Pellicle and method for manufacturing the same

Abstract

The present invention provides a pellicle with a good appearance and a method for manufacturing the same, in which large film twists, such as those exceeding 500 μm, are suppressed at the bonding portion between the adhesive layer and the pellicle film. [Solution] A pellicle having a pellicle frame, an adhesive layer on the upper end surface of the pellicle frame, and a pellicle film on the adhesive layer, wherein at the inner upper end of the pellicle frame, the angle between the upper end surface and the adjacent inner surface is 105° or less.

Description

Technical Field

[0001] The present invention relates to a lithography pellicle used for dust prevention of a lithography mask when manufacturing semiconductor devices such as LSIs and super LSIs, or liquid crystal display panels.

Background Art

[0002] In the manufacture of semiconductors such as LSIs and super LSIs, or in the manufacture of liquid crystal display panels, light is irradiated onto a semiconductor wafer or a raw plate for liquid crystals to form a pattern (Patent Document 1). If dust adheres to the exposure original plate used in this case, since this dust absorbs light or bends light, the transferred pattern is deformed, the edge becomes rough, and in addition, the base is blackened and soiled, resulting in problems such as deterioration of dimensions, quality, and appearance. In the present specification, the "exposure original plate" is a general term for a lithography mask and a reticle.

[0003] These operations are usually performed in a clean room, but it is difficult to always keep the exposure original plate clean even in this clean room. Therefore, a method of attaching a pellicle that allows light for exposure to pass well for dust prevention on the surface of the exposure original plate is adopted. In this case, since dust does not directly adhere to the surface of the exposure original plate but adheres to the pellicle film, if the focus is set on the pattern of the exposure original plate during lithography, the dust on the pellicle film becomes irrelevant to the transfer.

[0004] And the basic configuration of such a pellicle consists of a pellicle frame and a pellicle film stretched thereon. This pellicle film is made of nitrocellulose, cellulose acetate, fluorine-based polymers, etc. that transmit light (g-line, i-line, 248 nm, 193 nm, etc.) used for exposure well, and the pellicle frame is made of aluminum alloys such as A7075, A6061, A5052, etc. that have been subjected to black anodizing treatment, stainless steel, polyethylene, etc.

[0005] Furthermore, an adhesive layer made of an adhesive such as acrylic resin, epoxy resin, or fluororesin is provided on the upper part of the pellicle frame, and the pellicle film is bonded to it via this adhesive layer. In addition, an adhesive layer made of polybutene resin, polyvinyl acetate resin, acrylic resin, or silicone resin is provided on the lower part of the pellicle frame for mounting the exposure master plate, and a reticle adhesive protective liner is provided to protect the adhesive layer.

[0006] The pellicle, configured in this way, is installed to surround the pattern area formed on the surface of the exposure plate and is provided to prevent dust from adhering to the exposure plate. Therefore, this pattern area and the area outside the pellicle are isolated from each other to prevent dust from the outside of the pellicle from adhering to the pattern surface. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2022-160364 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] In this case, cosmetic problems sometimes arose with the pellicle film. For example, near the inner upper end of the pellicle frame (near the boundary between the bonded and non-bonded areas of the pellicle film and the adhesive layer), the shape of the inner end of the adhesive layer may not be sharp but rounded. As a result, the pellicle film may have areas where it adheres tightly to this rounded shape, and areas where it is slightly lifted without adhering to this rounded shape. Therefore, there was a drawback that irregularities or steps may occur on the surface of the pellicle film near the inner upper end of the pellicle frame, leading to cosmetic defects. In particular, the appearance is poor when large film deformations exceeding 500 μm occur.

[0009] When the shape of the inner edge of the adhesive layer affects the adhesion of the pellicle film, resulting in unevenness, fine steps and irregularities appear in the pellicle film near the inner upper edge of the pellicle frame. Such a pellicle film appears distorted, and this phenomenon will henceforth be referred to as film distortion.

[0010] The present invention aims to provide a pellicle with a good appearance and a method for manufacturing the same, in which large film twists, such as those exceeding 500 μm, are suppressed at the bonding portion between the adhesive layer and the pellicle film. [Means for solving the problem]

[0011] To achieve the above objective, the present invention provides a pellicle comprising a pellicle frame, an adhesive layer on the upper end surface of the pellicle frame, and a pellicle film on the adhesive layer, The present invention provides a pellicle characterized in that, at the inner upper end of the pellicle frame, the angle between the upper end surface and the adjacent inner surface is 105° or less.

[0012] With the pellicle of the present invention, the angle between the upper surface of the inner upper end of the pellicle frame and the adjacent surface (inner upper end angle) is 105° or less. Therefore, the shape of the inner end of the adhesive layer (near the inner upper end of the pellicle frame) can be sharp rather than rounded. As a result, the pellicle film can be prevented from having an uneven adhesion state with the adhesive layer near the inner upper end of the pellicle frame, and large film twists, such as those exceeding 500 μm, are suppressed. For these reasons, the pellicle film has an excellent appearance.

[0013] In this case, the surface roughness Ra of the upper end surface can be set to 0.30 μm or less.

[0014] Because the surface roughness Ra of the upper end surface is 0.30 μm or less, irregularities are suppressed on the surface of the adhesive layer on the upper end surface, resulting in a highly smooth surface. Therefore, in the pellicle film, similarly, the uneven adhesion state with the adhesive layer caused by the irregularities of the adhesive layer near the inner upper end of the pellicle frame is more effectively prevented, and relatively large film twists exceeding 200 μm are suppressed, for example. As a result, the appearance of the pellicle film is improved.

[0015] In this case, the adhesive in the adhesive layer is made of amorphous fluororesin. The pellicle film is made of amorphous fluororesin. The aforementioned pellicle can be one for use with an ArF excimer laser.

[0016] For pellicles used with ArF excimer lasers (193nm), high light resistance is required for the pellicle film, so amorphous fluororesin is often used. Furthermore, using amorphous fluororesin with high light resistance for the adhesive layer also results in a high-performance pellicle with even greater reliability during ArF excimer laser (193nm) exposure. Generally, in the case of an amorphous fluororesin adhesive layer, unlike a liquid adhesive such as an UV-curing adhesive to which the pellicle film is bonded and then cured, the pellicle film is bonded by, for example, bonding it to a solid adhesive layer. In this case, the shape of the inner edge of the adhesive layer near the inner upper end of the pellicle frame tends to be rounded rather than sharp. However, as described above, the present invention has an inner upper end angle within the above range, and as a result, film twisting can be suppressed. Therefore, the present invention is particularly effective for pellicles for ArF excimer lasers.

[0017] Furthermore, the angle between the upper end surface and the adjacent surface at the inner upper end can be 90° or less.

[0018] With this type of material, a superior pellicle is more reliably created, with film twisting exceeding 500 μm being suppressed.

[0019] Further, the pellicle film can be made of a polymer of butenyl vinyl ether. Further, the adhesive of the adhesive layer can be made of a polymer of allyl vinyl ether.

[0020] These materials are suitable as the adhesive of the pellicle film and the adhesive layer in the pellicle of the present invention.

[0021] Further, the present invention provides a method for manufacturing a pellicle, comprising preparing a pellicle frame, forming an adhesive layer on the upper end surface of the prepared pellicle frame, and laminating and adhering a pellicle film on the formed adhesive layer, As the pellicle frame, a pellicle frame is prepared in which the angle formed by the upper end surface and the adjacent inner surface at the inner upper end is 105° or less.

[0022] According to such a method for manufacturing a pellicle of the present invention, since the inner upper end angle of the prepared pellicle frame is 105° or less, uneven adhesion between the pellicle film and the adhesive layer can be prevented near the inner upper end of the pellicle frame, and film sag (exceeding 500 μm) can be suppressed. Therefore, a pellicle with an excellent appearance of the pellicle film can be manufactured.

[0023] At this time, as the pellicle frame, a pellicle frame having a surface roughness Ra of the upper end surface of 0.30 μm or less can be prepared.

[0024] Since the surface roughness Ra of the upper end surface of the prepared pellicle frame is 0.30 μm or less, uneven adhesion between the pellicle film and the adhesive layer can be more effectively prevented near the inner upper end of the pellicle frame, and film sag (exceeding 200 μm) can be suppressed. Therefore, a pellicle with an even more excellent appearance of the pellicle film can be manufactured.

[0025] In this case, an amorphous fluororesin is used as the adhesive for the adhesive layer. As the pellicle film, an amorphous fluororesin is used. As the aforementioned pellicle, one for use with an ArF excimer laser can be manufactured.

[0026] This method suppresses film sagging and allows for the creation of a high-performance pellicle with even greater reliability during ArF excimer laser exposure.

[0027] Furthermore, as the pellicle frame, one can be prepared in which the angle between the upper end surface and the adjacent surface at the inner upper end is 90° or less.

[0028] This method allows for more reliable suppression of film twisting (over 500 μm) and the acquisition of a superior pellicle.

[0029] Furthermore, when bonding the pellicle film onto the adhesive layer, The adhesive in the adhesive layer is in a solid state, allowing the pellicle film to be bonded to it.

[0030] In particular, when bonding a pellicle film to an adhesive layer in a solid state, conventional methods tend to result in a rounded shape at the inner edge of the adhesive layer near the upper inner edge of the pellicle frame, rather than a sharp shape, which can easily lead to film twisting. However, the manufacturing method of the present invention makes it possible to sharpen the shape of the inner edge and suppress film twisting, making it particularly effective for this type of bonding.

[0031] Furthermore, the bonded parts can be heated after bonding.

[0032] This method can further increase the adhesive strength between the pellicle film and the adhesive layer.

[0033] Furthermore, the pellicle film can be made of a polymer of butenyl vinyl ether. Furthermore, an adhesive made of a polymer of allyl vinyl ether can be used as the adhesive for the adhesive layer.

[0034] These materials can be suitably used as adhesives for the pellicle film and adhesive layer in the pellicle of the present invention. [Effects of the Invention]

[0035] The pellicle and its manufacturing method of the present invention can suppress uneven adhesion between the pellicle film and the adhesive layer near the inner upper end of the pellicle frame. Therefore, film twisting (over 500 μm) of the pellicle film can be suppressed, and the deterioration of its appearance can be prevented. [Brief explanation of the drawing]

[0036] [Figure 1] This is an explanatory diagram showing an example of the pellicle (90° < angle A ≤ 105°) of the present invention. [Figure 2] This is an explanatory diagram showing another example of the pellicle (angle A ≤ 90°) of the present invention. [Figure 3] This is an explanatory diagram showing an example of a conventional pellicle (angle A=135°: area where the film is not twisted). [Figure 4] This is an explanatory diagram showing an example of a conventional pellicle (angle A=135°: area where the film is twisted). [Figure 5] This is a plan view diagram of a conventional pellicle membrane where membrane twisting is occurring. [Figure 6] This is a flowchart showing an example of the steps in the method for manufacturing the pellicle according to the present invention. [Modes for carrying out the invention]

[0037] The present invention will be described in detail below with reference to the figures as an example of an embodiment, but the present invention is not limited to these. As mentioned above, defects in the adhesion between the adhesive layer and the pellicle film sometimes caused film twisting (large twists exceeding 500 μm). Therefore, the inventors conducted diligent research and found that the shape of the inner upper end of the pellicle frame and the surface roughness of the upper end of the pellicle frame are important and that it is necessary to control them. Specifically, they found that if a pellicle has a pellicle frame, an adhesive layer on the upper end surface of the pellicle frame, and a pellicle film on the adhesive layer, and the angle between the upper end surface and the adjacent inner surface at the inner upper end of the pellicle frame is 105° or less, then film twisting (over 500 μm) of the pellicle film near the inner upper end of the pellicle frame can be suppressed, resulting in a pellicle with a good appearance, and thus completed the present invention.

[0038] Furthermore, we have discovered that if we manufacture a pellicle by preparing a pellicle frame, forming an adhesive layer on the upper end surface of the prepared pellicle frame, and bonding a pellicle film onto the formed adhesive layer, and the pellicle frame is prepared such that the angle between the upper end surface and the adjacent inner surface at the inner upper end is 105° or less, then the film twisting of the pellicle film (over 500 μm) described above can be suppressed, and a pellicle with an excellent appearance can be manufactured, thus completing the present invention.

[0039] Figure 1 shows an example of the pellicle of the present invention. Figure 2 shows an example of another embodiment of the pellicle of the present invention. The pellicle 1 of the present invention comprises a pellicle frame 2, an adhesive layer 3 on the upper end surface S1 of the pellicle frame 2, and a pellicle film 4 on the adhesive layer 3. Here, at the inner upper end P of the pellicle frame 2, the angle formed between the upper end surface S1 and the adjacent inner surface S2 is defined as the inner upper end angle A (hereinafter also simply referred to as angle A).

[0040] <Regarding the inner upper corner A> In this invention, the angle A at the inner upper end P of the pellicle frame 2 is 105° or less. Figure 1 shows an example where angle A is greater than 90° and less than or equal to 105°. In this case, the upper right corner of the pellicle frame 2 in Figure 1 is chamfered, so angle A is greater than 90° and less than or equal to 105°. In this case, this chamfered surface corresponds to the adjacent surface S2. Furthermore, the other three corners (the upper left, lower left, and lower right corners of the pellicle frame 2 in Figure 1) can be chamfered, for example.

[0041] With this design, the shape of the inner edge Q of the adhesive layer 3 near the inner upper edge P is not so rounded but relatively sharp (it is more perpendicular to the upper surface S1 compared to the outer edge of the adhesive layer near the upper left corner [C chamfer: 135°] of the pellicle frame 2). Therefore, non-uniformity of the adhesion state between the pellicle film 4 and the adhesive layer 3 near the inner upper edge P can be suppressed, and film twisting of the pellicle film 4 (large ones exceeding 500 μm) can be suppressed.

[0042] Figure 2 also shows an example where angle A is 90° or less. In this case, the upper right corner of Figure 2 is not chamfered, and the inner surface of the pellicle frame corresponds to the adjacent surface S2. When the angle A is 90° or less, the shape of the inner end Q of the adhesive layer 3 can be made sharper than in the case of Figure 1, which is preferable because it allows for a more reliable suppression of the non-uniformity of the adhesive state and film twisting (over 500 μm). The lower limit of angle A is not particularly limited and can be greater than 0°, but it can be, for example, around 75°.

[0043] Here, we will describe a conventional pellicle in contrast to the pellicle of the present invention. Conventionally, pellicle frames are generally chamfered to ensure good handling and a stable appearance during the frame manufacturing process. In the conventional pellicle 100 shown in Figure 3, all four corners of the pellicle frame 200 are chamfered, and the angle A at the inner upper end P is 135° (i.e., greater than 105°). When angle A is greater than 105°, the inner end Q of the adhesive layer 300 formed on top of it tends to be more rounded.

[0044] In this case, as shown in Figure 4, a portion of the pellicle film 400 may adhere to the rounded inner edge Q. In other words, as shown in the plan view in Figure 5, the adhesion state differs depending on the location (resulting in an uneven adhesion state). In Figure 5, M1 is a location where the pellicle film 400 does not adhere to the inner edge Q (Figure 3), and M2 is a location where the pellicle film 400 adheres to the inner edge Q (Figure 4) (resulting in film deformation exceeding 500 μm). Such large film deformations can impair the appearance.

[0045] On the other hand, in the pellicle 1 of the present invention, where angle A is 105° or less, the inner edge Q of the adhesive layer 3 is sharper than in conventional products. Therefore, adhesion of the pellicle film 4 to the inner edge Q is less likely to occur, and the large film twisting described above can be suppressed to an extreme degree. Even if film twisting occurs, it can be made smaller than in the case of conventional products.

[0046] <Regarding the surface roughness Ra of the upper surface> Furthermore, in the present invention, the surface roughness Ra of the upper end surface S1 of the pellicle frame 2 on which the adhesive layer 3 is formed is not particularly limited, but it is preferably 0.30 μm or less. With this configuration, the surface of the adhesive layer 3 on the upper end surface S1 is made smoother by suppressing irregularities. Therefore, near the inner upper end P of the pellicle frame 2 (especially around the entire inner circumference), the occurrence of uneven adhesion between the pellicle film 4 and the adhesive layer 3 caused by the aforementioned irregularities can be further prevented, and film twisting (relatively large ones exceeding 200 μm) is suppressed. The smaller the surface roughness Ra, the smoother the surface. For example, controlling it to 0.15 μm or less is even preferable, as it further prevents film twisting (over 200 μm).

[0047] To reiterate, in the pellicle 1 of the present invention, the surface roughness of corner A and upper end surface S1 is adjusted to within the above numerical range, so film twisting is extremely suppressed, resulting in a good appearance. In conventional products, large film deformations exceeding 500 μm can sometimes be observed near the inner upper end P, caused by the inner edge of the rounded adhesive layer. However, as in the present invention, by adjusting the corner A, it is possible to prevent such deformations or suppress their size. Furthermore, in conventional products, relatively large film deformations exceeding, for example, 200 μm may be observed near the inner upper end P due to surface irregularities of the adhesive layer. However, as in the more preferred embodiment of the present invention, the occurrence of such deformations can be prevented or their size suppressed by adjusting the surface roughness Ra of the upper end surface.

[0048] <Regarding the adhesive in the adhesive layer and the material of the pellicle film> Furthermore, the material of each part of the pellicle 1 of the present invention is not particularly limited. For example, the pellicle frame 2 may be made of aluminum alloys such as A7075, A6061, and A5052, stainless steel, or polyethylene, which may have been treated with black anodizing. Furthermore, the pellicle film 4 can be made of a polymer of butenyl vinyl ether. Also, the adhesive of the adhesive layer 3 can be made of a polymer of allyl vinyl ether. However, the materials can be appropriately determined depending on the light used for exposure. The pellicle film 4 may be made of nitrocellulose, cellulose acetate, fluorine polymer, etc., and the adhesive for the adhesive layer 3 may be made of acrylic resin, epoxy resin, fluororesin, etc.

[0049] Here, the pellicle 1 can be for use with a KrF excimer laser, but it can be specifically for use with an ArF excimer laser. In this case, a suitable example of the material is an amorphous fluororesin for the pellicle film 4, and an amorphous fluororesin for the adhesive in the adhesive layer 3.

[0050] In recent years, LSI design rules have been miniaturizing to the sub-quarter micron level, and consequently, exposure light sources are being shortened in wavelength. Specifically, there is a shift from the previously dominant KrF excimer laser (248nm) to ArF excimer lasers (193nm) and ArF excimer laser (193nm) immersion lithography.

[0051] For pellicles used in ArF excimer lasers, high light resistance is required for the pellicle film, so amorphous fluororesin is preferred as described above. For example, it can be made of a polymer of perfluorobutenyl vinyl ether. Furthermore, the adhesive for the adhesive layer is preferably made of amorphous fluororesin with high light resistance. For example, it can be made of a polymer of perfluoroallyl vinyl ether. This combination makes it possible to obtain a high-performance pellicle with even greater reliability, especially when exposed to ArF excimer lasers (193nm).

[0052] In ArF excimer laser (193nm) immersion lithography, the exposure light is obliquely incident on the pellicle, so to maintain light transmittance, the pellicle film thickness should be about one-third that of a typical ArF excimer laser (193nm) pellicle film. Therefore, the pellicle film is very delicate, and conventional products tend to adhere to the inner edge of the adhesive layer, resulting in an uneven adhesion state. Accordingly, the present invention, which can solve this problem, is particularly effective for ArF excimer laser (193nm) immersion lithography.

[0053] Next, the method for manufacturing the pellicle according to the present invention will be described. As shown in Figure 6, the steps in the method of the present invention mainly consist of (step 1) preparation of the pellicle frame, (step 2) formation of the adhesive layer, and (step 3) bonding of the pellicle film. The following explanation uses the example of manufacturing a pellicle for an ArF excimer laser, but the present invention is not limited to this.

[0054] (Step 1: Preparing the pellicle frame) Prepare a pellicle frame 2 having an angle A (105° or less) as described above (more preferably having a surface roughness Ra (0.30 μm or less) on the upper end surface). In the pellicle frame 2, the finished shape can be adjusted, and the chamfering angle can be adjusted during the chamfering process, so that an angle A within the above numerical range can be obtained at the inner upper end P. Furthermore, more preferably, the surface roughness Ra of the upper end surface S1 can be adjusted to the above numerical range by applying a polymer coating to the surface of the pellicle frame 2. Polishing or other treatments can also be applied. In this way, irregularities on the upper end surface S1 and the adhesive layer 3 formed thereon can be suppressed, resulting in a smooth surface. In other words, the fine irregularities seen in the adhesive layer near the inner upper end of the pellicle frame in conventional products can be suppressed.

[0055] (Step 2: Formation of the adhesive layer) An adhesive (for example, one made of amorphous fluororesin, such as a polymer solution of perfluoroallyl vinyl ether) is applied to the upper end surface S1 of the pellicle frame 2, and then heated to remove the solvent and form a solid adhesive layer 3. Furthermore, by applying the adhesive solution thinly and evenly at this time, it is possible to more effectively sharpen the shape of the inner edge Q of the adhesive layer 3.

[0056] (Step 3: Laminating the pellicle film) In this process, the pellicle film 4 is first prepared. A pellicle film formation solution (for example, one made of amorphous fluororesin, such as a polymer solution of perfluorobutenyl vinyl ether) is applied to a clean substrate with a polished surface, such as synthetic quartz, and finished to the desired thickness by spin coating. After spin coating, the substrate is heated on a hot plate or the like to evaporate the solvent. At this time, the residual solvent in the film on the substrate after spin coating is controlled by precisely controlling the heating temperature and time. After heating, the film is peeled from the deposition substrate into a frame slightly larger than the pellicle frame to obtain the pellicle film 4.

[0057] Then, the pellicle film 4 is bonded to the pellicle frame 2, which has the adhesive layer 3 (in a solid state) formed on it. After bonding, the pellicle film 4 and the pellicle frame 2 are heated to a predetermined temperature to further increase the adhesive strength between the pellicle film 4 and the pellicle frame 2 via the adhesive layer 3. In this way, even when using an adhesive made of amorphous fluororesin, film twisting exceeding 500 μm, and even exceeding 200 μm, can be suppressed, and the pellicle 1 of the present invention, which has an excellent appearance, can be manufactured. [Examples]

[0058] (Example 1) The following items were prepared as the pellicle frame. <Basic configuration> [Frame shape] Frame outer dimensions: 149mm x 115mm x 3.15mm Frame thickness: 2mm, Shape of the four corner sections in plan view: outer radius R5, inner radius R3. As shown in Figure 2, the shape of the four corners in a vertical cross-sectional view: the inner upper edge has a 90° finish without chamfering, while the others have a C200 chamfer. [process] After black anodizing, polymer electrodeposition treatment is performed.

[0059] The surface roughness of the upper end faces of the three prepared pellicle frames was measured and found to be Ra: 0.15, 0.13, and 0.12 μm. A polymer solution of perfluoroallyl vinyl ether was applied around the entire circumference of the upper end face of these pellicle frames, and the solvent was removed by heating at 100°C for 30 minutes to form an adhesive layer.

[0060] Next, a 5% concentration of perfluorobutenyl vinyl ether polymer was applied to a 6-inch (15 cm) synthetic quartz mask substrate and a uniform coating film was obtained by spin coating (800 rpm, 10 seconds). The substrate was heated at 180°C for 5 minutes to partially remove the solvent, and the film was peeled off the substrate to obtain a transparent amorphous fluoropolymer film with a thickness of 0.82 μm as a pellicle film.

[0061] The pellicle frame and pellicle film prepared above were bonded together and heated in an oven at 100°C for 10 minutes. After removing from the oven, any excess film that had protruded from the outside of the pellicle frame was removed to complete the pellicle.

[0062] When the three completed pellicle films and the area near the pellicle frame (near the inner upper edge) were inspected using a visual inspection machine (CA-H500CX manufactured by Keyence Corporation), no film deformation exceeding 500 μm in size toward the inner upper edge of the frame was observed, nor were any film deformations exceeding 200 μm in size observed, and the overall film appearance near the frame was good.

[0063] (Example 2) Regarding the basic configuration, a pellicle frame similar to that in Example 1 was prepared, except that the inner upper end had a 75° finish without chamfering (the inner surface of the pellicle frame has an overhang shape from the upper end to the lower end, and the width of the lower end is approximately 0.83 mm). The surface roughness of the upper end faces of the three prepared frames was measured and found to be Ra: 0.12, 0.15, and 0.13 μm. A pellicle film was also prepared in the same manner as in Example 1. The two were joined together and heated in an oven at 100°C for 10 minutes. After removing from the oven, the pellicle was completed in the same manner as in Example 1.

[0064] When the three completed pellicles were inspected using an appearance inspection machine in the same manner as in Example 1, no film deformation exceeding 500 μm in size toward the frame was observed near the inner upper edge, nor any film deformation exceeding 200 μm in size was observed, and the overall film appearance near the frame was good.

[0065] (Example 3) Regarding the <basic configuration>, the inner upper end was chamfered to an angle of 105° (corner A becomes 105°). All other than that, the pellicle frame was prepared in the same manner as in Example 1. The surface roughness of the upper end faces of the three prepared frames was measured and found to be Ra: 0.13, 0.11, and 0.12 μm. A pellicle film was also prepared in the same manner as in Example 1. The two were joined together and heated in an oven at 100°C for 10 minutes. After removing from the oven, the pellicle was completed in the same manner as in Example 1.

[0066] When the three completed pellicles were inspected using an appearance inspection machine in the same manner as in Example 1, no film deformation exceeding 500 μm in size toward the frame was observed near the inner upper edge, nor any film deformation exceeding 200 μm in size was observed, and the overall film appearance near the frame was good.

[0067] (Example 4) The frame shape in the <Basic Configuration> is the same as in Example 1, and a pellicle frame was prepared by polishing the upper end surface of the frame and then applying a black anodized finish. The surface roughness of the upper end faces of the three prepared frames was measured and found to be Ra: 0.29, 0.26, and 0.28 μm. A pellicle film was also prepared in the same manner as in Example 1. The two were joined together and heated in an oven at 100°C for 10 minutes. After removing from the oven, the pellicle was completed in the same manner as in Example 1.

[0068] When the three completed pellicles were inspected using an appearance inspection machine in the same manner as in Example 1, no film deformation exceeding 500 μm in size in the direction inward of the frame was observed near the inner upper edge. Although very fine irregularities were observed near the inner upper edge, most were small, about 100 μm in size, and there was no film deformation exceeding 200 μm, and the overall film appearance near the frame was good.

[0069] (Example 5) Regarding the <basic configuration>, the inner upper end was chamfered to an angle of 105° (angle A becomes 105°). In addition, a pellicle frame was prepared by polishing the upper end surface of the frame and then applying a black anodized finish. All other than that, the pellicle frame was prepared in the same way as in Example 1. The surface roughness of the upper end faces of the three prepared frames was measured and found to be Ra: 0.30, 0.27, and 0.26 μm. A pellicle film was also prepared in the same manner as in Example 1. The two were joined together and heated in an oven at 100°C for 10 minutes. After removing from the oven, the pellicle was completed in the same manner as in Example 1.

[0070] When the three completed pellicles were inspected using an appearance inspection machine in the same manner as in Example 1, no film deformation exceeding 500 μm in size in the direction inward of the frame was observed near the inner upper edge. Although very fine irregularities were observed near the inner upper edge, most were small, about 100 μm in size, and there was no film deformation exceeding 200 μm, and the overall film appearance near the frame was good.

[0071] (Comparative Example 1) Regarding the basic configuration, a C200 chamfer was applied to the inner upper end so that it forms a 135° angle (corner A becomes 135°). All other parts of the pellicle frame were prepared in the same manner as in Example 1. The surface roughness of the upper end faces of the three prepared frames was measured and found to be Ra: 0.13, 0.11, and 0.13 μm. A pellicle film was also prepared in the same manner as in Example 1. The two were joined together and heated in an oven at 100°C for 10 minutes. After removing from the oven, the pellicle was completed in the same manner as in Example 1.

[0072] When the three completed pellicles were inspected using a visual inspection machine in the same manner as in Example 1, it was found that the film had been deformed in the direction towards the frame by more than 500 μm near the inner upper edge in the first pellicle (4 locations on the long side and 2 locations on the short side), the second pellicle (3 locations on the long side and 2 locations on the short side), and the third pellicle (4 locations on the long side and 4 locations on the short side). As a result, there were significant defects in the film appearance near the frame.

[0073] (Comparative Example 2) Regarding the basic configuration, the inner upper end was chamfered so that it forms a 120° angle (corner A becomes 120°). Otherwise, the pellicle frame was prepared in the same manner as in Example 1. The surface roughness of the upper end faces of the three prepared frames was measured and found to be Ra: 0.14, 0.11, and 0.12 μm. A pellicle film was also prepared in the same manner as in Example 1. The two were joined together and heated in an oven at 100°C for 10 minutes. After removing from the oven, the pellicle was completed in the same manner as in Example 1.

[0074] When the three completed pellicles were inspected using a visual inspection machine in the same manner as in Example 1, several film deformations exceeding 500 μm in size were observed near the inner upper edge. One deformation was found on the long side of the first pellicle, two on the long side of the second pellicle, and one on the long side and one on the short side of the third pellicle. As a result, there were significant defects in the film appearance near the frame.

[0075] (Example 6) A frame was prepared in which the [frame shape] of the <basic configuration> was the same as in Example 1, but without polymer electrodeposition treatment after black anodizing. The surface roughness of the upper end faces of the three prepared frames was measured and found to be Ra: 0.49, 0.57, and 0.43 μm. A pellicle film was also prepared in the same manner as in Example 1. The two were joined together and heated in an oven at 100°C for 10 minutes. After removing from the oven, the pellicle was completed in the same manner as in Example 1.

[0076] When the three completed pellicles were inspected using a visual inspection machine in the same manner as in Example 1, no film twists exceeding 500 μm in size in the direction inward of the frame were observed near the inner upper end of any of the three pellicles. However, numerous fine film twists exceeding 200 μm were observed around the entire inner circumference of the pellicle frame (the entire area near the inner upper end). These fine film twists were not observed in Examples 1-3, 5, and Comparative Examples 1 and 2, and were larger than the fine irregularities observed in Example 4. Nevertheless, the film appearance near the frame was considerably better than that of Comparative Examples 1 and 2.

[0077] Table 1 summarizes the results described above. [Table 1]

[0078] From these results, it was found that by making the angle A at the inner upper end of the pellicle frame 105° or less, the shape of the inner end of the adhesive layer, such as amorphous fluororesin, could be made sharper, and the occurrence of film twisting exceeding 500 μm in the inward direction of the frame, which is observed at the bonded / unbonded boundary of the pellicle film (near the inner upper end of the pellicle frame), could be suppressed. Furthermore, we confirmed that even fine film twisting of about 200 μm can be suppressed by reducing the surface roughness Ra of the upper end surface of the pellicle frame to 0.30 μm or less. Only Examples 1-5 were able to achieve suppression of both types of film twisting. Furthermore, while Example 6 was able to suppress film twisting exceeding 500 μm, Comparative Examples 1-2 still exhibited noticeable film twisting exceeding 500 μm.

[0079] The findings obtained in this invention indicate that by modifying the shape of the inner upper end of the pellicle frame (i.e., angle A ≤ 105°) (and furthermore, by controlling the surface roughness Ra of the upper end surface to 0.30 μm or less), it becomes easier to manufacture a superior pellicle that does not have undesirable film twists exceeding 500 μm (and even suppresses film twists exceeding 200 μm).

[0080] This specification includes the following embodiments: [1]: A pellicle having a pellicle frame, an adhesive layer on the upper end surface of the pellicle frame, and a pellicle film on the adhesive layer, A pellicle in which, at the inner upper end of the pellicle frame, the angle between the upper end surface and the adjacent inner surface is 105° or less. [2]: The pellicle of [1], wherein the surface roughness Ra of the upper end surface is 0.30 μm or less. [3]: The adhesive of the adhesive layer is made of amorphous fluororesin, The pellicle film is made of amorphous fluororesin. The pellicle described above [1] or [2], wherein the pellicle is for use with an ArF excimer laser. [4]: Any of the pellicles described in [1] to [3] above, wherein the angle between the upper end surface and the adjacent surface at the inner upper end is 90° or less. [5]: Any of the pellicles described in [1] to [4] above, wherein the pellicle film is made of a polymer of butenyl vinyl ether. [6]: Any of the pellicles described in [1] to [5] above, wherein the adhesive in the adhesive layer is made of a polymer of allyl vinyl ether. [7]: A method for manufacturing a pellicle by preparing a pellicle frame, forming an adhesive layer on the upper end surface of the prepared pellicle frame, and bonding a pellicle film onto the formed adhesive layer, As the aforementioned pellicle frame, A method for manufacturing a pellicle, wherein at the inner upper end, the angle between the upper end surface and the adjacent inner surface is 105° or less. [8]: The method for manufacturing the pellicle according to [7], wherein the pellicle frame is prepared such that the surface roughness Ra of the upper end surface is 0.30 μm or less. [9]: As the adhesive for the adhesive layer, an amorphous fluororesin is used. As the pellicle film, an amorphous fluororesin is used. A method for manufacturing the pellicle described in [7] or [8] above, which is used for an ArF excimer laser.

[10] : A method for manufacturing a pellicle according to any of the above [7] to [9], wherein the pellicle frame is prepared such that the angle between the upper end surface and the adjacent surface at the inner upper end is 90° or less.

[11] : When the pellicle film is bonded to the adhesive layer, A method for manufacturing a pellicle according to any of the above [7] to

[10] , wherein the adhesive in the adhesive layer is in a solid state and the pellicle film is bonded to it.

[12] : A method for manufacturing the pellicle of

[11] , wherein the pellicle is heated after bonding.

[13] : A method for producing a pellicle according to any of the above [7] to

[12] , wherein the pellicle membrane is made of a polymer of butenyl vinyl ether.

[14] : A method for producing a pellicle according to any of the above [7] to

[13] , wherein the adhesive for the adhesive layer is made of a polymer of allyl vinyl ether. Labels for use.

[0081] It should be noted that the present invention is not limited to the embodiments described above. The embodiments described above are illustrative, and any configuration that has substantially the same technical idea as described in the claims of the present invention and achieves similar effects is included within the technical scope of the present invention. [Explanation of Symbols]

[0082] 1...Pellicle of the present invention, 2...Pellicle frame, 3...Adhesive layer, 4…Pellicle membrane, A... The angle formed between the upper end surface of the pellicle frame and the adjacent inner surface (inner upper end angle) S1... Upper end surface of the pellicle frame, S2... Inner adjacent surfaces of the upper end surface of the pellicle frame, P...Inner upper end of the pellicle frame, Q: The inner edge of the adhesive layer.

Claims

1. A pellicle comprising a pellicle frame, an adhesive layer on the upper end surface of the pellicle frame, and a pellicle film on the adhesive layer, A pellicle characterized in that, at the inner upper end of the pellicle frame, the angle between the upper end surface and the adjacent inner surface is 105° or less.

2. The pellicle according to claim 1, characterized in that the surface roughness Ra of the upper end surface is 0.30 μm or less.

3. The adhesive in the aforementioned adhesive layer is made of amorphous fluororesin. The pellicle film is made of amorphous fluororesin. The pellicle according to claim 1, characterized in that the pellicle is for use with an ArF excimer laser.

4. The pellicle according to claim 1, characterized in that the angle between the upper end surface and the adjacent surface at the inner upper end is 90° or less.

5. The pellicle according to claim 1, characterized in that the pellicle film is made of a polymer of butenyl vinyl ether.

6. The pellicle according to claim 1, characterized in that the adhesive in the adhesive layer is made of a polymer of allyl vinyl ether.

7. A method for manufacturing a pellicle by preparing a pellicle frame, forming an adhesive layer on the upper end surface of the prepared pellicle frame, and bonding a pellicle film onto the formed adhesive layer, As the aforementioned pellicle frame, A method for manufacturing a pellicle, characterized by preparing one in which the angle between the upper end surface and the adjacent inner surface is 105° or less at the inner upper end.

8. The method for manufacturing a pellicle according to claim 7, characterized in that the pellicle frame prepared has a surface roughness Ra of 0.30 μm or less on its upper end surface.

9. As the adhesive for the aforementioned adhesive layer, an amorphous fluororesin is used. As the pellicle film, an amorphous fluororesin is used. The method for manufacturing a pellicle according to claim 7, characterized in that the pellicle is manufactured for use with an ArF excimer laser.

10. The method for manufacturing a pellicle according to claim 7, characterized in that the pellicle frame prepared has an angle of 90° or less between the upper end surface and the adjacent surface at the inner upper end.

11. When the pellicle film is bonded to the adhesive layer, The method for manufacturing a pellicle according to claim 7, characterized in that the adhesive in the adhesive layer is in a solid state and the pellicle film is bonded to it.

12. The method for manufacturing a pellicle according to claim 11, characterized in that the pellicle is heated after bonding.

13. The method for producing a pellicle according to claim 7, characterized in that the pellicle membrane is made of a polymer of butenyl vinyl ether.

14. The method for producing a pellicle according to claim 7, characterized in that an adhesive made of a polymer of allyl vinyl ether is used as the adhesive for the adhesive layer.

Images