Light source device, exposure device, and method for manufacturing articles

Abstract

To provide a technique that is advantageous for reducing wavelength unevenness caused by temperature unevenness between multiple light-emitting elements. [Solution] A light source device is provided. This light source device has an element array section in which a plurality of light-emitting elements are arranged. The plurality of light-emitting elements include a first light-emitting element and a second light-emitting element whose temperature characteristics, which show the relationship between the element temperature and the peak wavelength, are different from those of the first light-emitting element. The first light-emitting element and the second light-emitting element are arranged according to the temperature unevenness in the element array section.

Description

Technical Field

[0001] The present invention relates to a light source device, an exposure device, and an article manufacturing method.

Background Art

[0002] An exposure device is a device that transfers a pattern formed on a reticle onto a substrate. It illuminates the reticle with light through an illumination optical system and projects an image of the pattern of the reticle onto the substrate through a projection optical system. Conventionally, a mercury lamp has been used as a light source for exposure, but in recent years, it has been expected to be replaced with a light-emitting diode (LED), which is a light-emitting element. The LED has a short time from when current is passed through a circuit that controls light emission until the light output becomes stable, and it does not need to emit light constantly like a mercury lamp, so it is energy-saving and has a long lifespan.

[0003] Since the luminance per LED is smaller than that of a mercury lamp, it is necessary to use an LED array in which a plurality of LEDs are arranged as a light source. The higher the integration degree of the LED array and the larger the input power, the larger the total amount of heat generated from the LED array. As the temperature of the LED rises, a phenomenon occurs in which the peak wavelength or dominant wavelength of the emission wavelength characteristics shifts to the longer wavelength side (temperature dependence). Therefore, when temperature unevenness occurs among a plurality of LEDs, for example, by individually controlling the current values of the plurality of LEDs, variation in the peak wavelength (wavelength unevenness) occurs.

[0004] Patent Document ˙1 discloses a surface light-emitting device in which a plurality of light-emitting elements are arranged in a planar shape. In Patent Document 1, a first light-emitting element arranged on the outer periphery and a second light-emitting element arranged inside thereof are provided, and the first light-emitting element and the second light-emitting element use those having different peak wavelengths of the emitted light. It is described that this reduces color unevenness.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2024-035053 [Overview of the project] [Problems that the invention aims to solve]

[0006] When multiple LEDs are used as light sources in an exposure apparatus, wavelength unevenness due to temperature dependence can affect illumination uniformity and resolution. Therefore, it is desirable to reduce wavelength unevenness. However, the technology disclosed in Patent Document 1 cannot reduce wavelength unevenness.

[0007] The present invention provides an advantageous technique for reducing wavelength unevenness caused by temperature unevenness between multiple light-emitting elements. [Means for solving the problem]

[0008] According to one aspect of the present invention, a light source device is provided having an element array portion in which a plurality of light-emitting elements are arranged, wherein the plurality of light-emitting elements include a first light-emitting element and a second light-emitting element having a temperature characteristic that shows the relationship between the element temperature and the peak wavelength different from that of the first light-emitting element, and the first light-emitting element and the second light-emitting element are arranged according to the temperature unevenness in the element array portion. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a technique that is advantageous for reducing wavelength unevenness caused by temperature unevenness between multiple light-emitting elements. [Brief explanation of the drawing]

[0010] [Figure 1] A diagram showing the configuration of the light source device. [Figure 2] A graph showing the temperature-peak wavelength characteristics of a light-emitting element. [Figure 3] A diagram illustrating the arrangement of multiple light-emitting elements in the element array section. [Figure 4] A diagram showing the configuration of the element array section. [Figure 5] A diagram illustrating the heat sink channel and the arrangement of multiple light-emitting elements in the element array section. [Figure 6] A diagram showing the configuration of an exposure apparatus. [Modes for carrying out the invention]

[0011] The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the invention as defined in the claims. While the embodiments describe multiple features, not all of these features are essential to the invention, and the features may be combined in any way. Furthermore, in the attached drawings, identical or similar configurations are given the same reference numerals, and redundant descriptions are omitted.

[0012] <First Embodiment> Figure 1 shows the configuration of the light source device 10 in the first embodiment. The light source device 10 may include an element array section 3 in which a plurality of light-emitting elements 1 are arranged in a matrix, a power supply 4, and a control unit 7. Each of the plurality of light-emitting elements 1 is composed of an LED. The amount of light emitted from the element array section 3 in this embodiment is variable.

[0013] Since a single light-emitting element 1 has less radiant energy than a mercury lamp, it is necessary to use multiple light-emitting elements 1. The multiple light-emitting elements 1 are arranged in a matrix. The number of light-emitting elements 1 can be, for example, around 1000, but this invention is not limited to a specific number. In Figure 1, for convenience, the multiple light-emitting elements 1 are arranged to form a 6x6 matrix. Here, the horizontal direction is the row and the vertical direction is the column. In Figure 1, the multiple light-emitting elements 1 are arranged in a square grid, but this is not limited to this, and they may be arranged in a staggered pattern, for example. Each of the multiple light-emitting elements 1 may be a UV-LED element that emits ultraviolet light. When each of the multiple light-emitting elements 1 is a UV-LED element, the nominal emission peak wavelengths are, for example, 365 nm, 385 nm, 405 nm, etc.

[0014] Multiple light-emitting elements 1 are interconnected by conductors 2 to form a circuit. In the example shown in Figure 1, the light-emitting elements 1 in each row are connected in series by conductors 2, and each row is connected in parallel to the power supply 4. By passing current through the circuit, light is emitted from each of the multiple light-emitting elements 1. In the example shown in Figure 1, current is supplied from the power supply 4 to the light-emitting elements 1 in each column via conductors 2, causing each light-emitting element 1 to emit light. At this time, each of the multiple light-emitting elements 1 may generate heat. The package type of the element array 3 with this configuration is generally called Chip On Board (COB). COB is advantageous because it can integrate many light-emitting elements (LED chips), thus enabling the acquisition of a large amount of light.

[0015] The control unit 7 may consist of a general-purpose or dedicated computer with a program installed, or a combination of all or part thereof. The control unit 7 may include, for example, a processor 8 and a memory unit 9. The processor 8 determines the current value to flow through each row of the element array 3 and drives the power supply 4. In the configuration of Figure 1, the power supply 4 cannot drive the multiple light-emitting elements 1 of the element array 3 individually, but it can drive them to light up row by row.

[0016] LEDs used as light-emitting elements have a temperature dependence in which the peak wavelength or dominant wavelength of light emitted from the LED changes depending on the element temperature of the LED. Multiple light-emitting elements 1 may include a first light-emitting element A, a second light-emitting element B, and a third light-emitting element C, each having different temperature characteristics (temperature-peak wavelength characteristics) that show the relationship between element temperature and peak wavelength. Figure 2 is a graph showing the temperature-peak wavelength characteristics of the first light-emitting element A, the second light-emitting element B, and the third light-emitting element C. In Figure 2, the horizontal axis represents the temperature of the light-emitting element (LED), and the vertical axis represents the peak wavelength of the light-emitting element. According to Figure 2, the peak wavelengths of the first light-emitting element A, the second light-emitting element B, and the third light-emitting element C at a reference temperature (e.g., 23°C) are λA, λB, and λC, respectively.

[0017] Referring to FIG. 3, an arrangement example of the first light-emitting element A, the second light-emitting element B, and the third light-emitting element C in the element array unit 3 is shown. FIG. 3 is a diagram schematically showing the light-emitting surface in the element array unit 3. The element array unit 3 may have a central region 31 including the center of the light-emitting surface of the element array unit 3, a first outer peripheral region 32 surrounding the central region 31, and a second outer peripheral region 33 surrounding the first outer peripheral region 32. The second outer peripheral region 33 is located at the outermost periphery of the element array unit 3. Note that, without distinguishing between the first outer peripheral region 32 and the second outer peripheral region 33, only one outer peripheral region surrounding the central region 31 may be defined. Also, the first outer peripheral region 32 may be further divided into a plurality of regions.

[0018] According to the characteristics shown in FIG. 2, when current is flowing through the first light-emitting element A, the second light-emitting element B, and the third light-emitting element C (during energization), the temperatures (average temperatures) of the first light-emitting element A, the second light-emitting element B, and the third light-emitting element C are TA, TB, and TC, respectively. However, TA < TB < TC. In other words, when the temperatures of the first light-emitting element A, the second light-emitting element B, and the third light-emitting element C are TA, TB, and TC, respectively, when current is flowing, the wavelengths of the light output from the first light-emitting element A, the second light-emitting element B, and the third light-emitting element C become the same.

[0019] In the element array unit 3 in which light-emitting elements are integrated, the temperature tends to be higher in a region where the number of surrounded heat-generating bodies (light-emitting elements) is larger. For example, the central region 31 has a higher temperature than the first outer peripheral region 32, and the first outer peripheral region 32 has a higher temperature than the second outer peripheral region 33. Thus, unevenness in temperature occurs in the element array unit 3, which may cause unevenness in wavelength among the plurality of light-emitting elements.

[0020] Therefore, in the present embodiment, the light-emitting elements are arranged according to the temperature unevenness in the element array unit 3. That is, the light-emitting element having a long peak wavelength at the reference temperature is arranged in the region where the temperature is low, and the light-emitting element having a short peak wavelength at the reference temperature is arranged in the region where the temperature is high. Specifically, as shown in FIG. 3, the first light-emitting element A having a peak wavelength of λA at the reference temperature is arranged in the second outer peripheral region 33. Further, the second light-emitting element B having a peak wavelength of λB at the reference temperature is arranged in the first outer peripheral region 32. Furthermore, the third light-emitting element C having a peak wavelength of λC at the reference temperature is arranged in the central region 31. Thereby, the peak wavelengths at the time of energization of the first light-emitting element A, the second light-emitting element B, and the third light-emitting element C can be made to coincide.

[0021] As described above, in the above example, among the first light-emitting element A, the second light-emitting element B, and the third light-emitting element C, the third light-emitting element C having the shortest peak wavelength at the reference temperature is arranged in the central region 31. Further, the second light-emitting element B having the next shortest peak wavelength at the reference temperature is arranged in the first outer peripheral region 32, and the first light-emitting element A having the longest peak wavelength at the reference temperature is arranged in the second outer peripheral region 33.

[0022] When the first light-emitting element A, the second light-emitting element B, and the third light-emitting element C are UV-LEDs, it is preferably set so that they have temperature-wavelength characteristics such that the peak wavelengths at the time of energization fall within a predetermined allowable range (for example, within 366 ± 2 nm). Alternatively, it is more preferable that the predetermined allowable range is, for example, within 366 ± 1 nm.

[0023] In the above example, the case where the plurality of light-emitting elements 1 include three types of light-emitting elements having different temperature characteristics has been described. On the other hand, when the plurality of light-emitting elements 1 have only two types of light-emitting elements (for example, the first light-emitting element A and the second light-emitting element B) having different temperature characteristics, the first outer peripheral region 32 and the second outer peripheral region 33 are not distinguished, and only the central region and the outer peripheral region are defined. In this case, among the first light-emitting element A and the second light-emitting element B, the one having the shorter peak wavelength at the reference temperature is arranged in the central region, and the other is arranged in the outer peripheral region.

[0024] With the above configuration, even when there are temperature variations within the element array section 3 during power supply, wavelength variations between multiple light-emitting elements can be reduced.

[0025] <Second Embodiment> Figure 4 shows the configuration of the element array section 3 in the second embodiment. Figure 4(a) is a schematic cross-sectional view of the element array section 3 as seen from the x direction, and Figure 4(b) is a schematic view of the element array section 3 as seen from the z direction. Multiple light-emitting elements 1 are arranged in a matrix in the XY direction on the base 21.

[0026] The light emitted from multiple light-emitting elements 1 has an emission angle of approximately 60-70° in half-angles. Considering that the numerical aperture NA of a typical projection optical system for flat panel displays is approximately 0.1 (equivalent to approximately 5.7° in angle), this represents a very large angular distribution. Therefore, in order to capture the radiated light beams from the multiple light-emitting elements 1 without loss in the downstream optical system, a light-collecting unit 23 that collimates the radiated light beams can be placed directly above each of the multiple light-emitting elements 1. The light-collecting unit 23 is equipped with collimating lenses corresponding to the light-emitting elements 1. In Figure 4(b), the intersections of the dashed lines represent the optical axes of each collimating lens included in the light-collecting unit 23.

[0027] In UV-LED elements, only about 30-50% of the power input can be used as desired light, and the rest is converted into heat. Therefore, a cooler 24 is provided to suppress temperature changes in the multiple light-emitting elements 1. The cooler 24 is, for example, a liquid-cooled heat sink. In this case, the cooler 24 is arranged to pass near each of the multiple light-emitting elements 1 and has a heat sink channel through which a refrigerant flows. A refrigerant adjusted to a predetermined temperature is supplied from a supply unit 25 to the heat sink channel. As the refrigerant flows through the heat sink channel, it absorbs heat transferred from the light-emitting elements 1 via the base 21, thereby cooling the light-emitting elements 1. The refrigerant that has absorbed heat from the light-emitting elements 1 is recovered via a recovery unit 26. The recovered refrigerant is cooled in an adjustment unit (not shown) and supplied back to the cooler 24.

[0028] Parameters related to cooling (cooling conditions) include the flow rate of the refrigerant and the temperature of the refrigerant. Increasing the flow rate of the refrigerant and lowering the temperature of the refrigerant improves cooling performance and allows for the removal of more heat from the light-emitting element 1. Generally, the temperature of the refrigerant can be set to near the ambient temperature (room temperature) of the light source device 10. Since the room temperature of a cleanroom for semiconductor and FPD manufacturing is generally around 22-24°C, temperatures within this temperature range can be considered the ambient temperature or room temperature.

[0029] Figure 5 shows an example of a heat sink channel 41 that constitutes the cooler 24. The heat sink channel 41 is arranged to meander near each of the multiple light-emitting elements 1, for example, from the upper left position to the lower left position of the element array section 3. One end of the heat sink channel 41 at the upper left position of the element array section 3 is fluidly connected to the supply section 25, and the other end of the heat sink channel 41 at the lower left position of the element array section 3 is fluidly connected to the recovery section 26. In the heat sink channel 41 shown in Figure 5, the region in the top two rows of the 6x6 matrix of the multiple light-emitting elements 1 is defined as the upstream region 51, the region in the bottom two rows is defined as the downstream region 53, and the region in the two intermediate rows between the upstream and downstream regions is defined as the middle region 52. Note that the middle region 52 may be omitted, and only the upstream region 51 and the downstream region 53 may be defined. The temperature of the refrigerant flowing through the heat sink channel 41 increases as it moves from the upstream region 51 to the middle region 52 and then to the downstream region 53.

[0030] According to the characteristics shown in Figure 2, the temperature of the first light-emitting element A is TA when energized, the temperature of the second light-emitting element B is TB (higher than TA), and the temperature of the third light-emitting element C is TC (higher than TB). Therefore, in the second embodiment, as shown in Figure 5, the first light-emitting element A, whose peak wavelength at the reference temperature is λA, is placed in the upstream region 51. The second light-emitting element B, whose peak wavelength at the reference temperature is λB, is placed in the midstream region 52. Furthermore, the third light-emitting element C, whose peak wavelength at the reference temperature is λC, is placed in the downstream region 53. This makes it possible to match the peak wavelengths of the first light-emitting element A, the second light-emitting element B, and the third light-emitting element C when energized.

[0031] Thus, in the above example, among the first light-emitting element A, the second light-emitting element B, and the third light-emitting element B, the one with the longest peak wavelength at the reference temperature is placed in the upstream region of the flow path, the one with the next longest peak wavelength is placed in the middle region of the flow path, and the one with the shortest peak wavelength is placed in the downstream region of the flow path.

[0032] The above example described a case where multiple light-emitting elements 1 include three types of light-emitting elements with different temperature characteristics. In contrast, if multiple light-emitting elements 1 have only two types of light-emitting elements with different temperature characteristics (for example, a first light-emitting element A and a second light-emitting element B), the matrix of multiple light-emitting elements 1 will define only two watershed regions: an upstream region and a downstream region. In this case, one of the first light-emitting element A and the second light-emitting element B, which has a longer peak wavelength at the reference temperature, is placed on the upstream side of the flow path, and the other is placed on the downstream side of the flow path.

[0033] With the above configuration, even when there are temperature variations within the element array 3 due to temperature changes in the refrigerant, wavelength variations between multiple light-emitting elements can be reduced.

[0034] <Third Embodiment> Figure 6 shows the configuration of an exposure apparatus 400 according to the third embodiment. The exposure apparatus 400 is an exposure apparatus using the light source device 10 in the first or second embodiment described above. The exposure apparatus 400 may include, for example, a light source device 10, a shutter device 420, an illumination optical system 430, a master plate holder 440, a projection optical system 450, and a substrate holder 460. The illumination optical system 430 may include an i-line band filter 432. The master plate holder 440 holds the master plate 442. The master plate holder 440 is positioned by a master plate positioning mechanism (not shown), thereby positioning the master plate 442. The substrate holder 460 holds the substrate 462. The exposure apparatus 400 is supplied with a substrate 462 coated with resist (photosensitive material) by a resist coating device. The substrate holder 460 is positioned by a substrate positioning mechanism (not shown), thereby positioning the substrate 462. The shutter device 420 is positioned to block the light beam in the optical path between the light source device 10 and the original plate holder 440. Blocking the light beam may also be substituted by stopping the emission of light from the LED in the light source device 10. The illumination optical system 430 illuminates the original plate 442 using light from the light source device 10. The projection optical system 450 projects the pattern of the original plate 442, illuminated by the illumination optical system 430, onto the substrate 462, thereby exposing the substrate 462. This exposure forms a latent image pattern on the resist coated on the substrate 462. The latent image pattern is developed by a developing device (not shown), thereby forming a resist pattern on the substrate 462.

[0035] Since the projection optical system 450 uses an imaging optical system, if the peak wavelengths of the multiple light-emitting elements 1 in the light source device 10 vary, the refractive index of the lens will differ depending on the wavelength, thus reducing the pattern imaging performance on the substrate 462. In addition, the i-line band filter 432 cuts the peak wavelength of the light from the light source device 10 with a wavelength width matched to the lens performance, so if wavelength unevenness occurs within the light source device, the peak wavelength of the composite light will broaden, and the illuminance will decrease. For example, if the half-width of the i-line band filter 432 is 10 nm, a wavelength drift of 1 nm will cause about 10% of the light to be cut off.

[0036] In order to avoid degrading the imaging performance of the projection optical system 450, it is preferable that the wavelength variation of the multiple light-emitting elements 1 in the light source device is ±1 nm or less. Furthermore, since the light source device 10 uses LEDs as a replacement for a UV lamp, in the optical system designed for a UV lamp, it is preferable that the wavelength when energized falls within the range of 366 nm ± 1 nm, taking into account the wavelength of the UV lamp.

[0037] As described above, by using the light source device of the first or second embodiment in the exposure apparatus, good resolution and illuminance can be achieved.

[0038] <Embodiment of Article Manufacturing Method> The article manufacturing method according to an embodiment of the present invention is suitable for manufacturing articles such as microdevices, semiconductor devices, and elements having a microstructure. The article manufacturing method of this embodiment includes the steps of forming a latent image pattern on a photosensitive agent coated on a substrate using the above-described exposure apparatus (a step of exposing the substrate) and developing the substrate on which the latent image pattern was formed in the above step. Furthermore, this manufacturing method includes other well-known steps (oxidation, film formation, vapor deposition, doping, planarization, etching, resist stripping, dicing, bonding, packaging, etc.). The article manufacturing method of this embodiment is advantageous over conventional methods in at least one of the performance, quality, productivity, and production cost of the article.

[0039] The disclosures herein include at least the following technologies: (Item 1) It has an element array section in which multiple light-emitting elements are arranged, The plurality of light-emitting elements are First light-emitting element, A second light-emitting element has a temperature characteristic that shows the relationship between element temperature and peak wavelength, which is different from that of the first light-emitting element, Includes, The first light-emitting element and the second light-emitting element are arranged according to the temperature unevenness in the element array. A light source device characterized by the following features. (Item 2) The element array portion has a central region including the center of the light-emitting surface of the element array portion, and an outer peripheral region surrounding the central region. Of the first and second light-emitting elements, the one with the shorter peak wavelength at the reference temperature is placed in the central region, and the other is placed in the outer peripheral region. A light source device as described in item 1, characterized by the features described herein. (Item 3) The plurality of light-emitting elements further include a third light-emitting element whose temperature characteristics differ from those of the first and second light-emitting elements. The element array portion has a central region including the center of the light-emitting surface of the element array portion, a first outer peripheral region surrounding the central region, and a second outer peripheral region surrounding the first outer peripheral region. Of the first, second, and third light-emitting elements, the one with the shortest peak wavelength at the reference temperature is placed in the central region, the one with the next shortest peak wavelength at the reference temperature is placed in the first outer region, and the one with the longest peak wavelength at the reference temperature is placed in the second outer region. A light source device as described in item 1, characterized by the features described herein. (Item 4) The present invention further includes a cooler having a flow path through which a refrigerant flows, which is arranged to pass near each of the aforementioned plurality of light-emitting elements. Of the first and second light-emitting elements, the one with the longer peak wavelength at the reference temperature is placed on the upstream side of the flow path, and the other is placed on the downstream side of the flow path. A light source device as described in item 1, characterized by the features described herein. (Item 5) The present invention further includes a cooler having a flow path through which a refrigerant flows, which is arranged to pass near each of the aforementioned plurality of light-emitting elements. The plurality of light-emitting elements further include a third light-emitting element whose temperature characteristics differ from those of the first and second light-emitting elements. Of the first, second, and third light-emitting elements, the one with the longest peak wavelength at a reference temperature is placed in the upstream region of the flow path, the one with the next longest peak wavelength at a reference temperature is placed in the middle region of the flow path, and the one with the shortest peak wavelength at a reference temperature is placed in the downstream region of the flow path. A light source device as described in item 1, characterized by the features described herein. (Item 6) The light source device according to any one of items 1 to 5, characterized in that, with the first light-emitting element and the second light-emitting element arranged according to the temperature unevenness in the element array, the difference between the peak wavelength of the first light-emitting element and the peak wavelength of the second light-emitting element when energized is within a predetermined allowable range. (Item 7) Each of the plurality of light-emitting elements is a UV-LED element that emits ultraviolet light, The light source device according to item 6, characterized in that the predetermined tolerance range is within 366 ± 2 nm. (Item 8) The light source device according to item 7, characterized in that the predetermined tolerance range is within 366 ± 1 nm. (Item 9) An illumination optical system that illuminates the original plate with light from a light source device described in any one of items 1 to 8, A projection optical system that projects the pattern of the original plate illuminated by the illumination optical system onto a substrate, An exposure apparatus characterized by having the following features. (Item 10) The process of exposing the substrate using the exposure apparatus described in item 9, The process of developing the exposed substrate, A method for manufacturing an article, characterized by including a developed substrate and manufacturing an article from the developed substrate.

[0040] The invention is not limited to the embodiments described above, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, claims are attached to disclose the scope of the invention. [Explanation of symbols]

[0041] 10: Light source device, 1: Light-emitting element, 2: Conductor, 3: Element array section, 4: Power supply, 7: Control section

Claims

1. It has an element array section in which multiple light-emitting elements are arranged, The plurality of light-emitting elements are First light-emitting element, A second light-emitting element has a temperature characteristic that shows the relationship between element temperature and peak wavelength, which is different from that of the first light-emitting element, Includes, The first light-emitting element and the second light-emitting element are arranged according to the temperature unevenness in the element array. A light source device characterized by the following features.

2. The element array portion has a central region including the center of the light-emitting surface of the element array portion, and an outer peripheral region surrounding the central region. Of the first and second light-emitting elements, the one with the shorter peak wavelength at the reference temperature is placed in the central region, and the other is placed in the outer peripheral region. The light source device according to feature 1.

3. The plurality of light-emitting elements further include a third light-emitting element whose temperature characteristics differ from those of the first and second light-emitting elements. The element array portion has a central region including the center of the light-emitting surface of the element array portion, a first outer peripheral region surrounding the central region, and a second outer peripheral region surrounding the first outer peripheral region. Of the first, second, and third light-emitting elements, the one with the shortest peak wavelength at the reference temperature is placed in the central region, the one with the next shortest peak wavelength at the reference temperature is placed in the first outer region, and the one with the longest peak wavelength at the reference temperature is placed in the second outer region. The light source device according to feature 1.

4. The present invention further includes a cooler having a flow path through which a refrigerant flows, which is arranged to pass near each of the aforementioned plurality of light-emitting elements. Of the first and second light-emitting elements, the one with the longer peak wavelength at the reference temperature is placed on the upstream side of the flow path, and the other is placed on the downstream side of the flow path. The light source device according to feature 1.

5. The present invention further includes a cooler having a flow path through which a refrigerant flows, which is arranged to pass near each of the aforementioned plurality of light-emitting elements. The plurality of light-emitting elements further include a third light-emitting element whose temperature characteristics differ from those of the first and second light-emitting elements. Of the first, second, and third light-emitting elements, the one with the longest peak wavelength at a reference temperature is placed in the upstream region of the flow path, the one with the next longest peak wavelength at a reference temperature is placed in the middle region of the flow path, and the one with the shortest peak wavelength at a reference temperature is placed in the downstream region of the flow path. The light source device according to feature 1.

6. The light source device according to claim 1, characterized in that, with the first light-emitting element and the second light-emitting element arranged according to the temperature unevenness in the element array, the difference between the peak wavelength of the first light-emitting element and the peak wavelength of the second light-emitting element when energized is within a predetermined allowable range.

7. Each of the aforementioned plurality of light-emitting elements is a UV-LED element that emits ultraviolet light, The light source device according to claim 6, characterized in that the predetermined allowable range is within 366 ± 2 nm.

8. The light source device according to claim 7, characterized in that the predetermined allowable range is within 366 ± 1 nm.

9. An illumination optical system for illuminating a master plate with light from a light source device according to any one of claims 1 to 8, A projection optical system that projects the pattern of the original plate illuminated by the illumination optical system onto a substrate, An exposure apparatus characterized by having the following features.

10. A step of exposing a substrate using the exposure apparatus described in claim 9, The process of developing the exposed substrate, A method for manufacturing an article, characterized by including a developed substrate and manufacturing an article from the developed substrate.

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