Pellicle frame, pellicle, and exposure original plate

Abstract

This pellicle frame comprises a first surface for supporting a pellicle film, and a second surface provided on a photomask side positioned on the reverse side from the first surface, wherein: in a cross section along the width direction of the pellicle frame, the length of the second surface is smaller than the length of the first surface; the pellicle frame has, on the outside thereof, a first shape having a recess between the first surface and the second surface; and when an imaginary U shape having the same area as the first shape is created from the first shape, the cross-sectional secondary moment of the first shape is greater than the cross-sectional secondary moment of the U shape.

Description

Pellicle frame, pellicle, and exposure master plate

[0001] This disclosure relates to a pellicle frame, a pellicle, and an exposure master plate.

[0002] In photolithography, a technique that forms patterns on the surface of objects such as electronic components, printed circuit boards, and display panels by coating them with a photosensitive material and exposing them to light, a transparent substrate called a photomask, on which a pattern is formed on one side, is used. In recent years, as the resolution of exposure patterns has increased, the use of EUV (Extreme Ultra Violet) light, which has a shorter wavelength, has expanded as an exposure light source, replacing DUV (Deep Ultra Violet) light. In exposure methods using EUV light, a photomask equipped with a reflective layer that reflects the exposure light is sometimes used.

[0003] For example, Patent Document 1 discloses a lithography device characterized in that the surface roughness of the inner surface of the pellicle frame is in the range of Ra 0.3 to 0.9 μm, Rt 4.0 to 8.5 μm, and RMS 0.3 to 1.1 μm, and the inner surface of the frame is coated with an adhesive resin.

[0004] For example, Patent Document 2 describes a pellicle area of ​​1000 cm². ２ In the above-mentioned large pellicle for liquid crystals, a large pellicle for liquid crystals is disclosed characterized in that the surface roughness of the pellicle film adhesion surface of the frame is Ra 0.4 μm to 4 μm, and the pellicle film is attached via an adhesive.

[0005] For example, Patent Document 3 discloses that a blast treatment is applied to the pellicle frame to make it easier to detect when dirt or other debris adheres to it.

[0006] Japanese Patent Publication No. 11-167198, Japanese Patent Publication No. 2006-184704, Japanese Patent Publication No. 2012-159671

[0007] For pellicles used in photomasks, it is desirable to improve the throughput of the exposure apparatus or to make it easier to control the mask stage to the desired position even when it is moved at a higher speed. To achieve this, there is a need for a pellicle frame that has reduced mass, is less prone to deformation when peeling the photomask from the pellicle frame, and makes it easy to peel the photomask. For example, a pellicle frame with reduced mass and high rigidity in the thickness direction is preferable.

[0008] One embodiment of this disclosure aims to solve the problem of a pellicle frame having reduced mass and high rigidity in the thickness direction, as well as a pellicle and exposure plate equipped with the pellicle frame.

[0009] Specific means for solving the above problems include the following embodiments: <1> A pellicle frame having a first surface for supporting a pellicle film and a second surface on the photomask side located on the opposite side from the first surface, wherein in a cross section along the width direction of the pellicle frame, the length of the second surface is smaller than the length of the first surface, and the pellicle frame has a first shape with a recess between the first surface and the second surface on the outside, and when a hypothetical U-shape having the same area as the first shape is created from the first shape, the second moment of area of ​​the first shape is larger than the second moment of area of ​​the U-shape. <2> A pellicle frame comprising a first surface for supporting a pellicle film and a second surface on the photomask side located opposite to the first surface, wherein in a cross section along the width direction of the pellicle frame, it comprises a frame support portion, a first extension portion which together with the frame support portion constitutes the first surface and extends to the outside of the frame support portion, a second extension portion which together with the frame support portion constitutes the second surface and extends to the outside of the frame support portion, and a recess portion located between the first extension portion and the second extension portion, and the length of the first extension portion is greater than the length of the second extension portion, A pellicle frame having a ratio of 0.44 to 2.00, where b1 is the length of the second extension, b3 is the length of the first extension, b5 is the total length of the frame support and the first extension, h1 is the height of the second extension, h2 is the height of the frame support, h3 + h6 is the height of the first extension (where h1 × (b3 - b1) = h6 × b3), and R is the hollowing ratio (where R = [(h2 - h1 - h3 - h6) × b3] / (h2 × b5)), and where h2 / b5 is between 0.44 and 2.00, and also satisfying one of the following conditions 1A to 8A. (Condition 1A) When R is greater than 5% and less than or equal to 15%, h1 / h2 is 0.28 to 0.85, b3 / b5 is 0.15 to 0.90, b1 / b3 is 0.95 to 6.37, and (h3+h6) / h2 is 0.14 to 0.34. (Condition 2A) When R is greater than 15% and less than or equal to 25%, h1 / h2 is 0.28 to 0.75, b3 / b5 is 0.30 to 0.90, b1 / b3 is 0.67 to 3.03, and (h3+h6) / h2 is 0.14 to 0.34.(Condition 3A) When R is greater than 25% and less than or equal to 35%, h1 / h2 is 0.28 to 0.66, b3 / b5 is 0.45 to 0.90, b1 / b3 is 0.78 to 1.90, and (h3+h6) / h2 is 0.14 to 0.25. (Condition 4A) When R is greater than 35% and less than or equal to 45%, h1 / h2 is 0.28 to 0.47, b3 / b5 is 0.60 to 0.90, b1 / b3 is 0.83 to 1.34, and (h3+h6) / h2 is 0.15 to 0.22. (Condition 5A) When R is greater than 45% and less than or equal to 55%, h1 / h2 is 0.28 to 0.38, b3 / b5 is 0.75 to 0.90, b1 / b3 is 0.79 to 1.02, and (h3+h6) / h2 is 0.15 to 0.19. (Condition 6A) When R is greater than 55% and less than or equal to 65%, h1 / h2 is 0.19 to 0.28, b3 / b5 is 0.75 to 0.90, b1 / b3 is 0.77 to 1.10, and (h3+h6) / h2 is 0.09 to 0.15. (Condition 7A) When R is greater than 65% and less than or equal to 75%, h1 / h2 is 0.19 to 0.24, b3 / b5 is 0.83 to 0.90, b1 / b3 is 0.72 to 0.77, and (h3+h6) / h2 is 0.10 to 0.11. (Condition 8A) When R is greater than 75% and less than or equal to 85%, h1 / h2 is 0.09 to 0.14, b3 / b5 is 0.80 to 0.90, b1 / b3 is 0.69 to 0.72, and (h3+h6) / h2 is 0.05 to 0.06.<3> A pellicle frame comprising a first surface for supporting a pellicle film and a second surface on the photomask side located opposite to the first surface, wherein in a cross section along the width direction of the pellicle frame, it comprises a frame support portion, a first extension portion which together with the frame support portion constitutes the first surface and extends to the outside of the frame support portion, a second extension portion which together with the frame support portion constitutes the second surface and extends to the outside of the frame support portion, and a recess portion located between the first extension portion and the second extension portion, and the length of the first extension portion is greater than the length of the second extension portion, A pellicle frame having a length of b1 for the second extension, a length of b3 for the first extension, a total length of b5 for the frame support and the first extension, a height of h1 for the second extension, a height of h2 for the frame support, a height of h3 + h6 for the first extension (where h1 × (b3 - b1) = h6 × b3), and a hollowing ratio of R (where R = [(h2 - h1 - h3 - h6) × b3] / (h2 × b5)), wherein h2 / b5 satisfies 0.27 to 0.43 and satisfies any one of the following conditions 1B to 8B. (Condition 1B) When R is greater than 5% and less than or equal to 15%, h1 / h2 is 0.50 to 0.64, b3 / b5 is 0.30 to 0.90, b1 / b3 is 1.08 to 3.22, and (h3+h6) / h2 is 0.23 to 0.26. (Condition 2B) When R is greater than 15% and less than or equal to 25%, h1 / h2 is 0.21 to 0.64, b3 / b5 is 0.30 to 0.90, b1 / b3 is 0.94 to 3.32, and (h3+h6) / h2 is 0.12 to 0.25. (Condition 3B) When R is greater than 25% and less than or equal to 35%, h1 / h2 is 0.21 to 0.64, b3 / b5 is 0.45 to 0.90, b1 / b3 is 0.79 to 2.16, and (h3+h6) / h2 is 0.13 to 0.23. (Condition 4B) When R is greater than 35% and less than or equal to 45%, h1 / h2 is 0.36 to 0.50, b3 / b5 is 0.75 to 0.90, b1 / b3 is 0.79 to 1.10, and (h3+h6) / h2 is 0.19 to 0.22. (Condition 5B) When R is greater than 45% and less than or equal to 55%, h1 / h2 is 0.21 to 0.36, b3 / b5 is 0.75 to 0.90, b1 / b3 is 0.83 to 1.22, and (h3 + h6) / h2 is 0.14 to 0.19.(Condition 6B) When R is greater than 55% and less than or equal to 65%, h1 / h2 is 0.21 to 0.29, b3 / b5 is 0.83 to 0.90, b1 / b3 is 0.69 to 0.98, and (h3+h6) / h2 is 0.15 to 0.18. (Condition 7B) When R is greater than 65% and less than or equal to 75%, h1 / h2 is 0.21 to 0.29, b3 / b5 is 0.85 to 0.90, b1 / b3 is 0.63 to 0.66, and (h3+h6) / h2 is 0.11 to 0.16. (Condition 8B) When R is greater than 75% and less than or equal to 85%, h1 / h2 is 0.07 to 0.14, b3 / b5 is 0.88 to 0.90, b1 / b3 is 0.56 to 0.89, and (h3 + h6) / h2 is 0.09 to 0.15. <4> A pellicle frame according to <1> or <3>, comprising a film support on the first surface that adheres to the pellicle film. <5> A pellicle frame according to any one of <1> to <4>, comprising an adhesive layer on the second surface. <6> A pellicle frame according to any one of <1> to <5>, wherein there is no quadrilateral recess between the first surface and the second surface on the inside of the pellicle frame. <7> A pellicle frame according to any one of <1> to <5>, wherein there is no recess between the first surface and the second surface on the inside of the pellicle frame. <8> A pellicle comprising a pellicle frame as described in any one of <1> to <7>, and a pellicle film disposed on the first surface side of the pellicle frame. <9> An exposure master plate comprising a master plate having a pattern, and the pellicle described in <8> attached to the pattern side of the master plate.

[0010] According to one embodiment of the present disclosure, it is possible to provide a pellicle frame with reduced mass and high rigidity in the thickness direction, as well as a pellicle and exposure plate equipped with the pellicle frame.

[0011] This is a schematic diagram showing an example of a pellicle frame of the present disclosure. This is a cross-sectional view taken along line A-A in Figure 1. This is a schematic diagram showing the cross-sectional shape of a pellicle frame equipped with a film support. This is a schematic diagram showing how to determine the second moment of area of ​​a pellicle frame. This is a schematic diagram showing a method for creating a hypothetical U-shape in the first embodiment. This is a schematic diagram showing an example of a pellicle frame of the second embodiment of the present disclosure. This is a schematic diagram showing a method for creating a hypothetical U-shape in the second embodiment. This is a schematic diagram showing another example of a pellicle frame of the present disclosure. This is a schematic cross-sectional view showing another example of a pellicle frame of the present disclosure. This is a schematic cross-sectional view of an EUV exposure apparatus, which is an example of an exposure apparatus. This is a schematic diagram showing another example of a pellicle frame of the present disclosure.

[0012] In this disclosure, numerical ranges indicated using "~" mean ranges that include the numbers before and after "~" as the minimum and maximum values, respectively. In numerical ranges described in stages in this disclosure, the upper or lower limit stated in one numerical range may be replaced with the upper or lower limit of another numerical range described in stages. Also, in numerical ranges described in this disclosure, the upper or lower limit stated in one numerical range may be replaced with the value shown in the example. In this disclosure, a combination of two or more preferred embodiments is a more preferred embodiment. In this disclosure, the amount of each component means the total amount of multiple substances if there are multiple substances corresponding to each component, unless otherwise specified. In this specification, the term "process" includes not only independent processes but also processes that cannot be clearly distinguished from other processes, as long as the intended purpose of the process is achieved. In this specification, "pellicle frame of this disclosure" may be read as the pellicle frame of the first embodiment, the pellicle frame of the second embodiment, or the pellicle frame of the third embodiment. The configurations and preferred configurations in each embodiment may be combined as appropriate.

[0013] ≪Pellicle≫ (First Embodiment) The pellicle frame of the first embodiment of the present disclosure is a pellicle frame comprising a first surface that supports a pellicle film and a second surface on the photomask side located on the opposite side from the first surface, wherein in a cross section along the width direction of the pellicle frame, the length of the second surface is smaller than the length of the first surface, and the pellicle frame has a first shape with a recess between the first surface and the second surface on the outside, and when a hypothetical U-shaped shape having the same area as the first shape is created from the first shape, the second moment of area of ​​the first shape is larger than the second moment of area of ​​the U-shaped shape.

[0014] The pellicle frame of the first embodiment has a first shape with the aforementioned recess in a cross section along the width direction of the pellicle frame, and the second moment of area of ​​the first shape is greater than the second moment of area of ​​a hypothetical U-shape over the same area. As a result, the pellicle frame of the first embodiment has reduced mass and high rigidity in the thickness direction.

[0015] Furthermore, when peeling the pellicle frame from the photomask, distortion of the pellicle frame can cause problems such as cracking of easily ruptured films like polysilicon films, or thin films like films containing carbon nanotubes. Therefore, it is necessary to minimize the distortion of the pellicle frame when peeling it from the photomask. The pellicle frame of this disclosure has high rigidity in the thickness direction, so it is less likely to deform when peeling off the photomask, and it is easier to suppress the rupture of the pellicle film due to distortion of the pellicle frame.

[0016] For example, the distortion of the pellicle frame when it is detached from the photomask can be calculated from equation (1) below, which is a fixed-end, center-loaded equation.

[0017]

[0018] In equation (1), δ (strain [m]), P (load on the pellicle frame [N]), L (length of the pellicle frame [m]), I (second moment of area of ​​the pellicle frame [m]) ４ E represents the Young's modulus [N / m] of the material constituting the pellicle frame. As shown in equation (1), δ decreases as the second moment of area increases.

[0019] The shape of the pellicle frame corresponds to the shape of the photomask. Examples of pellicle frame shapes include rectangular and square frames. The pellicle frame has through-holes. These through-holes represent the spaces through which the exposure transmitted through the pellicle film passes to reach the photomask.

[0020] An example of a pellicle frame is shown in Figure 1. The pellicle frame 10 shown in Figure 1 is a rectangular or square frame-shaped member having a through hole 11 in the central part when viewed from the thickness direction. Figure 1 is a view of the pellicle frame 10 from the first surface 1 side, with the second surface 2 located on the opposite side of the first surface 1.

[0021] In a cross-section along the width direction of the pellicle frame 10, the length of the second surface 2 is smaller than the length of the first surface 1. In Figure 1, the length of the second surface 2 is smaller than the length of the first surface 1 around the entire circumference of the pellicle frame 10, but the disclosure is not limited to this, and it is sufficient if the length of the second surface is smaller than the length of the first surface in a part of the circumference of the pellicle frame.

[0022] For example, the length of the second face may be smaller than the length of the first face by 5% to 100%, 10% to 50%, or 10% to 30% of the total circumference of the pellicle frame. Alternatively, the length of the second face may be smaller than the length of the first face by 50% to 100%, 70% to 100%, or 90% to 100% of the total circumference of the pellicle frame. If the pellicle frame is polygonal, such as rectangular or square, the length of the second face may be smaller than the length of the first face on only one side, or on two or more sides (for example, two opposite sides).

[0023] Figure 2 is a cross-sectional view taken along line A-A in Figure 1. As shown in Figure 2, in the width direction of the pellicle frame 10, the length of the second surface 2 (L2) is smaller than the length of the first surface 1 (L1). Furthermore, a recess 3 is located between the first surface 1 and the second surface 2 on the outside of the pellicle frame 10. The cross-sectional shape of the pellicle frame shown in Figure 2 is an example of the first shape in this disclosure.

[0024] As shown in Figure 2, when the height of the pellicle frame 10 is H1, it is preferable that H1 / L1 satisfies 0.44 to 2.00.

[0025] The first surface 1 is the surface that supports the pellicle film, and the second surface 2 is the surface facing the photomask. The second surface 2 may or may not have an adhesive layer.

[0026] The first surface 1 may support the pellicle membrane without other members, or it may support the pellicle membrane via a membrane support that supports the pellicle membrane. Figure 3 shows the cross-sectional shape of a pellicle frame equipped with a membrane support. As shown in Figure 3, a membrane support 11 that supports the pellicle membrane may be arranged on the side of the first surface 1. The membrane support 11 is arranged along the length direction of the pellicle frame 20 and is preferably a frame-shaped member similar to the pellicle frame 20.

[0027] Even when the membrane support 11 is provided on the pellicle frame 20, as shown in Figure 3, in the width direction of the pellicle frame 20, the length of the second surface 2 (L2') is smaller than the length of the first surface 1 (L1'). Furthermore, when the height of the pellicle frame 20 is H1', ​​it is preferable that H1' / L1' satisfies 0.27 to 0.43.

[0028] The Young's modulus of the membrane support 11 is preferably 90 GPa or higher. This suppresses deformation of the pellicle frame 20 caused by strain on the membrane support 11 due to the tension of the pellicle membrane. The Young's modulus of the pellicle frame 20 is not particularly limited and may be, for example, 60 GPa or less. The Young's modulus is measured by a tensile test (JIS G0567J).

[0029] The material of the film support 11 is not particularly limited, but from the viewpoint of suppressing deformation of the pellicle frame 20, examples include silicon, titanium, glass-like carbon, quartz, and glass.

[0030] The pellicle frame 20 and the membrane support 11 may be integrated together by a known adhesive, or they may be integrated together by fastening components.

[0031] The second moment of area of ​​the first shape (for example, the cross-sectional shape of the pellicle frame shown in Figure 2 or Figure 3) can be obtained, for example, by subtracting the second moment of area of ​​the cut-out portion from the second moment of area of ​​the rectangle. Specifically, if the first shape is as shown in Figure 4(d), the second moment of area of ​​the rectangle shown in Figure 4(a) is I ０ From the second moment of area of ​​the weight-reducing section shown in Figures 4(b) and 4(c) (I １ and I ２ By subtracting ), the second moment of area I of the first shape can be determined.

[0032] A hypothetical U-shape having the same area as the first shape can be created, for example, by the procedure shown in Figure 5. The first shape is shown in Figure 5(a). First, as shown in Figure 5(b), a region X is added to the end of the second face of the first shape so that the length of the first face and the length of the second face are the same. Next, as shown in Figure 5(c), a region Y with the same area as the added region X is found in the side wall portion of the recess on the first face side. Then, as shown in Figure 5(d), region Y is removed from the side wall portion of the recess. Through these operations, a hypothetical U-shape having the same area as the first shape can be created. The second moment of area of ​​the created U-shape can then be calculated. In the pellicle frame of the first embodiment, the second moment of area of ​​the first shape is larger than the second moment of area of ​​the hypothetical U-shape.

[0033] The material of the pellicle frame is not particularly limited, but it is preferably a material capable of supporting the pellicle film described later. Examples of materials constituting the pellicle frame include metallic materials such as aluminum, titanium, and stainless steel; carbon-based materials such as glass-like carbon; ceramic materials such as silicon, glass, and quartz; and resin materials such as polyethylene. The pellicle frame may contain only one of the aforementioned materials, or it may contain two or more.

[0034] The pellicle frame is preferably made of aluminum, titanium, glass-like carbon, quartz glass, or silicon, and more preferably silicon or glass-like carbon. The pellicle frame may also have a laminated structure of multiple materials.

[0035] From the perspective of suppressing the amount of outgassing without a large water content, the pellicle frame may be treated to make its surface hydrophobic, or its surface may be coated with a material having a low water content (for example, an inorganic material, a ceramic-based material, etc.).

[0036] The shape of the pellicle frame is preferably a rectangular frame or a square frame. The length of one side of the pellicle frame (for example, the length in a direction perpendicular to the width and height) is preferably 200 mm or less. The size of the pellicle frame, etc. is standardized according to the type of exposure apparatus. That the length of one side of the pellicle frame is 200 mm or less satisfies the standardized size for exposure using EUV light.

[0037] The length of one side can be, for example, 5 mm to 180 mm, preferably 80 mm to 170 mm, more preferably 100 mm to 160 mm.

[0038] The height of the pellicle frame (that is, the length of the pellicle frame in the thickness direction) is not particularly limited, preferably 5.0 mm or less, more preferably 3.0 mm or less, still more preferably 2.4 mm or less, particularly preferably 2.375 mm or less. The height of the pellicle frame may be 1.5 mm or more, may be 1.9 mm or more, or may be 2.0 mm or more. Thereby, the pellicle frame satisfies the standardized size for EUV exposure. The height of the pellicle frame standardized for EUV exposure is, for example, 2.375 mm.

[0039] When combining the pellicle frame with the above-described film support, the height of the pellicle frame (that is, the length of the pellicle frame in the thickness direction) is not particularly limited, preferably 2.0 mm or less, more preferably 1.8 mm or less, still more preferably 1.7 mm or less, particularly preferably 1.6 mm or less. The height of the pellicle frame may be 1.0 mm or more, may be 1.1 mm or more, or may be 1.2 mm or more.

[0040] The mass of the pellicle frame is not particularly limited, but is preferably 20 g or less, more preferably 15 g or less, and even more preferably 12 g or less. This makes the pellicle frame suitable for EUV exposure applications.

[0041] (Second Embodiment) The pellicle frame of the second embodiment of the present disclosure is a pellicle frame comprising a first surface for supporting a pellicle film and a second surface on the photomask side located opposite to the first surface, wherein in a cross section along the width direction of the pellicle frame, it comprises a frame support portion, a first extension portion which together with the frame support portion constitutes the first surface and extends to the outside of the frame support portion, a second extension portion which together with the frame support portion constitutes the second surface and extends to the outside of the frame support portion, and a recess portion located between the first extension portion and the second extension portion, wherein the length of the first extension portion is the same as the second The frame has a second shape that is larger than the length of the extension, and when the length of the second extension is b1, the length of the first extension is b3, the total length of the frame support and the first extension is b5, the height of the second extension is h1, the height of the frame support is h2, the height of the first extension is h3 + h6 (where h1 × (b3 - b1) = h6 × b3), and the hollowing ratio is R (where R = [(h2 - h1 - h3 - h6) × b3] / (h2 × b5)), the h2 / b5 satisfies 0.44 to 2.00 and satisfies any one of the following conditions 1A to 8A. (Condition 1A) When R is greater than 5% and less than or equal to 15%, h1 / h2 is 0.28 to 0.85, b3 / b5 is 0.15 to 0.90, b1 / b3 is 0.95 to 6.37, and (h3+h6) / h2 is 0.14 to 0.34. (Condition 2A) When R is greater than 15% and less than or equal to 25%, h1 / h2 is 0.28 to 0.75, b3 / b5 is 0.30 to 0.90, b1 / b3 is 0.67 to 3.03, and (h3+h6) / h2 is 0.14 to 0.34. (Condition 3A) When R is greater than 25% and less than or equal to 35%, h1 / h2 is 0.28 to 0.66, b3 / b5 is 0.45 to 0.90, b1 / b3 is 0.78 to 1.90, and (h3+h6) / h2 is 0.14 to 0.25. (Condition 4A) When R is greater than 35% and less than or equal to 45%, h1 / h2 is 0.28 to 0.47, b3 / b5 is 0.60 to 0.90, b1 / b3 is 0.83 to 1.34, and (h3+h6) / h2 is 0.15 to 0.22.(Condition 5A) When R is greater than 45% and less than or equal to 55%, h1 / h2 is 0.28 to 0.38, b3 / b5 is 0.75 to 0.90, b1 / b3 is 0.79 to 1.02, and (h3+h6) / h2 is 0.15 to 0.19. (Condition 6A) When R is greater than 55% and less than or equal to 65%, h1 / h2 is 0.19 to 0.28, b3 / b5 is 0.75 to 0.90, b1 / b3 is 0.77 to 1.10, and (h3+h6) / h2 is 0.09 to 0.15. (Condition 7A) When R is greater than 65% and less than or equal to 75%, h1 / h2 is 0.19 to 0.24, b3 / b5 is 0.83 to 0.90, b1 / b3 is 0.72 to 0.77, and (h3+h6) / h2 is 0.10 to 0.11. (Condition 8A) When R is greater than 75% and less than or equal to 85%, h1 / h2 is 0.09 to 0.14, b3 / b5 is 0.80 to 0.90, b1 / b3 is 0.69 to 0.72, and (h3+h6) / h2 is 0.05 to 0.06.

[0042] The pellicle frame of the second embodiment is a frame that satisfies any one of conditions 1A to 8A, thereby ensuring that the second moment of area of ​​the second shape is greater than or equal to the second moment of area of ​​a hypothetical U-shape over the same area. As a result, the pellicle frame of the second embodiment is a pellicle frame with reduced mass and high rigidity in the thickness direction. In conditions 1A to 8A, the units of b1, b3, b5, h1, h2, h3, and h6 may be mm.

[0043] The pellicle frame of the second embodiment is a frame that satisfies any one of conditions 1A to 8A, and it is preferable that h1 and h3+h6 are each independently 0.2 mm or more, and (h2-h1-h3-h6) is 0.3 mm or more. h1 and h3+h6 may each be independently 1.5 mm or less, and (h2-h1-h3-h6) may be 2 mm or less.

[0044] From the viewpoint of ease of processing and robustness as a pellicle frame, it is preferable that the pellicle frame of the second embodiment is a frame that further satisfies any one of the following conditions 1C to 8C. (Condition 1C) When R is greater than 5% and 15% or less, h1 / h2 is 0.47 to 0.85, b3 / b5 is 0.30 to 0.90, b1 / b3 is 0.97 to 3.10, and (h3+h6) / h2 is 0.15 to 0.34. (Condition 2C) When R is greater than 15% and 25% or less, h1 / h2 is 0.28 to 0.56, b3 / b5 is 0.30 to 0.90, b1 / b3 is 1.04 to 3.03, and (h3+h6) / h2 is 0.14 to 0.25. (Condition 3C) When R is greater than 25% and less than or equal to 35%, h1 / h2 is 0.28 to 0.66, b3 / b5 is 0.45 to 0.90, b1 / b3 is 0.78 to 1.90, and (h3+h6) / h2 is 0.14 to 0.25. (Condition 4C) When R is greater than 35% and less than or equal to 45%, h1 / h2 is 0.28 to 0.47, b3 / b5 is 0.60 to 0.90, b1 / b3 is 0.83 to 1.34, and (h3+h6) / h2 is 0.15 to 0.22. (Condition 5C) When R is greater than 45% and less than or equal to 55%, h1 / h2 is 0.28 to 0.38, b3 / b5 is 0.75 to 0.90, b1 / b3 is 0.79 to 0.99, and (h3+h6) / h2 is 0.15 to 0.19. (Condition 6C) When R is greater than 55% and less than or equal to 65%, h1 / h2 is 0.19 to 0.28, b3 / b5 is 0.75 to 0.90, b1 / b3 is 0.77 to 0.90, and (h3+h6) / h2 is 0.09 to 0.15. (Condition 7C) When R is greater than 65% and less than or equal to 75%, h1 / h2 is 0.19 to 0.24, b3 / b5 is 0.85 to 0.90, b1 / b3 is 0.72 to 0.77, and (h3+h6) / h2 is 0.10 to 0.11. (Condition 8C) When R is greater than 75% and less than or equal to 85%, h1 / h2 is 0.09 to 0.14, b3 / b5 is 0.83 to 0.90, b1 / b3 is 0.69 to 0.72, and (h3+h6) / h2 is 0.05 to 0.06.

[0045] Figure 6 shows an example of a pellicle frame according to the second embodiment of this disclosure. Figure 6 shows the positional relationship of the length and height of each component in the pellicle frame.

[0046] The pellicle frame 30 shown in Figure 6 comprises a frame support portion 24, a first extension portion 25, a second extension portion 26, and a recess portion 23. The first extension portion 25 is a portion that extends outward from the frame support portion 24 at one end in the height direction of the frame support portion 24, and together with the frame support portion 24, constitutes a first surface 21. The second extension portion 26 is a portion that extends outward from the frame support portion 24 at the other end in the height direction of the frame support portion 24, and together with the frame support portion 24, constitutes a second surface 22. The length (b3) of the first extension portion 25 is greater than the length (b1) of the second extension portion 26. The recess portion 23 is a recess located between the first extension portion 25 and the second extension portion 26. The cross-sectional shape of the pellicle frame shown in Figure 6 is an example of the second shape in this disclosure.

[0047] When the height of the pellicle frame 30 is h2, h2 / b5 satisfies 0.44 to 2.00.

[0048] The first surface 21 is the surface that supports the pellicle film, and the second surface 22 is the surface facing the photomask. The second surface 22 may or may not have an adhesive layer.

[0049] Preferably, the first surface 21 supports the pellicle film without the need for other components.

[0050] The second moment of area of ​​the second shape (for example, the cross-sectional shape of the pellicle frame shown in Figure 6) can be determined, for example, by subtracting the second moment of area of ​​the cut-out section from the second moment of area of ​​the rectangle. Specifically, if the second shape is as shown in Figure 6, the second moment of area of ​​the second shape can be determined by subtracting the second moment of area of ​​the cut-out section with height h1 and length (b3-b1) and the second moment of area of ​​the cut-out section with height (h2-h1-h3-h6) and length b3 from the second moment of area of ​​the rectangle with height h2 and length b5.

[0051] A hypothetical U-shape having the same area as the second shape can be created by the following procedure. First, as shown in Figure 7, a region X (area h1 × (b3 - b1)) is added to the end of the second surface 22 so that the length of the first surface 21 and the length of the second surface 22 are the same as in the second shape. Next, a region Y (area h6 × b3) with the same area as the added region X is found in the side wall portion of the recess 23 on the first surface 21 side. Then, region Y is removed from the side wall portion of the recess 23. Through these operations, a hypothetical U-shape having the same area as the second shape can be created. The second moment of area of ​​the created U-shape can then be calculated.

[0052] Conditions 1A to 8A show the relationship between the length and height of each member when the hollowing ratio R is varied, such that the second moment of area of ​​the second shape is equal to or greater than the second moment of area of ​​a hypothetical U-shape having the same area as the second shape. The hollowing ratio R refers to the total area of ​​the hollowed-out portion relative to the area of ​​a rectangle with height h2 and length b5.

[0053] In the second embodiment, the total length b5 of the frame support portion 24 and the first extension portion 25 can be, for example, 3 mm to 20 mm, preferably 4 mm to 15 mm, and more preferably 4 mm to 10 mm.

[0054] In the second embodiment, the height h2 of the pellicle frame 30 (i.e., the length of the pellicle frame 30 in the thickness direction) is not particularly limited, but is preferably 5.0 mm or less, more preferably 3.0 mm or less, even more preferably 2.4 mm or less, and particularly preferably 2.375 mm or less. The height h2 of the pellicle frame 30 may be 1.5 mm or more, 1.9 mm or more, or 2.0 mm or more.

[0055] (Third Embodiment) The pellicle frame of the third embodiment of the present disclosure is a pellicle frame comprising a first surface for supporting a pellicle film and a second surface on the photomask side located opposite to the first surface, wherein in a cross section along the width direction of the pellicle frame, it comprises a frame support portion, a first extension portion which together with the frame support portion constitutes the first surface and extends to the outside of the frame support portion, a second extension portion which together with the frame support portion constitutes the second surface and extends to the outside of the frame support portion, and a recess portion located between the first extension portion and the second extension portion, wherein the length of the first extension portion is the same as the second The frame has a second shape that is larger than the length of the extension, and when the length of the second extension is b1, the length of the first extension is b3, the total length of the frame support and the first extension is b5, the height of the second extension is h1, the height of the frame support is h2, the height of the first extension is h3 + h6 (where h1 × (b3 - b1) = h6 × b3), and the hollowing ratio is R (where R = [(h2 - h1 - h3 - h6) × b3] / (h2 × b5)), then h2 / b5 satisfies 0.27 to 0.43 and satisfies any one of the following conditions 1B to 8B. (Condition 1B) When R is greater than 5% and less than or equal to 15%, h1 / h2 is 0.50 to 0.64, b3 / b5 is 0.30 to 0.90, b1 / b3 is 1.08 to 3.22, and (h3+h6) / h2 is 0.23 to 0.26. (Condition 2B) When R is greater than 15% and less than or equal to 25%, h1 / h2 is 0.21 to 0.64, b3 / b5 is 0.30 to 0.90, b1 / b3 is 0.94 to 3.32, and (h3+h6) / h2 is 0.12 to 0.25. (Condition 3B) When R is greater than 25% and less than or equal to 35%, h1 / h2 is 0.21 to 0.64, b3 / b5 is 0.45 to 0.90, b1 / b3 is 0.79 to 2.16, and (h3+h6) / h2 is 0.13 to 0.23. (Condition 4B) When R is greater than 35% and less than or equal to 45%, h1 / h2 is 0.36 to 0.50, b3 / b5 is 0.75 to 0.90, b1 / b3 is 0.79 to 1.10, and (h3+h6) / h2 is 0.19 to 0.22.(Condition 5B) When R is greater than 45% and less than or equal to 55%, h1 / h2 is 0.21 to 0.36, b3 / b5 is 0.75 to 0.90, b1 / b3 is 0.83 to 1.22, and (h3+h6) / h2 is 0.14 to 0.19. (Condition 6B) When R is greater than 55% and less than or equal to 65%, h1 / h2 is 0.21 to 0.29, b3 / b5 is 0.83 to 0.90, b1 / b3 is 0.69 to 0.98, and (h3+h6) / h2 is 0.15 to 0.18. (Condition 7B) When R is greater than 65% and less than or equal to 75%, h1 / h2 is 0.21 to 0.29, b3 / b5 is 0.85 to 0.90, b1 / b3 is 0.63 to 0.66, and (h3+h6) / h2 is 0.11 to 0.16. (Condition 8B) When R is greater than 75% and less than or equal to 85%, h1 / h2 is 0.07 to 0.14, b3 / b5 is 0.88 to 0.90, b1 / b3 is 0.56 to 0.89, and (h3+h6) / h2 is 0.09 to 0.15.

[0056] The pellicle frame of the third embodiment is a frame that satisfies any one of conditions 1B to 8B, thereby making the second moment of area of ​​the second shape greater than or equal to the second moment of area of ​​a hypothetical U-shape over the same area. As a result, the pellicle frame of the third embodiment is a pellicle frame with reduced mass and high rigidity in the thickness direction. In conditions 1B to 8B, the units of b1, b3, b5, h1, h2, h3, and h6 may be mm.

[0057] The pellicle frame of the third embodiment is a frame that satisfies any one of conditions 1B to 8B, and further preferably h1 and h3+h6 are each independently 0.2 mm or more, and (h2-h1-h3-h6) is 0.3 mm or more. h1 and h3+h6 may each be independently 1.5 mm or less, and (h2-h1-h3-h6) may be 2 mm or less.

[0058] From the viewpoint of ease of processing and robustness as a pellicle frame, it is preferable that the pellicle frame of the second embodiment is a frame that further satisfies any one of the following conditions 1D to 8D. (Condition 1D) When R is greater than 5% and 15% or less, h1 / h2 is 0.57 to 0.64, b3 / b5 is 0.30 to 0.60, b1 / b3 is 1.58 to 3.00, and (h3+h6) / h2 is 0.24 to 0.25. (Condition 2D) When R is greater than 15% and 25% or less, h1 / h2 is 0.50 to 0.64, b3 / b5 is 0.45 to 0.90, b1 / b3 is 0.94 to 1.90, and (h3+h6) / h2 is 0.21 to 0.24. (Condition 3D) When R is greater than 25% and less than or equal to 35%, h1 / h2 is 0.36 to 0.64, b3 / b5 is 0.60 to 0.90, b1 / b3 is 0.79 to 1.52, and (h3+h6) / h2 is 0.17 to 0.23. (Condition 4D) When R is greater than 35% and less than or equal to 45%, h1 / h2 is 0.36 to 0.50, b3 / b5 is 0.75 to 0.90, b1 / b3 is 0.79 to 1.10, and (h3+h6) / h2 is 0.19 to 0.21. (Condition 5D) When R is greater than 45% and less than or equal to 55%, h1 / h2 is 0.29 to 0.36, b3 / b5 is 0.80 to 0.90, b1 / b3 is 0.83 to 1.03, and (h3+h6) / h2 is 0.18 to 0.19. (Condition 6D) When R is greater than 55% and less than or equal to 65%, h1 / h2 is 0.21 to 0.29, b3 / b5 is 0.83 to 0.90, b1 / b3 is 0.69 to 0.98, and (h3+h6) / h2 is 0.15 to 0.17. (Condition 7D) When R is greater than 65% and less than or equal to 75%, h1 / h2 is 0.21 to 0.29, b3 / b5 is 0.85 to 0.90, b1 / b3 is 0.63 to 0.66, and (h3+h6) / h2 is 0.11 to 0.16. (Condition 8D) When R is greater than 75% and less than or equal to 85%, h1 / h2 is 0.07 to 0.14, b3 / b5 is 0.88 to 0.90, b1 / b3 is 0.56 to 0.89, and (h3+h6) / h2 is 0.09 to 0.15.

[0059] The pellicle frame of the third embodiment differs from the pellicle frame of the second embodiment, which satisfies h2 / b5 between 0.44 and 2.00 and satisfies one of conditions 1A to 8A, in that the pellicle frame of the third embodiment satisfies h2 / b5 between 0.27 and 0.43 and satisfies one of conditions 1B to 8B. Details common to the first or second embodiment will be omitted.

[0060] Furthermore, the pellicle frame of the third embodiment may include a membrane support on the first surface that adheres to the pellicle film. This allows the first surface to support the pellicle film via the membrane support that supports the pellicle film. The preferred configuration of the membrane support in the third embodiment is the same as the preferred configuration of the membrane support in the first embodiment described above.

[0061] In the third embodiment, when the pellicle frame and the film support are combined, the height of the pellicle frame (i.e., the length of the pellicle frame in the thickness direction) is not particularly limited, but is preferably 2.0 mm or less, more preferably 1.8 mm or less, even more preferably 1.7 mm or less, and particularly preferably 1.6 mm or less. The height of the pellicle frame may be 1.0 mm or more, 1.1 mm or more, or 1.2 mm or more.

[0062] The pellicle frame of this disclosure may or may not have an adhesive layer on the second surface. The adhesive layer enables the pellicle of this disclosure to be adhered to a photomask.

[0063] The adhesive layer is a gel-like viscoelastic material. The adhesive layer possesses viscosity and cohesive force. Viscosity refers to its liquid-like properties, wetting the photomask upon contact. Cohesive force refers to its solid-like properties, resisting peeling from the photomask.

[0064] The adhesive layer is formed by applying a coating composition to the coating composition, heating, drying, and curing. The adhesive constituting the adhesive layer is not particularly limited. From the viewpoint of reducing the amount of outgassing generated from the pellicle, the adhesive preferably contains at least one selected from the group consisting of acrylic adhesives, silicone adhesives, styrene-butadiene adhesives, urethane adhesives, and olefin adhesives, more preferably contains an acrylic adhesive, and even more preferably an acrylic adhesive.

[0065] If the pellicle frame of this disclosure further comprises an adhesive layer, it may or may not further comprise a liner (release film). The liner protects at least the surface of the adhesive layer that is in contact with the photomask. The liner is peelable from the adhesive layer.

[0066] As shown in Figure 8, when the pellicle frame is rectangular, square, or other rectangular frame shape, the length of the second face may be shorter than the length of the first face on two opposing sides. In this case, the lengths of the first face 31 and the second face 32 may be the same, and a hook portion 34 may be formed on the two sides as indicated by the arrow. By hooking a member onto this hook portion, the pellicle frame, pellicle, etc., can be easily transported. The shape of the hook portion 34 is not particularly limited and may be a recess provided in the width direction, a through hole, or a handle. When the hook portion is a recess or a through hole, the width of the recess or through hole may be 1 mm to 5 mm or 1 mm to 3 mm.

[0067] The hook portion may be provided in a region where the length of the second surface is shorter than the length of the first surface. For example, as shown in Figure 9, the pellicle frame 50 may have a hook portion 4 provided on the bottom surface of the recess 3.

[0068] In the pellicle frame of this disclosure, as described above, there is a recess between the first surface and the second surface on the outside of the pellicle frame, but on the inside of the pellicle frame, there may or may not be a recess between the first surface and the second surface. Figure 11 shows a pellicle frame having a recess between the first surface and the second surface on the inside of the pellicle frame. In Figure 11, a recess 3 is located between the first surface 1 and the second surface 2 on the outside of the pellicle frame 100, and a recess 4 is located between the first surface 1 and the second surface 2 on the inside of the pellicle frame 100.

[0069] From the viewpoint of simplifying the shape of the pellicle frame while ensuring rigidity in the thickness direction, it is preferable that there is no recess between the first and second surfaces on the inside of the pellicle frame. Furthermore, the absence of a recess on the inside of the pellicle frame prevents foreign matter such as dirt from adhering to the recess.

[0070] In a cross-section along the width direction of the pellicle frame, it is preferable that the pellicle frame does not have a quadrilateral recess between the first and second surfaces on the inside of the pellicle frame. Examples of quadrilateral recesses include rectangles, squares, trapezoids, and parallelograms. The quadrilateral shape consists of a combination of three sides constituting the recess and one side (the dotted line portion shown in Figure 11) which is an imaginary line segment connecting the two ends of the opening of the recess in the aforementioned cross-section. Figure 11 illustrates a case where the cross-sectional shape of the recess is quadrilateral, but the shape of the recess is not limited to a quadrilateral shape in this disclosure.

[0071] In the pellicle frame of this disclosure, at least a portion of the inner wall between the first surface and the second surface may be curved, or the entire wall may not be curved. If at least a portion of the inner wall between the first surface and the second surface is curved, it may be curved toward the outer wall or toward the inner wall. If at least a portion of the inner wall between the first surface and the second surface is curved toward the outer wall, the depth of the recess formed by the curvature in a cross section along the width direction of the pellicle frame may be 10% or less of the length of the second surface (L2 in Figure 2), or 5% or less.

[0072] In the pellicle frame of the present disclosure, the inner wall between the first surface and the second surface may be flat, a combination of two or more flat surfaces (for example, a combination of a C-surface and other flat surfaces), or a combination of one or more flat surfaces and one or more curved surfaces (for example, a combination of an R-surface and a flat surface).

[0073] ≪Pellicle≫ The pellicle of the present disclosure comprises a pellicle frame of the present disclosure and a pellicle film disposed on the first surface side of the pellicle frame. Since the pellicle of the present disclosure comprises a pellicle frame of the present disclosure, it has the same effects as the pellicle frame of the present disclosure.

[0074] <Pellicle film> The pellicle film in this disclosure is not particularly limited and includes carbon-based films, polysilicon-based films, boron nitride films, silicon nitride films, transition metal disulfide films, and the like.

[0075] Examples of carbon-based films include films containing carbon nanotubes (also called "CNTs") (also called "CNT films"), films containing graphene, films containing graphite, films containing diamond-like carbon, films containing amorphous carbon, and films containing silicon carbide.

[0076] From the viewpoint of increasing the transmittance of EUV light, the carbon-based film preferably has a carbon content of 40% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more, and particularly preferably 80% by mass or more. As long as the carbon content of the carbon-based film is 100% by mass or less, there is no upper limit to the carbon content.

[0077] The carbon content in carbon-based films is measured by X-ray photoelectron spectroscopy (also known as XPS). Since the information obtained by XPS is limited to compositional information in a shallow region of a few nanometers from the surface of the thin film, when measuring carbon-based pellicle films with a coating layer on the surface, the composition of the coating layer may be primarily detected. Therefore, when measuring the carbon content in carbon-based films using XPS, compositional analysis is performed while etching the pellicle film by ion sputtering, and the carbon content is calculated from the total amount of the depth-direction profile.

[0078] The CNT film may be a single-walled carbon nanotube, a multi-walled carbon nanotube, or may include single-walled carbon nanotubes and multi-walled carbon nanotubes.

[0079] The polysilicon-based film is preferably a film containing polysilicon as a main component. The content of polysilicon is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 80% by mass or more. The upper limit of the silicon content is not limited as long as the silicon content of the polysilicon-based film is 100% by mass or less.

[0080] The boron nitride film is preferably a film containing boron nitride as a main component. The content of boron nitride is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 80% by mass or more. The upper limit of the boron nitride content is not limited as long as the boron nitride content of the boron nitride film is 100% by mass or less.

[0081] The silicon nitride film is preferably a film containing silicon nitride as a main component. The content of silicon nitride is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 80% by mass or more. The upper limit of the silicon nitride content is not limited as long as the silicon nitride content of the silicon nitride film is 100% by mass or less.

[0082] The transition metal disulfide film is preferably a film containing transition metal disulfide as a main component. The content of transition metal disulfide is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 80% by mass or more. The upper limit of the transition metal disulfide content is not limited as long as the transition metal disulfide content of the transition metal disulfide film is 100% by mass or less.

[0083] The transition metal disulfide is MoS ２ , MoSe ２ , WS ２ or WSe ２That's fine.

[0084] In the pellicle film of this disclosure, a carbon-based film, a polysilicon-based film, a boron nitride film, a silicon nitride film, a transition metal disulfide film, or the like (hereinafter also referred to as "the first film") may be laminated with other layers.

[0085] In the pellicle film of this disclosure, if the first film is laminated with other layers, it is preferable that the thickness of the first film is greater than the thickness of the other layers. If the first film is laminated with other layers, it is preferable that the outermost layer of the pellicle is one of the other layers. If the first film is laminated with other layers, it is preferable that the thickness of the first film is 50% or more, and more preferably 70% or more, of the total thickness of the pellicle film including the other layers. If the first film is laminated with other layers, the thickness of the first film may be 99% or less, or 90% or less, of the total thickness of the pellicle film including the other layers. Alternatively, the thickness of the first film may be 100% of the total thickness of the pellicle film including the other layers. In other words, the first film may not be laminated with other layers, and the pellicle film of this disclosure may consist only of the first film. Examples of other layers include the following layers.

[0086] <Antioxidant Layer> The pellicle film of this disclosure may further include an antioxidant layer on at least one side. By further including an antioxidant layer in the pellicle film, oxidation of the pellicle film can be suppressed during light irradiation or pellicle storage.

[0087] The type of the antioxidant layer is not particularly limited, as long as it is made of a material that is stable against light (preferably EUV light). For example, SiO ｘ (x ≤ 2), Si ｘ N ｙ (x / y is 0.7 to 1.5), SiON, Y ２ O ３ This could be a layer consisting of YN, Mo, Ru, Rb, Sr, Y, Zr, Nb, or Rh.

[0088] To avoid inhibiting light transmission, the thickness of the antioxidant layer is preferably about 1 nm to 10 nm, and more preferably about 2 nm to 5 nm. By setting the thickness of the antioxidant layer to about 1 nm to 10 nm, the absorption of light by the antioxidant layer can be suppressed, thereby suppressing a decrease in transmittance.

[0089] The ratio of the thickness of the antioxidant layer to the thickness of the pellicle film is preferably in the range of 0.03 to 1.0. Within this numerical range, it is possible to suppress the absorption of light by the antioxidant layer and suppress the decrease in transmittance.

[0090] Furthermore, when an antioxidant layer is laminated onto the pellicle film, light reflection may occur at the newly formed layer interfaces, namely the interface between the antioxidant layer and air, and the interface between the antioxidant layer and the pellicle film, potentially reducing transmittance. The reflectance of light at these layer interfaces can be calculated depending on the thickness of the pellicle film and the antioxidant layer, as well as the types of elements that make up the pellicle film and the antioxidant layer. And, similar to the principle of anti-reflective coatings, the reflectance can be reduced by optimizing the thickness of the film.

[0091] The thickness of the oxidation-preventive layer should preferably be an optimal thickness that suppresses the reduction in light transmittance due to absorption and reflection, while maintaining oxidation-preventive performance.

[0092] The thickness uniformity and surface roughness of the antioxidant layer are not particularly limited. As long as there are no problems in the exposure patterning process, such as uneven transmittance due to uneven thickness or surface roughness, or interference due to light scattering, the antioxidant layer may be a continuous layer or an island-like structure, and it may have uneven thickness or surface roughness.

[0093] The average refractive index of the pellicle film, including the anti-oxidation layer, is preferably in the range of 1.9 to 5.0. The refractive index can be measured by methods such as spectroscopic ellipsometry. The average density of the pellicle film, including the anti-oxidation layer, is 1.5 g / cm³. ３ ~5.0 g / cm ３ It is preferable that the density is within this range. The density can be measured by methods such as X-ray reflection.

[0094] The thickness of the pellicle film (total thickness if it consists of two or more layers) can be, for example, 10 nm to 200 nm, preferably 10 nm to 100 nm, more preferably 10 nm to 70 nm, and even more preferably 10 nm to 50 nm.

[0095] <Adhesive Layer> The pellicle of this disclosure may include an adhesive layer containing an adhesive. Examples of the adhesive layer include (a) and (b) below: (a) An adhesive layer for bonding the support frame and the master plate (also called the master plate adhesive layer) (b) An adhesive layer for bonding multiple support frames together when there are multiple support frames (also called the support frame adhesive layer)

[0096] (Adhesive) There are no particular restrictions on the adhesive contained in the adhesive layer. Examples of adhesives include acrylic resin adhesives, epoxy resin adhesives, polyimide resin adhesives, silicone resin adhesives, inorganic adhesives, double-sided adhesive tapes, polyolefin adhesives, hydrogenated styrene adhesives, etc.

[0097] (Uses of the pellicle) The pellicle of this disclosure may be used not only as a protective member to prevent foreign matter from adhering to the master plate in an EUV exposure apparatus, but also as a protective member to protect the master plate during storage, transportation, etc. For example, if the pellicle is attached to the master plate (exposure master plate), it can be stored as is after being removed from the EUV exposure apparatus. Methods for attaching the pellicle to the master plate include adhesive bonding, electrostatic adsorption, and mechanical fixing.

[0098] The pellicle of this disclosure is suitably used for exposure using short-wavelength exposure light (e.g., EUV light, light with an even shorter wavelength than EUV light, etc.). Among the above, the pellicle film of this disclosure is suitably used for exposure using EUV light.

[0099] In this disclosure, EUV (Extreme Ultra Violet) light refers to light with a wavelength of 5 nm to 30 nm. The wavelength of EUV light is preferably between 5 nm and 13.5 nm. In this disclosure, EUV light and light with a shorter wavelength than EUV light are collectively referred to as "EUV light, etc."

[0100] ≪Exposure Master Plate≫ The exposure master plate of this disclosure includes a master plate having a pattern and a pellicle of this disclosure attached to the patterned side of the master plate. Since the exposure master plate of this disclosure is equipped with the pellicle of this disclosure, it produces the same effects as the pellicle of this disclosure.

[0101] The method for attaching the master plate to the pellicle of this disclosure is not particularly limited. For example, the master plate may be directly attached to the support frame, via an adhesive layer for master plates on one end face of the support frame, mechanically fixed, or fixed to the support frame using the attractive force of a magnet or the like.

[0102] Here, the master plate used can include a support substrate, a reflective layer laminated on the support substrate, and an absorber layer formed on the reflective layer. The absorber layer partially absorbs light (e.g., EUV light), thereby forming a desired image on a sensitive substrate (e.g., a semiconductor substrate with a photoresist film). The reflective layer may be a multilayer film of molybdenum (Mo) and silicon (Si). The absorber layer may be a material with high absorption of EUV light, such as chromium (Cr) or tantalum nitride.

[0103] <<Exposure Apparatus>> The exposure apparatus of this disclosure may have the exposure master plate described above. More specifically, the exposure apparatus of this disclosure comprises a light source that emits exposure light, the exposure master plate of this disclosure, and an optical system that guides the exposure light emitted from the light source to the exposure master plate, wherein the exposure master plate is arranged so that the exposure light emitted from the light source passes through the pellicle film and irradiates the master plate. For this reason, the exposure apparatus of this disclosure produces the same effect as the exposure master plate of this disclosure.

[0104] The exposure apparatus of the present disclosure comprises a light source that emits exposure light, an exposure master plate of the present disclosure, and an optical system that guides the exposure light emitted from the light source to the exposure master plate, wherein the exposure master plate is preferably arranged so that the exposure light emitted from the light source passes through the pellicle film and irradiates the master plate. According to this embodiment, in addition to being able to form a finely detailed pattern (for example, with a line width of 32 nm or less) using EUV light, it is possible to perform pattern exposure with reduced resolution problems due to foreign matter, even when using EUV light, which is prone to problems with resolution problems due to foreign matter.

[0105] In this disclosure, the exposure light is preferably EUV light.

[0106] <Method for Manufacturing a Semiconductor Device> The method for manufacturing a semiconductor device according to the present disclosure includes the steps of: irradiating an exposure master plate with exposure light emitted from a light source, passing it through the pellicle film of the exposure master plate according to the present disclosure, and reflecting the light off the master plate; and irradiating a sensitive substrate with the exposure light reflected by the master plate, passing it through the pellicle film, thereby exposing the sensitive substrate in a patterned manner.

[0107] Hereinafter, an example of a method for manufacturing a semiconductor device according to the present disclosure will be described with reference to Figure 10. Figure 10 is a schematic cross-sectional view of an EUV exposure apparatus 800, which is an example of an exposure apparatus according to the present disclosure. As shown in Figure 10, the EUV exposure apparatus 800 includes a light source 831 that emits EUV light, an exposure master plate 850 which is an example of an exposure master plate according to the present disclosure, and an illumination optical system 837 that guides the EUV light emitted from the light source 831 to the exposure master plate 850. The exposure master plate 850 includes a pellicle 810 including a pellicle film 812 and a support frame 814, and a master plate 833. The exposure master plate 850 is arranged so that the EUV light emitted from the light source 831 passes through the pellicle film 812 and irradiates the master plate 833. The master plate 833 reflects the irradiated EUV light in a pattern. The pellicle 810 is an example of a pellicle according to the present disclosure.

[0108] In the EUV exposure apparatus 800, filter windows 820 and 825 are installed between the light source 831 and the illumination optical system 837, and between the illumination optical system 837 and the original plate 833, respectively. The EUV exposure apparatus 800 also includes a projection optical system 838 that guides the EUV light reflected from the original plate 833 to the sensitive substrate 834.

[0109] In the EUV exposure apparatus 800, EUV light reflected by the master plate 833 is guided onto the sensitive substrate 834 through the projection optical system 838, and the sensitive substrate 834 is exposed in a patterned manner. The EUV exposure is performed under reduced pressure conditions.

[0110] The EUV light source 831 emits EUV light toward the illumination optical system 837. The EUV light source 831 includes a target material and a pulsed laser irradiation unit. EUV light is obtained by irradiating the target material with a pulsed laser to generate plasma. If the target material is Sn, EUV light with a wavelength of 13 nm to 14 nm can be obtained. The wavelength of the light emitted by the EUV light source is not limited to 13 nm to 14 nm; any light with a wavelength suitable for the purpose within the range of 5 nm to 30 nm is acceptable.

[0111] The illumination optical system 837 focuses the light emitted from the EUV light source 831, equalizes the illuminance, and illuminates the original plate 833. The illumination optical system 837 includes multiple multilayer mirrors 832 for adjusting the EUV light path, and an optical coupler (optical integrator), etc. The multilayer mirrors are multilayer films in which molybdenum (Mo) and silicon (Si) are alternately stacked.

[0112] The method of mounting the filter windows 820 and 825 is not particularly limited and can be done by attaching them with an adhesive or by mechanically fixing them inside the EUV exposure apparatus. The filter window 820, positioned between the light source 831 and the illumination optical system 837, captures scattered particles (debris) generated from the light source and prevents them from adhering to elements inside the illumination optical system 837 (for example, the multilayer mirror 832). On the other hand, the filter window 825, positioned between the illumination optical system 837 and the master plate 833, captures particles (debris) scattered from the light source 831 and prevents them from adhering to the master plate 833.

[0113] Furthermore, foreign matter adhering to the master plate absorbs or scatters EUV light, causing poor resolution on the wafer. Therefore, the pellicle 810 is mounted so as to cover the EUV light irradiation area of ​​the master plate 833. EUV light passes through the pellicle film 812 and is irradiated onto the master plate 833.

[0114] EUV light reflected by the master plate 833 passes through the pellicle film 812 and is irradiated onto the sensitive substrate 834 via the projection optical system 838. The projection optical system 838 focuses the light reflected by the master plate 833 and irradiates the sensitive substrate 834. The projection optical system 838 includes multiple multilayer mirrors 835, 836, etc., for preparing the EUV optical path.

[0115] The sensitive substrate 834 is a substrate on which a resist is coated on a semiconductor wafer, and the resist hardens in a patterned manner due to EUV reflected by the master plate 833. By developing this resist and etching the semiconductor wafer, a desired pattern is formed on the semiconductor wafer.

[0116] Furthermore, the pellicle 810 is attached to the master plate 833 via an adhesive layer for the master plate, etc. Foreign matter adhering to the master plate absorbs or scatters EUV, causing poor resolution on the wafer. Therefore, the pellicle 810 is attached so as to cover the EUV light irradiation area of ​​the master plate 833, and the EUV passes through the pellicle film 812 and is irradiated onto the master plate 833.

[0117] The method for attaching the pellicle 810 to the original plate 833 is not limited to any method that allows the pellicle to be attached to the original plate without foreign matter adhering to its surface. Examples include attaching the support frame 814 to the original plate 833 with an adhesive, electrostatic adsorption, or mechanical fixing. Preferably, the method of attaching with an adhesive is used.

[0118] The disclosure of Japanese Patent Application No. 2024-182202 is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually noted to be incorporated by reference.

Claims

1. A pellicle frame comprising a first surface for supporting a pellicle film and a second surface on the photomask side located opposite to the first surface, wherein in a cross section along the width direction of the pellicle frame, the length of the second surface is smaller than the length of the first surface, there is no quadrilateral recess between the first surface and the second surface on the inside of the pellicle frame, and there is a recess between the first surface and the second surface on the outside of the pellicle frame, and when a hypothetical U-shape having the same area as the first shape is created from the first shape, the second moment of area of ​​the first shape is greater than the second moment of area of ​​the U-shape.

2. A pellicle frame comprising a first surface for supporting a pellicle film and a second surface on the photomask side located opposite to the first surface, wherein in a cross-section along the width direction of the pellicle frame, it comprises a frame support portion, a first extension portion which together with the frame support portion constitutes the first surface and extends to the outside of the frame support portion, a second extension portion which together with the frame support portion constitutes the second surface and extends to the outside of the frame support portion, and a recess portion located between the first extension portion and the second extension portion, and the length of the first extension portion is greater than the length of the second extension portion, A pellicle frame having a ratio of 0.44 to 2.00, where b1 is the length of the second extension, b3 is the length of the first extension, b5 is the total length of the frame support and the first extension, h1 is the height of the second extension, h2 is the height of the frame support, h3 + h6 is the height of the first extension (where h1 × (b3 - b1) = h6 × b3), and R is the hollowing ratio (where R = [(h2 - h1 - h3 - h6) × b3] / (h2 × b5)), and where h2 / b5 is between 0.44 and 2.00, and also satisfying one of the following conditions 1A to 8A. (Condition 1A) When R is greater than 5% and less than or equal to 15%, h1 / h2 is 0.28 to 0.85, b3 / b5 is 0.15 to 0.90, b1 / b3 is 0.95 to 6.37, and (h3+h6) / h2 is 0.14 to 0.

34. (Condition 2A) When R is greater than 15% and less than or equal to 25%, h1 / h2 is 0.28 to 0.75, b3 / b5 is 0.30 to 0.90, b1 / b3 is 0.67 to 3.03, and (h3+h6) / h2 is 0.14 to 0.

34. (Condition 3A) When R is greater than 25% and less than or equal to 35%, h1 / h2 is 0.28 to 0.66, b3 / b5 is 0.45 to 0.90, b1 / b3 is 0.78 to 1.90, and (h3+h6) / h2 is 0.14 to 0.

25. (Condition 4A) When R is greater than 35% and less than or equal to 45%, h1 / h2 is 0.28 to 0.47, b3 / b5 is 0.60 to 0.90, b1 / b3 is 0.83 to 1.34, and (h3+h6) / h2 is 0.15 to 0.

22. (Condition 5A) When R is greater than 45% and less than or equal to 55%, h1 / h2 is 0.28 to 0.38, b3 / b5 is 0.75 to 0.90, b1 / b3 is 0.79 to 1.02, and (h3 + h6) / h2 is 0.15 to 0.19.(Condition 6A) When R is greater than 55% and less than or equal to 65%, h1 / h2 is 0.19 to 0.28, b3 / b5 is 0.75 to 0.90, b1 / b3 is 0.77 to 1.10, and (h3+h6) / h2 is 0.09 to 0.

15. (Condition 7A) When R is greater than 65% and less than or equal to 75%, h1 / h2 is 0.19 to 0.24, b3 / b5 is 0.83 to 0.90, b1 / b3 is 0.72 to 0.77, and (h3+h6) / h2 is 0.10 to 0.

11. (Condition 8A) When R is greater than 75% and less than or equal to 85%, h1 / h2 is 0.09 to 0.14, b3 / b5 is 0.80 to 0.90, b1 / b3 is 0.69 to 0.72, and (h3 + h6) / h2 is 0.05 to 0.

06.

3. A pellicle frame comprising a first surface for supporting a pellicle film and a second surface on the photomask side located opposite to the first surface, wherein in a cross-section along the width direction of the pellicle frame, it comprises a frame support portion, a first extension portion which together with the frame support portion constitutes the first surface and extends to the outside of the frame support portion, a second extension portion which together with the frame support portion constitutes the second surface and extends to the outside of the frame support portion, and a recess portion located between the first extension portion and the second extension portion, and the length of the first extension portion is greater than the length of the second extension portion, A pellicle frame having a length of b1 for the second extension, a length of b3 for the first extension, a total length of b5 for the frame support and the first extension, a height of h1 for the second extension, a height of h2 for the frame support, a height of h3 + h6 for the first extension (where h1 × (b3 - b1) = h6 × b3), and a hollowing ratio of R (where R = [(h2 - h1 - h3 - h6) × b3] / (h2 × b5)), wherein h2 / b5 satisfies 0.27 to 0.43 and satisfies any one of the following conditions 1B to 8B. (Condition 1B) When R is greater than 5% and less than or equal to 15%, h1 / h2 is 0.50 to 0.64, b3 / b5 is 0.30 to 0.90, b1 / b3 is 1.08 to 3.22, and (h3+h6) / h2 is 0.23 to 0.

26. (Condition 2B) When R is greater than 15% and less than or equal to 25%, h1 / h2 is 0.21 to 0.64, b3 / b5 is 0.30 to 0.90, b1 / b3 is 0.94 to 3.32, and (h3+h6) / h2 is 0.12 to 0.

25. (Condition 3B) When R is greater than 25% and less than or equal to 35%, h1 / h2 is 0.21 to 0.64, b3 / b5 is 0.45 to 0.90, b1 / b3 is 0.79 to 2.16, and (h3+h6) / h2 is 0.13 to 0.

23. (Condition 4B) When R is greater than 35% and less than or equal to 45%, h1 / h2 is 0.36 to 0.50, b3 / b5 is 0.75 to 0.90, b1 / b3 is 0.79 to 1.10, and (h3+h6) / h2 is 0.19 to 0.

22. (Condition 5B) When R is greater than 45% and less than or equal to 55%, h1 / h2 is 0.21 to 0.36, b3 / b5 is 0.75 to 0.90, b1 / b3 is 0.83 to 1.22, and (h3 + h6) / h2 is 0.14 to 0.19.(Condition 6B) When R is greater than 55% and less than or equal to 65%, h1 / h2 is 0.21 to 0.29, b3 / b5 is 0.83 to 0.90, b1 / b3 is 0.69 to 0.98, and (h3+h6) / h2 is 0.15 to 0.

18. (Condition 7B) When R is greater than 65% and less than or equal to 75%, h1 / h2 is 0.21 to 0.29, b3 / b5 is 0.85 to 0.90, b1 / b3 is 0.63 to 0.66, and (h3+h6) / h2 is 0.11 to 0.

16. (Condition 8B) When R is greater than 75% and less than or equal to 85%, h1 / h2 is 0.07 to 0.14, b3 / b5 is 0.88 to 0.90, b1 / b3 is 0.56 to 0.89, and (h3 + h6) / h2 is 0.09 to 0.

15.

4. The pellicle frame according to claim 3, further comprising a membrane support on the first surface that adheres to the pellicle film.

5. The pellicle frame according to claim 1, further comprising an adhesive layer on the second surface.

6. A pellicle comprising a pellicle frame according to any one of claims 1 to 5, and a pellicle film disposed on the first surface side of the pellicle frame.

7. An exposure master plate comprising: a master plate having a pattern; and a pellicle according to claim 6 attached to the patterned side of the master plate.

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