WO2024038538A1

WO2024038538A1 - Light source unit, illumination unit, exposure device, and exposure method

Info

Publication number: WO2024038538A1
Application number: PCT/JP2022/031214
Authority: WO
Inventors: 吉田亮平; 鈴木智也; 櫻井友紀也; 犬童真成; 岩永正也
Original assignee: 株式会社ニコン
Priority date: 2022-08-18
Filing date: 2022-08-18
Publication date: 2024-02-22

Abstract

This light source unit comprises: a plurality of light source elements that are two-dimensionally arranged on a surface of a fixation target; and protruding portions that protrude from the fixation target and that are each provided between one of the plurality of light source elements and at least one of the other light source elements adjacent to said one light source element. The ends of the protruding portions are located at a position higher than the lower surfaces of the light source elements.　

Description

Light source unit, lighting unit, exposure device, and exposure method

It relates to a light source unit, a lighting unit, an exposure device, and an exposure method.

In recent years, liquid crystal display panels have been widely used as display elements for personal computers, televisions, etc. A liquid crystal display panel is manufactured by forming a circuit pattern of thin film transistors on a plate (glass substrate) using a photolithography method. As a device for this photolithography process, an exposure device is used that projects and exposes an original pattern formed on a mask onto a photoresist layer on a plate via a projection optical system (for example, Patent Document 1). .

In general, there is a need to realize a high-brightness surface light source that can be applied to various optical devices including the above-mentioned exposure apparatus.

Japanese Patent Application Publication No. 2000-21712

According to the first aspect of the disclosure, the light source unit includes a plurality of light source elements two-dimensionally arranged on the surface of a fixed object, each light source element of the plurality of light source elements protruding from the fixed object, a protrusion provided between each of the light source elements and at least one of the other adjacent light source elements, and an end of the protrusion is located at a higher position than a lower surface of each of the light source elements.

According to the second aspect of the disclosure, the illumination unit includes the light source unit and an illumination optical system that guides the light emitted from the light source unit to the irradiated object.

According to a third aspect of the disclosure, the illumination unit includes a plurality of the above-mentioned light source units and a combining optical element that combines the light emitted from the plurality of light source units, and the combined light emitted from the combining optical element. an illumination optical system that guides the light to the irradiated object.

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

Note that the configurations of the embodiments described below may be modified as appropriate, and at least a portion thereof may be replaced with other components. Further, the configuration elements whose arrangement is not particularly limited are not limited to the arrangement disclosed in the embodiments, but can be arranged at a position where the function can be achieved.

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 the lighting unit. FIG. 3(A) is a plan view schematically showing the configurations of the first and second light source arrays, and FIG. 3(B) is a diagram schematically showing the internal configurations of the first and second light source units. be. 4(A) is a plan view showing the substrate according to the embodiment, and FIG. 4(B) is a sectional view taken along the line AA in FIG. 4(A). 5(A) to 5(H) are diagrams showing a method of manufacturing the first light source array. 6(A) is a plan view showing an example of a protrusion according to Modification 1, and FIG. 6(B) is a sectional view taken along line AA in FIG. 6(A). 7(A) is a plan view showing an example of a protrusion according to modification 2, and FIG. 7(B) is a sectional view taken along the line AA in FIG. 7(A). 8(A) is a plan view showing an example of a protrusion according to modification 3, and FIG. 8(B) is a sectional view taken along the line AA in FIG. 8(A).

An exposure apparatus 10 according to one embodiment will be described based on FIGS. 1 to 5(H).

(Configuration of exposure device)
First, the configuration of an exposure apparatus 10 according to an embodiment will be described using FIG. 1. FIG. 1 is a diagram schematically showing the configuration of an exposure apparatus 10 according to an embodiment.

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

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

The exposure apparatus 10 includes an illumination system IOP, a mask stage MST that holds a mask MSK, a projection optical system PL, a body 70 that supports these, a substrate stage PST that holds a substrate P, a control system for these, and the like. The control system centrally controls each component of the exposure apparatus 10.

The body 70 includes a base (vibration isolator) 71,

columns

72A, 72B, an optical surface plate 73, a support 74, and a slide guide 75. The base (vibration isolation table) 71 is placed on the floor F, isolates vibrations from the floor F, and supports the

columns

72A, 72B, etc.

Columns

72A and 72B each have a frame shape, and column 72A is arranged inside column 72B. The optical surface plate 73 has a flat plate shape and is fixed to the ceiling of the column 72A. The support body 74 is supported on the ceiling of the column 72B via a slide guide 75. Slide guide 75 includes an air ball lifter and a positioning mechanism, and positions support body 74 (that is, mask stage MST, which will be described later) at an appropriate position in the X-axis direction with respect to optical surface plate 73.

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

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

Positional information (including rotational information in the θz direction) of mask stage MST in the XY plane is measured by an interferometer system. The interferometer system irradiates a length measurement beam onto a movable mirror (or mirror-finished reflective surface (not shown)) provided at the end of mask stage MST, and receives reflected light from the movable mirror. Measure the position of mask stage MST. The measurement results are supplied to a control device (not shown), and the control device drives mask stage MST via a drive system according to the measurement results of the interferometer system.

Projection optical system PL is supported by optical surface plate 73 below mask stage MST (-Z side). The projection optical system PL is configured similarly to the projection optical system disclosed in, for example, U.S. Pat. 7), and forms a rectangular image field whose longitudinal direction is the Y-axis direction. Here, four projection optical units 100 are arranged at predetermined intervals in the Y-axis direction, and the remaining three projection optical units 100 are spaced apart from the four projection optical units 100 on the +X side and at predetermined intervals in the Y-axis direction. It is located in As each of the plurality of projection optical units 100, for example, one that forms an erect normal image with a double-sided telecentric, equal-magnification system is used. Note that the plurality of projection areas of the projection optical units 100 arranged in a staggered manner are collectively referred to as an exposure area.

When the illumination region on the mask MSK is illuminated by the illumination light IL from the illumination system IOP, the illumination light IL that has passed through the mask MSK illuminates the circuit pattern of the mask MSK in the illumination region through the projection optical system PL. A projected image (partially erected image) is formed in an irradiation area (exposure area (conjugate to the illumination area)) on the substrate P arranged on the image plane side of the projection optical system PL. Here, a resist (sensitizer) is applied to the surface of the substrate P. The mask stage MST and substrate stage PST are driven synchronously, that is, the mask MSK is driven in the scanning direction (X-axis direction) with respect to the illumination area (illumination light IL), and the substrate P is moved into the exposure area (illumination light IL). By driving in the same scanning direction, the substrate P is exposed and the pattern of the mask MSK is transferred onto the substrate P.

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

Position information in the XY plane of substrate stage PST (including rotation information (yawing amount (rotation amount θz in the θz direction), pitching amount (rotation amount θx in the θx direction), rolling amount (rotation amount θy in the θy direction))) is measured by an interferometer system. The interferometer system irradiates a length measurement beam from an optical surface plate 73 onto a movable mirror (or a mirror-finished reflective surface (not shown)) provided at the end of the substrate stage PST, and collects the reflected light from the movable mirror. By receiving light, the position of substrate stage PST is measured. The measurement results are supplied to a control device (not shown), and the control device drives substrate stage PST according to the measurement results of the interferometer system.

The exposure apparatus 10 performs alignment measurement (eg, EGA, etc.) prior to exposure, and uses the results to expose the substrate P according to the following procedure. First, according to instructions from a control device, mask stage MST and substrate stage PST are synchronously driven in the X-axis direction. As a result, the first shot area on the substrate P is scanned and exposed. When the scanning exposure for the first shot area is completed, the control device moves (steps) substrate stage PST to a position corresponding to the second shot area. Then, scanning exposure is performed for the second shot area. Similarly, the control device transfers the pattern of the mask MSK to all shot areas on the substrate P by repeating stepping between shot areas of the substrate P and scanning exposure for the shot areas.

(Configuration of lighting system IOP)
Next, the configuration of the illumination system IOP in this embodiment will be explained. The illumination system IOP includes a plurality of illumination units 90 corresponding to each of the plurality of projection optical units 100 included in the projection optical system PL. FIG. 2 is a diagram schematically showing the configuration of the lighting unit 90.

The illumination unit 90 includes a first light source unit OPU1, a second light source unit OPU2, and an illumination optical system 80.

(Configuration of light source unit)
The first light source unit OPU1 includes a first light source array 20A and a first enlarging optical system 30A, and the second light source unit OPU2 includes a second light source array 20B and a second enlarging optical system 30B.

FIG. 3(A) is a plan view schematically showing the configurations of the first light source array 20A and the second light source array 20B. Moreover, FIG. 3(B) is a diagram schematically showing the internal configurations of the first light source unit OPU1 and the second light source unit OPU2.

As shown in FIG. 3A, the first light source array 20A includes, for example, a plurality of (5×5 in FIG. 3A) LED (Light Emitting Diode) chips 23A arranged two-dimensionally on a substrate 21A. Be prepared. The number of LED chips 23A may be changed as necessary. The LED chips 23A are arranged at a pitch P1, and the pitch P1 is the distance between the centers of adjacent LED chips 23A.

Each of the plurality of LED chips 23A has a light emitting section 231A, and the peak wavelength of light emitted from the light emitting section 231A is within the range of 380 to 390 nm. That is, the light emitting section 231A is an ultraviolet LED (UV LED). More preferably, the peak wavelength of the light emitted from the light emitting section 231A is 385 nm. The light emitting surface of the light emitting section 231A is square, and the length of one side thereof is a1. In the following description, the two directions in which the LED chips 23A are arranged are referred to as the X1 direction and the Y1 direction. The X1 direction and the Y1 direction are orthogonal. Further, the direction perpendicular to the X1 direction and the Y1 direction is defined as the Z1 direction. The Z1 direction is approximately parallel to the optical axis OA of light emitted by the light emitting section 231A.

The first enlarging optical system 30A is an enlarging optical system for forming an enlarged image of the light emitting portion 231A of each LED chip 23A on a predetermined plane PP. As shown in FIG. 3(B), the first enlarging optical system 30A includes a plurality of lens portions 31A arranged to correspond to the arrangement of the LED chips 23A. Each of the lens sections 31A is a bilateral telecentric optical system that enlarges and projects the light emitting section 231A at a magnification M1 equal to or greater than (array pitch P1 of the LED chips 23A)/(length a1 of one side of the light emitting surface of the light emitting section 231A). . In addition, in FIG. 3(B), for clarity of the drawing, only four LED chips 23A (23B) lined up in a row along the Y1 direction are shown.

The second light source array 20B includes, for example, a plurality of (5×5 in FIG. 3A) LED chips 23B arranged two-dimensionally on a substrate 21B. The number of LED chips 23B may be changed as necessary. The LED chips 23B are arranged at a pitch P2, and the pitch P2 is the distance between the centers of adjacent LED chips 23B. The arrangement pitch P1 of the LED chips 23A and the arrangement pitch P2 of the LED chips 23B may be the same or different.

Each of the plurality of LED chips 23B has a light emitting section 231B, and the peak wavelength of light emitted from the light emitting section 231B is within the range of 360 to 370 nm. That is, the light emitting section 231B is a UV LED. More preferably, the peak wavelength of the light emitted from the light emitting section 231B is 365 nm. The light emitting surface of the light emitting section 231B is square, and the length of one side thereof is a2.

The second enlarging optical system 30B is an enlarging optical system for forming an enlarged image of the light emitting portion 231B of each LED chip 23B on a predetermined plane PP. The second magnifying optical system 30B includes a plurality of lens sections 31B arranged so as to correspond to the arrangement of the LED chips 23B, as shown in FIG. 3(B). Each of the lens sections 31B is a double-sided telecentric optical system that magnifies and projects the light emitting section 231B at a magnification M2 equal to or greater than (array pitch P2 of the LED chips 23B)/(length a2 of one side of the light emitting surface of the light emitting section 231B). .

In this embodiment, each of the

lens sections

31A and 31B includes four plano-convex lenses, but the invention is not limited to this. For example, the

lens sections

31A and 31B include two biconvex lenses. Alternatively, it may include three biconvex lenses. Further, the

lens portions

31A and 31B may include, for example, a plano-convex lens and a biconvex lens.

Here, in the manufacturing process of the first light source array 20A and the second light source array 20B, when arranging and fixing the

LED chips

23A and 23B on the

substrates

21A and 21B (more specifically, when reflowing cream solder ), the fixed positions of the

LED chips

23A, 23B may shift from the designed positions. The positional deviation of the

LED chips

23A and 23B causes a decrease in the illuminance of the light emitted from the first light source unit OPU1 and the second light source unit OPU2.

Therefore, the

substrates

21A, 21B according to this embodiment are provided with protrusions 211 made of a part of the

substrates

21A, 21B to suppress the positional shift of the

LED chips

23A, 23B during manufacturing. 4(A) and 4(B) are diagrams for explaining the protruding portions 211 provided on the

substrates

21A and 21B, and FIG. 4(A) is a plan view of the

substrates

21A and 21B, and FIG. B) is a sectional view taken along line AA in FIG. 4(A). Note that since the structures of the protrusions 211 provided on the

substrates

21A and 21B are the same, only the substrate 21A will be described here. In FIGS. 4(A) and 4(B), a part of the LED chip 23A is illustrated for explanation. Further, in FIG. 4(B), hatching of the LED chip 23A is omitted.

The protrusion 211 is provided between the plurality of LED chips 23A. In this embodiment, as shown in FIGS. 4A and 4B, a cross-shaped protrusion 211 is provided adjacent to the corner of each LED chip 23A. As shown in FIG. 4B, the end 211a of the protrusion 211 is located at a higher position than the lower surface (-Z1 side surface) of the LED chip 23A. The height of the protrusion 211 may be such that the end 211a is located higher than the lower surface of the LED chip 23A and does not block the light emitted from the LED chip 23A. Further, the shape of the protrusion 211 may be any shape as long as the light emitted from the LED chip 23A does not enter the protrusion 211. The protrusion 211 and the LED chip 23A may be in contact with each other, or there may be a gap between the protrusion 211 and the LED chip 23A.

When manufacturing the first light source array 20A, the LED chips 23A are arranged in the area defined by the four adjacent protrusions 211 (the area surrounded by the four protrusions 211). Since the end 211a of the protrusion 211 is located at a higher position than the lower surface of the LED chip 23A, movement of the LED chip 23A placed in this area is restricted. Therefore, when the LED chip 23A is fixed to the substrate 21A, the positional shift of the LED chip 23A is suppressed. This suppresses a decrease in illuminance due to the positional shift of the LED chip 23A, and allows the first light source unit OPU1 to emit high-intensity light.

(Configuration of illumination optical system 80)
Returning to FIG. 2, the illumination optical system 80 includes a first condensing optical system (first optical system) 81A that includes a first dichroic mirror DM1, and a second condensing optical system (second optical system). (optical system) 81B, a second dichroic mirror DM2, an imaging optical system 83, a fly's eye lens FEL, and a condenser optical system 84.

The first condensing optical system 81A forms a pupil of an enlarged image of the light emitting section 231A formed by the first enlarging optical system 30A. That is, the rear focal position of the first condensing optical system 81A is the position of the pupil. The first condensing optical system 81A includes a first dichroic mirror DM1 in the middle of the optical path, and reflects at least a portion of the light having a peak wavelength of 385 nm. As a result, the light beam enters the second dichroic mirror DM2. Note that the first condensing optical system 81A may be configured without the first dichroic mirror DM1, and in that case, the arrangement of the first light source unit OPU1 and each lens of the first condensing optical system 81A may be changed. The arrangement may be appropriately adjusted so that the light beam is incident on the second dichroic mirror DM2. Further, the first condensing optical system 81A may be composed of one lens, or may be composed of a lens group including a plurality of lenses.

The second condensing optical system 81B forms a pupil of an enlarged image of the light emitting section 231B formed by the second enlarging optical system 30B. That is, the rear focal position of the second condensing optical system 81B is the position of the pupil. The second condensing optical system 81B may be composed of one lens, or may be composed of a lens group including a plurality of lenses.

The second dichroic mirror DM2 transmits at least part of the light with a peak wavelength of 385 nm and reflects at least part of the light with a peak wavelength of 365 nm. Thereby, a composite image is formed in which the pupil image formed by the first condensing optical system 81A and the pupil image formed by the second condensing optical system 81B are superimposed.

In this embodiment, the second dichroic mirror DM2 superimposes the pupil image formed by the first condensing optical system 81A and the pupil image formed by the second condensing optical system 81B to create a composite image. form. That is, the second dichroic mirror DM2 is arranged at a position that is the rear focal position of the first condensing optical system 81A and the rear focal position of the second condensing optical system 81B. Thereby, the second dichroic mirror DM2 is illuminated by Koehler illumination with the light emitted from the first light source unit OPU1 and the light emitted from the second light source unit OPU2. By performing Koehler illumination, it is possible to reduce the change in illuminance of the light flux of the pupil image formed by the first condensing optical system 81A and the change in the illuminance of the light flux of the pupil image formed by the second condensing optical system 81B. can. Note that, without being limited to the configuration of the present embodiment, the first condensing optical system 81A and the second condensing optical system 81B respectively attach the image of the first light source unit OPU1 and the second condensing optical system to the second dichroic mirror DM2. It may be configured to perform critical illumination to form an image of the light source unit OPU2.

The illumination unit 90 includes a detector DT10 for monitoring light with a peak wavelength of 385 nm, a detector DT20 for monitoring light with a peak wavelength of 365 nm, and a detector DT20 for monitoring light with a peak wavelength of 385 nm and light with a peak wavelength of 365 nm. A detector DT30 is provided for the detection.

Specifically, the detector DT10 detects the illuminance of the light with a peak wavelength of 385 nm reflected by the first dichroic mirror DM1. The detector DT20 detects the illuminance of the light having a peak wavelength of 365 nm reflected by the second dichroic mirror DM2. The detector DT30 detects the illuminance of the 385 nm light unintentionally reflected by the second dichroic mirror DM2 and the illuminance of the 365 nm light unintentionally transmitted by the second dichroic mirror DM2.

The detection results of the detectors DT10 to DT30 are output to a control device (not shown), and the control device outputs the LED chips 23A of the first light source unit OPU1 and the second light source unit OPU2, respectively, based on the detection results of the detectors DT10 to DT30. and controls the value of the current supplied to 23B.

The imaging optical system 83 is a double-sided telecentric optical system that projects the composite image synthesized by the second dichroic mirror DM2 at the same magnification onto the incident end of the fly's eye lens FEL. Note that the imaging optical system 83 may reduce and project the composite image synthesized by the second dichroic mirror DM2 onto the incident end of the fly's eye lens FEL.

The fly's eye lens FEL is constructed by densely arranging a large number of lens elements each having, for example, positive refractive power, vertically and horizontally so that their optical axes are parallel to the reference optical axis AX. Each lens element constituting the fly's 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 substrate P).

Therefore, the light beam incident on the fly's eye lens FEL is wavefront-divided by a large number of lens elements, and one light source image is formed at or near the rear focal plane (output surface) of each lens element. That is, a substantial surface light source, ie, a secondary light source, consisting of a large number of light source images is formed at or near the rear focal plane (output surface) of the fly's eye lens FEL. A light beam from a secondary light source formed at or near the rear focal plane (output surface) of the fly's eye lens FEL enters an aperture stop 85 arranged near it. In this embodiment, the rear focal plane (output surface) of the fly's eye lens FEL and the first light source array 20A and the second light source array 20B are optically conjugate.

The aperture stop 85 is arranged at a position that is optically approximately conjugate with the entrance pupil plane of the projection optical system PL, and has a variable aperture 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 aperture to determine the σ value (the aperture of the secondary light source image on the pupil plane of the projection optical system relative to the aperture diameter of the pupil plane of the projection optical system), which determines the illumination condition. ratio) to the desired value. The light from the secondary light source passes through the aperture diaphragm 85 and, after being condensed by the condenser optical system 84, illuminates the mask MSK in which a predetermined pattern is formed in a superimposed manner.

Note that the wavelengths of the light emitted by the first light source unit OPU1 and the second light source unit OPU2 are not limited to those described above, and the first light source unit OPU1 and the second light source unit OPU2 may be The light source unit OPU1 and the second light source unit OPU2 may be configured. For example, the first light source unit OPU1 may emit light with a peak wavelength of 405 nm, and the second light source unit OPU2 may emit light with a peak wavelength of 385 nm. Alternatively, the first light source unit OPU1 may emit light with a peak wavelength of 395 nm, and the second light source unit OPU2 may 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 if the combination of the wavelength of the light emitted by the first light source unit OPU1 and the wavelength of the light emitted by the second light source unit OPU2 is a combination other than that of the first embodiment, dichroic dichroic may be used as appropriate depending on the wavelength used. It is preferable to change the material of the mirror.

(Method for manufacturing light source array)
Next, a method of manufacturing the first light source array 20A and the second light source array 20B will be described. Since the manufacturing method of the first light source array 20A and the second light source array 20B is the same, the first light source array 20A will be described here.

FIGS. 5(A) to 5(H) are diagrams showing a method of manufacturing the first light source array 20A. 5(B) is a sectional view taken along the line AA in FIG. 5(A), FIG. 5(D) is a sectional view taken along the BB line in FIG. 5(C), and FIG. , and FIG. 5(H) is a sectional view taken along the line DD in FIG. 5(G).

First, as shown in FIGS. 5(A) and 5(B), a substrate 21A is prepared. The substrate 21A is, for example, a substrate made of metal such as copper (Cu).

As shown in FIGS. 5(C) and 5(D), posts 212 and protrusions 211 are formed by etching the substrate 21A. As a result, the protrusion 211 is formed from a part of the substrate 21A, thereby increasing the strength of the protrusion 211. Etching is performed, for example, using a resist patterned by a photolithography process as a mask.

Next, as shown in FIGS. 5E and 5F, an insulating layer 221 and a wiring layer 222 are sequentially formed on the substrate 21A. Next, as shown in FIG. 5(G) and FIG. 5(H), cream solder 223 is applied to the upper surface of the post 212 and the wiring layer 222, and the LED chip 23A is placed in the area defined by the protrusion 211. Deploy. Thereafter, the LED chip 23A is fixed to the substrate 21A by reflow. At this time, since the movement of the LED chip 23A is restricted by the protrusion 211, displacement of the LED chip 23A is suppressed. Through the above processing, it is possible to obtain the first light source array 20A in which the positional shift of the LED chips 23A is suppressed. Note that, as shown in the figure, in this embodiment, each LED chip 23A is connected in series in the X1 direction.

As described above in detail, according to the present embodiment, the first light source unit OPU1 includes a plurality of LED chips 23A arranged two-dimensionally on the surface of the substrate 21A, and a plurality of LED chips protruding from the substrate 21A. 23A. The end 211a of the protrusion 211 is located at a higher position than the lower surface of the LED chip 23A. As a result, when the LED chip 23A is fixed to the substrate 21A, the protrusion 211 restricts the movement of the LED chip 23A, and the displacement of the LED chip 23A is suppressed, so that a decrease in the illuminance of the first light source unit OPU1 is suppressed. Ru. Therefore, the first light source unit OPU1 can realize a high-intensity surface light source.

Furthermore, according to this embodiment, the substrate 21A is formed of a metal material. Thereby, the protrusion 211 can be easily formed by etching or the like.

Furthermore, according to the present embodiment, the protrusion 211 is formed of a part of the substrate 21A. Thereby, the protrusion 211 has high strength.

(Modification 1)
In the above embodiment, the protrusion 211 was provided adjacent to the corner of the LED chip 23A, but the present invention is not limited to this. The protrusion 211 may be provided between each LED chip 23A and at least one of the other LED chips 23A adjacent to the LED chip 23A.

FIG. 6(A) is a plan view showing an example of a protrusion 211A according to Modification 1, and FIG. 6(B) is a cross-sectional view taken along line AA in FIG. 6(A). As shown in FIGS. 6(A) and 6(B), the protruding portion 211A according to Modification Example 1 has a cylindrical shape. In modification example 1, when the LED chips 23A arranged in 2 rows x 2 rows in the X1 direction and the Y1 direction are set as one set (indicated by a two-dot chain line), the protrusion 211A is arranged in the X1 direction within one set. It is provided between adjacent LED chips 23A and between adjacent LED chips 23A in the Y1 direction. Further, although the protruding parts 211A are not provided between adjacent sets in the X1 direction and the Y1 direction, the protruding parts 211A may be provided between adjacent sets. The protrusion 211A and the LED chip 23A may be in contact with each other, or there may be a gap between the protrusion 211A and the LED chip 23A.

When the substrate 21A has such a protrusion 211A, when manufacturing the first light source array 20A, by pressing the LED chip 23A against the protrusion 211A using a jig or the like and performing reflow, the displacement of the LED chip 23A can be suppressed. can do. Note that a mechanism for pressing the LED chip 23A against the protrusion 211A may be provided on the substrate 21A.

When using the cylindrical protrusion 211A as in Modification 1, the LED chip 23A and the protrusion 211A contact each other at points, which improves the positioning accuracy of the LED chip 23A.

For example, in one set, a cross-shaped protrusion 211 is arranged in the center, and a circle is formed between the LED chips 23A adjacent to each other in the X1 direction and between the LED chips 23A adjacent to each other in the Y1 direction. A columnar protrusion 211A may be arranged.

(Modification 2)
FIG. 7(A) is a plan view showing an example of a protrusion 211B according to modification 2, and FIG. 7(B) is a cross-sectional view taken along the line AA in FIG. 7(A). As shown in FIGS. 7(A) and 7(B), in Modification 2, wall-shaped protrusions 211B are placed between adjacent LED chips 23A in the X1 direction within one set indicated by two-dot chain lines. and between adjacent LED chips 23A in the Y1 direction. Also in this case, as in Modification 1, by pressing the LED chip 23A against the protrusion 211B and reflowing it, it is possible to suppress the displacement of the LED chip 23A. The protrusion 211B and the LED chip 23A may be in contact with each other, or there may be a gap between the protrusion 211B and the LED chip 23A. Further, in the second modification, the protrusions 211B are not provided between adjacent sets in the X1 direction and the Y1 direction, but the protrusions 211B may be provided between adjacent sets.

Note that the wall-shaped protrusion 211B may be provided adjacent to each side of the LED chip 23A. In this case, positional shift of the LED chip 23A can be suppressed by arranging the LED chip 23A in a region surrounded by the wall-shaped protrusion 211B.

(Modification 3)
In the above embodiment and modified examples 1 and 2, the

protrusions

211, 211A, and 211B are adjacent to, for example, a part of the side of the LED chip 23A, but the protrusion 211 is arranged so as to surround the entire circumference of the LED chip 23A. may be formed. 8(A) is a plan view showing an example of a protrusion 211C according to modification 3, and FIG. 8(B) is a sectional view taken along line AA in FIG. 8(A). In modification 3, the protrusion 211C is realized by forming a recess 213 in the substrate 21A to accommodate the LED chip 23A. Thereby, the protrusion 211C surrounds the entire circumference of the LED chip 23A. By housing the LED chip 23A in the recess 213, displacement of the LED chip 23A can be suppressed.

Note that in the above embodiment and modifications 1 to 3, the case where the

protrusions

211, 211A, 211B, and 211C are formed as part of the substrate 21A has been described, but the present invention is not limited to this. For example, in the embodiment and modifications 1 and 2, the

protrusions

211, 211A, and 211B may be members different from the substrate 21A (members separate from the substrate 21A) that come into contact with the substrate 21A. That is, the

protrusions

211, 211A, and 211B may be formed by fixing (soldering or bonding) a member different from the substrate 21A to the substrate 21A. In this case, the

protrusions

211, 211A, and 211B may be made of the same material as the substrate 21A, or may be made of a different material.

Furthermore, in the above embodiment and modifications 1 to 3, the LED chips 23A are arranged on the substrate 21A, but the present invention is not limited to this. The LED chips 23A may be arranged on a heat sink. The same applies to the LED chip 23B. Examples of the heat sink include a microchannel heat sink having a flow path for passing a coolant therein, and a fin type heat sink. Although the light intensity of the LED decreases as the temperature of the LED chip 23A increases, by arranging the LED chip 23A on a heat sink, the temperature increase of the LED chip 23A can be suppressed.

Furthermore, in the above embodiments and modifications 1 to 3, the illumination unit 90 included the illumination optical system 80 including the first light source unit OPU1, the second light source unit OPU2, and the second dichroic mirror DM2. However, it is not limited to this. For example, the lighting unit 90 may include only one of the first light source unit OPU1 and the second light source unit OPU2. In this case, the illumination optical system 80 can have any configuration as long as it can guide the light emitted from the first light source unit OPU1 or the second light source unit OPU2 to the mask MSK.

The embodiments described above are examples of preferred implementations of the present invention. However, the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention.

10 Exposure device 20A First light source array 20B Second

light source array

21A,

21B Substrate

23A,

23B LED chips

31A, 31B Lens part 80 Illumination optical system 90 Illumination unit 100 Projection

optical unit

211, 211A, 211B, 211C Projection part

211a End part

231A, 231B Light emitting part DM2 Second dichroic mirror MSK Mask OPU1 First light source unit OPU2 Second light source unit P Substrate

Claims

a plurality of light source elements arranged two-dimensionally on the surface of a fixed object;
a protrusion protruding from the fixed object and provided between each light source element of the plurality of light source elements and at least one other light source element adjacent to each light source element;
Equipped with
The end of the protrusion is located at a higher position than the lower surface of each light source element.
light source unit.
The fixed object is a substrate or a heat sink,
The light source unit according to claim 1.
The heat sink has a flow path for passing a refrigerant therein.
The light source unit according to claim 2.
the fixed object is made of a metal material;
The light source unit according to any one of claims 1 to 3.
The protruding portion is made of a part of the fixed object,
The light source unit according to any one of claims 1 to 4.
The protrusion is made of a member different from the fixed object and comes into contact with the fixed object.
The light source unit according to any one of claims 1 to 4.
the light emitted from the plurality of light source elements does not enter the protrusion;
The light source unit according to any one of claims 1 to 6.
Among the plurality of light source elements, when one set includes light source elements arranged in 2 rows x 2 rows in a first direction and a second direction intersecting the first direction, the protruding portion is arranged in one set. provided between light source elements adjacent in the first direction and between light source elements adjacent in the second direction,
The light source unit according to any one of claims 1 to 7.
In at least one of the first direction and the second direction, the protrusion is not provided between adjacent sets of the light source elements;
The light source unit according to claim 8.
Each of the plurality of light source elements includes a light emitting part that emits light,
further comprising a lens array in which a plurality of lens parts that form an enlarged image of the light emitting part of each of the plurality of light source elements are arranged on a two-dimensional plane;
The light source unit according to any one of claims 1 to 9.
The light source element is a light emitting diode element,
The light source unit according to any one of claims 1 to 10.
The light source element emits light with a wavelength of 400 nm or less,
The light source unit according to any one of claims 1 to 11.
The light source unit according to any one of claims 1 to 12,
an illumination optical system that guides the light emitted from the light source unit to an irradiated object;
A lighting unit with.
A plurality of light source units according to any one of claims 1 to 12,
an illumination optical system including a combining optical element that combines light emitted from the plurality of light source units, and guiding the combined light emitted from the combining optical element to an irradiated object;
A lighting unit with.
The lighting unit according to claim 13 or 14,
a projection optical system that projects a pattern image of the 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 15.
An exposure method using the exposure apparatus according to claim 15 or 16,
Illuminating the mask with the lighting unit;
Projecting the pattern image of the mask onto a photosensitive substrate using the projection optical system;
Exposure methods including.