Exposure device, exposure container, and exposure system

Abstract

Provided is an exposure device capable of improving accuracy in three-dimensional optical shaping of a swollen gel. An exposure device (1) comprises: an imaging optical system that forms an image on a swollen gel (41) by an exposure beam (LE); an illumination optical system (20) that irradiates a substrate (a bottom plate of a petri dish 42) on which the gel (41) is placed with illumination light (LL); and a detection optical system (30) that forms an image of reflected or scattered light of the illumination light (LL) reflected or scattered at each point on the substrate (a bottom plate 421 of the petri dish 42) at each point of a photodetector (35).

Description

Exposure apparatus, exposure container, and exposure system

[0001] The present invention relates to an exposure apparatus, an exposure container, and an exposure system.

[0002] A stereolithography method is known in which a desired pattern is formed in a swollen gel by exposing the gel to light. An example of such a stereolithography method is the Implosion Fabrication (hereinafter abbreviated as ImpFab) method (see Patent Document 1 and Non-Patent Document 1). The ImpFab method exposes the gel using a high-magnification, high-NA objective lens, allowing for stereolithography of micrometer-scale or nanometer-scale patterns. An example of an objective lens used in the ImpFab method is an objective lens with a magnification of 20x and an NA of 1.0. When using this objective lens, the actual field of view is, for example, approximately 600 μm × 600 μm. Furthermore, the ImpFab method applies the principle of multiphoton absorption to perform stereolithography. Therefore, in addition to stereolithography in the in-plane direction parallel to the main surface of the gel, stereolithography can also be performed in the thickness direction perpendicular to the main surface of the gel.

[0003] US Patent Application Publication No. 2017 / 0081489

[0004] Daniel Oran et. al., Science 362, 1281-1285 (2018) 14 December 2018

[0005] The swollen gel to be exposed is often transparent or light-transmitting, and the refractive index of the swollen gel is often close to that of the medium (e.g., water) surrounding the gel. For example, the refractive index of sodium polyacrylate, a typical gel used in the ImpFab method, is approximately 1.4. The refractive index of water is approximately 1.3.

[0006] In conventional methods for forming a two-dimensional pattern or a three-dimensional object by exposing an exposure object, a position reference mark that serves as a reference for the coordinate system of the exposure object is often provided on the exposure object to correspond to the coordinate system of the exposure apparatus. This position reference mark is also called an alignment mark. The coordinate system of the exposure apparatus can also be said to be the coordinate system of the exposure beam.

[0007] However, in the case of the ImpFab method in which the object to be exposed is a swollen gel, it is difficult to provide positional reference marks on the gel.

[0008] Furthermore, when observing a swollen gel using a microscope, it is difficult to clearly determine the boundary between the gel and the medium. This is because, as mentioned above, the refractive index of the gel is close to that of the medium. Therefore, it is difficult to identify the shape of the gel when viewed in plan, and it is also difficult to use a point on the outline of the gel as a position reference mark based on the shape of the gel.

[0009] Therefore, in the conventional ImpFab method, when repeated exposure is performed (for example, when performing three-dimensional photofabrication), it is difficult to reproducibly associate the coordinate system of the exposure object with the coordinate system of the exposure device, and as a result, it is difficult to improve the accuracy of three-dimensional photofabrication.

[0010] One aspect of the present invention has been made in consideration of the above-mentioned problems, and its purpose is to provide an exposure technique that can improve the accuracy in three-dimensional photo-fabrication using swollen gel.

[0011] In order to solve the above problems, an exposure apparatus according to one embodiment of the present invention comprises an imaging optical system that images an exposure beam onto a swollen gel, which is the exposure object; an illumination optical system that irradiates illumination light onto a substrate on which the gel is placed; and a detection optical system that images the reflected or scattered light of the illumination light reflected or scattered at each point on the substrate onto each point on a photodetector.

[0012] In order to solve the above problems, one embodiment of the exposure container of the present invention is an exposure container in which a swollen gel, which is the object to be exposed, is placed on a bottom plate, and the bottom plate includes a translucent area made of a translucent material, and a mark that reflects or scatters light is formed in the translucent area.

[0013] In order to solve the above problem, an exposure system according to one aspect of the present invention comprises a swollen gel that is an object to be exposed, a substrate on which the gel is placed, and an exposure apparatus according to one aspect of the present invention.

[0014] According to one aspect of the present invention, it is possible to provide an exposure technique that can improve the accuracy of three-dimensional optical shaping.

[0015] FIG. 1 is a schematic diagram of an exposure apparatus according to a first embodiment of the present invention, illustrating the optical path of an exposure beam. The inset is a plan view of a petri dish in which a gel has been placed. FIG. 1 is a schematic diagram of an exposure apparatus according to a first embodiment of the present invention, illustrating the optical path of illumination light. FIG. 1 is a schematic diagram of an exposure apparatus according to a first embodiment of the present invention, illustrating the optical path of reflected light or scattered light. FIG. 1 is a front view obtained when looking at the front of an optical path selector provided in a modified example of the exposure apparatus shown in FIG. 1. The left figure is a front view and plan view of the optical path selector shown in FIG. 4, and the right figure is a front view and plan view of a modified example of the optical path selector shown in FIG. 4.

[0016] An exposure apparatus 1 according to one embodiment of the present invention will be described with reference to FIGS.

[0017] Figures 1 to 3 are all schematic diagrams of an exposure apparatus 1. The configuration of the exposure apparatus 1 illustrated in each of Figures 1 to 3 is the same, but the light being described is different. Figure 1 is a schematic diagram illustrating the optical path of an exposure beam LE, Figure 2 is a schematic diagram illustrating the optical path of illumination light LL, and Figure 3 is a schematic diagram illustrating the optical path of reflected light or scattered light. The inset in Figure 1 is a plan view of a petri dish 42 in which a gel 41, which is the exposure object, is placed. Note that the solvent 43 and glass plate 44 are not shown in the inset in Figure 1.

[0018] 1 to 3, the direction parallel to the optical axis of each objective lens 13 (described later) is defined as the Z-axis direction (the up-down direction in each figure), one direction perpendicular to the Z-axis direction is defined as the X-axis direction (the depth direction in each figure), and the direction perpendicular to both the Z-axis direction and the X-axis direction is defined as the Y-axis direction (the left-right direction in each figure). Furthermore, the direction in which the exposure beam propagates in the Z-axis direction is defined as the positive Z-axis direction (the downward direction in each figure), and the positive X-axis direction (the forward direction in each figure) and the positive Y-axis direction (the rightward direction in each figure) are defined so that, together with the Z-axis direction, they form a right-handed Cartesian coordinate system. In each of FIGS. 1 to 3, the Z-axis direction is parallel to the vertical direction.

[0019] [Object to be Exposed] The exposure apparatus 1 is an exposure apparatus used for stereolithography using the Implosion Fabrication (ImpFab) method described in Patent Document 1, Non-Patent Document 1, etc. In this embodiment, as shown in FIGS. 1 to 3, a gel 41 is used as the object to be exposed. The gel 41 can be appropriately selected from gels used in the ImpFab method. In this embodiment, a hydrogel is used as the gel 41.

[0020] The volume of a hydrogel increases when it absorbs an aqueous solvent and decreases when it dries. In the ImpFab method, a swollen hydrogel is exposed to light, and the exposed hydrogel is dried to shrink it. By shrinking the hydrogel after exposure in this way, a stereolithography object with a finer structure than at the time of exposure can be obtained.

[0021] In this embodiment, as shown in FIGS. 1 to 3, a petri dish 42 is used as an example of an exposure container that contains a gel 41.

[0022] The petri dish 42 is an example of an exposure container according to one aspect of the present invention. The petri dish 42 includes a bottom plate 421 and a side wall 422. The bottom plate 421 is a plate-like member having a circular outline in a plan view and is an example of a substrate. The side wall 422 is a cylindrical wall that stands on one main surface of the bottom plate 421 (the main surface on the positive Z-axis direction side in FIG. 1 ) and is provided along the outline of the bottom plate 421. The upper end (the end on the positive Z-axis direction side) of the side wall 422 is open, forming an opening. A plate-like member whose outer diameter is approximately the same as the inner diameter of the opening is used as the lid 44 that seals the opening.

[0023] In this embodiment, glass (quartz glass in this embodiment) is used as the material for the bottom plate 421 and sidewall 422 of the Petri dish 42 and the lid 44. However, this material is not limited to glass, but it is preferable that at least the region irradiated with the exposure beam LE is made of a light-transmitting material, and more preferably made of glass. Glass is an example of a light-transmitting material that has good light-transmitting properties for visible light.

[0024] Note that an area of ​​the bottom plate 421 made of a light-transmitting material is called a light-transmitting area. In this embodiment, the entire area of ​​the bottom plate 421 is a light-transmitting area. However, the light-transmitting area may be provided in a partial area of ​​the bottom plate 421. In other words, the area of ​​the bottom plate 421 other than the light-transmitting area may be made of a non-light-transmitting material that does not have light-transmitting properties.

[0025] 1, a lattice-shaped grid 423 is formed in the light-transmitting region of the bottom plate 421. The grid 423 is an example of a mark that reflects or scatters irradiated light.

[0026] The shape of the mark that reflects or scatters irradiated light in one embodiment of the present invention is not limited to a lattice shape such as the grid 423, and can be determined appropriately. Furthermore, the mark may be formed of lines such as straight lines or curved lines, may be formed by arranging a plurality of dots in a predetermined pattern, or may be formed by arranging a predetermined pattern such as a cross shape in a plurality of locations.

[0027] Furthermore, in this embodiment, the straight line portions that make up the grid 423 are made up of solid lines, but they may also be made up of broken lines or dotted lines.

[0028] Furthermore, numbers or letters for specifying a position may be added independently to the vertical and horizontal axes of the grid 423. By treating these numbers or letters as a combination of coordinates, the position being observed can be determined simply by observing a partial area of ​​the grid 423.

[0029] In the present embodiment, the grid 423 is formed on one of the main surfaces of the bottom plate 421 (the main surface on the positive Z-axis direction side in FIG. 1 ). However, the position in the depth direction at which the grid 423 is formed on the bottom plate 421 is not limited. That is, the grid 423 may be formed on one of the main surfaces of the bottom plate 421, on the other main surface of the bottom plate 421 (the main surface on the negative Z-axis direction side in FIG. 1 ), or inside the bottom plate 421.

[0030] Furthermore, it is preferable that a fixing member for fixing the gel 41 is provided on one main surface of the bottom plate 421. By fixing the gel 41 to the bottom plate 421, the coordinate system on the bottom plate 421 can be used as the coordinate system on the gel 41.

[0031] The type of force used by the fixing member to fix the gel 41 is not limited. For example, this force may be a force resulting from chemical bonding or a physical force. When a force resulting from chemical bonding is used for fixation, a material known as a silane coupling material is an example of a fixing member. The gel 41 can be fixed to the bottom plate 421 by forming a silane coupling material in a predetermined region on one main surface of the bottom plate 421 and placing the gel 41 on the silane coupling material. Alternatively, when a physical force is used for fixation, a method can be considered in which the lid 44 is also used as a cover glass, the lid 44 is brought into close contact with the gel 41, and downward pressure is applied from the lid 44 to the gel 41. With this method, the gel 41 is pressed against the bottom plate 421 by the downward pressure applied from the lid 44. Therefore, the gel 41 can be more firmly fixed to the bottom plate 421 than when there is no pressure from the lid 44.

[0032] Furthermore, if the gel 41 can be reliably fixed to the bottom plate 421 using a fixing member, the orientation of the gel 41 and the Petri dish 42 shown in Fig. 1 can be reversed upside down. That is, in the state shown in Fig. 1, one main surface of the bottom plate 421 is located on the upper side, and the gel 41 is located on this one main surface. However, one main surface of the bottom plate 421 can also be located on the lower side, and the gel 41 can be located below this one main surface.

[0033] Even when the gel 41 is not positively fixed to the bottom plate 421, a frictional force acts at the interface between the gel 41 and the bottom plate 421. Therefore, even in such a case, the coordinate system on the bottom plate 421 can be used as the coordinate system on the gel 41.

[0034] In the exposure apparatus 1, a grid 423 is formed at a certain depth in the bottom plate 421, the exposure beam LE is focused at a focus P41 located at a certain depth in the gel 41, and the grid 423 is observed using illumination light LL different from the exposure beam LE, thereby making it possible to correspond the coordinate system in the gel 41 with the coordinate system in the exposure apparatus 1.

[0035] As described above, the Petri dish 42 is an exposure container in which the gel 41 is placed on one main surface of the bottom plate 421. The bottom plate 421 includes a light-transmitting region made of a light-transmitting material, and the light-transmitting region is formed with a grid 423 that reflects or scatters light. In addition, the bottom plate 421 is preferably provided with a fixing member that fixes the gel 41.

[0036] The interior space of the petri dish 42 is filled with an aqueous solvent 43. A glass plate 44 is placed on the solvent 43, allowing an immersion lens to be used as the objective lens 13 described below. The solvent 43 may also contain a dye that reacts with the hydrogel when exposed to light.

[0037] A petri dish 42 containing gel 41 is placed on a stage provided in the exposure apparatus 1. Note that the stage is not shown in Fig. 1. In the exposure apparatus 1, the stage and an optical system including the objective lens 13 are configured so that their relative positions can be changed. Note that the optical system including the objective lens 13 will be described later.

[0038] 1, the exposure apparatus 1 includes an imaging optical system 10, an illumination optical system 20, and a detection optical system 30. The exposure apparatus 1 also includes a stage as described above.

[0039] <Imaging Optical System> As shown in FIG. 1, the imaging optical system 10 includes an imaging lens 11 and an objective lens 13 .

[0040] The imaging lens 11 is an example of an imaging lens arranged on the optical path of the exposure beam LE. In the exposure apparatus 1, the imaging lens 11 is composed of a single lens, as shown in Fig. 1. However, in one aspect of the exposure apparatus 1, the imaging lens 11 may be composed of a compound lens that combines multiple lenses.

[0041] The imaging optical system 10 is an optical system that images the exposure beam LE onto the gel 41 .

[0042] In this embodiment, an immersion lens is used as the objective lens 13. In FIG. 1 , the exit surface of the objective lens 13 and the surface of the glass plate 44 (the main surface exposed to the atmosphere) are shown as being spaced apart in the Z-axis direction, but in reality, they are close to each other. A matching liquid (not shown in FIG. 1 ) is interposed between the exit surface of the objective lens 13 and the surface of the glass plate 44 to match the refractive indexes of the two. In the exposure apparatus 1, the objective lens 13 is composed of a compound lens that combines multiple lenses. In FIG. 1 , a rectangle is used to illustrate the objective lens 13, which schematically represents the lens barrel that houses the compound lens. However, in one aspect of the exposure apparatus 1, the objective lens 13 may be composed of a single lens.

[0043] <Optical System Related to Exposure Beam> Of the optical systems related to the exposure beam LE of the exposure apparatus 1, the optical system located before the imaging optical system 10 will be described. This optical system is located before the imaging lens 11, and as shown in FIG. 1 , includes a laser 14, a Pockels cell 15, a galvanometer scanner 16, and a field lens 17. In this optical system, the exposure beam LE output by the laser 14 passes through the Pockels cell 15, the galvanometer scanner 16, the field lens 17, the imaging lens 11, and the objective lens 13 and reaches the gel 41 (see FIG. 1 ). In this optical system related to the exposure beam LE, when viewed along the propagation direction of the exposure beam LE, the side closer to the emission point of the exposure beam LE (i.e., the laser 14) is called the upstream side, and the side closer to the irradiation point of the exposure beam LE (i.e., the gel 41) is called the downstream side.

[0044] The laser 14 is a laser light source that outputs an exposure beam LE. The exposure apparatus 1 is an exposure apparatus used for stereolithography using the ImpFab method. Therefore, the laser 14 can be appropriately selected from laser light sources used in the ImpFab method. The laser 14 may be a fixed wavelength laser that cannot change the wavelength of the exposure beam it outputs, or a tunable laser that can change the wavelength of the exposure beam it outputs. In this embodiment, a Ti:sapphire laser, which is an example of a tunable laser, is used as the laser 14.

[0045] In this embodiment, the wavelength of the laser 14 is 780 nm. However, the wavelength of the laser 14 is not limited to this. In addition to 780 nm, other preferred wavelengths of the laser 14 include 915 nm and 1060 nm. However, the wavelength of the laser 14 is not limited to these and can be appropriately selected depending on the material constituting the gel 41 and the dye contained in the solvent 43.

[0046] In addition, the ImpFab method performs optical shaping by applying the principle of multiphoton absorption, and therefore the laser 14 is preferably a pulsed laser.

[0047] The Pockels cell 15 is disposed after the laser 14 and is an example of an intensity modulator that modulates the intensity of the exposure beam output from the laser 14, and is classified as an electro-optic modulator (EOM). Other examples of intensity modulators include an acousto-optic modulator (AOM) and a semiconductor optical modulator (SOM).

[0048] The galvano scanner 16 is disposed after the Pockels cell 15 and before the imaging lens 11, and is an example of a scanning optical system that switches the direction of the chief ray of the exposure beam LE intensity-modulated by the Pockels cell 15. A fixed point P16 of the galvano scanner 16 is disposed so as to be conjugate to the aperture stop (more specifically, pupil P13) of the objective lens 13 on the optical path of the exposure beam LE intensity-modulated by the Pockels cell 15. In FIG. 1 , the fixed point P16 and pupil P13, which are in a conjugate relationship, are each illustrated as an open square.

[0049] In the exposure apparatus 1 configured as described above, a point located downstream of the galvano scanner 16 where the exposure beam LE is focused is referred to as a focus PC, and a point where the exposure beam LE emitted from the objective lens 13 is imaged at a desired depth in the gel 41 is referred to as a focus P41. The focus PC is located at a conjugate point to the focus P41 on the optical path of the exposure beam LE intensity-modulated by the Pockels cell 15. In other words, the focus PC is located at a conjugate position of the focus P41 with respect to the imaging optical system 10 (the imaging lens 11 and the objective lens 13). In FIG. 1 , the conjugate foci P41 and PC are each shown as a black circle.

[0050] The position of the objective lens 13 on the optical path of the exposure beam LE, in a direction parallel to the optical path of the exposure beam LE (the Z-axis direction in FIG. 3), is configured to be adjustable. By adjusting the position of the objective lens 13 in the Z-axis direction, the depth of the focus P41 in the gel 41 described above can be adjusted.

[0051] The field lens 17 is a lens located near the fixed point P16 of the galvano scanner 16, and adjusts the direction of travel of light not only in the center of the exposure beam LE but also in the peripheral area. As a result, the area that can be exposed can be expanded compared to when the field lens 17 is omitted. Note that the field lens 17, like the imaging lens 11 and the objective lens 13, may be composed of either a single lens or a compound lens.

[0052] <Illumination Optical System> The illumination optical system 20 is an optical system that irradiates illumination light LL onto the bottom plate 421 on which the gel 41 is placed.

[0053] As shown in FIG. 2 , the illumination optical system 20 includes a laser 21, an afocal unit 22, a mirror 23, a field lens 24, and a mirror 25. The illumination optical system 20 also shares the imaging lens 11 and the objective lens 13 with the imaging optical system 10, and shares the field lens 17 with an optical system related to the exposure beam LE that is located upstream of the imaging optical system 10. Therefore, the illumination optical system 20 also includes the field lens 17 and the imaging optical system 10. A description of the imaging optical system 10 will be omitted here. In this optical system, illumination light LL output by the laser 21 passes through the afocal unit 22, the mirror 23, the field lens 24, the mirror 25, the galvanometer scanner 16, the field lens 17, the imaging lens 11, and the objective lens 13 before reaching the gel 41 (see FIG. 2 ). In such an optical system for illumination light LL, when viewed along the direction in which the illumination light LL propagates, the side closer to the emission point of the illumination light LL (i.e., the laser 21) is called the front side, and the side closer to the irradiation point of the exposure beam LE (i.e., the gel 41) is called the rear side.

[0054] It should be noted that the illumination optical system 20 described here is merely one example of an illumination optical system provided in an exposure apparatus according to one aspect of the present invention. The illumination optical system is not limited to the configuration of the illumination optical system 20 shown in Fig. 2 as long as it is configured to be able to irradiate the illumination light LL onto the grid 423 formed on the bottom plate 421. In other words, the illumination optical system may be configured so that the illumination light LL is incident on the grid 423 from any location or angle.

[0055] The laser 21 is a laser light source that outputs illumination light LL. The wavelength of the laser 21 is preferably different from the wavelength of the laser 14. In this embodiment, the wavelength of the laser 21 is 440 nm. However, the wavelength of the laser 21 is not limited to this. Furthermore, the light source that outputs illumination light LL is not limited to a laser and may be an LED.

[0056] As described above, the solvent 43 contained in the internal space of the Petri dish 42 together with the gel 41 may contain a dye. Examples of the dye include rhodamine B, cyanine-3, and cyanine-5. These dyes may emit fluorescence when irradiated with the exposure beam LE.

[0057] For example, when rhodamine B is used as the dye, rhodamine B has a large absorption peak in the wavelength range of 450 nm to 580 nm, and multiple, though less large, absorption peaks in the wavelength range of 400 nm or less. Furthermore, when the wavelength of the exposure beam LE is 780 nm, the energy of two-photon absorption corresponds to the energy of light with a wavelength of 390 nm, and the energy of three-photon absorption corresponds to the energy of light with a wavelength of 260 nm. Rhodamine B excited by the exposure beam LE with a wavelength of 780 nm absorbs at least one of light with wavelengths of 390 nm and 260 nm and emits broad fluorescence with a peak wavelength near 550 nm. The fluorescence of rhodamine B spans a wavelength range of approximately 520 nm to 750 nm. Therefore, considering the absorption spectrum of rhodamine B, the wavelength of the illumination light LL is preferably within the wavelength range of 400 nm to less than 450 nm, or within the wavelength range of 600 nm or greater. Furthermore, when the fluorescence spectrum as well as the absorption spectrum of rhodamine B is taken into consideration, the wavelength of the illumination light LL is more preferably in the wavelength range of 400 nm or more and less than 450 nm. As described above, in this embodiment, rhodamine B is used as the dye, and 440 nm is adopted as the wavelength of the illumination light LL, which is within the more preferable wavelength range of 400 nm or more and less than 450 nm.

[0058] Furthermore, when cyanine-3 is used as the dye, cyanine-3 has a large absorption peak in the wavelength range of 450 nm or more and 600 nm or less. Excited cyanine-3 absorbs at least one of light having a wavelength of 390 nm and light having a wavelength of 260 nm and emits broad fluorescence with a peak wavelength around 570 nm. The fluorescence of cyanine-3 spans a wavelength range of approximately 520 nm or more and 750 nm or less. Therefore, considering the absorption spectrum of cyanine-3, it is preferable that the wavelength of the illumination light LL be within the wavelength range of 400 nm or more and less than 450 nm, or within a wavelength range longer than 600 nm. Furthermore, considering the fluorescence spectrum of cyanine-3 in addition to the absorption spectrum, it is more preferable that the wavelength of the illumination light LL be within the wavelength range of 400 nm or more and less than 450 nm.

[0059] Furthermore, when cyanine-5 is used as the dye, cyanine-5 has a large absorption peak in the wavelength range of 500 nm or more and 700 nm or less. Excited cyanine-5 emits broad fluorescence with a peak wavelength near 670 nm. The fluorescence of cyanine-5 spans a wavelength range of approximately 610 nm or more and 800 nm or less. Therefore, considering the absorption spectrum of cyanine-5, it is preferable that the wavelength of the illumination light LL be within the wavelength range of 400 nm or more and less than 500 nm, or within a wavelength range longer than 700 nm. Furthermore, considering the fluorescence spectrum of cyanine-5 in addition to the absorption spectrum, it is more preferable that the wavelength of the illumination light LL be within the wavelength range of 400 nm or more and less than 500 nm.

[0060] As described above, it is preferable to select the wavelength of the illumination light LL from a wavelength range in which the dye has a higher transmittance than a wavelength equivalent to 1 / 2 or 1 / 3 of the wavelength of the exposure beam LE and in which the dye does not emit fluorescence. Here, the threshold for determining whether or not fluorescence is being emitted is set to 1% of the fluorescence intensity at the fluorescence peak. In other words, if the fluorescence intensity is 1% or less of the fluorescence intensity at the fluorescence peak, it is considered that no fluorescence is being emitted at that wavelength.

[0061] Furthermore, the wavelength of the illumination light LL is preferably a wavelength at which the transmittance of the gel 41 is higher than the transmittance of the gel 41 at the wavelength of the exposure beam LE. In other words, the illumination light LL is preferably light having a wavelength that is more easily transmitted through the gel 41 (less easily absorbed by the gel 41) than the exposure beam LE. Because the illumination light LL is more easily transmitted through the gel 41 than the exposure beam LE, stronger illumination light LL can be irradiated onto the grid 423 provided on the bottom plate 421. Furthermore, the ease with which the illumination light LL is transmitted through the gel 41 means that the detection light LD, which has the same wavelength as the illumination light LL, is also more easily transmitted through the gel 41. Therefore, the intensity of the detection light LD detected using the photodetector 35 described below can be increased.

[0062] The laser 21 is configured to emit illumination light LL, which is parallel light.

[0063] The afocal unit 22 is an optical system for expanding the beam width of the illumination light LL, which is parallel light and is output from the laser 21. The configuration of the afocal unit 22 is not limited. In this embodiment, as shown in FIG. 2 , the afocal unit 22 is configured using two convex lenses 221 and 222 as a lens combination. By appropriately designing the focal length f221 of the convex lens 221, the focal length f222 of the convex lens 222, and the inter-lens distance between the convex lenses 221 and 222, the afocal unit 22 can convert the beam width of the illumination light LL output from the laser 21 into a desired beam width. In this embodiment, because it is desired to irradiate the gel 41 with the illumination light LL as parallel light with a wide beam width, the afocal unit 22 is used to expand the beam width of the illumination light LL.

[0064] The mirror 23 is disposed after the afocal unit 22 and before the mirror 23. The mirror 23 bends the optical path of the illumination light LL by reflecting the illumination light LL.

[0065] The field lens 24 is a lens disposed near the mirror 23, and focuses the illumination light LL onto a fixed point P16 of the galvano scanner 16 while adjusting the traveling direction of the light not only in the center but also in the peripheral portions of the illumination light LL. As a result, the intensity distribution of the illumination light LL in the area of ​​the gel 41 irradiated with the illumination light LL can be made closer to uniform compared to when the field lens 24 is omitted. The field lens 24 may be composed of either a single lens or a compound lens.

[0066] The mirror 25 is a dichroic mirror that transmits light in a transmission band that includes the wavelength of the exposure beam LE (780 nm in this embodiment) and reflects light in a reflection band that includes the wavelength of the illumination light LL (440 nm in this embodiment). The reflectance in the reflection band of the mirror 25 is preferably as high as possible, and ideally is 1. The transmittance in the transmission band of the mirror 25 is also preferably as high as possible, and ideally is 1.

[0067] The mirror 25 transmits the exposure beam LE and reflects the illumination light LL, thereby aligning the optical path of the exposure beam LE with the optical path of the illumination light LL. In other words, the mirror 25 aligns the chief ray direction of the exposure beam LE with the chief ray direction of the illumination light LL.

[0068] The illumination light LL, whose direction of travel is adjusted by the field lens 24 and reflected by the mirror 25, is focused at a fixed point P16 and then reflected by the galvanometer scanner 16. As will be described later, the field lens 24 also functions as a collimating lens that corrects changes in the parallelism of the illumination light LL that accompany changes in the position of the objective lens 13 in the vertical direction (Z-axis direction) and irradiates the illumination light LL in a collimated state onto the gel 41 and the bottom plate 421. Therefore, the position of the field lens 24 in the vertical direction is adjusted in accordance with changes in the position of the objective lens 13 in the vertical direction so that the illumination light LL irradiated onto the gel 41 and the bottom plate 421 becomes collimated light.

[0069] The exposure beam LE and illumination light LL, whose optical paths are bent by the galvano scanner 16, pass through the above-mentioned field lens 17 and the imaging lens 11 and objective lens 13, which are the coupling optical system, and are irradiated onto the gel 41 and the bottom plate 421. As shown in Fig. 1, the exposure beam LE is irradiated in a state in which it is imaged at a position at a predetermined depth in the gel 41. On the other hand, the illumination light LL is irradiated onto the gel 41 and the bottom plate 421 in a state of approximately parallel light, as shown in Fig. 2.

[0070] As described in the problem to be solved by the invention, repeated exposure is carried out in the ImpFab method. This repeated exposure will be briefly described below.

[0071] First, in the ImpFab method, the direction of the chief ray of the exposure beam LE is manipulated using the galvanometer scanner 16 while the depth at which the exposure beam LE is focused in the gel 41 is kept constant (e.g., a first depth). This completes exposure of a first layer whose depth in the gel 41 is constant at the first depth. Next, the depth at which the exposure beam LE is focused in the gel 41 is changed to a second depth, and exposure of a second layer is completed while the depth is maintained at the second depth. Repeated exposure means that layers of different depths are exposed while the depth at which the exposure beam LE is focused in the gel 41 is changed in sequence.

[0072] In the exposure apparatus 1 of this embodiment, the position of the objective lens 13 in the vertical direction (Z-axis direction) is changed to change the depth at which the exposure beam LE is focused in the gel 41. The parallelism of the illumination light LL irradiated onto the gel 41 and the bottom plate 421 changes as the position of the objective lens 13 is changed in the vertical direction. The exposure apparatus 1 employs a configuration for adjusting the vertical position of the field lens 24 so that the illumination light LL can be irradiated onto the gel 41 and the bottom plate 421 in a collimated state even when the depth at which the exposure beam LE is focused in the gel 41 is changed. This configuration allows the illumination light LL to be irradiated onto the gel 41 and the bottom plate 421 in a collimated state even when the depth at which the exposure beam LE is focused in the gel 41 is changed.

[0073] The illumination light LL irradiated onto the bottom plate 421 becomes reflected light or scattered light by being reflected or scattered by the grid 423. Hereinafter, the reflected light and scattered light will be collectively referred to as detection light LD.

[0074] Etching is a widely used method for forming the grid 423 on the main surface of the bottom plate 421. When observing such a grid 423 using the detection optical system 30 described below, an observation image with better contrast can often be obtained by using the illumination light LL as dark-field illumination rather than as bright-field illumination. When the illumination light LL is used as dark-field illumination, the annular aperture may be disposed at point PAP located between the convex lenses 221 and 222 of the afocal unit 22, where the beam width of the illumination light LL is most narrowed.

[0075] The illumination optical system 20 shares the imaging lens 11 and the objective lens 13 with the imaging optical system 10. Therefore, on the optical path of the illumination light LL, the fixed point P16 of the galvano scanner 16 is also arranged so as to be conjugate with the aperture stop (more specifically, the pupil P13) of the objective lens 13 (see the open square in FIG. 2).

[0076] Furthermore, on the optical path of the illumination light LL, the point PAP at which the annular aperture is located is a conjugate point of the fixed point P16 (see the open square shown in FIG. 2).

[0077] <Detection optical system> The detection optical system 30 is an optical system that forms an image of the reflected or scattered light (i.e., detection light LD) of the illumination light LL that is reflected or scattered at each point on the bottom plate 421 (more specifically, each point on the grid 423) at each point on the photodetector 35. The detection light LD is light that is generated by the illumination light LL being reflected or scattered. Therefore, the wavelength of the detection light LD is equal to the wavelength of the illumination light LL. Therefore, in this embodiment, the wavelength of the detection light LD is 440 nm.

[0078] As shown in FIG. 3 , the detection optical system 30 includes a mirror 31, a field lens 32, a mirror 33, a focus lens 34, and a photodetector 35. The detection optical system 30 also shares the imaging lens 11 and the objective lens 13 with the imaging optical system 10. Therefore, the detection optical system 30 further includes the imaging optical system 10. A description of the imaging optical system 10 will be omitted here. In this optical system, the detection light LD generated at the bottom plate 421 passes through the objective lens 13, the imaging lens 11, the mirror 31, the field lens 32, the mirror 33, and the focus lens 34 to reach the photodetector 35 (see FIG. 3 ). In such an optical system for the detection light LD, when viewed along the propagation direction of the detection light LD, the side closer to the emission point of the detection light LD (i.e., the bottom plate 421) is referred to as the front-stage side, and the side closer to the irradiation point of the detection light LD (i.e., the photodetector 35) is referred to as the rear-stage side.

[0079] The mirror 31 is a dichroic mirror that partially reflects light in a reflection band including the wavelengths of the illumination light LL and the detection light LD (440 nm in this embodiment) and transmits light in a transmission band including the wavelength of the exposure beam LE (780 nm in this embodiment). The transmission band of the mirror 31 preferably includes not only the wavelength of the exposure beam LE but also the wavelength range of the fluorescence of rhodamine B (e.g., a wavelength range of 520 nm to 750 nm). In this case, the cutoff wavelength of the mirror 31 can be appropriately selected from a wavelength range longer than 440 nm and shorter than 520 nm. An example of the cutoff wavelength of the mirror 31 is 450 nm. With this configuration, of the detection light LD and fluorescence propagating upward, the mirror 31 reflects the detection light LD toward the photodetector 35 and transmits the fluorescence directly upward. Therefore, when viewed from the photodetector 35, the mirror 31 functions as a kind of filter that removes the fluorescence propagating along the optical path of the exposure beam LE.

[0080] Furthermore, a filter that transmits the wavelength of the illumination light LL and the detection light LD (440 nm in this embodiment) but does not transmit the wavelength range of the fluorescence (for example, a wavelength range of 520 nm to 750 nm) can be provided on the optical path of the detection light LD between the field lens 32 and the focus lens 34. This filter can be, for example, a short-pass filter whose cutoff wavelength is selected similarly to the cutoff wavelength of the mirror 31 described above, which transmits wavelengths below the cutoff wavelength and removes wavelengths above the cutoff wavelength. By removing the fluorescent component from the optical path of the detection light LD, noise due to fluorescence can be reduced when an image of the grid 423 is obtained using the photodetector 35 described below.

[0081] Unlike the mirror 25, the mirror 31 is required to transmit the exposure beam LE in the forward direction (negative direction of the Z axis) and to reflect the detection light LD having the same wavelength as the exposure beam LE in the return direction (positive direction of the Z axis). Therefore, the reflectance in the reflection band of the mirror 31 is set so as to reflect a portion of the light in the reflection band. In other words, the reflectance can be set appropriately within a range greater than 0 and less than 1. An example of the reflectance is 0.5.

[0082] In the exposure apparatus 1, the illumination light LL is light output from the laser 21, and its power can be designed with a relatively high degree of freedom. On the other hand, the detection light LD is light reflected or scattered by the grid 423, and therefore its power is expected to be significantly lower than that of the illumination light LL. In addition, when the photodetector 35 described below detects a portion of the detection light LD reflected by the mirror 31, there is also a preferred power. The reflectance in the reflection band of the mirror 31 can be determined appropriately depending on (1) the power of the illumination light LL, (2) the power of the detection light LD, and (3) the power preferred for the photodetector 35.

[0083] The field lens 32 is disposed after the mirror 31 and before the mirror 33. The field lens 32 is a lens disposed near the mirror 33, and adjusts the direction of travel of the detection light LD not only in the center but also in the peripheral portion. The field lens 32, together with the focus lens 34 described later, focuses the detection light LD reflected or scattered at each point on the bottom plate 421 (specifically, each point on a grid 423 formed on the bottom plate 421) and a portion of the detection light LD reflected by the mirror 31 onto each point included in the light receiving surface of the photodetector 35 described later. The field lens 32 may be composed of either a single lens or a compound lens.

[0084] The mirror 33 is disposed after the field lens 32 and before the focus lens 34. The mirror 33 bends the optical path of the detection light LD by reflecting the detection light LD.

[0085] The focus lens 34, together with the field lens 32, focuses the detection light LD reflected or scattered at each point on the bottom plate 421 and a portion of the detection light LD reflected by the mirror 31 onto each point included in the light receiving surface of the photodetector 35, which will be described later. The focus lens 34 may be composed of either a single lens or a compound lens.

[0086] The position of the field lens 32 is fixed on the optical path of the detection light LD. Meanwhile, the position of the focus lens 34 on the optical path of the detection light LD, in a direction parallel to the optical path of the detection light LD (the Z-axis direction in FIG. 3 ), is adjustable. Because the position of the focus lens 34 in the Z-axis direction is adjustable, the detection light LD can be imaged on the light-receiving surface of the photodetector 35 even when the position of the objective lens 13 in the Z-axis direction is adjusted to adjust the depth of the focal point P41. That is, because the position of the focus lens 34 in the Z-axis direction is adjustable, the light-receiving surface of the photodetector 35 can be positioned at a conjugate point of each point on the bottom plate 421 (specifically, each point on the grid 423 formed on the bottom plate 421) even when the position of the objective lens 13 in the Z-axis direction moves. In FIG. 3 , each point on the bottom plate 421 and the light-receiving surface of the photodetector 35 that are in a conjugate relationship are indicated by a black triangle.

[0087] As described above, in the exposure apparatus 1, the focal point P41 is located at a certain depth in the gel 41, and the grid 423 is located at a predetermined depth in the bottom plate 421 (in this embodiment, on one of the main surfaces of the bottom plate 421). In this way, since the grid 423 is located at a depth different from the focal point P41, the light receiving surface of the photodetector 35 is not located at a conjugate point of the focal point P41. In Figure 3, the focal point P41 and its conjugate point are shown as black circles.

[0088] According to the above configuration, only the image of the grid 423 is formed on the light receiving surface of the photodetector 35, and no image of the focal point P41 is formed.

[0089] The photodetector 35 converts light incident on the light-receiving surface into an electrical signal. The photodetector 35 is a two-dimensional image sensor having a light-receiving element provided for each of a plurality of pixels arranged in a matrix. The photodetector 35 generates image data representing an image of the grid 423 formed on the light-receiving surface. Note that the image represented by the image data is preferably a moving image, but may also be a still image.

[0090] (Modifications of the illumination optical system and the detection optical system) The illumination optical system 20 shown in FIG. 2 is configured to irradiate the gel 41 and the bottom plate 421 with the illumination light LL in a substantially parallel state. Furthermore, the detection optical system 30 shown in FIG. 3 is configured to image the reflected or scattered light (i.e., detection light LD) of the illumination light LL reflected or scattered at each point on the bottom plate 421 (more specifically, each point on the grid 423) at each point on the light-receiving surface of the photodetector 35. However, in one aspect of the present invention, the configurations of the illumination optical system and the detection optical system are not limited to the configurations of the illumination optical system 20 and the detection optical system 30. It is sufficient that the illumination optical system is configured to irradiate at least a partial area (which may be a point) included in the actual field of view of the objective lens 13 with the illumination light LL. Furthermore, it is sufficient that the detection optical system is configured to image the reflected or scattered light (i.e., detection light LD) of the illumination light LL reflected or scattered at each point on the bottom plate 421 on the light-receiving surface of the photodetector 35 using at least the objective lens 13.

[0091] For example, instead of irradiating the gel 41 and the bottom plate 421 with illumination light LL, which is substantially parallel light, the illumination optical system may be configured to irradiate the gel 41 and the bottom plate 421 with illumination light LL that is condensed so that its focal point is located inside the gel 41. In this case, for example, a configuration may be adopted in which the field lens 24 is omitted from the configuration of the illumination optical system 20 shown in FIG. 2 . By omitting the field lens 24, the illumination light LL output from the afocal unit 22 enters the galvano scanner 16 as substantially parallel light and is condensed at the focal point P41 of the gel 41. Furthermore, in this case, by using the galvano scanner 16, the illumination light LL can be scanned within the field of view of the objective lens 13.

[0092] Furthermore, when illumination light LL is irradiated onto the gel 41 and the bottom plate 421 in a state where the illumination light LL is concentrated so that its focal point is located inside the gel 41, the detection optical system can be based on the configuration of the detection optical system 30 shown in Figure 3, with a pinhole provided near a position that is conjugate with the focal point P41 (the black circle shown inside the gel 41) of the illumination light LL (the black circle located downstream of the photodetector 35), and the photodetector 35 can be positioned so that its light receiving surface is located downstream of the pinhole.

[0093] With this configuration, the detection light LD can be detected while the galvanometer scanner 16 scans the position where the illumination light LL is irradiated on the gel 41. Therefore, the position of the grid 423 can be identified even when the condensed illumination light LL is irradiated on the gel 41 and the bottom plate 421. Illumination light LL (referred to as noise light) reflected or scattered at points other than those on the bottom plate 421 (more specifically, at points on the grid 423) is likely to become a noise component in the detection light LD. However, with this configuration, some of the noise light is blocked by areas other than the pinhole opening and therefore cannot pass through the pinhole. That is, some of the noise light cannot be incident on the light-receiving surface of the photodetector 35. This reduces the intensity of the noise light relative to the intensity of the detection light LD, thereby improving the S / N ratio. That is, even when the intensity of the detection light LD is weaker, the photodetector 35 can detect the detection light LD.

[0094] 1 to 3, the imaging optical system 10 includes a single imaging lens 11 arranged on the optical path of the exposure beam LE, and a single objective lens 13 that corresponds one-to-one with the imaging lens 11. The expressions "single imaging lens" and "single objective lens" indicate that there is a one-to-one correspondence between the imaging lens 11 and the objective lens 13, and do not indicate that the imaging lens 11 and the objective lens 13 are composed of single lenses.

[0095] (Configuration of Optical Path Selector) In an imaging optical system 10A, which is a modified example of the imaging optical system 10, an objective lens group 13G consisting of multiple objective lenses (three objective lenses 131 to 133 in this modified example) can be used instead of the single objective lens 13, as shown in FIG. 4. In this case, an optical path selector 12 is interposed between the imaging lens 11 and each of the objective lenses 131 to 133 on the optical path of the exposure beam LE. To reiterate, the expression "single imaging lens" indicates that the correspondence between the imaging lens and the objective lenses 131, 132, and 133 constituting the objective lens group 13G, which will be described later, is one-to-many (one-to-three in this embodiment), and does not indicate that the imaging lens 11 is composed of a single lens.

[0096] In this modification, the optical path selector 12 will be described with reference to FIGS. 4 and 5. FIG. 4 is a front view obtained when looking at the front of the optical path selector 12. The left diagram in FIG. 5 is a front view (lower left diagram) and a plan view (upper left diagram) of the optical path selector 12, and the right diagram in FIG. 5 is a front view (lower right diagram) and a plan view (upper right diagram) of the optical path selector 12A. The optical path selector 12A is a modification of the optical path selector 12, as will be described later. Note that the Cartesian coordinates shown in FIGS. 4 and 5 are the same Cartesian coordinates as those shown in FIGS. 1 to 3.

[0097] The optical path selector 12 is configured to switch the exposure beam LE that has passed through the imaging lens 11 to be incident on any one of the objective lenses 131, 132, and 133. The optical path selector 12 also functions as an optical path length adjustment unit that aligns the air-equivalent optical path lengths of the optical paths from the imaging lens 11 to the objective lenses 131, 132, and 133.

[0098] The optical path selector 12 is disposed after the imaging lens 11 and before the objective lens group 13. In the following, on the optical path of the exposure beam, the distance from the center of the imaging lens 11 to the incident point of the exposure beam on the mirror 124 is defined as length a1, and the distance from this incident point to the entrance pupil P131 is defined as length a2. Furthermore, the optical path from the center of the imaging lens 11 to the incident point of the exposure beam on the mirror 124 is divided into an optical path along which the exposure beam propagates in air and an optical path along which the exposure beam propagates through the optical path selector 12. In the following, of length a1, the length of the optical path along which the exposure beam propagates in air is defined as length a11, and the length of the optical path along which the exposure beam propagates through the optical path selector 12 is defined as length a12. Also, on the optical path of the exposure beam, the distance from the incident point of the exposure beam on mirror 125 to entrance pupil P132 and the distance from the incident point of the exposure beam on mirror 126 to entrance pupil P133 are both the same length a2.

[0099] The optical path selector 12 is a block made of glass (quartz glass in this embodiment). Front views of the optical path selector 12 are shown in the lower left drawings of Figures 4 and 5, and a plan view of the optical path selector 12 is shown in the upper left drawing of Figure 5.

[0100] The optical path selector 12 includes a first block 121, a second block 122, a third block 123, a mirror 124, a mirror 125, and a mirror 126. In this embodiment, the first block 121, the second block 122, and the third block 123 are integrally molded, and there are no clear boundaries between them. However, in one aspect of the optical path selector 12, the first block 121, the second block 122, and the third block 123 may be molded as separate bodies and joined to each other (for example, by adhesion or fusion).

[0101] The shape of the front surface of the first block 121 is a parallelogram. In this embodiment, of the two pairs of diagonal angles of the first block 121, one pair of diagonal angles is 45° and the other pair of diagonal angles is 135°. The angle of each of the two pairs of diagonal angles is not limited to 45°.

[0102] In this embodiment, one pair of opposite sides of the first block 121 is arranged parallel to the Y-axis direction. That is, the other pair of opposite sides of the first block 121 is arranged so as to form a 45° angle with the negative Z-axis direction. Hereinafter, the length of the pair of opposite sides of the first block 121 that is arranged parallel to the Y-axis direction is referred to as length a3 (see the plan view in FIG. 5 ).

[0103] Hereinafter, of the surfaces perpendicular to the front surface of the first block 121, the surfaces parallel to the XY plane will be referred to as the lower and upper surfaces. The lower surface is located on the negative side of the Z axis, and the upper surface is located on the positive side of the Z axis. Furthermore, of the surfaces perpendicular to the front surface of the first block 121, the surfaces other than the upper and lower surfaces will be referred to as the left and right surfaces. The left surface is located on the negative side of the Y axis, and the right surface is located on the positive side of the Y axis.

[0104] The upper and lower base surfaces of the first block 121 are congruent rectangles.

[0105] The shape of the front surface of the second block 122 is a parallelogram. In this embodiment, of the two pairs of diagonal angles of the second block 122, one pair of diagonal angles is 45° and the other pair of diagonal angles is 135°. The angles of the two pairs of diagonal angles are not limited to this.

[0106] In this embodiment, one pair of opposite sides of the second block 122 is arranged parallel to the Y-axis direction. That is, the other pair of opposite sides of the second block 122 is arranged so that the angle between the pair of opposite sides and the negative Z-axis direction is 45°. Hereinafter, the length of the pair of opposite sides of the second block 122 that is arranged parallel to the Y-axis direction is longer by a length a4 than the length a3 of the pair of opposite sides of the first block 121 that is arranged parallel to the Y-axis direction (see the plan view in FIG. 5 ). Note that in this embodiment, the lengths a3 and a4 are equal. Therefore, the sum of the lengths a3 and a4 of the pair of opposite sides of the second block 122 that are arranged parallel to the Y-axis direction is twice the length a3.

[0107] The method for defining the upper, lower, right, and left sides of the second block 122 in a plane perpendicular to the front surface is the same as the method for defining the upper, lower, right, and left sides of the first block 121 in a plane perpendicular to the front surface.

[0108] The upper and lower base surfaces of the second block 122 are congruent rectangles.

[0109] The front shape of the third block 123 is rectangular, that is, the third block 123 is a rectangular parallelepiped.

[0110] In this embodiment, one pair of opposite sides of the two pairs of opposite sides that form the front surface of the third block 123 is arranged parallel to the Y-axis direction.

[0111] The method of defining the upper, lower, right, and left sides of the third block 123 in a plane perpendicular to the front surface is the same as the method of defining the upper, lower, right, and left sides of the first block 121 in a plane perpendicular to the front surface.

[0112] In this embodiment, the first block 121 and the second block 122 are arranged so that their left side surfaces are located on the same plane (i.e., flush) (see the left side of FIG. 5 ). Hereinafter, when the left side surface of the first block 121 and the left side surface of the second block 122 are not distinguished, they are collectively referred to simply as the left side surface of the optical path selector 12. Furthermore, because the first block 121 and the second block 122 are integrally molded, the rear surface of the first block 121 and the front surface of the second block 122 are in close contact with each other (see the upper left diagram of FIG. 5 ). Furthermore, because the second block 122 and the third block 123 are integrally molded, the lower bottom surface of the second block 122 and the upper bottom surface of the third block 123 are in close contact with each other (see the lower left diagram of FIG. 5 ).

[0113] A metal film is formed on each of the left side surface of the optical path selector 12, the right side surface of the first block 121, and the right side surface of the second block 122. The interface between each metal film and the first block 121, and each metal film and the second block 122 function as a reflective surface that reflects the exposure beam LE incident on the optical path selector 12. The material constituting the metal film may be any material that has a specularly reflective surface, and may be appropriately selected from such materials. In this embodiment, aluminum is used as the material constituting the metal film. However, other examples of such materials include gold and silver. Alternatively, a dielectric multilayer film may be used instead of each metal film constituting the reflective surface together with the first block 121 or the second block 122.

[0114] In the following, the metal film formed on the left side of the optical path selector 12 will be referred to as mirror 124, and the metal films formed on the right side of the first block 121 and the right side of the second block 122 will be referred to as mirror 125 and mirror 126, respectively.

[0115] The mirror 124 is an example of a first reflecting surface that reflects the exposure beam LE that has passed through the imaging lens 11. One of the mirrors 125 and 126 is an example of a second reflecting surface that further reflects the exposure beam LE reflected by the mirror 124 (an example of a first reflecting surface). In the exposure apparatus 1, the mirror 124 can be considered as the first reflecting surface and the mirror 125 can be considered as the second reflecting surface, or the mirror 126 can be considered as the second reflecting surface. In this embodiment, the mirrors 124 and 125 will be described as the first reflecting surface and the second reflecting surface, respectively. The mirror 126 will also be described as the third reflecting surface.

[0116] As shown in Fig. 4, the optical path selector 12 is disposed on the optical path of the exposure beam LE that has passed through the imaging lens 11. That is, the optical path selector 12 is disposed after the imaging lens 11. The optical path selector 12 is configured so that it can mechanically translate in a direction perpendicular to the propagation direction of the exposure beam LE (in this embodiment, the X-axis direction in the coordinate system shown in Fig. 4). As a mechanical mechanism for translating the optical path selector 12, a stage that can translate in at least one axial direction can be used.

[0117] In this way, since the mirrors 124, 125, and 126 can be translated, the optical path selector 12 can be mechanically inserted into or removed from the optical path of the exposure beam LE.

[0118] When the position of the optical path selector 12 in the X-axis direction is determined so that the exposure beam LE does not enter the optical path selector 12, i.e. so that the exposure beam LE does not enter the mirror 124, the exposure beam LE directly enters the objective lens 131. In this way, a state in which the exposure beam LE does not enter the mirror 124, in other words, a state in which the mirror 124 does not reflect the exposure beam LE, will hereinafter be referred to as a state in which the mirror 124 is disabled.

[0119] On the other hand, when the position of the optical path selector 12 in the X-axis direction is determined so that the exposure beam LE is incident on an area of ​​the mirror 124 corresponding to the left side of the first block 121, the exposure beam LE reflected by the mirror 124 propagates inside the first block 121 in the positive direction of the Y-axis, is further reflected by the mirror 125, and is incident on the objective lens 132. In this way, the state in which the exposure beam LE is incident on the mirror 124, in other words, the state in which the mirror 124 is reflecting the exposure beam LE, will hereinafter be referred to as the state in which the mirror 124 is enabled. Similarly, the state in which the exposure beam LE is incident on the mirror 125, in other words, the state in which the mirror 125 is reflecting the exposure beam LE, will hereinafter be referred to as the state in which the mirror 125 is enabled.

[0120] Furthermore, when the position of the optical path selector 12 in the X-axis direction is determined so that the exposure beam LE is incident on an area of ​​the mirror 124 that corresponds to the left side surface of the second block 122, the exposure beam LE reflected by the mirror 124 propagates inside the second block 122 in the positive direction of the Y-axis, is further reflected by the mirror 126, and is incident on the objective lens 133. This state is the state in which the mirror 124 is activated. Furthermore, as in the case of the mirror 125, the state in which the exposure beam LE is incident on the mirror 126, in other words, the state in which the mirror 126 is reflecting the exposure beam LE, is referred to as the state in which the mirror 126 is activated.

[0121] In the optical path selector 12 configured as described above, (1) when the mirror 124 is disabled, the mirrors 125 and 126 are also disabled, and the exposure beam LE is incident on the objective lens 131, (2) when the mirrors 124 and 125 are enabled, the exposure beam LE is incident on the objective lens 132, and (3) when the mirrors 124 and 126 are enabled, the exposure beam LE is incident on the objective lens 133. In this way, the optical path selector 12 mechanically inserts and removes the mirrors 124, 125, and 126 into and from the optical path of the exposure beam LE, thereby switching between the objective lens 131, the objective lens 132, and the objective lens 133 onto which the exposure beam LE is incident.

[0122] Furthermore, when the function of the optical path selector 12 is expressed from the perspective of the objective lens group 13G, (1) the exposure beam LE obtained when the mirror 124 of the optical path selector 12 is disabled is incident on the objective lens 131, (2) when the mirror 124 is enabled, the exposure beam LE reflected by the mirror 124 is further reflected by the mirror 125 and incident on the objective lens 132, and (3) when the mirror 124 is enabled, the exposure beam LE reflected by the mirror 124 is further reflected by the mirror 126 and incident on the objective lens 133.

[0123] Next, the function of the optical path selector 12 as an optical path length adjuster will be described. As shown in Fig. 4, the optical path L1 of the exposure beam LE from the imaging lens 11 to the objective lens 131 is linear. On the other hand, the optical path L2 of the exposure beam LE from the imaging lens 11 to the objective lens 132 via the mirrors 124 and 125 is crank-shaped. Similarly, the optical path L3 of the exposure beam LE from the imaging lens 11 to the objective lens 133 via the mirrors 124 and 126 is also crank-shaped.

[0124] 4, when comparing the optical path lengths of the optical paths L1 to L3, the optical path length of the optical path L1 is the shortest, the optical path length of the optical path L2 is longer than the optical path L1 by a length a3, and the optical path length of the optical path L3 is longer than the optical path L1 by the sum of the lengths a3 and a4. The optical path adjustment unit is configured to make the air-equivalent optical path lengths of the optical paths L1 to L3, which are different from one another, uniform.

[0125] In the optical path selector 12, a mirror 124 and a mirror 125 are formed on the left and right sides, respectively, of the first block 121. Therefore, in the optical path L2, quartz glass is interposed between the mirror 124 and the mirror 125 and between the mirror 125 and the objective lens 132. In other words, a high refractive index medium is disposed on the optical path L2 from the imaging lens 11 to the objective lens 132.

[0126] Similarly, in the optical path selector 12, a mirror 124 and a mirror 126 are formed on the left and right sides, respectively, of the second block 122. Therefore, in the optical path L3, quartz glass is interposed between the mirror 124 and the mirror 126 and between the mirror 126 and the objective lens 133. In other words, a high refractive index medium is disposed on the optical path L3 from the imaging lens 11 to the objective lens 133.

[0127] Silica glass is an example of a high-refractive index medium having a refractive index higher than that of air. The relative refractive index of silica glass to air is approximately 1.5. If the relative refractive index of the high-refractive index medium is N, the optical path length of the optical path in the high-refractive index medium is L, and the air-equivalent optical path length of the optical path is L', then the air-equivalent optical path length L' is given by L' = L / N. Because the relative refractive index N of the high-refractive index medium is greater than 1, the air-equivalent optical path length L' can be made shorter than the optical path length L.

[0128] Here, the optical path lengths L(L1), L(L2), and L(L3) of the optical paths L1, L2, and L3 are respectively as follows: L(L1) = a1 + a5 + a6 + a7 L(L2) = a1 + a3 + a5 + a6 + a7 L(L3) = a1 + a3 + a4 + a5 + a6 + a7 Furthermore, the air-equivalent optical path lengths L'(L1), L'(L2), and L'(L3) of the optical paths L1, L2, and L3 are respectively as follows: L'(L1) = a11 + a12 / N + a5 + a6 + a7 L'(L2) = a11 + a12 / N + (a3 + a5) / N + a6 + a7 L'(L3) = a11 + a12 / N + (a3 + a4 + a5 + a6) / N + a7 Here, in order to align (in other words match) the air-equivalent optical path lengths L'(L1), L'(L2), and L'(L3), the shape of the optical path selector 12 may be designed so that a5 + a6 + a7, (a3 + a5) / N + a6 + a7, and (a3 + a4 + a5 + a6) / N + a7 are equal. In this embodiment, the shape of the optical path selector 12 is designed so that the air-equivalent optical path length L' (L1), the air-equivalent optical path length L' (L2), and the air-equivalent optical path length L' (L3) are equal.

[0129] Note that the optical paths L1 to L3 in the optical path selector 12 configured in this manner do not change even when the propagation direction of light is reversed. Therefore, the exposure beam LE and illumination light LL that have passed through the imaging lens 11 have one of the optical paths L1 to L3 selected by the optical path selector 12 and are incident on an objective lens (e.g., objective lens 132) corresponding to the selected optical path (e.g., optical path L2), and the detection light (corresponding to the detection light LD shown in FIG. 3) generated by the foci P411 to P413 reflecting or scattering the illumination light LL is input to the optical path selector 12 after passing through the objective lenses 131 to 133 corresponding to each of the foci P411 to P413, and is output from the optical path selector 12 after the optical paths are combined into one by the optical path selector 12.

[0130] In FIG. 4, only the symbol for the exposure beam LE is shown as a representative of the exposure beam LE and the illumination light LL.

[0131] Therefore, even if the exposure apparatus 1 described in Figures 1 to 3 further includes an optical path selector 12, the imaging optical system 10 can image the exposure beam LE onto the gel 41, the illumination optical system 20 can irradiate the illumination light LL onto the bottom plate 421 on which the gel 41 is placed, and the detection optical system 30 can image the detection light LD reflected or scattered at each point on the bottom plate 421 onto each point on the photodetector 35.

[0132] (Modification of Optical Path Selector) Next, an optical path selector 12A, which is a modification of the optical path selector 12, will be described with reference to the right diagram of FIG.

[0133] The optical path selector 12A is a block made of glass (quartz glass in this embodiment) like the optical path selector 12. The lower right diagram in Fig. 5 shows a front view of the optical path selector 12A, and the upper right diagram in Fig. 5 shows a plan view of the optical path selector 12A.

[0134] The optical path selector 12A includes a first block 121A, a second block 122A, a third block 123A, a mirror 124A, a mirror 125A, and a mirror 126A. In this embodiment, the first block 121A and the second block 122A are molded as separate bodies. The second block 122A and the third block 123A are molded as a single body. However, in one aspect of the optical path selector 12A, the second block 122A and the third block 123A may be molded as separate bodies and joined to each other (for example, by adhesion or fusion).

[0135] The first block 121A has the same shape as the first block 121 of the optical path selector 12. That is, the shape of the front of the first block 121A is a parallelogram, with one pair of diagonals at 45° and the other pair of diagonals at 135°. Of the two pairs of opposite sides of the first block 121A, the length of the pair of opposite sides that are arranged parallel to the Y-axis direction is a3 (see the plan view in FIG. 5). Here, a description of the first block 121A will be omitted.

[0136] The second block 122A has the same shape as the first block 121A. That is, the front shape of the second block 122A is a parallelogram, with one pair of diagonal angles at 45° and the other pair of diagonal angles at 135°. Of the two pairs of opposite sides of the second block 122A, the pair of opposite sides that are parallel to the Y-axis direction has a length a4 (see the plan view in FIG. 5 ) that is equal to the length a3. Here, a description of the second block 122A will be omitted.

[0137] The third block 123A has the same shape as the third block 123 of the optical path selector 12. That is, the third block 123A is a rectangular parallelepiped. Here, a description of the third block 123A will be omitted.

[0138] In this embodiment, a mirror 124A (described later) is provided on the left side surface of the first block 121A. A mirror 125A (described later) is provided between the right side surface of the first block 121A and the left side surface of the second block 122A. A mirror 126A (described later) is provided on the right side surface of the second block 122A.

[0139] The mirror 124A is an example of a first reflecting surface that reflects the exposure beam LE that has passed through the imaging lens 11. One of the mirrors 125A and 126A is an example of a second reflecting surface that further reflects the exposure beam LE reflected by the mirror 124A (an example of a first reflecting surface). In the optical path selector 12A, the mirror 124A can be considered as the first reflecting surface and the mirror 125A as the second reflecting surface, or the mirror 126A can be considered as the second reflecting surface. In this embodiment, the mirrors 124A and 125A will be described as the first reflecting surface and the second reflecting surface, respectively. The mirror 126A will also be described as the third reflecting surface.

[0140] In the optical path selector 12, metal films are used as the mirrors 124 to 126. On the other hand, in the optical path selector 12A, mirrors called dimming mirrors or switchable mirror devices are used as the mirrors 124A to 126A. Mirrors called dimming mirrors or switchable mirror devices can be electrically switched between a light reflecting state and a light transmitting state. In the following, for each of the mirrors 124A to 126A, the light reflecting state is referred to as the enabled state of the mirror, and the light transmitting state is referred to as the disabled state of the mirror.

[0141] In the optical path selector 12A configured as described above, (1) when the mirror 124A is disabled, the exposure beam LE that is incident on the mirror 124A is incident on the objective lens 131, (2) when the mirrors 124A and 125A are enabled, the exposure beam LE is incident on the objective lens 132, and (3) when the mirrors 124A and 126A are enabled, the exposure beam LE is incident on the objective lens 133. In this way, the optical path selector 12A switches between the objective lens 131, the objective lens 132, and the objective lens 133 onto which the exposure beam LE is incident, by electrically controlling whether the mirrors 124A, 125A, and 126A transmit or reflect the exposure beam LE.

[0142] Furthermore, when the function of the optical path selector 12A is expressed from the perspective of the objective lens group 13G, (1) the exposure beam LE obtained when the mirror 124A of the optical path selector 12A is disabled is incident on the objective lens 131, (2) when the mirrors 124A and 125A are enabled, the exposure beam LE reflected by the mirror 124A is further reflected by the mirror 125A and incident on the objective lens 132, and (3) when the mirrors 124A and 126A are enabled, the exposure beam LE reflected by the mirror 124A is further reflected by the mirror 126A and incident on the objective lens 133.

[0143] The function of the optical path selector 12A as an optical path length adjustment unit is the same as the function of the optical path selector 12 as an optical path length adjustment unit. Therefore, here, a description of the function of the optical path selector 12A as an optical path length adjustment unit will be omitted.

[0144] [Summary 1] In order to solve the above problems, the exposure apparatus according to aspect 1-1 of the present invention comprises an imaging optical system that images an exposure beam onto a swollen gel, which is the exposure object, an illumination optical system that irradiates illumination light onto a substrate on which the gel is placed, and a detection optical system that images the reflected or scattered light of the illumination light reflected or scattered at each point on the substrate onto each point on a photodetector.

[0145] With the above configuration, the exposure beam is focused onto the swollen gel using a coupling optical system, while the photodetector detects the image formed by the collection of points on the substrate. Therefore, if the relative position of the gel to the substrate is considered to be unchanged, the coordinate system on the substrate can be regarded as the coordinate system on the gel. Therefore, this exposure apparatus can reproducibly associate the coordinate system on the gel with the coordinate system on the exposure apparatus, thereby improving the accuracy of three-dimensional photofabrication using gel.

[0146] The exposure apparatus according to one aspect of the present invention exposes a gel without determining a reference point serving as a reference for a coordinate system at any position on the gel. The swollen gel used in the ImpFab method is suitable as an exposure target for applying this exposure apparatus, since it is difficult to determine a reference point at any position on the gel.

[0147] Furthermore, in the exposure apparatus according to aspect 1-2 of the present invention, in addition to the configuration of the exposure apparatus according to aspect 1-1 described above, the exposure apparatus further includes an objective lens shared by the imaging optical system, the illumination optical system, and the detection optical system, an imaging lens arranged in front of the objective lens and shared by the imaging optical system, the illumination optical system, and the detection optical system, and a scanning optical system arranged in front of the imaging lens and switching the direction of the chief ray of the exposure beam, and the scanning optical system is arranged so as to be at a conjugate position with the objective lens on the optical path shared by the exposure beam and the illumination light.

[0148] According to the above configuration, the gel can be patterned by scanning the exposure beam within the range of the field of view of the objective lens. In this exposure device, the scanning optical system and the objective lens are located at a common conjugate point, so the target can be exposed by effectively utilizing the field of view of the objective lens. Therefore, the exposable area can be reliably expanded without changing the relative position of the imaging optical system and the gel.

[0149] Furthermore, in the exposure apparatus according to aspect 1-3 of the present invention, in addition to the configuration of the exposure apparatus according to aspect 1-2 described above, the detection optical system further includes a focus lens, and the position of the focus lens is determined so as to image the reflected light or the scattered light reflected or scattered at each point on the substrate onto the photodetector.

[0150] As described above, the exposure beam is imaged on the gel. Meanwhile, with the above configuration, the position of the substrate and the position of the photodetector are in a conjugate relationship, so an image of the substrate is imaged on the photodetector by the detection optical system. Therefore, this exposure apparatus can observe the substrate while exposing the gel using the exposure beam. Furthermore, because the focus of the exposure beam is located at a different depth from the substrate, an image of the focus of the exposure beam is not imaged on the photodetector. Therefore, the substrate can be observed without being affected by the exposure beam.

[0151] Furthermore, in the exposure apparatus according to aspect 1-4 of the present invention, in addition to the configuration of the exposure apparatus according to any one of aspects 1-1 to 1-3 described above, a configuration is adopted in which the wavelength of the illumination light is a wavelength at which the transmittance of the gel is higher than the transmittance of the gel at the wavelength of the exposure beam.

[0152] According to the above configuration, the illumination light easily penetrates the gel compared to the exposure beam, allowing each point on the substrate to be irradiated with stronger illumination light. Furthermore, the ease with which the illumination light penetrates the gel also means that reflected light and scattered light having the same wavelength as the illumination light also easily penetrate the gel. Therefore, the intensity of the reflected light and scattered light from each point on the substrate can be increased.

[0153] Furthermore, in the exposure apparatus according to aspect 1-5 of the present invention, in addition to the configuration of the exposure apparatus according to any one of aspects 1-1 to 1-4 described above, a configuration is adopted in which the gel is placed in a solution containing a dye, and the wavelength of the illumination light is a wavelength at which the transmittance of the dye is higher than a wavelength corresponding to 1 / 2 or 1 / 3 of the wavelength of the exposure beam, and is a wavelength at which the dye does not emit fluorescence.

[0154] According to the above configuration, when the reflected light or scattered light of the illumination light is detected using the photodetector, it is possible to reduce the influence of noise due to fluorescence.

[0155] Furthermore, in the exposure apparatus according to aspect 1-6 of the present invention, in addition to the configuration of the exposure apparatus according to aspect 1-5 described above, a configuration is adopted in which the substrate is made of a light-transmitting material, and a mark that reflects or scatters the illumination light is formed on the substrate.

[0156] According to the above configuration, since the image of the mark formed on the substrate can be observed by the photodetector, the reference point of the coordinate system on the substrate can be determined based on the pattern of the mark. If it is assumed that the relative position of the gel with respect to the substrate does not change, the coordinate system on the substrate can be regarded as the coordinate system on the exposure object and used, so the reference point of the coordinate system on the gel can be determined based on the pattern of the mark.

[0157] Furthermore, in the exposure apparatus according to aspect 1-7 of the present invention, in addition to the configuration of the exposure apparatus according to any one of aspects 1-1 to 1-6 described above, a configuration is adopted in which the swollen gel is fixed to one of the main surfaces of the substrate.

[0158] With this configuration, the coordinate system on the substrate and the coordinate system on the gel can be more closely matched than when the gel is not fixed to the substrate, and therefore the exposure apparatus can further improve the accuracy of three-dimensional stereolithography.

[0159] Furthermore, in the exposure apparatus according to aspect 1-8 of the present invention, in addition to the configuration of the exposure apparatus according to either aspect 1-2 or aspect 1-3 described above, it is equipped with a plurality of objective lenses including the objective lens, an optical path selector that switches which of the plurality of objective lenses the exposure beam that has passed through the imaging lens is to be incident on, and an optical path length adjustment unit that aligns the air-equivalent optical path length of the optical path from the imaging lens to each of the plurality of objective lenses.

[0160] According to the above configuration, by using an optical path selector to select the objective lens to be used for exposure, it is possible to expose the exposure area corresponding to each objective lens without changing the relative position between the imaging optical system and the exposure object. For example, if the number of objective lenses provided in this exposure apparatus is n, this exposure apparatus can expose an exposure area with an area n times larger than that of an exposure apparatus that uses a single objective lens. Therefore, this exposure apparatus can expand the area that can be exposed without changing the relative position between the imaging optical system and the exposure object.

[0161] In order to solve the above problems, the exposure container according to aspects 1-9 of the present invention is an exposure container in which a swollen gel, which is the object to be exposed, is placed on a bottom plate, and the bottom plate includes a light-transmitting area made of a light-transmitting material, and a mark that reflects or scatters light is formed in the light-transmitting area.

[0162] The exposure container configured in this manner can be suitably used as an exposure container to place a swollen gel in during the ImpFab method. In addition, since a mark that reflects or scatters light is formed in the light-transmitting region of the bottom plate of the exposure container, the same effect as the exposure device according to the first aspect described above can be achieved.

[0163] Furthermore, in the exposure container according to aspect 1-10 of the present invention, in addition to the configuration of the exposure container according to aspect 1-9 described above, a configuration is adopted in which the bottom plate is provided with a fixing member for fixing the gel.

[0164] According to the above configuration, the same effects as those of the exposure apparatus according to the above-mentioned aspect 1-7 can be achieved.

[0165] In order to solve the above problem, an exposure system according to aspect 1-11 of the present invention comprises a swollen gel as an exposure object, a substrate on which the gel is placed, and an exposure apparatus according to any one of aspects 1-1 to 1-8 described above.

[0166] The exposure system according to Aspect 1-11 has the same effects as the exposure apparatus according to any one of Aspects 1-1 to 1-8.

[0167] [Summary 2] The ImpFab methods described in Patent Document 1 and Non-Patent Document 1 have the following problems: when repeated exposures are performed (for example, when performing three-dimensional stereolithography), it is difficult to reproducibly associate the coordinate system of the exposure object with the coordinate system of the exposure apparatus, which in turn makes it difficult to improve the accuracy of three-dimensional stereolithography; in addition, there is another problem that the area that can be exposed is narrow when the relative position between the imaging optical system and the exposure object is not changed. Therefore, in the conventional ImpFab method, when stereolithography is performed to form a pattern that spans an area larger than the field of view (FOV) of the objective lens, exposure is repeated while changing the relative position between the imaging optical system and the exposure object many times.

[0168] One aspect of the present invention has been developed in consideration of another of the problems mentioned above, and a secondary objective is to provide an exposure apparatus that can expand the area that can be exposed without changing the relative position between the imaging optical system and the object to be exposed.

[0169] In order to solve the other problem described above, an exposure apparatus according to aspect 2-1 of the present invention comprises a single imaging lens arranged on the optical path of an exposure beam, a plurality of objective lenses that focus the exposure beam on an exposure object, an optical path selector that switches which of the plurality of objective lenses the exposure beam that has passed through the imaging lens is incident on, and an optical path length adjustment unit that aligns the air-equivalent optical path length of the optical path from the imaging lens to each of the plurality of objective lenses.

[0170] According to the above configuration, by using an optical path selector to select the objective lens to be used for exposure, it is possible to expose the exposure area corresponding to each objective lens without changing the relative position between the imaging optical system and the exposure object. For example, if the number of objective lenses provided in this exposure apparatus is n, this exposure apparatus can expose an exposure area with an area n times larger than that of a conventional exposure apparatus that uses a single objective lens. Therefore, this exposure apparatus can expand the area that can be exposed without changing the relative position between the imaging optical system and the exposure object.

[0171] In addition, in an exposure apparatus according to aspect 2-2 of the present invention, in addition to the configuration of the exposure apparatus according to aspect 2-1 described above, the optical path selector includes a first reflecting surface that reflects the exposure beam that has passed through the imaging lens, and a second reflecting surface that further reflects the exposure beam reflected by the first reflecting surface, the multiple objective lenses include a first objective lens onto which the exposure beam obtained when the first reflecting surface is disabled is incident, and a second objective lens other than the first objective lens, the second reflecting surface causes the exposure beam reflected by the first reflecting surface to be incident on the second objective lens when the first reflecting surface is enabled, and the optical path length adjustment unit includes a high refractive index medium arranged on the optical path from the first reflecting surface to the second objective lens.

[0172] Here, the optical path from the first reflecting surface to the first objective lens when the optical path selector selects the first objective lens is called the "first optical path," and the optical path length from the first reflecting surface to the second objective lens when the optical path selector selects the second objective lens is called the "second optical path." Since the second optical path is reflected by each of the first reflecting surface and the second reflecting surface, the optical path length of the second optical path is longer than the optical path length of the first optical path. In this exposure apparatus, a high-refractive-index medium is disposed on the optical path from the first reflecting surface to the second objective lens, so that the difference between the air-equivalent optical path length of the first optical path and the air-equivalent optical path length of the second optical path can be reduced.

[0173] Furthermore, in the exposure apparatus according to aspect 2-3 of the present invention, in addition to the configuration of the exposure apparatus according to aspect 2-2 described above, the optical path selector is configured to switch between causing the exposure beam to be incident on the first objective lens or causing the exposure beam to be incident on the second objective lens by mechanically inserting and removing the first reflecting surface and the second reflecting surface from the optical path of the exposure beam.

[0174] Furthermore, in the exposure apparatus according to aspect 2-4 of the present invention, in addition to the configuration of the exposure apparatus according to aspect 2-2 described above, the optical path selector is configured to electrically control whether the first reflecting surface transmits or reflects the exposure beam, thereby switching between making the exposure beam incident on the first objective lens or making the exposure beam incident on the second objective lens.

[0175] As in the exposure apparatus according to aspect 2-3, the selection of whether to enable or disable the first and second reflecting surfaces can be performed by mechanically inserting or removing the first and second reflecting surfaces. Also, as in the exposure apparatus according to aspect 2-4, the selection can be performed by electrical control.

[0176] Furthermore, in the exposure apparatus according to aspect 2-5 of the present invention, in addition to the configuration of the exposure apparatus according to any one of aspects 2-1 to 2-4 described above, an intensity modulator that intensity-modulates the exposure beam output from a light source, and a scanning optical system that switches the direction of the chief ray of the exposure beam intensity-modulated by the intensity modulator, the scanning optical system being positioned at a common conjugate point with respect to the plurality of objective lenses on the optical path of the exposure beam intensity-modulated by the intensity modulator, are provided upstream of the imaging lens.

[0177] According to the exposure apparatus of the second to fifth aspects, an object can be patterned by scanning an intensity-modulated exposure beam within the range of the field-of-view size of the objective lens. In this exposure apparatus, the scanning optical system and each of the objective lenses are located at a common conjugate point, so the field-of-view size of each objective lens can be effectively utilized to expose the object. Therefore, the exposable area can be reliably expanded without changing the relative position between the imaging optical system and the exposure object.

[0178] Furthermore, in the exposure apparatus according to aspect 2-6 of the present invention, in addition to the configuration of the exposure apparatus according to any one of aspects 2-1 to 2-4 described above, the exposure apparatus further comprises, in front of the imaging lens, a scanning optical system that switches the direction of the chief ray of the exposure beam output from the light source, a spatial intensity modulator that performs two-dimensional spatial intensity modulation on the exposure beam output from the scanning optical system, and a projection lens that is positioned at a common conjugate point with respect to the plurality of objective lenses on the optical path of the exposure beam that has been spatial intensity modulated by the spatial intensity modulator.

[0179] According to the exposure apparatus of the second to sixth aspects, an object can be patterned by irradiating it with a spatially modulated exposure beam within the range of the field of view size of the objective lens. In this exposure apparatus, the projection lens and each of the objective lenses are positioned at a common conjugate point, so the field of view size of each objective lens can be effectively utilized to expose the object. Therefore, the exposable area can be reliably expanded without changing the relative position between the imaging optical system and the exposure object.

[0180] [Additional Notes] The present invention is not limited to the above-described embodiments and modifications, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in the embodiments and modifications are also included in the technical scope of the present invention.

[0181] 1 Exposure apparatus 10, 10A Imaging optical system 11 Imaging lens 12, 12A Optical path selector 121, 121A First block 122, 122A Second block 123, 123A Third block 124 to 126, 124A to 126A Mirror 13G Objective lens group 13, 131 to 133 Objective lens 14 Light source (laser) 15 Intensity modulator (Pockels cell, DMD) 16 Galvano scanner 17 Field lens 20 Illumination optical system 21 Light source (laser) 22 Afocal part 23 Mirror 24 Field lens 25 Mirror 30 Detection optical system 31 Mirror 32 Field lens 33 Mirror 34 Focus lens 35 Photodetector (two-dimensional image sensor) 41 Gel 42 Petri dish (exposure container) 421 Bottom plate 422 Side wall 423 Grid (mark) 43 Solvent 44 Glass plate

Claims

1. An exposure device comprising: an imaging optical system that focuses an exposure beam on a swollen gel, which is the object to be exposed; an illumination optical system that irradiates illumination light onto a substrate on which the gel is placed; and a detection optical system that focuses the reflected or scattered light of the illumination light reflected or scattered at each point on the substrate onto each point on a photodetector.

2. The exposure apparatus according to claim 1, further comprising: an objective lens shared by the imaging optical system, the illumination optical system, and the detection optical system; an imaging lens located in front of the objective lens and shared by the imaging optical system, the illumination optical system, and the detection optical system; and a scanning optical system located in front of the imaging lens and switching the direction of the chief ray of the exposure beam, wherein the scanning optical system is located so as to be conjugate with the objective lens on the optical path shared by the exposure beam and the illumination light.

3. The exposure apparatus according to claim 2, wherein the detection optical system further includes a focus lens, and the position of the focus lens is determined so as to focus the reflected light or the scattered light reflected or scattered at each point on the substrate onto the photodetector.

4. An exposure apparatus according to any one of claims 1 to 3, wherein the wavelength of the illumination light is a wavelength at which the transmittance of the gel is higher than the transmittance of the gel at the wavelength of the exposure beam.

5. An exposure apparatus according to any one of claims 1 to 4, wherein the gel is placed in a solution containing a dye, and the wavelength of the illumination light is a wavelength at which the transmittance of the dye is higher than a wavelength corresponding to 1 / 2 or 1 / 3 of the wavelength of the exposure beam, and at which the dye does not emit fluorescence.

6. The exposure apparatus according to claim 5, wherein the substrate is made of a light-transmitting material, and a mark that reflects or scatters the illumination light is formed on the substrate.

7. The exposure apparatus according to any one of claims 1 to 6, wherein the swollen gel is fixed to one of the main surfaces of the substrate.

8. An exposure apparatus as described in claim 2 or 3, comprising: a plurality of objective lenses including the objective lens; an optical path selector that switches which of the plurality of objective lenses the exposure beam that has passed through the imaging lens is incident on; and an optical path length adjustment unit that aligns the air-equivalent optical path lengths of the optical paths from the imaging lens to each of the plurality of objective lenses.

9. An exposure container in which a swollen gel, which is an object to be exposed, is placed on a bottom plate, the bottom plate including a light-transmitting area made of a light-transmitting material, and a mark that reflects or scatters light is formed in the light-transmitting area.

10. The exposure container according to claim 9, wherein the bottom plate is provided with a fixing member for fixing the gel.

11. An exposure system comprising a swollen gel as an exposure object, a substrate on which the gel is placed, and an exposure apparatus according to any one of claims 1 to 8.

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