Exposure apparatus, and method for manufacturing article

Abstract

To enhance heat dissipation efficiency of heat generated by light from a light source.SOLUTION: An exposure apparatus includes: a heat dissipation member that dissipates heat; and a heat transfer member that transfers heat generated by absorbing light from a light source to the heat dissipation member, wherein, a film containing a material having a higher melting point than a material of the heat transfer member is disposed on the surface of the heat transfer member on the light source side.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a heat dissipation unit, an exposure apparatus, and a method for manufacturing an article. [Background technology]

[0002] Some exposure equipment that uses a mercury lamp as a light source uses a cold mirror to reflect the light of the wavelength used for exposure (exposure wavelength) and transmit the light of wavelengths not required for exposure (non-exposure wavelength). If the light of the non-exposure wavelengths is not collected, the temperature of the entire equipment will rise, which may cause damage to the components that make up the equipment and a decrease in exposure accuracy. For this reason, it is necessary to receive the light of the non-exposure wavelengths with a heat sink, convert it into heat, and then conduct the heat to a heat sink to dissipate it efficiently.

[0003] Furthermore, in exposure apparatuses, it is required to increase the output of the light source in order to improve productivity, but as the output of the light source increases, problems may occur in which the heat sink or heat sink melts. In Patent Document 1, the heat sink is made of a ceramic material with a high melting point, which can prevent the heat sink or heat sink from melting. Patent Document 1 also discloses that the durability of the heat sink can be improved by dividing the heat sink and arranging it so that the temperature difference inside the heat sink does not become large, compared to when the heat sink is not divided. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-205806 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, ceramic materials have a lower thermal conductivity than metals and other materials, making it difficult to efficiently conduct heat to a heat sink for dissipating heat. In addition, when a heat sink is divided and arranged, gaps are generated, which reduces thermal conductivity compared to when the heat sink is not divided. The reduced thermal conductivity reduces the efficiency of dissipating heat generated by light from the light source.

[0006] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a heat dissipation unit that is advantageous in improving the efficiency of dissipating heat generated by light from a light source. [Means for solving the problem]

[0007] In order to achieve the above-mentioned object, a heat dissipation unit as one aspect of the present invention has a heat dissipation member that dissipates heat, and a heat transfer member that transfers heat generated by absorbing light from a light source to the heat dissipation member, and is characterized in that a film containing a material having a higher melting point than the material of the heat transfer member is disposed on the surface of the heat transfer member facing the light source. Effect of the Invention

[0008] According to the present invention, it is possible to provide a heat dissipation unit that is advantageous in improving the efficiency of dissipating heat generated by light from a light source. [Brief description of the drawings]

[0009] [Figure 1] 2 is a schematic diagram showing a configuration of a heat dissipation unit in the first embodiment. FIG. [Diagram 2] FIG. 11 is a schematic diagram showing a configuration of a heat dissipation unit in a second embodiment. [Diagram 3] FIG. 11 is a schematic diagram showing a configuration of a heat dissipation unit in a third embodiment. [Figure 4] FIG. 1 is a schematic diagram showing a configuration of an exposure apparatus. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to refer to the same components, and duplicated explanations will be omitted.

[0011] First Embodiment 1 is a cross-sectional view of a heat dissipation unit 30 in this embodiment. The heat dissipation unit 30 is composed of a heat dissipation member 31 and a heat transfer member 32. The heat transfer member 32 is disposed closer to the light source 1 than the heat dissipation member 31, and is disposed in contact with the heat dissipation member 31. The heat dissipation member 31 has a function of dissipating heat generated by light 70 from the light source 1. The heat dissipation member 31 may be an air-cooled cooling mechanism or a liquid-cooled cooling mechanism. An air-cooled cooling mechanism is superior in that it can provide cooling with a simple structure, and a liquid-cooled cooling mechanism is superior in that it has a higher cooling effect than an air-cooled type.

[0012] The heat transfer member 32 is desirably made of a material with high thermal conductivity in order to efficiently conduct heat to the heat dissipation member 31. In this embodiment, the heat transfer member 32 is made of a metal with high thermal conductivity, and the heat generated by the light 70 can be efficiently transferred to the heat dissipation member 31. The thickness of the heat transfer member 32 (the length from the contact surface between the heat transfer member 32 and the heat dissipation member 31 to the surface of the heat transfer member 32 on the light source 1 side) is about 10 mm. Specific examples of materials used for the heat transfer member 32 include silver, copper, aluminum, nickel, platinum, and the like. In addition, the heat transfer member 32 can be made to have an integrated structure that is not divided or a structure that is divided to a minimum extent, thereby reducing the number of parts and the manufacturing cost.

[0013] However, when the heat transfer member 32 is made of metal, there is a risk that the heat transfer member 32 will melt due to the light 70. Furthermore, if the heat transfer member 32 melts, the light 70 may strike the heat dissipation member 31 without passing through the heat transfer member 32, causing the heat dissipation member 31 to be thermally deformed and damaged.

[0014] Furthermore, if the heat transfer member 32 is changed to a material (e.g., a ceramic-based material) with a higher melting point than metal so that the heat transfer member 32 does not melt, the thermal conductivity will be lower than when metal is used. Therefore, the temperature gradient between the area directly irradiated with the light 70 and the other areas will be large, and the heat transfer member 32 may be damaged by thermal shock due to the temperature gradient. In order to prevent such damage, a method of dividing the heat transfer member 32 and arranging it in parts is also conceivable, but in addition to using a material with a lower thermal conductivity than metal, the gaps at the boundaries of the divided parts will be factors that further reduce the heat transfer efficiency.

[0015] Therefore, in this embodiment, by disposing the film 33 on the light source side surface of the heat transfer member 32 made of a metal with high thermal conductivity, it is possible to prevent the heat transfer member 32 from melting due to heat generated by absorbing the light 70 from the light source 1. Furthermore, since the film 33 in this embodiment is made of a material having a higher melting point than the heat transfer member 32 so that the film 33 does not melt, it is possible to reduce the possibility that the film 33 will melt and the heat transfer member 32 made of metal will be directly irradiated with light from the light source 1. The film 33 may be disposed on the entire light source side surface of the heat transfer member 32, or may be disposed on a partial area that is directly irradiated with light.

[0016] The film 33 in this embodiment will be described. The film 33 is made of a material having a higher melting point than the heat transfer member 32, and is made of, for example, ceramics (alumina, zirconia, titania, chromia, yttria, magnesia, chromium oxide, the above ceramics, and composite oxides of two or more kinds). The film 33 may also be made of high-melting-point metal materials (tungsten, tantalum, molybdenum, niobium, the above metal alloys), metals and heat-resistant alloys (aluminum, stainless steel, MCrAlX alloys, nickel, Ni-based alloys, high-carbon iron-chromium, cobalt alloys, copper), etc. In the MCrAlX alloys, M is Ni, Co, NiCo, etc., and X is Y, Hf, Si, Ta, etc. By using oxides as the material of the film 33, it is possible to prevent discoloration or deterioration due to surface oxidation of the heat transfer member 32.

[0017] If the melting point of the film 33 is low, the heat transfer member 32 may melt, so it is desirable that the material of the film 33 has a melting point of 1100 degrees or more. Here, the characteristics of ceramic-based materials will be described. As a ceramic-based material, for example, alumina has a melting point of about 2050 degrees and a thermal conductivity of about 32 W / m·K. Silicon carbide ceramics has a melting point of about 2600 degrees and a thermal conductivity of about 60 W / m·K. Aluminum nitride ceramics has a melting point of about 2200 degrees and a thermal conductivity of about 150 W / m·K. Zirconia has a melting point of about 2700 degrees and a thermal conductivity of about 3 W / m·K. The above ceramic-based materials have a melting point of 1100 degrees or more. When a higher heat resistance effect is required for the film 33, it is preferable that the material has a melting point of 1800 degrees or more. On the other hand, aluminum, a metallic material, has a melting point of approximately 660°C and a thermal conductivity of approximately 237 W / m K. In this way, ceramic materials have the characteristic of having a higher melting point than aluminum, a metallic material, but a lower thermal conductivity.

[0018] In this embodiment, the thickness of the film 33 is preferably a thin layer of 1 mm or less. This is because by making the thickness of the film 33 thin, the heat transfer from the heat transfer member 32 to the heat dissipation member 31 can be efficiently performed without excessively restricting the absorption of the light 70 by the heat transfer member 32. On the other hand, if the thickness of the film 33 is too thin, the heat transfer member 32 may melt, so the thickness of the film 33 is preferably 0.01 mm or more. If higher durability is required for the film 33, the thickness is preferably 0.1 mm or more. In addition, the film 33 in this embodiment can be formed by spraying a material having a higher melting point than the heat transfer member 32 on the surface of the heat transfer member 32 on which the light 70 is incident. In surface treatment by spraying, it is difficult to form a film uniformly over the entire range to be sprayed, so there is a risk of unevenness occurring in the film 33. Therefore, it is required that the film 33 has a thickness that does not melt the heat transfer member 32 at the part where the film 33 is thinnest. The appropriate film thickness varies depending on the material used for film 33, but for example, when a ceramic film is formed by surface treatment using thermal spraying, a thickness of about 0.1 mm to 0.3 mm is typical.

[0019] Furthermore, due to the difference in linear expansion coefficient between the heat transfer member 32 and the film 33, it is expected that the film 33 will peel off from the surface of the heat transfer member 32. To prevent this, an intermediate layer (base) (not shown) may be disposed between the heat transfer member 32 and the film 33. Examples of materials used for the intermediate layer include Ni, Ni-Cr, Ni-Al, and MCrAlY (M is Ni, Co, NiCo, etc.).

[0020] As described above, in this embodiment, by disposing the film 33 made of a material having a higher melting point than the heat transfer member 32 on the surface of the heat transfer member 32 facing the light source 1, it is possible to prevent the heat transfer member 32 from melting due to heat generated by absorbing the light 70 from the light source 1. This makes it possible to improve the efficiency of dissipating heat generated by the light from the light source.

[0021] <Second embodiment> The heat dissipation unit 30 of this embodiment will be described. Matters not mentioned in this embodiment will follow those of the first embodiment. Fig. 2 is a cross-sectional view of the heat dissipation unit 30 of this embodiment. The heat dissipation unit 30 of this embodiment differs from the heat dissipation unit described in the first embodiment in that it has an intermediate member 34.

[0022] In the first embodiment, the heat dissipation unit has been described as having a configuration in which the heat dissipation member 31 and the heat transfer member 32 are in contact with each other. However, there is a risk of gaps occurring due to minute irregularities, warping, undulations, etc. on the contact surfaces between the heat dissipation member 31 and the heat transfer member 32.

[0023] Therefore, in the heat dissipation unit 30 of the present embodiment, the gap between the heat dissipation member 31 and the heat transfer member 32 is filled with an intermediate member 34, thereby making it possible to bring the heat dissipation member 31 and the heat transfer member 32 into close contact with each other. Fig. 2 is a cross-sectional view of the heat dissipation unit 30 in which the intermediate member 34 is disposed between the heat dissipation member 31 and the heat transfer member 32. The configuration of the heat dissipation unit shown in Fig. 2 improves the efficiency of heat transfer to the heat dissipation member 31 via the heat transfer member 32, whereby the heat generated by the film 33 receiving the light 70 can be improved in heat dissipation efficiency of the heat dissipation unit 30.

[0024] It is desirable that the material of the intermediate member 34 has high thermal conductivity, is soft, and has high adhesion. Examples of the material of the heat transfer member 36 include a graphite sheet, silicon grease, and paste containing metal powder.

[0025] As described above, in this embodiment, by disposing the intermediate member 34 in the gap between the heat dissipation member 31 and the heat transfer member 32, the efficiency of dissipating heat generated by light from the light source can be improved.

[0026] <Third embodiment> The heat dissipation unit 30 of this embodiment will be described. Matters not mentioned in this embodiment will follow those of the first embodiment. Fig. 3 is a cross-sectional view of the heat dissipation unit 30 of this embodiment. In the heat dissipation unit 30 of this embodiment, a heat sink 35 of an air-cooling type cooling mechanism is applied as the heat dissipation member described in the first embodiment.

[0027] FIG. 3 is a cross-sectional view of a heat dissipation unit 30 that employs a heat sink 35 as a heat dissipation member. The heat sink 35 is made of a material with high thermal conductivity, such as aluminum, gold, silver, or copper. The melting point of aluminum is about 660 degrees, and the thermal conductivity is about 237 W / m·K. The melting point of gold is about 1064 degrees, and the thermal conductivity is about 315 W / m·K. The melting point of silver is about 962 degrees, and the thermal conductivity is about 427 W / m·K. The melting point of copper is about 1083 degrees, and the thermal conductivity is about 398 W / m·K. By using a material with high thermal conductivity for the heat sink 35, the cooling efficiency of the heat generated by the light 70 is improved.

[0028] The heat sink 35 in this embodiment has an air-cooling type cooling mechanism. The heat sink 35 has an uneven surface (the surface opposite to the light source 1) that comes into contact with the air in order to increase the contact area with the air. A fan 36 that emits gas is provided to efficiently cool the heat sink 35, and the fan 36 blows the gas onto the heat sink 35. The gas blown by the fan 36 may be the gas in the atmosphere, or may be a gas different from the gas in the atmosphere. The temperature of the gas may be the same as the temperature in the atmosphere, or may be cooled.

[0029] The heat sink 35 is desirably formed with an uneven shape so that the gas discharged from the fan 36 can cool the entire heat sink 35. Specifically, it is preferable that the concave (or convex) portions of the heat sink 35 are formed along the direction in which the gas discharged from the fan 36 flows. The fan 35 may be disposed so that more gas is blown onto an area of ​​the heat sink 35 where the temperature is likely to become high (for example, the center). A plurality of fans 35 may be provided.

[0030] In this embodiment, the heat sink 35 is described as an air-cooled cooling mechanism, but a liquid-cooled cooling mechanism may be used. When a liquid-cooled cooling mechanism is used, the heat sink 35 can be cooled with higher cooling efficiency than the air-cooled type by flowing a cooling refrigerant into the inside of the heat sink 35 or in contact with the heat sink 35.

[0031] As described above, in this embodiment, by using the heat sink 35 of the air-cooling mechanism as a heat dissipation member, the cooling efficiency can be improved, and the efficiency of dissipating heat generated by light from the light source can be improved.

[0032] <Embodiments of Exposure Apparatus> In this embodiment, an example will be described in which the heat dissipation unit 30 described in the first to third embodiments is applied to an exposure apparatus. Fig. 4 is a schematic diagram of an exposure apparatus 100 having a heat dissipation unit 30. The exposure apparatus 100 has a light source 1 (e.g., a mercury lamp or a laser), an illumination optical system that illuminates an original 12 (e.g., a mask or a reticle) with light from the light source 1, and a projection optical system 14 that projects the pattern of the original 12 onto a substrate 15 (e.g., a wafer or a glass plate).

[0033] Light emitted from the light source 1 is collected by the collecting mirror 2 and enters the cold mirror 3 (optical element). The cold mirror 3 transmits the light 70 (one light) of the non-exposure wavelength not used for exposure, and reflects the light 60 (the other light) of the exposure wavelength used for exposure. The cold mirror 3 only needs to have a function of separating the light 60 of the exposure wavelength from the light 70 of the non-exposure wavelength, so it may be configured to transmit the light 60 of the exposure wavelength and reflect the light of the non-exposure wavelength. The light 70 of the non-exposure wavelength is, for example, light of a wavelength of 436 nm or more, which is the wavelength of the g-line of a mercury lamp, and the light 60 of the exposure wavelength is, for example, light of a wavelength shorter than 436 nm.

[0034] Light 70 of a non-exposure wavelength is incident on the heat dissipation unit 30 and converted into heat. The heat generated here is dissipated by the heat dissipation member 31. Since a film 33 made of a material with a high melting point is arranged on the light receiving surface of the heat dissipation unit 30, the heat dissipation unit 30 does not melt even if the light source 1 is a high-output mercury lamp. The heat dissipation unit 30 may be provided inside the exposure apparatus 100 or outside the exposure apparatus 100. In the latter case, the light 70 is guided to the outside of the exposure apparatus 100 through a window not shown.

[0035] Light 60 of the exposure wavelength reflected by the cold mirror 3 is collected by a condenser lens 5 and homogenized by an optical integrator 6, and the shape of the light illuminating the original is adjusted by an aperture 7. The light 60 of the exposure wavelength then passes through a condenser lens 8, a bending mirror 9, a masking blade 10, and an imaging lens 11 to be irradiated onto the original 12. The optical positional relationship between the original 12 and the substrate 15 is maintained as conjugate by a projection optical system 14. The original 12 is driven by an original stage 13, and the substrate 15 is driven by a substrate stage 16.

[0036] The following describes a specific configuration of the heat dissipation unit 30 suitable for use in the exposure apparatus 100. It is assumed that a mercury lamp with an output of 12 kW is used as the light source 1, and light with a wavelength of 436 nm or more is considered to be a non-exposure wavelength.

[0037] The following describes the commonly used materials for each member of the heat dissipation unit. The heat transfer member 32 is preferably a monolithic piece of oxygen-free copper (C1020). This is because oxygen-free copper has a thermal conductivity of 391 [W / (m·k)] and is a material with excellent thermal conductivity and workability. It is preferable to form an intermediate layer (bonding coat) of 50 to 100 μm on the heat transfer member 32 using MCrAlY (M is Ni, Co, NiCo), and then spray zirconia to a thickness of 200 to 300 μm to form the film 33.

[0038] It is preferable to dispose a graphite sheet, which has good adhesion and can withstand high temperatures, as an intermediate member 34 between the heat transfer member 32 and the heat dissipation member 31. The graphite sheet used has a density of, for example, 1 [g / cm 3 ], thermal conductivity in the thickness direction of 5 [W / (m·K)] or more, and linear expansion coefficient in the thickness direction of 0.0002 [ / K] should be used.

[0039] An air-cooled heat sink is used for the heat dissipation member 31, and aluminum, which has high thermal conductivity, is preferably used. A fan 36 is used to exhaust air at a volume of 4 [m3] so that air flows parallel to the convex parts of the heat sink. 3 It is preferable to perform thermal exhaust at a rate of [1 / min].

[0040] <Embodiments of the method for manufacturing an article> The method for manufacturing an article according to an embodiment of the present invention is suitable for manufacturing, for example, a flat panel display (FPD). The method for manufacturing an article according to this embodiment includes a step of forming a latent image pattern on a photosensitive agent applied on a substrate using the above-mentioned exposure apparatus (a step of exposing the substrate), and a step of developing the substrate on which the latent image pattern has been formed in this step. Furthermore, this manufacturing method includes other well-known steps (oxidation, film formation, deposition, doping, planarization, etching, resist stripping, dicing, bonding, packaging, etc.). The method for manufacturing an article according to this embodiment is advantageous in at least one of the performance, quality, productivity, and production cost of the article compared to conventional methods.

[0041] Although the preferred embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. [Explanation of symbols]

[0042] 1 light source 30 Heat dissipation unit 31 Heat dissipation materials 32 Heat transfer materials 33 membrane 70 light

Claims

1. A heat dissipation member that dissipates heat; a heat transfer member that transfers heat generated by absorbing light from a light source to the heat dissipation member, A heat dissipation unit, comprising: a film including a material having a melting point higher than that of the material of the heat transfer member, the film being disposed on a surface of the heat transfer member facing the light source.

2. The heat dissipation unit according to claim 1 , wherein the thickness of the film is 1 mm or less.

3. The heat dissipation unit according to claim 2 , wherein the thickness of the film is 0.01 mm or more.

4. 4. The heat dissipation unit according to claim 1, wherein the film is sprayed onto a surface of the heat transfer member facing the light source.

5. 5. The heat dissipation unit according to claim 1, wherein the material of the film is a ceramic material.

6. 6. The heat dissipation unit according to claim 1, wherein the material of the film has a melting point of 1100 degrees or higher.

7. 7. The heat dissipation unit according to claim 1, wherein the material of the film contains at least one of alumina, zirconia, titania, chromia, yttria, magnesia, and chromium oxide.

8. The heat dissipation unit according to any one of claims 1 to 6, characterized in that the material of the film contains at least one of tungsten, tantalum, molybdenum, niobium, aluminum, stainless steel, MCrAlX alloy, nickel, Ni-based alloy, high carbon iron chromium, cobalt alloy, and copper.

9. 9. The heat dissipation unit according to claim 1, wherein the heat transfer member is an integral structure that is not divided.

10. 10. The heat dissipation unit according to claim 1, wherein the material of the heat transfer member contains at least one of silver, copper, aluminum, nickel, and platinum.

11. 11. The heat dissipation unit according to claim 1, wherein the light has a wavelength of 436 nm or more.

12. The heat dissipation member and the heat transfer member may be filled with an intermediate member.

12. The heat dissipation unit according to claim 1, wherein the intermediate member is any one of a graphite sheet, silicon grease, and paste containing metal powder.

13. An intermediate layer is provided between the heat transfer member and the film to prevent the film from peeling off from the surface of the heat transfer member.

13. The heat dissipation unit according to claim 1, wherein the material of the intermediate layer includes at least one of Ni, Ni--Cr, Ni--Al, and MCrAlY.

14. A heat dissipation unit according to any one of claims 1 to 13; A light source; an optical element that separates the light emitted from the light source; the heat dissipation unit dissipates heat generated by absorbing one of the lights separated by the optical element; an illumination optical system for illuminating with the other light separated by the optical element;

15. An illumination optical system according to claim 14; a projection optical system for exposing a pattern of the original onto a substrate, the optical element separates the light emitted from the light source into light of an exposure wavelength and light of a non-exposure wavelength, The heat dissipation unit dissipates heat generated by absorbing the light of the non-exposure wavelengths, an illumination optical system for illuminating the original with light having the exposure wavelength;

16. the light having an exposure wavelength of less than 436 nm; 16. An exposure apparatus according to claim 15, wherein the light having a non-exposure wavelength has a wavelength of 436 nm or more.

17. an exposure step of exposing a substrate using the exposure apparatus according to claim 15 or 16; a developing step of developing the substrate exposed in the exposure step; A method for manufacturing an article, comprising the steps of: manufacturing an article from the substrate developed in the developing step;

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