Pericle and method for manufacturing the pericle

Abstract

The present invention addresses the problem of providing a pellicle with which impact resistance can be increased and generation of foreign matter can be suppressed.　A pellicle (120) comprises: a pellicle film (10); a support (30) that supports the pellicle film (10); and a second reinforcing layer (50) that reinforces the pellicle film (10). When the pellicle film (10) supported by the support (30) is viewed in plan view, the second reinforcing layer (50) is disposed in a region where the pellicle film (10) and the support (30) overlap, and on the side of a second pellicle film surface (12) on the reverse side from a first pellicle film surface (11) facing the support (30).

Description

Technical Field

[0001] The present invention relates to a pellicle and a method for manufacturing the pellicle.

Background Art

[0002] In a manufacturing process of a semiconductor device or the like, for example, a photoresist is applied to a substrate such as a semiconductor wafer, and light is irradiated onto the substrate coated with the photoresist using a photomask, and then the photoresist is removed, whereby a target circuit pattern is formed on the substrate.

[0003] When light is irradiated with foreign matter adhering to the photomask, the adhering foreign matter may cause a problem in the circuit pattern formed on the substrate. Therefore, in order to suppress the adhesion of foreign matter to the photomask, a pellicle provided with a pellicle film for capturing foreign matter may be used. The pellicle is arranged above the photomask at a distance where the pellicle film does not contact the photomask.

[0004] In recent years, in order to form a finer circuit pattern, the use of extreme ultraviolet light (EUV) has been studied. EUV refers to light having a wavelength of 1 nm or more and 100 nm or less. As EUV, for example, specifically, light rays of about 13.5 nm ± 0.3 nm are being used. When EUV is irradiated onto the pellicle film, although EUV passes through the pellicle film, a part of the irradiated EUV is absorbed by the pellicle film. The light energy of the absorbed EUV is converted into thermal energy, whereby the temperature of the pellicle film rises. Therefore, the pellicle film is required to have EUV transmittance, heat resistance, durability, and the like.

[0005] For example, Patent Document 1 describes that the strength of the pellicle film can be improved by heat-treating (annealing) the pellicle film. In addition, Patent Document 2 describes a pellicle for photolithography composed of a pellicle film and a pellicle frame, wherein the pellicle film is provided on the upper end surface of the pellicle frame via an adhesive or a pressure-sensitive adhesive.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] Although Patent Document 1 describes a method capable of improving the strength of the pellicle film, there is a need for a technique to further improve the impact resistance of the pellicle. In addition, in the pellicle of Patent Document 2, the pellicle film is fixed to a support (pellicle frame) via an adhesive or a pressure-sensitive adhesive. Since the adhesive and the pressure-sensitive adhesive are not heat-resistant materials, they may decompose into foreign matters when irradiated with high-energy light such as EUV.

[0008] An object of the present invention is to provide a pellicle capable of improving impact resistance and suppressing foreign matter generation, and a method for manufacturing a pellicle for manufacturing the pellicle.

Means for Solving the Problems

[0009] [1]. A pellicle film, a support having a frame portion and an opening surrounded by the frame portion, and supporting the pellicle film, and a second reinforcing layer for reinforcing the pellicle film. The frame portion has a support surface facing the pellicle film. The pellicle film has a first pellicle film surface facing the support and a second pellicle film surface opposite to the first pellicle film surface. The second reinforcing layer is a region where the pellicle film supported by the support overlaps with the support when viewed in plan view, and is disposed on the second pellicle film surface side, and is a pellicle.

[0010] [2]. In the pellicle according to [1], The second reinforcing layer contains one or more materials selected from the group consisting of carbon nanotubes, graphene, graphite, diamond-like carbon, amorphous carbon, silicon, silicon carbide, silicon nitride, and boron nitride, and is a pellicle.

[0011] [3]. In the pellicle according to [2], The second reinforcing layer contains carbon nanotubes, The carbon nanotubes in the second reinforcing layer are oriented in a direction parallel to the support surface of the frame portion, and is a pellicle.

[0012] [4]. In the pellicle according to any one of [1] to [3], The pellicle film is an inorganic thin film or an organic thin film, and is a pellicle.

[0013] [5]. In the pellicle according to any one of [1] to [4], The pellicle film contains one or more materials selected from the group consisting of carbon nanotubes, graphene, graphite, diamond-like carbon, amorphous carbon, silicon, silicon carbide, silicon nitride, and boron nitride, and is a pellicle.

[0014] [6]. In the pellicle according to any one of [1] to [5], The pellicle film contains carbon nanotubes, and is a pellicle.

[0015] [7]. In the pellicle according to any one of [1] to [6], a pellicle in which the material of the pellicle film is the same as the material of the second reinforcing layer.

[0016] [8]. In the pellicle according to any one of [1] to [7], a pellicle further comprising a first reinforcing layer disposed between the pellicle film and the support on the side of the first pellicle film surface.

[0017] [9]. In the pellicle according to [8], the first reinforcing layer contains one or more materials selected from the group consisting of carbon nanotubes, graphene, graphite, diamond-like carbon, amorphous carbon, silicon, silicon carbide, silicon nitride, and boron nitride.

[0018]

[10] . In the pellicle according to [8] or [9], the first reinforcing layer contains carbon nanotubes, and the carbon nanotubes in the first reinforcing layer are oriented in a direction parallel to the support surface of the frame portion.

[0019]

[11] . A method for manufacturing a pellicle, which is a method for manufacturing a pellicle, a step of attaching a pellicle film so as to cover the opening portion and be supported by the support surface of the frame portion with respect to a support having an opening portion and a frame portion surrounding the opening portion; a step of disposing a second reinforcing layer in a region on the second pellicle film surface opposite to the first pellicle film surface facing the support of the pellicle film, the region where the pellicle film and the support overlap when the pellicle film is viewed in plan view.

[0020]

[12] . A method for manufacturing a pellicle for manufacturing a pellicle, a step of disposing a second reinforcing layer on the pellicle film; a step of attaching the pellicle film on which the second reinforcing layer is disposed to a support having an opening and a frame portion surrounding the opening so as to cover the opening and be supported by a support surface of the frame portion, and including, In the step of disposing the second reinforcing layer, the second reinforcing layer is disposed in a region on the second pellicle film surface opposite to the first pellicle film surface facing the support of the pellicle film, and when the pellicle film after being attached to the support is viewed in plan, the second reinforcing layer is disposed in advance in a region where the pellicle film and the support overlap, a method for manufacturing a pellicle.

[0021]

[13] . A method for manufacturing a pellicle according to

[11] or

[12] , wherein the second reinforcing layer contains one or more materials selected from the group consisting of carbon nanotubes, graphene, graphite, diamond-like carbon, amorphous carbon, silicon, silicon carbide, silicon nitride, and boron nitride, a method for manufacturing a pellicle.

[0022]

[14] . A method for manufacturing a pellicle according to

[13] , wherein the second reinforcing layer contains carbon nanotubes, and the second reinforcing layer is formed such that the carbon nanotubes in the second reinforcing layer are oriented in a direction parallel to the film surface of the pellicle film, a method for manufacturing a pellicle.

[0023]

[15] . A method for manufacturing a pellicle according to any one of

[11] to

[14] , further including a step of disposing a first reinforcing layer on an outer peripheral side of the opening and on the support surface of the frame portion before the step of attaching the pellicle film, The first reinforcing layer contains one or more materials selected from the group consisting of carbon nanotubes, graphene, graphite, diamond-like carbon, amorphous carbon, silicon, silicon carbide, silicon nitride, and boron nitride. A method for manufacturing a pellicle, comprising, in the step of attaching the pellicle film, attaching the pellicle film so as to cover the opening and be supported by the first reinforcing layer.

[0024]

[16] . In the method for manufacturing a pellicle according to

[15] , the first reinforcing layer contains carbon nanotubes, A method for manufacturing a pellicle, wherein the first reinforcing layer is formed such that the carbon nanotubes in the first reinforcing layer are oriented in a direction parallel to the support surface of the frame portion.

[0025] According to one aspect of the present invention, it is possible to provide a pellicle capable of improving impact resistance and suppressing foreign matter generation, and a manufacturing method for manufacturing the pellicle.

Brief Description of the Drawings

[0026]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5A

Figure 5B

Figure 6

Embodiments for Carrying Out the Invention

[0027] 〔First Embodiment〕 (Pericle) The pericle according to the first embodiment includes a pericle film, a support for supporting the pericle film, and a second reinforcing layer for reinforcing the pericle film. In this specification, ordinal numbers such as "first" and "second" are attached to the text for the purpose of distinguishing configurations and the like, and are not attached to the text for the purpose of specifying an order. When ordinal numbers are attached for the purpose of specifying an order in this specification, the purpose is separately specified. Therefore, for example, the "first" and "second" in the first reinforcing layer (see the second embodiment) and the second reinforcing layer are attached to the text of "reinforcing layer" for the purpose of distinguishing a plurality of reinforcing layers in view of the fact that a plurality of different reinforcing layers are provided in the pericle. In this specification, since the second reinforcing layer is disposed on the front side of the pericle film, the second reinforcing layer can also be referred to as the front side reinforcing layer, and since the first reinforcing layer is disposed inside the pericle film, the first reinforcing layer can also be referred to as the inner side reinforcing layer.

[0028] Hereinafter, with reference to the drawings, an example of the pericle according to the first embodiment will be described. The present invention is not limited to the illustrated pericle. In the drawings described with reference to the drawings in this specification, there are parts illustrated with magnification or reduction for ease of explanation.

[0029] In FIGS. 1 and 2, as an example of the first embodiment, a pericle 120 is shown. FIG. 1 shows a plan view of the pericle 120 viewed in plan from the side where the pericle film 10 is attached, and FIG. 2 shows a cross-sectional view of the pericle 120 shown in FIG. 1.

[0030] The pericle 120 includes a pericle film 10, a support 30 for supporting the pericle film 10, and a second reinforcing layer 50 for reinforcing the pericle film 10.

[0031] (Support) The support 30 has a frame portion 31 and an opening 32 surrounded by the frame portion 31. The frame portion 31 has a support surface 34 facing the pellicle film 10. Specifically, the support surface 34 faces the first pellicle film surface 11 of the pellicle film 10 when supporting the pellicle film 10. The opening 32 penetrates from one surface to the other surface of the support 30. Both the frame portion 31 and the opening 32 are formed in a rectangular shape. In the present embodiment, the four corners of the outer shape of the frame portion 31 are all rounded, but the shape of the frame portion 31 is not limited to such a shape. As the material of the support 30, known materials can be used. For example, resin materials (such as polyethylene), metal materials (such as aluminum, aluminum alloy, magnesium alloy, stainless steel, titanium, titanium alloy, and invar), ceramic materials (such as SiC and SiN), quartz, and fiber-reinforced plastic materials (such as carbon fiber-reinforced plastic and glass fiber-reinforced plastic) can be used.

[0032] (Pellicle film) The pellicle film 10 has a first pellicle film surface 11 facing the support 30 and a second pellicle film surface 12 opposite to the first pellicle film surface 11. The peripheral portion 13 of the pellicle film 10 is fixed to a part of the support surface 34 of the frame portion 31 and covers the opening 32 of the support 30. In the pellicle 120, it is preferable that the pellicle film 10 and the support surface 34 are in direct contact.

[0033] The pellicle film 10 is preferably an inorganic thin film or an organic thin film. The pellicle film 10 preferably contains one or more materials selected from the group consisting of carbon nanotubes, graphene, graphite, diamond-like carbon, amorphous carbon, silicon, silicon carbide, silicon nitride, and boron nitride.

[0034] The pellicle film 10 preferably contains carbon nanotubes, and preferably consists essentially of only carbon nanotubes. Here, "consisting essentially of only carbon nanotubes" means that excluding the metal catalyst used in the production of carbon nanotubes, 98% by mass or more in the pellicle film is carbon nanotubes. That is, "consisting essentially of only carbon nanotubes" means that the percentage of the mass of carbon nanotubes to the total mass of the pellicle film 10 after subtracting the mass of the metal catalyst used in the production of carbon nanotubes and contained in the pellicle film 10 is 98% by mass or more. When the pellicle film 10 consists essentially of only carbon nanotubes, substances that are not intentionally added to the pellicle film 10 and are inevitable impurities mixed in during the raw material or manufacturing process may or may not be contained in the pellicle film 10.

[0035] The carbon nanotubes contained in the pellicle film 10 are not particularly limited, and are preferably at least one selected from the group consisting of multi-walled carbon nanotubes (MWCNT), few-walled carbon nanotubes (FWCNT), double-walled carbon nanotubes (DWCNT), and single-walled carbon nanotubes (SWCNT).

[0036] In the present embodiment, the multi-walled carbon nanotubes are, for example, carbon nanotubes having 4 or more and 20 or less concentric layers and a diameter of 4 nm or more and 100 nm or less. The few-walled carbon nanotubes are, for example, carbon nanotubes having 2 or 3 concentric layers and a diameter of 2 nm or more and 8 nm or less. The single-walled carbon nanotubes are, for example, 1 layer and have a tube diameter of 0.2 nm or more and 5 nm or less.

[0037] Carbon nanotubes can be obtained, for example, by chemical vapor deposition, laser ablation, or arc discharge method.

[0038] In this embodiment, the length of the carbon nanotubes is preferably, for example, 0.1 μm or more and 1000 μm or less. In this embodiment, the length of the carbon nanotubes is more preferably 0.5 μm or more, and even more preferably 1 μm or more. In this embodiment, the length of the carbon nanotubes is more preferably 600 μm or less, and even more preferably 400 μm or less.

[0039] In this embodiment, the cross-sectional diameter of the carbon nanotubes is preferably 0.2 nm or more and 50 nm or less. In this embodiment, the cross-sectional diameter of the carbon nanotubes is more preferably 0.5 nm or more, and even more preferably 1 nm or more. In this embodiment, the cross-sectional diameter of the carbon nanotubes is more preferably 30 nm or less, and even more preferably 20 nm or less.

[0040] The pellicle film according to this embodiment preferably has self-supporting property from the viewpoint of improving transparency to exposure light. That the pellicle film has self-supporting property means that the pellicle film itself is in a self-supporting state, which means that the pellicle film is a film having self-supporting property (also referred to as a self-supporting film). That is, the pellicle film having self-supporting property is a film that can maintain its shape by itself without the presence of a substrate or the like.

[0041] In the pellicle 120, the material of the pellicle film 10 and the material of the second reinforcing layer 50 may be the same or different. For example, it is also preferable that both the material of the pellicle film 10 and the material of the second reinforcing layer 50 are carbon nanotubes. By forming the pellicle film 10 and the second reinforcing layer 50 with the same material, the adhesion between the pellicle film 10 and the second reinforcing layer 50 can be improved.

[0042] The thickness of the pellicle film according to this embodiment is not particularly limited, and is preferably 3 nm or more and 1000 nm or less. The thickness of the pellicle film is preferably 10 nm or more, more preferably 20 nm or more, and even more preferably 30 nm or more. The thickness of the pellicle film is preferably 600 nm or less, more preferably 300 nm or less. If the thickness of the pellicle film is, for example, 3 nm or more and 1000 nm or less, the strength of the pellicle film is further improved and it becomes easier to ensure EUV transmittance.

[0043] (Second Reinforcement Layer) When the pellicle film 10 supported by the support 30 is viewed in plan view, the second reinforcement layer 50 is an area where the pellicle film 10 and the support 30 overlap, and is disposed on the side of the second pellicle film surface 12. The second reinforcement layer 50 is disposed along the peripheral edge portion 13 of the pellicle film 10. In the pellicle 120, it is preferable that the pellicle film 10 and the second reinforcement layer 50 are in direct contact with each other.

[0044] The thickness of the second reinforcement layer 50 is preferably greater than the thickness of the pellicle film 10, and from the viewpoint of easily obtaining impact resistance, it is preferably 0.05 μm or more, and more preferably 0.1 μm or more. Also, from the viewpoints of productivity and suppression of foreign matter generation due to heating, the thickness of the second reinforcement layer 50 is preferably 1 μm or less, and more preferably 0.5 μm or less.

[0045] The second reinforcement layer 50 may project toward the opening 32 side of the support 30 in the plan view of the pellicle 120 within a range that does not interfere with development (a range that does not block the exposure light necessary for development). Also, as shown in FIG. 2, the inner end portion of the second reinforcement layer 50 may be aligned with the inner end surface of the frame portion 31. Further, the inner end portion of the second reinforcement layer 50 may be formed to be located inside the inner end surface of the frame portion 31 within a range that does not interfere with the reinforcement of the pellicle film 10.

[0046] The second reinforcing layer 50 preferably contains one or more materials (reinforcing materials) selected from the group consisting of carbon nanotubes, graphene, graphite, diamond-like carbon, amorphous carbon, silicon, silicon carbide, silicon nitride, and boron nitride. By containing these materials in the second reinforcing layer 50, the pellicle 120 functions stably against heat during exposure, has excellent durability, and furthermore, it is difficult for particles (fine particles with a size of several hundred nanometers to several tens of nanometers) to be generated from the second reinforcing layer 50. The content of these materials (reinforcing materials) in the second reinforcing layer 50 is preferably 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, or 98% by mass or more. The second reinforcing layer 50 more preferably contains one or more materials selected from the group consisting of carbon nanotubes, graphene, silicon carbide, silicon nitride, and boron nitride. The second reinforcing layer 50 is more preferably formed of carbon nanotubes or graphene. Nanocarbon materials such as carbon nanotubes and graphene have excellent heat resistance. The content of the nanocarbon material in the second reinforcing layer 50 is preferably 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, or 98% by mass or more.

[0047] The second reinforcing layer 50 more preferably contains carbon nanotubes, and even more preferably consists essentially of carbon nanotubes only. Here, "consisting essentially of carbon nanotubes only" means that excluding the metal catalyst used in the production of carbon nanotubes, 98% by mass or more of the second reinforcing layer 50 is carbon nanotubes. That is, for the second reinforcing layer 50 to "consist essentially of carbon nanotubes only" means that the percentage of the mass of carbon nanotubes to the total mass of the second reinforcing layer 50 after subtracting the mass of the metal catalyst used in the production of carbon nanotubes and contained in the second reinforcing layer 50 is 98% by mass or more. When the second reinforcing layer 50 consists essentially of carbon nanotubes only, substances that are not intentionally added to the second reinforcing layer 50 and are inevitable impurities mixed in during the raw materials or manufacturing process may or may not be contained in the second reinforcing layer 50.

[0048] Since the second reinforcing layer 50 is formed in a range that does not interfere with development (a range that does not block the exposure light required for development), the content of carbon nanotubes in the second reinforcing layer 50 (for example, the mass of carbon nanotubes per unit area of the film) can be increased compared to the pellicle film 10. As a result, the strength of the second reinforcing layer 50 is improved, and the impact resistance of the pellicle film 10 is also improved.

[0049] When the second reinforcing layer 50 contains carbon nanotubes, the carbon nanotubes contained in the second reinforcing layer 50 are not particularly limited, and are preferably at least one selected from the group consisting of multi-walled carbon nanotubes, few-walled carbon nanotubes, double-walled carbon nanotubes, and single-walled carbon nanotubes.

[0050] When the second reinforcing layer 50 contains carbon nanotubes, the carbon nanotubes in the second reinforcing layer 50 are preferably oriented in a direction parallel to the support surface 34 of the frame portion 31. That is, the long axis direction of each carbon nanotube is preferably along the direction of the support surface 34 of the frame portion 31.

[0051] When the second reinforcing layer 50 contains carbon nanotubes, the carbon nanotubes in the second reinforcing layer 50 may be oriented in a direction perpendicular to the support surface 34 of the frame portion 31. The second reinforcing layer 50 is preferably a carbon nanotube forest. A carbon nanotube forest is a grown body in which a plurality of carbon nanotubes are grown on a support or a substrate so as to be oriented in a direction perpendicular to the surface of the support or the substrate, and may also be referred to as an "array". When comparing reinforcing layers using the same mass of carbon nanotubes, a CNT layer in which the carbon nanotubes are oriented in the vertical direction has better impact resistance than a CNT layer in which the carbon nanotubes are oriented in the horizontal direction. Therefore, when the carbon nanotubes in the second reinforcing layer 50 are oriented in the vertical direction, the impact absorbency of the second reinforcing layer 50 is improved.

[0052] In this specification, "oriented in the vertical direction" means being oriented substantially perpendicular to the surface of the support or the substrate, and "substantially perpendicular" means that the angle of the orientation direction of the material (such as carbon nanotubes) in the second reinforcing layer 50 with respect to the surface of the support or the substrate is 90 degrees ± 20 degrees (70 degrees or more and 110 degrees or less).

[0053] (Method for manufacturing a pellicle) Next, a method for manufacturing a pellicle according to the first embodiment (hereinafter, may be referred to as the manufacturing method of the first embodiment) will be described. The manufacturing method of the first embodiment may be an aspect including the following steps (P1) and (P2), or may be an aspect including the following steps (P3) and (P4).

[0054] Step (P1) is a step of attaching the pellicle film 10 to the support 30 having the opening 32 and the frame portion 31 surrounding the opening 32. More specifically, step (P1) is a step of attaching the pellicle film 10 so as to cover the opening 32 and be supported by the support surface 34 of the frame portion 31 on the support surface 34 side of the frame portion 31.

[0055] Step (P2) is a step of disposing a second reinforcing layer 50 in a region on the second pellicle film surface 12 opposite to the first pellicle film surface 11 facing the support 30 of the pellicle film 10, in a region where the pellicle film 10 and the support 30 overlap when the pellicle film 10 is viewed in plan. That is, in the manufacturing method carried out in the order of steps (P1) and (P2), first, the pellicle film 10 is attached to the support 30, and then the second reinforcing layer 50 is disposed on the second pellicle film surface 12 of the pellicle film 10.

[0056] Step (P3) is a step of disposing the second reinforcing layer 50 on the pellicle film 10. Specifically, it is a step of disposing the second reinforcing layer 50 in a region on the second pellicle film surface 12 opposite to the first pellicle film surface 11 of the pellicle film 10. In this step (P3) (the step of disposing the second reinforcing layer), when the pellicle film 10 attached to the support 30 is viewed in plan, the second reinforcing layer 50 is disposed in advance in a region or position where the pellicle film 10 and the support 30 overlap. That is, in step (P3), the second reinforcing layer 50 is disposed on the pellicle film 10 in advance, and the pellicle film 10 with the second reinforcing layer 50 is manufactured.

[0057] Step (P4) is a step of covering the opening 32 on the support surface 34 side of the frame portion 31 and attaching the pellicle film 10 with the second reinforcing layer 50 so as to be supported by the support surface 34 of the frame portion 31. That is, in the manufacturing method carried out in the order of steps (P3) and (P4), first, the second reinforcing layer 50 is disposed on the pellicle film 10, and then the first pellicle film surface 11 side of the pellicle film 10 with the second reinforcing layer 50 is attached to the support 30.

[0058] As a method of disposing the second reinforcing layer 50 on the pellicle film 10, a method of forming the second reinforcing layer 50 at a predetermined position on the pellicle film 10 can be mentioned.

[0059] The second reinforcing layer 50 may be formed using a material appropriately selected according to the material of the pellicle film 10 and the area to be disposed on the pellicle film 10, etc. The forming method of the second reinforcing layer 50 may be appropriately selected according to the material to be used.

[0060] For example, a material (reinforcing material) to be contained in the second reinforcing layer 50 is dispersed in a solvent to prepare a reinforcing material dispersion liquid. This reinforcing material dispersion liquid is applied to the pellicle film 10, and the solvent is evaporated to form a film made of the reinforcing material as the second reinforcing layer 50.

[0061] When the second reinforcing layer 50 is a layer containing carbon nanotubes (CNT layer), it is preferable to form the second reinforcing layer 50 so that the carbon nanotubes in the second reinforcing layer 50 are oriented in a direction parallel to the film surface of the pellicle film 10. Since the carbon nanotubes in the second reinforcing layer 50 are oriented in this way, entanglement occurs with the pellicle film in which the carbon nanotubes are also oriented in the parallel direction, and an improvement in the reinforcing effect can be expected.

[0062] When the second reinforcing layer 50 is a CNT layer, for example, the CNT layer can be formed by a chemical vapor deposition (CVD) method, a laser ablation method, or an arc discharge method. The CNT layer may be directly formed on the pellicle film 10 by the CVD method, or the CNT layer on the substrate may be transferred onto the pellicle film 10 after the CNT layer is formed on the substrate. For example, a substrate corresponding to the position and shape of the second reinforcing layer 50 to be disposed on the pellicle film 10 is prepared, the CNT layer is formed on the substrate, and the CNT layer is transferred to the pellicle film 10, whereby the second reinforcing layer 50 can be disposed on the pellicle film 10 with good accuracy. The substrate on which the CNT layer is formed may be fixed to the pellicle film 10.

[0063] When the second reinforcing layer 50 is a carbon nanotube forest, a carbon nanotube forest may be formed by directly growing a plurality of carbon nanotubes on the pellicle film 10. Alternatively, a carbon nanotube forest may be formed on a substrate, and the substrate may be fixed to the pellicle film 10, or the carbon nanotube forest may be transferred to the pellicle film 10.

[0064] When forming a CNT layer on a substrate, as the substrate, a conventionally known substrate can be appropriately used. For example, at least one substrate selected from the group consisting of a plastic substrate, a glass substrate, a silicon substrate, and a metal substrate (a substrate containing a metal such as iron and copper or an alloy thereof (e.g., stainless steel)) can be used. A silicon dioxide film may be laminated on the surface of these substrates. The substrate on which the CNT layer as the second reinforcing layer 50 is formed may be fixed to the peripheral edge portion 13 of the pellicle film 10 by an adhesive member (e.g., a double-sided tape). The carbon nanotubes to be chemically vapor grown on the substrate are preferably at least one selected from the group consisting of multi-walled carbon nanotubes, few-walled carbon nanotubes, and single-walled carbon nanotubes, and may also be a mixture composed of a plurality of types of carbon nanotubes.

[0065] When the second reinforcing layer 50 is a layer containing graphene (graphene layer), the graphene layer as the second reinforcing layer 50 can also be formed by the CVD method. For example, the graphene layer may be directly formed on the pellicle film 10 by the CVD method, or after forming the graphene layer on a substrate of a metal foil (e.g., Ni foil or Cu foil, etc.) by the CVD method, the graphene layer on the substrate may be transferred onto the pellicle film 10. The graphene layer as the second reinforcing layer 50 may have a single-layer structure consisting of one layer, but from the viewpoint of enhancing the effect of reinforcing the pellicle film, it may also have a multi-layer structure consisting of two or more layers. Since the second reinforcing layer 50 is formed within a range that does not hinder development, even if the graphene layer has a multi-layer structure, development is not hindered. When the graphene layer has a multi-layer structure, the graphene layer may be formed into multiple layers in advance and then transferred onto the pellicle film 10.

[0066] The manufacturing method of the first embodiment may include a step (P5) of preparing a support and a step (P6) of preparing a pellicle film before the step (P1) or the step (P3).

[0067] In the step (P5) of preparing a support, a support having a desired shape may be prepared by using the material constituting the above-described support and by a known method.

[0068] The step of preparing the pellicle film (P6) may be to prepare the pellicle film according to the first embodiment. For example, the pellicle film according to the first embodiment can also be manufactured by the method for manufacturing a pellicle film described below.

[0069] (Method for manufacturing a pellicle film) The method for manufacturing a pellicle film is not particularly limited and may be appropriately selected according to the materials used.

[0070] An example of a preferred method for manufacturing a pellicle film containing carbon nanotubes includes, for example, a step of dispersing carbon nanotubes (PE1), a step of sedimenting and depositing the dispersed carbon nanotubes on a breathable member to obtain a carbon nanotube film formed in a mat shape on the breathable member (PE2), and a step of removing the breathable member from the carbon nanotube film to obtain a pellicle film (PE3).

[0071] First, in step (PE1), carbon nanotubes are dispersed in a liquid to prepare a carbon nanotube dispersion in which the carbon nanotubes are dispersed in the liquid. The liquid is preferably a liquid containing water. The carbon nanotube dispersion may contain only carbon nanotubes, or may contain various additives such as a dispersant for dispersing the carbon nanotubes in addition to the carbon nanotubes.

[0072] Next, in step (PE2), the dispersed carbon nanotubes are sedimented and deposited on the breathable member. For example, by filtering the carbon nanotube dispersion prepared in step (PE1) with a filter membrane as the breathable member, the carbon nanotubes are sedimented and deposited to form a carbon nanotube film formed in a mat shape on the filter membrane. The filter membrane is preferably, for example, a membrane filter or the like.

[0073] Next, in step (PE3), a pellicle film containing carbon nanotubes is obtained by removing the filter film from the carbon nanotube film formed in a mat shape. Before removing the filter film from the carbon nanotube film formed in a mat shape or after removing the filter film from the carbon nanotube film formed in a mat shape, a drying step may be provided as necessary. The obtained pellicle film is a self-supporting film.

[0074] The manufacturing method of the first embodiment may include a step (P7) of providing an adhesive layer on at least a part of the support surface 34 of the frame portion 31 as necessary. When an adhesive layer is provided on at least a part of the support surface 34 of the frame portion 31, the pellicle film 10 is installed so as to be supported by the support surface 34 of the frame portion 31 via the adhesive layer. When various adhesives are used for the adhesive layer, the step of providing the adhesive layer is to apply the adhesive to the support surface 34 to provide an adhesive layer containing the adhesive.

[0075] The pellicle 120 is used, for example, as a dust-proof cover when manufacturing a semiconductor device, an IC package, a printed circuit board, a liquid crystal display, an organic EL display, or the like. The pellicle 120 is disposed, for example, above the photomask and spaced apart from the photomask so that the first pellicle film surface 11 faces the photomask. By using the pellicle 120, the adhesion of foreign matter to the photomask is suppressed.

[0076] (Effect of the First Embodiment) According to the pellicle according to the first embodiment, since the second reinforcing layer 50 is disposed on the second pellicle film surface 12 side of the pellicle film 10, the pellicle film 10 is less likely to be damaged, and the impact resistance of the pellicle 120 is improved.

[0077] In the pellicle according to the first embodiment, since the region where the second reinforcing layer 50 is disposed is the region where the pellicle film 10 and the support 30 overlap in plan view of the pellicle 120, the transparency of the second reinforcing layer 50 may be low. Therefore, the options for materials that can be used for the second reinforcing layer 50 are expanded, and the content of the reinforcing material in the second reinforcing layer 50 (for example, the mass of the reinforcing material per unit area of the film) can be increased compared to the pellicle film 10. As a result, the strength of the second reinforcing layer 50 is improved, and the impact resistance of the pellicle 120 is also improved. Since the region where the second reinforcing layer 50 is disposed is the peripheral edge portion 13 of the pellicle film 10, the peripheral edge portion 13 of the pellicle film 10 can be more effectively protected.

[0078] In the pellicle according to the first embodiment, since the second reinforcing layer 50 is formed of a material having excellent heat resistance instead of an adhesive layer or an adhesive layer, it is difficult to decompose even when irradiated with high-energy light such as EUV. Therefore, even if the second reinforcing layer 50 is provided as in the pellicle according to the first embodiment, generation of foreign matters can be suppressed.

[0079] According to the manufacturing method of the first embodiment, a pellicle with further improved impact resistance can be manufactured.

[0080] 〔Second Embodiment〕 (Pellicle) Next, the configuration of the pellicle according to the second embodiment will be described. In the description of the second embodiment, the same components as those in the first embodiment will be denoted by the same reference numerals and names, and the description will be omitted or simplified. In the second embodiment, for structures, materials, etc. not particularly mentioned, the same structures, materials, etc. as those described in the first embodiment can be adopted.

[0081] The pellicle according to the second embodiment is different from the pellicle according to the first embodiment in that it further includes a first reinforcing layer disposed between the pellicle film and the support on the first pellicle film surface side. Other points are the same as those in the first embodiment. That is, in the second embodiment, the periphery of the pellicle film is reinforced while being sandwiched between the first reinforcing layer and the second reinforcing layer, and is supported by the support.

[0082] Hereinafter, with reference to the drawings, an example of the pellicle according to the second embodiment will be described. The present invention is not limited to the illustrated pellicle.

[0083] In FIGS. 3 and 4, as an example of the second embodiment, a pellicle 110 is shown. FIG. 3 shows a plan view of the pellicle 110 as viewed from the surface side on which the pellicle film 10 is installed, and FIG. 4 shows a cross-sectional view of the pellicle 110 shown in FIG. 3.

[0084] The pellicle 110 includes a pellicle film 10, a support 30 that supports the pellicle film 10, a first reinforcing layer 40 that reinforces the pellicle film 10, and a second reinforcing layer 50.

[0085] (First Reinforcing Layer) When the first reinforcing layer 40 is viewed in plan with the pellicle film 10 supported by the support 30, it is a region where the pellicle film 10 and the support 30 overlap, and is disposed between the pellicle film 10 and the support 30 on the side of the first pellicle film surface 11. The first reinforcing layer 40 is disposed along the peripheral edge 13 of the pellicle film 10. It is also preferable that the first reinforcing layer 40 is disposed in direct contact with the support surface 34. The support 30 on which the first reinforcing layer 40 is disposed on the support surface 34 may be referred to as a pellicle support 30A.

[0086] The first reinforcing layer 40 may protrude toward the opening 32 side of the support 30 in a plan view of the pellicle 110 within a range that does not interfere with development (a range that does not block the exposure light required for development). Further, the inner end portion (the end portion on the opening 32 side) of the first reinforcing layer 40 may be formed flush with the inner end surface (the end surface on the opening 32 side) of the frame portion 31 as shown in FIG. 4. Further, the inner end portion of the first reinforcing layer 40 may be formed to be located inside the inner end surface of the frame portion 31 within a range that does not interfere with the support and reinforcement of the pellicle film 10.

[0087] The thickness of the first reinforcing layer 40 is preferably greater than the thickness of the pellicle film 10, and from the viewpoint of easily obtaining impact resistance, it is preferably 0.05 μm or more, and more preferably 0.1 μm or more. Further, from the viewpoints of productivity and suppression of foreign matter generation due to heating, the thickness of the first reinforcing layer 40 is preferably 1 μm or less, and more preferably 0.5 μm or less.

[0088] The first reinforcing layer 40 preferably contains one or more materials (reinforcing materials) selected from the group consisting of carbon nanotubes, graphene, graphite, diamond-like carbon, amorphous carbon, silicon, silicon carbide, silicon nitride, and boron nitride. By the first reinforcing layer 40 containing these materials, the pellicle 110 functions stably even against heat during exposure, has excellent durability, and further, particles (fine particles having a size of several hundred nm to several tens of nm) from the first reinforcing layer 40 are hardly generated. The content of these materials (reinforcing materials) in the first reinforcing layer 40 is preferably 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, or 98% by mass or more. The first reinforcing layer 40 more preferably contains one or more materials selected from the group consisting of carbon nanotubes, graphene, silicon carbide, silicon nitride, and boron nitride. The first reinforcing layer 40 is more preferably formed of carbon nanotubes or graphene. Since nanocarbon materials such as carbon nanotubes and graphene have excellent heat resistance, the first reinforcing layer 40 containing the nanocarbon material has improved heat resistance. The content of the nanocarbon material in the first reinforcing layer 40 is preferably 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, 95% by mass or more, or 98% by mass or more.

[0089] When the first reinforcing layer 40 contains carbon nanotubes, the carbon nanotubes in the first reinforcing layer 40 are preferably oriented in a direction parallel to the support surface 34 of the frame portion 31. That is, the longitudinal axis direction of each carbon nanotube is preferably a direction along the support surface 34 of the frame portion 31.

[0090] When the first reinforcing layer 40 contains carbon nanotubes, the carbon nanotubes in the first reinforcing layer 40 may be oriented in a direction perpendicular to the support surface 34 of the frame portion 31. The first reinforcing layer 40 is also preferably a carbon nanotube forest. When the carbon nanotubes in the first reinforcing layer 40 are oriented in the vertical direction, the shock absorption of the first reinforcing layer 40 is improved.

[0091] More preferably, the first reinforcing layer 40 contains carbon nanotubes, and even more preferably, it consists essentially of only carbon nanotubes. Here, "consisting essentially of only carbon nanotubes" means that, excluding the metal catalyst used in the production of carbon nanotubes, 98% by mass or more of the first reinforcing layer 40 is carbon nanotubes. That is, when the first reinforcing layer 40 "consists essentially of only carbon nanotubes", it means that the percentage of the mass of carbon nanotubes to the total mass of the first reinforcing layer 40 after subtracting the mass of the metal catalyst used in the production of carbon nanotubes and contained in the first reinforcing layer 40 is 98% by mass or more. When the first reinforcing layer 40 consists essentially of only carbon nanotubes, substances that are not intentionally added to the first reinforcing layer 40 and are inevitable impurities mixed in during the raw materials or manufacturing process may or may not be contained in the first reinforcing layer 40.

[0092] When the first reinforcing layer 40 contains carbon nanotubes, the carbon nanotubes contained in the first reinforcing layer 40 are not particularly limited, and are preferably at least one selected from the group consisting of multi-walled carbon nanotubes, few-walled carbon nanotubes, double-walled carbon nanotubes, and single-walled carbon nanotubes.

[0093] In the pellicle 110, the material of the first reinforcing layer 40 and the material of the second reinforcing layer 50 may be the same or different.

[0094] (Second reinforcing layer) The second reinforcing layer 50 in the second embodiment is the same as that in the first embodiment.

[0095] (Pellicle film) The pellicle film 10 in the second embodiment is the same as that in the first embodiment. In the pellicle 110, the material of the pellicle film 10 and the material of the first reinforcing layer 40 may be the same or different. For example, it is also preferable that both the material of the pellicle film 10 and the material of the first reinforcing layer 40 are the same carbon nanotubes. By forming the pellicle film 10 and the first reinforcing layer 40 of the same material, the adhesion between the pellicle film 10 and the first reinforcing layer 40 can be improved. Also, the material of the pellicle film 10, the material of the first reinforcing layer 40, and the material of the second reinforcing layer 50 may be the same or different. When the material of the pellicle film 10, the material of the first reinforcing layer 40, and the material of the second reinforcing layer 50 are the same, their adhesion is improved. It is preferable that the material of the pellicle film 10, the material of the first reinforcing layer 40, and the material of the second reinforcing layer 50 are carbon nanotubes.

[0096] (Manufacturing method of pellicle) Next, the manufacturing method of the pellicle according to the second embodiment (hereinafter, may be referred to as the manufacturing method of the second embodiment) will be described. The manufacturing method of the second embodiment further includes a step (PS1) of disposing the first reinforcing layer 40 on the outer peripheral side of the opening 32 and on the support surface 34 of the frame portion 31 before the step of attaching the pellicle film 10 to the support 30. The step (P5) of preparing the support described in the first embodiment corresponds to the step (PS1) of manufacturing the pellicle support 30A in the present embodiment.

[0097] (Manufacturing method of pellicle support) The process (PS1) is a process of manufacturing the pellicle support 30A by forming the first reinforcing layer 40 on the support surface 34 of the support 30.

[0098] The first reinforcing layer 40 may be formed using a material appropriately selected according to the material of the pellicle film 10 and the area for supporting the pellicle film 10, etc. The method of forming the first reinforcing layer 40 may be appropriately selected according to the material to be used.

[0099] For example, a material (reinforcing material) to be contained in the first reinforcing layer 40 is dispersed in a solvent to prepare a reinforcing material dispersion liquid, this reinforcing material dispersion liquid is applied to the support surface 34 of the support 30, and the solvent is evaporated to form a film made of the reinforcing material as the first reinforcing layer 40.

[0100] When the first reinforcing layer 40 is a layer containing carbon nanotubes (CNT layer), it is preferable to form the first reinforcing layer 40 so that the carbon nanotubes in the first reinforcing layer 40 are oriented in a direction parallel to the support surface 34 of the frame portion 31.

[0101] When the first reinforcing layer 40 is a CNT layer, for example, the CNT layer can be formed by a chemical vapor deposition (CVD) method, a laser ablation method, or an arc discharge method. The CNT layer may be directly formed on the support surface 34 of the support 30 by the CVD method, or after forming the CNT layer on a substrate, the CNT layer on the substrate may be transferred onto the support surface 34, or the substrate on which the CNT layer is formed may be fixed to the support surface 34.

[0102] When the first reinforcing layer 40 is a carbon nanotube forest, a carbon nanotube forest can be formed by directly growing a plurality of carbon nanotubes so as to be oriented in a direction perpendicular to the support surface 34 of the support 30. Alternatively, a carbon nanotube forest may be formed on a substrate, and the CNT layer on the substrate may be transferred onto the support surface 34, or the substrate may be fixed to the support surface 34.

[0103] When forming a CNT layer on a substrate, as the substrate, a publicly known substrate can be appropriately used. For example, at least one substrate selected from the group consisting of a plastic substrate, a glass substrate, a silicon substrate, and a metal substrate (a substrate containing a metal such as iron and copper or an alloy thereof (e.g., stainless steel)) can be used. A silicon dioxide film may be laminated on the surface of these substrates. The substrate on which the CNT layer as the first reinforcing layer 40 is formed may be fixed to the support surface 34 by an adhesive member (e.g., double-sided tape). The carbon nanotubes grown by chemical vapor deposition on the substrate are preferably at least one selected from the group consisting of multi-walled carbon nanotubes, few-walled carbon nanotubes, and single-walled carbon nanotubes, and may also be a mixture composed of a plurality of types of carbon nanotubes.

[0104] Since the first reinforcing layer 40 is formed in a range that does not interfere with development (a range that does not block the exposure light required for development), the content of carbon nanotubes in the first reinforcing layer 40 (e.g., the mass of carbon nanotubes per unit area of the film) can be increased compared to the pellicle film 10. As a result, the strength of the first reinforcing layer 40 is improved, and the impact resistance of the pellicle film 10 is also improved.

[0105] When the first reinforcing layer 40 is a layer containing graphene (graphene layer), the graphene layer as the first reinforcing layer 40 can also be formed by the CVD method. For example, the graphene layer may be directly formed on the support surface 34 of the support 30 by the CVD method, or after forming the graphene layer on a base material of a metal foil (e.g., Ni foil or Cu foil, etc.) by the CVD method, the graphene layer on the base material may be transferred onto the support surface 34. The graphene layer as the first reinforcing layer 40 may have a single-layer structure consisting of one layer, but from the viewpoint of enhancing the effect of reinforcing the pellicle film, it may also have a multilayer structure consisting of two or more layers. Since the first reinforcing layer 40 is formed in a range that does not interfere with development, even if the graphene layer has a multilayer structure, no problem will occur in development. When the graphene layer has a multilayer structure, the graphene layer may be formed into multiple layers in advance and then transferred onto the support surface 34.

[0106] The manufacturing method of the second embodiment includes the following steps (PX1) and (PX2) or the following steps (PX3) and (PX4) after the step (PS1) of manufacturing the pellicle support 30A.

[0107] Step (PX1) is a step of attaching the pellicle film 10 to the pellicle support 30A. More specifically, step (PX1) is a step of attaching the pellicle film 10 so as to cover the opening 32 and be supported by the first reinforcing layer 40 on the support surface 34 side of the frame portion 31. Step (PX1) is the same as step (P1) of the first embodiment except that the object to which the pellicle film 10 is attached is the pellicle support 30A on which the first reinforcing layer 40 has been disposed.

[0108] Step (PX2) is a step of disposing the second reinforcing layer 50 in a region on the second pellicle film surface 12 of the pellicle film 10, which is a region where the pellicle film 10 and the support 30 overlap when the pellicle film 10 is viewed in plan. That is, in step (PX2), the pellicle film 10 is first attached to the pellicle support 30A, and then the second reinforcing layer 50 is disposed on the second pellicle film surface 12 of the pellicle film 10. Step (PX2) is the same as step (P2) of the first embodiment except that the object on which the second reinforcing layer 50 is disposed is the pellicle film 10 supported by the pellicle support 30A.

[0109] Step (PX3) is a step of disposing the second reinforcing layer 50 on the pellicle film 10, specifically, a step of disposing the second reinforcing layer 50 in a region on the second pellicle film surface 12 of the pellicle film 10. Step (PX3) is the same as step (P3) of the first embodiment.

[0110] Step (PX4) is a step of attaching the pellicle film 10 with the second reinforcing layer 50 to the pellicle support 30A. More specifically, step (PX4) is a step of covering the opening 32 on the support surface 34 side of the frame portion 31 and attaching the pellicle film 10 with the second reinforcing layer 50 so as to be supported by the first reinforcing layer 40. Step (PX4) is the same as step (P4) of the first embodiment except that the object to which the pellicle film 10 with the second reinforcing layer 50 is attached is the pellicle support 30A on which the first reinforcing layer 40 has been disposed.

[0111] The manufacturing method of the second embodiment may also include a step of manufacturing the pellicle film described in the first embodiment before step (PX1).

[0112] The pellicle 110 is used as a dust cover, similar to the pellicle 120 of the first embodiment.

[0113] (Effect of the Second Embodiment) According to the pellicle according to the second embodiment, the same effects as those of the pellicle according to the first embodiment are achieved. Further, since the pellicle according to the second embodiment has the first reinforcing layer 40 on the first pellicle film surface 11 side, the pellicle film 10 is further reinforced, and the impact resistance of the pellicle 110 is further improved.

[0114] In the pellicle and the pellicle support according to the second embodiment, since the first reinforcing layer 40 is formed of a material having excellent heat resistance instead of an adhesive layer and an adhesive layer, it is difficult to be decomposed even when irradiated with high-energy light such as EUV. Therefore, according to the pellicle and the pellicle support according to the second embodiment, foreign matter generation can be suppressed as compared with a pellicle in which the pellicle film is fixed to the support via an adhesive layer or an adhesive layer.

[0115] In the pellicle and the pellicle support according to the second embodiment, when the first reinforcing layer 40 is a CNT layer (for example, a carbon nanotube forest) in which carbon nanotubes are oriented in the vertical direction, compared with reinforcing layers using the same mass of carbon nanotubes, the CNT layer in which carbon nanotubes are oriented in the vertical direction has further improved impact resistance than the CNT layer in which carbon nanotubes are oriented in the horizontal direction.

[0116] In the pellicle and the pellicle support according to the second embodiment, since the region where the first reinforcing layer 40 is disposed is the region where the pellicle film 10 and the support 30 overlap in a plan view of the pellicle 110, the transparency of the first reinforcing layer 40 may be low. Therefore, the options for materials that can be used for the first reinforcing layer 40 are expanded, and the content of the reinforcing material in the first reinforcing layer 40 (for example, the mass of the reinforcing material per unit area of the film) can be increased compared to the pellicle film 10. As a result, the strength of the first reinforcing layer 40 is improved, and the impact resistance of the pellicle 110 is also improved.

[0117] According to the pellicle and the pellicle support according to the second embodiment, since the impact resistance is improved, the number of times of pellicle replacement is reduced, and the productivity of the manufacturing process using the pellicle (for example, the manufacturing process of semiconductor devices, etc.) can be improved.

[0118] According to the manufacturing method of the second embodiment, a pellicle with improved impact resistance can be manufactured.

[0119] 〔Modifications of the Embodiment〕 Note that the present invention is not limited to the above-described embodiment, and modifications, improvements, etc. within the scope that can achieve the object of the present invention are included in the present invention. Although an example of the pellicle according to the first embodiment and the second embodiment has been described with reference to FIGS. 1 to 4, the pellicle according to the present invention is not limited to these examples of the pellicle.

[0120] The pellicle according to the present invention can adopt various forms as long as the effects of the pellicle using the pellicle films according to the aforementioned first and second embodiments can be obtained. The shape, dimensions, etc. of each part of each member constituting the pellicle according to the first and second embodiments may be determined according to, for example, the dimensions of a photomask (not shown) when the pellicles according to the first and second embodiments are used.

[0121] Also, for example, the pellicle films 10 and the supports 30 of the pellicles 110 and 120 shown in FIGS. 1 to 4 are all formed in a rectangular shape. The pellicle according to the present invention is not limited to this, and may be formed in any desired shape such as circular, elliptical, and polygonal.

[0122] Also, in the pellicle 120 shown in FIGS. 1 and 2, the second reinforcing layer 50 is disposed at the peripheral edge 13 of the pellicle film 10, but the pellicle according to the present invention is not limited to such an example. For example, the second reinforcing layer 50 may not only be disposed at the peripheral edge 13 of the pellicle film 10, but also extend to a region of the support surface 34 where the pellicle film 10 is not attached. The second reinforcing layer 50 may extend to the support surface 34 side and also cover the side portion of the pellicle film 10. By covering the side portion of the pellicle film 10 with the second reinforcing layer 50, it is possible to suppress the peeling of the pellicle film 10 from the support 30. The second reinforcing layer 50 may extend from the peripheral edge 13 of the pellicle film 10 and be in contact with a part or all of the exposed portion of the support surface 34 where the first reinforcing layer 40 is not disposed. Also in the pellicle 110 shown in FIGS. 3 and 4, the second reinforcing layer 50 may extend to the support surface 34 side.

[0123] Further, for example, in the pellicle 110 shown in FIGS. 3 and 4, the peripheral edge 13 of the pellicle film 10 is fixed by a first reinforcing layer 40 disposed on a part of the support surface 34 of the support 30. The pellicle according to the present invention is not limited to such an example, and the peripheral edge 13 of the pellicle film 10 may be fixed by a first reinforcing layer 40 disposed on the entire support surface 34 of the support. For example, the first reinforcing layer 40 may extend not only to the region supporting the pellicle film 10 but also to the region of the support surface 34 where the pellicle film 10 is not attached. The first reinforcing layer 40 extending in this way and the second reinforcing layer 50 extending as described above may be in contact with each other. By arranging the first reinforcing layer 40 and the second reinforcing layer 50 so as to be in contact with each other in this way, the peripheral edge 13 of the pellicle film 10 is sandwiched between the first reinforcing layer 40 and the second reinforcing layer 50, and the effect of reinforcing the pellicle film 10 is further improved.

Example

[0124] Hereinafter, the present invention will be described in more detail with reference to examples. The present invention is not limited to these examples at all.

[0125] [Example 1] With reference to FIGS. 5A and 5B, the production of the pellicle according to Example 1 will be described. FIG. 5A schematically shows a plan view of the pellicle WK viewed from the W side of the pellicle film 10 in plan view. FIG. 5B schematically shows a side view of the pellicle WK viewed from the side along the short side direction. As the support 30W, an acrylic plate (2 cm × 5 cm × 2 mm) having an opening 32W with a size of 1 cm × 1 cm was prepared. The opening 32W is located near the center on the side of the first end E1 of the support 30W. Next, SWCNT was dispersed in water to prepare a first SWCNT dispersion. Using a membrane filter, the first SWCNT dispersion was filtered to form a film consisting only of SWCNT on the membrane filter as the pellicle film 10W. The entire membrane filter was submerged in water, and the pellicle film 10W consisting only of SWCNT was isolated on the water surface. The support 30W was submerged in water where the pellicle film 10W was isolated, and the support 30W was lifted out of the water. The pellicle film 10W was picked up as a self - standing film so as to cover the opening 32W. In this way, the pellicle WK was produced. In the pellicle WK, the pellicle film 10W (CNT self - standing film) was integrated with the support 30W. Next, a second SWCNT dispersion was prepared by dispersing SWCNT in water at a higher concentration compared to the first SWCNT dispersion. Next, when the pellicle film 10W supported by the support 30W was viewed in plan view, in the region where the pellicle film 10W and the support 30 overlapped, and at the peripheral edge of the pellicle film 10W, the second SWCNT dispersion was dropped and allowed to dry naturally, forming a second reinforcing layer 50W containing SWCNT oriented in the horizontal direction. In this way, the pellicle WK according to Example 1 was produced. In the pellicle WK according to Example 1, a second reinforcing layer 50W with a significantly increased SWCNT content compared to the pellicle film 10W could be formed.

[0126] [Reference Example 1] First, MWCNT was dispersed in water to prepare a first MWCNT dispersion. The first MWCNT dispersion was dropped on the outer periphery of the opening 32W of the support 30W and allowed to dry naturally, forming a first reinforcing layer containing MWCNT oriented in the horizontal direction. In this way, a support 30W (pellicle support) with a first reinforcing layer was obtained. Next, in the same manner as in Example 1, a pellicle film 10W composed only of SWCNT was isolated on the water surface. The support 30W (pellicle support) with the first reinforcing layer was submerged in the water where the pellicle film 10W was isolated, and the support 30W was lifted out of the water. The pellicle film 10W was picked up as a self - standing film so as to cover the opening 32W and be supported on the first reinforcing layer. In this way, the pellicle according to Reference Example 1 was produced. In the pellicle according to Reference Example 1, the pellicle film 10W (CNT self - standing film) was integrated with the support 30W and reinforced by the first reinforcing layer.

[0127] [Comparative Example 1] The pellicle according to Comparative Example 1 was produced in the same manner as in Example 1, except that the second reinforcing layer 50W was not provided.

[0128] [Impact Resistance Evaluation] The evaluation method was carried out according to the following procedure. FIG. 6 schematically shows a method for evaluating the strength of the pellicle film using the pellicle WK, and shows a state in which the pellicle WK is viewed from the side along the short side direction. As shown in FIG. 6, first, the pellicle WK was placed on a horizontal table T. A stopper S was arranged so as to be in contact with the second end E2 side of the pellicle WK. Next, with the second end E2 side of the pellicle WK being made non-slip, the first end E1 side was lifted, and a plate-like member B with a thickness of 1 mm was sandwiched between the table T and the pellicle WK. Next, the plate-like member B was extracted in the horizontal direction H, and the pellicle WK was dropped. After dropping the pellicle WK, the presence or absence of damage to the pellicle film 10W was visually confirmed. If there was no damage, plate-like members B with a thickness of 1 mm were stacked, two plate-like members B were sandwiched, the two plate-like members B were extracted in the horizontal direction H, and the pellicle WK was dropped. This operation was repeated until damage occurred to the pellicle film 10W, and the maximum height at the time of dropping when the pellicle film 10W did not suffer damage was evaluated as the impact resistance of the pellicle film 10W. Note that the maximum height corresponds to the maximum number of plate-like members B when the plate-like members B with a thickness of 1 mm are stacked. The impact resistance evaluation of the pellicle film 10W was performed three times according to the above procedure, and the average value of the three times was taken. Table 1 shows the results of the impact resistance evaluation of the pellicles according to Example 1, Reference Example 1, and Comparative Example 1.

[0129]

Table 1

[0130] As shown in Table 1, according to the pellicle according to Example 1 in which the second reinforcing layer is disposed on the second pellicle film surface side of the pellicle film, the pellicle film is less likely to be damaged and the impact resistance is improved. The pellicle according to Example 1 exhibited even better impact resistance than the pellicle according to Reference Example 1 having the first reinforcing layer in which MWCNTs are oriented in the horizontal direction. Further, since the second reinforcing layer is formed of carbon nanotubes and has excellent heat resistance, it is difficult to decompose even when irradiated with high-energy light such as EUV.

Explanation of Signs

[0131] 10… pellicle film, 10W… pellicle film, 11… first pellicle film surface, 12… second pellicle film surface, 13… peripheral portion, 30… support, 30A… pellicle support, 30W… support, 31… frame portion, 32… opening, 32W… opening, 34… support surface, 40… first reinforcing layer, 50… second reinforcing layer, 50W… second reinforcing layer, 110… pellicle, 120… pellicle, B… plate-like member, E1… first end, E2… second end, H… horizontal direction, S… stopper, T… stage, WK… pellicle.

Claims

1. A pellicle film, a support having a frame portion and an opening surrounded by the frame portion, and supporting the pellicle film, a first reinforcing layer, and a second reinforcing layer for reinforcing the pellicle film, wherein the frame portion has a support surface facing the pellicle film, the pellicle film has a first pellicle film surface facing the support and a second pellicle film surface opposite to the first pellicle film surface, when the pellicle film supported by the support is viewed in plan view, the second reinforcing layer is an area where the pellicle film and the support overlap, and is disposed on the second pellicle film surface side, the second reinforcing layer does not protrude beyond the opening side of the support, and the inner end of the second reinforcing layer is formed flush with the inner end face of the frame portion or is formed to be located inside the inner end face of the frame portion, the second reinforcing layer contains one or more materials selected from the group consisting of carbon nanotubes, graphene, graphite, diamond-like carbon, and amorphous carbon, the first reinforcing layer is on the first pellicle film surface side and is disposed between the pellicle film and the support, the first reinforcing layer contains one or more materials selected from the group consisting of carbon nanotubes, graphene, graphite, diamond-like carbon, amorphous carbon, silicon carbide, silicon nitride, and boron nitride, the pellicle film contains one or more materials selected from the group consisting of carbon nanotubes, graphene, graphite, diamond-like carbon, amorphous carbon, silicon carbide, silicon nitride, and boron nitride.

2. In the pellicle according to Claim 1, the first reinforcing layer is disposed in direct contact with the support surface.

3. In the pellicle according to Claim 1 or Claim 2, the second reinforcing layer contains carbon nanotubes, and the carbon nanotubes in the second reinforcing layer are oriented in a direction parallel to the support surface of the frame portion.

4. In the pellicle according to Claim 1 or Claim 2, the pellicle film contains carbon nanotubes.

5. In the pellicle according to Claim 1 or Claim 2, the material of the pellicle film is the same as the material of the second reinforcing layer.

6. In the pellicle according to Claim 1 or Claim 2, the first reinforcing layer includes carbon nanotubes, A pellicle, wherein the carbon nanotubes in the first reinforcing layer are oriented in a direction parallel to the support surface of the frame.

7. The pellicle according to claim 2, the second reinforcing layer contains carbon nanotubes, The pellicle membrane contains carbon nanotubes, A pellicle, wherein the first reinforcing layer contains carbon nanotubes.

8. The pellicle according to claim 7, the carbon nanotubes in the second reinforcing layer are oriented in a direction parallel to the support surface of the frame; A pellicle, wherein the carbon nanotubes in the first reinforcing layer are oriented in a direction parallel to the support surface of the frame.

9. The pellicle according to claim 7 or claim 8, A pellicle in which the mass of carbon nanotubes per unit area of the membrane in the second reinforcing layer is increased compared to the pellicle membrane.

10. The pellicle according to claim 7 or claim 8, A pellicle in which the mass of carbon nanotubes per unit area of the membrane in the first reinforcing layer is increased compared to the pellicle membrane.

11. The pellicle according to claim 9, A pellicle in which the mass of carbon nanotubes per unit area of the membrane in the first reinforcing layer is increased compared to the pellicle membrane.

12. The pellicle according to claim 1 or claim 2, A pellicle, wherein the second reinforcing layer extends to an area of the support surface where the pellicle membrane is not attached and covers the sides of the pellicle membrane.

13. The pellicle according to claim 12, A pellicle, wherein the first reinforcing layer extends into an area of the support surface where the pellicle membrane is not attached and is in contact with the second reinforcing layer, which also extends into an area of the support surface where the pellicle membrane is not attached.

14. A method for manufacturing a pellicle, comprising: A step of attaching a pellicle membrane to a support having an opening and a frame portion surrounding the opening so as to cover the opening and be supported by a support surface of the frame portion; A method for manufacturing a pellicle, comprising: a step of placing a second reinforcing layer in a region on a second pellicle membrane surface opposite a first pellicle membrane surface facing the support, where the pellicle membrane and the support overlap when the pellicle membrane is viewed in a plane.

15. A method for manufacturing a pellicle according to claim 14, wherein the second reinforcing layer contains one or more materials selected from the group consisting of carbon nanotubes, graphene, graphite, diamond-like carbon, amorphous carbon, silicon, silicon carbide, silicon nitride, and boron nitride. A method for manufacturing a pellicle.

16. A method for manufacturing a pellicle according to claim 14, wherein in the step of disposing the second reinforcing layer, the second reinforcing layer does not protrude beyond the opening side of the support, and the inner end of the second reinforcing layer is aligned with the inner end face of the frame portion or formed to be located inside the inner end face of the frame portion. A method for manufacturing a pellicle.

17. A method for manufacturing a pellicle according to claim 14, wherein before the step of attaching the pellicle film, a step of disposing a first reinforcing layer on the outer peripheral side of the opening and on the support surface of the frame portion is further included, the first reinforcing layer contains one or more materials selected from the group consisting of carbon nanotubes, graphene, graphite, diamond-like carbon, amorphous carbon, silicon, silicon carbide, silicon nitride, and boron nitride, and in the step of attaching the pellicle film, the pellicle film is attached so as to cover the opening and be supported by the first reinforcing layer. A method for manufacturing a pellicle.

18. A method for manufacturing a pellicle according to claim 17, wherein the first reinforcing layer contains one or more materials selected from the group consisting of carbon nanotubes, graphene, graphite, diamond-like carbon, amorphous carbon, silicon carbide, silicon nitride, and boron nitride. A method for manufacturing a pellicle.

19. A method for manufacturing a pellicle for manufacturing a pellicle, comprising: a step of disposing a second reinforcing layer on a pellicle film; and a step of attaching the pellicle film provided with the second reinforcing layer to a support having an opening and a frame portion surrounding the opening so as to cover the opening and be supported by the support surface of the frame portion, and further including a step of disposing a first reinforcing layer on the outer peripheral side of the opening and on the support surface of the frame portion before the step of attaching the pellicle film. In the step of arranging the second reinforcing layer, the second reinforcing layer is pre-arranged in a region on a second pellicle membrane surface opposite to a first pellicle membrane surface facing the support, where the pellicle membrane and the support overlap when the pellicle membrane is attached to the support in a plan view, Furthermore, in the step of arranging the second reinforcing layer, the second reinforcing layer does not protrude toward the opening of the support body, and an inner end portion of the second reinforcing layer is formed to be aligned with an inner end surface of the frame portion or to be positioned more inward than the inner end surface of the frame portion, In the step of attaching the pellicle membrane, the pellicle membrane is attached so as to cover the opening and be supported by the first reinforcing layer; the first reinforcing layer contains one or more materials selected from the group consisting of carbon nanotubes, graphene, graphite, diamond-like carbon, amorphous carbon, silicon carbide, silicon nitride, and boron nitride; the second reinforcing layer contains one or more materials selected from the group consisting of carbon nanotubes, graphene, graphite, diamond-like carbon, and amorphous carbon; The method for manufacturing a pellicle, wherein the pellicle film contains one or more materials selected from the group consisting of carbon nanotubes, graphene, graphite, diamond-like carbon, amorphous carbon, silicon carbide, silicon nitride, and boron nitride.

20. A method for manufacturing a pellicle according to claim 17 or claim 19, comprising: A method for manufacturing a pellicle, wherein the first reinforcing layer is positioned in direct contact with the support surface.

21. 20. A method for manufacturing a pellicle according to claim 15 or 19, comprising: the second reinforcing layer includes carbon nanotubes, A method for manufacturing a pellicle, wherein the second reinforcing layer is formed so that the carbon nanotubes in the second reinforcing layer are oriented in a direction parallel to the membrane surface of the pellicle membrane.

22. 20. A method for manufacturing a pellicle according to claim 17 or 19, comprising: The method for manufacturing a pellicle, wherein the first reinforcing layer contains carbon nanotubes.

23. 20. The method for manufacturing a pellicle according to claim 17 or 19, the first reinforcing layer includes carbon nanotubes, A method for manufacturing a pellicle, comprising forming the first reinforcing layer so that the carbon nanotubes in the first reinforcing layer are oriented in a direction parallel to the support surface of the frame.

24. 20. The method for manufacturing a pellicle according to claim 14 or 19, The method for manufacturing a pellicle, wherein the pellicle membrane contains carbon nanotubes.

25. 20. The method for manufacturing a pellicle according to claim 14 or 19, A method for manufacturing a pellicle, wherein the material of the pellicle membrane and the material of the second reinforcing layer are the same.

26. A method for manufacturing a pellicle according to claim 20, comprising: the second reinforcing layer contains carbon nanotubes, The pellicle membrane contains carbon nanotubes, The method for manufacturing a pellicle, wherein the first reinforcing layer contains carbon nanotubes.

27. The pellicle according to claim 20, A method for manufacturing a pellicle, wherein the mass of carbon nanotubes per unit area of the membrane in the second reinforcing layer is increased compared to the pellicle membrane.

28. The pellicle according to claim 20, A method for manufacturing a pellicle, wherein the mass of carbon nanotubes per unit area of the membrane in the first reinforcing layer is increased compared to the pellicle membrane.

29. The pellicle according to claim 27, A method for manufacturing a pellicle, wherein the mass of carbon nanotubes per unit area of the membrane in the first reinforcing layer is increased compared to the pellicle membrane.

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