Illumination optical system, exposure apparatus, illumination method, device manufacturing method, and flat panel display manufacturing method

Abstract

This illumination optical system for illuminating a mask on which a predetermined pattern is formed comprises: a plurality of light sources that emit pulse light; a division unit that divides, into first pulse light and second pulse light, the pulse light emitted from each of the plurality of light sources; an optical system having a delay optical system that guides the second pulse light to a second optical path longer than a first optical path through which the first pulse light passes, and a synthesis / division unit that synthesizes the first pulse light and the second pulse light that has passed through the delay optical system and divides and emits the synthesized pulse light; and an illumination system that guides each of the pulse lights, emitted from the optical system, to the mask, thereby illuminating the mask.

Description

[Technical field]

[0001] The present invention relates to an illumination optical system, an exposure apparatus, and a method for manufacturing a flat panel display. This application claims priority based on Japanese Patent Application No. 2021-075408, filed on April 27, 2021, Japanese Patent Application No. 2021-075409, filed on April 27, 2021, and Japanese Patent Application No. 2021-075410, filed on April 27, 2021, the contents of which are incorporated herein by reference. [Background technology]

[0002] Conventionally, the lithography process for manufacturing electronic devices (microdevices) such as liquid crystal display elements and semiconductor elements (integrated circuits, etc.) has mainly used a step-and-repeat type projection exposure apparatus (known as a stepper) or a step-and-scan type projection exposure apparatus (known as a scanning stepper, also called a scanner).

[0003] In this type of exposure apparatus, a substrate such as a glass plate or a wafer with a photosensitive agent applied to its surface (hereinafter collectively referred to as substrate) is placed on a substrate stage device. A spatial light modulation element on which a circuit pattern is formed is irradiated with pulsed light, and the pulsed light that has passed through the spatial light modulation element is irradiated onto the substrate via an optical system such as a projection lens, thereby transferring the circuit pattern onto the substrate (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2006-171426 A Summary of the Invention

[0005] According to a first aspect of the present invention, there is provided an illumination optical system for illuminating a mask having a predetermined pattern formed thereon, the illumination optical system including: an optical system having a plurality of light sources which emit pulsed light; a splitting unit which splits the pulsed light respectively emitted from the plurality of light sources into a first pulsed light and a second pulsed light; a delay optical system which guides the second pulsed light to a second optical path which is longer than a first optical path through which the first pulsed light passes; and a combining and splitting unit which combines the first pulsed light and the second pulsed light which has passed through the delay optical system, divides the combined pulsed light, and emits the combined pulsed light; and an illumination system which guides each of the pulsed light emitted from the optical system to the mask and illuminates the mask.

[0006] According to a second aspect of the present invention, there is provided an exposure apparatus comprising: an illumination optical system as described above; an illumination optical system; a projection optical system which divides and exposes an exposure object by irradiating the exposure object with light emitted from the mask illuminated by the pulsed light; and a stage on which the exposure object can be placed.

[0007] According to a third aspect of the present invention, there is provided a method for manufacturing a flat panel display, the method including: exposing an exposure object using the above-mentioned exposure apparatus; and developing the exposed exposure object.

[0008] According to a fourth aspect of the present invention, there is provided an illumination optical system that illuminates a spatial light modulator in which a plurality of elements are individually controlled at a predetermined time interval, the illumination optical system comprising: a first light source that emits a first pulsed light at a first time; a second light source that emits a second pulsed light at a second time different from the first time; and an illumination system that guides the first and second pulsed lights, respectively, to the spatial light modulator and illuminates the spatial light modulator, wherein the second light source emits the second pulsed light at the second time, when the time interval from the first time is shorter than the predetermined time interval.

[0009] According to a fifth aspect of the present invention, there is provided an exposure apparatus comprising: an illumination optical system as described above; and a projection optical system which divides and exposes a substrate by irradiating the substrate with light emitted from each of the spatial light modulators illuminated by the first and second pulsed light.

[0010] According to a sixth aspect of the present invention, there is provided a method for manufacturing a flat panel display, the method including exposing a substrate for the flat panel display using the above-mentioned exposure apparatus, and developing the exposed substrate.

[0011] According to a seventh aspect of the present invention, there is provided an illumination method in an illumination optical system that illuminates a spatial light modulator having a plurality of elements individually controlled at a predetermined time interval, the illumination method including: a first light source emitting a first pulsed light at a first time; a second light source emitting a second pulsed light at a second time, the second time being a time interval from the first time that is shorter than the predetermined time interval and different from the first time; and an illumination system guiding the first and second pulsed lights, respectively, to the spatial light modulator to illuminate the spatial light modulator.

[0012] According to an eighth aspect of the present invention, there is provided a device manufacturing method comprising exposing an image of the spatial light modulator illuminated by the above-mentioned illumination method onto a substrate, and developing the exposed substrate.

[0013] According to a ninth aspect of the present invention, there is provided a method for manufacturing a flat panel display, comprising exposing an image of the spatial light modulator illuminated by the above-mentioned illumination method onto a substrate, and developing the exposed substrate.

[0014] According to a tenth aspect of the present invention, there is provided an illumination optical system for illuminating a mask formed with a predetermined pattern, the illumination optical system including: an optical system having a light source which emits pulsed light; a splitting unit which splits the pulsed light into a first pulsed light and a second pulsed light; a delay optical system which guides the second pulsed light to a second optical path which is longer than a first optical path through which the first pulsed light passes; and a combining unit which combines the first pulsed light and the second pulsed light which has passed through the delay optical system; and an illumination system which guides the first and second pulsed lights combined in the combining unit to the mask and illuminates the mask, wherein the delay optical system includes a reflecting unit which reflects the second pulsed light, and an optical member which makes the reflected second pulsed light incident again on the reflecting unit.

[0015] According to an eleventh aspect of the present invention, there is provided an exposure apparatus comprising: the above-mentioned illumination optical system; a projection optical system which divides and exposes an exposure object by irradiating the exposure object with light emitted from the mask illuminated by the pulsed light; and a stage on which the exposure object can be placed.

[0016] According to a twelfth aspect of the present invention, there is provided a method for manufacturing a flat panel display, the method including: exposing an exposure object using the above-mentioned exposure apparatus; and developing the exposed exposure object. [Brief description of the drawings]

[0017] [Figure 1] 1 is a diagram showing an outline of the external configuration of an exposure apparatus according to an embodiment of the present invention; [Diagram 2] 1 is a diagram showing an outline of the configuration of a lighting module and a projection module according to the present embodiment; [Diagram 3] 1 is a diagram showing an outline of a configuration of a lighting module according to an embodiment of the present invention; [Figure 4] FIG. 2 is a diagram showing an outline of the configuration of a light modulation unit of the present embodiment. [Diagram 5] FIG. 2 is a diagram showing an outline of the configuration of a light source unit according to the present embodiment. [Figure 6] 3A and 3B are diagrams illustrating details of the configuration of a light source unit according to the present embodiment. [Figure 7]FIG. 2 is a diagram illustrating an example of a polarizing beam splitter according to the present embodiment. [Figure 8] FIG. 2 is a diagram illustrating an example of a configuration of a distribution unit according to the present embodiment. [Figure 9] 5A to 5C are diagrams illustrating an example of a state of pulsed light emitted by a light source unit of the present embodiment. [Figure 10] 4 is a diagram showing an example of a position where pulsed light in the present embodiment is incident on an optical fiber. FIG. [Figure 11] FIG. 2 is a diagram showing an outline of the configuration of a retarder according to the present embodiment. [Figure 12] FIG. 2 is a diagram showing a first modified example of the configuration of the retarder of the present embodiment. [Figure 13] FIG. 13 is a diagram showing a second modified example of the configuration of the retarder of the present embodiment. [Figure 14] FIG. 13 is a diagram showing a third modified example of the configuration of the retarder of the present embodiment. [Figure 15] FIG. 13 is a diagram showing a fourth modified example of the configuration of the retarder of the present embodiment. [Figure 16] FIG. 13 is a diagram showing a fifth modified example of the configuration of the retarder of the present embodiment. [Figure 17] FIG. 13 is a diagram showing a sixth modified example of the configuration of the retarder of the present embodiment. [Figure 18] 13A and 13B are diagrams illustrating a modification of the distributor of the present embodiment. [Figure 19] 11A and 11B are diagrams illustrating modified examples of the correspondence relationship between the light source units and the lighting modules of the present embodiment. [Figure 20] FIG. 4 is a diagram showing a first modified example of the light source unit of the present embodiment. [Figure 21] FIG. 11 is a diagram showing a second modified example of the light source unit of the present embodiment. [Figure 22] FIG. 13 is a diagram showing a third modified example of the light source unit of the present embodiment. [Figure 23] FIG. 13 is a diagram showing a fourth modified example of the light source unit of the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following detailed description of the present invention is illustrative only and not limiting. The same or similar reference characters are used throughout the drawings and the following detailed description.

[0019] [Configuration of exposure equipment] FIG. 1 is a diagram showing an outline of the external configuration of an exposure apparatus 1 of this embodiment. The exposure apparatus 1 is an apparatus that irradiates an exposure object with modulated light. In a specific embodiment, the exposure apparatus 1 is a step-and-scan projection exposure apparatus, a so-called scanner, in which a rectangular (corner-shaped) glass substrate used in a liquid crystal display device (flat panel display) or the like is used as an exposure object. The glass substrate as the exposure object has at least one side length or diagonal length of 500 mm or more, and may be a substrate for a flat panel display. The exposure object (for example, a substrate for a flat panel display) exposed by the exposure apparatus 1 is developed and provided as a product. The main body of the exposure apparatus 1 is configured similarly to the main body of the exposure apparatus 1 disclosed in, for example, US Patent Application Publication No. 2008 / 0030702.

[0020] The exposure apparatus 1 includes a base 11, a vibration isolation table 12, a main column 13, a stage 14, an optical base 15, an illumination module 16, a projection module 17, a light source unit 18, an optical fiber 19, and an optical modulation section 20 (not shown). In the following, a three-dimensional orthogonal coordinate system will be used as necessary to explain the present invention, in which the direction parallel to the optical axis direction of the projection module 17 that irradiates the exposure object with the light modulated by the light modulation unit 20 is defined as the Z-axis direction, and the directions of a predetermined plane perpendicular to the Z-axis are defined as the X-axis direction and the Y-axis direction. The X-axis direction and the Y-axis direction are perpendicular to each other (intersect each other).

[0021] The base 11 is a base for the exposure apparatus 1, and is placed on a vibration isolation table 12. The base 11 supports a stage 14, on which an object to be exposed is placed, so that the stage 14 is movable in the X-axis and Y-axis directions.

[0022] The stage 14 supports an object to be exposed, and is used to position the object to be exposed with high accuracy with respect to a plurality of partial images of a circuit pattern projected via the projection module 17 during scanning exposure, and drives the object to be exposed in six degrees of freedom (the above-mentioned X-axis, Y-axis, and Z-axis directions and the θx, θy, and θz directions which are rotational directions relative to the respective axes). The stage 14 is moved in the X-axis direction during scanning exposure, and is moved in the Y-axis direction when changing the exposure target area on the object to be exposed. A plurality of exposure target areas are formed on the object to be exposed. The exposure apparatus 1 is capable of exposing a plurality of exposure target areas on one object to be exposed. The configuration of the stage 14 is not particularly limited, but a stage device with a so-called coarse and fine movement configuration including a gantry-type two-dimensional coarse movement stage and a fine movement stage that is finely driven relative to the two-dimensional coarse movement stage, as disclosed in U.S. Patent Application Publication No. 2012 / 0057140, etc., can be used. In this case, the coarse movement stage allows the exposure object to be moved in three degrees of freedom in a horizontal plane, and the fine movement stage allows the exposure object to be finely moved in six degrees of freedom.

[0023] The main column 13 supports an optical base 15 above the stage 14 (in the positive direction of the Z axis). The optical base 15 supports an illumination module 16, a projection module 17, and a light modulation unit 20.

[0024] FIG. 2 is a diagram showing an outline of the configuration of the illumination module 16, the projection module 17, and the light modulation section 20 of this embodiment. The lighting modules 16 are disposed on the upper part of the optical base 15, and are connected to the light source unit 18 via optical fibers 19. In one example of this embodiment, the lighting modules 16 include a first lighting module 16A, a second lighting module 16B, a third lighting module 16C, and a fourth lighting module 16D. In the following description, when there is no need to distinguish between the first lighting module 16A to the fourth lighting module 16D, they will be collectively referred to as the lighting modules 16. Each of the first lighting module 16A to the fourth lighting module 16D guides the light emitted from the light source unit 18 via a fiber 19 to the first light modulation section 20A, the second light modulation section 20B, the third light modulation section 20C, and the fourth light modulation section 20D, respectively. The lighting module 16 illuminates the light modulation section 20.

[0025] The light modulation unit 20, which will be described in more detail later, is controlled based on the circuit pattern to be transferred onto the exposure object, and modulates the illumination light from the illumination module. The modulated light modulated by the light modulation unit 20 is guided to the projection module 17. The first light modulation unit 20A to the fourth light modulation unit 20D are disposed at different positions on the XY plane. In the following description, when there is no need to distinguish between the first light modulation unit 20A to the fourth light modulation unit 20D, they will be collectively referred to as the light modulation unit 20.

[0026] The projection module 17 is disposed under the optical base 15, and irradiates the light modulated by the spatial light modulator 201 onto the exposure object placed on the stage 14. The projection module forms an image of the light modulated by the light modulation section 20 on the exposure object, and exposes the exposure object. In other words, the projection module projects the pattern on the light modulation section 20 onto the exposure object. In one example of this embodiment, the projection module 17 includes the first projection module 17A to the fourth projection module 17D corresponding to the above-mentioned first illumination module 16A to the fourth illumination module 16D and the first light modulation section 20A to the fourth light modulation section 20D. In the following description, when the first projection module 17A to the fourth projection module 17D are not distinguished from each other, they are collectively referred to as the projection module 17.

[0027] A unit consisting of the first illumination module 16A, the first light modulation section 20A, and the first projection module 17A is called a first exposure module. Similarly, a unit consisting of the second illumination module 16B, the second light modulation section 20B, and the second projection module 17B is called a second exposure module. Each exposure module is provided at a different position on the XY plane, and can expose a pattern at a different position on an exposure object placed on the stage 14. The stage 14 can scan and expose the entire surface of the exposure object or the entire surface of the exposure object region by moving relatively in the X-axis direction, which is the scanning direction, with respect to the exposure module.

[0028] The projection module 17 is also referred to as a projection unit. The projection module 17 (projection unit) may be a life-size system that projects an image of a pattern on the light modulation unit 20 at life-size, or may be a magnification system or a reduction system. The projection module 17 is preferably made of one or two types of glass material (particularly, quartz or fluorite).

[0029] In addition to the above-mentioned sections, the exposure apparatus 1 is equipped with a position measurement section (not shown) composed of an interferometer, an encoder, etc., which measures the relative position of the stage 14 with respect to the optical table 15. In addition to the above-mentioned sections, the exposure apparatus 1 is equipped with an AF (Auto Focus) section (not shown) which measures the position of the stage 14 or the exposure target on the stage 14 in the Z-axis direction. Furthermore, the exposure apparatus 1 is equipped with an alignment section (not shown) which measures the relative position of each pattern when exposing and superimposing another pattern on a pattern already exposed on the exposure target. The AF section and / or the alignment section may be configured as a TTL (Through the lens) which performs measurement via a projection module.

[0030] 3 is a diagram showing an outline of the configuration of the exposure module of this embodiment. Taking the first exposure module as an example, an example of a specific configuration of the illumination module 16, the light modulation section 20, and the projection module 17 will be described.

[0031] The illumination module 16 includes a module shutter 161 and an illumination optical system 162. The module shutter 161 switches whether or not the pulsed light supplied from the optical fiber 19 is guided to the illumination optical system 162.

[0032] The illumination optical system 162 emits pulsed light supplied from the optical fiber 19 to the light modulation unit 20 via a collimator lens, a fly-eye lens, a condenser lens, etc., to illuminate the light modulation unit 20 almost uniformly. The fly-eye lens divides the wavefront of the pulsed light incident on the fly-eye lens, and the condenser lens superimposes the wavefront-divided light on the light modulation unit. Note that the illumination optical system 162 may include a rod integrator instead of the fly-eye lens.

[0033] The light modulation unit 20 includes a mask. The mask may be a photomask or a spatial light modulator (SLM). The following describes the case where the mask is a spatial light modulator.

[0034] The light modulation unit 20 includes a spatial light modulator 201 and an off-light absorbing plate 202. The spatial light modulator 201 includes a liquid crystal element, a digital mirror device (digital micromirror device, DMD), a magneto-optic spatial light modulator (magneto-optic spatial light modulator, MOSLM), or the like. The spatial light modulator 201 may be a reflective type that reflects the illumination light from the illumination optical system 162, a transmissive type that transmits the illumination light, or a diffractive type that diffracts the illumination light. The spatial light modulator 201 can spatially and temporally modulate the illumination light. Hereinafter, an example will be described in which the spatial light modulator 201 is configured by a digital micromirror device (DMD).

[0035] FIG. 4 is a diagram showing an outline of the configuration of the spatial light modulator 201 of this embodiment. In the figure, a three-dimensional orthogonal coordinate system of Xm-axis, Ym-axis, and Zm-axis will be used for explanation. The spatial light modulator 201 includes a plurality of micromirrors arranged on an XmYm plane. The micromirrors form the elements (pixels) of the spatial light modulator 201. The spatial light modulator 201 can change the tilt angle around the Xm axis and the Ym axis. For example, the spatial light modulator 201 is turned on by tilting around the Ym axis, and turned off by tilting around the Xm axis.

[0036] The spatial light modulator 201 controls the direction in which the incident light is reflected for each element by switching the tilt direction of the micromirror for each micromirror. As an example, the digital micromirror device of the spatial light modulator 201 has a pixel count of about 4 Mpixels and can switch the micromirror between the on and off states at a frequency of about 10 kHz. In the spatial light modulator 201, a plurality of elements are individually controlled at a predetermined time interval. When the spatial light modulator 201 is a DMD, the elements are micromirrors, and the predetermined time interval is a period (for example, a period of 10 kHz) for switching the micromirrors between an on state and an off state.

[0037] 3, the off-light absorbing plate 202 absorbs light (off light) emitted (reflected) from elements of the spatial light modulator 201 that are in the off state. The light emitted from elements of the spatial light modulator 201 that are in the on state is guided to the projection module 17.

[0038] The projection module 17 projects the light emitted from the turned-on elements of the spatial light modulator 201 onto an object to be exposed. The projection module includes a magnification adjustment unit 171 and a focus adjustment unit 172. The light modulated by the spatial light modulator 201 (modulated light) is incident on the magnification adjustment unit 171. The magnification adjustment unit 171 adjusts the magnification of the image on the focal plane 163 of the modulated light emitted from the spatial light modulator 201, that is, on the surface of the exposure object, by driving some of the lenses in the optical axis direction. The focus adjustment unit 172 adjusts the imaging position, i.e., the focus, by driving the entire lens group in the optical axis direction so that the modulated light emitted from the spatial light modulator 201 is imaged on the surface of the exposure object measured by the AF unit described above. The projection module 17 projects only the image of light emitted from the ON-state elements of the spatial light modulator onto the surface of the exposure object. Therefore, the projection module 17 can project and expose the image of the pattern formed by the ON-state elements of the spatial light modulator 201 onto the surface of the exposure object. In other words, the projection module 17 can form spatially modulated modulated light on the surface of the exposure object. In addition, the spatial light modulator 201 can switch the ON and OFF states of the micromirrors at a predetermined cycle (frequency) as described above, so the projection module 17 can form temporally modulated modulated light on the surface of the exposure object. That is, the exposure apparatus 1 performs exposure by changing the substantial pupil state at any exposure position.

[0039] The illumination module 16 is also referred to as an illumination system. The illumination module 16 (illumination system) illuminates a spatial light modulator 201 (spatial light modulation element) with the pulsed light distributed by the distribution unit 184.

[0040] Conventionally, when a highly coherent single-pulse laser is used to illuminate a spatial light modulation element with an integrator (e.g., a fly-eye lens), speckles are generated, which may affect the quality of the circuit pattern transferred to the substrate by the spatial light modulation element. Note that a highly coherent laser light source refers to pulsed light that, when the emitted light is used to illuminate a spatial light modulation element with an optical integrator with one pulse and exposed to the spatial light modulation element pattern, causes a variation of more than 20% in the in-plane or pupil intensity distribution, which causes speckles. The exposure apparatus 1 of the present embodiment is equipped with a light source unit 18 that can reduce speckles and improve the quality of the circuit pattern transferred to the substrate. The light source unit 18 of the present embodiment will be described below.

[0041] [Light source unit configuration] 5 is a diagram showing an outline of the configuration of the light source unit 18 of the present embodiment. The light source unit 18 includes a light source section 181, a combining section 182, a retarder 183, and a distributor 184.

[0042] The light source unit 181 emits light of a predetermined wavelength. The light emitted by the light source unit 181 may be continuous light or pulsed light. The following describes the case where the light source unit 181 emits pulsed light. In addition, when the light source unit 181 emits continuous light, the light emitted from the light source unit 181 may be considered to be substantially pulsed light by converting the continuous light into pulsed light by switching a shutter (not shown), modulating it with an acousto-optical modulator (not shown), or the like.

[0043] The light source section 181 includes a first light source section 181A to an eighth light source section 181H. Each of the first light source section 181A to the eighth light source section 181H includes a seed light source, and emits pulsed light of a predetermined wavelength. As an example, the light source unit 181 includes a fiber, a pumping laser diode (LD), and a wavelength conversion crystal (none of which are shown in the figure). The light source unit 181 inputs a laser amplified by the fiber and the pumping LD into the wavelength conversion crystal, and emits a triple harmonic pulsed light.

[0044] The light source included in the light source unit 181 may be a highly coherent laser light source (for example, a fiber laser) or a UV-LD. The light source unit 181 may be a laser light source that emits light with a wavelength of 360 nm or less.

[0045] The combining unit 182 combines the pulsed light emitted from each of the multiple laser light sources included in the light source unit 181. The combining unit 182 generates a pulsed light with high intensity (high energy) by combining the pulsed light. The combining unit 182 outputs the combined pulsed light to the retarder 183. The retarder 183 repeatedly divides and combines the pulsed light output from the combiner 182, and changes the distribution of the time axis of the pulsed light by combining pulsed light with different delay times. The retarder 183 outputs the pulsed light with the changed distribution of the time axis to the distributor 184.

[0046] The retarder 183 is also referred to as a delay optical system. The retarder 183 (delay optical system) delays a part of the pulsed light. The retarder 183 (delay optical system) also splits a part of the pulsed light and guides it to a delay optical path, and changes the time characteristics of the pulsed light by combining the part of the pulsed light guided to the delay optical path with another part of the split pulsed light.

[0047] The distributor 184 distributes the pulsed light output from the retarder 183 to each of the multiple optical fibers 19. That is, the distributor 184 distributes the pulsed light to multiple exposure modules. For example, the distributor 184 guides the first pulse of pulsed light output from the retarder 183 to a first exposure module, and guides the second pulse of pulsed light to a second exposure module. The distributor 184 can also be said to be a switching unit because it changes the exposure module to which the pulse is to be guided for each pulse.

[0048] 6 is a diagram showing the details of the configuration of the light source unit 18 of this embodiment. The diagram shows the first light source section 181A to the fourth light source section 181D of the first light source section 181A to the eighth light source section 181H. The fifth light source section 181E to the eighth light source section 181H have the same configuration as the first light source section 181A to the fourth light source section 181D, so a description thereof will be omitted.

[0049] The combining unit 182 includes a prism mirror 1821, a polarizing beam splitter 1822, a wave plate 1823, a wave plate 1824, a prism mirror 1825, a polarizing beam splitter 1826, and a prism mirror 1827. The prism mirror 1821 guides the pulsed light (s-polarized) emitted by the first light source unit 181A to the polarizing beam splitter 1822. The wave plate 1823 changes the polarization state of the pulsed light (s-polarized) emitted by the second light source unit 181B, and guides the pulsed light (p-polarized) to the polarizing beam splitter 1822.

[0050] 7 is a diagram showing an example of the polarizing beam splitter 1822 of this embodiment. The polarizing beam splitter 1822 transmits the pulsed light when the incident pulsed light is p-polarized light. The polarizing beam splitter 1822 reflects the pulsed light when the incident pulsed light is s-polarized light.

[0051] Returning to FIG. 6, the polarizing beam splitter 1822 reflects the pulsed light (s-polarized light) reflected by the prism mirror 1821 and guides it to the wave plate 1824. The polarizing beam splitter 1822 also transmits the pulsed light (p-polarized light) that has passed through the wave plate 1823 and guides it to the wave plate 1824. That is, the pulsed light emitted by the first light source unit 181A is incident on the wave plate 1824 as s-polarized light (0-degree linearly polarized light), and the pulsed light emitted by the second light source unit 181B is incident on the wave plate 1824 as p-polarized light (90-degree linearly polarized light). That is, two types of pulsed light whose polarization directions are orthogonal to each other are combined at a ratio of 50% each and each enter the wave plate 1824.

[0052] Wave plate 1824 rotates the polarization direction of the incident pulsed light. Wave plate 1824 rotates the polarization direction of incident s-polarized light (linearly polarized at 0 degrees) to +45-degree linear polarization, and rotates the polarization direction of incident p-polarized light (linearly polarized at 90 degrees) to -45-degree linear polarization. Two types of pulsed light, namely, +45 degree linearly polarized light and −45 degree linearly polarized light, are emitted from the wave plate 1824. The two types of pulsed light emitted from the wave plate 1824 are reflected by a prism mirror 1825 and guided to a polarizing beam splitter 1826.

[0053] The polarizing beam splitter 1826 outputs the incident pulsed light to the retarder 183. Here, the above-mentioned +45 degree linearly polarized light from the first light source unit 181A and −45 degree linearly polarized light from the second light source unit 181B are incident on the polarizing beam splitter 1826. The polarizing beam splitter 1826 reflects the s-polarized components of the incident pulsed light, that is, the s-polarized light linearly polarized at +45 degrees and the s-polarized light linearly polarized at −45 degrees, and outputs them to the retarder 183. The polarizing beam splitter 1826 transmits the p-polarized components of the incident pulsed light, that is, the p-polarized light linearly polarized at +45 degrees and the p-polarized light linearly polarized at −45 degrees, and outputs them to the retarder 183 via the prism mirror 1827.

[0054] That is, the polarizing beam splitter 1822 coaxially synthesizes the pulsed light emitted by the first light source unit 181A and the pulsed light emitted by the second light source unit 181B, and outputs the result to the retarder 183. Although the polarizing beam splitter 1822 synthesizes the pulsed light emitted by the first light source unit 181A and the pulsed light emitted by the second light source unit 181B coaxially, the pulsed light may be synthesized in a state in which the optical axes of the respective light beams are slightly shifted, that is, paraxially. When the polarizing beam splitter 1822 is a plate type, when the p-polarized pulsed light passes through the polarizing beam splitter 1822, its optical axis moves slightly in parallel. This occurs when the pulsed light passing through the PBS is slightly refracted by the refractive index of the PBS, and light with an optical axis that is slightly shifted in parallel from the optical axis at the time of incidence is emitted from the PBS. By synthesizing in the paraxial direction, the energy (power) per unit area of ​​the pulsed light that hits the optical element, that is, the energy density, can be dispersed. As a result, deterioration including deformation of the optical elements can be suppressed. Similarly, the combining unit 182 combines the pulsed light emitted by the third light source unit 181C and the pulsed light emitted by the fourth light source unit 181D on the same axis, and outputs the combined light to the retarder 183.

[0055] In other words, the light source unit 18 includes a synthesizer. The synthesizer 182 is an example of the synthesizer. The synthesizer synthesizes the pulsed light beams emitted from the multiple light sources.

[0056] In the following description, the pulsed light emitted from the polarizing beam splitter 1826 to the retarder 183 is also referred to as the retarder incident light 183LI. Of the retarder incident light 183LI, the pulsed light emitted from the polarizing beam splitter 1826 to the retarder 183 without passing through the prism mirror 1827 is also referred to as the first retarder incident light 183LI1, and the pulsed light emitted from the polarizing beam splitter 1826 to the retarder 183 via the prism mirror 1827 is also referred to as the second retarder incident light 183LI2. That is, two types of pulsed light, the first retarder incident light 183LI1 and the second retarder incident light 183LI2, emitted from different light source units 181, are incident on the retarder 183. As described above, both the first retarder incident light 183LI1 and the second retarder incident light 183LI2 are light obtained by coaxially (or approximately coaxially) combining the pulsed light emitted from each of the light sources, the first light source unit 181A to the fourth light source unit 184D.

[0057] In addition, although the description will be given assuming that the first retarder incident light 183LI1 and the second retarder incident light 183LI2 are incident on the retarder 183, this is not limiting. The pulsed light incident on the retarder 183 may be only the first retarder incident light 183LI1.

[0058] 11 and the like, the retarder 183 includes an input stage beam splitter 1834A. The input stage beam splitter 1834A combines and splits a first retarder incident light 183LI1 and a second retarder incident light 183LI2. The split pulsed light enters the delay stage 1832, respectively. Although the beam synthesis and splitting have been described as being performed by a beam splitter using polarized light, the present invention is not limited to this, and a half mirror, a half prism, or the like may also be used.

[0059] The delay stage 1832 includes a delay optical path, and changes the distribution of the time axis of each of the first retarder incident light 183LI1 and the second retarder incident light 183LI2. The delay stage 1832 outputs the pulsed light with the time axis distribution changed to the distributor 184 as the first retarder output light 183LO1 and the second retarder output light 183LO2.

[0060] In other words, the retarder 183 (delay optical system) guides the second pulse light to pass through a second optical path that is longer than the first optical path through which the first pulse light passes. The retarder 183 (delay optical system) splits a part of the pulse light combined by the combining unit 182 (combining device) and guides the split part to the second optical path.

[0061] 8 is a diagram showing an example of the configuration of the distribution unit 184 of this embodiment. The distribution unit 184 includes a rotary switch 1841 and a distributor 1842. Note that in this figure, the first retarder output light 183LO1 is described, and the description of the second retarder output light 183LO2 is omitted. Also, in this figure, the rotary switch 1841 is omitted from illustration.

[0062] The distributor 1842 selects an optical fiber 19 into which the pulsed light is to be incident from among the plurality of optical fibers 19. Specifically, the distributor 1842 includes a polygon mirror device that rotates at a predetermined number of revolutions. The polygon mirror device reflects the pulsed light incident from the retarder 183 in a direction according to the rotational angular velocity.

[0063] The rotation of the polygon mirror device changes the angle of the reflecting surface of the polygon mirror device with respect to the pulsed light incident from the retarder 183. Therefore, the destination of the pulsed light incident from the retarder 183 and reflected by the reflecting surface of the polygon mirror device changes depending on the time. The rotation angular velocity of the polygon mirror device is determined according to the time interval of the emission timing of the pulsed light. For example, when the pulsed light is incident on the polygon mirror device in the order of a first pulse PL1, a second pulse PL2, and a third pulse PL3, the first pulse PL1 is incident on the first optical fiber 19A, the second pulse PL2 is incident on the second optical fiber 19B, and the third pulse PL3 is incident on the third optical fiber 19C. That is, the distributor 184 distributes the pulsed light output from the retarder 183 to each of the multiple optical fibers 19. That is, the distributor 184 can switch the optical fiber 19 to which the pulsed light output from the retarder 183 is input at regular intervals. Although not shown in FIG. 8, the rotation switch 1841 is provided between the retarder 183 and the distributor 1842. The rotation switch 1841 guides the pulsed light emitted from the retarder 183 to the first surface of the polygon mirror device during the time interval T1 (for example, between time t1 and time t2), and guides the pulsed light to the second surface of the polygon mirror device during the time interval T2 (for example, between time t2 and t3). Since the rotation switch 1841 is constantly rotating during the time interval T3 (for example, between time t3 and t4), the third surface of the polygon mirror device moves to the position where the first surface was originally located. Similarly, during the time interval T4 (for example, between time t4 and t5), the fourth surface of the polygon mirror device moves to the position where the second surface was located. That is, the first surface during the time interval T1 and the third surface during the time interval T3 have the same angle with respect to the pulsed light emitted from the retarder 183. Also, the second surface in the time interval T2 and the fourth surface in the time interval T4 have the same angle with respect to the pulsed light emitted from the retarder 183. That is, the rotary switch 1841 changes the surface on the polygon mirror that guides the pulsed light at every certain time interval. The pulsed light reflected on the first surface in the time interval T1 is incident, for example, on the first optical fiber 19A to the fifth optical fiber 19E in that order. The pulsed light reflected on the second surface in the time interval T2 is incident, for example, on the sixth optical fiber 19F to the tenth optical fiber 19J (not shown in the figure) in that order. The pulsed light reflected on the third surface in the time interval T3 is incident, for example, on the first optical fiber 19A to the fifth optical fiber 19E in that order. The pulsed light reflected on the fourth surface in the time interval T4 is incident, for example, on the sixth optical fiber 19F to the tenth optical fiber 19J (not shown in the figure) in that order. In this way, the rotary switch 1841 changes the surface on the polygon mirror that guides the pulsed light at every certain time interval.

[0064] In addition, the distribution unit 184 may have an optical path switching unit and a light guiding unit at a position where the output position where the pulsed light is output from the optical path switching unit (e.g., a polygon mirror device) and the input position of the pulsed light in the light guiding unit (e.g., an optical fiber 19) are approximately optically conjugate. Moreover, the distributor 184 may include a lens 1843 that focuses the pulsed light reflected by the polygon mirror device at the position of the incident end of each optical fiber 19, and may further include a relay lens that makes the reflecting surface of the polygon mirror device and the incident surface of the optical fiber 19 conjugate with each other. In other words, the light source unit 18 may include a relay lens between the optical path switching section (e.g., the polygon mirror device) and the light guiding section (e.g., the optical fiber 19) that makes the exit position where the pulsed light is emitted from the optical path switching section and the entrance position of the pulsed light in the light guiding section almost optically conjugate with each other. Moreover, instead of the polygon mirror device, the distributor 184 may utilize a change in the optical path caused by a galvanometer mirror or an acousto-optic modulator (AOM) that slightly vibrates the emission direction of the pulsed light.

[0065] The optical fiber 19 supplies the pulsed light distributed by the distributor 1842 to the lighting module 16 .

[0066] It can be said that the multiple optical fibers 19 are configured to guide the first pulse light and the second pulse light emitted from the different light source units 181 to one spatial light modulator 201 . Of the multiple light transmitting sections, the first light transmitting section guides the first pulsed light and the second pulsed light to a first spatial light modulator of the multiple spatial light modulators 201 provided. The second light transmission section of the multiple light transmission sections guides the first pulse light and the second pulse light to a second spatial light modulator of the multiple spatial light modulators 201 provided.

[0067] In addition, the light source unit 18 may have a light source and an optical path switching section disposed at a position where the emission position of the pulsed light from the light source (e.g., the light source section 181) and the incidence position where the pulsed light is incident on the optical path switching section (e.g., the distributor 1842) are approximately optically conjugate. According to the light source unit 18 configured in this manner, since the emission position of the pulsed light from the light source section 181 and the incident position where the pulsed light is incident on the distributor 1842 are conjugate, the incident position where the pulsed light is incident on the distributor 1842 can be easily adjusted by adjusting the emission position of the pulsed light from the light source section 181. Therefore, according to the light source unit 18 configured in this manner, the incident position where the pulsed light is incident on the distributor 1842 can be easily adjusted in the replacement work or position adjustment work of the light source section 181.

[0068] 6, the control unit 21 controls the state of the pulsed light emitted by the light source unit 181. An example of the pulsed light emitted by the light source unit 181 will be described with reference to FIG.

[0069] [Light source unit 18 operation] 9 is a diagram showing an example of the state of pulsed light emitted by the light source unit 181 of this embodiment. [A] in the same figure shows an example of the state of pulsed light emitted by a conventional light source unit. The conventional light source unit emits pulsed light with a pulse width of 20 ns and a period of 200 kHz.

[0070] 1B shows an example of the state of pulsed light emitted by the light source unit 181 of this embodiment. The light source unit 181 of this embodiment emits a group pulsed light having a pulse width of 2 ns, a pulse interval of 20 ns, a pulse number of 10, and a period of 200 kHz.

[0071] Here, in the light source section 181 of this embodiment, the multiple light source sections 181 emit group pulse light at different timings. As an example, the first light source section 181A and the second light source section 181B both emit group pulse light with a pulse width of 2 ns, a pulse interval of 20 ns, a pulse number of 10, and a period of 200 kHz. The second light source section 181B emits pulse light during the period of the pulse interval of 20 ns of the group pulse light emitted by the first light source section 181A. That is, the emission timing of the pulsed light from the first light source unit 181A and the emission timing of the pulsed light from the second light source unit 181B are shifted from each other. Although the first light source section 181A and the second light source section 181B have been described as an example, the emission timings of the first light source section 181A to the fourth light source section 181D may be shifted from each other.

[0072] That is, the light source unit 18 makes the emission timings of the plurality of pulsed beams different from one another, thereby making the states of the pulsed beams distributed by the distributor 184 different from one another. Specifically, as shown in [B] of the same figure, the first light source unit 181A emits a first pulsed light at a first time, and the second light source unit 181B emits a second pulsed light at a second time different from the first time. As described above, the illumination module 16 (illumination system) guides the first pulsed light and the second pulsed light to the spatial light modulator 201 to illuminate the spatial light modulator 201. The second light source unit 181B emits the second pulsed light at a second time when the time interval from the first time is shorter than the predetermined time interval. When the spatial light modulator 201 is a DMD, the predetermined time interval is a period for switching the micromirror between the on state and the off state.

[0073] The first light source unit 181A continuously emits the first pulse light at a predetermined period. The second light source unit 181B continuously emits the second pulse light at a predetermined period. The predetermined period is the period of the group pulse light shown in FIG. [B] (e.g., a period of 200 kHz). Continuous emission means emission as a group pulse light with a predetermined pulse width (e.g., pulse width 2 ns), a predetermined pulse interval (e.g., pulse interval 20 ns), and a predetermined pulse number (e.g., pulse number 10).

[0074] The second light source unit 181B emits a second pulse light during the time during which the successive first pulse light is emitted from the first light source unit 181 A. The time during which the successive first pulse light is emitted from the first light source unit 181 A is the time (e.g., 200 ns) during which one group of pulse light of the first pulse light is emitted.

[0075] The first light source unit 181A and the second light source unit 181B continuously emit the first pulse light and the second pulse light, respectively, at a predetermined period that is a time interval shorter than the predetermined time interval at which the elements of the spatial light modulator 201 are controlled. That is, the oscillation time interval of the group pulse light (the above-mentioned predetermined period, for example, a period of 200 kHz) is a time interval shorter than the predetermined time interval (for example, 10 kHz) at which the multiple elements of the spatial light modulator 201 are individually controlled.

[0076] According to the light source unit 18 configured in this manner, the emission timings of the plurality of pulsed beams are different from one another, and the coherence of the pulsed beams is reduced, so that the occurrence of speckles can be suppressed.

[0077] The emission timing of the pulsed light described above may be adjusted by the control unit 21 controlling the light source unit 181. The above-mentioned first light source unit 181A to eighth light source unit 181H each include a seed light source, and the control unit can control the oscillation timing of the pulsed light for each light source by controlling each of these various light sources. The control unit 21 makes the emission timings of the multiple pulsed lights different from one another, thereby making the states of the pulsed lights on the spatial light modulator 201 different from one another. The control unit 21 is an example of a state changing unit. Furthermore, the emission timing of the above-mentioned pulsed light may be preset in the light source unit 181 without being controlled by the control unit 21.

[0078] In the light source unit 181 of this embodiment, the wavelengths of the pulsed light emitted by the multiple light source units 181 may be different from each other. As an example, the central wavelengths of the pulsed light of the multiple light source units 181 are made to differ from each other by several picometers to several tens of picometers. The allowable value of the shift amount of the central wavelength that is made different for each light source unit 181 is determined, for example, by the chromatic aberration that occurs in the projection module due to the shift amount. If the allowable value is, for example, 100 pm and the number of light sources is five, the central wavelengths are shifted evenly by 20 pm for each light source. The shift amount does not have to be even. In other words, the central wavelength is shifted for each light source unit 181 to an extent that exposure failure does not occur due to chromatic aberration. As an example, the wavelength of the pulsed light emitted by the light source unit 181 changes due to a change in the operating environment temperature. The multiple light source units 181 make the wavelengths of the pulsed light different from each other by making the operating environment temperatures different from each other. In addition, let λ be the wavelength difference between the central wavelengths of the first pulse light and the second pulse light, Δ be the chromatic aberration of the projection optical system caused by the wavelength difference λ, and NA be the numerical aperture of the projection optical system. Then, λ>Δ×(NA^2) Meet the following.

[0079] The light source unit 18 may include a temperature control device (a heating device or a cooling device, neither of which is shown) that changes the operating environment temperature of the light source section 181. The temperature control device may be configured to change the operating environment temperature of the light source section 181 based on the control of the control section 21. In this case, the control section 21 controls the operating environment temperatures of the multiple light source sections 181, respectively, so that the wavelengths of the pulsed light emitted by the multiple light source sections 181 are different from each other. The light source unit 18 periodically varies the wavelength by actively varying the temperature of the seed light periodically, and can also periodically change the wavelength within a certain range.

[0080] The light source unit 18 may include a wavelength filter device (not shown) that allows transmission of a portion of the wavelength band of the pulsed light emitted by the light source section 181. The wavelength filter device may be configured to change the wavelength of the pulsed light to be transmitted based on the control of the control section 21. In this case, the control section 21 controls the wavelength filter device to transmit different wavelength bands for the multiple light source sections 181, thereby controlling the wavelengths of the pulsed light emitted by the multiple light source sections 181 to be different from each other.

[0081] The light source unit 18 is an example of a state changer. The light source unit 18 (state changer) changes the wavelengths of the multiple pulsed lights to different states of the pulsed lights distributed by the distributor 184. For example, the wavelength of the pulsed light emitted by the first light source unit 181A is different from the wavelength of the pulsed light emitted by the second light source unit 181B. The first light source unit 181A emits a first pulsed light having a different wavelength from that of the second pulsed light emitted from the second light source unit 181B.

[0082] The light source unit 18 may include a wavelength measurement device (not shown) that measures the wavelength of the emitted pulsed light. The control unit 21 controls the wavelength of the pulsed light emitted from the light source unit 181 based on the measurement result of the wavelength of the pulsed light by the wavelength measurement device. In other words, the control unit 21 makes the wavelengths of the plurality of pulsed beams different from one another, thereby making the states of the pulsed beams different from one another on the spatial light modulator 201. The control unit 21 is an example of a state changing unit.

[0083] According to the light source unit 18 configured in this manner, the wavelengths of the plurality of pulsed lights are different from one another, and the coherence of the pulsed lights is reduced, so that the occurrence of speckles can be suppressed.

[0084] Although the case where the wavelength of the first pulsed light and the wavelength of the second pulsed light are different from each other have been described, this is not limiting. The phase state of the first pulsed light and the phase state of the second pulsed light may be different from each other. In this case, the illumination system may have a phase change unit that changes the phase state of at least one of the first pulsed light and the second pulsed light.

[0085] 6, the control unit 21 controls the distributor 184 to control the position at which the pulsed light enters the optical fiber 19. An example of control of the position at which the pulsed light enters the optical fiber 19 will be described with reference to FIG.

[0086] FIG. 10 is a diagram showing an example of a position where the pulsed light enters the optical fiber 19 in this embodiment. As described above, pulsed light (for example, first retarder output light 183LO1) is incident on distributor 1842 (for example, polygon mirror device) from retarder 183. First retarder output light 183LO1 incident on distributor 1842 is reflected in a direction based on the incident angle to the polygon mirror device and the angle of the reflecting mirror at the time of incidence. The angle of the reflecting mirror at the time of incidence changes as the rotational speed (angular velocity) of the polygon mirror device changes. For example, if the rotation speed of the distributor 1842 is a predetermined angular velocity, the first retarder output light 183LO1 reflected by the distributor 1842 is incident on the optical fiber 19 at a position P1. If the rotation speed of the distributor 1842 is slower than the predetermined angular velocity, the first retarder output light 183LO1 reflected by the distributor 1842 is incident on the optical fiber 19 at a position P2. If the rotation speed of the distributor 1842 is faster than the predetermined angular velocity, the first retarder output light 183LO1 reflected by the distributor 1842 is incident on the optical fiber 19 at a position P3.

[0087] Here, the change in the position of incidence on the fiber has been described, but for example, the reflecting surface of the polygon mirror device and the fiber inlet may be conjugated by a lens. In other words, the distributor 184 may be provided with an optical path switching unit and a light guiding unit at a position where the output position of the pulsed light from the optical path switching unit (e.g., polygon mirror device) and the input position of the pulsed light in the light guiding unit (e.g., optical fiber 19) are almost optically conjugate. With the light source unit 18 configured in this way, the input position of the fiber does not change substantially, but the input angle to the fiber can be changed. That is, by changing the rotation speed (angular velocity) of the polygon mirror device, the incident position and incident angle of the pulsed light into the optical fiber 19 change. When the incident position and incident angle of the pulsed light into the optical fiber 19 change, the path of the pulsed light guided inside the optical fiber 19 changes, and the temporal characteristics of the pulsed light change.

[0088] The control unit 21 changes the rotation speed of the polygon mirror device to change the path of the pulsed light guided through the optical fiber 19, thereby changing the temporal characteristics of the pulsed light emitted from the illumination module 16. That is, the light source unit 18 causes the distributor 184 to distribute the pulsed light at different timings, thereby causing the states of the pulsed light distributed by the distributor 184 to differ from one another.

[0089] For example, the illumination system includes a light transmitting section that guides the first pulse light and the second pulse light to the spatial light modulator 201. The above-mentioned optical fiber 19 is an example of the light transmitting section. The phase changing section adjusts the incidence angle of the first pulse light and the second pulse light that are incident on the light transmitting section (for example, the optical fiber 19). The above-mentioned polygon mirror device whose rotational speed (angular velocity) changes is an example of the phase changing section.

[0090] In other words, the illumination system includes an optical path switching unit. The optical path switching unit switches the optical path of the synthesized pulsed light and sequentially guides the light to the multiple masks. The polygon mirror device is an example of the optical path switching unit. As described above, the mask may be a photomask or a spatial light modulator. In the case where the illumination system has an optical path switching unit that switches the optical path of the combined pulsed light and sequentially guides it to a plurality of masks, the control unit 21 differentiates the distribution timing of the pulsed light by the optical path switching unit, thereby differentiating the states of the pulsed light on the spatial light modulator 201. The control by the control unit 21 of the distribution timing of the pulsed light by the optical path switching unit is an example of a state changing unit.

[0091] That is, the illumination system has an optical path switcher that switches the optical paths of the first pulse light and the second pulse light sequentially oscillated from the first light source unit 181A and the second light source unit 181B and sequentially guides the light to a plurality of optical transmission units (for example, optical fibers 19). The above-mentioned polygon mirror device is an example of the optical path switcher.

[0092] The optical path switch has a reflecting surface that reflects the first pulsed light and the second pulsed light, and switches the optical path by changing the angle of incidence of the first pulsed light and the second pulsed light on the reflecting surface. The phase change section controls the optical path switcher to adjust the angles of incidence of the first and second pulsed lights incident on the optical transmission section.

[0093] The phase change section may have a diffusion plate that diffuses the light incident on the spatial light modulator 201. The phase change section may cause the phase change by vibrating the optical fiber 19 itself.

[0094] As described above, the exposure apparatus 1 includes a projection optical system that exposes the substrate in a divided manner by irradiating the substrate with light emitted from each of the multiple spatial light modulators 201 illuminated by the first pulse light and the second pulse light.

[0095] According to the light source unit 18 configured in this manner, the multiple pulsed beams have different temporal characteristics, and the coherence of the pulsed beams is reduced, making it possible to suppress the occurrence of speckles.

[0096] A diffuser plate may be disposed immediately before the input end of each fiber 19. The diffuser plate diffuses the pulsed light and can change the input position and input angle of the pulsed light into the fiber, thereby changing the phase and wavefront of the pulsed light. The diffused pulsed light overlaps with each other and is averaged. Therefore, the phase, wavefront, intensity, etc. of each pulsed light input to the same fiber 19 can be changed. The diffuser plate may be provided with a mechanism for rotating and / or translating. The mechanism can change the state in which the pulsed light passes on the diffuser plate, thereby changing the position and angle of incidence of the pulsed light into the fiber. The mechanism can change the phase and wavefront of the pulsed light by moving the diffuser plate after the first pulse passes and before the second pulse passes. In this way, the movement of the phase and wavefront diffuser plate for each pulsed light may be performed for each pulse or for multiple pulses. Also, one diffuser plate may be installed for multiple fibers, not for each fiber 19.

[0097] Note that the rotation speed (angular velocity) of the polygon mirror device is changed to change the incident position of the pulsed light into the optical fiber 19, but this is not limiting. The rotation speed of the polygon mirror device may be kept constant, and the incident end of the optical fiber 19 may be moved to shift the position where the pulsed light is incident. Note that the incident end of the optical fiber 19 may be moved while changing the rotation speed of the polygon mirror device.

[0098] The diffusion plate may be provided at the exit end of the optical fiber 19. Also, the diffusion plate may be provided at the exit end of each light source.

[0099] [Configuration of Retarder 183] As described above, the retarder 183 splits and combines the retarder incident light 183LI, and emits the retarder outgoing light 183LO in which the state of the pulsed light has been changed. Specifically, the retarder 183 splits the incident pulsed light into a plurality of parts (for example, two), and generates a delay in the pulsed light corresponding to the pulse width by making the optical path length of one of the split pulsed light longer than the optical path length of the other pulsed light. The retarder 183 combines the split pulsed light together, and outputs pulsed light whose state has been changed with respect to the incident pulsed light. A specific configuration of the retarder 183 will be described with reference to FIG. 11.

[0100] 11 is a diagram showing an outline of the configuration of the retarder 183 of this embodiment. As an example, the diagram shows an eight-stage retarder 183 in which nine beam splitters (e.g., half prisms) are arranged in series. The retarder 183 includes an input stage 1831 and a delay stage 1832. The input stage 1831 includes an input stage beam splitter 1834A.

[0101] Of the nine beam splitters described above, the input stage beam splitter 1834A is the beam splitter into which the pulsed light (retarder incident light 183LI) output from the synthesis unit 182 first enters. The input stage beam splitter 1834A splits the input pulsed light, and outputs one of the split light to the input stage mirror 1835 and the other to the second stage beam splitter. The pulsed light reflected by the input stage mirror 1835 enters the second stage beam splitter. In the following description, an optical path that passes through a prism mirror (for example, the input stage mirror 1835) is also called a delay optical path, and an optical path that does not pass through a prism mirror is also called a non-delay optical path.

[0102] The second-stage beam splitter is respectively input with the pulsed light output from the input-stage beam splitter 1834A (i.e., the pulsed light that has passed through the non-delay optical path and is not delayed) and the pulsed light reflected by the input-stage mirror 1835 (i.e., the pulsed light that has passed through the delay optical path and is delayed). In the second-stage beam splitter, the non-delayed pulsed light and the delayed pulsed light are combined and further split into the delay optical path and the non-delayed optical path.

[0103] As described above, the beam splitter included in the retarder 183 transmits a part of the pulsed light and reflects the other part, thereby synthesizing or splitting the pulsed light. That is, the retarder 183 (delay optical system) transmits a part of the pulsed light and reflects the other part, thereby synthesizing or splitting the pulsed light. Furthermore, the beam splitter (for example, a half prism) transmits or reflects the pulsed light regardless of the polarization state of the pulsed light (for example, p-polarized light and s-polarized light). The retarder 183 combines or splits the pulsed light by the beam splitter.

[0104] The retarder 183 (delay optical system) divides the pulsed light combined by the combining unit 182 and delays a part of each of the divided pulsed light. That is, the retarder 183 (delay optical system) delays a part of the pulsed light combined by the combining unit 182. More specifically, the retarder 183 (delay optical system) divides a part of the pulsed light, guides it to a delay optical path, and combines the part of the pulsed light guided to the delay optical path with another part of the divided pulsed light, thereby changing the time characteristics of the pulsed light. The retarder 183 (delay optical system) combines the pulsed light emitted from a plurality of light sources, and divides a part of the combined pulsed light to guide it to the delay optical path.

[0105] By repeating the division and synthesis of the pulse light up to the eighth stage of the retarder 183, one pulse light (see [B] in the same figure) is converted into 2 to the power of 8 (i.e., 256) group pulse lights (see [C] in the same figure).

[0106] That is, the illumination system has a splitting section that splits each of the first pulse light and the second pulse light into two pulse lights, and a light guiding optical system that guides one of the pulse lights that has passed through the splitting section along a first optical path and guides the other pulse light that has passed through the splitting section along a second optical path that is longer than the first optical path.

[0107] The optical system has a splitting unit that splits the pulsed light into a first pulsed light and a second pulsed light, a delay optical system that guides the second pulsed light to a second optical path that is longer than a first optical path through which the first pulsed light passes, and a combining unit that combines the first pulsed light and the second pulsed light that has passed through the delay optical system. The illumination system guides the first and second pulsed lights combined by the combining unit to a mask to illuminate the mask. As described above, the mask may be a photomask or a spatial light modulator.

[0108] According to the light source unit 18 configured in this manner, the multiple pulsed beams have different temporal characteristics, and the coherence of the pulsed beams is reduced, making it possible to suppress the occurrence of speckles.

[0109] In addition, the same figure [A] shows an example of a retarder 183 in which the delay optical path is formed by prism mirrors from the first to third stages, and the delay optical path is formed by optical fiber 1835A with relatively high transmittance from the fourth to eighth stages, but this is not limited to this.

[0110] In addition, although the case where one type of pulsed light is incident on the retarder 183 has been described in Fig. 15A, the present invention is not limited to this. A retarder 183 on which two types of pulsed light are incident will be described with reference to Fig. 12.

[0111] 12 is a diagram showing a first modified example of the configuration of the retarder 183 of this embodiment. In the same figure, as an example, a five-stage retarder 183 in which six beam splitters (for example, half prisms) are arranged in series is shown. In the retarder 183 of this modification, two types of pulsed light, a first retarder incident light 183LI1 and a second retarder incident light 183LI2, are incident on an input stage beam splitter 1834A. The final stage beam splitter 1834B outputs a first retarder output light 183LO1 and a second retarder output light 183LO2.

[0112] As described above, the retarder 183 (delay optical system) outputs pulsed light through a plurality of paths, for example, the first retarder output light 183LO1 and the second retarder output light 183LO2. The retarder 183 (delay optical system) outputs the pulsed light to a plurality of distributors 184 corresponding to the paths. That is, the retarder 183 of this modified example has two inputs and two outputs. In other words, the final stage beam splitter 1834B included in the retarder 183 (delay optical system) outputs pulsed light through a plurality of paths. The pulsed light is guided to a plurality of distributors 184 (optical path switching units) corresponding to the respective paths. That is, the delay optical system outputs pulsed light through a plurality of paths, and outputs the pulsed light to a plurality of optical path switching units corresponding to the paths. Note that the plurality of optical path switching units may be constituted by a plurality of distributors 1842, or may be constituted by mutually different reflecting surfaces of a single distributor 1842.

[0113] 13 is a diagram showing a second modified example of the configuration of the retarder 183 of this embodiment. In the same figure, a retarder 183 having a five-stage configuration in which six beam splitters are arranged in series is shown as an example. The retarder 183 of this modified example is configured such that the fifth stage delay optical path rotates between the mirrors. Specifically, the retarder 183 of this modified example includes a first orbit mirror 1835A, a second orbit mirror 1835B, a third orbit mirror 1835C, and a fourth orbit mirror 1835D. The first orbit mirror 1835A to the fourth orbit mirror 1835D configure the fifth stage delay optical path.

[0114] As shown in the figure, the retarder 183 has a reflecting portion (for example, a first circulating mirror 1835A) that reflects the second pulsed light, and an optical member that makes the reflected second pulsed light enter the reflecting portion again. The optical member has a reflecting member (for example, the second orbit mirror 1835B to the fourth orbit mirror 1835D). The reflecting member (for example, the second orbit mirror 1835B to the fourth orbit mirror 1835D) reflects the second pulsed light reflected by the reflecting portion (for example, the first orbit mirror 1835A) and makes the second pulsed light incident on the reflecting portion. That is, the retarder 183 includes an optical member that guides the pulsed light reflected by the reflecting portion back to the reflecting portion. The retarder 183 uses the reflecting portion and the optical member to make the optical path of the pulsed light circulate (for example, circulate in a spiral shape) between the reflecting portion and the optical member.

[0115] According to the retarder 183 configured in this manner, it is possible to prevent the device from becoming large while increasing the optical path length of the delay optical path (that is, while improving the speckle reduction performance).

[0116] The retarder 183 may include a beam splitter 1834C. The beam splitter 1834C is disposed on the circular optical path of the pulsed light formed by the first circular mirror 1835A to the fourth circular mirror 1835D, and guides a part of the circulating pulsed light to the circular optical path and the other part to the final stage beam splitter 1834B. According to the retarder 183 configured in this manner, it is possible to further increase the number of types of pulsed light having different optical path lengths, thereby making it possible to further improve the speckle reduction performance while suppressing an increase in the size of the device.

[0117] 14 is a diagram showing a third modified example of the configuration of the retarder 183 of this embodiment. The diagram shows an example of a four-stage retarder 183 in which five beam splitters are arranged in series. The retarder 183 of this modified example includes a relay lens 1836 and a focusing mirror 1837, and the delay optical path is configured using a Dyson optical system. More specifically, in the first stage retarder 183A, the pulsed light reflected by the input stage beam splitter 1834A is reflected by the collecting mirror 1837 via the relay lens 1836, and again enters the second stage beam splitter 1834-2 via the relay lens 1836. In the second stage retarder 183B to the fifth stage retarder 183E, similar to the first stage retarder 183A, the pulsed light is collected and reflected repeatedly, thereby forming a delay optical path. The input stage beam splitter 1834A functions as a splitting section that splits the light into a first pulse light and a second pulse light. The relay lens 1836 and the collecting mirror 1837 function as a delay optical system that guides the second pulse light to a second optical path that is longer than the first optical path through which the first pulse light passes. The second stage beam splitter 1834-2 functions as a combining section that combines the first pulse light and the second pulse light that has passed through the delay optical system (the relay lens 1836 and the collecting mirror 1837).

[0118] As described above, relay lens 1836 has the position of the surface of collecting mirror 1837 as the back focal point. This back focal point is the focal point of the pulsed light incident from first stage retarder 183A and also the focal point of the pulsed light output to second stage retarder 183B. That is, relay lens 1836 guides the pulsed light incident from first stage retarder 183A and the pulsed light output to second stage retarder 183B through a common focal point. That is, for relay lens 1836, the division surface of first stage retarder 183A and the division surface of second stage retarder 183B are conjugate. Here, the first stage retarder 183A is also referred to as a first division / combination section, and the second stage retarder 183B is also referred to as a second division / combination section. That is, in the retarder 183 (delay optical system), among a plurality of beam splitters (splitting and combining sections), the splitting surface of a first stage retarder 183A (first splitting and combining section) that splits a pulsed light into a first pulsed light and a second pulsed light and guides the first pulsed light to the delay optical path is conjugate with the splitting surface of a second stage retarder 183B (second splitting and combining section) that combines the first pulsed light and the second pulsed light output from the delay optical path. In addition, when both pulsed lights can be regarded as almost parallel lights, especially when the optical path difference is short, the splitting surface of the first stage retarder 183A (first splitting / combining unit) and the splitting surface of the second stage retarder 183B (second splitting / combining unit) do not need to be in a strictly conjugate relationship. In this case, it is sufficient to arrange them so that one of the pulsed lights is delayed by a predetermined distance.

[0119] The relay lens 1836 is also referred to as an optical member, and the focusing mirror 1837 is also referred to as a reflecting portion. That is, the retarder 183 (delay optical system) includes a relay lens 1836 (optical member) and a focusing mirror 1837 (reflecting portion). The focusing mirror 1837 (reflecting section) reflects the first pulsed light emitted from the first-stage retarder 183A (first dividing and combining section) toward the second-stage retarder 183B (second dividing and combining section). The relay lens 1836 (optical component) is disposed on the optical path between the first stage retarder 183A (first division and synthesis section) and the second stage retarder 183B (second division and synthesis section), and causes the first pulse light emitted from the first stage retarder 183A (first division and synthesis section) to be incident on the focusing mirror 1837 (reflection section), and causes the first pulse light reflected by the focusing mirror 1837 (reflection section) to be incident on the second stage retarder 183B (second division and synthesis section).

[0120] In other words, the retarder 183 (delay optical system) includes a reflecting section (e.g., a collecting mirror 1837) and an optical member (e.g., a relay lens 1836). The reflecting section reflects the second pulse light and guides it to a combining section (e.g., a second stage beam splitter 1834-2). The optical member is disposed between a splitting section (e.g., an input stage beam splitter 1834A) and the reflecting section and between the reflecting section and the combining section, and causes the second pulse light to be incident on the reflecting section and the second pulse light reflected by the reflecting section to be incident on the combining section. The retarder 183 (delay optical system) has a splitting section and a combining section disposed at a position where a splitting surface of the splitting section (e.g., input stage beam splitter 1834A) that splits the pulsed light into a first pulsed light and a second pulsed light and a combining surface of a combining section (e.g., second stage beam splitter 1834-2) that combines the first pulsed light that has passed through the first optical path and the second pulsed light that has passed through the second optical path are optically conjugate.

[0121] As described above, the retarder 183 (delay optical system) is configured with at least two stages, the first stage retarder 183A and the second stage retarder 183B. In other words, the retarder 183 (delay optical system) has at least two relay lenses 1836 (optical members) arranged at positions facing each other with the traveling direction of the second pulsed light as an axis. Of these multiple optical members, the optical axis of one optical member and the optical axis of the other optical member are spaced apart in the axial direction. That is, the reflecting section has a first reflecting section and a second reflecting section. The optical member has a first optical member that causes the second pulsed light split by the splitting section to enter the first reflecting section, and a second optical member that causes the second pulsed light reflected by the first reflecting section to enter the second reflecting section. The first optical member and the second optical member are arranged with their optical axes spaced apart from each other.

[0122] As shown in the figure, a reflecting section (eg, a collecting mirror 1837) is provided at a position where the focal position of an optical member (eg, a relay lens 1836) becomes a reflecting surface that reflects the second pulsed light. The reflecting section (e.g., collecting mirror 1837) reflects the second pulsed light so that the second pulsed light is incident on a position in the optical member different from the position through which the second pulsed light incident on the reflecting section passes. That is, the second reflecting section reflects the second pulsed light and guides the second pulsed light again to the first reflecting section via the second optical system. The reflecting section has a third reflecting section. The optical member has a third optical member. The second reflecting section reflects the second pulsed light and guides the second pulsed light to the third reflecting section via the second optical system and the third optical system.

[0123] The second stage beam splitter 1834-2 of the retarder 183 has both the function of a splitting section and a combining section of the pulsed light. The second stage beam splitter 1834-2 (combining section) splits the first pulsed light into a third pulsed light and a fourth pulsed light, and splits the second pulsed light into a fifth pulsed light and a sixth pulsed light.

[0124] 15 is a diagram showing a fourth modified example of the configuration of the retarder 183 of this embodiment. In the figure, a five-stage retarder 183 in which six beam splitters are arranged in series is shown as an example. The retarder 183 of this modified example includes a first stage retarder 183A to a fifth stage retarder 183E. Each of the first stage retarder 183A to the fifth stage retarder 183E includes a relay lens 1836 and a collecting mirror 1837, and is configured using a Dyson optical system. More specifically, in the first stage retarder 183A, the pulsed light reflected by the input stage beam splitter 1834A is reflected by the collecting mirror 1837 via the relay lens 1836, and again enters the second stage beam splitter 1834-2 via the relay lens 1836. In the second stage retarder 183B to the fifth stage retarder 183E, similar to the first stage retarder 183A, the pulsed light is collected and reflected repeatedly, thereby forming a delay optical path.

[0125] The optical path length of the delay optical path increases exponentially with each stage of the retarder 183. The retarder 183 of this modification includes a plurality of relay lenses 1836 and a focusing mirror 1837 in the third stage retarder 183C and subsequent stages, and has a configuration in which the optical path is folded back in the direction of the retarder width 183W. The retarder 183 configured in this manner can form a delay optical path with a longer optical path length while suppressing an increase in the dimension in the retarder width 183W direction.

[0126] In the figure, a case where each stage of the retarder 183 is configured using a Dyson optical system is shown. That is, the retarder 183 has a lens (corresponding to the relay lens 1836 in FIG. 14) that collects the second pulse light that has passed through the beam splitter 1834 (splitting section) on a reflecting section (corresponding to the collecting mirror 1837 in FIG. 14). The lens guides the second pulse light reflected by the collecting mirror (reflecting member) to the reflecting mirror (reflecting member) of the next stage.

[0127] Each stage of the retarder 183 does not have to be configured using the Dyson optical system. The retarder 183 may be configured by alternately using a delay optical path based on the Dyson optical system shown in FIG. 14 and a delay optical path based on the prism mirror shown in FIG. 12 for each stage. In this case, the retarder 183 has a relay lens (lens section) that focuses the second pulse light that has passed through the beam splitter (splitting section) on a focusing mirror. The relay lens guides the second pulse light reflected by the focusing mirror to the beam splitter at the next stage. The beam splitter at the next stage guides the second pulse light to a prism mirror (reflecting section).

[0128] Furthermore, the retarder 183 in the subsequent stage (for example, the fifth stage retarder 183E) where the number of turns of the optical path increases can be configured as shown in FIG.

[0129] 16 is a diagram showing a fifth modified example of the configuration of the retarder 183 of this embodiment. This diagram shows an example of a delay optical path using a Dyson optical system, which is adopted instead of the fifth stage retarder 183E shown in FIG. Fifth stage retarder 183E of this modification includes a first relay lens 1836A, a first focusing mirror 1837A, a second relay lens 1836B, and a second focusing mirror 1837B. First collecting mirror 1837A is disposed at the back focal position of first relay lens 1836A. First light L1 incident on first relay lens 1836A is reflected by first collecting mirror 1837A and again incident on first relay lens 1836A as second light L2. Second light L2 incident on first relay lens 1836A is incident on second relay lens 1836B. The second collecting mirror 1837B is disposed at the back focal position of the second relay lens 1836B. The second light L2 incident on the second relay lens 1836B is reflected by the second collecting mirror 1837B and again incident on the second relay lens 1836B as the third light L3. The third light L3 incident on the second relay lens 1836B is incident on the first relay lens 1836A. The third light L3 incident on the first relay lens 1836A is reflected by the first collecting mirror 1837A and is incident again on the first relay lens 1836A as the fourth light L4.

[0130] The optical axis AX2 of the second relay lens 1836B is disposed offset from the optical axis AX1 of the first relay lens 1836A in the arrangement direction of the beam splitters 1834 (direction D1 shown in FIGS. 15 and 16). The position where the third light L3 enters the first relay lens 1836A is shifted in the direction D1 by the offset amount described above with respect to the position where the first light L1 enters the first relay lens 1836A. Therefore, the angle of incidence of the first light L1 on the first collecting mirror 1837A and the angle of incidence of the third light L3 on the first collecting mirror 1837A are different from each other. Therefore, the optical path of the second light L2 reflected by the first collecting mirror 1837A and the optical path of the fourth light L4 are different from each other, and the second light L2 and the fourth light L4 can be geometrically separated. Therefore, the fifth-stage retarder 183E can extract the fourth light L4 as the retarder output light 183LO.

[0131] In other words, the relay lens 1836 is disposed so that its optical axis is spaced apart from the optical axis of the lens portion.

[0132] The retarder 183 configured in this manner can configure a delay optical path with a longer optical path length while suppressing an increase in the number of parts such as the relay lens 1836 and the focusing mirror 1837. Note that, in this modification, the delay optical path configured to repeat focusing and reflection three times has been described, but the number of times focusing and reflection are repeated is not limited to this, and the delay optical path may be configured to repeat more times.

[0133] Here, the direction D1 is also referred to as the traveling direction of the second pulsed light. The retarder 183 (delay optical system) includes a pair of a relay lens 1836 (optical member) and a collecting mirror 1837 (reflecting section) as a delay optical path at positions facing each other with the traveling direction (direction D1) of the second pulsed light as an axis. The pair of the relay lens 1836 and the collecting mirror 1837 is, for example, a pair of "first relay lens 1836A and first collecting mirror 1837A" and a pair of "second relay lens 1836B and second collecting mirror 1837B". The delay optical path formed by the pair of "first relay lens 1836A and first focusing mirror 1837A" is also referred to as the first delay optical path, and the delay optical path formed by the pair of "second relay lens 1836B and second focusing mirror 1837B" is also referred to as the second delay optical path. Of the delay optical paths of the retarder 183 (delay optical system), the optical axis of an optical member constituting the first delay optical path (e.g., the first relay lens 1836A) and the optical axis of an optical member constituting the second delay optical path (e.g., the second relay lens 1836B) are offset in direction D1 (i.e., spaced apart in the axial direction).

[0134] 17 is a diagram showing a sixth modified example of the configuration of the retarder 183 of this embodiment. The diagram shows an example of a three-stage retarder 183 in which four beam splitters are arranged in series. The retarder 183 of this modified example is configured using two sets of Dyson optical systems arranged opposite each other with the arrangement direction of the beam splitter 1834 (direction D1 in the diagram) as the symmetric axis. According to the retarder 183 configured in this manner, it is possible to configure a delay optical path with a longer optical path length while suppressing an increase in the number of parts of the relay lens 1836 and the condenser mirror 1837. In addition, when the incident light can be considered to be almost parallel, the light beam of the concave mirror (for example, the first condenser mirror 1837A or the second condenser mirror) becomes small and may be damaged in a high-power laser, but it is possible to increase the light beam diameter on the concave mirror by concentrating the light on the half prism on the incident side with a lens as in this embodiment. In this case, it is desirable to make the light beams of the non-delay part and the delay part have the same diameter, and it is desirable to slightly shift the conjugate relationship between the prism mirror positions. It is desirable to shift the positions in Figs. 14 and 15 in the same way, but when the light beams can be considered to be almost parallel like a laser, it is not particularly problematic. In the above, the delay optical system splits and combines light using a beam splitter (e.g., a half prism). However, taking into account the variation in transmittance and reflectance characteristics of thin films, it may be configured with a wave plate and a polarizing beam splitter, and the transmitted and reflected light may be adjusted by rotating the wave plate.

[0135] [Modification of distribution section] 18 is a diagram showing a modified example of the distributor 184. The distributor 184 of this modified example includes two distributors 1842 (a first distributor 1842A and a second distributor 1842B). The first distributor 1842A distributes the first retarder output light 183LO1 output from the final stage beam splitter 1834B. The second distributor 1842B distributes the second retarder output light 183LO2 output from the final stage beam splitter 1834B.

[0136] That is, in the configuration of the distributor 184 shown in Fig. 6 described above, the first retarder output light 183LO1 is divided by the first reflecting surface, and the second retarder output light 183LO2 is divided by the second reflecting surface, among two different reflecting surfaces of one distributor 1842. On the other hand, the distributor 184 of this modification differs from the configuration of the distributor 184 shown in Fig. 6 described above in that it includes a first distributor 1842A that divides the first retarder output light 183LO1 and a second distributor 1842B that divides the second retarder output light 183LO2.

[0137] The distributor 184 configured as in this modified example can control the rotation speeds of the two distributors 1842. Therefore, the distributor 184 configured as in this modified example can make the rotation speeds of the two distributors 1842 different from each other, reducing the coherence of the pulsed light and further improving the speckle reduction performance.

[0138] [Modification of the Correspondence Between Distributors and Lighting Modules] In the above example, the case where there is one distributor 1842 that guides pulsed light to one lighting module 16 has been described, but the present invention is not limited to this. There may be a plurality of distributors 1842 that guide pulsed light to one lighting module 16. A modified example of the correspondence relationship between the distributor 1842 and the lighting module 16 will be described with reference to FIG. 19.

[0139] FIG. 19 is a diagram showing a modified example of the correspondence relationship between the light source unit 18 and the illumination module 16 of the present embodiment. In this modification, the distributor 1842 includes a first distributor 1842A and a second distributor 1842B. To each of the lighting modules 16, light is guided from the first distributor 1842A via a first optical fiber 19A, and light is guided from the second distributor 1842B via a second optical fiber 19B. That is, in this modified example, the distributors 1842 and the lighting modules 16 are provided in an n:1 ratio (n is a natural number. In this example, n=2).

[0140] According to the exposure apparatus 1 configured according to this modified example, pulsed light in different states distributed from n (e.g., two) distributors 1842 can be guided to the illumination module 16. Therefore, according to the exposure apparatus 1 configured according to this modified example, the state of the pulsed light emitted from the illumination module 16 can be made more diverse, the coherence of the pulsed light can be reduced, and the speckle reduction performance can be further improved.

[0141] FIG. 20 is a diagram showing a first modified example of the light source unit 18 of the present embodiment. The light source unit 18 of this modification includes, as an example, four light source sections 181 (first light source section 181A to fourth light source section 181D). The light source unit 18 of this modification also emits two retarder output light beams 183LO (first retarder output light beam 183LO1 and second retarder output light beam 183LO2) from the retarder 183 to the distributor 1842. That is, the light source unit 18 of this modification has a 4-input-2-output configuration.

[0142] The combining unit 182 includes a prism mirror 1821, a prism mirror 1821A, a prism mirror 1821B, a polarizing beam splitter 1822, a wave plate 1823, a prism mirror 1825, a half prism 1826A, and a prism mirror 1827 for the first light source unit 181A and the second light source unit 181B. The prism mirror 1821 guides the pulsed light (s-polarized) emitted by the first light source unit 181A to the polarizing beam splitter 1822. The prism mirror 1821A and the prism mirror 1821B guide the pulsed light (s-polarized) emitted by the second light source unit 181B to the wave plate 1823. The wave plate 1823 changes the polarization state of the pulsed light (s-polarized) emitted by the second light source unit 181B, and guides the pulsed light (p-polarized) to the polarizing beam splitter 1822.

[0143] The combining unit 182 has a configuration corresponding to the configurations of the first light source unit 181A and the second light source unit 181B with respect to the third light source unit 181C and the fourth light source unit 181D. That is, the combining unit 182 guides the pulsed light from the third light source unit 181C and the fourth light source unit 181D to the polarizing beam splitter 1822.

[0144] The half prism 1826A is incident with the first light from the first light source unit 181A and the second light source unit 181B and the second light from the third light source unit 181C and the fourth light source unit 181D. The half prism 1826A reflects a part of the first light, transmits a part of the second light, combines the lights, and makes the first retarder incident light 183LI1 incident on the input stage beam splitter 183 provided in the retarder 183. The half prism 1826A also transmits the other part of the first light, reflects the other part of the second light, and combines the lights. The combined light is reflected by the prism mirror 1827 as the second retarder incident light 183LI2, and is incident on the input stage beam splitter 183.

[0145] The retarder 183 changes the distribution of the time axis of the pulsed light by a delay optical path between the input stage beam splitter 1834A and the final stage beam splitter 1834B. The retarder 183 outputs the pulsed light whose distribution of the time axis has been changed to the distributor 184 as a first retarder output light 183LO1 and a second retarder output light 183LO2.

[0146] The distributor 184 of this modification includes two distributors 1842 (a first distributor 1842A and a second distributor 1842B). The first distributor 1842A distributes the first retarder output light 183LO1 output from the final stage beam splitter 1834B. The second distributor 1842B distributes the second retarder output light 183LO2 output from the final stage beam splitter 1834B.

[0147] Note that the synthesis unit 182 may not include the prism mirror 1827 as a component, that is, the first light source unit 181A and the second light source unit 181B may include the prism mirror 1821, the prism mirror 1821A, the prism mirror 1821B, the polarizing beam splitter 1822, the wave plate 1823, the prism mirror 1825, and the half prism 1826A. When the synthesis unit has such a configuration, the retarder 183 includes the half prism 1826A and the prism mirror 1827 as components in addition to the components described above. Considered in this way, the half prism 1826A is a part of the synthesis unit 182, and can be said to be an input stage beam splitter of the retarder 183. 20, a difference occurs in the optical path until the first light incident on the input stage beam splitter 1834A and the second light reflected by the prism mirror and incident on the input stage beam splitter 1834A, and it can be seen that the half prism 1826A and the prism mirror 1827 are part of the retarder 183. This configuration is not limited to this modified example, and is similar to other embodiments and other modified examples described later.

[0148] That is, the light source unit 18 of this modification includes a plurality of light sources, an optical system, and an illumination system. The optical system includes a splitting section, a delay optical system, and a combining and splitting section (for example, a final stage beam splitter 1834B). The splitting unit splits the pulsed light emitted from each of the multiple light sources into a first pulsed light and a second pulsed light. The delay optical system guides the second pulsed light to a second optical path that is longer than a first optical path through which the first pulsed light passes. The combining unit combines the first pulsed light and the second pulsed light that has passed through the delay optical system. The optical system outputs the pulsed light combined by the combiner as a number (for example, two, the first retarder output light 183LO1 and the second retarder output light 183LO2) up to the number of light sources (for example, four).

[0149] The optical system may be configured to split the pulsed light combined by the combining / splitting unit into at least two and emit the split light. In this case, the illumination system illuminates at least two masks by directing the split pulsed light to different masks.

[0150] That is, the combining / splitting unit combines pulsed light based on the polarization characteristics of the pulsed light emitted from the multiple light sources.

[0151] According to the light source unit 18 configured in this manner, the distributions of the time axis of the multiple pulsed lights are different from each other, and the coherence of the pulsed lights is reduced, so that the occurrence of speckles can be suppressed. Also, according to the light source unit 18 configured to emit a smaller number (e.g., two) of pulsed lights than the number (e.g., four) of the light source sections 181, the power of the pulsed lights can be increased by providing the multiple light source sections 181, while the pulsed lights with reduced coherence can be emitted.

[0152] The light source unit 18 may have a splitting section and a combining section at a position where a predetermined position on the delay optical path split by the splitting section and a combining surface where the pulsed light is combined in the combining section are optically almost conjugate. More specifically, the light source unit 18 may have a splitting section and a combining section at a position where a position where the pulsed light emitted from the beam splitter 1834C to the non-delay side optical path enters the next beam splitter (e.g., the final stage beam splitter 1834B) and is combined and split is optically almost conjugate with a predetermined position (e.g., position P5 shown in FIG. 20) of the pulsed light emitted from the beam splitter 1834C to the delay side optical path is optically almost conjugate. The light source unit 18 may also have a relay lens (not shown) on the delay optical path that optically almost conjugates a predetermined position on the delay optical path split by the splitting section (e.g., position P5 shown in FIG. 20) and a combining surface where the pulsed light is combined in the combining section (e.g., position P4 shown in FIG. 20). This is because the delay optical path is long when passing through a retarder, for example, the distance between the splitting surface of beam splitter 1834C and the splitting surface of final beam splitter 1834B becomes long, so by providing a single conjugate point between the splitting surfaces, it becomes easier to relay the light. According to the light source unit 18 configured in this manner, the pulsed light split by the splitting section and guided to the delay optical path and the pulsed light guided to the non-delay optical path are easily combined at the combination surface, thereby making it possible to further reduce speckle.

[0153] Furthermore, in the light source unit 18, the optical paths along which the pulsed light beams are incident from the multiple light source sections 181 to the input stage beam splitter 1834A may have optical path lengths that are approximately equal to each other. According to the light source unit 18 configured in this manner, the time axis conditions of the pulsed light emitted from each of the multiple light source sections 181 can be aligned, making it easier to adjust the pulsed light to reduce speckle.

[0154] Furthermore, in the light source unit 18, the optical paths along which the pulsed light beams are incident from the multiple light source sections 181 to the input stage beam splitter 1834A may have optical path lengths that are different from one another. According to the light source unit 18 configured in this manner, even if pulsed light is simultaneously emitted from a plurality of light source sections 181, it is possible to provide variation in the time axis conditions between the emitted pulsed light, thereby facilitating adjustment of the pulsed light for speckle reduction.

[0155] FIG. 21 is a diagram showing a second modified example of the light source unit 18 of the present embodiment. The light source unit 18 of this modification includes, as an example, four light source sections 181 (first light source section 181A to fourth light source section 181D). The light source unit 18 of this modification also emits two retarder output light beams 183LO (first retarder output light beam 183LO1 and second retarder output light beam 183LO2) from the retarder 183 to the distributor 1842. That is, the light source unit 18 of this modification has a 4-input-2-output configuration.

[0156] The light source unit 18 of this modification includes a triangular prism mirror 1828 instead of the polarizing beam splitter 1822 and the wave plate 1823 of the first modification described above. The combining section 182 includes a prism mirror 1821C, a prism mirror 1821D, a triangular prism mirror 1828, a prism mirror 1825, a half prism 1826A, and a prism mirror 1827 for the first light source section 181A and the second light source section 181B. Prism mirror 1821C guides the pulsed light (s-polarized light) emitted by first light source unit 181A to triangular prism mirror 1828. Prism mirror 1821D guides the pulsed light (s-polarized light) emitted by second light source unit 181B to triangular prism mirror 1828. The triangular prism mirror 1828 guides the pulsed light emitted by the first light source unit 181A and the pulsed light emitted by the second light source unit 181B via the prism mirror 1825 to the half prism 1826A.

[0157] The combining unit 182 has a configuration corresponding to the configurations of the first light source unit 181A and the second light source unit 181B with respect to the third light source unit 181C and the fourth light source unit 181D. That is, the combining unit 182 guides the pulsed light from the third light source unit 181C and the fourth light source unit 181D to the half prism 1826A via a triangular prism mirror.

[0158] The half prism 1826A is incident with the first light from the first light source unit 181A and the second light source unit 181B and the second light from the third light source unit 181C and the fourth light source unit 181D. The half prism 1826A reflects a part of the first light, transmits a part of the second light, combines the lights, and makes the first retarder incident light 183LI1 incident on the input stage beam splitter 183 provided in the retarder 183. The half prism 1826A also transmits the other part of the first light, reflects the other part of the second light, and combines the lights. The combined light is reflected by the prism mirror 1827 as the second retarder incident light 183LI2, and is incident on the input stage beam splitter 183. That is, in this modification, the triangular prism mirror 1828 combines the pulsed light from the multiple light source units 181 into a visual field and makes it incident on the half prism 1826A. Here, visual field combination means combining the pulsed light by bringing the optical paths of the pulsed light, in other words, the optical axes, close to each other. Also, visual field combination can be said to mean bringing the optical paths of the pulsed light close to each other so that they can be relayed by a single optical system.

[0159] That is, the light source unit 18 of this modified example includes a light guiding section including a triangular prism mirror 1828. The light guiding section brings the optical paths of the pulsed lights emitted from the multiple light sources (e.g., first light source section 181A and second light source section 181B) close to each other within a range in which the pulsed lights can enter the splitting section (e.g., half prism 1826A), and guides the pulsed lights to the splitting section.

[0160] According to the light source unit 18 configured in this manner, the distributions of the time axis of the multiple pulsed lights are different from each other, and the coherence of the pulsed lights is reduced, so that the occurrence of speckles can be suppressed. Also, according to the light source unit 18 configured to emit a smaller number (e.g., two) of pulsed lights than the number (e.g., four) of the light source sections 181, the power of the pulsed lights can be increased by providing the multiple light source sections 181, while the pulsed lights with reduced coherence can be emitted. Furthermore, according to the light source unit 18 configured in this manner, in consideration of the laser resistance and lifespan of the optical components, the optical paths of the pulsed lights can be actively shifted from one another by the triangular prism mirror 1828. By shifting the optical paths of the pulsed lights from one another (for example, by increasing the distance between the optical paths of the pulsed lights), it is possible to reduce the degree to which the power of a plurality of pulsed lights is concentrated in an optical component such as the half prism 1826A, and it is possible to extend the lifespan of the optical components.

[0161] FIG. 22 is a diagram showing a third modified example of the light source unit 18 of the present embodiment. The light source unit 18 of this modification includes, for example, eight light source sections 181 (first light source section 181A to eighth light source section 181H). The light source unit 18 of this modification also emits two retarder output light beams 183LO (first retarder output light beam 183LO1 and second retarder output light beam 183LO2) from the retarder 183 to the distributor 1842. That is, the light source unit 18 of this modification has an 8-input-2-output configuration.

[0162] The light source unit 18 of this modified example combines pulsed light by combining the synthesis based on the polarization characteristics of pulsed light using the polarizing beam splitter 1822 in the first modified example described above and the field of view synthesis using the triangular prism mirror 1828 in the second modified example.

[0163] According to the light source unit 18 configured in this manner, the pulsed light from a larger number (e.g., eight) of light source sections 181 can be combined, so that the coherence of the pulsed light can be further reduced and the occurrence of speckles can be suppressed.

[0164] FIG. 23 is a diagram showing a fourth modified example of the light source unit 18 of the present embodiment. The light source unit 18 of this modification includes, for example, eight light source sections 181 (first light source section 181A to eighth light source section 181H). The light source unit 18 of this modification also emits two retarder output light beams 183LO (first retarder output light beam 183LO1 and second retarder output light beam 183LO2) from the retarder 183 to the distributor 1842. That is, the light source unit 18 of this modification has an 8-input-2-output configuration. The light source unit 18 of this modified example combines eight pulsed lights by visual field combination using the triangular prism mirror 1828 in the above-described second modified example.

[0165] The retarder 183 of this modification includes a polarizing beam splitter 1826C, a polarizing beam splitter 1826D, a wave plate 1823A, and a wave plate 1823B, instead of the half prism 1826B of the retarder 183 in the second modification described above. The wave plate 1823A changes the polarization state of the pulsed light incident on the polarizing beam splitter 1826C from the delay optical path. The polarizing beam splitter 1826C combines the pulsed light incident from the non-delay optical path and the pulsed light incident from the wave plate 1823A, and the combined pulsed light is output to position P6 shown in the figure. The wave plate 1823B changes the polarization state of the pulsed light incident from the position P6 (that is, the pulsed light combined in the polarizing beam splitter 1826C). The polarizing beam splitter 1826D splits the pulsed light incident from the wave plate 1823B into a first retarder outgoing light 183LO1 and a second retarder outgoing light 183LO2 based on the polarization state of the pulsed light, and outputs the split light.

[0166] In this modified example, the wavelength plate 1823B and the polarizing beam splitter 1826D may not be provided, and the pulsed light at the position P6 (i.e., the pulsed light synthesized in the polarizing beam splitter 1826C) may be output to the distributor 1842. In this configuration, the light source unit 18 has an 8-input-1-output configuration.

[0167] In the above-mentioned embodiment and its modified examples, the visual field synthesis is described as being realized by the triangular prism mirror 1828, but the present invention is not limited to this. For example, the visual field synthesis may be realized by the above-mentioned polarizing beam splitter. Also, for example, in a polarizing beam splitter or a non-polarizing half prism, the visual field synthesis may be realized by shifting the incident position of the pulsed light on the splitting surface that splits the pulsed light.

[0168] The above-mentioned method for reducing the coherence of the pulsed light may cause a decrease in contrast of the integrated image when scanning exposure is performed. This decrease in contrast of the integrated image when scanning exposure is performed occurs as image flow caused by the image moving during exposure. It is preferable to keep the amount of image flow within about 1 / 3 to 1 / 4 of the resolution. For example, if the amount of image flow that causes a decrease in the contrast of the integrated image during scanning exposure is to be kept to 1 / 4 of the resolution, the allowable delay time Δt of the pulsed light is Δt = 2 / 4 / 1000 = 0.5 μsec, assuming a resolution of 2 μm and a scanning speed of 1000 mm / s. Here, if the pulse emission width is 4 ns, it can be divided into a maximum of 125 (≒ 128) pulses. For example, if the reduction in contrast of the integrated image during scanning exposure is to be limited to 1 / 3 of the resolution, the allowable delay time Δt of the pulsed light is Δt = 2 / 3 / 1000 = 0.67 μsec, assuming a resolution of 2 μm and a scanning speed of 1000 mm / s. In this way, it is preferable that the pulse width of the group pulse light synthesized from the pulse light delayed by the delay optical system of the retarder 183 is set so that the product of the image flow due to the scanning speed of the exposure apparatus 1 is 1 / 3 or less of the resolution.

[0169] For example, in the exposure apparatus 1, when the stage 14 relatively moves with respect to the projection module 17 (projection optical system) at a predetermined speed, if the time difference between the first time which is the emission timing of the first pulsed light and the second time which is the emission timing of the second pulsed light is δ, the predetermined speed is V, and the resolution is R, then R / 3 < V·δ is satisfied.

[0170] Further, the first light source unit 181A and the second light source unit 181B emit the first pulsed light and the second pulsed light that satisfy λ > Δ×(NA^2). Here, λ represents the wavelength difference between the first pulsed light and the second pulsed light, Δ represents the chromatic aberration of the projection optical system generated by the wavelength difference between the first pulsed light and the second pulsed light, and NA represents the numerical aperture of the projection optical system. ^2 means squared.

[0171] Note that the disclosures of all U.S. Patent Application Publication Specifications and U.S. Patent Specifications related to the exposure apparatus and the like cited in the above embodiment are incorporated herein by reference and made part of the description of this specification.

[0172] As described above, the illumination apparatus and the exposure apparatus of the present invention are suitable for irradiating an object with illumination light for exposure in a lithography process. Further, the flat panel display manufacturing method of the present invention is suitable for the production of flat panel displays.

Description of Reference Numerals

[0173] 1... Exposure apparatus, 16... Illumination module, 1621... Light modulation unit, 17... Projection module, 18... Light source unit, 181... Light source part, 182... Combining part, 183... Retarder, 184... Distribution part, 19... Optical fiber, 21... Control part

Claims

1. In an illumination optical system that illuminates a mask on which a predetermined pattern is formed, A plurality of light sources that emit pulsed light; an optical system including: a splitting unit that splits the pulsed light emitted from each of the plurality of light sources into a first pulsed light and a second pulsed light; a delay optical system that guides the second pulsed light to a second optical path that is longer than a first optical path through which the first pulsed light passes; and a combining and splitting unit that combines the first pulsed light and the second pulsed light that has passed through the delay optical system, and divides and emits the combined pulsed light; an illumination system that guides each of the pulsed beams emitted from the optical system to the mask and illuminates the mask, the combining / splitting unit splits the combined pulsed light into at least two and emits the split light, The illumination system is an illumination optical system that illuminates at least two of the masks by directing the divided pulsed light to the masks different from each other.

2. In an illumination optical system that illuminates a mask on which a predetermined pattern is formed, A plurality of light sources that emit pulsed light; an optical system including a combining / splitting unit that combines the pulsed light beams emitted from the plurality of light sources and splits and emits the combined pulsed light beam; an illumination system that guides each of the pulsed beams emitted from the optical system to the mask and illuminates the mask, the combining / splitting unit splits the combined pulsed light into at least two and emits the split light, The illumination system is an illumination optical system that illuminates at least two of the masks by directing the divided pulsed light to the masks different from each other.

3. The combining / splitting unit splits the combined pulsed light into a number of light sources up to the number of the light sources.

3. The illumination optical system according to claim 1, wherein the light is emitted from the illumination optical system.

4. An illumination optical system for illuminating a mask on which a predetermined pattern is formed, comprising: A plurality of light sources that emit pulsed light; an optical system including: a splitting unit that splits the pulsed light emitted from each of the plurality of light sources into a first pulsed light and a second pulsed light; a delay optical system that guides the second pulsed light to a second optical path that is longer than a first optical path through which the first pulsed light passes; and a combining and splitting unit that combines the first pulsed light and the second pulsed light that has passed through the delay optical system, and divides and emits the combined pulsed light; an illumination system that guides each of the pulsed beams emitted from the optical system to the mask and illuminates the mask, The optical system includes a light guide section that brings the optical paths of the pulsed light beams emitted from the plurality of light sources close to each other within a range in which the pulsed light beams can enter the optical system, and guides the pulsed light beams to the optical system. Equipped with 3 . The illumination optical system according to claim 1 , wherein the light guiding section brings the pulsed light beams close to each other within a range in which a plurality of the pulsed light beams can be incident on the same light guiding member among the light guiding members included in the illumination system.

5. An illumination optical system for illuminating a mask on which a predetermined pattern is formed, comprising: A plurality of light sources that emit pulsed light; an optical system including a combining / splitting unit that combines the pulsed light beams emitted from the plurality of light sources and splits and emits the combined pulsed light beam; an illumination system that guides each of the pulsed beams emitted from the optical system to the mask and illuminates the mask, The optical system includes a light guide section that brings the optical paths of the pulsed light beams emitted from the plurality of light sources close to each other within a range in which the pulsed light beams can enter the optical system, and guides the pulsed light beams to the optical system. Equipped with The light guiding unit brings the pulsed light beams close to each other within a range in which the plurality of pulsed light beams can be incident on the same light guiding member among the light guiding members included in the illumination system. Illumination optical system.

6. 6. The illumination optical system according to claim 4, wherein the light guiding section brings the pulsed beams close to each other so that an interval between the emission positions of the plurality of pulsed beams is narrower than a diameter of the light guiding member.

7. An illumination optical system for illuminating a mask on which a predetermined pattern is formed, comprising: A plurality of light sources that emit pulsed light; an optical system including: a splitting unit that splits the pulsed light emitted from each of the plurality of light sources into a first pulsed light and a second pulsed light; a delay optical system that guides the second pulsed light to a second optical path that is longer than a first optical path through which the first pulsed light passes; and a combining and splitting unit that combines the first pulsed light and the second pulsed light that has passed through the delay optical system, and divides and emits the combined pulsed light; an illumination system that guides each of the pulsed beams emitted from the optical system to the mask and illuminates the mask, The optical system includes a light guide section that brings the optical paths of the pulsed light beams emitted from the plurality of light sources close to each other within a range in which the pulsed light beams can enter the optical system, and guides the pulsed light beams to the optical system. Equipped with The light guide section reflects the incident pulsed light to change the direction of the light path, A reflecting member is provided to bring the optical paths of the pulsed light closer to each other. Illumination optical system.

8. An illumination optical system for illuminating a mask on which a predetermined pattern is formed, comprising: A plurality of light sources that emit pulsed light; an optical system including a combining / splitting unit that combines the pulsed light beams emitted from the plurality of light sources and splits and emits the combined pulsed light beam; an illumination system that guides each of the pulsed beams emitted from the optical system to the mask and illuminates the mask, The optical system includes a light guide section that brings the optical paths of the pulsed light beams emitted from the plurality of light sources close to each other within a range in which the pulsed light beams can enter the optical system, and guides the pulsed light beams to the optical system. Equipped with The light guide unit includes a reflecting member that reflects the incident pulsed light and changes the direction of the light path, thereby bringing the light paths of the pulsed light closer to each other. Illumination optical system.

9. An illumination optical system for illuminating a mask on which a predetermined pattern is formed, comprising: A plurality of light sources that emit pulsed light; an optical system including: a splitting unit that splits the pulsed light emitted from each of the plurality of light sources into a first pulsed light and a second pulsed light; a delay optical system that guides the second pulsed light to a second optical path that is longer than a first optical path through which the first pulsed light passes; and a combining and splitting unit that combines the first pulsed light and the second pulsed light that has passed through the delay optical system, and divides and emits the combined pulsed light; an illumination system that guides each of the pulsed beams emitted from the optical system to the mask and illuminates the mask, The optical system includes a light guide section that brings the optical paths of the pulsed light beams emitted from the plurality of light sources close to each other within a range in which the pulsed light beams can enter the optical system, and guides the pulsed light beams to the optical system. Equipped with The light guiding unit includes a polarizing member that brings optical paths of the pulsed light emitted from the plurality of light sources closer to each other based on the polarization characteristics of the pulsed light. Illumination optical system.

10. An illumination optical system for illuminating a mask on which a predetermined pattern is formed, comprising: A plurality of light sources that emit pulsed light; an optical system including a combining / splitting unit that combines the pulsed light beams emitted from the plurality of light sources and splits and emits the combined pulsed light beam; an illumination system that guides each of the pulsed beams emitted from the optical system to the mask and illuminates the mask, The optical system includes a light guide section that brings the optical paths of the pulsed light beams emitted from the plurality of light sources close to each other within a range in which the pulsed light beams can enter the optical system, and guides the pulsed light beams to the optical system. Equipped with The light guiding unit includes a polarizing member that brings the optical paths of the pulsed light beams close to each other based on the polarization characteristics of the pulsed light beams emitted from the plurality of light sources. Illumination optical system.

11. An illumination optical system for illuminating a mask on which a predetermined pattern is formed, comprising: A plurality of light sources that emit pulsed light; an optical system including: a splitting unit that splits the pulsed light emitted from each of the plurality of light sources into a first pulsed light and a second pulsed light; a delay optical system that guides the second pulsed light to a second optical path that is longer than a first optical path through which the first pulsed light passes; and a combining and splitting unit that combines the first pulsed light and the second pulsed light that has passed through the delay optical system, and divides and emits the combined pulsed light; an illumination system that guides each of the pulsed beams emitted from the optical system to the mask and illuminates the mask, the illumination system has an optical path switching unit that switches an optical path of the pulsed light emitted from the optical system and sequentially guides the pulsed light to a plurality of the masks provided, The light source and the optical path switching unit are provided at positions where an emission position of the pulsed light from the light source and an incidence position where the pulsed light is incident on the optical path switching unit are optically almost conjugate. Illumination optical system.

12. An illumination optical system for illuminating a mask on which a predetermined pattern is formed, comprising: A plurality of light sources that emit pulsed light; an optical system including a combining / splitting unit that combines the pulsed light beams emitted from the plurality of light sources and splits and emits the combined pulsed light beam; an illumination system that guides each of the pulsed beams emitted from the optical system to the mask and illuminates the mask, the illumination system has an optical path switching unit that switches an optical path of the pulsed light emitted from the optical system and sequentially guides the pulsed light to a plurality of the masks provided, The light source and the optical path switching unit are provided at positions where an emission position of the pulsed light from the light source and an incidence position where the pulsed light is incident on the optical path switching unit are optically almost conjugate. Illumination optical system.

13. the illumination system includes a light guiding unit that guides the pulsed light emitted from the light path switching unit to the mask, The optical path switching unit and the light guiding unit are provided at a position where an output position where the pulsed light is output from the optical path switching unit and an input position of the pulsed light in the light guiding unit are optically almost conjugate.

13. The illumination optical system according to claim 11.

14. The illumination system includes a relay lens between the optical path switching unit and the light guiding unit, the relay lens making an emission position at which the pulsed light is emitted from the optical path switching unit and an incidence position of the pulsed light on the light guiding unit substantially optically conjugate with each other. The illumination optical system according to claim 13.

15. An illumination optical system for illuminating a mask on which a predetermined pattern is formed, comprising: A plurality of light sources that emit pulsed light; an optical system including: a splitting unit that splits the pulsed light emitted from each of the plurality of light sources into a first pulsed light and a second pulsed light; a delay optical system that guides the second pulsed light to a second optical path that is longer than a first optical path through which the first pulsed light passes; and a combining and splitting unit that combines the first pulsed light and the second pulsed light that has passed through the delay optical system, and divides and emits the combined pulsed light; an illumination system that guides each of the pulsed beams emitted from the optical system to the mask and illuminates the mask, When the optical system includes a plurality of stages of the combining / splitting sections, the combining / splitting sections in the front and rear stages are provided at positions where a predetermined position on the delay optical path divided by the combining / splitting section in the front stage is optically almost conjugate with a combining surface where the pulsed light is combined in the combining / splitting section in the rear stage. Illumination optical system.

16. An illumination optical system for illuminating a mask on which a predetermined pattern is formed, comprising: A plurality of light sources that emit pulsed light; an optical system including a combining / splitting unit that combines the pulsed light beams emitted from the plurality of light sources and splits and emits the combined pulsed light beam; an illumination system that guides each of the pulsed beams emitted from the optical system to the mask and illuminates the mask, When the optical system includes a plurality of stages of the combining / splitting sections, the combining / splitting sections in the front and rear stages are provided at positions where a predetermined position on the delay optical path split by the combining / splitting section in the front stage is approximately optically conjugate with a combining surface where the pulsed light is combined in the combining / splitting section in the rear stage.

17. An illumination optical system for illuminating a mask on which a predetermined pattern is formed, comprising: A plurality of light sources that emit pulsed light; an optical system including: a splitting unit that splits the pulsed light emitted from each of the plurality of light sources into a first pulsed light and a second pulsed light; a delay optical system that guides the second pulsed light to a second optical path that is longer than a first optical path through which the first pulsed light passes; and a combining and splitting unit that combines the first pulsed light and the second pulsed light that has passed through the delay optical system, and divides and emits the combined pulsed light; an illumination system that guides each of the pulsed beams emitted from the optical system to the mask and illuminates the mask, When the optical system includes a plurality of stages of the combining / splitting sections, a relay lens is provided on the delay optical path, which is optically almost conjugate between a predetermined position on the delay optical path split by the combining / splitting section of a previous stage and a combining surface where the pulsed light is combined in the combining / splitting section of a subsequent stage. Illumination optical system.

18. An illumination optical system for illuminating a mask on which a predetermined pattern is formed, comprising: A plurality of light sources that emit pulsed light; an optical system including a combining / splitting unit that combines the pulsed light beams emitted from the plurality of light sources and splits and emits the combined pulsed light beam; an illumination system that guides each of the pulsed beams emitted from the optical system to the mask and illuminates the mask, When the optical system includes a plurality of stages of the combining / splitting sections, a relay lens is provided on the delay optical path, which is optically almost conjugate between a predetermined position on the delay optical path split by the combining / splitting section of a previous stage and a combining surface where the pulsed light is combined in the combining / splitting section of a subsequent stage. Illumination optical system.

19. The optical path lengths of the optical paths of the pulsed light beams incident on the optical system from the plurality of light sources are approximately equal to each other.

3. An illumination optical system according to claim 1.

20. The optical path lengths of the optical paths of the pulsed light beams incident on the optical system from the plurality of light sources are different from each other.

3. An illumination optical system according to claim 1.

21. An illumination optical system for illuminating a mask on which a predetermined pattern is formed, comprising: A plurality of light sources that emit pulsed light; an optical system including: a splitting unit that splits the pulsed light emitted from each of the plurality of light sources into a first pulsed light and a second pulsed light; a delay optical system that guides the second pulsed light to a second optical path that is longer than a first optical path through which the first pulsed light passes; and a combining and splitting unit that combines the first pulsed light and the second pulsed light that has passed through the delay optical system, and divides and emits the combined pulsed light; an illumination optical system including an illumination system that guides each of the pulsed beams emitted from the optical system to the mask and illuminates the mask; a projection optical system for dividing and exposing an exposure target by irradiating the exposure target with light emitted from the mask illuminated by the pulsed light; a stage on which the exposure target can be placed; Equipped with an exposure apparatus in which the pulse width of a group of pulsed light obtained by synthesizing the pulsed light delayed by a delay optical system of the optical system is set so that the product of the image flow due to the scanning speed of the exposure apparatus is 1 / 3 or less of the resolution.

22. An illumination optical system for illuminating a mask on which a predetermined pattern is formed, comprising: A plurality of light sources that emit pulsed light; an optical system including a combining / splitting unit that combines the pulsed light beams emitted from the plurality of light sources and splits and emits the combined pulsed light beam; an illumination optical system including an illumination system that guides each of the pulsed beams emitted from the optical system to the mask and illuminates the mask; a projection optical system for dividing and exposing an exposure target by irradiating the exposure target with light emitted from the mask illuminated by the pulsed light; a stage on which the exposure target can be placed; Equipped with an exposure apparatus in which the pulse width of a group of pulsed light obtained by synthesizing the pulsed light delayed by a delay optical system of the optical system is set so that the product of the image flow due to the scanning speed of the exposure apparatus is 1 / 3 or less of the resolution.

23. the light source is a laser light source emitting light with a wavelength of 360 nm or less; the projection optical system is made of a single or two types of glass material; 23. The exposure apparatus according to claim 21 or 22.

24. The glass material is quartz or fluorite. The exposure apparatus according to claim 23.

25. The exposure target is a substrate for a flat panel display, with at least one side or diagonal length of 500 mm or more.

24. An exposure apparatus according to claim 22 or 23.

26. The mask is a spatial light modulator.

24. An exposure apparatus according to claim 22 or 23.

27. Exposing an exposure object using the exposure apparatus according to claim 22 or 23; developing the exposed exposure target; A method for manufacturing a flat panel display comprising the steps of:

28. In an illumination optical system that illuminates a spatial light modulator in which a plurality of elements are individually controlled at a predetermined time interval, a first light source that emits a first pulsed light at a first time; a second light source that emits a second pulsed light at a second time different from the first time; an illumination system that guides the first and second pulsed beams to the spatial light modulator and illuminates the spatial light modulator; The second light source emits the second pulsed light at the second time when a time interval from the first time becomes shorter than the predetermined time interval.

29. the first light source continuously emits the first pulsed light at a predetermined period; 29. The illumination optical system according to claim 28, wherein the second light source continuously emits the second pulsed light at the predetermined period.

30. 30. The illumination optical system according to claim 29, wherein the second light source emits the second pulsed light during a time period between successive emission of the first pulsed light from the first light source.

31. 31. The illumination optical system according to claim 29, wherein the first and second light sources continuously emit the first pulsed light and the second pulsed light, respectively, at the predetermined period that is a time interval shorter than the predetermined time interval at which the element is controlled.

32. The first light source includes a first type light source, 31. The illumination optical system according to claim 28, wherein the second light source has a second type light source different from the first type light source, and the illumination optical system controls the second type light source to emit the second pulsed light at the second time.

33. 31. The illumination optical system according to claim 28, wherein the first light source emits the first pulsed light having a wavelength different from that of the second pulsed light emitted from the second light source.

34. 31. The illumination optical system according to claim 28, wherein the illumination system has a phase changing section that changes a phase state of at least one of the first pulsed light and the second pulsed light over time.

35. the illumination system includes a light transmitting unit that guides the first pulsed light and the second pulsed light to the spatial light modulator; 35. The illumination optical system according to claim 34, wherein the phase change section adjusts at least one of an angle of incidence or an incidence position of the first and second pulsed light beams incident on the optical transmission section.

36. 36. The illumination optical system according to claim 35, further comprising an optical path switcher that switches optical paths of the first and second pulsed light sequentially emitted from the first and second light sources and sequentially guides the first and second pulsed light to a plurality of the optical transmission units.

37. the optical path switcher has a reflecting surface that reflects the first and second pulsed beams, and switches the optical path by changing an incident angle of the first and second pulsed beams on the reflecting surface; 37. The illumination optical system according to claim 36, wherein the phase change section controls the optical path switcher so as to adjust angles of incidence of the first and second pulsed beams incident on the optical transmission section.

38. 36. The illumination optical system according to claim 35, wherein the plurality of light transmitting sections guide the first pulsed light and the second pulsed light to one of the spatial light modulators.

39. a first light transmission section among the plurality of light transmission sections guides the first pulsed light and the second pulsed light to a first spatial light modulator among the plurality of spatial light modulators provided; 36. The illumination optical system according to claim 35, wherein a second light transmission section of the plurality of light transmission sections guides the first pulsed light and the second pulsed light to a second spatial light modulator of the plurality of spatial light modulators.

40. 36. The illumination optical system according to claim 35, wherein the phase change section has a diffusion plate that diffuses the light incident on the spatial light modulator.

41. 31. The illumination optical system according to claim 28, further comprising: a delay optical system including: a splitting member that splits each of the first pulsed light and the second pulsed light into two pulsed lights; and a light guiding optical system that guides one of the pulsed lights that has passed through the splitting member along a first optical path and guides the other pulsed light that has passed through the splitting member along a second optical path that is longer than the first optical path.

42. 42. The illumination optical system according to claim 41, wherein at least one of the first optical path and the second optical path is made variable.

43. An illumination optical system according to any one of claims 28 to 30, a projection optical system that exposes the substrate in a divided manner by irradiating the substrate with light emitted from each of the spatial light modulators illuminated by the first and second pulsed light.

44. 44. An exposure apparatus according to claim 43, wherein exposure is performed by changing a pupil luminance state due to substantial illumination light at any exposure position.

45. An illumination optical system according to any one of claims 28 to 30, a projection optical system that projects an image of the spatial light modulator illuminated by the illumination optical system onto a substrate; a substrate stage that supports the substrate and moves relatively at a predetermined speed with respect to the projection optical system when exposing the image of the spatial light modulator onto the substrate, Let δ be the time difference between the first time and the second time, V be the predetermined speed, and R be the resolution of the image. R / 3<V·δ Meet the exposure device.

46. An illumination optical system according to claim 33; a projection optical system that projects an image of the spatial light modulator illuminated by the illumination optical system onto a substrate. When a wavelength difference between the first pulsed light and the second pulsed light is λ, a chromatic aberration of the projection optical system caused by the wavelength difference between the first pulsed light and the second pulsed light is Δ, and a numerical aperture of the projection optical system is NA, λ>Δ×(NA^2) an exposure apparatus that emits the first pulsed light and the second pulsed light, each of which satisfies the above condition.

47. the first light source and the second light source are laser light sources emitting light with a wavelength of 360 nm or less; 44. The exposure apparatus according to claim 43, wherein the projection optical system is made of a single or two types of glass material.

48. 48. The exposure apparatus according to claim 47, wherein the glass material is quartz or fluorite.

49. exposing the substrate using an exposure apparatus according to claim 43; and developing the exposed substrate.

50. Exposing a substrate for a flat panel display using the exposure apparatus of claim 43; and developing the exposed substrate.

51. In an illumination optical system that illuminates a spatial light modulator in which a plurality of elements are individually controlled at a predetermined time interval, A first light source emits a first pulsed light at a first time; a second light source emitting a second pulsed light at a second time, the second time being a time interval from the first time shorter than the predetermined time interval and different from the first time; an illumination system directing the first and second pulsed beams to the spatial light modulator and illuminating the spatial light modulator; A lighting method comprising:

52. exposing an image of the spatial light modulator illuminated by the illumination method of claim 51 onto a substrate; and developing the exposed substrate.

53. exposing an image of the spatial light modulator illuminated by the illumination method of claim 51 onto a substrate; and developing the exposed substrate.

54. In an illumination optical system that illuminates a mask on which a predetermined pattern is formed, A light source that emits pulsed light; an optical system including: a splitting unit that splits the pulsed light into a first pulsed light and a second pulsed light; a delay optical system that guides the second pulsed light to a second optical path that is longer than a first optical path through which the first pulsed light passes; and a combining unit that combines the first pulsed light and the second pulsed light that has passed through the delay optical system; an illumination system that guides the first and second pulsed light beams combined by the combining unit to the mask and illuminates the mask, The delay optical system is an illumination optical system having a reflecting section that reflects the second pulsed light, and an optical member that makes the reflected second pulsed light enter the reflecting section again.

55. 55. The illumination optical system according to claim 54, wherein the optical member includes a reflecting member that reflects the second pulsed light reflected at the reflecting portion and causes the second pulsed light to be incident on the reflecting portion.

56. the delay optical system includes a lens that focuses the second pulsed light that has passed through the splitting unit onto the reflecting unit, 56. The illumination optical system according to claim 55, wherein the lens guides the second pulsed light reflected by the reflecting portion to the reflecting member.

57. the optical member has a lens portion that condenses the second pulsed light reflected by the reflecting portion onto the reflecting member, 57. The illumination optical system according to claim 56, wherein the lens portion guides the second pulsed light reflected by the reflecting member to the reflecting portion.

58. 58. The illumination optical system according to claim 57, wherein the lens is disposed such that its optical axis is spaced apart from the optical axis of the lens portion.

59. the optical member has a lens portion that condenses the second pulsed light reflected by the reflecting portion onto the reflecting member, 56. The illumination optical system according to claim 55, wherein the lens portion guides the second pulsed light reflected by the reflecting member to the reflecting portion.

60. In an illumination optical system that illuminates a mask on which a predetermined pattern is formed, A light source that emits pulsed light; an optical system including: a splitting unit that splits the pulsed light into a first pulsed light and a second pulsed light; a delay optical system that guides the second pulsed light to a second optical path that is longer than a first optical path through which the first pulsed light passes; and a combining unit that combines the first pulsed light and the second pulsed light that has passed through the delay optical system; an illumination system that guides the first and second pulsed light beams combined by the combining unit to the mask and illuminates the mask, the delay optical system includes a reflecting section that reflects the second pulsed light and guides the second pulsed light to the combining section, and an optical member that is disposed between the splitting section and the reflecting section and between the reflecting section and the combining section, and causes the second pulsed light to be incident on the reflecting section and the second pulsed light reflected by the reflecting section to be incident on the combining section, the delay optical system is an illumination optical system, in which a splitting surface of the splitting unit that splits the pulsed light into the first pulsed light and the second pulsed light and a combining surface of the combining unit that combines the first pulsed light that has passed through the first optical path and the second pulsed light that has passed through the second optical path are provided at positions that are optically conjugate with each other.

61. the reflecting portion has a first reflecting portion and a second reflecting portion, the optical member includes a first optical member that causes the second pulsed light split by the splitting section to be incident on the first reflecting section, and a second optical member that causes the second pulsed light reflected by the first reflecting section to be incident on the second reflecting section, 61. The illumination optical system according to claim 60, wherein the first and second optical members are arranged with their optical axes spaced apart from each other.

62. 62. The illumination optical system according to claim 61, wherein the second reflecting section reflects the second pulsed light and guides the second pulsed light again to the first reflecting section via the second optical member.

63. The reflecting portion has a third reflecting portion, the optical member includes a third optical member, 62. The illumination optical system according to claim 61, wherein the second reflecting section reflects the second pulsed light and guides the second pulsed light to the third reflecting section via the second optical member and the third optical member.

64. 64. The illumination optical system according to claim 60, wherein the reflecting section reflects the second pulsed light at a focal position of the optical member.

65. The illumination optical system according to any one of claims 60 to 63, wherein the reflecting section reflects the second pulsed light so that the second pulsed light is incident on a position within the optical member different from a position through which the second pulsed light incident on the reflecting section passes.

66. 64. The illumination optical system according to claim 60, wherein the combining unit divides the first pulse light into a third pulse light and a fourth pulse light, divides the second pulse light into a fifth pulse light and a sixth pulse light, combines the third pulse light and the fifth pulse light, and combines the fourth pulse light and the sixth pulse light.

67. 64. The illumination optical system according to claim 60, wherein the illumination system has an optical path switching section that switches an optical path of the combined pulsed light and sequentially guides it to a plurality of the masks.

68. The delay optical system transmits a part of the pulsed light and reflects the other part, thereby combining or splitting the pulsed light. An illumination optical system according to any one of claims 54 to 63.

69. The delay optical system combines or splits the pulsed light based on the polarization state of the pulsed light. An illumination optical system according to any one of claims 54 to 63.

70. A state changing unit that changes the states of the pulsed light on the spatial light modulation element to different states. The illumination optical system according to any one of claims 54 to 63, further comprising:

71. The state changing unit changes the states of the pulsed light on the spatial light modulation element to different states by changing the wavelengths of the plurality of pulsed light.

71. The illumination optical system according to claim 70.

72. The state changing unit changes the emission timings of the plurality of pulsed beams to be different from one another, thereby changing the states of the pulsed beams on the spatial light modulation element to be different from one another.

72. The illumination optical system according to claim 71.

73. In a case where the illumination system has an optical path switching unit that switches an optical path of the synthesized pulsed light and sequentially guides the synthesized pulsed light to a plurality of the masks, The state changing unit changes the distribution timing of the pulsed light by the optical path switching unit, thereby changing the states of the pulsed light on the spatial light modulation element.

71. The illumination optical system according to claim 70.

74. The mask is a spatial light modulator. An illumination optical system according to any one of claims 54 to 63.

75. An illumination optical system according to any one of claims 54 to 63; a projection optical system for dividing and exposing an exposure target by irradiating the exposure target with light emitted from the mask illuminated by the pulsed light; a stage on which an exposure target can be placed; An exposure apparatus comprising:

76. the light source is a laser light source emitting light with a wavelength of 360 nm or less; the projection optical system is made of a single or two types of glass material; 76. The exposure apparatus of claim 75.

77. The glass material is quartz or fluorite.

77. The exposure apparatus of claim 76.

78. The pulse width of the group pulsed light obtained by synthesizing the pulsed light delayed by the delay optical system is set so that the product of the image flow due to the scanning speed of the exposure device is 1 / 3 or less of the resolution.

76. The exposure apparatus of claim 75.

79. The exposure target is a substrate for a flat panel display, with at least one side or diagonal length of 500 mm or more.

76. The exposure apparatus of claim 75.

80. The mask is a spatial light modulator.

76. The exposure apparatus of claim 75.

81. Exposing an exposure object using the exposure apparatus according to claim 75; developing the exposed exposure target; A method for manufacturing a flat panel display comprising the steps of:

Images