JP2022119372A - Heat releasing unit, exposure device, and manufacturing method of article - Google Patents

Abstract

To improve heat releasing efficiency of heat generated by light from a light source.SOLUTION: A heat releasing unit comprises a heat releasing member that releases heat; and a heat transfer member that transfers heat generated by absorbing light from a light source to the heat releasing member, in which a film containing a material having a higher melting point than the material of the heat transfer member is arranged on a surface on the light source side of the heat transfer member.SELECTED DRAWING: Figure 3

Description

The present invention relates to a heat dissipation unit, an exposure apparatus, and an article manufacturing method.

Exposure equipment that uses a mercury lamp as a light source has a cold mirror that reflects the light of the wavelength used for exposure (exposure wavelength) and transmits the light of the wavelength that is unnecessary for exposure (non-exposure wavelength) through the cold mirror. be. If the light of the non-exposure wavelength is not recovered, the temperature of the entire apparatus may rise, which may lead to damage to parts constituting the apparatus and deterioration of exposure accuracy. Therefore, it is required that the radiation plate receives the light of the non-exposure wavelength, converts it into heat, conducts the heat to the heat sink, and efficiently dissipates the light.

Further, in the exposure apparatus, it is required to increase the output of the light source in order to improve productivity. In Patent Literature 1, the heat sink and the heat sink can be prevented from melting by forming the heat sink from a ceramic-based material having a high melting point. In addition, Patent Document 1 also discloses that the durability of the heat sink is improved compared to the case where the heat sink is not divided by dividing the heat sink so that the temperature difference inside the heat sink does not increase. ing.

Japanese Unexamined Patent Application Publication No. 2010-205806

However, since ceramic-based materials have lower thermal conductivity than materials such as metals, it is difficult to efficiently conduct heat to a heat sink for dissipating heat. In addition, when the heat sink is divided and arranged, a gap is generated, so the thermal conductivity is lowered as compared with the case where the heat sink is not divided. As the thermal conductivity decreases, the efficiency of dissipating heat generated by the light from the light source decreases.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a heat dissipation unit that is advantageous in improving the heat dissipation efficiency of heat generated by light from a light source.

To achieve the above object, a heat dissipation unit as one aspect of the present invention 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. and a film containing a material having a higher melting point than the material of the heat transfer member is disposed on the light source side surface of the heat transfer member.

According to the present invention, it is possible to provide a heat dissipation unit that is advantageous in improving the heat dissipation efficiency of heat generated by light from a light source.

It is a schematic diagram showing the configuration of a heat dissipation unit in the first embodiment. It is a schematic diagram showing the configuration of a heat dissipation unit in the second embodiment. It is a schematic diagram showing the configuration of a heat dissipation unit in the third embodiment. 1 is a schematic diagram showing the configuration of an exposure apparatus; FIG.

Preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings. In addition, in each figure, the same reference numerals are given to the same members, and redundant explanations are omitted.

<First Embodiment>
FIG. 1 is a cross-sectional view of a 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 arranged closer to the light source 1 than the heat radiating member 31 and is arranged in contact with the heat radiating member 31 . The heat dissipation member 31 has a function of dissipating heat generated by the light 70 from the light source 1 . The heat radiating member 31 may be an air-cooled cooling mechanism or a liquid-cooled cooling mechanism. The air-cooling type cooling mechanism is superior in that it can cool with a simple structure, and the liquid-cooling type cooling mechanism is superior in that it has a higher cooling effect than the air-cooling type.

The heat transfer member 32 is desirably made of a material with high thermal conductivity in order to efficiently conduct heat to the heat radiating member 31 . In this embodiment, the heat transfer member 32 is made of a metal having 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 approximately 10 mm. Examples of specific materials used for the heat transfer member 32 include silver, copper, aluminum, nickel, and platinum. In addition, the heat transfer member 32 can have an integral structure that is not divided or a structure that is divided to a minimum, so that the number of parts can be suppressed and the manufacturing cost can be reduced.

However, if the heat transfer member 32 is made of metal, the light 70 may melt the heat transfer member 32 . Further, if the heat transfer member 32 melts, the light 70 may hit the heat dissipation member 31 without passing through the heat transfer member 32 and the heat dissipation member 31 may also be thermally deformed and thermally damaged.

Moreover, when the heat transfer member 32 is changed to a material having a higher melting point than metal (for example, a ceramic-based material) so that the heat transfer member 32 does not melt, the thermal conductivity is lower than when metal is used. it gets lower. As a result, the temperature gradient between the portion directly irradiated with the light 70 and the other portion increases, and the heat transfer member 32 may be damaged due to the thermal shock caused by the temperature gradient. In order to prevent the occurrence of such damage, a method of dividing and arranging the heat transfer member 32 is conceivable. It becomes a factor that further reduces the heat conduction efficiency.

Therefore, in this embodiment, the heat generated by absorbing the light 70 from the light source 1 is disposed on the surface of the heat transfer member 32 on the light source side of the heat transfer member 32 made of a metal having high thermal conductivity. It is possible to prevent the heat transfer member 32 from melting. In addition, 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, the film 33 melts and becomes the heat transfer member 32 made of metal. It is possible to reduce the possibility that the light from the light source 1 is directly irradiated. The film 33 may be arranged on the entire surface of the heat transfer member 32 on the light source side, or may be arranged on a part of the area that is directly irradiated with light.

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

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° C. or higher. Here, the characteristics of the ceramic-based material will be described. As a ceramic 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 material has a melting point of 1100° C. or higher. When the film 33 is required to have a higher heat resistance effect, it is preferable that the material has a melting point of 1800° C. or higher. On the other hand, aluminum, which is a metal material, has a melting point of about 660 degrees and a thermal conductivity of about 237 W/m·K. Thus, ceramic materials have a higher melting point than aluminum, which is a metal material, but have a lower thermal conductivity.

In this embodiment, the thickness of the film 33 is desirably a thin layer of 1 mm or less. By reducing the thickness of the film 33, heat can be efficiently conducted from the heat transfer member 32 to the heat dissipation member 31 without excessively restricting the absorption of the light 70 to the heat transfer member 32. be. 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 the film 33 is required to have higher durability, the thickness is preferably 0.1 mm or more. Also, the film 33 in this embodiment can be formed by spraying a material having a higher melting point than the heat transfer member 32 onto the surface of the heat transfer member 32 on which the light 70 is incident. In the surface treatment by thermal spraying, it is difficult to form a uniform film over the entire sprayed area, so there is a possibility that the film 33 may be uneven. Therefore, the thickness of the film 33 is required to be such that the heat transfer member 32 does not melt at the portion where the film 33 is the thinnest. Although the appropriate film thickness varies depending on the material used for the film 33, for example, when a ceramic-based film is formed by surface treatment by thermal spraying, the thickness is generally about 0.1 mm to 0.3 mm. is.

Moreover, it is assumed that the film 33 is peeled off from the surface of the heat transfer member 32 due to the difference in linear expansion coefficient between the heat transfer member 32 and the film 33 . In order to prevent this, an intermediate layer (underlayer) (not shown) may be arranged between the heat transfer member 32 and the film 33 . Examples of materials used for the intermediate layer include Ni, Ni--Cr, Ni--Al, MCrAlY (M is Ni, Co, NiCo, etc.).

As described above, in the present embodiment, the film 33 made of a material having a higher melting point than the heat transfer member 32 is arranged on the surface of the heat transfer member 32 on the light source 1 side, so that the light 70 from the light source 1 is It is possible to prevent the heat transfer member 32 from melting due to the heat generated by the absorption. As a result, it is possible to improve the heat radiation efficiency of the heat generated by the light from the light source.

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

Although the heat dissipation unit in the first embodiment has been described as a form in which the heat dissipation member 31 and the heat transfer member 32 are in contact with each other, the contact surface between the heat dissipation member 31 and the heat transfer member 32 may have minute unevenness, warpage, or undulation. For example, there is a risk that a gap may occur.

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 the intermediate member 34, so that the heat dissipation member 31 and the heat transfer member 32 can be brought 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 arranged between the heat dissipation member 31 and the heat transfer member 32. As shown in FIG. With the configuration of the heat dissipation unit shown in FIG. can be improved.

The material of the intermediate member 34 is desirably high in thermal conductivity, soft and highly adhesive. Examples of the material of the heat transfer member 36 include a graphite sheet, silicon grease, paste containing metal powder, and the like.

As described above, in the present embodiment, by arranging the intermediate member 34 in the gap between the heat radiating member 31 and the heat transfer member 32, it is possible to improve the heat radiating efficiency of the heat generated by the light from the light source.

<Third Embodiment>
The heat dissipation unit 30 of this embodiment will be described. Matters not mentioned in this embodiment follow the first embodiment. FIG. 3 is a cross-sectional view of the heat dissipation unit 30 in this embodiment. In the heat dissipation unit 30 of the present embodiment, the heat sink 35 of the air-cooled cooling mechanism is applied as the heat dissipation member described in the first embodiment.

FIG. 3 is a cross-sectional view of a heat dissipation unit 30 employing 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. Aluminum has a melting point of about 660 degrees and a thermal conductivity of about 237 W/m·K. Gold has a melting point of about 1064 degrees and a thermal conductivity of about 315 W/m·K. Silver has a melting point of about 962 degrees and a thermal conductivity of about 427 W/m·K. Copper has a melting point of about 1083 degrees and a thermal conductivity of about 398 W/m·K. By using a material with high thermal conductivity for the heat sink 35, the efficiency of cooling the heat generated by the light 70 is improved.

The heat sink 35 in this embodiment has an air-cooled cooling mechanism. In order to increase the contact area with the air, the heat sink 35 has an uneven shape on the contact surface with the air (the surface on the side opposite to the light source 1). In order to cool the heat sink 35 efficiently, a fan 36 for releasing gas is provided, 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 it may be cooled.

It is desirable that the heat sink 35 has an uneven shape so that the gas emitted from the fan 36 can cool the entire heat sink 35 . Specifically, it is preferable that the concave portion (or convex portion) of the heat sink 35 is formed along the direction in which the gas discharged from the fan 36 flows. Further, the fan 35 may be arranged so that a large amount of gas is blown to a region (for example, central portion) of the heat sink 35 where the temperature tends to be high. A plurality of fans 35 may be provided.

In this embodiment, the heat sink 35 is described as an air-cooled cooling mechanism, but it may be a liquid-cooled cooling mechanism. When a liquid-cooling type cooling mechanism is adopted, the heat sink 35 can be cooled with a higher cooling efficiency than the air-cooling type by inflowing a cooling coolant inside the heat sink 35 or in contact with the heat sink 35. .

As described above, in this embodiment, by using the heat sink 35 of the air-cooled cooling mechanism as the heat dissipation member, 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.

<Embodiment of exposure apparatus>
In this embodiment, an example in which the heat dissipation unit 30 described in the first to third embodiments is applied to an exposure apparatus will be described. FIG. 4 is a schematic diagram of an exposure apparatus 100 having a heat dissipation unit 30. As shown in FIG. The exposure apparatus 100 includes a light source 1 (for example, a mercury lamp or laser), an illumination optical system that illuminates an original 12 (for example, a mask or a reticle) with light from the light source 1, and a pattern of the original 12 onto a substrate 15 (for example, a wafer). and a glass plate).

Light emitted from a light source 1 is condensed by a condensing mirror 2 and enters a cold mirror 3 (optical element). The cold mirror 3 transmits the non-exposure wavelength light 70 (one light) that is not used for exposure, and reflects the exposure wavelength light 60 (the other light) that is 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. It may be configured to reflect light. The non-exposure wavelength light 70 is, for example, light with a wavelength of 436 nm or longer, which is the g-line wavelength of a mercury lamp, and the exposure wavelength light 60 is, for example, light with a wavelength shorter than 436 nm.

The non-exposure wavelength light 70 enters the heat dissipation unit 30 and is converted into heat. The heat generated here is radiated by the heat radiating member 31 . Since the 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 when the light source 1 is a high output mercury lamp. Note that the heat dissipation unit 30 may be provided inside the exposure apparatus 100 or may be provided outside the exposure apparatus 100 . In the latter case, the light 70 is guided outside the exposure apparatus 100 through a window (not shown).

The exposure wavelength light 60 reflected by the cold mirror 3 is condensed by the condenser lens 5, homogenized by the optical integrator 6, and the aperture 7 adjusts the shape of the light that illuminates the original. After that, the exposure wavelength light 60 passes through the condenser lens 8 , the folding mirror 9 , the masking blade 10 and the imaging lens 11 and is irradiated onto the original 12 . The projection optical system 14 maintains the optical positional relationship between the original 12 and the substrate 15 to be conjugate. The original 12 is driven by the original stage 13 and the substrate 15 is driven by the substrate stage 16 .

A specific configuration of the preferred heat dissipation unit 30 applied to the exposure apparatus 100 will be described below. 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 defined as a non-exposure wavelength.

Preferred materials used for each member of the heat dissipation unit will be described. It is preferable that the heat transfer member 32 be an integral body of oxygen-free copper (C1020). This is because oxygen-free copper has a thermal conductivity of 391 [W/(m·k)] and is a material excellent in thermal conductivity and workability. After forming an intermediate layer (bonding coat) of 50 to 100 μm with MCrAlY (M is Ni, Co, or NiCo) on the heat transfer member 32, zirconia is thermally sprayed to a thickness of 200 to 300 μm. 33 is preferably formed.

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

An air-cooled heat sink is preferably used for the heat radiating member 31, and aluminum, which has high thermal conductivity, is preferably used. Heat is preferably exhausted by the fan 36 at an exhaust air volume of 4 [m ³ /min] so that the air flows parallel to the convex portions of the heat sink.

<Embodiment of method for manufacturing article>
A method for manufacturing an article according to an embodiment of the present invention is suitable for manufacturing a flat panel display (FPD), for example. The method for manufacturing an article according to the present embodiment comprises a step of forming a latent image pattern on a photosensitive agent coated on a substrate using the above exposure apparatus (a step of exposing the substrate), and forming a latent image pattern in this step. and developing the coated substrate. In addition, such manufacturing methods include other well-known steps (oxidation, deposition, deposition, doping, planarization, etching, resist stripping, dicing, bonding, packaging, etc.). The article manufacturing method of the present embodiment is advantageous in at least one of article performance, quality, productivity, and production cost compared to conventional methods.

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.

Reference Signs List 1 light source 30 heat dissipation unit 31 heat dissipation member 32 heat transfer member 33 film 70 light

Claims (17)

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, wherein a film containing a material having a higher melting point than a material of the heat transfer member is arranged on a surface of the heat transfer member facing the light source. 2. The heat dissipation unit according to claim 1, wherein the film has a thickness of 1 mm or less. 3. The heat dissipation unit according to claim 2, wherein the film has a thickness of 0.01 mm or more. 4. The heat dissipation unit according to claim 1, wherein the film is thermally sprayed on the surface of the heat transfer member on the light source side. 5. The heat dissipation unit according to any one of claims 1 to 4, wherein the material of the film is a ceramic material. 6. The heat dissipation unit according to claim 1, wherein the film is made of a material having a melting point of 1100 degrees or higher. The heat dissipation unit according to any one of claims 1 to 6, wherein the material of the film includes at least one of alumina, zirconia, titania, chromia, yttria, magnesia, and chromium oxide. The material of the film includes 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. The heat dissipation unit according to any one of claims 1 to 6. The heat dissipation unit according to any one of claims 1 to 8, wherein the heat transfer member has an integral structure that is not divided. 10. The heat dissipation unit according to any one of claims 1 to 9, wherein the material of the heat transfer member contains at least one of silver, copper, aluminum, nickel, and platinum. The heat dissipation unit according to any one of claims 1 to 10, wherein the light has a wavelength of 436 nm or longer. further comprising an intermediate member that fills a gap between the heat radiating member and the heat transfer member;
12. The heat dissipation unit according to any one of claims 1 to 11, wherein the intermediate member is any one of a graphite sheet, silicon grease, and paste containing metal powder. further comprising an intermediate layer between the heat transfer member and the film for preventing the film from peeling off from the surface of the heat transfer member;
The heat dissipation unit according to any one of claims 1 to 12, wherein the material of the intermediate layer includes at least one of Ni, Ni--Cr, Ni--Al and MCrAlY. A heat dissipation unit according to any one of claims 1 to 13;
a light source;
and an optical element that separates 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 characterized by illuminating with the other light separated by the optical element. an illumination optical system according to claim 14;
a projection optical system for exposing the pattern of the original onto the substrate,
The optical element separates the light emitted from the light source into light with an exposure wavelength and light with a non-exposure wavelength,
The heat dissipation unit dissipates heat generated by absorbing the light of the non-exposure wavelength,
An exposure apparatus, wherein the illumination optical system illuminates the original with light of the exposure wavelength. The light of the exposure wavelength is light of a wavelength shorter than 436 nm,
16. An exposure apparatus according to claim 15, wherein said non-exposure wavelength light is light with a wavelength of 436 nm or more. 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 exposing step;
A method for producing an article, comprising producing an article from the substrate developed in the developing step.

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