exposure equipment

Abstract

To prevent changes of a line width or thickness of a transfer pattern even in the case of using a non-additive photosensitive material.SOLUTION: An exposure apparatus includes: a stage which holds a substrate; a fly-eye lens including first and second lens elements; a first shading part which shades the first lens element; a second shading part which shades the second lens element; a diaphragm which sets an irradiation region of the substrate; and a control system which moves the first and second light shielding parts in a predetermined direction such that a shading amount changes. On an incidence plane, each of the first and second lens elements includes a first region corresponding to the diaphragm, and a second region corresponding to an opening of the diaphragm. In the state where, in an optical axis direction of the fly-eye lens, an end in a predetermined direction of the first shading part overlaps the first region of the first lens element but does not overlap the second region, and an end in a predetermined direction of the second shading part overlaps the second region of the second lens element, the control system moves the first and second shading part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an exposure apparatus. [Background technology]

[0002] A scanning exposure apparatus is known as an apparatus for exposing and transferring a pattern original on a mask to a large substrate by scanning the mask and substrate relative to a projection optical system. By scanning exposure, the exposure field is expanded in the scanning direction (scanning direction). In order to further expand the exposure field in a direction intersecting the scanning direction (non-scanning direction), exposure apparatuses that perform multiple scanning exposures with the exposure areas overlapping in the non-scanning direction are also known. Furthermore, a method is also known in which multiple projection optical systems are arranged in parallel in the non-scanning direction, and exposure is performed while overlapping a portion of the exposure field exposed by the multiple projection optical systems, thereby exposing and transferring an electronic circuit onto a substrate in a single scan (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2016-54230 Summary of the Invention

[0004] According to a first aspect, an exposure apparatus includes a stage for holding a substrate, a first lens element, and a second lens element, a fly's eye lens having an incident surface onto which illumination light is incident and positioned conjugate with the substrate, a first light-shielding portion positioned on the incident surface side of the fly's eye lens and shading at least a portion of the first lens element, a second light-shielding portion positioned on the incident surface side of the fly's eye lens and shading at least a portion of the second lens element, an aperture positioned on an optical path between the fly's eye lens and the substrate and conjugate with the substrate, and setting an irradiation area of ​​the substrate with the illumination light, and an amount of light shading of the first lens element by the first light-shielding portion and an amount of light shading of the second lens element by the second light-shielding portion. and a control system that moves the first light-shielding portion and the second light-shielding portion in a predetermined direction so as to change the amount of light-shielding of the second lens element that is incident on the first lens element and the second lens element, wherein, on the incident surface, each of the first lens element and the second lens element includes a first region that corresponds to the diaphragm and a second region that corresponds to an opening of the diaphragm, and the control system moves the first light-shielding portion and the second light-shielding portion in the predetermined direction in a state in which, in an optical axis direction of the fly's eye lens, an end of the first light-shielding portion in the predetermined direction overlaps with the first region of the first lens element but does not overlap with the second region of the second lens element. [Brief explanation of the drawings]

[0005] [Figure 1] FIG. 1 is a side view showing the configuration of an exposure apparatus according to a first embodiment. [Figure 2] FIG. 1 is a perspective view showing a part of an exposure apparatus according to a first embodiment. [Figure 3] FIG. 2 is an enlarged perspective view showing from the fly's eye lens to the mask of the exposure apparatus of the first embodiment. [Figure 4]4(a1), 4(a2), and 4(a3) are diagrams showing the relationship between the field of view on the mask and the field of view on the substrate in the exposure apparatus of the first embodiment. Figures 4(a1), 4(a2), and 4(a3) are diagrams showing the field of view on the mask, the field stop in the projection optical system, and the field of view on the substrate in the projection optical system 19c in Figure 1, respectively. Figures 4(b1), 4(b2), and 4(b3) are diagrams showing the field of view on the mask, the field stop in the projection optical system, and the field of view on the substrate in the projection optical system 19b in Figure 1, respectively. [Figure 5] 5(a) and 5(d) are diagrams showing an example of the exposure energy irradiated onto a substrate and the effective photosensitivity of a photosensitive material when the exposure apparatus of the first embodiment performs scanning exposure on the substrate. Fig. 5(a) shows the exposure field on the substrate of each projection optical system, Fig. 5(b) shows the exposure area formed on the substrate 22, Fig. 5(c) shows an example of the integrated exposure dose irradiated onto the substrate, and Fig. 5(d) shows an example of the effective photosensitivity of the photosensitive material. [Figure 6] FIG. 2 is a diagram showing the fly's eye lens, the light blocking member, and the light blocking member holding unit of the exposure apparatus of the first embodiment, as viewed from the light source side. [Figure 7] 7(a) and 7(c) are diagrams showing an example of the exposure energy irradiated onto a substrate and the effective photosensitivity of a photosensitive material when the exposure apparatus of the first embodiment performs scanning exposure on the substrate, respectively. Fig. 7(a) shows the exposure field of each projection optical system on the substrate, Fig. 7(b) shows an example of the integrated exposure dose irradiated onto the substrate, and Fig. 7(c) shows an example of the effective photosensitivity of the photosensitive material. DETAILED DESCRIPTION OF THE INVENTION

[0006] (First embodiment of exposure apparatus) Figure 1 is a side view showing exposure apparatus 100 of the first embodiment. As will be described later, exposure apparatus 100 is equipped with five projection optical systems 19a to 19e, but only two of these, projection optical systems 19a and 19b, are shown in Figure 1. The projection optical systems 19a to 19e are optical systems that form erect images with a projection magnification (lateral magnification) of +1, and transfer the pattern drawn on the mask 15 onto a photosensitive material formed on the upper surface of the substrate 22 by exposure.

[0007] The substrate 22 is held by a substrate stage 27 via a substrate holder (not shown). The substrate stage 27 is capable of scanning in the X direction on a substrate stage base 28 and moving in the Y direction by a linear motor (not shown) or the like. The position of the substrate stage 27 in the X direction is measured by a laser interferometer 25 via the position of a movable mirror 24 attached to the substrate stage 27. Similarly, the position of the substrate stage 27 in the Y direction is measured by a laser interferometer (not shown). The position detection optical system 23 detects the position of an existing pattern such as an alignment mark formed on the substrate 22 .

[0008] The mask 15 is held by a mask stage 16. The mask stage 16 is driven by a linear motor (not shown) or the like to scan in the X direction on a mask stage base 17 and is also movable in the Y direction. The position of the mask stage 16 in the X direction is measured by a laser interferometer 14 via the position of a movable mirror 13 attached to the mask stage 16. Similarly, the position of the mask stage 16 in the Y direction is measured by a laser interferometer (not shown).

[0009] A control system (not shown) controls linear motors (not shown) and the like based on measurement values ​​from laser interferometers 14, 25, etc. to control the XY positions of mask stage 16 and substrate stage 27. When exposing substrate 22 with the mask pattern, the control system (not shown) scans mask 15 and substrate 22 in the X direction at approximately the same speed relative to projection optical systems 19a to 19e while maintaining the imaging relationship between them formed by projection optical systems 19a to 19e. In this specification, the direction in which the substrate 22 is scanned during exposure (X direction) is also referred to as the "scanning direction." Furthermore, the direction (Y direction) that is included within the plane of the substrate 22 and is perpendicular to the X direction is also referred to as the "non-scanning direction." The Z direction is the direction perpendicular to the X and Y directions. In addition, the X, Y, and Z directions indicated by arrows in FIG. 1 and the following figures are positive directions.

[0010] 2 is a perspective view showing the portion from the downstream part of illumination optical systems ILa to ILe of exposure apparatus 100 of the first embodiment to substrate 22. Below, the description will continue with reference to FIG. 2, of the five projection optical systems 19a to 19e, three projection optical systems 19a, 19c, and 19e (hereinafter collectively or individually referred to as "first row projection optical system 19F") are arranged side by side in the Y direction. Two projection optical systems 19b and 19d (hereinafter collectively or individually referred to as "second row projection optical system 19R") are arranged side by side in the Y direction, and are located on the +X side of the first row projection optical system 19F. The optical axes of the projection optical systems 19F in the first row are arranged at predetermined intervals in the Y direction. The optical systems of the projection optical systems 19R in the second row are arranged in the same manner as the projection optical systems 19F in the first row. Furthermore, the projection optical system 19b is arranged so that the position of its optical axis in the Y direction coincides with approximately the center of the line connecting the optical axes of the projection optical systems 19a and 19c. Furthermore, the projection optical system 19d is arranged in the same manner as the projection optical system 19b.

[0011] The exposure apparatus 100 of the first embodiment is equipped with multiple illumination optical systems ILa-ILe, one for each of the projection optical systems 19a-19e. As an example, as shown in FIG. 1, the illumination optical system ILa corresponding to the projection optical system 19a is equipped with an input lens 8a, a fly's-eye lens 11a, and a condenser lens 12a along the optical axis IXa. Similarly, the other illumination optical systems ILb-ILe include input lenses 8b-8e, fly's-eye lenses 11b-11e, and condenser lenses 12b-12e. As mentioned above, FIG. 2 shows only the fly's-eye lenses 11a-11e and condenser lenses 12a-12e of the illumination optical systems ILa-ILe. 1, which is a side view, projection optical systems 19c to 19e are not shown because their positions in the X direction overlap with those of projection optical system 19a or 19b. Similarly, illumination optical systems ILc to ILe are not shown because their positions in the X direction overlap with those of illumination optical system ILa or ILb.

[0012] Illumination light supplied from a light source 1 such as a lamp is supplied to each of illumination optical systems ILa-ILe via a light-guiding optical system including an elliptical mirror 2, a bending mirror 3, a relay lens 4, a bending mirror 5, a relay lens 6, and an optical fiber 7. The optical fiber 7 splits the illumination light incident on a single incident side 71 approximately evenly and outputs it to five exit sides 72a-72e. The illumination light output from each of the five exit sides 72a-72e of the optical fiber 7 enters input lenses 8a-8e in each of illumination optical systems ILa-ILe. The illumination light then passes through fly-eye lenses 11a-11e and condenser lenses 12a-12e and is irradiated onto each of illumination areas MIa-MIe on a mask 15.

[0013] FIG. 3 is an enlarged perspective view of a fly-eye lens 11c and a condenser lens 12c included in the illumination optical system ILc, and an illumination area MIc on the mask 15, as an example. The fly's eye lens 11c is formed by arranging a plurality of lens elements 110 in the X and Y directions, each having a rectangular cross-sectional shape (shape in the XY plane) that is elongated in the Y direction and similar to the illumination area MIc. The incident surface of each lens element 110 (the upper surface in FIG. 3, i.e., the surface on the +Z side) is a conjugate plane with respect to the illumination area MIc on the mask 15, due to the optical system consisting of each lens element 110 and the condenser lens 12c. Therefore, it is also a conjugate plane with respect to the exposure field PIc on the substrate 22. The illumination light irradiated onto the incident surface of each lens element 110 is irradiated onto the illumination area MIc on the mask 15 in a superimposed manner. This makes the illuminance of the illumination light within the illumination area MIc approximately uniform.

[0014] The configurations of the illumination optical systems ILa to ILe other than the illumination optical system ILc are similar to the configuration shown in FIG. The fly-eye lenses 11a to 11e are an example of an optical integrator that irradiates the illumination areas MIa to MIe with superimposed illumination light.

[0015] Each of the projection optical systems 19a to 19e is configured, for example, by a double-imaging optical system in order to form an erect, normal image. In this case, an intermediate image of the pattern of the mask 15 is formed on an intermediate image plane 20 located near the middle of each of the projection optical systems 19a to 19e in the direction of the optical axes PXa to PXe (Z direction) by the optical system that constitutes the upper half of each of the projection optical systems 19a to 19e. The intermediate image is then re-imaged by the optical system that constitutes the lower half of each of the projection optical systems 19a to 19e, and an image of the pattern of the mask 15 is formed on the substrate 22.

[0016] Since the intermediate image plane 20 is conjugate with the substrate 22, by placing field stops 21a to 21e at the intermediate image plane 20 in each projection optical system 19a to 19e, respectively, it is possible to define the exposure fields PIa to PIe on the substrate 22 by each projection optical system 19a to 19e.

[0017] FIG. 4 is a diagram showing the relationship between illumination areas MIa to MIe on mask 15, field stops 21a to 21e, and exposure fields PIa to PIe. FIG. 4(a1) is a diagram showing an illumination area MIc on the mask 15 corresponding to the projection optical system 19c, and the illumination area MIc has a rectangular shape similar to the cross-sectional shape of the lens element 110 of the fly-eye lens 11c.

[0018] 4(a2) is a diagram showing the field stop 21c in the projection optical system 19c and the illumination light MIc2 irradiated thereto. The field stop 21c is irradiated with the illumination light MIc2 indicated by the dashed line, which is an intermediate image of the illumination area MIc on the mask 15. Of the illumination light MIc2, the illumination light irradiated onto the light-shielding portion of the field stop 21c (the portion indicated by diagonal lines) is blocked by the field stop 21c. On the other hand, the illumination light transmitted through the opening 21co of the field stop 21c is imaged again on the substrate 22 by the optical system that constitutes the lower half of the projection optical system 19c, forming an exposure field PIc on the substrate 22.

[0019] FIG. 4( a 3 ) is a diagram showing the exposure field PIc on the substrate 22 . As an example, when the projection optical systems 19c-19e are all refractive optical systems, the intermediate image, illumination light MIC2, is an inverted, normal image relative to the illumination area MIc (the image is inverted in both the X and Y directions and is not a mirror image), and the exposure field PIc is an inverted, normal image relative to the field stop 21c. Therefore, as shown in Figures 4(a2) and 4(a3), the shape of the opening 21co of the field stop 21c and the shape of the exposure field PIc are the same as if they were rotated 180 degrees around the Z axis.

[0020] As an example, the exposure field PIc is a trapezoid with the shorter side of the two sides parallel to the Y direction on the +X side and the longer side on the -X side. Here, the rectangular region of the exposure field PIc enclosed by the entire short side on the +X side and part of the long side on the -X side is called the central region PIcc. Meanwhile, the end of the exposure field PIc in the +Y direction that is not included in the central region PIcc is called the left edge region PIcl, and the end of the exposure field PIc in the -Y direction that is not included in the central region PIcc is called the right edge region PIcr. The length (width) in the Y direction of the central region PIcc is called width Ws, and the lengths (widths) in the Y direction of the left edge region PIcl and the right edge region PIcr are equal and called width Wo.

[0021] On the other hand, Figures 4(b1) to 4(b3) are diagrams showing the illumination area MIb on the mask 15, the field stop 21b, and the exposure field PIb, which correspond to the projection optical system 19b, respectively. As shown in Figure 4(b2), in the projection optical system 19b, the shape of the opening 21bo of the field stop 21b is the inverse in the X direction of the shape of the opening 21co of the field stop 21c of the projection optical system 19c. As a result, as shown in Figure 4(b3), the shape of the exposure field PIb of the projection optical system 19b is the inverse in the X direction of the shape of the exposure field PIc of the projection optical system 19c.

[0022] As with the above-described exposure field PIc, the rectangular region of the exposure field PIb enclosed by the entire short side on the -X side and part of the long side on the +X side is called the central region PIbc. The end of the exposure field PIb in the +Y direction that is not included in the central region PIbc is called the left edge region PIbl, and the end of the exposure field PIb in the -Y direction that is not included in the central region PIbc is called the right edge region PIcr.

[0023] 5(a) is a diagram showing the exposure fields PIa to PIe of the five projection optical systems 19a to 19e on the substrate 22. The exposure fields PIa and PIe of the projection optical systems 19a and 19e, which are the first row of projection optical systems 19F, are trapezoids, with the shorter of the two sides parallel to the Y direction on the +X side and the longer of the two sides parallel to the Y direction on the -X side, similar to the exposure field PIc of the projection optical system 19c described above. On the other hand, the exposure field PId of the projection optical system 19d, which is the second row of projection optical systems 19R, is a trapezoid, with the shorter of the two sides parallel to the Y direction on the -X side and the longer of the two sides parallel to the Y direction on the +X side, similar to the exposure field PIb of the projection optical system 19b described above.

[0024] Similarly to the above-described exposure fields PIb and PIc, the exposure fields PIa, PId, and PIe of the projection optical systems 19a, 19d, and 19e can also be defined as having central regions PIac, PIdc, and PIec, as well as left edge regions PIal, PIdl, and PIel, and right edge regions PIar, PIdr, and PIer. However, the exposure field PIa, located at the end in the -Y direction, does not have a right edge region PIar because the field stop 21a blocks the illumination light so that its -Y edge is parallel to the X direction. The exposure field PIe, located at the end in the +Y direction, does not have a left edge region PIal because the field stop 21a blocks the illumination light so that its +Y edge is parallel to the X direction. The shapes of the field stops 21a and 21e may be different from the shape of the field stop 21c, or a separate member may be used to block the illumination light so that the right edge region PIar does not exist in the exposure field PIa.

[0025] The length in the Y direction of each of the central regions PIac-PIec of each of the exposure fields PIa-PIe is equal to the width Ws, and the lengths of the left edge regions PIal-PIdl and right edge regions PIbr-PIer are equal to the width Wo. In two of the exposure fields PIa-PIe that are adjacent in the Y direction, the positions in the Y direction of the adjacent left edge regions PIal-PIdl and right edge regions PIbr-PIer coincide. The shapes and positions of the exposure fields PIa to PIe are set by setting the positions of the projection optical systems 19a to 19e and the shapes and positions of the openings 21ao to 21eo of the field stops 21a to 21e.

[0026] Fig. 5(b) is a diagram showing exposure areas formed on the substrate 22 when the substrate 22 is scanned in the X direction by the substrate stage and exposed by the exposure fields PIa-PIe shown in Fig. 5(a). Scanning exposure fields SIa-SIe are formed on the substrate 22, exposed by each exposure field PIa-PIe through scanning exposure. In Fig. 5(b), the scanning exposure fields SIa, SIc, and SIe formed by the first row of projection optical systems 19a, 19c, and 19e are indicated by two-dot chain lines, and the scanning exposure fields SIb and SId formed by the second row of projection optical systems 19b and 19d are indicated by one-dot chain lines.

[0027] These scanning exposure fields SIa-SIe are formed by extending the exposure fields PIa-PIe in the X direction through scanning exposure in the X direction. The Y-direction (non-scanning direction) end of each scanning exposure field SIa-SIe overlaps with the non-scanning direction end of each adjacent scanning exposure field SIa-SIe. For example, the exposure area by the left edge region PIal and the exposure area by the right edge region PIbr coincide with each other. This is the same for the other exposure fields, so a description thereof will be omitted.

[0028] 5(c) is a graph showing the integrated exposure amount E exposed on substrate 22 by scanning exposure in the X direction. The vertical axis of the graph represents the integrated exposure amount, and the horizontal axis represents the coordinate in the Y direction. As shown in FIG. 5(a), the values ​​obtained by integrating each of exposure fields PIa-PIe in the X direction in each small section in the Y direction are equal, and the illuminance in each of exposure fields PIa-PIe is uniform due to the action of fly's eye lens 11, etc., so the integrated exposure amount E on substrate 22 is a constant value E1. That is, in the Y direction, the integrated exposure amount E in the portion Sa to Se exposed by one of the scanning exposure fields SIa to SIe (hereinafter also referred to as the "non-overlapping portion") and the integrated exposure amount E in the portion Oa to Od exposed by two of the scanning exposure fields SIa to SIe overlapping each other (hereinafter also referred to as the "overlapping portion") are both equal, with the value of the integrated exposure amount E being E1.

[0029] In photosensitive materials such as photoresists used in the manufacturing process of electronic devices, the effective photosensitivity (hereinafter referred to as "effective photosensitivity") is proportional to the cumulative exposure. In other words, if the cumulative exposure is the same, the effective photosensitivity of the photosensitive material remains the same whether the exposure is performed continuously or in multiple divided periods. Therefore, the effective amount of light exposure to the photosensitive material also becomes a constant value.

[0030] However, with some photosensitive materials, the effective photosensitivity of the photosensitive material changes depending on whether the exposure is continuous or divided into multiple periods, even if the cumulative exposure amount is the same. Specifically, when the exposure is divided into multiple periods, the effective photosensitivity decreases compared to when the exposure is continuous.

[0031] FIG. 5(d) is a graph showing the effective photosensitivity EE of some of such photosensitive materials (hereinafter also referred to as "non-additive photosensitive materials") when scanning exposure is performed in the X direction using the exposure fields PIa to PIe shown in FIG. 5(a). The overlapping portions Oa-Od, which are exposed when two of the scanning exposure fields SIa-SIe overlap, are first exposed by the first row of projection optical systems 19a, 19c, and 19e, and then by the second row of projection optical systems 19b and 19d, resulting in temporally separated exposure. In other words, the overlapping portions Oa-Od are exposed discretely. Therefore, the effective photosensitivity EE of the overlapping portions Oa-Od is lower than the effective photosensitivity EE of the non-overlapping portions Sa-Se, which are exposed by one of the scanning exposure fields SIa-SIe without being temporally separated. Specifically, the effective photosensitivity EE of the non-overlapping portions Sa-Se is EE1, while the effective photosensitivity EE of the overlapping portions Oa-Od is smaller than EE1.

[0032] As a result, when a pattern is exposed and transferred using a non-additive photosensitive material, the effective photosensitivity EE differs between the overlapping portions Oa-Od and the non-overlapping portions Sa-Se, resulting in changes in the line width and thickness of the transferred pattern.

[0033] Therefore, in the exposure apparatus 100 of the first embodiment, light shielding members 10a-10e are provided on the incident surface side of each of the fly-eye lenses 11a-11e of the illumination optical systems ILa-ILe, that is, at positions between the input lenses 8a-8e and the fly-eye lenses 11a-11e, and in the vicinity of the incident surfaces of the fly-eye lenses 11a-11e. The light shielding members 10a-10e are held by light shielding member holders 9a-9e so as to be movable in the X direction, which is a direction substantially perpendicular to the optical axes Ixa-Ixe of the illumination optical systems ILa-ILe, respectively.

[0034] Fig. 6 is a view of the fly-eye lens 11c, light blocking member 10c, and light blocking member holder 9c provided in the illumination optical system ILc, viewed from the input lens 8c side. The light blocking member 10c and light blocking member holder 9c provided in the illumination optical system ILc will be described below with reference to Fig. 6, but the same applies to the light blocking members 10a-10e and light blocking member holders 9a-9e provided in the other illumination optical systems ILa-ILe.

[0035] The fly's eye lens 11c has a plurality of lens blocks arranged in the Y direction, each of which has a rectangular cross section that is longer in the Y direction and is arranged in the X direction. Each lens element 110 is conjugate to the exposure field PIc formed on the substrate 22, and therefore in Figure 6, an area (exposure field corresponding area) IPIc corresponding to the exposure field PIc is shown by a dashed line within each lens element 110. Of the exposure field corresponding area IPIc, the width in the Y direction of a portion corresponding to the central area PIcc of the exposure field PIc is width IWs.

[0036] Two light-shielding members 10c1 and 10c2 constituting light-shielding member 10c are arranged near the +Z side of one or more lens elements 110 arranged on the -X direction side of two of the lens blocks. Widths W1 and W2 in the Y direction of light-shielding members 10c1 and 10c2 are approximately equal to the width IWs described above.

[0037] Light shielding members 10c1 and 10c2 are held by a slider 9c1 that is part of light shielding member holding unit 9c, and slider 9c1 is movable in the X direction relative to the main body of light shielding member holding unit 9c by a control system (not shown). The relative positional relationship between slider 9c1 and the main body of light shielding member holding unit 9c is measured by an encoder or the like. Light-shielding member holding unit 9c moves light-shielding members 10c1 and 10c2 in the X direction, thereby allowing light-shielding members 10c1 and 10c2 to shield some of lens elements 110. As described above, light-shielding members 10c1 and 10c2 have widths W1 and W2 in the Y direction that are substantially equal to width IWs. Therefore, light-shielding members 10c1 and 10c2 can block light that is irradiated from some of lens elements 110 onto a central region PIcc of an exposure field PIc on substrate 22. Furthermore, by controlling slider 9c1, the number of lens elements 110 that are shielded by light-shielding members 10c1 and 10c2 and the proportion of the light-shielded portion within each lens element 110 can be changed. This allows the illuminance of the central region PIcc of the exposure field PIc to be reduced substantially continuously and variably relative to the illuminance of the left edge region PIcl and the right edge region PIcr.

[0038] Therefore, the light blocking member 10c can be interpreted as an illuminance changing member that reduces the integrated exposure amount to the non-overlapping portion on the substrate 22 relative to the integrated exposure amount to the overlapping portion. The light-shielding member 10c may be a thin metal plate or a light-shielding film formed of a light-shielding member on a transparent glass plate. The light-shielding member 10c is not limited to a member that completely blocks illumination light like a filter, but may be a member that blocks or transmits only a portion of illumination light. In other words, the light-shielding member 10c may be an illuminance-changing member that changes illuminance. The light shielding members 10a to 10e and light shielding member holders 9a to 9e provided in the other illumination optical systems ILa to ILe have the same structures as the light shielding member 10c and light shielding member holder 9c described above.

[0039] Figure 7 is a diagram illustrating the results when a pattern is exposed and transferred using a non-additive photosensitive material in the exposure apparatus 100 of the first embodiment equipped with light-shielding members 10a to 10e. Figure 7(a) shows the exposure fields PIa to PIe on the substrate 22, similar to Figure 5(a). Figure 7(b) is a graph showing the integrated exposure amount E exposed on the substrate 22 by scanning exposure in the X direction, similar to Figure 5(c). 7(b), light shielding members 10a-10e are inserted into the entrance planes of fly-eye lenses 11a-11e by light shielding member holders 9a-9e. Therefore, the integrated exposure amount E2 of non-overlapping portions Sa-Se exposed by one of scanning exposure fields SIa-SIe is smaller than the integrated exposure amount E3 of overlapping portions Oa-Od exposed by overlapping two of scanning exposure fields SIa-SIe.

[0040] Fig. 7(c) is a graph showing the effective exposure amount EE produced in the non-additive photosensitive material described above by the integrated exposure amount shown in Fig. 7(b). By reducing the integrated exposure amount E2 of the non-overlapping portions Sa-Se, which are exposed without being divided in time, compared to the integrated exposure amount E3 of the overlapping portions Oa-Od, which are exposed in divided in time, the characteristics of the non-additive photosensitive material are offset, and the effective exposure amount EE can be kept at a substantially constant value EE2. This makes it possible to prevent changes in the line width and thickness of the transferred pattern between the overlapping areas Oa-Od where each scanning exposure field SIa-SIe overlaps and the non-overlapping areas Sa-Se, even when a pattern is exposed and transferred using a non-additive photosensitive material.

[0041] Because the light blocking member 10c is disposed at a position a predetermined distance in the Z direction from the incident surface of the fly-eye lens 11c, the edges of the light blocking member 10c in the X and Y directions are projected blurred on the incident surface of the fly-eye lens 11c. Conversely, the distance in the Z direction from the incident surface of the fly-eye lens 11c to the substrate 22 can be determined based on the lateral magnification between the incident surface of the fly-eye lens 11c and the substrate 22 and the numerical aperture of the illumination light at the incident surface of the fly-eye lens 11c, which are parameters that determine the amount of penumbra of the edge of the light blocking member 10c on the substrate 22. Furthermore, the Y-direction width of the overlapping portions Oa to Od on the substrate 22 can also be taken into consideration when determining the distance. In addition, the light-shielding member holding portions 9a to 9e may be configured to be able to change the position of the light-shielding members 10a to 10e in the Z direction relative to the incident surfaces of the fly-eye lenses 11a to 11e, that is, to be able to change the distance between the light-shielding members 10a to 10e and the fly-eye lenses 11a to 11e in the Z direction.

[0042] As an example, when the width of the overlapping portions Oa to Od in the Y direction is DW, the lateral magnification of the substrate 22 with respect to the incident surface of the fly-eye lens 11c is β, and the numerical aperture of the illumination light at the incident surface of the fly-eye lens 11c is NA, the distance D of the light blocking member 10c in the Z direction from the incident surface of the fly-eye lens 11c is 0 ≦ D ≦ 1.2×DW / (β·NA) ···(1) It is best to do so. When the distance D satisfies the formula (1), the influence of the change in the exposure amount (unevenness in the exposure amount) on the substrate 22 due to the edge of the light-shielding member 10c can be further reduced, and the integrated exposure amount of the overlapping portions Oa to Od can be prevented from decreasing more than necessary.

[0043] The relationship between the effective photosensitivity and cumulative exposure of a non-additive photosensitive material for exposures that are divided into time periods differs for each non-additive photosensitive material. Therefore, before actually exposing a specific non-additive photosensitive material, it is advisable to perform test exposures under a number of conditions, for example, by setting the insertion amount (position in the X direction) of the light blocking member 10c at several different levels, that is, by changing the number of lens elements 110 blocked by the light blocking member 10c, and then determine the optimal insertion amount from the results. Furthermore, when determining the insertion amount of the light blocking member 10c, it is advisable to use the illuminance sensor 26 provided on the substrate stage 27 while measuring the illuminance in the central area PIcc within the exposure field of view PIc.

[0044] 6, the +X-direction ends of the two light-shielding members 10c1 and 10c2 that make up the light-shielding member 10c are offset by half the pitch PX of the X-direction arrangement of the lens elements 110 of the fly's-eye lens 11c. As described above, each lens element 110 has an exposure field-corresponding area IPIc that corresponds to the exposure field PIc, but the exposure field-corresponding area IPIc does not extend over the entire surface of the lens element 110 in the X direction. In other words, the X-direction ends of the lens element 110 do not correspond to the exposure field PIc on the substrate 22, but are projected onto the field stop 21c in the projection optical system 19c and are blocked by the field stop 21c.

[0045] Therefore, if the +X-direction ends of the light-shielding members 10c1 and 10c2 are near the X-direction ends of the lens element 110, the integrated exposure amount on the substrate 22 cannot be changed even if the light-shielding members 10c1 and 10c2 are moved in the X direction. Therefore, in the first embodiment, the +X direction ends of the two light blocking members 10c1 and 10c2 are shifted by half the pitch PX of the arrangement of the lens elements 110 in the X direction.

[0046] With this arrangement, when the +X-direction end of one of the two light-shielding members 10c1, 10c2 is near both ends of the lens element 110 in the X direction, the +X-direction end of the other is located near the center of the lens element 110 in the X direction. Therefore, by moving both the two light-shielding members 10c1, 10c2 in the X direction, the integrated exposure amount on the substrate 22 can be constantly changed. Note that the lengths of the two light-shielding members 10c1, 10c2 in the X direction may be equal. In this case, it is preferable to configure the light-shielding members 10c1 and 10c2 so that they can be moved independently in the X direction. This allows the light-shielding amount to be different for each lens element 110.

[0047] The number of light blocking members 10c1 and 10c2 is not limited to two as described above, but may be three or more, and each may be arranged in a different lens block. In this case, too, if the number of light blocking members is m (m is a natural number greater than or equal to 2), it is preferable that the end of each light blocking member in the +X direction is shifted by PX / m with respect to the pitch PX.

[0048] Although the light blocking member 10c has been described as being disposed at a position a predetermined distance in the Z direction from the incident surface of the fly-eye lens 11c, this is not limiting. The light blocking member 10c may be disposed at a position that is the incident surface of the fly-eye lens 11c, i.e., a conjugate plane of the substrate. In this case, the light blocking member 10c may be one whose shape (width) in the Y direction changes according to the position in the X direction, or one whose light blocking rate for illumination light changes continuously according to the position in the Y direction, like a filter whose transmittance changes depending on the location. If the light blocking member 10c completely blocks illumination light, there is a risk that the ratio of the integrated exposure amount of the overlapping portions Oa-Od to ​​the integrated exposure amount of the non-overlapping portions Sa-Se will change discontinuously, and this can be prevented.

[0049] (Variation) In the first embodiment described above, there are five projection optical systems 19a to 19e, but the number of projection optical systems is not limited to five and may be any number, such as three or eight. Furthermore, in the first embodiment described above, there are multiple projection optical systems 19a to 19e, and multiple exposure fields SIa to SIe formed by each projection optical system overlap each other in the Y direction with one scan in the X direction. However, it is also possible to use a single projection optical system, perform scanning exposure of substrate 22 in the X direction multiple times while moving substrate 22 and mask 15 in the Y direction, and have multiple exposure fields formed by each scanning exposure overlap each other in the Y direction. In this case, too, it is desirable that the illumination optical system corresponding to one projection optical system has a configuration similar to that of the illumination optical systems ILa to ILe described above. An apparatus having a plurality of projection optical systems 19a to 19e as in the first embodiment described above can expose a larger area on the substrate 22 in one scanning exposure, and has excellent processing capacity.

[0050] In the first embodiment described above, the plurality of projection optical systems 19a to 19e are all-refractive optical systems, but the present invention is not limited to this, and catadioptric systems or all-reflection optical systems may also be used. Furthermore, in the first embodiment described above, the shape of the exposure fields PIa to PIe is a trapezoid, but this is not limited to a trapezoid, and for example, the shape of the part corresponding to the central part may be an arc, and the field may have triangular right and left end regions at both ends of the arc.

[0051] In the above embodiment, the optical axes PXa to PXe of the projection optical systems 19a to 19e and the optical axes IXa to IXe of the illumination optical systems ILa to ILe are basically set parallel to the Z direction. However, if a bending mirror is used in any of the optical systems, the orientation of the optical axis will no longer be parallel to the Z direction. Furthermore, if a deflection mirror is used in any of the optical systems, the movement direction of the light blocking members 10a-10e will also be different from the scanning direction (X direction) of the substrate 22. However, even in this case, the light blocking members 10a-10e should be movable in a direction optically corresponding to the scanning direction of the substrate 22 based on the conjugate relationship between the substrate 22 including the deflection mirror and the fly-eye lenses 11a-11e.

[0052] Furthermore, in the above embodiment, each of the projection optical systems 19a to 19e is arranged in two rows in the X direction, namely, the first row of projection optical systems 19F and the second row of projection optical systems 19R. However, this is not limited to two rows, and three or more rows of optical systems may be arranged in the X direction.

[0053] A rod integrator can be used as the optical integrator instead of the above-described fly-eye lens 11. When a rod integrator is used, the conjugate plane between the substrate 22 and the mask 15 is on the exit side (the side of the mask 15) of the rod integrator, so the light-shielding member 10 is also placed near the exit side of the rod integrator. This is configured to partially shield the vicinity of one end of the exit surface of the rod integrator on the X side.

[0054] Instead of arranging the light-shielding members 10a-10e inside the illumination optical systems ILa-ILe, they may be arranged near the intermediate image plane 20 of the projection optical systems 19a-19e. In this case, too, the light-shielding members are configured to shield the portions near the intermediate image plane 20 that correspond to the central regions PIac-PIec of the exposure fields PIa-PIe.

[0055] Instead of placing field stops 21a to 21e within the projection optical systems 19a to 19e, an intermediate image plane (a conjugate plane to the mask 15) may be provided within the illumination optical systems ILa to ILe, and a field stop that determines the shape of the exposure field PIa to PIe on the substrate 22 may be provided at the intermediate image plane within the illumination optical systems ILa to ILe.

[0056] In the above embodiment, the projection optical systems 19a to 19e and the illumination optical systems ILa to ILe are fixed, and the substrate 22 is moved by the substrate stage 27. Alternatively, the projection optical systems 19a to 19e and the illumination optical systems ILa to ILe may be mounted on a scanning stage and scanned relative to the substrate 22. Furthermore, the mask 15 is not limited to a mask in which a pattern is formed on a glass substrate, but may be a variable shaping mask made of a digital multi-mirror device or a liquid crystal device.

[0057] According to the first embodiment and the modified example described above, the following advantageous effects can be obtained. (1) The exposure apparatus of the first embodiment or the modified example comprises projection optical systems 19a to 19e, illumination optical systems ILa to ILe that supply illumination light to the projection optical systems 19a to 19e, and a scanning stage (substrate stage) 27 that relatively scans the exposed substrate 22 and the projection optical systems 19a to 19e in the scanning direction, and exposes the exposed substrate 22 by overlapping multiple scanning exposure fields SIa to SIe by the projection optical systems 19a to 19e in the non-scanning direction, and the illumination optical systems ILa to ILe or the projection optical systems 19a to 19e have illuminance changing members 10a to 10e that set the integrated exposure amount of non-overlapping portions Sa to Se that are exposed without overlap on the exposed substrate 22 during exposure to be smaller than the integrated exposure amount of overlapping portions Oa to Od that are exposed with overlap on the exposed substrate 22. With this configuration, even when a pattern is exposed and transferred using a non-additive photosensitive material in which the effective photosensitivity is reduced when exposure is performed in multiple time segments compared to when exposure is performed continuously, it is possible to prevent changes in the line width and thickness of the transferred pattern between the overlapping areas Oa-Od where each scanning exposure field SIa-SIe overlaps and the non-overlapping areas Sa-Se.

[0058] (2) The illumination optical systems ILa to ILe include optical integrators 11a to 11e, and the illuminance changing members 10a to 10e are light-shielding members 10a to 10e that are provided in the vicinity of the conjugate plane of the optical integrators 11a to 11e with the exposed substrate 22, and are positioned a predetermined distance away from the conjugate plane in the direction of the optical axes IXa to IXe of the illumination optical systems ILa to ILe, determined according to the width Wo of the overlapping portions Oa to Od in the non-scanning direction, the lateral magnification between the conjugate plane and the exposed substrate 22, and the numerical aperture of the illumination light at the conjugate plane, and the illuminance changing members 10a to 10e have light-shielding member holding portions 9a to 9e that hold the light-shielding members 10a to 10e movably in a first direction that is approximately perpendicular to the optical axes IXa to IXe of the illumination optical systems ILa to ILe and optically corresponds to the scanning direction. With this configuration, by moving the light blocking members 10a to 10e in the first direction, the ratio of the integrated exposure amount of the overlapping portions Oa to Od to ​​the integrated exposure amount of the non-overlapping portions Sa to Se can be reduced while being changed almost continuously.

[0059] Although various embodiments and modifications have been described above, the present invention is not limited to these. Furthermore, each embodiment and modification may be applied independently or in combination. Other aspects conceivable within the scope of the technical concept of the present invention are also included within the scope of the present invention.

[0060] The disclosures of the following priority applications are incorporated herein by reference: Japanese Patent Application No. 2019-002235 (filed January 9, 2019) [Explanation of symbols]

[0061] 100: exposure apparatus, 1: light source, ILa to ILe: illumination optical system, 10a to 10e: light blocking member (illuminance changing member), 11a to 11e: fly-eye lens, 12a to 12e: condenser lens, 15: mask, MIa to MIe: illumination field, 19a to 19e: projection optical system, 21a to 21e: field stop, 22: substrate, SIa to SIe: scanning exposure field, Sa to Se: non-overlap portion, Oa to Od: overlap portion

Claims

1. a stage for holding the substrate; a fly-eye lens including a first lens element and a second lens element, the incident surface of which is incident on the illumination light and is located at a position conjugate with the substrate; a first light-shielding portion located on the incident surface side of the fly-eye lens and blocking at least a portion of the first lens element; a second light-shielding portion located on the incident surface side of the fly-eye lens and blocking at least a portion of the second lens element; a diaphragm that is located on an optical path between the fly-eye lens and the substrate and at a position conjugate with the substrate, and that sets an irradiation area of ​​the substrate with the illumination light; a control system that moves the first light-blocking portion and the second light-blocking portion in a predetermined direction so that an amount of light blocking of the first lens element by the first light-blocking portion and an amount of light blocking of the second lens element by the second light-blocking portion are changed, On the entrance surface, each of the first lens element and the second lens element includes a first region corresponding to the diaphragm and a second region corresponding to an opening of the diaphragm, an exposure apparatus, wherein the control system moves the first light-shielding portion and the second light-shielding portion in the predetermined direction in a state in which, in the optical axis direction of the fly-eye lens, an end of the first light-shielding portion in the predetermined direction overlaps with the first region of the first lens element but does not overlap with the second region, and an end of the second light-shielding portion in the predetermined direction overlaps with the second region of the second lens element.

2. 2. The exposure apparatus according to claim 1, the first light-shielding portion and the second light-shielding portion are provided near the incident surface of the fly-eye lens, the fly's eye lens includes a first lens block including a plurality of the first lens elements arranged in a first direction, and a second lens block including a plurality of the second lens elements arranged in the first direction and aligned with the first lens block in a second direction intersecting the first direction, an exposure device, wherein the first light-shielding portion and the second light-shielding portion each extend in the predetermined direction so that, as the first light-shielding portion and the second light-shielding portion move in the predetermined direction, the number of first lens elements that overlap with the first light-shielding portion and the number of second lens elements that overlap with the second light-shielding portion increase in the optical axis direction.

3. 3. The exposure apparatus according to claim 2, a projection optical system including the aperture, the stage moves the substrate relative to the projection optical system in the scanning direction and in a non-scanning direction intersecting the scanning direction so that an overlapping portion of the substrate extending in the scanning direction is irradiated a plurality of times with light passing through the projection optical system; an exposure apparatus, wherein the first and second light-shielding portions are provided at positions away from the incident surface in the optical axis direction by a predetermined distance determined according to the width of the overlapping portion in the non-scanning direction, the lateral magnification between the incident surface and the substrate, and the numerical aperture of the illumination light at the incident surface.

4. 2. The exposure apparatus according to claim 1, an exposure apparatus, wherein the first light-shielding portion and the second light-shielding portion are provided at the incident surface, or at a conjugate position conjugate with the incident surface that is closer to the light source than the incident surface, or at a position a predetermined distance away from the conjugate position.

5. 5. The exposure apparatus according to claim 4, The exposure apparatus, wherein the control system moves the first light-shielding portion and the second light-shielding portion independently in the predetermined direction.

6. 6. The exposure apparatus according to claim 5, a projection optical system including the aperture, the stage moves the substrate relative to the projection optical system in the scanning direction and in a non-scanning direction intersecting the scanning direction so that an overlapping portion of the substrate extending in the scanning direction is irradiated a plurality of times with light passing through the projection optical system; an exposure apparatus, wherein the first and second light-shielding portions are provided at positions away from the incident surface in the optical axis direction by a predetermined distance determined according to the width of the overlapping portion in the non-scanning direction, the lateral magnification between the incident surface and the substrate, and the numerical aperture of the illumination light at the incident surface.

7. 7. The exposure apparatus according to claim 6, In the fly-eye lens, a plurality of lens blocks each including a plurality of lens elements arranged in a first direction intersecting the optical axis direction are arranged in a second direction intersecting the optical axis direction and the first direction, An exposure apparatus, wherein the shading member shades at least a portion of a portion of one or more lens elements arranged on one side of at least one of the lens blocks in the first direction that is conjugate with a non-overlapping portion other than the overlapping portion.

8. 8. The exposure apparatus according to claim 7, An exposure apparatus, wherein m light blocking members are arranged corresponding to m lens blocks (m is a natural number of 2 or more) out of the plurality of lens blocks.

9. 9. The exposure apparatus according to claim 8, an exposure apparatus, wherein the ends of the m light-shielding members on the other side opposite the one side in the first direction are set at positions that differ from each other by P / m in the first direction, where P is the period of the arrangement of the lens elements in the lens block in the first direction.

10. 10. The exposure apparatus according to claim 6, a plurality of illumination optical systems, each including the projection optical system and the fly-eye lens, arranged in parallel; an exposure apparatus that exposes the substrate by overlapping scanning exposure fields of a plurality of the projection optical systems in the non-scanning direction in a single scanning exposure;

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