Carbon sheet for pellicle, pellicle, and method for producing carbon sheet for pellicle

Abstract

The present disclosure provides a carbon sheet for a pellicle, a pellicle, and a method for manufacturing a carbon sheet for a pellicle, the carbon sheet having excellent transmittance to ultraviolet light and being capable of free-standing.SOLUTION: According to an exemplary embodiment of the present disclosure, it is possible to provide a carbon sheet for a pellicle, which includes a bundle composed of a plurality of carbon nanotubes and has a ratio (P / D) of a porosity (P) to a linear density (D, [g / km]) of 0.2 or more to 10 or less, a pellicle having excellent UV transmittance and capable of free-standing, and a method of manufacturing the carbon sheet for a pellicle.SELECTED DRAWING: Figure 1

Description

Detailed Description of the Invention

[0001] [Technical field] The present disclosure relates to a carbon sheet for a pellicle, a pellicle for a photomask, and a method for manufacturing a carbon sheet for a pellicle.

[0002] [Background technology] Photolithography is a technique for transferring a pattern onto a substrate (e.g., a wafer) using a photomask pattern and light. In recent years, extreme ultraviolet (EUV) light has been used in photolithography to facilitate the high integration and miniaturization of semiconductors.

[0003] Pellicles are used to protect photomasks used in photolithography. A pellicle covers one side of a photomask to prevent foreign matter from adhering to the photomask.

[0004] [Summary of the Invention] [Problem to be solved by the invention] The technical problem to be solved by the present disclosure is to provide a carbon sheet for a pellicle that has excellent transmittance to ultraviolet light and is free-standing, a pellicle, and a method for manufacturing a carbon sheet for a pellicle.

[0005] The technical problems of the present disclosure are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

[0006] [Means for solving the problem] A carbon sheet according to an embodiment of the present disclosure may be used for a pellicle. The carbon sheet according to an embodiment of the present disclosure may include a bundle of carbon nanotubes, and may have a ratio (P / D) of porosity (P) to linear density (D, [g / km]) of 0.2 or more and 10 or less.

[0007] In the carbon sheet according to one embodiment of the present disclosure, the porosity (P) may be 0.5 or more and 0.95 or less.

[0008] In the carbon sheet according to one embodiment of the present disclosure, the linear density (D) may be greater than 0.5 g / km and less than or equal to 2.8 g / km.

[0009] In a carbon sheet according to an embodiment of the present disclosure, the bundles may have a diameter of 10 nm or more and 100 nm or less.

[0010] In a carbon sheet according to one embodiment of the present disclosure, at least a portion of the plurality of carbon nanotubes may include one or more selected from the group consisting of single-walled carbon nanotubes (SWCNTs), double-walled carbon nanotubes (DWCNTs), and multi-walled carbon nanotubes (MWCNTs).

[0011] The carbon sheet according to an embodiment of the present disclosure may further include a metal element.

[0012] The carbon sheet according to an embodiment of the present disclosure may further include sulfur (S).

[0013] A pellicle according to an embodiment of the present disclosure may be for protecting a photomask. The pellicle according to the embodiment of the present disclosure may include a carbon sheet including bundles of carbon nanotubes and a pellicle frame supporting the carbon sheet, and the carbon sheet may have a ratio (P / D) of porosity (P) to linear density (D, [g / km]) of 0.2 or more and 10 or less.

[0014] A pellicle according to an embodiment of the present disclosure may have a structure in which multiple carbon sheets are stacked.

[0015] A method for manufacturing a carbon sheet for a pellicle according to one embodiment of the present disclosure includes reacting a raw material containing a carbon source to form a bundle of carbon nanotubes, and the carbon sheet for a pellicle includes a bundle of carbon nanotubes, and the ratio (P / D) of the porosity (P) to the linear density (D, [g / km]) of the carbon sheet may be 0.2 or more and 10 or less.

[0016] In the method for manufacturing a carbon sheet for a pellicle according to an embodiment of the present disclosure, the raw material may further include a catalyst containing a metal element and a catalyst activator containing a sulfur element (S).

[0017] In a method for manufacturing a carbon sheet for a pellicle according to an embodiment of the present disclosure, raw materials may be reacted at a reaction temperature of 500°C to 2,000°C.

[0018] In a method for manufacturing a carbon sheet for a pellicle according to one embodiment of the present disclosure, raw materials are introduced into a reaction zone of a reaction chamber to react, and the rate at which the raw materials are introduced into the reaction zone may be greater than 15 g / h and less than 30 g / h.

[0019] A method for manufacturing a carbon sheet for a pellicle according to an embodiment of the present disclosure may further include adjusting the temperature of the reaction region of the reaction chamber to a reaction temperature before introducing the raw material into the reaction region.

[0020] A method for manufacturing a carbon sheet for a pellicle according to an embodiment of the present disclosure may further include adjusting the temperature of the reaction region to a reaction temperature before introducing the raw material into the reaction region of the reaction chamber, and then introducing a gas into the reaction region.

[0021] Further details of the embodiments are included in the detailed description and drawings.

[0022] [Effects of the invention] The present disclosure can provide a carbon sheet for a pellicle that has excellent transmittance to ultraviolet light and is free-standing, a pellicle, and a method for manufacturing a carbon sheet for a pellicle.

[0023] The effects of the present disclosure are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the following description. [Brief explanation of the drawings]

[0024] The drawings shown in this disclosure are by way of example, and the proportions of width, width or height (or thickness) of each component are for the purpose of explaining this disclosure in detail, and these proportions may differ from the actual proportions.

[0025] [Figure 1] 1A and 1B are diagrams illustrating a pellicle for a photomask and an ultraviolet lithography technique according to an embodiment of the present disclosure. [Figure 2] 1 shows images of the carbon sheets produced in Example 1, Example 2, and Comparative Example 1 taken with a scanning electron microscope (microscope magnification: ×30,000, scale bar size: 2 μm). [Figure 3] This is an image obtained by performing binary imaging on FIG. 2 (microscope magnification: ×30,000, scale bar size: 2 μm).

[0026] [Mode for Carrying Out the Invention] Prior to the detailed description of the present disclosure, the terms and words used in the specification and claims should not be interpreted as being limited to their ordinary and dictionary meanings. Furthermore, the inventor may interpret the terms and words in a way that is consistent with the technical idea of ​​the present disclosure, based on the principle that the concept of the terms can be appropriately defined in order to best describe his or her invention. The embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present disclosure and may not represent the entire technical idea of ​​the present disclosure. Therefore, at the time of filing of the present disclosure, there may be various equivalents and modifications that can be substituted for them.

[0027] The same reference numbers or symbols in the drawings attached to this specification may indicate parts or components that perform substantially the same functions. For ease of explanation and understanding, the same reference numbers or symbols may be used in different embodiments. In other words, even if components having the same reference numbers are shown in multiple drawings, it may not mean that all of the multiple drawings refer to the same embodiment.

[0028] In the following description, the singular includes the plural unless the context clearly dictates otherwise. Terms such as "comprise" or "comprise" are intended to specify the presence of a feature, number, step, operation, component, part, or combination thereof stated in the specification, and may be understood as not precluding the presence or possibility of addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0029] In the following description, terms such as upper, top, lower, side, front, and rear are used based on the direction of the drawings, and may be expressed differently if the direction of the corresponding object is changed. Other similar terms describing the positional relationship between components may also be interpreted in the same manner as above.

[0030] Furthermore, in this specification and claims, terms including ordinal numbers, such as "first," "second," etc., may be used to distinguish between components. Such ordinal numbers may be used to distinguish between identical or similar components, and the use of such ordinal numbers should not be interpreted as limiting the meaning of the terms. For example, the numbers of components combined with such ordinal numbers should not be interpreted as limiting the order of use or arrangement. If necessary, each ordinal number may be used interchangeably.

[0031] The term "room temperature" as used herein refers to a natural temperature that is neither heated nor cooled, and may refer to, for example, any temperature within the range of 10°C to 30°C, such as about 15°C or higher, about 18°C ​​or higher, about 20°C or higher, about 23°C or higher, about 27°C or lower, or a temperature of 25°C. Unless otherwise specified herein, the unit of temperature is Celsius (°C). Furthermore, when the measurement temperature affects a physical property mentioned herein, the physical property may be measured at 25°C unless otherwise specified.

[0032] As used herein, the term "normal pressure" refers to natural pressure without pressure or decompression, and typically refers to atmospheric pressure of approximately 700 mmHg to 800 mmHg. Unless otherwise specified herein, the unit of pressure may be mmHg. Furthermore, when the measurement pressure affects a physical property mentioned herein, the physical property may be measured at normal pressure unless otherwise specified.

[0033] Physical properties referred to herein may have units according to the SI system (international system of units) unless otherwise specified.

[0034] 1 is a diagram illustrating a pellicle 100 and ultraviolet lithography technology according to an embodiment of the present disclosure. The pellicle 100 can be used, for example, for a photomask. The ultraviolet lithography technology involves irradiating ultraviolet light generated by a light source L onto a photomask 200, and then focusing the ultraviolet light reflected from the photomask 200 via a lens 300 onto a substrate 400 coated with photoresist (PR), thereby transferring a mask pattern 200P of the photomask 200 onto the photoresist (PR).

[0035] In one example, if foreign matter is attached to the photomask 200, the ultraviolet light may be partially absorbed or scattered by the foreign matter, preventing the transfer of the mask pattern 200P and resulting in a decrease in the production yield of semiconductor chips. In particular, since the mask pattern 200P is formed finer due to the use of ultraviolet light, even a small size of the foreign matter can have a direct impact on the production yield of semiconductor chips.

[0036] In one example, ultraviolet light in the present disclosure may refer to light having a wavelength of 10 nm or more and 400 nm or less. In one example, ultraviolet light in the present disclosure may refer to extreme ultraviolet light. Extreme ultraviolet light may refer to light having a wavelength of, for example, 121 nm or less, and specifically, extreme ultraviolet light may refer to light having a wavelength of, for example, 10 nm or more and 121 nm or less. In one example, the wavelength of extreme ultraviolet light may be 13.5 nm. Furthermore, among the physical properties referred to in this specification, if the wavelength of ultraviolet light affects the physical property, the physical property may be measured using extreme ultraviolet light having a wavelength of 13.5 nm unless otherwise specified.

[0037] The pellicle 100 according to an embodiment of the present disclosure may be for protecting the above-described photomask 200. That is, the photomask 200 may prevent foreign matter from adhering to the mask pattern 200P through the pellicle 100, thereby preventing a decrease in the production yield of semiconductor chips.

[0038] In one example, the pellicle 100 may be spaced apart from the photomask 200 by a predetermined distance in a first direction D1, which is perpendicular to the surface of the carbon sheet 110 described below. The distance between the pellicle 100 and the photomask 200 may be, for example, 15 nm or less, or may be 1 nm or more to 10 nm or less.

[0039] In one example, pellicle 100 may have a transmittance of 80% or more, 85% or more, or 90% or more for ultraviolet light. In one example, pellicle 100 may have a transmittance of 80% or more, 85% or more, or 90% or more for light with a wavelength of 13.5 nm. The transmittance herein may be expressed as a percentage of the radiant flux (W) of light before passing through pellicle 100 compared to the radiant flux of light after passing through pellicle 100. Pellicle 100 may have excellent transmittance for extreme ultraviolet light through carbon sheet 110, which will be described later, or the like.

[0040] The transmittance of the pellicle 100 for a specific wavelength may refer to the transmittance of the carbon sheet 110 for a specific wavelength, which will be described in detail later. That is, the carbon sheet 110 may have a transmittance of 80% or more, 85% or more, or 90% or more for ultraviolet light, and may have a transmittance of 80% or more, 85% or more, or 90% or more for light with a wavelength of 13.5 nm.

[0041] The pellicle 100 according to an embodiment of the present disclosure may include a carbon sheet 110 that is transparent to ultraviolet light. In one example, the carbon sheet 110 may include a bundle of carbon nanotubes. In one example, the carbon sheet 110 may be in the form of a thin film. The carbon sheet 110 may be used for the pellicle 100.

[0042] In one example, the pellicle 100 may include a pellicle frame 120 that supports the carbon sheet 110. In one example, the pellicle frame 120 may be disposed on an edge of the carbon sheet 110 to support the carbon sheet 110. The pellicle frame 120 may space the carbon sheet 110 at a predetermined distance from the photomask 200. In one example, when viewed from a first direction D1 that is perpendicular to the surface of the carbon sheet 110, the pellicle frame 120 may have a rectangular or circular frame structure, and may preferably have the same shape as the carbon sheet 110.

[0043] In one example, pellicle 100 may be free-standing while having excellent transmittance to ultraviolet light by including a carbon sheet 110 containing bundles made of carbon nanotubes.

[0044] In one example, the carbon sheet 110 may have a ratio (P / D) of porosity (P) to linear density (D, [g / km]) of 0.2 or more, 0.21 or more, 0.22 or more, 0.23 or more, 0.24 or more, 0.25 or more, 0.26 or more, 0.27 or more, 0.28 or more, 0.29 or more, 0.3 or more, 0.31 or more, 0.32 or more, 0.33 or more, or 0.34 or more, or 10 or less, 9.5 or less, 9 or less, 8.5 or less, 8 or less, 7.5 or less, 7 or less, 6.5 or less, 6 or less, 5.5 or less, 5 or less, 4.5 or less, 4 or less, 3.5 or less, 3 or less, 2.5 or less, 2 or less, or 1.5 or less. The ratio (P / D) of porosity (P) to linear density (D, [g / km]) of the carbon sheet 110 may be within a range formed by selecting the upper and lower limits described above.

[0045] In one example, the carbon sheet 110 may also be free-standing. On the other hand, if the ratio (P / D) of the porosity (P) to the linear density (D, [g / km]) of the carbon sheet 110 satisfies the above-mentioned range, the carbon sheet 110 may be free-standing while having excellent transmittance to ultraviolet light.

[0046] In one example, the carbon sheet 110 may have a porosity (P) of 0.5 or more, 0.51 or more, 0.52 or more, 0.53 or more, 0.54 or more, 0.55 or more, 0.56 or more, 0.57 or more, 0.58 or more, 0.59 or more, 0.6 or more, or 0.61 or more, or 0.95 or less, 0.94 or less, 0.93 or less, 0.92 or less, 0.91 or less, or 0.9 or less. The porosity (P) of the carbon sheet 110 may be within a range formed by selecting the upper and lower limits described above. When the porosity (P) of the carbon sheet 110 satisfies the above range, the carbon sheet 110 may be freestanding while having excellent transmittance to ultraviolet light. In this specification, the porosity (P) may be measured by photographing the carbon sheet 110 using a scanning electron microscope (SEM) to generate a photographed image, converting the generated photographed image into a binary image (e.g., using Otsu's method), and then measuring the porosity (P) from the brightness distribution after performing the binary imaging. A computer program (e.g., Calporosity_AXR) may be used to measure the porosity (P) from the brightness distribution.

[0047] In one example, the carbon sheet 110 has a linear density (D) of greater than 0.5 g / km, 0.51 g / km or greater, 0.52 g / km or greater, 0.53 g / km or greater, 0.54 g / km or greater, 0.55 g / km or greater, 0.56 g / km or greater, 0.57 g / km or greater, 0.58 g / km or greater, 0.59 g / km or greater, 0.6 g / km or greater, 0.61 g / km or greater, 0.62 g / km or greater, 0.63 g / km or greater, 0.64 g / km or greater, 0.65 g / km or greater, or 0.66 g / km or greater, or 2.8 g / km or greater. The linear density (D) of the carbon sheet 110 may be within a range defined by selecting the upper and lower limits described above. When the linear density (D) of the carbon sheet 110 is within the above range, the carbon sheet 110 may be freestanding while exhibiting excellent transmittance to ultraviolet light. The linear density herein can be measured, for example, according to KS K ISO 7211-2.

[0048] In one example, the diameter of the bundles may be 10 nm or more, 15 nm or more, 20 nm or more, 25 nm or more, 30 nm or more, 35 nm or more, 40 nm or more, 45 nm or more, or 50 nm or more, or 100 nm or less, 95 nm or less, 90 nm or less, 85 nm or less, 80 nm or less, 75 nm or less, 70 nm or less, or 65 nm or less. The diameter of the bundles may be within a range formed by selecting the upper and lower limits described above. When the diameter of the bundles satisfies the above range, a freestanding carbon sheet 110 can be formed that has excellent UV transmittance. The diameter of the bundles may be, for example, the arithmetic average of the diameters measured for 100 or more bundles.

[0049] In one example, the carbon sheet 110 can include a plurality of carbon nanotubes. The diameter of at least some of the plurality of carbon nanotubes can be less than 10 nm, 9.5 nm or less, 9 nm or less, 8.5 nm or less, 8 nm or less, 7.5 nm or less, 7 nm or less, 6.5 nm or less, 6 nm or less, 5.5 nm or less, 5 nm or less, 4.5 nm or less, 4 nm or less, 3.5 nm or less, 3 nm or less, 2.5 nm or less, 2 nm or less, 1.5 nm or less, or 1 nm or less. The diameter of the carbon nanotubes can be, for example, 0.1 nm or more, but is not particularly limited. By including a plurality of carbon nanotubes in the carbon sheet 110, it is possible to form a free-standing carbon sheet 110 that has excellent transmittance to ultraviolet light. In one example, the content of bundles in the carbon sheet 110 can be greater than the content of carbon nanotubes.

[0050] In one example, at least a portion of the plurality of carbon nanotubes may include one or more selected from the group consisting of single-walled carbon nanotubes (SWCNT), double-walled carbon nanotubes (DWCNT), and multi-walled carbon nanotubes (MWCNT).

[0051] In one example, the carbon sheet 110 may include a carbon-based material other than carbon nanotubes. The carbon-based material may include, but is not limited to, one or more selected from the group consisting of graphene, graphene oxide, fullerene, and amorphous carbon. By including the carbon-based material, the carbon sheet 110 may ensure durability against heat generated by high-energy ultraviolet rays and minimize deterioration caused by ultraviolet rays. The carbon-based material may include defects, and the defects may be sp 3The defects may include one or more selected from the group consisting of carbon atoms, oxygen atoms, nitrogen atoms, and carbon vacancies. The defects may have various forms, such as line defects such as grain boundaries, or point defects.

[0052] In one example, the carbon sheet 110 may include a metal element. Examples of the metal element include, but are not limited to, iron (Fe), molybdenum (Mo), titanium (Ti), rubidium (Ru), copper (Cu), aluminum (Al), gold (Au), platinum (Pt), and silver (Ag). The metal element may exist in a pure state or in a compound state, such as a metal oxide, a metal nitride, or a metal chalcogenide-based material. The types of compounds are not limited thereto. Specifically, examples of the metal oxide and metal nitride include iron oxide, molybdenum oxide, molybdenum nitride, and titanium nitride. Examples of the metal chalcogenide-based material include transition metal chalcogenides. The carbon sheet 110 contains a metal element, thereby ensuring durability against heat generated by ultraviolet rays, minimizing deterioration caused by ultraviolet rays, and increasing transmittance of ultraviolet rays.

[0053] In one example, the carbon sheet 110 may contain elemental sulfur (S). By containing elemental sulfur, the carbon sheet 110 may ensure durability against heat generated by ultraviolet rays, minimize deterioration due to ultraviolet rays, and increase transmittance to ultraviolet rays.

[0054] In one example, the carbon sheet 110 may have a structure in which multiple carbon sheets 110 are stacked. Even when multiple carbon sheets 110 are stacked, the carbon sheets 110 may satisfy the above-mentioned physical properties. When multiple carbon sheets 110 are stacked and satisfy the above-mentioned physical properties, the carbon sheets 110 may be free-standing while having excellent UV transmittance. In one example, the structure in which multiple carbon sheets 110 are stacked may include, for example, 2 or more, 3 or more, 4 or more, or 100 or less, 50 or less, or 10 or less carbon sheets 110.

[0055] In one example, the carbon sheet 110 may have a pyrolysis temperature of 800°C or higher. In another example, the carbon sheet 110 may have a pyrolysis temperature of 850°C or higher, 900°C or higher, 950°C or higher, 1,000°C or higher, 1,050°C or higher, 1,100°C or higher, 1,150°C or higher, or 1,200°C or higher. The upper limit of the pyrolysis temperature of the carbon sheet 110 is not particularly limited, and may be, for example, 2,000°C or lower, 1,950°C or lower, 1,900°C or lower, 1,850°C or lower, 1,800°C or lower, 1,750°C or lower, 1,700°C or lower, 1,650°C or lower, 1,600°C or lower, 1,550°C or lower, 1,500°C or lower, 1,450°C or lower, or 1,400°C or lower. The pyrolysis temperature of the carbon sheet 110 may be within a range formed by selecting the above upper and lower limits. The carbon sheet 110 may have the aforementioned pyrolysis temperature by including bundles of the aforementioned carbon nanotubes. In this specification, the pyrolysis temperature may refer to the temperature at which a weight loss rate of about 20% (i.e., a remaining weight of 80%) occurs when thermogravimetric analysis is performed in an air atmosphere.

[0056] In one example, the thickness of the carbon sheet 110 can be determined taking into consideration the ratio (P / D) of the porosity (P) to the linear density (D, [g / km]) described above. For example, the carbon sheet 110 can have a thickness of 100 nm or less. In one example, the carbon sheet 110 can have a thickness of 70 nm or less or 50 nm or less. The thickness of the carbon sheet 110 is not particularly limited as long as it has excellent durability, high transmittance to ultraviolet light, and is freestanding. For example, the thickness of the carbon sheet 110 can be 10 nm or more, 20 nm or more, 30 nm or more, or 40 nm or more.

[0057] In one example, the carbon sheet 110 may include 80% by weight or more, 81% by weight or more, 82% by weight or more, 83% by weight or more, 84% by weight or more, 85% by weight or more, 86% by weight or more, 87% by weight or more, 88% by weight or more, 89% by weight or more, 90% by weight or more, 91% by weight or more, 92% by weight or more, or 93% by weight or more of bundles relative to the total weight. Since a higher content of bundles in the carbon sheet 110 can improve optical properties such as UV transmittance, the content is not particularly limited. For example, the carbon sheet 110 may include 100% by weight or less, less than 100% by weight, 99% by weight or less, 98% by weight or less, 97% by weight or less, 96% by weight or less, or 95% by weight or less of bundles relative to the total weight. The carbon sheet 110 may include bundles within a range formed by selecting the above upper and lower limits. This allows the carbon sheet 110 to have excellent UV transmittance while being freestanding.

[0058] In one example, the carbon sheet 110 may contain carbon (C) at a content of 60 wt% or more, 65 wt% or more, 70 wt% or more, 75 wt% or more, 80 wt% or more, 85 wt% or more, 90 wt% or more, 95 wt% or more, 99 wt% or more, or 99.9 wt% or more relative to the total weight. The upper limit of the carbon (C) content in the carbon sheet 110 is not particularly limited. For example, the carbon sheet 110 may contain oxygen (C) at a content of 100 wt% or less, less than 100 wt%, or 99.99 wt% or less relative to the total weight. The carbon sheet 110 may contain carbon (C) within a range determined by selecting the above upper and lower limits. As a result, the carbon sheet 110 may be freestanding while exhibiting excellent UV transmittance.

[0059] In one example, the carbon sheet 110 may contain metal elements at 1 wt% or more, 1.5 wt% or more, 2 wt% or more, 2.5 wt% or more, 3 wt% or more, 3.5 wt% or more, 4 wt% or more, 4.5 wt% or more, or 5 wt% or more, or 15 wt% or less, 14.5 wt% or less, 14 wt% or less, 13.5 wt% or less, 13 wt% or less, 12.5 wt% or less, 12 wt% or less, 11.5 wt% or less, 11 wt% or less, 10.5 wt% or less, 10 wt% or less, 9.5 wt% or less, 9 wt% or less, 8.5 wt% or less, 8 wt% or less, 7.5 wt% or less, 7 wt% or less, 6.5 wt% or less, or 6 wt% or less, based on the total weight of the carbon sheet 110. The carbon sheet 110 may contain metal elements within a range formed by selecting the upper and lower limits described above. This allows the carbon sheet 110 to be free-standing while having excellent transmittance to ultraviolet rays.

[0060] In one example, the carbon sheet 110 may contain elemental sulfur in an amount of 0.01 wt% or more, 0.05 wt% or more, 0.1 wt% or more, 0.15 wt% or more, 0.2 wt% or more, 0.25 wt% or more, or 0.3 wt% or more, or 1 wt% or less, 0.9 wt% or less, 0.8 wt% or less, 0.7 wt% or less, 0.6 wt% or less, 0.5 wt% or less, or 0.4 wt% or less, based on the total weight of the carbon sheet 110. The carbon sheet 110 may contain elemental sulfur within a range defined by selecting the upper and lower limits described above. This allows the carbon sheet 110 to have excellent transmittance to ultraviolet light while being freestanding.

[0061] In one example, the method for manufacturing the carbon sheet 110 may include reacting a raw material. The method for manufacturing the carbon sheet 110 may be, for example, a method for manufacturing a carbon sheet 110 for a pellicle. The method for manufacturing the carbon sheet 110 may include reacting the raw material to form a bundle composed of a plurality of carbon nanotubes. For characteristics of the carbon sheet 110, please refer to the above content.

[0062] In one example, a method for manufacturing the carbon sheet 110 may include reacting source materials at a reaction temperature to form bundles of carbon nanotubes. Unless otherwise specified, the reaction temperature may refer to a temperature at which source materials react to form the carbon sheet 110 including bundles of carbon nanotubes.

[0063] In one example, the reaction temperature may be 500°C or higher, 550°C or higher, 600°C or higher, 650°C or higher, 700°C or higher, 750°C or higher, 800°C or higher, 850°C or higher, 900°C or higher, 950°C or higher, or 1,000°C or higher, or 2,000°C or lower, 1,900°C or lower, 1,800°C or lower, 1,700°C or lower, 1,600°C or lower, 1,500°C or lower, 1,400°C or lower, 1,300°C or lower, 1,200°C or lower, or 1,100°C or lower. The reaction temperature may be within a range formed by appropriately selecting the upper and lower limits described above. That is, the method for producing the carbon sheet 110 may include reacting the raw materials at a reaction temperature within the above range. This may result in the formation of a carbon sheet 110 having the above physical properties from the raw materials.

[0064] In one example, a method for manufacturing a carbon sheet 110 may include introducing a source material into a reaction region of a reaction chamber and reacting the source material. That is, the source material may be introduced into the reaction region of the reaction chamber and reacted. Here, the reaction chamber may include a heater, and the reaction region may be heated to a reaction temperature through the heater. Although not particularly limited, a method for manufacturing a carbon sheet 110 may include heating the reaction region of the reaction chamber to a reaction temperature before introducing the source material into the reaction region of the reaction chamber. In this way, a carbon sheet 110 having the above-described physical properties may be formed from the source material.

[0065] In one example, the rate at which the raw material is introduced into the reaction zone of the reaction chamber may be greater than 15 g / h, 15.5 g / h or more, 16 g / h or more, 16.5 g / h or more, 17 g / h or more, 17.5 g / h or more, 18 g / h or more, 18.5 g / h or more, or 19 g / h or more, or may be 30 g / h or less, 29 g / h or less, 28 g / h or less, 27 g / h or less, 26 g / h or less, 25 g / h or less, 24 g / h or less, or 23 g / h or less. The rate at which the raw material is introduced into the reaction zone of the reaction chamber may be within a range formed by appropriately selecting the above-mentioned upper and lower limits. This allows the carbon sheet 110 having the above-mentioned physical properties to be formed from the raw material.

[0066] In one example, the method for manufacturing the carbon sheet 110 may include adjusting the temperature of the reaction region of the reaction chamber to a reaction temperature before introducing the source material into the reaction region, and then introducing a gas into the reaction region. This may minimize side reactions of the source material. The gas introduced into the reaction region may include, for example, hydrogen (H) and an inert gas (e.g., a gas containing an element of Group 18 of the periodic table, such as argon (Ar)).

[0067] In one example, the source material may include a carbon source. The carbon source may include a carbon compound that is liquid or gaseous at room temperature and pressure. For example, the carbon source may include one or more selected from the group consisting of alkanes, alkenes, alkynes, alcohols, and ketones. The alkanes may include one or more of methane, ethane, butane, propane, and hexane. The alkenes may include one or more of ethylene, propylene, and butylene. The alkynes may include one or more of acetylene, methyl acetylene, and vinyl acetylene. The alcohols may include one or more of methanol, ethanol, isopropyl alcohol, butanol, pentanol, cetyl alcohol, ethylene glycol, propylene glycol, glycerol, erythritol, xylitol, sorbitol, volemitol, allyl alcohol, geraniol, propargyl alcohol, inositol, and menthol. Ketones can include, for example, one or more of acetone and dimethyl ketone, by way of example only and not limitation.

[0068] In one example, the source material may include a catalyst. For example, the catalyst may include a metal element. The catalyst may include a metallocene. The metallocene may include a central metal and an organic ligand. The central metal may be a metal element included in the catalyst. For example, the central metal may include one or more of iron (Fe), molybdenum (Mo), titanium (Ti), rubidium (Ru), copper (Cu), aluminum (Al), gold (Au), platinum (Pt), and silver (Ag). For example, the organic ligand may include one or more of a cyclopentadienyl group, a metacyclopentadienyl group, a pentamethylcyclopentadienyl group, an indenyl group, and a fluorenyl group. For example, the metallocene may include ferrocene containing iron (Fe).

[0069] In one example, the source material can include a catalyst activator that can lower the activation temperature of the catalyst. For example, the catalyst activator can include elemental sulfur (S). The catalyst activator can include thiophene.

[0070] In one example, the raw material may contain carbon (C) in an amount of 60 wt% or more, 65 wt% or more, 70 wt% or more, 75 wt% or more, 80 wt% or more, 85 wt% or more, 90 wt% or more, 95 wt% or more, 99 wt% or more, or 99.9 wt% or more relative to the total weight. The upper limit of the carbon (C) content in the raw material is not particularly limited, and for example, the raw material may contain carbon (C) in an amount of 100 wt% or less, less than 100 wt%, or 99.99 wt% or less relative to the total weight. The raw material may contain carbon (C) within a range determined by selecting the above upper and lower limits. This may produce a freestanding carbon sheet 110 with excellent UV transmittance.

[0071] In one example, the raw material may contain metal elements at 1 wt% or more, 1.5 wt% or more, 2 wt% or more, 2.5 wt% or more, 3 wt% or more, 3.5 wt% or more, 4 wt% or more, 4.5 wt% or more, or 5 wt% or more, or 15 wt% or less, 14.5 wt% or less, 14 wt% or less, 13.5 wt% or less, 13 wt% or less, 12.5 wt% or less, 12 wt% or less, 11.5 wt% or less, 11 wt% or less, 10.5 wt% or less, 10 wt% or less, 9.5 wt% or less, 9 wt% or less, 8.5 wt% or less, 8 wt% or less, 7.5 wt% or less, 7 wt% or less, 6.5 wt% or less, or 6 wt% or less, based on the total weight of the raw material. The raw material may contain metal elements within a range defined by selecting the upper and lower limits described above. This may produce a freestanding carbon sheet 110 with excellent UV transmittance.

[0072] In one example, the raw material may contain elemental sulfur at 0.01 wt% or more, 0.05 wt% or more, 0.1 wt% or more, 0.15 wt% or more, 0.2 wt% or more, 0.25 wt% or more, or 0.3 wt% or more, or 1 wt% or less, 0.9 wt% or less, 0.8 wt% or less, 0.7 wt% or less, 0.6 wt% or less, 0.5 wt% or less, or 0.4 wt% or less, based on the total weight of the raw material. The raw material may contain elemental sulfur within a range determined by selecting the upper and lower limits described above. This may produce a freestanding carbon sheet 110 with excellent UV transmittance.

[0073] In one example, the source material includes a metal element (M) and sulfur element (S), and the weight ratio of the metal element (M) to the sulfur element (S) (M / S) may be 1 or more, 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, 7 or more, 8 or more, 9 or more, 10 or more, 11 or more, 12 or more, 13 or more, 14 or more, or 15 or more, or 50 or less, 45 or less, 40 or less, 35 or less, 30 or less, 25 or less, or 20 or less. The weight ratio of the metal element (M) to the sulfur element (S) contained in the source material (M / S) may be within a range formed by selecting the above-mentioned upper and lower limits. This allows the production of a free-standing carbon sheet 110 with excellent UV transmittance.

[0074] In one example, the source material includes sulfur (S) and carbon (C), and the weight ratio of sulfur (S) to carbon (C) (S / C) may be 0.0001 or more, 0.0005 or more, 0.001 or more, 0.0015 or more, 0.002 or more, 0.0025 or more, 0.003 or more, 0.0035 or more, or 0.004 or more, or 0.1 or less, 0.05 or less, or 0.01 or less. The weight ratio of sulfur (S) to carbon (C) contained in the source material (S / C) may be within a range formed by selecting the above-mentioned upper and lower limits. This allows the production of a free-standing carbon sheet 110 with excellent UV transmittance.

[0075] In one example, the method for manufacturing pellicle 100 can include manufacturing carbon sheet 110. In one example, the manufacturing method for carbon sheet 110 described above can be referenced for manufacturing carbon sheet 110. In one example, the method for manufacturing pellicle 100 can include bonding carbon sheet 110 to pellicle frame 120. Carbon sheet 110 can be bonded to pellicle frame 120 so that carbon sheet 110 can be supported by being positioned on the edge of carbon sheet 110.

[0076] Hereinafter, the present application will be further described with reference to specific examples. The examples and comparative examples are merely illustrative of the present application and do not limit the scope of the appended claims. It will be apparent to those skilled in the art that various changes and modifications to the examples are possible within the scope and technical spirit of the present application. It is also understood that such changes and modifications fall within the scope of the appended claims.

[0077] Example 1 The reaction chamber was heated to a reaction zone temperature of approximately 1,200°C. A gas containing hydrogen (H2) and argon (Ar) was then introduced into the reaction zone for several hours while maintaining the reaction zone temperature. Then, while maintaining the reaction zone temperature, raw materials containing ferrocene, acetone, and a sulfur-containing catalytic activator were introduced into the reaction zone to produce a carbon sheet 110 containing bundles of carbon nanotubes. The raw materials had a weight ratio of iron (Fe) to sulfur (S) (Fe / S) of approximately 17 and a weight ratio of sulfur (S) to carbon (C) (S / C) of approximately 0.004. The carbon sheet 110 contained approximately 94 wt% bundles and approximately 94 wt% carbon (C) relative to its total weight. The raw materials were introduced into the reaction zone at a rate of approximately 19.2 g / h.

[0078] Example 2. The carbon sheet 110 was produced in the same manner as in Example 1, except that the raw material was fed at a rate of about 23 g / h.

[0079] Comparative Example 1 A carbon sheet was produced in the same manner as in Example 1, except that the raw material feeding rate was set to about 31.2 g / h.

[0080] Comparative Example 2 A carbon sheet was produced in the same manner as in Example 1, except that the raw material was fed at a rate of about 15 g / h.

[0081] Experimental Example 1: Porosity measurement The carbon sheets 110 manufactured in the examples and comparative examples were prepared as unit test pieces. Images of the unit test pieces were taken using a scanning electron microscope (SEM), and the images were converted into binary images using a computer program (Calporosity_AXR), and the porosity was measured based on the light-dark distribution.

[0082] Experimental Example 2: Linear Density Measurement The carbon sheets 110 manufactured in the examples and comparative examples were prepared as unit test pieces. The unit test pieces were placed in water, and the weight of the fiber per 1 km was calculated to measure the linear density (unit: g / km).

[0083] Experimental Example 3: Transmittance measurement The carbon sheets 110 manufactured in the examples and comparative examples were prepared as unit test pieces. Light with a wavelength of about 13.5 nm was irradiated onto the unit test piece perpendicular to the thickness direction of the unit test piece, and the transmittance was measured by expressing the ratio of the radiant flux of the light irradiated onto the unit test piece and the radiant flux of the light transmitted through the unit test piece as a percentage.

[0084] The physical properties of the carbon sheets produced in the above examples and comparative examples are summarized in Table 1 below, and in Figures 2 and 3. Figure 2 is an image taken with a scanning electron microscope of the carbon sheets produced in Examples 1, 2, and Comparative Example 1. Figure 3 is an image obtained by performing binary imaging on Figure 2.

[0085] [Table 1]

[0086] Referring to Table 1, Figures 2 and 3, the carbon sheets produced in Examples 1, 2 and Comparative Example 1 were all capable of freestanding, but Comparative Example 2, which had a relatively low linear density, was not capable of freestanding.

[0087] Referring to Table 1, Examples 1 and 2, which have a porosity (P) / linear density (D) within the aforementioned range, were shown to have excellent transmittance to ultraviolet light. On the other hand, Comparative Example 1, which has a porosity (P) / linear density (D) outside the aforementioned range, was shown to have a transmittance to ultraviolet light of less than 80%.

[0088] Although the embodiments of the present disclosure have been described above with reference to the accompanying drawings, the present disclosure is not limited to the above embodiments and can be manufactured in various different forms, and a person skilled in the art to which the present disclosure pertains will understand that the present disclosure can be embodied in other specific forms without changing the technical spirit or essential characteristics of the present disclosure. Therefore, the above-described embodiments should be understood as illustrative in all respects and not restrictive.

[0089] [Explanation of symbols] 100: Pericle 110: Carbon sheet 120: Pelicle Frame 200: Photomask 300: Lens 400: Substrate

Claims

1. The carbon nanotube bundle includes a plurality of carbon nanotubes. A carbon sheet for a pellicle, having a ratio (P / D) of porosity (P) to linear density (D, [g / km]) of 0.2 or more and 10 or less.

2. 2. The carbon sheet for a pellicle according to claim 1, wherein the porosity (P) is 0.5 or more and 0.95 or less.

3. 2. The carbon sheet for a pellicle according to claim 1, wherein the linear density (D) is greater than 0.5 g / km and not greater than 2.8 g / km.

4. The carbon sheet for a pellicle according to claim 1 , wherein the bundles have a diameter of 10 nm or more and 100 nm or less.

5. 2. The carbon sheet for pellicles according to claim 1, wherein at least a portion of the plurality of carbon nanotubes comprises one or more selected from the group consisting of single-walled carbon nanotubes (SWCNTs), double-walled carbon nanotubes (DWCNTs), and multi-walled carbon nanotubes (MWCNTs).

6. The carbon sheet for a pellicle according to claim 1 , further comprising a metal element.

7. The carbon sheet for a pellicle according to claim 1 , further comprising elemental sulfur (S).

8. A carbon sheet including a bundle composed of a plurality of carbon nanotubes; a pellicle frame supporting the carbon sheet; The carbon sheet has a ratio (P / D) of porosity (P) to linear density (D, [g / km]) of 0.2 or more and 10 or less.

9. The pellicle according to claim 8 , wherein the carbon sheet has a structure in which a plurality of sheets are laminated.

10. A method for manufacturing a carbon sheet for a pellicle, comprising: reacting a source material including a carbon source to form a bundle of carbon nanotubes; the carbon sheet for a pellicle includes a bundle composed of the plurality of carbon nanotubes, A method for manufacturing a carbon sheet for a pellicle, wherein the carbon sheet has a ratio (P / D) of porosity (P) to linear density (D, [g / km]) of 0.2 or more and 10 or less.

11. The method for manufacturing a carbon sheet for a pellicle according to claim 10 , wherein the raw material further comprises a catalyst containing a metal element and a catalyst activator containing sulfur (S).

12. The method for manufacturing a carbon sheet for a pellicle according to claim 10, wherein the raw materials are reacted at a reaction temperature of 500°C to 2,000°C.

13. The raw material is introduced into a reaction region of a reaction chamber to react with the raw material; The method for manufacturing a carbon sheet for a pellicle according to claim 12, wherein the rate at which the raw material is introduced into the reaction zone is greater than 15 g / h and less than 30 g / h.

14. The method for manufacturing a carbon sheet for a pellicle according to claim 13, further comprising adjusting the temperature of the reaction region of the reaction chamber to a reaction temperature before the source material is introduced into the reaction region.

15. 15. The method for manufacturing a carbon sheet for a pellicle according to claim 14, further comprising: adjusting the temperature of the reaction region of the reaction chamber to a reaction temperature before introducing the raw material into the reaction region, and then introducing a gas into the reaction region.

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