes the first illumination optical system 10 that makes the second focal point of the elliptical mirror 2 and the incident surface of the optical integrator 4 in a conjugate relationship, but may include a first illumination optical system that does not have such a relationship. A wavelength filter (not shown) that blocks light in a specific wavelength range is arranged near the pupil plane of the first relay lens 3, and the exposure wavelength (the wavelength of light that exposes the substrate W) is determined by the wavelength filter.

[0021] The optical integrator 4 is an internal reflection type optical integrator including an incident surface, a reflecting surface, and an exit surface ES. The optical integrator 4 forms a uniform light intensity distribution (illuminance distribution) on the exit surface ES by reflecting the light incident on the incident surface by the reflecting surface multiple times. In this embodiment, the optical integrator 4 has a rectangular shape in a cross section (XY plane) perpendicular to the optical axis AX, but may have other shapes (e.g., polygonal). Furthermore, the optical integrator 4 is not limited to an internal reflection type optical integrator, and may be a microlens array type optical integrator such as a fly-eye lens.

[0022] The second illumination optical system 12 illuminates the original R using light from the exit surface ES of the optical integrator 4. The second relay lens 5 includes an imaging optical system, with its front focal point located on the exit surface ES of the optical integrator 4 and its rear focal point located on the surface on which the original R is placed. In other words, the second relay lens 5 makes the exit surface ES of the optical integrator 4 and the placement surface of the original R in a conjugate relationship. The second relay lens 5 forms a light intensity distribution (illuminance distribution) of the exit surface ES of the optical integrator 4 on the placement surface of the original R.

[0023] In the exposure apparatus 100 of this embodiment, the second illumination optical system 12 incorporates a light-transmitting optical element 6 that functions as a correction filter for correcting the illuminance distribution on the illuminated surface. The optical element 6 is disposed on the illuminated surface of the illumination optical system 101 (for example, the surface on which the original R is disposed), on a conjugate surface that is in a conjugate relationship with the illuminated surface, or in the vicinity of the illuminated surface or the conjugate surface. In this embodiment, the optical element 6 is disposed in the vicinity of the surface on which the original R is disposed, specifically, on the surface of the illumination optical system 101 closest to the projection optical system 103 so that an optical thin film formed on the surface of the optical element 6, which will be described later, faces the original R.

[0024] FIG. 2 is a schematic diagram showing the configuration of a light-transmitting optical element 6. As shown in FIG. 2, the optical element 6 has an optical thin film C formed on at least one surface (surface of the optical element 6) of a substrate 7 (base material) and functioning (acting) as an anti-reflection film. In this embodiment, for any portion (part) of the optical thin film C having a thickness (maximum thickness) D, the optical thin film C is partially removed in the thickness direction (Z-axis direction) of the optical thin film C by an amount of removal δ, thereby forming a thickness distribution in the optical thin film plane. In this way, the optical thin film C exists across the surface of the optical element 6 (substrate 7) and has a thickness distribution in this surface. In other words, the optical thin film C includes a portion where the optical thin film C is partially removed in the thickness direction in the surface of the optical element 6, and at least a part of the optical thin film C remains in this portion.

[0025] The antireflection film as the optical thin film C is formed by stacking a plurality of thin films made of materials with different refractive indices on the substrate 7, and uses optical interference to reduce the reflectance and obtain a high overall transmittance. The number, material, thickness, etc. of the thin films constituting the antireflection film are usually adjusted so that a predetermined transmittance or reflectance is obtained, and the optical interference conditions are optimized. Therefore, the transmittance or reflectance of the optical thin film C can be changed according to the removal amount δ when the optical thin film C is partially removed in the thickness direction. The type (film type) of the optical thin film C is not limited to a dielectric multilayer film, and may be a single layer film.

[0026] On the other hand, if the optical thin film C formed on the substrate 7 is completely removed in the thickness direction, the portion of the optical thin film C from which it has been completely removed in the thickness direction will no longer function as an antireflection film. However, for the purpose of correcting the illuminance distribution on the illuminated surface, that is, for the purpose of making the illuminance distribution uniform, the amount δ of the optical thin film C removed may be sufficient to adjust the film thickness (film thickness distribution) of the outermost thin film among the multiple thin films that make up the antireflection film. Therefore, in this embodiment, the effect of partial removal of the optical thin film C in the thickness direction on its function as an antireflection film is extremely small and can be ignored.

[0027] A method for manufacturing the optical element 6 will be described below with reference to Fig. 3. In S01 (first step), an optical thin film C that functions as an anti-reflection film is formed on the surface of the substrate 7. As described above, the optical thin film C formed in S01 has the number, material, thickness, etc. of the thin films that make up the optical thin film C adjusted to optimize the optical interference conditions. In this embodiment, the optical thin film C having a uniform thickness D is formed on the surface of the substrate 7.

[0028] In S02 (second step), the optical thin film C formed in S01 is removed in the thickness direction. At this time, the optical thin film C is removed in the thickness direction so that at least a part of the optical thin film C remains even in the region where the optical thin film C is removed. Therefore, even after S02, at least a part of the optical thin film C formed on the surface of the base material 7 remains in the thickness direction of the optical thin film C across the surface of the base material 7. In this embodiment, the optical thin film C is partially removed in the thickness direction of the optical thin film C by a removal amount δ for any location of the optical thin film C having a thickness D. This makes it possible to manufacture a transmission type optical element 6 in which the optical thin film C is formed, which exists across the surface of the base material 7 and has a thickness distribution across the surface, as shown in FIG. 2.

[0029] Now, with reference to FIG. 4, the step of removing the optical thin film C in the thickness direction (step S02) will be described in detail.

[0030] In S21 (third step), the illuminance distribution formed on the illuminated surface by the light from the illumination optical system 101 with the transmissive optical element 6 removed is acquired. Specifically, the measurement unit 105 provided on the original stage is placed on the surface on which the original R is placed, and the measurement unit 105 (light quantity sensor) measures the light from the illumination optical system 101 with the transmissive optical element 6 removed, thereby acquiring the illuminance distribution on the illuminated surface. Fig. 5(a) is a diagram showing an example of the illuminance distribution on the illuminated surface acquired in S21. In the illuminance distribution shown in Fig. 5(a), the illuminance is locally low at coordinate a on the illuminated surface.

[0031] In S22, a transmittance distribution in the optical thin film C that functions as an anti-reflection film is designed so as to cancel the illuminance distribution on the illuminated surface acquired in S21. Fig. 5(b) is a diagram showing an example of the transmittance distribution in the optical thin film C designed in S22. The transmittance distribution shown in Fig. 5(b) is a transmittance distribution designed for the illuminance distribution shown in Fig. 5(a), and has a maximum transmittance T max has.

[0032] In S23 (fourth step), the film thickness distribution of the optical thin film C is determined based on the illuminance distribution on the illuminated surface acquired in S21 and the transmittance distribution of the optical thin film C designed in S22. Note that the determination of the film thickness distribution of the optical thin film C means determining the portion (coordinates in the optical thin film surface) where the optical thin film C should be removed on the surface of the optical element 6 (substrate 7) and the removal amount δ of the optical thin film C in the portion. Specifically, as shown in FIG. 5(c), the illuminance distribution shown in FIG. 5(a) is multiplied with the transmittance distribution shown in FIG. 5(b) to determine the film thickness distribution of the optical thin film C so that the illuminance distribution on the illuminated surface is uniform (i.e., so that the transmittance distribution shown in FIG. 5(b) is realized). Referring to FIG. 5(c), the film thickness distribution of the optical thin film C is determined based on the maximum transmittance T max The removal amount δ at coordinate A in the optical thin film plane is set to zero, and the maximum transmittance T max and the transmittance difference T at each coordinate (position) (T max The removal amount δ is determined according to the transmittance difference (T max By acquiring such a relationship in advance, the transmittance difference (T max -T), it is possible to determine the removal amount δ according to the

[0033] In S24, the optical thin film C formed on the substrate 7 in S01 is subjected to a removal process to partially remove the optical thin film C in the thickness direction in accordance with the film thickness distribution (the removal amount δ at each coordinate in the optical thin film plane) determined in S23. As a result, the optical thin film C exists across the surface of the substrate 7, and has a film thickness distribution within the surface of the substrate 7 that corresponds to the illuminance distribution that should be formed by the light transmitted through the optical element 6. A specific method for the removal process performed in S24 will be described later.

[0034] In S25, the optical element 6 that has been subjected to the removal processing in S24 is incorporated into the illumination optical system 101. In this embodiment, as described above, the optical element 6 is incorporated into the surface of the illumination optical system 101 that is closest to the projection optical system 103, so that the optical thin film C faces the original R.

[0035] In S26, the illuminance distribution formed on the illuminated surface by the light from the illumination optical system 101 with the transmissive optical element 6 incorporated therein is acquired. Specifically, the measurement unit 105 provided on the original stage is disposed on the surface on which the original R is disposed, and the measurement unit 105 (light quantity sensor) measures the light from the illumination optical system 101 with the transmissive optical element 6 incorporated therein to acquire the illuminance distribution on the illuminated surface. Fig. 5(d) is a diagram showing an example of the illuminance distribution on the illuminated surface acquired in S26. In the illuminance distribution shown in Fig. 5(d), the illuminance is uniform within the illuminated surface.

[0036] In this way, according to this embodiment, it is possible to manufacture (provide) a transmissive optical element 6 that realizes a uniform illuminance distribution on the illuminated surface. An exposure apparatus 100 having an illumination optical system 101 incorporating such a transmissive optical element 6 is able to uniformly illuminate the original R, and can satisfactorily transfer the pattern of the original R to the resist on the substrate.

[0037] An example of a specific technique for the removal process (S24) of partially removing the optical thin film C in the thickness direction will be described with reference to Fig. 7. The removal process may use a processing technique, so-called IBF (Ion Beam Figuring), in which an ion beam is irradiated onto a portion of the optical thin film C to be removed, thereby removing the optical thin film C in the thickness direction in that portion.

[0038] 7 is a schematic diagram showing the configuration of an ion beam processing apparatus 200 that realizes the IBF. The ion beam processing apparatus 200 has a chamber 21 for maintaining a vacuum state, an ion beam generating unit 22, a driving stage 24, and a current density measuring unit 25. The ion beam generating unit 22, the driving stage 24, and the current density measuring unit 25 are provided inside the chamber 21.

[0039] An ion beam 23 from an ion beam generating unit 22 is irradiated onto a transmission type optical element 6, which is a workpiece held (mounted) on a driving stage 24, specifically, onto an optical thin film C formed on a substrate 7. The driving stage 24 is driven to scan and irradiate an arbitrary portion (position) of the optical thin film C with the ion beam 23, thereby performing a removal process that partially removes the optical thin film C in the thickness direction.

[0040] It is possible to measure the beam profile of the ion beam 23 by irradiating the ion beam 23 from the ion beam generating unit 22 to a current density measuring unit 25 provided on the driving stage 24. By optimizing the beam profile of the ion beam 23 measured by the current density measuring unit 25 for processing conditions such as the removal amount δ (processing amount) of the optical thin film C and the processing pitch, it is possible to realize highly accurate removal processing.

[0041] By using such an ion beam processing apparatus 200 for the removal processing (S24), it is possible to manufacture (provide) a transmissive optical element 6 that corrects the non-uniformity of the illuminance distribution on the illuminated surface with high precision, i.e., that realizes uniformity of the illuminance distribution on the illuminated surface.

[0042] Another example of a specific technique for the removal process (S24) of partially removing the optical thin film C in the thickness direction will be described with reference to Fig. 8. The removal process may use a processing technique called MRF (Magneto-Rheological Finishing), which polishes the portion of the optical thin film C to be removed with a magnetic fluid containing abrasive grains, thereby removing the optical thin film C in the thickness direction in the portion. MRF is a high-precision polishing technique that uses magnetic force.

[0043] Specifically, as shown in Fig. 8, a magnetic fluid 31 containing abrasive grains is poured between an optical thin film C formed on a substrate 7 and a stage 32. When a magnetic force 34 is applied to the magnetic fluid 31 from an electromagnet 33, the magnetic abrasive grains contained in the magnetic fluid 31 come into contact with the surface of the optical thin film C due to the influence of the magnetic force 34. At this time, by driving the stage 32, the magnetic fluid 31 flows over the surface of the optical thin film C, and the optical thin film C is polished by the magnetic fluid 31. By controlling the magnetic force 34 by the electromagnet 33, a highly accurate removal process can be realized.

[0044] By using such high-precision polishing technology in the removal process (S24), it is possible to manufacture (provide) a transmissive optical element 6 that corrects the non-uniformity of the illuminance distribution on the illuminated surface with high precision, i.e., that realizes a uniform illuminance distribution on the illuminated surface.

[0045] 9(a) to 9(d), a description will be given of yet another example of a specific technique for the removal process (S24) of partially removing the optical thin film C in the thickness direction. The removal process may be a process technique for etching the portion of the optical thin film C to be removed, thereby removing the optical thin film C in the thickness direction in the portion, for example, an etching technique using a resist.

[0046] Specifically, first, as shown in FIG. 9(a), a resist 41 is applied onto the optical thin film C formed on the substrate 7. Next, as shown in FIG. 9(b), a portion 42 where the optical thin film C is to be removed is exposed to light using an exposure device or the like and developed, thereby removing the resist 41 from the portion 42. Next, as shown in FIG. 9(c), an etching process is performed on the portion 42, thereby removing (cutting) the optical thin film C from the portion 42. Then, as shown in FIG. 9(d), the resist 41 applied onto the optical thin film C is peeled off. By going through the steps shown in FIG. 9(a) to FIG. 9(d), a highly accurate removal process can be achieved for any portion of the optical thin film C.

[0047] By using such an etching technique for the removal process (S24), it is possible to manufacture (provide) a transmissive optical element 6 that corrects non-uniformity in the illuminance distribution on the illuminated surface with high precision, i.e., that realizes uniform illuminance distribution on the illuminated surface.

[0048] 10(a) to 10(c), a further example of a specific technique for the removal process (S24) for partially removing the optical thin film C in the thickness direction will be described. The removal process may use a processing technique for removing the optical thin film C in the thickness direction in the portion where the optical thin film C is to be removed by applying a remover to the portion. For example, HF (hydrofluoric acid) is used as the remover.

[0049] Specifically, first, as shown in Fig. 10(a), a mask 51 including openings 52 is placed on the optical thin film C formed on the substrate 7. Next, as shown in Fig. 10(b), a release agent 53 is poured into the openings 52 of the mask 51 to remove (peel off) the optical thin film C in the portion exposed in the openings 52. Then, as shown in Fig. 10(c), the mask 51 placed on the optical thin film C is removed. Through the steps shown in Figs. 10(a) to 10(c), highly accurate removal processing can be achieved for any portion of the optical thin film C.

[0050] By using such a technique using a release agent in the removal process (S24), it is possible to manufacture (provide) a transmissive optical element 6 that corrects the non-uniformity of the illuminance distribution on the illuminated surface with high precision, i.e., that realizes a uniform illuminance distribution on the illuminated surface.

[0051] The manufacturing method of an article according to an embodiment of the present invention is suitable for manufacturing articles such as semiconductor elements, flat panel displays, liquid crystal display elements, and MEMS. The manufacturing method includes a step of exposing a substrate coated with a photosensitive agent using the above-mentioned exposure apparatus 100, and a step of developing the exposed photosensitive agent. In addition, an etching step, an ion implantation step, and the like are performed on the substrate using the developed pattern of the photosensitive agent as a mask, and a circuit pattern is formed on the substrate. These steps of exposure, development, etching, and the like are repeated to form a circuit pattern consisting of multiple layers on the substrate. In a post-process, dicing (processing) is performed on the substrate on which the circuit pattern is formed, and chip mounting, bonding, and inspection steps are performed. In addition, the manufacturing method may include other well-known steps (oxidation, film formation, deposition, doping, planarization, resist peeling, and the like). The manufacturing method of an article according to the present embodiment is advantageous in at least one of the performance, quality, productivity, and production cost of the article compared to the conventional method.

[0052] The invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0053] 100: exposure device 101: illumination optical system 103: projection optical system 6: transmission optical element 7: substrate C: optical thin film

Claims

1. A method for manufacturing a light-transmitting optical element to be incorporated in an illumination optical system that illuminates an illuminated surface, comprising the steps of: forming an optical thin film on a surface of the optical element by superposing a plurality of thin films having refractive indices different from each other; acquiring an illuminance distribution formed on the illuminated surface; designing a light transmittance distribution of the optical thin film based on the acquired illuminance distribution; determining a portion of the surface of the optical element where the optical thin film should be removed and an amount of the optical thin film to be removed in that portion according to the light transmittance distribution; removing the optical thin film formed on the surface of the optical element in a thickness direction of the optical thin film by the removal amount so that a portion of the optical thin film remains in the portion to be removed.

2. The method according to claim 1 , wherein the optical thin film includes an anti-reflection film.

3. 3. The manufacturing method according to claim 1, wherein in the removing step, an ion beam is irradiated onto a portion of the surface where the optical thin film is to be removed, thereby removing the optical thin film in the thickness direction at that portion.

4. 3. The manufacturing method according to claim 1, wherein in the removing step, a portion of the surface from which the optical thin film is to be removed is polished using a magnetic fluid containing abrasive grains, thereby removing the optical thin film in the thickness direction in that portion.

5. 3. The method according to claim 1, wherein in the removing step, a portion of the surface where the optical thin film is to be removed is etched, thereby removing the optical thin film in the thickness direction in that portion.

6. 3. The manufacturing method according to claim 1, wherein in the removing step, a stripping agent is applied to a portion of the surface from which the optical thin film is to be removed, thereby removing the optical thin film in the thickness direction in that portion.

7. The manufacturing method according to claim 1 , wherein in the determining step, the portion and the amount of removal are determined so that an illuminance distribution that cancels out the illuminance distribution is formed on the illuminated surface by light transmitted through the optical element.

8. An exposure apparatus that exposes a substrate through an original, comprising: an illumination optical system that illuminates the original disposed on an illumination surface; a projection optical system that projects the pattern of the original illuminated by the illumination optical system onto the substrate, the illumination optical system includes a transmission type optical element having an anti-reflection film formed on a surface thereof, the anti-reflection film being formed by overlapping a plurality of thin films having refractive indices different from each other; the anti-reflection film is formed on at least one entire surface of the optical element, and has a film thickness distribution determined so as to make the illuminance distribution on the illuminated surface uniform. An exposure apparatus comprising:

9. 9. The exposure apparatus according to claim 8, wherein the optical element is disposed on a surface to be illuminated of the illumination optical system or on a conjugate surface of the surface to be illuminated.

10. 9. An exposure apparatus according to claim 8, wherein the optical element is disposed on the side of the illumination optical system that is closest to the projection optical system, so that the anti-reflection film faces the original.

11. exposing a substrate using the exposure apparatus according to any one of claims 9 to 10; developing the exposed substrate; producing an article from the developed substrate; A method for producing an article, comprising the steps of:

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