Composite optical element, illumination unit, exposure device, and exposure method

Abstract

In order to achieve a large-area dichroic mirror, a composite optical element is provided with: a plurality of optical elements each having a first substrate and a dichroic film; and a second substrate, wherein the plurality of optical elements are arranged on the second substrate.

Description

Technical Field

[0001] The invention relates to a synthetic optical element, an illumination unit, an exposure device, and an exposure method. Background Art

[0002] In recent years, liquid crystal display panels have been widely used as display elements for personal computers, televisions, etc. Liquid crystal display panels are manufactured by forming a circuit pattern of a thin film transistor on a plate (glass substrate) using a photolithography technique. As a device used in the photolithography process, an exposure device is used that projects and exposes the original pattern formed on the photomask onto the photoresist layer on the plate via a projection optical system.

[0003] In various optical devices including the above-mentioned exposure device, it has been proposed to use a light source using a light emitting diode (for example, Patent Document 1).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2006-201476 Summary of the invention

[0007] According to the first disclosed aspect, a synthetic optical element includes: a plurality of optical elements having a first substrate and a dichroic film; and a second substrate on which the plurality of optical elements are arranged.

[0008] According to the second disclosed aspect, the lighting unit comprises: a first light source emitting light having a first wavelength characteristic; a second light source emitting light having a second wavelength characteristic different from the first wavelength characteristic; the above-mentioned synthetic optical element; and a light homogenizing element that emits the light beam emitted from the synthetic optical element as a light beam with a uniform illumination distribution, the dichroic film transmitting the light having the first wavelength characteristic and reflecting the light having the second wavelength characteristic.

[0009] According to a third disclosed aspect, an exposure apparatus includes: the lighting unit described above; and a projection optical system that projects a pattern image of a photomask illuminated by the lighting unit onto a photosensitive substrate.

[0010] According to a fourth disclosed aspect, an exposure method is an exposure method using the above-mentioned exposure device, comprising: illuminating the photomask using the lighting unit; and projecting a pattern image of the photomask onto the photosensitive substrate using the projection optical system.

[0011] It should be noted that the configuration of the embodiments described below may be appropriately improved, and at least a portion may be replaced by other components. Moreover, the technical features that are not particularly limited in their configuration are not limited to the configuration disclosed in the embodiments, and can be configured at a position that can achieve their functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram showing the structure of the exposure apparatus according to the first embodiment.

[0013] Figure 2 This is a schematic diagram showing the structure of the lighting unit.

[0014] Figure 3 (A) is a plan view schematically showing the configuration of the first light source array and the second light source array. Figure 3 (B) is a diagram schematically showing the internal structure of the first light source unit and the second light source unit.

[0015] Figure 4 (A) is a top view of the dichroic mirror of the first embodiment, Figure 4 (B) is Figure 4 (A) AA line cross-sectional view.

[0016] Figure 5 (A) is a view of the fly-eye lens from the +Z direction (top view). Figure 5 (B) is a diagram for explaining the relationship between the gap between the small-area dichroic mirrors and the boundary between the lens elements of the fly-eye lens.

[0017] Figure 6 (A) is a top view showing a dichroic mirror according to a first modification of the first embodiment. Figure 6 (B) is a plan view showing a dichroic mirror according to a second modification of the first embodiment.

[0018] Figure 7 (A) is a top view showing a dichroic mirror according to a third modification of the first embodiment. Figure 7 (B) is Figure 7 (A) AA line cross-sectional view.

[0019] Figure 8 (A) is a top view showing a dichroic mirror according to a fourth modification of the first embodiment. Figure 8 (B) is Figure 8 (A) AA line cross-sectional view.

[0020] Fig. 9 (A) is a plan view showing another example of a dichroic mirror according to a fourth modification of the first embodiment. Fig. 9 (B) is Fig. 9(A) AA line cross-sectional view.

[0021] Fig.10 (A) and Fig.10 (B) is a diagram illustrating changes in the illumination intensity of the illumination light.

[0022] Fig.11 (A) is a diagram for explaining the relationship between the fly-eye lens and the small-area dichroic mirror in the second embodiment. Fig.11 (B) and Fig.11 (C) is a diagram for explaining the change in the illuminance of the illumination light in the second embodiment.

[0023] Fig.12 It is a top view showing a dichroic mirror according to Modification 1 of the second embodiment. DETAILED DESCRIPTION

[0024] 《First Implementation Method》

[0025] based on Figure 1 to Figure 5 , an exposure device 10 according to one embodiment is described.

[0026] (Configuration of Exposure Apparatus)

[0027] Figure 1 It is a figure which shows roughly the structure of the exposure apparatus 10 which concerns on 1st Embodiment.

[0028] The exposure device 10 is a scanning stepper (scanner) that drives the mask MSK and the glass substrate (hereinafter referred to as "plate") P in the same direction and at the same speed relative to the projection optical system PL, thereby transferring the pattern formed on the mask MSK to the plate P. The plate P is, for example, a rectangular glass substrate used in a liquid crystal display device (flat panel display), and the length of at least one side or the diagonal length is 500 mm or more.

[0029] Below, the direction in which the mask MSK and the plate P are driven during scanning exposure (scanning direction) is set as the X-axis direction, the direction in the horizontal plane perpendicular to it is set as the Y-axis direction, the direction perpendicular to the X-axis and the Y-axis is set as the Z-axis direction, and the rotation (tilt) directions around the X-axis, Y-axis, and Z-axis are set as θx, θy, and θz directions, respectively.

[0030] The exposure device 10 includes an illumination system IOP, a mask stage MST holding a mask MSK, a projection optical system PL, a main body 70 supporting these components, a substrate stage PST holding a plate P, and control systems for these components. The control system collectively controls the components of the exposure device 10 .

[0031] The main body 70 includes a base (vibration-proof table) 71, columns 72A and 72B, an optical fixing plate 73, a support body 74, and a sliding guide 75. The base (vibration-proof table) 71 is arranged on the ground F, and supports the columns 72A and 72B and the like while isolating vibration from the ground F. The columns 72A and 72B each have a frame shape, and the column 72A is arranged inside the column 72B. The optical fixing plate 73 has a flat plate shape and is fixed to the top of the column 72A. The support body 74 is supported on the top of the column 72B via the sliding guide 75. The sliding guide 75 has a balloon lifter and a positioning mechanism, and positions the support body 74 (i.e., the mask stage MST described later) at an appropriate position in the X-axis direction relative to the optical fixing plate 73.

[0032] The illumination system IOP is arranged above the main body 70. The illumination system IOP irradiates the mask MSK with illumination light IL. The detailed configuration of the illumination system IOP will be described later.

[0033] The mask stage MST is supported by a support body 74. It has a pattern surface ( Figure 1 The mask MSK (the lower surface of the optical system) is fixed to the mask stage MST by, for example, vacuum adsorption (or electrostatic adsorption). The mask stage MST is driven by a drive system including, for example, a linear motor with a predetermined stroke in the scanning direction (X-axis direction) and is slightly driven in the non-scanning direction (Y-axis direction and θz direction).

[0034] The position information of the mask stage MST in the XY plane (including the rotation information in the θz direction) is measured by the interferometer system. The interferometer system irradiates the moving mirror (or the reflective surface (not shown) obtained by mirror processing) provided at the end of the mask stage MST with a length measurement beam, receives the reflected light from the moving mirror, and thereby measures the position of the mask stage MST. The measurement result is supplied to the control device (not shown), and the control device drives the mask stage MST with the help of the drive system according to the measurement result of the interferometer system.

[0035] The projection optical system PL is an Offner type optical system supported by an optical fixing plate 73 below the mask stage MST (-Z side). The projection optical system PL forms, for example, an arc-shaped image field with the Y-axis direction as the long side direction. It should be noted that the projection area of ​​the projection optical system PL is sometimes referred to as an exposure area.

[0036] When the illumination area on the mask MSK is illuminated by the illumination light IL from the illumination system IOP, the illumination light IL that has passed through the mask MSK forms a projection image (partial erect image) of the circuit pattern of the mask MSK in the illumination area on the plate P arranged on the image plane side of the projection optical system PL using the illumination light IL. Here, a resist (sensitizer) is applied on the surface of the plate P. The mask stage MST and the substrate stage PST are driven synchronously, that is, the mask MSK is driven in the scanning direction (X-axis direction) relative to the illumination area (illumination light IL), and the plate P is driven in the same scanning direction relative to the exposure area (illumination light IL), thereby exposing the plate P and transferring the pattern of the mask MSK onto the plate P.

[0037] The substrate stage PST is disposed on a base (anti-vibration table) 71 below (at the −Z side) the projection optical system PL. The plate P is held on the substrate stage PST via a substrate holder (not shown).

[0038] The position information of the substrate stage PST in the XY plane (including rotation information (deflection amount (rotation amount θz in the θz direction), pitch amount (rotation amount θx in the θx direction), roll amount (rotation amount θy in the θy direction))) is measured by the interferometer system. The interferometer system irradiates a length measurement beam from the optical fixing plate 73 to a movable mirror (or a reflective surface obtained by mirror processing (not shown)) provided at the end of the substrate stage PST, receives reflected light from the movable mirror, and thereby measures the position of the substrate stage PST. The measurement results are supplied to a control device (not shown), and the control device drives the substrate stage PST according to the measurement results of the interferometer system.

[0039] In the exposure device 10, alignment measurement (for example, EGA, etc.) is performed before exposure, and the plate P is exposed according to the following steps using the result. First, according to the instruction of the control device, the mask stage MST and the substrate stage PST are synchronously driven along the X-axis direction. Thus, scanning exposure to the first shooting area on the plate P is performed. If the scanning exposure relative to the first shooting area is completed, the control device moves (steps) the substrate stage PST to a position corresponding to the second shooting area. Then, scanning exposure relative to the second shooting area is performed. The control device repeats the stepping between the shooting areas of the plate P and the scanning exposure relative to the shooting areas in the same way, and transfers the pattern of the mask MSK to all the shooting areas on the plate P.

[0040] (Composition of the lighting system IOP)

[0041] Next, the configuration of the illumination system IOP in the present embodiment will be described. The illumination system IOP includes an illumination unit 90 . Figure 2 It is a diagram schematically showing the structure of the lighting unit 90.

[0042] The lighting unit 90 includes a first light source unit OPU1 , a second light source unit OPU2 , an illumination optical system 80 , and a control unit CU.

[0043] (Configuration of light source unit)

[0044] The first light source unit OPU1 includes a first light source array 20A and a first magnifying optical system 30A, and the second light source unit OPU2 includes a second light source array 20B and a second magnifying optical system 30B.

[0045] Figure 3 (A) is a plan view schematically showing the configuration of the first light source array 20A and the second light source array 20B. The first light source array 20A includes a plurality of light sources (in Figure 3 In (A), there are 5×5) LED (Light Emitting Diode) chips 23A. The number of LED chips 23A can also be appropriately changed as needed. The plurality of LED chips 23A respectively have a light emitting portion 231A, and the peak wavelength of the light emitted from the light emitting portion 231A is in the range of 380 to 390 nm. That is, the light emitting portion 231A is an ultraviolet LED (UV LED). The peak wavelength of the light emitted from the light emitting portion 231A is more preferably 385 nm. The light emitting surface of the light emitting portion 231A is a square, and the length of one side thereof is a1. The LED chips 23A are arranged at a pitch P1. The pitch P1 is the distance between the centers of adjacent LED chips 23A.

[0046] The second light source array 20B includes, for example, a plurality of light sources arranged on a substrate 21B ( Figure 3 (A) is 5×5) LED chips 23B. The number of LED chips 23B can also be appropriately changed as needed. Multiple LED chips 23B respectively have a light-emitting portion 231B, and the peak wavelength of light emitted from the light-emitting portion 231B is in the range of 360 to 370 nm. That is, the light-emitting portion 231B is a UVLED. The peak wavelength of light emitted from the light-emitting portion 231B is more preferably 365 nm. The light-emitting surface of the light-emitting portion 231B is a square, and the length of one side thereof is a2. The LED chips 23B are arranged at a pitch P2.

[0047] The arrangement pitch P1 of the LED chips 23A and the arrangement pitch P2 of the LED chips 23B may be the same or different. In addition, the length a1 of one side of the light-emitting surface of the light-emitting portion 231A and the length a2 of one side of the light-emitting surface of the light-emitting portion 231B may be the same or different. It should be noted that the LED chips 23A and 23B may not be arranged on the substrate, for example, they may be arranged on a heat sink.

[0048] The control unit CU controls the current values ​​supplied to the light emitting portion 231A of the LED chip 23A and the light emitting portion 231B of the LED chip 23B, respectively, and adjusts the intensity of light emitted from each of the light emitting portion 231A and the light emitting portion 231B.

[0049] Figure 3 (B) is a diagram schematically showing the internal structure of the first light source unit OPU1 and the second light source unit OPU2. It should be noted that the internal structure of the first light source unit OPU1 and the second light source unit OPU2 is the same, so here, the structure of the first light source unit OPU1 is used as a representative for description. Here, the two directions in which the LED chips 23A are arranged are set as the X1 direction and the Y1 direction. The X1 direction and the Y1 direction are orthogonal. In addition, the direction orthogonal to the X1 direction and the Y1 direction is set as the Z1 direction. The Z1 direction is approximately parallel to the optical axis OA of the light emitted from the light emitting portion 231A. Figure 3 In (B), in order to make the drawing clearer, only four LED chips 23A arranged in a row along the Y1 direction are shown.

[0050] like Figure 3 As shown in (B), the first magnifying optical system 30A is a magnifying optical system for forming magnified images of the light emitting portion 231A of each LED chip 23A on a predetermined surface PP. The first magnifying optical system 30A has a plurality of lens portions 31A arranged in a manner corresponding to the arrangement of the LED chips 23A. The lens portions 31A are double telecentric optical systems that magnify and project the light emitting portions 231A at a magnification M1.

[0051] In the present embodiment, each lens portion 31A includes four plano-convex lenses, but the present invention is not limited thereto, and each lens portion 31A may include, for example, two biconvex lenses or three biconvex lenses. In addition, each lens portion 31A may include, for example, a plano-convex lens and a biconvex lens.

[0052] In the present embodiment, the lens portion 31A, for example, magnifies and projects the light emitting portion 231A at a magnification M1. The magnification M1 is, for example, (the arrangement pitch P1 of the LED chips 23A) / (the length a1 of one side of the light emitting surface of the light emitting portion 231A). In this case, the magnified images of the plurality of light emitting portions 231A are substantially in contact with each other in the prescribed plane PP. It should be noted that the magnification M1 may also be greater than (the arrangement pitch P1 of the LED chips 23A) / (the length a1 of one side of the light emitting surface of the light emitting portion 231A).

[0053] On the other hand, the lens portion 31B of the second magnifying optical system 30B magnifies and projects the light emitting portion 231B, for example, at a magnification M2. The magnification M2 is, for example, (the arrangement pitch P2 of the LED chips 23B) / (the length a2 of one side of the light emitting surface of the light emitting portion 231B). In this case, the magnified images of the plurality of light emitting portions 231B are substantially in contact with each other in the prescribed plane PP. It should be noted that the magnification M2 may also be greater than (the arrangement pitch P2 of the LED chips 23B) / (the length a2 of one side of the light emitting surface of the light emitting portion 231B).

[0054] (Configuration of Illumination Optical System 80)

[0055] Refer again Figure 2 , the configuration of the illumination optical system 80 will be described. The illumination optical system 80 includes a first condensing optical system 81A, a second condensing optical system 81B, a dichroic mirror DM, an imaging optical system 83, a fly-eye lens FEL, an aperture stop 85, and a condenser optical system 84.

[0056] The first condensing optical system 81A is disposed on or near the predetermined surface PP to form a pupil of the magnified image of the light emitting unit 231A formed by the first enlarging optical system 30A. The first condensing optical system 81A may be composed of a single lens or a lens group including a plurality of lenses.

[0057] The second condensing optical system 81B is disposed on the predetermined plane PP or in the vicinity thereof to form a pupil of the magnified image of the light emitting unit 231B formed by the second enlarging optical system 30B. The second condensing optical system 81B may be composed of a single lens or a lens group including a plurality of lenses.

[0058] The dichroic mirror DM transmits at least a portion of the light with a peak wavelength of 385 nm, and reflects at least a portion of the light with a peak wavelength of 365 nm. Thus, a synthetic image is formed in which the pupil image formed by the first light-converging optical system 81A overlaps with the pupil image formed by the second light-converging optical system 81B, and the dichroic mirror DM is Kohler illuminated by the first light-converging optical system 81A and the second light-converging optical system 81B. It should be noted that the configuration of this embodiment is not limited thereto, and the first light-converging optical system 81A and the second light-converging optical system 81B may also be configured to be critically illuminated, and the image of the first light source unit OPU1 and the image of the second light source unit OPU2 are formed in the dichroic mirror DM, respectively.

[0059] In the present embodiment, the illumination field size of the illumination optical system 80 at the light mask surface is, for example, 750 mm × 200 mm or more, or 880 mm × 245 mm or more. In this case, in order to ensure the synthesis efficiency of the light from the first light source unit OPU1 and the light from the second light source unit OPU2 to suppress the decrease in illumination, a large-sized dichroic mirror DM of, for example, 325 mm × 300 mm or more is required. The size of the dichroic mirror DM may be, for example, 342 mm × 315 mm or more.

[0060] For example, RAS (Radical Assisted Sputtering) is used to form a high-quality dichroic film. However, it is difficult to form a dichroic film over a large area due to the structure of a sputtering device using the RAS method.

[0061] Therefore, in this embodiment, a large-area dichroic mirror DM is realized by bonding a plurality of small-area dichroic mirrors SDM.

[0062] (Constitution of the dichroic mirror DM)

[0063] Figure 4 (A) is a top view of the dichroic mirror DM according to the first embodiment. Figure 4 (B) is Figure 4 (A) AA line cross-sectional view.

[0064] like Figure 4 As shown in (A), the dichroic mirror DM has multiple (in Figure 4 (A) shows four small-area dichroic mirrors SDM.

[0065] like Figure 4 As shown in (B), each small-area dichroic mirror SDM includes a substrate 51 and a dichroic film 52. The dichroic film 52 is formed on the first surface 51a of the substrate 51. The substrate 51 is a light-transmitting substrate. Considering the peak wavelength of light emitted by the light-emitting portions 231A and 231B of the LED chips 23A and 23B, the substrate 51 is preferably a quartz glass substrate, for example.

[0066] A plurality of small-area dichroic mirrors SDM are arranged on the first surface 50a of the substrate 50 having an area larger than the small-area dichroic mirrors SDM. As described above, in order to ensure the synthesis efficiency of the light from the first light source unit OPU1 and the light from the second light source unit OPU2 to suppress the decrease in illumination, a dichroic mirror DM having a large size of 325 mm×300 mm or more is required. Therefore, the length of each side of the substrate 50 is at least 300 mm or more. In the present embodiment, a plurality of small-area dichroic mirrors SDM are arranged separately from each other.

[0067] The substrate 50 is a light-transmitting substrate. Thus, light from the second surface 50b (the opposite side of the first surface 50a) of the substrate 50 is incident on a plurality of small-area dichroic mirrors SDM. Considering the peak wavelength of light emitted by the light-emitting portions 231A and 231B of the LED chips 23A and 23B, the substrate 50 is preferably a quartz glass substrate, for example. It should be noted that the substrate 51 and the substrate 50 may be made of the same material or different materials.

[0068] The small-area dichroic mirror SDM is fixed to the substrate 50 by, for example, an adhesive. The method of fixing the small-area dichroic mirror SDM to the substrate 50 is not limited to the adhesive. For example, the substrate 50 and the small-area dichroic mirror SDM may be bonded by optical contact by high-precision grinding of the second surface 51b of the substrate 51 on the opposite side to the first surface 51a on which the dichroic film 52 is formed, and the first surface 50a of the substrate 50. In addition, the small-area dichroic mirror SDM may be fixed to the substrate 50 by using a leaf spring or the like.

[0069] As described above, in the present embodiment, a large-area dichroic mirror DM is realized by bonding a plurality of small-area dichroic mirrors SDM to the substrate 50. Thus, the illumination optical system 80 can realize an illumination field size of 750 mm × 200 mm or more, or 880 mm × 245 mm or more in the light mask surface. It should be noted that the dichroic mirror DM can be configured in a manner that allows light from the first light source unit OPU1 to be incident from the side of the surface on which the dichroic film 52 is formed, or can be configured in a manner that allows light from the first light source unit OPU1 to be incident from the surface opposite to the surface on which the dichroic film 52 is formed (i.e., the second surface 50b side).

[0070] Back to Figure 2 The imaging optical system 83 is a double telecentric optical system that projects the composite image synthesized by the dichroic mirror DM to the incident end of the fly-eye lens FEL at the same magnification. It should be noted that the imaging optical system 83 can also reduce the composite image synthesized by the dichroic mirror DM and project it to the incident end of the fly-eye lens FEL.

[0071] Figure 5 (A) is a view of the fly-eye lens FEL from the +Z direction (top view). Figure 5 As shown in (A), the fly-eye lens FEL is configured by, for example, placing a plurality of lens elements having positive refractive power so that their optical axes are aligned with the reference optical axis AX (reference Figure 2 Each lens element 60 constituting the fly-eye lens FEL has a rectangular cross section similar to the shape of the illumination field to be formed on the mask MSK (the shape of the exposure area to be finally formed on the plate P).

[0072] Figure 5(B) is a diagram for explaining the relationship between the gap between the small-area dichroic mirrors SDM and the boundary between the lens elements 60 of the fly-eye lens FEL. Figure 5 In (B), the fly-eye lens FEL is represented by a dotted line.

[0073] In this embodiment, in order to suppress the decrease in the uniformity of the illumination light IL, Figure 5 As shown in (B), the dichroic mirrors DM are arranged so that the gaps between adjacent small-area dichroic mirrors SDM overlap with the boundaries 61 between the plurality of lens elements 60 included in the fly-eye lens FEL in a plan view (viewed from above).

[0074] If the gap between the small-area dichroic mirrors SDM overlaps with a portion of the lens element 60 excluding the boundary 61 , the illumination intensity of the illumination light IL in this portion decreases, and therefore the light uniformizing function of the fly-eye lens FEL cannot be fully exerted because the illumination uniformity of the illumination light IL decreases.

[0075] By arranging the dichroic mirrors DM as in the present embodiment, it is possible to minimize the area where the gap between the small-area dichroic mirrors SDM and the lens element 60 overlap, thereby suppressing a decrease in the uniformity of the illumination light IL.

[0076] Back to Figure 2 The light beam incident on the fly-eye lens FEL is split by the wavefronts of the plurality of lens elements 60, and a light source image is formed on or near the rear focal plane of each lens element 60. That is, a substantial surface light source composed of a plurality of light source images, i.e., a secondary light source, is formed on or near the rear focal plane of the fly-eye lens FEL. The light beam from the secondary light source formed on or near the rear focal plane of the fly-eye lens FEL is incident on the aperture stop 85 disposed near the rear focal plane.

[0077] The aperture stop 85 is arranged at a position that is almost optically conjugate with the incident pupil plane of the projection optical system PL, and has a variable aperture portion for defining a range that contributes to the illumination of the secondary light source. Furthermore, the aperture stop 85 sets the σ value (the ratio of the aperture of the secondary light source image on the pupil plane of the projection optical system to the aperture of the pupil plane) that determines the illumination condition to a desired value by changing the aperture of the variable aperture portion. The light from the secondary light source that has passed through the aperture stop 85 is subjected to the focusing action of the condenser optical system 84, and then overlaps and illuminates the mask MSK formed with a predetermined pattern.

[0078] As described above, when the illumination area on the mask MSK is illuminated by the illumination light IL from the illumination system IOP, a projection image (partial erect image) of the circuit pattern of the mask MSK in the illumination area is formed on an irradiation area (exposure area (conjugate with the illumination area)) on the plate P disposed on the image plane side of the projection optical system PL by the illumination light IL that has passed through the mask MSK. Thus, the plate P is exposed and the pattern of the mask MSK is transferred to the plate P.

[0079] As described above in detail, according to the first embodiment, the dichroic mirror DM includes: a plurality of small-area dichroic mirrors SDM, which have a substrate 51 and a dichroic film 52; and a substrate 50, which has a plurality of small-area dichroic mirrors SDM arranged on a first surface 50a, and allows light from a second surface 50b side opposite to the first surface 50a to be incident on the plurality of small-area dichroic mirrors SDM. Since the small-area dichroic mirrors SDM whose size is easy to manufacture are combined, it is easy to manufacture a large-sized dichroic mirror DM. In addition, it is possible to realize a dichroic mirror DM of a size (area) that is not easy to form a dichroic film using a sputtering device of the RAS method.

[0080] In addition, in the first embodiment, the illumination unit 90 includes a first light source unit OPU1 that emits light with a peak wavelength of 385 nm, a second light source unit OPU2 that emits light with a peak wavelength of 365 nm, a dichroic mirror DM, and a fly-eye lens FEL that emits the light beam emitted from the dichroic mirror DM as a light beam with uniform illumination distribution, and the dichroic film 52 transmits the light with a peak wavelength of 385 nm and reflects the light with a peak wavelength of 365 nm. Thus, light with different peak wavelengths can be synthesized as illumination light IL.

[0081] In the first embodiment, the fly-eye lens FEL has a plurality of lens elements (60), and in a plan view, gaps between adjacent small dichroic mirrors SDM overlap with boundaries 61 between the lens elements 60. This can suppress uneven illumination of the illumination light IL.

[0082] In addition, in the first embodiment, the first light source unit OPU1 includes a first light source array 20A in which a plurality of LED chips 23A are arranged, wherein the LED chip 23A has a light emitting portion 231A that emits light with a peak wavelength of 385 nm, and the second light source unit OPU2 includes a second light source array 20B in which a plurality of LED chips 23B are arranged, wherein the LED chip 23B has a light emitting portion 231B that emits light with a peak wavelength of 365 nm. Thus, compared with a case where a mercury lamp is used instead of an LED chip, the power consumption of the first light source unit OPU1 and the second light source unit OPU2 can be reduced.

[0083] It should be noted that in the first embodiment, the dichroic film 52 can transmit light with a peak wavelength of 365 nm and reflect light with a peak wavelength of 385 nm. In this case, the first light source unit OPU1 emits light with a peak wavelength of 365 nm, and the second light source unit OPU2 emits light with a peak wavelength of 385 nm.

[0084] It should be noted that the wavelengths of the light emitted by the first light source unit OPU1 and the second light source unit OPU2 are not limited to the above-mentioned wavelengths, and the first light source unit OPU1 and the second light source unit OPU2 may be appropriately combined to emit LED chips having a peak wavelength in the range of 360 to 440 nm. For example, it may be configured so that the first light source unit OPU1 emits light having a peak wavelength of 405 nm, and the second light source unit OPU2 emits light having a peak wavelength of 385 nm. In addition, it may be configured so that the first light source unit OPU1 emits light having a peak wavelength of 395 nm, and the second light source unit OPU2 emits light having a peak wavelength of 385 nm. The combination of the wavelength of the light emitted from the first light source unit OPU1 and the wavelength of the light emitted from the second light source unit OPU2 is not limited to these examples. It should be noted that, when the combination of the wavelength of the light emitted from the first light source unit OPU1 and the wavelength of the light emitted from the second light source unit OPU2 is set to a combination other than the first embodiment, it is preferred to appropriately change the material of the dichroic film 52 according to the wavelength used.

[0085] (Variation Example)

[0086] Next, a modification of the dichroic mirror DM will be described.

[0087] Figure 6 (A) is a top view showing a dichroic mirror DM1 according to a first modification of the first embodiment. Figure 6 As shown in (A), in the dichroic mirror DM1 of the modification example 1, the adjacent small-area dichroic mirrors SDM1 are arranged to contact each other. In this way, there may be no gap between the adjacent small-area dichroic mirrors SDM1. The other configurations are the same as those of the first embodiment, and therefore, detailed descriptions thereof are omitted.

[0088] Figure 6 (B) is a top view showing a dichroic mirror DM2 according to a second modification of the first embodiment. Figure 6 As shown in (B), in the dichroic mirror DM2 of Modification 2, the plane shape of the small-area dichroic mirror SDM2 is not rectangular, but fan-shaped. Like this, the plane shape of the small-area dichroic mirror SDM2 may not be rectangular. It should be noted that in Modification 2, there is no gap between adjacent small-area dichroic mirrors SDM2, but adjacent small-area dichroic mirrors SDM2 may also be separated. Other structures are the same as those in the first embodiment, and therefore, detailed description is omitted.

[0089] Figure 7 (A) is a top view showing a dichroic mirror DM3 according to a third modification of the first embodiment. Figure 7 (B) is Figure 7 The AA line section view of (A). Figure 7 As shown in (A), in the dichroic mirror DM3 of Modification 3, the substrate 50A is a light-opaque substrate and has one opening 54A in the center. Each small-area dichroic mirror SDM3 is arranged so that at least a portion overlaps with the opening 54A in a plan view.

[0090] The substrate 50A has an opening 54A in the center, so that light irradiated from the second surface 50b of the substrate 50A through the opening 54A can be incident on a plurality of small-area dichroic mirrors SDM3. As such, the substrate 50A can be an opaque substrate. For example, the substrate 50A can be a metal substrate or a resin substrate. The other configurations are the same as those of the first embodiment, and therefore, detailed descriptions thereof are omitted. It should be noted that in Figure 7 In (A), the adjacent small-area dichroic mirrors SDM3 are in contact with each other, but there may be a gap between the adjacent small-area dichroic mirrors SDM3.

[0091] Figure 8 (A) is a top view showing a dichroic mirror DM4 according to a fourth modification of the first embodiment. Figure 8 (B) is Figure 8 The AA line section view of (A). Figure 8 As shown in FIG. 5A , in the dichroic mirror DM4 of Modification 4, the substrate 50B is a light-impermeable substrate and has a plurality of openings 54B. A lattice 57 is provided between the plurality of openings 54B.

[0092] exist Figure 8 In (B), a plurality of small-area dichroic mirrors SDM4 are provided in a manner corresponding to the plurality of openings 54B. As described above, the substrate 50B has a plurality of openings 54B, so that light irradiated from the second surface 50b side of the substrate 50B through the openings 54B can be incident on the plurality of small-area dichroic mirrors SDM4.

[0093] It should be noted that in the modification example 4, a plurality of small-area dichroic mirrors SDM4 are provided in a manner corresponding to the plurality of openings 54B, respectively. Fig. 9 (A) and Fig. 9 As shown in (B), for example, one small-area dichroic mirror SDM4 may correspond to two openings 54B. The other configurations are the same as those of the first embodiment, and therefore detailed descriptions thereof will be omitted.

[0094] In the first embodiment and its modifications 1 to 4, the dichroic mirror includes four small-area dichroic mirrors. However, as shown in another example of modification 4, the number of small-area dichroic mirrors in the dichroic mirror is not limited to four, and may be two or more.

[0095] When using the dichroic mirrors DM1 to DM3 of Modifications 1 to 3, the dichroic mirrors DM1 to DM3 may be arranged so that the boundary 55 between adjacent small-area dichroic mirrors SDM1 to SDM3 overlaps the boundary 61 between the lens elements 60 of the fly-eye lens FEL.

[0096] When the dichroic mirror DM4 of Modification 4 and the other example is used, the dichroic mirror DM4 may be arranged so that the lattice 57 between the openings 54B of the substrate 50B overlaps the boundary 61 between the lens elements 60 of the fly-eye lens FEL.

[0097] <<Second Implementation Method>>

[0098] In the first embodiment and this modification, the dichroic mirrors are arranged so that the boundary between adjacent small-area dichroic mirrors or the gap between adjacent small-area dichroic mirrors overlaps with the boundary 61 between the lens elements 60 of the fly-eye lens FEL. In this case, for example, if the dichroic mirror DM is misaligned, the illumination intensity of the illumination light IL emitted by the illumination unit 90 decreases.

[0099] In this regard, use Fig.10 (A) and Fig.10 (B) is used for explanation. Fig.10 (A) shows a state where the gap between adjacent small-area dichroic mirrors SDM overlaps with the boundary 61 between the lens elements 60 of the fly-eye lens FEL. Fig.10 (B) shows a state in which the gap between the adjacent small-area dichroic mirrors SDM does not overlap with the boundary 61 between the lens elements 60 of the fly-eye lens FEL due to the misalignment of the dichroic mirrors DM.

[0100] exist Fig.10 In the case of (B), the gap between the adjacent small-area dichroic mirrors SDM overlaps with the lens element 60 of the fly-eye lens FEL, and the amount of light incident on the lens element 60 is reduced, so that the illuminance of the illumination light IL is reduced.

[0101] Fig.11 (A) is a diagram illustrating the relationship between the fly-eye lens FEL and the small-area dichroic mirror SDM in the second embodiment. Fig.11As shown in (A), in a plan view, the dichroic mirror DM is arranged so that each side 56 of the small-area dichroic mirror SDM crosses obliquely with respect to the boundary 61 between the lens elements 60 of the fly-eye lens FEL. In other words, the dichroic mirror DM is arranged so that the portion corresponding to the gap between the small-area dichroic mirrors SDM crosses the boundary 61 between the lens elements 60 obliquely.

[0102] In this case, if Fig.11 (B) and Fig.11 As shown in (C), even if the dichroic mirror DM is misaligned, the area of ​​the portion corresponding to the gap between the small-area dichroic mirror SDM and the lens element 60 overlaps almost unchanged before and after the misalignment. Fig.10 (A) and Fig.10 Compared with the case shown in (B), the illumination change can be reduced.

[0103] The other configurations are the same as those of the first embodiment, and therefore detailed descriptions thereof are omitted. It should be noted that the configuration of the second embodiment can also be applied to Modifications 1 to 4 of the first embodiment.

[0104] (Variation Example)

[0105] In the first and second embodiments described above, the plurality of small-area dichroic mirrors have the same shape and size and are regularly arranged, but the present invention is not limited thereto.

[0106] Fig.12 FIG. 4 is a top view showing a dichroic mirror DM5 according to a first variation of the second embodiment. Fig.12 As shown, the dichroic mirror DM5 includes a plurality of small-area dichroic mirrors SDMa, SDMb, SDMc, SDMd, ... having different sizes. The small-area dichroic mirrors SDMa, SDMb, SDMc, SDMd, ... are randomly arranged in a manner that the sides 56 are inclined and crossed with respect to the boundary 61 between the lens elements 60 of the fly-eye lens FEL in a plan view. It should be noted that at least two of the plurality of small-area dichroic mirrors only need to have different sizes from each other.

[0107] By arranging a plurality of small-area dichroic mirrors in a mosaic pattern as described above, it is possible to suppress changes in illumination when the dichroic mirrors are misaligned.

[0108] It should be noted that in the first embodiment and this modification, at least two of the plurality of small-area dichroic mirrors may have sizes different from each other.

[0109] It should be noted that, in the above-mentioned first and second embodiments and their variations, the plurality of small-area dichroic mirrors may have different film characteristics due to manufacturing errors during film formation, etc. In this case, the film characteristics of each small-area dichroic mirror are measured in advance, and the control unit CU may also adjust the intensity of the light emitted by each light-emitting portion 231A of the first light source array 20A and the intensity of the light emitted by each light-emitting portion 231B of the second light source array 20B according to the film characteristics of each small-area dichroic mirror. Thus, more uniform illumination light IL can be irradiated to the mask MSK.

[0110] The above-mentioned embodiments are preferred examples of the present invention, but are not limited thereto, and various modifications can be made without departing from the gist of the present invention.

[0111] Description of Reference Numerals

[0112] 10Exposure device

[0113] 20A 1st light source array

[0114] 20B Second light source array

[0115] 23A, 23B LED chips

[0116] 50, 50A, 50B substrate

[0117] 50a Side 1

[0118] 50b Page 2

[0119] 51 substrate

[0120] 52 dichroic film

[0121] 54A, 54B opening

[0122] 60 lens elements

[0123] 61 Boundary

[0124] 90 lighting units

[0125] 231A, 231B light emitting unit

[0126] DM, DM1, DM2, DM3, DM4, DM5 dichroic mirrors

[0127] FEL compound eye lens

[0128] MSK mask

[0129] OPU1 1st light source unit

[0130] OPU2 Second Light Source Unit

[0131] PL projection optical system

[0132] SDM, SDM1, SDM2, SDM3, SDMa, SDMb, SDMc, SDMd small area dichroic mirror

[0133] P glass substrate.

Claims

1. A synthetic optical element, comprising: A plurality of optical elements having a first substrate and a dichroic film; and 2nd substrate, The plurality of optical elements are arranged on the second substrate.

2. The synthetic optical element according to claim 1, wherein: The second substrate includes a first surface on which the plurality of optical elements are arranged and a second surface on the opposite side of the first surface, and the second substrate guides light incident from the second surface side to the plurality of optical elements.

3. The synthetic optical element according to claim 2, wherein: The plurality of optical elements are regularly arranged on the first surface of the second substrate.

4. The synthetic optical element according to claim 2, wherein: The plurality of optical elements are randomly arranged on the first surface of the second substrate.

5. The synthetic optical element according to any one of claims 1 to 4, wherein: At least two optical elements of the plurality of optical elements have different sizes from each other.

6. The synthetic optical element according to any one of claims 1 to 5, wherein: The first substrate and the second substrate are light-transmitting substrates.

7. The synthetic optical element according to claim 6, wherein: The first substrate and the second substrate are quartz glass substrates.

8. The synthetic optical element according to any one of claims 1 to 5, wherein: The first substrate is a light-transmitting substrate. The second substrate is a light-impermeable substrate. The second substrate has an opening, In a plan view, at least a portion of each of the plurality of optical elements overlaps with the opening.

9. The synthetic optical element according to claim 8, wherein: The second substrate has a plurality of openings. At least a portion of each of the plurality of optical elements overlaps with at least one of the plurality of openings.

10. The synthetic optical element according to any one of claims 1 to 9, wherein: The second substrate has a rectangular shape, The length of each side of the second substrate is at least 300 mm.

11. The synthetic optical element according to any one of claims 1 to 10, wherein: The size of the second substrate is larger than the upper limit size of the dichroic film that can be formed by the RAS sputtering device.

12. A lighting unit comprising: a first light source emitting light having a first wavelength characteristic; a second light source emitting light having a second wavelength characteristic different from the first wavelength characteristic; The synthetic optical element according to any one of claims 1 to 9; and a light uniformizing element for making the light beam emitted from the synthetic optical element have a uniform illumination distribution and emit the light beam; The dichroic film transmits light having the first wavelength characteristic and reflects light having the second wavelength characteristic.

13. The lighting unit according to claim 12, wherein: The light homogenizing element is a fly-eye lens having a plurality of lens elements. In a plan view, a boundary between adjacent optical elements among the plurality of optical elements or a gap between the adjacent optical elements overlaps with a boundary between the plurality of lens elements.

14. The lighting unit according to claim 12, wherein: The light homogenizing element is a fly-eye lens having a plurality of lens elements. In a plan view, the sides of the plurality of optical elements are inclined to cross with respect to the boundaries between the plurality of lens elements.

15. The lighting unit according to any one of claims 12 to 14, wherein: The first light source includes a first light source array in which a plurality of first light source elements are arranged, and the first light source element includes a first light emitting portion that emits light having the first wavelength characteristic. The second light source includes a second light source array in which a plurality of second light source elements are arranged, and the second light source element includes a second light emitting portion that emits light having the second wavelength characteristic.

16. The lighting unit according to claim 15, wherein: An adjustment unit is provided for adjusting the intensity of the light emitted from each of the first light emitting parts and the intensity of the light emitted from each of the second light emitting parts based on the optical characteristics of each of the plurality of optical elements.

17. An exposure device comprising: The lighting unit according to any one of claims 12 to 16; and The projection optical system projects the pattern image of the mask illuminated by the illumination unit onto the photosensitive substrate.

18. The exposure apparatus according to claim 17, wherein: The length of at least one side or the diagonal length of the photosensitive substrate is 500 mm or more.

19. An exposure method using the exposure apparatus according to claim 17 or 18, the exposure method comprising: illuminating the light shield using the illumination unit; as well as The pattern image of the mask is projected onto the photosensitive substrate using the projection optical system.

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