Pellikel for an EUV lithography mask and a method for its production

Abstract

Pellicle (10) for an EUV-reflective mask (5), comprising: a first layer (20), a second layer (30) and a main membrane (100) arranged between the first layer (20) and second layer (30), wherein: the main membrane (100) contains several coaxial nanotubes, each of which contains an inner tube (210) and two outer tubes (220, 230) surrounding the inner tube (210), and Each of the inner tube (210) and the two outer tubes (220, 230) is made of different materials and is selected from the group consisting of a carbon nanotube, a boron nitride nanotube, a TMD (transition metal dichalcogenide) nanotube, where TMD is represented by MX2, where M is one or more of Mo, W, Pd, Pt or Hf and X is one or more of S, Se or Te.

Description

BACKGROUND

[0001] A pellicle is a thin, transparent film stretched over a frame that is adhered to one side of a photomask to protect the photomask from damage, dust, and / or moisture. In EUV lithography, a pellicle with high transmittance in the EUV wavelength range, high mechanical strength, and low thermal expansion is generally required.

[0002] WO 2021 / 037662 A1 discloses a pellicle membrane for a lithographic device, wherein the membrane comprises coated carbon nanotubes. BRIEF DESCRIPTION OF THE DRAWINGS

[0003] Aspects of this disclosure are best understood with reference to the following detailed description in conjunction with the accompanying drawings. It should be noted that, in accordance with industry practice, various features are not shown to scale. In fact, the dimensions of the various features may have been arbitrarily enlarged or reduced for the sake of clarity. Fig. 1A, Fig. 1B, Fig. 1C and Fig. Figure 1D shows different views of a pellicle for an EUV photomask according to an embodiment of the present disclosure. Fig. 2A, Fig. 2B, Fig. 2C and Fig. 2D shows different views of multi-walled nanotubes according to embodiments of the present disclosure. Fig. 3A, Fig. 3B and Fig. Figure 3C shows different views of mesh membranes of a pellicle for an EUV photomask according to embodiments of the present disclosure. Fig. 4A, Fig. 4B, Fig. 4C, Fig. 4D, Fig. 4E, Fig. 4F, Fig. 4G, Fig. 4H, Fig. 4I and Fig. Figure 4J shows different views of mesh membranes of a pellicle for an EUV photomask according to embodiments of the present disclosure. Fig. 5A shows a manufacturing process of a mesh membrane, Fig. 5B shows a flowchart of the same and Fig. 5C and Fig. 5D shows manufacturing processes of multi-walled nanotubes according to an embodiment of the present disclosure. Fig. Figure 6 shows a manufacturing process of a mesh membrane according to an embodiment of the present disclosure. Fig. 7A and Fig. Figure 7B shows a cross-sectional view and a plan view (top view) of one of the various manufacturing stages of a pellicle for an EUV photomask according to an embodiment of the present disclosure. Fig. 8A and Fig. Figure 8B shows a cross-sectional view and a plan view (top view) of one of the various manufacturing stages of a pellicle for an EUV photomask according to an embodiment of the present disclosure. Fig. 9A and Fig. Figure 9B shows a cross-sectional view and a plan view (top view) of one of the various manufacturing stages of a pellicle for an EUV photomask according to an embodiment of the present disclosure. Fig. 10A and Fig. Figure 10B shows a cross-sectional view and a plan view (top view) of one of the various manufacturing stages of a pellicle for an EUV photomask according to an embodiment of the present disclosure. Fig. 11A and Fig. Figure 11B shows a cross-sectional view and a plan view (top view) of one of the various manufacturing stages of a pellicle for an EUV photomask according to an embodiment of the present disclosure. Fig. Figure 11C shows a cross-sectional view of one of the various manufacturing stages of a pellicle for an EUV photomask according to embodiments of the present disclosure. Fig. Figure 11D shows a cross-sectional view of one of the various manufacturing stages of a pellicle for an EUV photomask according to embodiments of the present disclosure. Fig. 12A and Fig. Figure 12B shows a cross-sectional view and a plan view (top view) of one of the various manufacturing stages of a pellicle for an EUV photomask according to an embodiment of the present disclosure. Fig. 13A and Fig. Figure 13B shows a cross-sectional view and a plan view (top view) of one of the various manufacturing stages of a pellicle for an EUV photomask according to an embodiment of the present disclosure. Fig. 14A and Fig. Figure 14B shows a cross-sectional view and a plan view (top view) of one of the various manufacturing stages of a pellicle for an EUV photomask according to an embodiment of the present disclosure. Fig. 15A, Fig. 15B and Fig. Figure 15C shows cross-sectional views of one of the various manufacturing stages of a pellicle for an EUV photomask according to embodiments of the present disclosure. Fig. Figure 16A shows a cross-sectional view of one of the various manufacturing stages of a pellicle for an EUV photomask according to an embodiment of the present disclosure. Fig. Figure 16B shows cross-sectional views of the various manufacturing stages of a pellicle for an EUV photomask according to an embodiment of the present disclosure. Fig. 17A, Fig. 17B, Fig. 17C and Fig. Figure 17D shows cross-sectional views of a pellicle for an EUV photomask according to embodiments of the present disclosure. Fig. 18A, Fig. 18B, Fig. 18C, Fig. 18D, Fig. 18E and Fig. Figure 18F shows flowcharts for the manufacture of a pellicle for an EUV photomask according to embodiments of the present disclosure. Fig. Figure 19A shows a flowchart of a process that manufactures a semiconductor device, and Fig. 19B, Fig. 19C, Fig. 19D and Fig. Figure 19E shows a sequential manufacturing operation of a method for manufacturing a semiconductor device according to embodiments of the present disclosure. DETAILED DESCRIPTION

[0004] It is clear 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 the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, the dimensions of elements are not limited to the disclosed range or values ​​but may depend on process conditions and / or desired properties of the device.Furthermore, the formation of a first structural element above or on top of a second structural element, as described below, can include embodiments in which the first and second structural elements are in direct contact, and can also include embodiments in which additional structural elements can be formed between the first and second structural elements, so that the first and second structural elements might not be in direct contact. For the sake of simplicity and clarity, various structural elements can be drawn at different scales. In the accompanying drawings, some layers / structural elements may be omitted for simplification.

[0005] Furthermore, spatially relative terms such as "underlying," "below," "under," "superior," "above," and the like may be used herein to facilitate description and to describe the relationship of one element or structural element to another element(s) or structural element(s), as illustrated in the figures. These spatially relative terms are intended to encompass various orientations of the device in use or operation in addition to the orientation depicted in the figures. The device may be oriented differently (rotated by 90 degrees or in other orientations), and the spatially relative descriptive terms used herein may be interpreted accordingly. Additionally, the term "made of" may mean either "comprising" or "consisting of."Furthermore, in the following manufacturing process, one or more additional operations may be present between the operations described, and the order of the operations may be changed. In the present disclosure, the phrase "at least one of A, B, and C" means either one of A, B, C, A+B, A+C, B+C, or A+B+C, and does not mean one of A, one of B, and one of C, unless otherwise stated. Materials, configurations, structures, operations, and / or dimensions described in one embodiment may be applied to other embodiments, and their detailed description may be omitted.

[0006] EUV lithography is one of the key techniques for extending Moore's Law. However, due to the wavelength scaling from 193 nm (ArF) to 13.5 nm, the EUV light source suffers from significant power degradation due to environmental adsorption. Even when a stepper / scanner chamber is operated under vacuum to prevent strong EUV adsorption by gas, maintaining a high EUV transmittance from the EUV light source to a wafer remains a critical factor in EUV lithography.

[0007] A pellicle generally requires high transparency and low reflectivity. In UV or DUV lithography, the pellicle film is made of a transparent resin film. However, in EUV lithography, a resin-based film would not be acceptable, and a non-organic material, such as a polysilicon, silicide, or metal film, is used.

[0008] Carbon nanotubes (CNTs) are one of the materials suitable for a pellicle in an EUV reflective photomask, as CNTs exhibit a high EUV transmittance of over 96.5%. In general, a pellicle for an EUV reflective mask requires the following properties: (1) long durability in a hydrogen-rich radical operating environment within an EUV stepper / scanner; (2) high mechanical strength to minimize sagging during vacuum pumping and ventilation operations; (3) high or perfect blocking properties for particles larger than approximately 20 nm (killer particles); and (4) good heat dissipation to prevent the pellicle from being burned out by EUV radiation.

[0009] In the present disclosure, a pellicle for an EUV photomask comprises a mesh membrane with multiple multi-walled nanotubes and a two-dimensional material layer covering the mesh membrane. Such a pellicle exhibits a high degree of EUV transmittance and improved mechanical strength, blocks killer particles upon impact with an EUV mask, and / or exhibits improved durability.

[0010] Fig. 1A, Fig. 1B and Fig. Figure 1C shows an EUV pellicle 10 mounted on an EUV reflective mask 5, according to an embodiment of the present disclosure. Fig. 1A is a cross-sectional view in the X direction, Fig. 1B is a cross-sectional view in the Y direction and Fig. 1C is a top view (plan view).

[0011] In some embodiments, a pellicle 10 for an EUV reflective mask comprises a first cover layer 20, a second cover layer 30, and a main mesh membrane 100 positioned between the first cover layer 20 and the second cover layer 30. In some embodiments, the main mesh layer comprises multiple multi-walled nanomaterials, such as nanotubes and / or nanoplatelets made of two-dimensional materials. In some embodiments, a support frame 15 is attached to the main mesh membrane 100 and / or the first cover layer 20 to maintain a space between the pellicle membrane and the EUV mask 5 (structural area) when mounted on the EUV mask 5. One or both of the first cover layer 20 and the second cover layer 30 comprise a two-dimensional material in which one or more two-dimensional layers are stacked.In some embodiments, a “two-dimensional” layer refers to one or a few crystalline layers of an atomic matrix or network with a thickness in the range of approximately 0.1–5 nm.

[0012] The support frame 15 of the pellicle is attached to the surface of the EUV photomask 5 with a suitable bonding material. In some embodiments, the bonding material is an adhesive, such as an acrylic- or silicon-based glue or an AB-curing type adhesive. The size of the frame structure is larger than the area of ​​the black borders of the EUV photomask, so that the pellicle covers not only the circuit structure area of ​​the photomask but also the black borders.

[0013] In some embodiments, the two-dimensional materials of the first cover layer 20 and the second cover layer 30 are the same or different. In some embodiments, the first cover layer contains a first two-dimensional material and the second cover layer contains a second two-dimensional material.

[0014] In some embodiments, the two-dimensional material for the first cover layer 20 and / or the second cover layer 30 contains at least one of boron nitride (BN), graphene and / or transition metal dichalcogenides (TMDs), represented by MX2, where M = Mo, W, Pd, Pt and / or Hf and X = S, Se and / or Te. In some embodiments, a TMD is one of MoS2, MoSe2, WS2 or WSe2.

[0015] In some embodiments, the total thickness of each of the first cover layer 20 and the second cover layer 30 is in the range of approximately 0.3 nm to approximately 3 nm, and in other embodiments, it is in the range of approximately 0.5 nm to approximately 1.5 nm. In some embodiments, the number of two-dimensional layers of each of the two-dimensional materials of the first and / or second cover layer is 1 to approximately 20, and in other embodiments, it is 2 to approximately 10. If the thickness and / or the number of layers is greater than these ranges, the EUV transmittance of the pellicle 10 may be reduced, and if the thickness and / or the number of layers is less than these ranges, the mechanical strength of the pellicle may be insufficient.

[0016] In some embodiments, such as in Fig. 1A and Fig. As shown in Figure 1B, the first cover layer 20 and the second cover layer 30 are sealed around their circumference to completely encapsulate the main mesh membrane 100. In some embodiments, the first cover layer 20 and the second cover layer 30 form a vacuum-tight structure. In some embodiments, the pressure inside the vacuum-tight structure is approximately 0.01 Pa to approximately 100 Pa. If the internal pressure is too high, for example, higher than the internal pressure of an EUV lithography unit in operation, the pellicle may rupture due to the pressure differential. In some embodiments, one or more vent holes are formed in the first cover layer 20 and / or the second cover layer 30.

[0017] In some embodiments, a protective layer 40 is further arranged over the first cover layer 20, the second cover layer 30 and the support frame 15, as shown in Fig. Figure 1D shows the protective layer 40. In some embodiments, the protective layer 40 contains at least one layer of an oxide, such as HfO2, Al2O3, ZrO2, Y2O3, or La2O3. In some embodiments, the protective layer 40 contains at least one layer of non-oxide compounds, such as B4C, YN, Si3N4, BN, NbN, RuNb, YF3, TiN, or ZrN. In some embodiments, the protective layer 40 contains at least one metal layer of, for example, Ru, Nb, Y, Sc, Ni, Mo, W, Pt, or Bi. In some embodiments, the protective layer 40 is a single layer, and in other embodiments, two or more layers of these materials are used as the protective layer 40. In some embodiments, the thickness of the protective layer is in the range of about 0.1 nm to about 5 nm, and in other embodiments, it is in the range of about 0.2 nm to about 2.0 nm.If the thickness of the protective layer 40 is greater than these areas, the EUV transmittance of the pellicle 10 may be reduced, and if the thickness of the protective layer 40 is less than these areas, the mechanical strength of the pellicle may be insufficient.

[0018] When using the first and / or second cover layer and / or the protective layer, which do not have holes such as an opening and / or spaces larger than about 10-20 nm, it is possible to completely block killer particles larger than about 20 nm from passing through the main mesh membrane 100 and falling onto the surface of the EUV mask 5.

[0019] In some embodiments, the nanotubes in the main network membrane contain 100 multi-walled nanotubes, which are also referred to as coaxial nanotubes. Fig. Figure 2A shows a perspective view of a multi-walled coaxial nanotube with three tubes 210, 220 and 230 and Fig. Figure 2B shows a cross-sectional view of it. In some embodiments, the inner tube 210 is a carbon nanotube and two outer tubes 220 and 230 are boron nitride nanotubes.

[0020] The number of tubes in the multi-walled nanotubes is not limited to three. In some embodiments, the multi-walled nanotube has two coaxial nanotubes, as in Fig. 2C shown, and in other embodiments the multi-walled nanotube contains the innermost tube 210 and the first to N-th nanotubes containing the outermost tube 200N, where N is a natural number from 1 to about 20, as in Fig. 2D shown. In some embodiments, N is up to 10 or up to 5. In some embodiments, at least one of the first to Nth outer layers is a nanotube that coaxially surrounds the innermost nanotube 210. In some embodiments, two of the innermost nanotubes 210 and the first to Nth outer layers 220, 230, ... 200N are made of different materials. In some embodiments, N is at least two (i.e., three or more tubes), and two of the innermost nanotubes 210 and the first to Nth outer tubes 220, 230, ... 200N are made of the same materials. In other embodiments, three of the innermost nanotubes 210 and the first to Nth outer tubes 220, 230, ... 200N are made of different materials.

[0021] In some embodiments, each of the nanotubes of the multiwalled nanotube is selected from the group consisting of a carbon nanotube, a boron nitride nanotube, a transition metal dichalcogenide nanotube (TMD nanotube), where TMD is represented by MX2, where M is one or more of Mo, W, Pd, Pt, or Hf, and X is one or more of S, Se, or Te. In some embodiments, at least two of the nanotubes of the multiwalled nanotube are made of different materials. In some embodiments, two adjacent layers (tubes) of the multiwalled nanotube are made of different materials.

[0022] In some embodiments, the multi-walled nanotube contains three coaxially layered tubes made of different materials. In other embodiments, the multi-walled nanotube contains three coaxially layered tubes in which the innermost tube (first tube) and the second tube surrounding the innermost tube are made of different materials, and the third tube surrounding the second tube is made of the same material as, or a different material than, the innermost tube or the second tube.

[0023] In some embodiments, the multi-walled nanotube contains four coaxially layered tubes, each made of different materials A, B, or C. In some embodiments, the materials of the four layers from the innermost (first) tube to the fourth tube are A / B / A / A, A / B / A / B, A / B / A / C, A / B / B / A, A / B / B / B, A / B / B / C, A / B / C / A, A / B / C / B, or A / B / C / C.

[0024] In some embodiments, all of the tubes of the multi-walled nanotube are crystalline nanotubes. In other embodiments, one or more tubes are a non-crystalline (e.g., amorphous) layer wrapped around the one or more inner tubes. In some embodiments, the outermost tube is, for example, made of a layer of HfO₂, Al₂O₃, ZrO₂, Y₂O₃, La₂O₃, B₄C, YN, Si₃N₄, BN, NbN, RuNb, YF₃, TiN, ZrN, Ru, Nb, Y, Sc, Ni, Mo, W, Pt, or Bi. In some embodiments, the outermost layer is made of the same material as the protective layer 40.

[0025] In some embodiments, the diameter of the innermost nanotube is in the range of approximately 0.5 nm to approximately 20 nm, and in other embodiments, it is in the range of approximately 1 nm to approximately 10 nm. In some embodiments, the diameter of the multi-walled nanotubes (i.e., the diameter of the outermost tube) is in the range of approximately 3 nm to approximately 40 nm, and in other embodiments, it is in the range of approximately 5 nm to approximately 20 nm. In some embodiments, the length of the multi-walled nanotube is in the range of approximately 0.5 µm to approximately 50 µm, and in other embodiments, it is in the range of approximately 1.0 µm to approximately 20 µm.

[0026] Fig. 3A, Fig. 3B and Fig. Figure 3C shows various mesh membranes 100 of a pellicle for an EUV photomask according to embodiments of the present disclosure.

[0027] In some embodiments, the network membrane 100 contains several multi-walled nanotubes 101. In some embodiments, the several multi-walled nanotubes are arranged randomly to form a network structure. In some embodiments, the several multi-walled nanotubes may contain only one type of multi-walled nanotube in terms of material and structure (number of layers). In other embodiments, the several multi-walled nanotubes contain two or more types of multi-walled nanotubes in terms of material and structure (number of layers). For example, the several multi-walled nanotubes contain a first type of multi-walled nanotube, e.g., two-walled nanotubes, and a second type of multi-walled nanotube, e.g., three-walled nanotubes; a first type of multi-walled nanotube, e.g., two-walled nanotubes of layer A and layer B, and a second type of multi-walled nanotube, e.g.,Double-walled nanotubes consisting of layer A and layer C.

[0028] In some embodiments, the main network layer 100 contains several of one or more types of multi-walled nanotubes 101 and several of one or more types of single-walled nanotubes 111, as in Fig. Figure 3B shows that in some embodiments, the quantity (weight) of the single-walled nanotubes 111 is less than the quantity of the multi-walled nanotubes 101. In other embodiments, the quantity (weight) of the single-walled nanotubes 111 is greater than the quantity of the multi-walled nanotubes 101. In some embodiments, the quantity (weight) of the multi-walled nanotubes 101 is at least approximately 20 wt.% relative to the total weight of the network membrane 100, or in other embodiments, at least 40 wt.%. If the quantity of the multi-walled nanotubes is less than these values, sufficient network membrane strength cannot be achieved.

[0029] In some embodiments, the main network membrane 100 contains several multi-walled nanotubes 101 and several platelets 121 (nanoplates) made of a two-dimensional material in which one or more two-dimensional layers are stacked, as in Fig. 3C shown.

[0030] In some embodiments, the two-dimensional material platelets 121 contain at least one of boron nitride (BN), graphene and / or transition metal dichalcogenides (TMDs), represented by MX2, where M = Mo, W, Pd, Pt and / or Hf and X = S, Se and / or Te. In some embodiments, a TMD is one of MoS2, MoSe2, WS2 or WSe2.

[0031] In some embodiments, the thickness of a two-dimensional material platelet 121 is in the range of approximately 0.3 nm to approximately 3 nm, and in other embodiments in the range of approximately 0.5 nm to approximately 1.5 nm. In some embodiments, the number of two-dimensional layers of the two-dimensional material platelet 121 is 1 to approximately 20, and in other embodiments, it is 2 to approximately 10. If the thickness and / or the number of layers is greater than these ranges, the EUV transmittance of the pellicle 10 may be reduced, and if the thickness and / or the number of layers is less than these ranges, the mechanical strength of the pellicle may be insufficient.

[0032] In some embodiments, the shape of the two-dimensional material platelets 121 is random. In other embodiments, the shape of the two-dimensional material platelets 121 is triangular or hexagonal. In certain embodiments, the shape of the two-dimensional material platelets 121 is a triangle formed by three atoms or a hexagon formed by six atoms. In some embodiments, the size (area) of each of the two-dimensional material platelets 121 is in a range of about 10 nm. 2 up to about 10 µm 2 and in other embodiments is in a range of about 100 nm 2 up to about 1 µm 2 In some embodiments, the two-dimensional material platelets 121 are embedded in or mixed with several nanotubes 101.

[0033] In some embodiments, the quantity (weight) of the two-dimensional material platelets 121 is in the range of approximately 5 wt.% to approximately 30 wt.% relative to the total weight of the mesh membrane 100, and in other embodiments, it is in the range of approximately 10 wt.% to approximately 20 wt.%. If the quantity of two-dimensional material platelets is greater than these ranges, the EUV transmittance of the pellicle 10 may be reduced, and if the quantity of two-dimensional material platelets is less than these ranges, the mechanical strength of the pellicle may be insufficient. In some embodiments, the multiple nanotubes are similar to multi-walled nanotubes. Fig. 3 and in other embodiments, the multiple nanotubes are a mixture of single-walled nanotubes and multi-walled nanotubes similar to Fig. 3B.

[0034] Fig. 4A, Fig. 4B, Fig. 4C, Fig. 4D, Fig. 4E, Fig. 4F, Fig. 4G, Fig. 4H, Fig. 4I and Fig. Figure 4J shows various views of mesh membranes of a pellicle for an EUV photomask according to embodiments of the present disclosure. In some embodiments, the mesh membrane 100 has a single-layer structure or a multi-layer structure.

[0035] In some embodiments, the network membrane 100 has a single layer 110 made up of several multi-walled nanotubes, as in Fig. 4A shown. In some embodiments, the network membrane 100 has two layers of multi-walled nanotubes 110 and 112 of different types, as shown in Fig. 4B shown. The thickness of layer 110 and layer 112 are the same or different. In some embodiments, the mesh membrane 100 has three layers of nanotubes 110, 112 and 114, as shown in Fig. 4C shown. At least adjacent layers are of different types in some embodiments (e.g., material and / or number of walls). The thicknesses of layers 110, 112, and 114 are the same or different. In some embodiments, a single nanotube layer is arranged between two multi-walled nanotube layers. In some embodiments, the mesh membrane 100 has a single layer 115 made of a mixture of different nanotubes, as shown in Fig. Shown in 4D.

[0036] In some embodiments, the network membrane 100 has a nanotube layer 110 and a two-dimensional platelet layer 120, as in Fig. 4E and Fig. 4F shown. The thicknesses of layer 110 and layer 120 are the same or different. Layer 110 can be a mixed layer 115, as shown in Fig. 4D shown. In some embodiments, the network membrane 100 has a two-dimensional platelet layer 120 arranged between a first nanotube layer 110 and a second nanotube layer 112, as shown in Fig. 4G shown. In some embodiments, the first and second nanotube layers are of the same type or of different types. In some embodiments, the network membrane 100 has a nanotube layer 110 arranged between a first two-dimensional platelet layer 120 and a second two-dimensional platelet layer 122, as shown in Fig. 4H shown. In some embodiments, the first and second two-dimensional platelet layers are made of the same material or of different materials. In some embodiments, the network membrane 100 has a nanotube layer 110, a first two-dimensional platelet layer 120 above the nanotube layer 110, and a second two-dimensional platelet layer 122 arranged above the first two-dimensional platelet layer 120, as shown in Fig. 4I shown. In some embodiments, the network membrane 100 comprises one or more nanotube layers of the same or different types and one or more two-dimensional platelet layers of the same or different materials. In some embodiments, the network membrane 100 comprises a single layer 125 of a mixture of nanotubes and two-dimensional platelets, as shown in Fig. 4J shown.

[0037] Fig. 5A shows a manufacturing process of a mesh membrane and Fig. Figure 5B shows a flowchart for this according to one embodiment of the present disclosure.

[0038] In some embodiments, nanotubes are dispersed in a solution, as in Fig. Figure 5A shows the solution as a solvent containing water or an organic solvent such as sodium dodecyl sulfate (SDS). The nanotubes are of one, two, or more types (material and / or number of walls). In some embodiments, the nanotubes are single-walled. In some embodiments, the single-walled nanotubes are carbon nanotubes formed by various processes, such as arc discharge, laser ablation, or chemical vapor deposition (CVD). Similarly, single-walled BN nanotubes and single-walled TMD nanotubes are also formed by a CVD process.

[0039] As in Fig. Figure 5A shows a support membrane positioned between a chamber or cylinder containing the solution-dispersed nanotube and a vacuum chamber. In some embodiments, the support membrane is an organic or inorganic porous or mesh material. In some embodiments, the support membrane is a woven or nonwoven fabric. In some embodiments, the support membrane has a circular shape that can accommodate a pellicle or a 150 mm × 150 mm square (the size of an EUV mask).

[0040] As in Fig. As shown in Figure 5A, the pressure in the vacuum chamber is reduced, so that pressure is exerted on the solvent in the chamber or cylinder. Since the mesh or pore size of the support membrane is sufficiently smaller than the size of the nanotubes, the nanotubes are trapped by the support membrane, while the solvent passes through it. The support membrane on which the nanotubes are deposited is controlled by the filtration unit. Fig. 5A dissolved and then dried. In some embodiments, the deposition is repeated by filtration to obtain a desired thickness of the nanotube network layer, as in Fig. Figure 5B shows that in some embodiments, after the nanotubes have been deposited in the solution, other nanotubes are dispersed in the same or a new solution, and the filter deposition is repeated. In other embodiments, another filter deposition is performed after the nanotubes have been dried. In some embodiments, the same type of nanotube is used in the repetition, while in other embodiments, different types of nanotubes are used.

[0041] In some embodiments, the nanotubes dispersed in the solution contain multi-walled nanotubes. In some embodiments, multi-walled nanotubes are used by CVD using single-walled nanotubes as seeds, as in Fig. Figure 5C shows that in some embodiments, single-walled nanotubes, such as carbon nanotubes, BN nanotubes, or TMD nanotubes formed by CVD, are placed over a substrate. Source materials, such as source gases, are then provided over the substrate containing the seed nanotubes. In the case of CVD for the formation of a MoS₂ layer, Mo(CO)₆ gas, MoCl₅ gas, and / or MoOCl₄ gas are used as a Mo source, and H₂S gas and / or dimethyl sulfide gas are used as a S source in some embodiments. In other embodiments, MoO₃ gas, sublimed from a solid MoO₃ or MoCl₅ source, and / or S gas, sublimed from a solid S source, can be used, as shown in Figure 5C. Fig. 5C shown. As in Fig. As shown in Figure 5C, solid sources of Mo and S are placed in a reaction chamber, and a carrier gas containing an inert gas, such as Ar, N2, and / or He, flows into the reaction chamber. The solid sources are heated to generate gaseous sources by sublimation, and the generated gaseous sources react to form MoS2 molecules. The MoS2 molecules are then deposited around the seed nanotubes above the substrate. In some embodiments, the substrate is heated appropriately. In other embodiments, the entire reaction chamber is heated by induction heating. Other TMD layers can also be formed by CVD using suitable source gases. For example, metal oxides, such as WO3, PdO2, and PtO2, can be used as a sublimation source for W, Pd, and Pt, respectively, and metal compounds, such as W(CO)6, WF6, WOCl4, PtCl2, and PdCl2, can also be used as a metal source.

[0042] In other embodiments, such as in Fig. As shown in 5D, the germ nanotubes are immersed in, dispersed in, or treated with one or more metal precursors, such as (NH4)WS4, WO3, (NH4)MoS4 or MoO3, and placed over the substrate, and then a sulfur gas is supplied over the substrate to form multi-walled nanotubes.

[0043] In other embodiments, a carbon source is used to form a carbon nanotube as an outer layer over a BN or TMD inner nanotube. Three or more coaxial nanotubes are formed in some embodiments by repeating the processes described above. In some embodiments, multi-walled nanotubes are arranged in solution, as in Fig. Figure 5A shows that in some embodiments a mixture of single-walled nanotubes and multi-walled nanotubes is arranged in the solution.

[0044] Fig. Figure 6 shows a fabrication process for a network membrane according to an embodiment of the present disclosure. If the main network membrane contains 100 nanotubes and two-dimensional material platelets, the deposition by filtration for nanotubes and the deposition by filtration for the platelets are repeated as shown in Figure 6. Fig. Figure 6 shows. In some embodiments, a mixture of single- and / or multi-walled nanotubes and platelets is dispersed in the solvent and deposition by filtration is carried out to form a mixed network layer of nanotubes and two-dimensional material platelets.

[0045] Two-dimensional material layers are formed on a substrate using a CVD process, and then the deposited layer is peeled off the substrate. After the two-dimensional material layer has been peeled off, it is, in some embodiments, broken down into platelets.

[0046] Fig. Figures 7A and 7B through 11A and 11B show cross-sectional views (the “A” figures) and plan views (top views) (the “B” figures) of the various manufacturing stages of a pellicle for an EUV photomask according to an embodiment of the present disclosure. It is clear that additional operations are carried out before, during, and after the processes described by Fig. The operations shown in Figures 7A-11B may be provided, and some of the operations described below may be substituted or eliminated for additional embodiments of the method. The order of the operations / processes may be interchangeable. Materials, configurations, procedures, processes, and / or dimensions, as explained with respect to the preceding embodiments, are applicable to the following embodiments, and their detailed description is omitted.

[0047] As in Fig. As shown in Figures 5A-5D or 6, a nanotube layer 90 is formed on a support membrane 80 by deposition through filtration. In some embodiments, the nanotube layer 90 contains only single-walled nanotubes. The nanotube layer 90 is then released by a deposition device, as shown in Fig. 7A and Fig. 7B shown.

[0048] Then, as in Fig. 8A and Fig. Figure 8B shows a support frame 15 attached to the nanotube layer 90. In some embodiments, the support frame 15 is formed from one or more layers of crystalline silicon, polysilicon, silicon oxide, silicon nitride, ceramic, metal, or organic material. In some embodiments, as shown in Fig. As shown in Figure 9B, the support frame 15 has a rectangular (containing square) frame shape that is larger than the black border area of ​​an EUV mask and smaller than the substrate of the EUV mask.

[0049] Then, as in Fig. 9A and Fig. As shown in Figure 9B, in some embodiments the nanotube layer 90 and the support membrane 80 are cut into a rectangular shape that is the same size as, or slightly larger than, the support frame 15, and then the support substrate 80 is dissolved and removed. If the support substrate 80 is made of an organic material, it is removed by wet settling using an organic solvent.

[0050] Then, one or more outer tubes are formed around each of the nanotubes (e.g., a single nanotube) of the nanotube layer that forms the network membrane 100, which contains multi-walled nanotubes. In some embodiments, a CVD process similar to Fig. 5C or Fig. 5D is performed using the nanotube layer 90 as the seed layer. The CVD process is repeated a desired number of times to form three or more outer tubes.

[0051] Furthermore, as in Fig. 11A and Fig. As shown in Figure 11B, a first cover layer 20 and a second cover layer 30 are formed to seal the nanotube network layer 100. One or both of the first cover layer 20 and the second cover layer 30 contain a two-dimensional material. The two-dimensional material is formed, for example, by a CVD process on a substrate, and then the deposited two-dimensional layer(s) are peeled off the substrate. The peeled two-dimensional layer(s) are then transferred over the nanotube network layer 100.

[0052] In some embodiments, the first and / or second cover layer contains a two-dimensional TMD layer, where a TMD layer, represented by MX2, is formed by CVD. In some embodiments, a MoS2 layer is formed by CVD using source gases, such as Mo(CO)6 gas, MoCl5 gas, and / or MoOCl4 gas as a Mo source; and H2S gas and / or dimethyl sulfide gas as a S source. In other embodiments, MoO3 gas is sublimed from a solid MoO3 or MoCl5 source, and / or S gas is sublimed from a solid S source. Solid sources of Mo and S are placed in a reaction chamber, and a carrier gas containing an inert gas, such as Ar, N2, and / or He, flows in the reaction chamber. The solid sources are heated to generate gaseous sources by sublimation, and the generated gaseous sources react to form MoS2 molecules. The MoS2 molecules are then deposited onto the substrate.In some embodiments, the substrate is heated appropriately. In other embodiments, the entire reaction chamber is heated by induction heating. Other TMD layers can also be formed by CVD using suitable source gases. For example, metal oxides such as WO3, PdO2, and PtO2 can be used as a sublimation source for W, Pd, and Pt, respectively, and metal compounds such as W(CO)6, WF6, WOCl4, PtCl2, and PdCl2 can also be used as a metal source. In some embodiments, the substrate on which the two-dimensional TMD layer is formed contains one of Si (101), γ-Al2O3 (101), Ga2O3 (010), or MgO (101). In other embodiments, a layer of hexagonal boron nitride (h-BN) or graphene is formed as the first cover layer 20 over a substrate by CVD. In some embodiments, the substrate contains one of SiC (0001), Si (111) or Ge (111).

[0053] In some embodiments, furthermore, as in Fig. Figure 11C shows a top layer 40 formed over the first and second top layers and the support frame 15 using CVD, ALD or any other suitable film formation process.

[0054] In some embodiments, the second cover layer 30 is attached to the sides of the first cover layer 20 and the support frame 15, as shown in Fig. 11D shown.

[0055] Fig. Figures 12A and 12B through 14A and 14B and 15A show cross-sectional views (the “A” figures) and plan views (top views) (the “B” figures) of the various manufacturing stages of a pellicle for an EUV photomask according to an embodiment of the present disclosure. It is clear that additional operations may be provided before, during, and after the processes described by Fig. Figures 12A-14B show that some of the operations described below can be substituted or eliminated for additional embodiments of the method. The order of the operations / processes may be interchangeable. Materials, configurations, procedures, processes, and / or dimensions, as explained with respect to the preceding embodiments, are applicable to the following embodiments, and their detailed description is omitted.

[0056] Once the nanotube layer 90 is formed above the support substrate 80, as shown in Fig. 7A and Fig. As shown in Figure 7B, a first cover layer 20 is formed over the nanotube layer 90, as in Fig. 12A and Fig. 12B shown. Then, as in Fig. 12A and Fig. As shown in Figure 12B, a support frame 15 is attached to the first top layer 20.

[0057] Then, as in Fig. 13A and Fig. As shown in Figure 13B, the first cover layer 20, the nanotube layer 90 and the support membrane 80 are cut into a rectangular shape the same size as the support frame 15 or slightly larger, and then in some embodiments the support substrate 80 is dissolved or removed.

[0058] Then, similar to the businesses that, in relation to Fig. 10A and Fig. As explained in 10B, one or more outer tubes are formed over the nanotubes of the nanotube layer 90, as shown in Fig. 14A and Fig. 14B shown.

[0059] Furthermore, similarly Fig. 11A and Fig. 11B, a second cover layer 30 formed over the nanotube layer 90, as in Fig. Figure 15A shows the operations for forming the second cover layer 30, which is a two-dimensional material, are the same as or similar to those for the first cover layer 20, as described above. In some embodiments, the first cover layer 20 and the second cover layer 30 are sealed at their periphery to completely encapsulate the nanotube layer 90.

[0060] In some embodiments, the second cover layer 30 is attached to the sides of the first cover layer 20 and the support frame 15, as shown in Fig. 15B shown. In some embodiments, the second cover layer 30 has a flange section to which the second cover layer 30 is fixed or bonded to the first cover layer 20, as shown in Fig. 15C shown.

[0061] Furthermore, similarly Fig. 11C, a protective layer 40 is formed over the first cover layer 20, the second cover layer and the support frame 15. In some embodiments, the protective layer 40 is formed by CVD, physical vapor deposition (PVD) or atomic layer deposition (ALD).

[0062] In some embodiments, when multi-walled nanotubes are dispersed in the solution during filter separation, as in Fig. 5A or Fig. As shown in Figure 6, a nanotube layer 91 containing multi-walled nanotubes is formed over the support substrate 80, as shown in Fig. 16A shown. In some embodiments, as in Fig. 16B shown once the nanotube layer 90, which contains single-walled nanotubes, is positioned above the support substrate similarly Fig. Once 7A is formed, the individual nanotubes are converted into multi-walled nanotubes over the support substrate 80. As soon as the nanotube layer 91, which contains multi-walled nanotubes, is formed over the support substrate, the operations are carried out as described in relation to Fig. 8A, Fig. 8B, Fig. 9A, Fig. 9B, Fig. 11A and Fig. 11B (and 11C) or Fig. 12A, Fig. 12B, Fig. 13A, Fig. 13B and Fig. 15A explained, carried out.

[0063] Fig. 17A, Fig. 17B, Fig. 17C and Fig. Figure 17D shows various views of pellicles for an EUV photomask according to an embodiment of the present disclosure. In some embodiments, the first cover layer is not used and only the second cover layer 30 is deposited over the main mesh membrane 100, as shown in Fig. 17A shown. In some embodiments, the second cover layer is not used and only the first cover layer 20 is deposited over the main network membrane 100, as shown in Fig. 17B shown. In some embodiments, the first cover layer is not used and only the second cover layer 30 is deposited over the main network membrane 100 and a protective layer 40 is formed on the second cover layer and network membrane 100, forming a covered network layer 119, as shown in Fig. Figure 17C shows that in some embodiments the protective layer is formed around each of the multi-walled nanotubes, and in other embodiments the protective layer covers an outer circumference of the main network membrane 100. In some embodiments the second cover layer is not used and only the first cover layer 20 is deposited over the main network membrane 100 and a protective layer 40 is formed on the second cover layer and network membrane 100, forming a covered network layer 119, as shown in Fig. Figure 17D shows that in some embodiments the protective layer is formed around each of the multi-walled nanotubes, and in other embodiments the protective layer covers an outer circumference of the main network membrane 100.

[0064] Fig. 18A, Fig. 18B, Fig. 18C, Fig. 18D, Fig. 18E and Fig. Figure 18F shows flowcharts for the production of a pellicle for an EUV photomask according to embodiments of the present disclosure. It is clear that additional operations are required before, during, and after the processes described in Figure 18F. Fig. The process blocks shown in Figures 18A-18E may be provided, and some of the operations described below may be substituted or eliminated for additional embodiments of the method. The sequence of operations / processes may be interchangeable. Materials, configurations, procedures, processes, and / or dimensions, as explained with respect to the preceding embodiments, are applicable to the following embodiments, and their detailed description is omitted.

[0065] In some embodiments, as in Fig. Figure 18A shows a nanotube layer containing single-walled nanotubes being formed over a support substrate by a filter deposition process in block S101. A pellicle frame is then formed over the nanotube layer in block S102. In block S103, the nanotube layer and the support substrate are cut into a desired shape, and the support substrate is removed in block S104. In block S105, one or more outer tubes are formed around single-walled nanotubes. In block S106, one or more cover layers made of a two-dimensional material are formed to seal the multi-walled nanotube layer. Optionally, a protective layer is formed over the cover layers in block S107.

[0066] In some embodiments, as in Fig. Figure 18B shows a nanotube layer containing single-walled nanotubes being formed over a support substrate by a filter deposition process in block S201. Then, in block S202, one or more outer tubes are formed around the single-walled nanotubes. In block S203, a pellicle frame is formed over the multi-walled nanotube layer. In block S204, the multi-walled nanotube layer and the support substrate are cut into a desired shape, and in block S205, the support substrate is removed. In block S206, one or more cover layers made of a two-dimensional material are formed to seal the multi-walled nanotube layer. In block S207, a protective layer is optionally formed over the cover layers.

[0067] In some embodiments, as in Fig. Figure 18C shows a nanotube layer containing single-walled nanotubes being formed over a support substrate by a filter deposition process in block S301. Then, in block S302, a first cover layer made of a two-dimensional material is formed over the nanotube layer on the support substrate. In block S303, a pellicle frame is formed over the first cover layer. In block S304, the nanotube layer and the support substrate are cut into a desired shape, and the support substrate is removed. In block S305, one or more outer tubes are formed around single-walled nanotubes. In block S306, a second cover layer made of a two-dimensional material is formed to seal the multi-walled nanotube layer. In block S307, a protective layer is optionally formed over the cover layers.

[0068] In some embodiments, as in Fig. Figure 18D shows a nanotube layer containing single-walled nanotubes being formed on a support substrate by a filter deposition process in block S401. Then, in block S402, one or more outer tubes are formed around the single-walled nanotubes. In block S403, a first cover layer, made of a two-dimensional material, is formed over the nanotube layer on the support substrate. In block S404, a pellicle frame is formed over the first cover layer. In block S405, the multi-walled nanotube layer and the support substrate are cut into a desired shape, and the support substrate is removed. In block S406, a second cover layer, made of a two-dimensional material, is formed to seal the multi-walled nanotube layer. In block S407, a protective layer is optionally formed over the cover layers.

[0069] In some embodiments, as in Fig. Figure 18E shows a nanotube layer containing multiwall nanotubes being formed over a support substrate by a filter deposition process in block S501. A pellicle frame is then formed over the multiwall nanotube layer in block S502. In block S503, the multiwall nanotube layer and the support substrate are cut into a desired shape, and the support substrate is removed in block S504. In block S505, one or more cover layers made of a two-dimensional material are formed to seal the multiwall nanotube layer. Optionally, a protective layer is formed over the cover layers in block S506. In some embodiments, one or more additional outer tubes are formed around the multiwall nanotubes between blocks S501 and S502 and / or between blocks S504 and S505.

[0070] In some embodiments, as in Fig. Figure 18F shows a nanotube layer containing multiwall nanotubes being formed over a support substrate by a filter deposition process in block S601. Then, in block S602, a first cover layer is formed over the multiwall nanotube layer on the support substrate. In block S603, a pellicle frame is formed over the first cover layer. In block S604, the multiwall nanotube layer and the support substrate are cut into a desired shape, and the support substrate is removed. In block S605, a second cover layer, made of a two-dimensional material, is formed to seal the multiwall nanotube layer. Optionally, a protective layer is formed over the cover layers in block S606. In some embodiments, one or more additional outer tubes are formed around the multiwall nanotubes between blocks S601 and S602 and / or between blocks S604 and S605.

[0071] Fig. 19A shows a flowchart of a process for manufacturing a semiconductor device and Fig. 19B, Fig. 19C, Fig. 19D and Fig. Figure 19E discloses a sequential fabrication process for producing a semiconductor device according to embodiments of the present disclosure. A semiconductor substrate or other suitable substrate to be structured for forming an integrated circuit is provided. In some embodiments, the semiconductor substrate contains silicon. Alternatively or additionally, the semiconductor substrate contains germanium, silicon germanium, or another suitable semiconductor material, such as a Group III-V semiconductor material. In S801 of Fig. 19A A target layer to be structured is formed over the semiconductor substrate. In certain embodiments, the target layer is the semiconductor substrate. In some embodiments, the target layer contains a conductive layer, such as a metallic 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 is formed over an underlying structure, such as insulating structures, transistors, or wiring. In S802, of Fig. 19A, a photoresist layer is formed over the target layer, as in Fig. shown in Figure 19B. The photoresist layer is sensitive to radiation from the exposure source during a subsequent photolithography exposure process. In the present embodiment, the photoresist layer is sensitive to EUV light used in the photolithography exposure process. The photoresist layer can be formed over the target layer by spin coating or another suitable technique. The coated photoresist layer can further be baked to drive off solvents in the photoresist layer. In S803 of Fig. 19A the photoresist layer is applied using an EUV-reflective mask with a pellicle, as described above, as in Fig. Figure 19C shows a structured photoresist layer. The structuring of the photoresist layer involves performing a photolithography exposure process using an EUV exposure system and an EUV mask. During the exposure process, the integrated circuit (IC) design structure defined on the EUV mask is mapped onto the photoresist layer to form a latent structure. The photoresist layer structuring further includes developing the exposed photoresist layer to form a structured photoresist layer with one or more openings. In an embodiment where the photoresist layer is a positive photoresist layer, the exposed portions of the photoresist layer are removed during the development process. The photoresist layer structuring may also include other process steps, such as various baking steps at different stages.For example, a post-exposure baking (PEB) process can be performed after the photolithography exposure process and before the development process.

[0072] In S804 of Fig. 19A, the target layer is structured using the structured photoresist layer as an etching mask, as in Fig. Figure 19D shows that in some embodiments, the structuring of the target layer involves applying an etching process to the target layer using the structured photoresist layer as an etching mask. The portions of the target layer exposed in the openings of the structured photoresist layer are etched, while the remaining portions are protected from etching. Furthermore, the structured photoresist layer can be removed by wet stripping or plasma ashing, as shown in Figure 19D. Fig. 19E shown.

[0073] The pellicles according to embodiments of the present disclosure offer higher strength and thermal conductivity (dissipation), as well as a higher EUV transmittance, than conventional pellicles. In the preceding embodiments, multi-walled nanotubes are used as a main mesh membrane to increase the mechanical strength of the pellicle and achieve a high EUV transmittance. Furthermore, a two-dimensional material layer is used as a cover layer (first and / or second cover layer) and / or in conjunction with nanotubes to increase the mechanical strength of a pellicle. Additionally, by using a two-dimensional material layer and / or a protective layer enclosing the main mesh membrane, it is possible to increase the mechanical strength of the pellicle and provide a high or perfect blocking property against killer particles.Furthermore, in some embodiments, the use of two-dimensional material platelets improves heat dissipation to prevent the pellicle from being burned out by EUV radiation.

[0074] It is clear that not all advantages have necessarily been discussed here, no particular advantage is necessary for all embodiments or examples, and other embodiments or examples may offer different advantages.

[0075] According to one aspect of the present disclosure, a pellicle for an EUV photomask comprises a first layer, a second layer, and a main membrane arranged between the first and second layers. The main membrane contains several coaxial nanotubes, each of which contains an inner tube and one or more outer tubes surrounding the inner tube, and two of the inner tubes and the one or more outer tubes are made of different materials. In one or more of the preceding and following embodiments, each of the inner tubes and the one or more outer tubes is selected from the group consisting of a carbon nanotube, a boron nitride nanotube, a transition metal dichalcogenide nanotube (TMD nanotube), where TMD is represented by MX2, where M is one or more of Mo, W, Pd, Pt, or Hf, and X is one or more of S, Se, or Te.In one or more of the preceding and following embodiments, the inner tube is a carbon nanotube. In one or more of the preceding and following embodiments, each of the multiple coaxial nanotubes contains the inner tube and an outer tube made of a different material than the inner tube. In one or more of the preceding and following embodiments, each of the multiple coaxial nanotubes contains the inner tube and two outer tubes, all of which are made of different materials. In one or more of the preceding and following embodiments, each of the multiple coaxial nanotubes contains two outer tubes made of the same material and the inner tube. In one or more of the preceding and following embodiments, the main membrane further contains multiple single-walled nanotubes.

[0076] According to another aspect of the present disclosure, a pellicle for an extreme ultraviolet (EUV) reflecting mask comprises a first layer, a support frame attached to the first layer, and a main membrane arranged over the first layer. The main membrane contains several nanotubes, each of which includes an inner nanotube and first to Nth outer layers, each coaxially surrounding the inner nanotube, where N is a natural number from 1 to 10. In one or more of the preceding and following embodiments, at least one of the first to Nth outer layers is a nanotube coaxially surrounding the inner nanotube. In one or more of the preceding and following embodiments, two of the inner nanotube and the first to Nth outer layers are made of different materials.In one or more of the preceding and following embodiments, N is at least two, and two of the inner nanotubes and the first to Nth outer layers are made of the same materials. In one or more of the preceding and following embodiments, N is at least two, and three of the inner nanotubes and the first to Nth outer layers are made of different materials. In one or more of the preceding and following embodiments, the inner nanotube is selected from the group consisting of a carbon nanotube, a boron nitride nanotube, a transition metal dichalcogenide nanotube (TMD nanotube), where TMD is represented by MX2, where M is one or more of Mo, W, Pd, Pt, or Hf, and X is one or more of S, Se, or Te.In one or more of the preceding and following embodiments, each of the first to Nth outer layers is made of a carbon, boron nitride, transition metal dichalcogenide (TMD), where TMD is represented by MX2, where M is one or more of Mo, W, Pd, Pt, or Hf, and X is one or more of S, Se, or Te. In one or more of the preceding and following embodiments, the pellicle further comprises a protective layer. In one or more of the preceding and following embodiments, the material of the protective layer is the same as that of the Nth outer layer.

[0077] According to another aspect of the present disclosure, a pellicle for an extreme ultraviolet (EUV) reflecting mask comprises a first layer, a second layer, and a main membrane arranged between the first and second layers. The main membrane contains several nanotubes, each of which contains an inner nanotube and first to Nth outer nanotubes, each coaxially surrounding the inner nanotube, where N is a natural number from 1 to 10. At least one of the first layer or the second layer comprises a two-dimensional material in which one or more two-dimensional layers are stacked. In one or more of the preceding and following embodiments, the two-dimensional material comprises at least one selected from the group consisting of boron nitride (BN), graphene, MoS₂, MoSe₂, WS₂, and WSe₂.In one or more of the preceding and following embodiments, the main membrane further comprises several nanoplatelets of a two-dimensional material, the latter comprising at least one selected from the group consisting of boron nitride (BN), graphene, MoS₂, MoSe₂, WS₂, and WSe₂. In one or more of the preceding and following embodiments, the pellicle further comprises a protective layer arranged over the first and second layers. In one or more of the preceding and following embodiments, the protective layer comprises at least one selected from the group consisting of HfO₂, Al₂O₃, ZrO₂, Y₂O₃, La₂O₃, B₄C, YN, Si₃N₄, BN, NbN, RuNb, YF₃, TiN, ZrN, Ru, Nb, Y, Sc, Ni, Mo, W, Pt, and Bi.

[0078] According to another aspect of the present disclosure, a pellicle for an extreme ultraviolet (EUV) reflecting mask comprises a first layer, a support frame attached to the first layer, and a main membrane arranged over the first layer. The main membrane contains a network structure of several multi-walled nanotubes, each having several coaxial tubes, and at least two of the several coaxial tubes are made of different materials. In one or more of the preceding and following embodiments, each of the several coaxial tubes is selected from the group consisting of a carbon nanotube, a boron nitride nanotube, a transition metal dichalcogenide nanotube (TMD nanotube), where TMD is represented by MX2, where M is one or more of Mo, W, Pd, Pt, or Hf, and X is one or more of S, Se, or Te.In one or more of the preceding and following embodiments, an innermost tube of the multiple coaxial tubes is selected from the group consisting of a carbon nanotube, a boron nitride nanotube, a transition metal dichalcogenide nanotube (TMD nanotube), where TMD is represented by MX2, where M is one or more of Mo, W, Pd, Pt, or Hf, and X is one or more of S, Se, or Te. In one or more of the preceding and following embodiments, each of the multiple coaxial tubes, except the innermost tube, is made of carbon, boron nitride nanotube, or transition metal dichalcogenide (TMD), where TMD is represented by MX2, where M is one or more of Mo, W, Pd, Pt, or Hf, and X is one or more of S, Se, or Te.In one or more of the preceding and following embodiments, an outermost tube of the multiple coaxial tubes is made of at least one selected from the group consisting of HfO2, Al2O3, ZrO2, Y2O3, La2O3, B4C, YN, Si3N4, BN, NbN, RuNb, YF3, TiN, ZrN, Ru, Nb, Y, Sc, Ni, Mo, W, Pt, and Bi. In one or more of the preceding and following embodiments, each of the multiple multi-walled nanotubes has three or four coaxial tubes, and at least three of the three or four coaxial tubes are made of different materials. In one or more of the preceding and following embodiments, the main membrane further comprises multiple single-walled nanotubes. In one or more of the preceding and following embodiments, the first layer comprises a two-dimensional material in which one or more two-dimensional layers are stacked.In one or more of the preceding and following embodiments, the two-dimensional material comprises at least one selected from the group consisting of boron nitride (BN), graphene, and a transition metal dichalcogenide (TMD), where TMD is represented by MX2, where M is one or more of Mo, W, Pd, Pt, or Hf, and X is one or more of S, Se, or Te. In one or more of the preceding and following embodiments, the thickness of the first layer is in the range of 0.3 nm to 3 nm. In one or more of the preceding and following embodiments, the number of one or more two-dimensional layers of the first layer is 1 to 20. In one or more of the preceding and following embodiments, the first layer is arranged between the support frame and the main membrane.In one or more of the preceding and following embodiments, a portion of the main membrane is arranged between the first layer and the support frame. In one or more of the preceding and following embodiments, the pellicle further comprises a second layer. In one or more of the preceding and following embodiments, the main membrane is arranged between the first layer and the second layer. In one or more of the preceding and following embodiments, the second layer comprises a two-dimensional material in which one or more two-dimensional layers are stacked.In one or more of the preceding and following embodiments, the two-dimensional material comprises at least one selected from the group consisting of boron nitride (BN), graphene, and a transition metal dichalcogenide (TMD), where TMD is represented by MX2, where M is one or more of Mo, W, Pd, Pt, or Hf, and X is one or more of S, Se, or Te. In one or more of the preceding and following embodiments, the thickness of the first layer is in the range of 0.3 nm to 3 nm. In one or more of the preceding and following embodiments, the number of one or more two-dimensional layers of the first layer is 1 to 20. In one or more of the preceding and following embodiments, the pellicle further comprises a protective layer arranged over both sides of the first layer.In one or more of the preceding and following embodiments, the protective layer comprises at least one selected from the group consisting of HfO2, Al2O3, ZrO2, Y2O3, and La2O3. In one or more of the preceding and following embodiments, the protective layer comprises at least one selected from the group consisting of B4C, YN, Si3N4, BN, NbN, RuNb, YF3, TiN, and ZrN. In one or more of the preceding and following embodiments, the protective layer comprises a metal layer made of at least one selected from the group consisting of Ru, Nb, Y, Sc, Ni, Mo, W, Pt, and Bi. In one or more of the preceding and following embodiments, the thickness of the protective layer is in the range of 0.1 nm to 5 nm. In one or more of the preceding and following embodiments, the protective layer is also formed to cover the multiple nanotubes of the main membrane.In one or more of the preceding and following embodiments, a protective layer material is the same as an outermost material of the multiple coaxial nanotubes. In one or more of the preceding and following embodiments, the multiple multiwalled nanotubes comprise multiple first multiwalled nanotubes and multiple second multiwalled nanotubes that differ from the multiple first multiwalled nanotubes. In one or more of the preceding and following embodiments, a number of wall layers of each of the multiple first multiwalled nanotubes differs from a number of wall layers of each of the multiple second multiwalled nanotubes. In one or more of the preceding and following embodiments, a number of wall layers of each of the multiple first multiwalled nanotubes is the same as a number of wall layers of each of the multiple second multiwalled nanotubes.In one or more of the preceding and following embodiments, the layered structure of the material of each of the first multiwalled nanotubes differs from the layered structure of the material of each of the second multiwalled nanotubes. In one or more of the preceding and following embodiments, the main membrane further comprises several platelets, each containing two-dimensional material in which one or more two-dimensional layers are stacked. In one or more of the preceding and following embodiments, the two-dimensional material comprises at least one selected from the group consisting of boron nitride (BN), graphene, MoS₂, MoSe₂, WS₂, and WSe₂. In one or more of the preceding and following embodiments, the size of each of the platelets is in the range of 10 nm. 2 up to 10 µm 2In one or more of the preceding and following embodiments, the thickness of each of the multiple platelets is in the range of 0.3 nm to 3 nm. In one or more of the preceding and following embodiments, the number of one or more two-dimensional layers of each of the multiple platelets is 1 to 20.

[0079] According to another aspect of the present disclosure, in a process for producing a pellicle for an extreme ultraviolet (EUV) reflecting mask, a nanotube layer containing multiple nanotubes is formed over a support substrate. A pellicle frame is formed over the nanotube layer. The nanotube layer is detached from the support substrate. One or more outer tubes are formed around each of the multiple nanotubes as an inner nanotube, thereby forming a mesh membrane containing multiple coaxial tubes, each containing the inner nanotube and the one or more outer tubes that coaxially surround the inner nanotube. At least two of the inner nanotubes and the one or more outer tubes are made of different materials.In one or more of the preceding and following embodiments, after the pellicle frame has been formed and before the one or more outer tubes have been formed, at least the nanotube layer is cut into a polygonal shape. In one or more of the preceding and following embodiments, each of the several coaxial tubes is selected from the group consisting of a carbon nanotube, a boron nitride nanotube, a transition metal dichalcogenide nanotube (TMD nanotube), where TMD is represented by MX2, where M is one or more of Mo, W, Pd, Pt, or Hf, and X is one or more of S, Se, or Te.In one or more of the preceding and following embodiments, the inner nanotube is selected from the group consisting of a carbon nanotube, a boron nitride nanotube, and a transition metal dichalcogenide nanotube (TMD nanotube), where TMD is represented by MX2, where M is one or more of Mo, W, Pd, Pt, or Hf, and X is one or more of S, Se, or Te. In one or more of the preceding and following embodiments, each of the one or more outer nanotubes is made of carbon, boron nitride, or a transition metal dichalcogenide (TMD), where TMD is represented by MX2, where M is one or more of Mo, W, Pd, Pt, or Hf, and X is one or more of S, Se, or Te.In one or more of the preceding and following embodiments, each of the multiple coaxial tubes comprises a total of three or four coaxial tubes, and at least three of the three or four coaxial tubes are made of different materials. In one or more of the preceding and following embodiments, the mesh membrane further comprises multiple single-walled nanotubes.

[0080] According to another aspect of the present disclosure, in a method for producing a pellicle for an extreme ultraviolet (EUV) reflecting mask, a nanotube layer containing several multi-walled nanotubes is formed, a pellicle frame is formed over the nanotube layer, and a first cover layer and a second cover layer are formed such that the nanotube layer is positioned between the first and second cover layers. The multi-walled nanotube contains an inner nanotube and one or more outer tubes, and at least one of the first and second cover layers contains a two-dimensional material in which one or more two-dimensional layers are stacked. In one or more of the preceding and following embodiments, the first cover layer contains a first two-dimensional material, and the second cover layer contains a second two-dimensional material.In one or more of the preceding and following embodiments, each of the first and second two-dimensional materials comprises at least one selected from the group consisting of boron nitride (BN), graphene, MoS₂, MoSe₂, WS₂, and WSe₂. In one or more of the preceding and following embodiments, the first two-dimensional material differs from the second two-dimensional material. In one or more of the preceding and following embodiments, the thickness of each of the first and second cover layers is in the range of 0.3 nm to 3 nm. In one or more of the preceding and following embodiments, the number of one or more two-dimensional layers of each of the first and second two-dimensional materials is from 1 to 20.In one or more of the preceding and following embodiments, a protective layer is formed over the first top layer, the second top layer, and a pellicle frame. In one or more of the preceding and following embodiments, the protective layer comprises at least one selected from the group consisting of HfO2, Al2O3, ZrO2, Y2O3, La2O3, B4C, YN, Si3N4, BN, NbN, RuNb, YF3, TiN, ZrN, Ru, Nb, Y, Sc, Ni, Mo, W, Pt, and Bi.

[0081] According to another aspect of the present disclosure, in a process for producing a pellicle for an extreme ultraviolet (EUV) reflecting mask, a nanotube layer containing multiple nanotubes and platelets made of one or more two-dimensional materials is formed over a support substrate, a pellicle frame is formed over the first cover layer, the nanotube layer is cut to form a cut pellicle membrane, and a first cover layer and a second cover layer are formed to encapsulate the cut pellicle membrane. In one or more of the preceding and following embodiments, the nanotube layer contains a network structure of multiple multi-walled coaxial nanotubes, and at least two of the multiple multi-walled coaxial nanotubes are made of different materials.In one or more of the preceding and following embodiments, each of the one or more two-dimensional materials comprises at least one selected from the group consisting of boron nitride (BN), graphene, MoS2, MoSe2, WS2, and WSe2. In one or more of the preceding and following embodiments, the size of each of the platelets is in the range of 10 nm. 2 up to 10 µm 2In one or more of the preceding and following embodiments, the thickness of each platelet is in the range of 0.3 nm to 3 nm. In one or more of the preceding and following embodiments, the number of one or more two-dimensional layers of each platelet is 1 to 20. In one or more of the preceding and following embodiments, each of the multiple multi-walled coaxial nanotubes is selected from the group consisting of a carbon nanotube, a boron nitride nanotube, and a transition metal dichalcogenide nanotube (TMD nanotube), where TMD is represented by MX2, where M is one or more of Mo, W, Pd, Pt, or Hf, and X is one or more of S, Se, or Te.

Claims

[1] Pellicle (10) for an EUV-reflective mask (5), comprising: a first layer (20), a second layer (30) and a main membrane (100) arranged between the first layer (20) and second layer (30), wherein: the main membrane (100) contains several coaxial nanotubes, each of which contains an inner tube (210) and two outer tubes (220, 230) surrounding the inner tube (210), and Each of the inner tube (210) and the two outer tubes (220, 230) is made of different materials and is selected from the group consisting of a carbon nanotube, a boron nitride nanotube, a TMD (transition metal dichalcogenide) nanotube, where TMD is represented by MX2, where M is one or more of Mo, W, Pd, Pt or Hf and X is one or more of S, Se or Te. [2] Pellicle (10) according to claim 1, wherein the inner tube (210) is a carbon nanotube. [3] Pellicle (10) according to one of the preceding claims, wherein the main membrane (100) further comprises several single-walled nanotubes (111). [4] Pellicle for an EUV-reflective mask, comprising: a first layer (20), a support frame (15) attached to the first layer (20), and a main membrane (100) arranged over the first layer (20), wherein the main membrane (100) contains several nanotubes, each of which contains an inner nanotube (210) and first to Nth outer layers (220, 230) coaxially surrounding the inner nanotube (210), where N is a natural number and exactly two; wherein three of the inner nanotubes (210) and the first to Nth outer layers (220, 230) are made of different materials. [5] Pellicle according to claim 4, wherein at least one of the first to Nth outer layers (220, 230) is a nanotube that coaxially surrounds the inner nanotube (210). [6] Pellicle according to claim 4 or 5, wherein two of the inner nanotube (210) and the first to Nth outer layers (220, 230) are made of different materials. [7] Pellicle according to any one of claims 4 to 6 above, wherein the inner nanotube (210) is selected from the group consisting of a carbon nanotube, a boron nitride nanotube, a TMD (transition metal dichalcogenide) nanotube, wherein TMD is represented by MX2, wherein M is one or more of Mo, W, Pd, Pt or Hf and X is one or more of S, Se or Te. [8] Pellicle according to claim 7, wherein each of the first to Nth outer layers (220, 230) is made of a carbon, boron nitride, TMD, wherein TMD is represented by MX2, where M is one or more of Mo, W, Pd, Pt or Hf and X is one or more of S, Se or Te. [9] Pellicle according to any one of claims 4 to 8 above, further comprising a protective layer (40), wherein a material of the protective layer (40) is the same as that of the N-th outer layer (220, 230). [10] Method for manufacturing a pellicle (10) for an EUV-reflective mask (5), comprising: Forming a nanotube layer (90) containing multiple nanotubes over a support substrate (80); Formation of a pellicle frame (15) over the nanotube layer (90); Detachment of the nanotube layer (90) from the support substrate (80); and Forming one or more outer tubes (220, 230) around each of the multiple nanotubes as an inner nanotube (210), thereby forming a network membrane (100) comprising multiple coaxial tubes (101, 210-230), each comprising the inner nanotube (210) and the one or more outer tubes (220, 230) that each coaxially surround the inner nanotube (210), wherein at least two of the inner nanotubes (210) and the one or more outer tubes (220, 230) are made of different materials. [11] Method according to claim 10, further comprising, after the pellicle frame (15) has been formed and before the one or more outer tubes (220, 230) have been formed, cutting at least the nanotube layer (90) into a polygonal shape. [12] Method according to claim 10 or 11, wherein each of the multiple coaxial tubes (101, 210-230) is selected from the group consisting of a carbon nanotube, a boron nitride nanotube, a TMD (transition metal dichalcogenide) nanotube, wherein TMD is represented by MX2, where M is one or more of Mo, W, Pd, Pt or Hf and X is one or more of S, Se or Te. [13] Method according to any one of the preceding claims 10 to 12, wherein the inner nanotube (210) is selected from the group consisting of a carbon nanotube, a boron nitride nanotube, a TMD nanotube, wherein TMD is represented by MX2, wherein M is one or more of Mo, W, Pd, Pt or Hf and X is one or more of S, Se or Te. [14] Method according to claim 13, wherein each of the one or more outer tubes (220, 230) is made of carbon, boron nitride, TMD, wherein TMD is represented by MX2, wherein M is one or more of Mo, W, Pd, Pt or Hf and X is one or more of S, Se or Te.

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