Light source device, exposure device, and method for producing article

Abstract

To provide a light source device advantageous for obtaining a desired amount of light.SOLUTION: On a substrate, there are a first group of LEDs and a second group of LEDs, each connected in series, along with a connector that supplies current to the multiple LEDs. The first group of LEDs includes the first LED, which has the highest potential among the first group of LEDs, and the second LED, which has the lowest potential among the first group of LEDs. The second group of LEDs includes the third LED, which has the lowest potential among the second group of LEDs, and the fourth LED, which has the highest potential among the second group of LEDs. The first and the second groups of LEDs are arranged so that the series circuit bends back on the side opposite to the connector, with the second LED and the third LED arranged to be adjacent or the first LED and the fourth LED arranged to be adjacent. The distance between the first group of LEDs and the second group of LEDs is shorter than the distance between the first LED and the second LED.SELECTED DRAWING: Figure 3

Description

Technical Field

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

Background Art

[0002] An exposure device is a device that transfers a pattern of a master (reticle or mask) to a photosensitive substrate (such as a wafer or glass plate having a resist layer formed on its surface) through a projection optical system in a lithography process, which is a manufacturing process for semiconductor devices, liquid crystal display devices, and the like. For example, in a projection exposure device that transfers a pattern to a liquid crystal display device, in recent years, it has been required to perform batch exposure of a larger area pattern on the mask onto the substrate. In order to meet this requirement, a step-and-scan type scanning projection exposure device that can obtain high resolution and expose a large screen has been proposed. This scanning exposure device transfers a pattern illuminated by a slit light beam onto a substrate by a scanning operation through a projection optical system.

[0003] As a light source of an exposure device, for example, a mercury lamp has been used. In recent years, however, it has been expected to replace the mercury lamp with a light emitting diode (LED), which is a solid light emitting element. Since the time until the light output stabilizes after passing an electric current through a substrate circuit that controls light emission of an LED is short and it is not necessary to emit light constantly like a mercury lamp, the LED has advantages of energy saving and long life.

[0004] In order to use an LED as a light source for an exposure device, for example, it is necessary to arrange several thousand LEDs on a substrate and superimpose the light from each LED. However, when there is a potential difference between adjacent LEDs, it is necessary to separate the LEDs according to the potential difference, which causes the substrate to become larger. Patent Document 1 discloses that by devising the arrangement of electric elements (resistive elements), the resistive elements can be arranged so that the substrate size does not increase.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-207381 [Summary of the Invention] [Problems to be Solved by the Invention]

[0006] When forming a plurality of series circuits of LEDs, by arranging the series circuits so as to be bent (for example, in a U-shape), the LEDs connected to the power supply at one end of the substrate can be grouped together. However, it is necessary to space the distances between the U-shaped circuits according to the potential difference between adjacent LEDs. Also, although increasing the pattern width of the LED circuit can increase the amount of current flowing through the LEDs, due to the above circumstances, it may become difficult to design a wide pattern width.

[0007] Therefore, an object of the present invention is to provide a light source device that is advantageous in obtaining a desired light amount. [Means for Solving the Problems]

[0008] In order to achieve the above object, a light source device according to one aspect of the present invention is a light source device having, on a substrate, a first LED group and a second LED group in which a plurality of LEDs are respectively connected in series, and a connector that supplies current to the plurality of LEDs, wherein the first LED group includes a first LED having the highest potential among the first LED group and a second LED having the lowest potential among the first LED group, the second LED group includes a third LED having the lowest potential among the second LED group and a fourth LED having the highest potential among the second LED group, the first LED group and the second LED group are arranged such that the series circuits are folded back on the side opposite to the connector, the second LED and the third LED are arranged adjacent to each other, or the first LED and the fourth LED are arranged adjacent to each other, and the distance between the first LED group and the second LED group is shorter than the distance between the first LED and the second LED.

Advantages of the Invention

[0009] According to the present invention, a light source device advantageous for obtaining a desired amount of light can be provided.

Brief Description of the Drawings

[0010]

Figure 1

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Figure 8

Embodiments for Carrying Out the Invention

[0011] Hereinafter, preferred embodiments of the present invention will be described in detail based on the accompanying drawings. In each figure, the same members are denoted by the same reference numerals, and redundant explanations are omitted.

[0012] <First Embodiment> Hereinafter, preferred embodiments of the present invention will be described in detail based on the accompanying drawings. In each figure, the same members are denoted by the same reference numerals, and redundant explanations are omitted. Further, in the following embodiments, it is described on the premise that it is a light source device applied to the light source of the exposure apparatus 100, but it is not limited thereto, and it may be applied to other light source devices for general illumination or the like.

[0013] FIG. 1 is a schematic diagram showing the configuration of an exposure apparatus 100. The exposure apparatus 100 is a lithography apparatus that illuminates a mask (original plate) M with light including a plurality of wavelength regions and transfers the pattern of the mask M onto a plate (substrate) P. The exposure apparatus 100 is an apparatus for manufacturing flat panel displays, semiconductor elements, MEMS (Micro Electro Mechanical Systems), and the like.

[0014] The exposure apparatus 100 includes an illumination optical system 55 that illuminates the mask M, which is the surface to be illuminated, with light from a light source, and a projection optical system 101 that projects an image of the pattern formed on the mask M onto the plate P. Further, the exposure apparatus 100 includes a mask stage 37 that holds, drives, or positions the mask M, a plate stage 38 that holds, drives, or positions the plate P, and a main control unit 39. The mask M is disposed on the object plane of the projection optical system 101, and the plate P is disposed on the image plane of the projection optical system 101, which is optically conjugate to the object plane.

[0015] The exposure light emitted from the illumination optical system 55 passes through the mask M and is projected onto the plate P via the projection optical system 101. The projection optical system 101 includes a trapezoidal mirror 32, a concave mirror 34, and a convex mirror 36.

[0016] FIG. 2 is a schematic diagram of the illumination optical system 55 in the exposure apparatus 100. The illumination optical system 55 includes a light source device 50, a relay lens 51, an optical integrator 52 that equalizes light, and a condenser lens optical system 53. The illumination optical system 55 superimposes the light from the light source device 50 near the position where the exit surface of the following fly-eye lens is disposed on the pupil plane of the illumination optical system 55, and forms a desired light intensity distribution on the pupil plane.

[0017] The light emitted from the light source device 50 is condensed by the relay lens 51 and irradiated onto the optical integrator 52. In terms of the positional relationship, the emission surface of the light source device 50 is positioned near the front focal position of the relay lens 51, and the incident surface of the optical integrator 52 is positioned near the rear focal position of the relay lens 51. The optical integrator 52 is, for example, a fly-eye lens and can be composed of a number of identical lens elements. The optical integrator 52 divides the wavefront of the light on the incident surface and forms a multiple light source image of the light source device 50 on its emission surface. In other words, an optical image of the light source device 50 is formed on each incident surface of the numerous lens elements that make up the optical integrator 52, which serves as a secondary light source and controls the angular distribution of the light irradiating the mask M. Then, the light transmitted through the optical integrator 52 is condensed by the condenser lens optical system 53 and irradiated onto the mask M. The optical integrator 52 may be a rod integrator.

[0018] Next, the light source device in this embodiment will be described. FIG. 3 is a circuit diagram showing the configuration of the light source device 50. The light source device 50 may include a substrate 20, a plurality of LEDs including LEDs 3 to 6, a connector 7, and wirings 8 to 11. The connector 7 is connected to a power source (not shown), and current is supplied from the power source to the LED group through the connector 7.

[0019] A plurality of LEDs are mounted on the substrate 20, and the LEDs are connected and mounted by wirings with a wiring pattern width F for passing current between the LEDs. A plurality of LEDs connected in series by the wirings are regarded as one LED group, and a first LED group 1 and a second LED group 2 are formed.

[0020] Among the LEDs in the first LED group 1, the LED 3 (the first LED) with the highest potential and the LED 4 (the second LED) with the lowest potential are arranged so as to be close to the connector 7. Also, among the LEDs in the second LED group 2, the LED 5 (the third LED) with the lowest potential and the LED 6 (the fourth LED) with the highest potential are arranged so as to be close to the connector 7. For example, the potentials of the LED 3 and the LED 6 can be 70 V, and the potentials of the LED 4 and the LED 5 can be 0 V. The first LED group 1 and the second LED group 2 can each be independently controlled in terms of the current amount (light emission amount). Since the potential difference between the LED 4 and the LED 5 is 0, the LED 4 and the LED 5 can be arranged at a distance B shorter than the distance D. For example, the distance B is less than or equal to half of the distance D, more preferably less than or equal to 1 / 4.

[0021] The first LED group 1 and the second LED group 2 are arranged in a folded-back manner, and each LED group is formed in a U-shape. Also, as shown in FIG. 3, the LED 4 (the second LED) and the LED 5 (the third LED) are arranged adjacent to each other. Alternatively, the LED 3 (the first LED) and the LED 6 (the fourth LED) are arranged adjacent to each other. Hereinafter, it will be described assuming that the LED 4 (the second LED) and the LED 5 (the third LED) are adjacent to each other as shown in FIG. 3.

[0022] Here, the distance between the wiring 9 (the second wiring) connected to the LED 4 (the second LED) and the wiring 10 (the third wiring) connected to the LED 5 (the third LED) is defined as the distance B. That is, the distance between the first LED group 1 and the second LED group 2 is B. Also, the distance between the LED 3 (the first LED) and the LED 4 (the second LED), or the distance between the LED 5 (the third LED) and the LED 6 (the fourth LED) is defined as the distance D.

[0023] In this embodiment, the first LED group 1 and the second LED group 2 are arranged such that the distance B is shorter than the distance D. The distance D is equal to or greater than the minimum distance determined by the potential difference between the LED with the highest potential and the LED with the lowest potential within the LED group. The pattern width F of the wiring can be equal to or greater than the diameter of the chip size of the LED in order to allow a large current to flow. Also, if the pattern width F is too large, many LEDs cannot be arranged, so the pattern width F can be equal to or less than 1.5 times the chip size of the LED.

[0024] The distance E between the center position of the distance D of the first LED group 1 and the center position of the distance D of the second LED group can be expressed as "E = D + 2×F + B". By arranging the LEDs such that the distance B is shorter than the distance D, the pattern width of the wiring can be increased without changing the substrate size. As a result, a large current can flow, and the light output of the light source device can be improved.

[0025] Note that the LED may be in a form in which the chip is directly mounted, or in a form in which a packaged one is mounted. The arrangement of the LEDs within the LED group may be at equal intervals or at unequal intervals. In this embodiment, an example in which one LED group is composed of four LEDs has been described, but a different number may be used. In this embodiment, an example in which the light source device is composed of two LED groups has been described, but a different number of LED groups may be used.

[0026] Also, in FIG. 3, an example in which the LED group is in a U shape has been described, but the present invention is not limited to this. FIGS. 4 and 5 are diagrams showing modified examples of the light source device 50 in the present embodiment. The LED group may be in a U shape as shown in FIG. 4, or in a V shape as shown in FIG. 5. That is, any configuration in which the LED group is folded back on the side opposite to the connector 7 is acceptable.

[0027] <Second Embodiment> In this embodiment, a light source device having a circuit different from that of the first embodiment will be described. Note that matters not mentioned in this embodiment follow the first embodiment.

[0028] The light source device in this embodiment will be described. FIG. 6 is a circuit diagram showing the configuration of the light source device 60. The light source device 60 may include a substrate 20, a plurality of LEDs including LEDs 12 to 19, a connector 7, and a plurality of wirings.

[0029] A plurality of LEDs are mounted on the substrate 20, and the LEDs are connected and mounted by wirings with a pattern width F for passing current between the LEDs. A plurality of LEDs connected in series by the wirings are regarded as one LED group, and a first LED group 1 and a second LED group 2 are formed.

[0030] In this embodiment, for example, the potentials of LED 12 (the first LED) and LED 19 (the fourth LED) may be 140 V, and the potentials of LED 15 (the second LED) and LED 16 (the third LED) may be 0 V. The first LED group 1 and the second LED group 2 can be independently controlled in terms of the amount of current (luminous amount). Since the potential difference between LED 15 and LED 16 is 0, LED 15 and LED 16 can be arranged at a distance B shorter than the distance D.

[0031] In this embodiment, the first LED group 1 and the second LED group 2 are arranged such that the distance B is shorter than the distance D. The distance D is equal to or greater than the minimum distance determined by the potential difference between the LED with the highest potential and the LED with the lowest potential in the LED group. The pattern width F may be equal to or greater than the LED chip size. The distance E between the center position of the distance D of the first LED group 1 and the center position of the distance D of the second LED group can be expressed as "E = D + 2 × F + B". By arranging the LEDs such that the distance B is shorter than the distance D, the pattern width can be increased without changing the substrate size. As a result, more current can flow, and the light output of the light source device can be improved.

[0032] <Third Embodiment> In this embodiment, the light source device 70 may further include a heat sink 30. Also, in this embodiment, the light source device 70 may further include a control unit 31. FIG. 7 is a diagram showing the configuration of the light source device 70 in this embodiment.

[0033] The heat sink 30 cools the substrate 20 by means of a refrigerant flowing inside. It is desirable to use a heat sink 30 with high thermal conductivity in order to efficiently recover heat. For example, copper or aluminum can be used.

[0034] The control unit 31 controls each part of the light source device 70. The control unit 31 can control the current amount (light emission amount) for each LED group. Further, the control unit 31 can control the cooling capacity by the heat sink 30.

[0035] <Embodiment of a method for manufacturing an article> The method for manufacturing an article according to an embodiment of the present invention is suitable for manufacturing articles such as flat panel displays (FPDs), semiconductor devices, sensors, and optical elements, for example. FIG. 8 is a flowchart of the method for manufacturing an article according to the present embodiment. The method for manufacturing an article according to the present embodiment includes a step of forming a latent image pattern by exposure with the above-described exposure apparatus 100 on a photosensitive material applied on a substrate to obtain an exposed substrate (exposure step, step S11). Further, the method includes a step of developing the substrate exposed in such a step to obtain a developed substrate (development step, step S12). Furthermore, such a manufacturing method includes other well-known steps (oxidation, film formation, vapor deposition, doping, planarization, etching, resist stripping, dicing, bonding, packaging, etc.) (processing step, step S13). The method for manufacturing an article according to the present embodiment is advantageous in at least one of the performance, quality, productivity, and production cost of the article as compared with the conventional method.

[0036] As described above, the preferred embodiments of the present invention have been described. Needless to say, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist thereof.

[0037] The disclosure of this specification includes at least the following light source device, exposure device, and article manufacturing method.

[0038] (Item 1) A light source device having, on a substrate, a first LED group and a second LED group in which a plurality of LEDs are respectively connected in series, and a connector for supplying current to the plurality of LEDs, The first LED group includes a first LED having the highest potential among the first LED group and a second LED having the lowest potential among the first LED group, The second LED group includes a third LED having the lowest potential among the second LED group and a fourth LED having the highest potential among the second LED group, The first LED group and the second LED group are arranged such that the series circuit is folded back on the side opposite to the connector, The second LED and the third LED are arranged adjacent to each other, or the first LED and the fourth LED are arranged adjacent to each other, The distance between the first LED group and the second LED group is shorter than the distance between the first LED and the second LED, A light source device characterized by the above.

[0039] (Item 2) The light source device according to item 1, wherein the first LED, the second LED, the third LED, and the fourth LED are connected to the connector.

[0040] (Item 3) The light source device according to item 1 or 2, wherein the distance between the first LED group and the second LED group is half or less of the distance between the first LED and the second LED.

[0041] (Item 4) The light source device according to any one of items 1 to 3, wherein the pattern width of the wiring of the first LED group and the second LED group is a length equal to or greater than the diameter of the chips of the plurality of LEDs.

[0042] (Item 5) The light source device according to item 4, wherein the pattern width is a length of 1.5 times or less the diameter of the chips of the plurality of LEDs.

[0043] (Item 6) The light source device according to any one of Items 1 to 5, further comprising a heat sink for cooling the substrate.

[0044] (Item 7) The light source device according to any one of Items 1 to 6, further comprising a control unit for controlling the amount of current flowing through the first LED group and the second LED group.

[0045] (Item 8) An illumination optical system having the light source device according to any one of Items 1 to 7, the illumination optical system superimposing the light from the light source device on the pupil plane of the illumination optical system and forming a desired light intensity distribution on the pupil plane, a relay lens for condensing the light from the light source device, an integrator for homogenizing the light that has passed through the relay lens, characterized by comprising.

[0046] (Item 9) An exposure device for illuminating a master with the light from the illumination optical system according to Item 8 and forming the pattern of the master on a substrate, having a projection optical system for projecting the light that has passed through the master onto the substrate, characterized by this.

[0047] (Item 10) An exposure step of exposing a substrate using the exposure device according to Item 9 to obtain an exposed substrate, a development step of developing the exposed substrate to obtain a developed substrate, and a method for manufacturing an article, characterized by manufacturing an article from the developed substrate.

Explanation of Reference Numerals

[0048] 1 First LED group 2 Second LED group 3, 12 LED (First LED) 4, 15 LED (Second LED) 5, 16 LED (Third LED) 6, 19 LEDs (4th LED) 20 Substrate 50, 60, 70 Light source device

Claims

1. A light source device having, on a substrate, a first LED group and a second LED group in which a plurality of LEDs are respectively connected in series, and a connector for supplying current to the plurality of LEDs, wherein the first LED group includes a first LED having the highest potential among the first LED group and a second LED having the lowest potential among the first LED group, the second LED group includes a third LED having the lowest potential among the second LED group and a fourth LED having the highest potential among the second LED group, the first LED group and the second LED group are arranged such that a series circuit is folded back on the side opposite to the connector, the second LED and the third LED are arranged adjacent to each other, or the first LED and the fourth LED are arranged adjacent to each other, a distance between the first LED group and the second LED group is shorter than a distance between the first LED and the second LED, characterized in that it is a light source device.

2. The light source device according to claim 1, wherein the first LED, the second LED, the third LED, and the fourth LED are connected to the connector.

3. The light source device according to claim 1, wherein a distance between the first LED group and the second LED group is equal to or less than half of a distance between the first LED and the second LED.

4. The light source device according to claim 1, wherein a pattern width of wirings of the first LED group and the second LED group is equal to or longer than a diameter of chips of the plurality of LEDs.

5. The light source device according to claim 4, wherein the pattern width is equal to or less than 1.5 times a diameter of chips of the plurality of LEDs.

6. The light source device according to claim 1, further comprising a heat sink for cooling the substrate.

7. The light source device according to claim 1, further comprising a control unit for controlling amounts of current flowing through the first LED group and the second LED group.

8. An illumination optical system having the light source device according to any one of claims 1 to 7, wherein light from the light source device is superimposed on a pupil plane of the illumination optical system to form a desired light intensity distribution on the pupil plane, the illumination optical system comprising: a relay lens for condensing light from the light source device; an integrator for homogenizing light that has passed through the relay lens; characterized in that it has the above.

9. An exposure apparatus that illuminates a master with light from the illumination optical system according to claim 8 and forms a pattern of the master on a substrate, having a projection optical system that projects the light that has passed through the master onto the substrate, characterized by the exposure apparatus.

10. An exposure step of exposing a substrate using the exposure apparatus according to claim 9 to obtain an exposed substrate, including a development step of developing the exposed substrate to obtain a developed substrate, characterized by a method for manufacturing an article, which manufactures an article from the developed substrate.

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