Protective film frame, protective film, exposure original plate, and use thereof

Abstract

The present application provides a protective film frame, a protective film, a lithographic original with the protective film, an application of the lithographic original, and a manufacturing method of a semiconductor or liquid crystal display. The protective film frame is a frame of a protective film used in photolithography. The outer peripheral side surface of the protective film frame is formed in a streamline shape, and the width of the outer peripheral portion formed in the streamline shape is 50% or more of the height of the protective film frame. By setting the outer peripheral side surface of the protective film frame in a specific streamline shape, the air separation is reduced, the air resistance is reduced, and as a result, the turbulence in high-speed scanning movement is suppressed, and the deterioration of the cover after exposure is suppressed.

Description

Technical Field

[0001] This invention relates to a protective film frame, a protective film, an exposure master with a protective film, their applications, and a method for manufacturing semiconductors or liquid crystal displays. Background Technology

[0002] In the photolithography process of manufacturing semiconductor devices or liquid crystal displays, patterns are created by irradiating a semiconductor wafer or liquid crystal coated with resist with light. If foreign matter is attached to the photomask and reticle (hereinafter, photomask) used at this time, the foreign matter will absorb light or bend the light, thus deforming the transferred pattern or causing rough edges. In addition, there are also problems such as the substrate being blackened, and damage to size, quality, and appearance.

[0003] These photolithography steps are usually performed in a clean room, but even so, it is difficult to keep the exposure master clean at all times. Therefore, the method of exposing the master is usually to set a foreign matter remover called a protective film.

[0004] This type of protective film typically includes: a frame-shaped protective film frame, a protective film sheet stretched on the upper surface of the protective film frame, and an airtight gasket formed on the lower surface of the protective film frame. The protective film sheet contains a material that exhibits high transmittance to exposed light, and the airtight gasket uses an adhesive.

[0005] If this protective film is placed on the photomask, foreign objects will not adhere directly to the photomask, but rather to the protective film. Moreover, if the focus is made to be on the pattern of the photomask during photolithography, foreign objects on the protective film will be irrelevant to the transfer, thus suppressing problems such as pattern deformation.

[0006] Furthermore, in this photolithography technology, the trend towards shorter wavelengths of exposure light sources is being pursued as a means to improve resolution. Until now, the exposure light source has shifted from mercury lamp-based gamma rays (436nm) and i rays (365nm) to KrF excimer lasers (248nm), and in recent years, ArF excimer lasers (193nm) have been used most frequently for micro-processing.

[0007] In recent years, immersion exposure apparatuses have been used to perform finer processing using ArF excimer lasers. By filling the space between the objective lens of the exposure apparatus and the silicon wafer with liquid, a higher numerical aperture (NA) is achieved, resulting in higher resolution. If the exposure apparatus is thus configured to have a high NA, the angle of oblique incidence in the peripheral portion of the light transmitted through the protective film increases. The transmittance of the protective film is usually set to achieve maximum transmittance for perpendicularly incident light, but a decrease in transmittance is observed as the incident angle increases. The degree of this decrease in transmittance is significant when the protective film is thick. Therefore, to achieve high transmittance even for obliquely incident light, the protective film is typically made thinner.

[0008] However, if the protective film is made thinner, the film's strength decreases. Specifically, during exposure, the photomask unit, fabricated by attaching the protective film to the photomask substrate, undergoes high-speed scanning. Therefore, if the protective film has low strength, it is prone to vibration due to turbulence during high-speed scanning. This vibration causes the exposure light to become disordered as it passes through the protective film, potentially leading to pattern displacement from its intended target position and deterioration of pattern positional accuracy (overlay).

[0009] Furthermore, the following public disclosures can be cited as examples of prior art related to the process of improving coverage.

[0010] Existing technical documents

[0011] Patent documents

[0012] Patent Document 1: Japanese Patent Application Publication No. 2018-508048

[0013] Patent Document 2: International Publication No. 2012 / 080008 Summary of the Invention

[0014] The problem that the invention aims to solve

[0015] The present invention was made in view of the above circumstances, and its object is to provide a protective film frame and a protective film using the same, an exposure master with a protective film, an exposure method, and a method for manufacturing a semiconductor or liquid crystal display. The protective film frame can suppress turbulence that is easily generated during high-speed scanning motion, mitigate the vibration of the protective film sheet during high-speed scanning motion during exposure, and suppress coverage deterioration.

[0016] Technical means to solve the problem

[0017] The inventors conducted diligent research to solve the aforementioned problem, and as a result, obtained the following insights, thus forming the present invention: by setting the outer peripheral side of the protective film frame into a specific streamlined shape, air stripping is reduced, air resistance is decreased, and as a result, turbulence during high-speed scanning motion can be suppressed, and the deterioration of the coverage after exposure can be suppressed.

[0018] Therefore, the present invention provides the following protective film frame, protective film, exposure master with protective film and exposure method, and manufacturing method of semiconductor or liquid crystal display.

[0019] 1. A protective film frame, which constitutes a protective film for photolithography, wherein: the outer peripheral side of the protective film frame is formed in a streamlined shape, and the width of the outer peripheral side portion formed in the streamlined shape is more than 50% of the height of the protective film frame.

[0020] 2. A protective film frame, wherein: the outer peripheral side has a portion formed in a streamlined shape, and the width of the outer peripheral side portion formed in the streamlined shape is more than 50% of the height of the protective film frame.

[0021] 3. The protective film frame according to 1 or 2, wherein the streamline shape is an arc shape.

[0022] 4. The protective film frame according to 1 or 2, wherein the width (w) of the protective film frame disposed on one side (lower end face side) of the exposure original is greater than the width (B) of the protective film frame disposed on the one side (upper end face side) of the protective film sheet.

[0023] 5. The protective film frame according to 1 or 2, wherein the width (B) of the protective film frame is less than 60% of the width (w) of the protective film frame.

[0024] 6. The protective film frame according to 1 or 2, wherein the width of the outer peripheral side gradually decreases from the side disposed on the exposure original (lower end face side) toward the side on which the protective film sheet is disposed (upper end face side).

[0025] 7. A protective film, comprising: a protective film frame according to claim 1 or 2 and a protective film sheet.

[0026] 8. The protective film according to claim 7, wherein the thickness of the protective film sheet is 500 nm or less.

[0027] 9. The protective film described in 7 is a protective film used in exposure at a scanning speed of 300 mm / s or higher.

[0028] 10. An exposure master with a protective film, wherein: the exposure master is provided with the protective film according to 7.

[0029] 11. An exposure method, wherein: a substrate is exposed by means of an exposure master with a protective film as described in 10.

[0030] 12. The exposure method according to 11, wherein the substrate is exposed at a scanning speed of 300 mm / s or more.

[0031] 13. A method for manufacturing a semiconductor, comprising the step of exposing a substrate using an exposure master with a protective film as described in 10.

[0032] 14. The semiconductor manufacturing method according to 13, wherein the step of exposing the substrate is a step of exposing the substrate at a scanning speed of 300 mm / s or more.

[0033] 15. A method for manufacturing a liquid crystal display, comprising the step of exposing a substrate using an exposure master with a protective film as described in 10.

[0034] 16. The method for manufacturing a liquid crystal display according to 15, wherein the step of exposing the substrate is a step of exposing the substrate at a scanning speed of 300 mm / s or more.

[0035] The effects of the invention

[0036] According to the protective film frame of the present invention, compared with existing protective film frames, by making the outer shape of the frame streamlined, turbulence easily generated during high-speed scanning motion can be suppressed, the vibration of the protective film sheet during high-speed scanning motion during exposure can be mitigated, and coverage deterioration can be suppressed, which is effective in the fine pattern formation step. Therefore, the protective film using the protective film frame of the present invention, the exposure master with the protective film and the exposure method, and the manufacturing method of semiconductor or liquid crystal display are useful in photolithography technology. Attached Figure Description

[0037] Figure 1 This is a plan view of the protective film frame of the present invention.

[0038] Figure 2 yes Figure 1 A cross-sectional view of the protective film frame along the XX direction.

[0039] [Explanation of Symbols]

[0040] 10: Protective film frame

[0041] 10a: Straight section

[0042] 10b: Corner

[0043] 10c: Outer lateral portion

[0044] L1: Longitudinal length of the protective film frame

[0045] L2: Lateral length of the protective film frame

[0046] H: Height of the protective film frame

[0047] w: Width of the protective film frame

[0048] b: Bottom width of the arc section / Width of the outer peripheral side section

[0049] B: Width of the protective film frame Detailed Implementation

[0050] The following describes one embodiment of the present invention in detail, but the present invention is not limited thereto.

[0051] Regarding the protective film frame of the present invention, its shape is a polygonal frame, and it has a straight portion 10a and a corner portion 10b. Typically, it is as follows: Figure 1 It is a quadrilateral frame as shown. Figure 1 The corner 10b where the straight section 10a intersects can be set to an R shape. Although not specifically illustrated, it can also be provided with a vent or a clamping hole.

[0052] The protective film frame of the present invention, by setting the outer shape of the frame to a streamlined shape, can suppress turbulence generated during high-speed scanning motion, mitigate vibration of the protective film sheet caused by high-speed scanning motion during exposure, and effectively suppress coverage deterioration compared with existing protective film frames.

[0053] All or part of the outer peripheral side surface of the protective film frame is formed in a streamlined shape. Preferably, the streamlined shape is curved or bent, specifically, arc-shaped, elliptical arc-shaped, etc. In particular, the outer peripheral side surface of the protective film frame ideally exhibits a shape in which the width gradually decreases from the side where the exposure master is disposed (lower end face side) towards the side where the protective film sheet is disposed (upper end face side).

[0054] like Figure 2 As shown, the width of the streamlined outer peripheral side portion 10c of the protective film frame refers to the maximum width b of the outer peripheral side portion within the overall width (w = B + b) of the cross-section of the protective film frame. Figure 2 The width of the arc portion is b.

[0055] The width b of the streamlined outer peripheral side portion of the protective film frame is preferably 50% or more of the height H of the protective film frame, more preferably 70% or more, further preferably 90% or more, and most preferably 100%. If the width b of the outer peripheral side portion is less than 50%, the air resistance borne by the streamlined portion increases during high-speed scanning motion, and the film is prone to vibration due to turbulence, raising concerns about coverage degradation. Furthermore, from the viewpoint of ensuring exposure area, the upper limit of the width b of the outer peripheral side portion is approximately 200% of the height H of the protective film frame.

[0056] In addition, Figure 2 In this embodiment, the overall width w of the protective film frame, i.e., the width w of the protective film frame disposed on one side (lower end face side) of the exposure master, is preferably greater than the width B of the protective film frame disposed on the one side (upper end face side). In this case, the width B of the protective film frame is preferably 60% or less of the width w of the protective film frame, more preferably 50% or less, and even more preferably 40% or less. There is no particular limitation on the lower limit, but for ease of disposing of the protective film, it is preferably 30% or more.

[0057] There are no particular limitations on the material of the protective film frame; existing materials can be used. Examples include: metals or alloys such as aluminum, aluminum alloy, steel, stainless steel, brass, invar, and super invar; engineering plastics such as polyethylene (PE) resin, polyamide (PA) resin, and polyetheretherketone (PEEK) resin; and fiber composite materials such as glass fiber reinforced plastics (GFRP) and carbon fiber reinforced plastics (CFRP).

[0058] Preferably, the surface of the protective film frame is treated to be black, and surface treatments such as coating are applied as needed to prevent dust generation. For example, when using aluminum alloys, surface treatments such as aluminite process or chemical conversion treatment are preferred; when using steel, stainless steel, etc., surface treatments such as black chrome plating are preferred.

[0059] To capture or fix airborne foreign objects, an adhesive substance such as an acrylic adhesive or a silicone adhesive can be applied to the inner surface of the protective film frame. Alternatively, to prevent dust generation, a non-adhesive resin film such as an acrylic resin or a fluorinated resin can be formed on only the inner surface or the entire surface of the protective film frame. These adhesive and non-adhesive resin films can be formed using existing methods such as spraying, dipping, powder coating, and electrodeposition coating.

[0060] Additionally, multiple clamping holes or slots may be provided on the outer surface of the protective film frame for handling and other purposes. Furthermore, markings such as model number, manufacturing number, and barcode can be applied by mechanical engraving or laser marking.

[0061] Regarding the protective film frame of the present invention, a protective film can be made by providing a protective film sheet, an adhesive layer, etc. on it.

[0062] The protective film is fabricated by selecting the most preferred material from cellulose-based resins, fluorine-based resins, etc., based on the exposure light source used, and selecting the most preferred film thickness from the range of approximately 0.1 μm to 10 μm in terms of transmittance and mechanical strength. An anti-reflective layer may be added as needed. In particular, when using extreme ultraviolet light (EUV light) as the exposure light source, extremely thin silicon films, graphene films, cobalt-like carbon films, carbon nanotube films, etc., with a film thickness of less than 1 μm can be used. Specifically, the film thickness of the protective film is preferably 500 nm or less, more preferably 300 nm or less. Regarding the strength of the protective film, the lower limit of the film thickness is suitable to be 20 nm or more.

[0063] The protective film is not limited to a thin film; it can also include a support frame that supports the protective film. For example, the protective film can be fabricated by forming it on a silicon wafer and removing the silicon wafer by back-side etching only the portion used as the protective film. In this case, the protective film can be obtained while being supported by a silicon frame. Furthermore, existing adhesives such as acrylic adhesives, fluorine adhesives, and silicone adhesives can be used for bonding the protective film to the upper surface of the protective film frame.

[0064] Regarding the protective film using the protective film frame of the present invention, vents can be provided to adjust the internal air pressure, and filters can be installed on its outer side to prevent the intrusion of foreign objects. These filters may contain porous membranes such as polytetrafluoroethylene (PTFE). In this case, the filter can be installed by providing an adhesive layer of appropriate material and directly attaching it to the outer surface of the protective film frame. Furthermore, the location, number, and shape of these vents or filters can be appropriately determined considering the required ventilation or the specific treatment conditions.

[0065] The adhesive layer used to attach the protective film to the photomask is disposed on the lower end face of the protective film frame. As the material of the adhesive layer, existing materials such as rubber-based adhesives, urethane-based adhesives, acrylic adhesives, styrene-ethylene-butylene-styrene (SEBS) adhesives, styrene-ethylene-propylene-styrene (SEPS) adhesives, and silicone adhesives can be used. Furthermore, a material that generates less escaping gas, which is a cause of haze, is preferred.

[0066] To ensure the stability of the protective film after it is applied to the photomask or to reduce its impact on the photomask, the flatness of the adhesive layer surface is preferably set to 30 μm or less. Furthermore, the cross-sectional shape or thickness can be selected as needed; for example, the cross-sectional shape can be a semi-circular convex shape.

[0067] On the surface of the adhesive layer, a release liner made of polyethylene terephthalate (PET) film or similar material with a thickness of approximately 50 μm to 300 μm can be applied. This is to protect the adhesive layer and can be omitted by means of a protective film shell or a support for the protective film.

[0068] Regarding the protective film using the aforementioned protective film frame, patterning is performed while the photomask unit, which is fabricated by attaching the protective film to the photomask substrate, is undergoing high-speed scanning motion. The coverage accuracy can be evaluated by the positional offset from the target position in the X and Y directions; the smaller the offset in both directions, the better. For next-generation semiconductor devices or liquid crystal displays, extremely fine patterns are required, and the positional accuracy of the coverage is preferably below 1 nm. The measurement of the positional offset from the patterned target position in the X and Y directions can be performed, for example, using a wafer verification machine such as the ASML YIELDSTAR T-250D.

[0069] The protective film using the protective film frame of the present invention is particularly effective in applications such as semiconductor manufacturing, where photomask distortion is a significant problem, but it is not limited to such applications. For example, it can be applied not only to applications for manufacturing semiconductors with a side length of about 150 mm, but also to applications for manufacturing printed circuit boards with a side length of 200 mm to 300 mm, and to applications for manufacturing liquid crystal and organic electroluminescence (EL) displays with a side length of approximately 500 mm to 2000 mm, and to all protective films where photomask deformation is a problem due to the application of the protective film.

[0070] The protective film of the present invention can be used not only as a protective component to prevent foreign matter from adhering to the exposure plate within the exposure apparatus, but also as a protective component to protect the exposure plate during storage or transport. Methods for attaching the protective film to exposure plates such as photomasks and manufacturing exposure plates with the protective film include methods such as attaching it to the photomask with an adhesive, electrostatic adsorption, and mechanical fixing.

[0071] The semiconductor or liquid crystal display manufacturing method according to embodiments of the present invention includes the step of exposing a substrate (semiconductor wafer or liquid crystal substrate) using an exposure master with a protective film. For example, in the photolithography step, which is one of the manufacturing steps of a semiconductor or liquid crystal display, an exposure master with a protective film is placed on a stepper for exposure in order to form a photoresist pattern corresponding to integrated circuits, etc., on the substrate. Typically, in EUV exposure, EUV light is reflected by the exposure master and guided to the substrate using a projection optics system, which is performed under reduced pressure or vacuum. Therefore, even if foreign matter adheres to the protective film during the photolithography step, this foreign matter will not be imaged on the wafer coated with photoresist, thus preventing short circuits or open circuits in integrated circuits, etc., caused by the image of foreign matter. Therefore, by using an exposure master with a protective film, the yield in the photolithography step can be improved.

[0072] Exposure apparatuses used in the manufacture of semiconductors and the like typically employ contact exposure, proximity exposure, mirror-projection exposure, step-and-repeat projection exposure apparatuses, and step-and-scan projection exposure apparatuses. In a step-and-scan projection exposure apparatus, for example, the pattern on the exposure master is scanned with a narrow slit while the circuit pattern is transferred onto the wafer. Therefore, the exposure master and the wafer move synchronously at a scanning speed corresponding to the magnification of the projection optics system. At the same time, the protective film adhered to the exposure master also moves.

[0073] In this invention, setting the scanning speed to 300 mm / s or higher allows for effective friction between the external gas and the protective film, enabling the protective film frame to become charged. While a slower scanning speed has little impact, faster speeds increase the influence of vibrations on the protective film, photomask, substrate, and components of the exposure apparatus, leading to a higher frequency of unwanted foreign matter generation. Therefore, the faster the scanning speed of the protective film of this invention, the more effective it is, and it can handle scanning speeds of 550 mm / s or higher, and even ultra-high-speed scanning speeds of 700 mm / s or higher. The upper limit of the scanning speed depends on the performance of the exposure apparatus and is typically around 2000 mm / s.

[0074] Example

[0075] The following examples and comparative examples illustrate the present invention, but the present invention is not limited to the following examples.

[0076] [Example 1]

[0077] In Example 1, firstly, a quadrilateral frame-shaped protective film frame made of aluminum alloy with a streamlined outer perimeter is prepared. The external dimensions of the protective film frame are 149mm × 115mm × 3.15mm, and the frame width is 1.95mm. Additionally, a filter hole with a diameter of 0.5mm is provided at the center of the short side of the protective film frame.

[0078] Furthermore, the cross-sectional shape of the protective film frame is as follows: Figure 2 The shape is as shown, with B = 1.95mm, H = 3.15mm, and b = 3.15mm. Here, b (the bottom width of the arc) is 100% of the length relative to H (the frame height), and the width-to-width ratio of b to H is 100%.

[0079] Secondly, after cleaning the prepared protective film frame with pure water, apply a silicone adhesive (KE-101A / B manufactured by Shin-Etsu Chemical Co., Ltd.) to the upper surface of the protective film frame and an acrylic adhesive (SK-Dyne 1495 manufactured by Soken Chemical Co., Ltd.) to the lower surface.

[0080] Subsequently, a protective film sheet is attached to the upper surface of the protective film frame coated with silicone adhesive. The protective film sheet contains a polymer with perfluorobutene vinyl ether as the main component. The protective film sheet that extends further outward than the protective film frame is removed, thereby completing the protective film.

[0081] The fabricated protective film was attached to a 150 mm square photomask substrate, and the coverage accuracy was evaluated. The result showed a coverage of 0.54 nm. Furthermore, the conditions for attaching the protective film to the photomask were set as a load of 5 kgf and a load time of 30 seconds.

[0082] [Example 2]

[0083] In Example 2, firstly, a quadrilateral frame-shaped protective film frame made of aluminum alloy with a streamlined outer perimeter is prepared. The external dimensions of the protective film frame are 149mm × 115mm × 3.15mm, and the frame width is 1.95mm.

[0084] Furthermore, the cross-sectional shape of the protective film frame is as follows: Figure 2 The shape is as shown, with B = 1.95mm, H = 3.15mm, and b = 2.835mm. Here, b (the bottom width of the arc) is 90% of the length relative to H (the frame height), and the width-to-width ratio of b to H is 90%.

[0085] The fabricated protective film was attached to a 150mm square photomask substrate, and the coverage accuracy was evaluated. The result showed that the coverage was 0.55nm.

[0086] [Example 3]

[0087] In Example 3, firstly, a quadrilateral frame-shaped protective film frame made of aluminum alloy with a streamlined outer perimeter is prepared. The external dimensions of the protective film frame are 149mm × 115mm × 3.15mm, and the frame width is 1.95mm.

[0088] Furthermore, the cross-sectional shape of the protective film frame is as follows: Figure 2 The shape is as shown, with B = 1.95mm, H = 3.15mm, and b = 2.52mm. Here, b (the bottom width of the arc) is 80% of the length relative to H (the frame height), meaning the width-to-width ratio of b to H is 80%.

[0089] The fabricated protective film was attached to a 150mm square photomask substrate, and the coverage accuracy was evaluated. The result showed that the coverage was 0.67nm.

[0090] [Example 4]

[0091] In Example 4, firstly, a quadrilateral frame-shaped protective film frame made of aluminum alloy with a streamlined outer perimeter is prepared. The external dimensions of the protective film frame are 149mm × 115mm × 3.15mm, and the frame width is 1.95mm.

[0092] Furthermore, the cross-sectional shape of the protective film frame is as follows: Figure 2 The shape is as shown, with B = 1.95mm, H = 3.15mm, and b = 2.205mm. Here, b (the bottom width of the arc) is 70% of the length relative to H (the frame height), meaning the width-to-width ratio of b to H is 70%.

[0093] The fabricated protective film was attached to a 150mm square photomask substrate, and the coverage accuracy was evaluated. The result showed that the coverage was 0.75nm.

[0094] [Example 5]

[0095] In Example 5, firstly, a quadrilateral frame-shaped protective film frame made of aluminum alloy with a streamlined outer perimeter is prepared. The external dimensions of the protective film frame are 149mm × 115mm × 3.15mm, and the frame width is 1.95mm.

[0096] Furthermore, the cross-sectional shape of the protective film frame is as follows: Figure 2 The shape is as shown, with B = 1.95mm, H = 3.15mm, and b = 1.89mm. Here, b (the bottom width of the arc) is 60% of the length relative to H (the frame height), and the width-to-width ratio of b to H is 60%.

[0097] The fabricated protective film was attached to a 150mm square photomask substrate, and the coverage accuracy was evaluated. The result showed that the coverage was 0.88nm.

[0098] [Example 6]

[0099] In Example 6, firstly, a quadrilateral frame-shaped protective film frame made of aluminum alloy with a streamlined outer perimeter is prepared. The external dimensions of the protective film frame are 149mm × 115mm × 3.15mm, and the frame width is 1.95mm.

[0100] Furthermore, the cross-sectional shape of the protective film frame is as follows: Figure 2 The shape is as shown, with B = 1.95mm, H = 3.15mm, and b = 1.575mm. Here, b (the bottom width of the arc) is 50% of the length relative to H (the frame height), and the width-to-width ratio of b to H is 50%.

[0101] The fabricated protective film was attached to a 150mm square photomask substrate, and the coverage accuracy was evaluated. The result showed that the coverage was 0.97nm.

[0102] [Comparative Example 1]

[0103] In Comparative Example 1, firstly, a quadrilateral frame-shaped protective film frame made of aluminum alloy with a streamlined outer perimeter was prepared. The external dimensions of the protective film frame were 149mm × 115mm × 3.15mm, and the frame width was 1.95mm.

[0104] Furthermore, the cross-sectional shape of the protective film frame is as follows: Figure 2 The shape is as shown, with B = 1.95mm, H = 3.15mm, and b = 1.26mm. Here, b (the bottom width of the arc) is 40% of the length relative to H (the frame height), and the width-to-width ratio of b to H is 40%.

[0105] The fabricated protective film was attached to a 150mm square photomask substrate, and the coverage accuracy was evaluated. The result showed that the coverage was 1.07nm.

[0106] [Comparative Example 2]

[0107] In Comparative Example 2, firstly, a quadrilateral frame-shaped protective film frame made of aluminum alloy with a streamlined outer perimeter was prepared. The external dimensions of the protective film frame were 149mm × 115mm × 3.15mm, and the frame width was 1.95mm.

[0108] Furthermore, the cross-sectional shape of the protective film frame is as follows: Figure 2 The shape is as shown, with B = 1.95mm, H = 3.15mm, and b = 0.945mm. Here, b (the bottom width of the arc) is 30% of the length relative to H (the frame height), and the width-to-width ratio of b to H is 30%.

[0109] The fabricated protective film was attached to a 150mm square photomask substrate, and the coverage accuracy was evaluated. The result showed that the coverage was 1.15nm.

[0110] [Comparative Example 3]

[0111] In Comparative Example 3, firstly, a quadrilateral frame-shaped protective film frame made of aluminum alloy with a streamlined outer perimeter was prepared. The external dimensions of the protective film frame were 149mm × 115mm × 3.15mm, and the frame width was 1.95mm.

[0112] Furthermore, the cross-sectional shape of the protective film frame is as follows: Figure 2 The shape is as shown, with B = 1.95mm, H = 3.15mm, and b = 0.63mm. Here, b (the bottom width of the arc) is 20% of the length relative to H (the frame height), and the width-to-width ratio of b to H is 20%.

[0113] The fabricated protective film was attached to a 150mm square photomask substrate, and the coverage accuracy was evaluated. The result showed that the coverage was 1.20nm.

[0114] [Comparative Example 4]

[0115] In Comparative Example 4, firstly, a quadrilateral frame-shaped protective film frame made of aluminum alloy with a streamlined outer perimeter was prepared. The external dimensions of the protective film frame were 149mm × 115mm × 3.15mm, and the frame width was 1.95mm.

[0116] Furthermore, the cross-sectional shape of the protective film frame is as follows: Figure 2 The shape is as shown, with B = 1.95mm, H = 3.15mm, and b = 0.315mm. Here, b (the bottom width of the arc) is 10% of the length relative to H (the frame height), and the width-to-width ratio of b to H is 10%.

[0117] The fabricated protective film was attached to a 150mm square photomask substrate, and the coverage accuracy was evaluated. The result showed that the coverage was 1.24nm.

[0118] [Comparative Example 5]

[0119] In Comparative Example 5, firstly, a quadrilateral protective film frame made of aluminum alloy was prepared. The external dimensions of the protective film frame were 149mm × 115mm × 3.15mm, and the frame width was 1.95mm. Furthermore, the outer periphery of the protective film frame did not have a streamlined shape (not shown).

[0120] The fabricated protective film was attached to a 150mm square photomask substrate, and the coverage accuracy was evaluated. The result showed that the coverage was 1.24nm.

[0121] [Table 1]

[0122]

[0123] Based on Table 1 summarizing the above results, it was confirmed by comparing Examples 1 to 6 with Comparative Examples 1 to 5 that if a streamlined shape is formed on the outer periphery of the frame and the ratio of the bottom width of the streamlined arc portion to the frame height is increased, there is a tendency for the coverage to deteriorate and decrease.

Claims

1. A protective film frame which is a protective film frame of a protective film for photolithography, characterized by comprising: a lower end surface side provided on an exposure original plate; an upper end surface side on which a protective film sheet is provided; and an outer peripheral side surface which is a streamline shape, wherein the streamline shape of the outer peripheral side surface of the protective film frame is a curved shape or a curved shape so that a width of the outer peripheral side surface of the protective film frame is gradually reduced from the lower end surface side toward the upper end surface side, and a first width (b) of the outer peripheral side surface portion formed in the streamline shape is 50% or more of a height of the protective film frame, and a total width (w) of the protective film frame provided on the lower end surface side of the exposure original plate is larger than a second width (B) of the protective film frame provided on the upper end surface side on which the protective film sheet is provided. characterized by comprising: a lower end surface side provided on an exposure original plate; an upper end surface side on which a protective film sheet is provided; and an outer peripheral side surface which has a portion formed in a streamline shape, wherein the streamline shape of the outer peripheral side surface of the protective film frame is a curved shape or a curved shape so that a width of the outer peripheral side surface of the protective film frame is gradually reduced from the lower end surface side toward the upper end surface side, and a first width (b) of the outer peripheral side surface portion formed in the streamline shape is 50% or more of a height of the protective film frame, and a total width (w) of the protective film frame provided on the lower end surface side of the exposure original plate is larger than a second width (B) of the protective film frame provided on the upper end surface side on which the protective film sheet is provided.

3. The protective film frame according to claim 1 or 2, wherein the streamline shape is a circular arc shape.

4. The protective film frame according to claim 1 or 2, wherein the second width (B) of the protective film frame is 60% or less of the total width (w) of the protective film frame. comprising: the protective film frame according to claim 1 or 2 and a protective film sheet.

2. A protective film frame, characterized by, 6. The protective film according to claim 5, wherein a film thickness of the protective film sheet is 500 nm or less.

7. The protective film according to claim 5, which is a protective film used in exposure at a scan speed of 300 mm / sec or more. an exposure original plate equipped with the protective film according to claim 5. exposure of a substrate by the exposure original plate with the protective film according to claim 8.

10. The exposure method according to claim 9, wherein the substrate is exposed at a scan speed of 300 mm / sec or more. comprising: a step of exposing a substrate using the exposure original plate with the protective film according to claim 8.

12. The method of manufacturing a semiconductor according to claim 11, wherein the step of exposing a substrate is a step of exposing a substrate at a scan speed of 300 mm / sec or more.

5. A protective film, characterized by comprising: a step of exposing a substrate using the exposure original plate with the protective film according to claim 8. ​ ​ ​ 8. An exposure original with a protective film, characterized by: ​ 9. An exposure method characterized by: ​ ​ 11. A method of manufacturing a semiconductor, characterized by, ​ ​ ​ 13. A method of manufacturing a liquid crystal display device, characterized by comprising: ​ ​ 14. The method for manufacturing a liquid crystal display device according to claim 13, wherein the step of exposing the substrate is a step of exposing the substrate at a scanning speed of 300 mm / sec or more.

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