WO2025013286A1 - Illumination unit, exposure device, and exposure method - Google Patents

Abstract

An illumination unit comprising: a light source; a first optical system that forms an intermediate image of the light source; and a control mechanism that can switch between a first state in which a dimming member is disposed at or near the position of the intermediate image, and a second state in which the dimming member is not disposed there.

Description

Illumination unit, exposure apparatus, and exposure method

Related to lighting units, exposure devices, and exposure methods.

In recent years, liquid crystal display panels have come into widespread use as display elements for personal computers, televisions, and the like. Liquid crystal display panels are manufactured by forming a circuit pattern of thin-film transistors on a plate (glass substrate) using photolithography techniques. An exposure device is used for this photolithography process, which projects and exposes an original pattern formed on a mask onto a photoresist layer on the plate via a projection optical system. One such exposure device that has been proposed is one that uses an LED (Light Emitting Diode) as the light source (see, for example, Patent Document 1).

Even in exposure equipment that uses LEDs as the light source, it is desirable for the illumination unit that illuminates the mask to be small.

JP 2016-184127 A

According to the first aspect of the disclosure, the lighting unit includes a light source, a first optical system that forms an intermediate image of the light source, and a control mechanism that can switch between a first state in which a dimming member is disposed at or near the position of the intermediate image, and a second state in which the dimming member is not disposed.

According to the second aspect of the disclosure, the lighting unit includes a plurality of light sources, a combining optical element that combines the light emitted from the plurality of light sources, a first optical system that forms an intermediate image of the plurality of light sources using the combined light emitted from the combining optical element, and a control mechanism that can switch between a state in which a light-reducing member is disposed at or near the position of the intermediate image and a state in which the light-reducing member is not disposed.

According to a third disclosed aspect, the exposure apparatus includes the illumination unit and a projection optical system that projects a pattern image of a mask illuminated by the illumination unit onto a photosensitive substrate.

According to a fourth aspect of the disclosure, an exposure method is an exposure method using the above-mentioned exposure apparatus, and includes illuminating a mask with the illumination unit, and projecting a pattern image of the mask onto a photosensitive substrate using the projection optical system.

The configuration of the embodiments described below may be modified as appropriate, and at least a portion may be replaced with other components. Furthermore, components that are not specifically limited in their placement may be placed in any position that achieves their function, not limited to the placement disclosed in the embodiments.

FIG. 1 is a schematic diagram showing the configuration of an exposure apparatus according to an embodiment. FIG. 2 is a schematic diagram showing the configuration of a lighting unit according to the embodiment. FIG. 3A is a plan view that shows a schematic configuration of a light source array, and FIG. 3B is a diagram that shows a schematic internal configuration of a light source unit. FIG. 4 is a diagram for explaining the configuration of the aerial image measuring device. FIG. 5 is a diagram for explaining the aerial image measuring device. FIG. 6 is a plan view showing the configuration of the module shutter. 7A and 7B are plan views showing another example of the configuration of the module shutter. FIG. 8 is a schematic diagram showing a configuration of an illumination unit according to the first modification. FIG. 9 is a schematic diagram showing the configuration of an exposure apparatus according to the second modification.

The exposure device 10 according to one embodiment will be described with reference to Figures 1 to 6.

(Configuration of Exposure Apparatus)
FIG. 1 is a diagram that shows roughly the configuration of an exposure apparatus 10 according to the present embodiment.

The exposure apparatus 10 is a scanning stepper (scanner) that transfers a pattern formed on the mask MSK onto a glass substrate (hereafter referred to as "plate") P by driving the mask MSK and the glass substrate P in the same direction and at the same speed relative to the projection optical system PL. The plate P is a rectangular glass substrate used, for example, in liquid crystal display devices (flat panel displays), with at least one side or diagonal length of 500 mm or more.

In the following, the direction in which the mask MSK and plate P are driven during scanning exposure (scanning direction) is defined as the X-axis direction, the direction perpendicular to this in the horizontal plane is defined as the Y-axis direction, the direction perpendicular to the X-axis and Y-axis is defined as the Z-axis direction, and the rotation (tilt) directions around the X-axis, Y-axis, and Z-axis are defined as the θx, θy, and θz directions, respectively.

The exposure apparatus 10 comprises an illumination optical system IOP, a mask stage MST that holds the mask MSK, a projection optical system PL, a body 70 that supports these, a substrate stage PST that holds the plate P, and a control device CNT that controls these. The control device CNT provides overall control over each component of the exposure apparatus 10. In addition, in order to perform high-precision exposure, the exposure apparatus 10 comprises an aerial image measurement device (AIS: Airial Image Sensor) 40 (not shown in FIG. 1) that determines the relationship between the position of the pattern on the mask MSK and the position of the pattern projected onto the plate P.

The body 70 comprises a base (vibration isolation table) 71, columns 72A and 72B, an optical base 73, a support 74, and a slide guide 75. The base (vibration isolation table) 71 is placed on a floor F and supports the columns 72A, 72B, etc. by isolating vibrations from the floor F. The columns 72A and 72B each have a frame shape, and the column 72A is placed inside the column 72B. The optical base 73 has a flat plate shape and is fixed to the ceiling of the column 72A. The support 74 is supported by the ceiling of the column 72B via a slide guide 75. The slide guide 75 comprises an air ball lifter and a positioning mechanism, and positions the support 74 (i.e., the mask stage MST described later) at an appropriate position in the X-axis direction relative to the optical base 73.

The illumination optical system IOP is disposed above the body 70. The illumination optical system IOP irradiates the mask MSK with illumination light IL. The detailed configuration of the illumination optical system IOP will be described later.

The mask stage MST is supported by a support 74. A mask MSK having a pattern surface (the lower surface in FIG. 1) on which a circuit pattern is formed is fixed to the mask stage MST by, for example, vacuum adsorption (or electrostatic adsorption). The mask stage MST is driven by a drive system including, for example, a linear motor at a predetermined stroke in the scanning direction (X-axis direction) and is also slightly driven in the non-scanning directions (Y-axis direction and θz direction).

The position information of the mask stage MST in the XY plane (including rotation information in the θz direction) is measured by an interferometer system. The interferometer system measures the position of the mask stage MST by irradiating a measurement beam onto a movable mirror (or a mirror-finished reflective surface (not shown)) provided at the end of the mask stage MST and receiving the reflected light from the movable mirror. The measurement results are supplied to the control device CNT, which drives the mask stage MST via the drive system in accordance with the measurement results of the interferometer system.

The projection optical system PL is supported by the optical base 73 below (-Z side) the mask stage MST. The projection optical system PL is configured in the same manner as the projection optical system disclosed in, for example, US Pat. No. 5,729,331, and includes a plurality of (for example, seven) projection optical units 100 (multi-lens projection optical units) in which the projection areas of the pattern image of the mask MSK are arranged in a staggered pattern, forming a rectangular image field with the Y-axis direction as the longitudinal direction. Here, four projection optical units 100 are arranged at a predetermined interval in the Y-axis direction, and the remaining three projection optical units 100 are arranged at a predetermined interval in the Y-axis direction, spaced apart from the four projection optical units 100 on the +X side. For each of the multiple projection optical units 100, for example, a system that is bilaterally telecentric and forms an erect normal image is used. The multiple projection areas of the projection optical units 100 arranged in a staggered pattern are collectively referred to as the exposure area.

When the illumination area on the mask MSK is illuminated by the illumination light IL from the illumination optical system IOP, the illumination light IL that has passed through the mask MSK forms a projected image (partial upright image) of the circuit pattern of the mask MSK in the illumination area via the projection optical system PL in the irradiation area (exposure area (conjugate to the illumination area)) on the plate P arranged on the image plane side of the projection optical system PL. Here, a resist (sensitizer) is applied to the surface of the plate P. By synchronously driving the mask stage MST and the substrate stage PST, i.e., by driving the mask MSK in the scanning direction (X-axis direction) relative to the illumination area (illumination light IL) and driving the plate P in the same scanning direction relative to the exposure area (illumination light IL), the plate P is exposed and the pattern of the mask MSK is transferred onto the plate P.

The substrate stage PST is placed on a base (vibration isolation table) 71 below (on the -Z side) the projection optical system PL. A plate P is held on the substrate stage PST via a substrate holder (not shown).

The position information of the substrate stage PST in the XY plane (including rotation information (yawing amount (amount of rotation in the θz direction θz), pitching amount (amount of rotation in the θx direction θx), and rolling amount (amount of rotation in the θy direction θy))) is measured by an interferometer system. The interferometer system measures the position of the substrate stage PST by irradiating a measurement beam from the optical base 73 to a movable mirror (or a mirror-finished reflective surface (not shown)) provided at the end of the substrate stage PST and receiving the reflected light from the movable mirror. The measurement result is supplied to the control device CNT, which drives the substrate stage PST in accordance with the measurement result of the interferometer system.

In the exposure apparatus 10, alignment measurement (e.g., EGA, etc.) is performed prior to exposure, and the plate P is exposed using the results in the following procedure. First, the mask stage MST and substrate stage PST are synchronously driven in the X-axis direction according to instructions from the control device CNT. This performs scanning exposure on the first shot area on the plate P. When scanning exposure on the first shot area is completed, the control device CNT moves (steps) the substrate stage PST to a position corresponding to the second shot area. Then, scanning exposure is performed on the second shot area. Similarly, the control device CNT repeats stepping between the shot areas of the plate P and scanning exposure on the shot areas to transfer the pattern of the mask MSK to all shot areas on the plate P.

(Configuration of illumination optical system IOP)
Next, the configuration of the illumination optical system IOP in this embodiment will be described The illumination optical system IOP includes a plurality of illumination units 90 corresponding to the plurality of projection optical units 100 included in the projection optical system PL, respectively.

FIG. 2 is a diagram showing a schematic configuration of the illumination unit 90. As shown in FIG. 2, the illumination unit 90 includes a light source unit OPU and an illumination optical system 80.

(Configuration of the light source unit)
The light source unit OPU includes a light source array 20 and a magnifying optical system 30 .

Figure 3 (A) is a plan view showing a schematic configuration of the light source array 20. The light source array 20 includes a plurality of LED (Light Emitting Diode) chips 23 (5 x 5 in Figure 3 (A)) arranged in an array on a substrate 21, for example. In other words, the light source unit OPU is an LED light source. The number of LED chips 23 may be changed as necessary.

Each of the multiple LED chips 23 has a light-emitting portion 231, and the peak wavelength of the light emitted from the light-emitting portion 231 is, for example, in the range of 360 to 370 nm, the range of 380 to 390 nm, or the range of 400 to 410 nm. In other words, the light-emitting portion 231 is an ultraviolet LED (UV LED). The light-emitting surface of the light-emitting portion 231 is a square, and the length of one side is L. The LED chips 23 are arranged at a pitch P1. The pitch P1 is the distance between the centers of adjacent LED chips 23. The LED chips 23 may be arranged not on a substrate but on, for example, a heat sink.

Figure 3 (B) is a diagram showing a schematic internal configuration of the light source unit OPU. The two directions in which the LED chips 23 are arranged are the X1 direction and the Y1 direction. The X1 direction and the Y1 direction are perpendicular to each other. The direction perpendicular to the X1 direction and the Y1 direction is the Z1 direction. The Z1 direction is approximately parallel to the optical axis OA of the light emitted by the light-emitting portion 231.

As shown in FIG. 3B, the magnifying optical system 30 is an optical system for forming a magnified image of the light-emitting portion 231 of each LED chip 23 on a predetermined plane PP. The magnifying optical system 30 has a plurality of lens portions 31 arranged to correspond to the arrangement of the LED chips 23. Each lens portion 31 is a double-telecentric optical system that enlarges and projects the light-emitting portion 231 at a magnification M of at least (arrangement pitch P1 of the LED chips 23)/(length L of one side of the light-emitting surface of the light-emitting portion 231).

In this embodiment, the lens unit 31 has four plano-convex lenses, but is not limited to this, and the lens unit 31 may have, for example, two biconvex lenses or three biconvex lenses. Furthermore, the lens unit 31 may have, for example, a plano-convex lens and a biconvex lens.

(Configuration of the illumination optical system 80)
2, the following describes the configuration of the illumination optical system 80. The illumination optical system 80 includes an imaging optical system 81, a fly-eye lens FEL, an aperture stop 85, a condenser optical system 86, and an illumination correction filter 87.

The imaging optical system 81 is a double-telecentric optical system that projects the image of the light source unit OPU (light source array 20) at 1:1 magnification onto the incident end of the fly-eye lens FEL. The imaging optical system 81 includes a first optical system 81a that forms an intermediate image of the light source unit OPU, a module shutter 81b, an illumination wedge 81c, and a second optical system 81d that focuses the intermediate image of the light source unit OPU onto the fly-eye lens FEL.

The fly-eye lens FEL is constructed by arranging a large number of lens elements having positive refractive power, for example, densely and vertically so that their optical axes are parallel to the reference optical axis AX1. Each lens element constituting the fly-eye lens FEL has a rectangular cross section similar to the shape of the illumination field to be formed on the mask MSK (and thus the shape of the exposure area to be formed on the plate P).

Therefore, the light beam incident on the fly-eye lens FEL is wavefront split by multiple lens elements, and one light source image is formed on or near the rear focal plane (exit surface) of each lens element. In other words, a substantial surface light source, i.e., a secondary light source, consisting of multiple light source images is formed on or near the rear focal plane (exit surface) of the fly-eye lens FEL. The light beam from the secondary light source formed on or near the rear focal plane (exit surface) of the fly-eye lens FEL is incident on an aperture stop 85 arranged nearby. Note that in this embodiment, the rear focal plane (exit surface) of the fly-eye lens FEL and the light source array 20 are optically conjugate.

The aperture stop 85 is positioned at a position that is nearly optically conjugate with the entrance pupil plane of the projection optical system PL, and has a variable opening for defining the range that contributes to the illumination of the secondary light source. The aperture stop 85 changes the aperture diameter of the variable opening to set the σ value (the ratio of the aperture diameter of the secondary light source image on the pupil plane of the projection optical system to the aperture diameter of the pupil plane) that determines the illumination conditions to a desired value. The light from the secondary light source that passes through the aperture stop 85 is subjected to the focusing action of the condenser optical system 86, and then its illuminance is corrected by the illuminance correction filter 87, and the light is superimposed to illuminate a mask MSK on which a predetermined pattern is formed.

The wavelength of the light emitted by the light source unit OPU is not limited to the above, and the light source unit OPU may be configured by appropriately combining LED chips that emit light with a peak wavelength in the range of 360 to 440 nm.

(Configuration of the aerial image measuring device 40)
Next, the configuration of the aerial image measuring device 40 will be described with reference to FIG.

As shown in FIG. 4, the aerial image measuring device 40 has a reference member 43 and an AIS light receiving system (measuring device) 46. The reference member 43 is disposed on the surface of the substrate stage PST on the projection optical unit 100 side. More specifically, the reference member 43 is disposed at a predetermined position at the end (-X side) of the substrate stage PST in the scanning direction, and extends along the Y-axis direction. Note that the position at which the reference member 43 is disposed is not limited to this.

The reference member 43 has reference marks M1 formed thereon, which are spaced at a predetermined interval in the Y-axis direction. In the following description, the reference marks M1 formed on the reference member 43 of the substrate stage PST will be referred to as the "substrate-side AIS marks (reference marks)" where appropriate.

As shown in FIG. 4, the formation position (height) in the Z-axis direction of the substrate-side AIS mark M1 formed on the reference member 43 is set so as to approximately coincide with the surface (exposure surface) of the plate P. An AIS light-receiving system 46 capable of receiving light that has passed through the reference member 43 is provided below the reference member 43 so as to be embedded in the substrate stage PST. The AIS light-receiving system 46 includes a lens system 44 and an image sensor 45 such as a CMOS (Complementary Metal-Oxide-Semiconductor) or a CCD (Charge Coupled Device) that receives light via the lens system 44. The light reception result of the AIS light-receiving system 46 (image sensor 45) is output to the control device CNT.

On both sides (±X sides) of the mask MSK in the scanning direction, a mark formation area having a plurality of marks (mark groups) is provided. In the mark formation area on the -X side, a plurality of first mask marks M2 are formed, which are arranged at a predetermined interval in the Y-axis direction. On the other hand, in the mark formation area on the +X side, a plurality of second mask marks M3 are formed, which are arranged at a predetermined interval in the Y-axis direction. In the following explanation, the first mask marks M2 and second mask marks M3 formed on the mask MSK are appropriately referred to as "mask-side AIS marks".

FIG. 5 is a diagram showing the state in which the AIS light receiving system 46 is detecting the AIS mark. As shown in FIG. 5, the control device CNT detects the mask side AIS mark M2 (M3) and the substrate side AIS mark M1 with the AIS light receiving system 46 (image sensor 45) by the so-called through-the-lens (TTL) method, and determines the relative position of the mask MSK and the substrate stage PST based on this detection result. Specifically, the control device CNT moves the mask stage MST and the substrate stage PST so that the image of the mask side AIS mark M2 (M3) and the image of the substrate side AIS mark M1 coincide with each other on the image sensor 45, and illuminates the mask side AIS mark M2 (M3) with the illumination optical system IOP. The illumination light (exposure light) that passes through the mask MSK passes through the projection optical unit 100 and the substrate side AIS mark M1, and is guided to the image sensor 45. The control device CNT measures each imaging characteristic (shift, scaling, rotation) of the projection optical unit 100 by measuring the relative position (positional deviation amount) of the mask side AIS mark M2 (M3) and the substrate side AIS mark M1 via the projection optical unit 100. Based on the measurement results of the obtained imaging characteristics, the control device CNT obtains a correction amount so that the imaging characteristics of the projection optical unit 100 are within the guaranteed accuracy range, and corrects the imaging characteristics based on the obtained correction amount.

When performing such spatial image measurement, it is necessary to reduce the amount of light from the light source array 20 to a predetermined amount of light. For example, by using a neutral density filter, the amount of light from the light source array 20 can be reduced to a predetermined amount of light. However, the configuration of the lighting unit 90 shown in FIG. 2 does not have space for a neutral density filter. Also, for example, if the relay optical system is increased in the lighting unit 90 shown in FIG. 2, space can be secured for a neutral density filter, but this increases the size of the lighting unit 90 and the manufacturing cost (component cost) of the lighting unit 90 also increases.

Therefore, in the lighting unit 90 according to this embodiment, the module shutter 81b also functions as a neutral density filter. In this embodiment, the module shutter 81b is disposed near the position IIM (see FIG. 2) of the intermediate image of the light source array 20 formed by the first optical system 81a. The module shutter 81b may also be disposed at the position IIM of the intermediate image of the light source array 20.

FIG. 6 is a plan view showing the configuration of a module shutter 81b according to this embodiment. The module shutter 81b has a rotation axis AX2 that is approximately parallel to the reference optical axis AX1 (the optical axis of the first optical system 81a), and a light-transmitting base material 811 is formed with a light-attenuating section 812 that functions as a light-attenuating member that attenuates the light from the light source unit OPU, a light-shielding section 813 that functions as a light-shielding member that blocks the light from the light source unit OPU, and a transmitting section 814 that transmits the light beam of the intermediate image. The light-transmitting base material 811 may be omitted. In this case, for example, a circular frame may hold the light-attenuating section 812 and the light-shielding section 813 as shown in FIG. 6. In this case, nothing exists in the part corresponding to the transmitting section 814 (it is a gap).

6, the light reducing section 812 has a light blocking portion 812a that does not transmit light, and four hole portions 812b that are formed in the light blocking portion 812a and transmit light, and reduces the amount of light from the light source array 20 to, for example, 1.2 mW/cm2 ^or less. The amount of light to be reduced may be adjusted within a range that can be detected by the image sensor 45. The light transmittance of the light blocking portion 812a is 0%.

The light-shielding portion 813 does not transmit light. In other words, the light transmittance of the light-shielding portion 813 is 0%. The light-shielding portion 813 functions as a shutter. On the other hand, the transparent portion 814 does not attenuate the light from the light source array 20. In other words, the light transmittance of the transparent portion 814 is 100%.

Module shutter 81b has a circular outer shape, and light-attenuating section 812, light-shielding section 813, and transmitting section 814 each have a sector shape. In this embodiment, light-attenuating section 812 and light-shielding section 813 are each disposed between two transmitting sections 814 in the circumferential direction of a circle centered on rotation axis AX2.

The control device CNT rotates the module shutter 81b around the rotation axis AX2 to switch between a state in which the dimming section 812 is positioned near the position IIM of the intermediate image of the light source array 20, a state in which the transmitting section 814 is positioned near the position IIM of the intermediate image, and a state in which the light blocking section 813 is positioned near the position IIM of the intermediate image.

That is, when measuring an aerial image, the control device CNT rotates the module shutter 81b around the rotation axis AX2 to realize a state in which the light attenuation unit 812 is disposed near the position IIM of the intermediate image of the light source array 20. In order to correct the spectral sensitivity of the image sensor 45, a color correction filter may be disposed in one or more locations within the lens system 44 or between the lens system 44 and the image sensor 45. In this case, the light from the light source array 20 is attenuated by the light attenuation unit 812 to an amount of light of, for example, 1.2 mW/ ^cm2 or less, and then further attenuated by the color correction filter before entering the image sensor 45.

In addition, when the pattern of the mask MSK is exposed onto the plate P, the control device CNT realizes a state in which the transmissive portion 814 is positioned near the position IIM of the intermediate image of the light source array 20.

The control device CNT also realizes a state in which the light-shielding portion 813 is positioned near the position IIM of the intermediate image of the light source array 20 while the plate P is being replaced, etc.

In this way, by giving the module shutter 81b the function of a light-reducing member, it is possible to reduce the amount of light from the light source array 20 during aerial image measurement without increasing the size of the illumination unit 90.

As described above in detail, according to this embodiment, the illumination unit 90 includes a light source unit OPU, a first optical system 81a that forms an intermediate image of the light source unit OPU, and a control device CNT that can switch between a state in which the dimming unit 812 is located near the position IIM of the intermediate image and a state in which the dimming unit 812 is not located. Because the dimming unit 812 is located near the position IIM of the intermediate image, the size of the dimming unit 812 can be made smaller than when the dimming unit 812 is located at the position of parallel light. This makes it possible to reduce the amount of light from the light source array 20 during aerial image measurement without increasing the size of the illumination unit 90.

In this embodiment, the illumination unit 90 has a rotation axis AX2 that is approximately parallel to the reference optical axis AX1 (the optical axis of the first optical system 81a), and includes a module shutter 81b in which a light-transmitting base material 811 is provided with a light-attenuating section 812 that functions as a light-attenuating member, a light-shielding section 813 that functions as a light-shielding member, and a transmission section 814 that transmits the light beam of the intermediate image. The control device CNT rotates the module shutter 81b around the rotation axis AX2 to switch between a state in which the light-attenuating section 812 is located near the position IIM of the intermediate image, a state in which the light-shielding section 813 is located, and a state in which the transmission section 814 is located. This allows the state of the light from the light source unit OPU to be an appropriate state according to the process executed by the exposure device 10.

In addition, in this embodiment, two transmitting sections 814 are provided, and the light-reducing section 812 and the light-shielding section 813 are each disposed between the two transmitting sections 814 in the circumferential direction of a circle centered on the rotation axis AX2. This allows for quick switching from a state in which the transmitting section 814 is disposed to a state in which the light-reducing section 812 is disposed or a state in which the light-shielding section 813 is disposed.

In the above embodiment, the light-reducing section 812 and the light-shielding section 813 are each disposed between two transmitting sections 814 in the circumferential direction of a circle centered on the rotation axis AX2, but this is not limited to the above. For example, the light-reducing section 812 and the light-shielding section 813 may be disposed adjacent to each other in the circumferential direction of a circle centered on the rotation axis AX2, as in the module shutters 81b' and 81b'' shown in Figures 7(A) and 7(B).

In the above embodiment, the light-reducing section 812 has four holes 812b, but is not limited to this. As long as the amount of light from the light source array 20 can be reduced to 1.2 mW/ ^cm2 or less, the number, arrangement, shape, size, etc. of the holes 812b can be appropriately changed.

In the above embodiment, the module shutter 81b has a circular outer shape, but this is not limited to this. The module shutter 81b may have, for example, a rectangular outer shape. Also, for example, the module shutter may have a light-reducing section 812, a light-shielding section 813, and a light-transmitting section 814 arranged in a line.

(Variation 1)
The lighting unit to which the module shutter 81b is applied is not limited to the above embodiment. Fig. 8 is a schematic diagram showing the configuration of a lighting unit 90A according to a first modified example.

The illumination unit 90A includes a first light source unit OPU1, a second light source unit OPU2, and an illumination optical system 80A. The first light source unit OPU1 includes a first light source array 20A and a first magnifying optical system 30A, and the second light source unit OPU2 includes a second light source array 20B and a second magnifying optical system 30B. The configurations of the first light source array 20A and the second light source array 20B are the same as those of the light source array 20 according to the above embodiment, and therefore detailed descriptions are omitted. The configurations of the first magnifying optical system 30A and the second magnifying optical system 30B are the same as those of the magnifying optical system 30 according to the above embodiment, and therefore detailed descriptions are omitted.

The illumination optical system 80A includes a first focusing optical system 83A including a first dichroic mirror DM1, a second focusing optical system 83B, a second dichroic mirror DM2, an imaging optical system 81A, a fly-eye lens FEL, an aperture stop 85, a condenser optical system 86, and an illuminance correction filter 87.

The first focusing optical system 83A forms the pupil of the magnified image of the light emitting unit 231 formed by the first magnifying optical system 30A. That is, the rear focal position of the first focusing optical system 83A is the position of the pupil. The first focusing optical system 83A has a first dichroic mirror DM1 in the middle of the optical path, and reflects at least a part of the light with a peak wavelength of 385 nm. As a result, the light beam is incident on the second dichroic mirror DM2. Note that the first focusing optical system 83A may be configured without the first dichroic mirror DM1. In that case, the arrangement of the first light source unit OPU1 and the arrangement of each lens of the first focusing optical system 83A may be appropriately adjusted so that the light beam is incident on the second dichroic mirror DM2. The first focusing optical system 83A may be configured with one lens, or may be configured with a lens group including multiple lenses.

The second focusing optical system 83B forms the pupil of the magnified image of the light emitting section 231 formed by the second magnifying optical system 30B. In other words, the rear focal position of the second focusing optical system 83B is the pupil position. The second focusing optical system 83B may be composed of a single lens, or may be composed of a lens group including multiple lenses.

The second dichroic mirror DM2 transmits at least a portion of the light with a peak wavelength of 385 nm and reflects at least a portion of the light with a peak wavelength of 365 nm. This forms a composite image by superimposing the pupil image formed by the first focusing optical system 83A and the pupil image formed by the second focusing optical system 83B.

The first optical system 81aA of the imaging optical system 81A forms an intermediate image of the first light source unit OPU1 (first light source array 20A) and the second light source unit OPU2 (second light source array 20B) using the combined light emitted from the second dichroic mirror DM2. The module shutter 81b is disposed near the position IIM of the intermediate images of the first light source unit OPU1 and the second light source unit OPU2.

The rest of the configuration is the same as in the above embodiment, so detailed description will be omitted. In this way, even in an exposure device having multiple light source units, by using the module shutter 81b, it is possible to reduce the amount of combined light emitted from the second dichroic mirror DM2 during aerial image measurement without increasing the size of the illumination unit 90A.

(Variation 2)
FIG. 9 is a schematic diagram showing the configuration of an exposure apparatus 10B according to the second modification.

In exposure device 10B, illumination unit 90B includes a first light source unit OPU1, a second light source unit OPU2, and an illumination optical system 80B. The first light source unit OPU1 and the second light source unit OPU2 are the same as those in modification example 1, so detailed description will be omitted.

The illumination optical system 80B includes a first focusing optical system 83A1, a second focusing optical system 83B1, a third dichroic mirror DM3, an imaging optical system 81B, a fly-eye lens FEL, an aperture stop 85, a condenser optical system 86B, and an illuminance correction filter 87.

The first focusing optical system 83A1 is disposed on or near the above-mentioned predetermined plane PP, and forms the pupil of the magnified image of the light-emitting part 231 formed by the first magnifying optical system 30A. The first focusing optical system 83A1 may be composed of a single lens, or may be composed of a lens group including multiple lenses.

The second focusing optical system 83B1 is disposed on or near the above-mentioned predetermined plane PP, and forms the pupil of the magnified image of the light-emitting part 231 formed by the second magnifying optical system 30B. The second focusing optical system 83B1 may be composed of a single lens, or may be composed of a lens group including multiple lenses.

The third dichroic mirror DM3 transmits at least a portion of the light with a peak wavelength of 385 nm and reflects at least a portion of the light with a peak wavelength of 365 nm. This forms a composite image by superimposing the pupil image formed by the first focusing optical system 83A1 and the pupil image formed by the second focusing optical system 83B1.

The imaging optical system 81B is a double-telecentric optical system that projects the composite image created by the third dichroic mirror DM3 at the same magnification onto the incident end of the fly-eye lens FEL. Note that the imaging optical system 81B may also reduce and project the composite image created by the third dichroic mirror DM3 onto the incident end of the fly-eye lens FEL.

The imaging optical system 81B includes a first optical system 81aB, a module shutter 81b, and a second optical system 81dB.

The first optical system 81aB of the imaging optical system 81B forms an intermediate image of the first light source array 20A and the second light source array 20B by the combined light emitted from the third dichroic mirror DM3. The module shutter 81b is disposed near the position IIM of the intermediate images of the first light source unit OPU1 and the second light source unit OPU2. The second optical system 81dB forms the intermediate images of the first light source unit OPU1 and the second light source unit OPU2 on the fly-eye lens FEL.

The light beam incident on the fly-eye lens FEL is wavefront-split by multiple lens elements, and one light source image is formed on or near the rear focal plane of each lens element. The light beam from the secondary light source formed on or near the rear focal plane of the fly-eye lens FEL is incident on an aperture stop 85 located nearby.

The light from the secondary light source passing through the aperture stop 85 is focused by the condenser optical system 86B, and then its illuminance is corrected by the illuminance correction filter 87, illuminating the mask MSK on which a predetermined pattern is formed in a superimposed manner.

In addition, in exposure apparatus 10B, projection optical system PL is an Offner type optical system supported by an optical base 73 below (-Z side) mask stage MST. Projection optical system PL forms, for example, an arc-shaped image field with the Y-axis direction as the longitudinal direction.

When the illumination area on the mask MSK is illuminated by the illumination light IL from the illumination optical system IOP, the illumination light IL that passes through the mask MSK forms a projected image (partial upright image) of the circuit pattern of the mask MSK in the illumination area in an irradiation area (exposure area (conjugate to the illumination area)) on the plate P placed on the image plane side of the projection optical system PL by way of the projection optical system PL. This exposes the plate P and transfers the pattern of the mask MSK onto the plate P.

As shown in Modification 2, the module shutter 81b may be applied to an exposure apparatus equipped with an Offner-type projection optical system PL.

The wavelengths of the light emitted by the first light source unit OPU1 and the second light source unit OPU2 are not limited to those described above, and the first light source unit OPU1 and the second light source unit OPU2 may be configured by appropriately combining LED chips that emit light with a peak wavelength in the range of 360 to 440 nm.

For example, the first light source unit OPU1 may be configured to emit light with a peak wavelength of 405 nm, and the second light source unit OPU2 may be configured to emit light with a peak wavelength of 365 nm. The first light source unit OPU1 may be configured to emit light with a peak wavelength of 395 nm, and the second light source unit OPU2 may be configured to emit light with a peak wavelength of 385 nm. The combination of the wavelength of the light emitted from the first light source unit OPU1 and the wavelength of the light emitted from the second light source unit OPU2 is not limited to these examples. Note that when the combination of the wavelength of the light emitted from the first light source unit OPU1 and the wavelength of the light emitted from the second light source unit OPU2 is a combination other than that of this embodiment, it is preferable to change the material of the dichroic mirror appropriately depending on the wavelength to be used.

In the above embodiment and its modified examples, the exposure apparatus has been described as being used to manufacture liquid crystal display devices (flat panel displays), but the exposure apparatus may also be used to manufacture semiconductors by exposing silicon wafers.

The above-described embodiment is a preferred example of the present invention. However, the present invention is not limited to this embodiment, and various modifications are possible without departing from the spirit of the present invention.

10, 10B Exposure apparatus 20 Light source array 20A First light source array 20B Second light source array 21 Substrate 23 LED chip 80, 80A, 80B Illumination optical system 81a, 81aA, 81aB First optical system 81b Module shutter 811 Substrate 812 Light-attenuating section 813 Light-shielding section 814 Transmitting section 90, 90A, 90B Illumination unit 100 Projection optical unit AX1 Reference optical axis AX2 Rotation axis CNT Control device DM2 Second dichroic mirror DM3 Third dichroic mirror FEL Fly's eye lens IIM Position of intermediate image MSK Mask OPU Light source unit OPU1 First light source unit OPU2 Second light source unit PL Projection optical system P Glass substrate

Claims (16)

A light source;
a first optical system that forms an intermediate image of the light source;
a control mechanism capable of switching between a first state in which a light-reducing member is disposed at or near the position of the intermediate image and a second state in which the light-reducing member is not disposed;
A lighting unit comprising: The lighting unit of claim 1, wherein in the second state, the luminous flux of the intermediate image is not dimmed. The second state is either a third state in which a light blocking member is arranged at or near the position of the intermediate image, or a fourth state in which neither the light reducing member nor the light blocking member is arranged at or near the position of the intermediate image.
2. The lighting unit according to claim 1. a shutter having a rotation axis substantially parallel to an optical axis of the first optical system, the shutter including a light-transmitting base material on which a light-attenuating section functioning as the light-attenuating member, a light-shielding section functioning as the light-shielding member, and a light-transmitting section for transmitting a light beam of the intermediate image are formed;
The lighting unit according to claim 3 , wherein the control mechanism switches between the first state, the third state, and the fourth state by rotating the shutter about the rotation axis. the shutter has a circular outer shape;
The light attenuating portion, the light blocking portion, and the light transmitting portion each have a sector shape.
5. The lighting unit according to claim 4. Two of the transmission sections are provided,
In a circumferential direction of a circle centered on the rotation axis, the light attenuating portion and the light blocking portion are each disposed between two of the light transmitting portions.
The lighting unit according to claim 4 or 5. The light-reducing member reduces the amount of light from the light source to 1.2 mW/cm2 or ^less .
The lighting unit according to any one of claims 1 to 6. The light source is an LED light source.
The lighting unit according to any one of claims 1 to 7. The LED light source has a plurality of LED elements arranged in an array.
9. The lighting unit according to claim 8. The peak wavelength of the light emitted from the light source is in the range of 360 to 370 nm.
The lighting unit according to any one of claims 1 to 9. The peak wavelength of the light emitted from the light source is in the range of 380 to 390 nm.
The lighting unit according to any one of claims 1 to 9. The peak wavelength of the light emitted from the light source is in the range of 400 to 410 nm.
10. The lighting unit according to claim 1. A plurality of light sources;
a combining optical element that combines the light emitted from the plurality of light sources;
a first optical system that forms an intermediate image of the plurality of light sources by using a combined light emitted from the combining optical element;
a control mechanism capable of switching between a state in which a light-reducing member is disposed at or near the position of the intermediate image and a state in which the light-reducing member is not disposed;
A lighting unit comprising: A lighting unit according to any one of claims 1 to 13,
a projection optical system that projects a pattern image of a mask illuminated by the illumination unit onto a photosensitive substrate;
An exposure apparatus comprising: The photosensitive substrate has at least one side length or diagonal length of 500 mm or more.
The exposure apparatus according to claim 14. An exposure method using the exposure apparatus according to claim 14 or 15,
illuminating a mask with the illumination unit;
projecting a pattern image of the mask onto a photosensitive substrate using the projection optical system;
An exposure method comprising:

Images