Method for manufacturing a graphene membrane pellicle for EUV exposure equipment

Abstract

Provided is a method for manufacturing a graphene membrane pellicle for EUV exposure equipment. Provided is a method for manufacturing a graphene membrane pellicle for EUV exposure equipment capable of manufacturing a pellicle for protecting a photomask of EUV exposure equipment using a catalyst metal film on which graphene is deposited. The graphene membrane pellicle obtained by the method for manufacturing a graphene membrane pellicle according to the present invention has an advantage in that the thickness can be adjusted because laminated graphene is used.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a graphene membrane pellicle for EUV exposure equipment. More specifically, it relates to a method for manufacturing a graphene membrane pellicle for EUV exposure equipment for manufacturing a pellicle for protecting a photomask of EUV exposure equipment by using a catalyst metal film on which graphene is deposited.

Background Art

[0002] Generally, graphene is a substance in which carbon atoms are connected to each other in a hexagonal form to form a two-dimensional planar structure in a honeycomb pattern. It has the characteristics of being very thin, transparent, and having very high electrical conductivity. Graphene is as thin as 0.2 nm and highly transparent, and can transmit a current more than 100 times that of copper and 100 times faster than silicon at room temperature. Moreover, graphene has a thermal conductivity more than twice that of diamond, which has the highest thermal conductivity.

[0003] Graphene can be produced by using the chemical vapor deposition (CVD) method. High-quality graphene is mass-produced by depositing process gas on a metal catalyst film supplied in a roll-to-roll manner.

[0004] Graphene is more than 200 times stronger in mechanical strength than steel, has good stretchability, and does not lose its electrical conductivity even when stretched or folded. Due to such excellent properties, it is a next-generation material that can be applied to flexible displays and transparent displays that are in the spotlight in future technologies, as well as wearable computers. Recently, there have been attempts to use graphene as a pellicle for protecting photomasks used in lithographic apparatuses. Fine circuit patterns are formed on photomasks, and the circuit patterns of the photomasks are formed on silicon through the lithographic apparatus. However, if fine dust adheres to the photomask due to air pollution, the shape of the fine dust will also be formed on the silicon, resulting in product defects.

[0005] In particular, extreme ultraviolet (EUV) lithographic apparatus is an apparatus that forms fine circuit patterns of several nanometers on a photomask and irradiates extreme ultraviolet light to form circuit patterns on a silicon substrate. By performing the exposure process with a light source having an extreme ultraviolet wavelength, not only can semiconductor circuit patterns be fabricated more densely, but also the number of processes can be reduced, productivity can be increased, and high-performance chips can be ensured.

[0006] As a result, with the development of EUV lithographic apparatus, the competition to develop pellicles for protecting photomasks and protecting them from air pollution to reduce defects in silicon substrates has also intensified.

[0007] A pellicle is a structure made of a thin film placed on a photomask. It prevents foreign matter from adhering to the photomask to protect the photomask and defocuses the image of the foreign matter, thereby preventing deformation of the circuit pattern caused by the image of the foreign matter appearing on the silicon substrate. The pellicles of existing projection optical exposure equipment are fixed and replaced at an appropriate time, and the process has proceeded efficiently through cost reduction by mask cleaning and replacement.

[0008] However, in the case of EUV exposure equipment, the wavelength of extreme ultraviolet light is short, and most of the light is absorbed by the existing organic pellicles, bringing various problems to the application of existing pellicles.

[0009] Therefore, certain prerequisite requirements are imposed on the pellicles for EUV exposure equipment. The requirements for EUV pellicles are: 1) a high transmittance of 90% or more, 2) mechanical safety, 3) minimization of thermal deformation, etc. Thus, EUV pellicles are required to have a thickness of 60 nm or less and a transmittance of 90% or more and mechanical safety. Membrane materials such as polysilicon, CNT, graphene, and silicon carbide (SiC) stand out among those that satisfy such conditions, and the number of applications related to related technologies is also increasing.

Summary of the Invention

Problems to be Solved by the Invention

[0010] In order to solve the above problems, the present invention aims to provide a method for manufacturing a graphene membrane pellicle for EUV exposure equipment that can be used in EUV exposure equipment by laminating and transferring a graphene film obtained through chemical vapor deposition onto a pellicle frame of the EUV exposure equipment.

Means for Solving the Problems

[0011] In order to achieve the above object, the present invention provides a method for manufacturing a graphene membrane pellicle for EUV exposure equipment, comprising: (a) a graphene deposition film in which graphene is deposited on a catalytic metal foil, transferring the graphene to a thermal separation tape and repeatedly laminating to form a laminated graphene to form a graphene laminated film forming step; (b) attaching the thermal separation tape of the graphene laminated film to a base film, thermally separating the thermal separation tape, and transferring the laminated graphene to the base film to form a graphene transfer film forming step; (c) applying a constant heat to the graphene transfer film to perform a heat treatment step for the laminated graphene to supplement the laminated graphene; (d) cutting the graphene transfer film on which the supplemented laminated graphene is formed to a constant size according to the standard of the pellicle frame to form a graphene transfer film cutting step; (e) removing the base film with the cut graphene transfer film to separate the supplemented laminated graphene and forming a graphene membrane to form a graphene membrane forming step; and (f) attaching the graphene membrane to a pellicle frame to form a graphene membrane attaching step. A method for manufacturing a graphene membrane pellicle for EUV exposure equipment is provided, characterized in that it is made up of these steps.

[0012] In step (a) of the present invention, it comprises: (a-1) attaching the graphene deposition surface of the graphene deposition film to the thermal separation tape; (a-2) putting the thermal separation tape with the graphene deposition film attached into an etching solution to remove the catalytic metal foil and transfer the graphene to the thermal separation tape; (a-3) washing the thermal separation tape on which the graphene is transferred; and (a-4) repeating steps (a-1) to (a-3) up to n times to form a laminated graphene laminated n times on the thermal separation tape. The graphene laminated film formed by the thermal separation tape on which the laminated graphene is formed is formed, which is characterized in that. In the present invention, n times is performed 2 to 100 times, and the thickness of the laminated graphene is 5 to 100 nm, which is characterized in that.

[0013] In step (a) of the present invention, there are further included: a step of attaching a capping material vapor deposition film, on which a capping material is vapor deposited, to the laminated graphene surface of the graphene laminated film; a step of putting the graphene laminated film with the capping material vapor deposition film attached thereto into an etching solution to remove the catalyst metal foil and form a capping layer on the surface of the laminated graphene; and a step of washing the graphene laminated film with the capping formed thereon.

[0014] In step (c) of the present invention, there are a residue treatment step of heating at a constant temperature to remove the residue of the thermal separation tape remaining on the laminated graphene of the graphene transfer film, and a laminated graphene complementing step of enlarging the graphene crystal size of the graphene transfer film with the residue treated or further vapor depositing graphene.

[0015] In step (c) of the present invention, there is further included a capping layer forming step of vapor depositing a capping material on the laminated graphene surface of the complemented graphene transfer film to form a capping layer. The base film in the present invention is made of Cu or Ni.

[0016] In step (f) of the present invention, there are: a step of preparing the pellicle frame so that the graphene membrane can be attached; a step of horizontally putting the graphene membrane on the surface of a water tank filled with an aqueous solution; a step of vertically putting the pellicle frame into the aqueous solution; and a step of attaching the graphene membrane from the upper part to the lower part of the membrane attachment surface of the pellicle frame while vertically lifting the pellicle frame put into the aqueous solution.

[0017] In the present invention, the pellicle frame includes a frame body formed with a front surface and a rear surface in a flat plate form, a through hole formed in the central portion of the frame body, and an inclined surface portion formed on the front surface of the frame body around the through hole, wherein the angle formed between the inclined surface portion and the rear surface of the frame body is an acute angle. In the present invention, the graphene membrane is characterized in that it is attached to the inclined surface portion or the rear surface of the front surface of the frame body so as to cover the through hole.

[0018] In the present invention, the pellicle frame includes a frame body formed with a front surface and a rear surface in a flat plate form, a through hole formed in the central portion of the frame body, a front inclined surface portion formed on the front surface of the frame body around the through hole, and a rear inclined surface portion formed on the rear surface of the frame body around the through hole.

[0019] In the present invention, the front inclined surface portion includes an upper front inclined surface portion, a lower front inclined surface portion formed at a certain length away from the upper front inclined surface portion, and side inclined surface portions formed by connecting both sides of the upper inclined surface portion and the lower inclined surface portion to each other to form an inclined surface, and is formed on the front surface of the frame. The angle formed between the front inclined surface portion and the front surface of the frame body is an acute angle. The graphene membrane is characterized in that it is attached to the front inclined surface portion so as to cover the through hole.

[0020] In the present invention, the rear inclined surface portion includes an upper rear inclined surface portion, a lower rear inclined surface portion formed at a certain length away from the upper rear inclined surface portion, and rear side inclined surface portions formed by connecting both sides of the upper rear inclined surface portion and the lower rear inclined surface portion to each other to form an inclined surface, and is formed around the through hole on the rear surface of the frame body. The angle formed between the rear inclined surface portion and the rear surface of the frame body is an acute angle. The graphene membrane is characterized in that it is attached to the rear inclined surface portion of the frame body so as to cover the through hole. In the present invention, the graphene membrane is characterized in that the extreme ultraviolet transmittance at a wavelength of 13.5 nm is 92 to 96%.

Advantages of the Invention

[0021] The graphene membrane pellicle for EUV exposure equipment according to the present invention can manufacture a graphene membrane with adjustable thickness because laminated graphene is used. In addition, the graphene membrane pellicle for EUV exposure equipment according to the present invention has the advantage of being able to compensate for defects generated during the lamination process.

[0022] In addition, the graphene membrane pellicle for EUV exposure equipment according to the present invention has the advantage that since the graphene membrane can be attached to both sides of the pellicle frame, the thickness of the laminated graphene can be further reduced, and the cost and labor force due to graphene lamination can be saved.

[0023] In addition, the graphene membrane pellicle for EUV exposure equipment according to the present invention has the advantage that since the thickness of the graphene can be adjusted, it can be adjusted to a transmittance suitable for EUV exposure equipment.

[0024] In addition, the graphene membrane pellicle for EUV exposure equipment according to the present invention has the advantage that the defect rate of the product can be minimized in the photomask process because the mechanical strength of the graphene membrane is appropriate and the transmittance can also be increased.

[0025] In addition, the graphene membrane pellicle for EUV exposure equipment according to the present invention has the advantage that even when the graphene membrane is ruptured, there is almost no possibility of damage to the exposure equipment due to fragments due to the characteristics of the graphene membrane.

Brief Description of the Drawings

[0026]

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Mode for Carrying Out the Invention

[0027] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, this is for the purpose of explaining in detail to such an extent that those having ordinary knowledge in the technical field to which the present invention pertains can easily implement the invention, and it does not mean that the technical idea and scope of the present invention are limited thereby.

[0028] FIG. 1 is a flowchart of a method for manufacturing a graphene membrane pellicle for EUV exposure equipment according to the present invention. As shown in the drawings, the method for manufacturing a graphene membrane pellicle according to the present invention includes: (a) a graphene deposition film in which graphene is deposited on a catalytic metal foil, transferring the graphene to a thermal separation tape and repeatedly laminating to form a laminated graphene, a graphene laminated film forming step (S1); (b) attaching the thermal separation tape of the graphene laminated film to a base film, thermally separating the thermal separation tape, and transferring the laminated graphene to the base film, a graphene transfer film forming step (S2); (c) applying a constant heat to the graphene transfer film to perform a heat treatment on the laminated graphene for supplementing the laminated graphene, a laminated graphene heat treatment step (S3); (d) cutting the graphene transfer film on which the supplemented laminated graphene is formed into a certain size according to the standard of the pellicle frame, a graphene transfer film cutting step (S4); (e) removing the base film with the cut graphene transfer film to separate the supplemented laminated graphene and forming a graphene membrane, a graphene membrane forming step (S5); and (f) attaching the graphene membrane to a pellicle frame, a graphene membrane attaching step (S6). Hereinafter, each step will be described in detail with reference to the drawings.

[0029] First, in a graphene deposition film 120 where graphene 122 is deposited on a catalyst metal foil 121, a graphene lamination film forming step (S1) is performed in which the graphene 122 is transferred to a thermal separation tape 110 and repeatedly laminated to form a laminated graphene 122'. FIG. 2 is a drawing of the graphene lamination apparatus 1, and FIG. 4(a) shows the configuration of the graphene deposition film 120. As shown in FIG. 4, the graphene deposition film 120 is composed of graphene 122 and a catalyst metal foil 121 on which the graphene 122 is deposited. The graphene lamination film forming step includes, in detail, a step S11 of attaching the thermal separation tape 110 to the graphene deposition surface of the catalyst metal foil 121 on which the graphene 122 is deposited, a step S12 of removing the catalyst metal foil 121 by etching with the graphene deposition film 120 attached to the thermal separation tape 110 to transfer and laminate the graphene 122 to the thermal separation tape 110, a step S13 of washing the thermal separation tape 110 from which the catalyst metal foil 121 has been removed, and a step S14 of repeating the attachment step (S11) to the washing step (S13) n times. The graphene 122 is deposited on the catalyst metal foil 121 by chemical vapor deposition (CVD: Chemical Vapor Deposition). With reference to the graphene lamination apparatus 1 in FIG. 2, the step of laminating the graphene 122 with the thermal separation tape 110 will be specifically described in detail. The graphene deposition film 120 is supplied in a state of being wound around a roll, and in FIG. 2, the graphene deposition film 120 is supplied through a graphene deposition film supply roller 12. The graphene deposition surface of the graphene deposition film 120 supplied by the graphene deposition film supply roller 12 is attached to the thermal separation tape 110 supplied by the thermal separation tape supply roller 11. The graphene deposition film 120 attached to the thermal separation tape 110 is continuously laminated while being rotated by drive rollers 21 and 23.

[0030] The lamination process first involves attaching to the thermal separation tape 110, where the catalytic metal foil 121 is etched at the etching section 30, and thereby the graphene 122 is transferred to the thermal separation tape 110. Such a process is continuously repeated n times until the desired thickness is reached for lamination. That is, the process of attaching the graphene deposition surface of the graphene deposition film 120 to the graphene lamination surface of the thermal separation tape 110 and removing the catalytic metal foil 121 by etching is repeated, and the graphene 122 is transferred and laminated onto the thermal separation tape 110 to form the laminated graphene 122' with graphene laminated n times. n is the number of times continuously repeated and laminated until the lamination thickness of the graphene reaches the desired thickness. The laminated graphene 122' laminated up to n times on the thermal separation tape 110 can be adjusted with high precision so that, due to being a fine thin film, the lamination thickness can be adjusted to a constant thickness by adjusting the lamination times. The laminated graphene 122' transferred and laminated n times and the thermal separation tape 110 form the graphene lamination film 100. After the laminated graphene 122' is formed, a step for forming a capping layer on the laminated graphene can further be included. The step of forming the capping layer includes the step (S15) of attaching the capping material deposition film 120' with the capping material 123 deposited on the catalytic metal foil 121 to the surface of the laminated graphene 122' of the graphene lamination film 100, the step (S16) of putting the graphene lamination film 100 with the capping material deposition film 120' attached into an etching solution to remove the catalytic metal foil 121 and transfer and laminate the capping layer 123 onto the surface of the laminated graphene 122', and the step (S17) of washing the graphene lamination film with the capping layer 123 formed can further be included. The capping material deposition film 120' is made of the catalytic metal foil 121 and the capping layer 123 deposited with the capping material as shown in FIG. 4(b). Since the capping layer 123 must be transferred and laminated onto the laminated graphene 122', the catalytic metal foil 121 is removed through etching and the capping layer 123 is transferred and laminated onto the laminated graphene 122'.Examples of the capping material include nano-graphite, carbon nano sheet, carbon nano tube, SiC (silicone carbide), B4C (boron carbide), and the like.

[0031] The graphene laminated film 100 with the lamination of graphene completed up to the n-th order is cut by the cutter 27, and the cut graphene laminated film 100 is wound around the winding roller 60. When the winding of the graphene laminated film 100 around the winding roller 60 is completed, the winding roller 60 is removed from the graphene laminating apparatus 1. The n-th order, which is the number of times graphene is laminated, can be made 2 to 100 times. The thickness of the laminated graphene 122' laminated at the n-th order can be formed to be 5 to 100 nm.

[0032] Next, the thermal separation tape 110 of the graphene laminated film 100 is attached to the base film 130 to thermally separate the thermal separation tape 110, and a graphene transfer film forming step (S2) is performed to transfer the laminated graphene 122' to the base film 130. When a certain amount of heat is applied to the thermal separation tape 110, it is separated from the laminated graphene 122'. Therefore, a certain amount of heat is applied to remove the thermal separation tape 110, and the laminated graphene 122' is transferred to the base film 130 to form a graphene transfer film 100'. FIG. 5 shows a thermal transfer device 90 that removes the thermal separation tape 110 from the graphene laminated film 100 and transfers the laminated graphene 122' to the base film 130. While passing the graphene laminated film 100 and the base film 130 through the heating rollers 92 and 93, the thermal separation tape 110 and the laminated graphene 122' are separated from each other, and the laminated graphene 122' is transferred to the base film 130 to form a graphene transfer film 100'. FIG. 6a(a) is the graphene laminated film 100 before the laminated graphene 122' is transferred, and FIG. 6a(b) is the graphene transfer film 100' after the laminated graphene 122' is transferred to the base film 130. As shown in FIG. 6a, the laminated graphene 122' is transferred from the graphene laminated film 100 to the graphene transfer film 100' through thermal transfer.

[0033] Here, for the catalyst metal foil and the base film used, a metal foil made of Cu or Ni can be used. FIG. 6b(a) is the graphene laminated film 100a in which the capping layer 123 is transferred to the laminated graphene 122', and FIG. 6b(b) is the graphene transfer film 100a' formed by transferring the capping layer 123 to the laminated graphene 122' and then to the base film 130. FIG. 6b is the same as FIG. 6a except for the capping layer 123. Therefore, the laminated graphene 122' and the capping layer 123 are thermally transferred to the base film 130 by the thermal separation tape 110. Thereby, it is thermally transferred from the graphene laminated film 100a to the base film to form a graphene transfer film 100a'.

[0034] Next, a stacked graphene heat treatment step (S3) is performed in which a constant heat is applied to the graphene transfer film 100' to post-heat treat the stacked graphene 122'. The heat treatment step (S3) includes a residue treatment step (S31) of heating at a constant temperature to remove the residue of the thermal separation tape 110 remaining on the stacked graphene 122' of the graphene transfer film 100', and a stacked graphene complementing step (S32) of enlarging the graphene crystal size of the stacked graphene 122' or further depositing graphene to complement the graphene defects of the stacked graphene 122' of the graphene transfer film 100'. Each step will be specifically described. First, a step of removing the residue of the thermal separation tape remaining on the upper surface of the stacked graphene 122' transferred to the base film 130 is performed. Organic substances of the thermal separation tape 110 can remain on the thermal separation tape adhesion surface of the graphene transfer film 100'.

[0035] Since the residue of such a thermal separation tape is an organic substance, it is desirable to remove it beforehand because it can cause damage to graphene even when used in a graphene membrane without removing the organic substance. Accordingly, the graphene transfer film 100' is heat-treated at a temperature of 300 to 400 °C to burn and remove the organic substances remaining on the adhesion surface of the thermal separation tape. Next, a step of complementing the laminated graphene 122' is performed by expanding the graphene crystals or further depositing graphene to complement the defects of the laminated graphene 122'. The graphene transfer film 100' is introduced into a graphene deposition apparatus (not shown) to complement the laminated graphene 122'. The graphene deposition and the expansion of the graphene crystals are performed in a deposition chamber of the graphene deposition apparatus into which deposition gases (such as CH4, C2H6, and H2) are introduced, and the defects of the laminated graphene 122' can be complemented through the graphene deposition and the expansion of the graphene crystals. Fig. 7a(a) shows a state in which the graphene transfer film 100' is heat-treated to remove the organic substances remaining on the adhesion surface of the thermal separation tape, and Fig. 7a(b) shows the graphene transfer film 100" having the laminated graphene 122" complemented after the deposition and complementation steps of the laminated graphene 122' are completed. Accordingly, the graphene transfer film 100" is made of the base film 130 and the complemented laminated graphene 122". Further, Fig. 7b(a) shows the graphene transfer film 100a' before heat treatment in which the base film 130 is attached to the capping layer 123 and the laminated graphene 122', and Fig. 7b(b) shows the graphene transfer film 100a" after the laminated graphene 122" is complemented by heat treatment. In the case of Fig. 7a, the capping layer 123 can also be formed by depositing the capping layer 123 in the deposition chamber on the complemented laminated graphene 122" after the heat treatment is completed. Examples of the capping substance include nano-graphite, carbon nano sheet, carbon nano tube, SiC (silicone carbide), and B4C (boron carbide).

[0036] Next, a graphene transfer film cutting step (S4) is performed in which the graphene transfer film 100" on which the complemented laminated graphene 122" is formed is cut to a fixed size according to the standard of the pellicle frame 300. Since the laminated graphene 122" complemented by heat treatment is in a state where it can be used in the graphene membrane 200, the graphene transfer film 100" is cut to a size that fits the pellicle frame 300. Since the pellicle frame 300 is usually in a rectangular form, it can be cut in a rectangular form.

[0037] Next, a graphene membrane forming step (S5) is performed in which the base film 130 is removed from the cut graphene transfer film 100" to separate the complemented laminated graphene 122", and the graphene membrane 200 is formed. When a fixed graphene transfer film 100" is cut, the base film 130 made of a metal material of the graphene transfer film 100" is removed by etching, and only the complemented laminated graphene 122" remains to form the graphene membrane 200. The cut graphene transfer film 100" is put into a water tank into which an etching solution is introduced, and the base film 130 made of a metal material is removed with the etching solution. When the base film 130 is removed with the etching solution, only the complemented laminated graphene 122" layer remains. The complemented laminated graphene 122’ is used for the graphene membrane 200. FIG. 8 shows the graphene membrane 200. The graphene membrane 200 can have a thickness in the range of 10 to 100 nm and an extreme ultraviolet transmittance of 92 to 96% at a wavelength of 13.5 nm. The graphene membrane 200 can further include a capping layer 210.

[0038] Next, the graphene membrane attachment step of attaching the graphene membrane 200 to the pellicle frame 300 is performed (via S6). FIG. 9 shows that the graphene membrane 200 is attached to the pellicle frame 300, and FIGS. 10 and 11 show the step of attaching the graphene membrane 200 to the pellicle frames 300, 300', 300", 300"'. FIG. 10 shows the process of attaching the graphene membrane 200 to one side of the pellicle frames 300, 300', and FIG. 11 shows the process of attaching the graphene membrane 200 to both sides of the pellicle frames 300", 300"'. FIG. 12 shows the pellicle frames 300, 300' of the first and second embodiments, and FIG. 13 shows the pellicle frames 300", 300" of the third and fourth embodiments. FIGS. 14 to 16 show the graphene membrane 200 attached to each of the pellicle frame embodiments 300, 300', 300", 300"'. FIGS. 17 to 18 show that the inclined end forms an acute angle (θ). Hereinafter, the process of attaching the graphene membrane to the pellicle frame will be described with reference to FIGS. 10 to 18. First, prepare the pellicle frame so that the graphene membrane can be attached (S61). Prepare the pellicle frame in the form as shown in FIGS. 12 and 13.

[0039] As shown in Fig. 12(a), the pellicle frame 300 of the first embodiment is composed of a frame body 301 having a flat front surface and a rear surface, an inclined surface portion 302 formed at the center of the front surface of the frame body 301, and a through hole 303 formed on the front surface of the frame body 301. The inclined surface portion 302 is composed of an upper inclined surface portion 3021, a lower inclined surface portion 3022 formed at a certain length away from the upper inclined surface portion 3021, and side inclined surface portions 3023 formed by connecting both sides of the upper inclined surface portion 3021 and the lower inclined surface portion 3022 to each other. As shown in the drawing, the inclined surface is formed by a straight line. Also, the pellicle frame 300' of the second embodiment in Fig. 12(b) is also composed of a frame body 301 having a flat front surface and a rear surface, an inclined surface portion 302' formed at the center of the front surface of the frame body 301, and a through hole 303 formed on the front surface of the frame body 301. The second embodiment 300' has differences from the first embodiment 300 in the inclined surface portion 302'. In the second embodiment, the inclined surface portion 302' of the pellicle frame 300' is composed of an upper inclined surface portion 3021', a lower inclined surface portion 3022' formed at a certain distance away from the upper inclined surface portion 3021', and side inclined surface portions 3023' that connect the upper inclined surface portion 3021' and the lower inclined surface portion 3022' to each other on both sides. Since each inclined surface is formed by a curve, a cut curve may not be formed at the portion where the upper inclined surface portion 3021' and the lower inclined surface portion 3022' meet the side inclined surface portion 3023'. Accordingly, when the graphene membrane 200 is attached, a cut curve may not be formed at the portion where the inclined surface portions meet. As shown in Fig. 17, the angles (θ) of the corners 3024, 3024' where the front inclined surface portions 302, 302' and the rear surface 3012 meet are formed to have acute angles. The reason for forming the angle (θ) formed by the inclined surface portion and the rear surface to have an acute angle is to allow the solution not to be trapped at the ends 3024, 3024' of the inclined surface while the graphene membrane 200 adheres to the inclined surface and to fall to the lower side by the load, or to prevent the water droplets from smoldering by forming the ends of the inclined surface portion sharply.When the end of the inclined surface is not formed at an acute angle, a water droplet can smolder at the end where the front inclined surface portion 302 and the rear surface 3012 meet. When the water droplet smolders, it is to prevent damage caused by the surface tension of water lifting the graphene membrane 200. The acute angle can be made 45° or less.

[0040] Figures 13(a) and 13(b) show the third embodiment 300" and the fourth embodiment 300"‘ of the pellicle frame. The pellicle frame 300" in Figure 13(a) is composed of a frame body 301 formed with a flat front surface and a rear surface, a through hole 303 formed in the central portion of the frame body, a front inclined surface portion 302a" formed on the front surface of the frame body 301 around the through hole 303, and a rear inclined surface portion 302b" formed on the rear surface of the frame body 301 around the through hole 303. Further, the front inclined surface portion 302a" is composed of a front upper inclined surface portion 3021a", a front lower inclined surface portion 3022a" formed at a certain length separation from the front upper inclined surface portion 3021a", and side inclined surface portions 3023a" formed by connecting both sides of the front upper inclined surface portion 3021a" and the front lower inclined surface portion 3022a" to each other.

[0041] Also, the rear inclined surface portion 302b" is equal to the front inclined surface portion 302a", but the rear inclined surface portion 302b" is composed of an upper rear inclined surface portion 3021b", a lower rear inclined surface portion 3022b" formed at a certain length away from the upper rear inclined surface portion 3021b", and side inclined surface portions 3023b" formed by connecting both sides of the upper rear inclined surface portion 3021b" and the lower rear inclined surface portion 3022b" to each other. In the pellicle frame 300" of the third embodiment, all the front inclined surfaces and rear inclined surfaces are formed as straight lines. The pellicle frame 300"" of the fourth embodiment in Fig. 13(b) also has the same configuration as the pellicle frame 300" of the third embodiment, but has a difference in that the inclined surfaces are formed as curves. Specifically, the front inclined surface portion 302a"" is composed of an upper front inclined surface portion 3021a"", a lower front inclined surface portion 3022a"" formed at a certain distance away from the upper front inclined surface portion 3021a"", and front side inclined surface portions 3023a"" that connect the upper front inclined surface portion 3021a"" and the lower front inclined surface portion 3022a"" to each other on both sides. Also, the rear inclined surface portion 302b"" has a configuration corresponding to the front inclined surface portion 302a"", and thereby is composed of an upper rear inclined surface portion 3021b"", a lower rear inclined surface portion 3022b"" formed at a certain distance away from the upper rear inclined surface portion 3021b"", and rear side inclined surface portions 3023b"" that connect the upper rear inclined surface portion 3021b"" and the lower rear inclined surface portion 3022b"" to each other on both sides. Due to being formed as curves, there may be no cut curve formed at the portion where the upper front inclined surface portion 3021a"" and the lower front inclined surface portion 3022a"" meet the front side inclined surface portion 3023a"", and the same applies to the rear inclined surface portion 302b"". As shown in Fig. 18, the end portions 3024", 3024"" where the inclined surfaces meet are formed at an acute angle (θ) equal to those in the embodiment where the inclined surfaces are formed as straight lines and the embodiment where the inclined surfaces are formed as curves, so that the end portions can be formed sharply. The fact that the end portions 3024", 3024"" of the inclined surfaces form an acute angle is to prevent the moiré from fading at the end portions of the inclined surfaces.

[0042] Next, as shown in FIGS. 10 and 11, the graphene membrane 200 is horizontally floated on the surface of a water tank 300 filled with an aqueous solution 311. If the graphene membrane 200 is horizontally floated on the aqueous solution 311, the graphene membrane 200 will be maintained in a floating state above the aqueous solution 311. A doping solution can be further introduced into the aqueous solution.

[0043] Next, as shown in FIGS. 10 and 11, the pericle frames 300, 300', 300", 300''' are vertically inserted into the aqueous solution 401. The procedure of inserting the pericle frame into the aqueous solution and floating the graphene membrane on the aqueous solution can be either inserting the graphene membrane first and then vertically inserting the pericle frame, or vertically inserting the pericle frame first and then inserting the graphene membrane into the aqueous solution. It is clarified that such a change in procedure is obvious to those with ordinary knowledge in the technical field to which the present invention pertains.

[0044] Next, while vertically lifting the pericle frames 300, 300', 300", 300''' inserted into the aqueous solution, the graphene membrane 200 is attached from the upper part to the lower part of the membrane attachment surface of the pericle frame. While the pericle frames 300, 300', 300", 300''' are lifted from the upper part to the lower part, the graphene membrane 200 is attached to the pericle frame and, when dried, the production of the pericles 2, 2' is completed.

[0045] FIG. 14 illustrates that the graphene membrane 200 is attached to the rear surface 3012 of the frame body 301 of the first embodiment 300 and the second embodiment 300' of the perimeter frame (FIGS. 14(a) and 14(b)), and FIG. 14(c) shows that the graphene membrane 200 with the capping layer 210 formed on the surface is attached to the frame body 301. FIG. 15 illustrates that the graphene membrane 200 is attached to the inclined surface portions 302 and 302' of the frame body 301 of the first embodiment 300 and the second embodiment 300' of the perimeter frame (FIGS. 15(a) and 15(b)), and FIG. 15(c) shows that the capping layer 210 is formed on the surface of the graphene membrane 200. Since the ends 3024 and 3024' sides of the inclined surface portions are formed at acute angles, the ends are sharp. Accordingly, it is considered that it is almost impossible for water droplets of the aqueous solution to smolder at the ends of the inclined surface portions.

[0046] FIG. 16 shows that the graphene membrane 200 is attached to the third embodiment 300" and the fourth embodiment 300"‘ of the pellicle frame. FIG. 16(a) shows that the graphene membrane 200 is attached to the pellicle frame of the third embodiment 300", and FIG. 16(b) shows that the graphene membrane 200 is attached to the pellicle frame of the fourth embodiment 300"‘. FIG. 16(c) shows that the graphene membrane 200 is attached to the pellicle frame of the third embodiment 300", and a capping layer 210 (210a, 210b) is formed on the surface of the graphene membrane 200. In FIG. 16, the graphene membrane 200 is illustrated as being attached to both sides, but it can also be attached to the front inclined surface portion 302a", 302a"‘ or the rear inclined surface portion 302b", 302b"‘, or all to the front inclined surface portion and the rear inclined surface portion. When attached to both sides of the front inclined surface portion 302a", 302a"‘ and the rear inclined surface portion 302b", 302b"‘, the thickness of the graphene membrane 200 can be doubled, which has the advantage of reducing the graphene stacking process. That is, if the thickness of the graphene membrane 200 is 10 nm, a 5-nm graphene membrane can be attached to both sides, so that the graphene stacking process can be reduced, and thereby cost savings and labor savings can be achieved. Further, when the graphene membrane 200 with the capping layer 210 formed is attached to both sides of the frame body 301, the graphene membrane 200 can be firmly protected by the capping layer 210.

[0047] Figure 2 is a structural diagram of the graphene laminating apparatus 1. As shown in the drawing, the graphene laminating apparatus 1 includes a supply roller section 10 formed by a thermal separation tape supply roller 11 and a catalyst metal foil supply roller 12 on which graphene is laminated, a circulation section 20 that circulates a thermal separation tape on which graphene is transferred and laminated a certain number of times continuously, an etching section 30 for etching the catalyst metal foil during the circulation process, a washing section 40 for washing the graphene laminated film 100 etched by the etching section 30, a drying section 50 for drying the washed graphene laminated film 100, and a winding roller 60 for winding up the laminated graphene 122’ and the thermal separation tape 110 after the lamination is completed.

[0048] Referring to FIGS. 2 to 4 and examining the operation process of the graphene laminating apparatus 1 in detail, first, the thermal separation tape 110 is supplied from the thermal separation tape supply roller 11 so that the thermal separation tape 110 can be circulated. The circulation of the thermal separation tape 110 is carried out by the primary drive rollers 21 (21a, 21b), the driven rollers 22, and the secondary drive rollers 23 (23a, 23b) so as to rotate continuously. Once the thermal separation tape 110 starts to rotate, on the primary drive roller 21 side, graphene 122 and the catalyst metal foil 121 on which graphene 122 is deposited, which form the graphene deposition film 120, are supplied and adhered to the thermal separation tape 110. The graphene deposition film 120 adhered to the thermal separation tape 110 rotates together with the thermal separation tape 110, and the graphene on the outer side can be removed by a scraper 24 because the graphene 122 on the inner surface where the graphene deposition film 120 is adhered to the thermal separation tape 110 is transferred to the thermal separation tape 110. Further, a tension roller 25 can be provided so that the thermal separation tape 110 can be circulated while maintaining a constant tension. After the thermal separation tape 110 is adhered, the graphene deposition film 120 is first fed into the etching section 30 while rotating, and the catalyst metal foil 121 of the graphene deposition film 120 is removed by etching. The etching section 30 can be composed of one or more etching sections, and can also be composed of a first etching section 30a and a second etching section 30b for complete removal of the catalyst metal foil by etching. As shown in the drawing, the etching section 30 is composed of a water tank 31 and an etching solution 32. Since the thermal separation tape 110 is immersed in the etching solution 32 of the etching section 30, washing is necessary. Therefore, washing water is sprayed by the washing section 40 to wash the thermal separation tape 110, and the washed thermal separation tape 110 is dried by hot air in the drying section 50.The dried thermal separation tape 110 is advanced by the secondary drive roller 23. The sensor unit 26 senses the rotation speed of the target element 112 to determine the n-th layer stacking condition and sends a signal to a controller (not shown). The controller that receives the signal transmission from the sensor unit 26 drives the cutter 27 to cut the graphene stacked film 100. The cut graphene stacked film 100 is wound onto the winding roller 60.

[0049] Once the graphene stacked film 100 is wound onto the winding roller 60, the graphene stacked film 100 is fed into the thermal transfer stage. Figure 5 shows the stage where the stacked graphene 122’ is thermally transferred from the graphene stacked film 100 to the base film 130. The thermal transfer is composed of a supply unit 70, a thermal transfer unit 90, and a winding unit 80. The supply unit 70 consists of a graphene transfer film supply roller 71 and a base film supply roller 72 for supplying the base film 130. The thermal transfer unit 90 consists of a chamber 91, an inlet thermal transfer roller 92 and an outlet thermal transfer roller 93 mounted in the chamber 91. The winding unit 80 consists of a thermal separation tape winding roller 81 and a base film winding roller 82 onto which the stacked graphene 122’ is transferred. The graphene stacked film 100 is supplied through the thermal separation tape supply roller 71, and the base film 130 is supplied through the base film supply roller 72. While passing through the thermal transfer rollers 92 and 93 of the thermal transfer unit 90, the stacked graphene 122’ is transferred onto the base film 130 to form the graphene transfer film 100’. Figures 6a and 6b show that the stacked graphene 122’ has been transferred from the thermal separation tape 110 to the base film 130. Figures 7a and 7b show the graphene transfer film 100’ after heat treatment to become the completed graphene transfer film 100"). Figure 9 shows the pellicle 2 formed by attaching the graphene membrane 200 to the pellicle frame 300.

[0050] It is self-evident to those with ordinary knowledge in the technical field to which the present invention pertains that the present invention can be implemented with various modifications and deformations within the scope not departing from the technical gist of the present invention without being limited to the above-described embodiments.

Industrial Applicability

[0051] The present invention relates to a method for manufacturing a graphene membrane pellicle for EUV exposure equipment. The present invention is an invention with high industrial applicability for a pellicle used for pattern formation using EUV exposure equipment, which is one process of the semiconductor manufacturing process.

Claims

1. In a method for manufacturing a graphene membrane pellicle for EUV exposure equipment, (a) a graphene lamination film forming step of forming a laminated graphene by transferring the graphene to a thermal separation tape and repeatedly laminating it using a graphene vapor deposition film in which graphene is vapor deposited on a catalyst metal foil; (b) a graphene transfer film forming step of attaching the thermal separation tape of the graphene lamination film to a base film, thermally separating the thermal separation tape, and transferring the laminated graphene to the base film; (c) a laminated graphene heat treatment step of applying a constant heat to the graphene transfer film to supplement the laminated graphene; (d) a graphene transfer film cutting step of cutting the graphene transfer film on which the supplemented laminated graphene is formed to a constant size according to the standard of the pellicle frame; (e) a graphene membrane forming step of removing the base film with the cut graphene transfer film to separate the supplemented laminated graphene and forming a graphene membrane; (f) a graphene membrane attaching step of attaching the graphene membrane to a pellicle frame, characterized in that it is made by the method for manufacturing a graphene membrane pellicle for EUV exposure equipment.

2. The step (a) is (a-1) a step of attaching the graphene vapor deposition surface of the graphene vapor deposition film to the thermal separation tape; (a-2) a step of putting the thermal separation tape to which the graphene vapor deposition film is attached into an etching solution to remove the catalyst metal foil and transfer the graphene to the thermal separation tape; (a-3) a step of washing the thermal separation tape to which the graphene is transferred; (a-4) a step of repeating the steps (a-1) to (a-3) up to n times to form a laminated graphene in which the graphene is laminated n times on the thermal separation tape, and a graphene lamination film made of the thermal separation tape on which the laminated graphene is formed is formed. The method for manufacturing a graphene membrane pellicle for EUV exposure equipment according to Claim 1.

3. The n times is performed 2 to 100 times, and the thickness of the laminated graphene is 5 to 100 nm. The method for manufacturing a graphene membrane pellicle for EUV exposure equipment according to Claim 2.

4. The step (a) is (a-5) attaching a capping material vapor-deposited film in which a capping material is vapor-deposited on a catalyst metal foil to the laminated graphene surface of the graphene laminated film; (a-6) putting the graphene laminated film with the capping material vapor-deposited film attached thereto into an etching solution to remove the catalyst metal foil and form a capping layer on the surface of the laminated graphene; (a-7) washing the graphene laminated film with the capping layer formed thereon; is further included The method for manufacturing a graphene membrane pellicle for EUV exposure equipment according to claim 3.

5. The step (c) is (c-1) a residue treatment step of heating at a constant temperature to remove the residue of the thermal separation tape remaining on the laminated graphene of the graphene transfer film; (c-2) a laminated graphene complementing step of enlarging the graphene crystal size of the graphene transfer film with the residue treated or further vapor-depositing graphene. The method for manufacturing a graphene membrane pellicle for EUV exposure equipment according to claim 1.

6. The step (c) is (c-3) a capping layer forming step of vapor-depositing a capping material on the laminated graphene surface of the complemented graphene transfer film to form a capping layer, and is further included The method for manufacturing a graphene membrane pellicle for EUV exposure equipment according to claim 5.

7. The base film is made of Cu or Ni The method for laminating graphene for a pellicle of EUV exposure equipment according to claim 1.

8. The step (f) is (f-1) a step of preparing the pellicle frame so as to attach the graphene membrane; (f-2) a step of horizontally putting the graphene membrane on the surface of a water tank filled with an aqueous solution; (f-3) a step of vertically putting the pellicle frame into the aqueous solution; (f-4) a step of attaching the graphene membrane from the upper part to the lower part of the membrane attaching surface of the pellicle frame while vertically lifting the pellicle frame put into the aqueous solution. The method for manufacturing a graphene membrane pellicle for EUV exposure equipment according to claim 1.

9. The pellicle frame is A frame body formed by a front surface and a rear surface in a flat plate form, a through hole formed in a central portion of the frame body, and an inclined surface portion formed on the front surface of the frame body surrounding the through hole, The angle formed by the inclined surface portion and the rear surface of the frame body is formed as an acute angle The manufacturing method of the graphene membrane pellicle for EUV exposure equipment according to claim 8.

10. The graphene membrane is attached to the inclined surface portion or the rear surface of the front surface of the frame body so as to cover the through hole The manufacturing method of the graphene membrane pellicle for EUV exposure equipment according to claim 9.

11. The pellicle frame is A frame body formed by a front surface and a rear surface in a flat plate form, a through hole formed in a central portion of the frame body, a front inclined surface portion formed on the front surface of the frame body around the through hole, and a rear inclined surface portion formed on the rear surface of the frame body around the through hole The manufacturing method of the graphene membrane pellicle for EUV exposure equipment according to claim 8.

12. The front inclined surface portion is A front upper inclined surface portion, a front lower inclined surface portion formed at a certain length away from the front upper inclined surface portion, and side inclined surface portions formed by connecting both sides of the upper inclined surface portion and the lower inclined surface portion to each other to form an inclined surface, and is formed on the front surface of the frame, The angle formed by the front inclined surface portion and the front surface of the frame body is formed as an acute angle, The graphene membrane is attached to the front inclined surface portion so as to cover the through hole The manufacturing method of the graphene membrane pellicle for EUV exposure equipment according to claim 11.

13. The rear inclined surface portion is A rear upper inclined surface portion, a rear lower inclined surface portion formed at a certain length away from the rear upper inclined surface portion, and rear side inclined surface portions formed by connecting both sides of the rear upper inclined surface portion and the rear lower inclined surface portion to each other to form an inclined surface, and is formed on the rear surface of the frame body around the through hole, The angle formed by the rear inclined surface portion and the rear surface of the frame body is formed as an acute angle, The graphene membrane is attached to the rear inclined surface portion of the frame body so as to cover the through hole The manufacturing method of the graphene membrane pellicle for EUV exposure equipment according to claim 11.

14. The graphene membrane has an extreme ultraviolet transmittance of 92 to 96% at a wavelength of 13.5 nm The manufacturing method of the graphene membrane pellicle for EUV exposure equipment according to claim 1.

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