Manufacturing method of heat dissipation unit, exposure device and article

Abstract

This invention provides a heat dissipation unit, an exposure apparatus, and a method for manufacturing an article. The heat dissipation unit includes: a heat dissipation member for dissipating heat; and a heat transfer member for conducting heat generated by absorbing light from a light source to the heat dissipation member, wherein a film comprising 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 on the side where the light source is located.

Description

Technical Field

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

[0002] In exposure apparatuses that use mercury lamps as a light source, there are apparatuses that reflect light of the wavelength used for exposure (exposure wavelength) using a cold mirror, and transmit light of wavelengths not needed for exposure (non-exposure wavelength) using a cold mirror. Failure to recover non-exposure wavelength light leads to an increase in the overall temperature of the apparatus, potentially causing damage to components and a reduction in exposure accuracy. Therefore, it is necessary to utilize a heat sink to receive non-exposure wavelength light, convert it into heat, and then conduct this heat to a heat sink for efficient heat dissipation.

[0003] Furthermore, in exposure apparatuses, to improve productivity, it is required to increase the output of the light source. However, as the output of the light source increases, problems such as melting of the heat sink and radiator occur. In Patent Document 1, melting of the heat sink and radiator can be prevented by constructing the heat sink with a high-melting-point ceramic-based material. In addition, Japanese Patent Application Publication No. 2010-205806 also discloses that by arranging the heat sink in sections, the internal temperature difference of the heat sink is prevented from increasing, thus improving the durability of the heat sink compared to the case where the heat sink is not sectioned.

[0004] However, because ceramic materials have lower thermal conductivity than materials such as metals, it is difficult to efficiently conduct heat to the heat sink used for heat dissipation. Furthermore, gaps are created when the heat sink is arranged in a segmented manner, resulting in reduced thermal conductivity compared to an unsegmented heat sink. This reduced thermal conductivity decreases the efficiency of dissipating heat generated by light from the light source. Summary of the Invention

[0005] Therefore, the object of the present invention is to provide a heat dissipation unit that is advantageous in improving the heat dissipation efficiency of heat generated by light from a light source.

[0006] Solution for solving the problem

[0007] To achieve the above objectives, a heat dissipation unit according to one aspect of the present invention is characterized by having: a heat dissipation member for dissipating heat; and a heat transfer member for conducting heat generated by absorbing light from a light source to the heat dissipation member, wherein a film comprising 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 on the side where the light source is located.

[0008] The effects of the invention

[0009] According to the present invention, a heat dissipation unit is provided that is advantageous in improving the heat dissipation efficiency of heat generated by light from a light source. Attached Figure Description

[0010] Figure 1 This is a schematic diagram showing the structure of the heat dissipation unit in the first embodiment.

[0011] Figure 2 This is a schematic diagram showing the structure of the heat dissipation unit in the second embodiment.

[0012] Figure 3 This is a schematic diagram showing the structure of the heat dissipation unit in the third embodiment.

[0013] Figure 4 It is a schematic diagram showing the structure of the exposure device.

[0014] Explanation of reference numerals in the attached figures

[0015] 1 Light source; 30 Heat dissipation unit; 31 Heat dissipation component; 32 Heat transfer component; 33 Film; 70 Light. Detailed Implementation

[0016] Further features of the invention will become apparent from the following description of exemplary embodiments (with reference to the accompanying drawings).

[0017] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Furthermore, in the drawings, the same reference numerals are used to label the same components, and repeated descriptions are omitted.

[0018] [First Implementation Method]

[0019] Figure 1 This is a cross-sectional view of the heat dissipation unit 30 according to 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 at a position 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 the function of dissipating heat generated by the light 70 from the light source 1. The heat dissipation member 31 can be an air-cooled cooling mechanism or a liquid-cooled cooling mechanism. Air-cooled cooling mechanisms are superior in that they can perform cooling with a simple structure, while liquid-cooled cooling mechanisms are superior in that they have a higher cooling effect compared to air-cooled mechanisms.

[0020] In order to efficiently conduct heat to the heat dissipation component 31, the heat transfer component 32 is preferably made of a material with high thermal conductivity. In this embodiment, the heat transfer component 32 is made of a metal with high thermal conductivity, which can efficiently transfer the heat generated by the light 70 to the heat dissipation component 31.

[0021] 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 approximately 10 mm. Specific materials used for the heat transfer member 32 include, for example, silver, copper, aluminum, nickel, and platinum. Furthermore, by forming the heat transfer member 32 as an integral, undivided structure or by dividing it into minimal components, the number of parts can be reduced, thereby lowering manufacturing costs.

[0022] However, if the heat transfer member 32 is made of metal, there is a possibility that the heat transfer member 32 may melt due to the light 70. In addition, if the heat transfer member 32 melts, the light 70 will not pass through the heat transfer member 32 and will instead reach the heat dissipation member 31, which may also suffer thermal deformation and thermal damage.

[0023] Furthermore, when the heat transfer member 32 is changed to a material with a higher melting point than metal (e.g., a ceramic-based material) to prevent it from melting, the thermal conductivity decreases compared to using a metal. Therefore, the temperature gradient between the area directly exposed to light 70 and other areas increases, and the heat transfer member 32 may break due to thermal shock caused by this temperature gradient. To prevent such breakage, a method of segmenting the heat transfer member 32 has been considered; however, besides using a material with lower thermal conductivity than metal, the gaps at the segmented boundaries become a major cause of further reduction in thermal conductivity.

[0024] Therefore, in this embodiment, by distributing a film 33 on the surface of the heat transfer member 32, which is made of a metal with high thermal conductivity, on the light source side, it is possible to prevent the heat transfer member 32 from melting due to the heat generated by absorbing light 70 from the light source 1. Furthermore, the film 33 in this embodiment is a film of a material having a higher melting point than the heat transfer member 32, so that the film 33 does not melt. This reduces the possibility that the film 33 might melt and allow light from the light source 1 to directly irradiate the metal heat transfer member 32. The film 33 can be disposed on the entire surface of the heat transfer member 32 on the light source side, or it can be disposed on a portion of the area directly irradiated by light.

[0025] The membrane 33 in this embodiment will be described. The membrane 33 is made of a material having a higher melting point than the heat transfer member 32, such as a ceramic-based material (alumina, zirconium oxide, titanium dioxide, chromium oxide, yttrium oxide, magnesium oxide, chromium oxide, the above ceramics, and composite oxides of two or more). Alternatively, the membrane 33 can also be a high-melting-point metallic material (tungsten, tantalum, molybdenum, niobium, the above metal alloys), or a metal / heat-resistant alloy (aluminum, stainless steel, MCrAlX alloy, nickel, Ni-based alloys, high-carbon iron-chromium alloys, cobalt alloys, copper, etc.). In MCrAlX alloys, M is Ni, Co, NiCo, etc., and X is Y, Hf, Si, Ta, etc. By making the material of the membrane 33 an oxide, discoloration or deterioration caused by surface oxidation of the heat transfer member 32 can also be prevented.

[0026] Since the heat transfer component 32 may melt if the melting point of the film 33 is low, the material of the film 33 is preferably a material with a melting point of 1100 degrees Celsius or higher. Here, the properties of ceramic materials will be explained. For example, alumina has a melting point of approximately 2050 degrees Celsius and a thermal conductivity of approximately 32 W / m·K. Silicon carbide ceramics have a melting point of approximately 2600 degrees Celsius and a thermal conductivity of approximately 60 W / m·K. Aluminum nitride ceramics have a melting point of approximately 2200 degrees Celsius and a thermal conductivity of approximately 150 W / m·K. Zirconia has a melting point of approximately 2700 degrees Celsius and a thermal conductivity of approximately 3 W / m·K. The melting points of the above-mentioned ceramic materials are 1100 degrees Celsius or higher. When higher heat resistance is required for the film 33, a material with a melting point of 1800 degrees Celsius or higher is preferred. On the other hand, aluminum, as a metallic material, has a melting point of approximately 660 degrees Celsius and a thermal conductivity of approximately 237 W / m·K. Thus, ceramic materials have the characteristics of a higher melting point but lower thermal conductivity compared to aluminum, which is a metallic material.

[0027] 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 film 33 thinner, heat conduction from the heat transfer member 32 to the heat dissipation member 31 can be carried out efficiently without excessively restricting the absorption of light 70 into 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. When higher durability of the film 33 is required, a thickness of 0.1 mm or more is preferred. In addition, the film 33 in this embodiment can be formed by thermally spraying a material with a higher melting point than the heat transfer member 32 onto the surface where the light 70 is incident. Since it is difficult to uniformly form a film throughout the entire thermal spraying range based on the surface treatment, non-uniformity may occur on the film 33. Therefore, it is required that the film 33 has a thickness such that the heat transfer member 32 does not melt at its thinnest part. Depending on the material used for membrane 33, the appropriate membrane thickness varies. For example, in the case of forming a ceramic-based membrane by thermal spraying surface treatment, the thickness is generally around 0.1 mm to 0.3 mm.

[0028] Furthermore, due to the difference in the coefficients of linear expansion between the heat transfer member 32 and the film 33, it is foreseeable that the film 33 may peel off from the surface of the heat transfer member 32. To prevent this, an intermediate layer (substrate) (not shown) may be disposed between the heat transfer member 32 and the film 33. Examples of materials used as the intermediate layer include Ni, Ni-Cr, Ni-Al, and MCrAlY (where M represents Ni, Co, NiCo, etc.).

[0029] As described above, in this embodiment, by distributing a 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 on the light source 1 side, it is possible to prevent the heat transfer member 32 from melting due to absorbing heat generated from the light 70 from the light source 1. This improves the heat dissipation efficiency of the heat generated from the light source.

[0030] [Second Implementation]

[0031] The heat dissipation unit 30 of this embodiment will be described. Matters not mentioned in this embodiment shall be handled in accordance with the first embodiment. Figure 2 This 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.

[0032] Although the heat dissipation unit of the first embodiment is described in the form of contact between the heat dissipation member 31 and the heat transfer member 32, gaps may occur due to minor unevenness, warping, undulation, etc. on the contact surface between the heat dissipation member 31 and the heat transfer member 32.

[0033] Therefore, the heat dissipation unit 30 of this embodiment can make the heat dissipation member 31 and the heat transfer member 32 fit tightly by filling the gap between the heat dissipation member 31 and the heat transfer member 32 with the intermediate member 34. Figure 2 This is a cross-sectional view of a heat dissipation unit 30 in which an intermediate member 34 is disposed between the heat dissipation member 31 and the heat transfer member 32. According to... Figure 2 The structure of the heat dissipation unit shown can improve the efficiency of transferring the heat generated by the film 33 receiving light 70 to the heat dissipation component 31 via the heat transfer component 32, thereby improving the heat dissipation efficiency of the heat dissipation unit 30.

[0034] The intermediate component 34 is preferably made of a material with high thermal conductivity, flexibility, and good adhesion. Examples of materials that can be used for the heat transfer component 32 include graphite sheets, silicone grease, and pastes containing metal powder.

[0035] As described above, in this embodiment, by placing the intermediate member 34 in the gap between the heat dissipation member 31 and the heat transfer member 32, the heat dissipation efficiency of the heat generated by the light from the light source can be improved.

[0036] [Third Implementation Method]

[0037] The heat dissipation unit 30 of this embodiment will be described. Matters not mentioned in this embodiment shall be handled in accordance with the first embodiment. Figure 3 This is a cross-sectional view of the heat dissipation unit 30 of this embodiment. In the heat dissipation unit 30 of this embodiment, a radiator 35 with an air-cooled cooling mechanism is used as the heat dissipation member described in the first embodiment.

[0038] Figure 3 This is a cross-sectional view of a heat dissipation unit 30 using a heat sink 35 as a heat dissipation component. The heat sink 35 is made of a material with high thermal conductivity, such as aluminum, gold, silver, or copper. Aluminum has a melting point of approximately 660 degrees Celsius and a thermal conductivity of approximately 237 W / m·K. Gold has a melting point of approximately 1064 degrees Celsius and a thermal conductivity of approximately 315 W / m·K. Silver has a melting point of approximately 962 degrees Celsius and a thermal conductivity of approximately 427 W / m·K. Copper has a melting point of approximately 1083 degrees Celsius and a thermal conductivity of approximately 398 W / m·K. By using a material with high thermal conductivity in the heat sink 35, the cooling efficiency of the heat generated by the light 70 is improved.

[0039] The radiator 35 in this embodiment has an air-cooled cooling mechanism. To increase the contact area with air, the contact surface of the radiator 35 (the surface opposite to the light source 1) has a concave-convex shape. To efficiently cool the radiator 35, a fan 36 is provided to blow air onto the radiator 35.

[0040] The gas blown by fan 36 can be a gas from the atmosphere or a gas different from the atmosphere. The temperature of the gas can be the same as the temperature of the atmosphere, or it can be cooled.

[0041] The heat sink 35 is preferably formed in a concave-convex shape so that the gas emitted from the fan 36 can cool the entire heat sink 35. Specifically, it is preferable that the concave (or convex) portion of the heat sink 35 is formed along the direction of gas flow emitted from the fan 36. Furthermore, the fan 36 can be configured such that a large amount of gas is blown to areas of the heat sink 35 where the temperature is prone to rise (e.g., the central portion). Multiple fans 36 may also be provided.

[0042] Furthermore, in this embodiment, the radiator 35 is described as an air-cooled cooling mechanism, but it can also be a liquid-cooled cooling mechanism. When using a liquid-cooled cooling mechanism, by allowing coolant to flow into the interior of the radiator 35 or into the structure in contact with the radiator 35, the radiator 35 can be cooled with a higher cooling efficiency than an air-cooled mechanism.

[0043] As described above, in this embodiment, by using the radiator 35 of the air-cooled cooling mechanism as a heat dissipation component, the cooling efficiency can be improved, and the heat dissipation efficiency of the heat generated by the light from the light source can be improved.

[0044] [Implementation of the Exposure Apparatus]

[0045] In this embodiment, an example of applying the heat dissipation unit 30 described in the first to third embodiments to an exposure apparatus will be described. Figure 4 This is a schematic diagram of an exposure apparatus 100 having a heat dissipation unit 30. The exposure apparatus 100 includes a light source 1 (e.g., a mercury lamp or a laser), an illumination optics system that illuminates a master 12 (e.g., a mask or intermediate mask) with light from the light source 1, and a projection optics system 14 that projects the pattern of the master 12 onto a substrate 15 (e.g., a wafer or a glass plate).

[0046] Light emitted from light source 1 is focused by condenser mirror 2 and incident on cold mirror 3 (optical element). Cold mirror 3 transmits non-exposure wavelength light 70 (one side of the light) that is not used for exposure, and reflects the exposure wavelength light 60 (the other side of the light) that is used for exposure. Alternatively, cold mirror 3 only needs to have the function of separating the exposure wavelength light 60 from the non-exposure wavelength light 70; therefore, it can also be a structure that transmits the exposure wavelength light 60 and reflects the non-exposure wavelength light. Non-exposure wavelength light 70 refers to light with a wavelength of 436 nm or higher, such as the g-line wavelength of a mercury lamp, while exposure wavelength light 60 refers to light with a wavelength shorter than 436 nm, for example.

[0047] 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 through the heat dissipation member 31. Since a film 33, which is a high-melting-point material, is disposed on the light-receiving surface of the heat dissipation unit 30, the heat dissipation unit 30 will not melt even when the light source 1 is a high-output mercury lamp. In addition, the heat dissipation unit 30 can be disposed 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).

[0048] The light 60 of the exposure wavelength reflected by the cold mirror 3 is focused by the focusing lens 5, homogenized by the optical integrator 6, and the shape of the light illuminating the original plate is adjusted by the aperture 7. Then, the light 60 of the exposure wavelength passes through the focusing lens 8, the folding mirror 9, the shielding blade 10, and the imaging lens 11 and illuminates the original plate 12. The optical positional relationship between the original plate 12 and the substrate 15 is maintained as conjugate by the projection optical system 14. The original plate 12 is driven by the original plate stage 13, and the substrate 15 is driven by the substrate stage 16.

[0049] The specific structure of the preferred heat dissipation unit 30 suitable for the exposure apparatus 100 will be described below. Furthermore, a mercury lamp with an output of 12kW is used as the light source 1, and light with a wavelength of 436nm or higher is used as the non-exposure wavelength.

[0050] The suitable materials used for each component of the heat dissipation unit are described below. The heat transfer component 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 processability.

[0051] Preferably, after forming an intermediate layer (bonding coating) of 50 to 100 μm on the heat transfer component 32 with MCrAlY (M is Ni, Co, or NiCo), zirconium oxide is thermally sprayed with a thickness of 200 to 300 μm to form a film 33.

[0052] Preferably, a graphite sheet with good adhesion and high temperature resistance is disposed as an intermediate component 34 between the heat transfer component 32 and the heat dissipation component 31. The graphite sheet used, for example, can have a density of 1 g / cm³. 3 A graphite sheet with a thermal conductivity of 5 or more in the thickness direction and a linear expansion coefficient of about 0.0002 K in the thickness direction.

[0053] The heat dissipation component 31 preferably uses an air-cooled heat sink and is made of aluminum, which has high thermal conductivity. A fan 36 is preferably used to exhaust air at a flow rate of 4 m³ / s. 3 [ / min] Perform hot exhaust so that air flows parallel to the radiator protrusions.

[0054] [Implementation method of the item manufacturing method]

[0055] The article manufacturing method of the present invention is suitable, for example, for manufacturing flat panel displays (FPDs). The article manufacturing method of this embodiment includes a step of forming a latent image pattern on a photosensitive material coated on a substrate using the aforementioned exposure apparatus (a step of exposing the substrate), and a step of developing the substrate on which the latent image pattern is formed in this step. Furthermore, this manufacturing method includes other well-known steps (oxidation, film formation, vapor deposition, doping, planarization, etching, resist stripping, die cutting, bonding, encapsulation, etc.). The article manufacturing method of this embodiment is superior to conventional methods in at least one aspect of article performance, quality, productivity, and production cost.

[0056] The preferred embodiments of the present invention have been described above, but the present invention is of course not limited to these embodiments, and various modifications and alterations can be made within the scope of its spirit.

Claims

1. An exposure apparatus for exposing an image of an original pattern onto a substrate, characterized in that, The exposure device has the following features: Optical elements separate the light emitted from the light source into exposed light and non-exposed light; Heat dissipation components; A heat transfer component that conducts heat generated by irradiating the non-exposed light separated by the optical element to the heat dissipation component; as well as A projection optics system projects the exposure light separated by the optical elements onto the substrate. A film containing a material with a higher melting point than the material of the heat transfer member is disposed on the irradiated surface of the non-exposed light.

2. The exposure apparatus according to claim 1, characterized in that, The thickness of the membrane is less than 1 mm.

3. The exposure apparatus according to claim 2, characterized in that, The thickness of the membrane is 0.01 mm or more.

4. The exposure apparatus according to claim 1, characterized in that, The film is thermally sprayed onto the irradiated surface.

5. The exposure apparatus according to claim 1, characterized in that, The membrane is made of a ceramic-based material.

6. The exposure apparatus according to claim 1, characterized in that, The membrane is made of a material with a melting point of 1100 degrees or higher.

7. The exposure apparatus according to claim 1, characterized in that, The membrane is made of a material with a melting point of 1800 degrees or higher.

8. The exposure apparatus according to claim 1, characterized in that, The membrane material includes at least one of zirconium oxide, chromium oxide, yttrium oxide, magnesium oxide, and chromium oxide.

9. The exposure apparatus according to claim 1, characterized in that, The membrane material includes at least one of tungsten, tantalum, molybdenum, niobium, aluminum, stainless steel, MCrAlX alloy, nickel, Ni-based alloy, high-carbon iron-chromium alloy, cobalt alloy, and copper. In the MCrAlX alloy, M is any one of Ni, Co, and NiCo, and X is any one of Y, Hf, Si, and Ta.

10. The exposure apparatus according to claim 1, characterized in that, The heat transfer component is an integral, undivided structure.

11. The exposure apparatus according to claim 1, characterized in that, The material of the heat transfer component includes at least one of silver, copper, aluminum, nickel, and platinum.

12. The exposure apparatus according to claim 1, characterized in that, The exposure apparatus also has an intermediate component that fills the gap between the heat dissipation component and the heat transfer component. The intermediate component is any one of graphite sheet, silicone grease, or paste with added metal powder.

13. The exposure apparatus according to claim 1, characterized in that, The exposure apparatus also has an intermediate layer between the heat transfer member and the film to prevent the film from peeling off from the surface of the heat transfer member. The material of the intermediate layer includes at least one of Ni, Ni-Cr, Ni-Al, and MCrAlY. In the MCrAlY, M is any one of Ni, Co, and NiCo.

14. The exposure apparatus according to claim 1, characterized in that, The exposure light is light with a wavelength shorter than 436nm. The non-exposed light is light with a wavelength of 436nm or higher.

15. A method for manufacturing an article, characterized in that, The method for manufacturing this item includes: The exposure process involves exposing the substrate using the exposure apparatus according to any one of claims 1 to 14; and The developing process involves developing the substrate that was exposed in the exposure process. Articles are manufactured using substrates that have been developed in the development process.

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