Carbon nanotube type pellicle diaphragm

Abstract

A carbon nanotube pellicle membrane for a lithographic apparatus is provided, the pellicle membrane including a sacrificial coating. Also provided is a pellicle for a lithographic apparatus, the pellicle comprising such a pellicle membrane and a support frame for supporting the pellicle membrane, and a lithographic apparatus comprising such a pellicle membrane or pellicle. Also described are methods and apparatuses for manufacturing pellicle membranes, as well as the use of such pellicle membranes, pellicles, lithographic apparatuses, methods or manufacturing apparatuses in lithographic methods or apparatuses.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to EP application 23194949.6, filed on September 1, 2023, and EP application 24156760.1, filed on February 9, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to carbon nanotube-type surface films for use in photolithography equipment. This disclosure also relates to surface films including such surface films and a support frame, and to photolithography equipment including such surface films or surface films. This disclosure further relates to methods for manufacturing surface films, equipment for manufacturing surface films, and the use of such surface films, surface films, photolithography equipment, methods, or equipment in photolithography methods or equipment. This disclosure is particularly, but not exclusively, applicable to EUV lithography and can be used in any EUV-utilizing equipment. Background Technology

[0004] A photolithography apparatus is a machine configured to apply a desired pattern onto a substrate. Photolithography apparatus can be used, for example, in the manufacture of integrated circuits (ICs). A photolithography apparatus can, for example, project a pattern from a patterning apparatus (e.g., a mask) onto a layer of radiation-sensitive material (resist) disposed on a substrate.

[0005] The wavelength of radiation used by a lithography apparatus to project a pattern onto a substrate determines the minimum size of the feature that can be formed on that substrate. Compared to conventional lithography apparatus (which may use electromagnetic radiation with a wavelength of, for example, 193 nm), lithography apparatus using EUV radiation (which is electromagnetic radiation with wavelengths in the range of 4 nm to 20 nm) can be used to form smaller features on a substrate.

[0006] Photolithography equipment includes patterning apparatus (e.g., a mask or photomask). Radiation is provided that passes through or is reflected from the patterning apparatus to form a pattern on a substrate. A diaphragm assembly (also known as a surface film) may be provided to protect the patterning apparatus from airborne particles and other forms of contaminants. Contaminants on the surface of the patterning apparatus can lead to manufacturing defects on the substrate.

[0007] In addition to patterning apparatuses, the coating can also be provided for protecting optical components. The coating can also be used to provide channels for lithographic radiation between mutually sealed areas of a lithography apparatus. The coating can also be used as a filter (such as a spectral purity filter) or as part of a dynamic gas lock in a lithography apparatus. For example, in EUV utilization equipment (such as inspection equipment) that utilizes EUV radiation, a coating diaphragm can be used to similarly prevent contamination by providing a barrier that allows EUV radiation to pass through while blocking contaminants.

[0008] Because a surface coating exists in the optical path of the EUV radiation beam, it needs to have high EUV transmittance. High EUV transmittance allows a larger proportion of the incident radiation to pass through the surface coating. Reducing the amount of EUV radiation absorbed by the surface coating can lower its operating temperature. Since transmittance depends at least in part on the thickness of the surface coating, it is desirable to provide a surface coating that is as thin as possible while retaining sufficient reliable strength to withstand the sometimes harsh environment within lithography equipment. The surface coating diaphragm also needs to be strong enough to withstand the forces acting on it during transport and use. The surface coating diaphragm must also prevent imaging distortion, contamination of critical scanner components, and deflection beyond predetermined limits. Because some of these requirements are conflicting, such as the need for strength but also high transmittance, a balance of properties is required. For example, the pretension of a thin-film surface coating diaphragm can be increased to strengthen it, but this may increase the likelihood of mechanical failure. The surface coating diaphragm can also degrade over time during use, and mitigating the effects of degradation is desirable.

[0009] The present invention has been designed to attempt to solve at least some of the problems mentioned above. Summary of the Invention

[0010] According to a first aspect of this disclosure, a carbon nanotube-type surface membrane for a photolithography apparatus is provided, the surface membrane comprising a sacrificial coating.

[0011] In lithography equipment such as EUV lithography machines, the surface layer is encased in a low-pressure hydrogen atmosphere. During operation, the radiation used in the lithography machine (e.g., EUV radiation) interacts with the low-pressure hydrogen to generate plasma. Carbon nanotube (CNT) surface layers are easily etched by hydrogen plasma and thus face degradation. During exposure, carbon is gradually removed from the CNT surface layer, leading to damage to its structural integrity and shortening its operational life, as prolonged use may result in rupture. The surface layer is also heated during irradiation, but only in the irradiated area. If the surface layer is sufficiently heated, the heated area of ​​the CNT surface layer will not be degraded by the hydrogen plasma, but the surrounding area will still be degraded, still contributing to the risk of CNT surface layer degradation and rupture. To make CNTs more resistant to degradation-induced failures, the area surrounding the portion of the diaphragm heated by the radiation beam during irradiation has been coated with other elements, such as yttrium, to provide greater protection against degradation while preventing the irradiated area from being affected by the resulting reduction in EUV transmittance of the diaphragm. Even so, it has been found that this is insufficient to reduce degradation to an acceptable level because the coating is ineffective in preventing etching of the CNTs. Unwilling to be bound by scientific theory, it is believed that degradation still occurs because the substances responsible for degradation (such as hydrogen radicals and hydrogen ions) are not diffusion-limited. Therefore, these reactive substances will degrade the unprotected CNTs, and such reactive substances are not reduced by the protective coating. Adding additional CNT-type diaphragm patches in selected areas of the diaphragm (such as around the boundaries and outside the imaging area) is affected by manufacturing, preparation, and placement errors of the added CNT-type diaphragm patches and is not precise enough to follow the area around the imaging area. This may also introduce undesirable stress distributions on the diaphragm. Adding a sacrificial coating has been found to solve at least some of these problems. Providing a sacrificial coating, whether easily etchable or placed in a strongly etched area, protects the CNTs of the main film by pre-degrading them before they deteriorate, thereby delaying the onset of structure-related degradation of the CNTs and extending the lifespan of the main film. This sacrificial coating is one that is preferentially removed compared to the CNTs or competes with the etchant. Therefore, by using a more competitive sacrificial material than the CNTs, instead of being degraded in parallel with them, this sacrificial material will deteriorate first. Similarly, compared to applying a non-sacrificial coating (such as yttrium), the sacrificial material reacts with reactive substances to reduce the amount of reactive substances that may diffuse toward the irradiated portion of the film diaphragm.

[0012] The surface membrane can be a functionalized carbon nanotube (CNT) membrane. Functionalized CNT membranes can provide advantageous mechanical properties. The sacrificial coating can include carbon. The carbon can be amorphous carbon, and / or crystalline carbon, and / or annealed carbon. The carbon can be crystalline carbon, and / or annealed carbon, and / or graphene flakes, and / or carbon nanotubes, and / or diamond particles. The sacrificial coating can include one or more different structural forms of carbon. The carbon can be amorphous diamond-like carbon, and / or amorphous graphene-like carbon. The sacrificial coating can be applied to a portion of the surface membrane. The sacrificial coating can be a continuous thin film or a dense layer comprising particles, fibers, or flakes. By using a carbon sacrificial material, the carbon sacrificial material is preferentially eroded by hydrogen plasma before the CNTs forming the surface membrane, thereby protecting the CNTs. Furthermore, CNTs can be used as a sacrificial layer by controlling the placement of any sacrificial coating. The carbon can be in the form of graphene. The carbon can be in the form of graphene flakes. The flakes can include a single graphene sheet or multiple graphene sheets. Graphene sheets and / or diamond particles can range in diameter from about 0.1 micrometers to about 10 micrometers. Carbon can be in the form of carbon nanotubes. Carbon nanotubes can be single-walled or multi-walled. Carbon nanotubes can range in length from about 0.1 micrometers to about 10 micrometers. Graphene sheets, nanotubes, and / or diamond particles can be functionalized.

[0013] The sacrificial coating can be covalently bonded to the surface membrane. The sacrificial coating can also be non-covalently bonded to the surface membrane. It will be understood that non-covalent bonding means that the primary bonding is not via chemical covalent bonds, but via other bonds, such as van der Waals forces, or the physical entanglement or overlap of the surface membrane material with the sacrificial material. Preferably, the sacrificial coating is non-covalently bonded to the surface membrane. By avoiding covalent bonding of the sacrificial material to the CNTs, the effect on the stress within the CNTs of the surface membrane caused by the sacrificial material is smaller or non-existent. Furthermore, covalent bonds between the sacrificial material and the CNT-type membrane material may result in bond vacancies or other defects, which may lead to reduced mechanical and / or chemical stability. Corrosion of the sacrificial material during use will similarly not affect the stress within the CNTs over time. Additionally, there is less heat transfer between the membrane and the sacrificial coating. The effect of less heat transfer is a smaller variation in the location where the highest etching rate occurs during use, because this depends at least in part on the temperature of the surface membrane.

[0014] The sacrificial coating, which may be in the form of graphene flakes, CNTs, or other carbon-based particles, can be additionally secured by trapping the sacrificial coating between two CNT-type surface septa, at least one of which extends over the imaging area of ​​the mask during use. In this way, the sacrificial coating can be sandwiched between the two surface septa. Adding a second surface septa to hold the sacrificial coating serves to prevent its unintentional removal during processing.

[0015] The diaphragm has a quality region through which the radiation beam passes in nominal use. The diaphragm also has a non-quality region through which the radiation beam does not pass in nominal use. Preferably, a sacrificial coating is disposed in the non-quality region. By disposing of the sacrificial coating outside the quality region, this sacrificial coating has no effect on the structure of the radiation beam passing through the quality region of the diaphragm.

[0016] A sacrificial coating can be applied around the periphery of the mask diaphragm. By applying a sacrificial coating around the periphery, the area through which the radiation beam passes during nominal use (the so-called quality region) is kept free of additional material and therefore does not adversely affect transmittance. In some cases, where integrated circuit design requires that the irradiated area on the mask is smaller than the quality region, a sacrificial coating can be provided around the periphery of the irradiated area.

[0017] The thickness of the sacrificial material can be non-uniform. As mentioned above, etching of the CNT-type surface membrane is caused by exposure to hydrogen ions and free radicals in a hydrogen plasma. The irradiated area of ​​the surface membrane during nominal use is protected from etching to some extent because the temperature of the surface membrane causes the adsorbed atomic hydrogen to desorb, which significantly reduces the etching rate. This means that the etching rate of the irradiated area of ​​the surface membrane is lower than that of the surrounding area. In addition, at the periphery of the surface membrane, the plasma flux is lower and the temperature is also lower, resulting in a lower etching rate. There exists a region between the irradiated area and the periphery of the surface membrane where the etching rate reaches its maximum due to the combination of plasma flux and insufficient temperature for atomic hydrogen desorption. In use, there is a temperature gradient from the portion of the surface membrane irradiated by the radiation beam during irradiation at a high temperature (e.g., above T = +600°C) to the edge of the surface membrane at a much lower temperature (e.g., room temperature or ambient temperature). The etching rate depends at least in part on temperature, and there exists a temperature range below which the etching rate is highest for fixed hydrogen plasma parameters. This range is estimated to be from T = approximately +300°C to approximately +500°C. In this case, the diaphragm is present in the portion where the etching is fastest between the edge of the diaphragm and the area irradiated by the radiation beam. Therefore, by providing a thicker sacrificial material at the point of maximum etching rate in nominal use, the life of the diaphragm can be extended by using the additional sacrificial material most effectively.

[0018] The sacrificial coating can be thicker and / or denser in the areas of the diaphragm that are etched the most during nominal use. Under the same conditions, a thicker and / or denser sacrificial coating can withstand longer etching times than a thinner or less dense coating, so the coating can be selectively set to be thicker and / or denser in the areas with the highest etching rates.

[0019] The sacrificial coating can be formed as a gradient portion. The gradient portion can be a thickness gradient portion. Additionally or alternatively, the gradient portion can be a density gradient portion. While a sacrificial coating can be provided by laminating one or more additional layers of a carbon nanotube-type diaphragm with window cutouts, such that one or more additional layers form a frame around the quality region, this has several drawbacks. First, by stacking multiple layers, typically about ten layers, the transmittance drops from 95% or more to about 50%. Accurately placing the cutouts within the diaphragm is very difficult, requiring an accuracy of about 100 micrometers or less, a difficulty exacerbated by the need to stack multiple layers. Furthermore, there is little flexibility regarding the geometry of the sacrificial layer, and a different surface film will be required for each partially exposed mask, which is time-consuming, and manufacturers will need to disclose product-specific exposure areas to suppliers—sensitive information. Additionally, this option provides approximately ten times the carbon content, even in areas where etching is not critical, and also cools adjacent CNT-type surface film areas that are part of the exposure area. The high temperature in the exposed area is used to protect the area from etching, so cooling the area leads to an increase in the etching rate, which is undesirable. Therefore, adding a simple additional layer of surface membrane material with windows can be used to increase the etching rate in the quality area, which is the opposite of the desired effect.

[0020] The sacrificial coating can be formed as a gradient portion. The gradient portion can be a thickness gradient portion. Additionally or alternatively, the gradient portion can be a density gradient portion. The gradient portion can be provided on one or both of the inner and outer edges of the sacrificial coating.

[0021] By setting a gradient section, any abrupt changes in thickness and / or density can be avoided, thereby better controlling the thermal properties of the diaphragm, controlling the location of the maximum etching rate, and ensuring that this coincides with the location of the sacrificial layer.

[0022] The sacrificial coating can be applied to one or both sides of the diaphragm. Preferably, the sacrificial coating is applied to one side of the diaphragm. Although some degree of etching will exist on both sides of the diaphragm, most of the etching will be observed on the side of the diaphragm facing away from the mask, as this is where the hydrogen ion flux is highest.

[0023] The diaphragm can have 90% or greater EUV transmittance, 0.2% or less EUV transmittance inhomogeneity, and 0.2% or less EUV scattering in the quality region. For it to function as an effective surface diaphragm, the diaphragm needs not only to provide a barrier against contaminants falling onto the mask, but also to allow sufficient radiation to pass through to provide adequate yield of the wafer being imaged, without interfering with the patterning of the radiation beam passing through the diaphragm during use.

[0024] Sacrificial coatings can be provided using one or more of electron beam induced deposition (EBID), chemical vapor deposition (CVD), physical vapor deposition (PVD), and pulsed laser deposition (PLD). Other techniques for providing sacrificial coatings include evaporation, sublimation, and sputtering. Any technique capable of providing sacrificial coatings can be used.

[0025] In EBID, a carbon coating can be selectively deposited onto the surface membrane / septum by exciting an electron beam in an atmosphere containing hydrocarbons. The electrons promote the deposition of carbon from the hydrocarbons onto the surface membrane / septum. This provides a sacrificial carbon coating on the surface membrane / septum, and the carbon structure differs from that of CNTs. Because the electron beam is manipulated, the location control of the carbon sacrificial coating deposition is strong, and sacrificial carbon can be deposited precisely. Chemical vapor deposition and physical vapor deposition can also be used to deposit sacrificial carbon. Similarly, pulsed laser deposition can precisely control the deposition of sacrificial carbon on the surface membrane / septum.

[0026] According to another aspect of this disclosure, a carbon nanotube-type surface film separator for a photolithography apparatus is provided, the separator comprising a carbon nanotube layer supported by a support mesh.

[0027] Carbon nanotube-based (CNT)-based diaphragms have a random network of carbon nanotubes. Such diaphragms have low stiffness and are at risk of sagging, which could cause them to come into contact with other components within the lithography apparatus, leading to imaging problems, or even breakage if the elastic limit is exceeded. Therefore, supporting CNT-based diaphragms is useful. The support mesh is configured to provide additional structural support to the CNT-based diaphragm while minimizing the impact on any of the transmittance, uniformity, and scattering. The support mesh can be locally positioned, for example, to reinforce a portion of the diaphragm with a sacrificial coating.

[0028] One of the layers may include a network of carbon nanotubes, and the other layer may include a patterned layer of carbon nanotubes. The patterning of the carbon nanotube layer serves to increase the stiffness of the layer in order to provide additional support for the other layer.

[0029] Patterned carbon nanotube layers can be imprinted. In this way, the carbon nanotube layers are deformed into patterns that provide additional stiffness. Imprinting can wrinkle the carbon nanotube layers or otherwise include a series of ridges and grooves. In other words, the cross-section of the patterned layer can be zigzag or sinusoidal.

[0030] Imprinted patterns can have a periodicity smaller than the size of the smallest feature capable of projecting diffraction peaks onto the wafer. The smallest feature that can project diffraction peaks onto the wafer depends on the numerical aperture of the optics and the wavelength of the light used. For EUV lithography using a wavelength of 13.5 nm and a numerical aperture of 0.33, and considering the four-fold reduction in the distance between the mask and the wafer, the smallest feature that can still project diffraction peaks and thus be imaged on the wafer is approximately 164 micrometers. Therefore, by making the periodicity of the pattern smaller than 164 micrometers, any pattern on the surface film becomes too small to be imaged.

[0031] One of the layers may comprise a network of carbon nanotubes. These nanotubes may be randomly oriented. Another layer may comprise a grid with a periodicity of 165 micrometers or greater. At a 2-mm interval, a single point source on the mask diverges into spots with a radius of approximately 165 micrometers. Thus, the image, and therefore the pattern projected onto the wafer, is masked by the surface film. If a regular pattern appears in this region, a flash signal that can be projected onto the wafer is generated. If no regular pattern appears within the spot, the surface film does not affect imaging. Therefore, by setting a grid with a periodicity greater than this radius, there will be no regular pattern caused by the grid within any given spot, and thus imaging will not be adversely affected by the presence of the grid.

[0032] The grid consists of grid strips. The grid strips can be in any configuration capable of supporting the carbon nanotube layer. The grid strips can be square, rectangular, hexagonal, or any other polygonal shape. The grid strips can have an effective width of approximately 0.5 micrometers or less. This is the maximum calculated width of the grid strip, which will still allow for the avoidance of scattering from the strips in nominal use.

[0033] The grid stripes can have a pitch greater than 330 micrometers. By having a pitch greater than 330 micrometers (a pitch greater than 330 micrometers is twice the calculated spot radius), the possibility of interference with imaging is reduced or eliminated.

[0034] The grid may include a refractory metal. A refractory metal is a metal that maintains its structural integrity at temperatures within the photolithography apparatus, such as 500°C or higher, 550°C or higher, 600°C or higher, 650°C or higher, or 700°C or higher, and that the refractory metal is resistant to hydrogen plasma environments. Tungsten and molybdenum are particularly suitable.

[0035] The membrane diaphragm may also include any of the features of the first aspect of this disclosure. For example, the membrane diaphragm may include a sacrificial coating on the membrane diaphragm.

[0036] According to a second aspect of this disclosure, a film for a photolithography apparatus is provided, the film including a film diaphragm according to a first aspect of this disclosure and a support frame for supporting the film diaphragm.

[0037] According to a third aspect of this disclosure, a photolithography apparatus is provided, comprising a surface film diaphragm according to a first aspect of this disclosure or a surface film according to a second aspect of this disclosure. The photolithography apparatus may be an EUV-utilizing apparatus.

[0038] According to a fourth aspect of this disclosure, a method for manufacturing a membrane separator is provided, the method comprising the steps of: providing a carbon nanotube membrane separator; and providing a sacrificial coating on the carbon nanotube membrane separator.

[0039] The method may include: providing the carbon nanotube-type surface membrane in a vacuum chamber; providing a mask to cover a portion of the surface membrane, thereby providing a masked area and preventing coating deposition on the masked area; and depositing a sacrificial coating on the unmasked area of ​​the surface membrane. A mask may be provided on the opposite side of the surface membrane to protect it from accidental contamination.

[0040] Since it is desirable to maintain quality areas free of sacrificial coating, a mask can be provided to prevent sacrificial material from depositing in undesirable areas. This can be useful when the sacrificial material is provided by a technique that can deposit it over a wide area, such as electron beam induced deposition (EBID), chemical vapor deposition (CVD), physical vapor deposition (PVD), and pulsed laser deposition (PLD), especially CVD and PVD, which are less maneuverable than EBID and PLD.

[0041] The method may include: providing an electron source configured to generate an electron beam; and moving the surface membrane and the electron beam relative to each other to selectively deposit the sacrificial coating on the surface membrane. As a charged particle beam, the electron beam may be manipulated and / or focused, and the electron beam may scan the entire surface membrane to selectively deposit sacrificial material on the surface membrane. Additionally or alternatively, the surface membrane may be moved to selectively deposit sacrificial material on the surface membrane.

[0042] The vacuum chamber may include volatile carbonaceous compounds as a source of the sacrificial coating, optionally wherein the volatile carbonaceous compounds are C1-C5 hydrocarbons. Heavier hydrocarbons may be used. Preferably, saturated hydrocarbons are used because they generally form better graphite layers, but unsaturated hydrocarbons may also be used.

[0043] The method may include annealing the sacrificial coating. Annealing can be used to adjust the structural form of the carbon sacrificial material. Carbon deposited via EBID is inherently amorphous and primarily a mixture of different structural forms of carbon, ranging from polymeric compounds to amorphous diamond-like carbon. The electronic configuration of the deposited carbon may be relevant for its sacrificial purpose in the intended hydrogen plasma environment. In some models of carbon etching via hydrogen plasma, the carbon must undergo an sp3 hybridization state transition for carbon removal etching to occur. Heating of sp3 hybridized carbon is thought to induce a transition to sp2 hybridization via a process known as graphitization, and also results in the desorption of etched hydrogen material from the carbon nanotubes, which inhibits etching. It has been observed that CNTs at elevated temperatures are etched at a rate lower than necessarily expected. Therefore, during the hydrogen plasma etching process, amorphous EBID-deposited carbon comprising sp3 hybridized carbon is preferred over sp2 hybridized CNT carbon for use as a suitable sacrificial coating. In the transition zone from the hot zone to the cooler zone of the surface membrane, the sacrificial coating can be partially graphitized into sp2 hybrid carbon, while simultaneously becoming more etch-resistant due to the increased temperature and hydrogen desorption. Therefore, the underheated areas retain the sp3 hybrid state of the sacrificial carbon, thus preserving its sacrificial purpose. Similarly, amorphous diamond-like carbon can be a mixture of amorphous carbon and diamond-like carbon. Such materials can be advantageously deposited in specific deposition steps (e.g., CVD or plasma discharge from hydrocarbon gases such as methane). Different types of DLCs with different thermal degradation temperatures can be provided, and DLCs can have different temperatures above which they graphitize into an sp2 hybrid state. In this way, specific types of sacrificial carbon can be used to optimize the thermal etching behavior of the sacrificial coating. For example, if the etching rate of the DLC is lower than that of the amorphous carbon, deposition and / or annealing can be targeted at a larger proportion of the DLC in the sacrificial coating to control the rate at which the sacrificial material is etched. Graphene-like carbon can possess sp2 hybridization similar to CNTs, and therefore, in nominal use, the additional sacrificial carbon overlaps the graphite CNT with the additional graphite carbon. While the chemical stability of the graphite carbon sacrificial material would then correspond to that of the CNT, the additional graphite layer is fragmented and discontinuous, with a proportionally greater number of sp3 boundary states, contrasting with the longer-range graphite sp2 structure of the CNT. Therefore, the additional boundary-bonded carbon atoms in this fragmented graphite carbon sacrificial material are more easily eroded by hydrogen plasma, thus achieving the sacrificial purpose relative to the CNT.

[0044] The method may include controlling the structural form of the sacrificial coating. This may include relaxing the sacrificial coating, for example, by controlling crystallinity or amorphousness using ion beams, electron beams, light, or heating. Furthermore, the method may include a post-deposition treatment configured to remove unwanted contaminants, such as loose sacrificial coating that may detach during use.

[0045] The method may include providing a sacrificial coating by spraying. Spraying the sacrificial coating allows for controlled application of the coating and precise control over its placement.

[0046] The method may include providing a mixture of carbon sources in a carrier fluid. The concentration of the carbon source in the carrier fluid may be less than 1%. The typical size of the carbon particles, flakes, or fibers including the carbon source may be less than 10 μm, preferably less than 1 μm. The carbon source may include one or more of the following: single-walled or multi-walled CNTs, single-graphene flakes or multi-graphene flakes, diamond nanoparticles or microparticles, or diamond-like carbon nanoparticles or microparticles. The carbon particles may include functionalized graphene flakes, functionalized carbon nanotubes, and / or functionalized diamond particles. The carrier fluid may be polar or nonpolar. The carrier fluid may be aqueous. The carrier fluid may be water. The carrier fluid may include ethanol. The carrier fluid may include N-methyl-2-pyrrolidone (NMP). The carrier fluid may include dimethyl sulfoxide (DMSO). When the carrier fluid is polar, such as water or ethanol, the carbon source is preferably functionalized with polar groups. Functionalization facilitates the suspension of carbon particles, flakes, or fibers in the carrier fluid. Functionalization can include partial oxidation, which incorporates both the carbonyl and hydroxyl groups into the carbon source. For nonpolar solvents, the original, unfunctionalized carbon source can be used.

[0047] The method may include providing a second or auxiliary CNT-type diaphragm to cover the sacrificial coating, which comprises individual particles. This is used to prevent the sacrificial coating from detaching during airflow processing. The auxiliary CNT-type diaphragm may be larger than the sacrificial coating.

[0048] The method may include: forming an aerosol and spraying the aerosol onto the membrane diaphragm. The aerosol is formed by a carrier fluid and a carbon source, and then sprayed onto the membrane diaphragm. The aerosol droplets may be configured to be less than 100 μm or less than 10 μm to prevent damage to the membrane by spraying and to provide controlled localized deposition. The landing velocity of the aerosol droplets on the diaphragm may be limited to less than 10 m / s or less than 1 m / s to prevent damage to the membrane. The method may include: providing a mask to shield a portion of the membrane diaphragm. The mask may be equipped with a heater so that it can be heated to prevent the accumulation of the carrier fluid. A sacrificial coating covering the entire membrane diaphragm, particularly the quality area, is undesirable, and therefore providing a mask prevents the sacrificial coating from being applied to areas where it is not desired. The mask may be larger than the area of ​​the membrane diaphragm that will be exposed to EUV radiation during nominal use. This is to provide a margin for mounting the membrane. For example, the mask may be at least 0.1 mm larger than the area of ​​the diaphragm that will be exposed to EUV radiation in nominal use. The mask may be thin at its edges, such as from about 0.1 mm to about 1 mm high, where a steeper gradient is desired. The mask may also be thick at its edges, such as from 1 mm to about 10 mm, where a shallower gradient is desired. Since it may only be desired to provide a sacrificial coating in a region confined to a separate portion of the CNT-type diaphragm, a second mask may be provided such that the sacrificial layer is disposed only in the gap between the two masks, for example, in the shape of a frame.

[0049] The method may include operating a piezoelectric actuator and / or a gas jet to form the aerosol. The piezoelectric actuator may be driven at a frequency from about 10 kHz to about 10 MHz, preferably between about 100 kHz and about 1 MHz. The average diameter of the droplets within the aerosol may range from about 1 micrometer to about 10 micrometers. At a frequency of about 100 kHz, the piezoelectric actuator will produce droplets with a diameter of about 10 micrometers. At a frequency of about 1 MHz, the piezoelectric actuator will produce droplets with a diameter of about 1 micrometer. Such sizes are expected, at least in the case of an aqueous carrier fluid with a low carbon source concentration and no surfactant.

[0050] The method may include moving a spray relative to the surface membrane to selectively coat the surface membrane. One or both of the spray and the surface membrane may be moved to coat the surface membrane, but it is preferred to move the spray to avoid potential damage to the surface membrane.

[0051] The method may include spraying in an environment filled with gas at atmospheric pressure. The method may include spraying a spray generated by a gas jet, and using the gas to carry and guide aerosol particles. Because a sacrificial coating is being sprayed, it is not necessary to use any special increased or decreased pressure on any gas carrying the spray.

[0052] The method may include configuring the sacrificial coating as a gradient section. This can be achieved, for example, by changing the size of the aerosol droplets; changing the speed at which the spray travels across the surface membrane diaphragm; performing more than one pass of spraying on certain portions of the surface membrane diaphragm; using a mask to intercept a portion of the aerosol particles before they land on the surface membrane; or changing the rate at which the spray is delivered to the surface membrane diaphragm. As previously mentioned, having a gradient section allows for better control over the location of the highest etching rate during use.

[0053] The gradient portion can be one or both of a thickness gradient portion and a density gradient portion.

[0054] The method may include: heating the surface membrane to evaporate the carrier fluid.

[0055] The method can be performed at atmospheric pressure or at a pressure lower than atmospheric pressure.

[0056] The method may include: providing a substrate with a desired pattern; and pressing the substrate together with a carbon nanotube-based membrane to imprint the pattern into the carbon nanotube-based membrane. The pattern of the substrate may be selected based on the desired imprinted pattern in the carbon nanotube-based membrane.

[0057] The method may further include attaching a patterned carbon nanotube-based membrane to a mesh-like carbon nanotube-based membrane. Thus, the membrane will have a random mesh layer and a patterned layer providing additional structural strength and stiffness.

[0058] The method may include: masking a portion of the surface membrane. As mentioned above, it is desirable to provide a sacrificial coating at the location of the highest etching rate and to avoid adding a sacrificial coating to quality areas, as this may adversely affect yield or imaging quality.

[0059] The method may also include any of the steps according to the fourth aspect of this disclosure.

[0060] According to a fifth aspect of this disclosure, an apparatus for manufacturing a surface membrane diaphragm is provided, the apparatus comprising: a vacuum chamber; a support for the surface membrane diaphragm; an electron beam generator configured to generate an electron beam and guide the electron beam to the support; a volatile carbonaceous compound source configured to provide volatile carbonaceous compounds to the vacuum chamber, the electron beam being configured to deposit a carbon sacrificial coating onto the surface membrane diaphragm, wherein the apparatus includes one or both of: i) a mask configured to selectively cover a portion of the surface membrane diaphragm to prevent the sacrificial coating from depositing on the portion covered by the mask; and ii) means for moving the electron beam and the surface membrane diaphragm relative to each other to control the placement of the carbon sacrificial coating. The vacuum chamber may be part of a photolithography apparatus. It will be understood that manufacturing also encompasses the refurbishment or repair of existing surface membrane diaphragms.

[0061] An electron beam allows for the controlled deposition of carbon sacrificial material onto a surface membrane. In some embodiments, the electron beam can be large enough to irradiate most or all of the surface membrane. In such embodiments, sacrificial carbon would be deposited over the entire irradiated area unless a mask is provided. Therefore, a mask can be provided to prevent sacrificial material from being deposited on certain predetermined areas of the surface membrane, particularly quality areas radiated through in nominal use. Alternatively or additionally, the electron beam and the surface membrane can be moved relative to each other to control the placement of the sacrificial coating. This can be useful for larger surface membranes where the electron beam is not wide enough to cover the entire membrane. It will be understood that both a mask and relative movement of the electron beam and the surface membrane can be employed.

[0062] The device may include a heater configured to heat the surface membrane to anneal the carbon sacrificial layer. Any suitable heater may be used, such as a laser heater or an electric heater. A heater is suitable if it is capable of heating the sacrificial carbon up to a temperature sufficient to at least partially anneal the carbon. By annealing the sacrificial carbon and / or by controlling the deposition of the sacrificial carbon, the structure type of the carbon can be controlled, and thereby the relative rate at which the carbon is etched relative to the CNTs can be controlled.

[0063] According to the sixth aspect of this disclosure, the use of a diaphragm according to the first aspect of this disclosure, a diaphragm according to the second aspect of this disclosure, a lithography apparatus according to the third aspect of this disclosure, a method according to the fourth aspect of this disclosure, or an apparatus according to the fifth aspect of this disclosure in a lithography method or apparatus is provided.

[0064] It will be understood that features described with respect to one embodiment may be combined with any features described with respect to another embodiment, and all such combinations are expressly contemplated and disclosed herein. References to lithography equipment include references to EUV utilization equipment, which may be EUV lithography equipment used for imaging integrated circuits or inspection equipment such as mask inspection equipment. Attached Figure Description

[0065] Embodiments of the invention will now be described by way of example only with reference to the accompanying schematic diagrams, wherein corresponding reference numerals denote corresponding parts, and in the drawings:

[0066] Figure 1 A photolithography apparatus according to an embodiment of the present disclosure is described;

[0067] Figure 2 Embodiments of a method for manufacturing a membrane diaphragm according to the present disclosure are described;

[0068] Figure 3 Another embodiment of a method for manufacturing a membrane diaphragm according to the present disclosure is described;

[0069] Figure 4 A film assembly according to this disclosure is depicted;

[0070] Figure 5 This is a schematic depiction of the film, with the corresponding temperature distribution of the film, the ion flux to the film, and the effective etching rate of the film shown in the chart below (in order from top to bottom).

[0071] Figures 6a to 6c The surface film after exposure is depicted, showing weaker or thinner areas around the area irradiated during nominal use;

[0072] Figures 7a to 7c A membrane diaphragm according to this disclosure is depicted;

[0073] Figures 8a to 8b A close-up image depicts a cluster of CNTs or graphene sheets forming a sacrificial layer;

[0074] Figure 9 The schematic depiction of the film according to this disclosure shows the corresponding temperature distribution of the film, the ion flux to the film, and the effective etching rate of the film in the following graphs (in order from top to bottom).

[0075] Figure 10 The chambers that house the surface film and the sprayer for providing the sacrificial coating are depicted;

[0076] Figure 11 This is a schematic depiction of a method for providing a sacrificial layer by moving a sprayer;

[0077] Figure 12 It is a schematic depiction of a mask set on the surface membrane diaphragm;

[0078] Figure 13 This is a schematic depiction of a square grid, showing the highest and lowest transmission points of the subaperture spot; and

[0079] Figure 14 This is a schematic depiction of a method for imprinting a membrane diaphragm.

[0080] The features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, wherein the same reference numerals always identify corresponding elements. In the drawings, similar reference numerals generally denote the same, functionally similar, and / or structurally similar elements. Detailed Implementation

[0081] Figure 1 A lithography system according to the present invention is illustrated. The lithography system includes a radiation source SO and a lithography apparatus LA. The radiation source SO is configured to generate an extreme ultraviolet (EUV) radiation beam B. The lithography apparatus LA includes an illumination system IL, a support structure MT configured to support a pattern forming apparatus MA (e.g., a mask), a projection system PS, and a substrate stage WT configured to support a substrate W. The illumination system IL is configured to adjust the radiation beam RB before it is incident on the pattern forming apparatus MA. The projection system is configured to project the radiation beam RB (now patterned by the mask MA) onto the substrate W. The substrate W may include a previously formed pattern. In this case, the lithography apparatus aligns the patterned radiation beam B with the pattern previously formed on the substrate W. In this embodiment, a surface film 15 is described as being in the path of radiation and protecting the pattern forming apparatus MA. It will be appreciated that the surface film 15 can be located at any desired location and can be used to protect any of the mirrors in the lithography apparatus. The pattern forming apparatus MA may be referred to as a mask. The support structure MT may be referred to as a mask stage. It will be appreciated that this disclosure also applies to other EUV utilization equipment, such as, for example, inspection equipment, such as mask inspection equipment.

[0082] The radiation source SO, the irradiation system IL, and the projection system PS can all be configured and arranged to isolate them from the external environment. A gas (e.g., hydrogen) at a pressure below atmospheric pressure can be supplied to the radiation source SO. A vacuum can be provided in the irradiation system IL and / or the projection system PS. A small amount of gas (e.g., hydrogen) at a pressure far below atmospheric pressure can be supplied to the irradiation system IL and / or the projection system PS.

[0083] Figure 1The radiation source SO shown is a type that can be referred to as a laser-generated plasma (LPP) source. A laser (which can be, for example, a CO2 laser) is arranged to deposit energy onto a fuel (such as tin (Sn) supplied from a fuel emitter) via a laser beam. Although tin is described below, any suitable fuel can be used. The fuel can be, for example, in liquid form and can be, for example, a metal or alloy. The fuel emitter can include a nozzle configured to guide the tin, for example, in droplet form, along a track towards the plasma-forming region. The laser beam is incident on the tin at the plasma-forming region. The laser energy deposited on the tin generates plasma in the plasma-forming region. During the ion de-excitation and recombination of the plasma, radiation, including EUV radiation, is emitted from the plasma.

[0084] EUV radiation is collected and focused by a near-normal incident radiation collector (sometimes more generally referred to as a normal incident radiation collector). The collector may have a multi-layered structure arranged to reflect EUV radiation (e.g., EUV radiation with a desired wavelength such as 13.5 nm). The collector may have an elliptical configuration with two elliptical foci. The first focal point may be located at the plasma formation region, and the second focal point may be located at the intermediate focal point, as described below.

[0085] The laser can be separated from the radiation source SO. In this case, the laser beam can be transmitted from the laser to the radiation source SO with the aid of a beam transmission system (not shown), which includes, for example, suitable guiding mirrors and / or beam expanders, and / or other optical components. The laser and the radiation source SO can be considered together as a radiation system.

[0086] Radiation reflected by the collector forms a radiation beam B. Radiation beam B is focused at a point to form an image of the plasma formation region, which serves as a virtual radiation source for irradiating the system IL. The point where radiation beam B is focused can be referred to as the intermediate focus. The radiation source SO is arranged such that the intermediate focus is located at or near an opening in the surrounding structure of the radiation source.

[0087] A radiation beam B is transmitted from a radiation source SO to an irradiation system IL, which is configured to modulate the radiation beam. The irradiation system IL may include a faceted field mirror assembly 10 and a faceted pupil mirror assembly 11. The faceted field mirror assembly 10 and the faceted pupil mirror assembly 11 together provide a radiation beam B with a desired cross-sectional shape and a desired angular distribution. The radiation beam B passes through the irradiation system IL and is incident on a pattern forming apparatus MA held by a support structure MT. The pattern forming apparatus MA reflects and patternes the radiation beam B. Instead of or in addition to the faceted field mirror assembly 10 and the faceted pupil mirror assembly 11, the irradiation system IL may include other mirrors or devices. A heater may be positioned and configured to provide thermal energy, which is reflected by one or more of the mirror assemblies onto the substrate W.

[0088] After reflection from the patterning apparatus MA, the patterned radiation beam B' enters the projection system PS. The projection system includes multiple mirrors 13 and 14 configured to project the radiation beam B' onto the substrate W held by the substrate stage WT. The projection system PS can apply a reduction factor to the radiation beam to form an image with features smaller than the corresponding features on the patterning apparatus MA. For example, a reduction factor of 4 can be applied. Although in Figure 1 The projection system PS has two mirrors 13 and 14, but the projection system may include any number of mirrors (e.g., six mirrors). Preferably, the heater is positioned and configured to provide thermal energy that is reflected onto the substrate W by one or more of the mirror assemblies.

[0089] Figure 1 The radiation source SO shown may include components not shown. For example, a spectral filter may be provided in the radiation source. The spectral filter can essentially transmit EUV radiation, but essentially blocks radiation of other wavelengths (such as infrared radiation).

[0090] If the pattern forming apparatus MA is not protected, contamination may necessitate cleaning or disposal of the MA. Cleaning the MA interrupts valuable manufacturing time, while discarding it is costly. Replacing the MA also interrupts valuable manufacturing time.

[0091] Figure 2 Embodiments of an apparatus and method for manufacturing a film 15 according to this disclosure are depicted. An electron beam 16 is provided and configured to guide the electron beam onto the film 15. The film 15 includes a film support 17 supporting a film diaphragm 18. The film support 17 may include silicon. The film diaphragm 18 includes a non-quality region 19, which is not irradiated by EUV during nominal use. The film diaphragm 18 also includes a quality region (…). Figure 2 (Not shown in the image, as the quality area is covered by mask 20). The quality area is the portion of the surface membrane that EUV radiation passes through during nominal use. Mask 20 may have an arm 21 to hold the mask 20 in place, but other means for positioning the mask 20 in the desired location may be provided. The arm 21 may be configured such that it does not obstruct the electron beam to form a shadow that would result in the shadowed area not having the provided sacrificial coating. For example, the arm 21 may extend perpendicular to the plane of mask 20 such that it does not extend beyond the edge of mask 20. One or more additional masks (not shown) may be provided to protect other portions of the surface membrane from contamination during the deposition of the sacrificial coating.

[0092] When the surface diaphragm 18 is being manufactured or remanufactured, for example after the surface diaphragm 18 has been used for a predetermined period of time or after a predetermined amount of sacrificial material has been etched away through use, the surface diaphragm 18 is located within a vacuum chamber (not shown). The vacuum chamber may be a separate vacuum chamber or may be part of an EUV utilization apparatus (such as an EUV lithography apparatus or inspection apparatus). An electron beam 16 is directed toward the surface diaphragm and interacts with an atmosphere including hydrocarbons (such as C1-C5 hydrocarbons), resulting in a carbon sacrificial layer being provided on unmasked areas (such as non-quality areas 19) of the surface diaphragm 18. Figure 2 In the depiction, the electron beam 16 is wide enough to irradiate the entire surface membrane septum with the electron beam, and therefore a mask 20 is used to control which areas do not sacrifice material.

[0093] Figure 3 Similar to Figure 2 However, a scenario is depicted where the electron beam 16 is not wide enough to irradiate the entire surface membrane 18. Since the electron beam 16 can be accurately focused, a mask 20 is not necessary, and the quality region 21 may be maskless, although it will be understood that a mask may still be provided. The electron beam 16 moves relative to the surface membrane 18 along path 22. It will be understood that one or both of the electron beam 16 and the surface membrane 18 may move to scan the area where the sacrificial coating is to be applied. Figure 3 The path 22 depicted is exemplary, and any path that results in the deposition of the sacrificial layer in the desired area is acceptable. Path 22 may be performed one or more times to deposit the sacrificial material.

[0094] Figure 4A surface film 15 is depicted, comprising a support frame 17, a non-quality region 18, and a quality region 21. A sacrificial coating is provided in the non-quality region 18, while the quality region 21 has no sacrificial coating. In use, an EUV radiation beam passes through the quality region 21, causing it to heat up. This is believed to cause atomic hydrogen to desorb from the quality region 21, which reduces the rate of carbon etching from the carbon nanotubes including the surface film 18. The portion of the surface film 18 surrounding the quality region does not reach the same temperature as the quality region, and therefore atomic hydrogen is not desorbed, resulting in a higher etching rate. Further outward from the quality region, the temperature of the surface film 15 decreases further during nominal use, which reduces the etching rate. Therefore, the region of the surface film 15 experiencing the highest etching rate is the area just outside the quality region, and thus the sacrificial material is placed in such a region.

[0095] Figure 5 A surface film 120a, 15 is depicted mounted on a mask having a quality region 101, which is irradiated by EUV radiation 110. The mask includes an ultra-low expansion layer 100 and a back side 102. The surface film includes a frame 121 and a CNT-type thin film 122. The temperature distribution 201 of the surface film, the ion flux to the surface film 202, and the effective etch rate 203 illustrate the effect of accelerated chemical sputtering in the region surrounding the EUV beam 124. For example, in the case where the thin film is in contact with the frame acting as a heat sink, the intermediate temperature T_etch between T1 and T2 corresponds to a chemical sputtering or etch yield that is about one hundred times higher than at the maximum irradiation region, and about ten times higher than at ambient temperature. Therefore, as shown in the bottommost graph 203, the etch rate is highest just outside the EUV-irradiated region of the surface film diaphragm. Therefore, it is desirable to provide sacrificial material at the location where etching is most prevalent in nominal use.

[0096] Figures 6a to 6c The weakest region 124, where etching is fastest, is depicted. (Example) Figure 6a As shown, there is a thinner etched area 124 of the surface diaphragm 120a. This is for illustrative purposes only and is not a scaled representation or depiction of damage caused by etching. In some cases, only a portion of the mask needs to be illuminated for the layer being imaged, while the rest is obscured by masking blades, which means altering the etched area 124, such as... Figure 6b and Figure 6c As shown.

[0097] Figure 7a This is a cross-section of the surface membrane including the diaphragm according to the present disclosure. In this embodiment, the sacrificial layer 141 has a shallow gradient portion 142 on its outer edge. In other embodiments, the gradient portion is additionally or alternatively provided on the inner edge.

[0098] Figure 7b Similar to Figure 7a However, the gradient of the sacrificial layer 151 is steeper. In both cases, the sacrificial layers 141 and 151 are not in good thermal contact with the frame supporting the membrane diaphragm.

[0099] Figure 7c yes Figure 7a or Figure 7b A top view of the membrane diaphragm, showing the location of the sacrificial layer.

[0100] Figure 8a and Figure 8b yes Figure 7a and Figure 7b The highlighted section is a magnified view of segment 160. Figure 8a A carbon nanotube 170 sacrificial layer on a nominal CNT-type thin film 122 forming a surface membrane diaphragm is depicted, and Figure 8b A graphene sheet 180 sacrificial layer is depicted on a nominal CNT-type thin film 122. This is not a limiting example, and other forms of carbon forming sacrificial layers are possible, including mask deposition via electron beam and / or PVD and / or CVD, and mask particle deposition, for example, via aerosol.

[0101] Besides the existence of sacrifice layer 151, Figure 9 Similar to Figure 5 By using this localized placement of sacrificial carbon, the thermal distribution of CNT-type thin films can be designed and controlled so that the sacrificial layer falls within the strongest etched region during nominal use without adversely affecting yield or imaging quality.

[0102] Figure 10 This is a schematic depiction of a chamber in which a sacrificial coating can be provided to a surface membrane diaphragm using aerosol particles carrying CNTs, graphene flakes, or other forms of carbon nanoparticles or microparticles. A chamber 200 is provided, within which a surface membrane 120 is provided on a frame located on a retainer 230. Optionally, the surface membrane is heated to aid in the evaporation of the carrier fluid. A mask 220 is provided, defining a patterned deposition 221 of droplets 212 carrying carbon sacrificial material. A sprayer 210 provides a spray 211a of droplets, which are then captured by the mask 220 to define the pattern of the final sacrificial coating. Optional feeders 251 and 252 can be used to provide a uniform environment within the chamber 200 and to drain the evaporated carrier fluid. The profile of the resulting deposited sacrificial layer is defined by a mask offset H, a thickness W, and an opening size A of the surface membrane, as well as an offset B from the edge of the surface membrane frame. Afterward, the deposition chamber and mask can be cleaned to remove any excess carbon sacrificial material.

[0103] Besides spray 211b compared to Figure 10 Narrower in the middle, Figure 11 Similar to Figure 10 In this embodiment, the sprayer 210 is movable relative to the surface membrane diaphragm to spray the surface membrane diaphragm. The spray 211b can be tilted 230 or shifted 240 to allow for controlled thickness of the deposited layer at different surface membrane locations.

[0104] Figure 12 One method for positioning mask 222 is depicted. Supports offset from the mask plane 222 for holding the inner portions of masks 222a, 222b allow some droplets to deposit on the partially obstructed (viewpoint) area due to diffusion, Brownian motion, or flow. Masks 220a, 220b can accommodate any exposure area within the exposure region and can be configured according to the desired pattern of the final sacrificial layer.

[0105] Figure 13 This is a schematic depiction of a grid with grid lines. Although the grid is shown as a square grid, other grid shapes such as rectangles or hexagons are equally suitable. In use, the surface film is not located at the imaging position of the lithography device, but is set at a distance. This causes any sharp points (e.g., the mask) in the imaging plane to be blurred into disks of finite size at the surface film plane. The uniformity of EUV transmission across the surface film, considering the smoothness of this disk or spot, is necessary for proper imaging performance of the scanner. At a 2 mm interval, a single point source on the mask diverges into a spot with a radius of approximately 165 micrometers. Therefore, if a regular pattern appears within this radius, a flash signal will be projected onto the wafer. If no regular pattern appears within the disk or spot, the surface film does not affect imaging. Figure 13 This describes a disk or spot relative to the grid lines. Maximum transmittance exists when the spot does not overlap with the grid lines, and this has no effect on imaging. In the worst-case scenario, where the spot overlaps with the junction of two grid lines, there is the highest risk of affecting imaging. However, due to the lack of a regular repeating pattern, even in this worst-case scenario, there is no impact on imaging.

[0106] Figure 14 One method for fabricating patterned CNT-type separators is described. In a first step, a pattern is provided to a thin film, such as a thiolene film. As depicted, this is achieved by pressing an impression into the film, but other methods of patterning, such as etching, such as ion beam etching, are also suitable. This is accompanied by an increase in pressure and heat, followed by cooling and release of the patterned film. The CNT-type film is then placed on the patterned film, and pressure is applied to imprint the pattern into the CNT-type film. This pattern provides additional strength to the CNT-type film.

[0107] In summary, this disclosure proposes providing a sacrificial material on a carbon nanotube-based surface membrane that preferentially etches during nominal use to protect the carbon nanotubes, particularly those near the quality region of the surface membrane. By sacrificially etching the sacrificial material, the etch rate to the carbon nanotubes is reduced, thereby extending the lifetime of the surface membrane. The carbon sacrificial coating can be provided in a highly controlled manner using EBID, which allows the sacrificial coating to be applied to portions of the surface membrane that are not exposed to EUV radiation during nominal use, thereby maintaining the transmittance of the surface membrane. Alternatively, the sacrificial coating can be applied via an aerosol having suspended CNTs, graphene flakes, or other forms of carbon-based nano or micron-sized particles.

[0108] Although specific embodiments of the invention have been described above, it will be understood that the invention may be practiced in other ways than those described.

[0109] The above description is intended to be illustrative and not restrictive. Therefore, it will be apparent to those skilled in the art that modifications can be made to the described invention without departing from the scope of the claims and aspects set forth below.

[0110] 1. A carbon nanotube-type surface membrane for use in a photolithography apparatus, the surface membrane comprising a sacrificial coating.

[0111] 2. The membrane diaphragm according to aspect 1, wherein the membrane diaphragm is a functionalized carbon nanotube membrane.

[0112] 3. The membrane diaphragm according to any of the foregoing aspects, wherein the sacrificial coating comprises carbon.

[0113] 4. The membrane according to aspect 3, wherein the carbon of the sacrificial coating is amorphous carbon, and / or crystalline carbon, and / or annealed carbon, and / or graphene sheets, and / or carbon nanotubes, or diamond particles.

[0114] 5. The membrane according to aspect 4, wherein the graphene sheet is a single sheet or multiple sheets, and / or wherein the diameter of the graphene sheet is from about 0.1 micrometers to about 10 micrometers.

[0115] 6. The membrane according to aspect 4 or aspect 5, wherein the carbon nanotubes are single-walled or multi-walled, and / or wherein the length of the carbon nanotubes is from about 0.1 micrometers to about 10 micrometers.

[0116] 7. The membrane according to any one of aspects 4 to 6, wherein the diameter of the diamond particles is from about 0.1 micrometers to about 10 micrometers.

[0117] 8. The membrane according to any one of aspects 4 to 7, wherein the graphene sheet, the carbon nanotube, and / or the diamond particles are functionalized.

[0118] 9. The membrane according to any of the foregoing aspects, wherein the sacrificial coating is non-covalently bonded to the membrane, or wherein the sacrificial coating is covalently bonded to the membrane.

[0119] 10. The film separator according to any of the foregoing aspects, wherein the sacrificial coating is disposed between two carbon nanotube separators, at least one of the two carbon nanotube separators extending over the quality region of the mask in use.

[0120] 11. The membrane diaphragm according to any of the foregoing aspects, wherein the membrane diaphragm has a quality region and a non-quality region, the radiation beam passes through the quality region in nominal use, and the radiation beam does not pass through the non-quality region in nominal use.

[0121] 12. The membrane diaphragm according to aspect 11, wherein the sacrificial coating is disposed in the non-quality region, or at least in a portion of the non-quality region.

[0122] 13. The membrane diaphragm according to any of the foregoing aspects, wherein the sacrificial coating is configured to surround the periphery of the membrane diaphragm.

[0123] 14. The membrane diaphragm according to any of the foregoing aspects, wherein the thickness of the sacrificial coating is non-uniform.

[0124] 15. The membrane diaphragm according to any of the foregoing aspects, wherein the sacrificial coating is thicker and / or denser in the area of ​​the membrane diaphragm with the greatest etch during nominal use.

[0125] 16. The membrane diaphragm according to any of the foregoing aspects, wherein the sacrificial coating is formed as a gradient portion, optionally wherein the gradient portion is one or both of a thickness gradient portion and a density gradient portion.

[0126] 17. The membrane diaphragm according to aspect 16, wherein the gradient portion is disposed on one or both of the inner edge and the outer edge of the sacrificial coating.

[0127] 18. The membrane diaphragm according to any of the foregoing aspects, wherein the sacrificial coating is disposed on two or more discrete regions of the membrane diaphragm.

[0128] 19. The membrane diaphragm according to any of the foregoing aspects, wherein the sacrificial coating is disposed on one or both sides of the membrane diaphragm, preferably on one side.

[0129] 20. The membrane diaphragm according to any of the foregoing aspects, wherein the diaphragm has 90% or more EUV transmittance, 0.2% or less EUV transmittance nonuniformity, and 0.2% or less EUV scattering in the quality region.

[0130] 21. The surface membrane according to any of the foregoing aspects, wherein the sacrificial coating is provided by one or more of electron beam induced deposition, chemical vapor deposition, physical vapor deposition, pulsed laser deposition, and aerosol deposition, wherein any one of the electron beam induced deposition, chemical vapor deposition, physical vapor deposition, pulsed laser deposition, and aerosol deposition can include other methods or physical masks for achieving localized deposition.

[0131] 22. A carbon nanotube-type film separator for a photolithography apparatus, the separator comprising a carbon nanotube layer supported by a support mesh.

[0132] 23. The membrane according to aspect 22, wherein one of the layers comprises a network of carbon nanotubes, and the other layer comprises a patterned layer of carbon nanotubes.

[0133] 24. The membrane diaphragm according to aspect 23, wherein the patterned carbon nanotube layer is embossed.

[0134] 25. The membrane diaphragm according to aspect 24, wherein the embossed pattern has a periodicity of 164 micrometers or less.

[0135] 26. The membrane diaphragm according to aspect 22, wherein one of the layers comprises a network of carbon nanotubes, and the other layer comprises a grid having a periodicity of 165 micrometers or greater.

[0136] 27. The membrane diaphragm according to aspect 26, wherein the grid comprises grid strips having an effective width of about 0.5 micrometers or less and / or a pitch of more than 330 micrometers.

[0137] 28. The membrane diaphragm according to aspect 26 or 27, wherein the grid comprises a refractory metal, optionally wherein the refractory metal is tungsten or molybdenum.

[0138] 29. A membrane diaphragm according to any one of aspects 22 to 28, wherein the membrane diaphragm further comprises any one of the features according to any one of aspects 1 to 21.

[0139] 30. A film for a photolithography apparatus, the film comprising a film diaphragm according to any of the foregoing aspects and a support frame for supporting the film diaphragm.

[0140] 31. A photolithography apparatus comprising a diaphragm or a film according to any of the foregoing aspects.

[0141] 32. A method for manufacturing a membrane diaphragm, the method comprising the following steps:

[0142] Provide carbon nanotube-type surface membranes; and

[0143] A sacrificial coating is provided on the carbon nanotube-type membrane diaphragm.

[0144] 33. The method according to aspect 32, further comprising: providing the carbon nanotube-type surface membrane in a vacuum chamber; providing a mask to cover a portion of the surface membrane, thereby providing a masked area and preventing coating deposition on the masked area; and depositing a sacrificial coating on an unmasked area of ​​the surface membrane.

[0145] 34. The method according to aspect 32 or aspect 33, the method further comprising: providing an electron source configured to generate an electron beam; and moving the surface membrane and the electron beam relative to each other to selectively deposit the sacrificial coating on the surface membrane.

[0146] 35. The method according to aspect 33 or aspect 34, wherein the vacuum chamber includes volatile carbonaceous compounds as a source of the sacrificial coating, optionally wherein the volatile carbonaceous compounds are C1-C5 hydrocarbons.

[0147] 36. The method according to any one of aspects 32 to 35, wherein the method further comprises: annealing the sacrificial coating.

[0148] 37. The method according to any one of aspects 32 to 36, wherein the method comprises: controlling the structural form of the sacrificial coating, optionally wherein the method additionally or alternatively comprises: a step of removing contaminants from the sacrificial coating and / or the surface membrane, preferably removing contaminants from the sacrificial coating and / or the surface membrane after the deposition of the sacrificial coating.

[0149] 38. The method according to any one of aspects 32 to 37, wherein the method comprises: providing the sacrificial coating by spraying the surface membrane diaphragm with an aerosol; and providing a mask to limit the surface membrane diaphragm area on which the sacrificial coating is formed.

[0150] 39. The method according to any one of aspects 32 to 38, wherein the method comprises: providing a mixture of carbon sources in a carrier fluid for spraying an aerosol onto the surface membrane, optionally wherein the carrier liquid is polar or nonpolar, optionally wherein the carbon particles comprise functionalized graphene flakes and / or carbon nanotubes and / or diamond particles.

[0151] 40. The method according to any one of aspects 32 to 39, wherein the method comprises: forming an aerosol and spraying the aerosol onto the membrane diaphragm.

[0152] 41. The method according to aspect 40, wherein the step of forming the aerosol comprises: operating a piezoelectric actuator and / or a gas jet to form the aerosol, optionally wherein the piezoelectric actuator is driven from about 10 kHz to about 10 MHz, preferably from 100 kHz to 1 MHz, optionally wherein the average diameter of the droplets in the aerosol is from about 1 micrometer to about 10 micrometers.

[0153] 42. The method according to any one of aspects 38 to 41, wherein the method comprises: moving a spray relative to the surface membrane septum to selectively coat the surface membrane septum.

[0154] 43. The method according to any one of aspects 38 to 42, wherein the spray is carried by a gas at atmospheric pressure.

[0155] 44. The method according to any one of aspects 38 to 43, wherein the method comprises: setting the sacrificial coating as a gradient portion.

[0156] 45. The method according to aspect 44, wherein the gradient portion is one or both of a thickness gradient portion and a density gradient portion.

[0157] 46. ​​The method according to any one of aspects 38 to 45, wherein the method comprises: heating the surface membrane diaphragm to evaporate the carrier fluid.

[0158] 47. The method according to any one of aspects 38 to 46, wherein the method is performed at atmospheric pressure or less than atmospheric pressure.

[0159] 48. The method according to any one of aspects 32 to 47, wherein the method further comprises: providing a second membrane septum to sandwich the sacrificial layer between the two membrane septums.

[0160] 49. A method of manufacturing a carbon nanotube-based membrane separator, the method comprising: providing a substrate having a desired pattern; and pressing the substrate together with a carbon nanotube-based membrane to imprint the pattern into the carbon nanotube-based membrane.

[0161] 50. The method according to aspect 49, wherein the method further comprises: attaching a patterned carbon nanotube-based membrane to a mesh carbon nanotube-type membrane.

[0162] 51. The method according to aspect 50, wherein the method further comprises any step of any of aspects 32 to 41.

[0163] 52. An apparatus for manufacturing a membrane diaphragm, the apparatus comprising: a vacuum chamber; a support for the membrane diaphragm; an electron beam generator configured to generate an electron beam and direct the electron beam to the support; and a volatile carbonaceous compound source configured to provide volatile carbonaceous compounds to the vacuum chamber, the electron beam being configured to deposit a carbon sacrificial coating onto the membrane diaphragm, wherein the apparatus comprises one or both of the following:

[0164] i) a mask configured to selectively cover a portion of the surface membrane diaphragm to prevent the sacrificial coating from depositing on the portion covered by the mask; and

[0165] ii) A means for moving the electron beam and the surface membrane relative to each other to control the placement of the carbon sacrificial coating.

[0166] 53. The apparatus according to aspect 52, further comprising a controller configured to control the electron beam generator and / or control the relative position of the electron beam with respect to the membrane diaphragm.

[0167] 54. The apparatus according to aspect 52 or aspect 53, wherein the apparatus further comprises a heater configured to heat the surface membrane diaphragm to anneal the carbon sacrificial layer, and / or a heater for heating the mask.

[0168] 55. The use of a diaphragm according to any one of aspects 1 to 29, a diaphragm according to aspect 30, a lithography apparatus according to aspect 31, a method according to any one of aspects 32 to 51, or an apparatus according to any one of aspects 51 to 54 in a lithography method or apparatus.

Claims

1. A carbon nanotube-type surface film separator for a photolithography apparatus, the surface film separator having a quality region and a non-quality region, wherein a radiation beam passes through the quality region during nominal use and does not pass through the non-quality region during nominal use, wherein, The surface membrane includes a sacrificial coating disposed on at least a portion of the non-quality area of ​​the surface membrane.

2. The membrane diaphragm according to claim 1, wherein, The membrane is a functionalized carbon nanotube membrane.

3. The membrane diaphragm according to any of the preceding claims, wherein, The sacrificial coating comprises carbon.

4. The membrane diaphragm according to claim 3, wherein, The carbon in the sacrificial coating is amorphous carbon, and / or crystalline carbon, and / or annealed carbon, and / or graphene sheets, and / or carbon nanotubes, or diamond particles.

5. The membrane diaphragm according to claim 4, wherein, The graphene sheets, the carbon nanotubes, and / or the diamond particles are functionalized.

6. The membrane diaphragm according to any of the preceding claims, wherein, The sacrificial coating is non-covalently bonded to the surface membrane, or the sacrificial coating is covalently bonded to the surface membrane.

7. The membrane diaphragm according to any of the preceding claims, wherein, The sacrificial coating is disposed between two carbon nanotube membranes, at least one of which extends over the quality region of the mask during use.

8. The membrane diaphragm according to claim 7, wherein, The sacrificial coating is applied to the non-quality area.

9. The membrane diaphragm according to any of the preceding claims, wherein, The sacrificial coating is configured to surround the periphery of the surface membrane diaphragm.

10. The membrane diaphragm according to any of the preceding claims, wherein, The sacrificial coating is thicker and / or denser in the area of ​​the membrane diaphragm that is most etched during nominal use.

11. The membrane diaphragm according to any of the preceding claims, wherein, The sacrificial coating is formed as a gradient portion, wherein the gradient portion is one or both of a thickness gradient portion and a density gradient portion.

12. The membrane diaphragm according to claim 11, wherein, The gradient portion is disposed on one or both of the inner and outer edges of the sacrificial coating.

13. The membrane diaphragm according to any of the preceding claims, wherein, The sacrificial coating is applied to two or more discrete regions of the membrane diaphragm.

14. The membrane diaphragm according to any of the preceding claims, wherein, The sacrificial coating is disposed on one or both sides of the membrane diaphragm, preferably on one side.

15. The membrane diaphragm according to any of the preceding claims, wherein, The diaphragm has 90% or more EUV transmittance, 0.2% or less EUV transmittance non-uniformity, and 0.2% or less EUV scattering in the quality region.

16. A film for a photolithography apparatus, the film comprising a film diaphragm according to any of the preceding claims and a support frame for supporting the film diaphragm.

17. A method for manufacturing a membrane diaphragm, the method comprising the following steps: Provides carbon nanotube-type surface membranes and separators; as well as A sacrificial coating is provided on at least a portion of the non-quality region of the membrane diaphragm region, wherein the radiation beam does not pass through the non-quality region during nominal use.

18. An apparatus for manufacturing a membrane diaphragm, the apparatus comprising: Vacuum chamber; Support components for surface membrane diaphragms; An electron beam generator configured to generate an electron beam and guide the electron beam to the support. A volatile carbonaceous compound source, configured to provide volatile carbonaceous compounds to the vacuum chamber, and an electron beam configured to deposit a carbon sacrificial coating onto the surface membrane, wherein the apparatus comprises one or both of the following: i) A mask configured to selectively cover a portion of the surface membrane diaphragm to prevent the sacrificial coating from depositing on the portion covered by the mask; and ii) A means for moving the electron beam and the surface membrane relative to each other to control the placement of the carbon sacrificial coating.

19. The apparatus of claim 18, further comprising a controller configured to control the electron beam generator and / or control the relative position of the electron beam with respect to the membrane diaphragm.

20. The device according to claim 18 or claim 19, wherein, The device also includes a heater configured to heat the surface membrane to anneal the carbon sacrificial layer, and / or a heater for heating the mask.

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