Thin film structures for EUV lithography and methods of making same

Abstract

The invention relates to a thin film structure for EUV lithography and a method of manufacturing the same. A method of making a thin film includes heating a separator including a plurality of carbon nanotubes at a temperature sufficient to convert amorphous carbon to crystalline carbon. The diaphragm is heated in a chamber having a lower oxygen content than air. After heating the membrane, the membrane is used to form a thin film. In an embodiment, the membrane includes a plurality of carbon shells having a first level of crystallinity, and during heating of the membrane, the plurality of carbon shells having the first level of crystallinity is converted to a plurality of carbon shells having a second level of crystallinity, where the second level of crystallinity is greater than the first level of crystallinity. In an embodiment, the membrane includes a metal catalyst at a first concentration, and the first concentration of the metal catalyst is reduced to a second concentration during heating of the membrane.

Description

Technical Field

[0001] This disclosure relates to thin film structures for EUV lithography and methods for manufacturing the same. Background Technology

[0002] A pellicle is a thin, transparent film stretched onto a frame bonded to a photomask to protect it from damage, dust, and / or moisture. In extreme ultraviolet (EUV) lithography, pellicles with high transparency, high mechanical strength, and low or no contamination in the EUV wavelength region are typically used. Summary of the Invention

[0003] According to one aspect of this disclosure, a method for manufacturing a thin film is provided, comprising: heating a membrane comprising a plurality of carbon nanotubes at a temperature sufficient to convert amorphous carbon into crystalline carbon, wherein the membrane is heated in a chamber with an oxygen content lower than that of air; and forming a thin film comprising the membrane after heating the membrane.

[0004] According to one aspect of this disclosure, a method for manufacturing a thin film is provided, comprising: heating a membrane comprising a plurality of carbon nanotubes and a carbon shell in a chamber at a temperature of 1000°C to 3600°C with a metal catalyst; converting amorphous carbon in the carbon nanotubes and carbon shell into crystalline carbon; and forming a thin film comprising the membrane after heating the membrane.

[0005] According to one aspect of this disclosure, a thin film is provided, comprising: a diaphragm disposed on a frame, wherein the diaphragm comprises a plurality of crystalline carbon nanotubes and a plurality of carbon polyhedral hollow particles. Attached Figure Description

[0006] The various aspects of this disclosure can be best understood by reading in conjunction with the accompanying drawings through the following detailed description. It should be noted that, according to industry standard practice, the various features are not drawn to scale. In fact, for clarity of discussion, the dimensions of the various features may be arbitrarily enlarged or reduced.

[0007] Figure 1A and Figure 1B Nanotubes and thin films for EUV photomasks according to embodiments of the present disclosure are shown.

[0008] Figure 2A , Figure 2B , Figure 2C and Figure 2D Various views of multi-walled nanotubes according to embodiments of the present disclosure are shown.

[0009] Figure 3A , Figure 3B and Figure 3CThe process stages for manufacturing a thin film for an EUV photomask according to embodiments of the present disclosure are shown.

[0010] Figure 4 The process stages for manufacturing a thin film for an EUV photomask according to embodiments of the present disclosure are shown.

[0011] Figure 5A and Figure 5B Cross-sectional and plan view (top view) views of one of the various stages of manufacturing a thin film for an EUV photomask according to embodiments of the present disclosure are shown.

[0012] Figure 6A and Figure 6B Cross-sectional and plan view (top view) views of one of the various stages of manufacturing a thin film for an EUV photomask according to embodiments of the present disclosure are shown.

[0013] Figure 7A , Figure 7B , Figure 7C , Figure 7D and Figure 7E The process flow for manufacturing a thin film for an EUV photomask according to embodiments of the present disclosure is shown.

[0014] Figure 8A , Figure 8B , Figure 8C and Figure 8D The process flow for manufacturing a thin film for an EUV photomask according to embodiments of the present disclosure is shown.

[0015] Figure 9A , Figure 9B , Figure 9C and Figure 9D The process stages for manufacturing a thin film for an EUV photomask according to embodiments of the present disclosure are shown.

[0016] Figure 10A , Figure 10B , Figure 10C , Figure 10D , Figure 10E and Figure 10F The process stages for forming a crystalline hollow carbon shell according to embodiments of the present disclosure are shown.

[0017] Figure 11A , Figure 11B and Figure 11C The process stages for manufacturing a thin film for an EUV photomask according to embodiments of the present disclosure are shown.

[0018] Figure 12A , Figure 12B , Figure 12C and Figure 12DThe process stages for manufacturing a thin film for an EUV photomask according to embodiments of the present disclosure are shown.

[0019] Figure 13 The process stages for manufacturing a thin film for an EUV photomask according to embodiments of the present disclosure are shown.

[0020] Figure 14 A flowchart illustrating a method for manufacturing a thin film for an EUV photomask according to an embodiment of the present disclosure is shown.

[0021] Figure 15 A flowchart illustrating a method for manufacturing a thin film for an EUV photomask according to an embodiment of the present disclosure is shown.

[0022] Figure 16 A flowchart illustrating a method for manufacturing a thin film for an EUV photomask according to an embodiment of the present disclosure is shown.

[0023] Figure 17A A flowchart illustrating a method for manufacturing a semiconductor device according to embodiments of the present disclosure is shown, and Figure 17B , Figure 17C , Figure 17D and Figure 17E The sequential manufacturing operations of a method for manufacturing a semiconductor device according to embodiments of the present disclosure are illustrated. Detailed Implementation

[0024] It is to be understood that the following disclosure provides many different embodiments or examples for implementing various features of the invention. Specific embodiments or examples of components and arrangements are described below to simplify this disclosure. Of course, these are merely examples and not intended to be limiting. For example, the dimensions of elements are not limited to the disclosed range or values, but may depend on the device's manufacturing conditions and / or desired properties. Furthermore, forming a first feature on or over a second feature in the following description may include embodiments where the first and second features are formed in direct contact, and may also include embodiments where an additional feature may be formed between the first and second features such that the first and second features do not need to be in direct contact. For simplicity and clarity, various features may be drawn at arbitrary scales. In the drawings, some layers / features may be omitted for simplicity.

[0025] Furthermore, for ease of description, this document may use spatially relative terms such as “below,” “under,” “down,” “above,” “up,” etc., to describe the relationship between one element or feature as shown in the figures and another element(s) or feature(s). These spatially relative terms are intended to cover different orientations of the device in use or operation other than those depicted in the figures. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatially relative descriptors used herein may be interpreted accordingly. Additionally, the term “made of” may mean “comprising” or “consisting of.” Furthermore, one or more additional operations may occur between the operations during subsequent manufacturing processes, and the order of operations may be changed. In this disclosure, unless otherwise stated, the phrase “at least one of A, B, and C” means any one of A, B, C, A+B, A+C, B+C, or A+B+C, and does not mean one from A, one from B, and one from C. The materials, configurations, structures, operations, and / or dimensions explained using one embodiment may be applied to other embodiments, and detailed descriptions thereof may be omitted.

[0026] EUV lithography is one of the key technologies for extending Moore's Law. However, as the wavelength shrinks from 193 nm (ArF) to 13.5 nm, the EUV light source suffers severe power attenuation due to environmental absorption. Although the stepper lithography machine / scanning chamber operates under vacuum to prevent strong EUV absorption by the gas, maintaining high EUV transmittance from the EUV light source to the wafer remains an important factor in EUV lithography.

[0027] Thin films typically require high transparency and low reflectivity. In ultraviolet (UV) or deep UV (DUV) lithography, thin films are made of transparent resin films. However, in EUV lithography, resin-based films are unacceptable, and in some embodiments, non-organic materials such as polycrystalline silicon, silicides, or metal films are used.

[0028] One of the bottlenecks in EUV production performance is EUV mask film failure, such as deformation, cracking, and breakage.

[0029] Carbon nanotubes (CNTs) are one of the suitable thin film materials for EUV photomasks because CNTs have a high EUV transmittance of over 96.5%. Typically, thin films used for EUV reflective masks need the following properties: (1) long lifetime in the hydrogen radical-rich operating environment of EUV stepper / scanners; (2) high mechanical strength to minimize sagging effect during vacuum and venting operations; (3) high or perfect blocking properties for particles larger than about 20 nm (killer particles); and (4) good heat dissipation to prevent the film from being burned by EUV radiation.

[0030] However, strong CNT sp2 bonds can be easily etched by EUV-induced hydrogen and oxygen plasma in an EUV scanner environment. Protective coatings for CNTs include amorphous films. However, amorphous films are also easily etched in an EUV scanner environment, which reduces the usefulness of the protective coating. CNT inhomogeneity can also be a problem. This inhomogeneity can lead to poor patterning due to poor EUV transmittance (EUVT) and / or poor EUV reflectance (EUVR).

[0031] Furthermore, the film temperature increases with increasing EUV power. For example, at an EUV power of 436 ± 20 W, the film temperature can range from 527 ± 50°C. Some CNT films may not be able to withstand such high temperatures because they only exhibit thermal stability in the range of approximately 500°C to 700°C.

[0032] This disclosure discloses a method for providing EUV films with high transmittance, high strength, and enhanced chemical stability. According to some embodiments of this disclosure, the transmittance, strength, and chemical stability of the film can be improved by increasing the crystallinity of the film separator. In some embodiments of this disclosure, the film separator 100 comprises a plurality of CNTs 20b and a plurality of carbon shells 25b. In other embodiments, the film separator comprises a plurality of CNTs 20b. The crystallinity of the CNTs and carbon shells can be increased by subjecting them to high-temperature treatment. The high-temperature treatment converts the amorphous portions in the CNTs and carbon shells into crystalline portions. In some embodiments, the crystalline portions are graphite or graphene.

[0033] In some embodiments of this disclosure, the nanotube is an elongated tube having a diameter in the range of about 0.5 nm to about 100 nm.

[0034] In some embodiments of this disclosure, the thin film for an EUV photomask comprises a network diaphragm having multiple nanotubes and hollow shells forming a mesh structure. Furthermore, a method for producing thin films with enhanced mechanical strength, chemical resistance, and enhanced EUV transmittance is also disclosed.

[0035] Figure 1A and Figure 1BAn EUV film 10 according to an embodiment of the present disclosure is shown. In some embodiments, the film 10 for an EUV reflective mask includes a main network diaphragm 100 disposed on and attached to a film frame 15. In some embodiments, the main network diaphragm 100 is a transparent diaphragm that is transparent to electromagnetic radiation (e.g., EUV radiation). In some embodiments, the transparent diaphragm 100 has an EUV transmittance greater than 96.5%. The transparent diaphragm 100 may be opaque to some electromagnetic wavelengths (e.g., infrared or visible light radiation) and transparent to other electromagnetic wavelengths (e.g., EUV radiation or X-ray radiation). In some embodiments, such as Figure 1A As shown, the main network membrane 100 includes a plurality of nanotubes 20b (e.g., single-walled nanotubes 20S) and a plurality of hollow carbon shells 25b. In other embodiments, such as Figure 1B As shown, the nanotubes 20b constituting the main network membrane 100 include a plurality of multi-walled nanotubes 20M. In some embodiments, the nanotubes are joined or attached to each other to form nanotube bundles. In some embodiments, the main network membrane 100 is primarily composed of CNT 20b. In some embodiments, the main network membrane 100 is composed of more than 90% CNT 20b (by weight) and less than 10% carbon shell 25b (by weight). In some embodiments, the main network membrane 100 is composed of more than 95% CNT 20b (by weight) and less than 5% carbon shell 25b (by weight). In other embodiments, the main network membrane 100 is composed of more than 99% CNT 20b (by weight) and less than 1% carbon shell 25b (by weight). Therefore, in some embodiments, the main network membrane 100 contains almost no carbon shell 25b.

[0036] In some embodiments, multi-walled nanotubes are coaxial nanotubes having one or more walls coaxially surrounding one or more internal tubes. In some embodiments, the main network membrane 100 comprises only one type of nanotube (e.g., single-walled or multi-walled or a single material), and in other embodiments, different types of nanotubes form the main network membrane 100. In some embodiments, a number of multi-walled nanotubes form a bundle of nanotubes attached to each other.

[0037] In some embodiments, a thin film (support) frame or border 15 is attached to the main network diaphragm 100 to maintain the space between the main network diaphragm of the film and the EUV mask (patterned area) when mounted on an EUV mask. The thin film frame 15 is attached to the surface of the EUV photomask using a suitable bonding material. In some embodiments, the bonding material is an adhesive, such as acrylic, silicone, or cross-linked adhesive. The frame structure is larger than the black boundary area of ​​the EUV photomask, such that the film covers not only the circuit pattern area of ​​the photomask but also the black boundary.

[0038] Figure 2A , Figure 2B , Figure 2C and Figure 2D Various views of multi-walled nanotubes according to embodiments of the present disclosure are shown.

[0039] In some embodiments, the nanotubes in the main network diaphragm 100 include multi-walled nanotubes, also known as coaxial nanotubes. Figure 2A A perspective view of a multi-walled coaxial nanotube with three tubes 210, 220, and 230 is shown, and Figure 2B A cross-sectional view is shown.

[0040] The number of multi-walled nanotubes is not limited to three. In some embodiments, the multi-walled nanotube has two coaxial nanotubes, such as... Figure 2C As shown, and in other embodiments, the multi-walled nanotubes include an innermost tube 210 and first to Nth nanotubes (including an outermost tube 200N), where N is a natural number from 1 to about 30, such as Figure 2D As shown. In some embodiments, N ranges from 3 to 20, and in other embodiments, N ranges from 5 to 10. In some embodiments, at least one of the first to Nth outer layers is a nanotube coaxially surrounding the innermost nanotube 210.

[0041] In some embodiments, the diameter of the innermost nanotube is in the range of about 0.5 nm to about 20 nm; in other embodiments, the diameter of the innermost nanotube is in the range of about 1 nm to about 10 nm; and in still other embodiments, the diameter of the innermost nanotube is in the range of about 2 nm to about 5 nm. In some embodiments, the diameter of the multi-walled nanotube (i.e., the diameter of the outermost tube) is in the range of about 3 nm to about 40 nm; and in still other embodiments, it is in the range of about 5 nm to about 20 nm. In some embodiments, the length of the multi-walled nanotube is in the range of about 0.5 μm to about 50 μm; and in still other embodiments, it is in the range of about 1.0 μm to about 20 μm.

[0042] Figure 3A , Figure 3B and Figure 3C A method for manufacturing a nanotube network membrane for thin films according to embodiments of the present disclosure is shown.

[0043] In some embodiments, carbon nanotubes (CNTs) 20a are formed by a chemical vapor deposition (CVD) process. In some embodiments, the CVD process is performed using methods such as... Figure 3A The vertical furnace shown is used for execution, and the synthesized nanotubes are deposited in, as... Figure 3BThe network membrane 100 formed on the support diaphragm 80 is then separated from the support diaphragm 80 and transferred to the film frame 15, as shown. Figure 3C As shown.

[0044] exist Figure 3A In the illustrated embodiments, a floating catalyst CVD process is used to form carbon nanotubes (CNTs). In some embodiments, a funnel quartz design reactor 300 is used to form CNTs 20a. The reactor 300 includes a tubular quartz wall 310. The upper part of the quartz tube is cylindrical, and the lower part is conical. A heater 320 surrounds the quartz tube wall. Nanotubes 20a are deposited on a filter or support diaphragm 80. In some embodiments, a platform or mask 330 (on which the support diaphragm 80 is disposed) rotates continuously or intermittently (in a stepping manner), such that the synthesized nanotubes are deposited on the support diaphragm 80 in different or random orientations. In some embodiments, the diaphragm support is filter paper. In some embodiments, the mask 330 is a plate used to prevent CNTs 20a from penetrating the support diaphragm 80. In some embodiments, CNTs 20a can penetrate the filter paper in areas of the support diaphragm 80 not covered by the mask.

[0045] In some embodiments, the funnel-shaped quartz reactor has a tube diameter in the upper cylindrical portion ranging from about 1 cm to about 100 cm, which tapers to a diameter at the end of the lower tapered portion ranging from about 1 mm to about 10 cm. In some embodiments, the reactor height H1 ranges from about 200 cm to about 600 cm, and the height H2 of the tapered portion of the lower tapered portion ranges from about 10 cm to about 100 cm. In some embodiments, the taper angle θ of the lower tapered portion ranges from about 80° to about 160°.

[0046] To produce CNT 20a, a carbon source and catalyst are introduced together into reactor inlet 340. In some embodiments, a sulfur compound is also introduced into reactor inlet 340. In some embodiments, the carbon source comprises one or more hydrocarbon gases, including methane with a flow rate ranging from greater than 0 sccm to about 800 sccm, and ethane with a flow rate ranging from greater than 0 sccm to about 900 sccm. In some embodiments, the carbon source is introduced at a flow rate ranging from about 4 sccm to about 200 sccm. In some embodiments, the catalyst can be any suitable catalyst, such as iron or iron-containing catalysts, including ferrocene (Fe(C5H5)2); and transition metal carbonyl complexes, including M(CO). xM is a transition metal such as Cr, Mo, or W, and x is in the range of 3 to 10. Other suitable catalysts include one or more of CoFe, Co, CoNi, Ni, CoMo, and FeMo. In some embodiments, the catalyst is introduced into the reactor at a flow rate of greater than 0 sccm to about 1 sccm. In some embodiments, a sulfur-containing compound is introduced into the reactor. The sulfur-containing compound is one or more of hydrogen sulfide and thiophene. The sulfur-containing compound is introduced into the reactor at a flow rate of greater than 0 sccm to about 1 sccm. In some embodiments, hydrogen and a carrier gas are introduced into the reactor through gas inlet 350. The carrier gas may include one or more of argon, nitrogen, or oxygen. Hydrogen may be introduced into the reactor at a flow rate of greater than 0 sccm to about 1000 sccm. The carrier gas can be introduced into the reactor at the following flow rates: argon at about 0 sccm to about 50,000 sccm, nitrogen at about 0 sccm to about 60,000 sccm, and oxygen at about 0 sccm to about 1 sccm.

[0047] In some embodiments, the reactor is heated to a temperature ranging from about 300°C to about 1100°C during the CNT growth operation. In some embodiments, a temperature gradient 370 is maintained along the height of the reactor. For example, in some embodiments, the temperature gradually increases from the top of the reactor toward the bottom, or vice versa. In some embodiments, the temperature increases along the gradient from about 300°C to about 1100°C. In some embodiments, the mask or platform 330 is rotated at a speed of about 0 rpm to about 500 rpm. In some embodiments, a vacuum 360 is applied during the nanotube growth operation to provide a uniform CNT distribution. In some embodiments, the growth operation lasts for a sufficiently long period of time to obtain the desired thickness of the nanotube network layer.

[0048] Figure 4 Another method for fabricating a network membrane of nanotubes according to embodiments of the present disclosure is illustrated. In some embodiments, the nanotubes are formed by various other methods, such as CVD, arc discharge, or laser ablation, and the hollow carbon shell is formed by laser ablation, hydrothermal carbonization, electrochemical dealloying, co-electrolysis, or carbonation processes. The nanotubes and carbon shell are then dispersed in a solution. In some embodiments, the solution comprises a solvent (e.g., water or an organic solvent) and a surfactant (e.g., sodium dodecyl sulfate (SDS)).

[0049] like Figure 4As shown, a support diaphragm or filter 80 is placed between a chamber or cylinder (in which a solution of nanotubes and carbon shells are dispersed) and a vacuum chamber. In some embodiments, the support diaphragm is an organic or inorganic porous or mesh material. In some embodiments, the support diaphragm is a woven or nonwoven fabric. In some embodiments, the support diaphragm has a circular shape, in which a thin film with a size of 150 mm × 150 mm (the size of an EUV mask) can be placed.

[0050] like Figure 4 As shown, the pressure in the vacuum chamber is reduced, allowing pressure to be applied to the solvent in the chamber or cylinder. Because the mesh or pore size of the supporting diaphragm or filter is sufficiently small compared to the size of the nanotubes and carbon shells, the nanotubes 20a and carbon shells 25a are trapped by the supporting diaphragm as the solvent passes through it. The supporting diaphragm (on which the nanotubes are deposited) is separated from the filtration device and dried. In some embodiments, the filtration deposition is repeated to obtain a nanotube network layer of the desired thickness. In some embodiments, after the deposition of nanotubes and shells in solution, additional nanotubes and shells are dispersed in the same or a new solution, and the filtration deposition is repeated. In other embodiments, another filtration deposition is performed after the nanotubes and shells are dried. In the repetitions, the same type of nanotubes and shells are used in some embodiments, while different types of nanotubes are used in others. In some embodiments, the nanotubes dispersed in solution comprise multi-walled nanotubes.

[0051] Figure 5A and Figure 5B as well as Figure 6A and Figure 6B Cross-sectional views (“A”) and plan views (“B”) of various stages for fabricating a thin film for an EUV photomask according to embodiments of the present disclosure are shown. It will be understood that... Figures 5A-6B Additional operations are provided before, during, and after the process shown, and for additional embodiments of the method, some of the operations described below may be replaced or eliminated. The order of operations / processes may be interchanged. The materials, configurations, methods, processes, and / or dimensions described with respect to the foregoing embodiments are applicable to the following embodiments, and their detailed descriptions may be omitted.

[0052] like Figure 5A and Figure 5B As shown, a layer of CNT 20a and carbon shell 25a is formed on the supporting diaphragm 80 using one or more of the methods described above. In some embodiments, the nanotube 20 includes single-walled nanotubes, multi-walled nanotubes, or mixtures thereof. In some embodiments, the nanotube 20a includes only single-walled nanotubes.

[0053] like Figure 6A and Figure 6BAs shown, in some embodiments, a thin film frame or border 15 is attached to the layers of carbon nanotubes 20a and carbon shell 25a. In some embodiments, the thin film frame 15 is formed of one or more layers of crystalline silicon, polycrystalline silicon, silicon dioxide, silicon nitride, silicon carbide, alumina, zirconium dioxide, tantalum nitride, niobium nitride, or ceramic materials. In some embodiments, the thin film frame 15 is formed of one or more layers of graphite or ultra-high temperature ceramics, including HfCN, HfC, TaC, NbC, ZrC, HfN, HfB2, ZrB2, TiB2, TiC, NbB2, TaB2, TiN, or ZrN. In some embodiments, such as Figure 6B As shown, the thin film framework 15 has a rectangular (including square) framework shape, which is larger than the black boundary region of the EUV mask and smaller than the substrate of the EUV mask. In some embodiments, the thin film framework is attached to the nanotube layer by a cold welding operation.

[0054] In some embodiments, the layers of carbon nanotubes 20a and carbon shell 25a, as well as the support diaphragm 80, are subsequently cut into rectangular shapes that are the same size as or slightly larger than the film frame 15, and the support diaphragm 80 is then separated or removed. When the support diaphragm 80 is made of an organic material, it is removed by wet etching using an organic solvent.

[0055] Figures 7A-7E The sequential operation of a method 700 for manufacturing a thin film according to some embodiments of the present disclosure is illustrated. The frame 15 is first wetted with a suitable solvent (e.g., ethanol) to promote adhesion of the frame 15 to the main network diaphragm 100 of the nanotubes 20a or 20b and the shells 25a or 25b, as shown. Figure 7A As shown. Frame 15 is in contact with the main network diaphragm 100, and the structure is dried by air drying or vacuum drying, as... Figure 7B As shown, and then remove the supporting diaphragm, as... Figure 7C As shown. In some embodiments, in Figure 7D In this process, the main network membrane 100 is treated with a suitable solvent vapor 710 (e.g., ethanol vapor) to increase the density of the main network membrane. The solvent vapor facilitates the bundling of nanotubes within the main network membrane. During solvent vapor treatment, CNTs contact and bond with each other, thereby forming CNT bundles. Figure 7E In this process, the thin film structure is subsequently dried by air drying or vacuum drying to provide a thin film structure 720 having a diaphragm 100 (which includes bundled nanotubes). In some embodiments, the solvent vaporization process includes immersing the diaphragm in a high-boiling-point solvent (e.g., isoamyl acetate), then washing and drying the network diaphragm 100.

[0056] Figures 8A to 8DThe sequential operation of another method 800 for manufacturing a thin film according to some embodiments of the present disclosure is shown. This method is related to... Figures 7A-7E The method disclosed is similar, except that it does not include the step of wetting the frame 15 with a solvent. Therefore, Figure 8A The operation shown corresponds to Figure 7B The operation shown Figure 8B Corresponding to Figure 7C , Figure 8C Corresponding to Figure 7D ,and Figure 8D The operation shown corresponds to Figure 7E .

[0057] In some embodiments, the main network membrane 100 comprises a combination of individual nanotubes 20a, bundled nanotubes 30a, and metal catalyst particles having a low-crystallinity carbon shell 25a, such as Figure 9A As shown. Then, the main network diaphragm undergoes a heat treatment operation. In some embodiments, the temperature of the heat treatment operation is sufficient to convert amorphous carbon into crystalline carbon. In some embodiments, the crystalline carbon is graphite or graphene. As a result of the heat treatment operation, the percentage of crystallinity of the carbon nanotubes and carbon shell is increased by the heat treatment operation. In some embodiments, the diaphragm 100 is heated in a chamber with a temperature range of about 1000°C to about 3600°C. In some embodiments, the diaphragm 100 is heated in a chamber with a temperature range of about 2200°C to about 3200°C, wherein the oxygen concentration in the chamber does not exceed about 10 ppm during heating. In other embodiments, the diaphragm is heated in a vacuum chamber with a temperature range of about 1000°C to about 2200°C, wherein the pressure in the vacuum chamber is less than 1 ppm during heating. Torr, and in other embodiments, the diaphragm is heated in a temperature range of about 1500°C to about 2000°C.

[0058] The heat treatment process converts amorphous carbon into crystalline carbon, such as graphite or graphene, thereby increasing the crystallinity of the CNTs and the carbon shell. In some embodiments, the crystallinity of the CNTs and the carbon shell is increased to greater than 70%, while in other embodiments, the crystallinity is increased to greater than 90%. The heat treatment process also promotes carbon nanotube bundling, allowing more nanotubes to bundle together to form a larger nanotube bundle 30b, which has a higher crystallinity than the nanotube bundle 30a before the heat treatment process, such as... Figure 9BAs shown. In some embodiments, the heat treatment operation enables different carbon nanotubes to join together during heating of the diaphragm. In some embodiments, during the heat treatment operation, a bridging structure 35 composed of one or more carbon nanotubes is formed between different carbon nanotubes 20b or nanotube bundles 30b. In some embodiments, during the heat treatment operation, a connecting structure 40 is formed at the intersections between different nanotubes or nanotube bundles. In some embodiments, a specific angle α is formed in at least one CNT during the heat treatment operation. In some embodiments, at least one crystalline carbon nanotube 20b is bent at an angle of about 10° to about 170°. In other embodiments, the angle is in the range of about 30° to about 150°. In some embodiments, a carbon shell 25a with low crystallinity is converted into crystalline polyhedral hollow particles 25b with higher crystallinity.

[0059] The formation of bridging structures 35, connecting structures 40, and larger nanotube bundles 30b with higher degree of clustering allows the carbon nanotubes to be more firmly anchored to each other, thus preventing displacement and movement of the nanotubes relative to each other. This improved anchoring helps the membrane 100 maintain a fixed, consistent pore size. Prior to the high-temperature processing operation, although the CNTs 20a were interwoven, they were not significantly bonded to each other. Furthermore, once subjected to external forces, the CNTs 20a would slide against each other, causing changes in the pore size of the film 10.

[0060] Following the high-temperature processing, the metal catalyst causes carbon atoms to rearrange and recrystallize at high temperatures, allowing different CNTs 20b to form bridging structures 35 between each other in some embodiments, such that one or more CNTs span two different CNTs 20b. Furthermore, the metal catalyst particles tend to aggregate at the intersections of more than two CNTs 20a, causing the CNTs to bond together at these points after the high-temperature processing, thus forming connections 40. These properties contribute to enhanced mechanical strength of the film 10. Moreover, due to the significant adhesive forces at the connections 40 of the different CNTs 20b, the pore size of the film 10 is stable. This prevents pore size variations due to CNT slippage.

[0061] In some embodiments, heat treatment causes the CNT 20a and nanotube bundle 30a (such as...) to... Figure 9C (as shown) are connected to each other to form a T-shaped bundle 50 (as shown) Figure 9D (As shown). The T-shaped bundle 50 provides higher strength in some embodiments because the structure is joined together in more than one direction and there is a closer contact between adjacent bundles 30b. The T-shaped structure also prevents changes in aperture size due to slippage of the CNTs.

[0062] When the heat treatment temperature is below the disclosed range, the conversion of amorphous carbon to crystalline carbon may be insufficient, the removal of the metal catalyst may be insufficient, and the formation of bridging and bonding may be insufficient. When the heat treatment temperature is above the disclosed range, the membrane 100 may degrade, and the process may be economically unfeasible due to the increased energy required to maintain the higher temperature.

[0063] The formation of crystalline polyhedral particles 25 will refer to Figures 10A-10F Detailed explanation follows. During the formation of carbon nanotubes, metal catalyst particles 45 (e.g., iron particles) serve as sites for nanotube growth. In some embodiments, the initially formed main network membrane 100 comprises a metal catalyst particle core 45 (e.g., iron particles) surrounded by an amorphous or low-crystallinity carbon shell 25a, such as... Figure 10A As shown. The core / shell can be formed using any suitable technique, including laser ablation, hydrothermal carbonization, electrochemical dealloying, co-electrolysis, or carbonization processes.

[0064] In some embodiments, during the heat treatment operation, the temperature is gradually increased from room temperature to approximately 3600°C. In some embodiments, when the temperature exceeds approximately 500°C, carbon atoms begin to dissolve into the metal particles 45, such as... Figure 10B As shown. Carbon atoms continue to dissolve into metal particles 45 until the metal particles are filled with carbon atoms, as... Figure 10C As shown, the metal particles begin to evaporate as the temperature rises. In the case of iron particles, iron begins to evaporate at temperatures exceeding approximately 900°C, as... Figure 10D As shown, carbon atoms precipitate from the evaporated metal particles as the metal evaporates. With increasing temperature, the metal catalyst particles evaporate almost completely, leaving behind a low-crystallinity or amorphous carbon shell, such as... Figure 10E As shown. When the temperature exceeds approximately 2000°C, the low-crystallinity or amorphous carbon shell transforms into a high-crystallinity carbon shell, such as... Figure 10F As shown. In some embodiments, the highly crystalline carbon shell is a hollow carbon polyhedral particle comprising a number of planes having a two-dimensional graphite structure. On the other hand, the low-crystalline carbon shell does not have significant planes. In some embodiments, the angle between two adjacent planes is in the range of about 80° to about 160°, and in other embodiments, in the range of about 100° to about 150°. High temperature (greater than about 2000°C) also removes defects in the CNTs and the carbon shell. Because the metal catalyst particles are removed by the heat treatment operation, the transmittance of the membrane 100 is improved by the heat treatment operation.

[0065] The formation of the connection structure at the intersection of the two carbon nanotubes will Figures 11A-11CIn a more detailed description, see below. In some embodiments, CNTs are joined together at their junctions by the following manner: carbon atoms dissolve into the metal particles, followed by the precipitation and recrystallization of carbon atoms. Figure 11A As shown, in some embodiments, CNT 20a intersect each other at the position of the metal catalyst particles 45. Furthermore, the higher temperature also produces a carbon structure with higher crystallinity, which improves the EUVT of the film.

[0066] In some embodiments, the metal catalyst particles 45 are iron particles. During the heat treatment operation, carbon atoms dissolve into the metal catalyst particles, as described herein, and as... Figure 11B As shown. Then, as the membrane is further heated, carbon atoms precipitate from the evaporated metal catalyst particles, as described herein. The precipitated carbon atoms combine the cross-linked CNT 20b during the crystallization process, as... Figure 11C As shown. The metal catalyst particles 45 act as a binder, bonding each CNT 20a together at the joint by dissolving carbon into the metal particles and then precipitating it at a higher temperature. This prevents pore size variations due to CNT slippage. In addition to removing metal impurities to improve EUV transmittance, the high-temperature treatment also enhances the mechanical strength of the CNTs by increasing the crystallinity of the carbon material, thereby improving exposure life. This includes the mechanical strength of the CNTs themselves (as well as the carbon precipitated from the metal impurity particles at the joints, which bonds the different CNTs 20b together)).

[0067] In some embodiments, the heat treatment operation is performed in a vacuum or inert gas environment having an oxygen concentration of less than about 10 ppm; in other embodiments, the oxygen concentration is less than about 5 ppm; and in still other embodiments, the oxygen concentration is less than about 2 ppm. In some embodiments, the oxygen concentration is less than about 0.2 ppm to prevent oxidation of the CNTs and the carbon shell. In some embodiments, the oxygen concentration is less than about 0.01 ppm during the heat treatment operation; and in other embodiments, the oxygen concentration is less than about 0.001 ppm during the heat treatment operation. In some embodiments, the inert gas includes at least one of argon, neon, helium, xenon, krypton, and nitrogen. In some embodiments, the heat treatment operation is performed at a pressure less than about 10... - This is performed within the vacuum chamber of the Torr. In other embodiments, the pressure within the vacuum chamber is less than about 10 during the heat treatment operation. -7 Torr, and in other embodiments, the pressure is less than about 10. -8 Torr. When the oxygen concentration and chamber pressure exceed the published range, the main network diaphragm 100 may undergo oxidation and degradation.

[0068] In some embodiments, after the heat treatment operation, the ratio of the intensity of the D band to the intensity of the G band in the Raman spectrum of the diaphragm (Id) D / I G ) ≤ 0.1. In some embodiments, I D / I G ≤0.05, while in other embodiments, I D / I G ≤0.02. Ratio I D / I G Used to evaluate the structural quality and defect density of the membrane. In the Raman spectrum of carbon nanotubes, the D band (approximately 1350 nm) is... ¹) and G band (approximately 1580 c) ¹) is a significant feature. The D band is associated with disorder and defects, while the G band represents the first-order Raman mode of a perfect graphite lattice. The ratio of the intensities of these bands (I0) is significant. D / I G I0 is an indicator of defect density in carbon nanotubes. Lower I0 D / I G The ratio indicates fewer defects, and therefore higher structural quality.

[0069] In some embodiments, the film may be coated with a protective layer to prevent plasma damage during EUV exposure. By pre-enhancing the crystallinity of the carbon material, chemical stability can be improved, the impact of the coating process can be reduced, and greater flexibility can be provided for coating parameters.

[0070] In some embodiments, any suitable technology is used to heat the main network diaphragm 100, including electric arc furnace, induction heating, xenon flash lamp, pulsed laser heating, graphite furnace (including graphite resistance furnace), plasma torch, and Joule heating.

[0071] In some embodiments, Joule heating is used to heat-treat the main network diaphragm, such as... Figure 12A As shown. A diaphragm 100 and a diaphragm support 1235 supporting the diaphragm are placed on an insulating support 1245, and are clamped at the edge portions of the diaphragm support 1235 by portions of the insulating support 1245 and the electrode 1220 disposed on the diaphragm. In some embodiments, the insulating support 1245 is made of ceramic, and the electrode 1220 is made of metal, such as tungsten, copper, or steel. The electrode 1220 is attached to contact the diaphragm 100. In some embodiments, the electrode 1220 is attached to both sides of the diaphragm 100 (e.g., the left and right sides). In some embodiments, the electrode 1220 is connected to a current source (power supply) 1230 via wires.

[0072] like Figure 12A As shown, a Joule heating device 1200, on which a main network diaphragm 100 is mounted, is placed in a vacuum chamber 1240. In some embodiments, the vacuum chamber 1240 includes a bottom portion and an upper (cover) portion in which the Joule heating device is placed, and a gasket (e.g., an O-ring) is disposed between the bottom portion and the upper portion. The cable of the Joule heating device is connected to an external cable, which is connected to a power supply 1230.

[0073] In some embodiments, during Joule heating operation, the vacuum chamber is evacuated to a value equal to or less than about 10. -5 Torr pressure. Power source 1230 applies current to diaphragm 100, causing the current to pass through the diaphragm and generate heat. In some embodiments, the current is DC, while in other embodiments, the current is AC or a pulsed current. In some embodiments, the current from power source 1230 is adjusted such that the diaphragm is heated to a temperature ranging from about 1000°C to about 3600°C to induce the crystallization and / or bonding of amorphous carbon within the nanotubes and shell, as described herein.

[0074] In some embodiments, an electric arc furnace 1250 is used to perform heat treatment operations, such as Figure 12B As shown. A diaphragm 100 and a diaphragm support 1235 supporting the diaphragm are placed on an insulating support 1245. A plurality of electrodes 1255 are positioned on the diaphragm 100. In some embodiments, the insulating support 1245 is made of ceramic, and the electrodes 1255 are made of graphite. In some embodiments, the electrodes 1255 are connected to a power supply 1260 via wires.

[0075] like Figure 12B As shown, the main network diaphragm 100 is placed in the vacuum chamber 1265. In some embodiments, during electric arc furnace operation, the vacuum chamber is evacuated to a level equal to or less than about 10. -5 Torr pressure. Power source 1260 applies current to electrode 1255, and an electric arc is induced between electrode 1255 and diaphragm 100, thereby generating heat. In some embodiments, the current is DC, while in other embodiments, the current is AC or a pulsed current. In some embodiments, the current from power source 1255 is adjusted such that the diaphragm is heated to a temperature ranging from about 1000°C to about 3600°C to induce the crystallization and / or bonding of amorphous carbon within the nanotubes and shell, as described herein.

[0076] In some embodiments, an induction furnace 1270 is used to perform heat treatment operations, such as Figure 12CAs shown. The diaphragm 100 is placed on a suitable support within the crucible 1272 of the induction furnace 1270. A conductive coil 1274 (e.g., a copper coil) is wound around the crucible. In some embodiments, the furnace is surrounded by a shield 1276. An AC power supply 1278 applies alternating current to the conductive coil 1274. The current through the coil generates a rapidly changing magnetic field that induces eddy currents in the diaphragm 100, which heat the diaphragm through Joule heating. In some embodiments, the current from the power supply 1278 is adjusted such that the diaphragm is heated to a temperature in the range of about 1000°C to about 3600°C to induce the crystallization and / or bonding of amorphous carbon in the nanotubes and shell, as described herein.

[0077] In some embodiments, a graphite furnace 1280 (e.g., a graphite resistance furnace) is used to perform heat treatment operations, such as... Figure 12D As shown. The diaphragm 100 is placed on a suitable support 1288, such as a graphite table, in the heating zone 1286 of the furnace. A graphite heater 1284 is used to heat the furnace. Heat is generated by an electric current supplied to the graphite heater 1284 by a power source 1298. In some embodiments, the furnace is surrounded by a thermal shield 1290. In some embodiments, an insulating material 1292 (e.g., carbon fiber) surrounds the chamber 1282. In some embodiments, during heat treatment, an inert gas (e.g., argon or nitrogen) flows through the chamber 1282 via a gas inlet 1294 and a gas outlet 1296. In some embodiments, the current from the power source 1298 is adjusted such that the diaphragm is heated to a temperature in the range of about 1000°C to about 3600°C to induce the crystallization and / or bonding of amorphous carbon in the nanotubes and shell to each other, as described herein.

[0078] In some embodiments, the diaphragm support 1235 is a frame-shaped material. In some embodiments, the diaphragm support 1235 is made of a material that vaporizes at heat treatment temperatures and is therefore substantially completely removed from the diaphragm during the heat treatment operation. In other embodiments, the diaphragm support 1235 is composed of one or more layers of graphite or ultra-high temperature ceramic (e.g., HfCN, HfC, TaC, NbC, ZrC, HfN, HfB2, ZrB2, TiB2, TiC, NbB2, TaB2, TiN, or ZrN). In some embodiments, the diaphragm support is the frame 15 of the thin film 10. Because the diaphragm support is capable of withstanding high heat treatment temperatures in some embodiments, the thin film remains firmly attached to the diaphragm support after the heat treatment operation. In other embodiments, after performing the heat treatment operation, the main network diaphragm 100 is attached to the frame 15, as... Figure 6A and Figure 6B as well as Figure 7A and Figure 7B As shown.

[0079] like Figure 13 As shown, in some embodiments, a heat treatment operation causes individual, separate nanotubes 20a (single-walled or multi-walled nanotubes) to connect and form a highly crystalline nanotube bundle 30b with a seamless graphite structure, wherein the nanotubes not only contact each other but are also firmly bonded or linked together. Two or more nanotubes 20a may be joined (joined or linked) to form the nanotube bundle 30b. In some embodiments, 2-15 nanotubes are joined to form a medium-sized bundle. In some embodiments, 16-100 nanotubes are joined to form a larger bundle. In some embodiments, more than 100 nanotubes are joined to form a very large bundle.

[0080] Figures 14-16 A flowchart illustrating a method for manufacturing a thin film according to an embodiment of the present disclosure is shown. It will be understood that... Figures 14-16 Additional operations are provided before, during, and after the process shown, and some of the operations described below may be replaced or eliminated in additional embodiments of the method. The order of operations / processes may be interchanged.

[0081] Figure 14The flowchart illustrates a method 1400 for manufacturing a thin film 10 according to some embodiments of the present disclosure. Method 1400 includes operation S1405: heating a membrane 100 comprising a plurality of carbon nanotubes 20a at a temperature sufficient to convert amorphous carbon into crystalline carbon. In some embodiments, the membrane 100 is heated in a chamber with an oxygen content lower than that of air. Following the heating of the membrane in operation S1405, a thin film is formed using the membrane 100 in operation S1410. In some embodiments, the membrane 100 comprises a plurality of carbon shells 25a having a first crystallinity level, and during the heating of the membrane, in operation S1415, the plurality of carbon shells 25a having the first crystallinity level transforms into a plurality of carbon shells 25b having a second crystallinity level, wherein the second crystallinity level is greater than the first crystallinity level. In some embodiments, the membrane comprises a metal catalyst 45 at a first concentration, and during the heating of the membrane in operation S1405, in operation S1420, the first concentration of the metal catalyst decreases to a second concentration. In some embodiments, method 1400 includes operation S1425: joining different carbon nanotubes together during operation S1405 of heating the diaphragm. In some embodiments, method 1400 includes operation S1430: forming a bridging structure 35 between different carbon nanotubes 20b or nanotube bundles 30b during operation S1405 of heating the diaphragm. In some embodiments, method 1400 includes operation S1435: forming a connecting structure 40 between intersecting carbon nanotubes 20b or nanotube bundles 30b during operation S1405 of heating the diaphragm. In some embodiments, method 1400 includes operation S1440: forming a T-shaped structure 50 of carbon nanotubes 20b or nanotube bundles 30b during operation S1405 of heating the diaphragm.

[0082] Figure 15 The flowchart illustrates a method 1500 for manufacturing a thin film according to some embodiments of the present disclosure. Method 1500 includes operation S1505: heating a membrane 100 comprising a plurality of carbon nanotubes 20a and a carbon shell 25a with a metal catalyst 45 in a chamber 1240 at a temperature of 1000°C to 3600°C. In operation S1510, amorphous carbon in the carbon nanotubes 20a and the carbon shell 25a is converted into crystalline carbon. Following operation S1505 of heating the membrane, in operation S1515, the membrane 100 is used to form a thin film. In some embodiments, during operation S1505 of heating the membrane, the amount of metal catalyst 45 in the membrane 100 is reduced in operation S1520.

[0083] Figure 16A method 1600 for manufacturing a thin film according to some embodiments of the present disclosure is shown. Method 1600 includes operation S1605: heating a membrane material comprising a plurality of carbon nanotubes (CNTs) 20a and a carbon shell 25a having a first crystallinity percentage using a metal catalyst 45. Heating the membrane in operation S1605 includes operation S1610: heating the membrane material in an inert gas environment with an oxygen concentration not exceeding 10 ppm, at a temperature range of about 2200°C to 3200°C, or at a pressure below 1 ppm. Under the vacuum conditions of Torr, the membrane material is heated in a temperature range of approximately 1000°C to 2200°C. In operation S1615, the heated membrane material is used to form an EUV film 10. In some embodiments, method 1600 further includes step S1620: during operation S1605 of heating the membrane material, forming a bridging structure 35 between different carbon nanotubes 20b or nanotube bundles 30b. In some embodiments, method 1600 further includes step S1625: during operation S1605 of heating the membrane material, forming a connecting structure 40 between intersecting carbon nanotubes 20b or nanotube bundles 30b. In some embodiments, method 1600 further includes step S1630: during operation S1605 of heating the membrane material, forming carbon polyhedral hollow particles 20b having a second crystallinity percentage, wherein the second crystallinity percentage is higher than the first crystallinity percentage.

[0084] Figure 17A A flowchart of a method 1700 for fabricating a semiconductor device according to an embodiment of the present disclosure is shown, and Figure 17B , Figure 17C , Figure 17D and Figure 17E A sequential manufacturing method for fabricating a semiconductor device according to embodiments of the present disclosure is illustrated. A semiconductor substrate or other suitable substrate is provided to be patterned to form an integrated circuit thereon. In some embodiments, the semiconductor substrate comprises silicon. Alternatively or additionally, the semiconductor substrate comprises germanium, silicon-germanium, or other suitable semiconductor materials, such as group III-V semiconductor materials. Figure 17A At operation S1710, a target layer 115 to be patterned is formed on the semiconductor substrate 110. In some embodiments, the target layer 115 is a semiconductor substrate. In some embodiments, the target layer 115 includes: a conductive layer, such as a metal layer or a polysilicon layer; a dielectric layer, such as silicon oxide, silicon nitride, SiON, SiOC, SiOCN, SiCN, hafnium oxide, or aluminum oxide; or a semiconductor layer, such as an epitaxially formed semiconductor layer. In some embodiments, the target layer 115 is formed on a lower structure such as an isolation structure, a transistor, or wiring. At S1720, a photoresist layer 120 is formed on the target layer, such as... Figure 17BAs shown. The photoresist layer 120 is sensitive to radiation 70 from the exposure radiation source during subsequent photolithography exposure operations. In this embodiment, the photoresist layer 120 is sensitive to EUV light used for the photolithography exposure operation. The photoresist layer 120 can be formed on the target layer 115 by spin coating or other suitable techniques. The coated photoresist layer can be further baked to remove solvent from the photoresist layer. At operation S1730, the photoresist layer 120 is patterned in the photolithography exposure apparatus 165 by guiding EUV radiation 70 to a reflective photomask 60. As described herein, a thin film 10 covers the photomask 60. EUV radiation 70 is reflected away from the photomask 60 and guided to the photoresist layer 120. During the photolithography exposure operation, an integrated circuit (IC) design pattern defined on the photomask 60 is imaged onto the photoresist layer 120 to form a latent image pattern thereon. Patterning the photoresist layer also includes developing the exposed photoresist layer in operation S1740 to form a patterned photoresist layer having one or more openings 125. In one embodiment, if the photoresist layer is a positive photoresist layer, the exposed portion of the photoresist layer is removed during the development operation. In other embodiments, if the photoresist layer is a negative photoresist layer, the unexposed portion of the photoresist layer is removed during the development operation. Patterning the photoresist layer may also include other operations, such as various baking operations at different stages. For example, a post-exposure baking (PEB) process can be implemented after the photolithography exposure operation and before the development operation.

[0085] At operation S1750, a patterned photoresist layer 120 is used as an etching mask to transfer the pattern 125 in the photoresist layer onto the target layer 115, as follows. Figure 17D As shown. The portion of the target layer exposed in the openings of the patterned photoresist layer is etched, while the remaining portion is protected from etching. Furthermore, the patterned photoresist layer can be removed by wet stripping or plasma ashing, as... Figure 17E As shown.

[0086] Other embodiments include additional operations performed before, during, or after the operations described above. In some embodiments, the disclosed methods include forming a fin field-effect transistor (FinFET) structure. In some embodiments, a plurality of active fins are formed on a semiconductor substrate. These embodiments further include: etching the substrate through openings in a patterned hard mask to form trenches in the substrate; filling the trenches with a dielectric material; performing a chemical mechanical polishing (CMP) process to form shallow trench isolation (STI) features; and epitaxially growing or recessing the STI features to form fin-shaped active regions. In some embodiments, one or more gate electrodes are formed on the substrate. Some embodiments include forming gate spacers, doped source / drain regions, contacts for gate / source / drain features, etc. In other embodiments, the target pattern is formed as metal lines in a multilayer interconnect structure. For example, the metal lines may be formed in an interlayer dielectric (ILD) layer of the substrate, which has been etched to form a plurality of trenches. The trenches can be filled with a conductive material (e.g., a metal); and the conductive material can be polished using a process such as chemical mechanical planarization (CMP) to expose the patterned ILD layer, thereby forming metal lines within the ILD layer. The above are non-limiting examples of devices / structures fabricated and / or improved using the methods described herein.

[0087] In some embodiments of the present disclosure, active components are formed, such as diodes, field-effect transistors (FETs), metal-oxide-semiconductor field-effect transistors (MOSFETs), complementary metal-oxide-semiconductor (CMOS) transistors, bipolar transistors, high-voltage transistors, high-frequency transistors, chip FETs, FinFETs, gate-all-around FETs (GAA FETs), other three-dimensional (3D) FETs, other memory cells, and combinations thereof.

[0088] The methods disclosed herein include: (1) removing impurities that reduce EUV transmittance, such as metal particles, including transition metal particles; (2) converting amorphous carbon into crystalline carbon, such as graphite or graphene, which improves EUV transmittance; (3) improving the mechanical strength and chemical stability of the film to provide a longer service life in demanding EUV exposure environments; and (4) fixing the pore size of the film by cross-linked CNTs, which improves particle impermeability.

[0089] According to embodiments of this disclosure, high-temperature processing not only removes impurities but also converts amorphous carbon into crystalline carbon, thereby improving the crystallinity and EUV transmittance of the main network membrane. Embodiments of this disclosure provide EUV films with high transmittance and high strength, as well as main network membranes with low particle permeability, thereby improving the manufacturing efficiency of semiconductor devices.

[0090] Embodiments of this disclosure relate to a method of manufacturing a thin film, comprising heating a membrane comprising a plurality of carbon nanotubes at a temperature sufficient to convert amorphous carbon into crystalline carbon. The membrane is heated in a chamber with an oxygen content lower than that of air. After heating the membrane, a thin film comprising the membrane is formed. In embodiments, the membrane comprises a plurality of carbon shells having a first level of crystallinity, and during heating the membrane, the plurality of carbon shells having the first level of crystallinity transform into a plurality of carbon shells having a second level of crystallinity, wherein the second level of crystallinity is greater than the first level of crystallinity. In embodiments, the membrane comprises a metal catalyst at a first concentration, and during heating the membrane, the first concentration of the metal catalyst decreases to a second concentration. In embodiments, the membrane is heated at a temperature of 2200°C to 3200°C. In embodiments, during heating, the oxygen concentration in the chamber does not exceed 10 ppm. In embodiments, the membrane is heated at a temperature of 1000°C to 2200°C. In embodiments, during heating, the pressure in the chamber is less than 1 ppm. Torr. In one embodiment, the method includes: joining different carbon nanotubes together during heating of the diaphragm. In another embodiment, the method includes: forming a bridging structure between different carbon nanotubes during heating of the diaphragm. In yet another embodiment, the method includes: forming a connecting structure between intersecting carbon nanotubes, or forming a T-shaped structure from multiple carbon nanotubes or nanotube bundles.

[0091] Another embodiment of this disclosure relates to a method of manufacturing a thin film, comprising heating a membrane comprising a plurality of carbon nanotubes and a carbon shell in a chamber at a temperature of 1000°C to 3600°C using a metal catalyst. Amorphous carbon in the carbon nanotubes and carbon shell is converted into crystalline carbon. After heating the membrane, a thin film comprising the membrane is formed. In an embodiment, the temperature is 1000°C to 3200°C. In an embodiment, the oxygen concentration in the chamber does not exceed 10 ppm during the heating of the membrane. In an embodiment, the pressure in the chamber is less than 1 ppm during the heating of the membrane. Torr. In an embodiment, the amount of metal catalyst in the membrane is reduced during heating of the membrane. In an embodiment, the metal catalyst comprises Fe.

[0092] Another embodiment of this disclosure relates to a method of manufacturing a thin film, comprising heating a membrane material comprising a plurality of carbon nanotubes (CNTs) having a first crystallinity percentage and a carbon shell using a metal catalyst. Heating the membrane comprises: heating the membrane material in an inert gas environment with an oxygen concentration not exceeding 0.2 ppm, in a temperature range of about 2200°C to 3200°C, or at a pressure below 1 ppm. Under the vacuum conditions of Torr, a membrane material is heated in a temperature range of approximately 1000°C to 2200°C. After heating, an EUV film comprising the membrane material is formed. In one embodiment, the method includes forming a bridging structure between different CNTs during heating of the membrane material. In another embodiment, the method includes forming a connecting structure between intersecting CNTs during heating of the membrane material. In yet another embodiment, the method includes forming hollow carbon polyhedral particles having a second crystallinity percentage, wherein the second crystallinity percentage is higher than a first crystallinity percentage, during heating of the membrane material.

[0093] Another embodiment of this disclosure relates to a thin film comprising a membrane disposed on a frame. The membrane comprises a plurality of crystalline carbon nanotubes and a plurality of carbon polyhedral hollow particles. In an embodiment, the thickness of the membrane is 10 to 100 nm. In an embodiment, at least one crystalline carbon nanotube has an inner diameter of 0.5 nm to 10 nm. In an embodiment, at least one crystalline carbon nanotube comprises a plurality of coaxial walls. In an embodiment, bridging structures connect adjacent crystalline carbon nanotubes. In an embodiment, adjacent intersecting crystalline carbon nanotubes are connected by connecting structures. In an embodiment, at least one crystalline carbon nanotube is bent at an angle of 10° to 170°. In an embodiment, the angle is 30° to 150°. In an embodiment, the plurality of crystalline carbon nanotubes comprises bundles of crystalline carbon nanotubes connected together. In an embodiment, the carbon polyhedral hollow particles are composed of planes having a two-dimensional graphite structure. In an embodiment, the angle between two adjacent planes is 80° to 160°. In an embodiment, the ratio of the intensity of the D band to the intensity of the G band in the Raman spectrum of the membrane (I0) is... D / I G )≤0.1. In the embodiment, I D / I G ≤0.05. In the embodiment, I D / I G ≤0.02.

[0094] Another embodiment of this disclosure relates to a thin film including a diaphragm disposed on a frame. The frame is made of an inorganic material, and the diaphragm includes a plurality of crystalline carbon nanotube bundles and a plurality of carbon polyhedral hollow particles. Each crystalline carbon nanotube bundle includes at least two or more adjacent crystalline carbon nanotubes connected together along its length, and adjacent crystalline carbon nanotube bundles are connected to each other by crystalline carbon nanotube bridging structures. In an embodiment, the frame is formed of at least one layer of crystalline silicon, polycrystalline silicon, silicon oxide, silicon nitride, alumina, or ceramic material. In an embodiment, the thickness of the diaphragm ranges from 10 to 100 nm. In an embodiment, the ratio of the intensity of the D band to the intensity of the G band in the Raman spectrum of the diaphragm (IL) is... D / I G ≤0.1.

[0095] Another embodiment of this disclosure relates to a thin film comprising a diaphragm disposed on a frame, wherein the frame is made of an inorganic material. The diaphragm comprises a plurality of crystalline carbon nanotubes, a plurality of crystalline carbon nanotube bundles, and a plurality of crystalline carbon polyhedral hollow particles. Each crystalline carbon nanotube bundle comprises at least two or more adjacent crystalline carbon nanotubes connected together along its length. Adjacent crystalline carbon nanotube bundles are connected to each other by at least one of the plurality of crystalline carbon nanotubes. At least two adjacent crystalline carbon nanotubes are connected together at a first connection structure, and at least two adjacent crystalline carbon nanotube bundles are connected together at a second connection structure. In an embodiment, the ratio of the intensity of the D band to the intensity of the G band in the Raman spectrum of the diaphragm (IG) is... D / I G ≤0.1.

[0096] It is understood that not all advantages need to be discussed herein, no particular advantage is necessary for all embodiments or examples, and other embodiments or examples may provide different advantages.

[0097] The foregoing disclosure outlines features of several embodiments or examples, enabling those skilled in the art to better understand various aspects of this disclosure. Those skilled in the art should understand that they can readily use this disclosure as a basis for designing or modifying other processes and structures to implement the same purposes and / or achieve the same advantages of the embodiments or examples described herein. Those skilled in the art should also recognize that such equivalent constructions do not depart from the spirit and scope of this disclosure, and that various changes, substitutions, and modifications can be made herein without departing from the spirit and scope of this disclosure.

[0098] Example 1. A method of manufacturing a thin film, comprising: heating a membrane comprising a plurality of carbon nanotubes at a temperature sufficient to convert amorphous carbon into crystalline carbon, wherein the membrane is heated in a chamber with an oxygen content lower than that of air; and forming a thin film comprising the membrane after heating the membrane.

[0099] Example 2. The method according to Example 1, wherein the diaphragm further includes a plurality of carbon shells having a first crystallinity level, and during heating of the diaphragm, the plurality of carbon shells having the first crystallinity level transform into a plurality of carbon shells having a second crystallinity level, wherein the second crystallinity level is greater than the first crystallinity level.

[0100] Example 3. The method according to Example 1, wherein the membrane further includes a metal catalyst at a first concentration, and during heating of the membrane, the first concentration of the metal catalyst is reduced to a second concentration.

[0101] Example 4. The method according to Example 1, wherein the diaphragm is heated at a temperature of 2200°C to 3200°C.

[0102] Example 5. The method according to Example 4, wherein the oxygen concentration in the chamber does not exceed 10 ppm during heating.

[0103] Example 6. The method according to Example 1, wherein the diaphragm is heated at a temperature of 1000°C to 2200°C.

[0104] Example 7. The method according to Example 6, wherein the pressure in the chamber is less than 1 during heating. Torr.

[0105] Example 8. The method according to Example 1 further includes: joining different carbon nanotubes together during heating of the diaphragm.

[0106] Example 9. The method according to Example 1 further includes: forming a bridging structure between different carbon nanotubes during heating of the diaphragm.

[0107] Example 10. The method according to Example 1 further includes: forming a connecting structure between intersecting carbon nanotubes or forming a T-shaped structure from a plurality of carbon nanotubes or carbon nanotube bundles during heating of the diaphragm.

[0108] Example 11. A method of manufacturing a thin film, comprising: heating a membrane comprising a plurality of carbon nanotubes and a carbon shell in a chamber at a temperature of 1000°C to 3600°C with a metal catalyst; converting amorphous carbon in the carbon nanotubes and carbon shell into crystalline carbon; and forming a thin film comprising the membrane after heating the membrane.

[0109] Example 12. The method according to Example 11, wherein the temperature is from 1000°C to 3200°C.

[0110] Example 13. The method according to Example 11, wherein the oxygen concentration in the chamber does not exceed 10 ppm during heating of the diaphragm.

[0111] Example 14. The method according to Example 11, wherein the pressure in the chamber is less than 1 during heating of the diaphragm. Torr.

[0112] Example 15. The method according to Example 11 further includes: reducing the amount of the metal catalyst in the membrane during heating of the membrane.

[0113] Example 16. The method according to Example 11, wherein the metal catalyst comprises Fe.

[0114] Example 17. A thin film comprising: a diaphragm disposed on a frame, wherein the diaphragm comprises a plurality of crystalline carbon nanotubes and a plurality of carbon polyhedral hollow particles.

[0115] Example 18. The thin film according to Example 17, wherein the thickness of the diaphragm is 10 to 100 nm.

[0116] Example 19. The thin film according to Example 17, wherein at least one of the crystalline carbon nanotubes has an inner diameter of 0.5 nm to 10 nm.

[0117] Example 20. The thin film according to Example 17, wherein at least one of the crystalline carbon nanotubes comprises a plurality of coaxial walls.

Claims

1. A method for manufacturing a thin film, comprising: A membrane comprising multiple carbon nanotubes is heated at a temperature sufficient to convert amorphous carbon into crystalline carbon, wherein the membrane is heated in a chamber with an oxygen content lower than that of air; and After heating the diaphragm, a thin film including the diaphragm is formed.

2. The method according to claim 1, wherein, The diaphragm also includes a plurality of carbon shells having a first crystallinity level, and during heating of the diaphragm, the plurality of carbon shells having the first crystallinity level transform into a plurality of carbon shells having a second crystallinity level, wherein the second crystallinity level is greater than the first crystallinity level.

3. The method according to claim 1, wherein, The membrane also includes a metal catalyst at a first concentration, and during heating of the membrane, the first concentration of the metal catalyst decreases to a second concentration.

4. The method according to claim 1, wherein, The diaphragm is heated at a temperature of 2200°C to 3200°C.

5. The method according to claim 4, wherein, During heating, the oxygen concentration in the chamber does not exceed 10 ppm.

6. The method according to claim 1, wherein, The diaphragm is heated at a temperature of 1000°C to 2200°C.

7. The method according to claim 6, wherein, During heating, the pressure in the chamber is less than 10. -5 Torr.

8. The method according to claim 1, further comprising: During the heating of the membrane, different carbon nanotubes are joined together.

9. A method for manufacturing a thin film, comprising: A membrane comprising multiple carbon nanotubes and a carbon shell is heated with a metal catalyst in a chamber at a temperature of 1000°C to 3600°C. Convert amorphous carbon in carbon nanotubes and carbon shells into crystalline carbon; as well as After heating the diaphragm, a thin film including the diaphragm is formed.

10. A thin film, comprising: The diaphragm is set on top of the frame. The membrane comprises multiple crystalline carbon nanotubes and multiple carbon polyhedral hollow particles.

Images