Pellicle frame, pellicle, pellicle-equipped exposure master, exposure method, and semiconductor manufacturing method

Abstract

To provide a pellicle employing a pellicle frame which, in performing EUV exposure under vacuum, is resistant to pressure changes from atmospheric pressure to vacuum and hardly causes breakage of a pellicle membrane, where the pellicle frame has good machinability and hardly causes breakage in separating the pellicle.SOLUTION: The invention provides a pellicle with a frame-shaped metal pellicle frame having two end faces, where at least one end face of the pellicle frame has a recess connected from an outer face to an inner face, and where the pellicle frame has 28 to 250 through holes with openings at least in the inner face. Also provided are a pellicle-attached exposure original plate, an exposure method and a method for manufacturing a semiconductor that employ the pellicle.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pellicle frame attached to a lithography photomask to protect against foreign matter, a pellicle, an exposure master with a pellicle, an exposure method, a semiconductor manufacturing method, and a liquid crystal display panel manufacturing method. [Background technology]

[0002] In recent years, LSI design rules have been miniaturized to the sub-quarter micron level, and as a result, the wavelength of exposure light sources has been shortened. That is, exposure light sources have shifted from g-line (436 nm) and i-line (365 nm) from mercury lamps to KrF excimer lasers (248 nm) and ArF excimer lasers (193 nm), and further, EUV (Extreme Ultra Violet) exposure using EUV light with a dominant wavelength of 13.5 nm is being considered.

[0003] In the manufacture of semiconductors such as LSIs and VLSIs, or liquid crystal display panels, patterns are created by irradiating light onto semiconductor wafers or liquid crystal masters. However, if foreign matter adheres to the lithography photomasks and reticles (hereinafter collectively referred to as "exposure masters") used in this process, the foreign matter can absorb or bend the light, causing deformation of the transferred pattern, rough edges, and black staining of the base, resulting in problems such as impaired dimensions, quality, and appearance.

[0004] These operations are usually performed in a clean room, but it is still difficult to keep the exposure master clean at all times. Therefore, a common method is to attach a pellicle to the surface of the exposure master to prevent foreign particles before exposure. In this case, foreign particles do not adhere directly to the surface of the exposure master, but rather to the pellicle. Therefore, if the focus is aligned on the pattern of the exposure master during lithography, the foreign particles on the pellicle will not affect the transfer.

[0005] The basic structure of this pellicle is a pellicle frame made of aluminum or titanium, with a pellicle film that is highly transmissive to the light used for exposure stretched over the upper surface, and an airtight gasket formed on the lower surface. The airtight gasket generally uses an adhesive layer, and a protective sheet is attached to protect this adhesive layer. The pellicle film is made of materials such as nitrocellulose, cellulose acetate, and fluorine-based polymers that allow good transmission of the light used for exposure (g-line (436 nm) from a mercury lamp, i-line (365 nm), KrF excimer laser (248 nm), ArF excimer laser (193 nm), etc.). However, for EUV exposure, ultrathin silicon and carbon films are being considered as pellicle films.

[0006] Furthermore, since EUV exposure is performed in a vacuum, the EUV pellicle must be able to withstand the pressure change from atmospheric pressure to vacuum, and therefore the EUV pellicle must have a large ventilation area.

[0007] Therefore, Patent Document 1 proposes a pellicle having a pellicle frame in which two opposing side surfaces of the pellicle frame are provided with vent holes, each with an open area ratio of 50 to 90% relative to the other side surface. However, what affects the pressure change inside and outside the pellicle is the vent area relative to the internal space volume of the pellicle, and it is insufficient to discuss this only in terms of the open area ratio of the pellicle frame.

[0008] In addition, in Patent Document 2, the total flow path area of ​​the through holes provided in the ceramic frame is less than 1 cm of the volume of the internal space of the pellicle. 3 0.005cm per 2 We have proposed a pellicle frame that meets the above criteria. However, because ceramic materials lack ductility, it has become clear that when a strong localized force is applied to the pellicle frame, such as when peeling the pellicle, the pellicle frame may break, resulting in the generation of foreign matter. While increasing the pellicle frame's strength is generally achieved by increasing its thickness, EUV pellicles are limited to a maximum height of 2.5 mm, making it difficult to prevent breakage by increasing the pellicle frame thickness. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-294786 [Patent Document 2] Japanese Patent Application Publication No. 2018-200380 Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention has been made in consideration of the above circumstances, and aims to provide a pellicle that can withstand the pressure change from atmospheric pressure to vacuum when EUV exposure is performed in a vacuum, making it less likely for the pellicle film to be damaged, and that uses a pellicle frame that has good processability and is less likely to be damaged when the pellicle is peeled off. [Means for solving the problem]

[0011] The inventors have developed a frame-shaped pellicle frame having an upper end surface on which a pellicle membrane is provided and a lower end surface facing a photomask, and a notch is provided from the outer surface of the end surface of the pellicle frame toward the inner surface, and the ventilation area at any of the inner surface, the outer surface, the pellicle internal space side, and the pellicle external space side is set to 1 mm2 of the volume of the pellicle internal space. 3 0.001mm per 2 It was discovered that by setting the above, damage to the pellicle membrane during pressure changes can be suppressed. Furthermore, while providing multiple vents requires fine processing of the pellicle frame, it was discovered that using a ductile metal as the material reduces losses due to pellicle frame breakage during processing and also reduces the risk of the pellicle frame being damaged when the pellicle is peeled off from the photomask, leading to the present invention.

[0012] Accordingly, the present invention provides the following pellicle frame, pellicle, pellicle-equipped exposure master, exposure method, semiconductor manufacturing method, and liquid crystal display panel manufacturing method. 1. A frame-shaped pellicle frame having an upper end surface on which a pellicle film is provided and a lower end surface facing a photomask, the pellicle frame being made of metal, and having an open notch on the upper end surface or the lower end surface extending from the outer surface to the inner surface, and the total ventilation area on the inner surface being within 1 mm of the volume of the internal space of the pellicle. 3 0.001mm per 2 A pellicle frame characterized by the above. 2. A frame-shaped pellicle frame having an upper end surface on which a pellicle film is provided and a lower end surface facing a photomask, the pellicle frame being made of metal, and having an open notch on the upper end surface or the lower end surface extending from the outer surface to the inner surface, and the total ventilation area on the inner space side of the pellicle being equal to or less than 1 mm of the volume of the inner space of the pellicle. 3 0.001mm per 2 A pellicle frame characterized by the above. 3. A frame-shaped pellicle frame having an upper end surface on which a pellicle film is provided and a lower end surface facing a photomask, the pellicle frame being made of metal, and having an open notch on the upper end surface or the lower end surface extending from the outer surface to the inner surface, and the total ventilation area on the outer surface being within 1 mm of the volume of the internal space of the pellicle. 3 0.001mm per 2 A pellicle frame characterized by the above. 4. A frame-shaped pellicle frame having an upper end surface on which a pellicle film is provided and a lower end surface facing a photomask, the pellicle frame being made of metal, and having an open notch on the upper end surface or the lower end surface from the outer surface to the inner surface, and the total ventilation area on the outer space side of the pellicle is 1 mm2 or less of the volume of the inner space of the pellicle. 3 0.001mm per 2 A pellicle frame characterized by the above. 5. The pellicle frame according to any one of the above 1 to 4, wherein a through-hole having an opening on at least the inner surface is provided. 6. A pellicle frame according to any one of 1 to 4 above, wherein the metal material of the pellicle frame is selected from the group consisting of titanium, titanium alloys, aluminum and aluminum alloys. 7. The total ventilation area is the volume of the internal space of the pellicle (1 mm). 3 0.02mm per 2 5. A pellicle frame according to any one of the above items 1 to 4. 8. A pellicle frame according to any one of 1 to 4 above, wherein the height of the cutout is 50% or less of the thickness of the pellicle frame. 9. The pellicle frame according to any one of 1 to 4 above, wherein the thickness of the pellicle frame is 2.5 mm or less. 10. A pellicle comprising the pellicle frame according to any one of 1 to 9 above, and a pellicle membrane attached to the upper end surface of the pellicle frame via a pressure-sensitive adhesive or adhesive. 11. The pellicle according to claim 10, which is used for exposure under vacuum or reduced pressure. 12. A pellicle according to 10 or 11 above, used for EUV exposure. 13. A pellicle according to claim 10 or 11, wherein the height of the pellicle is 2.5 mm or less. 14. A pellicle according to claim 10 or 11, wherein the pellicle membrane is supported by a frame. 15. An exposure master with a pellicle, characterized in that the pellicle described in 10 above is attached to the exposure master. 16. The exposure master with pellicle according to the above item 15, wherein the exposure master is an exposure master for EUV. 17. A pellicle-equipped exposure master according to the above item 15, which is a pellicle-equipped exposure master used in EUV lithography. 18. An exposure method comprising exposing using the exposure master with a pellicle according to 15 above. 19. A method for manufacturing a semiconductor, comprising the step of exposing a substrate under vacuum or reduced pressure using the pellicle-equipped exposure master described in 15 above. 20. A method for producing a liquid crystal display panel, comprising the step of exposing a substrate under vacuum or reduced pressure using the pellicle-equipped exposure master described in 15 above. 21. A method for manufacturing a semiconductor, comprising the step of exposing a substrate to EUV light using the pellicle-equipped exposure master described in 15 above. 22. A method for manufacturing a liquid crystal display panel, comprising the step of exposing a substrate to EUV light using the pellicle-equipped exposure master described in 15 above. [Effects of the Invention]

[0013] The pellicle frame and pellicle of the present invention can provide a pellicle frame and pellicle in which the pellicle film is less likely to break when the pressure changes from atmospheric pressure to vacuum, and which is less likely to break when the pellicle frame is processed or when the pellicle is peeled off. Furthermore, the present invention is particularly useful for pellicles for EUV exposure, and by using the above pellicle, it is extremely useful in a method for manufacturing a semiconductor or liquid crystal display panel which includes a step of exposing a substrate using an exposure master with a pellicle attached. [Brief explanation of the drawings]

[0014] [Figure 1] 1A and 1B are schematic diagrams showing one embodiment of the pellicle frame of the present invention, in which (A) is a view from the top end surface side, (B) is a view from the long side outer surface side, and (C) is a view from the short side outer surface side. [Figure 2] FIG. 1 is a schematic diagram showing a state in which the pellicle of the present invention is attached to a photomask. [Figure 3] 1A and 1B are schematic diagrams showing another embodiment of the pellicle frame of the present invention, where (A) is a view from the top end surface side, (B) is a view from the long side outer surface side, and (C) is a view from the short side outer surface side. DETAILED DESCRIPTION OF THE INVENTION

[0015] The present invention will be described in more detail below. 1(A) to 1(C) show an example of a pellicle frame 1 of the present invention, with reference numeral 11 indicating the inner surface of the pellicle frame, reference numeral 12 indicating the outer surface of the pellicle frame, reference numeral 13 indicating the upper end surface of the pellicle frame, and reference numeral 14 indicating the lower end surface of the pellicle frame. A cutout portion 20 is provided in the upper end surface of the pellicle frame 1, with reference numeral 21 indicating the width of the cutout portion, reference numeral 22 indicating the depth of the cutout portion, and reference numeral 23 indicating the height of the cutout portion. Furthermore, the pellicle frame 1 is provided with a plurality of through-holes 30. Note that, typically, a jig hole used to peel the pellicle from the photomask is provided on the long side of the pellicle frame, but this is not specifically shown in FIG. 1.

[0016] 2 shows a pellicle-attached photomask 10 in which a pellicle is attached to a photomask, with a pellicle film 2 adhered or stuck to and stretched over the upper end surface of pellicle frame 1 with a pressure-sensitive adhesive or adhesive 4. The lower end surface of pellicle frame 1 is releasably adhered or stuck to photomask 3 with a pressure-sensitive adhesive or adhesive 5, protecting the pattern surface on photomask 3.

[0017] As shown in FIG. 1, the pellicle frame of the present invention is a frame-shaped pellicle frame having an upper end surface on which a pellicle membrane is provided and a lower end surface facing the photomask.

[0018] If the pellicle frame is frame-shaped, its shape corresponds to the shape of the photomask to which the pellicle is attached. Generally, it is a quadrilateral (rectangular or square) frame. The corners (edges) of the pellicle frame may be angular (sharp) as they are, or may be chamfered, such as with an R-chamfer or C-chamfer, to form a curved shape or other shape.

[0019] The pellicle frame also has a surface for providing a pellicle film (here referred to as the upper end surface) and a surface facing the photomask when the photomask is mounted (here referred to as the lower end surface).

[0020] As shown in Figure 2, a pellicle film is attached to the upper surface of the pellicle frame via an adhesive or the like, and a pressure-sensitive adhesive or the like is attached to the lower surface to attach the pellicle to a photomask, but this is not limited to this.

[0021] The pellicle frame is preferably made of a ductile metal. Furthermore, EUV exposure requires higher precision than ArF exposure, placing stricter demands on the flatness of the photomask. It is known that the flatness of the photomask is affected by the pellicle. To minimize the impact of the pellicle on the photomask, it is preferable to use lightweight titanium, titanium alloys, aluminum, or aluminum alloys.

[0022] The dimensions of the pellicle frame are not particularly limited, but if the height of the EUV pellicle is limited to 2.5 mm or less, the thickness of the EUV pellicle frame is smaller than that, preferably 2.5 mm or less. In particular, taking into account the thickness of the pellicle film, photomask adhesive, etc., the thickness of the EUV pellicle frame is preferably 1.5 mm or less. Furthermore, the lower limit of the thickness of the pellicle frame is preferably 1.0 mm or more.

[0023] The pellicle frame of the present invention has a cutout portion with an open upper or lower end surface extending from the outer surface to the inner surface. That is, the cutout portion refers to a depression (recess) formed on the upper or lower end surface of the pellicle frame and extending from the outer surface to the inner surface. For example, as shown in FIGS. 1(B) and 1(C), the cutout portion 20 has a generally U-shaped depression when viewed from the outer surface of the pellicle frame. The generally U-shaped depression may have sharp, squared corners or may have rounded corners. As shown in FIG. 1(A), the cutout portion 20 has a uniform width extending from the outer surface to the inner surface when viewed from the top. However, the cutout portion 20 may have a tapered shape that gradually narrows or widens from the outer surface to the inner surface. Furthermore, the height of the cutouts (see reference numeral 23 in FIG. 1) does not need to be constant from the outer surface to the inner surface, but may be tapered so as to gradually expand or contract. There are no particular limitations on the location or number of the cutouts.

[0024] Furthermore, while there are no particular limitations on the shape or dimensions of the cutout, increasing the height of the cutout (reference numeral 23 in Figure 1) reduces the thickness of the pellicle frame below the cutout. This can cause the pellicle frame to bend from its thinnest part when the pellicle is peeled off, potentially damaging the pellicle membrane. Damage to the pellicle membrane when the pellicle is peeled off is problematic because it requires time to regenerate the photomask. Therefore, the height of the cutout is preferably 50% or less of the thickness of the pellicle frame, more preferably 30% or less, and even more preferably 15% or less. On the other hand, for ease of processing, the height of the cutout is preferably 5% or more of the thickness of the pellicle frame.

[0025] In Figure 1, a cutout portion 20 is provided on the upper end surface of the pellicle frame 1, but as another embodiment of the pellicle frame, a pellicle frame in which a cutout portion 20 is provided on the lower end surface of the pellicle frame 1 is shown in Figures 3(A) to (C).

[0026] In addition, in the present invention, in order to prevent damage to the pellicle membrane when the pressure changes from atmospheric pressure to vacuum, the total ventilation area on either the inner surface, outer surface, inner space side of the pellicle, or outer space side of the pellicle frame is set to 1 mm2 of the volume of the inner space of the pellicle. 3 0.001mm per 2 The total ventilation area must be set to 1 / 100 of the volume of the space inside the pellicle. 3 0.0013mm per 2 More preferably, the value is 0.0015 mm. 2 The upper limit is preferably 0.02 mm from the viewpoint of preventing damage to the pellicle frame and maintaining its strength. 2 Less than or equal to 0.015 mm, preferably 2 The following is the result.

[0027] Furthermore, it is preferable that the pellicle frame of the present invention be provided with a through hole having an opening at least on the inner surface. That is, one opening of the through hole can be provided on the inner surface, and the other opening of the through hole can be formed on the outer surface of the pellicle frame or on the upper end surface where the pellicle membrane is located. When the other opening of the through hole is formed on the upper end surface of the pellicle frame, a filter can be provided on the upper end surface, which is particularly advantageous for EUV applications where the frame thickness is thin.

[0028] The through-holes (vent holes) are not particularly limited in shape or size, but are preferably circular, elliptical, or the like, and the opening area is 0.03 mm 2 For ease of processing, it is preferable that the thinnest part between the end face of the pellicle and the vent hole be 0.2 mm or more.

[0029] In the pellicle frame of Fig. 1, both a cutout portion and a through-hole (vent hole) are formed, but the present invention is not limited to this, and only a cutout portion may be employed. However, as will be described later, in order to ensure a certain area as a vent, to fully exert the desired effects of the present invention, and to ensure sufficient strength of the pellicle frame, it is desirable to use both a cutout portion and a through-hole. In this case, the area of ​​the cutout portion on each of the long and short sides of the pellicle frame is 0.05 to 400 mm 2 The number of holes ranges from 1 to 50, while the area of ​​the through holes ranges from 0.03 to 130 mm 2 The number can be set within the range of 1 to 250.

[0030] In the pellicle frame of the present invention, the ventilation area is calculated as the ventilation area at any one of the inner surface, outer surface, pellicle inner space side, and pellicle outer space side when the pellicle is completed. For example, if there are 40 ventilation holes with a diameter of 0.8 mm, 40 notches with a width of 10 mm (see reference numeral 21 in FIG. 1) and a height of 0.2 mm (see reference numeral 23 in FIG. 1) on the end surface on the pellicle membrane side, and the thickness of the pellicle membrane adhesive formed on the upper end surface other than the notches is 0.1 mm, the total ventilation area present in this pellicle is 140 mm. 2 In other words, the thickness of the adhesive is also calculated as the ventilation area. [Area of ​​ventilation holes: Formula 1] 0.4 x 0.4 x 3.14 x 40 (number) = 20.096 (mm 2 ) [Opening area of ​​the notch: Formula 2] 10 x (0.2 + 0.1) x 40 (number) = 120 (mm 2 )

[0031] In other words, when a cutout portion is provided in the pellicle frame, the cutout portion is easier to make than an air vent, and as described above, the thickness of the adhesive layer to be laminated is also added as a ventilation space other than the cutout portion, so there is a great advantage in the present invention in requiring a cutout portion as a ventilation portion.

[0032] In the present invention, the internal space volume of a pellicle means the true internal space volume including the thickness of the adhesive when the pellicle is completed. For example, if the internal dimensions of the pellicle frame are 143 mm length x 110 mm width x 1.5 mm height, the thickness of the adhesive for the pellicle film and the adhesive for the photomask is 0.1 mm, and the pellicle film is an ultra-thin single-crystal silicon film supported by a Si frame with a height of 0.725 mm, the ultra-thin silicon film is sufficiently thin that it can be ignored in volume calculations, and therefore the internal space volume of the pellicle is 38145 mm. 3 This becomes: [Internal space volume of pellicle: Equation 3] 143 x 110 x (1.5 + 0.1 + 0.1 + 0.725) = 38145.25 (mm 3 ) The total ventilation area at this time is 20.096 (mm 2 )+120(mm 2 ) / 38145mm 3 ≒0.0037. The volume of the space inside the pellicle is 1mm 3 Approximately 0.0037 mm per 2 This can be calculated as follows.

[0033] The ventilation section may be provided with a filter as needed.

[0034] In the pellicle of the present invention, a pellicle membrane is provided on the upper end surface of the pellicle frame as described above via a pressure-sensitive adhesive or adhesive for the pellicle membrane. There are no particular limitations on the pressure-sensitive adhesive or adhesive for the pellicle membrane, and known pressure-sensitive adhesives can be used. Generally, the pressure-sensitive adhesive or adhesive is formed over the entire circumferential direction of one end surface of the pellicle frame, with a width equal to or less than the width of the pellicle frame. If one end surface of the pellicle frame has a notch, it is preferably formed on the end surface other than the notch.

[0035] The material of the pellicle film is not particularly limited, but a material with high transmittance at the wavelength of the exposure light source and high light resistance is preferred. For example, for EUV exposure, an ultrathin silicon film, Si film, or carbon film is used. Examples of these carbon films include films of graphene, diamond-like carbon, and carbon nanotubes. If it is difficult to handle the pellicle film alone, a pellicle film supported by a frame such as silicon can be used. In this case, the pellicle can be easily manufactured by adhering the frame region to the pellicle frame.

[0036] Furthermore, a pressure-sensitive adhesive or adhesive for attaching the pellicle frame to a photomask is applied to the lower end surface of the pellicle frame. Generally, the pressure-sensitive adhesive or adhesive is applied to the entire circumferential direction of one end surface of the pellicle frame, with a width equal to or less than the width of the pellicle frame. If one end surface of the pellicle frame has a notch, the pressure-sensitive adhesive or adhesive is applied to the end surface other than the notch.

[0037] As the photomask adhesive, known adhesives can be used, and acrylic adhesives, silicone adhesives, rubber adhesives, etc. can be suitably used, with silicone adhesives being particularly preferred from the viewpoint of heat resistance. The adhesive may be processed into any shape as needed.

[0038] A release layer (separator) for protecting the adhesive may be attached to the lower end surface of the photomask adhesive. The material of the release layer is not particularly limited, but examples include polyethylene terephthalate (PET), polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), polyethylene (PE), polycarbonate (PC), polyvinyl chloride (PVC), and polypropylene (PP). If necessary, a release agent such as a silicone-based release agent or a fluorine-based release agent may be applied to the surface of the release layer.

[0039] The pellicle frame of the present invention may have protrusions facing outward or inward. Such protrusions can be used to form a filter. Furthermore, by providing the outward protrusions with a connection mechanism (screws, adhesive, etc.) for connecting to an exposure master, the adhesive for the photomask can be omitted.

[0040] The pellicle of the present invention can be used not only as a protective member for preventing foreign matter from adhering to an exposure master in an EUV exposure apparatus, but also as a protective member for protecting the exposure master during storage or transportation of the exposure master. Methods for attaching a pellicle to an exposure master such as a photomask to produce an exposure master with a pellicle include the method of attaching the pellicle with the photomask adhesive described above, as well as electrostatic adsorption and mechanical fixing methods.

[0041] A method for manufacturing a semiconductor or liquid crystal display panel according to an embodiment of the present invention includes a step of exposing a substrate (semiconductor wafer or liquid crystal display panel) using the above-described pellicle-attached exposure master. For example, in a lithography process, which is one of the processes for manufacturing semiconductors or liquid crystal display panels, the above-described pellicle-attached exposure master is placed on a stepper and exposed to light to form a photoresist pattern corresponding to an integrated circuit or the like on the substrate. Generally, EUV exposure uses a projection optical system in which EUV light is reflected from the exposure master and directed to the substrate, and this is performed under reduced pressure or vacuum. As a result, even if foreign particles adhere to the pellicle during the lithography process, these particles are not imaged on the wafer coated with photoresist, thereby preventing short circuits or disconnections in the integrated circuit or the like due to the image of the foreign particles. Therefore, the use of the pellicle-attached exposure master can improve yield in the lithography process. [Example]

[0042] EXAMPLES The present invention will be specifically explained below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0043] [Example 1] A titanium pellicle frame (inner dimensions: 143 mm x 110 mm x 1.5 mm height, frame width: 4 mm) was fabricated. A notch measuring 30 mm width x 0.1 mm height x 4 mm depth was provided on the upper end surface of the center of each side of the pellicle frame. In addition, 12 through-holes with a diameter of 0.8 mm were provided on each side. The pellicle frame was cleaned, and a 1 mm wide, 0.1 mm thick coating was applied to the top of the frame (uncut areas) using 100 parts by weight of silicone adhesive (Shin-Etsu Chemical Co., Ltd., "X-40-3264") and 1 part by weight of curing agent (Shin-Etsu Chemical Co., Ltd., "PT-56") and stirred. The bottom of the frame was coated with a 1 mm wide, 0.1 mm thick coating of photomask adhesive (100 parts by weight of acrylic adhesive (Soken Chemical & Engineering Co., Ltd., "SK-Dyne 1499M") and 0.1 part by weight of curing agent (Soken Chemical & Engineering Co., Ltd., "L-45") along the entire periphery. The pellicle frame was then heated at 100°C for 12 hours to cure the adhesive on the top and bottom surfaces. Next, an ultra-thin silicon film with a thickness of 50 nm supported by a 0.725 mm thick Si frame was attached to the adhesive on the upper surface of the pellicle frame to complete the pellicle.

[0044] [Example 2] An aluminum pellicle frame (inner dimensions: 143 mm x 110 mm x height: 1.5 mm, frame width: 4 mm) was fabricated. 48 through-holes with a diameter of 0.8 mm were drilled on each side of the pellicle frame. Other than the shape of the frame, the frame was the same as in Example 1.

[0045] [Comparative Example 1] A titanium pellicle frame (inner dimensions: 143 mm x 110 mm x 1.5 mm, frame width: 4 mm) was fabricated. A notch measuring 30 mm wide x 0.1 mm high x 4 mm deep was provided on the upper end surface of the center of each side of the pellicle frame. Other than the shape of this pellicle frame, the pellicle frame was the same as in Example 1.

[0046] Comparative Example 2 An attempt was made to fabricate the pellicle frame of Example 1 using alumina, which is a ceramic, but it broke during the fabrication process.

[0047] [Vacuum test] The pellicles prepared in Examples 1 and 2 and Comparative Example 1 were attached to a 6-inch square quartz mask and subjected to a vacuum test. In this vacuum test, the masked pellicle was placed in a vacuum chamber, the pressure was reduced from atmospheric pressure to 1 Pa in 170 seconds, and then the pressure was returned from 1 Pa to atmospheric pressure in 250 seconds, and it was confirmed whether the pellicle film was damaged. The results are shown in Table 1 below.

[0048] [Table 1]

[0049] From the results in Table 1 above, it can be seen that no damage to the pellicle membrane was observed in Examples 1 and 2, which was good, but damage to the pellicle membrane was observed in Comparative Example 1. [Explanation of symbols]

[0050] 1 Pellicle frame 11 Inner surface of pellicle frame 12 Outer surface of pellicle frame 13 Upper surface of pellicle frame 14 Lower end surface of pellicle frame 20 Notch 21 Width of cutout 22 Depth of cutout 23 Height of cutout 30 Through holes (ventilation holes) 2. Pellicle membrane 3 Photomask 4. Pellicle membrane adhesive or adhesive 5. Photomask adhesives or glues 10 Photomask with pellicle

Claims

1. A pellicle comprising a frame-shaped metal pellicle frame having two end faces, A pellicle characterized in that at least one end face of the pellicle frame has a recess that connects from the outer surface to the inner surface, and the pellicle frame has 28 to 250 through holes that have openings on at least the inner surface.

2. The total ventilation area on the inner surface of the pellicle frame is equal to the volume of the inner space of the pellicle of 1 mm 3 0.001mm per 2 The pellicle according to claim 1, wherein

3. The total ventilation area on the inner space side of the pellicle is 1 mm 3 0.001mm per 2 The pellicle according to claim 1, wherein

4. The total ventilation area on the outer surface of the pellicle frame is 1 mm 3 0.001mm per 2 The pellicle according to claim 1, wherein

5. The total ventilation area on the outer space side of the pellicle is 1 mm 3 0.001mm per 2 The pellicle according to claim 1, wherein

6. The pellicle according to any one of claims 2 to 5, wherein the thinnest part between the through hole and the end face of the pellicle frame is 0.2 mm or more.

7. 2. The pellicle according to claim 1, wherein the thinnest part between the through hole and the end face of the pellicle frame is 0.2 mm or more.

8. The total ventilation area is 1 mm of the volume of the internal space of the pellicle. 3 0.02 mm per 2 The pellicle according to any one of claims 2 to 6, wherein:

9. 9. The pellicle according to claim 1, wherein the height of the recess is 50% or less of the thickness of the pellicle frame.

10. 10. The pellicle according to claim 1, wherein the thickness of the pellicle frame is 2.5 mm or less.

11. 11. A pellicle according to claim 1, wherein the end face of the pellicle frame having the recess has a pellicle film thereon via an adhesive or a adhesive.

12. The pellicle according to any one of claims 1 to 11, which is used for exposure under vacuum or reduced pressure.

13. The pellicle according to any one of claims 1 to 11, which is used for EUV exposure.

14. An exposure master with a pellicle, comprising the pellicle according to any one of claims 1 to 13 attached to the exposure master.

15. An exposure method comprising exposing using the pellicle-equipped exposure master plate according to claim 14.

16. 15. A method for manufacturing a semiconductor device, comprising the step of exposing a substrate using the pellicle-equipped exposure master according to claim 14.

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